Anderson localization on the Falicov-Kimball model with Coulomb disorder

The role of Coulomb disorder is analysed in the Anderson-Falicov-Kimball model. Phase diagrams of correlated and disordered electron systems are calculated within dynamical mean-field theory applied to the Bethe lattice, in which metal-insulator transitions led by structural and Coulomb disorders and correlation can be identified. Metallic, Mott insulator, and Anderson insulator phases, as well as the crossover between them are studied in this perspective. We show that Coulomb disorder has a relevant role in the phase-transition behavior as the system is led towards the insulator regime

Effects of band filling in the Anderson-Falicov-Kimball model

In this work, we study the Anderson-Falicov-Kimball model within the dynamical mean field theory for the Bethe lattice, restricting our analysis to the nonmagnetic case. The one-particle density of states is obtained by both arithmetic and geometric averages over disorder, since only the latter can detect localization in the absence of an energy gap. Varying the strengths of Coulomb interaction and disorder at zero temperature, we construct phase diagrams for this model, where we distinguish spectral regions with localized states, with extended states, or with a correlation-induced gap. With this, we identify metal-insulator transitions driven by correlation and disorder, as well as the competition between these effects. This is done for various band fillings, since our main interest here is to study how the variation of the electron density affects the phase diagrams previously obtained for half-filling. The picture revealed by the density of states is further checked by evaluating the static and dynamic conductivities, including temperature effects

Response letter: Serological evidence confirms the presumed diagnosis of Zika virus congenital infection in infants with microcephaly and ocular findings

FAV, Recife, PE, BrazilHosp Olhos HOPE, Recife, PE, BrazilUniv Fed Sao Paulo UNIFESP, EPM, Dept Ophthalmol & Visual Sci, Sao Paulo, SP, BrazilInst Visiao, Sao Paulo, SP, BrazilHosp Barao de Lucena, Recife, PE, BrazilHUOC, Recife, PE, BrazilUniv Fed Sao Paulo UNIFESP, EPM, Dept Ophthalmol & Visual Sci, Sao Paulo, SP, BrazilWeb of Scienc

Avaliação do estado nutricional de agroecossistemas de café orgânico no estado de Minas Gerais.

A produção de café orgânico vem se constituindo uma tendência necessária e irreversível do agronegócio brasileiro. Essa atividade tem-se destacado como uma alternativa de renda para alguns cafeicultores, devido à crescente demanda mundial por alimentos mais saudáveis. Entretanto, grande parte das técnicas propostas pela agricultura orgânica está sendo aplicada empiricamente no cultivo de café, principalmente no Estado de Minas Gerais, maior região produtora de café do Brasil. Levando-se em consideração a baixa fertilidade natural dos solos dessa região cafeeira, bem como a elevada extração de nutrientes pelo cafeeiro, objetivou-se neste trabalho identificar possíveis fatores limitantes para a produção orgânica do cafeeiro, relacionados à fertilidade do solo e ao estado nutricional das plantas. Foram realizadas avaliações da fertilidade do solo e análise das folhas em vinte e uma lavouras orgânicas representativas do Estado de Minas Gerais. As amostras de solo foram analisadas para determinação do pH, acidez potencial e dos teores de P, K, Ca, Mg, S, Al e matéria orgânica. As amostras foliares foram analisadas para determinação dos teores de N, P, K, Ca, Mg, S, B, Cu, Fe, Mn e Zn. Com base nos padrões de interpretação para cafeeiros convencionais propostos pela literatura, estabeleceram-se as freqüências com que os caracteres analisados foram inferiores aos critérios de interpretação da fertilidade do solo e estado nutricional das plantas. A análise dos dados foi realizada por estatística descritiva. Novos trabalhos nessa nova área são necessários, visando a uma melhor interpretação da análise foliar e da fertilidade do solo, quando se trabalha com café orgânico

Protein methyltransferase 7 deficiency in Leishmania major increases neutrophil associated pathology in murine model

Leishmania major is the main causative agent of cutaneous leishmaniasis in the Old World. In Leishmania parasites, the lack of transcriptional control is mostly compensated by post-transcriptional mechanisms. Methylation of arginine is a conserved post-translational modification executed by Protein Arginine Methyltransferase (PRMTs). The genome from L. major encodes five PRMT homologs, including the cytosolic protein associated with several RNA-binding proteins, LmjPRMT7. It has been previously reported that LmjPRMT7 could impact parasite infectivity. In addition, a more recent work has clearly shown the importance of LmjPRMT7 in RNA-binding capacity and protein stability of methylation targets, demonstrating the role of this enzyme as an important epigenetic regulator of mRNA metabolism. In this study, we unveil the impact of PRMT7-mediated methylation on parasite development and virulence. Our data reveals that higher levels of LmjPRMT7 can impair parasite pathogenicity, and that deletion of this enzyme rescues the pathogenic phenotype of an attenuated strain of L. major. Interestingly, lesion formation caused by LmjPRMT7 knockout parasites is associated with an exacerbated inflammatory reaction in the tissue correlated with an excessive neutrophil recruitment. Moreover, the absence of LmjPRMT7 also impairs parasite development within the sand fly vector Phlebotomus duboscqi. Finally, a transcriptome analysis shed light onto possible genes affected by depletion of this enzyme. Taken together, this study highlights how post-transcriptional regulation can affect different aspects of the parasite biology

Low prevalence of renal, cardiac, pulmonary, and neurological extra-articular clinical manifestations in spondyloarthritis: analysis of the Brazilian Registry of Spondyloarthritis

