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991.
Learning & Behavior - Fish were allowed to choose, in a T-maze, between various combinations of goalboxes containing either food or a mirror, or nothing. Only food and a mirror maintained... 相似文献
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Morphine, which is obtained from poppies, has pharmacological properties which make it both a powerful pain-relieving drug and a narcotic feared for the dependency which it induces in those who use it. Study of the mode of action of morphine has revealed related endogenous substances in the brain. These brain opiates have remarkable properties, which researchers are just beginning to discover. 相似文献
996.
Jean J Fried 《Endeavour》1985,9(3):112-116
Because it is generally freely and plentifully available in temperate regions the importance of water tends to be under-rated. In reality, it is fundamental to the economic strength of all countries and ensuring adequate supplies in face of growing needs is of paramount importance. A comprehensive review of the water resources of the European Community reveals that while there are many regional differences — especially in the degree of dependence on ground, as opposed to surface, water — overall supplies are adequate, but only if very carefully managed. 相似文献
997.
Testosterone during Pregnancy and Gender Role Behavior of Preschool Children: A Longitudinal, Population Study 总被引:2,自引:1,他引:2
Melissa Hines Susan Golombok John Rust Katie J. Johnston Jean Golding & Avon Longitudinal Study of Parents Children Study Team 《Child development》2002,73(5):1678-1687
Levels of testosterone (T) and sex hormone–binding globulin (SHBG) were measured in blood samples from pregnant women and related to gender role behavior in 342 male and 337 female offspring at the age of 3.5 years. Gender role behavior was assessed using the Pre–School Activities Inventory, a standardized measure on which a parent indicates the child's involvement with sex–typical toys, games, and activities. Levels of T, but not SHBG, related linearly to gender role behavior in preschool girls. Neither hormone related to gender role behavior in boys. Other factors, including the presence of older brothers or sisters in the home, parental adherence to traditional sex roles, the presence of a male partner in the home, and maternal education, did not relate to gender role behavior in this sample and did not account for the relation observed between T and behavior. Although other, unmeasured factors may explain the relation, the results suggest that normal variability in T levels prenatally may contribute to the development of individual differences in the gender role behavior of preschool girls. 相似文献
998.
Mother-Child Relationships as Sources of Support or Stress: A Comparison of Competent, Average, Aggressive, and Anxious Dyads 总被引:1,自引:0,他引:1
We tested the proposition that mother-child relationships can be sources of support or stress, by comparing patterns of mother-child interactions in a problem-solving task that children completed with their own and with an unfamiliar mother. 4 groups of preschoolers (n = 30 in each group)—identified on the basis of teacher ratings as socially competent, average, aggressive, or anxious—participated. Mothers of competent and average children were highly positive and reciprocal toward their own and unfamiliar children. Mothers of aggressive and anxious children were only positive and reciprocal toward unfamiliar children but generally indiscriminate (aggressive group) or aversive and negatively reciprocal (anxious group) toward their own. Children in all 4 groups tended to be reciprocal toward their own mothers, but only competent and average children were reciprocal toward unfamiliar mothers also. Aggressive and anxious children generally responded to unfamiliar mothers by ignoring or actively rejecting their overtures. Results (1) indicate that the relationship with the primary caregiver may serve as a major source of support or stress in the preschool years; (2) focus attention on the dynamic organization of interactions rather than on the presence or frequency of particular behaviors, indicating that a dynamic of reciprocity enables children and mothers to adapt positively to the ever changing demands of new social situations; (3) point to the need to develop new means of assessing relationships to better understand how they influence development; and (4) highlight the importance of incorporating transactional models in the diagnosis and treatment of childhood dysfunctions rather than accounting for them solely in terms of limited skills in parents or children. 相似文献
999.
The purpose of this paper is to address the question of whethercomputer source code is speech protected by the First Amendmentto the United States Constitution or whether it is merelyfunctional, a ``machine', designed to fulfill a set task andtherefore bereft of protection. The answer to this question is acomplex one. Unlike all other forms of ``speech' computer sourcecode holds a unique place in the law: it can be copyrighted, likea book and it can be patented like a machine or process.Case law, intellectual property law and encryption exportregulations all reflect this contradictory dichotomy. 相似文献
1000.
The football shirt is of iconic significance, defining a club's visual identity through its role as sporting uniform and fan identifier, providing a canvas for commercial interactions and increasingly acting as the focus of nostalgia and collector culture. In this article we focus on the football shirt's extension from sportswear to a replica product worn as cross-generational leisurewear. We first consider how a replica's authenticity, its principal attribute, exists in objective, constructive and existential contexts. We then demonstrate how the subsequent focus of kit manufacturers and clubs on satisfying these differing interpretations of authenticity has influenced football shirt design. For two decades, replica kits were marketed as sportswear to children, with attempts to enhance the football shirt's authenticity through distinctiveness and exclusivity leading to copyrighted designs, manufacturer's logos and increased patterning. However, as the replica football shirt became adult leisurewear, the changing customer base led to retrospective and recycled shirt designs proclaiming a club's distinct identity through its heritage, fulfilling fans' nostalgic interpretations of a club's authentic kit, and reflecting fans' use of replica shirts to display their authenticity as a genuine fan. These ideals have also inspired a parallel retro-replica industry and, we argue, caused stagnation in the development of the aesthetic elements of contemporary kit design, which had previously demonstrated innovation interspersed with periods of consolidation, but had taken few retrospective turns. Genuine innovation in football shirt design has increasingly become restricted to technological advances and marketing strategies. 相似文献