Effect of cholesterol and cholestyramine feeding and of fasting on sterol synthesis in the liver, lleum, and lung of the guinea pig

The effects of feeding diest containing either cholesterol (0.24% w/w) or cholestyramine (2.5% w/w) and of fasting on sterol synthesis in the liver, ileum, and lung of both male and female guinea pigs have been studied by measuring the incorporation by tissue slices of 14C-labeled acetate into total digitoninpredipitable sterols. Cholesterol feeding significantly decreased (P less than 0.05) sterol synthesis in the liver, ileum, and lung of the males and in the ileum of females. Cholestyramine feeding stimulated the rate of hepatic sterol synthesis 13-fold but did not significantly affect sterologenesis in the ileum. Sterol synthesis in the lung was significantly increased (P less than 0.05) but to a much lesser extent than in the liver. Fatty acid synthesis in the liver, ileum, and lung was not significantly affected by either cholesterol or cholestyramine feeding. In guinea pigs fasted for 24 hr, sterol synthesis was inhibited in all three tissues, the most pronounced effect occurring in the liver. Only in the lung was fatty acid synthesis significantly decreased (P less than 0.001) by fasting. Cholesterol feeding resulted in increased concentrations of cholesterol in the plasma and liver. Cholestyramine feeding reduced plasma cholesterol concentration by 81% in females and by 64% in males. However, it did not significantly change the tissue cholesterol concentrations. Fasting resulted in a significant increase (P less than 0.05) in plasma cholesterol concentration but did not effect the concentration of cholesterol in the tissues. It was concluded that in the normal guinea pig, the feedback inhibition produced by both cholesterol and also possibly by bile acids suppresses sterol synthesis in the liver to very low rates compared to those in the small intestine, where sterologenesis is not only less sensitive to the cholesterol negative feedback system than that in the liver, but also is not subject to regulation by the bile acid negative feedback system.     

Virtual agent multimodal mimicry of humans

This work is about multimodal and expressive synthesis on virtual agents, based on the analysis of actions performed by human users. As input we consider the image sequence of the recorded human behavior. Computer vision and image processing techniques are incorporated in order to detect cues needed for expressivity features extraction. The multimodality of the approach lies in the fact that both facial and gestural aspects of the user’s behavior are analyzed and processed. The mimicry consists of perception, interpretation, planning and animation of the expressions shown by the human, resulting not in an exact duplicate rather than an expressive model of the user’s original behavior.     

Situational influences on ethical decision-making in an IT context

Processes of ethical decision-making are thought to depend on the issue faced when making the decision. We examined the processes by examining student's reactions to five scenarios involving IT use. Data were collected using a questionnaire following a group discussion. The results showed that ethical decision-making processes did indeed vary by scenario, suggesting that a single-issue approach is inadequate for studying ethical decision-making. Perceived importance of the ethical issue was a factor in the scenarios, but it did not have an all-inclusive influence on the decision-making of the participants. The results were considered in the context of theories and Mason's ethical issues of the information age. We offer advice to managers on how to limit unethical behavior.     

Computer-mediated group influence on ethical behavior

Drawing on previous research in ethical behavior in information technology, this study examines the effects of group discussion, using virtual teams, on an individual’s intention to behave ethically/unethically. It was hypothesized that behavioral intention would be influenced by an individual’s attitude (toward ethical behavior), personal normative beliefs, ego strength, locus of control, perceived importance, gender and the scenario, and that computer-mediated group discussion would impact an individual’s ethical behavioral intention. This was tested through an experiment using five different ethical scenarios involving information technology. The results show that for two of the five scenarios, individual behavioral intention was significantly more unethical after computer-mediated group discussion than before, while for one scenario, individual behavioral intention was significantly more ethical after computer-mediated group discussion than before. The results of this study may help organizations to develop realistic training programs for IT professionals that account for changes in employee’s personal ethical models after interacting with others.     

Virtual Human versus Human Administration of Photographic Lineups

One solution to mistaken identification by a crime's victims and eyewitnesses is to use a virtual officer to conduct identification procedures. Results from a study comparing a virtual officer with a live human investigator indicate that the virtual officer performs comparably to the human in terms of identification accuracy, emotional affect, and ease of use.     

Parent-child interactions during the initial weeks following brain injury in young children.

Objective: To understand how traumatic brain injury (TBI) affects parent-child interactions acutely following injury. Participants: Young children hospitalized for TBI (n = 80) and orthopedic injuries (OI; n = 113). Method: Raters coded videotaped interactions during free play and structured tasks for parental warmth/responsiveness and negativity and child warmth, behavior regulation, and cooperation. Raters also counted parental directives, critical/restricting statements, and scaffolds. Results: Parents of children with TBI exhibited less warm responsiveness and made more directive statements during a structured task than parents in the OI group. Children with TBI displayed less behavior regulation than children with OI. Parental warm responsiveness was more strongly related to child cooperativeness in the OI group than in the TBI group. Child behavior also mediated group differences in parental responsiveness and directiveness. TBI accounted for as much variance in parental behaviors as or more than did sociodemographic factors. Conclusion: TBI-related changes in child behavior may negatively influence parent-child interactions and disrupt the reciprocity between parent and child. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Behavioral medicine and aging.

A brief history of behavioral medicine and aging is followed by a series of perspectives that help to understand how age is used as a variable in this research, the relative importance of age to declines in cognitive functioning, and the impact of behavioral risk indicators on healthy survival. The authors discuss Alzheimer's disease and the role of age in clinical practice. Also discussed are potential problems in age-related research, ways to improve the knowledge base in behavioral medicine and aging, and thoughts about future challenges to enhance work in behavioral medicine and aging. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of encoding task on age-related differences in the functional neuroanatomy of face memory.

Age-related differences in brain activity mediating face recognition were examined using positron emission tomography. Participants encoded faces using a pleasant-unpleasant judgement, a right-left orientation task, and intentional learning. Scans also were obtained during recognition. Both young and old groups showed significant effects of encoding task on recognition accuracy, but older adults showed reduced accuracy overall. Increased brain activity in older adults was similar to that seen in young adults during conditions associated with deeper processing, but was reduced during the shallow encoding and recognition conditions. Differential correlations of brain activity and behavior were found that suggest older adults use unique neural systems to facilitate face memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cardiovascular responses to treadmill and cycle ergometer exercise in children and adults

This study was conducted to determine whether submaximal cardiovascular responses at a given rate of work are different in children and adults, and, if different, what mechanisms are involved and whether the differences are exercise-modality dependent. A total of 24 children, 7 to 9 yr old, and 24 adults, 18 to 26 yr old (12 males and 12 females in each group), participated in both submaximal and maximal exercise tests on both the treadmill and cycle ergometer. With the use of regression analysis, it was determined that cardiac output (Q) was significantly lower (P 相似文献