75 research outputs found

    Discovery of faint double-peak Halpha emission in the halo of low redshift galaxies

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    Aiming at the detection of cosmological gas being accreted onto galaxies of the local Universe, we examined the Halpha emission in the halo of 164 galaxies in the field of view of the Multi-Unit Spectroscopic Explorer Wide survey (\musew ) with observable Halpha (redshift < 0.42). An exhaustive screening of the corresponding Halpha images led us to select 118 reliable Halpha emitting gas clouds. The signals are faint, with a surface brightness of 10**(-17.3 pm 0.3) erg/s/cm2/arcsec2. Through statistical tests and other arguments, we ruled out that they are created by instrumental artifacts, telluric line residuals, or high redshift interlopers. Around 38% of the time, the Halpha line profile shows a double peak with the drop in intensity at the rest-frame of the central galaxy, and with a typical peak-to-peak separation of the order of pm 200 km/s. Most line emission clumps are spatially unresolved. The mass of emitting gas is estimated to be between one and 10**(-3) times the stellar mass of the central galaxy. The signals are not isotropically distributed; their azimuth tends to be aligned with the major axis of the corresponding galaxy. The distances to the central galaxies are not random either. The counts drop at a distance > 50 galaxy radii, which roughly corresponds to the virial radius of the central galaxy. We explore several physical scenarios to explain this Halpha emission, among which accretion disks around rogue intermediate mass black holes fit the observations best.Comment: pay attention to the last sentence of the abstract! Accepted for publication in Ap

    Comunidades energéticas sustentáveis: estudo de implementação de uma comunidade eólica no Algarve

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    Este livro aborda o tema da geração de eletricidade com recurso à energia eólica, dando assim o seu contributo para a redução das emissões de dióxido de carbono e demais gases causadores do efeito de estufa. O principal objetivo do trabalho nele descrito foi o de estudar a implementação de uma unidade de geração de eletricidade a partir da energia eólica, que permita satisfazer as necessidades de consumo de uma pequena comunidade local, na região do Algarve, e analisar a sua viabilidade financeira e económica. Acredita-se que este estudo possa, também, dar algum contributo para a maior utilização das energias renováveis na geração de eletricidade de forma descentralizada, em particular através da energia eólica. Nesse sentido, incentiva-se a constituição de sistemas locais de geração de eletricidade para autoconsumo de pequenas comunidades urbanas, indo ao encontro do conceito das Renewable Energy Communities, mais especificamente das Wind Communities.info:eu-repo/semantics/publishedVersio

    Does intake of bread supplemented with wheat germ have a preventive role on cardiovascular disease risk markers in healthy volunteers? A randomised, controlled, crossover trial

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    Objective Intake of whole grains is associated with a reduced risk of cardiovascular disease (CVD). This evidence is also strong for bran alone, but findings about germ are conflicting. Our aim was to elucidate the role of germ in primary prevention of cardiovascular events, and therefore, a staple food was selected for 6g of germ supplementation. This corresponds to sixfold increase in the global mean consumption of germ, while preserving the sensory proprieties of refined bread which is crucial for consumers acceptance. Design Randomised, double-blinded, crossover, controlled clinical trial with 15-week follow-up comprising a 2-week run-in, two intervention periods of 4weeks each and a 5-week washout period. Setting A single centre in the north of Portugal. Participants 55 eligible healthy adults (mean age of 34 years and body mass index between 19 and 38kg/m2) were randomly assigned. Interventions The study consisted of two intervention periods including daily intake of refined wheat bread enriched with 6g of wheat germ and control (non-enriched bread). Outcomes Changes in fasting cholesterol and triglycerides, fasting and postprandial glucose, insulin sensitivity and C reactive protein. Results We observed no significant effect of daily intake of wheat germ on cholesterol and triglycerides levels, on postprandial glucose response and on insulin sensitivity. Incremental area under curve glucose and homeostasis model assessment for insulin resistance did not change, suggesting that 6g of wheat germ have no effect on glucose metabolism. No effect was also observed in the subgroup of participants who complied with the protocol (n=47). Conclusions The absence of alterations on lipid and glucose profiles suggests that germ up to 6g/day may have no preventive effect on CVD risk. However, it is important to investigate other food vehicles that can accommodate higher doses of wheat germ in future studies.This work was supported by the Programa Operacional Competitividade e Internacionalização–COMPETE2020 and by National Funds through Fundação para a Ciência e a Tecnologia-FCT (through the operations FCOMP-01-0202-FEDER-038861 and POCI-01-0145-FEDER-007746).info:eu-repo/semantics/publishedVersio

    The growth of typical star-forming galaxies and their supermassive black holes across cosmic time since z~2

