127 research outputs found

    Geological imprint of methane seepage on the seabed and biota of the convergent Hikurangi Margin, New Zealand: box core and grab carbonate results

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    Short box cores (to 30 cm bsf) and seafloor carbonate grab samples were acquired at mapped hydrocarbon seep sites (600–1200 m water depths) during the 2007 RV SONNE SO191 cruise on the Hikurangi Margin offshore eastern North Island, New Zealand, to evaluate the influence of methane seepage on sedimentologic, biotic, mineralogic and stable isotopic attributes of seabed sediments. Sedimentary horizons in the box cores consist of siliciclastic silts and sands, shell beds and nodular, microcrystalline aragonite bands up to 15 cm thick. The megafauna is dominated by infaunal to semi-infaunal chemosymbiotic bivalves (Calyptogena, Lucinoma, and Acharax), as well as associated worms and carnivorous and grazing gastropods. Burrows in silts, some occupied by worms or juvenile Acharax, mainly have simple morphologies more typical of high-energy, nearshore settings than deep-sea environments, while a few are large and sparsely branched with wall scratch marks inferred to be of decapod crustacean origin. The box core silts and nodular carbonate samples vary in TOC content from 0.2 to 0.9 wt.%, carbonate content from 4 to 78%, and δ13C and δ18O values from − 50.3 to − 0.6‰ PDB and + 0.77 to + 3.2‰ PDB, respectively. Low carbonate content silt samples have the most enriched δ13C values, implying a seawater source for their pore water bicarbonate. Negative δ13C and positive δ18O values typify the nodular, microcrystalline aragonite bands, indicating formation during microbially mediated, sulphate-dependent anaerobic oxidation of methane (AOM) in a cold, near-seafloor environment, as is also supported by lipid biomarker data. A clear isotopic mixing trend of decreasing δ13C and increasing δ18O and carbonate content in the fine (< 100 µm) carbonate fraction of the host silts also has been reported from other methane seep provinces, and suggests a heterogeneous influx of methane-rich see

    Clinical care of incarcerated people with HIV, viral hepatitis, or tuberculosis

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    The burden of HIV/AIDS and other transmissible diseases is higher in prison and jail settings than in the non-incarcerated communities that surround them. In this comprehensive review, we discuss available literature on the topic of clinical management of people infected with HIV, hepatitis B and C viruses, and tuberculosis in incarcerated settings in addition to co-occurrence of one or more of these infections. Methods such as screening practices and provision of treatment during detainment periods are reviewed to identify the effect of community-based treatment when returning inmates into the general population. Where data are available, we describe differences in the provision of medical care in the prison and jail settings of low-income and middle-income countries compared with high-income countries. Structural barriers impede the optimal delivery of clinical care for prisoners, and substance use, mental illness, and infectious disease further complicate the delivery of care. For prison health care to reach the standards of community-based health care, political will and financial investment are required from governmental, medical, and humanitarian organisations worldwide. In this review, we highlight challenges, gaps in knowledge, and priorities for future research to improve health-care in institutions for prisoners

    Factors associated with optimal pharmacy refill adherence for antiretroviral medications and plasma HIV RNA non-detectability among HIV-positive crack cocaine users: a prospective cohort study

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    BACKGROUND: Crack cocaine use is known to contribute to poor adherence to antiretroviral medications; however, little is known about facilitators of or barriers to effective HIV treatment use among HIV-infected crack cocaine users. We sought to identify correlates of optimal pharmacy refill adherence for antiretroviral medications and plasma HIV RNA viral load (pVL) suppression among this population. METHODS: Data from a prospective cohort of HIV-positive people who use illicit drugs in Vancouver, Canada, were linked to comprehensive HIV clinical monitoring and pharmacy dispensation records. We used multivariable generalized linear mixed-effects modelling to longitudinally identify factors associated with ≥95 % adherence to pharmacy refills for antiretroviral medications and pVL <50 copies/mL among crack cocaine users exposed to highly-active antiretroviral therapy (HAART). RESULTS: Among 438 HAART-exposed crack cocaine users between 2005 and 2013, 240 (54.8 %) had ≥95 % pharmacy refill adherence in the previous 6 months at baseline. In multivariable analyses, homelessness (adjusted odds ratio [AOR]: 0.58), ≥daily crack cocaine smoking (AOR: 0.64), and ≥ daily heroin use (AOR: 0.43) were independently associated with optimal pharmacy refill adherence (all p < 0.05). The results for pVL non-detectability were consistent with those of medication adherence, except that longer history of HAART (AOR: 1.06), receiving a single tablet-per-day regimen (AOR: 3.02) and participation in opioid substitution therapies was independently associated with pVL non-detectability (AOR: 1.55) (all p < 0.05). CONCLUSIONS: Homelessness, and daily crack cocaine and/or heroin use were independently and negatively associated with optimal HAART-related outcomes. With the exception of opioid substitution therapies, no addiction treatment modalities assessed appeared to facilitate medication adherence or viral suppression. Evidence-based treatment options for crack cocaine use that also confer benefits to HAART need to be developed

