162 research outputs found

    Shelf‐basin exchange times of Arctic surface waters estimated from \u3csup\u3e228\u3c/sup\u3eTH/\u3csup\u3e228\u3c/sup\u3eRa disequilibrium

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    The transpolar drift is strongly enriched in 228Ra accumulated on the wide Arctic shelves with subsequent rapid offshore transport. We present new data of Polarstern expeditions to the central Arctic and to the Kara and Laptev seas. Because 226Ra activities in Pacific waters are 30% higher than in Atlantic waters, we correct 226Ra for the Pacific admixture when normalizing 228Ra with 226Ra. The use of 228Ra decay as age marker critically depends on the constancy in space and time of the source activity, a condition that has not yet adequately been tested. While 228Ra decays during transit over the central basin, ingrowth of 228Th could provide an alternative age marker. The high 228Th/228Ra activity ratio (AR = 0.8–1.0) in the central basins is incompatible with a mixing model based on horizontal eddy diffusion. An advective model predicts that 228Th grows to an equilibrium AR, the value of which depends on the scavenging regime. The low AR over the Lomonosov Ridge (AR = 0.5) can be due to either rapid transport (minimum age without scavenging 1.1 year) or enhanced scavenging. Suspended particulate matter load (derived from beam transmission and particulate 234Th) and total 234Th depletion data show that scavenging, although extremely low in the central Arctic, is enhanced over the Lomonosov Ridge, making an age of 3 years more likely. The combined data of 228Ra decay and 228Th ingrowth confirm the existence of a recirculating gyre in the surface water of the eastern Eurasian Basin with a river water residence time of at least 3 year

    The P4G-Getting to Zero Coalition Partnership: Finding and supporting opportunities to decarbonise shipping in Indonesia, Mexico and South Africa

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    The International Maritime Organization has committed to reducing greenhouse gases emissions from international shipping by at least 50% by 2050 compared to 2008 levels. To reach that goal, a shift towards new low- and zero-carbon fuels -such as hydrogen and ammonia- is urgently needed, along with the deployment of safe and reliable zero-emission vessels, technologies and infrastructure. With shipping being a potential significant demand driver for these new fuels, it can act as a trigger and catalyst for the broader energy transition, benefiting other sectors of the economy. The P4G-Getting to Zero (GtZ) Coalition Partnership is a two-year project that focuses on shipping decarbonisation business and development opportunities in Indonesia, Mexico and South Africa. To the project’s core is the priority of bringing forward the national voices, priorities and policies around climate change, energy transition, job generation and air pollution. To that end, the P4G-GtZ team detected and engaged with key national and international stakeholders that can provide the current countries’ landscape, diagnostic and synergies around shipping opportunities. Apart from generating a networking space for the different key stakeholders, the project delivered detailed shipping activity maps coupled with energy studies that throw light at which low/zero-carbon fuel offers better feasibility to decarbonise shipping taking into account policy, job generation and international competition. The poster introduces the P4G-GtZ Coalition Partnership and the progress done so far while highlighting key findings around shipping decarbonisation, hydrogen-based fuels potential and energy transitions

    HTLV-1 and HIV-2 Infection Are Associated with Increased Mortality in a Rural West African Community

