The effect of intracerebroventricular (ICV) injection of corticotrophin releasing hormone (CRH) and related compounds on appetite, behavior, and gastric motility in lines of chickens, one selected for low body weight (LWS) and the other high body weight (HWS), was determined. Nucleotide sequence and expression patterns of the CRHr2 receptor, involved in appetite regulation, were also determined. Some individuals of the LWS line are anorexics and many die simply from not eating while some individuals in the HWS line are compulsive eaters and exhibit obesity. CRH is a 41 residue peptide that initiates an organism's stress response and is a potent inhibitor of appetite. An ICV injection of CRH dose-dependently decreased feed intake in both lines but did not effect water intake. When CRH receptor antagonists were ICV injected an increase in feed intake in the LWS line but not in the HWS line was observed, however the appetite reducing effect of CRH was attenuated in the HWS line but not in the LWS line. The LWS line has higher concentration of corticosterone than does the HWS line. In both lines at all times treatment with CRH caused an increase in locomotion and no CRH-treated chicks from either line slept post injection. Chicks from the LWS line that were treated with CRH exhibited other anxiety related behaviors sooner than the HWS line. The LWS line showed a liner increase in crop emptying time as the dose of ICV CRH increased. The HWS line responded with a quadratic dose response to CRH treatment. Polymorphisms in the CRHr2 receptor were found in both lines in the same positions, thus we concluded these differences do not significantly contribute to body weight differences. However, differences detected in expression patterns between lines for the CRHr2 receptor may contribute to their different body weights. We conclude that differences in the CRH system, its concentrations and differential receptor action, of these two lines may be partly responsible for their altered body weight phenotype. / Ph. D.

No description available.

A research report submitted to the Faculty of Health Sciences, University of the Witwatersrand, in partial fulfillment of the requirements for the degree of Master of Medicine in the branch of Psychiatry Johannesburg, 2017 / Introduction. Eating disorders are an important group of mental illnesses in Psychiatry. The aetiology is multifactorial, developing from distorted beliefs around body image and shape, with resultant abnormal eating behaviours. This study explores the views and perceptions of a group of university students regarding their peers’ body image and shape and eating behaviours, which they experienced (at the time) during their senior high school years. The majority of these students attended high schools in Johannesburg. Method. This was an explorative, qualitative study using qualitative methods. A sample of 153 participants was voluntarily recruited from students in the Faculty of Health Sciences at the University of the Witwatersrand. A manually distributed anonymous questionnaire was used, with questions about their high school peers’ personality traits, early and late childhood experiences, eating behaviour, and the last three years of high school environment. Questions in each section were deconstructed and categorised into subthemes. Subthemes were further deconstructed into replicated ideas. These subthemes and ideas were presented in hierarchical tables. Findings in this study were compared with the literature. Results. The most commonly described subtheme of participants’ perceptions of high school peers’ personality traits was “poor self-confidence”. The most replicated subthemes of views on peers’ childhood experiences were “personal conflict with members of the family”, “a disruptive home environment” and “mother’s attitude”. In terms of peers’ eating behaviour, a subtheme on “body shapes” included “fat”, “skinny” and “fit” and “muscular” bodies. In terms of the high school environment, the subtheme of “bullying and peer discrimination” was regarded as important, while “the impact of media” was regarded as extremely important. Fifty percent of participants viewed body image to be important for social status. There were mixed views on whether specific programmes should be introduced to identify pupils at risk. Conclusion. Although bullying and peer pressure have been described as contributing factors in the development of eating behaviour problems in high school learners, as perceived by a group of university students, the most prominent potential contributing factor considered was the media, specifically social media. This finding could contribute to further research looking at the role of social media, not only its relationship in the potential development of a Psychiatric Illness, but possibly, too, its role in the educational and rehabilitation process. / MT2017

