Fifteen steers were used to evaluate the difference of diets (corn-based for 8 mo or hay-based for 12 mo) and breeds (Angus; n = 7 or Wagyu; n = 8) in a completely randomized design with 2 x 2 factorial arrangement of treatments to test the hypothesis that there are differences in fatty acid metabolism and cellularity in subcutaneous (s.c.) and intramuscular (i.m.) adipose tissue between these breeds types. Fat thickness, carcass weight, overall maturity, and yield grade of Angus steers were higher than those of Wagyu steers fed either corn (34%, 22%, 3%, and 8% higher, respectively) or hay diets (20%, 8%, 10%, and 8% higher, respectively) (P < 0.03). Moreover, marbling scores tended (P = 0.70) to be greater in Angus steers than in Wagyu steers fed either diet. Lipogenesis from acetate in both s.c and i.m. adipose tissue was higher in Wagyu steers (212.82 and 86.23 nmol/(105 cells per 2 h)) than in the Angus steers (86.23 and 29.66 nmol/(105 cells per 2 h)). Also, acetate incorporation into fatty acids was greater in s.c. adipose tissue than in i.m. adipose tissue (P < 0.05). Subcutaneous adipose tissue stearoyl-CoA desaturase (SCD) activity was significantly greater in corn-fed steers and than in hay-fed steers (P < 0.05), but there was no difference in SCD activity between Angus and Wagyu steers (P > 0.05). Adipocyte cellularity data demonstrated that both breeds have more cells per gram adipose tissue and smaller cell volumes in i.m. adipose tissue than in s.c. adipose tissue. In s.c. adipose tissue, saturated fatty acids tended to be lower in corn-fed Angus and Wagyu steers than in hay-fed steers (P < 0.06). Similarly, monounsaturated fatty acids were higher in corn-fed Wagyu and Angus steers than in hay-fed Wagyu and Angus steers (P < 0.01). Slip point was positively correlated with percentage stearic acid in corn-fed and hay-fed steers, and there was a negative correlation between slip point and the SCD index. These data demonstrated that corn-based diets provide not only increased contents of monounsaturated fatty acid in Angus and Wagyu adipose tissue but also increased lipogenic activity.

Fifteen steers were used to evaluate the difference of diets (corn-based for 8 mo or hay-based for 12 mo) and breeds (Angus; n = 7 or Wagyu; n = 8) in a completely randomized design with 2 x 2 factorial arrangement of treatments to test the hypothesis that there are differences in fatty acid metabolism and cellularity in subcutaneous (s.c.) and intramuscular (i.m.) adipose tissue between these breeds types. Fat thickness, carcass weight, overall maturity, and yield grade of Angus steers were higher than those of Wagyu steers fed either corn (34%, 22%, 3%, and 8% higher, respectively) or hay diets (20%, 8%, 10%, and 8% higher, respectively) (P < 0.03). Moreover, marbling scores tended (P = 0.70) to be greater in Angus steers than in Wagyu steers fed either diet. Lipogenesis from acetate in both s.c and i.m. adipose tissue was higher in Wagyu steers (212.82 and 86.23 nmol/(105 cells per 2 h)) than in the Angus steers (86.23 and 29.66 nmol/(105 cells per 2 h)). Also, acetate incorporation into fatty acids was greater in s.c. adipose tissue than in i.m. adipose tissue (P < 0.05). Subcutaneous adipose tissue stearoyl-CoA desaturase (SCD) activity was significantly greater in corn-fed steers and than in hay-fed steers (P < 0.05), but there was no difference in SCD activity between Angus and Wagyu steers (P > 0.05). Adipocyte cellularity data demonstrated that both breeds have more cells per gram adipose tissue and smaller cell volumes in i.m. adipose tissue than in s.c. adipose tissue. In s.c. adipose tissue, saturated fatty acids tended to be lower in corn-fed Angus and Wagyu steers than in hay-fed steers (P < 0.06). Similarly, monounsaturated fatty acids were higher in corn-fed Wagyu and Angus steers than in hay-fed Wagyu and Angus steers (P < 0.01). Slip point was positively correlated with percentage stearic acid in corn-fed and hay-fed steers, and there was a negative correlation between slip point and the SCD index. These data demonstrated that corn-based diets provide not only increased contents of monounsaturated fatty acid in Angus and Wagyu adipose tissue but also increased lipogenic activity.

