WR 25 is a colliding-wind binary star system comprising a very massive O2.5If∗/WN6 primary and an O-star secondary in an eccentric orbit with a 208 day period. These hot stars have strong, highly supersonic winds that interact to form a bright X-ray source from wind-collision shocks whose conditions change with stellar separation. Different views through the winds of Wolf-Rayet and O stars are afforded with orbital phase as the stars move about their orbits, allowing for exploration of wind structure in ways not easy or even possible for single stars. We have analyzed an on-axis Chandra/HETGS spectrum of WR 25 obtained shortly before periastron when the X-rays emanating from the system are the brightest. From the on-axis observations, we constrain the line fluxes, centroids, and widths of various emission lines, including He triplets of Si xiii and Mg xi. We have also been able to include several serendipitous off-axis HETG spectra from the archive and study their flux variation with phase. This is the first report on high-resolution spectral studies of WR 25 in X-rays.

Although maternal vitamin D status has been linked to asthma in offspring, the relationship between vitamin D status and asthma in adults still remains unclear. The current study assessed the relationship between measures of vitamin D status and self-reported asthma/wheeze in 186 healthy women aged 18-30 years. Although the risk of asthma/wheeze symptoms was three-times higher among women with low dietary vitamin D intake (<200 IU>/day) than in those with higher vitamin D intake, suboptimal serum levels of 25(OH)D ( <70 nmol>/L) were associated with a 48% lower risk of asthma/wheeze than “optimal” serum levels. These contradictory effects underscore the poor correlation between dietary vitamin D intake and serum vitamin levels and suggest that other components in vitamin D-rich foods may be protective. Alternatively, women with higher serum vitamin D levels may have spent more time outdoors, increasing their exposure to asthma triggers. This study also identified predictors of serum 25 (OH) D in this sample. In addition to total dietary vitamin D (r= 0.2; p=0.03), intake of cold cereal (p=0.02) also significantly predicted serum 25(OH)D levels. Among non-dietary factors, month of blood draw (p=0.05) and oral contraceptive use (p<0.0001) were positive predictors of serum 25(OH) D; sunscreen use (p=0.04) was a negative predictor. After adjusting for covariates, oral contraceptive use was associated with 25(OH)D levels that were on average 24 nmol/L greater than those observed in women who did not use oral contraceptives. Additional prospective studies are needed to further evaluate the relationship between vitamin D status and asthma.

No description available.

No description available.

Background: Calciferol (vitamin D) is an essential nutrient that can be synthesized in the skin upon exposure to ultraviolet-B (UVB) light, or obtained through dietary and supplement sources. Traditionally known for its role in bone metabolism, vitamin D is currently described as a pleiotropic hormone with genomic and non-genomic roles in most body tissues. Clinical practice guidelines related to vitamin D are inconsistent and controversial. The purpose of this dissertation was to describe current patterns of vitamin D-related clinical care in a variety of settings, and to evaluate the impact of vitamin D supplements on the health and performance of collegiate athletes, a group with high prevalence of low vitamin D (LVD). Methods: This dissertation consists of five studies: 1) a scoping review of the health services literature related to clinical management of vitamin D; 2) a retrospective analysis of clinical care following non-indicated vitamin D testing using electronic health record (EHR) data from a regional health system; 3) a survey study to assess vitamin D-related practices among National Collegiate Athletic Association (NCAA) Division I programs; 4) an open clinical trial to evaluate the efficacy of a specific vitamin D supplement protocol in treating collegiate basketball athletes with LVD; and 5) a randomized, double-blind clinical trial to determine health and performance effects of vitamin D supplements in collegiate swimmers participating in fall season training. Results: Substantial inconsistency in vitamin D-related care was observed throughout the first three studies. Exponential increases in vitamin D testing and treatment, and associated costs, were identified in the U.S. and several other countries. A high proportion of this care was considered non-indicated (i.e., counter to professional guidelines). A lower rate of non-indicated vitamin D-related services was conducted within the health system we studied, but a cascade of low value services followed non-indicated vitamin D testing. Vitamin D testing was regularly performed by more than 65% of NCAA programs. In basketball athletes, 10 weeks of daily vitamin D3 supplements (5000 or 10,000 IU based on initial vitamin D status) improved serum 25-hydroxyvitamin D [25(OH)D], the common biomarker of vitamin D status. In swimmers, a vitamin D supplement protocol (5,000 IU vitamin D3 daily for 12 weeks) was efficacious in attenuating a seasonal decline in 25(OH)D compared with placebo. Swimmers taking vitamin D supplements also showed greater improvements in strength, power, and fat free mass. In both athlete studies, taking vitamin D supplements was associated with higher free testosterone concentration. Conclusions: The provision of evidence-based care related to vitamin D is complicated by contradictory clinical practice guidelines, resulting in inconsistent and sometimes, non-indicated care. Focused research on specific populations at high-risk for LVD can inform best practices. Our results suggest that taking vitamin D supplements is an efficacious strategy for athletes to improve 25(OH)D, especially when UVB exposure is low, and to enhance strength and power in collegiate swimmers. / Ph.D. / Vitamin D is known as the “sunshine vitamin” since it can be synthesized by the human body when exposed to specific wavelengths of ultraviolet-B (UVB) light. Some foods and dietary supplements also contain vitamin D. A relationship between vitamin D and bone health is well-established, but emerging research has also associated vitamin D status with a number of different diseases and health problems, including cancer, cardiovascular disease, autoimmune conditions, and depression. Unfortunately, this research is currently inconclusive, and healthcare providers’ professional guidelines related to vitamin D are highly variable. Thus, providing evidence-based care related to vitamin D is complicated. This dissertation consists of a series of three research studies that describe healthcare providers’ vitamin D-related care considering the uncertain landscape, and two research studies that explore the role of vitamin D in collegiate athletes. We chose athletes since a high proportion of them have deficient or insufficient vitamin D status, and because some research has shown that this low vitamin D status affects athletic performance. Results of these studies showed that vitamin D-related health services such as blood testing have increased dramatically over the past 15 years, as have costs associated with these services. Opportunities to improve consistency and quality of care were observed in multiple settings. In the athlete studies, a high rate of vitamin D deficiency and insufficiency was observed among basketball athletes, and we identified vitamin D supplement treatment protocol effective in improving vitamin D status. In addition, swimmers who took vitamin D supplements performed better on strength and conditioning tests than those who took placebo supplements. A favorable relationship between testosterone concentrations and vitamin D status was shown in both basketball athletes and swimmers. Continuing to conduct research focused on specific populations can help healthcare providers develop consistent, high quality, evidence-based care related to vitamin D.

