TY - JOUR A1 - Alldrick, A. J. A1 - Lutz, Werner K. T1 - Covalent binding of [2-\(^{14}\)C]2-amino-3,8-dimethylimidazo[4,5-f]-quinoxaline (MeIQx) to mouse DNA in vivo N2 - Fernale BALB/c mice were administered intragastrically with equimolar amounts of either [2-\(^{14}\)C]2-amino-3,8-dimethyi[ 4,5-J]qulnoxaline (MeiQx) or 2-acetylamino[9-\(^{14}\)C]fluorene (2AAF). DNA was isolated from tissues of mice killed either 6 or 24 h after administration. Analysis of liver DNA nucleotide digests by HPLC analysis revealed that all of the radioactivity was attributable to adduct formation. Tbe specific activities of DNA samples were converted to covalent bindlog indices (CBI, J.LIDOI adduct per mol DNA nucleotides/mmol chemical app6ed per kg animal body weight). CBI values of 25 and 9 were detennined for 2AAF and MeiQx in tbe llvers of mice killed 6 h after dosing. The values were in general agreement with the moderate carcinogenic potency of these compounds. The specific activities of DNA preparations obtained from the lddneys, spleens, stomachs, small intestines and large intestlnes of mice treated witb MeiQx and killed 6 h after doslng were S- to 35-times less tban those obtained witb the llver. DNA isolated from tbe lungs (a target organ for MeiQx tumorigenicity) of MeiQx-treated mice was not radiolabeUed at tbe limit of detection (CBI <0.3). With tbe exception of tbe gastrolntestinal tract, the specific activities of DNA samples isolated from mice killed 6 h after administration were higher than those from mice killed after 24 h. KW - Toxikologie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-60832 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 - Baumhauer, Roland A1 - Busche, Detlef A1 - Sponholz, Barbara T1 - Reliefgeschichte und Paläoklima des saharischen Ost-Niger N2 - Der größte Teil des zentralsaharischen Reliefs ist unter dem Einfluß nicht-arider Klimate gebildet worden. Andererseits gab es im Pleistozän äolisch geprägte aride Phasen, die extremer als heutige gewesen sind. Der Kenntnisstand zur Reliefgeschichte erlaubt es, daraus die Grundzüge der Klimageschichte eines großen Teils der südlich-zentralen Sahara abzuleiten. KW - Geographie KW - Reliefgeschichte KW - Paläoklima KW - Ostniger Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-55378 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 - 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 - Bernards, R. A1 - Schackleford, G. M. A1 - Gerber, M. R. A1 - Horowitz, J. M. A1 - Friend, S. H. A1 - Schartl, Manfred A1 - Bogenmann, E. A1 - Rapaport, J. M. A1 - Mcgee, T. A1 - Dryja, T. P. T1 - Structure and expression of the murine retinoblastoma gene and characterization of its encoded protein N2 - No abstract available KW - Physiologische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-61819 ER - TY - JOUR A1 - Borasio, Gian Domenico A1 - John, Jacob A1 - Wittinghofer, Alfred A1 - Barde, Yves-Alain A1 - Sendtner, Michael A1 - Heumann, Rolf T1 - ras p21 protein promotes survival and fiber outgrowth of cultured embryonic neurons N2 - Although evidence obtained with the PC12 cell line has suggested a role for the ras oncogene proteins in the signal transduction of nerve growth factor-mediated fiber outgrowth, little is known about the signal transduction mechanisms involved in the neuronal response to neurotrophic factors in nontransformed cells. We report here that the oncogene protein T24-ras, when introduced into the cytoplasm of freshly dissociated chick embryonic neurons, promotes the in vitro survival and neurite outgrowth of nerve growth factor-responsive dorsal rootganglion neurons, brain-derived neurotrophic factor-responsive nodose ganglion neurons, and ciliary neuronotrophic factor-responsive ciliary ganglion neurons. The proto-oncogene product c-Ha-ras also promotes neuronal survival, albeit less strongly. No effect could be observed with truncated counterparts of T24-ras and c-Ha-ras lacking the 23 C-terminal amino acids including the membrane-an-choring, palmityl-accepting cysteine. These results sug-gest a generalized involvement of ras or ras-like proteins in the intracellular signal transduction pathway for neurotrophic factors. Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32621 ER - TY - JOUR A1 - Borkowski, John G. A1 - Schneider, Wolfgang A1 - Pressley, Michael T1 - The challenges of teaching good information processing to learning disabled students N2 - A MODEL of good information processing is sketched, describing how metacognitive knowledge influences strategy selection and use. Three factors pose particular problems for learning disabled students as they attempt to acquire metacognitive knowledge and to use study strategies productively: neurological impairments; deficiencies in general world knowledge; and negative beliefs, attitudes, and styles that limit self-efficacy. Creating an educational atmosphere that explicitly builds conceptual (domain-specific) knowledge and teaches positive beliefs about learning potential is essential in promoting metacognitively-oriented instruction. KW - Psychologie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62117 ER - TY - JOUR A1 - Carr, Martha A1 - Kurtz, Beth E. A1 - Schneider, Wolfgang A1 - Turner, Lisa A. A1 - Borkowski, John G. T1 - Strategy acquisition and transfer among American and German children: Environmental influences on metacognitive development N2 - This study explored the differential effects of strategy training on German and American elementaryschool children and assessed the role of parents in the development of their children's strategic behavior and metacognition. 184 German and 161 American children were pretested on memory and metamemory tasks. Children were then assigned to either an organizational strategy training condition or a control condition. All children were tested on the maintenance and far-transfer of the strategy and task-related metamemory 1 week following training. Parents completed questionnaires about strategy instruction in the home. Strategy maintenance and metacognition were reassessed 6 months following training. German children were more strategic than American children. Instructed children performed better than control children. German parents reported more instruction of strategies in the home. These data suggest that formal education is responsible for aspects of cognitive development that have sometimes been viewed as a function of age. KW - Psychologie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62082 ER - TY - JOUR A1 - Christl, Manfred A1 - Braun, Martin T1 - Generation and interception of 1-OXA-2,3-Cyclohexadiene and 1,2,4-Cyclohexatriene N2 - The cycloadducts 6 and 7 of tricyc1o[4.1.0.0 2 ,7)hepta- 3,4-diene (~) with styrene and 1,3-butadiene rearrange to unusual products on thermolysis, namely the cycloheptatriene derivatives ~ and 10. 1-0xa-3,4-cyclohexadiene (20) is generated smoothly from 6,6-dichloro-3-oxabicyclo[3.1.0]hexane (22) and n-butyllithium. 1-0xa-2,3-cyclohexadiene (11) is formed from 6-exo-bromo-6-endo-fluoro-2-oxabicyclo[ 3.1.0]hexane (30) and methyllithium. In the presence of activated olefins, this reaction provides an efficient route to 28 and 33 - 38, the trapping products of 21. Interestingly, [2+2]-cycloadditions do not take place at the same double bond of 21 as [4+2]-cycloadditions. The reactions of 1,3-cyclopentadiene and indene with bromofluorocarbene afford 6-exo-bromo-6-endo-fluorobicyclo[3.1.0]hex-2-ene (50) and its benzo derivative ~, respectively. On treatment of these compounds with methyl lithium in the presence of styrene, the interception products 53 and 47 of 1,2,4-cyc10- hexatriene (44) and its benzo derivative 43, respectively, are formed in good yields. KW - Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-56566 ER - TY - JOUR A1 - Christl, Manfred A1 - Braun, Martin T1 - Freisetzung und Abfangreaktionen von 1-Oxa-2,3-cyclohexadien T1 - Generation and Interception of 1-0xa-2,3-cyclohexadiene N2 - Umsetzung von 6,6-Dichlor-2-oxabicyclo[3.1.0)hexan (4a) in Styrol mit n-Butyllithium lieferte neben Polystyrol und t-Chlor-1- pbenylhexan (6) in geringer Ausbeute die Tet~hydrocyclobutapyrane 5, die Abfangprodukte des aus 4a generierten t-Oxa-2,3- cyclobexadiens (3). Das unbeständige 6,6-Dibrom-2-oxabicyclo( J.l.O]hexan (4b) wurde bei -60°C erzeugt un~ bei -30°C mit Methyllithium in Gegenwart von Styrol umgesetzt, woraus die Produkte 5 mit 24% Ausbeute hervorgingen. Als bei 20°C beständige Quelle für 3 erwies sich exo-6-Brom-e~o-6-fluor-2-oxabicyclo[ J.t.O]bexan (9), das aus 2,3-Dihydrofuran und Bromßuorcarben mit 25% Ausbeute bereitet wurde. Behandlung von 9 in Styrol, 2 KW - 4.03 KW - 5]beptanes KW - Long-range coupling constants KW - mtrogen extruston Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58489 ER - TY - JOUR A1 - Christl, Manfred A1 - Brunn, E. A1 - Roth, W. R. A1 - Lennartz, H.-W. T1 - 7-Methyl- and 7-Phenylcyclohepta-1,3,5-trienes from Benzvalene Via 3,3a,4,5,6,6a-Hexahydro-4,5,6-methenocyclopentapyrazoles and Tetracyclo[4.1.0.0\(^{2,4}\).0\(^{3,5}\)]heptanes N2 - No abstract available KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58471 ER - TY - JOUR A1 - Dandekar, Thomas A1 - Ribes, V. A1 - Tollervey, David T1 - Schizosaccharomyces pombe U4 small nuclear RNA closely resembles vertebrate U4 and is required for growth N2 - No abstract available Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29771 ER - TY - JOUR A1 - Dandekar, Thomas A1 - Tollervey, David T1 - Cloning of Schizosaccharomyces pombe genes encoding the U1,U2,U3 and U4 snRNAs N2 - No abstract available Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-29919 ER - TY - JOUR A1 - Ellgring, Johann Heinrich T1 - Facial expression as a behavioral indicator of emotional states N2 - This article gives an overview of possibilities for the assessment offacial behavior. With regard to validity, results from a longitudinal study of 36 depressed patients and nine controls as weil as often schizophrenic patients and their relatives will be referred to. These results are used to illustrate the following principles which have to be taken into account when studying facial behavior: a) communication strongly facilitates facial expression, b) activation of facial behavior follows the "principle of least effort", and c) the principle of individual specificity applies to the association of nonverbal behavior and mood states. Making allowance for these principles has, among others, consequences a) for situations or conditions under which to asses behavior (specifically conditions of communication), b) for data analysis (e.g., dealing with frequent and rare events), and c) for empirical or experimental strategies (e.g., aggregation of single-case longitudinal comparisons). From the results on facial behavior during depression it can be concluded that the nonverbal reaction tendencies of endogenous and neurotic depressed patients differ. Moreover, the differential behavioral pattems observed cast doubt on the assumption of a homogeneity of affects in depression. Taking into account the conditions which govern it, facial behavior has proved to be a valid and, especially, a differential indicator for pathoIogic affective states and their changes. Given the fact that a psychiatric illness generally incorporates emotional problems it is more than surprising that little attention has been paid to the systematic study of emotional behavior. Some of the reasons for this will be clarified in the following. N2 - Dieser Beitrag gibt eine Übersicht über die Möglichkeiten zur Erfassung mimischen Verhaltens. Zur Bewertung der Validität werden Ergebnisse aus einer Verlaufsuntersuchung an 36 depressiven Patienten und neun Kontrollpersonen sowie von zehn schizophrenen Patienten und ihren Angehörigen herangezogen. Diese Ergebnisse sollen die folgenden Prinzipien, die bei der Untersuchung mimischen Verhaltens zu berücksichtigen sind, illustrieren: a) Kommunikation erleichtert