Today's consumers have shown a greater concern in the relationship between dietary fat and human health. The demand for leaner meat is continuously on the rise. The reduction of fat deposits in the abdominal area of ready-to-cook fryers, considered a waste product in the poultry industry, has become a major opportunity for the researcher. Experiments were conducted to evaluate the merit of managerial practices affecting abdominal fat (AF) levels in broiler chickens. Factors studied included seasons of the year, source of the commercial broiler strain crosses, stocking densities, lighting systems, types of housing, dietary salt (NaCl) 1eve1s and feed restriction. Two housing types (open-sided and windowless) and different seasons were utilized to evaluate the influence on broiler performance and AF levels. Raising broilers from the same strain cross in an open-sided building did not affect performance and AF levels. Mean body weight (BW) were highest in fall season (1929 g ) and lowest in summer (1735 g) (p<.05) while highest and lowest % AF revels were observed in spring and winter (2.34, and 1.42 respectively). The comparative effect of feeding regime, (full feed, FF), 95 and 90% FF), dietary salt 1evels (0, 0.25, and 0.5% of the finisher diet), stocking densities (0.06, 0.07, and 0.09 m�� of floor space per bird) and type of housing (battery cages and litter pens) were examined on broiler performance and AF lever. Ninety % FF resulted in significantly lower body weights and AF levers compared to ad libitum feeding. At 49 days of age, mean BW of broilers fed 0.5% salt were higher (P<.05) than the group not provided with salt. Altering stocking densities and rearing in battery cages failed to show any significant improvements performance and % AF. Lighting regime 12 h light (L): 12 h dark (D), recycled during the rearing period resulted in lower (p<.05) mean BW than continuous lighting regime (CL) when applied from 5 days of age. Broilers raised on 16L:8D after 21 days had comparable performance to CL. Lighting regime of 12L:12D, recycled in combination with increasing stocking densities from 0. 06 to 0.8 m�� floor space/broiler and intermittent righting of lL:3D in combination with the addition of 0.5% salt to the diet resulted in improved (P<.05) BW with no corresponding increases in AF levels. Factors such as season of the year, feeding of salt, and manipulation of light (up to 8 h dark) can be used as tools in reducing % AF and overall production costs. / Graduation date: 1993

Thesis (Ph. D.)--University of North Carolina at Greensboro, 2006. / Advisor: Ron Morrison; submitted to the School of Human Environmental Sciences. Includes bibliographical references.

