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Basal metabolic rate (BMR), an individual bird's minimum rate of energy expenditure, was followed in adult and juvenile captive Knot throughout their annual cycle, in conjunction with measurements of total body mass (BM) and body composition (lean mass and fat mass, as predicted using Total Body Electrical Conductivity). Adult captive Knot increased significantly in BM during spring, primarily due to fat deposition. Most juvenile Knot did not display fat deposition in their first spring in captivity. A seasonal peak in BMR, often double the seasonal minimum, occurred during spring but typically took place, on average, 5,11 and 4 days (respectively) after the seasonal peaks in BM, lean mass and fat mass. Little of the variation in BMR seen within or amongst captive Knot, irrespective of physiological state, was explained by variation in a single parameter (BM, lean mass or fat mass). As variation in BMR was not simply a consequence of variation in total lean mass, the average metabolic output per gram of the lean tissues must also have altered seasonally. During fat deposition in spring, Knot exhibited a significant increase in liver mass and a significant elevation (approximately 50% higher) in the activity of succinate dehydrogenase (SDH, an indicator of metabolic activity) in the small intestine. Such adaptations may have assisted an increase in fat deposition rate. SDH activity decreased by approximately 60% in the pectoral muscle of Knot during this period. Such a reduction in SDH may also aid fat deposition as it lowered an individual’s overall BMR. As Knot BM decreased after the spring peak, then BMR decreased in parallel with a decrease in SDH activity in their pectoral muscles. The spring peak in overall BMR may indicate an increase in the maximal sustainable metabolic rate (MMR) of an individual during migratory flight. If a relationship exists between BMR and MMR, then variation in metabolic activity rather than variation in the mass of various lean tissues (e.g. pectoral muscle) will increase metabolic scope without increasing the energetic costs of flight.

It has been theorized that muscles generate more force on bone than body weight alone and therefore it is likely that muscle contraction drives and sustains bone adaptation (Frost 1999). Purpose: To investigate the relationship between the timing and tempo of peak growth velocities of lean tissue (LT) and bone mineral content (BMC) in boys and girls at three sites using data derived from individual growth curves. Methods: 72 boys and 70 girls were fitted with growth curves that had a distinguishable peak. Height and weight were measured for each participant and tissue assessment was performed annually using DXA. Factorial ANOVAs were completed to analyse data for differences in age, while forward regression analyses was used between LT and BMC. Results: The peak growth velocity for lean occurred significantly (P<0.05) earlier than the peak growth velocity for bone at all locations except the legs. There was a difference (P<0.001) between genders in the age of peak for both lean tissue and bone tissue at all locations with females peak growth occurring before that of males. When aligned by PHV a significant difference (P<0.05) in the timing of PBMCV was found between the arms and the legs with the peak in bone growth in the legs occurring significantly before peak bone growth in the arms. PLTV was independently associated with PBMCV at the arms (r2= .71, p<0.001), legs (r2= .53, p<0.001) and trunk (r2= .52, p<0.001). Conclusion: In conclusion, LT growth precedes BMC growth and after controlling for gender, size and maturity the magnitude of LT growth is associated with BMC growth. The findings of this study are in support the Muscle-bone Unit (Frost and Schoenau, 2000), which theorizes that localised muscle action is a driving force for bone growth. Future studies are needed to analyse bone strength as it relates to local muscle strength and usage while controlling for confounding variables.

