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This article examines the spatial relationships between avatars (i.e., graphical identities or icons) over time in a 2-dimensional online chat environment. The Spatial Distance Analysis Program (SDAP) was developed to measure the distance between avatars in a specially designed Palace environment. Correlations between distance and interpersonal communication constructs of (1) conversational appropriateness, (2) social attraction, and (3) uncertainty reduction indicate that distance effects are significant in an online environment. Specifically, it was found that general conversational appropriateness mediated between uncertainty reduction and specific conversational appropriateness for individuals who moved closer together and farther apart over time, respectively. Furthermore, the relationship between social attraction and distance indicated a significant positive parabolic function; that social attraction (i.e., liking) decreased at middle distances and increased at low and high distances. This finding suggests that there are three interpersonal distance zones in online communication.  相似文献   
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This investigation consolidated the recent research on gender differences in self-concept among children and youth by conducting a systematic meta-analysis of research published since 1980, particularly involving self-concept as a multidimensional phenomenon. Through a comprehensive search process, 22 studies representing over 19,000 child and adolescent participants were analyzed. The articles included participant samples from 7 nations: the US, Australia, Northern Ireland, South Africa, Finland, Norway, and Canada. Participants ranged from 1st grade through 12th grade. Mean effect size estimates across dimensions showed a complex pattern of gender differences and similarities, some of which were consistent across grade levels and others of which were not. Although some of the findings defied stereotypes, several were consistent with previous notions regarding differences in self-concept based on gender. The direction and complexity of these results emphasizes the importance of discussing developmental differences in self-concept in a thoughtful and careful manner and argues against the use of simplistic global generalizations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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This study focused on the use of callous–unemotional (CU) traits to identify a subgroup of children with both attention deficit/hyperactivity disorder (ADHD) and a conduct problem diagnosis (oppositional defiant disorder [ODD] or conduct disorder [CD]) who show characteristics similar to adults with psychopathy. In a clinic-referred sample of children aged 6 to 13 years (N?=?154), those with diagnoses of both ADHD and ODD/CD were divided on the basis of teacher ratings of CU traits. Children high on these traits showed features typically associated with psychopathy, such as a lack of fearfulness and a reward-dominant response style. Furthermore, children with CU traits seemed less distressed by their behavior problems. These findings are consistent with research on adults showing that impulsivity and antisocial behavior alone are insufficient to document persons who fit the construct of psychopathy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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To better understand the transmission and epidemiology of human listeriosis, 647 Listeria monocytogenes isolates obtained from human listeriosis cases in four U.S. locations (Michigan, Ohio, New York State, and New York City) over 61 months (1998 to 2003) were characterized by automated EcoRI ribotyping. A total of 65 ribotypes were differentiated among the characterized isolates; 393, 227, and 24 isolates were classified into lineages I, II, and III, respectively, and 3 isolates were not classified to lineage. The three most common ribotypes (responsible for 39% of all cases) represented L. monocytogenes epidemic clones, each of which had previously been linked to at least two human listeriosis outbreaks. Categorical analyses revealed that ribotypes and lineages were nonrandomly distributed among the four locations. Temporal cluster analysis of cases identified 13 statistically significant temporal subtype clusters, which represented 26% of all cases. Three of these clusters matched previously described human listeriosis outbreaks. Isolates involved in clusters belonged to nine ribotypes. Four, eight, and one cluster were caused by lineages I, II, and III, respectively. The two largest clusters were both caused by the epidemic clone representing ribotype DUP-1044A. Categorical analyses revealed no significant associations between lineage or ribotype and clinical manifestation (central nervous system infection, septicemia, fetal infection, or other infection) or disease outcome (fatal or not fatal). Although human listeriosis cases are caused by isolates belonging to a diversity of EcoRI ribotypes, specific lineage I epidemic clones cause a large number of human listeriosis cases. Many human listeriosis cases can be grouped into statistically significant temporal clusters, including widely distributed and region-specific clusters associated with isolates of various ribotypes. L. monocytogenes lineages and EcoRI ribotypes do not appear to differ in their likelihood of causing different clinical manifestations or mortality.  相似文献   
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The floss and oil of the common milkweed (Asclepias syriaca L.) seeds are currently used to produce comforters/pillows and skin care products, respectively. As an outcome of these products, copious quantities co-products (pressed seed meal and pod biomass) are disposed of each year despite the presence of potential health benefitting lipids. The objective of this project was to determine the feasibility of developing the lipid fraction from of these co-products for the fast growing dietary human health market. Although certain types of lipids were affected by the extraction solvent used (hexane and diethyl ether) as were overall amounts, analysis of the each extract showed novel lipid profiles with several potential health benefitting agents present at levels comparable to or exceeding those present in other typically consumed dietary oils or food systems (vitamin E, carotenoids, sterols and unsaturated free fatty acids, particularly the both omega 7-fatty acids).  相似文献   
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