219 research outputs found

    Acetylene Fuels TCE Reductive Dechlorination by Defined Dehalococcoides/Pelobacter Consortia.

    Get PDF
    Acetylene (C2H2) can be generated in contaminated groundwater sites as a consequence of chemical degradation of trichloroethene (TCE) by in situ minerals, and C2H2 is known to inhibit bacterial dechlorination. In this study, we show that while high C2H2 (1.3 mM) concentrations reversibly inhibit reductive dechlorination of TCE by Dehalococcoides mccartyi isolates as well as enrichment cultures containing D. mccartyi sp., low C2H2 (0.4 mM) concentrations do not inhibit growth or metabolism of D. mccartyi. Cocultures of Pelobacter SFB93, a C2H2-fermenting bacterium, with D. mccartyi strain 195 or with D. mccartyi strain BAV1 were actively sustained by providing acetylene as the electron donor and carbon source while TCE or cis-DCE served as the electron acceptor. Inhibition by acetylene of reductive dechlorination and methanogenesis in the enrichment culture ANAS was observed, and the inhibition was removed by adding Pelobacter SFB93 into the consortium. Transcriptomic analysis of D. mccartyi strain 195 showed genes encoding for reductive dehalogenases (e.g., tceA) were not affected during the C2H2-inhibition, while genes encoding for ATP synthase, biosynthesis, and Hym hydrogenase were down-regulated during C2H2 inhibition, consistent with the physiological observation of lower cell yields and reduced dechlorination rates in strain 195. These results will help facilitate the optimization of TCE-bioremediation at contaminated sites containing both TCE and C2H2

    Toll-like receptor gene variants and bacterial vaginosis among HIV-1 infected and uninfected African women.

    Get PDF
    Bacterial vaginosis (BV) is a common vaginal syndrome associated with altered microflora that increases the risk of preterm delivery and acquisition of sexually transmitted diseases. The cause of BV is unknown although toll-like receptors (TLRs), that are central to innate immune responses, may be important. We evaluated associations between TLR SNPs and BV among HIV-1 infected and uninfected African women. Logistic regression was used to assess associations between SNPs (N=99) in TLRs 2-4, 7-9 and BV (as classified by Nugent's criteria). Among HIV-1 uninfected women, TLR7 rs5743737 and TLR7 rs1634323 were associated with a decreased risk of BV, whereas TLR7 rs179012 was associated with an increased risk. TLR2 SNP rs3804099 was associated with a decreased risk of BV among HIV-1 infected women. Our findings indicate that there may be differences in TLR association with BV among HIV-1 infected and HIV-1 uninfected women

    Prophylactic Anticonvulsants in Intracerebral Hemorrhage

    Get PDF
    Background and Purpose Prophylactic anticonvulsants are routinely prescribed in the acute setting for intracerebral hemorrhage (ICH) patients, but some studies have reported an association with worse outcomes. We sought to characterize the prevalence and predictors of prophylactic anticonvulsant administration after ICH as well as guideline adherence. We also sought to determine whether prophylactic anticonvulsants were independently associated with poor outcome. Methods We performed a retrospective study of primary ICH in our two academic centers. We used a propensity matching approach to make treated and non-treated groups comparable. We conducted multiple logistic regression analysis to identify independent predictors of prophylactic anticonvulsant initiation and its association with poor outcome as measured by modified Rankin score. Results We identified 610 patients with primary ICH, of whom 98 were started on prophylactic anticonvulsants. Levetiracetam (97%) was most commonly prescribed. Age (OR 0.97, 95% CI 0.95–0.99, p < .001), lobar location (OR 2.94, 95% CI 1.76–4.91, p < .001), higher initial National Institutes of Health Stroke Scale (NIHSS) score (OR 2.31, 95% CI 1.40–3.79, p = .001), craniotomy (OR 3.06, 95% CI 1.51–6.20, p = .002), and prior ICH (OR 2.36, 95% CI 1.10–5.07, p = .028) were independently associated with prophylactic anticonvulsant initiation. Prophylactic anticonvulsant use was not associated with worse functional outcome [modified Rankin score (mRS) 4–6] at hospital discharge or with increased case-fatality. There was no difference in prescribing patterns after 2010 guideline publication. Discussion Levetiracetam was routinely prescribed following ICH and was not associated with worse outcomes. Future investigations should examine the effect of prophylactic levetiracetam on cost and neuropsychological outcomes as well as the role of continuous EEG in identifying subclinical seizures