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    BACKGROUND: Survival of people with HIV-2 and HTLV-1 infection is better than that of HIV-1 infected people, but long-term follow-up data are rare. We compared mortality rates of HIV-1, HIV-2, and HTLV-1 infected subjects with those of retrovirus-uninfected people in a rural community in Guinea-Bissau. METHODS: In 1990, 1997 and 2007, adult residents (aged ≥15 years) were interviewed, a blood sample was drawn and retroviral status was determined. An annual census was used to ascertain the vital status of all subjects. Cox regression analysis was used to estimate mortality hazard ratios (HR), comparing retrovirus-infected versus uninfected people. RESULTS: A total of 5376 subjects were included; 197 with HIV-1, 424 with HIV-2 and 325 with HTLV-1 infection. The median follow-up time was 10.9 years (range 0.0-20.3). The crude mortality rates were 9.6 per 100 person-years of observation (95% confidence interval 7.1-12.9) for HIV-1, 4.1 (3.4-5.0) for HIV-2, 3.6 (2.9-4.6) for HTLV-1, and 1.6 (1.5-1.8) for retrovirus-negative subjects. The HR comparing the mortality rate of infected to that of uninfected subjects varied significantly with age. The adjusted HR for HIV-1 infection varied from 4.0 in the oldest age group (≥60 years) to 12.7 in the youngest (15-29 years). The HR for HIV-2 infection varied from 1.2 (oldest) to 9.1 (youngest), and for HTLV-1 infection from 1.2 (oldest) to 3.8 (youngest). CONCLUSIONS: HTLV-1 infection is associated with significantly increased mortality. The mortality rate of HIV-2 infection, although lower than that of HIV-1 infection, is also increased, especially among young people

    Unique technique of surgery in an unusual variety of Scimitar syndrome: A Case Report

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    Scimitar syndrome is a rare congenital anomaly characterized by total or partial anomalous pulmonary venous drainage of the right lung to the inferior vena cava. We present a seven year old girl with a systolic murmur who was diagnosed as having a Scimitar syndrome with unusual drainage of the right pulmonary veins. The unique technique of surgery in this patient was appropriate to the unusual, previously not described anatomy

    Association of Serum Ustekinumab Levels With Clinical Response in Psoriasis

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    Importance: High-cost biologic therapies have transformed the management of immune-mediated inflammatory diseases. To optimize outcomes and reduce costs, dose adjustment informed by measurement of circulating drug levels has been shown to be effective in various settings. However, limited evidence exists for this approach with the interleukin 12 and interleukin 23 inhibitor ustekinumab. Objective: To evaluate clinical utility of therapeutic drug monitoring for ustekinumab in patients with psoriasis. Design, Setting, and Participants: A prospective observational cohort of 491 adults with psoriasis was recruited to the multicenter Biomarkers of Systemic Treatment Outcomes in Psoriasis study within the British Association of Dermatologists Biologic and Immunomodulators Register from June 2009 to December 2017; samples from some patients were taken between 2009 and 2011 as part of a pilot study with the same inclusion criteria. Exposure: Serum ustekinumab level measured at any point during the dosing cycle using an enzyme-linked immunosorbent assay. Main Outcomes and Measures@ Disease activity measured using the Psoriasis Area and Severity Index (PASI) score. Treatment response outcomes were PASI75 (75% reduction in PASI score from baseline [primary outcome]), PASI90 (90% reduction of PASI score from baseline), and absolute PASI score of 1.5 or less. Results: A total of 491 patients (171 women and 320 men; mean [SD] age, 45.7 [12.8] years) had 1 or more serum samples (total, 853 samples obtained 0-56 weeks from start of treatment) and 1 or more PASI scores within the first year of treatment. Antidrug antibodies were detected in only 17 of 490 patients (3.5%). Early measured drug levels (1-12 weeks after starting treatment) were associated with PASI75 response 6 months after starting treatment (odds ratio, 1.38; 95% CI, 1.11-1.71) when adjusted for baseline PASI score, age, and ustekinumab dose. However, this finding was not consistent across the other PASI outcomes (PASI90 and PASI score of ≤1.5). Conclusions and Relevance: This real-world study provides evidence that measurement of early serum ustekinumab levels could be useful to direct the treatment strategy for psoriasis. Adequate drug exposure early in the treatment cycle may be particularly important in determining clinical outcome

    Stent implantation into the tracheo-bronchial system in rabbits: histopathologic sequelae in bare metal vs. drug-eluting stents

