The GREATS Hβ\beta+[OIII] Luminosity Function and Galaxy Properties at z∼8\mathbf{z\sim8}: Walking the Way of JWST

The James Webb Space Telescope will allow to spectroscopically study an unprecedented number of galaxies deep into the reionization era, notably by detecting [OIII] and H$\beta$ nebular emission lines. To efficiently prepare such observations, we photometrically select a large sample of galaxies at $z\sim8$ and study their rest-frame optical emission lines. Combining data from the GOODS Re-ionization Era wide-Area Treasury from Spitzer (GREATS) survey and from HST, we perform spectral energy distribution (SED) fitting, using synthetic SEDs from a large grid of photoionization models. The deep Spitzer/IRAC data combined with our models exploring a large parameter space enables to constrain the [OIII]+H$\beta$ fluxes and equivalent widths for our sample, as well as the average physical properties of $z\sim8$ galaxies, such as the ionizing photon production efficiency with $\log(\xi_\mathrm{ion}/\mathrm{erg}^{-1}\hspace{1mm}\mathrm{Hz})\geq25.77$. We find a relatively tight correlation between the [OIII]+H$\beta$ and UV luminosity, which we use to derive for the first time the [OIII]+H$\beta$ luminosity function (LF) at $z\sim8$. The $z\sim8$ [OIII]+H$\beta$ LF is higher at all luminosities compared to lower redshift, as opposed to the UV LF, due to an increase of the [OIII]+H$\beta$ luminosity at a given UV luminosity from $z\sim3$ to $z\sim8$. Finally, using the [OIII]+H$\beta$ LF, we make predictions for JWST/NIRSpec number counts of $z\sim8$ galaxies. We find that the current wide-area extragalactic legacy fields are too shallow to use JWST at maximal efficiency for $z\sim8$ spectroscopy even at 1hr depth and JWST pre-imaging to $\gtrsim30$ mag will be required.Comment: 13 pages, 9 figures, accepted for publication in MNRA

Associação de marcadores moleculares SNP com o conteúdo de ácido linolênico em sementes de soja.

O objetivo deste trabalho foi validar a associação de marcadores moleculares do tipo ?single nucleotide polymorphism? (SNP) para os genes FAD3A, FAD3B e FAD3C com o conteúdo de ácido linolênico (18:3) em sementes de soja e analisar a influência dos parâmetros genéticos destes marcadores nesta característica. Foram genotipadas 185 progênies F2 derivadas do cruzamento entre A29 (mutante para os três genes FAD3, 1% de 18:3) e Tucunaré (genótipo selvagem, 11% de 18:3). Os marcadores moleculares para os genes FAD3A, FAD3B e FAD3C explicaram a variação do conteúdo de 18:3 nas populações segregantes F2 e F2:3. Além disso, as substituições alélicas no loco FAD3A proporcionam maiores variações no conteúdo de 18:3 que as substituições nos outros dois locos

Comportamento agronômico e qualidade culinária de feijão-caupi no Vale do São Francisco.

Neste trabalho avaliou-se o comportamento de 64 linhagens e de quatro cultivares de feijão-caupi, em dois experimentos de densidades populacionais, em vários ambientes do Vale do São Francisco nos anos de 2004 e 2005, tanto em regime irrigado, como de sequeiro, visando a recomendação de cultivares para a região

Efeito inibitório do extrato hexânico de Arrabidaea chica (Bignoniaceae) sobre peptidases de Leishmania chagasi.

No presente estudo investigou-se os efeitos anti-Leishmania chagasi do extrato hexânco A. chica, tendo como alvos celulares peptidases dos parasitos

Reaction of sugarcane genotypes to strains of the sugarcane mosaic virus.

Sugarcane crops are cultivated in nearly all tropical and sub-tropical regions worldwide andhave a prominent position in the agricultural scenario in Brazil. However, viral diseases can threaten the production of this important commodity leading to large production losses. In the present study, we evaluatedthe reaction of 20 sugarcane genotypes independently inoculated with two different strains of Sugarcane mosaic virus (SCMV) isolated from naturally infected sugarcane (SCMV-SGC) and maize (SCMV-MZ). The maize inbred line L19 was used as a control of susceptibility to the SCMV-MZ strain. Symptoms intensity was evaluated through a visual scale with three levels of severity: weak, intermediate, and intense. The viral infection was confirmed by PCR and DNA sequencing. We observed that, although both strains were able to infect sugarcane genotypes and the maize inbred line, SCMV-SGC was more aggressive, resulting in only four resistant genotypes: IN84-58 (S. spontaneum), RB855536, RB 928064, and SP71-6163. Thirteen genotypes were resistant to SCMV-MZ: IN84-58 (S.spontaneum), NA56-79, CB47-355,CB49-260, RB72454, RB855113, RB855536, RB867515, RB928064, SP70-1143, SP71-1406, SP71-6163, and SP81-3250. This is the first report showingSCMV strains capable of cross-infectingand causing mosaic in sugarcane and maize. Our data emphasize the importance of continuous monitoring and screening for virus resistantgenotypes to be used in breeding programs for the development of new resistant cultivars

