Chemical abundances and kinematics of barium stars

In this paper we present an homogeneous analysis of photospheric abundances based on high-resolution spectroscopy of a sample of 182 barium stars and candidates. We determined atmospheric parameters, spectroscopic distances, stellar masses, ages, luminosities and scale height, radial velocities, abundances of the Na, Al, $alpha$-elements, iron-peak elements, and s-process elements Y, Zr, La, Ce, and Nd. We employed the local-thermodynamic-equilibrium model atmospheres of Kurucz and the spectral analysis code {\sc moog}. We found that the metallicities, the temperatures and the surface gravities for barium stars can not be represented by a single gaussian distribution. The abundances of $alpha$-elements and iron peak elements are similar to those of field giants with the same metallicity. Sodium presents some degree of enrichment in more evolved stars that could be attributed to the NeNa cycle. As expected, the barium stars show overabundance of the elements created by the s-process. By measuring the mean heavy-element abundance pattern as given by the ratio [s/Fe], we found that the barium stars present several degrees of enrichment. We also obtained the [hs/ls] ratio by measuring the photospheric abundances of the Ba-peak and the Zr-peak elements. Our results indicated that the [s/Fe] and the [hs/ls] ratios are strongly anti-correlated with the metallicity. Our kinematical analysis showed that 90% of the barium stars belong to the thin disk population. Based on their luminosities, none of the barium stars are luminous enough to be an AGB star, nor to become self-enriched in the s-process elements. Finally, we determined that the barium stars also follow an age-metallicity relation.Comment: 30 pages, 26 figures, 18 tables, accepted for publication in MNRA

Characterization for enterotoxin production, virulence factors, and antibiotic susceptibility of Staphylococcus aureus isolates from various foods in Portugal

Staphylococcus aureus represents a public health challenge worldwide. The aim of this study was the characterization of different food isolates of S. aureus on the basis of their production of enterotoxins, hemolysins and resistance to antibiotics. A total of 148 coagulase-positive staphylococcal strains isolated from different food origins were identified to the species level. By multiplex PCR, 69% of the isolates were shown to be enterotoxigenic (SEs); the most common were sea seg, sea seg sei and seg sei. According to CLSI [CLSI, Clinical and Laboratory Standards Institute, 2007. Performance Standards for Antimicrobial Susceptibility Testing; Fifteenth Informational Supplement. CLSI document M100-S15. Clinical and Laboratory Standards Institute, Wayne, PA], 38% of the isolates were resistant to oxacillin ( 6 mg/mL; MRSA positives) but only 0.68% showed the presence of mecA gene. 70 and 73% of the S. aureus strains were resistant to b-lactams, ampicillin and penicillin, respectively. The virulence pattern was demonstrated to be origin and strain dependent. These findings emphasise the need to prevent the presence of S. aureus strains and SEs production in foodsinfo:eu-repo/semantics/acceptedVersio

Construção de modelo ecofisiologico de simulação para estimar a produtividade potencial de cana de açucar no Brasil e Australia.

Resumo: Neste artigo apresenta-se a construção de um modelo ecofisiológico-matemático (BrCane) para predizer a produtividade potencial - sem restrições nutricionais ou de água, a fim de analisar a sustentabilidade da expansão do cultivo de cana-de-açúcar em novas áreas para produção de etanol. A arquitetura do modelo BRCANE foi concebida para uma planta tipo C4, onde a evolução mensal da biomassa foi estimada em função da temperatura do ar e da radiação incidente. Nas simulações apresentadas a produção de biomassa levou em conta a taxa bruta de fotossíntese subtraída às perdas para respiração de manutenção, senescência de folhas e morte de perfilhos durante o ciclo da cultura. O modelo BRCANE também foi usado para descrever o comportamento fisiológico em função das condições ambientais relacionadas ao tempo termal. A implementação de tais condições permitiu ajustar os resultados das simulações a resultados experimentais disponíveis na literatura. As estimativas de biomassa foram comparadas com dados obtidos durante o ciclo da cultura em experimentos de campo com irrigação (Cultivares RB72 454, NA 56-79, CB 41-76, CB47-355, CP51-22, Q138 e Q141) no Estado de São Paulo (Brasil) e em Bundaberg e Queensland (Austrália) e os resultados foram expressos em toneladas de colmo por hectare (Mg.ha-1), por meio de uma relação linear para cada variedade (R2 = 0,89**) e superiores aos obtidos pelos modelos APSIM (R2=0,78*) e CANEGRO (R2=0,71*). O modelo apresentou resultados consistentes com dados experimentais para crescimento de biomassa no ciclo da cultura da cana-de-açúcar, oriundo de canaviais paulistas e de Bundaberg (Austrália).SIAGRO 2014