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    BACKGROUND: Stent implantation into the tracheo-bronchial system may be life-saving in selected pediatric patients with otherwise intractable stenosis of the upper airways. Following implantation, significant tissue proliferation may occur, requiring re-interventions. We sought to evaluate the effect of immunosuppressive coating of the stents on the extent of tissue proliferation in an animal model. METHODS: Bare metal and sirolimus-coated stents (Bx Sonic and Cypher Select, Johnson & Johnson, Cordis) were implanted into non-stenotic lower airways of New Zealand white rabbits (weight 3.1 to 4.8 kg). Three stents with sirolimus coating and six bare metal stents could be analyzed by means of histology and immunohistochemistry 12 months after implantation. RESULTS: On a macroscopic evaluation, all stents were partially covered with a considerable amount of whitish tissue. Histologically, these proliferations contained fiber-rich connective tissue and some fibromuscular cells without significant differences between both stent types. The superficial tissue layer was formed by typical respiratory epithelium and polygonal cells. Abundant lymphocyte infiltrations and moderate granulocyte infiltrations were found in both groups correspondingly, whereas foreign-body reaction was more pronounced around sirolimus-eluting stents. CONCLUSIONS: After stent implantation in the tracheo-bronchial system of rabbits, we found tissue reactions comparable to those seen after stent implantation into the vascular system. There was no difference between coated and uncoated stents with regard to quality and quantity of tissue proliferation. We found, however, a significantly different inflammatory reaction with a more pronounced foreign-body reaction in sirolimus-coated stents. In our small series, drug-eluting stents did not exhibit any benefit over bare metal stents in an experimental setting

    Particle fluxes associated with mesoscale eddies in the Sargasso Sea

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    Author Posting. © Elsevier B.V., 2008. This is the author's version of the work. It is posted here by permission of Elsevier B.V. for personal use, not for redistribution. The definitive version was published in Deep Sea Research Part II: Topical Studies in Oceanography 55 (2008): 1426-1444, doi:10.1016/j.dsr2.2008.02.007.We examined the impact of a cyclonic eddy and mode-water eddy on particle flux in the Sargasso Sea. The primary method used to quantify flux was based upon measurements of the natural radionuclide, 234Th, and these flux estimates were compared to results from sediment traps in both eddies, and a 210Po/210Pb flux method in the mode-water eddy. Particulate organic carbon (POC) fluxes at 150m ranged from 1 to 4 mmol C m-2 d-1 and were comparable between methods, especially considering differences in integration times scales of each approach. Our main conclusion is that relative to summer mean conditions at the Bermuda Atlantic Time-series Study (BATS) site, eddy-driven changes in biogeochemistry did not enhance local POC fluxes during this later, more mature stage of the eddy life cycle (>6 months old). The absence of an enhancement in POC flux puts a constraint on the timing of higher POC flux events, which are thought to have caused the local O2 minima below each eddy, and must have taken place >2 months prior to our arrival. The mode-water eddy did enhance preferentially diatom biomass in its center where we estimated a factor of 3 times higher biogenic Si flux than the BATS summer average. An unexpected finding in the highly depth resolved 234Th data sets are narrow layers of particle export and remineralization within the eddy. In particular, a strong excess 234Th signal is seen below the deep chlorophyll maxima which we attribute to remineralization of 234Th bearing particles. At this depth below the euphotic zone, de novo particle production in the euphotic zone has stopped, yet particle remineralization continues via consumption of labile sinking material by bacteria and/or zooplankton. These data suggest that further study of processes in ocean layers is warranted not only within, but below the euphotic zone.The EDDIES project was funded by the National Science Foundation Chemical, Biological, and Physical Oceanography Programs. Additional support for HPLC pigment analysis (Dr. Charles Trees, CHORS) was provided by NASA

    Molecular Epidemiology of Endemic Human T-Lymphotropic Virus Type 1 in a Rural Community in Guinea-Bissau

