The neonatal period in mammals is characterized by high growth rates and is dominated by skeletal muscle hypertrophy. Low birth weight (LBWT) neonates experience restricted growth and development of skeletal muscle, leading to metabolic perturbations later in life. The overall hypothesis of this dissertation was that in utero disturbances in glucose metabolism and increased energy requirements predisposes LBWT neonatal pigs to metabolic disturbances after birth. We sought to increase growth of skeletal muscle and improve glucose production through increasing dietary energy and to determine the changes in glucose catabolism and metabolic flexibility in different skeletal muscle fiber types in LBWT neonates. Piglets were considered normal birth weight (NBWT) and LBWT when birth weight was within 0.5 SD and below 2 SD of the litter average, respectively. Increasing dietary energy increased lean deposition in the longissimus dorsi (LD) in both NBWT and LBWT neonates. Although glucose rate of appearance was greater in LBWT compared to their NBWT sibling, glucose concentrations were reduced in LBWT compared to NBWT pigs, regardless of diet fed. Postprandial glucose concentrations were lower in LBWT compared to NBWT pigs, regardless of diet fed, although rate of appearance did not differ between them. This would suggest that glucose is being absorbed in the peripheral tissues to be utilized. However, expression of enzymes related to glycolysis were downregulated in both the soleus and LD of LBWT compared to NBWT neonatal pigs. In addition, expression of enzymes related to the catabolism of glucose in the serine biosynthetic pathway were decreased in both the soleus and LD muscles of LBWT compared to NBWT neonatal pigs. Expression of the pentose phosphate pathway was slightly increased in LBWT compared to NBWT siblings in both muscle types. Increased expression of pyruvate dehydrogenase 4 was exhibited in both the soleus and LD of LBWT pigs compared to NBWT siblings. This would indicate a switch in fuel utilization to more fatty acid oxidation. By contrast, CO2 production from the oxidation of palmitate was reduced in LBWT compared with NBWT pigs along with reduced oxidation of glucose and pyruvate. In conclusion, lipid supplementation increased growth at the expense of fat deposition in the liver of NBWT and LBWT pigs. However, supplementing with fat did not increase glucose production due to the contribution of glycerol remaining constant. Hypoglycemia cannot be attributed to greater catabolism in skeletal muscle due to decreased expression of glycolytic genes and the addition of fatty acids did not spare glucose oxidation in skeletal muscle of LBWT pigs. / PHD / During the neonatal period animals display the fastest growth rates, especially pertaining to muscle growth. Muscle development in low birth weight (LBWT) is restricted, leading not only to impaired postnatal growth but increases the risk for developing metabolic diseases later in life such as obesity and type 2 diabetes. LBWT is also characterized by decreased glucose concentrations and decreased body fat content at birth. In the present studies we sought to increase growth and improve glucose production by supplementing with a high energy diet and to compare the changes in glucose catabolism in different skeletal muscle fiber types along with analyzing the ability to switch fuel substrates in LBWT and NBWT neonatal pigs. Increasing dietary energy increased longissimus dorsi (LD) weight as a percentage of bodyweight, regardless of growth status. In addition, during fasting glucose production was higher in LBWT compared to their NBWT siblings, regardless of diet. However, glucose concentration in LBWT were lower compared to NBWT neonatal pigs. Although glucose concentrations were lower in LBWT compared to NBWT pigs after a meal, glucose production rate was unchanged among LBWT and NBWT siblings fed either a high or low energy diet. This suggests that glucose uptake is increased in peripheral tissues of LBWT pigs. However, enzymes related to glycolysis in the LD and soleus of LBWT pigs had lower expression than their NBWT sibling. In addition, the enzyme responsible for the shift in fuel selection, pyruvate dehydrogenase kinase 4 (PDK4) was highly expressed in LBWT compared to NBWT neonatal pigs in both the LD and soleus. This would suggest a switch in glucose oxidation to fatty acid oxidation in the skeletal muscle of LBWT neonatal pigs. However, oxidation of fatty acids in both the soleus and LD of LBWT was reduced compared to NBWT neonatal pigs. In conclusion, lipid supplementation increased growth at the expense of lipid deposition in the liver and did not increase glucose production. Reduced glucose concentrations are not due to greater catabolism in skeletal muscle due to decreased expression of glycolytic genes and the addition of fatty acids did not spare glucose oxidation in the skeletal muscle of LBWT pigs.