An extreme [OIII] emitter at z=3.2z=3.2: a low metallicity Lyman continuum source

[Abridged] We investigate the physical properties of a Lyman continuum emitter candidate at $z=3.212$ with photometric coverage from $U$ to MIPS 24$\mu$m band and VIMOS/VLT and MOSFIRE/Keck spectroscopy. Investigation of the UV spectrum confirms a direct spectroscopic detection of the Lyman continuum emission with $S/N>5$. Non-zero Ly$\alpha$ flux at the systemic redshift and high Lyman-$\alpha$ escape fraction suggest a low HI column density. The weak C and Si low-ionization absorption lines are also consistent with a low covering fraction along the line of sight. The [OIII]$\lambda\lambda4959,5007+\mathrm{H}\beta$ equivalent width is one of the largest reported for a galaxy at $z>3$ ($\mathrm{EW}([\mathrm{OIII}]\lambda\lambda4959,5007+\mathrm{H}\beta) \simeq 1600\AA$, rest-frame) and the NIR spectrum shows that this is mainly due to an extremely strong [OIII] emission. The large observed [OIII]/[OII] ratio ($>10$) and high ionization parameter are consistent with prediction from photoionization models in case of a density-bounded nebula scenario. Furthermore, the $\mathrm{EW}([\mathrm{OIII}]\lambda\lambda4959,5007+\mathrm{H}\beta)$ is comparable to recent measurements reported at $z\sim7-9$, in the reionization epoch. We also investigate the possibility of an AGN contribution to explain the ionizing emission but most of the AGN identification diagnostics suggest that stellar emission dominates instead. This source is currently the first high-$z$ example of a Lyman continuum emitter exhibiting indirect and direct evidences of a Lyman continuum leakage and having physical properties consistent with theoretical expectation from Lyman continuum emission from a density-bounded nebula.Comment: 14 pages, 11 figures, accepted for publication in A&A. Minor modifications, Figure 2 updated, Figure 9 adde

Johnsongrass mosaic virus infecting sorghum in Brazil.

Sorghum bicolor (L.) Moench is cultivated in several tropical and subtropical regions in the world. Among the diseases, the mosaic caused by potyvirus is an important constraint for the agricultural production causing reduction in grain and forage sorghum production. In Brazil, only Sugarcane mosaic virus (SCMV) had previously been reported as the potyvirus species causing mosaic in sorghum and maize. A survey was carried out in sorghum plantations of the State of Minas Gerais, Brazil, during the 2014/2015 crop season for monitoring mosaic disease. Samples of sorghum plants expressing virus disease symptoms were collected for molecular analyzes. Molecular characterization of coat protein (CP) of the potyviruses naturally infecting sorghum, allowed us to identify the Johnsongrass mosaic virus (JGMV) as a new causal agent of mosaic disease in sorghum in Brazil. The sequences of the Brazilian JGMV sorghum-infecting (JGMV-Sr) isolates were deposited in the GenBank under the accession numbers KY952241, KY952242, and KY952243. Comparisons of the CP gene sequences of these Brazilian JGMV-Sr isolates revealed high nucleotide (nt) and amino acid (aa) sequence identities, ranging from 97.93 to 98.23%, and 99.12 to 99.20%, respectively, with the U07218.1 (JGMV-MDKS1) isolate. The Brazilian JGMV-Sr isolates were distinct from the Brazilian forage grasses-infecting (JGMV-Fg) isolates (KT833782 and KT289893). Transmission evaluations showed susceptibility of the teosinte, Sorghum verticilliflorum and Sorghum bicolor (L.) Moench, except line QL3.Maize and sugarcane genotypes were not infected by the Brazilian JGMV-Sr isolate. However, it is important to test more genotypes. This is the first report showing the identification and molecular characterization of the JGMV species naturally infecting sorghum at field conditions, expanding the knowledge about the dynamic and range of the mosaic causal agent for this crop in Brazil

Validation of microsatellite markers for assisted selection of soybean resistance to cyst nematode races 3 and 14.

