757 research outputs found
Are the black hole masses in Narrow Line Seyfert 1 galaxies actually small?
Narrow Line Seyfert 1 galaxies (NLS1s) are generally considered peculiar
objects among the broad class of Type 1 active galactic nuclei, due to the
relatively small width of the broad lines, strong X-ray variability, soft X-ray
continua, weak [OIII], and strong FeII line intensities. The mass M_BH of the
central massive black hole (MBH) is claimed to be lighter than expected from
known MBH-host galaxy scaling relations, while the accretion rate onto the MBH
larger than the average value appropriate to Seyfert 1 galaxies. In this
Letter, we show that NLS1 peculiar M_BH and L/L_Edd turn out to be fairly
standard, provided that the broad line region is allowed to have a disc-like,
rather than isotropic, geometry. Assuming that NLS1s are rather ``normal''
Seyfert 1 objects seen along the disc axis, we could estimate the typical
inclination angles from the fraction of Seyfert 1 classified as NLS1s, and
compute the geometrical factor relating the observed FWHM of broad lines to the
virial mass of the MBH. We show that the geometrical factor can fully account
for the "black hole mass deficit" observed in NLS1s, and that L/L_Edd is (on
average) comparable to the value of the more common broad line Seyfert 1
galaxies.Comment: 5 pages, 3 figures. Accepted for publication in MNRAS Letters. Wrong
version was uploaded! Check for the correct one in the replacemen
Automatic cough detection for bovine respiratory disease in a calf house
peer-reviewedIn calf rearing, bovine respiratory disease (BRD) is a major animal health challenge. Farmers incur severe economic losses due to BRD. Additional to economic costs, outbreaks of BRD impair the welfare of the animal and extra expertise and labour are needed to treat and care for the infected animals. Coughing is recognised as a clinical manifestation of BRD. Therefore, the monitoring of coughing in a calf house has the potential to detect cases of respiratory infection before they become too severe, and thus to limit the impact of BRD on both the farmer and the animal. The objective of this study was to develop an algorithm for detection of coughing sounds in a calf house. Sounds were recorded in four adjacent compartments of one calf house over two time periods (82 and 96 days). There were approximately 21 and 14 calves in each compartment over the two time-periods, respectively. The algorithm was developed using 445 min of sound data. These data contained 664 different cough references, which were labelled by a human expert. It was found that, during the first time period in all 3 of the compartments and during the second period in 2 out of 4 compartments, the algorithm worked very well (precision higher than 80%), while in the 2 other cases the algorithm worked well but the precision was less (66.6% and 53.8%). A relation between the number of calves diagnosed with BRD and the detected coughs is shown
IMPORTÂNCIA DO BANCO DE COLOSTRO EM BOVINOCULTURA LEITEIRA E DEMONSTRAÇÃO PRÁTICA DE ANÁLISE DA QUALIDADE DE COLOSTRO EM GRAU BRIX
O colostro bovino é rico em imunoglobulinas, e contribui para a imunidade passiva neonatal, uma vez que a barreira placentária das vacas não permite a transferência de anticorpos da mãe para o feto durante a gestação. A imunidade transferida pelo colostro contribui para manutenção da saúde do bezerro, até que seu próprio sistema imune se desenvolva. Para que estes anticorpos possam ser absorvidos, há necessidade de que o colostro seja oferecido nas primeiras horas de vida. Caso os bezerros não sejam adequadamente colostrados, há maior risco para ocorrência de pneumonias, diarreias e óbitos. Devido à morte de vacas ou outras situações que impedem a mamada do colostro pelos bezerros, faz-se necessário, nas propriedades, o armazenamento e a estocagem de colostro para fornecimento aos neonatos. Desta forma, o banco de colostro é um importante recurso de manejo em bovinocultura leiteira. Para tanto, é necessário um rigoroso controle de qualidade em todas as etapas do processo (desde a colheita, acondicionamento, armazenamento, descongelamento até o fornecimento do colostro). Devido à relevância do tema, o objetivo da presente atividade é orientar produtores de leite; alunos dos cursos de agrárias e demais visitantes quanto à importância e viabilização do banco de colostro em propriedades leiteiras. A viabilização do banco de colostro em uma propriedade apresenta