465 research outputs found
Effect of Different Urine Cow Nitrogen Rates and Different Moisture Conditions on Nitrogen Mineralization in an Andisol from Southern Chile
Urea present in cattle urine contributes large amounts of nitrogen (N) to grazed pastures, which can be an equivalent to approximately 1000 kg N haâ1. However, there are no studies in volcanic soils of southern Chile on the effect of different concentrations of urinary N deposited in the soil, nor of different wetting and drying conditions mimicking the variation of weather conditions on the nitrification process, from urea to NH4+ and total oxidized nitrogen (TON), throughout time. In addition, the inhibition on nitrification driven by the accumulation of NH3 at high rates of N applied to an Andisol have not been evaluated. Fresh cattle urine was applied at three different rates of N equivalent to 247 kg N haâ1 (Low N), 461 kg N haâ1 (Medium N), 921 kg N haâ1 (High N), and de-ionized water as Control. Further, three moisture conditions were imposed: constant moisture (CM), drying-rewetting (DRW) cycles at 7 days interval, and soil drying (SD). Destructive soil cores samples were evaluated for top and bottom halves individually every 7 days over a 36-d period to measure changes on inorganic N and pH. There were no interaction effects for N rates and soil moisture. The main effect of the different rates of N on mineralization was significant throughout the incubation period, while the effect of the different moisture conditions was var-iable over time. The High N was associated with elevated NH3 concentrations and could explain that total N mineralization was partially inhibited. These results suggest that the presence of different nitrifying microorganisms in the soil under different chemical and physical conditions determines nitrification, thus, the oxidation of ammonia should be studied in more detail as the first step of nitrification, specifically in volcanic soils
AnĂĄlisis geogrĂĄfico, ambiental y ecolĂłgico del Cerro de Coatepec Universidad AutĂłnoma del Estado de MĂŠxico
El libro âLos espacios universitarios como objeto de estudio. AnĂĄlisis geogrĂĄfico, ambiental y ecolĂłgico del Cerro de Coatepec, Universidad AutĂłnoma del Estado de MĂŠxicoâ, es resultado de la participaciĂłn de un grupo multidisciplinario integrado por investigadores, profesores y estudiantes de la Universidad AutĂłnoma del Estado de MĂŠxico, asĂ como del grupo de asesores y consultores del Colegio de Ciencias GeogrĂĄficas del Estado de MĂŠxico, A. C. (COCIGEM), interesados en la problemĂĄtica ambiental y ecolĂłgica que ocurre en la Ciudad Universitaria ubicada geogrĂĄficamente en el Cerro de Coatepec, Toluca Estado de MĂŠxico, en el cual se encuentran establecidas algunas edificaciones de dependencias de educaciĂłn superior, centros e institutos de investigaciĂłn, difusiĂłn cultural, dependencias administrativas, bibliotecas, museos e instalaciones deportivas.Los ejes rectores de anĂĄlisis contenidos en este volumen son siete: a) la caracterizaciĂłn geogrĂĄfica, ecolĂłgica, ambiental, sociocultural e infraestructural del espacio que comprende el Cerro de Coatepec; b) el anĂĄlisis del Cerro de Coatepec como un ecosistema urbano en el contexto de la Zona Metropolitana del Valle de Toluca, Estado de MĂŠxico; c) la multifuncionalidad de las ĂĄreas verdes, las ĂĄreas arboladas y los espacios naturales del ecosistema; d) los impactos ambientales que han ocasionado y que ocasionan las etapas de preparaciĂłn del sitio, la construcciĂłn de edificaciones y la ejecuciĂłn de actividades docentes, de investigaciĂłn, difusiĂłn, deportivas y socioculturales; e) los riesgos que ocurren y pueden ocurrir en las ĂĄreas verdes, las ĂĄreas arboladas, los ambientes naturales y la infraestructura de las edificaciones; f) la responsabilidad ambiental e importancia de la participaciĂłn de los actores universitaritos en el cuidado del entorno universitario; y g) propuesta de acciones generales para el mejoramiento de las condiciones del paisaje y manejo del entorno universitario. Estos ejes rectores no se analizan de manera independiente, sino en una dimensiĂłn integral, ya que la alteraciĂłn de algĂşn componente del ambiente o la existencia de riesgos puede tener diferentes causas y por consiguiente diversos efectos.Universidad AutĂłnoma del Estado de MĂŠxico Colegio de Ciencias GeogrĂĄficas del Estado de MĂŠxico AC
Responsabilidad e Impacto Ambiental en un Territorio del Altiplano Mexicano. AnĂĄlisis ambiental, sociodemogrĂĄfico y econĂłmico
