325 research outputs found

    Comparison of two non-primitive methods for path integral simulations: Higher-order corrections vs. an effective propagator approach

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    Two methods are compared that are used in path integral simulations. Both methods aim to achieve faster convergence to the quantum limit than the so-called primitive algorithm (PA). One method, originally proposed by Takahashi and Imada, is based on a higher-order approximation (HOA) of the quantum mechanical density operator. The other method is based upon an effective propagator (EPr). This propagator is constructed such that it produces correctly one and two-particle imaginary time correlation functions in the limit of small densities even for finite Trotter numbers P. We discuss the conceptual differences between both methods and compare the convergence rate of both approaches. While the HOA method converges faster than the EPr approach, EPr gives surprisingly good estimates of thermal quantities already for P = 1. Despite a significant improvement with respect to PA, neither HOA nor EPr overcomes the need to increase P linearly with inverse temperature. We also derive the proper estimator for radial distribution functions for HOA based path integral simulations.Comment: 17 pages, latex, 6 postscript figure

    Quantitation and localization of ENaC subunit expression in fetal, newborn, and adult mouse lung

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    The newborn lung is cleared of fetal liquid by active Na+ transport. The heterotrimeric (α, β, γ) epithelial Na+ channel, ENaC, mediates this process. To understand the role of individual ENaC subunits in Na+ transport during development, we quantified murine ENaC (mENaC) subunit messenger RNA (mRNA) expression levels of fetal, neonatal, and adult mouse lung by Northern blot analysis and studied regional expression by in situ hybridization. αmENaC and γmENaC mRNA expression increased sharply in late fetal gestation and reached near-adult levels by Day 1 of postnatal life. βmENaC expression increased more gradually through late fetal and early postnatal life and increased progressively until adulthood. In situ hybridization studies showed similar localization patterns of αmENaC and γmENaC subunit expression in fetal and postnatal lung. γmENaC and αmENaC subunits were initially localized to fetal lung bud tubules and by late gestation both subunits were expressed in all regions (acinar and bronchiolar) of the distal lung epithelium. βmENaC was detected from 16 d gestation onward and was expressed most intensely in small airways. There was little expression of βmENaC in the alveolar region. In postnatal lung all three subunits were expressed intensely in small airways. In adult lung, αmENaC and γmENaC were expressed in a pattern consistent with an alveolar type II (ATII) cell distribution. The timing of quantitative changes in mENaC subunit expression is consistent with a role of Na+ transport in liquid clearance of the perinatal lung. Intense expression of mENaC subunits in medium and small airway epithelium and in ATII cells suggests that these regions are a primary location for liquid absorption in the perinatal and post-natal murine lung

    Using PROGRESS-Plus to identify current approaches to the collection and reporting of equity-relevant data: a scoping review

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    Objectives: Our objectives were to identify what and how data relating to the social determinants of health are collected and reported in equity-relevant studies and map these data to the PROGRESS-Plus framework. Study Design and Setting: We performed a scoping review. We ran two systematic searches of MEDLINE and Embase for equityrelevant studies published during 2021. We included studies in any language without limitations to participant characteristics. Included studies were required to have collected and reported at least two participant variables relevant to evaluating individual-level social determinants of health. We applied the PROGRESS-Plus framework to identify and organize these data. Results: We extracted data from 200 equity-relevant studies, providing 962 items defined by PROGRESS-Plus. A median of 4 (interquartile range 5 2) PROGRESS-Plus items were reported in the included studies. 92% of studies reported age; 78% reported sex/gender; 65% reported educational attainment; 49% reported socioeconomic status; 45% reported race; 44% reported social capital; 33% reported occupation; 14% reported place and 9% reported religion. Conclusion: Our synthesis demonstrated that researchers currently collect a limited range of equity-relevant data, but usefully provides a range of examples spanning PROGRESS-Plus to inform the development of improved, standardized practices.Emma L. Karrana, Aidan G. Cashina, Trevor Barker, Mark A. Boyd, Alessandro Chiarotto, Omar Dewidar, Vina Mohabir, Jennifer Petkovic Saurab Sharma, Sinan Tejani, Peter Tugwell, G. Lorimer Mosele

    A review of the ecological value of Cusuco National Park an urgent call forconservation action in a highly threatened Mesoamerican cloud forest