importante custo-benefício, uma vez que o investimento financeiro não é elevado, e a preservação da saúde dos bezerros proporcionada pela adequada colostragem contribui para a redução das despesas com tratamentos e redução do número de óbito de animais. Para o banco, é necessário um freezer; embalagens plásticas tipo ziploc para armazenamento do colostro; bandejas plásticas; sistema de banho-maria e refratômetro óptico de brix. A porcentagem de brix tem relação com a concentração de IgG do colostro, sendo que amostras de colostro com grau brix igual ou superior a 21% são consideradas satisfatórias para fornecimento aos bezerros. Desta forma, ao se avaliar a qualidade do colostro em grau brix, é possível classificar as amostras e realizar o armazenamento no banco, permitindo assim que amostras de colostro que estejam abaixo de 21% brix sejam misturadas com amostras com 25% ou mais de brix para fornecimento aos bezerros, garantindo assim a adequada transferência de imunidade passiva aos animais. O descongelamento de colostro deve ser realizado em banho-maria a 45°C-55°C, de forma gradual para evitar a desnaturação de nutrientes, e a oferta aos bezerros deve ser realizada com mamadeira ou balde devidamente higienizados, com o colostro em temperatura de 38°C. Vale ressaltar que no setor de bovinocultura leiteira do IFC campus Concórdia tem sido conduzido o banco de colostro desde 2020 com bastante êxito, de forma que a taxa de mortalidade dos bezerros reduziu a zero após sua implantação. Este dado reforça os benefícios do banco de colostro em propriedades leiteiras e por isso justifica-se a importância do incentivo aos produtores, alunos e demais visitantes sobre o tema, por meio deste dia de campo proposto. Edital PIBIC EM 56/21. Agradecemos a Rodrigo Pivatto e Fabiano Deola pelo auxílio nas atividades desenvolvidas
On the Faint End of the Galaxy Luminosity Function in the Epoch of Reionization: Updated Constraints from the HST Frontier Fields
Ultra-faint galaxies are hosted by small dark matter halos with shallow gravitational potential wells, hence their star formation activity is more sensitive to feedback effects. The shape of the faint end of the high-z galaxy luminosity function (LF) contains important information on star formation and its interaction with the reionization process during the Epoch of Reionization. High-z galaxies with {M}UV}≳ -17 have only recently become accessible thanks to the Frontier Fields (FFs) survey combining deep HST imaging and the gravitational lensing effect. In this paper we investigate the faint end of the LF at redshift >5 using the data of FFs clusters Abell 2744 (A2744), MACSJ0416.1-2403 (M0416), MACSJ0717.5+3745 (M0717), and MACSJ1149.5+2223 (M1149). We analyze both an empirical and a physically motivated LF model to obtain constraints on a possible turnover of LF at faint magnitudes. In the empirical model the LF drops fast when the absolute UV magnitude {M}UV} is much larger than a turnover absolute UV magnitude {M}UV}{{T}}. We obtain {M}UV}{{T}}≳ -14.6 (15.2) at the 1 (2)σ confidence level (C.L.) for z ∼ 6. In the physically motivated analytical model, star formation in halos with circular velocity below {v}c* is fully quenched if these halos are located in ionized regions. Using updated lensing models and new additional FFs data, we re-analyze previous constraints on {v}c* and f esc presented by Castellano et al. using a smaller data set. We obtain new constraints on {v}c* ≲ 59 km s-1 and f esc ≲ 56% (both at 2σ C.L.) and conclude that there is no turnover detected so far from the analyzed FFs data. Forthcoming JWST observations will be key to tightening these constraints further
Application note: Labelling, a methodology to develop reliable algorithm in PLF
Automatic animal monitoring through Precision Livestock Farming (PLF) tools is a method to support farmers in achieving farm sustainability. The development of PLF systems requires close interdisciplinary collaboration between sector experts, farmers, animal scientists and bio-engineers. Labelling is a key activity in the development of reliable algorithm to be included in PLF tools. It is a set of procedures that animal experts must embark to precisely define and interpret detailed variations in measured field signals. This application note will describe the fundamental aspects of sound and image labelling and how this has enabled the engineering of useful automated PLF systems.status: publishe
