844 research outputs found
Ultraviolet through far-infrared spatially resolved analysis of the recent star formation in M81 (NGC 3031)
The recent star formation (SF) in the early-type spiral galaxy M81 is characterized using imaging observations from the far-ultraviolet to the far-infrared. We compare these data with models of the stellar, gas, and dust emission for subgalactic regions. Our results suggest the existence of a diffuse dust emission not directly linked to the recent star formation. We find a radial decrease of the dust temperature and dust mass density, and in the attenuation of the stellar light. The IR emission in M81 can be modeled with three components: (1) cold dust with a temperature = 18 ± 2 K, concentrated near the H II regions but also presenting a diffuse distribution; (2) warm dust with = 53 ± 7 K, directly linked with the H II regions; and (3) aromatic molecules, with diffuse morphology peaking around the H II regions. We derive several relationships to obtain total IR luminosities from IR monochromatic fluxes, and we compare five different star formation rate (SFR) estimators for H II regions in M81 and M51: the UV, H alpha, and three estimators based on Spitzer data. We find that the H alpha luminosity absorbed by dust correlates tightly with the 24 mu m emission. The correlation with the total IR luminosity is not as good. Important variations from galaxy to galaxy are found when estimating the total SFR with the 24 mu m or the total IR emission alone. The most reliable estimations of the total SFRs are obtained by combining the H alpha emission (or the UV) and an IR luminosity (especially the 24 mu m emission), which probe the unobscured and obscured SF, respectively. For the entire M81 galaxy, about 50% of the total SF is obscured by dust. The percentage of obscured SF ranges from 60% in the inner regions of the galaxy to 30% in the outer zones
Sexual orientation and gender identity change efforts and suicide morbidity among sexual and gender minority adults in Colombia
Purpose: We assessed the association between sexual orientation and gender identity change efforts (SOGICE) experiences and lifetime suicide morbidity among sexual and gender minority (SGM) groups in Colombia.
Methods: A sample of 4160 SGM Colombian adults responded to an online cross-sectional survey. We used binary logistic regression to assess the relationship between SOGICE and suicide morbidity for the overall sample and stratified by SGM group. Results: We found a high prevalence of suicidal ideation (56%), suicide planning (54%), suicide attempt (25%), and SOGICE experiences (22%). There were significant differences in the prevalence of suicide morbidity and SOGICE experiences across SGM groups, with transgender men and gender nonbinary participants being generally most at risk. SOGICE experiences were associated with 69% increased odds of suicidal ideation, 55% increased odds of suicide planning, and 76% increased odds of suicide attempt. Stratified analyses by SGM group showed that the association of SOGICE experiences with suicide morbidity varied by SGM group, and it was particularly detrimental for cisgender sexual minority men. Conclusions: Suicide morbidity among SGM adults in Colombia is high, with rates that are 8–22 times higher than in the general population. SOGICE experiences further exacerbate suicide risk. The study findings highlight the need to design and implement policies affirming diverse sexual orientation and gender identities in Colombia and to ban SOGICE practices. These findings also highlight the importance of recognizing the variability within SGM groups and the need to examine these groups separately rather than treating them as a monolithic grou
Seroprevalence and risk factors associated with bovine herpesvirus 1 in dairy herds of Colombia
BACKGROUND AND AIM: Infectious bovine rhinotracheitis (IBR) is an infectious disease widely distributed globally and is considered the main cause of various reproductive and respiratory tract diseases in cattle and buffaloes. This study aimed to estimate seroprevalence and determine risk factors associated with the presentation of IBR in the municipality of Sotaquirá, Boyacá (Colombia). MATERIALS AND METHODS: A descriptive cross-sectional study with simple random sampling was performed, and the sample size was 1,000 cattle. Blood samples were obtained by coccygeal venipuncture and processed through indirect enzyme-linked immunosorbent assay using the Synbiotics(®) kit (Zoetis, New Jersey, USA) with a sensitivity and specificity of 