236 research outputs found

    Soil-transmitted helminth infections

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    More than a quarter of the world's population is at risk of infection with the soil-transmitted helminths Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), Trichuris trichiura, and Strongyloides stercoralis. Infected children and adults present with a range of medical and surgical conditions, and clinicians should consider the possibility of infection in individuals living in, or returning from, endemic regions. Although safe and effective drugs are donated free to endemic countries, only half of at-risk children received treatment in 2016. This Seminar describes the epidemiology, lifecycles, pathophysiology, clinical diagnosis, management, and public health control of soil-transmitted helminths. Previous work has questioned the effect of population-level deworming; however, it remains beyond doubt that treatment reduces the severe consequences of soil-transmitted helminthiasis. We highlight the need for refined diagnostic tools and effective control options to scale up public health interventions and improve clinical detection and management of these infections

    Dissociation of two-dimensional excitons in monolayer WSe<sub>2</sub>

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    In two-dimensional semiconductors excitons are strongly bound, suppressing the creation of free carriers. Here, the authors investigate the main exciton dissociation pathway in p-n junctions of monolayer WSe2 by means of time and spectrally resolved photocurrent measurements

    Towards Activity Context using Software Sensors

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    Service-Oriented Computing delivers the promise of configuring and reconfiguring software systems to address user's needs in a dynamic way. Context-aware computing promises to capture the user's needs and hence the requirements they have on systems. The marriage of both can deliver ad-hoc software solutions relevant to the user in the most current fashion. However, here it is a key to gather information on the users' activity (that is what they are doing). Traditionally any context sensing was conducted with hardware sensors. However, software can also play the same role and in some situations will be more useful to sense the activity of the user. Furthermore they can make use of the fact that Service-oriented systems exchange information through standard protocols. In this paper we discuss our proposed approach to sense the activity of the user making use of software

    Broken-Symmetry States in Quantum Hall Superlattices

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    We argue that broken-symmetry states with either spatially diagonal or spatially off-diagonal order are likely in the quantum Hall regime, for clean multiple quantum well (MQW) systems with small layer separations. We find that for MQW systems, unlike bilayers, charge order tends to be favored over spontaneous interlayer coherence. We estimate the size of the interlayer tunneling amplitude needed to stabilize superlattice Bloch minibands by comparing the variational energies of interlayer-coherent superlattice miniband states with those of states with charge order and states with no broken symmetries. We predict that when coherent miniband ground states are stable, strong interlayer electronic correlations will strongly enhance the growth-direction tunneling conductance and promote the possibility of Bloch oscillations.Comment: 9 pages LaTeX, 4 figures EPS, to be published in PR

    Ccaat/enhancer-binding protein delta (C/ebpδ): A previously unrecognized tumor suppressor that limits the oncogenic potential of pancreatic ductal adenocarcinoma cells

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    CCAAT/enhancer-binding protein δ (C/EBPδ) is a transcription factor involved in growth arrest and differentiation, which has consequently been suggested to harbor tumor suppressive activities. However, C/EBPδ over-expression correlates with poor prognosis in glioblastoma and promotes genomic instability in cervical cancer, hinting at an oncogenic role of C/EBPδ in these contexts. Here, we explore the role of C/EBPδ in pancreatic cancer. We determined C/EBPδ expression in biopsies from pancreatic cancer patients using public gene-expression datasets and in-house tissue microarrays. We found that C/EBPδ is highly expressed in healthy pancreatic ductal cells but lost in pancreatic ductal adenocarcinoma. Furthermore, loss of C/EBPδ correlated with increased lymph node involvement and shorter overall survival in pancreatic ductal adenocarcinoma patients. In accordance with this, in vitro experiments showed reduced clonogenic capacity and proliferation of pancreatic ductal adenocarcinoma cells following C/EBPδ re-expression, concurrent with decreased sphere formation capacity in soft agar assays. We thus report a previously unrecognized but important tumor suppressor role of C/EBPδ in pancreatic ductal adenocarcinoma. This is of particular interest since only few tumor suppressors have been identified in the context of pancreatic cancer. Moreover, our findings suggest that restoration of C/EBPδ activity could hold therapeutic value in pancreatic ductal adenocarcinoma, although the latter claim needs to be substantiated in future studies

    Prospective Study of TMVR Using Balloon-Expandable Aortic Transcatheter Valves in MAC: MITRAL Trial 1-Year Outcomes