The present study cloned full-length genes of peroxisome proliferators activated receptors (PPARs) of the cobia Rachycentron canadum and investigated their expressions in association with cobias¡¦ body adiposity and lipid-metabolism related physiological parameters. In addition to gene cloning, several studies evaluating the roles of PPARs were carried out, including: a time-series study on cage-farmed cobias from week 5 to week 52 post-hatching, a study comparing fish groups with contrasting growth performance and a study elucidating the effects of dietary fatty acids. Three isotypes, PPAR £\, PPAR£] and PPAR£^, that were cloned from cobia¡¦s cDNA contained 2046 bp, 2702 bp and 1943 bp, respectively. Their open reading frames encode 476, 510 and 531 amino acids, respectively. The identity in amino acid sequences between the PPARs are 52% (between PPAR£\ and PPAR£]), 52% (between PPAR£\ and PPAR£^), and 44% (between PPAR£] and PPAR£^), respectively. RT-PCR and real-time PCR (qPCR) analyses showed that expression of PPAR£\ mRNA predominated in red muscle, heart and liver, and at a lower level in the head kidney and dorsal muscle. PPAR£] transcripts were particularly abundant in the heart, liver, brain, and pyloric caeca. In contrast, PPAR£^ mRNA was detected primarily in the adipose tissues, liver, and pyloric caeca. In the time-series study, the PPARs expression was related to the body adiposity and lipid-metabolism related physiological parameters of the cobias that were raised for one year to approximately 4.5 Kg in a commercial cage-culture farm. Ten samplings were conducted on weeks 5, 7, 9, 14, 18, 23, 29, 34, 41, and 52 post-hatching. The cobias were raised in an outdoor nursery to 88 g before being transferred to an offshore cage on week 9. The adipocytes in the liver and ventral muscle showed a hypertrophic (increase in cell size) increase towards the end of the nursery phase. Their cell size decreased significantly after the cage transfer and was maintained afterwards a size spectrum dominated by small cells until week 34. The cobias grew rapidly after the offshore transfer and reached 330 g on week 14. They showed a concurrent increase in fat deposition in the liver and ventral muscle and a concurrent hyperplasia increase in density of adipocytes in the ventral and dorsal muscle. Adipocyte hypertrophy was obvious on week 41 and regressed afterwards. As the fish grew, serum phospholipids concentration increased significantly from approximately 380 to 750 mg/dL. Time-series pattern for the specific activity of two NADPH-generating enzymes, malic enzyme and glucose-6- phosphate dehydrogenase, were reciprocal and compensatory. The expression of liver PPAR£\ mRNA was negatively correlated to fat deposition and adiposity. There was a significant increase in body lipid deposition and hepatic PPAR£^ expression as the fish grew. Hepatic PPAR£^ expression could be a sufficient parameter describing its expression in whole body. These results showed that PPAR£^ and PPAR£\ played a pivotal role in the control of lipid metabolic and storage functions in the liver, muscle and visceral fat depot of the cobia. In the study comparing differential fish growth, two groups of cobias were selected based on their growth performance from a same batch of fish raised in a nursery. The large-size group that was regarded as superior grower was 54.1 cm in total length and 1,287 g in weight; while the small-size fish (inferior grower) was 36.8 cm and 386 g. Compared to large cobias, small cobias showed a similar hepatosomatic index and viscerasomatic index, but a significantly (p ¡Õ 0.05) smaller mesenteric fat index (MFI).The levels of crude lipid in the liver (35% vs. 26%) and the proportions of neutral lipids in lipid were higher in large cobias than in small cobias. Concentrations of serum phospholipids, free fatty acids and total protein of large cobias were significantly higher than those of small cobias. Adipocyte