96% and 98%, respectively. Data were processed using the statistical program EpiInfo(®) (Centers for Disease Control and Prevention; Atlanta, Georgia). RESULTS: A high seroprevalence of 57.5% was established. Seroprevalence was the highest in cattle >4 years of age (65.0% apparent seroprevalence [AS]; 67% true seroprevalence [TS]) and in the Holstein breed (65.5% AS; 67.8% TS). The breed and age of the animals were significantly associated with each other. The Holstein breed, age group >4 years, uncertified semen, and fetal death were established as risk factors for IBR. In comparison, the age groups of <1 and 1–2 years and the Normande breed were established as protective factors against the bovine herpesvirus-1 virus. CONCLUSION: Management factors, such as livestock from other owners and animal purchases, which affect disease presentation, are evident. The implementation and development of novel prevention and control measures for IBR at the national level are necessary
Nickel and cobalt ilmenites-based catalysts for upgrading pyrolytic oil during pyrolysis ofwaste tires
Pyrolysis as a waste treatment method has gained relevance because it can generate higher value-added products in addition to reducing the environment’s secondary pollution. In this study, the catalytic pyrolysis of waste tires was evaluated using NiTiO3 and CoTiO3 ilmenites as catalysts and precursors of metal catalysts with the aim to produce an oil enriched in high-value hydrocarbons, such as benzene, toluene, a xylenes mixture, and products less-reported, such as p-cymene and p-cymenene. The experiments were performed in an analytical pyrolyzer coupled to GC/MS. The effect of the nature of the catalysts on the product distribution was compared with the uncatalyzed reaction. The main products of uncatalyzed pyrolysis were D, L-limonene (~60%), and isoprene (~25%) due to the depolymerization of natural rubber. Meanwhile, Ni-ilmenites-based catalysts favored the formation of target compounds to expense D, L-limonene. Moreover, the presence of metal in reduced-ilmenite sharply enhanced the selectivity by ~50% concerning oxidized ilmenite and above 80% compared to the uncatalyzed reaction for p-cymene and p-cymenene. By contrast, the Co-ilmenites-based catalysts showed a marginal effect on secondary reactions. Finally, the feasibility of forming the aromatic terpenes, p-cymene, and p-cymenene from limonene in the non-catalytic pyrolysis was evaluated.Centro de Investigación y Desarrollo en Ciencias Aplicada
Gut-Brain Axis: Role of Microbiota in Parkinson’s Disease and Multiple Sclerosis
It has recently been discovered that the digestive tract is lined with about 100 million nerve cells; the digestive tract has been baptized, metaphorically speaking, as “the second brain,” which contains a multitude of neurotransmitters, viruses, and bacteria that help regulate our emotional state. This second brain, known as the enteric nervous system, is a unique anatomical unit that extends from the esophagus to the anus. Like the nervous system, it produces a whole series of psychoactive substances, such as serotonin, dopamine, and opioids for pain, and synthesizes benzodiazepines. In it, we find the microbiota: a set of microorganisms (viruses and bacteria). Together with the brain, the microbiota directly influences mood, character, or sleep. Knowledge about the possible relationship of the microbiota with frequent neurological diseases is still just beginning. Recently, possible changes in the microbiota have been linked to the onset of Parkinson’s disease (PD). Also, today, we know that there are differences between the microbiota of healthy people and people with multiple sclerosis and that these differences have also been related to the disease and its evolution
Expresión heteróloga y localización subcelular del candidato vacunal GPI4 de babesia bovis en el ciliado tetrahymena thermophila
Los glicosilfosfatidilinositoles (GPIs) se encuentran en abundancia en la superficie de protozoos parásitos como glicolípidos libres y como anclas de proteínas de superficie a la membrana plasmática. Se ha demostrado que las proteínas ancladas por GPIs están involucradas en el mecanismo de invasión a la célula huésped, por lo que representan blancos moleculares muy interesantes para el diseño de nuevas estrategias vacunales contra protozoos
