Color space distortions in patients with type 2 diabetes mellitus

Color vision impairment was examined in patients with type 2 diabetes mellitus (DM2) without retinopathy. We assessed the type and degree of distortions of individual color spaces. DM2 patients (n = 32), and age-matched controls (n = 20)were tested using the Farnsworth D-15 and the Lanthony D-15d tests. In addition, subsets of caps from both tests were employed in a triadic procedure (Bimler & Kirkland, 2004). Matrices of inter-cap subjective dissimilarities were estimated from each subject’s “odd-one-out” choices, and processed using non-metric multidimensional scaling. Two-dimensional color spaces, individual and group (DM2 patients; controls), were reconstructed, with the axes interpreted as the R0G and B0Y perceptual opponent systems. Compared to controls, patient results were not significant for the D-15 and D-15d. In contrast, in the triadic procedure the residual distances were significantly different compared to controls: right eye, P 0.021, and left eye, P 0.022. Color space configurations for the DM2 patients were compressed along the B0Y and R0G dimensions. The present findings agree with earlier studies demonstrating diffuse losses in early stages of DM2. The proposed method of testing uses color spaces to represent discrimination and provides more differentiated quantitative diagnosis, which may be interpreted as the perceptual color system affected. In addition, it enables the detection of very mild color vision impairment that is not captured by the D-15d test. Along with fundoscopy, individual color spaces may serve for monitoring early functional changes and thereby to support a treatment strategy

Análise filogenética de Lentivirus de pequenos ruminantes isolados do Ceará.

CAEV e MVV têm sido considerados geneticamente distintos, mas antigenicamente relacionados como patógenos de caprinos e ovinos. Além disso, foi demonstrado que estes vírus estão constantes e facilmente transgredindo a barreira entre caprinos e ovinos, com lentivirus CAEV infectando ovinos e lentiírus MVV infectando caprinos (Valas et al., 2000; Karr et al., 1996; Shah et al., 2004). Assim como todos os lentivírus, o genoma de CAEV tem uma alta taxa de mutação e o seu grau de heterogeneidade pode estar relacionado com a baixa fidelidade de transcriptase reversa, que carece da atividade de leitura da enzima exonuclease. A análise genética de Lentivírus de Pequenos Ruminantes (LVPRs) poderá ajudar a compreender a genética, proteínas e antigenicidade destes vírus; sua patogênese, epidemiologia, relações filogenéticas e, assim, a sua inclusão nos subgrupos de LVPRs recentemente criado (Shah et al., 2004a). Também pode ser relevante para o desenvolvimento de testes de diagnósticos sensíveis à raça local. A aplicação da análise filogenética para sequencias de CAEV e MVV é de crucial importância para a análise epidemiológica de infecções por LVPRs e para estudar possíveis diferenças na virulência entre estirpes de LVPRs circulantes. O principal objetivo deste trabalho foi estabelecer a filogenia de LVPRs como base para futuros estudos em epidemiologia molecular de lentivirais de pequenos ruminantes no Nordeste do Brasil em caprinos de rebanho leiteiro, com particular interesse no acompanhamento dos efeitos dos programas de erradicação em curso e futuros sobre a distribuição linhagens de LVPRs. Neste estudo, 250 caprinos foram analisados utilizando a técnica de IDGA, a soroprevalência deste rebanho foi de 4,4% de positivos. Seis caprinos positivos por IDGA com ou sem alteração nas articulações foram analisados por PCR, que amplificou parte do gene gag. Todos os animais foram positivos, apesar de três deles não terem sinais clínicos ou alteração nas articulações. Nós seqüenciamos o gene gag de quatro lentivírus isolados do norteste do Brasil de caprinos naturalmente infectados. Comparações de pareamentos entre sequencias do gene gag de linhagens brasileiras com sequencias do GenBank demonstraram que nossas sequencias estão mais relacionadas com linhagens caprinas que ovinas. Outras análises filogenéticas do gene gag confirmaram sua classificação inicial e mostrarm que eles constituem o subtipo B1 do grupo de CAEV. A análise das sequencias também mostrou que os vírus permaneceram geneticamente estáveis, apesar do tempo de evolução estar estimado em 20 anos. Neste artigo nós também indicamos que futuros estudos filogenéticos devem ser realizados com sequencias pol ou env, pois a região gag, por ser altamente preservada, retém menos sinais filogenéticos. Abstract - CAEV and MVV have been considered as genetically distinct but antigenically related pathogens of goats and sheep. Indeed, it was demonstrated that these viruses are constantly and easily transgressing the species barrier between goats and sheep ending with sheep harboring CAEV-like lentiviruses and goats infected with MVV-like viruses (Valas et al., 2000; Karr et al., 1996; Shah et al., 2004). Like all lentiviruses, CAEV genome has a high mutation rate and the extent of its heterogeneity may be related to low fidelity of reverse transcriptase which lacks the proof reading exonuclease activity. A genetic analysis of these SRLV may further help to understand the genetic, proteic and antigenic make-up of these viruses; their pathogenesis, epidemiology, phylogenetic relationships; and thus, their allocation into the recently established SRLV groups (Shah et al., 2004a). It may also be relevant for developing local-breed sensitive diagnostic tests. The application of phylogenetic analysis to CAEV and MVV sequences is of pivotal importance for this type of epidemiological analysis of SRLV infections in small ruminants and to study potential differences in virulence between circulating SRLV strains. The principal aim of this work was to establish a SRLV phylogeny as a basis for future studies of the molecular epidemiology of lentiviral infections in Northeast of Brazil dairy goat herds, with particular interest in monitoring the effects of ongoing and future eradication programs on the distribution of SRLV strains. In this study, one flock of 250 goat was analized using AGID, the seroprevalence in these flocks was 4,4% of positive tested sera. Six goats positive to AGID with and without alteration in the knee joint were analyzed using a PCR, which amplifies part of the gag gene. All the animals were found to be positive, despite the fact that three no had clinical signs or alteration in the knee joint. We determined the nucleotide sequences of gag gene from 4 Brazilian lentivirus isolates from naturally infected goats. Pairwise comparisons between the four gag gene sequence Brazil SRLV strains with the GenBank, demonstrating our sequences were closer to the caprine rather than the ovine strains. Further phylogenetic analysis of the proviral gag sequences confirmed the initial classification and showed that they constituted the Sbtipo B1 of the CAEV group. The sequence analyses also showed that the virus had remained genetically relatively stable, in spite of the time given for virus evolution, an estimated 20 years. In this paper, we indicate that future phylogenetic studies should rather be done on the pol or env regions than in the gag region, by be highly preserved retains less phylogenetic signal.Dissertação (Mestrado em Ciências Veterinárias) - Universidade Estadual do Ceará, Fortaleza. Orientadora: Diana Célia Sousa Nunes Pinheiro; Co-Orientadora: Maria Fátima da Silva Teixeira; Co-Orientador: Raymundo Rizaldo Pinheiro, Embrapa Caprinos (CNPC)

