Avaliação da relação seca/produtividade agrícola em cenário de mudanças climáticas.

As mudanças climáticas alertam para um possível aumento de eventos meteorológicos extremos em todo o mundo, sendo crescente a preocupação de como o clima pode mudar o ambiente e afetar a produção das culturas agrícolas. Este estudo investiga a relação entre a produtividade agrícola e a seca em algumas mesorregiões do estado de Minas Gerais, em cenários de mudanças climáticas. Foram utilizados dados meteorológicos diários projetados pelo modelo ECHAM5/MPI-OM, para o período de 2008 a 2020 para o cenário A1B. Utilizou-se a metodologia da zona agroecológica (AEZ) para estimar a produtividade futura do milho. Empregou-se o índice de seca Z de Palmer em um modelo de regressão linear com a produtividade do milho estimada pela metodologia da AEZ. O desempenho dos modelos foi verificado por meio das estatísticas: coeficiente de determinação (r2), raiz do erro quadrático médio(RMSE), erro absoluto médio (MAE) e índice de concordância de Willmott (d). Os resultados do índice de concordância de Willmott variaram entre 0,48 e 0,90, e os valores de r2 foram pouco expressivos.Contudo, a produtividade estimada pela metodologia AEZ projetou maiores perdas na produtividade do milho devido a limitações por água para os anos agrícolas de 2008/2009, 2009/2010, 2014/2015,2018/2019 para as mesorregiões Triângulo/Alto Paranaíba, Central Mineira e Jequitinhonha

Correlation between mineral profile, physical-chemical characteristics, and proximate composition of meat from Santa Ines ewes under water restriction.

This study aimed to evaluate the correlations between mineral profile, physical and chemical characteristics, and proximate composition of ewe meat receiving different water supply levels (100% - ad libitum group; 80%; 60% and 40% ad libitum group). Thirty-two Santa Ines ewes were assigned to a randomized block design, with 4 treatments, and 8 replications, during the 63-day experimental period. Significant correlations between all minerals (P<0.05) were found in the 60% and 40% water supply levels. A correlation (P<0.05) was observed for minerals P, K, Ca, Mg, S, Cu, and Fe with crude protein at 100% water supply. Negative correlations (P<0.05) between N, P, K, Ca, Mg, S, Cu, Fe, and Zn were detected in the meat of animals supplied with 60% water. Principal component analysis (PCA) of macrominerals explained 82.9% data variance. Zinc had a strong contribution to PC1. Cooking losses had a similar contribution to PC1 and PC2. PC1 and PC2 explained 66.7% data variance in chemical characteristics. The decrease in water supply causes the correlation of nitrogen with the other minerals in meat, in addition to altering the correlation between the physical and chemical profile of the meat. Key words: Calcium. Crude protein. Hardness. Iron. Principal componentes

Dietary Blue Pigments Derived from Genipin, Attenuate Inflammation by Inhibiting LPS-Induced iNOS and COX-2 Expression via the NF-κB Inactivation

The edible blue pigments produced by gardenia fruits have been used as value-added colorants for foods in East Asia for 20 years. However, the biological activity of the blue pigments derived from genipin has not been reported.The anti-inflammatory effect of blue pigments was studied in lipopolysaccharide (LPS) stimulated RAW 264.7 macrophage in vitro. The secretions of nitric oxide (NO) and prostaglandin E(2) (PGE(2)) were inhibited in concentration-dependent manner by blue pigments. Real-time reverse-transcription polymerase chain reaction (Real-time RT-PCR) analyses demonstrated that the mRNA expression of inducible nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), interleukin (IL)-6, and tumor necrosis factor alpha (TNF-α) was inhibited, moreover, ELISA results showed that the productions of IL-6 and TNF-α were inhibited. Cell-based ELISA revealed the COX-2 protein expression was inhibited. The proteome profiler array showed that 12 cytokines and chemokines involved in the inflammatory process were down-regulated by blue pigments. Blue pigments inhibited the nuclear transcription factor kappa-B (NF-κB) activation induced by LPS, and this was associated with decreasing the DNA-binding activity of p65 and p50. Furthermore, blue pigments suppressed the degradation of inhibitor of κB (IκB) α, Inhibitor of NF-κB Kinase (IKK) α, IKK-β, and phosphorylation of IκB-α. The anti-inflammatory effect of blue pigments in vivo was studied in carrageenan-induced paw edema and LPS-injecting ICR mice. Finally, blue pigments significantly inhibited paw swelling and reduced plasma TNF-α and IL-6 production in vivo.These results suggest that the anti-inflammatory properties of blue pigments might be the results from the inhibition of iNOS, COX-2, IL-6, IL-1β, and TNF-α expression through the down-regulation of NF-κB activation, which will provide strong scientific evidence for the edible blue pigments to be developed as a new health-enhancing nutritional food for the prevention and treatment of inflammatory diseases