density of liver and ventral muscle was increased with increasing fish size. The PPAR£\ mRNA expression in the liver of small cobias was significantly higher (p ¡Õ 0.05) than large cobias, ascribing to possible stress effect from their inferior growth. The growth superiority obviously affected PPAR£\ mRNA expression and fat deposition in the liver. In general, the expression of liver PPAR£\ mRNA was negatively correlated to body weight, body length, MFI, and serum NEFA, as well as lipid concentration, adiposity (adipocyte density and adipocyte size), G6PDH enzyme activity in the liver. The PPAR£^ mRNA expression in the liver was positively correlated to size of the adipocytes size. The effects of dietary fatty acids on PPARs expression were evaluated in a 10-week growth trial, in which cobias with an initial weight of 80 g were fed diets containing 15% lipid. Among the lipids, 6% was fish oil and the remaining 9% were fish oil (rich in EPA and DHA), perilla oil (C18:3n-3), safflower oil (C18:2n-6), olive oil (C18:1n-9) or palm oil (C16:0). Significant difference was detected in PPARs mRNA expression among dietary treatments and among tissues. In the liver, among the dietary treatments, significantly higher expression levels of PPAR£\ mRNA were detected in perilla oil and olive oil group, PPAR£] mRNA in palm oil group and PPAR£^ mRNA in fish oil group. Linear regression analysis showed that liver PPAR£\ mRNA expression was positively (p ¡Õ 0.05) correlated with dietary C18:3n-3 levels and negatively with dietary C18:0 levels. Liver PPAR£] mRNA expression was positively correlated to C16:0 or C18:0 levels in diets. The PPAR£^ expression was positively (p ¡Õ 0.001) correlated to dietary levels of C20:1n-9, C20:5n-3 and C22:6n-3. In summary, the mRNA expression pattern of PPARs was tissue or organ-specific with the expression of PPAR£\ occurred predominantly in the liver and PPAR£^ in the adipose tissues. The expressions of PPARs in the liver were more related to their physiological roles than in other tissues or organs studied in the present study. The expression of PPAR£\ in the liver was shown correlated negatively to body fat deposition; and reciprocally, expression of PPAR£^ was positively correlated to fat deposition. PPARs mRNA expression was also associated with major dietary fatty acids. Increased dietary C18:0 levels down-regulated PPAR£\ and up-regulated PPAR£]. Up-regulation of PPAR£^ was significantly related to increased levels of highly (C>20) unsaturated fatty acid in diets. Dietary C16¡VC18 fatty acids on the other hand were more related to expressions of PPAR£\ and PPAR£]. These results suggest that fish oil could be partially replaced by plant oils as the lipid source in the diet of the cobia. In addition to highly unsaturated fatty acids, reduction in dietary C18:3n-3 and increase in C18:0 lead to increased fat deposition, implicating a possible strategy to modulate body lipid contents of the cobia through dietary manipulation.

Over nine million children 6-17 years old are overweight in the United States. They may face the highest risk ever for overweight, obesity, and associated health problems as adults. This study’s purpose was to evaluate adiposity measurement methods in children by comparing accuracy, cost effectiveness, ease of use, and practicality. IRB approval, parental consent and student assent were obtained. Data were collected by trained employees at six elementary schools on 789 subjects for boys (n= 391) and girls (n=398) 5-11 years old African American children. Hip and waist circumferences, height, and weight were collected. BMI, Waist to Hip Ratio (WHR), and Waist to Height Ratio (WHTR) were calculated. Upon analysis, weight and hip circumference were correlated (r = .94135) and waist circumference was correlated to BMI (r = .92396). The measures of adiposity were highly correlated indicating that a variety of anthropometric measurements can be used for measuring children.

