Arsenic and high affinity phosphate uptake gene distribution in shallow submarine hydrothermal sediments

The toxicity of arsenic (As) towards life on Earth is apparent in the dense distribution of genes associated with As detoxification across the tree of life. The ability to defend against As is particularly vital for survival in As-rich shallow submarine hydrothermal ecosystems along the Hellenic Volcanic Arc (HVA), where life is exposed to hydrothermal fluids containing up to 3000 times more As than present in seawater. We propose that the removal of dissolved As and phosphorus (P) by sulfide and Fe(III)(oxyhydr)oxide minerals during sediment–seawater interaction, produces nutrient-deficient porewaters containing < 2.0 ppb P. The porewater arsenite-As(III) to arsenate-As(V) ratios, combined with sulfide concentration in the sediment and/or porewater, suggest a hydrothermally-induced seafloor redox gradient. This gradient overlaps with changing high affinity phosphate uptake gene abundance. High affinity phosphate uptake and As cycling genes are depleted in the sulfide-rich settings, relative to the more oxidizing habitats where mainly Fe(III)(oxyhydr)oxides are precipitated. In addition, a habitat-wide low As-respiring and As-oxidizing gene content relative to As resistance gene richness, suggests that As detoxification is prioritized over metabolic As cycling in the sediments. Collectively, the data point to redox control on Fe and S mineralization as a decisive factor in the regulation of high affinity phosphate uptake and As cycling gene content in shallow submarine hydrothermal ecosystems along the HVA

The State of Women Veterans' Health Research: Results of a Systematic Literature Review

OBJECTIVE: Assess the state of women veterans' health research. DESIGN: Systematic review of studies that pertained specifically to or included explicit information about women veterans. A narrative synthesis of studies in 4 domains/topics was conducted: Stress of military life; Health and performance of military/VA women; Health services research/quality of care; and Psychiatric conditions. MEASUREMENTS AND MAIN RESULTS: We identified 182 studies. Of these, 2 were randomized-controlled trials (RCTs) and the remainder used observational designs. Forty-five percent of studies were VA funded. We identified 77 studies pertaining to the stress of military life, of which 21 reported on sexual harassment or assault. Rates of harassment ranged from 55% to 79% and rates of sexual assault from 4.2% to 7.3% in active duty military women and 11% to 48% among women veterans. Forty-two studies concerned the health and performance of military/VA women, with 21 studies evaluating sexual assault and posttraumatic stress disorder (PTSD) and their effect on health. Fifty-nine studies assessed various aspects of health services research. Eight studies assessed quality of care and 5, patient satisfaction. Twenty-five studies assessed utilization and health care organization, and findings include that women veterans use the VA less than men, that gender-specific reasons for seeking care were common among female military and veteran personnel, that provision of gender-specific care increased women veterans' use of VA, and that virtually all VAs have available on-site basic women's health services. Fifty studies were classified as psychiatric; 31 of these were about the risk, prevalence, and treatment of PTSD. CONCLUSIONS: Most research on VA women's health is descriptive in nature and has concerned PTSD, sexual harassment and assault, the utilization and organization of care, and various psychiatric conditions. Experimental studies and studies of the quality of care are rare