Quenching or Bursting: Star Formation Acceleration--A New Methodology for Tracing Galaxy Evolution

We introduce a new methodology for the direct extraction of galaxy physical parameters from multi-wavelength photometry and spectroscopy. We use semi-analytic models that describe galaxy evolution in the context of large scale cosmological simulation to provide a catalog of galaxies, star formation histories, and physical parameters. We then apply stellar population synthesis models and a simple extinction model to calculate the observable broad-band fluxes and spectral indices for these galaxies. We use a linear regression analysis to relate physical parameters to observed colors and spectral indices. The result is a set of coefficients that can be used to translate observed colors and indices into stellar mass, star formation rate, and many other parameters, including the instantaneous time derivative of the star formation rate which we denote the {\it Star Formation Acceleration (SFA)}, We apply the method to a test sample of galaxies with GALEX photometry and SDSS spectroscopy, deriving relationships between stellar mass, specific star formation rate, and star formation acceleration. We find evidence for a mass-dependent SFA in the green valley, with low mass galaxies showing greater quenching and higher mass galaxies greater bursting. We also find evidence for an increase in average quenching in galaxies hosting AGN. A simple scenario in which lower mass galaxies accrete and become satellite galaxies, having their star forming gas tidally and/or ram-pressure stripped, while higher mass galaxies receive this gas and react with new star formation can qualitatively explain our results.Comment: 33 pages, 31 figures, ApJ accepte

Publicidade nos jogos de videogame

Este trabalho mostra a publicidade inserida nos jogos de videogame sendo, cada vez mais, usada como uma nova ferramenta de marketing. A metodologia utilizada refere-se a novas conquistas da mídia no que tange à inserção da mesma nos jogos de videogame. Essa análise é ilustrada com jogos eletrônicos, mostrando possibilidades e potencialidades nesta forma de publicidade, a qual tem alcançado novos públicos. Com resultados favoráveis para as empresas, é visto como um meio muito promissor, que trará bons resultados. Conclui-se que o desenvolvimento tecnológico dos videogames está trazendo a publicidade para uma nova era, com novos conceitos e formatos. O jogo de videogame não é mais usado apenas para diversão, já que ele proporciona um maior contato, da propaganda inserida, em relação ao consumidor. E isso proporciona uma melhor qualidade na diversão do século XX, fazendo com que o videogame seja uma ótima opção para crianças, jovens e adultos. Logo, percebe-se que, com a evolução tecnológica, tanto dos consoles como dos próprios jogos, passou a existir uma maior realidade humana dentro do mundo virtual

Timed Average Mean Maximum Velocity (TAMMV) of Cerebral Blood Flow of Children and Adolescents with Sickle cell Disease: correlation with clinical and hematological profiles in country

BackgroundDetection of abnormal TAMMV with transcranial Doppler is fundamental in primary stroke prevention in children with sickle cell disease (SCD). The study aimed at evaluating TAMMV and correlating it with clinical and hematological profiles of children and adolescent with SCD. MethodsTranscranial Doppler was performed on subjects aged 2-16 years, using a 2 MHz probe placed over the transtemporal windows. Pulse oximetry was used to determine the peripheral oxygen saturation while clinical and hematological profiles were retrieved from their medical records.Results One hundred and thirty five patients were recruited. The mean TAMMV was 125cm/s. Patients with HbSS had a significantly higher TAMMV (131cm/s) than those with HbSC (107cm/s). Only one (0.74%) patient had abnormal TAMMV. TAMMV correlated inversely with oxygen saturation, Hct and patient’s age, and positively with white cell and platelet counts. Previous history of acute chest syndrome (ACS) and recurrent painful crises increased the risk of development of abnormal and conditional velocity.Conclusion Frequency of abnormal TAMMV in this study was low. Younger children and those with HbSS had higher TAMMV. Age, oxygen saturation and haematocrit correlated negatively while white cell and platelet counts correlated positively with TAMMV. Previous history of ACS and recurrent bone pain were associated with increased risk of having abnormal and conditional TAMMV

Heterologous expression and functional characterization of a GH10 endoxylanase from \u3ci\u3eAspergillus fumigatus\u3c/i\u3e var. \u3ci\u3eniveus\u3c/i\u3e with potential biotechnological application

Xylanases decrease the xylan content in pretreated biomass releasing it from hemicellulose, thus improving the accessibility of cellulose for cellulases. In this work, an endo-β-1,4-xylanase from Aspergillus fumigatus var. niveus (AFUMN-GH10) was successfully expressed. The structural analysis and biochemical characterization showed this AFUMN-GH10 does not contain a carbohydrate-binding module. The enzyme retained its activity in a pH range from 4.5 to 7.0, with an optimal temperature at 60°C. AFUMN-GH10 showed the highest activity in beechwood xylan. The mode of action of AFUMNGH10 was investigated by hydrolysis of APTS-labeled xylohexaose, which resulted in xylotriose and xylobiose as the main products. AFUMN-GH10 released 27% of residual xylan from hydrothermally-pretreated corn stover and 14% of residual xylan from hydrothermally-pretreated sugarcane bagasse. The results showed that environmentally friendly pretreatment followed by enzymatic hydrolysis with AFUMN-GH10 in low concentration is a suitable method to remove part of residual and recalcitrant hemicellulose from biomass

