2,612 research outputs found

    Cost-effectiveness of diagnostic laparoscopy for assessing resectability in pancreatic and periampullary cancer.

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    Surgical resection is the only curative treatment for pancreatic and periampullary cancer, but many patients undergo unnecessary laparotomy because tumours can be understaged by computerised tomography (CT). A recent Cochrane review found diagnostic laparoscopy can decrease unnecessary laparotomy. We compared the cost-effectiveness of diagnostic laparoscopy prior to laparotomy versus direct laparotomy in patients with pancreatic and periampullary cancer with resectable disease based on CT scanning

    Cost-Effectiveness Analysis of Endoscopic Ultrasound versus Magnetic Resonance Cholangiopancreatography in Patients with Suspected Common Bile Duct Stones.

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    Patients with suspected common bile duct (CBD) stones are often diagnosed using endoscopic retrograde cholangiopancreatography (ERCP), an invasive procedure with risk of significant complications. Using endoscopic ultrasound (EUS) or Magnetic Resonance CholangioPancreatography (MRCP) first to detect CBD stones can reduce the risk of unnecessary procedures, cut complications and may save costs

    Agroecology and Climate Change Resilience: In Smallholder Coffee Agroecosystems of Central America

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    Arabica coffee production provides the principal source of monetary income for many smallholder households throughout the mountainous regions of Central America. Coffee agroecosystems serve several functions, which can include supporting livelihoods, and providing ecosystem services (e.g. carbon sequestration), and conserving biodiversity (De Beenhouwer et al., 2013; Valencia et al., 2014). For these reasons, coffee farming plays a key synergistic role in socioeconomic and ecological resilience. Despite these synergies, the livelihoods of Central American smallholder coffee farmers are in a precarious state due to their exposure and sensitivity to common stressors and shocks, including the seasonality of incomes, volatile commodity prices and natural disasters (Jha et al., 2014). This vulnerability makes it extremely difficult for growers to maintain (let alone build) their assets and capabilities, and to embark on pathways out of poverty

    Cost-effectiveness of laparoscopic versus open distal pancreatectomy for pancreatic cancer

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    BACKGROUND: A recent Cochrane review compared laparoscopic versus open distal pancreatectomy for people with for cancers of the body and tail of the pancreas and found that laparoscopic distal pancreatectomy may reduce the length of hospital stay. We compared the cost-effectiveness of laparoscopic distal pancreatectomy versus open distal pancreatectomy for pancreatic cancer. METHOD: Model based cost-utility analysis estimating mean costs and quality-adjusted life years (QALYs) per patient from the perspective of the UK National Health Service. A decision tree model was constructed using probabilities, outcomes and cost data from published sources. A time horizon of 5 years was used. One-way and probabilistic sensitivity analyses were undertaken. RESULTS: The probabilistic sensitivity analysis showed that the incremental net monetary benefit was positive (£3,708.58 (95% confidence intervals (CI) -£9,473.62 to £16,115.69) but the 95% CI includes zero, indicating that there is significant uncertainty about the cost-effectiveness of laparoscopic distal pancreatectomy versus open distal pancreatectomy. The probability laparoscopic distal pancreatectomy was cost-effective compared to open distal pancreatectomy for pancreatic cancer was between 70% and 80% at the willingness-to-pay thresholds generally used in England (£20,000 to £30,000 per QALY gained). Results were sensitive to the survival proportions and the operating time. CONCLUSIONS: There is considerable uncertainty about whether laparoscopic distal pancreatectomy is cost-effective compared to open distal pancreatectomy for pancreatic cancer in the NHS setting

    Wormhole Cosmic Censorship

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    We analyze the properties of a Kerr-like wormhole supported by phantom matter, which is an exact solution of the Einstein-phantom field equations. It is shown that the solution has a naked ring singularity which is unreachable to null geodesics falling freely from the outside. Similarly to Roger Penrose's cosmic censorship, that states that all naked singularities in the Universe must be protected by event horizons, here we conjecture from our results that a naked singularity can also be fully protected by the intrinsic properties of a wormhole's throat

    Cost-effectiveness of preoperative biliary drainage for obstructive jaundice in pancreatic and periampullary cancer.