The first objective of this study was to validate the feeding behavior measurements from a radio frequency electronic system (GrowSafe (TM) System Ltd., Airdrie, AB, Canada) and examine the software sensitivity to different parameter settings (MPS) to quantify feeding behavior traits. Data was continuously recorded 24 h per day using the GrowSafe™ system for 32 heifers over 81-d. Ten animals were randomly selected and evaluated over 6-d using time-lapse video recordings. Different parameter settings (MPS) from the electronic system (GrowSafe (TM)) used to record feeding behavior data, bunk visits (BV) frequency and BV duration, were compared with the observed (video) values. The second objective of this study was to quantify meal criterion; examine the associations between feeding behavior traits, performance, and feed efficiency; and the effects of breed type on feed efficiency (residual feed intake - RFI) and feeding behavior traits in heifers fed high-grain diets. Results from study one demonstrated that the GrowSafe (TM) system 4000E could accurately predict BV and meal data compared to observed data. The 100 s, used for the maximum duration between consecutive EID recordings to end an uninterrupted BV, was the appropriate MPS to predict BV frequency and duration, and meal frequency and duration compared to observed data using the GrowSafe (TM) 4000E system. The system’s ability to detect the animal’s presence or absence at the feed bunk was 86.4 and 99.6 percent, respectively. Results from the second study demonstrated that the meal criterion for heifers fed high-grain diets was 13.8 min. The 4 methods to calculate meal criterion demonstrated no differences in results of frequencies and durations of meal and the number of bunk visits per meal. Similar phenotypic correlations were found between the feeding behavior traits with RFI derived from the base model or with adjustments for final back fat. The adjustment of RFI to final back fat changed the RFI rank between breeds. The addition of feeding behavior traits to the RFI base model could accounted up to 40.4 percent of the variation in DMI not explained by ADG or MBW.

Diss. (sammanfattning) Göteborg : Göteborgs universitet, 2007. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Washington, 1997. / Vita. Includes bibliographical references (leaves [97]-104).

Thesis (M.S.)--University of Wisconsin-Madison, 1993. / Typescript. eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references (leaves 80-87).

We analyzed the relationship between prey capture and nematocyst distribution in the tentacles of the ambush predators, Aglantha digitale and Proboscidactyla flavicirrata, and the filter feeders, Clytia gregaria and Mitrocoma cellularia. we used video observations to compare capture locations of Artemia salina nauplii relative to the bell margin of each species. Tentacle pictures were analyzed to determine if nematocyst abundance changes along their length. By analyzing behavior and morphology simultaneously, we found that the ambush predators A. digitale and P. flavicirrata plus Sarsia tubulosa have higher nematocyst density at the tentacle tips and tend to capture more prey toward the tips. In contrast, the filter-feeders Aequorea victoria, C. gregaria and M. cellularia capture most of the prey close to the body, where they also show a slight increase in nematocyst densities.

The first aim of this dissertation was to monitor both rat and human responses to short-term perturbations in energy balance brought about through food energy restriction and refeeding, exercise training and the cessation of exercise training or surgical lipectomy. The second aim of this dissertation was to identify factors which might explain differences in food energy intake in weight-matched, weight-stable "large and small eaters". The final aim of this dissertation was to identify factors which might explain differences in resting energy expenditure in a large sample of weight-stable men and women, including exercising and non-exercising persons, and including persons who may be regarded as "restrained eaters".

archives@tulane.edu / In a laboratory setting, mosquito blood feeding is an essential step in investigating many aspects of mosquito biology. Standard laboratory procedures often place the blood membrane feeder on top or inside the cage. Previous research has suggested that blood feeding position improves mosquito feeding but was limited to vertical and horizontal placements. To enhance the current understanding of mosquito feeding behavior, this study sought to further optimize feeding at multiple angles between 0° and 180°. Aedes aegypti Rockefeller, field-derived New Orleans Aedes aegypti, field-derived New Orleans Aedes albopictus and Culex quinquefasciatus Orlando were tested to evaluate blood feeding success. A Hemotek feeding membrane system was attached to a custom-designed apparatus and four distinct mosquito colonies were fed separately during 30 minute feeding trials. Once fed, all mosquitoes were placed into emergence chambers and their eggs were collected. Ae. aegypti Rockefeller, field New Orleans Ae. aegypti and Cx. quinquefasciatus Orlando fed better at all angles measured compared to the control, suggesting that this trait has a potential role in mosquito feeding behavior. Lab-adapted mosquitoes laid on average more eggs at vertical and horizontal angles, suggesting physiological constraints. Feeding angle is proven to have an impact on mosquito feeding which may help improve future mosquito feeding assays. / 1 / Chance Erik Liedig