The main objective of this research was to investigate possible uses of Western-Canadian grown chickpea (<i>Cicer arietinum</i> L.) in the form of flour, starch and protein isolates in low-fat pork bologna. <p>In the first study, flour, starch and protein isolates from six chickpea cultivars (three Kabuli and three Desi) from two harvests (2005 and 2006) were evaluated for their physico-chemical, functional and thermal properties. Chickpea flour was made by grinding seed to pass through a 0.1mm screen, whereas protein isolates and starch were prepared by a wet milling process. Protein isolates were prepared from chickpea flour (23.2% protein on average) by alkaline extraction (pH 8.0) and isoelectric precipitation (pH 4.3). Protein isolates contained 72.8-85.3% protein; the starch fraction contained 93.0-98.0% starch. On SDS-PAGE, the chickpea flours and protein isolates contained similar polypeptide bands in the range of 30 to 55 kDa, with three major bands at approximately 50-55, 40 and 30 kDa. Least gelation concentration (LGC) for chickpea flours ranged from 6-14%; LGC for chickpea protein isolates ranged from 10-14%. Differential scanning calorimetry (DSC) of chickpea flour slurries revealed two endothermic peaks. One corresponded to starch gelatinization at approximately 64°C, which was slightly higher than for the starch fraction (~60°C). The second broad peak at approximately 96°C corresponded to the denaturation of the globulin protein fraction, which was also slightly higher than for the protein isolates (~91°C). Chickpea flour exhibited nitrogen solubility index values higher than those of chickpea protein isolates and soy and pea protein isolates. Chickpea protein isolates exhibited water holding capacities, oil absorption capacities, emulsion activity indeces and emulsion stability indeces higher than those of the chickpea flours. CDC Xena (Kabuli) and Myles (Desi), in general, most exhibited properties appropriate for meat applications. In the second study, the efficacy of flour, starch and protein from CDC Xena (Kabuli hereafter) and Myles (Desi hereafter) were investigated in low-fat pork bologna (LFPB). Low-fat pork bologna (<5% fat) was prepared by incorporating 2.5 or 5.0% flour, 1.5 or 3.0% protein isolate (protein basis), or 1.0 or 2.0% starch in the formulation. Controls were prepared without any binder, and formulations containing wheat or pea flour, soy or pea protein isolate, potato or pea starch, or extra meat were prepared for comparison. Inclusion of chickpea flour, protein or starch had a positive effect (P<0.05) on the cook yield, expressible moisture and purge of LFPB, and had little effect on colour. Increasing chickpea flour substitution from 2.5 to 5.0% altered the sensory and instrumental textural quality of LFPB significantly (P<0.05). Desi flour at 5.0% showed the highest TPA (texture profile analysis) hardness and chewiness, Allo-Kramer shear values and torsion shear stress. Similarly, LFPB containing chickpea protein isolate (CPI), soy protein isolate (SPI) or pea protein isolate (PPI) (3.0% protein basis) was firmer than either LFPB containing 1.5% protein from CPI, SPI or PPI or the control-I (with the same level of meat protein). Likewise, LFPB formulated with 2.0% Kabuli or Desi starch had higher TPA values than those prepared with pea or potato starch. For most flavour sensory properties, Kabuli and Desi chickpea flour and starch, irrespective of level of incorporation, performed similarly to the control. However, panellists noted more off-flavours with the addition of wheat flour or pea flour at 5.0%. Chickpea protein isolate, SPI or PPI at the 1.5% protein addition level did not alter the flavour properties of LFPB.<p>It was concluded that chickpea flour, starch and protein had potential for utilization as extenders in low-fat meat emulsion systems such as frankfurters and bologna.

Measuring human subcutaneous fat is useful for assessing health risks due to obesity and for monitoring athletes’ health status, body shapes and weight for various sports competitions such as gymnastics and wrestling. Our aim is to investigate the use of ultrasound imaging in automatically measuring human subcutaneous fat thickness. We proposed to use the spectrum properties extracted from the raw radio frequency (RF) signals of ultrasound for the purpose of fat boundary detection. Our fat detection framework consists of four main steps. The first step is capturing RF data from 11 beam steering angles and at four focal positions. Secondly, two spectrum properties (spectrum variance and integrated backscatter coefficient) are calculated from the local spectrum of RF data using the short time Fourier transform and moment analysis. The values of the spectrum properties are encoded as gray-scale parametric images. Thirdly, spatial compounding is used to reduce speckle noise in the parametric images and improve the visualization of the subcutaneous fat layer. Finally, we apply Rosin’s thresholding and Random Sample Consensus boundary detection on the parametric images to extract the fat boundary. The detection framework was tested on 36 samples obtained at the suprailiac, thigh and triceps of nine human participants in vivo. When compared to manual boundary detection on ultrasound images, the best result was obtained from segmenting the spatial compounded spectrum variance values averaged over multiple focuses. A reasonable result could also be obtained by using a single focus. Further, our automatic detection results were compared with the results using skinfold caliper measurements. We found that the correlation is high between our automatic detection and skinfold caliper measurement, and is similar to the previous studies which are not automatic. Our work has shown that the spatial compounded spectrum properties of RF data can be used to segment the subcutaneous fat layer. Based on our results, it is feasible to detect fat at the suprailiac, thigh and triceps sites using the spectrum variance. The values of spectrum variance change more rapidly in the fat tissue than the non-fat tissue.

