308 research outputs found
Glacier retreat and the value of ecosystem services associated with water resources in the Paron basin-Huascaran National Park (Cordillera Blanca), 2009-2018
[Español] Los glaciares tropicales son indicadores sensibles del cambio climático. La pérdida del volumen de los glaciares tropicales en la cuenca Parón (Cordillera Blanca, Perú) es una muestra de esto a nivel global y se espera que tales cambios afecten a los servicios ecosistémicos que son únicos e insustituibles. Este estudio estimó el valor económico de los servicios ecosistémicos asociados con el recurso hídrico impactados por el retroceso glaciar en la cuenca de Parón-Parque Nacional Huascarán (Cordillera Blanca, Perú) entre los años 2009 y 2018. La metodología inició cartografiando los glaciares de 2009 a 2018 usando imágenes satelitales de alta resolución tomadas en temporada seca. Luego, se reconstruyeron las superficies 3D de los mismos usando la herramienta GLABTOP permitiendo calcular el volumen. Con los datos obtenidos se calculó el valor del servicio ecosistémico del turismo y recreación, y provisión de flujo hídrico. Los resultados indican que los glaciares de la cuenca Parón se han reducción de ~1.82% del área glaciar y en una tasa de deglaciación máxima de 0.08 (km2/año). Los resultados de la reconstrucción 3D muestran un 1.8% más de espesores entre los 40 y 60 m, con una pérdida de hielo de 1.02 km3, a una tasa máxima de 0.14 km3/año. Los valores monetarios presentes de los servicios de 2009 a 2018 se estimaron en 3 213 258.21 para el servicio de provisión de flujo hídricos, calculados a 8% de tasa de descuento. Por lo tanto, se recomienda que se debe incrementar la inversión en programas sobre la red hídrica de la cuenca de Parón, como mayores servicios, usos poblacionales o industriales.[English] Tropical glaciers are sensitive indicators of climate change. The loss of the volume of tropical glaciers in the Paron basin (Cordillera Blanca, Peru), is an example of this at a global level and these changes are expected to affect ecosystem services that are unique and irreplaceable. This study estimated the economic value of ecosystem services associated with water resources impacted by glacial retreat in the Paron basin - Huascaran National Park (Cordillera Blanca, Peru) between the years 2009 and 2018. The methodology started by mapping glaciers from 2009 to 2018 using high-resolution satellite images taken during the dry season. Then, the 3D surfaces of the glaciers were reconstructed using the GLABTOP tool to calculate the volume. With the data obtained, the value of the Tourism and Recreation ecosystem service, provision of Water Flow, was calculated. The results indicate that the glaciers of the Paron basin have been reduced by ~1.82% of the glacial area and at a maximum deglaciation rate of 0.08 (km2/year). The results of the 3D reconstruction show 1.8% more thickness between 40 and 60 m with an ice loss of 1.02 km3, at a maximum rate of 0.14 km3/year. The present monetary values of the services from 2009 to 2018 were estimated at 3 213 258.21 for the water flow provision service, calculated at 8% discount rate. Therefore, it is recommended that investment in programs on the Paron watershed water network, such as increased services, population or industrial use, should be increased
Retroceso glaciar y el valor de los servicios ecosistémicos asociados con el recurso hídrico en la cuenca Parón-Parque Nacional Huascarán (Cordillera Blanca), 2009-2018
[Español] Los glaciares tropicales son indicadores sensibles del cambio climático. La pérdida del volumen de los glaciares tropicales en la cuenca Parón (Cordillera Blanca, Perú) es una muestra de esto a nivel global y se espera que tales cambios afecten a los servicios ecosistémicos que son únicos e insustituibles. Este estudio estimó el valor económico de los servicios ecosistémicos asociados con el recurso hídrico impactados por el retroceso glaciar en la cuenca de Parón-Parque Nacional Huascarán (Cordillera Blanca, Perú) entre los años 2009 y 2018. La metodología inició cartografiando los glaciares de 2009 a 2018 usando imágenes satelitales de alta resolución tomadas en temporada seca. Luego, se reconstruyeron las superficies 3D de los mismos usando la herramienta GLABTOP permitiendo calcular el volumen. Con los datos obtenidos se calculó el valor del servicio ecosistémico del turismo y recreación, y provisión de flujo hídrico. Los resultados indican que los glaciares de la cuenca Parón se han reducción de ~1.82% del área glaciar y en una tasa de deglaciación máxima de 0.08 (km2/año). Los resultados de la reconstrucción 3D muestran un 1.8% más de espesores entre los 40 y 60 m, con una pérdida de hielo de 1.02 km3, a una tasa máxima de 0.14 km3/año. Los valores monetarios presentes de los servicios de 2009 a 2018 se estimaron en 3 213 258.21 para el servicio de provisión de flujo hídricos, calculados a 8% de tasa de descuento. Por lo tanto, se recomienda que se debe incrementar la inversión en programas sobre la red hídrica de la cuenca de Parón, como mayores servicios, usos poblacionales o industriales.