Conformational and electronic interaction studies of p-substituted alpha-phenoxyacetones

The nu(CO) analysis of p-substituted alpha-phenoxy-acetones X-phi-O-CH2-C(O)-Me (1-6) indicates the existence of the cis/gauche rotational isomerism. The nearly constant increase in the cis/gauche population ratios for the whole series, on going from carbon tetrachloride to acetonitrile, and the small sensitivity of the carbonyl frequency shifts (Delta nu(C)) for the cis rotamer, on going from electron-attracting to electron-donating substituents, are interpreted as an interplay of the Field (F) and the inductive (-I) Effects, which originates an almost constant carbonyl bond order, and suggests that the cis rotamers have almost the same energy in the whole series. The decrease in the cis/gauche population ratios, in all solvents, and the deshielding effects on the carbonyl carbon atom, and on the methylene carbon atom in a weaker extent, observed in the C-13 NMR spectra, on going from electron-attracting to electron-donating substituents, are discussed in terms of pi*(CO)/n(O) orbital and Ardelta+-Odelta- - Cdelta+=Odelta- Coulombic, interactions, which stabilize the gauche rotamers of the investigated compounds.3261041105

Coliformes em água de abastecimento de lojas fast-food da Região Metropolitana de Recife (PE, Brasil) Coliforms in the water supply of fast-food chains in the Metropolitan Region of Recife, in the state of Pernambuco (Brazil)

A garantia do fornecimento de água potável nos serviços de alimentação é uma questão relevante para a saúde pública. Assim, o objetivo deste estudo foi avaliar a qualidade microbiológica da água destinada ao abastecimento de uma rede de lojas fast-food da cidade de Recife (PE) e Região Metropolitana e comparar os resultados aos padrões estabelecidos pela Portaria nº 518/2004 do Ministério da Saúde. Mensalmente, foi analisada uma amostra proveniente de uma das torneiras da área de manipulação das oito lojas investigadas, perfazendo 96 amostras ao longo de um ano, todas coletadas em duplicata. As análises seguiram a metodologia estabelecida na American Public Health Association (APHA) para realização do ensaio presuntivo utilizando o Teste Presença-Ausência, considerando-se o padrão de potabilidade determinado na legislação pertinente. Os resultados revelaram que 11,46% de todas as amostras apresentaram água contaminada por coliformes totais e 1,04% contaminação por coliformes termotolerantes. Conclui-se, portanto, que a qualidade da água disponível nos estabelecimentos produtores de alimentos estudados encontra-se em estado de alerta, uma vez que o percentual significativo das amostras analisadas mostrava-se impróprio para o consumo humano de acordo com a legislação vigente, a qual preconiza ausência de coliformes totais e termotolerantes.<br>A guaranteed supply of clean drinking water in food outlets is a relevant subject for public health. The scope of this study was to assess the microbiological quality of 96 water samples of a network of fast-food stores in the city of Recife (state of Pernambuco, Brazil) and Metropolitan Area and to compare the results to the standards established by Brazilian Health Ministry decree nº 518/2004. Every month, a double sample from one of the faucets in the food preparation area of the eight stores investigated was analyzed, totaling 96 samples over one year. The analyses followed the established methodology of American Public Health Association (APHA), in order to conduct the Presence-Absence Test, considering the potability standard in pertinent legislation. Results revealed that 11.46% and 1.04% of samples contained water contaminated with total coliforms and thermotolerant coliforms, respectively. The quality of the water in the food establishments studied is thus a health hazard since a significant percentage of samples analyzed were inappropriate for human consumption in accordance with current legislation, which stipulates the absence of total coliforms and thermotolerant coliforms

The genetics and conservation of Araucaria angustifolia: I. Genetic structure and diversity of natural populations by means of non-adaptive variation in the state of Santa Catarina, Brazil

The objective of this study was to generate information relative to the allele distribution and dynamics within and among populations of Araucaria angustifolia, a naturally-occurring conifer in the south of Brazil, being known popularly as "pinheiro-do-Paraná", "araucaria" or pine tree. In order to elucidate the levels and the distribution of the genetic variability, the population's genetic structure and the genetic distance among natural populations of this species with different levels of disturbance in different geographical areas were studied in detail. For this, samples of leaf tissue were collected from 328 adult individuals in nine natural populations in Santa Catarina State. To analyze the samples, the allozyme technique was applied in starch gel electrophoresis (penetrose 13%), with citrate/morfholine buffer. Nine enzymatic systems (PGM, PGI MDH, PRX, SKDH, 6PGDH, ACP, IDH and G6PDH) revealed 15 loci. The analysis provided values for He and Ho of 0.084 and 0.072, respectively. The general average of polymorphic loci was 73% in the species and 26.6% in the studied populations and the allele number per locus was 1.6. Wright's F-statistical estimates indicated the existence of inbreeding in populations (F IS= 0.148) and a low divergence among populations (F ST = 0.044). However, the inbreeding values were variable in different populations. Taken together, the results indicated that the greater part of the genetic variability is contained within populations. The working hypothesis that originally there was greater genetic diversity can be supported by these results which indicate that in the degraded populations the diversity indexes are lower in the degraded populations than those found in better-conserved populations. Thus the fragmentation of the forest followed by "araucaria" exploitation could have contributed to the genetic differentiation expressed through the allele frequency of the studied population