12 research outputs found
Foreground removal from WMAP 7yr polarization maps using an MLP neural network
One of the fundamental problems in extracting the cosmic microwave background
signal (CMB) from millimeter/submillimeter observations is the pollution by
emission from the Milky Way: synchrotron, free-free, and thermal dust emission.
To extract the fundamental cosmological parameters from CMB signal, it is
mandatory to minimize this pollution since it will create systematic errors in
the CMB power spectra. In previous investigations, it has been demonstrated
that the neural network method provide high quality CMB maps from temperature
data. Here the analysis is extended to polarization maps. As a concrete
example, the WMAP 7-year polarization data, the most reliable determination of
the polarization properties of the CMB, has been analysed. The analysis has
adopted the frequency maps, noise models, window functions and the foreground
models as provided by the WMAP Team, and no auxiliary data is included. Within
this framework it is demonstrated that the network can extract the CMB
polarization signal with no sign of pollution by the polarized foregrounds. The
errors in the derived polarization power spectra are improved compared to the
errors derived by the WMAP Team.Comment: Accepted for publication in Astrophysics & Space Scienc
Comportamento de células do sistema imune frente ao desafio com Salmonella Enteritidis em aves tratadas e não tratadas com ácidos orgânicos
A Salmonelose é uma importante zoonose, considerada a principal causa de infecções bacterianas, sendo associada ao consumo de produtos avícolas. Como alternativa de controle, ácidos orgânicos têm sido amplamente usados. No entanto, pouco se conhece sobre o estado imunológico de aves de produção, e uma avaliação deste status é necessária para proteger frente a enfermidades e para garantir à aplicação segura de agentes terapêuticos ou imunização profilática. Este trabalho teve como objetivo verificar o comportamento do sistema imunológico das aves previamente infectadas com Salmonella Enteritidis (SE) tratadas com um composto de ácidos orgânicos em diferentes concentrações administrado via água e ração comparando com as aves infectadas e não tratadas. Foram inoculados 120 frangos de corte com 1mL de SE, via oral, na concentração de 1,0 x 108 UFC/mL, no 1º e 2º dia de idade, divididos em seis tratamentos com duas repetições, utilizando 200, 400, 500 e 1000ppm do ácido orgânico. Aos 35 dias de vida das aves, foram coletados, de todos os grupos, alíquotas de sangue de 3mL em tubo contendo EDTA para a avaliação das células imunes através de citometria de fluxo. Foram analisadas as porcentagens circulantes de células CD4+, CD8β+, MHC I+, MHC II+, TCRVβ1+, TCRVβ2+ e CD28+. Para análise microbiológica foram coletadas tonsilas cecais destas aves. Observou-se com esse estudo que os ácidos orgânicos nas dosagens 1000ppm na água e 500ppm na ração durante, dois e sete dias respectivamente antes do abate, foram eficazes na redução da infecção por SE em frangos de corte, comprovadas pelo método microbiológico e demonstradas através do comportamento das células do sistema imune. No presente estudo as aves infectadas apresentaram uma proporção menor de células T auxiliares circulantes quando comparadas às aves infectadas, mas tratadas com o AO ou com o grupo não infectado. A mesma tendência pode ser observada para as células CD28+, TCRVβ1+ e MHC IIbright+, e, com menor resolução, para CD8β+
Efeito de diferentes fontes de gordura na dieta de vacas Jersey sobre o consumo, a produção e a composição do leite Effects of different dietary fat sources on intake and milk yield and composition of Jersey cows
Com o objetivo de investigar o efeito de diferentes fontes de gordura na dieta de vacas Jersey sobre os consumos de matéria seca (CMS), fibra em detergente neutro (CFDN) e extrato etéreo (CEE), sobre a composição e a produção de leite (PL), foram utilizadas oito vacas Jersey, distribuídas em dois quadrados Latinos (4 x 4). Os tratamentos utilizados foram: C = concentrado sem gordura; SB = concentrado com sebo bovino; GP = concentrado com gordura protegida comercial (sais de cálcio + óleo de palma); e GS = concentrado com grão de soja. Não houve diferença para os CMS e CFDN. O CEE foi mais elevado nos tratamentos que incluíram gordura nas dietas. Os tratamentos GP e SB proporcionaram produção leiteira (PL) e produção leiteira corrigida a 4% de gordura (PLCG4%) semelhantes entre si (25,6 e 23,6 kg/vaca/dia) e GP foi superior aos tratamentos C e GS, que resultaram em PLCG4% de 23,4 e 22,9 kg/vaca/dia, respectivamente. A eficiência da produção de leite (PLCG4%:CMS) diferiu entre tratamentos. O tratamento GP apresentou a melhor eficiência de produção (1,50), apesar de semelhante ao tratamento C (1,38). Os teores de gordura (G), proteína total (P), caseína (C), sólidos totais (ST), sólidos totais desengordurados (STD), densidade (D) e índice crioscópico (IC) não diferiram entre os tratamentos. Os resultados indicam a viabilidade do uso de gordura nas dietas para vacas leiteiras de alta produção, observando-se aumento na produção e melhoria da eficiência de produção, sem alterações no consumo de alimentos e na composição do leite produzido.<br>Eight high-yielding Jersey cows were randomly assigned to two 4x4 Latin squares to study the effects of different dietary fat sources on intakes of dry matter (DMI), neutral detergent fiber (NDFI), and ether extract (EEI) as well as on milk yield and composition. The following treatments were used: concentrate with no added fat (control = C); concentrate plus tallow (T); concentrate plus commercial ruminally protected fat (calcium salts + palm oil; PF); and concentrate plus whole soybean (WS). Both DMI and NDFI did not differ significantly among treatments. However, EEI was higher for cows fed diets containing the added fat sources than for those fed the C diet. Both milk yield and milk yield corrected for 4% fat (FCM) were highest on PF, intermediate on T, and lowest on C and WS diets. Cows fed PF had greater feed efficiency expressed as FCM/DMI (1.50), compared with those fed T or WS diets but it was similar to C (1.38). Contents of milk fat, crude protein, casein, total solids, solids-nonfat, density, and the cryoscopic index all were not affected by dietary treatments. It can be concluded that addition of fat sources to diets of lactating Jersey cows is recommended because improved milk yield and feed efficiency with no deleterious effects on DMI and milk composition
Tyrosine hydroxylase in the brain and its regulation by glucocorticoids
Early life stress events can produce long-lasting changes in neurochemistry and behaviors related to monoamine systems, with increased risks of cardiovascular, metabolic, neuroendocrine, psychiatric disorders, generalized anxiety and depression in adulthood. Tyrosine hydroxylase (TH), the key enzyme for catecholamine synthesis, also plays an important role in the activity of the noradrenergic system and may be a target for glucocorticoids during the perinatal programming of physiological functions and behavior. Administration of hydrocortisone or dexamethasone to female rats on day 20 of pregnancy and to 3-day-old neonatal pups significantly increased TH mRNA levels (real-time PCR) and enzyme activity as well as protein levels determined by ICH in the locus coeruleus. Moreover, our treatment led to increase in TH mRNA levels in 25- and 70-day-old animals, as well as an increase in enzyme activity in the brainstem and cerebral cortex of adult rats. The long-term changes in TH expression are limited by the perinatal period of development. Administration of hormones on day 8 of life was not accompanied by changes in TH mRNA levels or enzyme activity. Glucocorticoids use several mechanisms to bring about transactivation or transrepression of genes. The main mechanism includes direct binding of the hormone-activated GRs to glucocorticoid responsive elements (GREs) in the promoter region of genes. However, despite optimistic claims made the classical GRE was not found in the TH gene promoter. Protein – protein interactions between hormone-activated GR and other transcription factors, for example, AP-1, provide an additional mechanism for the effects of glucocorticoids on gene expression. An important feature of this mechanism is its dependence on the composition of proteins formed by AP-1. Hormone-activated GRs are able to enhance gene expression when AP-1 consists of the Jun / Jun homodimer, but do not do that when AP-1 appears as the Jun / Fos heterodimer. Furthermore, as has been shown recently, the GRE / AP-1 composite site is the major site of interaction of glucocorticoids with the TH gene in the pheochromocytoma cell line. Ontogenetic variation in the expression of Fos and Jun family proteins, which affects their ratio, can be one of the reasons for the TH gene regulation by glucocorticoids at near-term fetuses and neonates. However, to date this hypothesis has been supported only by in vitro data, and the existence of this mechanism in in vivo conditions needs to be explored in further studies