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221.
Kang SY Lee KY Park MJ Kim YC Markelonis GJ Oh TH Kim YC 《Neurobiology of learning and memory》2003,79(1):11-18
We previously reported that a total methanolic extract of the underground part of Angelica gigas Nakai (Umbelliferae) (here-in-after abbreviated AG) significantly inhibited acetylcholinesterase (AChE) activity. We characterized 12 coumarin derivatives including both decursin and decursinol from extracts of AG. In this study, we evaluated the anti-amnestic activity of decursin, a major coumarin constituent isolated from AG, in vivo using ICR mice with amnesia induced by scopolamine (1 mg/kg body weight, s.c.). Decursin, when administered to mice at 1 and 5 mg/kg body weight i.p., significantly ameliorated scopolamine-induced amnesia as measured in both the passive avoidance test and the Morris water maze test. Moreover, decursin significantly inhibited AChE activity by 34% in the hippocampus of treated mice. These results indicate that decursin may exert anti-amnestic activity in vivo through inhibition of AChE activity in the hippocampus. 相似文献
222.
223.
Lee M 《New directions for child and adolescent development》2003,(99):9-21
A 15-year-old girl's daily life is a vivid testimony to the hardships the Korean high school student is faced with. She leaves home for school at 7 A. M., taking two lunch bags, one for supper, with her. After regular classes end at 5 P.M., she attends the "autonomous study classes" studying by herself until 10 P.M. The exhausted young girl returns home at about 10:30 P.M. and gets to bed around midnight at the earliest. Under the current system, this will be her life for three years. Of course, there is no guarantee she will be able to enter the university she wants. She has no family life, except for Sundays, and they hardly ever see each other, let alone get together at the dining table for dinner. People call this "ipsi chiok," entrance examination hell. ["High School Students Deprived of Spring," 1996, p. 13]. 相似文献
224.
Helen Fielding 《Continental Philosophy Review》2003,36(4):451-452
Volume Contents
Volume contents 相似文献225.
Graham KS Lee AC Brett M Patterson K 《Cognitive, affective & behavioral neuroscience》2003,3(3):234-254
A novel, neuropsychologically informed paradigm (extended retrieval of events in response to a cue word) was used to investigate the neural basis of autobiographical and semantic memory. Contrasting retrieval of autobiographical memories with retrieval of semantic facts (ABM-SEM) in 24 subjects across three PET studies revealed bilateral involvement of the middle temporal gyrus (BA 21) and medial frontal cortex (BA 9/10). The opposite contrast, SEM-ABM, resulted in increased regional cerebral blood flow in left posterior temporal regions (BA 37) and left prefrontal cortex (BA 45/46). Laterality maps suggest that the bilateral pattern seen in our studies, but not often in other neuroimaging investigations, reflects the use of a task stressing retrieval of specific personal events. Further comparisons revealed that the activation in the right anterior temporal lobe during autobiographical recall was virtually identical to that seen during retrieval of information about famous people or events in contrast with retrieval of general semantic facts. These findings suggest that the retrieval of an autobiographical event requires participation from conceptual knowledge, and that this type of knowledge is bilaterally distributed in the temporal lobes. 相似文献
226.
The phonological codes activated in visual word recognition can be thought of minimally as strings of discrete and unstructured phoneme-like units. We asked whether these codes might additionally express a letter string's phonological form at a featural or gestural level. Specifically, we asked whether the priming of a word (e.g. sea, film, basic) by a rhyming non-word would depend on the non-word's phonemic-feature similarity to the word. The question was asked within a mask--prime--target--mask sequence with both brief (57 ms in Experiments 1 and 2) and long (486 ms in Experiment 1) prime durations. Non-word primes that differed from their targets by a single phonemic feature (initial voicing as in ZEA, VILM, PASIC) led to faster target lexical decisions than non-word primes that differed by more than a single phonemic feature (e.g. VEA, JILM, SASIC). Visual word recognition seems to involve a sub-phonemic level of processing. 相似文献
227.
Little research has been carried out on human performance in optimization problems, such as the Traveling Salesman problem
(TSP). Studies by Polivanova (1974, Voprosy Psikhologii, 4, 41–51) and by MacGregor and Ormerod (1996, Perception & Psychophysics, 58, 527–539) suggest that: (1) the complexity of solutions to visually presented TSPs depends on the number of points on the
convex hull; and (2) the perception of optimal structure is an innate tendency of the visual system, not subject to individual
differences. Results are reported from two experiments. In the first, measures of the total length and completion speed of
pathways, and a measure of path uncertainty were compared with optimal solutions produced by an elastic net algorithm and
by several heuristic methods. Performance was also compared under instructions to draw the shortest or the most attractive
pathway. In the second, various measures of performance were compared with scores on Raven's advanced progressive matrices
(APM). The number of points on the convex hull did not determine the relative optimality of solutions, although both this
factor and the total number of points influenced solution speed and path uncertainty. Subjects' solutions showed appreciable
individual differences, which had a strong correlation with APM scores. The relation between perceptual organization and the
process of solving visually presented TSPs is briefly discussed, as is the potential of optimization for providing a conceptual
framework for the study of intelligence.
Received: 28 December 1998 / Accepted: 20 January 2000 相似文献
228.
Kissell JL 《Theoretical medicine and bioethics》2001,22(1):1-4
Theoretical Medicine and Bioethics - 相似文献
229.
During summer, female meadow voles (Microtus pennsylvanicus) maintain territories and males do not engage in paternal care. As day length shortens, territories dissolve and males nest with females and young. Because paternal behavior has never been studied in free-living meadow voles during colder months or in the laboratory under short photoperiods, the authors examined whether males housed in short day (SD) lengths exhibited more frequent or better quality paternal behavior than males housed in long day (LD) lengths. Sexually and parentally inexperienced (naive) SD males exhibited proportionally more and qualitatively better paternal care than naive LD males. SD males were more responsive than LD males to classic social cues associated with prepartum aggression inhibition and paternal onset. SD sires also displayed qualitatively better paternal behavior than LD sires. These data suggest that meadow vole paternal state is regulated by specific social and environmental cues that may contain reliable information about ecological conditions that favor paternal care. 相似文献
230.
Making external attributions for negative events, though often considered “self-serving,” also implies that the attributor is not in control of critical resources. We hypothesized that making external attributions for negative events will lead to impressions of powerlessness. Because individuals in high-status roles are expected to have power and control, external attributions may violate these role expectations; thus, we further hypothesized that status would moderate the relationship between attributions and interpersonal outcomes. Specifically, more negative impressions and affect will be directed toward high-status individuals who make external attributions than toward their lower status counterparts. Three studies were conducted, one using a role-play methodology, one using an experimentally created hierarchy, and one using vignettes. The results supported our hypotheses: external attributions can be highly disserving for people in high-status positions. 相似文献