Purpose: The objective of this study was to examine the timing of the age and the magnitude of peak lean tissue mass accrual (peak lean tissue velocity, PLTV) as it relates to the age and magnitude of peak cross sectional area velocity (PCSAV) and section modulus velocity (PZV) of proximal femur in both males and females during adolescence. We hypothesized that the age of PLTV would precede the age of PCSAV and PZV and that there be a positive relationship between the magnitude of PLTV and both PCSAV and PZV in both genders. <p>Methods: 41 males and 42 females aged 8-18 years were selected from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2005). Participants total body lean tissue mass was assessed annually for 6 consecutive years using DXA. Narrow neck, intertrochanteric and femoral shaft cross sectional areas (CSA) and section modulus (Z) were determined annually using the hip structural analysis (HSA) program. Participants were aligned by maturational age (years from peak height velocity). Lean tissue mass, CSA, and Z were converted into whole year velocities and the maturational age of peak tissue velocities was determined using a cubic spline curve fitting procedure. A 2x3 (gender x tissue) factorial MANOVA with repeated measures was used to test for differences between age of PLTV and both, the age of PCSAV and PZV between males and females. Multiple regression analyses were used to determine the relationship between PLTV and both PCSAV and PZV.<p>Results: There were no sex differences in the ages at which tissue peaks occurred when aligned by maturational age. There were significant differences between the age of PLTV and both PCSAV and PZV at the narrow neck (p=0.001) and femoral shaft (p=0.03), where the age of PLTV preceded both PCSAV and PZV when pooled by gender. There were no significant differences at the intertrochanteric site (p=0.814). PLTV was a significant predictor of the magnitude of both PCSAV and PZV at all sites (p<0.05). <p> Conclusions: These findings support the hypothesis that the age of PLTV precedes the age of PCSA and PZV at the proximal femur and provides further evidence to support the muscle-bone relationship, suggesting that lean tissue mass accrual influences bone strength development at proximal femur during pubertal growth.

It has been theorized that muscles generate more force on bone than body weight alone and therefore it is likely that muscle contraction drives and sustains bone adaptation (Frost 1999). Purpose: To investigate the relationship between the timing and tempo of peak growth velocities of lean tissue (LT) and bone mineral content (BMC) in boys and girls at three sites using data derived from individual growth curves. Methods: 72 boys and 70 girls were fitted with growth curves that had a distinguishable peak. Height and weight were measured for each participant and tissue assessment was performed annually using DXA. Factorial ANOVAs were completed to analyse data for differences in age, while forward regression analyses was used between LT and BMC. Results: The peak growth velocity for lean occurred significantly (P<0.05) earlier than the peak growth velocity for bone at all locations except the legs. There was a difference (P<0.001) between genders in the age of peak for both lean tissue and bone tissue at all locations with females peak growth occurring before that of males. When aligned by PHV a significant difference (P<0.05) in the timing of PBMCV was found between the arms and the legs with the peak in bone growth in the legs occurring significantly before peak bone growth in the arms. PLTV was independently associated with PBMCV at the arms (r2= .71, p<0.001), legs (r2= .53, p<0.001) and trunk (r2= .52, p<0.001). Conclusion: In conclusion, LT growth precedes BMC growth and after controlling for gender, size and maturity the magnitude of LT growth is associated with BMC growth. The findings of this study are in support the Muscle-bone Unit (Frost and Schoenau, 2000), which theorizes that localised muscle action is a driving force for bone growth. Future studies are needed to analyse bone strength as it relates to local muscle strength and usage while controlling for confounding variables.

Purpose: The objective of this study was to examine the timing of the age and the magnitude of peak lean tissue mass accrual (peak lean tissue velocity, PLTV) as it relates to the age and magnitude of peak cross sectional area velocity (PCSAV) and section modulus velocity (PZV) of proximal femur in both males and females during adolescence. We hypothesized that the age of PLTV would precede the age of PCSAV and PZV and that there be a positive relationship between the magnitude of PLTV and both PCSAV and PZV in both genders. <p>Methods: 41 males and 42 females aged 8-18 years were selected from the Saskatchewan Pediatric Bone Mineral Accrual Study (1991-2005). Participants total body lean tissue mass was assessed annually for 6 consecutive years using DXA. Narrow neck, intertrochanteric and femoral shaft cross sectional areas (CSA) and section modulus (Z) were determined annually using the hip structural analysis (HSA) program. Participants were aligned by maturational age (years from peak height velocity). Lean tissue mass, CSA, and Z were converted into whole year velocities and the maturational age of peak tissue velocities was determined using a cubic spline curve fitting procedure. A 2x3 (gender x tissue) factorial MANOVA with repeated measures was used to test for differences between age of PLTV and both, the age of PCSAV and PZV between males and females. Multiple regression analyses were used to determine the relationship between PLTV and both PCSAV and PZV.<p>Results: There were no sex differences in the ages at which tissue peaks occurred when aligned by maturational age. There were significant differences between the age of PLTV and both PCSAV and PZV at the narrow neck (p=0.001) and femoral shaft (p=0.03), where the age of PLTV preceded both PCSAV and PZV when pooled by gender. There were no significant differences at the intertrochanteric site (p=0.814). PLTV was a significant predictor of the magnitude of both PCSAV and PZV at all sites (p<0.05). <p> Conclusions: These findings support the hypothesis that the age of PLTV precedes the age of PCSA and PZV at the proximal femur and provides further evidence to support the muscle-bone relationship, suggesting that lean tissue mass accrual influences bone strength development at proximal femur during pubertal growth.

