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排序方式: 共有97条查询结果,搜索用时 15 毫秒
11.
Md. Dilshad Manzar Wassilatul Zannat Jamal Ali Moiz David Warren Spence Seithikurippu R. Pandi-Perumal Ahmed S. Bahammam 《Biological Rhythm Research》2016,47(6):851-864
The Pittsburgh Sleep Quality Index (PSQI) is a rigorously validated questionnaire with extensive use in sleep assessment. Findings from numerous factor analytic studies of the PSQI have been interpreted to support a heterogeneous factor structure model for the test. Nevertheless, the literature continues to lack a focused evaluation of whether this heterogeneous factor structure is justified. A consideration of this issue led to a conclusion that a closer analysis of the PSQI’s factor structure was merited. To address this need a comparative confirmatory factor analysis for assessing the performance of the accepted factors models of the PSQI was conducted. A sample of university students (n = 418), age = 20.92 ± 1.81 years, BMI = 23.30 ± 2.57 kg/m2 completed the multi-structured sleep survey at Jamia Millia Islamia, New Delhi, India. Seventeen putative factor structures (three 1-Factor, eight 2-Factor, and six 3-Factor) of the PSQI from the existing literature were selected for analysis. Fourteen models (82.35%) had almost similar values for model fit indices. Two models were misfits, and one model was a poor fit. The two misfit models incorporated gender and age as covariates. The third poor fit model was used to produce a unique path diagram, which made it distinct from the remaining 16 models. The overlapping values in the fit range of the model fit indices did not support the often projected heterogeneous factor structures of the PSQI for the vast majority of the models. 相似文献
12.
“探究式学习”促使学生的学习方式和教师的教学方式发生深刻的变革.阐述了探究式学习、实验操作技能和探究式实验教学模式这三个概念的内涵.同时,对高中生物一个重要的验证性实验“叶绿体中色素的提取和分离”进行了改进,实施了探究式实验教学设计并进行了教学实践以及分析,旨在探讨如何培养学生的实验操作技能.由此可得出结论:开展探究式实验教学,既能通过规范的实验操作,培养学生的实验操作技能,又能培养学生的综合探究能力并树立实事求是的科学态度;利用随堂式的实验教学评价,能很好发挥探究式学习的成效. 相似文献
13.
A database of mouse locomotor path in spatial tests can be used to search in silico for behavioral measures that better discriminate between genotypes and are more replicable across laboratories. In this study, software for the exploration of exploration (SEE) was used to search a large database for a novel behavioral measure that would characterize complex movement paths. The database included mouse open-field behavior assessed in 3 laboratories, 7 inbred strains, several pharmacological treatments and hundreds of animals. The new behavioral measure, "path texture", was characterized using the local curvature of the path (the change of direction per unit distance, in degrees/cm) across several spatial scales, starting from scales smaller than the animal's body length and up to the scale of the arena size. Path texture analysis differs from fractal dimension analysis in that it does not assume self-similarity across scales. Path texture was found to discriminate inbred strains with relatively high broad-sense heritability (43%-71%) and high replicability across laboratories. Even genotypes that had similar path curvatures in some scales usually differed in other scales, and self-similarity across scales was not displayed by all genotypes. Amphetamine decreased the path curvature of C57BL/6 mice in small and medium scales, while having no effect on DBA/2J mice. Diazepam dose-dependently decreased the curvature of C57BL/6 mice across all scales, while 2 anxiogenic drugs, FG-7142 and pentylenetetrazole, increased it. Path texture thus has high potential for behavioral phenotyping and the study of drug effects in the mouse. 相似文献
14.
This review describes the large group of morphogenetic processes designated as search migrations. Search migrations typically include two stages: i) search, when a group of cells or of the cytoplasmic processes migrate over the cell-free spaces, and ii) choice, the stage when migrating cells reach specific loci where they stop and undergo specific differentiations induced by local factors such as cell-cell contacts and humoral agents. Migrating cells that do not meet their targets usually undergo apoptosis. Numerous examples of search migrations range from gastrulation to formation of axon-muscle connections. Critical stages of carcinogenesis such as acquisition of cell ability for invasion may be regarded as the genetic aberration of normal search migration: cancer cells perform an endless search but cannot make final choice. 相似文献
15.