Traditionally, and up to this date, Land Mobile Radio (LMR) systems have been interconnected via leased lines and microwave links across circuit-switched networks. With the recent deployment of digital LMR standards such as the Association of Public and Communications Officials (APCO) Project 25 and the Terrestrial Trunked Radio (TETRA), traffic exchange has become more bursty and non-uniform, and as such, less suitable for circuit-switched networks. This thesis proposes a framework for a packet-switched Inter-System Interface (ISI) for LMR systems. Packet-switched networks have the advantage of supporting traffic integration, utilize capacity efficiently, scale easily and seamlessly, and eliminate single points of failure by providing a distributed architecture. Session Initiation Protocol (SIP) signaling messages are defined for setting up and tearing down unit-to-unit calls across the ISI. The Session Description Protocol (SDP) is used to describe how the voice calls are encoded. Voice packets are exchanged between LMR users using the Real-Time Transport Protocol (RTP). Based on the proposed framework, we develop a simulation model to investigate the performance of the ISI when different numbers of LMR users try to establish unit-to-unit calls across the packet-switched ISI. Three packet transport technologies providing Wide Area Network (WAN) connectivity are considered, IP, ATM, and Frame Relay. The results indicate that a packet-switched ISI can take advantage of statistical multiplexing techniques to distribute network resources more efficiently. Quantitative results are obtained for throughput and link utilization. When using an access link providing T1 service, we show that the End-To-End (ETE) delay, and delay variation can be controlled at levels capable of supporting the timely delivery of real-time voice packets. Assuming link utilization is maintained below 100%, the maximum ETE delay experienced in all three packet transport technologies considered is 58 ms and the maximum call setup time is less than 300 ms. An ATM WAN provides the best performance for all time-dependent metrics considered, i.e., ETE delay, delay variation, and call setup time. An IP WAN provides the highest bandwidth efficiency. Selecting the appropriate packet transport technology for the WAN is a tradeoff between the delay that can be tolerated by the voice packets traversing the LMR network and the cost of bandwidth on the access link. / Master of Science

No description available.