    Persistence of low drug treatment coverage for injection drug users in large US metropolitan areas

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    <p>Abstract</p> <p>Objectives</p> <p>Injection drug users (IDUs) are at high risk for HIV, hepatitis, overdose and other harms. Greater drug treatment availability has been shown to reduce these harms among IDUs. Yet, little is known about changes in drug treatment availability for IDUs in the U.S. This paper investigates change in drug treatment coverage for IDUs in 90 metropolitan statistical areas (MSAs) during 1993-2002.</p> <p>Methods</p> <p>We define <it>treatment coverage </it>as the percent of IDUs who are in treatment. The number of IDUs in drug treatment is calculated from treatment entry data and treatment census data acquired from the Substance Abuse and Mental Health Service Administration, divided by our estimated number of IDUs in each MSA.</p> <p>Results</p> <p>Treatment coverage was low in 1993 (mean 6.7%; median 6.0%) and only increased to a mean of 8.3% and median of 8.0% coverage in 2002.</p> <p>Conclusions</p> <p>Although some MSAs experienced increases in treatment coverage over time, overall levels of coverage were low. The persistence of low drug treatment coverage for IDUs represents a failure by the U.S. health care system to prevent avoidable harms and unnecessary deaths in this population. Policy makers should expand drug treatment for IDUs to reduce blood-borne infections and community harms associated with untreated injection drug use.</p

    “Working the System”—British American Tobacco's Influence on the European Union Treaty and Its Implications for Policy: An Analysis of Internal Tobacco Industry Documents

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    Katherine Smith and colleagues investigate the ways in which British American Tobacco influenced the European Union Treaty so that new EU policies advance the interests of major corporations, including those that produce products damaging to health

    Incarceration history and risk of HIV and hepatitis C virus acquisition among people who inject drugs: a systematic review and meta-analysis

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    Background: People who inject drugs (PWID) experience high rates of incarceration and may be at high risk of HIV and hepatitis C (HCV) virus infection during or after incarceration. We conducted a systematic review and meta-analysis to assess whether incarceration history elevates HIV or HCV acquisition risk among PWID.Methods: MEDLINE, Embase and PsycINFO databases were searched for studies in any language published since 2000 assessing HIV or HCV incidence among PWID. Studies were included if they reported the association between recent (in last 3, 6 or 12 months or since last follow-up) or past incarceration and HIV or HCV (primary or reinfection) incidence. Authors of incidence studies not reporting these outcomes were contacted for data. Data were extracted and pooled using random-effects meta-analyses. Findings: Twenty published and 21 unpublished studies were included, originating from Australasia, Western and Eastern Europe, North and Latin America and East and Southeast Asia. Recent incarceration was associated with an 81% (rate ratio (RR):1.81, 95%CI: 1.40-2.34) and 62% (RR:1.62, 95%CI:1.28-2.05) increase in HIV and HCV acquisition risk, respectively. Past incarceration was associated with a 25% and 21% increase in HIV (RR:1.25, 95%CI:0.94-1.66) and HCV (RR:1.21, 95%CI:1.02-1.43) and acquisition risk, respectively.Interpretation: Incarceration is associated with substantial short-term HIV and HCV acquisition risk among PWID and could be a significant driver for HCV and HIV transmission among PWID. These findings support the need for developing novel interventions to minimise the risk of HCV acquisition – including addressing structural risks associated with drug laws and excessive incarceration of PWID

    Using Time-Series Aerial Thermal Infrared Surveys to Determine Near-Surface Thermal Processes at the Ohaaki Geothermal Field, New Zealand

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    ABSTRACT Repeat aerial thermal infrared surveys (TIR) are used to monitor changes in the extent and intensity of surface thermal activity. Aerial TIR surveys conducted in 1989 at the Ohaaki Geothermal Field, New Zealand, are compared and interpreted with respect to such changes. These may be caused by natural variations, or by reservoir pressure, temperature and phase changes associated with operation of the Ohaaki Geothermal Power Station, since its 1988 commissioning. Aerial TIR data shows areas of increased steam heating between 1989 and 1998. These were followed by cooling of some areas of steam-heated ground between 1998 and 2013, resulting in fewer active surface thermal features. Some locations of steam-heated surface thermal activity in 1998 and 2013 are somewhat different compared to locations observed in 1989. This suggests that near-surface permeable pathways, particularly for rising steam, have changed. This could be caused by the development of alternate pathways during the increased steam heating phase between 1989 and 1998, as well as other processes such as tension cracking of the ground surface at the edges of a local subsidence bowl. Thermal seeps into the adjacent Waikato River are identified in the aerial TIR data. Most river-side thermal seeps present in 1989 near bore BR20 (an area affected by subsidence) were no longer visible by 1998, and are inferred to have ceased or become submerged. Only a few small seepage areas were detectable by aerial TIR in 2013. Observations of the increase and then subsequent decrease in surface thermal activity based on the TIR data are consistent with other thermal feature monitoring data in the Ohaaki area
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