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 - Krüger, Hans-Peter T1 - Simultane U-Tests zur exakten Prüfung von Haupt- und Wechselwirkungen in 2x2-faktoriellen Versuchsplänen N2 - Ausgehend von einem Ansatz zur nichtparametrischen Prüfung von Wechselwirkungen (BREDENKAMP, 1974), der nur unter asymptotischen Bedingungen gilt, wird empfohlen, auf Wechselwirkung in dem praktisch wichtigen 22 -faktoriellen Versuchsplan exakt dadurch zu prüfen, daß man die Diagonalzellen überkreuzend zusammenfaßt und mittels V-Test (Cross-Over-V-Test) auf Lageunterschiede prüft. Zugleich kann durch Zeilen- und/oder Spaltenzusammenfassungen auf Hauptwirkungen geprüft werden. Drei simultane Tests können sodann eine parametrische ANOVA aussageinferentiell voll ersetzen! Die Durchflihrung der Tests wird an einem Beispiel illustriert. Zusätzlich wird auf die Möglichkeit der Prüfung auf Wechselwirkungen höherer Ordnung in 2n-faktoriellen Versuchsplänen hingewiesen. N2 - According to the results of non-parametric interaction testing (BREDENKAMP, 1974) an attempt is made to test exactly the interaction in a 22 factorial design in which a-symptotic testing sensu Bredenkamp is in appropriate. Assuming A+ and A- as modalities of factor A and B+ and B- as modalities of factor B, cross-over pooling A+B+ A-B- versus A+B- A-B+ results in a two sampie U-test for differences in location which is equivalent to a test for interaction effects between A and B. In a similar way rows and columns may be pooled thus helping to develop exact tests for main effects of A and B. Thus ANOVA may be substituted by three simultaneous U-tests. The respective procedure is illustrated by a numerical example and may be generalized on 2n factorial designs. Y1 - 1977 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41592 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 - Will, Antje A1 - Blank, Christine A1 - Röllinghoff, Martin A1 - Moll, Heidrun T1 - Murine epidermal Langerhans cells are potent stimulators of an antigen-specific T cell response to Leishmania major, the cause of cutaneous leishmaniasis N2 - Cutaneous leishmaniasis is initiated by the bite of an infected sandfly and inoculation of Leishmania major parasites into the mammalian skin. Macrophages are known to playa central role in the course of infection because they are the prime host cells and funetion as antigen-presenting eells (APC) for induetion of the eell-mediated immune response. However, in addition to maerophages in the dermis. the skin eontains epidermal Langerhans eells (LC) which ean present antigen (Ag) to T cells. Therefore, using a murine model of cutaneous leishmaniasis, we analyzed the ability of epidermal cells to induce a T eell response to L.major. The results demonstrated that freshly isolated LC, but not cuItured LC, are highly active in presenting L.major Ag in vitro to T cells from primed mice and to a L.major-specific T cell clone. Furthermore, freshly isolated LC had the ability to retain L.major Ag in immunogenic form for at least 2 days. Their efficiency was much greater than that of irradiated spleen cells, a standard population of APC. LC stimulated both T cell proliferation and production of the Iymphokines interleukin (IL)-2 and IL-4. The response was Ag specific and could be induced by lysate of L. major parasites and by live organisms. The data suggest that epidermal LC are important APC in eutaneous leishmaniasis. They may perform a critical funetion by eapturing L.major Ag in the skin and presenting it either to quiescent T eells circulating through the draining lymph node or locally to T effector cells infiltrating the cutaneous lesion. KW - Immunologie Y1 - 1992 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-45872 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 - Heller, Dieter A1 - Krüger, Hans-Peter T1 - Analyse dreistufig zu beantwortender Fragebogenitems N2 - In Fragebögen tauchen häufig ternäre Antwortmöglichkeiten auf (z.B. ja - nein - weiß nicht). Für eine Analyse solcher Hems werden Kennwerte vorgeschlagen. Dabei wird ein der Schwierigkeit analoger Popularitätsindex eingeführt, der in p+ den Anteil der Ja-Antworten angibt. Aus p+ und p-, dem