Pressure-induced Anderson-Mott transition in elemental tellurium

AbstractElemental tellurium is a small band-gap semiconductor, which is always p-doped due to the natural occurrence of vacancies. Its chiral non-centrosymmetric structure, characterized by helical chains arranged in a triangular lattice, and the presence of a spin-polarized Fermi surface, render tellurium a promising candidate for future applications. Here, we use a theoretical framework, appropriate for describing the corrections to conductivity from quantum interference effects, to show that a high-quality tellurium single crystal undergoes a quantum phase transition at low temperatures from an Anderson insulator to a correlated disordered metal at around 17 kbar. Such insulator-to-metal transition manifests itself in all measured physical quantities and their critical exponents are consistent with a scenario in which a pressure-induced Lifshitz transition shifts the Fermi level below the mobility edge, paving the way for a genuine Anderson-Mott transition. We conclude that previously puzzling quantum oscillation and transport measurements might be explained by a possible Anderson-Mott ground state and the observed phase transition.</jats:p

A molecular method for the detection of sally lightfoot crab larvae (Grapsus grapsus, Brachyura, Grapsidae) in plankton samples

The decapod Grapsus grapsus is commonly found on oceanic islands of the Pacific and Atlantic coasts of the Americas. In this study, a simple, quick and reliable method for detecting its larvae in plankton samples is described, which makes it ideal for large-scale studies of larval dispersal patterns in the species

Evapotranspiração e coeficientes de cultivo da beterraba orgânica sob cobertura morta de leguminosa e gramínea.

As práticas agrícolas que maximizam a produtividade e o uso da água são de vital importância para a agricultura. Assim, foram testados três tipos de manejo do solo com objetivo de determinar a evapotranspiração (ETc) e os coeficientes de cultivo (kc) da beterraba. Os tipos de manejo foram a utilização de coberturas mortas vegetais, denominadas capim cameroon (Pennisetum purpureum), gliricídia (Gliricidia sepium) e solo sem cobertura morta em área experimental do SIPA (Sistema Integrado de Produção Orgânica) localizado em Seropédica, Brasil. A lâmina de irrigação foi estimada com base no balanço de água no solo, cujo monitoramento foi realizado com a técnica da TDR. As ETc acumuladas para a cultura da beterraba foram 59,41; 55,31 e 119,62 mm, respectivamente, para capim cameroon, gliricídia e solo sem cobertura morta. A evapotranspiração de referência (ETo) foi obtida por meio do modelo de Penamn-Monteith. Os valores médios de kc obtidos para as fases inicial, média e final de desenvolvimento foram de 0,39; 0,42 e 1,02; 0,79; 0,76 e 1,18; e 0,56; 0,61 e 0,84, respectivamente, para capim cameroon, gliricídia e solo sem cobertura morta. O uso da cobertura do solo com gramínea ou leguminosa minimizou de forma expressiva a demanda hídrica da cultura da beterraba (Beta vulgaris)

Oral Administration of GW788388, an Inhibitor of Transforming Growth Factor Beta Signaling, Prevents Heart Fibrosis in Chagas Disease

Cardiac damage and dysfunction are prominent features in patients with chronic Chagas disease, which is caused by infection with the protozoan parasite Trypanosoma cruzi (T. cruzi) and affects 10–12 million individuals in South and Central America. Our group previously reported that transforming growth factor beta (TGFß) is implicated in several regulatory aspects of T. cruzi invasion and growth and in host tissue fibrosis. In the present work, we evaluated the therapeutic action of an oral inhibitor of TGFß signaling (GW788388) administered during the acute phase of experimental Chagas disease. GW788388 treatment significantly reduced mortality and decreased parasitemia. Electrocardiography showed that GW788388 treatment was effective in protecting the cardiac conduction system, preserving gap junction plaque distribution and avoiding the development of cardiac fibrosis. Inhibition of TGFß signaling in vivo appears to potently decrease T. cruzi infection and to prevent heart damage in a preclinical mouse model. This suggests that this class of molecules may represent a new therapeutic tool for acute and chronic Chagas disease that warrants further pre-clinical exploration. Administration of TGFß inhibitors during chronic infection in mouse models should be further evaluated, and future clinical trials should be envisaged

