Optimization of microwave-assisted extraction followed by solid phase micro extraction and gas chromatography-mass spectrometry detection for the assay of some semi volatile organic pollutants in sebum

Methodology using MAE/SPME/GC-MS is being pursued for the analysis of organic pollutants in sebum. The microwave-assisted extraction (MAE) of standards of semi volatile organic pollutants from sebum was optimized. All compounds were extracted from sebum with recoveries analyzed by GC/MS ranging from 94% to 100% under the optimum MAE conditions: 10mL acetone-hexane (2:1), 60 degrees C, and 10 min microwave heating. To improve the detection limits a SPME procedure was optimized. Linearity ranged from 0.70 ppb to 25 ppb. R.S.D. were in the range of 1-23% for the SPME step. Preliminary real samples were analyzed and a range of compounds was detected. The optimized MAE/SPME/GC-MS methodology promises to be useful for different applications.     

Niches, rather than neutrality, structure a grassland pioneer guild

Pioneer species are fast-growing, short-lived gap exploiters. They are prime candidates for neutral dynamics because they contain ecologically similar species whose low adult density is likely to cause widespread recruitment limitation, which slows competitive dynamics. However, many pioneer guilds appear to be differentiated according to seed size. In this paper, we compare predictions from a neutral model of community structure with three niche-based models in which trade-offs involving seed size form the basis of niche differentiation. We test these predictions using sowing experiments with a guild of seven pioneer species from chalk grassland. We find strong evidence for niche structure based on seed size: specifically large-seeded species produce fewer seeds but have a greater chance of establishing on a per-seed basis. Their advantage in establishment arises because there are more microsites suitable for their germination and early establishment and not directly through competition with other seedlings. In fact, seedling densities of all species were equally suppressed by the addition of competitors' seeds. By the adult stage, despite using very high sowing densities, there were no detectable effects of interspecific competition on any species. The lack of interspecific effects indicates that niche differentiation, rather than neutrality, prevails.     

The Impact of Comprehensive Case Management on HIV Client Outcomes

In 1990, New York State instituted Comprehensive Medicaid Case Management, also known as Target Case Management (TCM), for people dealing with multiple comorbid conditions, including HIV. The goal of TCM is to assist clients in navigating the health care system to increase care engagement and treatment adherence for individuals with complex needs. HIV-positive individuals engaged in care are more likely to be virally suppressed, improving clinical outcomes and decreasing chances of HIV transmission. The purpose of this study was to understand the impact of TCM management on outcomes for people with HIV. Data were obtained from Amida Care, which operates not-for-profit managed care Medicaid and Medicare Special Needs Plans (SNPs) for HIV clients. Changes in clinical, cost, as well as medical and pharmacy utilization data among TCM clients were examined between January 2011 through September 2012 from the start of case management enrollment through the end of the study period (i.e., up to 6 months after disenrollment). Additionally, CD4 counts were compared between Amida Care TCM clients and non-TCM clients. Notable findings include increased CD4 counts for TCM clients over the one-year study period, achieving parity with non-TCM clients (i.e., Mean CD4 count > 500). When looking exclusively at TCM clients, there were increases in medication costs over time, which were concomitant with increased care engagement. Current findings demonstrate that TCM is able to achieve its goals of improving care engagement and treatment adherence. Subsequent policy changes resulting from the Affordable Care Act and the New York State Medicaid Redesign have made the Health Home the administrator of TCM services. Government entities charged with securing and managing TCM and care coordination for people with HIV should provide thoughtful and reasonable guidance and oversight in order to maintain optimal clinical outcomes for TCM clients and reduce the transmission of HIV.     

Purification of a mammalian 5-lipoxygenase from rat basophilic leukemia cells

5-Lipoxygenase (5-lipox) has been purified to homogeneity from the 20,000 xg supernatant of sonicated rat basophilic leukemia (RBL-1) cells using a 4-step procedure. Purification was achieved primarily through the use of anion-exchange HPLC on two different media. Using the supernatant from 1 × 10 ⁹ cells, approximately 33 μg of the enzyme can be routinely isolated with an estimated net yield of 5–10%. Purified 5-lipox consists of a single Mr 73,000 band on SDS gels (reduced or unreduced). When the purified enzyme was incubated with radiolabeled arachidonic acid and products analyzed by both straight phase and reversed phase HPLC, 5-hydroperoxyeicosate-traenoic acid (5-HPETE) was the only enzymatic product detected. The purified enzyme exhibits the same characteristic lag phase and premature cessation of reaction as does the 5-lipox activity seen in crude cell homogenates.     