[English] Tropical glaciers are sensitive indicators of climate change. The loss of the volume of tropical glaciers in the Paron basin (Cordillera Blanca, Peru), is an example of this at a global level and these changes are expected to affect ecosystem services that are unique and irreplaceable. This study estimated the economic value of ecosystem services associated with water resources impacted by glacial retreat in the Paron basin - Huascaran National Park (Cordillera Blanca, Peru) between the years 2009 and 2018. The methodology started by mapping glaciers from 2009 to 2018 using high-resolution satellite images taken during the dry season. Then, the 3D surfaces of the glaciers were reconstructed using the GLABTOP tool to calculate the volume. With the data obtained, the value of the Tourism and Recreation ecosystem service, provision of Water Flow, was calculated. The results indicate that the glaciers of the Paron basin have been reduced by ~1.82% of the glacial area and at a maximum deglaciation rate of 0.08 (km2/year). The results of the 3D reconstruction show 1.8% more thickness between 40 and 60 m with an ice loss of 1.02 km3, at a maximum rate of 0.14 km3/year. The present monetary values of the services from 2009 to 2018 were estimated at 3 213 258.21 for the water flow provision service, calculated at 8% discount rate. Therefore, it is recommended that investment in programs on the Paron watershed water network, such as increased services, population or industrial use, should be increased
The clinical features of the piriformis syndrome: a systematic review
Piriformis syndrome, sciatica caused by compression of the sciatic nerve by the piriformis muscle, has been described for over 70 years; yet, it remains controversial. The literature consists mainly of case series and narrative reviews. The objectives of the study were: first, to make the best use of existing evidence to estimate the frequencies of clinical features in patients reported to have PS; second, to identify future research questions. A systematic review was conducted of any study type that reported extractable data relevant to diagnosis. The search included all studies up to 1 March 2008 in four databases: AMED, CINAHL, Embase and Medline. Screening, data extraction and analysis were all performed independently by two reviewers. A total of 55 studies were included: 51 individual and 3 aggregated data studies, and 1 combined study. The most common features found were: buttock pain, external tenderness over the greater sciatic notch, aggravation of the pain through sitting and augmentation of the pain with manoeuvres that increase piriformis muscle tension. Future research could start with comparing the frequencies of these features in sciatica patients with and without disc herniation or spinal stenosis
Comment on "The extent of forest in dryland biomes"
Bastin et al (Reports, 12 May 2017, p. 635) infer forest as more globally extensive than previously estimated using tree cover data. However, their forest definition does not reflect ecosystem function or biotic composition. These structural and climatic definitions inflate forest estimates across the tropics and undermine conservation goals, leading to inappropriate management policies and practices in tropical grassy ecosystems
Leishmania amazonensis Arginase Compartmentalization in the Glycosome Is Important for Parasite Infectivity
In Leishmania, de novo polyamine synthesis is initiated by the cleavage of L-arginine to urea and L-ornithine by the action of arginase (ARG, E.C. 3.5.3.1). Previous studies in L. major and L. mexicana showed that ARG is essential for in vitro growth in the absence of polyamines and needed for full infectivity in animal infections. The ARG protein is normally found within the parasite glycosome, and here we examined whether this localization is required for survival and infectivity. First, the localization of L. amazonensis ARG in the glycosome was confirmed in both the promastigote and amastigote stages. As in other species, arg− L. amazonensis required putrescine for growth and presented an attenuated infectivity. Restoration of a wild type ARG to the arg− mutant restored ARG expression, growth and infectivity. In contrast, restoration of a cytosol-targeted ARG lacking the glycosomal SKL targeting sequence (argΔSKL) restored growth but failed to restore infectivity. Further study showed that the ARGΔSKL protein was found in the cytosol as expected, but at very low levels. Our results indicate that the proper compartmentalization of L. amazonensis arginase in the glycosome is important for enzyme activity and optimal infectivity. Our conjecture is that parasite arginase participates in a complex equilibrium that defines the fate of L-arginine and that its proper subcellular location may be essential for this physiological orchestration
