Learning algebraic structures with the help of Borel equivalence relations

We study algorithmic learning of algebraic structures. In our framework, a learner receives larger and larger pieces of an arbitrary copy of a computable structure and, at each stage, is required to output a conjecture about the isomorphism type of such a structure. The learning is successful if the conjectures eventually stabilize to a correct guess. We prove that a family of structures is learnable if and only if its learning domain is continuously reducible to the relation E0 of eventual agreement on reals. This motivates a novel research program, that is, using descriptive set theoretic tools to calibrate the (learning) complexity of nonlearnable families. Here, we focus on the learning power of well-known benchmark Borel equivalence relations (i.e., E1, E2, E3, Z0, and Eset)

Potencial de Mimosa acutistipula (MART.) BENTH. e Senegalia paraensis (DUCKE) Seigler & Ebinger para revegetação de áreas contaminadas por arsênio.

O presente trabalho teve como objetivo avaliar o crescimento de Mimosa acutistipula (Mart.) Benth. e Senegalia paraensis (Ducke) Seigler & Ebinger cultivadas em solo com diferentes concentrações de arsênio. Os ensaios foram conduzidos em casa de vegetação em blocos casualizados com quatro repetições

Blocking CD248 molecules in perivascular stromal cells of patients with systemic sclerosis strongly inhibits their differentiation toward myofibroblasts and proliferation: A new potential target for antifibrotic therapy

Background: Fibrosis may be considered the hallmark of systemic sclerosis (SSc), the end stage triggered by different pathological events. Transforming growth factor-β (TGF-β) and platelet-derived growth factor BB (PDGF-BB) are profibrotic molecules modulating myofibroblast differentiation and proliferation, respectively. There is evidence linking CD248 with these two molecules, both highly expressed in patients with SSc, and suggesting that CD248 may be a therapeutic target for several diseases. The aim of this work was to evaluate the expression of CD248 in SSc skin and its ability to modulate SSc fibrotic process. Methods: After ethical approval was obtained, skin biopsies were collected from 20 patients with SSc and 10 healthy control subjects (HC). CD248 expression was investigated in the skin, as well as in bone marrow mesenchymal stem cells (MSCs) treated with TGF-β or PDGF-BB, by immunofluorescence, qRT-PCR, and Western blotting. Finally, in SSc-MSCs, the CD248 gene was silenced by siRNA. Results: Increased expression of CD248 was found in endothelial cells and perivascular stromal cells of SSc skin. In SSc-MSCs, the levels of CD248 and α-smooth muscle actin expression were significantly higher than in HC-MSCs. In both SSc- and HC-MSCs, PDGF-BB induced increased expression of Ki-67 when compared with untreated cells but was unable to modulate CD248 levels. After CD248 silencing, both TGF-β and PDGF-BB signaling were inhibited in SSc-MSCs. Conclusions: CD248 overexpression may play an important role in the fibrotic process by modulating the molecular target, leading to perivascular cells differentiation toward myofibroblasts and interfering with its expression, and thus might open a new therapeutic strategy to inhibit myofibroblast generation during SSc

Biodisponibilidade de Arsênio em Dois Solos de Granulometrias Distintas sob Adição de Fosfato e Arsenato.

? Nos coloides do solo, o fosfato e o arsenato competem por sítios de adsorção, sendo que a adição de fosfato por meio de fertilizantes, por exemplo, pode elevar os teores de As em solução, tornando-o mais disponível para as plantas. Por outro lado, por competirem por sítios de absorção nas raízes, maiores teores de As em solução podem inibir a absorção de P e vice-versa. Dessa forma, este experimento teve como objetivo avaliar a biodisponibilidade de arsênio ao longo de 2 meses após a aplicação de doses de fosfato e arsenato em dois solos de granulometrias distintas. O experimento foi conduzido em casa de vegetação do Departamento de Solos da Universidade Federal de Viçosa utilizando-se um solo arenoso e um muito argiloso. O solos receberam cinco doses de P (0, 44, 150, 256, e 300 mg.kg -1 ) na forma de fosfato de sódio e cinco doses de As (0, 22, 75, 128 e 150 mg.kg -1 ) na forma de arsenato de sódio. A biodisponibilidade de arsênio foi analisada aos 15, 30 e 60 dias após a aplicação dos tratamentos, através do método de Neubauer e Schneider (1923). O delineamento utilizado foi o delineamento Central Composto Rotacional (DCCR), com cinco repetições no ponto central e valor alfa igual a 1,41. Os dados foram analisados por meio de superfície de respostas e demonstraram que a alta concentração de fósforo em solução compensa a maior disponibilidade de arsenato, causada por sua adição, podendo, assim, amenizar os efeitos fitotóxicos do arsênio

Crescimento inicial de clones de eucalipto em função de doses de P e K em Porto Velho, Rondônia.