An Application of Combined Neural Networks to Remotely Sensed Images

Studies in the area of pattern recognition have indicated that in most cases a classifier performs differently from one pattern class to another. This observation gave birth to the idea of combining the individual results from different classifiers to derive a consensus decision. This work investigates the potential of combining neural networks to remotely sensed images. A classifier system is built by integrating the results of a plurarity of feed-forward neural networks, each of them designed to have the best performance for one class. Fuzzy Integrals are used as the combining strategy. Experiments carried out to evaluate the system, using a satellite image of an area undergoing a rapid degradation process, have shown that the combination may yield a better performance than that of a single neural network

Caracterização físico-química de jenipapo.

bitstream/CPATC-2010/21527/1/cot-99.pd

Saturation-specific pattern of acquired colour vision deficiency in two clinical populations revealed by the method of triads

Subjective colour spaces were reconstructed for persons occupationally exposed to mercury (Hg) and patients with diabetes mellitus type 2, two groups at risk for acquired colour-vision deficiency, and compared with healthy normal trichromats. Judgments of colour dissimilarity were collected with the method of triads, applied to a composite assortment of colour samples. These were drawn from two widely used colour arrangement tests—10 hues from the Farnsworth D-15 test and five from the Lanthony Desaturated D-15d test, ensuring that the assortment sampled two levels of lightness and saturation. The data were analyzed with maximum-likelihood multidimensional scaling (MDS) and within a novel individual-differences MDS model to estimate subject-specific parameters. The MDS solutions for the two clinical groups showed a compression along a blue-yellow axis, limited however to desaturated hues. This result was confirmed by the individual-differences model. In addition, the clinical groups were found to place significantly higher weights on the lightness differences between stimuli, conceivably to compensate for their reduced chromatic discrimination. The specific form of colour-space distortion in the clinical groups indicated an increase in their thresholds for blue-yellow signals, providing insights into the nature of impairment mechanisms. The results have implications for stimuli and diagnostic procedures for testing individual differences in color vision, and for analyzing the responses. This approach is sensitive to distinctive patterns of subtle colour-vision impairment underestimated by the conventional D-15d test

Breakdown of Energy Equipartition in a 2D Binary Vibrated Granular Gas

We report experiments on the equipartition of kinetic energy between grains made of two different materials in a mixture of grains vibrated in 2 dimensions. In general, the two types of grains do not attain the same granular temperature, Tg = 1/2m v^2. However, the ratio of the two temperatures is constant in the bulk of the system and independent of the vibration velocity. The ratio depends strongly on the ratio of mass densities of the grains, but is not sensitive to the inelasticity of grains. Also, this ratio is insensitive to compositional variables of the mixture such as the number fraction of each component and the total number density. We conclude that a single granular temperature, as traditionally defined, does not characterize a multi-component mixture.Comment: 4 pages, 5 figures, submitted to Physical Review Letters, updated reference

VULNERABILIDADE E MODELOS DE SIMULAÇÃO COMOESTRATÉGIAS MEDIADORAS: contribuição ao debate das mudanças climáticas e ambientais

O desenvolvimento de políticas urbanas adequadas aos atuais desafios impostos pelas mudanças climáticas e ambientais demanda uma compreensão cada vez mais apurada dos processos sociais e ecológicos que regem o sistema urbano e deve contar com a mobilização de profissionais de distintas áreas do conhecimento. Para avançar nesta direção integradora, propomos a adoção de estratégias mediadoras que promovam uma transposição de fronteiras., sejam elas entre disciplinas, entre ciência e política, ou entre ciência e sociedade. Como ponto de partida, é importante o estabelecimento de conceitos mediadores, ou seja, palavras já adotadas como conceitos em diferentes disciplinas, com significados negociáveis, que permitem que distintas partes discutam sobre a multidimensionalidade de questões de interesse comum. Em estudos que lidam com as relações sociedade-natureza, apresentamos como o termo vulnerabilidade assume uma posição estratégica como conceito mediador. Adicionalmente, para que um conceito mediador seja materializado de maneira a subsidiar estratégias de planejamento, surge a necessidade de objetos mediadores que permitam agir em situações de incerteza e interesses divergentes. Neste artigo, apontamos os modelos de simulação computacional como objetos mediadores promissores, que viabilizam uma leitura do sistema urbano que compartilha percepções e experiências e possibilita uma exploração .empírica. dos processos inerentes às dinâmicas de vulnerabilidade. Palavras-chave: Conceito mediador. Objeto mediador. Vulnerabilidade. Modelos de simula ção computacional