Measuring human subcutaneous fat is useful for assessing health risks due to obesity and for monitoring athletes’ health status, body shapes and weight for various sports competitions such as gymnastics and wrestling. Our aim is to investigate the use of ultrasound imaging in automatically measuring human subcutaneous fat thickness. We proposed to use the spectrum properties extracted from the raw radio frequency (RF) signals of ultrasound for the purpose of fat boundary detection. Our fat detection framework consists of four main steps. The first step is capturing RF data from 11 beam steering angles and at four focal positions. Secondly, two spectrum properties (spectrum variance and integrated backscatter coefficient) are calculated from the local spectrum of RF data using the short time Fourier transform and moment analysis. The values of the spectrum properties are encoded as gray-scale parametric images. Thirdly, spatial compounding is used to reduce speckle noise in the parametric images and improve the visualization of the subcutaneous fat layer. Finally, we apply Rosin’s thresholding and Random Sample Consensus boundary detection on the parametric images to extract the fat boundary. The detection framework was tested on 36 samples obtained at the suprailiac, thigh and triceps of nine human participants in vivo. When compared to manual boundary detection on ultrasound images, the best result was obtained from segmenting the spatial compounded spectrum variance values averaged over multiple focuses. A reasonable result could also be obtained by using a single focus. Further, our automatic detection results were compared with the results using skinfold caliper measurements. We found that the correlation is high between our automatic detection and skinfold caliper measurement, and is similar to the previous studies which are not automatic. Our work has shown that the spatial compounded spectrum properties of RF data can be used to segment the subcutaneous fat layer. Based on our results, it is feasible to detect fat at the suprailiac, thigh and triceps sites using the spectrum variance. The values of spectrum variance change more rapidly in the fat tissue than the non-fat tissue.

SPARC is a collagen‐binding, matricellular glycoprotein with diverse roles in tissue remodeling and development. Previous studies have demonstrated that SPARC is required in Drosophila for larval development and maintenance of the fat body, an organ that incorporates endocrine, growth and immune functions. I have characterized effects of loss and knockdown of SPARC in the fat body. Loss‐of‐function analyses revealed remodeling of adipocytes demarcated by cell rounding and dense accumulation of extracellular matrix (ECM) beneath an abnormally thick basement membrane. Remodeling of adipocytes mediated by expression of matrix metalloproteinase 2 (MMP2) was found to cause ECM breakdown and accumulation of hemocytes, indicating endogenous fat body remodeling is mechanistically distinct from that which occurs upon silencing of SPARC. Knockdown of the lysyl hydroxylase, dPlod, in the fat body, revealed abnormal intracellular co‐localization of SPARC with Collagen IV, but not with Laminin. The data indicate SPARC is required for ECM homeostasis during development.

