TY  - JOUR
A1  - Kutateladze, T. V.
A1  - Axelrod, V. D.
A1  - Gorboulev, Valentin G.
A1  - Belzhelarskaya, S. N.
A1  - Vartikyan, R. V.
T1  - New procedure of high-voltage electrophoresis in polyacrylamide gel and its application to the sequencing  of nucleic acids
N2  - Fractionation of nucleic acids and their fragments with polyacrylamide gel has been widely applied in sequencing of nucleic acids. Although the conditions of electrophoresis for this purpose have previously been suggested. we have found that polyacrylamide gel electrophoresis at 5000 V (100 V/cm) is possible and effective. An apparatus consisting of a horizontal thermostated plate is used to remove the heat which was formed during the electrophoretic process. The techniques for loading samples on the horizontal thin gel and the procedure for high-voltage gel electrophoresis are described and illustrated by the fractionation of the spleen phosphodiesterase partial digest of tRNA¥~1 as well as by the RNA synthesis by RNA polymerase from E. coli with poly[d(A- T)j as template in the presence of "terminator," 3'-O-methyluridine 5'-triphosphate. This same technique was used for electrophoresis of oligonucleotides on acetylcellulose and was incorporated into a two-dimensional system which was demonstrated by fingerprinting of the guanylo-RNase digest of tRNAT'P from baker's yeast. In the third part of the article a simple technique for the electric trapping of nucleic acids or their fragments from a slab gel on a DEAE-paper sheet is presented.
Y1  - 1979
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46927
ER  - 
TY  - JOUR
A1  - Artyukova, E. V.
A1  - Gorboulev, Valentin G.
A1  - Rodionova, N. P.
A1  - Krylov, A. V.
A1  - Atabekov, J. G.
T1  - Comparative study of structural peculiarities and translation of potexvirus RNAs
N2  - Structural peculiarities of the S'-end segments of genomic RNA were studied in F potato virus (F-PV) and white clover mosaic virus (WCMV). The methods of affinity chromatography on oligo(dT) cellulose and oligonucleotide mapping revealed a prolonged (up to 210 nucleotides) polyadenyl sequence at the 3'-end of F-PV RNA. A polyadenyl sequence is missing at the 3'end of WCMV RNA. A study of the translation products of WCMV and F-PV RNAs in a oe11-free protein-synthesizing system derived from rabbit reticulocytes showed that polypeptides electrophoretically comigrating with a structural protein of either virus were synthesized alongside high-molecular-weight polypeptides (M\(_r\)\(\approx\) 180-150 kdaltons).
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46985
ER  - 
TY  - JOUR
A1  - Rubtsov, P. M.
A1  - Oganessyan, R. G.
A1  - Gorboulev, Valentin G.
A1  - Skryabin, K. G.
A1  - Bayev, A. A.
T1  - Genetic engineering of peptide hormones : II. Possible polymorphism of preprolactin in cattle. Data of molecular cloning
N2  - Primary structure is determined of an insertion of a clone isolated from the library of hypophyseal cDNA of cattle by hybridization with a probe specific for prolactin. Analysis of nucleotide sequences showed that in the process of cloning, reorganization occurred in structure of preprolactin cDNA, including an inversion of the 5'-terminal and deletion of the central section of cDNA. Nevertheless, from structure of cDNA, nucleotide sequences can be deduced of extended 5'- and 3'-terminal sections of preprolactin mRNA in cattle with lengths of 257 and 551 nucleotide residues, respectively. When these sequences are compared to those established previously, some differences were found in primary structure. The most important of them is the presence of an additional codon which codes alanine at the position (-22) of the signal peptide. It is suggested that heterogeneity of preprolactin mRNA of cattle in the section coding the signal peptide is the result of alternative splicing, as was shown for preprolactin mRNA in rats.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46975
ER  - 
TY  - JOUR
A1  - Rubtsov, P. M.
A1  - Chernov, V. G.
A1  - Gorboulev, Valentin G.
A1  - Parsadanyan, A. S.
A1  - Sverdlova, P. S.
A1  - Chupeeva, V. V.
A1  - Golova, Yu. B.
A1  - Batchikova, N. V.
A1  - Zvirblis, G. S.
A1  - Skryabin, K. G.
A1  - Bayev, A. A.
T1  - Genetic engineering of peptide hormones
N2  - Peptide and polypeptide hormones represent an extensive group of biologically active compounds of important significance for medicine and agriculture. In recent years genetic engineering methods have been used to create strains of microorganisms synthesizing eukaryotic proteins, including hormones and their precursors. The first stage of such developments is the isolation of DNA coding the des~red product. We have accomplished the cloning of the cDNA of a number of polypeptide and peptide hormones of the pituitary of man and domestic animals. The model gene of human calcitonin has also been synthesized and cloned. The obtained genes are being used to develop methods for the microbiological synthesis of human and animal-hormones.
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46964
ER  - 
TY  - JOUR
A1  - Zvirblis, G. S.
A1  - Gorboulev, Valentin G.
A1  - Rubtsov, P. M.
A1  - Chernov, B. K.
A1  - Golova, Yu. B.
A1  - Pozmogova, G. E.
A1  - Skryabin, K. G.
A1  - Bayev, A. A.
T1  - Genetic engineering of peptide hormones : III. Cloning of cDNA of porcine growth hormone and construction of gene for expression of hormone in bacteria
N2  - Results are presented of cloning cDNA of procine growth hormone, analysis of its primary structure, and creation of a construction capable of expression of this cDNA in Esqheriahia coti cells. It is shown that in the population of mRNA coding porcine growth hormone, heterogeneity is noted which is manifested not only at the level of the nucleotide sequence, but also is reflected in the amino acid sequence of the mature hormone.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46958
ER  - 
TY  - JOUR
A1  - Tsfasman, I. M.
A1  - Nesmeyanova, M. A.
A1  - Gorboulev, Valentin G.
A1  - Rubtsov, P. M.
A1  - Skryabin, K. G.
T1  - Biosynthesis and secretion of bovine growth hormone in Escherichia coli under the control of the secretory vector containing a promoter and signal sequence of alkaline phosphatase gene
N2  - A recombinant plasmid was constructed containing the gene for bovine growth hormone joinea with the regulatory region and the region coding the signal sequence of the Escherichia coli alkaline phosphatase gene. In conditions of phosphorus starvation, which c~s derepression of alkaline phosphatase, expression was shown of the gene for bovine growth hormone, in addition to partial processing and secretion of protein into periplasm.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46932
ER  - 
TY  - JOUR
A1  - Kerkau, Thomas
A1  - Schmitt-Landgraf, Renate
A1  - Schimpl, Anneliese
A1  - Wecker, Eberhard
T1  - Downregulation of HLA Class I Antigensin HIV-1-Infected Cells
N2  - By means of indirect immunofluorescence analysis we investigated the effect of HIV -1 infection on HLA class I surface antigens. We report here that in CD4\(^+\) HeLa cells, in H9 cells, and in peripheral T Iymphocytes HLA class I antigens are down regulated following infection with HIV -1. The downregulation is effected at a posttranscriptional level since the amounts of HLA class I specific mRNA are similar in infected and uninfected cells. This phenomenon is not only correlated with the state of infection, that is, the presence of P24 of HIV-l in the cells, but also depends on the time of infection. Upon HLA class I downregulation by HIV infection, the specific lysis of peripheral blood cells by allogeneic CTL is reduced.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47172
ER  - 
TY  - JOUR
A1  - Boriskin, Yu S.
A1  - Desyatskova, R. G.
A1  - Bogomolova, N. N.
A1  - Gorboulev, Valentin G.
T1  - Stability of rubella virus after long-term persistence in human cell line
N2  - Primary infection of HEp-2 cells with rubella virus resulted in non-cytophatic longterm persistent infection. During four years of persistence the virus was produced in sufficient quantities (up to 6 logs PFU/ml) and did not differ from the parental variant in its pathogenicity for BHK-21 or RK-13 cells, or hemagglutinating activity, but formed smaller plaques. Persistent virus preserved the original antigenicity as judged from reciprocal hemagglutination-inhibition or plaque reduction-neutralization tests with polyclonal antisera. Both original and persistent rubella viruses were thermoresistant (T 56° C) and sligthly temperature-sensitive. Clonal analysis revealed presence of ts-mutants among both original and persistent virus clones with different degrees of plating efficiency at 40°/34° C. RNA fingerprinting showed only minor changes in persistent rubella virus.
KW  - Rubella virus
KW  - persistant infection
KW  - cell culture
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46944
ER  - 
TY  - JOUR
A1  - Bringmann, Gerhard
A1  - Hartung, Thomas
A1  - Goebel, Lothar
A1  - Schupp, Olaf
A1  - Ewers, Christian L. J.
A1  - Schoener, Bernd
A1  - Zagst, Rainer
A1  - Peters, Karl
A1  - Von Schnering, Hans Georg
A1  - Burschka, Christian
T1  - Novel concepts in directed biaryl synthesis, IX:  Synthesis and structure of benzonaphthopyranones,  useful bridged model precursors for stereoselective biaryl syntheses
N2  - A practicable two-step procedure for the preparation of a series of lactone-type bridged biaryls 7 as favorable substrates for subsequent atropisomer-selective ring-opening reactions is described. Due to the efficiency of the coupling step, which tolerates even a telt·butyl group next to the biaryl axis and avoids problems of regioselectivity, a variety of differently substituted representatives is prepared. These cover a broad range of steric hindrance and thus molecular distortion. The structures are investigated mainly by NMR spectroscopy and X-ray diffraction, showing the lactones 7 to be helically distorted, depending on the size of the residues R.
KW  - Chemie
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46635
ER  - 
TY  - JOUR
A1  - Bonte, Dries
A1  - Travis, Justin M. J.
A1  - De Clercq, Nele
A1  - Zwertvaegher, Ingrid
A1  - Lens, Luc
T1  - Thermal conditions during juvenile development affect adult dispersal in a spider
N2  - Abstract: Understanding the causes and consequences of dispersal is a prerequisite for the effective management of natural populations. Rather than treating dispersal as a fixed trait, it should be considered a plastic process that responds to both genetic and environmental conditions. Here, we consider how the ambient temperature experienced by juvenile Erigone atra, a spider inhabiting crop habitat, influences adult dispersal. This species exhibits 2 distinct forms of dispersal, ballooning (long distance) and rappelling (short distance). Using a half-sib design we raised individuals under 4 different temperature regimes and quantified the spiders' propensity to balloon and to rappel. Additionally, as an indicator of investment in settlement, we determined the size of the webs build by the spiders following dispersal. The optimal temperature regimes for reproduction and overall dispersal investment were 20 °C and 25 °C. Propensity to perform short-distance movements was lowest at 15 °C, whereas for long-distance dispersal it was lowest at 30 °C. Plasticity in dispersal was in the direction predicted on the basis of the risks associated with seasonal changes in habitat availability; long-distance ballooning occurred more frequently under cooler, spring-like conditions and short-distance rappelling under warmer, summer-like conditions. Based on these findings, we conclude that thermal conditions during development provide juvenile spiders with information about the environmental conditions they are likely to encounter as adults and that this information influences the spider's dispersal strategy. Climate change may result in suboptimal adult dispersal behavior, with potentially deleterious population level consequences.
KW  - Erigone atra
KW  - emigration
KW  - dispersal distance
KW  - immigration
KW  - behavior
KW  - plasticity
KW  - silk
KW  - body condition
KW  - seasonality
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48691
ER  - 
TY  - JOUR
A1  - Gros, Andreas
A1  - Hovestadt, Thomas
A1  - Poethke, Hans Joachim
T1  - Evolution of sex-biased dispersal : the role of sex-specific dispersal costs, demographic stochasticity, and inbreeding
N2  - Abstract: Inbreeding avoidance and asymmetric competition over resources have both been identified as factors favoring the evolution of sex-biased dispersal. It has also been recognized that sex-specific costs of dispersal would select for sex-biased dispersal, but there is little quantitative information on this aspect. In this paper we explore (i) the quantitative relationship between cost-asymmetry and a bias in dispersal, (ii) the influence of demographic stochasticity on this effect, and (iii) how inbreeding and cost-asymmetry interact in their effect on sex-specific dispersal. We adjust an existing analytical model to account for sex-specific costs of dispersal. Based on numerical calculations we predict a severe bias in dispersal already for small differences in dispersal costs. We corroborate these predictions in individual-based simulations, but show that demographic stochasticity generally leads to more balanced dispersal. In combination with inbreeding, cost asymmetries will usually determine which of the two sexes becomes the more dispersive.
KW  - asymmetric dispersal costs
KW  - kin-selection
KW  - numerical model
KW  - individual-based simulations
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48705
ER  - 
TY  - JOUR
A1  - Gros, Andreas
A1  - Poethke, Hans Joachim
A1  - Hovestadt, Thomas
T1  - Sex-specific spatio-temporal variability in reproductive success promotes the evolution of sex-biased dispersal
N2  - Abstract: Inbreeding depression, asymmetries in costs or benefits of dispersal, and the mating system have been identified as potential factors underlying the evolution of sex-biased dispersal. We use individual-based simulations to explore how the mating system and demographic stochasticity influence the evolution of sex-specific dispersal in a metapopulation with females competing over breeding sites, and males over mating opportunities. Comparison of simulation results for random mating with those for a harem system (locally, a single male sires all offspring) reveal that even extreme variance in local male reproductive success (extreme male competition) does not induce male-biased dispersal. The latter evolves if the between-parch variance in reproductive success is larger for males than females. This can emerge due to demographic stochasticity if the habitat patches are small. More generally, members of a group of individuals experiencing higher spatio-temporal variance in fitness expectations may evolve to disperse with greater probability than others.
KW  - sex-biased dispersal
KW  - demographic stochasticity
KW  - metapopulation
KW  - individual-based simulation
KW  - sex-specific competition
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48711
ER  - 
TY  - JOUR
A1  - Solbach, Werner
A1  - Moll, Heidrun
A1  - Röllinghoff, Martin
T1  - Lymphocytes play the music but the macrophage calls the tune
N2  - No abstract available
KW  - Immunologie
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45889
ER  - 
TY  - JOUR
A1  - Gillitzer, Reinhard
A1  - Moll, Heidrun
T1  - Simultaneous demonstration of two antigens with immunogold-silver staining and immunoenzymatic labeling
N2  - A novel technique for independent and simultaneous labeling of two antigens expressed on individual cells (referred to as mixed labeling) is presented. The staining procedure combined three-step (streptavidin-biotin) immunogold-silver staining with three-step immunoenzymatic labeling. To ensure both high specificity and high sensitivity, particular emphasis was placed on designing a protocol that avoids immunological crossreactivity between the antibody reagents and overlapping of the final color products. Two examples for usage of this mixed labeling technique are described: lymphocyte subpopulations were identified in inflammatory lesions of human skin and infected host cells were characterized in the skin of mice infected with the obligatory intracellular parasite Leishmania major, a cause of human cutaneous leishmaniasis.