ABSTRACT - The objective of this work was to validate microsatellite markers associated with resistance to soybean cyst nematode (Heterodera glycines Ichinohe) races 3 and 14, in soybean (Glycine max L.) genotypes, for use in marker-assisted selection (MAS) programs. Microsatellites of soybean linkage groups A2, D2 and G were tested in two populations, and their selection efficiencies were determined. The populations were 65 F2:3 families from Msoy8001 (resistant) x Conquista (susceptible) cross, and 66 F2:3 families of S5995 (resistant) x Renascença (susceptible) cross, evaluated for resistance to races 3 and 14, respectively. Families with female index up to 30% were considered moderately resistant. Markers of A2 and G linkage groups were associated with resistance to race 3. Markers Satt309 and GMENOD2B explained the greatest proportion of phenotypic variance in the different groups. The combinations Satt309+GMENOD2B and Satt309+Satt187 presented 100% selection efficiency. Resistance to race 14 was associated with markers of G linkage group, and selection efficiency in the Satt309+Satt356 combination was 100%. The selection differential obtained by phenotypic and marker assisted selection showed that both can result in similar gains. RESUMO - O objetivo deste trabalho foi validar marcadores microssatélites associados à resistência às raças 3 e 14 do nematóide-de-cisto (Heterodera glycines Ichinohe) da soja (Glycine max L.), para serem utilizados em programas de seleção assistida por marcadores moleculares (SAM). Microssatélites dos grupos de ligação A2, D2 e G da soja foram testados em duas populações, e suas eficiências de seleção foram determinadas. As populações foram 65 famílias F2:3,do cruzamento Msoy8001 (resistente) x Conquista (suscetível), e 66 famílias F2:3, do cruzamento S5995 (resistente) x Renascença (suscetível), avaliadas para a resistência às raças 3 e 14, respectivamente. Famílias com índice de fêmeas de até 30% foram consideradas moderadamente resistentes. Marcadores dos grupos de ligação A2 e G apresentaram associação com a resistência à raça 3. Os marcadores Satt309 e GMENOD2B explicaram a maior proporção da variância fenotípica nos diferentes grupos. As combinações Satt309+GMENOD2B e Satt309+Satt187 apresentaram eficiência de seleção de 100%. A resistência à raça 14 foi associada com marcadores do grupo de ligação G, e a eficiência de seleção da combinação Satt309+Satt356 foi de 100%. Os diferenciais de seleção fenotípica e de seleção assistida mostraram que os dois tipos de seleção podem proporcionar ganhos similares

Hubble imaging of the ionizing radiation from a star-forming galaxy at z=3.2 with fesc>50%

Star-forming galaxies are considered to be the leading candidate sources that dominate the cosmic reionization at z>7, and the search for analogs at moderate redshift showing Lyman continuum (LyC) leakage is currently a active line of research. We have observed a star-forming galaxy at z=3.2 with Hubble/WFC3 in the F336W filter, corresponding to the 730-890A rest-frame, and detect LyC emission. This galaxy is very compact and also has large Oxygen ratio [OIII]5007/[OII]3727 (>=10). No nuclear activity is revealed from optical/near-infrared spectroscopy and deep multi-band photometry (including the 6Ms X-ray, Chandra). The measured escape fraction of ionizing radiation spans the range 50-100\%, depending on the IGM attenuation. The LyC emission is detected at S/N=10 with m(F336W)=27.57+/-0.11 and it is spatially unresolved, with effective radius R_e<200pc. Predictions from photoionization and radiative transfer models are in line with the properties reported here, indicating that stellar winds and supernova explosions in a nucleated star-forming region can blow cavities generating density-bounded conditions compatible with optically thin media. Irrespective to the nature of the ionizing radiation, spectral signatures of these sources over the entire electromagnetic spectrum are of central importance for their identification during the epoch of reionization, when the LyC is unobservable. Intriguingly, the Spitzer/IRAC photometric signature of intense rest-frame optical emissions ([OIII]+Hbeta) observed recently at z~7.5-8.5 is similar to what is observed in this galaxy. Only the James Webb Space Telescope will measure optical line ratios at z>7 allowing a direct comparison with lower redshift LyC emitters, as reported here.Comment: 6 pages, 5 figures, ApJ submitted (comments welcome