A avicultura brasileira assumiu nos últimos anos importante papel dentro do PIB nacional, e a produção de ovos dentro do setor vem tomando cada vez maior importância. No decorrer dos últimos anos vários avanços foram observados no que se refere ao melhoramento genético de poedeiras comerciais, no sentido de maiores produtividade e longevidade. Ambos parâmetros podem ser afetados pela atuação de radicais livres e nutrição adequada. Embora o organismo vivo apresente mecanismos fisiológicos que visam diminuir os danos causados por radicais livres, a suplementação destes pode promover benefícios, desde a reprodução da ave até o desempenho produtivo de poedeiras oriundas de matrizes suplementadas com substâncias antioxidantes, dentre elas a cantaxantina. Recentemente vários estudos têm sido feitos para a nutrição adequada das aves com utilização adequada de aminoácidos, energia, fontes minerais, enzimas, etc., para que atinjam o máximo potencial produtivo. Porém, os níveis vitamínicos têm sido pouco estudados, e normalmente com foco em frangos de corte e/ou níveis mínimos a serem trabalhados para que o animal não entre em deficiência, trabalhos com níveis vitamínicos visando produtividade máxima em poedeiras comerciais não foram encontrados na literatura pesquisada. O presente estudo teve como objetivo avaliar poedeiras comerciais modernas, da linhagem Hisex Brown, em duas situações: origem de matrizes suplementadas com cantaxantina e 25 hidroxicolecalciferol, e níveis vitamínicos altos contra níveis vitamínicos praticados comercialmente. O experimento foi inteiramente casualizado e ocorreu nas dependências da granja experimental da USP de Pirassununga. As aves foram alojadas com 1 dia de idade e mantidas até as 70 semanas, passando pelas fases de cria, recria e produção, em que tiveram os parâmetros zootécnicos observados e comparados. Como resultados, observou-se no trabalho quanto à suplementação das matrizes: melhor peso corporal aos 35 dias, e daí até o final da recria (p<0,05), não apresentando maiores consumos de ração em relação ao grupo controle. Na fase de produção observou-se melhor peso dos ovos e espessura da casca para o grupo tratado e maior resistência da casca para o grupo controle (p<0,05). Quanto aos níveis vitamínicos observou-se: vantagem em peso aos 35 dias, o que não se observou às 17 semanas, e observou-se menor conversão alimentar no grupo controle. Durante a fase de produção, o grupo tratado apresentou resultados melhores em peso de ovos e resistência da casca (p<0,05) / Brazilian poultry has been taken an important part on brazilian economy on the past few years, and the egg production has been taken an important part on brazilian poultry. During the last years, several improvements has been done on the way of better production and longer lifetime of the layers. Both parameters are influenced by free radicals action and the correct use of nutrition. Although life animals have system to avoid damages caused by free radicals, suplementation with antioxidants can bring them benefits, since the reproduction of the breeder, until the production of the layer provided from light breeders suplemented, one of these substances is cantaxantin. Recently, studies have been conduced to determine the appropriate levels of aminoacids, energy, minerals, enzymes, etc., everything to permit the animal, the maximum production. However, vitamin levels haven´t been studied that much, and normally, the goal of theses studies are broilers and/or the minimum necessary to don´t let animals be deficient. This study had the goal to evaluate layers of Hisex Brown lineage, on two situations: the suplementation of the light breeder with cantaxantin and 25 hidroxicolecalciferol, and optimum vitamin nutrition against the ones comercially used. The experiment was entirely randomized designed, and occurred on the experimental houses of USP of Pirrasununga. The day old pullet were housed and maintained there for 70th weeks old, going throw rearing and production period, on which had its parameteres evaluated. As the results, on the work with breeders suplementation better body weight at 35 days old, and than until the end of rearing period (p<0,05), without higher feed consumption then control group. On the production period it was observed higher egg weight and thickness of the shell (p<0,05) for the suplemented breeder group, but better shell resistance for the control group. For the work wtih optimum vitamin nutrition results it was observed improvement of body weight at 35 days old (p<0,05) on the OVN group, but it was not observed until the end of rearing period. During the production time it was not observed any improvement but the weight and resistance of eggs on OVN group (p<0,05)

