3,555 research outputs found
Ensemble Modeling Informs Hypoxia Management In The Northern Gulf Of Mexico
A large region of low-dissolved-oxygen bottom waters (hypoxia) forms nearly every summer in the northern Gulf of Mexico because of nutrient inputs from theMississippi River Basin andwater column stratification. Policymakers developed goals to reduce the area of hypoxic extent because of its ecological, economic, and commercial fisheries impacts. However, the goals remain elusive after 30 y of research and monitoring and 15 y of goal-setting and assessment because there has been little change in river nitrogen concentrations. An intergovernmental Task Force recently extended to 2035 the deadline for achieving the goal of a 5,000-km(2) 5-y average hypoxic zone and set an interim load target of a 20% reduction of the spring nitrogen loading from the Mississippi River by 2025 as part of their adaptive management process. The Task Force has asked modelers to reassess the loading reduction required to achieve the 2035 goal and to determine the effect of the 20% interim load reduction. Here, we address both questions using a probabilistic ensemble of four substantially different hypoxia models. Our results indicate that, under typical weather conditions, a 59% reduction in Mississippi River nitrogen load is required to reduce hypoxic area to 5,000 km(2). The interim goal of a 20% load reduction is expected to produce an 18% reduction in hypoxic area over the long term. However, due to substantial interannual variability, a 25% load reduction is required before there is 95% certainty of observing any hypoxic area reduction between consecutive 5-y assessment periods
Diatom extraction: A new technique with heated H2O2. A technical note
The best method of diatom identification in animal and human tissues is still an important discussion topic, in terms of effectiveness and reliability. In this technical note, authors propose a new method of extraction of diatoms using heated hydrogen peroxide from animal and human tissue samples. This method has been compared with the traditional method of digestion with acids. The results of the comparison show that heated hydrogen peroxide extraction is more efficient in terms of reduction of sediment, extraction of the material and preservation of diatoms proving to be a viable alternative to conventional approaches with acids in terms of costs and operator safety
Ensemble modeling informs hypoxia management in the northern Gulf of Mexico
A large region of low-dissolved-oxygen bottom waters (hypoxia) forms nearly every summer in the northern Gulf of Mexico because of nutrient inputs from theMississippi River Basin andwater column stratification. Policymakers developed goals to reduce the area of hypoxic extent because of its ecological, economic, and commercial fisheries impacts. However, the goals remain elusive after 30 y of research and monitoring and 15 y of goal-setting and assessment because there has been little change in river nitrogen concentrations. An intergovernmental Task Force recently extended to 2035 the deadline for achieving the goal of a 5,000-km(2) 5-y average hypoxic zone and set an interim load target of a 20% reduction of the spring nitrogen loading from the Mississippi River by 2025 as part of their adaptive management process. The Task Force has asked modelers to reassess the loading reduction required to achieve the 2035 goal and to determine the effect of the 20% interim load reduction. Here, we address both questions using a probabilistic ensemble of four substantially different hypoxia models. Our results indicate that, under typical weather conditions, a 59% reduction in Mississippi River nitrogen load is required to reduce hypoxic area to 5,000 km(2). The interim goal of a 20% load reduction is expected to produce an 18% reduction in hypoxic area over the long term. However, due to substantial interannual variability, a 25% load reduction is required before there is 95% certainty of observing any hypoxic area reduction between consecutive 5-y assessment periods
Degradación de tierras y teledetección en planicies próximas a la localidad de Centenario, provincia de Neuquén
