La Traca : semanari pa la gent de tro: Año IX Número 142 - 17 enero 1892

Recurso electrónico. Valencia: BVNP, 2014

A EDUCAÇÃO E A SEGURANÇA DO TRABALHO EM ELETRICIDADE FRENTE À NORMA REGULAMENTADORA NR-10

Nossa dissertação tem como objetivo estudar a Educação e a Segurança do Trabalho em Eletricidade frente à Norma Regulamentadora NR-10 (Segurança em Instalações e Serviços em Eletricidade). Segundo os aspectos aparentes da própria NR-10 em seus noventa e nove (99) itens e nos dois anexos de treinamento: curso básico (NR-10) e complementar (Sistema Elétrico de Potência – SEP), sua finalidade consiste na garantia da segurança do trabalho em eletricidade, todavia, a partir de nossa análise (da NR-10) e de nossa experiência no trabalho em eletricidade surgiu à demanda representada na hipótese de que: os trabalhadores em eletricidade percebem que as medidas preconizadas na NR-10 e em seus treinamentos não correspondem integralmente as suas necessidades. Nossa estratégia é testar a NR-10 ao examinarmos: a) sua formatação e aplicação baseada do modelo tripartite; b) seus conceitos de segurança do trabalho; c) as consolidações de seus artigos jurídicos; d) as programações, carga horária, as estratégias didáticas e educacionais de seus treinamentos. Isto é, examinaremos a NR-10 frente aos conteúdos dos processos de Educação, Luta por Saúde e Condições de Vida da Classe Trabalhadora, excepcionalmente do trabalhador em eletricidade.(AU)

A EDUCAÇÃO E A SEGURANÇA DO TRABALHO EM ELETRICIDADE FRENTE À NORMA REGULAMENTADORA NR-10

Nossa dissertação tem como objetivo estudar a Educação e a Segurança do Trabalho em Eletricidade frente à Norma Regulamentadora NR-10 (Segurança em Instalações e Serviços em Eletricidade). Segundo os aspectos aparentes da própria NR-10 em seus noventa e nove (99) itens e nos dois anexos de treinamento: curso básico (NR-10) e complementar (Sistema Elétrico de Potência – SEP), sua finalidade consiste na garantia da segurança do trabalho em eletricidade, todavia, a partir de nossa análise (da NR-10) e de nossa experiência no trabalho em eletricidade surgiu à demanda representada na hipótese de que: os trabalhadores em eletricidade percebem que as medidas preconizadas na NR-10 e em seus treinamentos não correspondem integralmente as suas necessidades. Nossa estratégia é testar a NR-10 ao examinarmos: a) sua formatação e aplicação baseada do modelo tripartite; b) seus conceitos de segurança do trabalho; c) as consolidações de seus artigos jurídicos; d) as programações, carga horária, as estratégias didáticas e educacionais de seus treinamentos. Isto é, examinaremos a NR-10 frente aos conteúdos dos processos de Educação, Luta por Saúde e Condições de Vida da Classe Trabalhadora, excepcionalmente do trabalhador em eletricidade.(AU)

Solution structure of a 142-residue recombinant prion protein corresponding to the infectious fragment of the scrapie isoform

The scrapie prion protein (PrPSc) is the major, and possibly the only, component of the infectious prion; it is generated from the cellular isoform (PrPC) by a conformational change. N-terminal truncation of PrPSc by limited proteolysis produces a protein of ≈142 residues designated PrP 27–30, which retains infectivity. A recombinant protein (rPrP) corresponding to Syrian hamster PrP 27–30 was expressed in Escherichia coli and purified. After refolding rPrP into an α-helical form resembling PrPC, the structure was solved by multidimensional heteronuclear NMR, revealing many structural features of rPrP that were not found in two shorter PrP fragments studied previously. Extensive side-chain interactions for residues 113–125 characterize a hydrophobic cluster, which packs against an irregular β-sheet, whereas residues 90–112 exhibit little defined structure. Although identifiable secondary structure is largely lacking in the N terminus of rPrP, paradoxically this N terminus increases the amount of secondary structure in the remainder of rPrP. The surface of a long helix (residues 200–227) and a structured loop (residues 165–171) form a discontinuous epitope for binding of a protein that facilitates PrPSc formation. Polymorphic residues within this epitope seem to modulate susceptibility of sheep and humans to prion disease. Conformational heterogeneity of rPrP at the N terminus may be key to the transformation of PrPC into PrPSc, whereas the discontinuous epitope near the C terminus controls this transition.

