739 research outputs found
Brazing Titanium-Vapor-Coated Zirconia High-strength braze joints were obtained through the use of titanium vapor coatings to promote wetting on partially stabilized zirconia
Oxygen supersaturation mitigates the impact of the regime of contaminated sediment reworking on sea urchin fertilization process
Dismissed industrial plants with chronic environmental contamination globally affect all levels of biological organization in concert with other natural and anthropogenic perturbations. Assessing the impact of such perturbations and finding effective ways to mitigate them have clear ecological and societal implications. Through indoor manipulative experiments, we assessed here the effects of the temporal regime of reworking of contaminated sediment from the Bagnoli-Coroglio brownfield (Tyrrhenian Sea, Italy) on the fertilization process in Paracentrotus lividus. Adult sea urchins were kept for one month in tanks containing contaminated sediment that was re-suspended according to two temporal patterns of water turbulence differing in the time intervals between consecutive events of agitation (mimicking the storms naturally occurring in the study area) in seawater with natural vs. supersaturated oxygenation levels. At the end of the treatment, gametes were collected and used to test the hypothesis that the regime of contaminated sediment reworking negatively, but reversibly, affects morphological and physiological traits of the fertilized eggs. We found that aggregated events of sediment re-suspension had profound negative effects on gamete interactions and Ca2+ signaling at fertilization. The same experimental condition also inflicted marked ultrastructural changes in eggs. Importantly, however, such detrimental effects were inhibited by increased oxygenation. By contrast, the regime of sediment re-working with a longer interval between consecutive turbulent events had only marginal effects. Thus, the current and predicted changes of climate-related disturbance appear to modulate the biological effects of chronic contamination in post-industrial areas, suggesting that environmental rehabilitation via restoration of habitat-forming primary producers such as seagrasses or algal canopies could alleviate the pollutants’ effects on resident biota
The Role of Genotypes That Modify the Toxicity of Chemical Mutagens in the Risk for Myeloproliferative Neoplasms
Background: The etiology of myeloproliferative neoplasms (MPN) (polycythemia vera; essential thrombocythemia; primary myelofibrosis) is unknown, however they are associated with a somatic mutation—JAK2 V617F—suggesting a potential role for environmental mutagens. Methods: We conducted a population-based case-control study in three rural Pennsylvania counties of persons born 1921–1968 and residing in the area between 2000–2008. Twenty seven MPN cases and 292 controls were recruited through random digit dialing. Subjects were genotyped and odds ratios estimated for a select set of polymorphisms in environmentally sensitive genes that might implicate specific environmental mutagens if found to be associated with a disease. Results: The presence of NAT2 slow acetylator genotype, and CYP1A2, GSTA1, and GSTM3 variants were associated with an average 3–5 fold increased risk. Conclusions: Exposures, such as to aromatic compounds, whose toxicity is modified by genotypes associated with outcome in our analysis may play a role in the environmental etiology of MPNs
Genetic polymorphisms of phase I metabolizing enzyme genes, their interaction with lifetime grilled and smoked meat intake, and breast cancer incidence
To examine associations between 22 CYP single nucleotide polymorphisms (SNPs) and breast cancer incidence and their interactions with grilled–smoked meat intake, a source of polycyclic aromatic hydrocarbons
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