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-33019
ER  - 
TY  - JOUR
A1  - Moll, Heidrun
A1  - Fuchs, Harald
A1  - Blank, Christine
A1  - Röllinghoff, Martin
T1  - Langerhans cells transport Leishmania major from the infected skin to the draining lymph node for presentation to antigen-specific T cells
N2  - No abstract available
KW  - Immunologie
KW  - Langerhans cell
KW  - Leishmania major
KW  - T-cell
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46023
ER  - 
TY  - JOUR
A1  - Bonte, Dries
A1  - Clercq, Nele De
A1  - Zwertvaegher, Ingrid
A1  - Lens, Luc
T1  - Repeatability of dispersal behaviour in a common dwarf spider: evidence for different mechanisms behind short- and long-distance dispersal
N2  - Abstract: 1. The response of dispersal towards evolution largely depends on its heritability for which upper limits are determined by the trait's repeatability. 2. In the Linyphiid spider E. atra, we were able to separate long- and short-distance dispersal behaviours (respectively ballooning and rappelling) under laboratory conditions. By performing repeated behavioural trials for females, we show that average dispersal trait values decrease with increasing testing days. By comparing mated and unmated individuals during two periods (before and after mating for the mated group, and the same two periods for the unmated group), we show that mating has no effect on the mean displayed dispersal behaviour or its within-individual variation. Repeatabilities were high and consistent for ballooning motivation, but not for rappelling. 3. Ballooning motivation can be regarded as highly individual-specific behaviour, while general pre-dispersal and rappelling behaviours showed more individual variation. Such difference in repeatability between long-and short-distance dispersal suggests that short-and long-distance dispersal events are triggered by different ecological and evolutionary mechanisms.
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48242
ER  - 
TY  - JOUR
A1  - Bonte, Dries
A1  - Maes, Dirk
T1  - Trampling affects the distribution of specialised coastal dune arthropods
N2  - Abstract: From a conservation point of view, species- tolerances towards disturbance are often generalised and lack reference to spatial scales and underlying processes. In order to investigate how average typical species react to habitat fragmentation and disturbance, we adopted a multi-species approach to address occupancy patterns of five specialised dune arthropods (butterflies Hipparchia semele, Issoria lathonia; grasshopper Oedipoda caerulescens; spiders Alopecosa fabrilis, Xysticus sabulosus) in recently fragmented coastal dune habitats which are subjected to varying levels and modes of local disturbance, i.e. trampling by cattle or people. Occupancy patterns were assessed during two successive years in 133 grey dune fragments of the Flemish coastal dunes (Belgium, France). By treating species as a random factor in our models, emphasis was placed on generalisations rather than documenting species-specific patterns. Our study demonstrates that deteriorating effects of local disturbance on arthropod incidence cannot be interpreted independent of its landscape context, and appear to be more severe when patch area and connectivity decrease. When controlled for patch area and trampling intensity, the probability of species occupancy in poorly connected patches is higher under cattle trampling than under recreation. Incidences additionally decrease with increasing intensity of cattle trampling, but increases with trampling by tourists. This study provides evidence of mode- and landscape-dependent effects of local disturbance on species occupancy patterns. Most importantly, it demonstrates that trampling of sensitive dune fragments will lead to local and metapopulation extinction in landscapes where trampling occurs in a spatially autocorrelated way, but that the outcome (spatial patterns) varies in relation to disturbance mode, indicating that effects of disturbance cannot be generalised.
KW  - Araneae
KW  - grazing
KW  - grey dunes
KW  - Lepidoptera
KW  - multispecies metapopulation
KW  - Orthoptera
KW  - recreation
KW  - trampling
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48274
ER  - 
TY  - JOUR
A1  - Bonte, Dries
A1  - Lanckacker, Kjell
A1  - Wiersma, Elisabeth
A1  - Lens, Luc
T1  - Web building flexibility of an orb-web spider in a heterogeneous agricultural landscape
N2  - Abstract: Intensification of land-use in agricultural landscapes is responsible for a decline of biodiversity which provide important ecosystem services like pest-control. Changes in landscape composition may also induce behavioural changes of predators in response to variation in the biotic or abiotic environment. By controlling for environmentally confounding factors, we here demonstrate that the orb web spider Araneus diadematus alters its web building behaviour in response to changes in the composition of agricultural landscapes. Thereby, the species increases its foraging efficiency (i.e. investments in silk and web asymmetry) with an increase of agricultural land-use at intermediate spatial scales. This intensification is also related to a decrease in the abundance of larger prey. A negative effect of landscape properties at similar spatial scales on spider fitness was recorded when controlling for relative investments in capture thread length. This study consequently documents the web building flexibility in response to changes in landscape composition, possibly due to changes in prey availability.
KW  - Araneus diadematus
KW  - Araneidae
KW  - behavioural flexibility
KW  - orb web geometry
KW  - landscape
KW  - model selection
KW  - semi-natural habitats
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48262
ER  - 
TY  - JOUR
A1  - Blank, Christine
A1  - Fuchs, Harald
A1  - Rappersberger, Klemens
A1  - Röllinghoff, Martin
A1  - Moll, Heidrun
T1  - Parasitism of epidermal Langerhans cells in experimental cutaneous leishmaniasis with Leishmania major
N2  - Murine epidermal Langerhans cells (LC) have been demonstrated to stimulate a vigorous T cell response to Leishmania major, a cause of human cutaneous leishmaniasis. It was therefore of interest to analyze whether LC can take up viable parasites. Epidermal cells were obtained from mouse ear skin for incubation with L. major and subsequent detection of intracellular parasites by cytochemistry. Freshly isolated LC, but not cultured LC, phagocytosed L. major and the uptake was inhibited by antibodies to the complement receptor type 3. Electron microscopic studies revealed the presence of viable amastigotes within Le. Moreover, with double-Iabeling techniques, L. major-containing LC could also be detected in infected skin. The results demonstrate that LC can internalize L. major. Since the number of organisms per infected LC remained consistently low, the prime task of LC may not be the promotion of parasite spreading but the presentation of L. major antigen to T cells and, thus, the regulation of the cellular immunity during cutaneous leishmaniasis.
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45850
ER  - 
TY  - JOUR
A1  - Pfeffer, K.
A1  - Schoel, H.
A1  - Gulle, H.
A1  - Moll, Heidrun
A1  - Kromer, S.
A1  - Kaufmann, S. H. E.
A1  - Wagner, H.
T1  - Analysis of primary T cell responses to intact and fractionated microbial pathogens
N2  - Freshly isolated human T lymphocytes were tested for their response to mycobacteria, mycobacteriallysates, 2 dimensional (2D) PAGE separated mycobacteriallysates, leishmania and defined leishmanial antigen preparations. While,o T cells proliferated vigourously in the presence of mycobacteria and mycobacteria derived lysates, a significant stimulation from 2 D gel separated lysates was not detected. In addition '10 T cells failed to respond towards leishmania or leishmanial components. In the ab T cell compartment some donors, presumably according to their state of immunity against mycobacteria, responded to mycobacteria, mycobacterial lysates and 2 D gel separated mycobacterial lysates. Neither freshly isolated '10 T cells nor ab T cells from naive donors did mount a significant immune response against leishmania.
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46916
ER  - 
TY  - JOUR
A1  - Bonte, Dries
A1  - Hovestadt, Thomas
A1  - Poethke, Hans-Joachim
T1  - Male-killing endosymbionts: influence of environmental conditions on persistance of host metapopulation
N2  - Background: Male killing endosymbionts manipulate their arthropod host reproduction by only allowing female embryos to develop into infected females and killing all male offspring. Because of the reproductive manipulation, we expect them to have an effect on the evolution of host dispersal rates. In addition, male killing endosymbionts are expected to approach fixation when fitness of infected individuals is larger than that of uninfected ones and when transmission from mother to offspring is nearly perfect. They then vanish as the host population crashes. High observed infection rates and among-population variation in natural systems can consequently not be explained if defense mechanisms are absent and when transmission efficiency is perfect. Results: By simulating the host-endosymbiont dynamics in an individual-based metapopulation model we show that male killing endosymbionts increase host dispersal rates. No fitness compensations were built into the model for male killing endosymbionts, but they spread as a group beneficial trait. Host and parasite populations face extinction under panmictic conditions, i.e. conditions that favor the evolution of high dispersal in hosts. On the other hand, deterministic 'curing' (only parasite goes extinct) can occur under conditions of low dispersal, e.g. under low environmental stochasticity and high dispersal mortality. However, high and stable infection rates can be maintained in metapopulations over a considerable spectrum of conditions favoring intermediate levels of dispersal in the host. Conclusion: Male killing endosymbionts without explicit fitness compensation spread as a group selected trait into a metapopulation. Emergent feedbacks through increased evolutionary stable dispersal rates provide an alternative explanation for both, the high male-killing endosymbiont infection rates and the high among-population variation in local infection rates reported for some natural systems.
KW  - Metapopulation
KW  - Parasit
KW  - Wirt
KW  - Endosymbiont
KW  - Theoretische Ökologie
KW  - Host-parasite interactions
KW  - individual-based model
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45344
ER  - 
TY  - JOUR
A1  - Bonte, Dries
A1  - Hovestadt, Thomas
A1  - Poethke, Hans Joachim
T1  - Sex-specific dispersal and evolutionary rescue in metapopulations infected by male killing endosymbionts
N2  - Background: Male killing endosymbionts manipulate their arthropod host reproduction by only allowing female embryos to develop into infected females and killing all male offspring. Because the resulting change in sex ratio is expected to affect the evolution of sex-specific dispersal, we investigated under which environmental conditions strong sex-biased dispersal would emerge, and how this would affect host and endosymbiont metapopulation persistence. Results: We simulated host-endosymbiont metapopulation dynamics in an individual-based model, in which dispersal rates are allowed to evolve independently for the two sexes. Prominent male-biased dispersal emerges under conditions of low environmental stochasticity and high dispersal mortality. By applying a reshuffling algorithm, we show that kin-competition is a major driver of this evolutionary pattern because of the high within-population relatedness of males compared to those of females. Moreover, the evolution of sex-specific dispersal rescues metapopulations from extinction by (i) reducing endosymbiont fixation rates and (ii) by enhancing the extinction of endosymbionts within metapopulations that are characterized by low environmental stochasticity. Conclusion: Male killing endosymbionts induce the evolution of sex-specific dispersal, with prominent male-biased dispersal under conditions of low environmental stochasticity and high dispersal mortality. This male-biased dispersal emerges from stronger kin-competition in males compared to females and induces an evolutionary rescue mechanism.
KW  - Metapopulation
KW  - Theoretische Ökologie
KW  - Endosymbiont
KW  - Wirt
KW  - Parasit
KW  - Host-parasite interactions
KW  - individual-based model
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45351
ER  - 
TY  - JOUR
A1  - Gros, Andreas
A1  - Hovestadt, Thomas
A1  - Poethke, Hans Joachim
T1  - Evolution of local adaptions in dispersal strategies
N2  - The optimal probability and distance of dispersal largely depend on the risk to end up in unsuitable habitat. This risk is highest close to the habitat’s edge and consequently, optimal dispersal probability and distance should decline towards the habitat’s border. This selection should lead to the emergence of spatial gradients in dispersal strategies. However, gene flow caused by dispersal itself is counteracting local adaptation. Using an individual based model we investigate the evolution of local adaptations of dispersal probability and distance within a single, circular, habitat patch. We compare evolved dispersal probabilities and distances for six different dispersal kernels (two negative exponential kernels, two skewed kernels, nearest neighbour dispersal and global dispersal) in patches of different size. For all kernels a positive correlation between patch size and dispersal probability emerges. However, a minimum patch size is necessary to allow for local adaptation of dispersal strategies within patches. Beyond this minimum patch area the difference in mean dispersal distance between center and edge increases linearly with patch radius, but the intensity of local adaptation depends on the dispersal kernel. Except for global and nearest neighbour dispersal, the evolved spatial pattern are qualitatively similar for both, mean dispersal probability and distance. We conclude, that inspite of the gene-flow originating from dispersal local adaptation of dispersal strategies is possible if a habitat is of sufficient size. This presumably holds for any realistic type of dispersal kernel.
KW  - Ausbreitung
KW  - Evolution
KW  - Computersimulation
KW  - Ökologie
KW  - nearest-neighbour dispersal
KW  - global dispersal
KW  - evolution
KW  - individual based simulation
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45406
ER  - 
TY  - JOUR
A1  - Obermaier, Elisabeth
A1  - Heisswolf, Annette
A1  - Randlkofer, B.
A1  - Meiners, T.
T1  - Enemies in low places - insects avoid winter mortality and egg parasitism by modulating oviposition height
N2  - Oviposition site selection in insects is essential in terms of low egg mortality, high offspring survival and therefore a high reproductive output. Although oviposition height could be a crucial factor for the fitness of overwintering eggs, it has rarely been investigated. In this study the oviposition height of a polyphagous leaf beetle, Galeruca tanaceti Linnaeus in different habitats and at different times of the season was examined and its effect on egg clutch mortality was recorded. The leaf beetle occurs as an occasional pest on several agricultural plants. It deposits its eggs within herbaceous vegetation in autumn. Eggs are exposed to numerous biotic and abiotic mortality factors summarized as egg parasitism and winter mortality. Oviposition height of the leaf beetle was not uniform, but changed significantly with the structure of the habitat and during the season. Mean oviposition height per site (70.2±4.9 cm) was significantly higher than mean vegetation height (28.4±2.4 cm). Height of plants with egg clutches attached and oviposition height were significantly positively correlated. The results suggest that females try to oviposit as high as possible in the vegetation and on the plants selected. In accordance with this, the probability of egg parasitism and of winter egg clutch mortality significantly declined with increasing oviposition height. A preference of G. tanaceti for oviposition sites high up in the vegetation might therefore have evolved due to selection pressures by parasitoids and winter mortality.
KW  - abiotic factors
KW  - Chrysomelidae
KW  - enemy free space
KW  - Galeruca tanaceti
KW  - oviposition site
KW  - plant-animal interactions
KW  - Oomyzus galerucivorus
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48200
ER  - 
TY  - JOUR
A1  - Hovestadt, Thomas
A1  - Mitesser, Oliver
A1  - Elmes, Graham
A1  - Thomas, Jeremy A.
A1  - Hochberg, Michael E.
T1  - An Evolutionarily Stable Strategy model for the evolution of dimorphic development in the butterfly Maculinea rebeli, a social parasite of Myrmica Ant Colonies
N2  - Caterpillars of the butterfly Maculinea rebeli develop as parasites inside ant colonies. In intensively studied French populations, about 25% of caterpillars mature within 1 year (fast-developing larvae [FDL]) and the others after 2 years (slow-developing larvae [SDL]); all available evidence indicates that this ratio is under the control of egg-laying females. We present an analytical model to predict the evolutionarily stable fraction of FDL (pESS). The model accounts for added winter mortality of SDL, general and kin competition among caterpillars, a competitive advantage of SDL over newly entering FDL (priority effect), and the avoidance of renewed infection of ant nests by butterflies in the coming season (segregation). We come to the following conclusions: (1) all factors listed above can promote the evolution of delayed development; (2) kin competition and segregation stabilize pESS near 0.5; and (3) a priority effect is the only mechanism potentially selecting for. However, given the empirical data, pESS is predicted to fall closer to 0.5 than to the 0.25 that has been observed. In this particular system, bet hedging cannot explain why more than 50% of larvae postpone growth. Presumably, other fitness benefits for SDL, for example, higher fertility or longevity, also contribute to the evolution of delayed development. The model presented here may be of general applicability for systems where maturing individuals compete in small subgroups.