AbstractIn this paper the status of land degradation is analyzed in a plains sector near Centenario town in Neuquén Province. To carry on this analysis it was used digital processing of satellite images which were analyzed within the conceptual framework of landscape ecology (Forman and Godron, 1986).The study area comprises the old river terraces of Neuquén River, from a Pleistocene age, which have a sandy mantle that covers them, which usually constitutes the horizon where the soils that allow the development of a xeric vegetation, typical of the arid environments, in the eastern part of the Neuquén Province. This place is exposed to intense human activity for more than 50 years, related to hydrocarbon extraction what should be added, given the proximity of urban centers, the permanent removal of plant species for use as fuel.In addition to the information obtained during the field trips and the analysis of the background to this, the methodology involves the use of GIS Idrisi (Kilimanjaro version) for the digital processing of Landsat ETM satellite imagery provided by CONAE. The results were compared with information obtained from various field trips, and to recognize different matrices, patches and corridors, according to the methodology of Landscape Ecology.ResumenEn el presente trabajo se analiza el estado de la degradación de la tierra en un sector de planicies próximas a la localidad de Centenario en la provincia de Neuquén. Para ello se utilizó el procesamiento digital de imágenes satelitales las que fueron analizadas bajo el marco conceptual de la Ecología del Paisaje (Forman y Godron, 1986).El área de estudio está constituida por antiguas terrazas fluviales del río Neuquén, de edad Pleistoceno que poseen un manto arenoso que constituye el horizonte donde se forman los suelos, que permiten el desarrollo de una vegetación xerofítica, típica de los ambientes áridos de la zona oriental de la provincia. Estelugar se halla expuesto a una intensa actividad humana desde hace más de 50 años, relacionada con la extracción de hidrocarburos. A esto se le debe sumar, dada la proximidad con centros urbanos, la permanente extracción de especies vegetales, para utilizarlas como combustible.Además de la información obtenida durante las salidas de campo y del análisisde los antecedentes sobre este lugar, la metodología contempla el uso del SIG Idrisi (versión Kilimanjaro) para el tratamiento digital de imágenes satelitales tipo Landsat ETM provistas por la CONAE. Los resultados fueron confrontados con lainformación obtenida a partir de las distintas salidas de campo y para poderreconocer distintas matrices, parches y corredores, de acuerdo con la propuestametodológica de la Ecología del Paisaje.
label free discrimination of cells undergoing apoptosis by hyperspectral confocual reflectance imaging
Among the optical techniques used for exploring the properties of cells and tissues, those based on hyperspectral label-free analysis are particularly interesting due to their non-invasive character and their ability to fast collect a huge number of information on the different sample constituents and their spatial distribution. Here we present results obtained with a novel hyperspectral reflectance confocal microscope of label-free discrimination of cells undergoing apoptosis. Our data, analyzed by means of a powerful statistical method, enable to obtain information on the biological status at a single cell level through the local measurement of reflectivity. Furthermore, an optical model of the local dielectric response gives an additional insight of the parameters linking the optical responsivity to the biological status
Aplicação do método AID estendido na identificação de linhagens de frangos resistentes a coccidiosis (Eimeria tenella).
O objetivo foi analisar dados de pesagens (y) de bovinos. De cada animal foram feitas nove pesagens do nascimento aos dois anos de idade. A variável y foi transformada por yl = (yl-1)/l (l 1 0), a qual foi eficiente na redução dos coeficientes de assimetria e da heterogeneidade de variância dos dados
Development of reverse genetics systems for infectious bursal disease virus by yeast-based homologous recombination.
Projeto/Plano de Ação: 05.11.10.200-04
High-resolution tracking in a GEM-Emulsion detector
SHiP (Search for Hidden Particles) is a beam dump experiment proposed at the
CERN SPS aiming at the observation of long lived particles very weakly coupled
with ordinary matter mostly produced in the decay of charmed hadrons. The beam
dump facility of SHiP is also a copious factory of neutrinos of all three kinds
and therefore a dedicated neutrino detector is foreseen in the SHiP apparatus.
The neutrino detector exploits the Emulsion Cloud Chamber technique with a
modular structure, alternating walls of target units and planes of electronic
detectors providing the time stamp to the event. GEM detectors are one of the
possible choices for this task. This paper reports the results of the first
exposure to a muon beam at CERN of a new hybrid chamber, obtained by coupling a
GEM chamber and an emulsion detector. Thanks to the micrometric accuracy of the
emulsion detector, the position resolution of the GEM chamber as a function of
the particle inclination was evaluated in two configurations, with and without
the magnetic fiel
Changes of forest coverage and land uses as assessed by the inventory of land uses in Italy
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