The Role of Lipolysis in Regulating Plasma Glucose Concentrations in Mourning Doves

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Description
Birds have unusually high plasma glucose concentrations compared to mammals of similar size despite their high metabolic rate. While birds use lipids as their main source of energy, it is still unclear how and why they maintain high plasma glucose

Birds have unusually high plasma glucose concentrations compared to mammals of similar size despite their high metabolic rate. While birds use lipids as their main source of energy, it is still unclear how and why they maintain high plasma glucose concentrations. To investigate a potential underlying mechanism, this study looks at the role of lipolysis in glucose homeostasis. The purpose of this study is to examine the effects of decreased glycerol availability (through inhibition of lipolysis) on plasma glucose concentrations in mourning doves. The hypothesis is that decreased availability of glycerol will result in decreased production of glucose through gluconeogenesis leading to reduced plasma glucose concentrations. In the morning of each experiment, mourning doves were collected at the Arizona State University Tempe campus, and randomized into either a control group (0.9% saline) or experimental group (acipimox, 50mg/kg BM). Blood samples were collected prior to treatment, and at 1, 2, and 3 hours post-treatment. At 3 hours, doves were euthanized, and tissue samples were collected for analysis. Acipimox treatment resulted in significant increases in blood glucose concentrations at 1 and 2 hours post- treatment as well as renal triglyceride concentrations at 3 hours post-treatment. Change in plasma free glycerol between 0h and 3h followed an increasing trend for the acipimox treated animals, and a decreasing trend in the saline treated animals. These results do not support the hypothesis that inhibition of lipolysis should decrease blood glycerol and blood glucose levels. Rather, the effects of acipimox in glucose homeostasis appear to differ significantly between birds and mammals suggesting differing mechanisms for glucose homeostasis.
Date Created
2015-05
Agent

THE EFFECT OF SUPPLEMENTAL INSTRUCTION ON STUDENTS' PERCEIVED SELF-EFFICACY

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Description
Supplemental Instruction (SI) is a well-known non-remedial academic support program for high-risk courses, not students. The program offers regular SI study sessions open to all students, and attendance is voluntary. SI has been shown to decrease the number of failure

Supplemental Instruction (SI) is a well-known non-remedial academic support program for high-risk courses, not students. The program offers regular SI study sessions open to all students, and attendance is voluntary. SI has been shown to decrease the number of failure and withdrawals and to increase students' grades by one half to a full letter grade. A recent study has shown that SI bridges the gap in achievement between students who enrolled in college with low prior achievement and students with high prior achievement. Another study has shown that students of different academic abilities can all benefit from SI. It is well established in the education literature that perceived self-efficacy is an accurate predictor of academic performance and retention in college. Many of these studies have defined perceived self-efficacy as the belief in one's ability to excel in a task or achieve a goal. While many studies tackle the effectiveness of SI and its benefits to SI attendees and SI leaders, no prior study has examined the role of SI in fostering self-efficacy. The purpose of the study is to examine the relationship between perceived self-efficacy, attendance to SI sessions and academic performance. The hypothesis of this study is that attendance to SI sessions will increase students' self-efficacy. The SI participants in the high attendance group had marginally significant changes in self-efficacy while the SI participants in the low attendance group and the non-SI participants did not have significant changes in self-efficacy. The results from this study showed promising outlook that SI might be fostering self-efficacy and enhancing students' academic achievement. Additional studies are required to provide deeper insights into the role of supplemental instruction in fostering self-efficacy.
Date Created
2015-05
Agent