Anteil der Nein-Antworten, wird ein Aktualitätsindex definiert, der in den Grenzen zwischen 0 und 1 variiert und die Eliminierung wenig aktueller Fragen gestattet. Zur Bestimmung der Trennschärfe werden Punkt-Vierfelder- oder phi-Koeffizienten angegeben. die aus der Zerlegung des X2 einer 3x2-Tafel in eine 2x2-Tafel und in eine auf die Unbestimmtheitsantwort zurückgehende Restkomponente entstehen. Ebenso werden Koeffizienten für Iteminterkorrelationen aus 3x3-Tafeln und Indizes für die Reliabilität angegeben. N2 - In this paper the question is raised how to proceed in item-analysis if the answers may be given in three ways: "yes", "no" or "don't know". In defining and calculating parameters the following suggestions are made: define the difficulty index of an item as the proportion of the number of "yes" answers p+ within a random sampie of N Ss. Define an index of actuality as a function of p+ p- where p- is the proportion of the number of "no" answers such that min. f(p+p-) = 0 and max. f(p+p-) = 1 and eliminate items having low actuality indices. Define item-discriminating power (item-test correlation) by a point four-fold or phi coefficient determined by partitioning the chi square of a 3x2 contingency table into 2x2 contingency plus a residual due to "don't know" answers. In a similar way define item-intercorrelations on the basis of 3x3 contingency tables and reliability indices. Y1 - 1976 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41583 ER - TY - JOUR A1 - Krüger, Hans-Peter A1 - Kohnen, Ralf T1 - Eine neue Methode zur Prüfung der Wirkung von Psychopharmaka - Die "Weltbeschreibung" N2 - Kompensation und das Problem der Zuggebbarkeit werden als die beiden wichtigsten Störquellen bei der Erfassung pharmakonbedingter Befindlichkeitsänderungen dargestellt. Gefördert werden diese Prozesse durch eine Zentrierung der Methode auf die Selbstbeobachtung. Es wird die Hypothese aufgestellt, daß die Selbstbeobachtung ersetzbar ist durch eine Beschreibung der "Welt draußen". Die Person kann sich nur in der Welt erleben - folglich werden Veränderungen dieses Erlebnis auch Veränderungen in der Beschreibung der Welt nach sich ziehen. Ausgehend von dieser Hypothese wird ein Experiment konzipiert, in dem die Vpn lediglich die experimentelle Situation und die am Experiment beteiligten anderen Vpn beschreiben, nicht aber sich selbst. Es kann gezeigt werden, daß mit den so gewonnenen Maßen eindeutige Wirkungen des eingesetzten Tranquilizers nachgewiesen werden können, ebenso eindeutige Dosis-Wirkungs-Beziehungen. Die Konsequenzen für eine pharmakopsychologische Methodik werden diskutiert. Zudem wird herausgehoben, daß Tranquilantien dann als positiv bewertet werden können, wenn sie die Reagibilität der Vpn auf die Situation erhöhen und durch eine Verringerung des allgemeinen Aktivierungsniveaus eine adäquate Verarbeitung angstinduzierender Situatonen ermöglichen. N2 - Compensation and readiness to admit drug effects are described as the most important modifying factors in assessing changes of mood that is due to psychotropic drugs. Both processes are advanced by a methodology which focuses on the selfobservation of the experimental subjects. The authors propose the hypothesis that seifreports may be replaced by a description of the "outside world". The human being is only able to experience itself within its concrete world; consequently, changes of its experience entail changes of the description of the world. On the basis of this hypothesis an experiment is conceived in which the subjects describe only the experimental situation and the other participating subjects, not themselves, however. The authors hold that the parameters emerging from this approach give evidence both of clear-cut tranquilizer-effects and stable drug-dosage-relationships. Consequences for pharmaco-psychological methodology are discussed. The authors accentuate that tranquilizers can be seen as having positive effects if they help to enhance the subject's reagibility to the situation and, by reducing the general activation level, enable the subject to cope with anxiety inducing situations. Y1 - 1980 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41566 ER -