KW  - delayed development
KW  - growth dimorphism
KW  - evolutionarily stable strategy (ESS)
KW  - ant-butterfly interaction
KW  - social parasitism
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48165
ER  - 
TY  - JOUR
A1  - Poethke, Hans J.
A1  - Pfenning, Brenda
A1  - Hovestadt, Thomas
T1  - The relative contribution of individual and kin selection to the evolution of density-dependent dispersal rates
N2  - Questions: What are the relative contributions of kin selection and individual selection to the evolution of dispersal rates in fragmented landscapes? How do environmental parameters influence the relative contributions of both evolutionary forces? Features of the model: Individual-based simulation model of a metapopulation. Logistic local growth dynamics and density-dependent dispersal. An optional shuffling algorithm allows the continuous destruction of any genetic structure in the metapopulation. Ranges of key variables: Depending on dispersal mortality (0.05-0.4) and the strength of environmental fluctuations, mean dispersal probability varied between 0.05 and 0.5. Conclusions: For local population sizes of 100 individuals, kin selection alone could account for dispersal probabilities of up to 0.1. It may result in a ten-fold increase of optimal dispersal rates compared with those predicted on the basis of individual selection alone. Such a substantial contribution of kin selection to dispersal is restricted to cases where the overall dispersal probabilities are small (textless 0.1). In the latter case, as much as 30% of the total fitness of dispersing individuals could arise from the increased reproduction of kin left in the natal patch.
KW  - dispersal rate
KW  - dynamics
KW  - environmental correlation
KW  - evolutionary modelling
KW  - genetics
KW  - individual-based model
KW  - kin competition
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48225
ER  - 
TY  - JOUR
A1  - Hovestadt, Thomas
A1  - Poethke, Hans J.
A1  - Messner, Stefan
T1  - Variability in dispersal distances generates typical successional patterns: a simple simulation model
N2  - More recently, it became clear that conclusions drawn from traditional ecological theory may be altered substantially if the spatial dimension of species interactions is considered explicitly. Regardless of the details of these models, spatially explicit simulations of ecological processes have nearly universally shown that spatial or spatio-temporal patterns in species distributions can emerge even from homogeneous starting conditions; limited dispersal is one of the key factors responsible for the development of such aggregated and patchy distributions (cf., Pacala 1986, Holmes et al. 1994, Molofsky 1994, Tilman 1994, Bascompte and Sole 1995, 1997, 1998, Jeltsch et al. 1999). In line with these ideas, we wish to draw attention to the fact that in heterogeneous landscapes differences in characteristic dispersal distances between species are a sufficient precondition for the emergence of a successional pattern. We will use a simple, spatially explicit simulation program to demonstrate the validity of this statement. We will also show that the speed of the successional progress depends on scale and heterogeneity in the distribution of suitable habitat.
KW  - community
KW  - competition
KW  - environments
KW  - habitats
KW  - life-history
Y1  - 2000
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48178
ER  - 
TY  - JOUR
A1  - Bach, Ulrich
T1  - Oral rhetoric in writings for a mixed literate and illiterate audience
N2  - No abstract available
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47124
ER  - 
TY  - JOUR
A1  - Mahsberg, Dieter
T1  - Contact chemoreception of prey in hunting scorpions
N2  - Scorpions commonly are assumed to hunt on living prey. But under laboratory conditions they also respond very sensitively to dead insects lying on the substrate. In many cases the motionless prey is seized and consumed. It was investigated how this behavior can be elicited. The buthid scorpions Androctonus australis (L.) and Buthus occitanus (Am.) not only find motionless prey again which was stung but managed to escape before dying: They also respond to extracts of the cuticle of prey insects. After touching prey marks' either with the tips of the chelae fingers or the tarsi of the walking legs or the pectine organs specific responses (searching, seizing, feeding) are released at a high rate. Behavioral experiments demonstrate for the first time the chemosensitivity of the pectine organs for which only mechanosensitivity had been proofed formerly. Mechanical as well as contact chemical stimulation of these organs cause scorpions to orient towards the stimulus source which is grasped, retained and consumed or rejected depending on its quality. The probably responsible chemosensitive receptors are already described in the literature. The possible adaptive value and the biological significance of contact chemoreception in prey catching and in other aspects of the life of scorpions is discussed.
KW  - Skorpion
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45784
ER  - 
TY  - JOUR
A1  - Kaupp, Martin
A1  - Stoll, H.
A1  - Preuss, H.
T1  - Pseudopotential Calculations for Methyl Compounds of Zinc and Magnesium
N2  - Pseudopotentials and valence basis sets to be used in calculations for organometallic compounds of zinc and magnesium have been tested in calculations for the M(CH\(_3\))\(_n\) (M = Zn, Mg; n = 1,2) molecules. Valence correlation effects are treated at the SDCI and CEPA levels. The capability of a polarization potential on zinc to account for the valence shell contracting effect of core valence correlation is studied. Properties considered are geometries, force constants, Mulliken populations, ionization potentials, atomization, and binding energies. Differences in bonding between the two dimethyl compounds are discussed.
KW  - Zink
KW  - Magnesium
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-46194
ER  - 
TY  - JOUR
A1  - Berger, Susanne
A1  - Ellersiek, Ulrike
A1  - Westhoff, Peter
A1  - Steinmüller, Klaus
T1  - Studies on the expression of NDH-H, a subunit of the NAD(P)H-plastoquinone-oxidoreductase of higher-plant chloroplasts
N2  - The plastid genomes of higher plants contain eleven reading frames (ndhA-K) that are homologous to genes encoding subunits of the mitochondrial NADH-ubiquinone-oxidoreductase (complex I). The carboxyterminal end of the NDH-H subunit from rice (Oryza sativa L.) was expressed as a fusion protein in Escherichia coli and antibodies against the fusion protein were generated in rabbits. The antibody was used to study the expression of NDH-H, and the following results were obtained: (i) NDH-H is expressed in mono- and dicotyledonous plants, (ii) NDH-H is localized on the stroma lamellae of the thylakoid membrane and (iii) NDH-H is expressed in etioplasts. Together with the finding that two other ndh genes (ndhI and ndhK) are expressed in plastids, these results point to the existence of an NAD(P)H-plastoquinone-oxidoreductase on the thylakoid membrane. The possible function of the enzyme in plastids is discussed and it is suggested that it works in balancing the ATP/ADP and the NADPH/NADP ratios during changing external (i.e. light) or internal (i.e. ATP and NADPH demands of biosynthetic pathways of the plastid) conditions.
KW  - NAD(P)H-plastoquinone-oxidoreductase
KW  - ndhH gene
KW  - Plastid DNA
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31283
ER  - 
TY  - JOUR
A1  - Berger, Susanne
A1  - Ellersiek, Ulrike
A1  - Kinzelt, Dagmar
A1  - Steinmüller, Klaus
T1  - Immunopurification of a subcomplex of the NAD(P)H-plastoquinone-oxidoreductase from the cyanobacterium Synechocystis sp. PCC6803
N2  - An antibody against the NDH-K subunit of the NAD(P)H-dehydrogenase from the cyanobacterium Synechocystis sp. PCC6803 was used to isolate a subcomplex ofthe enzyme from Triton X-lOO solubilized total membranes by immunoaffinity chromatography. The isolated subcomplex consisted of seven major polypeptides with molecular masses of 43, 27, 24, 21, 18, 14 and 7 kDa. The amino-terminal amino acid sequences of the polypeptides were determined. By comparing the sequences with the amino acid sequences deduced from DNA. three proteins were identified as NDH-H (43 kDa). NDH-K (27 kDa) and NDH-J (24 kDa). A fourth subunit (NDH-J, 21 kDa) was identified by Western blot analysis with an NDH-J antibody.
KW  - NAD(P)H-dehydrogenase
KW  - Cyanobacteria
KW  - Synechocystis sp. PCC6803
KW  - NDH-H
KW  - NDH-I
KW  - NDH-J
KW  - NDH-K
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31249
ER  - 
TY  - JOUR
A1  - Berger, Susanne
A1  - Ellersiek, Ulrike
A1  - Steinmüller, Klaus
T1  - Cyanobacteria contain a mitochrondrial complex I-homologous NADH-dehydrogenase
N2  - Thylakoid and cytoplasmic membranes of the cyanobacterium Syncchocystis sp. PCC 6803 were purified by sucrose gradient centrifugation. Both membranes oxidize NADH in a rotenone-sensitive reaction. Antibodies prepared against psbG/ndhKand ndhJ fusion proteins detect the corresponding polypeptides in both membrane preparations. This demonstrates that a NADH-dehydrogenase, homologous to the mitochondrial NADHubiquinone-oxidoreductase (complex I of the respiratory chain) is present in cyanobacteria, The NADH-dehydrogenase can be solubilized with the detergent /-D-dodecylmaltoside. Sedimentation analysis of the solubilized enzyme on a sucrose gradient indicates that it is a multisubunit protein complex.
KW  - Respiratory chain
KW  - NADH-dehydrogenase
KW  - Cyanobacteria
KW  - Synechocystis 6803
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31223
ER  - 
TY  - JOUR
A1  - Mitesser, Oliver
A1  - Weissel, Norbert
A1  - Strohm, Erhard
A1  - Poethke, Hans-Joachim
T1  - Adaptive dynamic resource allocation in annual eusocial insects: Environmental variation will not necessarily promote graded control
N2  - Background: According to the classical model of Macevicz and Oster, annual eusocial insects should show a clear dichotomous "bang-bang" strategy of resource allocation; colony fitness is maximised when a period of pure colony growth (exclusive production of workers) is followed by a single reproductive period characterised by the exclusive production of sexuals. However, in several species graded investment strategies with a simultaneous production of workers and sexuals have been observed. Such deviations from the "bang-bang" strategy are usually interpreted as an adaptive (bet-hedging) response to environmental fluctuations such as variation in season length or food availability. To generate predictions about the optimal investment pattern of insect colonies in fluctuating environments, we slightly modified Macevicz and Oster's classical model of annual colony dynamics and used a dynamic programming approach nested into a recurrence procedure for the solution of the stochastic optimal control problem. Results: 1) The optimal switching time between pure colony growth and the exclusive production of sexuals decreases with increasing environmental variance. 2) Yet, for reasonable levels of environmental fluctuations no deviation from the typical bang-bang strategy is predicted. 3) Model calculations for the halictid bee Lasioglossum malachurum reveal that bet-hedging is not likely to be the reason for the graded allocation into sexuals versus workers observed in this species. 4) When environmental variance reaches a critical level our model predicts an abrupt change from dichotomous behaviour to graded allocation strategies, but the transition between colony growth and production of sexuals is not necessarily monotonic. Both, the critical level of environmental variance as well as the characteristic pattern of resource allocation strongly depend on the type of function used to describe environmental fluctuations. Conclusion: Up to now bet-hedging as an evolutionary response to variation in season length has been the main argument to explain field observations of graded resource allocation in annual eusocial insect species. However, our model shows that the effect of moderate fluctuations of environmental conditions does not select for deviation from the classical bang-bang strategy and that the evolution of graded allocation strategies can be triggered only by extreme fluctuations. Detailed quantitative observations on resource allocation in eusocial insects are needed to analyse the relevance of alternative explanations, e.g. logistic colony growth or reproductive conflict between queen and workers, for the evolution of graded allocation strategies.
KW  - Insekten
KW  - Fitness
KW  - Evolution
KW  - Sozialität
KW  - resource allocation
KW  - fitness
KW  - evolution
KW  - eusociality
KW  - insect
Y1  - 2007
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45412
ER  - 
TY  - JOUR
A1  - Mitesser, Oliver
A1  - Weissel, Norbert
A1  - Strohm, Erhard
A1  - Poethke, Hans J.
T1  - The evolution of activity breaks in the nest cycle of annual eusocial bees: A simple model of delayed exponential growth
N2  - Abstract: Background Social insects show considerable variability not only in social organisation but also in the temporal pattern of nest cycles. In annual eusocial sweat bees, nest cycles typically consist of a sequence of distinct phases of activity (queen or workers collect food, construct, and provision brood cells) and inactivity (nest is closed). Since the flight season is limited to the time of the year with sufficiently high temperatures and resource availability, every break reduces the potential for foraging and, thus, the productivity of a colony. This apparent waste of time has not gained much attention. Results We present a model that explains the evolution of activity breaks by assuming differential mortality during active and inactive phases and a limited rate of development of larvae, both reasonable assumptions. The model predicts a systematic temporal structure of breaks at certain times in the season which increase the fitness of a colony. The predicted pattern of these breaks is in excellent accordance with field data on the nest cycle of the halictid Lasioglossum malachurum. Conclusion Activity breaks are a counter-intuitive outcome of varying mortality rates that maximise the reproductive output of primitively eusocial nests.
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48196
ER  - 
TY  - JOUR
A1  - Poethke, Hans J. ;
A1  - Liebig, Jürgen
T1  - Risk-sensitive foraging and the evolution of cooperative breeding and reproductive skew
N2  - Abstract: Background Group formation and food sharing in animals may reduce variance in resource supply to breeding individuals. For some species it has thus been interpreted as a mechanism of risk avoidance. However, in many groups reproduction is extremely skewed. In such groups resources are not shared equally among the members and inter-individual variance in resource supply may be extreme. The potential consequences of this aspect of group living have not attained much attention in the context of risk sensitive foraging. Results We develop a model of individually foraging animals that share resources for reproduction. The model allows analyzing how mean foraging success, inter-individual variance of foraging success, and the cost of reproduction and offspring raising influence the benefit of group formation and resource sharing. Our model shows that the effects are diametrically opposed in egalitarian groups versus groups with high reproductive skew. For individuals in egalitarian groups the relative benefit of group formation increases under conditions of increasing variance in foraging success and decreasing cost of reproduction. On the other hand individuals in groups with high skew will profit from group formation under conditions of decreasing variance in individual foraging success and increasing cost of reproduction. Conclusion The model clearly demonstrates that reproductive skew qualitatively changes the influence of food sharing on the reproductive output of groups. It shows that the individual benefits of variance reduction in egalitarian groups and variance enhancement in groups with reproductive skew depend critically on ecological and life-history parameters. Our model of risk-sensitive foraging thus allows comparing animal societies as different as spiders and birds in a single framework.