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    Understanding galaxy formation and evolution requires studying the interplay between the growth of galaxies and the growth of their black holes across cosmic time. Here, we explore a sample of Hα-selected star-forming galaxies from the High Redshift Emission Line Survey and use the wealth of multiwavelength data in the Cosmic Evolution Survey field (X-rays, far-infrared and radio) to study the relative growth rates between typical galaxies and their central supermassive black holes, from z = 2.23 to z = 0. Typical star-forming galaxies at z ∼ 1–2 have black hole accretion rates (M˙BHM˙BH) of 0.001–0.01 M⊙ yr−1 and star formation rates (SFRs) of ∼10–40 M⊙ yr−1, and thus grow their stellar mass much quicker than their black hole mass (3.3±0.2 orders of magnitude faster). However, ∼3 per cent of the sample (the sources detected directly in the X-rays) show a significantly quicker growth of the black hole mass (up to 1.5 orders of magnitude quicker growth than the typical sources). M˙BHM˙BH falls from z = 2.23 to z = 0, with the decline resembling that of SFR density or the typical SFR (SFR*). We find that the average black hole to galaxy growth (M˙BHM˙BH/SFR) is approximately constant for star-forming galaxies in the last 11 Gyr. The relatively constant M˙BHM˙BH/SFR suggests that these two quantities evolve equivalently through cosmic time and with practically no delay between the two

    Daily intake of wheat germ-enriched bread may promote a healthy gut bacterial microbiota: a randomised controlled trial

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    Wheat bran fibre has a beneficial effect on gastrointestinal function, but evidence for wheat germ is scarce. Accordingly, we evaluated the effects of daily intake of wheat germ on gastrointestinal discomfort and gut microbiota by adding wheat germ to refined (white) wheat bread, the most consumed bread type. We hypothesised that an improvement in the composition of refined bread could beneficially affect intestinal health without compromising consumers' acceptance.AM-R, CC, and LFA were responsible for the study design, carrying out the trial, data analysis, manuscript writ-ing, and final revision. CM, HP, SN and DS were partially responsi-ble for the data collection and analysis. JAT collaborated in the study design and final revision of the manuscript. AM-R and LFA were responsible for the statistical analysis. CC and LFA were coordina-tors of the project, with an equal contribution. This work is part of the VALORINTEGRADOR project, and was supported by the Programa Operacional Competitividade e Internacionalização and by National Funds through the Fundação para a Ciência e a Tecnologia (through the operations FCOMP-01-0202-FEDER-038861 and POCI-01-0145-FEDER-007746). Our thanks to Germen and Padaria Ribeiro for the production of the bread used in this trial. We would like to thank Fran-cisca Mendes for her assistance in laboratory work. We are also espe-cially grateful to all participants for their enthusiastic collaboration in this study. We extend our thanks to Milaydis Sosa-Napolskij for proof reading this manuscript.info:eu-repo/semantics/publishedVersio

    FEEDMI: A Study Protocol to Determine the Influence of Infant-Feeding on Very-Preterm-Infant's Gut Microbiota

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    Background: Preterm infants are especially vulnerable to gut microbiota disruption and dysbiosis since their early gut microbiota is less abundant and diverse. Several factors may influence infants' gut microbiota, such as the mother's diet, mode of delivery, antibiotic exposure, and type of feeding. Objectives: This study aims to examine the factors associated with very-preterm neonate's intestinal microbiota, namely: (1) type of infant-feeding (breast milk, donor human milk with or without bovine protein-based fortifier, and preterm formula); (2) maternal diet; and (3) mode of delivery. Methods: This is an observational study conducted in a cohort of very preterm infants hospitalized in the neonatal intensive care unit of Maternidade Dr. Alfredo da Costa. After delivery, the mothers are asked to collect their own fecal samples and are invited to complete a semiquantitative food frequency questionnaire. The maternal diet will be classified in accordance to the Mediterranean Diet adherence score. Stool samples have been collected from very premature infants every 7 days for 21 days. DNA has been extracted from the fecal samples, and different bacterial genus and species will be quantified by real-time polymerase chain reaction. Results and conclusions: It is hypothesized that significant differences in the microbiota composition and clinical outcomes of very preterm infants will be observed depending on the type of infant feeding. In addition, this study will clarify how pasteurized donor's milk influences the intestinal microbiota colonization of preterm infants. This is a pioneer study developed in collaboration with the country's Human Milk Bank. We also expect to find microbiota alterations in infants according to the mode of delivery and to maternal diet. This study will contribute to increase the evidence on the effects of breast or donor human milk and its fortification with a bovine protein-based fortifier on infant microbiota.info:eu-repo/semantics/publishedVersio
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