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    OBJECTIVES: The aim of this study was to evaluate 1-year outcomes of valve-in-mitral annular calcification (ViMAC) in the MITRAL (Mitral Implantation of Transcatheter Valves) trial. BACKGROUND: The MITRAL trial is the first prospective study evaluating the feasibility of ViMAC using balloon-expandable aortic transcatheter heart valves. METHODS: A multicenter prospective study was conducted, enrolling high-risk surgical patients with severe mitral annular calcification and symptomatic severe mitral valve dysfunction at 13 U.S. sites. RESULTS: Between February 2015 and December 2017, 31 patients were enrolled (median age 74.5 years [interquartile range (IQR): 71.3 to 81.0 years], 71% women, median Society of Thoracic Surgeons score 6.3% [IQR: 5.0% to 8.8%], 87.1% in New York Heart Association functional class III or IV). Access was transatrial (48.4%), transseptal (48.4%), or transapical (3.2%). Technical success was 74.2%. Left ventricular outflow tract obstruction (LVOTO) with hemodynamic compromise occurred in 3 patients (transatrial, n = 1; transseptal, n = 1; transapical, n = 1). After LVOTO occurred in the first 2 patients, pre-emptive alcohol septal ablation was implemented to decrease risk in high-risk patients. No intraprocedural deaths or conversions to open heart surgery occurred during the index procedures. All-cause mortality at 30 days was 16.7% (transatrial, 21.4%; transseptal, 6.7%; transapical, 100% [n = 1]; p = 0.33) and at 1 year was 34.5% (transatrial, 38.5%; transseptal, 26.7%; p = 0.69). At 1-year follow-up, 83.3% of patients were in New York Heart Association functional class I or II, the median mean mitral valve gradient was 6.1 mm Hg (IQR: 5.6 to 7.1 mm Hg), and all patients had ≤1+ mitral regurgitation. CONCLUSIONS: At 1 year, ViMAC was associated with symptom improvement and stable transcatheter heart valve performance. Pre-emptive alcohol septal ablation may prevent transcatheter mitral valve replacement-induced LVOTO in patients at risk. Thirty-day mortality of patients treated via transseptal access was lower than predicted by the Society of Thoracic Surgeons score. Further studies are needed to evaluate safety and efficacy of ViMAC

    The First Post-Kepler Brightness Dips of KIC 8462852

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    We present a photometric detection of the first brightness dips of the unique variable star KIC 8462852 since the end of the Kepler space mission in 2013 May. Our regular photometric surveillance started in 2015 October, and a sequence of dipping began in 2017 May continuing on through the end of 2017, when the star was no longer visible from Earth. We distinguish four main 1%-2.5% dips, named Elsie, Celeste, Skara Brae, and Angkor, which persist on timescales from several days to weeks. Our main results so far are as follows: (i) there are no apparent changes of the stellar spectrum or polarization during the dips and (ii) the multiband photometry of the dips shows differential reddening favoring non-gray extinction. Therefore, our data are inconsistent with dip models that invoke optically thick material, but rather they are in-line with predictions for an occulter consisting primarily of ordinary dust, where much of the material must be optically thin with a size scale ≪1 μm, and may also be consistent with models invoking variations intrinsic to the stellar photosphere. Notably, our data do not place constraints on the color of the longer-term secular dimming, which may be caused by independent processes, or probe different regimes of a single process

    Avoiding Coral Reef Functional Collapse Requires Local and Global Action

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    oral reefs face multiple anthropogenic threats, from pollution and overfishing to the dual effects of greenhouse gas emissions: rising sea temperature and ocean acidification [1]. While the abundance of coral has declined in recent decades [2, 3], the implications for humanity are difficult to quantify because they depend on ecosystem function rather than the corals themselves. Most reef functions and ecosystem services are founded on the ability of reefs to maintain their three-dimensional structure through net carbonate accumulation [4]. Coral growth only constitutes part of a reef's carbonate budget; bioerosion processes are influential in determining the balance between net structural growth and disintegration [5, 6]. Here, we combine ecological models with carbonate budgets and drive the dynamics of Caribbean reefs with the latest generation of climate models. Budget reconstructions using documented ecological perturbations drive shallow (6-10 m) Caribbean forereefs toward an increasingly fragile carbonate balance. We then projected carbonate budgets toward 2080 and contrasted the benefits of local conservation and global action on climate change. Local management of fisheries (specifically, no-take marine reserves) and the watershed can delay reef loss by at least a decade under "business-as-usual" rises in greenhouse gas emissions. However, local action must be combined with a low-carbon economy to prevent degradation of reef structures and associated ecosystem services

    Tamoxifen and risk of contralateral breast cancer for BRCA1 and BRCA2 mutation carriers

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    Purpose To determine whether adjuvant tamoxifen treatment for breast cancer (BC) is associated with reduced contralateral breast cancer (CBC) risk for BRCA1 and/or BRCA2 mutation carriers. Methods Analysis of pooled observational cohort data, self-reported at enrollment and at follow-up from the International BRCA1, and BRCA2 Carrier Cohort Study, Kathleen Cuningham Foundation Consortium for Research into Familial Breast Cancer, and Breast Cancer Family Registry. Eligible women were BRCA1 and BRCA2 mutation carriers diagnosed with unilateral BC since 1970 and no other invasive cancer or tamoxifen use before first BC. Hazard ratios (HRs) for CBC associated with tamoxifen use were estimated using Cox regression, adjusting for year and age of diagnosis, country, and bilateral oophorectomy and censoring at contralateral mastectomy, death, or loss to follow-up. Results Of 1,583 BRCA1 and 881 BRCA2 mutation carriers, 383 (24%) and 454 (52%), respectively, took tamoxifen after first BC d
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