Y1  - 2008
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-48214
ER  - 
TY  - JOUR
A1  - Bonte, Dries
A1  - Hovestadt, Thomas
A1  - Poethke, Hans-Joachim
T1  - Evolution of dispersal polymorphism and local adaptation of dispersal distance in spatially structured landscapes
N2  - Many organisms show polymorphism in dispersal distance strategies. This variation is particularly ecological relevant if it encompasses a functional separation of short- (SDD) and long-distance dispersal (LDD). It remains, however, an open question whether both parts of the dispersal kernel are similarly affected by landscape related selection pressures. We implemented an individual-based model to analyze the evolution of dispersal traits in fractal landscapes that vary in the proportion of habitat and its spatial configuration. Individuals are parthenogenetic with dispersal distance determined by two alleles on each individual‘s genome: one allele coding for the probability of global dispersal and one allele coding for the variance of a Gaussian local dispersal with mean value zero. Simulations show that mean distances of local dispersal and the probability of global dispersal, increase with increasing habitat availability, but that changes in the habitat's spatial autocorrelation impose opposing selective pressure: local dispersal distances decrease and global dispersal probabilities increase with decreasing spatial autocorrelation of the available habitat. Local adaptation of local dispersal distance emerges in landscapes with less than 70% of clumped habitat. These results demonstrate that long and short distance dispersal evolve separately according to different properties of the landscape. The landscape structure may consequently largely affect the evolution of dispersal distance strategies and the level of dispersal polymorphism.
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47856
ER  - 
TY  - JOUR
A1  - Krüger, Hans-Peter
A1  - Kohnen, Ralf
T1  - Tranquillizer effects in an experimental analog of group psychotherapy
N2  - In an experimental analog of verbal examinations, the call-up situation, the effects of two dosages of a tranquillizing agent (lopirazepam) are compared to placebo treatment. 72 male and female, healthy, young volunteers have been randomly assigned to 12 groups of 6 subjects each. Pulse frequency and performance were registered. The results indicated differential drug effects which were interpreted according to the hypotheses of "differential effects of social stressors". If a situation was highly challenging for a subject, the application of a tranquillizer in an adequately high dosage enabled him to perform well in spite of or because of strong increases in pulse frequency.
KW  - Tranquillizer
KW  - Social stress situations
KW  - Group dynamics
KW  - Healthy subjects
KW  - Differential effects of stressors
KW  - Anxiolysis
KW  - Telemetry Activation
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41316
ER  - 
TY  - JOUR
A1  - Krüger, H.-P.
A1  - Bonerad, E. M.
A1  - Dennler, H. J.
A1  - Dunkl, E.
A1  - Friese, H. J.
A1  - Hain, C.
A1  - Kazenwadel, J.
A1  - Kohnen, Ralf
A1  - Maier, W.
A1  - Menzel, M.
T1  - Speech chronemics in drug evaluation
N2  - No abstract available
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41213
ER  - 
TY  - JOUR
A1  - Maschwitz, Ulrich
A1  - Fiala, Brigitte
A1  - Linsenmair, Karl Eduard
T1  - Clerodendrum fistulosum (Verbenanceae), an unspecific myrmecophyte from Borneo with spontaneously opening domatia
N2  - Clerodendrumjistulosum Becc. is a true myrmecophyte as it offers nesting space for ants in hollow intemodes. In contrast to previous reports our investigations proved that these domatia open by themselves, thus providing cavities for a variety of different ant species. In Sarawak, Malaysia, we did not find an obligate relationship between C. jistulosum and a specific ant-partner. For comparison, studies on herbarium material of other Clerodendrum species were carried out a further species, C. deflexum from the Malay Peninsula and Sumatra presumably also is myrmecophytic.
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31013
ER  - 
TY  - JOUR
A1  - Weising, K.
A1  - Fiala, Brigitte
A1  - Ramloch, K.
A1  - Kahl, K.
A1  - Epplen, J. T.
T1  - Olingonucleotide fingerprinting in angiosperms
N2  - No abstract available
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42884
ER  - 
TY  - JOUR
A1  - Marohn, Frank
T1  - Asymptotic sufficiency of order statistics for almost regular Weibull type densities
N2  - Consider a location family which is defined via a Weibull type density having shape parameter a = 1. We treat the problem, which portion of the order statistics is asymptotically sufficient. It turns out that the intermediate order statistics are relevant.
KW  - Weibull type density
KW  - intermediate order statistics
KW  - asymptotic sufficiency
KW  - local asymptotic normality
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45837
ER  - 
TY  - JOUR
A1  - Falk, Michael
A1  - Marohn, Frank
T1  - Asymptotically optimal tests for conditional distributions
N2  - No abstract available
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45823
ER  - 
TY  - JOUR
A1  - Janssen, A.
A1  - Marohn, Frank
T1  - On statistical information of extreme order statistics, local extreme value alternatives, and Poisson point processes
N2  - The aim of the present paper is to clarify the role of extreme order statistics in general statistical models. This is done within the general setup of statistical experiments in LeCam's sense. Under the assumption of monotone likelihood ratios, we prove that a sequence of experiments is asymptotically Gaussian if, and only if, a fixed number of extremes asymptotically does not contain any information. In other words: A fixed number of extremes asymptotically contains information iff the Poisson part of the limit experiment is non-trivial. Suggested by this result, we propose a new extreme value model given by local alternatives. The local structure is described by introducing the space of extreme value tangents. It turns out that under local alternatives a new class of extreme value distributions appears as limit distributions. Moreover, explicit representations of the Poisson limit experiments via Poisson point processes are found. As a concrete example nonparametric tests for Frechet type distributions against stochastically larger alternatives are treated. We find asymptotically optimal tests within certain threshold models.
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45816
ER  - 
TY  - JOUR
A1  - Falk, Michael
A1  - Marohn, Frank
T1  - Von Mises condition revisited
N2  - It is shown that the rate of convergence in the von Mises conditions of extreme value theory determines the distance of the underlying distribution function F from a generalized Pareto distribution. The distance is measured in terms of the pertaining densities with the limit being ultimately attained if and only if F is ultimately a generalized Pareto distribution. Consequently, the rate of convergence of the extremes in an lid sample, whether in terms of the distribution of the largest order statistics or of corresponding empirical truncated point processes, is determined by the rate of convergence in the von Mises condition. We prove that the converse is also true.
KW  - Von Mises conditions
KW  - extreme value theory
KW  - extreme value distribution
KW  - extreme order statistics
KW  - generalized Pareto distribution
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45790
ER  - 
TY  - JOUR
A1  - Fiala, Brigitte
A1  - Maschwitz, Ulrich
A1  - Pong, Tho, Yow
A1  - Helbig, Andreas J.
T1  - Studies of a South East Asian ant-plant association : protection of Macaranga trees by Crematogaster borneensis
N2  - In the humid tropics of SE Asia there are some 14 myrmecophytic species of the pioneer tree genus Macaranga (Euphorbiaceae). In Peninsular Malaysia a close association exists between the trees and the small, non-stinging myrmicine Crema togas ter borneensis. These ants feed mainly on food bodies provided by the plants and have their colonies inside the hollow intemodes. In a ten months field study we were able to demonstrate for four Macaranga species (M. triloba, M. hypoleuca, M. hosei, M. hulletti) that host plants also benefit considerably from ant-occupation. Ants do not contribute to the nutrient demands of their host plant, they do, however, protect it against herbivores and plant competition. Cleaning behaviour of the ants results in the removal of potential herbivores already in their earliest developmental stages. Strong aggressiveness and a mass recruiting system enable the ants to defend the host plant against many herbivorous insects. This results in a significant decrease in leaf damage due to herbivores on ant-occupied compared to ant-free myrmecophytes as well as compared to non-myrmecophytic Macaranga species. Most important is the ants' defense of the host plant against plant competitors, especially vines, which are abundant in the well-lit pioneer habitats where Macaranga grows. Ants bite off any foreign plant part coming into contact with their host plant. Both ant-free myrmecophytes and non-myrmecophytic Macaranga species had a significantly higher incidence of vine growth than specimens with active ant colonies. This may be a factor of considerable importance allowing Macaranga plants to grow at sites of strongest competition.
KW  - Ant/plant interaction
KW  - Myrmecophytes
KW  - Protection
KW  - Macaranga
KW  - Crematogaster borneensis
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42857
ER  - 
TY  - JOUR
A1  - Maschwitz, Ulich
A1  - Fiala, Brigitte
A1  - Lee, Ying Fah
A1  - Chey, Vun Khen
A1  - Tan, Fui Lian
T1  - New and little-known myrmecophytic associations from Bornean rain forests
N2  - The woody climber Millettia niuewenhuisii (Fabaceae) and the shrub Myrmeconauclea strigosa (Rubiaceae) in Sabah, Borneo are associated with ants. The hollow stems of Millettia nieuwenhuisii are regularly inhabited by an aggressive Cladomyrma sp., which keeps pseudococcids inside the stem. On Myrmeconauclea strigosa the ants live in hollow internodal swellings near the end of the branches. In this plant many different ant species use the nesting space in an opportunistic manner.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42957
ER  - 
TY  - JOUR
A1  - Maschwitz, Ulich
A1  - Fiala, Brigitte
A1  - Saw, L. G.
A1  - Norma-Rashid, Yusoff
A1  - Idris, Azarae Haji
T1  - Ficus obscura var. borneensis (Moraceae), a new non-specific ant-plant from Malesia
N2  - Ficus obscura var. borneensis is a true myrmecophyte. It spontaneously forms cavities (domatia) in parts of its twigs which open by slits, These occur in the internodes and are usually not swollen. The domatia are inhabited by a variety of non-specific tree-living ants including Crematogaster spp., Cataulacus sp., Tetramorium sp., Cardio condyla sp. and Camponotus sp.. Additionally the plant providL a su~ar-containing secretion from extrafloral nectaries on the lower surfaces of the leaves. Examination of herbarium specimens of 37 other South-east Asian Ficus species did not reveal a single specimen with domatia.
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42926
ER  - 
TY  - JOUR
A1  - Heisswolf, Annette
A1  - Obermaier, Elisabeth
A1  - Poethke, Hans-Joachim
T1  - Selection of large host plants for oviposition by a monophagous leaf beetle: nutritional quality or enemy-free space?
N2  - 1. Oviposition site selection is crucial for the reproductive success of herbivorous insects. According to the preference–performance hypothesis, females should oviposit on host plants that enhance the performance of their offspring. More specifically, the plant vigour hypothesis predicts that females should prefer large and vigorously growing host plants for oviposition and that larvae should perform best on these plants. 2. The present study examined whether females of the monophagous leaf beetle Cassida canaliculata Laich. (Coleoptera: Chrysomelidae) prefer to oviposit on large host plant individuals of the meadow clary and whether large host plants are of higher nutritional quality than small host plants. Subsequently, it was tested whether the female preference correlates with offspring performance and survival. 3. In the field, females preferred large host plant individuals for oviposition and host plant quality, i.e. leaf nitrogen content, was significantly higher in leaves of large than of small host plants. 4. In the laboratory, larval development time was shorter on leaves of large host plant individuals than on small host plant individuals, but this could not be shown in the field. 5. However, a predator-exclusion experiment in the field resulted in a higher survival of larvae on large host plants than on small host plants when all predators had free access to the plants. On caged host plants there was no difference in survival of larvae between plant size categories. 6. It is concluded that females of C. canaliculata select oviposition sites that enhance both performance and survival of their offspring, which meets the predictions of the plant vigour hypothesis.
KW  - Insekten
KW  - Eiablage
KW  - Fitness
KW  - Präferenz
KW  - Chrysomelidae
KW  - leaf nitrogen content
KW  - plant vigour
KW  - predator-exclusion
KW  - preference–performance hypothesis
Y1  - 2005
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47728
ER  - 
TY  - JOUR
A1  - Heisswolf, Annette
A1  - Poethke, Hans-Joachim
A1  - Obermaier, Elisabeth
T1  - Multitrophic influences on oviposition site selection in a specialized leaf beetle at multiple spatial scales
N2  - Egg distribution in herbivorous beetles can be affected by bottom-up (host plant), and by top-down factors (parasitoids and predators), as well as by other habitat parameters. The importance of bottom-up and top-down effects may change with spatial scale. In this study, we investigated the influence of host plant factors and habitat structure on egg distribution in the leaf beetle Cassida canaliculata Laich. (Coleoptera: Chrysomelidae), a monophagous herbivore on Salvia pratensis L. (Lamiales: Lamiaceae), on four spatial scales: individual host plant, microhabitat, macrohabitat, and landscape. At the individual host plant scale we studied the correlation between egg clutch incidence and plant size and quality. On all other scales we analyzed the relationship between the egg clutch incidence of C. canaliculata and host plant percentage cover, host plant density, and the surrounding vegetation structure. Vegetation structure was examined as herbivores might escape egg parasitism by depositing their eggs on sites with vegetation factors unfavorable for host searching parasitoids. The probability that egg clutches of C. canaliculata were present increased with an increasing size, percentage cover, and density of the host plant on three of the four spatial scales: individual host plant, microhabitat, and macrohabitat. There was no correlation between vegetation structure and egg clutch occurrence or parasitism on any spatial scale. A high percentage of egg clutches (38–56%) was parasitized by Foersterella reptans Nees (Hymenoptera: Tetracampidae), the only egg parasitoid, but there was no relationship between egg parasitism and the spatial distribution of egg clutches of C. canaliculata on any of the spatial scales investigated. However, we also discuss results from a further study, which revealed top-down effects on the larval stage.
N2  - Die Gelegeverteilung herbivorer Insekten kann sowohl durch bottom-up (Wirtspflanzen) und top-down Faktoren (Parasitoide und Prdatoren), als auch durch weitere Habitatparameter beeinflusst werden. Die Bedeutung der bottom-up und top-down Einflüsse kann zusätzlich von der räumlichen Skala abhängen. In dieser Studie untersuchen wir den Einfluss von Wirtspflanzenfaktoren und der Vegetationsstruktur auf die Gelegeverteilung des Blattkäfers Cassida canaliculata Laich. (Coleoptera: Chrysomelidae), einem auf Salvia pratensis L. (Lamiales: Lamiaceae) monophagen Herbivoren, auf vier räumlichen Skalen: dem Wirtspflanzenindividuum, Mikro- und Makrohabitat, sowie der Landschaft. Auf der Skala des Wirtspflanzenindividuums wurde der Zusammenhang zwischen der Gelegeinzidenz und der Größe und Qualität der Wirtspflanze untersucht. Auf allen anderen Skalen wurde die Korrelation zwischen der Gelegeinzidenz von C. canaliculata und der prozentualen Wirtspflanzendeckung und Wirtspflanzendichte, sowie der umgebenden Vegetationsstruktur analysiert. Die Vegetationsstruktur wurde untersucht, da die Herbivoren ihren Eiparasitoiden entkommen knönten, indem sie ihre Eigelege an Plätzen ablegen, deren Vegetationsstrukturparameter den Eiparasitoiden die Suche erschweren. Die Wahrscheinlichkeit, dass Eigelege von C. canaliculata vorhanden waren, nahm mit zunehmender Größe, prozentualer Deckung und Dichte der Wirtspflanze auf drei der vier untersuchten Skalen zu: Wirtspflanzenindividuum, Mikrohabitat und Makrohabitat. Die Vegetationsstruktur stand jedoch auf keiner räumlichen Skala in einem Zusammenhang mit der Gelegeinzidenz bzw. der Parasitierung der Eigelege. Ein hoher Anteil der Eigelege (38-56%) war durch den einzigen Eiparasitoiden Foersterella reptans Nees (Hymenoptera: Tetracampidae) parasitiert. Es konnte jedoch auf keiner der untersuchten räumlichen Skalen eine Korrelation zwischen der Parasitierung und der räumlichen Gelegeverteilung von C. canaliculata gefunden werden. Wir diskutieren aber auch Ergebnisse einer weiterführenden Studie, in der sich top-down Effekte auf das Larvalstadium zeigten.