El presente libro se sustenta en lo que establece el documento titulado ElaboraciĂłn, aprobaciĂłn, publicaciĂłn e inscripciĂłn de los Planes de Desarrollo Urbano de competencia Municipal, el cual en el numeral 2.3 Contenido de los Planes Municipales de Desarrollo Urbano, seĂąala lo siguiente: âPara el caso de los Planes Municipales de Desarrollo Urbano, la SecretarĂa de Desarrollo Urbano y Obras PĂşblicas, por conducto de la DirecciĂłn General de AdministraciĂłn Urbana, formulĂł una metodologĂa para la elaboraciĂłn de estos instrumentos de planeaciĂłnâ. Con base en el documento referido anteriormente, la estructura, contenido, terminologĂa y demĂĄs elementos complementarios que conforman este libro cumple, con lo establecido en los lineamientos oficiales para la elaboraciĂłn de PMDU en el Estado de MĂŠxico, sin embargo, es importante considerar que los espacios geogrĂĄficos y condiciones territoriales de los municipios del Estado de MĂŠxico no son homogĂŠneos, por lo que, en algunos aspectos o numerales, la informaciĂłn y anĂĄlisis se exponen de manera general o muy especĂfica, en algunos casos, se excluyeron numerales considerados no relevantes para el territorio del Municipio de Calimaya, ademĂĄs se incluye informaciĂłn sobre temas de responsabilidad ambiental, lĂmites, impacto ambiental, sustentabilidad y desarrollo urbano sustentable
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 factorsâthe 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¡6â58¡8) of global deaths and 41¡2% (39¡8â42¡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
The improbable transmission of Trypanosoma cruzi to human: the missing link in the dynamics and control of Chagas disease
Chagas disease has a major impact on human health in Latin America and is becoming of global concern due to international migrations. Trypanosoma cruzi, the etiological agent of the disease, is one of the rare human parasites transmitted by the feces of its vector, as it is unable to reach the salivary gland of the insect. This stercorarian transmission is notoriously poorly understood, despite its crucial role in the ecology and evolution of the pathogen and the disease. The objective of this study was to quantify the probability of T. cruzi vectorial transmission to humans, and to use such an estimate to predict human prevalence from entomological data. We developed several models of T. cruzi transmission to estimate the probability of transmission from vector to host. Using datasets from the literature, we estimated the probability of transmission per contact with an infected triatomine to be 5.8x10(-4) (95%CI: [2.6; 11.0] x 10(-4)). This estimate was consistent across triatomine species, robust to variations in other parameters, and corresponded to 900-4,000 contacts per case. Our models subsequently allowed predicting human prevalence from vector abundance and infection rate in 7/10 independent datasets covering various triatomine species and epidemiological situations. This low probability of T. cruzi transmission reflected well the complex and unlikely mechanism of transmission via insect feces, and allowed predicting human prevalence from basic entomological data. Although a proof of principle study would now be valuable to validate our models' predictive ability in an even broader range of entomological and ecological settings, our quantitative estimate could allow switching the evaluation of disease risk and vector control program from purely entomological indexes to parasitological measures, as commonly done for other major vector borne diseases. This might lead to different quantitative perspectives as these indexes are well known not to be proportional one to another
Performance and Operation of the CMS Electromagnetic Calorimeter
The operation and general performance of the CMS electromagnetic calorimeter
using cosmic-ray muons are described. These muons were recorded after the
closure of the CMS detector in late 2008. The calorimeter is made of lead
tungstate crystals and the overall status of the 75848 channels corresponding
to the barrel and endcap detectors is reported. The stability of crucial
operational parameters, such as high voltage, temperature and electronic noise,
is summarised and the performance of the light monitoring system is presented
Global oceanic diazotroph database version 2 and elevated estimate of global oceanic N<sub>2</sub> fixation
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