in hohem Maße das Auftreten mimischen Ausdrucks, b) die Aktivierung mimischen Verhaltens folgt dem "Prinzip des geringsten Aufwandes", und c) auf die Beziehung zwischen nonverbalem Verhalten und Stimmungszuständen trifft das Prinzip der Individuenzpezifität zu. Aus diesen Prinzipien ergeben sich Konsequenzen a)für die Situationen oder Bedingungen, unter denen Verhalten zu erfassen ist (speziell Bedingungen der Kommunikation), b) für die Datenanalyse (z. B. die statistische Behandlung häufiger und seltener Ereignisse) und c) für empirische oder experimentelle Strategien (z. B. die Aggregation von Einzelfall-Verlaufsbeobachtungen). Aus den Ergebnissen zum mimischen Verhalten in der Depression kann geschlossen werden, daß sich endogen und neurotisch depressive Patienten hinsichtlich ihrer nonverbalen Reaktionstendenzen unterscheiden. Darüber hinaus stellen die differentiellen Verhaltensmuster die Annahme einer Affekthomogenität in der Depression in Frage. Berücksichtigt man die Bedingungen, die das mimische Verhalten steuern, so erweist es sich als valider und insbesondere differentieller Indikator für pathologische affektive Zustände und deren Veränderungen. Angesichts der Tatsache, daß eine psychiatrische Erkrankung im allgemeinen emotionale Probleme beinhaltet, so ist es mehr als erstaunlich, daß bisher dem Studium des unmittelbaren emotionalen Ausdrucksverhaltens so wenig Aufmerksamkeit geschenkt wurde. Einigen Gründen hierfür wollen wir im folgenden nachgehen. KW - Psychologie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58753 ER - TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - Theoretical study of FC\(_2\)H\(_4\) N2 - Large-scale multireference configuration interaction (MRD-CI) calculations in a quite flexible AO basis are employed to study the energy hypersurface for the reaction intermediate FC\(_2\)H\(_4\) • The reaction F + C\(_2\)H\(_4\) -> FC\(_2\)H\(_4\) as weil as the 1,2 migration of the fluorine atom in FC\(_2\)H\(_4\) is investigated. In addition the rotation around the CC bond in the optimum conformation is studied. The absolute minimum in the potential energy is found for the asymmetric structure but the symmetric structure is also found to be stable with respect to the dissociation, so that a shuttling of the fluorine atom is in principle possible but highly unlikely because ( l) the activation energy is high ( II 5-130 kJ fmol) and the saddle point lies only 4(}-50 kJ jmol below the dissociation Iimit of F + C\(_2\)H\(_4\) and (2) the competitive motion, i.e., rotation around the CC axis, is nearly free (I 1-17 kJ/mol). KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58824 ER - TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S.D. T1 - The hyperfine coupling constants of the X\(^3\)Σ\(^-\) state of NH : Influence of polarization functions and configuration space on the description of spin polarization N2 - The hyperfine coupling constants for the \(^3\)Σ\(-\) ground state of the NH molecule are determined by configuration interaction calculations whereby the infl.uence of polarization functions as weil as of the configuration space on the spin polarization mechanism is analysed. The dipolar part Au(N) and Au(H) can be obtained very reliably without much computational effort (A .. (N) == -45·3 MHz and A"(H) = -62·3 MHz). The value for the isotropic contribution a1.., in the best AO basis and MRD-CI treatment is - 64·5 MHz for H and 16·6 MHz for nitrogen compared to the corresponding experimental quantities of -66 MHz and 19 MHz respectively. Their determination depends on a subtle balance of the lu, 2u and 3u shell correlation description, whereby the dominant contribution to a1..,(H) results from the 2u shell. It is shown that the often good agreement of a110 values with experiment in a small basis singledouble configuration interaction treatment results from a cancellation of two errors. KW - Organische Chemie Y1 - 1989 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58832 ER -