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    Cloud forests are amongst the most biologically unique, yet threatened, ecosystems in Mesoamerica. We summarize the ecological value and conservation status of a well-studied cloud forest site: Cusuco National Park (CNP), a 23,440 ha protected area in the Merendón mountains, northwest Honduras. We show CNP to have exceptional biodiversity; of 966 taxa identified to a species-level to date, 362 (37.5%) are Mesoamerican endemics, 67 are red-listed by the IUCN, and at least 49 are micro-endemics known only from the Merendón range. CNP also provides key ecosystem services including provision of drinking water and downstream flood mitigation, as well as carbon sequestration, with an estimated stock of 3.5 million megagrams of carbon in 2000. Despite its ecological importance, CNP faces multiple environmental threats and associated stresses, including deforestation (1,759 ha since 2000 equating to 7% of total forest area), poaching (7% loss of mammal relative abundance per year), amphibian declines due to chytridiomycosis (70% of species threatened or near-threatened), and climate change (a mean 2.6 °C increase in temperature and 112 mm decrease in rainfall by 2100). Despite conservation actions, including community ranger patrols, captive-breeding programmes, and ecotourism initiatives, environmental degradation of CNP continues. Further action is urgently required, including reinforcement and expansion of ranger programmes, greater stakeholder engagement, community education programmes, development of alternative livelihood projects, and legislative enforcement and prosecution. Without a thorough and rapid response to understand and mitigate illegal activities, the extirpation and extinction of species and the loss of vital ecosystem services are inevitable in the coming decades

    Public expectations of critical infrastructure operators in times of crisis

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    Maintaining a minimum level of service and recovering quickly after a shock are key components of critical infrastructure (CI) resilience. Nevertheless, recent literature indicates that there is an ‘expectation gap’ in relation to the services CI operators should provide to members of the public in the immediate aftermath of a disaster. However, few of these studies have empirically investigated what members of the public expect. As such, this paper explores this under-researched area by drawing on key themes that emerged from a literature review, results from an online questionnaire-based study (N = 403), and analysis of 22 semi-structured interviews with CI operators and other relevant stakeholders. Results indicate that the public appear willing to tolerate reductions in service during crisis. The public also expect CI operators to keep them informed about progress to restore these services and answer direct queries via both traditional and social media. Based on these findings, resilience recommendations are presented

    Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study

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    A41 Use of SMS texts for facilitating access to online alcohol interventions: a feasibility study In: Addiction Science & Clinical Practice 2017, 12(Suppl 1): A4

    Psychology and aggression

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/68264/2/10.1177_002200275900300301.pd

    Deficiências minerais em plantas de bertalha ( Basella alba, L.)

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    Basella alba is used as a major food on the Amazon region, north Brazil for its high mineral and vitamins content. The purpose of the present work was: a) obtain a clear picture of the macronutrient deficiency; b) growth of the plants in function of (1); c) analyptical levels found in the leaves. Young Basella alba plants (bertalha in Portuguese) were cultivated in pots containing fine pure quartz and irrigated by percolation with different nutrient solutions lacking one of the element at the time. Clear cut symptoms were obtained for all macronutrients. Only the omission of nitrogen and potassium affect the dry matter production of plants. The range in dry matter for unhealthy and healthy leaves were: N% = 1.25--3-55; P% = 0.17-0.36; K% = 0.46-3.55; Ca% = 0,62-1.78; Mg% = 0.37-0.80; S% = 0.19-0.13.Plantas de bertalha (Basella alba, L.) INPA-1 foram cultivadas em casa de vegetação em quartzo moído, irrigadas com soluções nutritivas conforme SARRUGE (1975) e submetidas aos seguintes tratamentos: completo, omissão de N, omissão de P, omissão de K, omissão de Ca, omissão de Mg e omissão de S, com o objetivo de: (a) obter sintomas de deficiência dos ma cronutrientes; (b) analisar o crescimento das plantas através da produção de matéria seca; (c) determinar a concentração dos macronutrientes nas folhas e caules das plantas cultivadas nos diversos tratamentos. Os sintomas visuais de deficiência foram identificados e descritos. As plantas foram coletadas e separadas em raiz, caule, folhas e determinaram-se os teores dos macronutrientes minerais neste material. Os resultados obtidos mostram: - os sintomas visuais de deficiência são bem definidos e de fácil caracterização para todos os nutrientes; - só foi possível detectar efeito na produção de matéria seca das folhas e caules para omissão de nitrogênio e para omissão de potássio nos caules; - os níveis de deficiência e adequação obtidos nas folhas foram respectivamente: N% = 1,25 e 2,63; P% = 0,17 e 0,36; K% = 0,46 e 3,55; Ca% = 0,62e 1,78; Mg% = 0,37 e 0,80; s%= 0,19 e 0,23. - os níveis de deficiência e adequação obtidos nos caules foram respectivamente: N% = 0,67 e 0,98; P% = 0,13 e 0,31; K% = 0,73 e 2,67; Ca% = 0,11 e 0,64; Mg% = 0,08 e 0,20; S% = 0,15 e 0,20