The neonatal period in mammals is characterized by high rates of growth, attributed to rapid myonuclear accretion and protein deposition in muscle. Low-birth-weight (LBWT) neonates experience restricted muscle development, which leads to impaired postnatal growth and metabolic disorders later in life. The overall hypothesis of this dissertation was that dysfunction of myogenic satellite cells and aberrant regulation of protein synthesis and degradation signaling predispose LBWT neonatal pigs to slower postnatal growth. We sought to determine the proliferation and differentiation of satellite cells (SCs) derived from skeletal muscle of LBWT neonatal pigs and to elucidate the cellular mechanisms that regulate protein synthesis and degradation in LBWT pig muscles. Newborn pigs were considered as normal-birth-weight (NBWT) or LBWT when weight at birth was within 0.5 SD and below 2 SD of litter average respectively. SCs isolated from longissimus dorsi (LD) muscle of NBWT and LBWT neonatal pigs displayed similar proliferation rates. Fusion was modestly diminished in SCs from muscle of LBWT pigs compared with their NBWT siblings, suggesting SCs were not intrinsically different between the two groups and were unlikely a major contributor to the impaired muscle growth of LBWT pigs. Plasma and muscle insulin-like growth factor (IGF)-I was diminished in LBWT compared with NBWT pigs. In addition, reduced activation of key components of IGF-I downstream signaling pathway in LBWT pigs muscle may lead to diminished translation initiation signaling and thus decreased protein synthesis in these animals. However, IGF-I receptor expression and myostatin signaling inversely correlated to LBWT, indicating they may participate in compensatory responses for the reduction in protein synthesis signaling. Expression of eukaryotic initiation factor (eIF) 4F complex subunits, eIF4E, eIF4G, and eIF4A was reduced in LBWT compared with NBWT pigs. This would suggest that diminished translation initiation signaling in skeletal muscle of LBWT pigs is the main factor that predisposes LBWT pigs to slower growth rates in the neonatal period. In contrast, changes in protein degradation signaling do not appear to affect protein turnover in LBWT neonatal pigs. / PHD

No

No / Despite an increasing literature on the decomposition of buried and exposed human remains it is important to recognise that specific microenviron-ments will either trigger, or delay the rate of decomposition. Recent casework in arid regions of the world has indicated a need for a more detailed understanding of the effects of burial over relatively short timescales. The decomposition of buried human remains in the coastal desert of Peru was investigated using pig cadavers (Sus scrofa) as body analogues. The project aims were to specifically examine the early phases of natural mummification and contrast the effects of direct burial in ground with burial in a tomb structure (i.e. with an air void). Temperature was logged at hourly intervals from both the surface, grave fill and core body throughout the experiment. In addition, air temperature and humidity were measured within the air void of the tomb. After two years all three pig graves were excavated, the temperature and humidity data downloaded and the pig carcasses dissected on site to evaluate condition. The results demonstrate that: (1) there were distinct differences in the nature/rate of decomposition according to burial mode; (2) after two years burial the carcasses had been subject to considerable desiccation of the outer tissues while remaining moist in the core; (3) the body had undergone putrefactive change and collapsed leading to slumping of soil within the grave fill following the curvature of the pig's back, although this was not evident from the surface; (4) there was a specific plume of body decomposition products that wicked both horizontally and also vertically from the head wounds in the sandy desert soil. These observations have widespread application for prospection techniques, investigation of clandestine burial, time since deposition and in understanding changes within the burial microenvironment under arid conditions.

No / Introduction: Potential-sensitive dyes have primarily been used to optically record action potentials (APs) in whole heart tissue. Using these dyes to record drug-induced changes in AP morphology of isolated cardiac myocytes could provide an opportunity to develop medium throughout assays for the pharmaceutical industry. Ideally, this requires that the dye has a consistent and rapid response to membrane potential, is insensitive to movement, and does not itself affect AP morphology. Materials and methods: We recorded the AP from isolated adult guinea-pig ventricular myocytes optically using di-8-ANEPPS in a single-excitation dual-emission ratiometric system, either separately in electrically field stimulated myocytes, or simultaneously with an electrical AP recorded with a patch electrode in the whole-cell bridge mode. The ratio of di-8-ANEPPS fluorescence signal was calibrated against membrane potential using a switch-clamp to voltage clamp the myocyte. Results: Our data show that the ratio of the optical signals emitted at 560/620 nm is linearly related to voltage over the voltage range of an AP, producing a change in ratio of 7.5% per 100mV, is unaffected by cell movement and is identical to the AP recorded simultaneously with a patch electrode. However, the APD90 recorded optically in myocytes loaded with di-8-ANEPPS was significantly longer than in unloaded myocytes recorded with a patch electrode (355.6 ± 13.5 vs. 296.2 ± 16.2ms; p< 0.01). Despite this effect, the apparent IC50 for cisapride, which prolongs the AP by blocking IKr, was not significantly different whether determined optically or with a patch electrode (91 ± 46 vs. 81 ± 20 nM). Discussion: These data show that the optical AP recorded ratiometrically using di-8- ANEPPS from a single ventricular myocyte accurately follows the action potential morphology. This technique can be used to estimate the AP prolonging effects of a compound, although di-8-ANEPPS itself prolongs APD90. Optical dyes require less technical skills and are less invasive than conventional electrophysiological techniques and, when coupled to ventricular myocytes, decreases animal usage and facilitates higher throughput assays.