Andrea L. Liebl Lynn B. Martin 《Proceedings. Biological sciences / The Royal Society》2012,279(1746):4375-4381
Global anthropogenic changes are occurring at an unprecedented rate; one change, human-facilitated introduction of species outside their native range, has had significant ecological and economic impacts. Surprisingly, what traits facilitate range expansions post-introduction is relatively unknown. This information could help predict future expansions of introduced species as well as native species shifting their ranges as climate conditions change. Here, we asked whether specific behavioural and physiological traits were important in the ongoing expansion of house sparrows (Passer domesticus) across Kenya. We predicted that birds at the site of initial introduction (Mombasa, introduced approx. 1950) would behave and regulate corticosterone, a stress hormone, differently than birds at the range edge (Kakamega, approx. 885 km from Mombasa; colonized within the last 5 years). Specifically, we predicted greater exploratory behaviour and stronger corticosterone response to stressors in birds at the range edge, which may facilitate the identification, resolution and memory of stressors. Indeed, we found that distance from Mombasa (a proxy for population age) was a strong predictor of both exploratory behaviour and corticosterone release in response to restraint (but only while birds were breeding). These results suggest that certain behavioural and neuroendocrine traits may influence the ability of species to colonize novel habitats. 相似文献
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Evolution of learning in fluctuating environments: when selection favors both social and exploratory individual learning 总被引:1,自引:0,他引:1
Borenstein E Feldman MW Aoki K 《Evolution; international journal of organic evolution》2008,62(3):586-602
Cumulative cultural change requires organisms that are capable of both exploratory individual learning and faithful social learning. In our model, an organism's phenotype is initially determined innately (by its genotypic value) or by social learning (copying a phenotype from the parental generation), and then may or may not be modified by individual learning (exploration around the initial phenotype). The environment alternates periodically between two states, each defined as a certain range of phenotypes that can survive. These states may overlap, in which case the same phenotype can survive in both states, or they may not. We find that a joint social and exploratory individual learning strategy-the strategy that supports cumulative culture-is likely to spread when the environmental states do not overlap. In particular, when the environmental states are contiguous and mutation is allowed among the genotypic values, this strategy will spread in either moderately or highly stable environments, depending on the exact nature of the individual learning applied. On the other hand, natural selection often favors a social learning strategy without exploration when the environmental states overlap. We find only partial support for the "consensus" view, which holds that individual learning, social learning, and innate determination of behavior will evolve at short, intermediate, and long environmental periodicities, respectively. 相似文献
19.
耕地非农化、非粮化的不断扩大严重影响了我国的粮食安全,亟需研究其演变机制和管控措施。基于1990、2000、2010和2020年四期土地覆盖数据和农业劳动力数据,利用耦合协调度模型和探索性时空数据分析(ESTDA)方法,分析了长江经济带县域耕地非农化、非粮化和乡村人口空心化的时空演化特征及其耦合协调关系。结果表明:①非农化呈现东高西低的格局,且存在围绕中心城市高值集聚的态势。非粮化则大致呈现出西高东低的倾向,远离大城市的边远县域非粮化程度较高。研究期内非农化和非粮化呈整体加剧趋势,乡村人口空心化程度显著提升。②非农化、非粮化和乡村人口空心化之间呈现较强耦合作用,失调区域逐渐扩大。③非农化、非粮化和乡村人口空心化耦合协调度存在明显的空间集聚现象并逐渐增强。高值集聚区主要分布在上游地区且数量逐渐减少,低值集聚区分布相对分散。④非农化、非粮化和乡村人口空心化耦合协调度具有较强时空动态特征,但县域及其邻域协同变动的比例较高,表明具有较强的局域整合性。 相似文献
20.
Shamsiiat Abdurakhmanova Svetlana Semenova T. Petteri Piepponen Pertti Panula 《Genes, Brain & Behavior》2019,18(8)
Hypothalamic histaminergic neurons regulate a variety of homeostatic, metabolic and cognitive functions. Recent data have suggested a modulatory role of histamine and histamine receptors in shaping striatal activity and connected the histaminergic system to neuropsychiatric disorders. We characterized exploratory behavior and striatal neurotransmission in mice lacking the histamine producing enzyme histidine decarboxylase (Hdc). The mutant mice showed a distinct behavioral pattern during exploration of novel environment, specifically, increased frequency of rearing seated against the wall, jumping and head/body shakes. This behavioral phenotype was associated with decreased levels of striatal dopamine and serotonin and increased level of dopamine metabolite DOPAC. Gene expression levels of dynorphin and enkephalin, opioids released by medium spiny neurons of striatal direct and indirect pathways respectively, were lower in Hdc mutant mice than in control animals. A low dose of amphetamine led to similar behavioral and biochemical outcomes in both genotypes. Increased striatal dopamine turnover was observed in Hdc KO mice after treatment with dopamine precursor l ‐Dopa. Overall, our study suggests a role for striatal dopamine and opioid peptides in formation of distinct behavioral phenotype of Hdc KO mice. 相似文献