    Global, regional, and national comparative risk assessment of 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks, 1990-2015: A systematic analysis for the Global Burden of Disease Study 2015

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    Background: The Global Burden of Diseases, Injuries, and Risk Factors Study 2015 provides an up-to-date synthesis of the evidence for risk factor exposure and the attributable burden of disease. By providing national and subnational assessments spanning the past 25 years, this study can inform debates on the importance of addressing risks in context. Methods: We used the comparative risk assessment framework developed for previous iterations of the Global Burden of Disease Study to estimate attributable deaths, disability-adjusted life-years (DALYs), and trends in exposure by age group, sex, year, and geography for 79 behavioural, environmental and occupational, and metabolic risks or clusters of risks from 1990 to 2015. This study included 388 risk-outcome pairs that met World Cancer Research Fund-defined criteria for convincing or probable evidence. We extracted relative risk and exposure estimates from randomised controlled trials, cohorts, pooled cohorts, household surveys, census data, satellite data, and other sources. We used statistical models to pool data, adjust for bias, and incorporate covariates. We developed a metric that allows comparisons of exposure across risk factors—the summary exposure value. Using the counterfactual scenario of theoretical minimum risk level, we estimated the portion of deaths and DALYs that could be attributed to a given risk. We decomposed trends in attributable burden into contributions from population growth, population age structure, risk exposure, and risk-deleted cause-specific DALY rates. We characterised risk exposure in relation to a Socio-demographic Index (SDI). Findings: Between 1990 and 2015, global exposure to unsafe sanitation, household air pollution, childhood underweight, childhood stunting, and smoking each decreased by more than 25%. Global exposure for several occupational risks, high body-mass index (BMI), and drug use increased by more than 25% over the same period. All risks jointly evaluated in 2015 accounted for 57·8% (95% CI 56·6–58·8) of global deaths and 41·2% (39·8–42·8) of DALYs. In 2015, the ten largest contributors to global DALYs among Level 3 risks were high systolic blood pressure (211·8 million [192·7 million to 231·1 million] global DALYs), smoking (148·6 million [134·2 million to 163·1 million]), high fasting plasma glucose (143·1 million [125·1 million to 163·5 million]), high BMI (120·1 million [83·8 million to 158·4 million]), childhood undernutrition (113·3 million [103·9 million to 123·4 million]), ambient particulate matter (103·1 million [90·8 million to 115·1 million]), high total cholesterol (88·7 million [74·6 million to 105·7 million]), household air pollution (85·6 million [66·7 million to 106·1 million]), alcohol use (85·0 million [77·2 million to 93·0 million]), and diets high in sodium (83·0 million [49·3 million to 127·5 million]). From 1990 to 2015, attributable DALYs declined for micronutrient deficiencies, childhood undernutrition, unsafe sanitation and water, and household air pollution; reductions in risk-deleted DALY rates rather than reductions in exposure drove these declines. Rising exposure contributed to notable increases in attributable DALYs from high BMI, high fasting plasma glucose, occupational carcinogens, and drug use. Environmental risks and childhood undernutrition declined steadily with SDI; low physical activity, high BMI, and high fasting plasma glucose increased with SDI. In 119 countries, metabolic risks, such as high BMI and fasting plasma glucose, contributed the most attributable DALYs in 2015. Regionally, smoking still ranked among the leading five risk factors for attributable DALYs in 109 countries; childhood underweight and unsafe sex remained primary drivers of early death and disability in much of sub-Saharan Africa. Interpretation: Declines in some key environmental risks have contributed to declines in critical infectious diseases. Some risks appear to be invariant to SDI. Increasing risks, including high BMI, high fasting plasma glucose, drug use, and some occupational exposures, contribute to rising burden from some conditions, but also provide opportunities for intervention. Some highly preventable risks, such as smoking, remain major causes of attributable DALYs, even as exposure is declining. Public policy makers need to pay attention to the risks that are increasingly major contributors to global burden. Funding: Bill & Melinda Gates Foundation
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