Although codistributed species are affected by the same abiotic factors, such as rivers and seasonal flooding regimes, ecological traits, such as locomotion habits and habitat preferences, may also influence differences in levels of genetic diversity and differentiation. We examined population genetic structure and diversity of Hylaeamys megacephalus and Oecomys aff. roberti, two cricetid rodent species from the mid-Araguaia River in central Brazil, using mitochondrial DNA sequence data. Specifically, we aim to test whether the Araguaia River acts as a barrier to the gene flow of these two species and to assess how ecological traits, such as locomotion habits and habitat preferences, may influence differences in levels of genetic diversity and differentiation. As both species occur in flooded forests, neither showed genetic differences related to river banks. Oecomys aff. roberti showed stronger population structure that appears to be associated with isolation by distance. This arboreal species maintained stable populations in the Araguaia River, while the terrestrial H. megacephalus was more affected by seasonal floods, resulting in a genetic signature of population expansion. Our initial predictions were largely supported by our results given that locomotion habits and habitat preferences of each species appears to have played a role on the genetic structure of these two sympatric rodent species.

Mangroves are vital part of the local economy for some communities in the region of Vitória, Brazil. Oysters, mussels, and crabs, which are naturally abundant in the mangroves, are harvested and largely consumed in restaurants and by the population. In recent years, unusually high rates of annual gastroenteritis cases have been reported in the region suggesting an association between the consumption of contaminated shellfish and the development of gastrointestinal diseases. The objective of this study was to evaluate water samples and mussels collected in the mangrove region using bacterial indicator Escherichia coli and enteric viruses (adenovirus, rotavirus, and norovirus). Our results showed that the region of study is impacted by a continuous discharge of domestic sewage. Although E. coli was detected at low densities in water samples, mussels were shown to be 400 times more contaminated throughout the period of the study. Adenovirus and rotavirus genomes were detected by nested-polymerase chain reaction respectively in 76 and 88% of water samples and 100% of mussel samples. Norovirus was found in 4.8% of water samples and was not detected in the mussels. The screening of bivalves for the presence of health-significant enteric viruses can help in the prevention of outbreaks among shellfish consumers and contribute to improvement of the estuarine environment.

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Results Semen assessments were obtained for 502 men. This group was representative of the general population regarding social class, education and geography. The median sperm concentration of samples was 48310 6 /ml, but after adjustment to a mean abstinence of 4 days, 64310 6 /ml. In these adjusted data, "low" sperm counts (below 20310 6 /ml) were found in 18% of men (95% CI 15% to 21%). However, the prevalence of "low" sperm counts showed no trend across the 10-year range of birth years. Conclusion This first report of sperm concentration in a random sample of a general population shows that nearly a fifth of men had poor semen quality. Further work is required to clarify the fertility relevance of a single low sperm concentration when there is no imposition of abstinence prior to sample, and to understand cause of the fertility deficit found in many survey participants. Background Environmental toxic metal exposure may adversely affect children's development and behaviour. Data are lacking about heavy metal exposure in children in UAE and Gulf countries. Objectives To determine blood concentrations of 12 heavy metals in school-age children in Al Ain City, UAE. Methods It was a cross sectional study. One hundred and forty seven subjects were selected from nine elementary schools. The mean age was 8.4 years (SD 62 years). ICP-MS instrument was used to determine the metal concentration. Data analysis was performed using the SPSS. Results The (mean6SD) blood level for study children (n¼146) of lead was 25.86613.06 ppb, cadmium 0.3160.25 ppb, arsenic 10.7464.71 ppb, mercury 1.3961.16 ppb, manganese 1.8561.09 ppb, nickel 9.1868.23 ppb, zinc 373161752 ppb, chromium 2.1061.53 ppb, cobalt 0.6560.40 ppb, copper 10646403 ppb, molybdenum 1.5961.25 ppb, and antinomy 0.6060.63 ppb. SP4-26 BURDEN OF TOXIC METAL EXPOSURE AMONG SCHOOL-AGED CHILDREN IN UNITED ARAB EMIRATESConclusions Reference values for the trace metals vary markedly; especially due to sampling, age, diet, exposure differences and analytical techniques used. In this study, the mean blood lead was below the CDC's recommended level of concern (>10 mg/dl) and with cadmium, mercury and chromium were comparable with similar studies elsewhere; manganese and zinc were slightly lower; copper and molybdenum were slightly higher while arsenic and cobalt much higher. Blood screening and surveillance linked to appropriate public health interventions is strongly recommended for UAE.

This study reports the occurrence of highly conserved d-loop sequences in the mitochondrial genome of the woolly mouse opossum genus Marmosa subgenus Micoureus (Mammalia, Didelphimorphia, Didelphidae). Sixty-six sequences of Marmosa (Micoureus) demerarae, Marmosa (Micoureus) constantiae, and Marmosa (Micoureus) paraguayanus were amplified using universal d-loop primers and virtually no genetic differences were detected within and among species. These sequences matched the control region of the mitochondrial marsupial genome. Analyses of qualitative aspects of these sequences revealed that their structural composition is very similar to the d-loop region of other didelphid species. However, the total lack of variability has not been reported from other closely related species. The data analyzed here support the occurrence of highly conserved d-loop sequences, and we found no support for the hypothesis that these sequences are d-loop-like nuclear pseudogenes. Furthermore, the control and flanking regions obtained with different primers corroborate the lack of variability of the d-loop sequences in the mitochondrial genome of Marmosa (Micoureus).