Evidence for Elevated X-ray Emission in Local Lyman Break Galaxy Analogs

In this paper, we study the relationship between the 2-10 keV X-ray luminosity (L_X), assumed to originate from X-ray binaries (XRBs), and star formation rate (SFR) in UV-selected z<0.1 Lyman break analogs (LBAs). We present Chandra observations for four new GALEX-selected LBAs. Including previously studied LBAs, Haro 11 and VV 114, we find that LBAs demonstrate L_X/SFR ratios that are elevated by ~1.5sigma compared to local galaxies, similar to the ratios found for stacked LBGs in the early Universe (z>2). We show that these LBAs are unlikely to harbor AGN, based on their optical and X-ray spectra and the spatial distribution of the X-rays in three spatially extended cases. We expect that high-mass X-ray binaries (HMXBs) dominate the X-ray emission in these galaxies, based on their high specific SFRs (sSFRs=SFR/M* > 10^{-9}/yr), which suggest the prevalence of young stellar populations. Since both LBAs and LBGs have lower dust attenuations and metallicities compared to similar samples of more typical local galaxies, we investigate the effects of dust extinction and metallicity on the L_X/SFR for the broader population of galaxies with high sSFRs (>10^{-10}/yr). The estimated dust extinctions (corresponding to column densities of N_H<10^{22}/cm^2) are expected to have insignificant effects on observed L_X/SFR ratio for the majority of galaxy samples. We find that the observed relationship between L_X/SFR and metallicity appears consistent with theoretical expectations from X-ray binary population synthesis models. Therefore, we conclude that lower metallicities, related to more luminous HMXBs such as ultraluminous X-ray sources (ULXs), drive the elevated L_X/SFR observed in our sample of z<0.1 LBAs. The relatively metal-poor, active mode of star formation in LBAs and distant z>2 LBGs may yield higher total HMXB luminosity than found in typical galaxies in the local Universe.Comment: 11 pages, 7 figures, Submitted to ApJ (references updated in v2

SEED MORPHOBIOMETRY AND GERMINATION OF Sesbania punicea (Cav.) Benth. AND Sesbania virgata (Cav.) Pers.

Belonging to the family Fabaceae, Sesbania punicia and S. virgata are characterized by their ecological potential in the recovery of degraded areas. The present study aimed to describe the physical, morphobiometric characteristics of seeds, the germination phases and the initial development of S. punicia and S. virgata seedlings, as well as the germination behavior of seeds at different temperatures and substrates. For the physical characterization of seeds, the weight of one thousand seeds, number of seeds per kilogram, dry biomass of one thousand seeds and the moisture content were determined. To evaluate the effect of substrate and temperature on germination, the experiment was conducted in a completely randomized design, using a 3 x 3 factorial scheme, three substrates (sand, vermiculite and blotting paper) and three temperatures (20, 25 and 30 °C). The following factors were evaluated: germination percentage, germination speed index, mean germination time and synchronization index. S. punicea presented 13,243 seeds and S. virgata presented 14,414 seeds per kilogram, with moisture content of 14.5 and 7.9 %, respectively. Both species present similar morphobiometry and seedling development. For S. punicea, the blotting paper substrate and the temperature of 25 °C were most efficient for germination. For S. virgata, all treatments were effective for germination

Invasion origin, rapid population expansion, and the lack of genetic structure of cotton bollworm (Helicoverpa armigera) in the Americas

In 2013, Helicoverpa armigera (Hubner) (Lepidoptera: Noctuidae) was officially declared as present in Brazil and, after two years, the species was detected in the Caribbean and North America. Information on genetic features and accurate distribution of pests is the basis for agricultural protection policies. Furthermore, such knowledge is imperative to develop control strategies, understand the geographical range, and genetic patterns of this species in the Americas. Here, we carried out the widest sampling of H. armigera in the South American continent and Puerto Rico, after we estimated the diversity, demographic parameters, and genetic structure. The Internal Transcribed Spacer 1 (ITS1) nuclear marker was used to investigate the presence of putative hybrids between H. armigera and H. zea, and they were observed at a frequency of 1.5%. An ABC analysis, based in COI gene fragment, suggested Europe as the origin of South America specimens of H. armigeraand following a movement northward through the Caribbean. Three mtDNA genes and three nDNA markers revealed high genetic diversity distributed without the defined population structure of H. armigera in South America. Most of the genetic variation is within populations with a multidirectional expansion of H. armigera among morphoclimatic regions. High genetic diversity, rapid population expansion, and hybridization have implications for pest management since they suggest that adaptive alleles are spread through wide areas in South America that favor rapid local adaptation of H. armigera to new and disturbed environments (e.g., in agricultural areas)9137378CAPES - Coordenação de Aperfeiçoamento de Pessoal e Nível SuperiorCNPQ - Conselho Nacional de Desenvolvimento Científico e TecnológicoFAPESP – Fundação de Amparo à Pesquisa Do Estado De São Paulo2014/10504-9; 2014/11495-3; 2015/02079-9; 2018/04478-6140866/2016-7; 309167/2015-900