OBJECTIVE: To describe the extra-articular manifestations (cardiac, renal, pulmonary, and neurological), usually not related to spondyloarthritis (SpA), in a large cohort of Brazilian patients. MATERIALS AND METHODS: This retrospective study analyzed 1,472 patients diagnosed with SpA and cared for at 29 health care centers distributed in the five major geographic regions in the country, participating in the Brazilian Registry of Spondyloarthritis (BRS). All patients were assessed for the prevalence of major extra-articular manifestations (cardiac, renal, pulmonary, and neurological), classified according to the diagnosis [ankylosing spondylitis (AS), psoriatic arthritis (PsA), reactive arthritis (ReA), arthritis associated with inflammatory bowel disease (IBD), undifferentiated spondyloarthritis (uSpA), and juvenile SpA], and according to the clinical presentation (axial, peripheral, mixed, and enthesitis). RESULTS: Of the patients with SpA assessed, 963 had AS, 271 PsA, 49 ReA, 48 arthritis associated with IBD, 98 uSpA, and 43 juvenile SpA. Cardiac involvement was reported in 44 patients (3.0%), pulmonary involvement in 19 (1.3%), renal involvement in 17 (1.2%), and neurological involvement in 13 patients (0.9%). Most patients with visceral involvement had AS or PsA, and the mixed (axial + peripheral) and/or predominantly axial clinical form. CONCLUSION: Cardiac, renal, pulmonary, and neurological extra-articular manifestations are quite infrequent in SpA, ranging from 0.9% to 3% in this large Brazilian cohort, and affected predominantly patients with AS and PsA.OBJETIVO: Descrever as manifestações extra-articulares (cardíacas, renais, pulmonares e neurológicas) geralmente não relacionadas às espondiloartrites (EpA) em uma grande coorte de pacientes brasileiros. MÉTODOS: Este estudo retrospectivo analisou 1.472 pacientes com o diagnóstico de EpA atendidos em 29 centros distribuídos pelas cinco principais regiões geográficas do Brasil, integrantes do Registro Brasileiro de Espondiloartrites. Todos os pacientes foram avaliados para a prevalência das principais manifestações extra-articulares (cardíacas, renais, pulmonares e neurológicas), divididas por diagnóstico [espondilite anquilosante (EA), artrite psoriásica (AP), artrite reativa (ARe), artrite associada a doença inflamatória intestinal (DII), EpA indiferenciada (EI) e EpA juvenil] e por forma clínica (axial, periférica, mista e entesítica). RESULTADOS: Dentre os pacientes avaliados com EpA, 963 apresentavam EA, 271 AP, 49 ARe, 48 artrite associada a DII, 98 EI e 43 EpA juvenil. Acometimento cardíaco foi observado em 44 pacientes (3,0%), seguido por acometimento pulmonar em 19 (1,3%), renal em 17 (1,2%) e neurológico em 13 pacientes (0,9%). A maioria dos casos de acometimento visceral ocorreu nos pacientes com EA ou AP e naqueles com forma clínica mista (axial e periférica) e/ou predominantemente axial. CONCLUSÃO: As manifestações extra-articulares cardíacas, renais, pulmonares e neurológicas são muito pouco frequentes nas EpA, variando de 0,9%-3% nesta grande coorte brasileira, estando mais associadas a EA e AP.37938

Atopic dermatitis : a cutaneous or systemic disease? The search for answers in the history of Dermatology

A dermatite atópica é doença inflamatória cutânea associada à atopia, predisposição a produzir resposta IgE a alérgenos ambientais, constituindo uma das manifestações das doenças atópicas, junto com a asma e a rinite alérgica. A dermatite atópica é caracterizada por episódios recorrentes de eczema associado a prurido, acometendo superfície cutânea geneticamente alterada, induzindo, por fenômenos imunológicos, a presença de inflamação. Trata-se de doença multifatorial, com enfoque nas alterações sistêmicas e alérgicas ou nas manifestações cutâneas, de acordo com diferentes visões da doença. A conceituação da dermatite atópica é importante, porque a conduta terapêutica pode variar segundo essas duas formas diferentes de analisá-la. Autores modernos discutem extensivamente esses aspectos sem, contudo, alcançar uma conclusão sobre a dermatite atópica como doença sistêmica ou cutânea. A procura dos conceitos sobre a doença, desde os primeiros relatos, associada à evolução do pensamento na dermatologia, poderia esclarecer a origem dessas dúvidas. Uma análise histórica demonstra que a dermatite atópica tem seus conceitos atuais oriundos dos estudos de diversos pensadores, que, em diferentes momentos históricos, descreveram a doença, e que muito do que acreditamos atualmente tem, nesses escritos, seus fundamentos.Atopic dermatitis is an inflammatory disease associated to atopy, which is a predisposition to produce an IgE response to environmental allergens and considered one of the manifestations of the atopic diseases, including asthma and allergic rhinitis. Atopic dermatitis is characterized by recurrent eczema flares, associated to pruritus, affecting a genetically disrupted skin surface, inducing, by immunological phenomena, the onset of inflammation. It is a multifactorial disease, with an emphasis on systemic and allergic alterations or skin manifestations, according to different concepts. The definition of atopic dermatitis is important, since its management may vary according to these two different points of view. Modern authors have extensively discussed these concepts, though with no conclusion as to its nature - systemic or cutaneous disease. The search for concepts about the disease, since its first descriptions, associated to the evolution of the dermatology rationale through history, may help understand the origin of these doubts. A historical analysis demonstrates that the currently accepted concepts of atopic dermatitis have their background from different researchers, who, at different historical moments, described the disease, and a great part of our beliefs about atopic dermatitis are related to these ancient writings