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To determine the effects of different algal diets on freshwater mussels, tissues of Elliptio complanata were sampled for physiological, somatic, and gametogenic condition from August 1999 to May 2000. Treatments included mussels fed Scenedesmus quadricauda (S), Neochloris oleoabundans (N), a no feed treatment (NF), and a reference group of mussels from the Nottoway River (NR), Virginia. The levels of protein and glucose differed among treatments (p<0.0001), but glycogen and percentage tissue moisture did not (p>0.17). Production of ripe and developing gametes differed significantly among treatments (p=0.001), but stage of gamete development did not (p=0.70). Lipid levels and muscle fiber areas of treatment groups differed significantly (p<0.0001). Results of the feeding trial indicate that S. quadricauda is a suitable feed for E. complanata, but future experiments should identify algal species higher in carbohydrates for a mixed algal diet. To determine sex and stage of gametogenesis, tissue histological sections from gonads of Villosa iris and Utterbackia imbecillis were evaluated. Occurrences of oogenic, spermatogenic, and hermaphroditic tissues were summarized in frequency tables. Visceral sites from which similar tissues were collected from conspecific specimens were evaluated for gametogenic stage. Sex was accurately determined in the central, visceral portion V. iris and female regions of U. imbecillis; and spermatogenic tissue was consistent in the dorsal-anterior areas of U. imbecillis. These areas also provided accurate determination of gamete stage in specimens. Reproductive asynchrony was observed among males and females (p<0.02). Male regions of U. imbecillis showed gamete stage characterized by mature and developing spermatogenic tissue, while 2 groups of mussels were showed oogenic development characterized by mature oocytes and resorption of gametes. Male V. iris showed early gamete development without mature spermatozoa, and 2 groups of female V. iris showed mature and developing gametes and resorption of gametes. Protocols for biopsy tissue collection from selected visceral areas were developed for U. imbecillis and V. iris for sex determination and staging of gametogenesis. The application of this biopsy protocol should be considered population specific, and protocols appropriate for other populations and species should be developed with methods of this study. / Ph. D.

A study was conducted to assess the relationship between the zinc/copper ratio and risk factors (hypertension, obesity, elevated serum cholesterol and triglycerides, cigarette smoking, and exercise activity level) associated with susceptibility to cardiovascular disease. A questionnaire technique for assessment of physical activity was presented. The zinc/copper ratio was determined from the zinc and copper concentrations of hair samples obtained from sixty-four male subjects, ranging in age from 19 to 59 years. Correlation coefficients revealed no discernible relationship between either the zinc and copper content of hair, or the zinc/copper ratio obtained from these values. Serum cholesterol and triglyceride values, zinc concentrations in hair and the zinc/copper ratio were tested for significant differences associated with age. Statistical analysis indicated that these parameters were not significantly different. Such results were attributed to the wide range of variation within groups for this sample population. Data was not supportive of Klevay's altered zinc/copper ratio hypothesis as the major factor in the etiology of cardiovascular disease. / Ph. D.

An eight week controlled feeding study was conducted to determine the effects of dietary zinc and copper on plasma zinc, copper, total cholesterol (TC), and high density lipoprotein cholesterol (HDL-C) levels in young adult males receiving two levels of zinc. Source of dietary calcium was also varied, however possible interactions or effects of calcium were not determined in this study. Subjects consumed zinc supplements of 10 mg/day, in combination with 1 of 3 diets, resulting in zinc:copper ratios of 30: 1 (Dairy Calcium, or DC group), 20:1 (Control or CO group), and 20:1 (Calcium Carbonate or CC group). Copper content of all diets was approximately 1 mg/day. Plasma levels of zinc, copper, TC, and HDL-C did not differ significantly between the groups. However, plasma levels of copper, zinc, and HDL-C, were found to be significantly affected by the specific week of controlled feeding across all 3 groups (p<.05). Plasma copper at baseline was significantly lower than at weeks 2,4,6, 8, and post treatment. Plasma zinc at baseline, and weeks 2 and 4, was found to be significantly lower than at weeks 6, 8, and post treatment. At week 6, plasma HDL-C was noted to be significantly higher than at baseline, weeks 2, 4, 8, and post treatment. Spearman correlation coefficients determined negative correlations between plasma copper and TC (r=-0.39, p<0.04), and plasma copper and zinc (r=-0.43, p<0.02) in the DC group. A positive correlation was also noted between plasma zinc and TC (r=0.32, p<0.10) in the DC group. Plasma copper and HDL-C were determined to be negatively correlated in the CO group (r=-0.48, p<0.005). Plasma zinc and HDL-C were found to be negatively correlated in the CC group (r=-0.58, p<0.001). / Master of Science