KW  - Eiablage
KW  - Pflanzenfressende Insekten
KW  - Eiparasitismus
KW  - Käfer
KW  - Chrysomelidae
KW  - egg parasitism
KW  - herbivore
KW  - hostparasitoid interactions
KW  - plant quality
Y1  - 2006
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47738
ER  - 
TY  - JOUR
A1  - Heisswolf, Annette
A1  - Reichmann, Stefanie
A1  - Poethke, Hans-Joachim
A1  - Schröder, Boris
A1  - Obermaier, Elisabeth
T1  - Habitat quality matters for the distribution of an endangered leaf beetle and its egg parasitoid in a fragmented landscape
N2  - Fragmentation, deterioration, and loss of habitat patches threaten the survival of many insect species. Depending on their trophic level, species may be differently affected by these factors. However, studies investigating more than one trophic level on a landscape scale are still rare. In the present study we analyzed the effects of habitat size, isolation, and quality for the occurrence and population density of the endangered leaf beetle Cassida canaliculata Laich. (Coleoptera: Chrysomelidae) and its egg parasitoid, the hymenopteran wasp Foersterella reptans Nees (Hymenoptera: Tetracampidae). C. canaliculata is strictly monophagous on meadow sage (Salvia pratensis), while F. reptans can also parasitize other hosts. Both size and isolation of habitat patches strongly determined the occurrence of the beetle. However, population density increased to a much greater extent with increasing host plant density ( = habitat quality) than with habitat size. The occurrence probability of the egg parasitoid increased with increasing population density of C. canaliculata. In conclusion, although maintaining large, well-connected patches with high host plant density is surely the major conservation goal for the specialized herbivore C. canaliculata, also small patches with high host plant densities can support viable populations and should thus be conserved. The less specialized parasitoid F. reptans is more likely to be found on patches with high beetle density, while patch size and isolation seem to be less important.
KW  - Fragmentierung
KW  - Pflanzenfressende Insekten
KW  - Eiparasitismus
KW  - Metapopulation
KW  - Habitat fragmentation
KW  - herbivore
KW  - host plant density
KW  - metapopulation
KW  - multitrophic
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47740
ER  - 
TY  - JOUR
A1  - Poethke, Hans-Joachim
A1  - Hovestadt, Thomas
A1  - Mitesser, Oliver
T1  - Local extinction and the evolution of dispersal rates: Causes and correlations
N2  - We present the results of individual-based simulation experiments on the evolution of dispersal rates of organisms living in metapopulations. We find conflicting results regarding the relationship between local extinction rate and evolutionarily stable (ES) dispersal rate depending on which principal mechanism causes extinction: if extinction is caused by environmental catastrophes eradicating local populations, we observe a positive correlation between extinction and ES dispersal rate; if extinction is a consequence of stochastic local dynamics and environmental fluctuations, the correlation becomes ambiguous; and in cases where extinction is caused by dispersal mortality, a negative correlation between local extinction rate and ES dispersal rate emerges. We conclude that extinction rate, which both affects and is affected by dispersal rates, is not an ideal predictor for optimal dispersal rates.
KW  - Ausbreitung
KW  - Evolution
KW  - Computersimulation
KW  - Metapopulation
KW  - dispersal
KW  - evolution
KW  - ESS
KW  - metapopulation
KW  - extinction
KW  - individual-based model
Y1  - 2003
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47718
ER  - 
TY  - JOUR
A1  - Kohnen, Ralf
A1  - Krüger, Hans-Peter
T1  - Drug Effects on Human Social Behavior: Chances in Talking Activities Induced by CGP 361/A, a Beta-blocking Agent
N2  - No abstract available
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41228
ER  - 
TY  - JOUR
A1  - Christl, Manfred
A1  - Roberts, John D.
T1  - Carbon-13 Nuclear Magnetic Resonance Spectroscopy : Conformational Analysis of Methyl-Substituted Cycloheptanes, Cycloheptanols, and Cycloheptanones
N2  - The 130 chemical shifts were determined of the carbons in 12 cycloheptanes, 21 cycloheptanols, and 8 cycloheptanones. In some cyc1oheptanols and cyc1oheptanones, the assignments have been obtained unambiguously by the synthesis of deuterated derivatives and the use of paramagnetic-shift reagents. Substituent effects for the different types of groups have been calculated. The most informative data about the cyc10heptane conformations were provided by the relatively well understood I' effects. The results are generally in,good agreement with predictions based on the twist-chair form, which has been predicted by Hendrickson to be the most stable conformation. Pairs of cis-trans isomers are found to have rather characteristic differences in their 130 spectra. This fact was used to assign the resonances found for cis-trans mixtures of methyl-substituted cyc1oheptanols to specific isomers.
Y1  - 1972
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41663
ER  - 
TY  - JOUR
A1  - Christl, Manfred
A1  - Leß, Roland
A1  - Müller, Heinrich
T1  - 6,7-Dimethylene-2,4-diphenylbicyclo[3.2.l]oct-3-en-2-yl Anion : A Test for the Origin of the Unusual Properties of the Bicyclo[3.2.l]octa-3,6-dien-2-yl Anion
N2  - No abstract available
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31547
ER  - 
TY  - JOUR
A1  - Gigstad, Kenneth M.
A1  - Ricci JR., John S.
A1  - Markgraf, J. Hodge
A1  - Christl, Manfred
A1  - Kraft, Arno
T1  - Strained Heterocyclic Systems : 18. Structure of 1,2,3-Methylidyne-2,3-dihydro-1H-cyclopenta[b]quinoxaline
N2  - No abstract available
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41645
SN  - 0108-2701
ER  - 
TY  - JOUR
A1  - Irngartinger, H.
A1  - Reimann, W.
A1  - Lang, R.
A1  - Christl, Manfred
T1  - Electron Density Distribution in a Bicyclo[l.l.0]butane
N2  - No abstract available
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31576
ER  - 
TY  - JOUR
A1  - Christl, Manfred
A1  - Leininger, Hartmut
A1  - Mattauch, Brigitte
T1  - The <sup>13</sup>C NMR Spectra of Some Tricyclo[2.2.0.0<sup>2,6</sup>]hexane Derivatives : Unexpected High Field Absorptions Due to Additive gamma-anti Subsituent Effects
N2  - By means of the BC NMR spectra of tricyclo{2.2.0~rfJ6Jhexane and thirteen of its derivatives the effects of substituents in endo-3- and endo-5-positions on the HC chemical shifts have been determined. The y-anti effects are at least as Jarge as in monosubstituted cyc1obutanes, where the shielding values of second-row hetero substituents exceed those in unstrained systems by far, and higher-row and carbon substituents still cause substantial upfield shifts. In the title system the y-anti effect of a substituent in the endo-3- and endo-5-position are operative additively, and thus shift the absorption of C-J upfieJd by a maximum of 27 ppm with respect to the unsubstituted hydrocarbon.
Y1  - 1983
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41620
SN  - x
ER  - 
TY  - JOUR
A1  - Krüger, Hans-Peter
T1  - Speech chronemics - a hidden dimension of speech. Theoretical background, measurement, and clinical validity
N2  - Der Begriff "speech chronemics" wird eingeführt, um eine Forschungsrichtung zu charakterisieren, die aus den physikalischen Qualitäten des Sprachsignals lediglich das Muster von "an" ("Sprechen") und "aus" ("Pausieren") herauszieht. Die Forschungen zu diesen on-off Mustern lassen sich in die methodischen Dimensionen "zeitliche Einheit", "Zahl der Sprecher" und "Art der prosodischen Maße" gliedern. Es wird gezeigt, daß die Entscheidung eines Untersuchers für eine bestimmte Methodik das Ergebnis seiner Untersuchung nicht unerheblich vorausbestimmt. Es wird dann mit dem Logoport ein neues tragbares Meßinstrument vorgestellt, das es erlaubt, das Sprechverhalten von Probanden bis zu 24 Stunden lang in deren normaler Umgebung aufzuzeichnen. Es werden zwei Experimente beschrieben. Im ersten wird gezeigt, daß die Messung von Artiku1ationspausen valide den psychophysiologischen Aktivierungsstatus abbilden kann. In der zweiten Studie wird die soziotrope Wirksamkeit einer neuen betablockierenden Substanz aufgezeigt: in einer Langzeitstudie verbesserte sich das Interaktionsverhalten von Probanden, die sich sozial schwer tun, im Vergleich zu Plazebo und zum Verhalten von Personen ohne solche Schwierigkeiten. Schließlich wird mit Blick auf neue Studien die Wichtigkeit einer überlegten theoretischen Einbettung und einer Standardisierung von situativen und methodischen Merkmalen betont.
N2  - The term "speech chronemics" is introduced to characterize a research strategy which extracts from the physical qualities of the speech signal only the pattern of ons ("speaking") and offs ("pausing"). The research in this field can be structured into the methodological dimension "unit of time", "number of speakers", and "quality of the prosodic measures". It is shown that a researcher's actual decision for one method largely determines the outcome of his study. Then, with the Logoport a new portable measurement device is presented. It enables the researcher to study speaking behavior over long periods of time (up to 24 hours) in the normal environment of his subjects. Two experiments are reported. The first shows the validity of articulation pauses for variations in the physiological state of the organism. The second study proves a new betablocking agent to have sociotropic effects: in a long-term trial socially high-strung subjects showed an improved interaction behavior (compared to placebo and socially easy-going persons) in their everyday life. Finally, the need for a comprehensive theoretical foundation and for standardization of measurement situations and methods is emphasized.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41037
ER  - 
TY  - JOUR
A1  - Kohnen, Ralf
A1  - Krüger, Hans-Peter
T1  - Tranquillizer effects in an experimental analog of verbal examinations
N2  - In an experimental analog of verbal examinations, the call-up situation, the effects of two dosages of a tranquillizing agent (lopirazepam) are compared to placebo treatment. 72 male and female, healthy, young volunteers have been randomly assigned to 12 groups of 6 subjects each. Pulse frequency and performance were registered. The results indicated differential drug effects which were interpreted according to the hypotheses of "differential effects of social stressors". If a situation was highly challenging for a subject, the application of a tranquillizer in an adequately high dosage enabled him to perform well in spite of or because of strong increases in pulse frequency.
KW  - Tranquillizer
KW  - Social stress
KW  - Examination
KW  - Healthy subjects
KW  - Differential effects of stressors
KW  - Telemetry
KW  - Activation
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41617
ER  - 
TY  - JOUR
A1  - Krüger, Hans-Peter
A1  - Stuckenberg, Annette
A1  - Vollrath, Mark
T1  - Stability and Variability in Interactive Behavior as Measured by Methods of "Speech Chronemics"
N2  - Dyadic interaction is modelled os an adaptive process between personality of the partners involved and the characteristics of the theme. The theme structure and the principles which control the adaptation process are referred to as "syntality". The material of the studies reported are the speech signals of the verbal interaction reduced to an on-off pattern. In a first study individual speech behavior was found to remain stable in dyads even if partners changed. The second study showed the stability of the speech patterns for different interaction themes even if dyads changed. These apparently contradictory results are reconciled by introducing the concept of "adaptive stability". Individual speech behavior does not happen at a stable activity level, but is characterized by a constant relationship (" less" or "more") to the respective activity of the other partner.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40908
ER  - 
TY  - JOUR
A1  - Arbuznikov, Alexey V.
A1  - Plakhutin, A. B.
T1  - Symmetric vector coupling coefficients for atomic non-Roothaan states in the d\(^N\) configuration
N2  - No abstract available
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47062
ER  - 
TY  - JOUR
A1  - Arbuznikov, Alexey V.
A1  - Plakhutin, B. N.
T1  - Exact expression for the Fock operator in the unified coupling operator method
N2  - No abstract available
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-47053
ER  - 
TY  - JOUR
A1  - Rostás, Michael
A1  - Blassmann, Katrin
T1  - Insects had it first: surfactants as a defence against predators
N2  - Insects have evolved an astonishing array of defences to ward off enemies. Well-known and widespread is the regurgitation of oral secretions (OS), fluids that repel attacking predators. In herbivores, the effectiveness of OS has been ascribed so far to the presence of deterrent secondary metabolites sequestered from the host plant. This notion implies, however, that generalists experience less protection on plants with low amounts of secondary metabolites or with compounds ineffective against potential enemies. Resolving the dilemma, we describe a novel defence mechanism that is independent of deterrents as it relies on the OS’ intrinsic detergent properties. The OS of Spodoptera exigua (and other species) was found to be highly amphiphilic and well capable of wetting the hydrophobic cuticle of predatory ants. As a result, affected ants stopped attacking and engaged in extensive cleansing. The presence of surfactants was sufficient to explain the defensive character of herbivore OS. We hypothesize that detergency is a common but unrecognised mode of defence which provides a base level of protection that may or may not be further enhanced by plant-derived deterrents. Our study also proves that insects ‘invented’ the use of defensive surfactants long before modern agriculture had started applying them as insecticides.
KW  - Pflanzenfressende Insekten
KW  - Grenzflächenaktiver Stoff
KW  - Ameisen
KW  - Zuckerrübeneule
KW  - Abwehr
KW  - Oralsekret
KW  - anti-predator defence
KW  - caterpillars
KW  - regurgitation
KW  - secondary metabolites
KW  - biosurfactants
Y1  - 2009
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-35031
ER  - 
TY  - JOUR
A1  - Ellgring, Johann Heinrich
A1  - Seiler, S.
A1  - Perleth, B.
A1  - Gasser, T.
A1  - Oertel, W.
T1  - An integrated approach for the neurological and psychological support of Parkinson patients
N2  - Introduction Although symptomatic therapy is available for Parkinson's disease, patients and relatives are faced with continuous severe psychological problems. These psychological problems include: 1. lack of emotional expression, 2. bradephrenia, 3. depression, 4. lack of motivation,S. social anxiety, 6. stress induced increase of symptoms. The first four of these may be at least in part due to the dopamine deficiency. However, even as part of the primary symptoms they have social and communicative impact for patients and relatives. Social anxiety and stress induced increase of symptoms on the other hand clearly result from an interaction of somatic and psychological factors. Social anxiety mainly develops in Parkinson I s disease as an indirect consequence of the motor symptoms. Patients are afraid of being negatively evaluated in the public, of receiving negative comments etc. Thus r social withdrawal increases and the improvement of neurological symptoms following drug treatment may not be fully exploited on the psychosocial level. Stress induced increase of motor symptoms is a commonly observed phenomenon in Parkinson's disease. Even minor stressors, mainly social in nature, can have extreme effects and may elicit or increase tremor or rigidity. A patient can be well in one moment, but unable to move in the next when being aware that he has to leave the house in an hour. Given this situation, patients and relatives have to develop strategies fo~ an emotional balance in the presence of a continuous confrontation with the direct and indirect consequences of the disease. A precondition for developing new psychologically based strategies is an optimwn medical treatment. The integrated approach for neurological and psychological support has the following goals: 1. improving medical treatment for the individual patient, 2. improving psychological coping and psychosocial adaptation for patients and relatives, and 3. evaluating and improving medical and psychological therapy. CONCLUSION Psychological intervention can provide considerable help for a substantial part of Parkinson patients. The main target is coping with stressful social situations. Relaxation and cognitive restructuring together with situational behavioral analysis and training of social skills specifically adapted to the disease are" the main strategies. Various problems remain open at the moment, like the maintenance of motivation which is especially critical for Parkinson patients. Parkins on 's disease is a neurological disease with a known pathological substrate and a therapy which is effective at least for several years on a symptomatic level. The symptoms are tightly connected with psychological emotional and cognitive processes. Moreover, patients and relatives have to cope with symptoms which strongly influence social interaction. And they have to cope together with this situation over a period of ten or twenty years. Thus not only for the patient but also for the health of the relatives, psychological aid is urgently needed. We suggest to integrate psychological approach into the neurological diagnosis and treatment.