Validação de variáveis de declarações de óbito por causas externas, Recife, PE, Brasil
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
SummaryBackground 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
Antimicrobial resistance among migrants in Europe: a systematic review and meta-analysis
BACKGROUND: Rates of antimicrobial resistance (AMR) are rising globally and there is concern that increased migration is contributing to the burden of antibiotic resistance in Europe. However, the effect of migration on the burden of AMR in Europe has not yet been comprehensively examined. Therefore, we did a systematic review and meta-analysis to identify and synthesise data for AMR carriage or infection in migrants to Europe to examine differences in patterns of AMR across migrant groups and in different settings. METHODS: For this systematic review and meta-analysis, we searched MEDLINE, Embase, PubMed, and Scopus with no language restrictions from Jan 1, 2000, to Jan 18, 2017, for primary data from observational studies reporting antibacterial resistance in common bacterial pathogens among migrants to 21 European Union-15 and European Economic Area countries. To be eligible for inclusion, studies had to report data on carriage or infection with laboratory-confirmed antibiotic-resistant organisms in migrant populations. We extracted data from eligible studies and assessed quality using piloted, standardised forms. We did not examine drug resistance in tuberculosis and excluded articles solely reporting on this parameter. We also excluded articles in which migrant status was determined by ethnicity, country of birth of participants' parents, or was not defined, and articles in which data were not disaggregated by migrant status. Outcomes were carriage of or infection with antibiotic-resistant organisms. We used random-effects models to calculate the pooled prevalence of each outcome. The study protocol is registered with PROSPERO, number CRD42016043681. FINDINGS: We identified 2274 articles, of which 23 observational studies reporting on antibiotic resistance in 2319 migrants were included. The pooled prevalence of any AMR carriage or AMR infection in migrants was 25·4% (95% CI 19·1-31·8; I2 =98%), including meticillin-resistant Staphylococcus aureus (7·8%, 4·8-10·7; I2 =92%) and antibiotic-resistant Gram-negative bacteria (27·2%, 17·6-36·8; I2 =94%). The pooled prevalence of any AMR carriage or infection was higher in refugees and asylum seekers (33·0%, 18·3-47·6; I2 =98%) than in other migrant groups (6·6%, 1·8-11·3; I2 =92%). The pooled prevalence of antibiotic-resistant organisms was slightly higher in high-migrant community settings (33·1%, 11·1-55·1; I2 =96%) than in migrants in hospitals (24·3%, 16·1-32·6; I2 =98%). We did not find evidence of high rates of transmission of AMR from migrant to host populations. INTERPRETATION: Migrants are exposed to conditions favouring the emergence of drug resistance during transit and in host countries in Europe. Increased antibiotic resistance among refugees and asylum seekers and in high-migrant community settings (such as refugee camps and detention facilities) highlights the need for improved living conditions, access to health care, and initiatives to facilitate detection of and appropriate high-quality treatment for antibiotic-resistant infections during transit and in host countries. Protocols for the prevention and control of infection and for antibiotic surveillance need to be integrated in all aspects of health care, which should be accessible for all migrant groups, and should target determinants of AMR before, during, and after migration. FUNDING: UK National Institute for Health Research Imperial Biomedical Research Centre, Imperial College Healthcare Charity, the Wellcome Trust, and UK National Institute for Health Research Health Protection Research Unit in Healthcare-associated Infections and Antimictobial Resistance at Imperial College London
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