Gizzard shad were illegally introduced to Claytor Lake in the late 1980s and soon established a thriving population. This study assessed 1) the degree to which gizzard shad were utilized by piscivores (pelagic - striped bass Morone saxatilis, hybrid striped bass M. chrysops x M. saxatilis, and walleye Stizostedion vitreum, and three littoral black basses Micropterus spp.), 2) the availability of gizzard shad as potential prey as determined from age and growth analysis, and 3) the performance (growth rates, relative weight, and relative abundance) of piscivores before versus after gizzard shad establishment. Gizzard shad were more highly utilized by pelagic predators (especially striped bass and their hybrids) than black basses. Rapid growth of gizzard shad (mean back-calculated length at age-1 = 155 mm TL) meant that almost all morphologically available shad were age-0. The reliance on one edible age class of gizzard shad resulted in an unstable food supply as evidenced by much greater striped bass shad consumption in Summer 1998 (63 % by weight) when age-0 shad were more abundant than in Summer 1997 (7 % by weight). Striped bass was the only species to exhibit faster growth rates and mean relative weight (Wr) values in the 1990s versus pre-shad years. Walleye (except age-1) and black bass growth rates declined, and mean Wr values either remained consistent or declined. Largemouth bass and walleye were the only sportfish to show increases in relative abundance. Benefits of gizzard shad as a forage fish appear to be limited to striped bass and its hybrid species. It is possible that gizzard shad have had, directly or indirectly, an adverse impact on the black basses of Claytor Lake, but explanatory analysis of these relationships was beyond the scope of this study. / Master of Science

Background: Dietary patterns that include recommended servings of fruits, vegetables, whole grains, dietary fiber, and dairy, combined with regular physical activity and frequent breakfast consumption are optimal choices for weight loss or weight maintenance over time. College students are at an increased risk for weight gain due to environmental and behavioral changes that are associated with decreased dietary quality and physical inactivity. Preventing weight gain in college students may have a profound impact on prevalence of overweight or obesity later in life. Objective: To examine associations between weight change and dietary patterns in college students. Design: A longitudinal observational study. Dietary intake and physical activity were self-reported on seven-day food records and compared to dietary guidelines for compliance with recommendations. Subjects/Setting: Data from 80 students enrolled in a fall semester introductory nutrition course at a large state university were analyzed in the fall and spring semester . Main outcome measures: Daily servings of total fruit (fruit and juice), total vegetables (fried and non-fried), dairy (regular and low-fat), whole grains, and dietary fiber, breakfast consumption, body weight changes and physical activity. Statistical Analysis Performed: Associations between diet quality and weight change were analyzed using Chi-square analysis. Weight change was analyzed by diet quality and breakfast consumption using t-test and by metabolic equivalents (METHRS/day) using one-way analysis of variance (ANOVA) (p<0.05). Significant associations were analyzed by Pearson's correlation (two-sided, p<0.05). Results: Weight and body mass index (BMI kg/m2) were significantly higher compared to baseline. The majority of students did not meet recommendations for daily servings of fruit, vegetable, dairy, whole grains, and dietary fiber. Higher diet quality was significantly associated with more frequent breakfast consumption and students who maintained or lost weight reported significantly higher intakes of total fruit, low-fat dairy and whole grains. Conclusion: Failure to meet dietary guidelines resulting in lower diet quality was distinctive of this population and was associated with significant changes in body weight over one academic year. Applications: Educational interventions aimed at improving diet quality may inhibit weight gain commonly seen in college students. / Master of Science

Metabolic flexibility plays a significant role in energy homeostasis by regulating fuel selection in correspondence to energy demand. Obese and type II diabetic populations have displayed a hindered ability to properly transition from fat oxidation while in a fasted state to carbohydrate oxidation once fed, leading to a buildup of mitochondrial metabolites such as acylcarnitines. Carnitine, essential for fatty acyl-CoA transport through the inner and outer mitochondrial membranes, can be an indicator of mitochondrial distress as elevated levels tend to spill over into plasma suggesting a disruption in oxidation. The current study was designed to examine the effect of short term, high fat feeding on plasma acylcarnitine species diversity and levels and if acylcarnitines are associated with metabolic flexibility. 13 healthy, non-obese, sedentary males, aged 18-40 years participated in this study. Following a 12-hour overnight fast a biopsy was taken from the quadricep before and 4 hours after a high fat meal. Blood draws were obtained pre-biopsy while fasted and every hour for 4 hours post high fat meal consumption. Acylcarnitines from plasma were converted to their butyl esters and analyzed by electrospray ionization tandem mass spectrometry (MS/MS). Changes were observed in acetylcarntine (P=0.0125), glucose oxidation (P=0.0295), C16:1/C16:0 desaturation index (P= 0.0397), and C18:1/C18:0 desaturation index (P=0.0012). We did not find that individual changes in flexibility correlated with circulating acylcarnitine measurements in a fasted state / Master of Science

