TY - JOUR A1 - Engels, Bernd A1 - Peyerimhoff, S.D. A1 - Skell, P.S. T1 - Theoretical study of the potential energy surface governing the stereochemistry in ClC\(_2\)H\(_4\) reactions N2 - Large-scale multireference configuration interaction calculations in a double·t·type AO basis including polarization functions are carried out for the potential surface of the ClC\(_2\)H\(_4\9 system. The charge distribution for various extreme points of the surface is discussed. The absolute minimum is found for an asymmetric ClC2H4 structure. The symmetrical bridged nuclear conformation is also found to be stable with respect to dissociation into Cl + C\(_2\)H\(_4\)• The activation energy for rotation about the C-C axis is calculated tobe around 18 kJ/mol, which is comparable tothat for the 1,2 migration {around 26 kJ/mol). The stereochemistry is governed by the fact that addition of CI to C\(_2\)H\(_4\) (or dissociation) is a two-step reaction proceeding through a symmetrica1 intermediate. The direct addition pathway possesses a small barrier of about 8 kJ jmol. KW - Organische Chemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58851 ER - TY - JOUR A1 - Kim, E. A1 - Christl, Manfred A1 - Kochl, J. K. T1 - Charge-Transfer Cycloaddition of Homobenzvalene with Tetracyanoethylene N2 - The transient yellow color observed in the cycloaddition of homobenzvalene (HB) with tetracyanoethylene (TCNE) is associated with the charge-transfer complex [HB, TCNE). The deliberate photoexcitation of [HB,TCNE) affords a mixture of charge-transfer cycloadducts (1, 2, and 3) that differs from that obtained in thermal cycloaddition. The relationship of {HB t TCNE•) radical-ion pair (as the critical reactive intermediate in charge-transfer cycloaddition) to the activation process for thermal cycloaddition is discussed. KW - Organische Chemie KW - Electron transfer KW - photochemical KW - Radical-ion pair KW - Photochemistry Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-58537 ER - TY - JOUR A1 - Kurtz, Beth E. A1 - Schneider, Wolfgang A1 - Carr, Martha A1 - Borkowski, John G. A1 - Rellinger, Elizabeth T1 - Strategy instruction and attributional beliefs in West Germany and the United States: Do teachers foster metacognitive development? N2 - Previous research has shown German children to be more strategic on sort-recall memory tasks than their American age-mates, and to show fewer effort-related attributions. We conducted this study to determine if those differences are due to systematic differences in the strategy instruction and attributional beliefs of German and U.S. teachers, and to explore metacognitive instructional practices in the two countries. Teachers responded to a questionnaire that inquired about their use of strategy instructions, fostering of reflective thinking in pupils, sources of children’s learning problems, and modeling of metacognitive skills such as monitoring. The second part of the questionnaire asked about the reasons underlying children’s academic successes and failures. German teachers reported more instruction of task-specific strategies, while American teachers showed more effort-related attributions. The types of strategies instructed and types of learning problems most frequently described varied across the two countries, and also according to how many years the teachers had taught. Results were discussed regarding their implications for metacognitive developmental theory, particularly regarding culture and other environmental influences on the development of controlled processing. KW - Psychologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62145 ER - TY - JOUR A1 - Krämer-Neubert, Sabine T1 - Mundart und Geschichte des Miltenberger Raumes N2 - No abstract available KW - Mundart KW - Miltenberg Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-73135 ER - TY - JOUR A1 - Epe, B. A1 - Harttig, U. A1 - Stopper, Helga A1 - Metzler, M. T1 - Covalent