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Populations of federally-listed gopher tortoises (Gopherus polyphemus) are in decline in Mississippi. Soil and forage quality may be linked to their health and recruitment. To gain a better understanding of existing soil and forage quality conditions on areas inhabited by gopher tortoises, I investigated soil chemistry parameters, forage nutrients, and plant community characteristics from 2012 to 2013. These parameters were collected on 7 soil and habitat management treatment types in uplands on public forest lands in south Mississippi. Soil sample analyses indicated that most pH levels in soils were acidic (pH < 5.0) to strongly acidic (pH < 4.5). Greatest soil calcium levels were detected on growing season burn, moderately suitable soil areas, and soil phosphorus levels were greatest on mowed, less suitable soil areas. Greatest levels of nutrients were detected at 0 – 10 cm soil depths. Weak, positive associations were detected between soil pH and soil calcium and magnesium levels, while weak, negative associations were detected between soil pH and soil phosphorus levels. Greater levels of calcium, magnesium, and phosphorus were detected in plants collected in mowed, less suitable soil areas. Cacti, forbs and, legumes were found to have greatest nutrient levels of all the plant growth forms. Moderate, positive associations were detected between soil pH and calcium levels in legumes and vines. Weak, positive associations were detected between soil pH and forage calcium levels in forbs and native grasses. Very weak, positive associations were detected between soil pH and forage phosphorus levels in vines. I found greatest species richness and percent coverage of legumes and forbs on moderately suitable soils that received growing season fire; whereas, greater species richness and percent coverage of native grasses were detected on moderately suitable soil regardless of season of burn. Greatest percent coverage of cacti (puntia sp.) and greatest quantities of above-ground plant biomass were detected on mowed, less suitable soil areas. This information can be valuable to habitat evaluation and management for gopher tortoises.

Um dos mais importantes achados dos últimos anos foi o de que o remodelamento ósseo está sujeito ao controle do SNC, com o SNS agindo como efetor periférico. Um estudo do nosso grupo demonstrou que camundongos <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- apresentam um fenótipo de alta massa óssea, como também são resistentes à osteopenia induzida pelo excesso de hormônio HT. Com o intuito de verificar a participação do <font face=\"Symbol\">a2A-AR-/- nestes processos, tivemos como objetivos: caracterizar o fenótipo ósseo de camundongos <font face=\"Symbol\">a2A-AR-/- e avaliar o efeito do HT na estrutura óssea desses camundongos tratados. Pudemos observar que o comprimento longitudinal dos ossos dos animais <font face=\"Symbol\">a2A-AR-/- são menores do que dos animais selvagens e a análise por <font face=\"Symbol\">mCT do fêmur mostrou uma diminuição da porosidade da cortical. Com relação ao tratamento com hormônio tireoideano, os animais <font face=\"Symbol\">a2A-AR-/- tratados com T3 foram resistentes à diminuição do comprimento dos ossos causado pelo excesso de HT e vimos, ainda, que o osso trabecular dos animais <font face=\"Symbol\">a2A-AR-/- foi mais sensível aos efeitos deletérios da tirotoxicose, entretanto o osso cortical e parâmetros biomecânicos ósseos dos animais KOs foram menos sensíveis. Em conclusão, o presente estudo sugere que o <font face=\"Symbol\">a2A-AR está envolvido no processo de crescimento ósseo e que esse receptor possa mediar, pelo menos parcialmente, ações negativas do T3 nesse processo como também do HT no osso cortical. / One of the most important finds of the recent years is that bone remodeling is subject to the control of the CNS, with SNS acting as the peripheral effector. However, a recent study of our group showed that mice <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- have a high bone mass phenotype, even though are resistant to the thyroid hormone-induced osteopenia. In order to verify the role of <font face=\"Symbol\">a2A-AR-/- in these cases, we had as objectives to evaluate whether the isolated inactivation of <font face=\"Symbol\">a2A-AR interferes with the bone structure, and to evaluate the action of HT on these animals. We have observed that the longitudinal length of the bones of <font face=\"Symbol\">a2A-AR-/- animals are lower than those of wild type animals and the analysis of the femur by <font face=\"Symbol\">mCT showed a lower cortical porosity. With regard to treatment with thyroid hormone, we observed that <font face=\"Symbol\">a2A-AR-/- animals were resistant to the bone length decrease caused by thyroid hormone excess. We also noticed that the trabecular bone of <font face=\"Symbol\">a2A-AR-/- animals was more sensitive to the deleterious effects of thyrotoxicosis. Moreover, the cortical bone and bone biomechanical parameters KO animals were less sensitive. In conclusion, the findings of this study suggest that <font face=\"Symbol\">a2A-AR is involved in the process of bone growth and that this receptor may mediate at least partly, negative actions of T3 in this process as well as the HT in the cortical bone.