This work is concerned with an attempt to clarify the role of cortisone in both the immune complement response and the progression of mouse leukemic tumor.

Este trabalho descreve o desenvolvimento de um algoritmo para avaliar o grau de corrosão em paredes de oleodutos, através de ultrassom. O algoritmo desenvolvido será implementado em um circuito digital, fazendo parte de um sistema que poderá ser embarcado em pigs ultrassônicos para inspeção de dutos à procura de corrosão. O modelo matemático conhecido como filtro casado é usado como base do algoritmo, além de um método de detecção de picos para localização dos sinais de eco de ultrassom, provenientes das reflexões do sinal nas paredes dos dutos. Um dos problemas é a definição do sinal (e do filtro) que será utilizado, mas por meio de sinais sintetizados (signal design) uma grande gama de alternativas foi analisada e apenas algumas foram selecionadas para testes em experimentos. Por último os melhores sinais foram utilizados na inspeção de um corpo de prova feito à partir de um duto corroído, e os resultados são analisados. A detecção da primeira parede do oleoduto apresenta resultados promissores em comparação com a medição tridimensional das mesmas paredes. O sistema foi capaz de reconstruir o perfil da parede interna do duto com elevada verossimilhança, mesmo em regiões severamente corroídas. A detecção da segunda parede apresenta resultados satisfatórios para baixos níveis de corrosão, porém alguns problemas foram encontrados para níveis mais altos de corrosão, prejudicando a medição direta da espessura da parede nestas condições. / This work describes the development of an algorithm to evaluate the degree of corrosion in pipeline walls, using ultrasound. The developed algorithm will be implemented in a dedicated digital circuit that can be embedded in ultrasonic pigs for pipeline corrosion inspection. The algorithm is based on the mathematic model known as matched filter, besides a peak detection method for the location of ultrasound echoes, originated from the signal reflections in the pipeline walls. One problem is the determination of the signal (and filter) that should be used, but using a signal design approach a large number of possibilities could be analyzed and only a few was tested in experiments. Finally, the best signals were used to inspect a test specimen made of a corroded pipeline section, and the results were analyzed. The first wall detection shows promising results when compared to the results of a three-dimensional inspection of the same walls. It was possible to reconstruct the profile of the internal wall with good likelihood, even at badly corroded areas. The second wall detection shows some satisfactory results on low corrosion levels, but show some problems with high corrosion levels, compromising the direct measurement of the wall of the pipeline.

Este trabalho descreve o desenvolvimento de um algoritmo para avaliar o grau de corrosão em paredes de oleodutos, através de ultrassom. O algoritmo desenvolvido será implementado em um circuito digital, fazendo parte de um sistema que poderá ser embarcado em pigs ultrassônicos para inspeção de dutos à procura de corrosão. O modelo matemático conhecido como filtro casado é usado como base do algoritmo, além de um método de detecção de picos para localização dos sinais de eco de ultrassom, provenientes das reflexões do sinal nas paredes dos dutos. Um dos problemas é a definição do sinal (e do filtro) que será utilizado, mas por meio de sinais sintetizados (signal design) uma grande gama de alternativas foi analisada e apenas algumas foram selecionadas para testes em experimentos. Por último os melhores sinais foram utilizados na inspeção de um corpo de prova feito à partir de um duto corroído, e os resultados são analisados. A detecção da primeira parede do oleoduto apresenta resultados promissores em comparação com a medição tridimensional das mesmas paredes. O sistema foi capaz de reconstruir o perfil da parede interna do duto com elevada verossimilhança, mesmo em regiões severamente corroídas. A detecção da segunda parede apresenta resultados satisfatórios para baixos níveis de corrosão, porém alguns problemas foram encontrados para níveis mais altos de corrosão, prejudicando a medição direta da espessura da parede nestas condições. / This work describes the development of an algorithm to evaluate the degree of corrosion in pipeline walls, using ultrasound. The developed algorithm will be implemented in a dedicated digital circuit that can be embedded in ultrasonic pigs for pipeline corrosion inspection. The algorithm is based on the mathematic model known as matched filter, besides a peak detection method for the location of ultrasound echoes, originated from the signal reflections in the pipeline walls. One problem is the determination of the signal (and filter) that should be used, but using a signal design approach a large number of possibilities could be analyzed and only a few was tested in experiments. Finally, the best signals were used to inspect a test specimen made of a corroded pipeline section, and the results were analyzed. The first wall detection shows promising results when compared to the results of a three-dimensional inspection of the same walls. It was possible to reconstruct the profile of the internal wall with good likelihood, even at badly corroded areas. The second wall detection shows some satisfactory results on low corrosion levels, but show some problems with high corrosion levels, compromising the direct measurement of the wall of the pipeline.