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    Human T-Lymphotropic Virus type 1 (HTLV-1) affects millions of people worldwide. It is very similar to Simian T-Lymphotropic Virus, a virus that circulates in monkeys. HTLV-1 causes a lethal form of leukemia (Adult T-cell Leukemia) and a debilitating neurological syndrome (HTLV-associated myelopathy/tropical spastic paraparesis) in approximately 5% of infected people. Based on sequence variation, HTLV-1 can be divided into 7 subtypes (1a–1g) with the Cosmopolitan subtype 1a further subdivided into subgroups (A–E). We examined HTLV-1 diversity in a rural area in Guinea-Bissau, a country in West Africa with a high HTLV-1 prevalence (5%). We found that most viruses belong to the Cosmopolitan subtype 1a, subgroup D, but 2 viruses belonged to subtype 1g. This subtype had thus far only been found in monkey hunters in Cameroon, who were probably recently infected by monkeys. Our findings indicate that this subtype has spread beyond Central Africa. An important, unresolved question is whether persons with this subtype were infected by monkeys or through human-to-human transmission

    Vaccinia Scars Associated with Improved Survival among Adults in Rural Guinea-Bissau

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    BACKGROUND: In urban Guinea-Bissau, adults with a vaccinia scar had better survival but also a higher prevalence of HIV-2 infection. We therefore investigated the association between vaccinia scar and survival and HIV infection in a rural area of Guinea-Bissau. METHODOLOGY/PRINCIPAL FINDINGS: In connection with a study of HIV in rural Guinea-Bissau, we assessed vaccinia and BCG scars in 193 HIV-1 or HIV-2 infected and 174 uninfected participants. Mortality was assessed after 2½–3 years of follow-up. The analyses were adjusted for age, sex, village, and HIV status. The prevalence of vaccinia scar was associated with age, village, and HIV-2 status but not with sex and schooling. Compared with individuals without any scar, individuals with a vaccinia scar had better survival (mortality rate ratio (MR) = 0.22 (95% CI 0.08–0.61)), the MR being 0.19 (95% CI 0.06–0.57) for women and 0.40 (95% CI 0.04–3.74) for men. Estimates were similar for HIV-2 infected and HIV-1 and HIV-2 uninfected individuals. The HIV-2 prevalence was higher among individuals with a vaccinia scar compared to individuals without a vaccinia scar (RR = 1.57 (95% CI 1.02–2.36)). CONCLUSION: The present study supports the hypothesis that vaccinia vaccination may have a non-specific beneficial effect on adult survival

    Health seeking behaviour, health system experience and tuberculosis case finding in Gambians with cough

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    BACKGROUND: Studies in Africa investigating health-seeking behaviour by interviewing tuberculosis patients have revealed patient knowledge issues and significant delays to diagnosis. We aimed to study health-seeking behaviour and experience of those with cough in The Gambia and to identify whether they had tuberculosis. METHODS: During a round of a population under 3-monthly demographic surveillance, we identified people >10 years old who had been coughing ≥ 3 weeks. A questionnaire was administered concerning demographic data, cough, knowledge, health seeking, and experience at health facilities. Case finding utilised sputum smear and chest X-ray. RESULTS: 122/29,871 coughing individuals were identified. Of 115 interviewed, 93 (81%) had sought treatment; 76 (81.7%) from the health system. Those that visited an alternative health provider first were significantly older than those who visited the health system first (p = 0.03). The median time to seek treatment was 2 weeks (range 0 – 106). 54 (58.1%) made their choice of provider because they believed it was right. Of those who left the health system to an alternative provider (n = 13): 7 believed it was the best place, 3 cited cost and 2 failure to improve. 3 cases were identified by sputum analysis, 11 more by X-ray; all had visited the health system first. Total 'excess' cough time was 1079 person weeks. CONCLUSION: The majority of people with cough in this population seek appropriate help early. Improved case detection might be achieved through the use of chest X-ray in addition to sputum smear
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