Um dos mais importantes achados dos últimos anos foi o de que o remodelamento ósseo está sujeito ao controle do SNC, com o SNS agindo como efetor periférico. Um estudo do nosso grupo demonstrou que camundongos <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- apresentam um fenótipo de alta massa óssea, como também são resistentes à osteopenia induzida pelo excesso de hormônio HT. Com o intuito de verificar a participação do <font face=\"Symbol\">a2A-AR-/- nestes processos, tivemos como objetivos: caracterizar o fenótipo ósseo de camundongos <font face=\"Symbol\">a2A-AR-/- e avaliar o efeito do HT na estrutura óssea desses camundongos tratados. Pudemos observar que o comprimento longitudinal dos ossos dos animais <font face=\"Symbol\">a2A-AR-/- são menores do que dos animais selvagens e a análise por <font face=\"Symbol\">mCT do fêmur mostrou uma diminuição da porosidade da cortical. Com relação ao tratamento com hormônio tireoideano, os animais <font face=\"Symbol\">a2A-AR-/- tratados com T3 foram resistentes à diminuição do comprimento dos ossos causado pelo excesso de HT e vimos, ainda, que o osso trabecular dos animais <font face=\"Symbol\">a2A-AR-/- foi mais sensível aos efeitos deletérios da tirotoxicose, entretanto o osso cortical e parâmetros biomecânicos ósseos dos animais KOs foram menos sensíveis. Em conclusão, o presente estudo sugere que o <font face=\"Symbol\">a2A-AR está envolvido no processo de crescimento ósseo e que esse receptor possa mediar, pelo menos parcialmente, ações negativas do T3 nesse processo como também do HT no osso cortical. / One of the most important finds of the recent years is that bone remodeling is subject to the control of the CNS, with SNS acting as the peripheral effector. However, a recent study of our group showed that mice <font face=\"Symbol\">a2A/<font face=\"Symbol\">a2C-AR-/- have a high bone mass phenotype, even though are resistant to the thyroid hormone-induced osteopenia. In order to verify the role of <font face=\"Symbol\">a2A-AR-/- in these cases, we had as objectives to evaluate whether the isolated inactivation of <font face=\"Symbol\">a2A-AR interferes with the bone structure, and to evaluate the action of HT on these animals. We have observed that the longitudinal length of the bones of <font face=\"Symbol\">a2A-AR-/- animals are lower than those of wild type animals and the analysis of the femur by <font face=\"Symbol\">mCT showed a lower cortical porosity. With regard to treatment with thyroid hormone, we observed that <font face=\"Symbol\">a2A-AR-/- animals were resistant to the bone length decrease caused by thyroid hormone excess. We also noticed that the trabecular bone of <font face=\"Symbol\">a2A-AR-/- animals was more sensitive to the deleterious effects of thyrotoxicosis. Moreover, the cortical bone and bone biomechanical parameters KO animals were less sensitive. In conclusion, the findings of this study suggest that <font face=\"Symbol\">a2A-AR is involved in the process of bone growth and that this receptor may mediate at least partly, negative actions of T3 in this process as well as the HT in the cortical bone.

An essential part of bioarchaeology is the study of diet and nutrition and its effects on the general health of a person. Interpretation of nutritional and metabolic disease related pathologies often provide additional insight into the daily social and cultural practices of people. It is therefore also an essential part of understanding differences amongst past populations from archaeological contexts and provides an alternative means for cross referencing historical accounts. In this study the skeletal remains of 36 Chinese indentured mine labourers, who worked and died on the Witwatersrand mines during the period AD 1904-1910, were assessed for any signs of metabolic or nutritionally related signs of disease. Historical information suggests that these indentured Chinese labourers came from poverty stricken communities in China where disease and malnutrition were often encountered. Once in South Africa they were again subjected to the harsh living and working conditions associated with mining. Analyses suggest that all 36 individuals were males between the ages of 16 and 45 years, with the majority being of young adult age (20-34 years). Pathology that could be observed included a high prevalence of nutrition-related changes and linear enamel hypoplasia which suggests that the Chinese miners had been subjected to long periods of malnutrition and illness throughout childhood continuing into adulthood. Nevertheless, a large proportion of lesions associated with malnutrition showed some degree of healing. A high frequency of traumatic lesions, specifically peri-mortem fractures, was observed and may have contributed to the death of many of the Chinese miners. It therefore seems that even though the healing of pathological lesions associated with malnutrition indicated a period of improved nutritional intake, possibly during their time on the Witwatersrand mines, the high prevalence of peri-mortem fractures attests to the hazardous working conditions associated with deep-level mining. In order to aid in the interpretation of skeletal pathology associated with metabolic and nutritional diseases non-specific signs of disease observed in a cadaver skeletal sample with known causes of death (related to specific metabolic or nutritional diseases) were compared to pathology observed in the Chinese miners. This provided pathological patterns which enabled a better interpretation of the pathology observed in the Chinese skeletal remains. / Dissertation (MSc)--University of Pretoria, 2014. / am2014 / Anatomy / unrestricted

Changes in bone and mineral metabolism and the role of vitamin D in very low birth weight infants. Firstly, the aim of dissertation work was to estimate physiological parathyroid hormone (PTH) levels and their relationship with bone metabolism parameters in otherwise healthy preterm newborns with birth weight 1000-1500 g. Secondly, to evaluate vitamin D status in mothers and their very low birth weight infants (VLBW) at birth and at discharge with currently recommended supplementation of vitamin D. Thirdly, to compare clinical outcomes of VLBW infants with 25-hydroxy vitamin D [25(OH)D] levels ≤ and > 25 nmol/l in umbilical cord blood and finally to evaluate umbilical cord vitamin D as a risk factor for respiratory distress syndrome in preterm infants. It is a set of prospective observational studies involving immature newborns with birth weight below 1500 g. The parameters of mineral and bone metabolism were analysed in umbilical cord blood and newborn serum and urine during hospitalisation (PTH, 25-hydroxy vitamin D, S-Ca, S-P, ALP, U-Ca, U-P) and in pregnant women before delivery (25-hydroxy vitamin D). Bone mineralization was evaluated by bone densitometry. In a pilot study, from the total 134 examined serum samples for PTH levels the estimated reference range was 1.6 - 9.3 pmol/l. From the...