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1.
F. Hauck 《Plant Systematics and Evolution》1878,28(9):288-295
Ohne Zusammenfassung 相似文献
2.
Dorjburgedaa Lkhagvadorj Markus Hauck Choimaa Dulamsuren Jamsran Tsogtbaatar 《Human ecology: an interdisciplinary journal》2013,41(5):725-735
The socioeconomics and the ecological impact of nomadic pastoralism were analyzed using interviews with 87 herder families and secondary information in the western Khangai, Mongolia. The pastoralists had an income above the national average for rural areas in Mongolia. Most herders continued traditional seasonal migration patterns, which involved ca. 10 moves per year over a total distance of ca. 100 km between summer and winter grazing grounds. As elsewhere in Mongolia, the number of goats owned by herders has greatly increased and cashmere has become the main source of cash income. Total livestock numbers rose considerably after decollectivization of the livestock sector in 1992, but in recent years have periodically been reduced by harsh winters, often combined with drought. Due to the high economic risk of these periodic livestock losses, many herders invest in better education for their children to enable them to migrate to the cities. 相似文献
3.
Using sugar and methylation analyses, and one- and two-dimensional 1H-NMR spectroscopy at 500 MHz it was established that poly-beta-1,2-4-deoxy-D-arabinohexopyranose occurs as O-specific chains of lipopolysaccharides in Citrobacter serotypes O4, O27 and O36. Strong serological cross-reactivity between these serotypes is in full agreement with the chemical identity of their O-specific polysaccharides. 相似文献
4.
E Romanowska A Gamian C Lugowski A Romanowska J Dabrowski M Hauck H J Opferkuch C W von der Lieth 《Biochemistry》1988,27(11):4153-4161
Novel enterobacterial core oligosaccharides were isolated from Citrobacter O4 and O36 lipopolysaccharides, and their structures were determined by methylation analysis, Smith degradation and enzymatic degradations, gas chromatography/mass spectrometry, and two-dimensional phase-sensitive correlated, relayed coherence transfer, double-quantum, triple-quantum-filtered, and nuclear Overhauser effect (NOE) 1H NMR spectroscopy at 500 MHz. In the formulas, all hexose residues are D-hexopyranoses, and heptoses are L-glycero-D-manno-heptopyranoses; the alternative locations of the side-chain heptose and pyrophosphorylethanolamine (PPEtN) residues are marked by dashed lines; dOclA stands for 3-deoxy-D-manno-octulosonic acid. (formula; see text) Along with these complete cores, incomplete ones, lacking the hexosamine trisaccharides, occur in the lipopolysaccharides of both types. Qualitative NOE data were in good agreement with the minimum energy conformation of the above O36 oligosaccharide, calculated with the aid of the SUGAR program [Sundin, A., Carter, R. E., & Liljefors, T. (1988) J. Mol. Graphics (in press)]. 相似文献
5.
A new estimator of a common odds ratio is proposed for case-control studies of familial aggregation. The proposed estimator is a modification to the usual Mantel-Haenszel estimator that relies on an empirical adjustment for the within-family clustering which is typical of such designs. A simulation study shows that the estimator tends to have smaller mean squared error than the unmodified Mantel-Haenszel estimator under conditions likely to arise in practice. The construction of confidence intervals is also discussed. 相似文献
6.
Janusz Dabrowski Michael Hauck Elzbieta Romanowska Andrzej Gamian 《Carbohydrate research》1988,180(2):163-174
The main features of the primary structure of the octasaccharide, -
-Glcp-(1→2)--
-Glcp-(1→2)-[-
-GalpNAc- (1→3)]--
-Galp-(1→3)--
-Glcp-(1→3)-[-
-Hepp-(1→7)]--
-Hepp-(1→3)--
-Hep, have been determined in the ab initio manner by 1H-n.m.r. spectroscopy without resorting to biochemical methods of analysis. Several nontypical interresidue n.O.e. values point to a preferred solution conformation of the molecule. 相似文献
7.
