A L\'evy flight for electrons in graphene: superdiffusive-to-diffusive transport transition

In this work we propose an electronic L\'evy flight device, analogous to a recent optical realization. To that end, we investigate the transmission of electrons in graphene nanoribbons in the presence of circular electrostatic clusters, whose diameter follow a power-law distribution. We analyze the effect of the electrostatic clusters on the electronic transport regime of the nanoribbons, in terms of its diffusion behavior. Our numerical calculations show that the presence of circular electrostatic clusters induces a transition from L\'evy (superdiffusive) to diffusive transport as the energy increases. Furthermore, we argue that in our electronic L\'evy flight device, superdiffusive transport is an exclusive feature of the low-energy quantum regime, while diffusive transport is a feature of the semiclassical regime. Therefore, we attribute the observed transition to the chiral symmetry breaking, once the energy moves away from the Dirac point of graphene.Comment: Accepted for publication as a Regular Article in Physical Review

An integrative approach assesses the intraspecific variations of Procamallanus (Spirocamallanus) inopinatus, a common parasite in Neotropical freshwater fishes, and the phylogenetic patterns of Camallanidae

Integrative taxonomy was used to evaluate two component populations of Procamallanus (Spirocamallanus) inopinatus in Brazil and the phylogeny Camallanidae. Parasite populations were collected in the characiform Anostomoides passionis from River Xingu (Amazon basin) and Megaleporinus elongatus from River Miranda (Paraguay basin). Morphology was analysed using light and scanning electron microscopy (SEM). Genetic characterization was based on partial sequences of the 18S and 28S rDNA, and COI mtDNA. Phylogenies were based on 18S and COI due to data availability. Generalized Mixed Yule Coalescent (GMYC), Poisson Tree Process (PTP) and BEAST were used for species delimitation and validation. SEM revealed for the first time the presence of minute denticles and pore-like structures surrounding the oral opening, phasmids in females and confirmed other important morphological aspects. Statistical comparison between the two-component populations indicated morphometric variations, especially among males. The different component population of P. (S.) inopinatus showed variable morphometry, but uniform morphology and were validated as conspecific by the GMYC, PTP and BEAST. Some camallanid sequences in GenBank have incorrect taxonomic labelling. Host, environment and geographic aspects seem to be related to some lineages within Camallanidae; however, their real phylogenetic meanings are still unclear.Fil: Ailan Choke, Lorena Gisela. Universidad Nacional de Salta. Facultad de Ciencias Naturales. Instituto para el Estudio de la Biodiversidad de Invertebrados; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Salta; ArgentinaFil: Tavares, Luiz E. R.. Universidade Federal do Mato Grosso do Sul; BrasilFil: Luque, José L.. Universidade Federal do Rio de Janeiro; BrasilFil: Pereira, Felipe B.. Universidade Federal de Minas Gerais. Instituto de Ciências Biológicas; Brasi

Toxoplasma gondii infection, congenital toxoplasmosis, toxoplasmic retinochoroiditis and neurotoxoplasmosis: an overview

Introduction: The toxoplasmosis disease resulting from Toxoplasma gondii infection can manifest itself in many ways, however, congenital, ocular and cerebral forms require greater care. The infection by this protozoan is directly related to environmental and economic factors of the region. Objective: The present study, through a review in the literature, aimed to reinforce the knowledge about the infection caused by Toxoplasma gondii and its main clinical manifestations. Methods: This is a literature overview from academic books and scientific articles available in the Scientific Electronic Library Online, US National Library of Medicine National Institutes of Health and Google Scholar databases. To search the publications, the following descriptors were used: Toxoplasma gondii, toxoplasmosis, congenital toxoplasmosis, ocular toxoplasmosis and cerebral toxoplasmosis. The most relevant articles corresponding to the period from 2000 to 2017 were selected. Development: Toxoplasmosis may be of congenital or acquired origin after birth. The congenital form occurs during the embryonic/fetal life and through the passage of Toxoplasma gondii through the transplacental route. Ocular disease is common in both congenital and acquired infections and is closely associated with the presence of neurotoxoplasmosis in AIDS patients. Conclusion: Thus, immunocompromised patients and immunosuppressed patients are considered to be risk groups for Toxoplasma gondii infection