Y1  - 1990
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42456
ER  - 
TY  - JOUR
A1  - Ellgring, Johann Heinrich
A1  - Clarke, Andrew H.
T1  - A video protocolling and retrieval system for the analysis of behaviour
N2  - A video protocolling and retrieval system for the analysis of behaviour. Rec~nt developments in the data processing and video technologies have enabled the desIgn of automatic systems for the handling of video software. The system for the protocoIling and retrieval of audiovisual data (PRA VDA) described here has been developed for applications in behavioural observation and analysis. The facilities available, including time coding, search routines and automatic editing are explained and the advantages of computer aided operation are dealt with. Current applications of the system are briefly discussed.
N2  - Ein System zum Protokollieren und Ruckholen audiovisueller Daten fur die Verhaltensanalyse. Neuere Entwicklungen der Datenverarbeitungs- und Video-Techno- 10gie ermoglichten den Aufbau automatischer Systeme fur die Bearbeitung von VideoSoftware. Das hier beschriebene System zum ProtokoIlieren und Riickholen AudioVisuellcr Daten (PRA VDA) wurde fUr den Einsatz in der Verhaltensbeobachtung und Verhaltensanalyse entwickelt. Die Moglichkeiten des Systems, u. a. Zeitcodierung, Such-Routinen und automatische Editierung werden erkHirt und die Vorteile corn puterunterstutzter Operationen aufgezeigt. Augenb lickliche Anwendungsbereiche des Systems werden kurz diskutiert. französisch: Un systeme de fixation et de notation video pour ranalyse du comportement. Des mises au point recentes dans le domaine dn traitement de Pinformation et des technologies video ont permis de concevoir des systemes automatiques pour le traitement des materiaux enregistres en video. Le systeme de fixation et de notation des informations audio-visueIles (PRA VDA) deedt ici a ete mis au point pour etre employe dans l'observation et l'analyse du comportement. Les avantagcs tels que le codage du temps, les recherches de routine et la mise en page automatique sont expliques, les possibilites de J'apport de l'ordinateur dans certaines operations presentees. Les applications courantes du systeme sont rapidement retracees.
Y1  - 1977
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42537
ER  - 
TY  - JOUR
A1  - Ellgring, Johann Heinrich
A1  - Oertel, W. H.
A1  - Ulm, G.
A1  - Gasser, T.
A1  - Perleth, B.
A1  - Seiler, S.
T1  - Partnership and depression in Parkinson's Disease
N2  - In this study, the influence of partnership on depression and coping with Parkinson's disease has been investigated. Twentythree single female patients, 46 married patients (23 female, 23 male) with unimpaired partnership and 42 patients (21 female, 21 male) whose partnership had worsened since the onset of disease, were compared with regard to depression and self reported extent of psychosocial distress. Single female patients tended to have higher depression scores than patients in a stable partnership, especially in items concerning personal worthlessness and senselessness of life. Patients differed in the extent of distress concerning social behavior, psychological problems/anxiety and efficiency. Within the group of single female patients two subgroups emerged: (1) patients with low extent of distress in all aspects; (2) patients who were highly distressed by psychological problems and physical disability but weakly distressed from social interaction. Male and female patients living in a stable partnership reported only a generally low to moderate extent of distress. More than half of the male and female patients who reported an impairment of their relationship also had scores of moderate to severe depression. These patients also had the h~ghest extent of distress in each ofthe aspects assessed. The results are dicussed with regard to possible interactive effects ofthe disease, quality of the partnership and availability of coping strategies.
KW  - Depression
KW  - Parkinson's disease
KW  - Partnership
KW  - Psychological distress
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42516
ER  - 
TY  - JOUR
A1  - Ellgring, Johann Heinrich
A1  - Clarke, A. H.
T1  - Event triggered observation as a method for the study of gestural behaviour
N2  - No abstract available
Y1  - 1977
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42491
ER  - 
TY  - JOUR
A1  - Bossert, Sabine
A1  - Laessle, Reinhold G.
A1  - Meiller, Caroline
A1  - Junker, Matthias
A1  - Ellgring, Johann Heinrich
A1  - Pirke, Karl-Martin
T1  - Visual palatability of food in patients with eating disorders and dieting women
N2  - The effects of 19 meals of different caloric content on slides on palatability and hypothetical duration of consumption were investigated in 7 patients with anorexia nervosa, 17 patients with bulimia nervosa at the beginning and after 8 weeks of hospital treatment. Nine healthy females served as controls. At the beginning of treatment, palatability of low caloric food was significantly higher and hypothetical duration of consumption of high caloric food was significantly longer in patients when compared to controls. After 8 weeks, in the patients palatability of low caloric food had decreased. Dislike for high caloric food remained stable in anorexics.
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42466
ER  - 
TY  - JOUR
A1  - Linsenmair, Karl Eduard
T1  - Some adaptations of the desert woodlouse Hemilepistus reaumuri (Isopoda, Oniscoidea) to desert environment
N2  - No abstract available
Y1  - 1974
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-44483
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
T1  - A novel type of chromatin organization in lampbrush chromosomes of Pleurodeles waltlii: visualization of clusters of tandemly repeated, very short transcriptional units
N2  - A novel chromatin configuration is described in lampbrush chromosomes of Pleurodeles waltlii oocytes which is different from transcriptionally inactive chromatin as weil as from the various forms of transcribed chromatin hitherto described. This novel type of chromatin is not arranged in Christmas tree-Iike configurations of densely packed lateral ribonucleoprotein (RNP) fibriIs but is characterized by a periodic alternating pattern of thick and thin regions which occur in clusters 01 some 10,000 repeats. Each thickened unit with an average length of 45 nm contains two c10sely spaced particles, the putative RNA polymerases, and each thickened unit is separated from the next one by a beaded chromatin spacer with a length of about 80 nm. This chromatin spacer contains on average two particles of approximately 14 nm in diameter, assumed to be nucleosomes. The thickened regions are interpreted to represent short transcriptional units containing approximately 130 base pairs of DNA which are separated from each other by nontranscribed spacers of 240-400 base pairs of DNA. The possibility is discussed that these transcriptional units represent 5S rRNA or tRNA genes.
KW  - Lampbrush chromosomes
KW  - Amphibian oocytes
KW  - Transcription units
KW  - Electron microscopy
Y1  - 1982
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41087
ER  - 
TY  - JOUR
A1  - Ellgring, Johann Heinrich
A1  - Schneider, F.
A1  - Friedrich, J.
A1  - Fus, I.
A1  - Beyer, T.
A1  - Heimann, H.
A1  - Himer, W.
T1  - The effects of neuroleptics on facial action in schizophrenic patients
N2  - This paper describes the influence of neuroleptic therapy on facial action in drug-naive schizophrenics. In a comparative study of medicated and unmedicated schizophrenic patients, the coordinates of 12 small light-reflecting points, attached to subjects' faces, were computer-recorded and analyzed automatically during a semistandardized clinical interview. In addition, facial activity in videotaped interviews was coded using the Facial Action Coding System (FACS). Each sample group comprised of eight patients with the DSMIII- R diagnostic criteria "schizophrenia" or "schizophreniform disorder". Subjects were studied on two occasions, one shortly after admission to the hospital, the other three weeks later. Group I was unmedicated during the first session, whereas group2 was medicated throughout the study. Three weeks after the start of medication, at the second interview, both recording methods showed a reduction in facial activity and facial expression across all subjects in group 1. The facial action of patients in group2, however, remained unchanged.
N2  - Ziel der vorliegenden Arbeit war die Untersuchung des Einflusses von Neuroleptika auf die Mimik von unmedizierten schizophrenen Patienten. Wiihrend eines halbstandardisierten klinischen Interviews worde die Beweglichkeit von zwolf kleinen, licht-reflektierenden Punkten, die in das Gesicht von medizierten und unmedizierten schizophrenen Patienten geklebt worden, automatisch im Zeitverlauf gemessen. Erganzend wurde der mirnische Ausdruck mit dem Facial Action Coding System (FACS) kodiert, wofiir die Patienten gleichzeitig mit Video aufgenommen worden. Jede der beiden Gruppen bestand aus acht Patienten mit den DSM-IIIR- Diagnosen "Schizophrenie" oder "Schizophrenieforme Storung". Die Patienten worden einmal direkt nach der stationaren Aufnahme und ein zweites Mal nach drei Wochen untersucht. Die Patienten der ersten Gruppe waren zum ersten Zeitpunkt nicht mit Neuroleptika mediziert, wiihrend die der zweiten Gruppe schon zu diesem Zeitpunkt entsprechende Medikamente einnahmen. Es konnte eine Reduktion der mimischen Beweglichkeit des gesamten Gesichtes im Sinne einer neuroleptisch bedingten Hypornimie der primiir Neuroleptika-unbehandelten Patienten bei der zweiten Untersuchung beobachtet werden. Die andere Gruppe Schizophrener, die zu beiden Zeitpunkten mit Neuroleptika behandelt waren, zeigte keine Veriinderung in ihrer mimischen Beweglichkeit.
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-43269
ER  - 
TY  - JOUR
A1  - Ellgring, Johann Heinrich
A1  - Gaebel, W.
T1  - Experimental psychopathology in biological psychiatry and pharmacology
N2  - No abstract available
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-43246
ER  - 
TY  - JOUR
A1  - Ellgring, Johann Heinrich
T1  - Nonverbal expression of psychological states in psychiatric patients
N2  - Nonverbal behavior, especially facial expression, appears as one of the most important means for communicating affective states. Studies on groups of psychiatric patients and control subjects are reported in which nonverbal behavior is analyzed from videotaped dialogues. Using a quantitative approach, results on facial behavior, speech, and gaze are described, which shed light on the expressive and communicative functions of nonverbal behavior. From longitudinal observations on depressed patients it emerged that individualspecific associations have to be taken into account for the relationship between expressive behavior and mood changes. The predominance of facial behavior in the speaker role of an individual found in patients and control groups points to the integrated communicative function of the verbal and nonverbal elements. However, recovered schizophrenic patients exhibited a dissociation of these elements. Implications for our understanding of nonverbal communications are discussed.
KW  - Nonverbal communications
KW  - Facial expression
KW  - Gaze behavior
KW  - Expression of mood states
KW  - Schizophrenia
KW  - Depression
KW  - Psychopathology
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-43179
ER  - 
TY  - JOUR
A1  - Heinsen, Helmut
A1  - Heinsen, Y. L.
T1  - Serial thick, frozen, gallocyanin stained sections of human central nervous system
N2  - A rapid method for macroscopic and microscopic investigation of human CNS is proposed. After fonnalin fixation, gelatin or agarose embedding, and cryoprotective treatment, frozen human spinal cords, brainstems, or hemispheres can be serially cut into 0.7 mm thick slices. Stained with gallocyanin-chromalum, these slices facilitate cytoarchitectonic, neuropathologic, and quantitative examination. Regions of interest from parallel fonnalin-stored unstained slices can be embedded into paraffin and stained by any irnrnunocytologic and histologic stain compatible with fonnalin fixation and paraffin embedding.
KW  - CNS
KW  - comparative anatomy
KW  - cytoarchitectonics
KW  - neuroimaging
KW  - neuropathology
KW  - Nissl stain
KW  - quantitative anatomy
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45741
ER  - 
TY  - JOUR
A1  - Heinsen, Helmut
A1  - Heinsen, YL
T1  - Strain-specific differences in the vermian granular layer of albino rats
N2  - Foliation of the cerebella of Sprague-Dawley rats (strain Han:SPRD) is more advanced than in Wistar rats (strain Chbb:THOM). The differences expressed as length of the granular layer in median sections were significant in lobules VIa, VIII, IX and X. The length of the other vermian lobules is generally higher in the former strain. With regard to the volume of the granular layer, the situation is reversed, indicating that the lateral extent and thickness of vermian lobules in Wistar rats (strain Chbb:THOM) is generally larger. These quantitative differences may express differences in cerebellar microcircuitry and fibre connections in the cortex of Wistar and Sprague-Dawley rats.
KW  - Albino rats
KW  - Cerebellum
KW  - Granular layer
KW  - Quantitative anatomy
KW  - Strain differences
Y1  - 1984
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45735
ER  - 
TY  - JOUR
A1  - Higgins, M. J.
A1  - Smilinich, N. J.
A1  - Sait, S.
A1  - Koenig, A.
A1  - Pongratz, J.
A1  - Gessler, Manfred
A1  - Richard III., C. W.
A1  - James, M. R.
A1  - Sanford, J. P.
A1  - Kim, B.-W.
A1  - Cattelane, J.
A1  - Nowak, N. J.
A1  - Winterpacht, A.
A1  - Zabel, B. U.
A1  - Munroe, D. J.
A1  - Bric, E.
A1  - Housman, D. E.
A1  - Jones, C.
A1  - Nakamura, Y.
A1  - Gerhard, D. S.
A1  - Shows, T. B.
T1  - An Ordered NotI Fragment Map of Human Chromosome Band 11p15
N2  - An ordered NotI fragment map containing over 60 loci and encompassing approximately 17 Mb has been constructed for human chromosome band llpl5. Forty-two probes, including 11 NotI-linking cosmids, were subregionaUy mapped to llpl5 using a subset of the Jl-deletion hybrids. These and 23 other probes defining loci previously mapped to 11p15 were hybridized to genomic DNA digested with NotI and 5 other infrequently cleaving restriction enzymes and separated by pulsed-field gel electrophoresis. Thirty-nine distinct NotI fragments were detected encompassing approximately 85% of the estimated length of llp15. The predicted order of the gene loci used is cenMYODI- PTH-CALCA-ST5-RBTNI-HPX-HBB-RRMlTH/ INS!1GF2-H19-CTSD-MUC2-DRD4-HRAS-RNHtel. This map wiu allow higher resolution mapping of new Ilp15 markers, facilitate positional cloning of disease genes, and provide a framework for the physical mapping of llp15 in clone contigs.
