Effects of polyethylene film wrap on cooler shrink and the microbial status of beef carcasses

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spatial variability of leaf nutrient contents in a drip irrigated citrus orchard

This study aimed to evaluate the spatial variability of leaf content of macro and micronutrients. The citrus plants orchard with 5 years of age, planted at regular intervals of 8 x 7 m, was managed under drip irrigation. Leaf samples were collected from each plant to be analyzed in the laboratory. Data were analyzed using the software R, version 2.5.1 Copyright (C) 2007, along with geostatistics package GeoR. All contents of macro and micronutrients studied were adjusted to normal distribution and showed spatial dependence.The best-fit models, based on the likelihood, for the macro and micronutrients were the spherical and matern. It is suggest for the macronutrients nitrogen, phosphorus, potassium, calcium, magnesium and sulfur the minimum distances between samples of 37; 58; 29; 63; 46 and 15 m respectively, while for the micronutrients boron, copper, iron, manganese and zinc, the distances suggests are 29; 9; 113; 35 and 14 m, respectively.

How does the taxonomic status of allopatric populations influence species richness within African cichlid fish assemblages?

Aim  Current estimates of species richness within rapidly evolving species flocks are often highly dependent on the species status of allopatric populations that differ in phenotypic traits. These traits may be unreliable indicators of biological species status and systematists may have inconsistently assigned species among lineages or locations on the basis of these traits, thus hampering comparative studies of regional species richness and speciation rates. Our aim was to develop a method of generating standardized estimates of regional species richness suitable for comparative analysis, and to use these estimates to examine the extent and consistency of species assignment of allopatric populations within rapidly evolving cichlid fish flocks present in three east African lakes. Location  Lakes Malawi, Victoria and Tanganyika. Methods  Using published taxon co-occurrence data, a novel approach was employed to calculate standardized ‘minimum’ estimates of regional species richness for hard substrate associated complexes of cichlids within each of the lakes. Minimum estimates were based on an explicit assumption that if taxa present on equivalent habitats have disjunct distributions, then they are allopatric forms of the same species. These estimates were compared with current observed ‘high-end’ regional species richness estimates for those complexes to determine the consistency of species assignment of allopatric populations between lineages within a lake. A ‘sympatry’ index was developed to enable comparisons of levels of species assignment of allopatric populations between-lakes to be made. Results  Within each lake, the minimum and high-end estimates for species richness were significantly correlated across complexes, indicating that the complexes that contain more recognized species contain the most genuine biological species. However, comparisons of complexes among lakes revealed considerable differences. For equivalent geographical areas, substantially higher proportions of recognized species were totally allopatric within the studied Lake Malawi and Lake Victoria complexes, than those of Lake Tanganyika. Main Conclusions  Among African lakes, levels of assignment to species status of allopatric populations were found to be distinctly different. It is unclear whether the discrepancies are a consequence of differences between the lake faunas in degrees of phenotypic divergence among allopatric populations, or are simply the result of inconsistent taxonomic practices. In either case, these results have considerable wider relevance for they emphasize that quantitative measures of regional and beta diversity are critically dependent on the species status of allopatric populations, an issue usually neglected in comparative studies of species richness. The technique introduced here can be used to standardize measures of regional diversity of lineages for comparative analyses, potentially enabling more accurate identification of processes influencing rates of speciation.

Household risk factors and the health and nutritional status of children in rural Honduras

During this cross-sectional study, both quantitative and qualitative research methods were used to elucidate the role that household environment and sanitation play in the nutritional status of children in a rural Honduran community. Anthropometric measurements were taken as measures of nutritional status among children under five years of age, while interviews regarding the household environment were conducted with their primary caregivers. Community participatory activities were conducted with primary caregivers, and results from water quality testing were analyzed for E. coli contamination. Anthropometric results were compared using the 1977 NCHS Growth Charts and the 2006 WHO Child Growth Standard to examine the implications of using the new WHO standard. The references showed generally good or excellent agreement between z-score categories, except among height-for-age classifications for males 24-35.9 months and weight-for-age classifications for males older than 24 months. Comparing the proportion of stunted, underweight, and wasted children, using the WHO standard generally resulted in higher proportions of stunting, lower underweight proportions, and higher overweight proportions. Logistic regression was used to determine which household and sanitation factors most influenced the growth of children. Results suggest only having water from a spring, stream, or other type of surface water as the primary source of drinking water is a significant risk factor for stunting. A protective association was seen between the household wealth index and stunting. Through participatory activities, the community provided insight on health issues important for improving child health. These activities yielded findings to be harnessed as a powerful resource to unify efforts for change. The qualitative findings were triangulated with the quantitative interview and water testing results to provide intervention recommendations for the community and its primary health care clinic. Recommendations include educating the community on best water consumption practices and encouraging the completion of at least some primary education for primary caregivers to improve child health. It is recommended that a community health worker program be developed to support and implement community interventions to improve water use and household sanitation behaviors and to encourage the involvement of the community in targeting and guiding successful interventions. ^

Carbonate saturation in the water column of station M8_056 off Cap Sao Vincente, Portugal (Table 1)

Changes in the dissolved oxygen content, the alkalinity, and the pH in sea water near the ocean floor are interpreted in terms of chemical and biochemical processes at the sediment water interface. A simple model provides a plausible explanation of the observed phenomena. Special emphasis is given to the importance of borate corrections in the calculation of the solution effects of calcium carbonate.

(Table 1) Surface water chemistry of northern Victoria Land lakes

Concentrations of major ions, silicate and nutrients (total N and P) were measured in samples of surface water from 28 lakes in ice-free areas of northern Victoria Land (East Antarctica). Sixteen lakes were sampled during austral summers 2001/02, 2003/04, 2004/05 and 2005/06 to assess temporal variation in water chemistry. Although samples showed a wide range in ion concentrations, their composition mainly reflected that of seawater. In general, as the distance from the sea increased, the input of elements from the marine environment (through aerosols and seabirds) decreased and there was an increase in nitrate and sulfate concentrations. Antarctic lakes lack outflows and during the austral summer the melting and/or ablation of ice cover, water evaporation and leaching processes in dry soils determine a progressive increase in water ion concentrations. During the five-year monitoring survey, no statistically significant variation in the water chemistry were detected, except for a slight (hardly significant) increase in TN concentrations. However, Canonical Correspondence Analysis (CCA) indicated that other factors besides distance from the sea, the presence of nesting seabirds, the sampling time and percentage of ice cover affect the composition of water in Antarctic cold desert environments.