The Secrets of a Functional Synapse – From a Computational and Experimental Viewpoint

BACKGROUND: Neuronal communication is tightly regulated in time and in space. The neuronal transmission takes place in the nerve terminal, at a specialized structure called the synapse. Following neuronal activation, an electrical signal triggers neurotransmitter (NT) release at the active zone. The process starts by the signal reaching the synapse followed by a fusion of the synaptic vesicle and diffusion of the released NT in the synaptic cleft; the NT then binds to the appropriate receptor, and as a result, a potential change at the target cell membrane is induced. The entire process lasts for only a fraction of a millisecond. An essential property of the synapse is its capacity to undergo biochemical and morphological changes, a phenomenon that is referred to as synaptic plasticity. RESULTS: In this survey, we consider the mammalian brain synapse as our model. We take a cell biological and a molecular perspective to present fundamental properties of the synapse:(i) the accurate and efficient delivery of organelles and material to and from the synapse; (ii) the coordination of gene expression that underlies a particular NT phenotype; (iii) the induction of local protein expression in a subset of stimulated synapses. We describe the computational facet and the formulation of the problem for each of these topics. CONCLUSION: Predicting the behavior of a synapse under changing conditions must incorporate genomics and proteomics information with new approaches in computational biology

Role of mprF1 and mprF2 in the Pathogenicity of Enterococcus faecalis

Aujourd hui, Enterococcus faecalis est considéré comme l un des plus importants agents pathogènes causant des maladies nosocomiales. En raison de sa résistance innée et acquise aux antibiotiques, l identification de nouvelles cibles pour le traitement de cette bactérie est une grande priorité. Le facteur Multiple Peptide Résistance (MprF), qui a été décrit en premier chez Staphylococcus aureus, modifie le phosphatidylglycérol avec de la lysine et réduit ainsi la charge négative de l enveloppe cellulaire. Ceci a comme conséquence d augmenter la résistance aux peptides antimicrobiens cationiques (PAC). Deux gènes paralogues putatifs (mprF1 et mprF2) ont été identifiés chez E. faecalis par recherche BLAST en utilisant le gène décrit chez S. aureus. Une caractérisation de ces deux gènes d E. faecalis ainsi que des mécanismes conduisant à une résistance aux PAC, pourrait aider à développer des nouvelles stratégies thérapeutiques contre ce pathogène. Deux mutants de délétion et un double mutant ont été construits par recombinaison homologue chez E. faecalis. L analyse des phospholipides des membranes cytoplasmiques des deux mutants mprF1 et mprF2 par chromatographie sur couche mince a montré que seule l inactivation de mprF2 inhibe la synthèse de trois amino-phosphatidlyglycérol distincts (comme la Lysine-PG, l Alanine-PG et l Arginine-PG). De plus, le mutant mprF2 est également plus sensible aux PAC que la souche sauvage. La capacité de formation d un biofilm est généralement considérée comme un facteur important de virulence, ce qui est également le cas pour les entérocoques. Le mutant mprF2 montre une capacité accrue dans ce phénomène. Ceci semble être du à une augmentation de la concentration d ADN extracellulaire dans le biofilm formé par ce mutant. Curieusement, cette augmentation est indépendante d une autolyse. Le mutant mprF2 est également plus résistant à l opsonophagocytose. Cependant, le gène mprF2 ne joue aucun rôle dans les bactériémies de souris et les endocardites de rats.En revanche, aucun phénotype n a été trouvé pour un mutant mprF1 jusqu à présent. Cette mutation ne modifie ni la synthèse de l aminoacyl-PG en condition de laboratoire ni la résistance aux PAC et à l opsonophagocytose. Par conséquent, il semble que mprF2 soit le seul gène mprF fonctionnel chez E. faecalis. Néanmoins, contrairement à d autres bactéries, mprF2 ne semble pas être un facteur de virulence majeur pour cette espèce.Enterococcus faecalis is regarded nowadays as one of the most important nosocomial pathogens. Due to its innate and acquired resistance to antibiotics, identification of new targets for antimicrobial treatment of E. faecalis is a high priority. The multiple peptides resistance factor (MprF), which was first described in Staphylococcus