KW  - Genom / Genkartierung / Genanalyse
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45766
ER  - 
TY  - JOUR
A1  - Benavente, Ricardo
A1  - Scheer, Ulrich
A1  - Chaly, Nathalie
T1  - Nucleocytoplasmic sorting of macromolecules following mitosis: fate of nuclear constituents after inhibition of pore complex function
N2  - PtK2 cells in which pore complex-mediated transport is blocked by microinjection early in mitosis of a monoclonal antibody (specific for an Mr 68000 pore complex glycoprotein) or of wheat germ agglutinin (WGA) complete cytokinesis. However, their nuclei remain stably arrested in a telophase-like organization characterized by highly condensed chromatin and the absence of nucleoli, indicating a requirement for pore-mediated transport for the reassembly of interphase nuclei. We have now examined this requirement more closely by monitoring the behavior of individual nuclear macromolecules in microinjected cells using immunofluorescence microscopy and have investigated the effect of microinjecting the antibody or WGA on cellular ultrastructure. The absence of nuclear transport did not affect the sequestration into daughter nuclei of components such as DNA, DNA topoisomerase I and the nucleolar protein fibrillarin that are carried through mitosis on chromosomes. On the other hand, lamins, snRNAs and the p68 pore complex glycoprotein, all cytoplasmic during mitosis, remained largely cytoplasmic in the telophase-arrested cells. Electron microscopy showed the nuclei to be surrounded by a doublelayered membrane with some inserted pore complexes. In addition, however, a variety of membranous structures with associated pore complexes was regularly noted in the cytoplasm, suggesting that chromatin may not be essential for the postmitotic formation of pore complexes. We propose that cellular compartmentalization at telophase is a two-step process. First, a nuclear envelope tightly encloses the condensed chromosomes, excluding non-selectively all macromolecules not associated with the chromosomes. Interphase nuclear organization is then progressively restored by selective pore complex-mediated uptake of nuclear proteins from the cytoplasm.
KW  - Cytologie
KW  - Nucleocytoplasmic transport
KW  - nuclear organization
KW  - nuclear envelope
KW  - nucleologenesis
KW  - mitosis
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40777
ER  - 
TY  - JOUR
A1  - Franke, Werner W.
A1  - Jarasch, Ernst-Dieter
A1  - Herth, Werner
A1  - Scheer, Ulrich
A1  - Zerban, Heide
T1  - Cytology : general and molecular cytology
N2  - The present review discusses some general aspects of membrane structure and problems of membrane isolation and membrane biochemistry, with particular focus on the endoplasmic reticulum.
KW  - Botanik
Y1  - 1975
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41458
ER  - 
TY  - JOUR
A1  - Spring, Herbert
A1  - Krohne, Georg
A1  - Franke, Werner W.
A1  - Scheer, Ulrich
A1  - Trendelenburg, Michael F.
T1  - Homogeneity and heterogeneity of sizes of transcriptional units and spacer regions in nucleolar genes of Acetabularia
N2  - The arrangement of genes of precursor molecules for ribosomal RNA (pre-rRNA) in primary nuclei from two green algae species, Acetabularia mediterranea and A. major, has been analyzed in an electron microscope study. The pattern of transcriptional units in individual strands of nucleolar chromatin was investigated using spread and positively stained preparations. The rDNA pattern is not uniform but differs in different strands. The predominant type of nucleolar chromatin exhibits a high degree of homogeneity in the sequence of matrix units (intercepts covered with fibrilst hat contain the pre-rRNA) and fibril-free spacer intercepts. Substantial differences, however, are observed between the patterns in different strands. In addition, there is evidence in some strands for intraaxial heterogeneity of both spacer and matrix units. The following major types can be distinguished: type la, ca. 2 micrometer long matrix units, extremely short spacer intercepts in A. mediterranea (ca. 1 micrometer long ones in A. major), completely homogeneous distribution; type Ib, as type la but with intercalated, isolated, significantly shorter and/or longer matrix units; type lIa, matrix unit sizes as in type la, but much longer spacer intercepts, high degree of homogeneity; type Ill, largely heterogeneous arrangements of matrix and spacer units of varying sizes. The matrix unit data are compared with the sizes of pre-rRNA as determined by polyacrylamide gelelectrophoresis under denaturing and non-denaturing conditions. The findings are discussed in relation to recent observations in amphibia and insects and with respect to current concepts of the species-specificity of rDNA arrangements.
Y1  - 1976
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41398
ER  - 
TY  - JOUR
A1  - Weber, Klaus
A1  - Osborn, Mary
A1  - Franke, Werner W.
A1  - Seib, Erinita
A1  - Scheer, Ulrich
A1  - Herth, Werner
T1  - Identification of microtubular structures in diverse plant and animal cells by immunological cross-reaction revealed in immunofluorescence microscopy using antibodies against tubulin from porcine brain
N2  - Antibody against tubulin from porcine brain was used to evaluate the immunological cross reactivity of tubulin from a variety of animal and plant cells. Indirect immunofluorescence microscopy revealed microtubule-containing structures including cytoplasmic microtubules, spindle microtubules, cilia and fIagella. Thus tubulin from diverse species of both mammals and plants show immunological cross-reactivity with tubulin from porcine brain. Results obtained by immunofluorescence microscopy are whenever possible compared with previously known ultrastructural results obtained by electron microscopy.
KW  - Cytologie
KW  - Microtubules
KW  - immunofluorescence
KW  - evolution
KW  - antibody
KW  - sperm
Y1  - 1977
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41383
ER  - 
TY  - JOUR
A1  - Trendelenburg, Michael F.
A1  - Franke, Werner W.
A1  - Scheer, Ulrich
T1  - Frequencies of circular units of nucleolar DNA in oocytes of two insects, Acheta domesticus and Dytiscus marginalis, and changes of nucleolar morphology during oogenesis
N2  - The organization of the extrachromosomal nucleolar material in oocytes of two insect species with different ovary types, the house cricket Acheta domesticus (panoistic ovary) and the water beetle Dytiscus marginalis (meroistic ovary), was studied with light and electron microscopic techniques. Stages early in oogenesis were compared with fully vitellogenic stages (mid-to-Iate diplotene). The arrangement of the nucleolar material undergoes a marked change from a densely aggregated to a dispersed state. The latter was characterized by high transcriptional activity. In spread and positively stained preparations of isolated nucleolar material, a high frequency of small circular units of transcribed rDNA was observed and rings with small numbers (1-5) of pre-rRNA genes were predominant. The observations suggest that the "extra DNA body" observed in early oogenic stages of both species represents a dense aggregate of numerous short circular units of nucleolar chromatin, with morphological subcomponents identifiable in ultrathin sections. These apparently remain in close association with the chromosomal nucleolar organizer(s). The observations further indicate that the individual small nucleolar subunit circles dissociate and are dispersed as actively transcribed rDNA units later in diplotene. The results are discussed in relation to principles of the ultrastructural organization of nucleoli in other cell types as well as in relation to possible mechanisms of gene amplification.
KW  - Zelldifferenzierung
Y1  - 1977
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41370
ER  - 
TY  - JOUR
A1  - Franke, Werner W.
A1  - Scheer, Ulrich
T1  - Morphology of transcriptional units at different states of activity
N2  - The morphology of two forms of transcription ally active chromatin, the nucleoli and the loops of lampbrush chromosomes, has been examined after fixation in situ or after isolation and dispersion of the material in media of low ionic strengths, using a variety of electron microscopic preparation techniques (e.g. spread preparations with positive or negative staining or without any staining at all, with bright and dark field illumination, with autoradiography, after pretreatment of the chromatin with specific detergents such as Sarkosyl NL-30; transmission and scanning transmission electron microscopy of ultrathin sections). Nucleolar chromatin and chromosomes from oocytes of various amphibia and insects as well as from green algae of the family of the Dasycladaceae were studied in particular detail. The morphology of transcriptional units that are densely packed with lateral ribonucleoprotein fibrils, indicative of great transcriptional activity, was compared with that of chromatin of reduced lateral fibril density, including stages of drug-induced inhibition. The micrographs showed that under conditions which preserve the nucleosomal organization in condensed chromatin studied in parallel, nucleosomes are not recognized in transcriptionally active chromatin. This holds for the transcribed regions as well as for apparently untranscribed (i.e. fibril-free) regions interspersed between ('spacer') and/or adjacent to transcribed genes and for the fibril-free regions within transcriptional units of reduced fibril density. In addition, comparison oflengths of repeating units of isolated rDNA with those observed in spread nucleolar chromatin indicated that this DNA is not foreshortened and packed into nucleosomal structures. Granular particles which were observed, at irregular frequencies and in variable patterns, in some spacer regions, did not result in a proportional shortening of the spacer axis, and were found to be resistant to detergent treatment effective in removing most of the chromatin associated proteins including histones. Thus, these particles behave like RNA polymerases rather than nucleosomes. It is suggested that structural changes from nucleosomal packing to an extended form of DNA are involved in the transcriptional activation of chromatin.
Y1  - 1978
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41363
ER  - 
TY  - JOUR
A1  - Hock, Robert
A1  - Moormann, Antoon
A1  - Fischer, Dagmar
A1  - Scheer, Ulrich
T1  - Absence of somatic histone H1 in oocytes and preblastula embryos of Xenopus laevis
N2  - Available data on the occurrence and expression of somatic histone HI during oogenesis and early embryogenesis of Xenopus laevis are contradictory. In particular the reported presence of a large storage pool of histone HIA in oocytes is difficult to reconcile with the high transcriptional activity of all gene classes in this specific cell type. In the present study we have used polyclonal antibodies raised against somatic Xenopus histone HI (HIA and HIA/B) for combined immunoblotting experiments to quantitate HI pools and immunolocalization studies to visualize chromosome- bound HI. Both approaches failed to detect soluble or chromosomal histone HI in vitellogenic oocytes, eggs, and cleavage-stage embryos up to early blastula. In addition, chromatin assembled in Xenopus egg extract was also negative for histone HI as revealed by immunofluorescence microscopy. Lampbrush chromosomes not only lacked histone HI but also the previously identified histone HI-like B4 protein (Smith et al., 1988, Genes Dev. 2,1284-1295). In contrast, chromosomes of eggs and early embryos fluoresced brightly with anti-B4 antibodies. Our results lend further support to the view that histone HI expression is developmentally regulated during Xenopus oogenesis and embryogenesis similar to what is known from other species.
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41350
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
T1  - Injection of antibodies into the nucleus of amphibian oocytes: an experimental means of interfering with gene expression in the living cell
N2  - No abstract available
Y1  - 1986
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41182
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
T1  - Structural organization of spacer chromatin between transcribed ribosomal RNA genes in amphibian oocytes
N2  - Transcribed nucleolar chomatin, including the spacer regions interspersed between the rRNA genes, is different from the bulk of nontranscribed chromatin in that the DNA of these regions appears to be in an extended (B) conformation when examined by electron microscopy. The possibility that this may reflect artificial unfolding of nucleosomes during incubation in very low salt buffers as routinely used in such spread preparations has been examined by studying the influence of various ion concentrations on nucleolar chromatin structure. Amplified nucleolar chromatin of amphibian oocytes (Xenopus laevis, Pleurodeles waltlii, Triturus cristatus) was spread in various concentrations of NaCl (range 0 to 20 mM). Below 1 mM salt spacer chromatin frequently revealed a variable number of irregularly shaped beads, whereas above this concentration the chromatin axis appeared uniformly smooth. At all salt concentrations studied, however, the length distribution of spacer and gene regions was identical. Preparations fixed with glutaraldehyde instead of formaldehyde, or unftxed preparations, were indistinguishable in this respect. The observations indicate that (i) rDNA spacer regions are not compacted into nucleosomal particles and into supranucleosomal structures when visualized at chromatin stabilizing salt concentrations (e.g., 20 mM NaCl), and (ii) spacer DNA is covered by a uniform layer of proteins of unknown nature which, at very low salt concentrations (below 1 mM NaCl), can artificially give rise to the appearance of small granular particles of approximately nucleosome-like sizes. These particles, however, are different from nucleosomes in that they do not foreshorten the associated spacer DNA. The data support the concept of an altered nucleohistone conformation not only in transcribed chromatin but also in the vicinity of transcriptional events.
KW  - Cytologie
KW  - Chromatin structure
KW  - rDNA
KW  - amphibian oocytes
Y1  - 1980
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41057
ER  - 
TY  - JOUR
A1  - Scheer, Ulrich
A1  - Messner, Karin
A1  - Hazan, Rachel
A1  - Raska, Ivan
A1  - Hansmann, Paul
A1  - Falk, Heinz
A1  - Spiess, Eberhard
A1  - Franke, Werner W.
T1  - High sensitivity immunolocalization of double and single-stranded DNA by a monoclonal antibody
N2  - A monoclonal antibody (AK 30-10) is described which specifically reacts with DNA both in double and single-stranded forms but not with other molecules and structures, including deoxyribonucleotides and RNAs. When used in immunocytochemical experiments on tissue sections and permeabilized cultured cells, this antibody detects DNA-containing structures, even when the DNA is present in very small amounts. Examples of high resolution detection include the DNA present in amplified extrachromosomal nucleoli, chromomeres of lampbrush chromosomes, mitochondria, chloroplasts and mycoplasmal particles. In immunoelectron microscopy using the immunogold technique, the DNA was localized in distinct substructures such as the "fibrillar centers" of nucleoli and certain stromal centers in chloroplasts. The antibody also reacts with DNA of chromatin of living cells, as shown by microinjection into cultured mitotic cells and into nuclei of amphibian oocytes. The potential value and the limitations of immunocytochemical DNA detection are discussed.
KW  - Cytologie
KW  - DNA antibodies
KW  - monoclonal antibodies
KW  - DNA immunolocalization
KW  - chromatin
KW  - mycoplasma tests
Y1  - 1987
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41063
ER  - 
TY  - JOUR
A1  - Hügle, Barbara
A1  - Scheer, Ulrich
A1  - Franke, Werner W.
T1  - Ribocharin: a nuclear M\(_r\) 40,000 protein specific to precursor particles of the large ribosomal subunit
N2  - Using a monoclonal antibody (No-194) we have identified, in Xenopus laevis and other amphibia, an acidic protein of M, 40,000 (ribocharin) which is specifically associated with the granular component of the nucleolus and nucleoplasmic 65S particles. These particles contain the nuclear 28S rRNA and apparently represent the precursor to the large ribosomal subunit in nucleocytoplasmic transit. By immunoelectron microscopy ribocharin has been localized in the granular component of the nucleolus and in interchromatin granules. During mitosis ribocharin-containing particles are associated with surfaces of chromosomes and are recollected in the reconstituting nucleoli in late telophase. We suggest that ribocharin is a specific component of precursor particles of the large ribosomal subunit, which dissociates from the 65S particle before passage through the nuclear envelope, and is reutilized in ribosome biogenesis.