Um dos objetivos no tratamento de Diabetes mellitus é aumentar a função, proliferação e sobrevivência de células beta pancreáticas, pois o transplante de ilhotas pancreáticas é severamente limitado pela escassez de doadores de órgãos. Nós mostramos que prolactina recombinante humana (rhPRL) apresenta efeitos benéficos em células beta, inibindo a apoptose. Recentemente reportamos o aumento dos níveis de expressão da proteína antiapoptótica HSP27/25, regulada por rhPRL em ilhotas humanas. Nosso objetivo é explorar o papel de HSP27/25 na citoproteção induzida por prolactina em células beta. Métodos: Células MIN6 parentais e silenciadas para HSP25 foram privadas de soro por 24h e cultivadas na presença ou ausência de rhPRL (300ng/mL). Posteriormente foram tratadas na presença ou ausência de uma combinação de citocinas (TNF-&#945;, INF-&#947 e IL-1&#946;) por diferentes períodos de tempo. A apoptose foi avaliada usando-se análise por citometria de fluxo. Os níveis de expressão gênica de HSP27/25 e membros da família BCL-2, da expressão proteica de membros desta mesma família, além de Caspase-9, Smac-Diablo HSP27/25, HSTF1, pP38 e pSTAT1 foram analisados por Westen blot. Ainda, foram avaliadas a atividade de Caspase-8 e -3, por ensaios fluorimétricos. Após o tratamento com rhPRL e citocinas, a proporção de núcleos fragmentados aumentou em células silenciadas para HSP25 (p<0,05), quando comparadas com células controles. A inibição da atividade de Caspase-3 e -8, tanto quanto os níveis de expressão proteica de caspase- 9, por rhPRL e o aumento da razão de expressão Bcl-2/Bax e BclxL/Bax foram revertidos em células silenciadas (p<0,05). Além disso, a cinética dos níveis de expressão de HSP27/25 e HSTF1 foram estudadas em culturas de ilhotas pancreáticas humanas, mostrando que enquanto HSTF1 apresenta um aumento significativo (p<0,01) nos níveis de expressão proteica após 10min de tratamento com rhPRL, HSP27 alcançou seu nível máximo após 2h do tratamento hormonal. Adicionalmente, foi detectado um aumento significante (p<0,05) nos níveis de fosforilação de STAT1 e de p38, após 10min, atingindo o pico de expressão após 30min (p<0,01) do tratamento com rhPRL. Estes estudos demonstram o papel chave de HSP27/25 sobre os efeitos citoprotetores induzidos por rhPRL, desde que a ausência desta proteína aboliu completamente os efeitos benéficos induzidos por PRL sobre a morte de células beta. Ainda, nós fornecemos pela primeira vez, evidências da corregulação de HSP27 e HSTF1 induzidas por rhPRL em células humanas pancreáticas, que pode estar sendo mediada pela ativação de STAT1 e p38. Coletivamente, nossos resultados podem conduzir para a atenuação da morte de células beta por meio da regulação de uma via de proteção endógena, a qual é independente da modulação do sistema imunológico. / One of the goals in Diabetes mellitus treatment is to enhance pancreatic &#946;-cell function, proliferation and survival since transplantation of pancreatic islets is severely limited by shortage of organ donors. We have shown that recombinant human prolactin (rhPRL) inhibits beta-cell apoptosis. We have recently reported PRL-induced up-regulation of the anti-apoptotic HSP25/27 in human islets. Since the function of HSP25/27 in beta-cells has not been directly studied, we set out to explore the role of HSP25/27 in prolactin-induced beta-cell cytoprotection. Methods: Parental and HSP25 knocked-down Min6 cells were serumstarved for 24h and then cultured in the presence or in the absence of rhPRL (300ng/mL) for different time periods. Apoptosis was evaluated using flow cytometry analysis. Levels of Bcl-2 gene family members, caspase-9, Bcl-2, BclxL, Bax, Smac-Diablo, HSP27/25, HSTF1, pStat- 1,pP38 were studied by western blot. Caspase-3 and -8 activity, were evaluated by fluorimetric assays. Upon cytokines and rhPRL treatment, the proportion of fragmented nuclei was increased in HSP25 silenced cells (p<0.05) when compared to control cells. The inhibition of cytokine-induced capase-3 and -8 activity as well as Bcl-2/Bax and BclxL/Bax ratios and caspase-9 protein levels mediated by rhPRL in wild type cells was reverted in knocked-down cells (p<0.05). Moreover, the kinetics of HSP 25/27 and HSTF1 expression levels studied in primary cultures of human pancreatic islets showed that while HSTF1 presented a significant increase (p<0.01) in protein expression level after 10 min of rhPRL treatment, HSP27 reached its maximum expression level upon 2h of hormonal treatment. Additionally, a significant (p<0.05) increase in both P38 and STAT1 phosphorylation levels were detected after 10min of rhPRL treatment reaching the highest levels upon 30 min (p<0.001) of hormonal treatment. Therefore, we demonstrated a key role for HSP25/27 in rhPRL-induced cytoprotective effects, since the lack of this protein completely abolished the beneficial effects induced by PRL on beta-cell death. Moreover, we provided for the first time, evidence for the co-regulation of HSP27 and HSTF1 induced by rhPRL in human pancreatic cells which could be mediated by activated STAT1 and P38. Collectively, our results could lead to the mitigation of beta-cell death through the up-regulation of an endogenous protective pathway which is independent on the modulation of the immune system.