Phosphatidic Acid (PA) is a natural phospholipid compound derived from lecithin which is commonly found in egg yolk, grains, fish, soybeans, peanuts and yeast. It has been suggested that PA is involved in several intracellular processes associated with muscle hypertrophy. Specifically, PA has been reported to activate protein synthesis through the mammalian target of rapamycin (mTOR) signaling pathway and thereby may enhance the anabolic effects of resistance training. To our knowledge, no one has examined the effect of PA supplementation in humans while undergoing a progressive resistance training program. To examine the effect of PA supplementation on lean soft tissue mass (LM) and strength after 8 weeks of resistance training. Fourteen resistance-trained men (mean ± SD; age 22.7 ± 3.3 yrs; height: 1.78 ± 0.10m; weight: 89.3 ± 16.3 kg) volunteered to participate in this randomized, double-blind, placebocontrolled, repeated measures study. The participants were assigned to a PA group (750mg/day; Mediator®, ChemiNutra, MN, n=7) or placebo group (PL; rice flower; n=7), delivered in capsule form that was identical in size, shape and color. Participants were tested for 1RM strength in the bench press (BP) and squat (SQ) exercise. LM was measured using dual-energy X-ray absorptiometry. After base line testing, the participants began supplementing PA or PLfor 8 weeks during a progressive resistance training program intended for muscular hypertrophy. Data was analyzed using magnitude-based inferences on mean changes for BP, SQ and LM. Furthermore, the magnitudes of the interrelationships between changes in total training volume and LM were interpreted using Pearson correlation coefficients, which had uncertainty (90% confidence limits) of approximately +0.25. iv In the PA group, the relationship between changes in training volume and LM was large(r=0.69, +0.27; 90%CL), however, in the PL group the relationship was small (r=0.21, +0.44; 90%CL). PA supplementation was determined to be likely beneficial at improving SQ and LM over PL by 26% and 64%, respectively. The strong relationship between changes in total training volume and LM in the PA group suggest that greater training volume most likely lead to the greater changes in LM, however, no such relationship was found with PL group. For the BP data, the PA group resulted in a 42% greater increase in strength over PL, although the effect was considered unclear. While more research is needed to elucidate mechanism of action; the current findings suggest that in experienced resistance trained men supplementing 750mg PA per day for 8 weeks may likely benefit greater changes in muscle mass and strength compared with resistance training only.

