EQUIVALÊNCIA DE ESTÍMULOS EM PARTICIPANTES COM SÍNDROME DE DOWN: EFEITOS DA UTILIZAÇÃO DE PALAVRAS COM DIFERENÇAS MÚLTIPLAS OU CRÍTICAS E ANÁLISE DE CONTROLE RESTRITO DE ESTÍMULOS

The present study attempted to investigate stimulus equivalence formation by participants with Down’s syndrome. Participants learned auditory-visual conditional discriminations with pseudo-words and was manipulated the stimulus similarity in two experimental conditions. The stimuli had multiple differences between them in the first condition, and had critical differences between them in the second condition. Four individuals with Down’ssyndrome participated. Relations between dictated words and pictures and between dictated and printed words were trained through matching to sample procedures. Two participants also learned responses of constructing the words by the ordinal selection of their elements. Performances tested were naming of printed words and pictures, and matching printed words to pictures and pictures to printed words. Results suggested that three of the four participants formed equivalence classes in both experimental conditions, whereas the other participant showed signs of class formation only in the first experimental condition. Two participants had more difficulties with training and testing in the second condition. The difficulties were attributed to restricted stimulus control.Key words: stimulus equivalence, reading, stimulus similarity, stimulus control, Down’s syndromeO presente trabalho teve o propósito de investigar a formação de equivalência de estímulos com indivíduos portadores de Síndrome de Down. Foram ensinadas discriminações condicionais auditivo-visuais para tais participantes, utilizando pseudo-palavras e manipulando distintamente o número de elementos idênticos (letras) presentes nas palavras em duas condições experimentais. Os estímulos utilizados foram palavras dissílabas do tipo consoante mais vogal. Na primeira das condições experimentais, as palavras apresentavam diferenças múltiplas (uma ou duas letras em comum) e na segunda, diferenças críticas entre si (palavras com três ou quatro letras em comum). Os participantes foram quatro indivíduos com Síndrome de Down. Foram treinadas, por meio de procedimentos de emparelhamento com o modelo, as relações entre palavras ditadas e figuras, e entre palavras ditadas e impressas. Com dois participantes, treinou-se também as respostas de construção por meio da seleção ordenada de cada elemento do estímulo impresso. Foram testadas as nomeações de palavras impressas e figuras e os emparelhamentos entre palavra impressa-figura e figura-palavra impressa. Os resultados sugerem que três dos quatro participantes apresentaram a formação de classes de equivalência nas duas condições experimentais. O outro participante mostrou indícios de formação de classes apenas na primeira condição experimental. Dois participantes apresentaram maiores dificuldades nos treinos e testes da segunda condição. As dificuldades encontradas por eles podem ser atribuídas a controle restrito de estímulos. Palavras-chave: equivalência de estímulos, leitura, similaridade entre os estímulos, controle de estímulos, Síndrome de Dow

A remote secondary binding pocket promotes heteromultivalent targeting of DC-SIGN

Dendritic cells (DC) are antigen-presenting cells coordinating the interplay of the innate and the adaptive immune response. The endocytic C-type lectin receptors DC-SIGN and Langerin display expression profiles restricted to distinct DC subtypes and have emerged as prime targets for next-generation immunotherapies and anti-infectives. Using heteromultivalent liposomes copresenting mannosides bearing aromatic aglycones with natural glycan ligands, we serendipitously discovered striking cooperativity effects for DC-SIGN+ but not for Langerin+ cell lines. Mechanistic investigations combining NMR spectroscopy with molecular docking and molecular dynamics simulations led to the identification of a secondary binding pocket for the glycomimetics. This pocket, located remotely of DC-SIGN’s carbohydrate bindings site, can be leveraged by heteromultivalent avidity enhancement. We further present preliminary evidence that the aglycone allosterically activates glycan recognition and thereby contributes to DC-SIGN-specific cell targeting. Our findings have important implications for both translational and basic glycoscience, showcasing heteromultivalent targeting of DCs to improve specificity and supporting potential allosteric regulation of DC-SIGN and CLRs in general

Geração de índices de vegetação diários em uma pastagem.

Os índices de vegetação são importantes ferramentas para a agricultura de precisão (AP), que fornecem informações para a tomada de decisão de manejo das culturas. Os espectros de luz refletidos pelo dossel de cada cultura podem fornecer informações sobre produção de biomassa, qualidade e da ocorrência de estresses bióticos e abióticos

Sortilin Participates in Light-dependent Photoreceptor Degeneration in Vivo

Both proNGF and the neurotrophin receptor p75 (p75NTR) are known to regulate photoreceptor cell death caused by exposure of albino mice to intense illumination. ProNGF-induced apoptosis requires the participation of sortilin as a necessary p75NTR co-receptor, suggesting that sortilin may participate in the photoreceptor degeneration triggered by intense lighting. We report here that light-exposed albino mice showed sortilin, p75NTR, and proNGF expression in the outer nuclear layer, the retinal layer where photoreceptor cell bodies are located. In addition, cone progenitor-derived 661W cells subjected to intense illumination expressed sortilin and p75NTR and released proNGF into the culture medium. Pharmacological blockade of sortilin with either neurotensin or the “pro” domain of proNGF (pro-peptide) favored the survival of 661W cells subjected to intense light. In vivo, the pro-peptide attenuated retinal cell death in light-exposed albino mice. We propose that an auto/paracrine proapoptotic mechanism based on the interaction of proNGF with the receptor complex p75NTR/sortilin participates in intense light-dependent photoreceptor cell death. We therefore propose sortilin as a putative target for intervention in hereditary retinal dystrophies

CMS physics technical design report : Addendum on high density QCD with heavy ions

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