Rationale & Background: During pregnancy, cardiometabolic adaptations occur to sustain fetal growth. Disruptions in maternal cardiometabolic status may arise related to maternal adiposity, dietary deficiencies or excesses, or sedentary behaviours in pregnancy. Clinically, maternal cardiometabolic dysfunction is associated with adverse health outcomes in both mothers and their offspring. We aimed to determine: 1) the contribution of maternal adiposity, diet and physical activity to maternal cardiometabolic status in early pregnancy using biomarkers of lipid and glucose profiles; 2) whether maternal adiposity measured by 4-site sum of skinfold thickness (SFT) or bioelectrical impedance analysis (BIA) yielded similar strength of association with cardiometabolic status. Study Design: Maternal blood samples, anthropometric and body adiposity, dietary and physical activity measures were collected from a subset of pregnant women in early pregnancy (12-17 wk gestation) prior to randomization to the Be Healthy in Pregnancy RCT. Blood samples were analyzed for fasting glucose, insulin, triglycerides, leptin, adiponectin, and C-reactive protein (CRP). Maternal adiposity was assessed by pre- pregnancy body mass index (pBMI) and two indirect quantitative measures of % body fat (BIA and 4-site SFT). Results: Of the 91 subjects (mean age= 31 ± 4 y), 46.2% were overweight/obese by pBMI. For both SFT and BIA, % body fat was positively associated with fasting glucose, insulin, triglyceride, leptin, and CRP concentrations, and negatively associated with adiponectin concentration, although the strength of the associations was greater for SFT than BIA. After adjustment for confounders, maternal adiposity remained significantly associated with all cardiometabolic biomarkers, except for adiponectin and CRP. Dietary polyunsaturated: saturated fat ratio, energy expenditure, high activity level, age, ethnicity and parity were significantly associated with some of the biomarkers. Conclusion: Maternal adiposity was predominantly associated with leptin, insulin, and glucose status in early pregnancy although dietary fat, energy, activity level, age, ethnicity and parity were also significantly associated with some biomarkers. Body fat estimated by SFT or BIA are generally comparable for use as a screening tool for cardiometabolic dysfunction in early pregnancy. In the clinical setting, BIA may be more easily adopted as it is faster and requires fewer technical skills by the operator than SFT measures. / Thesis / Master of Science (MSc)

<p>A large proportion of the variation in traits between individuals can be attributed to variation in the nucleotide sequence of the genome. The most commonly studied traits in human genetics are related to disease and disease susceptibility. Although scientists have identified genetic causes for over 4,000 monogenic diseases, the underlying mechanisms of many highly prevalent multifactorial inheritance disorders such as diabetes, obesity, and cardiovascular disease remain largely unknown. Identifying genetic mechanisms for complex traits has been challenging because most of the variants are located outside of protein-coding regions, and determining the effects of such non-coding variants remains difficult. In this dissertation, I evaluate the hypothesis that such non-coding variants contribute to human traits and diseases by altering the regulation of genes rather than the sequence of those genes. I will specifically focus on studies to determine the functional impacts of genetic variation associated with two related complex traits: gestational hyperglycemia and fetal adiposity. At the genomic locus associated with maternal hyperglycemia, we found that genetic variation in regulatory elements altered the expression of the HKDC1 gene. Furthermore, we demonstrated that HKDC1 phosphorylates glucose in vitro and in vivo, thus demonstrating that HKDC1 is a fifth human hexokinase gene. At the fetal-adiposity associated locus, we identified variants that likely alter VEPH1 expression in preadipocytes during differentiation. To make such studies of regulatory variation high-throughput and routine, we developed POP-STARR, a novel high throughput reporter assay that can empirically measure the effects of regulatory variants directly from patient DNA. By combining targeted genome capture technologies with STARR-seq, we assayed thousands of haplotypes from 760 individuals in a single experiment. We subsequently used POP-STARR to identify three key features of regulatory variants: that regulatory variants typically have weak effects on gene expression; that the effects of regulatory variants are often coordinated with respect to disease-risk, suggesting a general mechanism by which the weak effects can together have phenotypic impact; and that nucleotide transversions have larger impacts on enhancer activity than transitions. Together, the findings presented here demonstrate successful strategies for determining the regulatory mechanisms underlying genetic associations with human traits and diseases, and value of doing so for driving novel biological discovery.</p> / Dissertation

Research Doctorate - Doctor of Philosophy (PhD) / Introduction: Surveillance data and other studies have indicated that the prevalence of overweight and obesity in preschool children in Ho Chi Minh City (HCMC) is increasing, particularly in urban areas. No studies have examined the speed at which this public health problem is emerging in child populations in urban Vietnam. Knowledge of the risk factors for preschool-aged child obesity is limited since earlier studies have been cross-sectional in design and potential risk factors at different levels have not been fully investigated. Objectives: This study aimed to assess the prevalence and trends in overweight and obesity, and to identify the risk factors associated with longitudinal changes in adiposity over a one year period in preschool children in urban areas of HCMC. In addition, a sub-study aimed to validate a proxy-questionnaire for use in measuring physical activity of preschool