binding of reactive estrogen metabolites to microtubular protein as a possible mechanism of aneuploidy induction and neoplastic cell transformation N2 - Neoplastic cell transfonnation induced by estrogens and some other carcinogen& such as benzene appears to involve the induction of mitotic aneuploidy rather than DNA damage and point mutations. As metabolic activation may also play an important roJe in the mechanism of carcinogenesis of these nongenotoxic compounds, we have studied the Interaction of reactive quinone metabolites of various estrogens and of benzene with the major microtubular protein, tubulin, in a cell-free system. Covalent binding of the radioactively labeled metabolites to the a- and 13-subunit of tubulin was found to depend on the structure of the metabolite. When the adducted tubulins were tested in vitro for their ability to polymerize to microtubules, Inhibition of microtubule assembly was obsened in every case, although to varying extents. It is proposed that the fonnation of covalent tubulin adducts may impair the formation of mitotic spindies and thus contribute to chromosomal nondisjunction and aneuploidy induction. KW - Toxikologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63478 ER - TY - JOUR A1 - Pressley, Michael A1 - Borkowski, John G. A1 - Schneider, Wolfgang T1 - Good information processing: What it is and how education can promote it N2 - The nature of good information processing is outlined as determined by intact neurology, information stored in long-term memory, and general cognitive tendencies, attitudes, and styles. Educators can promote the development of good information processing by promoting what is in long-term memory. This can be accomplished by teaching important literary, scientific, and cultural knowledge; teaching strategies; motivating the acquisition and use of important conceptual knowledge and strategies; and encouraging the general tendencies supporting good information processing. Good information processing can be produced by years of appropriate educational input. Good information processors cannot be produced by short-term interventions. KW - Psychologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62127 ER - TY - JOUR A1 - Merz, H. A1 - Fliedner, A. A1 - Lehrnbecher, T. A1 - Sebald, Walter A1 - Müller-Hermelink, H. K. A1 - Feller, A. C. T1 - Cytokine expression in B-cell non-Hodgkin lymphomas N2 - No abstract available KW - Biochemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62539 ER - TY - JOUR A1 - Liebert, U. G. A1 - Schneider-Schaulies, Sibylle A1 - Baczko, K. A1 - ter Meulen, V. T1 - Antibody-induced restriction of viral gene expression in measles encephalitis in rats N2 - No abstract available KW - Virologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62271 ER - TY - JOUR A1 - Schneider-Schaulies, Sibylle A1 - Liebert, U. G. A1 - Baczko, K. A1 - ter Meulen, V. T1 - Restricted expression of measles virus in primary rat astroglial cells N2 - No abstract available KW - Virologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62283 ER - TY - JOUR A1 - Schneider-Schaulies, Jürgen A1 - von Brunn, A. A1 - Schachner, M. T1 - Recombinant peripheral myelin protein P\(_o\) confers both adhesion and neurite outgrowth promoting properties N2 - To probe into the functional properties of the major peripheral myelin cell surface glycoprotein P 0 , its ability to confer adhesion and neurite outgrowth-promoting properfies was studied in cell culture. Tothis aim, Po was expressed as integral membrane glycoprotein at the surface of CV -1 cells with the help of a recombinant vaccinia virus expression system. Furthermore, the immunoglobulin-like extracellular domain of P0 (P0 -ED) was expressed as soluble profein in a bacterial expression system and used as substrafe coated to plastic dishes or as competitor in cell adhesion and neurite outgrowth-promoting assays. The adhesion of P0 -expressing