A new strategy for using banana as an ingredient in the brewing process

Beer is a traditionally fermented beverage made from malted grains of barley, hops, yeast, and water, while banana is an important food crop cultivated widely in tropical and subtropical areas and is one of the major fruits in Brazil. Besides, the banana is also very favorable to food industry (e.g. fermented beverages) due to its rich content on soluble solids, presence of minerals, and providing low acidity. In this context, the objective of this work was to evaluate a new strategy for using banana as adjunct to increase the fermentable sugars and to supply a specific aroma in pilot-plant brewing experiments. For this, static fermentations were conducted in a 180 L cylindrical-conical reactor using 140 L as working volume. Addition of banana was evaluated when changing the concentration of the wort from 10 to 12 ºP and from 10 to 13.5 ºP (ºP is the weight of the extract or the sugar equivalent in 100 g solution, at 20 ºC) and fermented under a constant temperature of 10 and 12.5 ºC, respectively. The results showed that the increment in the initial sugar concentration (12 to 13.5 ºP, due to the use of banana juice as adjunct), and in the temperature (10 to 12.5 ºC), increased approximately 17% the ethanol productivity. Thus, it was concluded that by using of simple preparation techniques of banana juice, banana can be used as adjunct in brewing processes, helping in the development of new products as well as in the elaboration of more concentrated worts when compared the traditional brewing worts.Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Malteria do ValeCorn Products BrasilWallerstein Industrial e ComercialDiverseyLever (Brazil)Fundação para a Ciência e a Tecnologia (FCT)CAPES/GRICES (Brazil/Portugal

SIMBA: a web tool for managing bacterial genome assembly generated by Ion PGM sequencing technology

Background The evolution of Next-Generation Sequencing (NGS) has considerably reduced the cost per sequenced-base, allowing a significant rise of sequencing projects, mainly in prokaryotes. However, the range of available NGS platforms requires different strategies and software to correctly assemble genomes. Different strategies are necessary to properly complete an assembly project, in addition to the installation or modification of various software. This requires users to have significant expertise in these software and command line scripting experience on Unix platforms, besides possessing the basic expertise on methodologies and techniques for genome assembly. These difficulties often delay the complete genome assembly projects. Results In order to overcome this, we developed SIMBA (SImple Manager for Bacterial Assemblies), a freely available web tool that integrates several component tools for assembling and finishing bacterial genomes. SIMBA provides a friendly and intuitive user interface so bioinformaticians, even with low computational expertise, can work under a centralized administrative control system of assemblies managed by the assembly center head. SIMBA guides the users to execute assembly process through simple and interactive pages. SIMBA workflow was divided in three modules: (i) projects: allows a general vision of genome sequencing projects, in addition to data quality analysis and data format conversions; (ii) assemblies: allows de novo assemblies with the software Mira, Minia, Newbler and SPAdes, also assembly quality validations using QUAST software; and (iii) curation: presents methods to finishing assemblies through tools for scaffolding contigs and close gaps. We also presented a case study that validated the efficacy of SIMBA to manage bacterial assemblies projects sequenced using Ion Torrent PGM. Conclusion Besides to be a web tool for genome assembly, SIMBA is a complete genome assemblies project management system, which can be useful for managing of several projects in laboratories. SIMBA source code is available to download and install in local webservers at http://ufmg-simba.sourceforge.net

Benthic foraminiferal response to variations in temperature, salinity, dissolved oxygen and organic carbon, in the Guanabara Bay, Rio de Janeiro, Brazil