W W Hauck 《Biometrics》1984,40(4):1117-1123
The finite-sample properties of various point estimators of a common odds ratio from multiple 2 X 2 tables have been considered in a number of simulation studies. However, the conditional maximum likelihood estimator has received only limited attention. That omission is partially rectified here for cases of relatively small numbers of tables and moderate to large within-table sample sizes. The conditional maximum likelihood estimator is found to be superior to the unconditional maximum likelihood estimator, and equal or superior to the Mantel-Haenszel estimator in both bias and precision. 相似文献
8.
Gabriella Fóris MD PhD George A. Medgyesi Mátyás Hauck 《Molecular and cellular biochemistry》1986,69(2):127-137
Summary Met-enkephalin (ME) exerts a bimodal effect on functional activities of rat peritoneal macrophages (PM); in a range of low concentration (10-9-10-7 M) antibody dependent cellular cytotoxicity (ADCC)was markedly stimulated with a simultaneous decrease of Fc receptor (FcR) mediated phagocytosis while the opposite was observed at 10-6-10-5 M concentrations.Studying the possible underlying mechanism(s) the followings were recorded: (1) ME in all applied concentrations induced an early Na+ influx which was followed by a Ca2+ efflux in the range of low concentrations. In the range of high concentrations Na+ influx was accompanied by a Ca2+ influx. (2) ME at 10-8 M concentration induced a rise in cGMP level with a plateau in the 60–120th min of incubation. This effect was prevented by 10-5 M of naloxone. At 10-6 M concentration a transient rise of cAMP level was recorded which was not affected by naloxone. (3) Verapamil in 10-6 M abolished both the Ca2+ influx and the rise in cAMP level induced by 10-6-10-5 M ME but not the rise in cGMP level induced by lower ME concentrations. (4) cAMP elevation by high ME concentrations was abolished by enkephalinase inhibitory puromycin. (5) PM-enkephalinase as assessed by the cleavage of fluorogenic substrate L-alanine beta naphthylamide (ABNA), was inhibited by 10-6-10-5 M of ME. This inhibition was abolished by verapamil, but not affected by naloxone. In the range of low concentrations ME appears to act on specific delta opioid receptors and its action is positively coupled to guanylate cyclase. In relatively higher concentrations ME-action is not mediated by specific delta opioid receptors and it appears to involve Ca2+ influx, adenylate cyclase activation as well as the processing of hormone by PM-enkephalinase. 相似文献
9.
Choimaa Dulamsuren Tobias Wommelsdorf Fengjun Zhao Yaoqin Xue Bulat Z. Zhumadilov Christoph Leuschner Markus Hauck 《Ecosystems》2013,16(8):1536-1549
The larch forests at the southern limit of the Siberian boreal forest in Central Asia have repeatedly experienced strong recent growth declines attributed to decreasing summer precipitation in the course of climate warming. Here, we present evidence from the southernmost Larix sibirica forests in eastern Kazakhstan that these declines are primarily caused by a decrease in effective moisture due to increasing summer temperatures, despite constant annual, and summer precipitation. Tree-ring chronologies (>800 trees) showed a reduction by 50–80% in mean ring width and an increase in the frequency of missing rings since the 1970s. Climate-response analysis revealed a stronger (negative) effect of summer temperature (in particular of the previous year’s June and July temperature) on radial growth than summer precipitation (positive effect). It is assumed that a rise in the atmospheric vapor pressure deficit, which typically increases with temperature, is negatively affecting tree water status and radial growth, either directly or indirectly through reduced soil moisture. Larch rejuvenation ceased in the 1950s, which is partly explained by increasing topsoil desiccation in a warmer climate and a high drought susceptibility of larch germination, as was demonstrated by a germination experiment with variable soil moisture levels. The lack of regeneration and the reduced annual stem increment suggest that sustainable forest management aiming at timber harvesting is no longer feasible in these southern boreal forests. Progressive climate warming is likely to cause a future northward shift of the southern limit of the boreal forest. 相似文献
10.