This investigation was undertaken to study the effects of feeding two levels of caloric density factorially with two levels of activity on the growth rate and body composition of male weanling pups from 25 to 67 days of age. The effects of ad libitum feeding the dams of these pups the same two diets during gestation and lactation on the growth rates and activity levels of these pups were also examined. Following weaning, the pups in both Studies A and B, were placed by weight in outcome groups of four each. The pups in each outcome group were then randomly assigned to one of the following four treatments: I - high-fat diet, spontaneous exercise; II - high-fat diet, restricted exercise; III - chow diet, spontaneous exercise; IV - chow diet, restricted exercise. The pups whose dams were given the 60% fat ration during gestation and lactation (B) attained a higher weaning weight (73 g) than the pups of the dams fed a 4.5% fat ration (Purina Chow) during gestation and lactation - A (55 g). The final body dimensions (length and width) did not appear to be different (Tables IV and V). Pups in Study B tended to run considerably more meters per day than the pups in Study A although the differences were uncertain because of the wide variation. The final body weights attained were greater for the pups in Study B than the pups in Study A except for treatment I. Except for treatment I, the Except for treatment I, the order of the weight gains within treatments among experiments was comparable. It appeared that the differences in final body weight attained could be attributed to the initial differences present at weaning which reflected the dietary treatments of the dams during gestation and lactation. The difference of treatment I in Study B from the trends exhibited by the other three treatments, was manifest by the lower final body weight attained (246.25 ± 9 g) and the lower total weight gain (170.77 ± 8 g) of Study A. The animals in Study B all consumed a greater number of kcal per day than the animals in the corresponding treatments in Study A. The differences in feed consumption between the two experiments appeared to be significant only for those animals receiving the 60%-fat diet. / Master of Science

Skeletal muscle is highly involved in macronutrient metabolism. To maintain proper energy metabolism and physiology, skeletal muscle must adapt to nutrient supply. Thus, diet macronutrient composition is an important modulator of skeletal muscle metabolism. Evidence from rodent and human models show high-fat diets contribute to impaired insulin signaling, as well as decreased fatty acid and glucose oxidation. Utilizing proteomic analysis of metabolic proteins in humans may lead to the mechanism behind skeletal muscle adaption to macronutrient composition, potentially providing the groundwork for characterizing the etiology of high-fat feeding induced metabolic disease. The objective of this study was to compare the substrate oxidation patterns and the levels of metabolic proteins in the fasted skeletal muscle of lean, healthy males that either increased fatty acid oxidation in response to the high-fat diet, termed responders, or males that decreased fatty acid oxidation, termed non-responders. We employed a controlled feeding study design, where the participants served as their own controls. Following a 2-week control diet (30% fat, 55% carbohydrate and 15% protein), participants came to the lab fasted overnight and a muscle biopsy was taken from their vastus lateralis muscle. Participants were then placed on a 5-day high-fat diet (50% fat [45% saturated fat], 35% carbohydrate, and 15% protein). Following this diet, participants again came to the lab fasted overnight and another muscle biopsy was taken from their vastus lateralis muscle. Both the control and the high-fat diets were isocaloric to habitual diets. Muscle from the biopsies were utilized for substrate metabolism measures and mass spectrometry. We did not observe any significant differences in glucose oxidation between responders and non-responders, prior to or following the high-fat diet. Our proteomic analysis identified 81 proteins and protein subunits involved in substrate metabolism but only 6 were differentially regulated by the high-fat diet. Independent of the high-fat diet, compared to non-responders, responders contained an overall higher content of protein subunits belonging to Complex I and ATP synthase. The findings from this study suggest that adaption to high-fat feeding is individual specific and proteomic changes alone cannot explain high-fat feeding induced metabolic changes. / Ph. D. / Skeletal muscle is highly involved in macronutrient metabolism, which consist of the breakdown and utilization of glucose and fatty acids, thus making the foods we ingest a major modulator of skeletal muscle metabolism. Over the last few decades, Americans have increased their ingestion of foods high in saturated fats, which has coincided with the increased prevalence of obesity and type 2 diabetes. Further, evidence suggests these metabolic diseases are associated with the skeletal muscle’s inability to switch between the utilization of glucose and fatty acid in response to nutrient supply. Analyzing metabolic protein content in humans may lead to the mechanism behind skeletal muscle adaption to macronutrient composition, potentially leading to the cause behind the development of high-fat feeding induced metabolic disease. The objective of our controlled feeding study was to compare the macronutrient metabolism and the content of metabolic proteins in the fasted skeletal muscle of healthy males that either increased fatty acid utilization in response to a high-fat diet, termed responders, or males that decreased fatty acid utilization, termed non-responders. Following a 2-week control diet (30% fat, 55% carbohydrate and 15% protein), participants came to the lab fasted overnight and a biopsy was taken from their thigh muscle called the vastus lateralis. Participants then began a 5-day high-fat diet (50% fat [45% saturated fat], 35% carbohydrate, and 15% protein). Following this diet, participants came to the lab fasted overnight and another biopsy was taken from their vastus lateralis muscle. Both the control and the high-fat diets were isocaloric to habitual diets. The muscle samples were used to analyze macronutrient metabolism and identify metabolic protein content. We did not observe differences in glucose utilization between responders and non-responders, prior to or following the high-fat diet. We identified 81 metabolic proteins and protein subunits but only 6 were differentially regulated by the high-fat diet. Independent of diet, responders contained higher levels of subunits from 2 proteins involved in cell energy production, Complex I and ATP synthase. Our findings suggest that adaption to high-fat feeding is individual specific and protein content changes alone cannot explain high-fat feeding induced metabolic changes.