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961.
962.
We analysed, under laboratory test conditions, how German cockroach larvae oriented their outgoing foraging trip from their
shelter. Our results stressed the importance of external factors, like availability and spatial distribution of food sources,
in the choice of a foraging strategy within their home range. When food sources were randomly distributed, larvae adopted
a random food search strategy. When food distribution was spatially predictable and reliable, cockroaches were able to relate
the presence of food with a landmark during a 3-day training period and to develop an oriented search strategy. Cockroaches
were able to associate learned spatial information about their home range to the presence of food resources and then to improve
their foraging efficiency. However, conflict experiments revealed that detection of food odour overrode learned landmark cues.
Received: 16 October 1999 / Accepted after revision: 18 July 2000 相似文献
963.
The study of paraconsistent logic as a branch of mathematics and logic has been pioneered by Newton da Costa. With the growing advent of distributed and often inconsistent databases over the last ten years, there has been growing interest in paraconsistency amongst researchers in databases and knowledge bases. In this paper, we provide a brief survey of work in paraconsistent databases and knowledge bases affected by Newton da Costa's important and lasting contributions to the field. 相似文献
964.
Peter Muris Merel Kindt Susan Bögels Harald Merckelbach Björn Gadet Véronique Moulaert 《Journal of psychopathology and behavioral assessment》2000,22(2):183-199
The current study examined the relationship between childhood anxiety and threat perception abnormalities. Children (N = 105) were exposed to stories reflecting three types of anxiety: social anxiety, separation anxiety, and generalized anxiety. From children's reactions to the stories, a number of threat perception indices were derived. Children's level of anxiety was assessed by means of questionnaires and a structured diagnostic interview. Results indicated that high levels of anxiety, as measured by questionnaires and interview, were accompanied by a high frequency of threat perception, high ratings of threat, a high frequency of threatening interpretations, high levels of negative feelings and cognitions, and an early detection of threat. Furthermore, results seemed to suggest that threat perception abnormalities were mediated by children's general level of anxiety rather than by levels of specific anxiety symptoms. 相似文献
965.
Bacterial meningitis is a life threatening infection of the central nervous system. This illness is most prevalent early in life when the healthy child is rapidly acquiring language. This study investigated whether children with a history of bacterial meningitis were at risk for language difficulties post illness. Thirty post-meningitic children, aged between 9 years 0 months and 11 years 0 months, participated in this study. Each subject was administered a measure of non-verbal cognitive ability and a range of language tasks. These children performed poorly on applied language tasks, which tap skills used in effective discourse. These deficits occurred despite age appropriate performances on measures of linguistic/grammatical knowledge. These findings clearly illustrate that bacterial meningitis has implications for ongoing language development, which emphasises the importance of long term follow up. In developmental terms, this discrepancy between verbal knowledge and problem solving represents a dissociation between language skills which develop early in life and those which emerge later. This pattern of results suggests that bacterial meningitis may result in a delay in language development. A young age at illness was identified as an additional risk factor for adverse outcome. This study highlights the need to inform parents/guardians that post-meningitic children are at risk for experiencing language difficulties throughout childhood. 相似文献
966.
Research on the benefits of social support groups has been inconclusive. One reason is that individual differences in intervention responses have rarely been examined. The authors determined the extent to which individual difference variables moderated the effects of an information-based educational group and an emotion-focused peer discussion group on the mental and physical functioning of women with breast cancer (n = 230). The authors administered the SF-36 (S.E. Ware, K.K. Snow, M. Kosinski, & B. Gandek, 1993), a multidimensional quality of life instrument, pre- and postintervention. Educational groups showed greater benefits on the physical functioning of women who started the study with more difficulties compared with less difficulties (e.g., lacked support or fewer personal resources). Peer discussion groups were helpful for women who lacked support from their partners or physicians but harmful for women who had high levels of support. Implications of these results for clinical interventions are discussed. 相似文献
967.
968.
This paper offers new insights into the behavioural origins of the ‘favourite–longshot’ bias — an established feature of betting markets, whereby longshots win less often than the subjective probabilities imply and favourites more often. A number of alternative explanations has been offered for this phenomenon but the main debate focuses on whether it is caused by the behaviour of those supplying betting markets (bookmakers) or of the demand‐side agents in these markets (bettors) . This study analyses a new data source which offers detailed information for a large sample of recent UK horseraces on decision‐making behaviour within the parimutuel and the parallel bookmaker‐based betting markets. The results offer strong evidence for the existence of the ‘favourite–longshot’ bias in bookmaker‐based markets, with a corresponding absence of such an effect in the parimutuel case. These results offer support for the view that the origins of the ‘favourite–longshot’ bias lie principally in the decisions of bookmakers rather than in the decisions of bettors. Copyright © 2000 John Wiley & Sons, Ltd. 相似文献
969.
970.
We report results of an experiment designed to test a principle formulated by Budescu and Wallsten (1995), that, when communicating uncertainty information, mode choices are sensitive to sources and degrees of vagueness. In addition, we examined subjects’ efficacy in using such uncertainty information as a function of communication mode, source, and vagueness. In phase one of the experiment, subjects in a dyad used precise (numerical) or imprecise (verbal) expressions to communicate to a remote partner precise or vague uncertainty about the likelihoods of events. Spinner outcomes were used to generate precise uncertainty while answers to almanac questions were used to elicit vague uncertainty. In phase two, subjects saw the events paired with their partners’ estimates of similar events, and were asked to gamble on one event from each pair. Communication mode preferences were measured as the relative frequency that subjects chose the numerical mode to either express or receive uncertainty information regarding the events. Efficacy was measured as the relative frequency that subjects choose from the pair the event associated with the objectively more probable uncertainty expression. Underlying uncertainty interacted with direction of communication to affect preferences for modes of expression of the probabilities. Subjects preferred precise (numerical) information, especially for precise events (spinners). For vague events (questions), their preference for precise (numerical) information was stronger when receiving than when communicating information. Similar preferences were reflected in the efficiency of subsequent gamble decisions based on the probability estimates. Specifically, decisions were more efficacious (i.e. consistent with Expected Utility) when degrees of precision in events and estimates matched. © 1997 by John Wiley & Sons, Ltd. 相似文献