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

Superlubricity mechanism of diamond-like carbon with glycerol. Coupling of experimental and simulation studies

We report a unique tribological system that produces superlubricity under boundary lubrication conditions with extremely little wear. This system is a thin coating of hydrogen-free amorphous Diamond-Like-Carbon (denoted as ta-C) at 353 K in a ta-C/ta-C friction pair lubricated with pure glycerol. To understand the mechanism of friction vanishing we performed ToF-SIMS experiments using deuterated glycerol and 13C glycerol. This was complemented by first-principles-based computer simulations using the ReaxFF reactive force field to create an atomistic model of ta-C. These simulations show that DLC with the experimental density of 3.24 g/cc leads to an atomistic structure consisting of a 3D percolating network of tetrahedral (sp3) carbons accounting for 71.5% of the total, in excellent agreement with the 70% deduced from our Auger spectroscopy and XANES experiments. The simulations show that the remaining carbons (with sp2 and sp1 character) attach in short chains of length 1 to 7. In sliding simulations including glycerol molecules, the surface atoms react readily to form a very smooth carbon surface containing OH-terminated groups. This agrees with our SIMS experiments. The simulations find that the OH atoms are mostly bound to surface sp1 atoms leading to very flexible elastic response to sliding. Both simulations and experiments suggest that the origin of the superlubricity arises from the formation of this OH-terminated surface

A comparative study on the functionality of S- and P-based lubricant additives by combined first principles and experimental analysis

Sulfur and phosphorus are key elements for the functionality of lubricant additives used in extreme pressure applications, such as synchronizer systems in cars. To understand their mechanism of action we combine first principles calculations and gas phase lubrication experiments. The surface spectroscopy analysis performed in situ after the tribological test indicates that iron sulfide (phosphide) is formed by rubbing steel-on-steel in the presence of organo-sulfur (-phosphorus) molecules. We, thus, study the effects of elemental sulfur and phosphorus on the interfacial properties of iron by spin-polarized density functional theory calculations. The results show that both the elements are very effective in reducing the adhesion and shear strength of iron. Sulfur is predicted to be more effective than phosphorus, especially at high pressure. Gas phase lubrication experiments confirm these results, indicating that the friction coefficient of iron-sulphide is lower than that of iron-phosphide and both S and P dramatically reduce the friction of steel-on-steel. These results indicate that the release of elemental sulfur and phosphorus may be the key mechanism to controlling the tribological properties of the metal interface and elucidate that the underling microscopic phenomenon is metal passivation. © 2016 The Royal Society of Chemistry.Sulfur and phosphorus are key elements for the functionality of lubricant additives used in extreme pressure applications, such as synchronizer systems in cars. To understand their mechanism of action we combine first principles calculations and gas phase lubrication experiments. The surface spectroscopy analysis performed in situ after the tribological test indicates that iron sulfide (phosphide) is formed by rubbing steel-on-steel in the presence of organo-sulfur (-phosphorus) molecules. We, thus, study the effects of elemental sulfur and phosphorus on the interfacial properties of iron by spin-polarized density functional theory calculations. The results show that both the elements are very effective in reducing the adhesion and shear strength of iron. Sulfur is predicted to be more effective than phosphorus, especially at high pressure. Gas phase lubrication experiments confirm these results, indicating that the friction coefficient of iron-sulphide is lower than that of iron-phosphide and both S and P dramatically reduce the friction of steel-on-steel. These results indicate that the release of elemental sulfur and phosphorus may be the key mechanism to controlling the tribological properties of the metal interface and elucidate that the underling microscopic phenomenon is metal passivation

GGE biplot for stability and adaptability in cashew tree clones.