Recent benthic foraminiferal distribution patterns in Guanabara Bay are investigated in relation to temperature, salinity, dissolved oxygen and organic carbon content. Patterns of foraminiferal fauna differ between the entrance of the bay and inner parts. The primary result of the present study is that the distribution of Cassidulina subglobosa and Discorbis williamsoni appear to be governed by lower temperature and higher salinities being found in the entrance of the bay. According to dissolved oxygen content it was observed that Quinqueloculina seminulum occurs when values are higher than 2 mg/l, being intolerant to low oxygen bottom water conditions. By the other hand, Buliminella elegantissima, Bolivina striatula and Bulimmina elongata flourishes under low oxygen waters and in sediment where the organic matter accumulation is high, being found mainly in the central parts of the bay.Padrões de distribuição de foraminíferos bentônicos recentes são investigados com relação a temperatura, salinidade, oxigênio dissolvido e conteúdo de carbono orgânico. A distribuição de foraminíferos é diferente na entrada da baía se comparada às partes internas. Os primeiros resultados mostram que Cassidulina subglobosa e Discorbis williamsoni são encontradas em ambientes com baixa temperatura e altas salinidades na entrada da baía. De acordo com o teor de oxigênio dissolvido foi observado que Quinqueloculina seminulum ocorre quando os valores são mais altos que 2mg/l, sendo intolerante às condições. Por outro lado, Buliminella elegantissima, Bolivina striatula e Bulimmina elongata aparecem nas partes centrais da baía, que são locais com baixa oxigenação e sedimentos onde a acumulação de matéria orgânica é alta

Protective effects of Amburoside A, a phenol glucoside from Amburana cearensis, against CCl4-induced hepatotoxicity in rats.

The aim of this study was to investigate the possible beneficial effects of amburoside A, AMB [4-(0-b-d-glycopyranosyl) benzyl protocatechoate], against carbon tetrachloride (CCl) toxicity in rats

Análise da fermentação em bioreatores cilindrocônicos de bancada na elaboração de cerveja com adjunto de banana

O aumento do extrato inicial de fermentação e uso de adjuntos na substituição do malte vem sendo uma alternativa para diminuição de custos na produção de cervejas. Uma outra característica deste processo tem sido a utilização de nutrientes para aumentar a produtividade volumétrica em etanol. Pelo fato da banana ser uma fruta abundante no Brasil e ser pouco qualificada para a exportação, pode-se utilizá-la como alternativa de adjunto do malte. Neste estudo foi elaborada cerveja utilizando a banana como adjunto do malte e estudado os parâmetros fermentativos principais obtidos no ponto otimizado em bioreatores cilindrocônicos de bancada. Para isso os mostos foram fermentados à 17,5 °P e 15 °C suplementados no início da fermentação com 420 mg/L de MgSO4. A produtividade volumétrica (Qp) alcançada foi de 0,68 g/L.h no tempo de 64 h de fermentação. Essa suplementação gerou um benefício, devido ao aumento de 6 % do valor de Qp

Ocorrência de Cabassous tatouay (Cingulata, Dasypodidae) e seu potencial de distribuição para o sul do Brasil

Cabassous tatouay Desmarest, 1804 é considerada espécie rara no sul da América do Sul, apresentando registros escassos e imprecisos para o Rio Grande do Sul. O presente estudo descreve 40 localidades de ocorrência de C. tatouay e apresenta de um mapa de distribuição geográfica potencial, gerado por Modelagem Ecológica de Nicho. A modelagem de nicho sugere uma associação da espécie com áreas de matriz campestre, incluindo o Pampa e os Campos de Cima da Serra, associados à Mata Atlântica. Este estudo contribui para o melhor conhecimento do tatu-de-rabo-mole no Sul do Brasil e fornece dados-chave para sua conservação.Cabossous tatouay Desmarest, 1804 is considered a rare species in southern South America, and Rio Grande do Sul State, Brazil, records of the species are scarce and inaccurate. This study reports 40 localities for C. tatouay, and provides a map of the species' potential distribution using ecological niche modeling (ENM). The ENM indicated that in this region C. tatouay is associated with open grasslands, including the areas of "Pampas" and the open fields in the highlands of the Atlantic Forest. This study contributes to the information about the greater naked-tailed armadillo in southern Brazil, and provides data key to its future conservation