The tomato ethylene receptors NR and LeETR4 are negative regulators of ethylene response and exhibit functional compensation within a multigene family

The plant hormone ethylene is involved in many developmental processes, including fruit ripening, abscission, senescence, and leaf epinasty. Tomato contains a family of ethylene receptors, designated LeETR1, LeETR2, NR, LeETR4, and LeETR5, with homology to the Arabidopsis ETR1 ethylene receptor. Transgenic plants with reduced LeETR4 gene expression display multiple symptoms of extreme ethylene sensitivity, including severe epinasty, enhanced flower senescence, and accelerated fruit ripening. Therefore, LeETR4 is a negative regulator of ethylene responses. Reduced expression of this single gene affects multiple developmental processes in tomato, whereas in Arabidopsis multiple ethylene receptors must be inactivated to increase ethylene response. Transgenic lines with reduced NR mRNA levels exhibit normal ethylene sensitivity but elevated levels of LeETR4 mRNA, indicating a functional compensation of LeETR4 for reduced NR expression. Overexpression of NR in lines with lowered LeETR4 gene expression eliminates the ethylene-sensitive phenotype, indicating that despite marked differences in structure these ethylene receptors are functionally redundant.

Plasmodium falciparum subtilisin-like protease 2, a merozoite candidate for the merozoite surface protein 1–42 maturase

The process of human erythrocyte invasion by Plasmodium falciparum parasites involves a calcium-dependent serine protease with properties consistent with a subtilisin-like activity. This enzyme achieves the last crucial maturation step of merozoite surface protein 1 (MSP1) necessary for parasite entry into the host erythrocyte. In eukaryotic cells, such processing steps are performed by subtilisin-like maturases, known as proprotein convertases. In an attempt to characterize the MSP1 maturase, we have identified a gene that encodes a P. falciparum subtilisin-like protease (PfSUB2) whose deduced active site sequence resembles more bacterial subtilisins. Therefore, we propose that PfSUB2 belongs to a subclass of eukaryotic subtilisins different from proprotein convertases. Pfsub2 is expressed during merozoite differentiation and encodes an integral membrane protein localized in the merozoite dense granules, a secretory organelle whose contents are believed to participate in a late step of the erythrocyte invasion. PfSUB2’s subcellular localization, together with its predicted enzymatic properties, leads us to propose that PfSUB2 could be responsible for the late MSP1 maturation step and thus is an attractive target for the development of new antimalarial drugs.

Diffusible, nonfibrillar ligands derived from Aβ1–42 are potent central nervous system neurotoxins

Aβ1–42 is a self-associating peptide whose neurotoxic derivatives are thought to play a role in Alzheimer’s pathogenesis. Neurotoxicity of amyloid β protein (Aβ) has been attributed to its fibrillar forms, but experiments presented here characterize neurotoxins that assemble when fibril formation is inhibited. These neurotoxins comprise small diffusible Aβ oligomers (referred to as ADDLs, for Aβ-derived diffusible ligands), which were found to kill mature neurons in organotypic central nervous system cultures at nanomolar concentrations. At cell surfaces, ADDLs bound to trypsin-sensitive sites and surface-derived tryptic peptides blocked binding and afforded neuroprotection. Germ-line knockout of Fyn, a protein tyrosine kinase linked to apoptosis and elevated in Alzheimer’s disease, also was neuroprotective. Remarkably, neurological dysfunction evoked by ADDLs occurred well in advance of cellular degeneration. Without lag, and despite retention of evoked action potentials, ADDLs inhibited hippocampal long-term potentiation, indicating an immediate impact on signal transduction. We hypothesize that impaired synaptic plasticity and associated memory dysfunction during early stage Alzheimer’s disease and severe cellular degeneration and dementia during end stage could be caused by the biphasic impact of Aβ-derived diffusible ligands acting upon particular neural signal transduction pathways.