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    A recent Cochrane Review found that preoperative biliary drainage (PBD) in patients with resectable pancreatic and periampullary cancer undergoing surgery for obstructive jaundice is associated with similar mortality but increased serious morbidity compared with no PBD. Despite this clinical evidence of its lack of effectiveness, PBD is still in use. We considered the economic implications of PBD versus direct surgery for obstructive jaundice in patients with pancreatic and periampullary cancer

    Chromosomal disorders:estimating baseline birth prevalence and pregnancy outcomes worldwide

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    Chromosomal disorders, of which Down syndrome is the most common, can cause multi-domain disability. In addition, compared to the general population, there is a higher frequency of death before the age of five. In many settings, large gaps in data availability have hampered policy-making, programme priorities and resource allocation for these important conditions. We have developed methods, which overcome this lack of data and allow estimation of the burden of affected pregnancies and their outcomes in different settings worldwide. For example, the methods include a simple equation relating the percentage of mothers 35 and over to Down syndrome birth prevalence. The results obtained provide a starting point for consideration of services that can be implemented for the care and prevention of these disorders

    Graphene Bilayer Field-Effect Phototransistor for Terahertz and Infrared Detection

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    A graphene bilayer phototransistor (GBL-PT) is proposed and analyzed. The GBL-PT under consideration has the structure of a field-effect transistor with a GBL as the channel and the back and top gates. The positive bias of the back gate results in the formation of conducting source and drain sections in the channel, while the negatively biased top gate provides the potential barrier which is controlled by the charge of the photogenerated holes. The features of the GBL-PT operation are associated with the variations of both the potential distribution and the energy gap in different sections of the channel when the gate voltages and the charge in the barrier section change. Using the developed GBL-PT device model, the spectral characteristics, dark current, responsivity and detectivity are calculated as functions of the applied voltages, energy of incident photons, intensity of electron and hole scattering, and geometrical parameters. It is shown that the GBL-PT spectral characteristics are voltage tuned. The GBL-PT performance as photodetector in the terahertz and infrared photodetectors can markedly exceed the performance of other photodetectors.Comment: 7 Pages, 7 figure

    Impacts of anthropogenic climate change on tropical montane forests: an appraisal of the evidence

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    This is the final version. Available from Wiley via the DOI in this record. In spite of their small global area and restricted distributions, tropical montane forests (TMFs) are biodiversity hotspots and important ecosystem services providers, but are also highly vulnerable to climate change. To protect and preserve these ecosystems better, it is crucial to inform the design and implementation of conservation policies with the best available scientific evidence, and to identify knowledge gaps and future research needs. We conducted a systematic review and an appraisal of evidence quality to assess the impacts of climate change on TMFs. We identified several skews and shortcomings. Experimental study designs with controls and long-term (≥10 years) data sets provide the most reliable evidence, but were rare and gave an incomplete understanding of climate change impacts on TMFs. Most studies were based on predictive modelling approaches, short-term (<10 years) and cross-sectional study designs. Although these methods provide moderate to circumstantial evidence, they can advance our understanding on climate change effects. Current evidence suggests that increasing temperatures and rising cloud levels have caused distributional shifts (mainly upslope) of montane biota, leading to alterations in biodiversity and ecological functions. Neotropical TMFs were the best studied, thus the knowledge derived there can serve as a proxy for climate change responses in under-studied regions elsewhere. Most studies focused on vascular plants, birds, amphibians and insects, with other taxonomic groups poorly represented. Most ecological studies were conducted at species or community levels, with a marked paucity of genetic studies, limiting understanding of the adaptive capacity of TMF biota. We thus highlight the long-term need to widen the methodological, thematic and geographical scope of studies on TMFs under climate change to address these uncertainties. In the short term, however, in-depth research in well-studied regions and advances in computer modelling approaches offer the most reliable sources of information for expeditious conservation action for these threatened forests.Natural Environment Research Council (NERC)Mexican National Council of Science and Technology (CONACyT)University of Southampto
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