Higher Estimated Net Endogenous Acid Production May Be Associated with Increased Prevalence of Nonalcoholic Fatty Liver Disease in Chinese Adults in Hong Kong

Nonalcoholic fatty liver disease (NAFLD) has been associated with reduced growth hormone levels and signaling. Such hormonal changes also occur in metabolic acidosis. Since mild metabolic acidosis can be diet induced, diet-induced acid load may constitute a nutritional factor with possible influence on NAFLD development. This study explored whether a higher diet-induced acid load is associated with an increased likelihood of NAFLD. Apparently healthy Chinese adults (330 male, 463 female) aged 19-72 years were recruited through population screening between 2008 and 2010 in a cross-sectional population-based study in Hong Kong. Estimated net endogenous acid production (NEAP) was calculated using Frassetto’s method and potential renal acid load (PRAL) was calculated using Remer’s method based on dietary data from a food frequency questionnaire. NAFLD was defined as intrahepatic triglyceride content at >5% by proton-magnetic resonance spectroscopy. Possible advanced fibrosis was defined as liver stiffness at >7.9 kPa by transient elastography. Multivariate logistic regression models were used to examine the association between each measure of dietary acid load and prevalent NAFLD or possible advanced fibrosis with adjustment for potential anthropometric and lifestyle factors. 220 subjects (27.7%) were diagnosed with NAFLD. Estimated NEAP was positively associated with the likelihood of having NAFLD after adjustment for age, sex, body mass index, current drinker status and the presence of metabolic syndrome [OR (95% CI) = 1.25 (1.02-1.52), p = 0.022]. The association was slightly attenuated but remained significant when the model was further adjusted for other dietary variables. No association between PRAL and NAFLD prevalence was observed. Both estimated NEAP and PRAL were not associated with the presence of possible advance fibrosis. Our findings suggest that there may be a modest association between diet-induced acid load and NAFLD. More studies are needed to ascertain the link between diet-induced acid load and NAFLD and to investigate the underlying mechanisms.     

Living on Climate-Changed Country: Indigenous Health,Well-Being and Climate Change in Remote Australian Communities

Closing the gap between the health and well-being status of Indigenous people living in remote areas of northern Australia and non-Indigenous Australians has long been a major target of federal health policy. With climate projections suggesting large increases in hot spells in desert regions and more extremes in rainfall in other areas of the north, direct and indirect impacts resulting from these changes are likely to further entrench this health and well-being disparity. This paper argues that it is time to explicitly draw on Indigenous definitions of health, which directly address the need to connect individual and community health to the health of their country, in order to develop effective climate adaptation and health strategies. We detail how current health policies overlook this ‘missing’ dimension of Indigenous connection to country, and why that is likely to be detrimental to the health and well-being of people living in remote communities in a climate-changed future.     

Extreme plasticity in life‐history strategy allows a migratory predator (jumbo squid) to cope with a changing climate

Dosidicus gigas (jumbo or Humboldt squid) is a semelparous, major predator of the eastern Pacific that is ecologically and commercially important. In the Gulf of California, these animals mature at large size (>55 cm mantle length) in 1–1.5 years and have supported a major commercial fishery in the Guaymas Basin during the last 20 years. An El Niño event in 2009–2010, was accompanied by a collapse of this fishery, and squid in the region showed major changes in the distribution and life‐history strategy. Large squid abandoned seasonal coastal‐shelf habitats in 2010 and instead were found in the Salsipuedes Basin to the north, an area buffered from the effects of El Niño by tidal upwelling and a well‐mixed water column. The commercial fishery also relocated to this region. Although large squid were not found in the Guaymas Basin from 2010 to 2012, small squid were abundant and matured at an unusually small mantle‐length (<30 cm) and young age (approximately 6 months). Juvenile squid thus appeared to respond to El Niño with an alternative life‐history trajectory in which gigantism and high fecundity in normally productive coastal‐shelf habitats were traded for accelerated reproduction at small size in an offshore environment. Both small and large mature squid, were present in the Salsipuedes Basin during 2011, indicating that both life‐ history strategies can coexist. Hydro‐acoustic data, reveal that squid biomass in this study area nearly doubled between 2010 and 2011, primarily due to a large increase in small squid that were not susceptible to the fishery. Such a climate‐driven switch in size‐at‐maturity may allow D. gigas to rapidly adapt to and cope with El Niño. This ability is likely to be an important factor in conjunction with longerterm climate‐change and the potential ecological impacts of this invasive predator on marine ecosystems.