CV-1 cells to P0 -ED substrafe was specifically inhibitable by polyclonal Po antibodies (54% :t 6% ). In addition, the specific interaction between Po molecules could be reduced ( 49% ± 8%) by adding soluble P0 -ED to the culture medium, demonstrating that the homophilic inter~ction between recombinant Po molecules can be mediated, at least on one partner of interacting molecules, by the unglycosylated Ig-like domain. Substrate-coated p -ED also conferred adhesion and neurite outgrowth ability to dorsal root ganglion neurons with neurites of a mean length of about 150 ,_..m. This neurite outgrowth was specifically inhibitable by soluble P" (74% ± 14%) and P 0 antibodies (65% ± 9% ). These observations indicate that Po is capable of displaying two different types of functional roles in the myelination process of . peripheral nerves: The heterophilic interaction with neurons may be responsible for the recognition between axon and myelinating Schwann cell at the onset of myelination, whereas the homophilic interacton may indicate its roJe in the selfrecognition of the apposing loops of Schwann cell surface membranes during the myelination process and in the mature compact myelin sheath. KW - Immunologie KW - immunoglobulin superfamily KW - peripheral nervous system KW - vaccinia virus KW - Po Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-54841 ER - TY - JOUR A1 - Sirén, Anna-Leena A1 - Feuerstein, G. T1 - Cardiovascular effects of anatoxin-a in the conscious rat N2 - Cardiovascular Effects of Anatoxin-A in the Conscious Rat. SJREN, A.-L., AND FEUERSTEIN, G. (1990). Toxicol. Appl. Pharmacol. 102,91-100. The effects ofanatoxin-A on mean arterial pressure (MAP), heart rate, cardiac index (CI), and blood flow (BF) in hindquarter (HQ), renal (R). and mesenteric (M) vascular beds were studied after intravenous (iv) and intracerebroventricular (icv) administration in the conscious rat. The pharmacological profile of anatoxin-A was further compared to nicotine administered iv and icv. MAP and heart rate were measured from femoral artery, CI by thermodilution method, and blood flow by Doppler velocimetry. Anatoxin-A and nicotine (30, 100 and 300 1-!g/kg iv) produced an increase in MAP with concomitant bradycardia. The highest doses increased Cl. MBF and RBF decreased due to a vasoconstriction in M and R vasculature. These effects were attenuated by the ganglion blocker chlorisondamine (5 mg/kg, iv). Anatoxin-A ( 100 1-!g/k~ iv) increased plasma epinephrine Ievels by 2- fold with virtually no effect on norepinephrine whereas nicotine ( 100 ~oLg/kg, iv) increased plasma epinephrine and norepinephrine by 20- to 30-fold. Central administration of anatoxin-A and nicotine (30-100 ,ug/kg icv) increased MAP with no effect on heart rate and produced M and R vasoconstriction. In summary, the present study demonstrates that anatoxin-A acts as a nicotinic cholinergic agonist in the c.onscious rat after both systemic and centrat administration. Anatoxin-A and nicotine produced pressor and reno-splanchnic vasoconstrictor responses and at high doses increased cardiac output. These effects were mediated by activation ofthe nicotinic receptors in the adrenal medulla and sympathetic ganglia. However, marked differences were found in the potency ofanatoxin-A versus nicotine to stimulate the sympathoadrenomedullary axis. KW - Neurobiologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63103 ER - TY - JOUR A1 - Paakkari, P. A1 - Paakkari, I. A1 - Sirén, Anna-Leena A1 - Feuerstein, G. T1 - Respiratory and locomotor stimulation by low doses of dermorphin - a Mu\(_1\)-receptor mediated effect N2 - The selective opioid mu receptor agonist dermorphin increased the locomotor activity of rats dose dependently at 1 0 to 1 00 pmol/kg i.c.v. Respiratory rate, relative tidal volume and respiratory minute volume also increased unrelated to changes in locomotor activity. Higher doses, on the other