1,226 research outputs found

    Multi-semicircle-based single- and dual-band frequency-selective surfaces: achieving narrower bandwidth and improved oblique incidence angular stability

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    This article proposes two new frequency-selective surface (FSS) designs based on specific combinations of a multiple number of semicircles. One of the proposed designs makes use of four semicircles, yielding a single-band frequency response. The other consists of a combination of eight semicircles arranged in a square-like shape, producing a dual-band frequency response. The proposed designs were simulated with commercial electromagnetic simulation software.Ministerio de Economía y Competitividad | Ref. TEC2014-55735-C03-3RFundação para a Ciência e a Tecnologia | Ref. QREN-POPHEuropean Regional Development Fund | Ref. POCI-01-0247-FEDER-01786

    Molecular phylogeny and character-mapping support the synonymy of Cordobia and Gallardoa in Mionandra (Malpighiaceae)

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    Background and aims – Cordobia, Gallardoa, Mionandra, and Peixotoa (Stigmaphylloid clade, Malpighiaceae) are four small, closely related genera comprising shrubs or lianas endemic to South American savannas, dry forests, and temperate steppes. Their generic limits have significantly changed in the last century, and past molecular phylogenetic studies of Malpighiaceae have not tested the morphological characters of this group to identify synapomorphies supporting these clades/genera. Material and methods – We sampled the monospecific Cordobia and Gallardoa, one species of Mionandra (out of 2 spp.), nine species of Peixotoa (out of 29 spp.), and a single species of Camarea and Janusia as outgroups. Bayesian and Maximum Likelihood analyses were carried out for this clade based on five molecular markers (i.e. ETS, ITS, PHYC, matK, and ndhF). A set of 16 macromorphological characters was scored and coded for identifying synapomorphies under the Maximum Likelihood criteria. Key results – Our molecular phylogeny recovered Peixotoa as monophyletic and sister to the clade comprising Cordobia + Gallardoa + Mionandra, strongly corroborating previous phylogenetic studies of Malpighiaceae. The character-mapping analyses recovered two synapomorphies supporting the Cordobia + Gallardoa + Mionandra + Peixotoa clade, six supporting Mionandra s.l. (i.e. Cordobia + Gallardoa + Mionandra), and five supporting Peixotoa. Cordobia and Gallardoa are proposed as synonyms of Mionandra, alongside the necessary combinations, typifications, and identification keys. Conclusions – Morphological characters related to the degree of connation of the stipules, leaf indumentum type, petiole length, inflorescence architecture, number of flowers per inflorescence, presence of a peduncle in the 1-flowered cincinni, sepal connation, posture and texture, petal width and margin integrity, staminode presence, shape and size, and the shape of the apex of styles were key in circumscribing these lineages. Mionandra s.l. is proposed and characterised, including a new combination, an identification key to distinguish its species, a distribution map, and taxonomy notes

    Identification and analysis of seven effector protein families with different adaptive and evolutionary histories in plant-associated members of the Xanthomonadaceae.

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    The Xanthomonadaceae family consists of species of non-pathogenic and pathogenic γ-proteobacteria that infect different hosts, including humans and plants. In this study, we performed a comparative analysis using 69 fully sequenced genomes belonging to this family, with a focus on identifying proteins enriched in phytopathogens that could explain the lifestyle and the ability to infect plants. Using a computational approach, we identified seven phytopathogen-enriched protein families putatively secreted by type II secretory system: PheA (CM-sec), LipA/LesA, VirK, and four families involved in N-glycan degradation, NixE, NixF, NixL, and FucA1. In silico and phylogenetic analyses of these protein families revealed they all have orthologs in other phytopathogenic or symbiotic bacteria, and are involved in the modulation and evasion of the immune system. As a proof of concept, we performed a biochemical characterization of LipA from Xac306 and verified that the mutant strain lost most of its lipase and esterase activities and displayed reduced virulence in citrus. Since this study includes closely related organisms with distinct lifestyles and highlights proteins directly related to adaptation inside plant tissues, novel approaches might use these proteins as biotechnological targets for disease control, and contribute to our understanding of the coevolution of plant-associated bacteria

    A new classification system and taxonomic synopsis for Malpighiaceae (Malpighiales, Rosids) based on molecular phylogenetics, morphology, palynology, and chemistry