Conselho Nacional de Desenvolvimento CientÃfico e TecnolÃgico / Foi avaliada a composiÃÃo relativa dos cortes comerciais da carcaÃa e a composiÃÃo tecidual (mÃsculo, osso e gordura) da perna, lombo e paleta de cabritos mestiÃos Boer, Anglo Nubiano e os do tipo sem raÃa definida (SPRD), esse Ãltimo usado como grupo controle. Foram utilizados 44 caprinos, sendo 20 de diferentes graus de sangue Anglo Nubiano x SPRD (13  Anglo Nubiano x  SPRD e 07  Anglo Nubiano x  SPRD), 16 Boer x SPRD (07  Boer x  SPRD e 09  Boer x  SPRD) e 8 cabritos SPRD. Os animais foram abatidos, em mÃdia, com 12 meses de idade e 30 kg de peso vivo. ApÃs resfriamento (2ÂC) da carcaÃa por 24 horas, foram separados os seguintes cortes comerciais: perna, lombo (anterior e posterior), paleta, peito, costela, pescoÃo e fraldinha, sendo obtidos os rendimentos em relaÃÃo ao peso da carcaÃa fria. Em seguida, a perna, o lombo (anterior e posterior) e a paleta foram dissecados, separando-se os tecidos muscular, adiposo e Ãsseo. A partir dos pesos desses tecidos, foram estimadas as relaÃÃes mÃsculo:osso (RMO) e mÃsculo:gordura (RMG). O desenho experimental obedeceu a um delineamento inteiramente casualizado, e os dados foram analisados pelo procedimento GLM do pacote estatÃstico SAS, em que as mÃdias foram comparadas pelo teste de Tukey. Os rendimentos mÃdios dos cortes foram: perna = 29,8%, lombo = 24,7% (anterior = 18,3% e posterior = 6,4%), paleta = 20,8%, peito = 5,0%, pescoÃo = 7,16%, costela = 3,3% e fraldinha = 5,8%, sem que tenham sido observadas diferenÃas significativas (P>0,05) entre os grupos genÃticos para os cortes estudados, exceto para costela e pescoÃo. Nos cabritos mestiÃos Boer, observaram-se rendimentos superiores (P<0,05) no tecido muscular (64,88%) e na RMO (5,40). Jà nos cabritos mestiÃos Anglo Nubiano, observou-se rendimento superior (P<0,05) para o tecido adiposo (9,46%), enquanto os cabritos SPRD apresentaram superioridade no rendimento do tecido Ãsseo (21,35%) e na RMG (10,5). Conclui-se que, nos cortes de maior valor comercial, a carcaÃa de cabritos mestiÃos Boer apresenta uma maior proporÃÃo de tecido muscular que os cabritos mestiÃos Anglo Nubiano e os SPRD / In this study, the relative composition of the commercial cuts of the carcass and the tissue composition (muscle, bones and fat) of the thigh, loin and shoulders of half-blooded Boer, Anglo Nubian and undefined-breed kids (SPRD) were evaluated. The SPRDâs were used as control group. Forty-four pieces were used, of which 20 units of mixed-blooded Anglo Nubian x SPRD (13  Anglo Nubian x  SPRD and 7  Anglo Nubiano x  SPRD), sixteen Boer x SPRD (07  Boer x  SPRD and 09  Boer x  SPRD), and the remaining 8 heads being SPRDâs. The animals were slaughtered at the average age and weight of 12 months and 30 kg respectively live weight. After cooling the carcass at 2 degrees centigrade for 24 hours the following commercial cuts were set apart: thigh, loin ( front and hind ) shoulders, breast, ribs, neck, sirloin and the proportional weights were figured out in relation to the total weight of the cold carcass. Next, the thigh, loin (front and hind) and shoulders were dissected and the relationship between the weight of the cold carcass and yield was determined, setting apart the muscular, bone and grease tissues. From the weights of such tissues the relations muscle/bones (RMB) and muscle/fate (RMF) were estimated. The experimental scratch was designed in an entirely random way and the data was analyzed according to the GLM procedures in the SAS statistics package in the which the measurements were compared according to the Tukey test. The average yield of the cuts was: tight 29.8%, loin 24.7% ( front 18.3% and hind 6.4%), shoulders 20.8% , breast 5.0%, neck 7.16%, ribs 3.3%, sirloin 5.8%. No significant differences (P>0.05) were found among the genetic groups studied except for the neck and ribs. In the Boer mixed blooded animals higher yield (P>0.05) in the muscular tissues (64.88 %) and in RMB (5.40%) were absorbed. The Anglo Nubian mixed blooded animals showed a higher yield (P<0.05) in the grease tissues (9.46 %), whereas the SPRDâs showed a superior yield in the bone tissue (21.35%) and in the RMF (10.5). The conclusion was that in the cuts of greater commercial value, the carcass of Boer mixed shows a better yield of muscular tissue than the Anglo Nubian and SPRDâs half breeds

No description available.