hand, produced catalepsy and respiratory depression. Pretreatment of the rats with the mu,-selective antagonist naloxonazine (10 mg/kg i.v.) blocked the stimulant locomotor and respiratory effects of low doses of dermorphin (1 0--1 00 pmol/kg), but potentiated the respiratory depressant effect of a high dose (1 0 nmol/kg) of dermorphin. The selective benzodiazepine antagonist flumazenil (5 mg/kg), which has been shown previously to antagonize catalepsy and respiratory depression produced by relatively high doses of dermorphin, did not antagonize the respiratory or locomotor stimulant effect of dermorphin. The data suggest that mu\(_1\)-opioid receptors are responsible for the low dose stimulant effects of dermorphin on locomotor activity and respiration whereas mu\(_2\) receptors mediate the respiratory depressant effect of dermorphin. KW - Neurobiologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-63110 ER - TY - JOUR A1 - Sodian, Beate A1 - Schneider, Wolfgang T1 - Children's understanding of cognitive cueing: How to manipulate cues to fool a competitor N2 - 4-6-year-old children's understanding of cognitive cuing was studied in 2 experiments using a strategic interaction paradigm. Ghildren could fool a competitor by hiding targets in locations that were labeled with semantically weakly associated cues and help a cooperative partner by hiding them in semantically highly associated locations. Very few 4-year-olds, half the 5-year-olds, and almost all 6-year-olds appropriately chose semantically highly vs. weakly associated hiding places to make the targets easy vs. difficult to find. The second experiment showed that 4-year-olds did not strategically manipulate cues as sources of information, although they themselves proficiently used them as such in a search task. These findings are discussed with regard to research on children's developing understanding of origins of knowledge and belief and with regard to recent claims that young preschoolers possess a metacognitive understanding of cognitive cuing. KW - Psychologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-62132 ER - TY - JOUR A1 - Oeschger, Bernhard A1 - Fackler, Guido A1 - Hamer, Jens A1 - Burkhard, Antje T1 - Die Landesstelle für Volkskunde Freiburg 1960-1990 N2 - No abstract available KW - Volkskunde KW - Freiburg Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-41796 ER - TY - JOUR A1 - Fiala, Brigitte T1 - Extrafloral nectaries versus ant-Homoptera mutualisms : a comment on Becerra and Venable N2 - No abstract available KW - Nektarium KW - Ameise Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-32948 ER - TY - JOUR A1 - Künzler, Jan T1 - Familiale Arbeitsteilung bei Studierenden mit Kleinkindern : Erste Ergebnisse einer Zeitbudgetstudie N2 - Gerade bei jungen Frauen und Männern mit hohem Bildungsniveau haben sich in den letzten Jahren die Einstellungen zur familialen Arbeitsteilung stark gewandelt. Mittlerweile wird eine partnerschaftlieh- egalitäre Verteilung der Pflichten im Haushalt mehrheitlich begrüßt. Um festzustellen, ob veränderte Einstellun· gen auch verhaltenswirksam geworden sind, wurden 66 Studentinnen und Studenten mit Kleinkindern mit Methoden der Zeitbudgetforschung zu Tagesablauf und Zeitverwendung befragt. Bei insgesamt im Vergleich zur Erwerbsbevöl· kerung hoher Gesamtbelastung waren auch hier Hausarbeit und Kinderbetreuung ungleich, und zwar zu Lasten der Frauen, verteilt. Studentinnen können daher wesentlich weniger Zeit in ihr Studium investieren als Studenten. Immerhin hatte eine relativ große Minderheit partnerschaftliehe Formen der Arbeitsteilung verwirklicht. KW - Soziologie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-50752 ER - TY - JOUR A1 - Wieber, M. A1 - Walz, J. A1 - Burschka, Christian T1 - Organostibonsäureester. II [1]: Darstellung und Eigenschaften von Methanstibonsäureestern. Struktur von Di-μ-methoxy-bis[dibromo-methoxy-methyl-antimon(V)] N2 - Dimere alkoxyverbrückte Verbindungen des Typs [CH\(_3\)SbX\(_2\)(OR)(μ-OR)]\(_2\) (X = Cl, Br; R = CH\(_3\), C\(_2\)H\(_5\)) können durch Oxidation von CH\(_3\)Sb(OR)\(_2\) mit Br\(_2\) oder S0\(_2\)Cl\(_2\) in CH\(_2\)Cl\(_2\) unterhalb -60°C als lichtempfindliche kristalline Feststoffe erhalten werden. Die Struktur der Verbindung [CH\(_3\)SbBr\(_2\)(OCH\(_3\))(μ-OCH\(_3\))]\(_2\) konnte mittels Röntgenstrukturanalyse bestimmt werden. Umsetzungen mit Natriumalkoholaten in den entsprechenden Alkoholen bei 0°C führen zu dimeren Tetraalkoxymethylstiboranen. Austauschreaktionen von Tetramethoxymethylstiboran mit Ethanol ergeben das Ethoxyderivat und mit Diolen symmetrische spirocyclische Methanstibonsäureester. N2 - Dimeric alkoxy-bridged compounds of the type [CH\(_3\)SbX\(_2\)(OR)(μ-OR)]\(_2\) (X = Cl, Br; R = CH\(_3\), C\(_2\)H\(_5\)) are prepared by oxidation of CH\(_3\)Sb(OR)\(_2\) with Br\(_2\) or S0\(_2\)Cl\(_2\) in CH\(_2\)Cl\(_2\) below -60°C as light sensitive erystals. The structure of [CH\(_3\)SbBr\(_2\)(OCH\(_3\))(μ-OCH\(_3\))]\(_2\) was determined by X-Ray analysis. By reaction with sodium alkoxides in the corresponding alcohol at 0°C dimeric tetraalkoxymethylstiboranes are obtained. Exchange reactions of tetramethoxymethylstiborane with ethanol give the ethoxy derivative and with diols symmetrie spirocyclic esters of methanestibonic acid. KW - Chemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31909 ER - TY - JOUR A1 - Wieber, M. A1 - Hoehl, H. A1 - Burschka, Christian T1 - Diphenylantimonalkoxide und -thiolate als Liganden in Metallcarbonylkomplexen des Chroms und Molybdäns; Kristallstruktur von Tris[diphenyl(phenylthiolato)stiban]molybdäntricarbonyl T1 - Diphenylantimony Alkoxides and Thiolates as Ligands in Carbonyl Complexes of Chromium and Molybdenum; Crystal Structure of Tris [diphenyl(phenylthiolato)stibane] Molybdenum Tricarbonyl N2 - Diorganoantimonverbindungen R\(_2\)SbX (R = C\(_6\)H\(_5\) X = S-Organyl, O-Organyl) reagieren mit Cycloheptatrienylmolybdäntricarbonyl zu Produkten des Typs [R\(_2\)SbX]\(_3\)Mo(CO)\(_3\). Die analogen Komplexe des Chroms können durch Reaktion von Tris(acetonitril) chromtricarbonyl mit den Antimon-Liganden dargestellt werden. (1,5-Cyclooctadien)molybdäntetracarbonyl reagiert unter Substitution mit Diorganoantimonderivaten R\(_2\)SbX (R = C\(_6\)R\(_5\), X = S-Organyl) zu den Verbindungen [R\(_2\)SbX]\(_2\)Mo(CO)\(_4\) Synthese und Eigenschaften der StibanKomplexe sowie die Kristallstruktur der Verbindung [(C\(_6\)H\(_5\))\(_2\)SbSC\(_6\)H\(_5\)]\(_3\)Mo(CO)\(_3\) werden beschrieben. N2 - Diorganoantimony compounds R\(_2\)SbX (R = C\(_6\)H\(_5\), X = S-organyl, O-organyl) react with cycloheptatrienemolybdenum tricarbonyl to yield products of the type [R\(_2\)SbX]\(_3\)Mo(CO)\(_3\). Analogous complexes of chromium are prepared by reaction oftris(acetonitrile)chromium tricarbonyl with the stibane Ugands. Tetracarbonyl-l,5-cyclooctadienemolybdenum undergoes substitution reaction with diorganoantimony compounds R\(_2\)SbX (R = C\(_6\)R\(_5\), X = S-organyl) to give [R\(_2\)SbX]\(_2\)Mo(CO)\(_4\) Synthesis and properties of the stibane complexes as weil as an X-ray determination of [(C\(_6\)H\(_5\))\(_2\)SbSC\(_6\)H\(_5\)]\(_3\)Mo(CO)\(_3\) are described. KW - Chemie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-31919 ER - TY - CHAP A1 - Wehgartner, Irma T1 - Bemerkungen zum Bild der Frau in der etruskischen Kunst N2 - No abstract available KW - Etrusker KW - Kunst KW - Frau Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-53444 ER - TY - JOUR A1 - Sponholz, Barbara T1 - Sedimentologische Untersuchungen an Verfüllungen von Silikatkarstformen im Djado und an der Stufe von Bilma (NE-Niger) N2 - Vorstellung eines durch die Jubiläumsstiftung der Universität Würzburg geförderten Forschungsvorhabens KW - Geographie Y1 - 1990 U6 - http://nbn-resolving.de/urn/resolver.pl?urn:nbn:de:bvb:20-opus-56650 ER -