aureus, modifies phosphatidylglycerol with lysine and reduces the negative charge of the membrane, thus increasing resistance to cationic antimicrobial peptides (CAMPs). Two putative mprF paralogs (mprF1 and mprF2) were identified in E. faecalis by Blast search using the well-described S. aureus gene as a lead. A better understanding of these two genes and mechanisms leads to enterococcal resistance to CAMPs might help designing therapeutic strategies against this bacteria. Two single deletion mutants and double mutant in E. faecalis were created by homologues recombination. Analysis of cell membrane phospholipids from both mutants by thin-layer chromatography showed that inactivation of mprF2 abolished the synthesis of three distinct amino-phosphatidylglycerol (mostly likely Lysin-PG, Alanine-PG and Argine-PG). The CAMPs testing assay demonstrated that the deletion mutant of mprF2 was more susceptible to CAMPs than the wild type. Biofilm formation is usually regarded as a virulence factor which provides an important way for enterococci to cause infections. Inactivation of mprF2 led to increase the biofilm formation which we showed that it was due to the accumulation of eDNA in the biofilm, but the release of eDNA is independent from autolysis. The mprF2 mutant was resistance to killing by opsonophagocytosis more than wild type. However, the mprF2 gene plays no role in bacteremia in mice and rat endocarditis. Our results showed that non polar effect mprF1 mutant does not affect in the synthesis of aminoacyl-PG in the laboratory condition. It also has no effect on susceptible to CAMPs, opsonic killing and autolysis. Therefore, it seems that mprF2 is the only functional mprF gene in E. faecalis in the laboratory condition. Unlike mprF found in other bacteria, mprF does not seem to be a major virulence factor in enterococci.CAEN-BU Sciences et STAPS (141182103) / SudocSudocFranceF

Large-Scale Screening of a Targeted Enterococcus faecalis Mutant Library Identifies Envelope Fitness Factors

Spread of antibiotic resistance among bacteria responsible for nosocomial and community-acquired infections urges for novel therapeutic or prophylactic targets and for innovative pathogen-specific antibacterial compounds. Major challenges are posed by opportunistic pathogens belonging to the low GC% Gram-positive bacteria. Among those, Enterococcus faecalis is a leading cause of hospital-acquired infections associated with life-threatening issues and increased hospital costs. To better understand the molecular properties of enterococci that may be required for virulence, and that may explain the emergence of these bacteria in nosocomial infections, we performed the first large-scale functional analysis of E. faecalis V583, the first vancomycin-resistant isolate from a human bloodstream infection. E. faecalis V583 is within the high-risk clonal complex 2 group, which comprises mostly isolates derived from hospital infections worldwide. We conducted broad-range screenings of candidate genes likely involved in host adaptation (e.g., colonization and/or virulence). For this purpose, a library was constructed of targeted insertion mutations in 177 genes encoding putative surface or stress-response factors. Individual mutants were subsequently tested for their i) resistance to oxidative stress, ii) antibiotic resistance, iii) resistance to opsonophagocytosis, iv) adherence to the human colon carcinoma Caco-2 epithelial cells and v) virulence in a surrogate insect model. Our results identified a number of factors that are involved in the interaction between enterococci and their host environments. Their predicted functions highlight the importance of cell envelope glycopolymers in E. faecalis host adaptation. This study provides a valuable genetic database for understanding the steps leading E. faecalis to opportunistic virulence

Multi-messenger observations of a binary neutron star merger

On 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of ~1.7 s with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg2 at a luminosity distance of 40+8-8 Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 Mo. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at ~40 Mpc) less than 11 hours after the merger by the One- Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ~10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position ~9 and ~16 days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta