356 research outputs found

    Nutrient and Microbial Movement from Seasonally-Used Septic Systems

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    Unanswered seasonal vacation communities present unique problems for on-site sewage disposal. Seasonal occupancy may promote the transmission of contaminants to groundwater due to incomplete formation of a biological clogging mat in the soil absorption system. Groundwater surrounding three seasonally-used septic systems was monitored to determine the movement and attenuation of nitrogen, phosphorus and two bacterial indicators of human fecal contamination, fecal coliforms and Clostridium perfringens. Nitrate-N concentrations were often three to four-fold greater than the drinking water standard at wells 6 m from the soil absorption systems. Minimal phosphorus migration occurred from these systems. Although more than 1.5 m of unsaturated soil separated the bottom of the soil absorption system from the groundwater, elevated numbers of both bacterial indicators were observed in groundwater at both 2 m and 6 m away from the absorption systems. Biological clogging mats, which are considered to be critical for even distribution of wastewater within a drainfield, were not ground when the systems were excavated at the end of summer occupancy. Siting seasonally-used shoreline septic systems may require improved effluent distribution to achieve wastewater renovation

    Intrinsic Coulomb blockade in multi-wall carbon nanotubes

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    Carbon nanotubes provide a new class of molecular wires that display new and exciting mesoscopic transport properties. We provide a detailed theoretical description for transport in multi-wall nanotubes, where both disorder and strong interactions are important. The interplay of both aspects leads to a particularly effective intrinsic Coulomb blockade for tunneling. The relation to recent experiments is discussed.Comment: 13 pages, incl 2 figs, for: Special issue "Transport in Molecular Wires" in Chemical Physics, ed. by P. Hanggi, M. Ratner, S. Yalirak

    Keeping Your Eyes Continuously on the Ball While Running for Catchable and Uncatchable Fly Balls

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    When faced with a fly ball approaching along the sagittal plane, fielders need information for the control of their running to the interception location. This information could be available in the initial part of the ball trajectory, such that the interception location can be predicted from its initial conditions. Alternatively, such predictive information is not available, and running to the interception location involves continuous visual guidance. The latter type of control would predict that fielders keep looking at the approaching ball for most of its flight, whereas the former type of control would fit with looking at the ball during the early part of the ball's flight; keeping the eyes on the ball during the remainder of its trajectory would not be necessary when the interception location can be inferred from the first part of the ball trajectory. The present contribution studied visual tracking of approaching fly balls. Participants were equipped with a mobile eye tracker. They were confronted with tennis balls approaching from about 20 m, and projected in such a way that some balls were catchable and others were not. In all situations, participants almost exclusively tracked the ball with their gaze until just before the catch or until they indicated that a ball was uncatchable. This continuous tracking of the ball, even when running close to their maximum speeds, suggests that participants employed continuous visual control rather than running to an interception location known from looking at the early part of the ball flight.</p

    When a fly ball is out of reach: catchability judgments are not based on optical acceleration cancelation.

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    The optical acceleration cancelation (OAC) strategy, based on Chapman’s (1968) analysis of the outfielder problem, has been the dominant account for the control of running to intercept fly balls approaching head on. According to the OAC strategy, outfielders will arrive at the interception location just in time to catch the ball when they keep optical acceleration zero. However, the affordance aspect of this task, that is, whether or not an approaching fly ball is catchable, is not part of this account. The present contribution examines whether the scope of the OAC strategy can be extended to also include the affordance aspect of running to catch a fly ball. This is done by considering a fielder’s action boundaries (i.e., maximum running velocity and – acceleration) in the context of the OAC strategy. From this, only when running velocity is maximal and optical acceleration is non-zero, a fielder would use OAC to perceive a fly ball as uncatchable. The present contribution puts this hypothesis to the test. Participants were required to try to intercept fly balls projected along their sagittal plane. Some fly balls were catchable whereas others were not. Participants were required to catch as many fly balls as possible and to call ‘no’ when they perceived a fly ball to be uncatchable. Participants’ running velocity and –acceleration at the moment of calling ‘no’ were examined. Results showed that participants’ running velocity was submaximal before or while calling ‘no’. Also running acceleration was often submaximal. These results cannot be explained by the use of OAC in judging catchability and ultimately call for a new strategy of locomotor control in running to catch a fly ball

    Cost-Effectiveness of Nintedanib for Patients with Progressive Fibrosing Interstitial Lung Disease (PF-ILD)

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    Objectives Progressive fibrosing interstitial lung disease (PF-ILD) is characterised by increased pulmonary fibrosis, lung function decline, acute exacerbations, decreased quality of life and increased mortality. Nintedanib may slow down disease progression, but long-term outcomes are unknown. We aimed to assess the cost-effectiveness of nintedanib in comparison to placebo, both on top of usual care in patients with PF-ILD. Methods An individual PF-ILD patient simulation model was created, using data and extrapolations from the nintedanib and placebo arms of the INBUILD trial. Clinical outcomes (mortality, exacerbations, lung transplants), economic outcomes (direct and indirect costs) and the cost-effectiveness of nintedanib over a 10-year time horizon were forecasted using the Netherlands as a case example. Disease progression was driven by lung function decline, with forced vital capacity (FVC) health states ranging from = 110 FVC of % predicted. Sensitivity and scenario analyses were performed to assess the impact of parameter assumptions on the cost-effectiveness and to test model robustness. Results Over a 10-year follow-up, nintedanib gained an average of 1.31 discounted life years and an average of 0.87 discounted quality-adjusted life years (QALYs), resulting in an incremental cost-effectiveness ratio (ICER) of (sic)60,690 per QALY. Sensitivity analyses showed cost variations had a minor impact on the ICER. Results were mainly driven by mortality probabilities and diseaserelated utilities. Scenario analyses indicated most sensitivity to the time horizon and lung transplantation costs. Conclusion Long-term treatment with nintedanib could result in considerable health gains for patients with PF-ILD and can be considered cost-effective under the common willingness-to-pay threshold

    Economic Evaluation of Family Planning Interventions in Low and Middle Income Countries:A Systematic Review

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    Background A significant number of women in low and middle income countries (L-MICs) who need any family planning, experience a lack in access to modern effective methods. This study was conducted to review potential cost effectiveness of scaling up family planning interventions in these regions from the published literatures and assess their implication for policy and future research. Study design A systematic review was performed in several electronic databases i.e Medline (Pubmed), Embase, Popline, The National Bureau of Economic Research (NBER), EBSCOHost, and The Cochrane Library. Articles reporting full economic evaluations of strategies to improve family planning interventions in one or more L-MICs, published between 1995 until 2015 were eligible for inclusion. Data was synthesized and analyzed using a narrative approach and the reporting quality of the included studies was assessed using the Consolidated Health Economic Evaluation Reporting Standards (CHEERS) statement. Results From 920 references screened, 9 studies were eligible for inclusion. Six references assessed cost effectiveness of improving family planning interventions in one or more LMICs, while the rest assessed costs and consequences of integrating family planning and HIV services, concerning sub-Saharan Africa. Assembled evidence suggested that improving family planning interventions is cost effective in a variety of L-MICs as measured against accepted international cost effectiveness benchmarks. In areas with high HIV prevalence, integrating family planning and HIV services can be efficient and cost effective; however the evidence is only supported by a very limited number of studies. The major drivers of cost effectiveness were cost of increasing coverage, effectiveness of the interventions and country-specific factors. Conclusion Improving family planning interventions in low and middle income countries appears to be cost-effective. Additional economic evaluation studies with improved reporting quality are necessary to generate further evidence on costs, cost-effectiveness, and affordability, and to support increased funding and investments in family planning programs

    Giant magnetoresistance of multiwall carbon nanotubes: modeling the tube/ferromagnetic-electrode burying contact

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    We report on the giant magnetoresistance (GMR) of multiwall carbon nanotubes with ultra small diameters. In particular, we consider the effect of the inter-wall interactions and the lead/nanotube coupling. Comparative studies have been performed to show that in the case when all walls are well coupled to the electrodes, the so-called inverse GMR can appear. The tendency towards a negative GMR depends on the inter-wall interaction and on the nanotube le ngth. If, however, the inner nanotubes are out of contact with one of the electrodes, the GMR remains positive even for relatively strong inter-wall interactions regardless of the outer nanotube length. These results shed additional light on recently reported experimental data, where an inverse GMR was found in some multiwall carbon nanotube samples.Comment: 5 pages, 5 figure

    Electron scattering in multi-wall carbon-nanotubes

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    We analyze two scattering mechanisms that might cause intrinsic electronic resistivity in multi-wall carbon nanotubes: scattering by dopant impurities, and scattering by inter-tube electron-electron interaction. We find that for typically doped multi-wall tubes backward scattering at dopants is by far the dominating effect.Comment: 6 pages, 2 figures, to appear in Phys. Rev.

    Language and memory for object location

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    In three experiments, we investigated the influence of two types of language on memory for object location: demonstratives (this, that) and possessives (my, your). Participants first read instructions containing demonstratives/possessives to place objects at different locations, and then had to recall those object locations (following object removal). Experiments 1 and 2 tested contrasting predictions of two possible accounts of language on object location memory: the Expectation Model (Coventry, Griffiths, & Hamilton, 2014) and the congruence account (Bonfiglioli, Finocchiaro, Gesierich, Rositani, & Vescovi, 2009). In Experiment 3, the role of attention allocation as a possible mechanism was investigated. Results across all three experiments show striking effects of language on object location memory, with the pattern of data supporting the Expectation Model. In this model, the expected location cued by language and the actual location are concatenated leading to (mis)memory for object location, consistent with models of predictive coding (Bar, 2009; Friston, 2003)

    Health economic evaluation of gene replacement therapies:Methodological issues and recommendations

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    Objective: To provide recommendations for addressing previously identified key challenges in health economic evaluations of Gene Replacement Therapies (GRTs), including: 1) the assessment of clinical effectiveness; 2) the valuation of health outcomes; 3) the time horizon and extrapolation of effects beyond trial duration; 4) the estimation of costs; 5) the selection of appropriate discount rates; 6) the incorporation of broader elements of value; and 7) affordability. Methods: A literature review on economic evaluations of GRT was performed. Interviews were conducted with 8 European and US health economic experts with experience in evaluations of GRT. Targeted literature reviews were conducted to investigate further potential solutions to specific challenges. Recommendations: Experts agreed on factors to be considered to ensure the acceptability of historical cohorts by HTA bodies. Existing prospective registries or, if not available, retrospective registries, may be used to analyse different disease trajectories and inform extrapolations. The importance of expert opinion due to limited data was acknowledged. Expert opinion should be obtained using structured elicitation techniques. Broader elements of value, beyond health gains directly related to treatment, can be considered through the application of a factor to inflate the quality-adjusted life years (QALYs) or a higher cost-effectiveness threshold. Additionally, the use of cost-benefit analysis and saved young life equivalents (SAVE) were proposed as alternatives to QALYs for the valuations of outcomes of GRT as they can incorporate broader elements of value and avoid problems of eliciting utilities for paediatric diseases. Conclusions: While some of the limitations of economic evaluations of GRT are inherent to limited clinical data and lack of experience with these treatments, others may be addressed by methodological research to be conducted by health economists
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