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991.
T. A. Krapivnitskaya 《Human physiology》2007,33(1):85-88
A clinical and psychological examination of civil aviation pilots, including ones with a history of attempted suicide, and an in-depth study of the personality qualities of the pilots by means of a modified standardized multifactor personality study and a portrait choice method based on a modification of Szondi’s test for eight drives were performed. The analysis of psychological features in pilots with a history of attempted suicide showed a neurotic type of maladaptation formed on the basis of the domination of hyposthenic traits in the personality structure. Neurotic behavior, pessimism, increased anxiety, and introversion that had become acute under the specific social and occupational conditions transformed into depressive signs and avoidance of social problems. 相似文献
992.
S. G. Prokushkin T. N. Bugaenko N. D. Sorokin L. N. Kaverzina O. A. Zyryanova 《Biology Bulletin》2004,31(1):42-50
It is shown that larch of the prefire generation is the main edificator at the early stages of progressive successions in burned-out areas. Its environment-forming effect manifests itself most strongly in the phytogenic field of living trees, where edaphic conditions similar to those in primary larch forests are formed within ten years after the fire. This is accompanied by an increase in the numbers of microorganisms utilizing organic and mineral nitrogen, as well as in the rate of nitrogen mineralization in plant microgroups of this zone. Hence, living trees remaining in a burned-out area promote restoration of the initial edaphic conditions. 相似文献
993.
Elaine R. Reynolds Eric A. Stauffer Laura Feeney Elizabeth Rojahn Benjamin Jacobs Carol McKeever 《Developmental neurobiology》2004,58(4):503-513
Drosophila bang‐sensitive (bs) mutants exhibit a stereotypic seizure and paralysis following exposure to mechanical shock. In a physiological preparation, seizures and failures corresponding to the defective behavior are observed in response to high frequency stimulation. The amplitude of the stimulus necessary to produce bs behavior, or seizure threshold, varies with bs mutant and its gene dosage. In many respects, the bs defects are similar to those observed in mammalian seizure disorders. Antiepileptic drugs (AEDs) were administered by feeding to easily shocked2 (eas2), a representative bs mutant. The mean recovery times of treated flies were examined in comparison to control cultures. Some of the drugs administered, including carbamazeprine, ethosuximide, and vigabactrin, had little or no effect on the bs behavior of eas2. Gabapentin, however, showed a reduction in mean recovery time with chronic drug exposure. Phenytoin also had a significant effect on the bs behavior of treated flies. There was a reduction of both mean recovery time and the percentage of flies that displayed bang‐sensitive behavior with both acute and chronic treatment. The adult giant fiber preparation was used to examine the effects of phenytoin physiologically. Treated eas2 flies showed changes in their response to normal stimulation as well as alterations in seizure threshold in response to high frequency stimulation. Gabapentin was also effective against two other bs mutants, bangsenseless1 and slamdanceiso7.8, at strain‐specific concentrations, while phenytoin also reduced bang‐sensitive behaviors in bangsenseless1 in a dose dependent manner. AEDs, therefore, can be used to dissect aspects of bs behavior and this model may be useful in understanding the underlying basis of seizure disorders. © 2003 Wiley Periodicals, Inc. J Neurobiol 58: 503–513, 2004 相似文献
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995.
I. G. Minkevich A. D. Satroutdinov E. G. Dedyukhina T. I. Chistyakova E. N. Kaparullina A. V. Koshelev O. N. Okunev 《World journal of microbiology & biotechnology》2006,22(11):1205-1213
The effect of temperature on the maximum specific growth rate and the cell yield was studied during cultivation of two bacterial strains (LPM-4 and Pseudomonas sp. LPM-410) on EDTA under unlimited cell growth conditions in a pH-auxostat. Both strains displayed linear dependence of reciprocal biomass yield against reciprocal specific growth rate, from which the values of rate of substrate expenditure for cell maintenance and the “maximum” yield (i.e., hypothetical yield without cell maintenance processes) were estimated. Analysis of the maximum yield values based on mass–energy balance theory suggested that oxidation of the carboxylic acid side chains of EDTA by a monooxygenase had zero or low energetic efficiency. An Arrhenius equation with different values of Arrhenius parameters within different temperature ranges gave a good fit with the temperature dependence of both growth rate and biomass yield. Specific growth rates of both strains showed a more pronounced temperature dependence than did the cell yields. A possible kinetic mechanism was suggested which might be responsible for the modes of the temperature dependences of specific growth rate and yield that were found. The mechanism is based on a hypothetical key substance governing the metabolic flows, which is formed in a zero-order reaction and destroyed in a first-order reaction, both rate constants depending on temperature according to the Arrhenius law. 相似文献
996.
J. A. Hawkins 《Diversity & distributions》2006,12(1):27-33
Phylogenetic methods hold great promise for the reconstruction of the transition from precursor to modern flora and the identification of underlying factors which drive the process. The phylogenetic methods presently used to address the question of the origin of the Cape flora of South Africa are considered here. The sampling requirements of each of these methods, which include dating of diversifications using calibrated molecular trees, sister pair comparisons, lineage through time plots and biogeographical optimizations, are reviewed. Sampling of genes, genomes and species are considered. Although increased higher-level studies and increased sampling are required for robust interpretation, it is clear that much progress is already made. It is argued that despite the remarkable richness of the flora, the Cape flora is a valuable model system to demonstrate the utility of phylogenetic methods in determining the history of a modern flora. 相似文献
997.
Electric toothbrushes were evaluated using a model of plaque removal by fluid shear forces. Sucrose supplementation during plaque development did not affect the removal of bacteria from biofilm exposed to low-energy shear but did increase their resistance to high-energy shear. The toothbrush supplying high-energy shear forces removed significantly more viable bacteria. 相似文献
998.
CECILIA A. L. DAHLSJÖ 《Ecological Entomology》2016,41(6):741-744
1. Termites are one of the most important invertebrate ecosystem engineers in tropical regions, which may be quantified using termite biomass data. However, biomass data are particularly difficult to collect as they rely on termites being weighed in the field, which may neither be possible nor convenient. Local scale linear regression models, based on termite head widths (mm) and body masses (mg), have been used in the past to estimate termite biomass using head width and abundance data. However, these models represent very limited numbers of termite taxa from single sites. In the present study, I provide one of the most representative linear regression models available based on 90 samples from three different countries (Peru, Kenya, and Malaysia). 2. Although the linear regression model under‐ or overestimated body weights of taxa with characteristic features (e.g. large heads of Odontotermes workers or elongated abdomens of Kalotermitidae) it provides a robust method for estimating termite biomass at the community level. Additionally, while there are limitations related to the general model, which may be solved by focusing on taxa specific data and the use of higher accuracy equipment, it is the first model to facilitate termite biomass estimates using the head with and abundance data only. 3. This study encourages the use of termite biomass data to gain a better understanding of termites in ecosystem processes and calls for comparative data to be gathered for the purpose of creating models that may be representative of the variability among termite taxa. 相似文献
999.
1000.