Y1  - 1985
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41169
ER  - 
TY  - JOUR
A1  - Weber, Thomas
A1  - Schmidt, Erwin
A1  - Scheer, Ulrich
T1  - Mapping of transcription units on Xenopus laevis lampbrush chromosomes by in situ hybridization with biotin-labeled cDNA probes
N2  - A non-radioactive in situ hybridization method is described for the localization of transcription units of defined genes to lateral loops of Xenopus laevis lampbrush chromosomes. Two Xenopus cONA probes were used encoding the nucleolar protein N038/ B23 and cytokeratin 1(8). Both proteins are known to be synthesized in Xenopus oocytes, and Northern blot analysis revealed the presence of the corresponding mRNAs in different oogenic stages. The probes were enzymatically labeled with biotin-dCTP and hybridized to lampbrush chromosomes. The sites of hybridization were detected either by indirect immunofluorescence microscopy using rabbit antibodies against biotin and fluorescein-conjugated antirabbit IgG or enzymatically using peroxidase-conjugated streptavi din. The probe encoding the nucleolar protein hybridized to two sets of lateral loops on different bivalents, the cytokeratin probe to at least four. Our finding that each probe hybridized to more than one chromosomal locus may reflect the tetraploid nature of the Xenopus laevis genome or results from cross-hybridization to other transcriptionally active members of the N038/ B23-nucleoplasmin or the cytokeratin-Iamin gene families. The method described should facilitate further in situ hybridization studies with appropriate genomic clones in order to map specific DNA sequences to defined loop regions and to come to a better understanding of the relationship between loop organization and gene transcription unit.
KW  - Cytologie
KW  - Lampbrush chromosomes
KW  - in situ hybridization
KW  - transcription units
KW  - Xenopus oocytes
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40763
ER  - 
TY  - JOUR
A1  - Benavente, Ricardo
A1  - Dabauvalle, Marie-Christine
A1  - Scheer, Ulrich
A1  - Chaly, Nathalie
T1  - Functional role of newly formed pore complexes in postmitotic nuclear reorganization
N2  - Many nuclear proteins are released into the cytoplasm at prometaphase and are transported back into the daughter nuclei at the end of mitosis. To determine the role of this reentry in nuclear remodelling during early interphase, we experimentally manipulated nuclear protein uptake in dividing cells. Recently we and others have shown that signal-dependent, pore complex-mediated uptake of nuclear protein is blocked in living cells on microinjection of the lectin wheat germ agglutinin (WGA), or of antibodies such as PI1 that are directed against WGA-binding pore complex glycoproteins. In the present study, we microinjected mitotic PtKz cells with WGA or antibody PIt and followed nuclear reorganization of the daughter cells by immunofluorescence and electron microscopy. The inhibitory effect on nuclear protein uptake was monitored by co-injection of the karyophilic protein nucleoplasmin. When injected by itself early in mitosis, nucleoplasmin became sequestered into the daughter nuclei as they entered telophase. In contrast, nucleoplasmin was excluded from the daughter nuclei in the presence of WGA or antibody PI1 . Although PtKz cells with blocked nuclear protein uptake completed cytokinesis, their nuclei showed a telophaselike organization characterized by highly condensed chromatin surrounded by a nuclear envelope containing a few pore complexes. These findings suggest that pore complexes become functional as early as telophase, in close coincidence with nuclear envelope reformation. They further indicate that the extensive structural rearrangement of the nucleus during the telophase-G1 transition is dependent on the influx of karyophilic proteins from the cytoplasm through the pore complexes, and is not due solely to chromosome- associated components.
Y1  - 1989
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40754
ER  - 
TY  - JOUR
A1  - Thiry, Marc
A1  - Scheer, Ulrich
A1  - Goessens, Guy
T1  - Immunoelectron microscopic study of nucleolar DNA during mitosis in Ehrlich tumour cells
N2  - In order to investigate the DNA localization within Ehrlich tumor cell nucleoli during mitosis, two recent immunocytochemical methods using either an anti-DNA or an anti-bromodeoxyuridine (BrdU) monoclonal antibody have been applied. In both cases, the immunogold labeling has been performed on ultrathin sections of cells embedded either in Lowicryl K4M or in Epon, respectively. Identical results are observed with both immunocytochemical approaches. In the interphase nucleolus, besides the labeling of the perinucleolar chromatin shell and of its intranucleolar invaginations which penetrate into the nucleolar body and often terminate at the fibrillar centers, a few gold particles are also preferentially found towards the peripheral region of the fibrillar centers. In contrast, the dense fibrillar component and the granular component are never labeled. During mitosis, the fibrillar centers persist at the chromosomal nucleolus organizing regions (NOR's) and can be selectively stained by the silver method. However, these metaphase fibrillar centers are no longer decorated by the DNA- or BrdU antibodies. These results indicate that until the end of prophase, rRNA genes are present inside the fibrillar center material, disappear during metaphase and reappear in reconstituting nucleoli during telophase. Thus, fibrillar centers appear to represent structures sui generis, which are populated by rRNA genes only when the nucleolus is functionally active. In segregated nucleoli after actinomycin D treatment, the DNA labeling is exclusively restricted to the perinucleolar chromatin blocks. These findings also suggest that the DNA content of the fibrillar center material varies according to the rRNA transcription level of the cells. The results are discussed in the light of the present knowledge of the functional organization of the nucleolus.
KW  - Cytologie
KW  - Nucleolus
KW  - DNA
KW  - mitosis
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40745
ER  - 
TY  - JOUR
A1  - Sendtner, Michael
A1  - Thoenen, Hans
T1  - Oxidative stress and motorneuron disease
N2  - Transgenic mice carrying mutated Cu/Zn superoxide dismutase genes provide insights into the pathogenesis of human motorneuron diseases and may be useful as models in the development and testing of therapies.
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42684
ER  - 
TY  - JOUR
A1  - Sendtner, Michael
A1  - Thoenen, Hans
A1  - Holtmann, B.
A1  - Kohlbeck, R.
A1  - Barde, Y.-A.
T1  - Brain-derived neurotrophic factor prevents the death of motoneurons in newborn rats after nerve section
N2  - Motoneurons innervating the skeletal musculature were among the first neurons shown to require the presence of their target cells to develop appropriatelyl,2. But the characterization of molecules allowing motoneuron survival has been difficult. Ciliary neurotrophic factor prevents the death of motoneurons3-6, but its gene is not expressed during development7. Although the presence of a neurotrophin receptor on developing motoneurons8-1O has suggested a role for neurotrophins, none could be shown to promote motoneuron survival in vitro3. We report here that brainderived neurotrophic factor can prevent the death of axotomized motoneurons in newborn rats, suggesting a role for this neurotrophin for motoneuron survival in vivo.
Y1  - 1992
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42673
ER  - 
TY  - JOUR
A1  - Hughes, Simon M.
A1  - Lillien, Laura E.
A1  - Raff, Martin C.
A1  - Rohrer, Hermann
A1  - Sendtner, Michael
T1  - Ciliary neurotrophic factor induces type-2 astrocyte differentiation in culture
N2  - We have been studying a population of bipotential glial progenitor cells in the perinatal rat optic nerve and brain in an attempt to understand how cells choose between alternative fates in the developing mammalian central nervous system (CNS). This cell population gives rise initially to oligodendrocytes and then to type-2 astrocytes1 both of which apparently collaborate in sheathing axons in the CNS2,3. In vitro studies suggest that oligodendrocyte differentiation is the constitutive pathway of development for the oligodendrocyte-type-2-astrocyte (O-2A) progenitor cell4,5, whereas type-2 astrocyte differentiation depends on a specific inducing protein6. This protein is present in the developing optic nerve when type-2 astrocytes are differentiating and can induce 0-2A progenitor cells in vitro to express glial fibrillary acidic protein (GFAP)6, a marker of astrocyte differentiation7. Here we show that the type-2-astrocyte-inducing protein is similar or identical to ciliary neutrotrophic factor (CNTF)8,9, which promotes the survival of some types of peripheral neurons in vitro8, including ciliary ganglion neurons8,10. This suggests that CNTF, in addition to its effect on neurons, may be responsible for triggering type-2 astrocyte differentiation in the developing CNS.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42660
ER  - 
TY  - JOUR
A1  - Sendtner, Michael
A1  - Thoenen, Hans
A1  - Hughes, R. A.
T1  - Members of several gene families influence survival of rat motoneurons in vitro and in vivo
N2  - The survival and functional maintenance of spinal motoneurons, both during the period of developmental cell death and in adulthood, have been shown to be dependent on trophic factors. In vitro experiments have previously been used to identify several survival factors for motoneurons, including CNTF, UF, and members of the neurotrophin, FGF, and IGF gene families. Some of these factors have also been shown to be active in vivo, either on chick motoneurons during embryonic development or on lesioned facial and spinal motoneurons of the newborn rat. Here we demonstrate that lesioned newborn rat facial motoneurons can be rescued by NT-4/5, IGF-I, and UF. Furthermore, in contrast to chick motoneurons, the survival of isolated embryonic rat motoneurons can be maintained by the neurotrophins BDNF, NT-3, and NT-4/5. IGF-I and FGF-5 were also active in this system, each supporting more than 50% of the originally plated neurons. The responsiveness of motoneurons to multiple factors in vitro and in vivo suggests that motoneuron survival and function are regulated by the coordinated actions of members of different gene families.
KW  - Immunopanning
KW  - Facial Nerve Transection
KW  - Neurotrophin
KW  - Fibroblast Growth Factor
KW  - Insulinlike Growth Factor
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42652
ER  - 
TY  - JOUR
A1  - Benavente, Ricardo
A1  - Reimer, Georg
A1  - Rose, Kathleen M.
A1  - Hügle-Dörr, Barbara
A1  - Scheer, Ulrich
T1  - Nucleolar changes after microinjection of antibodies to RNA polymerase I into the nucleus of mammalian cells
N2  - After microinjection of antibodies against RNA polymerase I into the nuclei of cultured rat kangaroo (PtKz) and rat (RVF-SMC) cells alterations in nucleolar structure and composition were observed. These were detected by electron microscopy and double-label immunofluorescence microscopy using antibodies to proteins representative of the three major components of the nucleolus. The microinjected antibodies produced a progressive loss of the material of the dense fibrillar component (DFC) from the nucleoli which, at 4 h after injection, were transformed into bodies with purely granular component (GC) structure with attached fibrillar centers (FCs). Concomitantly, numerous extranucleolar aggregates appeared in the nucleoplasm which morphologically resembled fragments of the DFC and contained a protein (fibrillarin) diagnostic for this nucleolar structure. These observations indicate that the topological distribution of the material constituting the DFC can be experimentally influenced in interphase cells, apparently by modulating the transcriptional activity of the rRNA genes. These effects are different from nucleolar lesions induced by inhibitory drugs such as actinomycin D-dependent "nucleolar segregation". The structural alterations induced by antibodies to RNA polymerase I resemble, however, the initial events of nucleolar disintegration during mitotic prophase.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-40666
ER  - 
TY  - JOUR
A1  - Barres, B. A.
A1  - Schmid, R.
A1  - Sendtner, Michael
A1  - Raff, Martin C.
T1  - Multiple extracellular signals are required for long-term oligodendrocyte survival
N2  - We showed previously that oligodendrocytes and their precursors require continuous signalling by protein trophic factors to avoid programmed cell death in culture. Here we show that three classes of such trophic factors promote oligodendrocyte survival in vitro: (1) insulin and insulin-like growth factors (IGFs), (2) neurotrophins, particularly neurotrophin-3 (NT -3), and (3) ciliary-neurotrophic factor (CNTF), leukemia inhibitory factor (LIF) and interleukin 6 (IL-6). A single factor, or combinations of factors within the same class, promote only short-term survival of oligodendrocytes and their precursors, while combinations of factors from different classes promote survival additively. Long-term survival of oligodendrocytes in vitro requires at least one factor from each class, suggesting that multiple signals may be required for long-term oligodendrocyte survival in vivo. We also show that CNTF promotes oligodendrocyte survival in vivo, that platelet-derived growth factor (PDGF) can promote the survival of oligodendrocyte precursors in vitro by acting on a novel, very high affinity PDGF receptor, and that, in addition to its effect on survival, NT-3 is a potent mitogen for oligodendrocyte precursor cells.
KW  - neurotrophins
KW  - programmed cell death
KW  - apoptosis
KW  - ciliary-neurotrophic factor
KW  - interleukin 6
KW  - insulin
KW  - insulin-likegrowth factor I
Y1  - 1993
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42644
ER  - 
TY  - JOUR
A1  - Dittrich, Falk
A1  - Thoenen, Hans
A1  - Sendtner, Michael
T1  - Ciliary neurotrophic factor: pharmacokinetics and acute-phase response in rat
N2  - No abstract available
Y1  - 1994
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42639
ER  - 
TY  - JOUR
A1  - Kaupmann, Klemens
A1  - Sendtner, Michael
A1  - Stöckli, Kurt A.
A1  - Jockusch, Harald
T1  - The gene of ciliary neurotrophic factor (cntf) maps to murine chromosome 19 and its expression is not affected in the hereditary motoneuron disease 'wobbler' of the mouse
N2  - The cDNA for ciliary neurotrophic factor (CNTF), a polypeptide involved in the survival of motoneurons in mammals, has recently been cloned (Stöckli et al., Nature, 342, 920 - 923, 1989; Lin et al. Science, 246, 1023 - 1025, 1989). We have now localized the corresponding gene Cntf to chromosome 19 in the mouse, using an interspecific cross between Mus spretus and Mus musculus domesticus. The latter was carrying the gene wobbler (wr) for spinal muscular atrophy. DNA was prepared from backcross individuals and typed for the segregation of species-specific Cntf restriction fragments in relation to DNA markers of known chromosomal location. The M.spretus allele of Cntf cosegregated with chromosome 19 markers and mapped closely to Ly-1, to a region of mouse chromosome 19 with conserved synteny to human chromosome 11q. Cntf is not linked to wr, and the expression of CNTF mRNA and protein appears close to normal in facial and sciatic nerves, of affected (wr/wr) mice, suggesting that motoneuron degeneration of wobbler mice has its origin in defects other than reduced CNTF expression.
KW  - Mus spretus
KW  - interspeific backcross
KW  - spinal muscular atrophy
KW  - linkage
KW  - restriction fragment length polymorphism
Y1  - 1991
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42626
ER  - 
TY  - JOUR
A1  - Sendtner, Michael
A1  - Gnahn, H.
A1  - Wakade, A.
A1  - Thoenen, Hans
T1  - Is activation of the Na\(^+\)K\(^+\) pump necessary for NGF-mediated neuronal survival?
N2  - The ability of nerve growth factor to cause rapid activation of the Na+K+ pump of its responsive cells was examined by measuring the uptake of 86Rb+. A significant increase in 86Rb+ uptake in Ea chick dorsal root ganglion sensory neurons after NGF treatment was seen only if the cells had been damaged during the preparation procedure. Such damaged cells could not survive in culture in the presence of NGF, and undamaged cells that did survive in response to NGF exhibited no increased 86Rb+ uptake rate. Furthermore, cultured calf adrenal medullary cells did not show an increase in 86Rb+ uptake after treatment with NGF, although these cells respond to NGF with an increased synthesis of catecholaminergic enzymes. These results are incompatible with the hypothesis that the mechanism of action of NGF that promotes neuronal survival and enzyme induction results from an initial stimulation of the Na+K+ pump.
Y1  - 1988
U6  - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-42610
ER  -