children. Method: Based on the available data from a cross-sectional study conducted with preschool children in HCMC in 2002, a restricted sample of 492 children aged four to five years from urban areas of HCMC was used for examining the trends in overweight and obesity in this child population, over the period from 2002 to 2005. The original study using the multi-stage cluster sampling was performed in preschool children aged one to six years in both urban and sub-urban areas of HCMC. A total of 1780 children aged one to six years participated in this study. Anthropometry of the subjects was measured using standard methods. Socio-demographic information was collected using a self-administered questionnaire. The one year follow-up study, using multi-stage cluster sampling, was conducted from 2005 to 2006 with children aged four to five years in preschools in urban areas of HCMC. At baseline, 670 children participated in the study and of these, 526 children completed two follow-up measurements at 6 month intervals. Information on neighbourhood, preschool and home environments, socio-economic status, the child’s and parental characteristics were collected using pre-coded, structured, interviewer-administered questionnaires. Dietary intake and physical activity were measured in the home and preschool settings using modified, validated questionnaires. Anthropometry including weight, height, skinfold thickness at triceps, subscapular and suprailiac sites were measured using standard methods. The trends in overweight and obesity were examined based on data from the 2002 study and the baseline study of the cohort study. Data were collected in 2002 and made available for these secondary analyses. The validation study of the proxy-questionnaire to measure physical activity of children aged four to five years was conducted from July, 2005 to November, 2005, using accelerometers as the criterion method. A subset of 83 children from the entire cohort study participated in this study. Physical activity data over the three months, reported by the teacher and the parents, were compared with data collected from the accelerometers for seven consecutive days. Main outcomes: Body mass index (BMI) was calculated from measured weight and height. Overweight and obesity were defined using IOTF cut-off points. Underweight was classified using the 5th percentile cut-off point for weight for age, based on the 2000 CDC Growth Reference. Results: The findings indicated that the significance of overweight and obesity in preschool children in urban areas of HCMC is not only in its magnitude (obverweight: 20.5% and obesity: 16.3% in 2005), but also in the rapidly increasing trend in prevalence from 21.4% in 2002 to 36.8% in 2005. There exists an imbalance in food intake in this young child population. Dietary patterns have shifted towards higher energy obtained from protein and fat (particularly animal protein and fat) and less energy from carbohydrates, than is recommended. The risk factors of overweight and obesity in the four to six year old child population in HCMC were identified at multiple levels. The contextual variables in the community, school and home environments, interacted with individual characteristics influencing the changes in adiposity and overweight and obesity development over time. Risk factors for changes in adiposity and risk of developing overweight and obesity differed for boys and girls. The proxy-questionnaire was shown to be valid for ranking the child’s sedentary behaviour but it was not suitable for measuring the child’s physical activity patterns in absolute values. Conclusion: An obesity epidemic has been taking place in the young child population in urban areas of HCMC. Boys appear to be more vulnerable to this epidemic than girls. The diet of this child population has shifted to higher energy from protein and fat, and less energy from carbohydrate. The aetiology of overweight and obesity of preschool children ismulti-factorial. It is time for action to control this public health problem in young children in urban areas of HCMC, Vietnam.

Chapter One introduces the field of evolutionary psychology as well as provides a review of factors influencing facial attractiveness. Chapter Two presents empirical evidence that online studies may provide a distorted perspective on cross-cultural face preferences since online samples are not representative of the populations in developing countries. In El Salvador, participants without internet access preferred more feminine men as well as heavier and more masculine women when compared to participants with internet access. One possible explanation for such findings is that the level of harshness in the environment may be influencing preferences. One individual difference that is influenced by environmental harshness is age of menarche. Chapter Three thus provides exploratory evidence that age of menarche also influences masculinity preferences. Chapter Four further examines this environmental harshness hypothesis by repeatedly testing students undergoing intensive training at an army camp. Increases in the harshness of the environment led to an increased male attraction to cues of higher weight in female faces. Such changes in preferences may be adaptive because they allow for more opportunities to form partnerships with individuals who are better equipped to survive. An alternative explanation for the empirical findings in Chapters Two and Four is that familiarity may also influence preferences. Chapter Five tests this familiarity hypothesis by examining the faces of participants in different areas of El Salvador and Malaysia. Rural participants preferred heavier female faces than urban participants. Additionally, the faces of female participants from rural areas were rated as looking heavier. This finding suggests that familiarity may indeed influence attractiveness perceptions. Lastly, Chapter Six draws conclusions from the empirical findings reported in Chapters Two-Five and lists proposals of future research that could further enhance our understanding of what we find attractive.