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    Malpighiaceae has undergone unprecedented changes in its traditional classification in the past two decades due to several phylogenetic studies shedding light on the non-monophyly of all subfamilies and most tribes and genera. Even though morphological characters were used to reconstruct the last molecular generic phylogeny of Malpighiaceae, a new classification system has never been proposed for this family. Based on a comprehensive review of the last twenty years of published studies for this family, we propose a new classification system and provide a taxonomic synopsis for Malpighiaceae based on molecular phylogenetics, morphology, palynology, and chemistry as a baseline for the systematics, conservation, and taxonomy of this family worldwide. Malpighiaceae currently comprises two subfamilies (Byrsonimoideae and Malpighioideae), 12 tribes ( Acmanthereae , Acridocarpeae trib. nov., Barnebyeae trib. nov., Bunchosieae trib. nov., Byrsonimeae, Galphimieae, Gaudichaudieae, Hiptageae, Hiraeeae, Malpighieae, Mcvaughieae trib. nov., and Ptilochaeteae trib. nov.), 72 genera (incl. Mamedea gen. nov.), and 1,499 accepted species (715 of which are currently under some kind of extinction threat). We present identification keys for all subfamilies, tribes, and genera, a full morphological description for the proposed new genus, the re-circumscription of ten genera alongside the needed new combinations, the proposition of several new synonyms, the typification of several names, and notes on the taxonomy, distribution, conservation, and ecology up to the genus rank. Morphological plates are also provided to illustrate the immense diversity of morphological traits used in the new classification and synopsis

    A globally applicable PCR-based detection and discrimination of BK and JC polyomaviruses

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    BKV and JCV belong to the Polyomaviridae family and are opportunistic agents associated with complications in immunocompromised individuals. Although a single screening assay for both viruses would be convenient, the diversity of BKV and JCV serotypes and genotypes is a methodological challenge. In this paper, we developed a PCR method able to detect and segregate BKV and JCV, despite these genetic discrepancies. A duplex semi-nested PCR (duplex snPCR) was designed to target a conserved region (639nt-1516nt) within the VP2 gene. In the first PCR, a primer set common to all BKV and JCV serotypes/ genotypes was used, followed by a semi-nested PCR with internal primers for BKV and JCV segregation. The limit of detection of the duplex snPCR was as low as 10 copies of BKV or JCV plasmids/µL. Specific products were observed when JCV and BKV plasmids were mixed in the same reaction. In field sample testing, the duplex snPCR detected and distinguished both viruses in different biological samples. Results were confirmed by Sanger’s sequencing. The geographical complexity of BKV and JCV serotypes and genotypes imposes limits to a simple and universal method that could detect each virus. However, we describe here a sensitive and reliable PCR technique for BKV and JCV diagnosis that overcomes these limitations and could be universally applied

    Efecto de la Temperatura de Deposición en los Parámetros Estructurales y de Transición Metal-Aislante, de Películas Delgadas de Dióxido de Vanadio (VO2)

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    Se investigó el efecto de la temperatura de deposición en los parámetros estructurales y de transición de la fase metal–aislante en películas delgadas de VO2, producidas mediante la técnica de Erosión Iónica en atmósfera reactiva. Las muestras fueron producidas como monocapas y depositadas a distintas temperaturas sobre substratos de SiO2/Si (100). La caracterización estructural por difracción de rayos X (XRD) mostró la presencia de la fase M1 del VO2. Los parámetros de red y el volumen de la celda unitaria cambian levemente con el aumento de la temperatura de deposición. La caracterización eléctrica de la resistencia como función de la temperatura, por el método de cuatro puntas, muestra transición de fase reversible, con histéresis térmica en todas las muestras. Conforme aumenta la temperatura de deposición, se observó un incremento en la temperatura de transición (TMIT), entre 67 °C y 73 °C, para el ciclo de calentamiento, manifestándose además, una disminución en la variación de la resistencia eléctrica durante la transición, afectando la forma y tamaño del lazo de histéresis. Los resultados experimentales demuestran que las películas delgadas de VO2 son policristalinas y que la temperatura de deposición afecta los parámetros estructurales y de transición metal–aislante, explicando la aparición de estrés en el material depositado.Se investigó el efecto de la temperatura de deposición en los parámetros estructurales y de transición de la fase metal–aislante en películas delgadas de VO2, producidas mediante la técnica de Erosión Iónica en atmósfera reactiva. Las muestras fueron producidas como monocapas y depositadas a distintas temperaturas sobre substratos de SiO2/Si (100). La caracterización estructural por difracción de rayos X (XRD) mostró la presencia de la fase M1 del VO2. Los parámetros de red y el volumen de la celda unitaria cambian levemente con el aumento de la temperatura de deposición. La caracterización eléctrica de la resistencia como función de la temperatura, por el método de cuatro puntas, muestra transición de fase reversible, con histéresis térmica en todas las muestras. Conforme aumenta la temperatura de deposición, se observó un incremento en la temperatura de transición (TMIT), entre 67 °C y 73 °C, para el ciclo de calentamiento, manifestándose además, una disminución en la variación de la resistencia eléctrica durante la transición, afectando la forma y tamaño del lazo de histéresis. Los resultados experimentales demuestran que las películas delgadas de VO2 son policristalinas y que la temperatura de deposición afecta los parámetros estructurales y de transición metal–aislante, explicando la aparición de estrés en el material depositado