O objetivo deste trabalho foi avaliar o crescimento inicial de clones de eucalipto sob combinações de doses de P2O5 e K2O em Porto Velho, RO. O experimento foi instalado no Campo Experimental de Porto Velho, da Embrapa Rondônia, sobre um Plintossolo Háplico de textura média/argilosa. Foram avaliados os clones Urocam, GG100, VM01 e H13, sob quatro doses de P2O5 (0, 50, 100 e 150 kg ha-1) e três de K2O (0, 50 e 100 kg ha-1), aplicadas na forma de superfosfato triplo e KCl, coroando-se as plantas, três meses após o plantio. O delineamento utilizado foi o fatorial completo (4x4x3) com quatro repetições em blocos casualizados. Foram utilizadas parcelas de 25 plantas (5x5), sendo nove plantas úteis. O espaçamento utilizado foi de 3x2 m. Após doze meses de cultivo, foi avaliada a altura do povoamento. Houve diferença de crescimento entre os clones, sendo: VM01>GG100=H13>Urocam (teste Tukey a 5 % de significância). A análise de regressão mostrou resposta quadrática para a altura de todos os clones em função da dose de P2O5, com ponto de máxima em torno de 110 kg ha-1. O efeito da aplicação de K2O não foi significativo (p>0,05). Avaliações nos anos posteriores permitirão aperfeiçoar a recomendação de clones e adubação para Porto Velho

Evaluation of phenotype-driven gene prioritization methods for Mendelian diseases.

Yuan et al. recently described an independent evaluation of several phenotype-driven gene prioritization methods for Mendelian disease on two separate, clinical datasets. Although they attempted to use default settings for each tool, we describe three key differences from those we currently recommend for our Exomiser and PhenIX tools. These influence how variant frequency, quality and predicted pathogenicity are used for filtering and prioritization. We propose that these differences account for much of the discrepancy in performance between that reported by them (15-26% diagnoses ranked top by Exomiser) and previously published reports by us and others (72-77%). On a set of 161 singleton samples, we show using these settings increases performance from 34% to 72% and suggest a reassessment of Exomiser and PhenIX on their datasets using these would show a similar uplift

A Bayesian dose-response meta-analysis model: simulation study and application

Dose-response models express the effect of different dose or exposure levels on a specific outcome. In meta-analysis, where aggregated-level data is available, dose-response evidence is synthesized using either one-stage or two-stage models in a frequentist setting. We propose a hierarchical dose-response model implemented in a Bayesian framework. We present the model with cubic dose-response shapes for a dichotomous outcome and take into account heterogeneity due to variability in the dose-response shape. We develop our Bayesian model assuming normal or binomial likelihood and accounting for exposures grouped in clusters. We implement these models in R using JAGS and we compare our approach to the one-stage dose-response meta-analysis model in a simulation study. We found that the Bayesian dose-response model with binomial likelihood has slightly lower bias than the Bayesian model with the normal likelihood and the frequentist one-stage model. However, all three models perform very well and give practically identical results. We also re-analyze the data from 60 randomized controlled trials (15,984 participants) examining the efficacy (response) of various doses of antidepressant drugs. All models suggest that the dose-response curve increases between zero dose and 40 mg of fluoxetine-equivalent dose, and thereafter is constant. We draw the same conclusion when we take into account the fact that five different antidepressants have been studied in the included trials. We show that implementation of the hierarchical model in Bayesian framework has similar performance to, but overcomes some of the limitations of the frequentist approaches and offers maximum flexibility to accommodate features of the data

Crescimento inicial de um eucalipto clonado sob diferentes adubações em Porto Velho, Rondônia.

O objetivo deste trabalho foi avaliar o crescimento inicial de um clone de eucalipto sob combinações de doses de P2O5 e K2O no plantio e adubação de cobertura em Porto Velho, RO

Área de Preservação Permanente (APP) e Reserva Legal (RL).

Esta publicação tem por objetivo listar os principais benefícios das APPs e RLs para as propriedades rurais citando exemplos de como elas podem contribuir para a sustentabilidade econômica das atividades agrícolas e o bem-estar da população.bitstream/item/123187/1/folder-preservacao-ambiental.pd