    Narratives of self and identity in women's prisons: stigma and the struggle for self-definition in penal regimes

    No full text
    A concern with questions of selfhood and identity has been central to penal practices in women's prisons, and to the sociology of women's imprisonment. Studies of women's prisons have remained preoccupied with women prisoners’ social identities, and their apparent tendency to adapt to imprisonment through relationships. This article explores the narratives of women in two English prisons to demonstrate the importance of the self as a site of meaning for prisoners and the central place of identity in micro-level power negotiations in prisons

    Disparities and guideline adherence in drugs of abuse screening in intracerebral hemorrhage

    Get PDF
    OBJECTIVE: To characterize the pattern of urine drug screening in a cohort of intracerebral hemorrhage (ICH) patients at our academic centers. METHODS: We identified cases of primary ICH occurring from 2009 to 2011 in our academic centers. Demographic data, imaging characteristics, processes of care, and short-term outcomes were ascertained. We performed logistic regression to identify predictors for screening and evaluated preguideline and postguideline reiteration screening patterns. RESULTS: We identified 610 patients with primary ICH in 2009-2011; 379 (62.1%) were initially evaluated at an outside hospital. Overall, 142/610 (23.3%) patients were screened, with 21 positive for cocaine and 3 for amphetamine. Of patients <55 years of age, only 65/140 (46.4%) were screened. Black patients <55 years of age were screened more than nonblack patients <55 years of age (38/61 [62.3%] vs 27/79 [34.2%]; p = 0.0009). In the best multivariable model, age group (p = 0.0001), black race (p = 0.4529), first Glasgow Coma Scale score (p = 0.0492), current smoking (p < 0.0001), and age group × black race (p = 0.0097) were associated with screening. Guideline reiteration in 2010 did not improve the proportion <55 years of age who were screened: 42/74 (56.8%) were screened before and 23/66 (34.9%) after (p = 0.01). CONCLUSIONS: We found disparities in drugs of abuse (DOA) screening and suboptimal guideline adherence. Systematic efforts to improve screening for DOA are warranted. Improved identification of sympathomimetic exposure may improve etiologic classification and influence decision-making and prognosis counseling

    Organic farming provides reliable environmental benefits but increases variability in crop yields: a global meta-analysis

    Get PDF
    To promote food security and sustainability, ecologically intensive farming systems should reliably produce adequate yields of high-quality food, enhance the environment, be profitable, and promote social wellbeing. Yet, while many studies address the mean effects of ecologically intensive farming systems on sustainability metrics, few have considered variability. This represents a knowledge gap because producers depend on reliable provisioning of yields, profits, and environmental services to enhance the sustainability of their production systems over time. Further, stable crop yields are necessary to ensure reliable access to nutritious foods. Here we address this by conducting a global meta-analysis to assess the average magnitude and variability of seven sustainability metrics in organic compared to conventional systems. Specifically, we explored the effects of these systems on (i) biotic abundance, (ii) biotic richness, (iii) soil organic carbon, (iv) soil carbon stocks, (v) crop yield, (vi) total production costs, and (vii) profitability. Organic farms promoted biotic abundance, biotic richness, soil carbon, and profitability, but conventional farms produced higher yields. Compared to conventional farms, organic farms had lower variability in abundance and richness but greater yield variability. Organic farms thus provided a “win-win” (high means and low variability) for environmental sustainability, while conventional farms provided a “win-win” for production by promoting high crop yields with low variability. Despite lower yields, and greater yield variability, organic systems had similar costs to conventional systems and were more profitable due to organic premiums. Our results suggest certification guidelines for organic farms successfully promote reliable environmental benefits, but greater reliance on ecological processes may reduce predictability of crop production