The main objective of this research was to investigate possible uses of Western-Canadian grown chickpea (<i>Cicer arietinum</i> L.) in the form of flour, starch and protein isolates in low-fat pork bologna. <p>In the first study, flour, starch and protein isolates from six chickpea cultivars (three Kabuli and three Desi) from two harvests (2005 and 2006) were evaluated for their physico-chemical, functional and thermal properties. Chickpea flour was made by grinding seed to pass through a 0.1mm screen, whereas protein isolates and starch were prepared by a wet milling process. Protein isolates were prepared from chickpea flour (23.2% protein on average) by alkaline extraction (pH 8.0) and isoelectric precipitation (pH 4.3). Protein isolates contained 72.8-85.3% protein; the starch fraction contained 93.0-98.0% starch. On SDS-PAGE, the chickpea flours and protein isolates contained similar polypeptide bands in the range of 30 to 55 kDa, with three major bands at approximately 50-55, 40 and 30 kDa. Least gelation concentration (LGC) for chickpea flours ranged from 6-14%; LGC for chickpea protein isolates ranged from 10-14%. Differential scanning calorimetry (DSC) of chickpea flour slurries revealed two endothermic peaks. One corresponded to starch gelatinization at approximately 64°C, which was slightly higher than for the starch fraction (~60°C). The second broad peak at approximately 96°C corresponded to the denaturation of the globulin protein fraction, which was also slightly higher than for the protein isolates (~91°C). Chickpea flour exhibited nitrogen solubility index values higher than those of chickpea protein isolates and soy and pea protein isolates. Chickpea protein isolates exhibited water holding capacities, oil absorption capacities, emulsion activity indeces and emulsion stability indeces higher than those of the chickpea flours. CDC Xena (Kabuli) and Myles (Desi), in general, most exhibited properties appropriate for meat applications. In the second study, the efficacy of flour, starch and protein from CDC Xena (Kabuli hereafter) and Myles (Desi hereafter) were investigated in low-fat pork bologna (LFPB). Low-fat pork bologna (<5% fat) was prepared by incorporating 2.5 or 5.0% flour, 1.5 or 3.0% protein isolate (protein basis), or 1.0 or 2.0% starch in the formulation. Controls were prepared without any binder, and formulations containing wheat or pea flour, soy or pea protein isolate, potato or pea starch, or extra meat were prepared for comparison. Inclusion of chickpea flour, protein or starch had a positive effect (P<0.05) on the cook yield, expressible moisture and purge of LFPB, and had little effect on colour. Increasing chickpea flour substitution from 2.5 to 5.0% altered the sensory and instrumental textural quality of LFPB significantly (P<0.05). Desi flour at 5.0% showed the highest TPA (texture profile analysis) hardness and chewiness, Allo-Kramer shear values and torsion shear stress. Similarly, LFPB containing chickpea protein isolate (CPI), soy protein isolate (SPI) or pea protein isolate (PPI) (3.0% protein basis) was firmer than either LFPB containing 1.5% protein from CPI, SPI or PPI or the control-I (with the same level of meat protein). Likewise, LFPB formulated with 2.0% Kabuli or Desi starch had higher TPA values than those prepared with pea or potato starch. For most flavour sensory properties, Kabuli and Desi chickpea flour and starch, irrespective of level of incorporation, performed similarly to the control. However, panellists noted more off-flavours with the addition of wheat flour or pea flour at 5.0%. Chickpea protein isolate, SPI or PPI at the 1.5% protein addition level did not alter the flavour properties of LFPB.<p>It was concluded that chickpea flour, starch and protein had potential for utilization as extenders in low-fat meat emulsion systems such as frankfurters and bologna.

This paper considers the high-moments and uses the skew generalized error distribution (SGED) to explain the financial market data which have leptokurtic, fat-tailed and skewness. And we compare performance with the commonly used symmetrical distribution model such as normal distribution, student¡¦s t distribution and generalized error distribution (GED). To research when returns of asset have leptokurtic and fat-tailed phenomena, what model has better predictive power for volatility forecasting? The empirical procedure is as follows: First step, make the descriptive statistics of raw data, and know that the GARCH effect should be considered, followed by selecting the optimal order of ARMA-GARCH. The second steps, make the parameter estimations of full-sample, and pick up the best model. Finally, forecast out-of-sample volatility for 1-day, 2-day, 5-day, 10-day and 20-day respectively, not only use different loss function to measure the performance, but also use DM test to compare the relative predictive power of the models under the different error distribution.