    Absence of the caspases 1/11 modulates liver global lipid profile and gut microbiota in high-fat-diet-induced obese mice

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    Obesity is a chronic disease with rising worldwide prevalence and largely associated with several other comorbidities, such as cancer, non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome. Hepatic steatosis, a hallmark of NAFLD, is strongly correlated with obesity and has been correlated with changes in the gut microbiota, which can promote its development through the production of short-chain fatty acids (SCFAs) that regulate insulin resistance, bile acid, choline metabolism, and inflammation. Recent studies have suggested a controversial role for the inflammasome/caspase-1 in the development of obesity and non-alcoholic steatohepatitis (NASH). Here, we evaluated the role of inflammasome NLRP3 and caspases 1/11 in the establishment of obesity and hepatic steatosis in diet-induced obese mice, correlating them with the global lipid profile of the liver and gut microbiota diversity. After feeding wild-type, caspases 1/11, and NLRP3 knockout mice with a standard fat diet (SFD) or a high-fat diet (HFD), we found that the caspases 1/11 knockout mice, but not NLRP3 knockout mice, were more susceptible to HFD-induced obesity, and developed enhanced hepatic steatosis even under SFD conditions. Lipidomics analysis of the liver, assessed by MALDI-MS analysis, revealed that the HFD triggered a significant change in global lipid profile in the liver of WT mice compared to those fed an SFD, and this profile was modified by the lack of caspases 1/11 and NLRP3. The absence of caspases 1/11 was also correlated with an increased presence of triacylglycerol in the liver. Gut microbial diversity analysis, using 16S rRNA gene sequencing, showed that there was also an increase of Proteobacteria and a higher Firmicutes/Bacteroidetes ratio in the gut of caspases 1/11 knockout mice fed an HFD. Overall, mice without caspases 1/11 harbored gut bacterial phyla involved with weight gain, obesity, and hepatic steatosis. Taken together, our data suggest an important role for caspases 1/11 in the lipid composition of the liver and in the modulation of the gut microbial community composition. Our results further suggest that HFD-induced obesity and the absence of caspases 1/11 may regulate both lipid metabolism and gut microbial diversity, and therefore may be associated with NAFLD and obesity10CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESP312359/2016-02016/22577-6This research was funded by Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq -#312359/2016-0). CM was funded by the Canada Research Chair Program, the Canadian Foundation for Innovation, McGill University, and the Canadian Institutes for Health Research (PJT-149098). ME was funded by the São Paulo Research Foundation (FAPESP) (2016/22577-6)

    Contribution of the institutions in the Northern region of Brazil to the development of plant cultivars and their impact on agriculture

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    This paper describes the development of breeding programs in northern Brazil and their main impacts on agriculture. Their contribution to the breeding of the species palm oil, acai fruit, cacao, cupuaçu, guarana, tomato, camu-camu, cocona, peach palm, and rubber was laid out in detail. Advances in breeding programs of institutions such as Embrapa, Ceplac, Inpa, and Universities require investments in infrastructure and in human and financial resources to ensure continuity and efficiency in economic, social and environmental gains. The improvement of native species, the main focus of the breeding programs of the institutions in the Northern region of Brazil, is a form of exploiting the Amazonian biodiversity for the benefit of society. Therefore, policies to foster research institutions should be a subject of deliberation and action of the scientific and technological community in Brazil

    Integrative overview of the herpetofauna from serra da mocidade, a granitic mountain range in northern Brazil

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    The Brazilian mountain ranges from the Guiana Shield highlands are largely unexplored, with an understudied herpetofauna. Here the amphibian and reptile species diversity of the remote Serra da Mocidade mountain range, located in extreme northern Brazil, is reported upon, and biogeographical affinities and taxonomic highlights are discussed. A 22-days expedition to this mountain range was undertaken during which specimens were sampled at four distinct altitudinal levels (600, 960, 1,060 and 1,365 m above sea level) using six complementary methods. Specimens were identified through an integrated approach that considered morphological, bioacoustical, and molecular analyses. Fifty-one species (23 amphibians and 28 reptiles) were found, a comparable richness to other mountain ranges in the region. The recorded assemblage showed a mixed compositional influence from assemblages typical of other mountain ranges and lowland forest habitats in the region. Most of the taxa occupying the Serra da Mocidade mountain range are typical of the Guiana Shield or widely distributed in the Amazon. Extensions of known distribution ranges and candidate undescribed taxa are also recorded. This is the first herpetofaunal expedition that accessed the higher altitudinal levels of this mountain range, contributing to the basic knowledge of these groups in remote areas. © Leandro J.C.L. Moraes et al
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