Administration of a polyphenol-enriched feed to farmed sea bass (Dicentrarchus labrax L.): Kidney melanomacrophages response
The reinforcement of the defense mechanism of fish, through the administration of immunostimulants, is considered as a promising alternative to vaccines. Natural immunostimulants such as polyphenols, flavanoids, pigments and essential oils can modulate the innate immune response. In lower vertebrates, melano-macrophage centres, i.e. clusters of pigment-containing cells forming the extracutaneous pigment system, are wide-spread in the stroma of the haemopoietic tissue, mainly in kidney and spleen. In fishes, melano-macrophage centres play an important role in the immune response against antigenic stimulants and pathogens. In the present study, we evaluated the effect of a polyphenol-enriched diet on the health status of European sea bass (Dicentrarchus labrax L.). Farmed sea bass were administered a feed containing a phytocomplex, rich in catechins and epigallocatechins, which was obtained from the seeds of Canosina Nero di Troia Vitis vinifera and mixed with conventional feed at two different concentrations. The effects of such a diet were investigated in juvenile and commercial size samples, i.e. undergoing a short- and long-term period of diet, respectively, focusing on their extracutaneous pigmentary system and, in more detail, on the enzymatic activities leading to melanin biosynthesis. Our results show that prolonged dietary treatments with higher concentration of polyphenols might modulate tyrosinase activity and gene expression in commercial size fishes. An increase of melano-macrophage activity is correlated to a stimulation of cytoprotective functions against antigenic stimulants and pathogens, as an expression of a robust and protective adaptive immune response
Aggradation and lateral migration shaping geometry of a tidal point bar: an example from salt marshes of the Northern Venice Lagoon (Italy).
none7sirestrictedBrivio, L.; Ghinassi, M.; D'Alpaos, A.; Finotello, A.; Fontana, A.; Roner, M.; Howes, N.Brivio, Lara; Ghinassi, Massimiliano; D'Alpaos, Andrea; Finotello, Alvise; Fontana, Alessandro; Roner, Marcella; Howes, N
Alpha-lactalbumin forms with oleic acid a high molecular weight complex displaying cytotoxic activity
\u3b1-Lactalbumin (LA) forms with oleic acid (OA) a complex which has been reported to induce the selective death of tumor cells. However, the mechanism by which this complex kills a wide range of tumor cell lines is as yet largely unknown. The difficulty in rationalizing the cytotoxic effects of the LA/OA complex can be due to the fact that the molecular aspects of the interaction between the protein and the fatty acid are still poorly understood, in particular regarding the oligomeric state of the protein and the actual molar ratio of OA over protein in the complex. Here, the effect of LA addition to an OA aqueous solution has been examined by dynamic light scattering measurements and transmission electron microscopy. Upon protein addition, the aggregation state of the rather insoluble OA is dramatically changed, and more water-soluble and smaller aggregates of the fatty acid are formed. A mixture of LA and an excess of OA forms a high molecular weight complex that can be isolated by size-exclusion chromatography and that displays cellular toxicity toward Jurkat cells. On the basis of gel filtration data, cross-linking experiments with glutaraldehyde, and OA titration, we evaluated that the isolated LA/OA complex is given by 4-5 protein molecules that bind 68-85 OA molecules. The protein in the complex adopts a molten globule-like conformation, and it interacts with the fatty acid mostly through its \u3b1-helical domain, as indicated by circular dichroism measurements and limited proteolysis experiments. Overall, we interpret our and previous data as indicating that the cellular toxicity of a LA/OA complex is due to the effect of a protein moiety in significantly enhancing the water solubility of the cytotoxic OA and, therefore, that the protein/OA complex can serve mainly as a carrier of the toxic fatty acid in a physiological milieu
Use of an automated calf cough sound detection algorithm for the early detection of bovine respiratory disease
Early recognition of bovine respiratory disease (BRD), allows earlier treatment intervention. Initial results show that periods with increased coughing can be detected by a cough sound detection system and these correspond with BRD incidences.status: publishe
- …