patógenos de importancia veterinaria. Además, los GPIs libres actúan como potentes moduladores de la respuesta inmunológica. Tetrahymena thermophila es un protozoo ciliado de vida libre que expresa en la superficie abundantes proteínas ancladas por GPI, y ha sido utilizado como plataforma biotecnológica para la expresión de antígenos recombinantes.Instituto de PatobiologíaFil: Montes, M. G. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; Argentina. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Flores, Daniela. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: Rodriguez, Anabel Elisa. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; ArgentinaFil: González Maglio, D. H. Universidad de Buenos Aires. Instituto de Estudios de la Inmunidad Humoral (IDEHU); Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Florin-Christensen, Monica. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiologia; ArgentinaFil: Nusblat, Alejandro David. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Nanobiotecnología; ArgentinaFil: Schnittger, Leonhard. Instituto Nacional de Tecnología Agropecuaria (INTA). Instituto de Patobiología; Argentin
"I am your mother and your father!": In vitro derived gametes and the ethics of solo reproduction
In this paper, we will discuss the prospect of human reproduction achieved with gametes originating from only one person. According to statements by a minority of scientists working on the generation of gametes in vitro, it may become possible to create eggs from men’s non-reproductive cells and sperm from women’s. This would enable, at least in principle, the creation of an embryo from cells obtained from only one individual: ‘solo reproduction’. We will consider what might motivate people to reproduce in this way, and the implications that solo reproduction might have for ethics and policy. We suggest that such an innovation is unlikely to revolutionise reproduction and parenting. Indeed, in some respects it is less revolutionary than in vitro fertilisation as a whole. Furthermore, we show that solo reproduction with in vitro created gametes is not necessarily any more ethically problematic than gamete donation—and probably less so. Where appropriate, we draw parallels with the debate surrounding reproductive cloning. We note that solo reproduction may serve to perpetuate reductive geneticised accounts of reproduction, and that this may indeed be ethically questionable. However, in this it is not unique among other technologies of assisted reproduction, many of which focus on genetic transmission. It is for this reason that a ban on solo reproduction might be inconsistent with continuing to permit other kinds of reproduction that also bear the potential to strengthen attachment to a geneticised account of reproduction. Our claim is that there are at least as good reasons to pursue research towards enabling solo reproduction, and eventually to introduce solo reproduction as an option for fertility treatment, as there are to do so for other infertility related purposes
Strong Ultraviolet Pulse From a Newborn Type Ia Supernova
Type Ia supernovae are destructive explosions of carbon oxygen white dwarfs.
Although they are used empirically to measure cosmological distances, the
nature of their progenitors remains mysterious, One of the leading progenitor
models, called the single degenerate channel, hypothesizes that a white dwarf
accretes matter from a companion star and the resulting increase in its central
pressure and temperature ignites thermonuclear explosion. Here we report
observations of strong but declining ultraviolet emission from a Type Ia
supernova within four days of its explosion. This emission is consistent with
theoretical expectations of collision between material ejected by the supernova
and a companion star, and therefore provides evidence that some Type Ia
supernovae arise from the single degenerate channel.Comment: Accepted for publication on the 21 May 2015 issue of Natur
Measurement of the cosmic ray spectrum above eV using inclined events detected with the Pierre Auger Observatory
A measurement of the cosmic-ray spectrum for energies exceeding
eV is presented, which is based on the analysis of showers
with zenith angles greater than detected with the Pierre Auger
Observatory between 1 January 2004 and 31 December 2013. The measured spectrum
confirms a flux suppression at the highest energies. Above
eV, the "ankle", the flux can be described by a power law with
index followed by
a smooth suppression region. For the energy () at which the
spectral flux has fallen to one-half of its extrapolated value in the absence
of suppression, we find
eV.Comment: Replaced with published version. Added journal reference and DO
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