Low density ferromagnetism in biased bilayer graphene

We compute the phase diagram of a biased graphene bilayer. The existence of a ferromagnetic phase is discussed with respect both to carrier density and temperature. We find that the ferromagnetic transition is first order, lowering the value of $U$ relatively to the usual Stoner criterion. We show that in the ferromagnetic phase the two planes have unequal magnetization and that the electronic density is hole like in one plane and electron like in the other.Comment: 4 pages, 4 figures, added section on disorder and gamma_3 effect

Influência de boro no rendimento do girassol.

O objetivos do trabalho foram estudar o efeito de doses de boro nos componentes de rendimento de girassol na movimentação do nutriente no perfil de um Latossolo vermelho eutroférrico emlondrina, PR, Brasil

Spatial analysis of erosive processes in plateaus and depressions of the Upper Paraguai river basin.

Natural characteristics may contribute to the erosion of the soil and to environmental imbalances, and in most cases, they initiate the imbalances that will be exacerbated by human activities. The presence of asymmetry in a frequency diagram is a valuable fact, and may indicate irregularity in the occurrence of events or aggregation of events in preferred locations. Thus, this work aims to demonstrate the use of Geographic Information Systems (GIS) of statistical analysis based on patterns of frequency, density, distribution and spatial dependence of sample points through a cutout of the mapping of the geotechnical aspects conducted for the State of Mato Grosso, generated for the entire area of plateaus and depressions of the Upper Paraguai river basin and its internal units of drainage basins. In most cutouts used in the analysis, the values indicated that is void the possibility that the distribution patterns of erosive events were resulted of chance. The aggregate pattern shown may tend to attract new points, facilitating the transmission of the sample’s qualities through these, favored by your proximity and by the characteristics of the occurrence area.Especial - Geopantanal 2016

The contribution of a whey protein film incorporated with green tea extract to minimize the lipid oxidation of salmon (Salmo salar L.)

Active packaging is becoming progressively more significant as a response to the dynamic changes in current consumer demand and market tendencies. Active packaging is projected to interact directly with the packaged food or with the headspace within the package with the aim of maintaining or extending product quality and shelf-life. Aiming for sustainability, the potential application as biodegradable films of whey protein concentrate (WPC) was evaluated. Aromatic plant's extracts present high antioxidant properties, representing an alternative for synthetic food additives. The main objective of this study was to verify the effectiveness of an edible WPC film incorporated with a plant-based extract on retarding the lipid oxidation of fresh salmon. Green tea extract (GTE) was chosen to be incorporated into the active film. Fresh salmon was packaged with the control film (WPC) and with active film (WPC-GTE). The oxidation level of non-packaged samples and packaged samples were tested for different storage times. Four methods were applied to evaluate lipid oxidation state of fresh salmon: peroxide value, p-anisidine value, thiobarbituric acid reactive substances (TBARS) assay, and monitoring of hexanal. The results obtained in this study indicate that the whey protein active film was successfully produced, and it was effective in delaying lipid oxidation of fresh salmon samples until the 14th day of storage.Mariana Andrade is grateful for her research grant (SFRH/BD/138730/2018) funded by the Foundation for Science and Technology (FCT). M.F.V. acknowledges the support of FCT, through Mechanical Engineering Institute (IDMEC), under Associated Laboratory for Energy, Transports and Aeronautics (LAETA), project UID/EMS/50022/2019.info:eu-repo/semantics/publishedVersio

Reação de genótipos de sorgo a quatro populações de Colletotrichum sublineolum.

Trabalho apresentado no 42º Congresso Brasileiro de Fitopatologia, 2009. Rio de Janeiro, RJ

Modelagem para fertilização e calagem na cultura de cana-de-açúcar.

Resumo. O objetivo deste trabalho foi desenvolver uma metodologia em Sistema para calcular o Balanço Nutricional e Recomendação de corretivos e fertilizantes para a cultura de Cana-de-açúcar, por meio da organização das informações necessárias para modelar a demanda de nutrientes para determinada produtividade esperada. O balanço entre o que será dem andado requerimento da planta) e o que pode ser disponibilizado (suprimento do solo) é a base de desenvolvimento do sistema. O cálculo do balanço nutricional irá indicar a necessidade, ou não, da aplicação e incorporação de corretivos e fertilizantes.SBIAgro 2013