The interaction genotype versus environment makes it difficult the genetic improvement of the species for the selection of more adapted and stable genotypes. Thus, the objective of this work was to evaluate new clones of early dwarf cashews, in terms of stability and adaptability, employing the GGE biplot methodology. The experimental design was based on randomized blocks with four replications and 15 treatments (different clones). The variables evaluated were cashew production per plant (PCP), average mass of chashew (MMC) and early harvest (PRE). The clones G1 and G3 for MMC, G15, G2, G14 and G8 for PRE and G3, G10 and G2 for PCP approached the ideotype; the clones identified as top for each characteristic were not coincident; the majority of the clones were stable for MMC, while for PRE and PCP were not stable; the clone G4 had the best average in PRE, but with low stability; in the GGE biplot the environments A3 for MMC, A4 to PRE and A5 for PCP were the most discriminating; all environments had greater contribution in the differentiation of clones in PRE and MMC, for PCP were the environments A4 and A5; in relation at the average representativeness the environments A1 in MMC and A2 for PRE and PCP stood out. = A interação genótipos versus ambientes dificulta o melhoramento genético das espécies para a seleção de genótipos adaptados e estáveis. Assim, objetivou-se com este trabalho avaliar novos clones de cajueiro-anão precoce, quanto a estabilidade e adaptabilidade, empregando a metodologia Biplot GGE. O delineamento experimental foi em blocos casualizados com quatro repetições e 15 tratamentos (diferentes clones). As variáveis avaliadas foram produção de castanha por planta (PCP), massa média de castanha (MMC) e precocidade de colheita (PRE). Os clones G1 e G3 para MMC; G15, G2, G14 e G8 para PRE e, G3, G10 e G2 para PCP se aproximaram do ideótipo; os clones identificados como superiores para cada característica não foram coincidentes; a maioria dos clones foram estáveis para MMC, enquanto que para PRE e PCP não foram estáveis; o clone G4 teve a melhor média em PRE, mas com baixa estabilidade; no GGE Biplot os ambientes A3 para MMC, A4 para PRE e A5 para PCP foram os mais discriminadores; todos os ambientes tiveram maior contribuição na diferenciação dos clones em PRE e MMC, para PCP foram os ambientes A4 e A5 e; em relação a representatividade média os ambientes A1 em MMC e A2 para PRE e PCP se destacaram

GGE biplot for stability and adaptability in cashew tree clones.

The interaction genotype versus environment makes it difficult the genetic improvement of the species for the selection of more adapted and stable genotypes. Thus, the objective of this work was to evaluate new clones of early dwarf cashews, in terms of stability and adaptability, employing the GGE biplot methodology. The experimental design was based on randomized blocks with four replications and 15 treatments (different clones). The variables evaluated were cashew production per plant (PCP), average mass of chashew (MMC) and early harvest (PRE). The clones G1 and G3 for MMC, G15, G2, G14 and G8 for PRE and G3, G10 and G2 for PCP approached the ideotype; the clones identified as top for each characteristic were not coincident; the majority of the clones were stable for MMC, while for PRE and PCP were not stable; the clone G4 had the best average in PRE, but with low stability; in the GGE biplot the environments A3 for MMC, A4 to PRE and A5 for PCP were the most discriminating; all environments had greater contribution in the differentiation of clones in PRE and MMC, for PCP were the environments A4 and A5; in relation at the average representativeness the environments A1 in MMC and A2 for PRE and PCP stood out

GGE biplot for stability and adaptability in cashew tree clones.

The interaction genotype versus environment makes it difficult the genetic improvement of the species for the selection of more adapted and stable genotypes. Thus, the objective of this work was to evaluate new clones of early dwarf cashews, in terms of stability and adaptability, employing the GGE biplot methodology. The experimental design was based on randomized blocks with four replications and 15 treatments (different clones). The variables evaluated were cashew production per plant (PCP), average mass of chashew (MMC) and early harvest (PRE). The clones G1 and G3 for MMC, G15, G2, G14 and G8 for PRE and G3, G10 and G2 for PCP approached the ideotype; the clones identified as top for each characteristic were not coincident; the majority of the clones were stable for MMC, while for PRE and PCP were not stable; the clone G4 had the best average in PRE, but with low stability; in the GGE biplot the environments A3 for MMC, A4 to PRE and A5 for PCP were the most discriminating; all environments had greater contribution in the differentiation of clones in PRE and MMC, for PCP were the environments A4 and A5; in relation at the average representativeness the environments A1 in MMC and A2 for PRE and PCP stood out

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