<p>  </p> <p>In commercial settings, piglet weaning and transportation occur concurrently due to the expansive application of multi-site production systems across the United States and the combination of these events can be defined as an early life stressor. Early life stress is known to reduce pig performance, efficiency, and immune resilience contributing to reduced welfare and increased production losses. To combat the deleterious effects of stress on pigs, the essential amino acid tryptophan (Trp) supplemented above current National Research Council (NRC 2012) recommended levels, improves neuroendocrine responses to stress, lowers plasma cortisol and norepinephrine concentrations, and improves hypothalamic-pituitary-adrenal axis recovery time following stress. However, there are discrepancies concerning the Trp requirement for nursery pigs, suggesting the 2012 recommendations for Trp may be inaccurate for optimizing growth performance and health in modern pigs. Three experiments were conducted to determine the effects of supplemented standard ileal digestible Trp above NRC (2012) recommended levels on performance, feed efficiency, immune vigor, and stress tolerance. The objective of experiment 1 was to eliminate or reduce short- and long-term, transport-induced reductions in piglet feed efficiency and growth by supplementing Trp above NRC (2012) recommendations pre-weaning and/or during the nursery phase. An oral gavage of Trp or a control milk carrier was provided to pre-allotted piglets beginning at day 5 of lactation and continuing to weaning. At weaning all pigs were blocked by sex, weaning weight and pre-wean treatment and randomly assigned to transport and post-wean treatments. Pigs were fed in four nursery phases with diets containing 1X or 2X NRC recommended concentrations of SID Trp and a common grower diet fed in 6 phases during the grow-finish period. At market, loin characteristics were measured via ultrasound and carcass data was collected from the packing plant. Pre-weaning Trp supplementation had no effect on pre-weaning growth performance; however, post-wean Trp increased overall body weight and average daily gain in nursery pigs when Trp was supplemented pre-wean. The objective for experiment 2 was to mitigate the adverse effects of early life transport stress on subsequent immune challenges by providing supplemental Trp during the nursery period. At weaning, pigs were transported for 8 hours and assigned to treatments of vaccine-induced immune challenge and dietary treatment. Pigs were fed standard nursery diets, in four phases, over 35 days with pigs receiving 1X or 2X the NRC (2012) recommended Trp concentration. Half the pigs on each dietary treatment were subjected to a 3-wk vaccine challenge consisting of circovirus, mycoplasma, and influenza vaccines administered in wk 2, 3, and 4 post-wean, respectively. At market, loin characteristics were measured via ultrasound and carcass data was collected.  At the culmination of the nursery period, unchallenged pigs supplemented with Trp were heavier compared to control pigs. This resulted from an overall improvement in average daily gain for 2X Trp fed pigs. However, increasing Trp did not affect market weight, loin eye area, or lean percent in market pigs, although 2X Trp increased back fat. The objective of experiment 3 was to determine what ratio of SID tryptophan, relative to lysine, maximizes growth performance and feed efficiency in weaned pigs during the nursery period. Pigs were blocked by sex and weaning weight and randomly allotted to one of five dietary treatments with Trp increasing stepwise by 0.33%-units, respectively. Pigs were fed standard nursery diets, in four phases, over 35 days with pigs receiving 1X, 1.33X, 1.66X, 2X, or 2.33X the NRC (2012) recommended Trp concentration.  Overall, there were no differences in performance or efficiency across dietary treatments during a 35-day nursery period in unstressed healthy pigs.  In conclusion, increasing Trp in swine diets prior to and/or following stress events can mitigate stress-related perturbations in performance and efficiency.      </p>

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