    Predictors of linkage to care following community-based HIV counseling and testing in rural Kenya

    Get PDF
    Despite innovations in HIV counseling and testing (HCT), important gaps remain in understanding linkage to care. We followed a cohort diagnosed with HIV through a community-based HCT campaign that trained persons living with HIV/AIDS (PLHA) as navigators. Individual, interpersonal, and institutional predictors of linkage were assessed using survival analysis of self-reported time to enrollment. Of 483 persons consenting to follow-up, 305 (63.2%) enrolled in HIV care within 3 months. Proportions linking to care were similar across sexes, barring a sub-sample of men aged 18–25 years who were highly unlikely to enroll. Men were more likely to enroll if they had disclosed to their spouse, and women if they had disclosed to family. Women who anticipated violence or relationship breakup were less likely to link to care. Enrolment rates were significantly higher among participants receiving a PLHA visit, suggesting that a navigator approach may improve linkage from community-based HCT campaigns.Vestergaard Frandse

    Spongivory in the Wakatobi Marine National Park, Southeast Sulawesi, Indonesia

    Get PDF
    Sponges are functionally important coral reef fauna and there is strong evidence from the Caribbean that predation has important impacts on sponge-Assemblage dynamics; whether the same is true for Indo-Pacific sponges remains unknown. As a first step toward understanding the potential effects of spongivores on sponge diversity and abundance, we identified sponge predators at nine sites in Wakatobi Marine National Park, Indonesia, and conducted a short-Term caging experiment to examine the effects of excluding predators on noncryptic reef sponges at this location. Nudibranchs were the most abundant invertebrate spongivores, although their low densities are likely to limit their influence on sponges. Fish were the most abundant vertebrate spongivores with 16 species from six families observed feeding on sponges. Based on their abundance and our feeding observations, the fish with the greatest potential to influence sponge assemblages in Wakatobi Marine National Park were Zanclus cornutus, Chaetodon kleinii, Pygoplites diacanthus, and Pomacanthus sexstriatus. We did not detect an effect of excluding spongivores on noncryptic reef sponge abundance in our caging experiment, which may be due to these species having evolved chemical defenses against predators. Important areas for further research include the chemical ecology of Indo-Pacific sponges and whether spongivory currently restricts some species to cryptic or nonreef habitats

    The lifetime of nitrogen oxides in an isoprene-dominated forest

    Get PDF
    The lifetime of nitrogen oxides (NO_x) affects the concentration and distribution of NO_x and the spatial patterns of nitrogen deposition. Despite its importance, the lifetime of NO_x is poorly constrained in rural and remote continental regions. We use measurements from a site in central Alabama during the Southern Oxidant and Aerosol Study (SOAS) in summer 2013 to provide new insights into the chemistry of NO_x and NO_x reservoirs. We find that the lifetime of NO_x during the daytime is controlled primarily by the production and loss of alkyl and multifunctional nitrates (ΣANs). During SOAS, ΣAN production was rapid, averaging 90 ppt h^(−1) during the day, and occurred predominantly during isoprene oxidation. Analysis of the ΣAN and HNO_3 budgets indicate that ΣANs have an average lifetime of under 2 h, and that approximately 45 % of the ΣANs produced at this site are rapidly hydrolyzed to produce nitric acid. We find that ΣAN hydrolysis is the largest source of HNO_3 and the primary pathway to permanent removal of NO_x from the boundary layer in this location. Using these new constraints on the fate of ΣANs, we find that the NO_x lifetime is 11 ± 5 h under typical midday conditions. The lifetime is extended by storage of NO_x in temporary reservoirs, including acyl peroxy nitrates and ΣANs
    corecore