Body adiposity is generally considered the most pertinent factor in puberty attainment; however, recent data suggests that pre-pubertal reproductive tract development may be altered by dietary sugar consumption. Two experiments were conducted to delineate the direct effects of fructose on the maturation of the pre-pubertal reproductive tract and fertility. At three weeks of age, forty gilts were placed on one of five dietary treatments (n=8) containing 15% fat (FAT), 35% fructose (FRU), both fat and fructose (HFHF), or two different controls: one standard industry (IND) diet meant to result in optimal lean growth and a second diet to account for the reduced lysine (LYS) intake in the treatment diets. Body weights did not differ amongst any of the five treatments on the day of sacrifice (P=0.32). As a percentage of BW, total reproductive tracts were heavier in fructose fed gilts (1.3±0.1 v. 0.8±0.1%; P=0.01) compared to non-fructose gilts. In the second experiment, starting at 130d of age, gilts were checked twice daily for puberty attainment. Gilts that attained puberty were artificially inseminated (AI) on their third estrous cycle. On gestational day 38±3, pregnant gilts were harvested for reproductive tract collection. Fewer fructose fed (FRU and HFHF) pigs became pregnant than non-fructose fed (IND, LYS, and FAT) gilts (25% v. 75% respectively; P=0.03). All HFHF gilts failed to become pregnant. Placental weights were greater in LYS fetuses than FAT fetuses (79.07 ± 6.55g v. 47.26 ± 6.45g, respectively, P= 0.04). Taken together, these results demonstrate that fructose consumption increases reproductive tract size, but that reproductive capabilities are reduced. / Master of Science

Background: Tower Hamlets is a socioeconomically disadvantaged borough, home to the UK’s largest South Asian population, a group at increased risk of obesity-related diseases. Previous studies in this population have reported high levels of adiposity and inactivity. No borough-wide study has been conducted objectively measuring physical activity patterns. This study aimed to investigate pedometer-determined activity levels of Tower Hamlets' schoolchildren, their association with adiposity and differences according to ethnicity and socioeconomic status (SES). The study was preceded by reviews investigating the association between step counts and adiposity in children and investigating the validity of pedometers as a measure of physical activity in young people. Methods: Participants were recruited from Tower Hamlets' secondary schools (n=884; 584 boys, 300 girls). A pedometer was worn for 7 days. Internationally recognised mean daily step count cut-offs (boys = 15000, girls = 12000) were used to define activity level. Body mass index (BMI), bioelectrical impedance analysis (BIA)-determined percentage body fat (%bf) and waist circumference (WC) were all measured. Children were classified as being of normal weight, overweight or obese according to international cut-off points. A questionnaire was administered to establish socioeconomic status and ethnicity. Results: A total of 884 schoolchildren were recruited (66% boys, 34% girls). Of this, 657 (74%) provided a full set of pedometer, anthropometric and socio-demographic data. Sixty-five percent of all participants were South Asian and 55% received free school meals. Significant differences in anthropometric variables were observed according to gender, ethnicity and school. The prevalence of overweight/obesity ranged widely for boys (35%, 53% and 65%) and girls (33%, 55% and 55%) according to BMI, %bf and WC, respectively. The majority of participants provided 4 or 5 days of activity data, with 15% providing data for 7 days. Inactivity was high, 83% of boys and 72% of girls failed to meet the minimum recommended daily step counts. Activity was greater during the week compared to the weekend and those that were most active during the week were also more active at the weekend. Boys (11580±3560) took significantly more steps than girls (10062±3239) and differences were also observed between schools. No significant differences in activity levels were observed according to ethnicity, SES or adiposity levels. Conclusion: The vast majority of schoolchildren in Tower Hamlets fail to reach current physical activity recommendations, irrespective of ethnicity or socioeconomic class. Inactivity is greater at the weekend. The prevalence of overweight/obesity is also higher than national averages. Intervention strategies to increase physical activity and tackle overweight/obesity in this cohort are required.