Fibroblast Growth Factor (FGF) 21 is a liver-derived endocrine factor with multiple metabolic effects on glucose and lipid homeostasis in animals. The adipose tissue has been proposed as a major target of FGF21, where it enhances glucose uptake and modulates lipolysis as well as thermogenesis. However, the molecular mechanisms underlying the pleiotropic effects of FGF21 in adipocytes and the physiological roles of FGF21 in regulating energy homeostasis remain poorly characterized. Therefore, the present study aimed to investigate: 1) the signal transduction pathway whereby FGF21 enhances glucose uptake in white adipocytes; 2) the role of FGF21 in lipolysis in both mouse and human white adipose tissues (WAT) and its underlying mechanisms involved; 3) the phenotypes of FGF21 knockout (KO) mice with respect to energy expenditure and adiposity under both standard chow and high fat diet. Key findings: 1. In vitro studies demonstrated that extracellular signal-regulated kinases (ERK1/2) play an obligatory role in mediating FGF21-induced upregulation of glucose transporter-1 (GLUT1) expression and hence elevation of glucose uptake in 3T3-L1 adipocytes. 2. Chromatin immunoprecipitation assay revealed that Serum Response Factor (SRF) and ETS-like protein-1 (Elk-1), the two transcription factors which are known as the downstream targets of ERK1/2, were recruited to the endogenous GLUT1 promoter in adipocytes. A conserved binding motif for these two transcription factors was also identified in the GLUT1 promoter responsive to FGF21 stimulation in 3T3-L1 adipocytes by site-directed mutagenesis and luciferase assay. 3. In WAT of diet-induced obese mice, FGF21-evoked downstream signaling events, including the phosphorylation of ERK1/2 and SRF/Elk-1, the upregulation of GLUT1, and the increased glucose uptake, were markedly blunted compared to lean controls, suggesting the existence of “FGF21 resistance” in obesity. 4. In vivo and ex vivo studies on fasted wild type and FGF21 KO mice demonstrated that FGF21 acutely suppressed basal and forskolin-stimulated lipolysis in WAT. 5. FGF21-inhibited lipolysis was mediated by Akt-dependent reduction of cyclic adenosine monophosphate (cAMP) levels in both mouse and human WAT. 6. FGF21 KO mice were resistant to diet- and aging-induced obesity, which was attributed to decreased fat mass. The increased lipolysis and fatty acid oxidation in FGF21 KO mice may explain in part the lean phenotype of FGF21 KO mice. Conclusions: These results collectively suggest FGF21 as a key modulator of glucose and lipid metabolism in WAT, by activation of ERK1/2 kinase and Akt respectively. FGF21 and its signaling components may represent potential targets for the future development of new strategies for treating obesity and its medical complications. / published_or_final_version / Medicine / Doctoral / Doctor of Philosophy

Introduction Globesity, the worldwide obesity epidemic, represents a major threat and public health burden. An uncontrolled expansion of the adipose tissue followed by a chronic low-grade inflammation leads to the dysfunction of the adipose organ resulting in obesity and its associated metabolic complications. Uncovering the mechanisms of adipogenesis, the development of adipocytes, therefore strikes as a key strategy in combating the disease. MicroRNAs (miRs), a class of small non-coding RNAs, have emerged in recent years as crucial modulators of diverse biological processes such as cell proliferation, differentiation, and signal transduction emphasizing their large potential as targets. Numerous miRs have been associated with the adipose tissue and metabolism and their dysregulation has repeatedly been linked to diseases including diabetes and obesity. This study aimed to investigate the role of miR-34a, an obesity-related miR, in the regulation of pre-adipocyte differentiation. Materials and Methods Mouse 3T3-L1 pre-adipocytes were employed as an in vitro system to study adipogenesis. Oil Red O staining served to evaluate the degree of adipogenesis and the over-expression of miR-34a in adipocytes was achieved by a lentiviral system. MiR and messenger RNA (mRNA) levels were analysed using TaqMan and SYBR Green-based quantitative real time PCR (qPCR) respectively. Results The expression of miR-34a was substantially down-regulated upon treatment of differentiation medium for two days and remained significantly low during the differentiation period compared with undifferentiated pre-adipocytes. Lentivirus-mediated over-expression of miR-34a successfully up-regulated miR-34a. Higher levels of miR-34a in turn mitigated adipogenesis as evidenced by blunted Oil Red O staining. This observation was found to be in good agreement with the qPCR analysis, which showed a down-regulation of several key adipogenic markers. Conclusion The down-regulation of miR-34a is required during pre-adipocyte differentiation for the efficient proceedings of the adipogenic programme. Further investigation is needed to evaluate the potential therapeutic implication of miR-34a-based treatment in managing obesity. / published_or_final_version / Medicine / Master / Master of Medical Sciences