O diabetes mellitus (DM) é uma doença com prevalência e morbidade elevadas em todo o mundo, sendo que o DM1 é responsável por 5-10% dos casos. A vitamina D, hormônio de ação pleiotrópica, pode melhorar o curso do DM1, embora os mecanismos não estejam completamente elucidados. Dessa forma, ampliar o conhecimento sobre a ação desse hormônio pode auxiliar no prognóstico, bem como na compreensão dos possíveis mecanismos envolvidos na prevenção do DM. Neste trabalho, foram avaliados os efeitos fisiológicos da suplementação de vitamina D (800 UI/dia/sete dias; via oral) em camundongos machos (n=31; linhagem C57BL/6) distribuídos em quatro grupos: Controle + Água (CA; n=9); Controle + Vitamina D (CV; n=9); Diabético + Água (DA; n=6) e Diabético + Vitamina D (DV; n=7). Os camundongos tornados diabéticos (aloxana, 60 mg/Kg, intravenosa), quando comparados aos controles, exibiram redução do peso corporal e concentrações plasmáticas de glicose mais elevadas durante o período experimental de 10 dias (características do estado insulinopênico). Entretanto, a suplementação com vitamina D não alterou essa condição. Camundongos tornados diabéticos, em relação aos controles, exibiram redução do peso corporal (p<0,05) e concentrações plasmáticas de glicose (p<0,001) mais elevadas durante o período experimental. Animais suplementados com vitamina D apresentaram, em relação aos controles, níveis de 25(OH)D mais elevados (CA vs CV, p<0,001; DA vs DV, p<0,001). Níveis séricos maiores de ureia (CA vs DA, p<0,05; CA vs DV, p<0,01; CV vs DA, p<0,05; CV vs DV, p<0,01) e creatinina (CA vs DA, p<0,001; CA vs DV, p<0,001; CV vs DA, p<0,001; CV vs DV, p<0,001), espessamento da cápsula de Bowman, hipertrofia glomerular e destruição de hepatócitos foram observados em camundongos diabéticos em relação aos controles. Entretanto, a suplementação com vitamina D não alterou estas condições. O grupo DA apresentou menor nível sérico de albumina em relação aos grupos CA (p<0,05) e CV (p<0,05); níveis inferiores de hemoglobina (p<0,05) e hematócrito (p<0,05) em relação ao grupo DV; e menor leucometria (p<0,05) e mononucleares sanguíneos (p<0,05) em relação ao grupo CA. Os resultados sugerem que a vitamina D possa influenciar a resposta imunológica em animais diabéticos, modulando hematócrito, hemoglobina, bem como os níveis séricos de albumina / Diabetes mellitus (DM) is a disease with high prevalence and morbidity worldwide, and the DM1 is responsible for 5-10% of cases. The vitamin D hormone pleiotropic action, can improve the course of T1DM, although the mechanisms are not fully elucidated. Thus, better understanding the action of this hormone can aid in prognosis as well as in understanding the possible mechanisms involved in the prevention of diabetes. We evaluated the physiological effects of vitamin D (800 IU/day/seven days, v.o.) in male mice (n=31, C57BL/6 strain) divided into four groups: Control + Water (CW, n=9); Control Vitamin D + (CV n=9); Diabetic + Water (DW, n=6) Diabetic + Vitamin D (VD, n=7). The mice induced-diabetes by alloxan (60 mg/kg, i.v.), when compared to controls, exhibited reduced body weight and plasma glucose concentrations were higher during the experimental period of 10 days (features insulinopenic state). However, vitamin D supplementation did not alter this condition. Diabetic mice, compared to controls, exhibited reduced body weight (p<0,05) and plasma glucose concentrations (p <0.001) higher during the trial period. Animals supplemented with vitamin D showed higher levels of 25 (OH) D than controls (CW vs CV, p <0,001; DW vs DV, p<0,001). Higher serum urea (CW vs. DW, p <0,05; CW vs DV, p <0,01; CV vs DA, p <0,05; CV vs DV, p <0,01) and creatinine (CW vs. DW, p <0,001; CW vs DV, p <0,001; CV vs DW, p <0,001; CV vs DW, p <0,001), thickening of Bowman\'s capsule, glomerular hypertrophy and destruction of hepatocytes were observed in diabetic mice compared to controls. However, vitamin D supplementation did not alter these conditions. The DW group showed lower serum albumin compared to CW (p<0,05) and CV (p<0,05) groups; lower hemoglobin (p<0,05) and hematocrit (p <0,05) compared to the DV group; and lower leukocyte counts compared to CW (p <0,05) and mononuclear blood (p <0,05) compared to the CW group. The results suggest that Vitamin D may influence the immune response in diabetic animals, modulating hematocrit, hemoglobin and serum albumin