Effect of synbiotic supplementation in children and adolescents with cystic fibrosis: a randomized controlled clinical trial

BACKGROUND/OBJECTIVES:Cystic fibrosis (CF) is characterized by excessive activation of immune processes. The aim of this study was to evaluate the effect of synbiotic supplementation on the inflammatory response in children/adolescents with CF. SUBJECTS/METHODS:A randomized, placebo-controlled, double-blind, clinical-trial was conducted with control group (CG, n = 17), placebo-CF-group (PCFG, n = 19), synbiotic CF-group (SCFG, n = 22), PCFG negative (n = 8) and positive (n = 11) bacteriology, and SCFG negative (n = 12) and positive (n = 10) bacteriology. Markers of lung function (FEV1), nutritional status [body mass index-for age (BMI/A), height-for-age (H/A), weight-for-age (W/A), upper-arm fat area (UFA), upper-arm muscle area (UMA), body fat (%BF)], and inflammation [interleukin (IL)-12, tumor necrosis factor-alpha (TNF-α), IL-10, IL-6, IL-1β, IL-8, myeloperoxidase (MPO), nitric oxide metabolites (NOx)] were evaluated before and after 90-day of supplementation with a synbiotic. RESULTS:No significance difference was found between the baseline and end evaluations of FEV1 and nutricional status markers. A significant interaction (time vs. group) was found for IL-12 (p = 0.010) and myeloperoxidase (p = 0.036) between PCFG and SCFG, however, the difference was not maintained after assessing the groups individually. NOx diminished significantly after supplementation in the SCFG (p = 0.030). In the SCFG with positive bacteriology, reductions were found in IL-6 (p = 0.033) and IL-8 (p = 0.009) after supplementation. CONCLUSIONS: Synbiotic supplementation shown promise at diminishing the pro-inflammatory markers IL-6, IL-8 in the SCFG with positive bacteriology and NOx in the SCFG in children/adolescents with CF

Genome of the Avirulent Human-Infective Trypanosome—Trypanosoma rangeli

Background: Trypanosoma rangeli is a hemoflagellate protozoan parasite infecting humans and other wild and domestic mammals across Central and South America. It does not cause human disease, but it can be mistaken for the etiologic agent of Chagas disease, Trypanosoma cruzi. We have sequenced the T. rangeli genome to provide new tools for elucidating the distinct and intriguing biology of this species and the key pathways related to interaction with its arthropod and mammalian hosts.  Methodology/Principal Findings: The T. rangeli haploid genome is ,24 Mb in length, and is the smallest and least repetitive trypanosomatid genome sequenced thus far. This parasite genome has shorter subtelomeric sequences compared to those of T. cruzi and T. brucei; displays intraspecific karyotype variability and lacks minichromosomes. Of the predicted 7,613 protein coding sequences, functional annotations could be determined for 2,415, while 5,043 are hypothetical proteins, some with evidence of protein expression. 7,101 genes (93%) are shared with other trypanosomatids that infect humans. An ortholog of the dcl2 gene involved in the T. brucei RNAi pathway was found in T. rangeli, but the RNAi machinery is non-functional since the other genes in this pathway are pseudogenized. T. rangeli is highly susceptible to oxidative stress, a phenotype that may be explained by a smaller number of anti-oxidant defense enzymes and heatshock proteins.  Conclusions/Significance: Phylogenetic comparison of nuclear and mitochondrial genes indicates that T. rangeli and T. cruzi are equidistant from T. brucei. In addition to revealing new aspects of trypanosome co-evolution within the vertebrate and invertebrate hosts, comparative genomic analysis with pathogenic trypanosomatids provides valuable new information that can be further explored with the aim of developing better diagnostic tools and/or therapeutic targets