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941.
In two experiments, we examined how preexposure to discriminative stimuli and introduction of a 21-day retention interval
affected the latent inhibition (LI) and perceptual learning (PL) of rats in a choice-maze discrimination task. Experimental
groups were preexposed to three wall patterns, one in each of three arms of a maze. Control groups were preexposed only to
white arms. PL groups were trained to discriminate A versus B, and LI groups, to discriminate A or B versus C. The A and B
patterns shared many elements not shared with the C pattern. In Experiment 1, both at the end of training and after the subsequent
retention interval, the PL groups performed better than controls, whereas the LI groups performed worse. In Experiment 2,
inserting the 21-day retention interval between preexposure and discrimination training disrupted final measures of LI but
not PL performance. Implications for current concepts of PL and LI are discussed. 相似文献
942.
We tested a California sea lion for visual oddity learning by presenting problems composed of three two-dimensional black-and-white
stimuli, two identical (S−) and one different (S+). In the first experimental stage, a single problem per session was presented
until learning criterion was reached. In the second experimental stage, all problems were presented only five times in succession;
then a new problem was introduced (six problems/session). In the third experimental stage, each problem was presented only
once. The sea lion mastered all stages of oddity learning. A final transfer test with oddity problems composed of completely
new stimuli yielded performance significantly above chance. Data analyses suggested learning of specific stimulus properties
in the first stage, learning set formation in the second stage, but oddity conceptualization in the third stage. 相似文献
943.
OBJECTIVE: To determine whether there is an age-specific incidence of hospitalized cases of Shaken Baby Syndrome (SBS) that has similar properties to the previously reported "normal crying curve," as a form of indirect evidence that crying is an important stimulus for SBS. DESIGN AND SETTING: The study analyzed cases of Shaken Baby Syndrome by age at hospitalization from hospital discharge data for California hospitals from October 1996 through December 2000. PATIENTS: All cases of children less than 18 months (78 weeks) of age for whom the diagnostic code for Shaken Baby Syndrome (995.55) in the International Classification of Disease, Ninth Edition, Clinical Modification was assigned. RESULTS: There were 273 hospitalizations for SBS. Like the "normal crying curve," the curve of age-specific incidence starts at 2-3 weeks, has a clear peak, and declines to baseline by about 36 weeks of age. In contrast to the normal crying curve that peaks at 5-6 weeks, the peak of SBS hospitalizations occurs at 10-13 weeks. CONCLUSIONS: The age-specific incidence curve of hospitalized SBS cases has a similar starting point and shape to the previously reported normal crying curve but the peak occurs about 4-6 weeks later. Of the likely predisposing causes, this pattern is only consistent with the properties of early crying. There are numerous explanations for the lag in the peaks between crying and SBS hospitalizations, including the possibility of repeat shakings prior to hospitalization. The importance of crying as a stimulus to SBS may provide an opportunity for preventive intervention. 相似文献
944.
Information literacy, often described as a person's ability to effectively find and evaluate answers to questions using a variety of information resources, is of particular importance to health care workers. This paper presents the results of an information literacy survey presented to occupational therapy (OT) students at Thomas Jefferson University during a series of required class activities. Also described are the authors' activities with the faculty and courses at Jefferson. The survey was made available to first-, second-, third-, and fourth-year occupational therapy students along with nursing students and pharmacy students. The survey is designed to identify research habits, skills, and preferences. Results confirm some commonly held perceptions about searching skills of young adults and an interesting dichotomy in students' learning habits. The paper concludes with a discussion of recommendations to OT faculty and librarians on how to improve information literacy education. The survey can be obtained by contacting the authors. 相似文献
945.
The experience gained in the development of the system of simulation modeling of intelligent agent interaction (SMIAI) is
described. It is based on the general model of agent interaction proposed by G.V. Rybina, who developed the works on intelligent
dialog systems, including the well-known Popov’s communication model, in the late 1990s. The goal of SMIAI is to validate
the applicability of the proposed models, methods, and algorithms of intelligent agent interactions and their architecture
in developing MAS prototypes for different problem areas. The SMIAI architecture, support means for simulation experiments,
transmission and processing of messages, and other components are considered. Realized MAS prototypes for several applications
are presented as examples. The models of local, thematic, and global dialog structure for intelligent agents are presented
and the problems of intelligent agent communications behavior formation are analyzed. The creation of the models under consideration
by means of G2 and Microsoft Visual Studio is described. 相似文献
946.
947.
The problem of independent force and position control of multitask cooperating manipulators is studied. Each manipulator is in a non-singular configuration and the object can be driven by the contact forces exerted by the end effectors of the manipulators. The design requirement is to control each coordinate of the position of the object as well as each component of the “rest” forces, except the moving forces that are determined uniquely from the object's position. The present design requirement has been proved to be always satisfied together with asymptotic and BIBO stability. A class of controllers solving the above simultaneous problem is analytically determined. The proposed state feedback controller does not depend upon the specific object dynamics and thus the resulting closed-loop multimanipulator system performs as required, not only when handling various objects but also when the dynamics of the objects are unknown or hard to compute or disturbed by external forces. 相似文献
948.
949.
950.
Abstract The ideal of bildung as a goal for higher education and research (HER) in European Union member states is losing ground to more pragmatic goals such as innovation and growth. This shift in the policy perspective about the role of science in society has given rise to a system of multi layered governance which in turn is progressively giving rise to the emergence of a new normative regime for the HER sector. This normative regime involves the blurring of boundaries between the public and the private and the introduction of social accountability as a criterion for evaluating scientific knowledge. The paper concludes that the elision of the boundary between private and public disguises real problems about defining who owns what particularly in the light of the increasing commercialisation of public funded science. Further, the limitation of social accountability to select groups of actors who can afford to pay for influencing research raises questions about the ability of the new governance regime for HER to achieve the democratic aims that it purports to pursue. 相似文献