Calibration of liquid argon and neon detectors with 83Krm^{83}Kr^m

We report results from tests of $^{83}$Kr$^{\mathrm{m}}$, as a calibration source in liquid argon and liquid neon. $^{83}$Kr$^{\mathrm{m}}$ atoms are produced in the decay of $^{83}$Rb, and a clear $^{83}$Kr$^{\mathrm{m}}$ scintillation peak at 41.5 keV appears in both liquids when filling our detector through a piece of zeolite coated with $^{83}$Rb. Based on this scintillation peak, we observe 6.0 photoelectrons/keV in liquid argon with a resolution of 6% ($\sigma$/E) and 3.0 photoelectrons/keV in liquid neon with a resolution of 19% ($\sigma$/E). The observed peak intensity subsequently decays with the $^{83}$Kr$^{\mathrm{m}}$ half-life after stopping the fill, and we find evidence that the spatial location of $^{83}$Kr$^{\mathrm{m}}$ atoms in the chamber can be resolved. $^{83}$Kr$^{\mathrm{m}}$ will be a useful calibration source for liquid argon and neon dark matter and solar neutrino detectors.Comment: 7 pages, 12 figure

Classifying multiyear agricultural land use data from Mato Grosso using time-series MODIS vegetation index data.

MODIS 250-m NDVI and EVI datasets are now regularly used to classify regional-scale agricultural land-use practices in many different regions of the globe, especially in the state of Mato Grosso, Brazil, where rapid land-use change due to agricultural development has attracted considerable interest from researchers and policy makers. Variation exists in which MODIS datasets are used, how they are processed for analysis, and what ground reference data are used. Moreover, various and-use/land-cover classes are ultimately resolved, and as yet, crop-specific classifications (e.g. soy?corn vs. soy?cotton double crop) have not been reported in the literature, favoring instead generalized classes such as single vs. double crop. The objective of this study is to present a rigorous multiyear evaluation of the applicability of time-series MODIS 250-m VI data for crop classification in Mato Grosso, Brazil. This study shows progress toward more refined crop-specific classification, but some grouping of crop classes remains necessary. It employs a farm field polygon-based ground reference dataset that is unprecedented in spatial and temporal coverage for the state, consisting of 2003 annual field site samples representing 415 unique field sites and five crop years (2005-2009). This allows for creation of a dataset containing "best-case" or "pure" pixels, which we used to test class separability in a multiyear cross validation framework applied to boosted decision tree classifiers trained on MODIS data subjected to different pre-processing treatments. Reflecting the agricultural landscape of Mato Grosso as a whole, cropping practices represented in the ground reference dataset largely involved soybeans, and soy-based classes (primarily double crop "soy-commercial" and single crop "soy-cover") dominated the analysis along with cotton and pasture. With respect to the MODIS data treatments, the best results were obtained using date-ofacquisition interpolation of the 16-day composite VI time series and outlier point screening, for which five-year out-of-sample accuracies were consistently near or above 80% and Kappa values were above 0.60. It is evident that while much additional research is required to fully and reliably differentiate more specific crop classes, particular groupings of cropping strategies are separable and useful for a number of applications, including studies of agricultural intensification and extensification in this region of the world

Potencial e limitações do monitoramento agrícola com imagens do satélite MODIS.

Resumo: O debate sobre as estratégias brasileiras para enfrentamento das polêmicas relacionadas ao desenvolvimento da agricultura e à preservação ambiental envolve, invariavelmente, questões relacionadas à mudança dos padrões de uso das terras, sobretudo no que diz respeito às taxas de conversão de sistemas naturais para agrícolas na região da Amazônia Legal. Conhecer esse contexto é fundamental para a definição de estratégias e políticas públicas que pretendam ampliar os benefícios advindos do setor produtivo agropecuário nacional e, ao mesmo tempo, minimizar seus impactos ambientais locais e globais. Este estudo teve como objetivo mapear, entre 2005 e 2009, as áreas de agricultura mecanizada no Mato Grosso, através da utilização de imagens do índice de vegetação do sensor orbital MODIS (Moderate Resolution Imaging Spectroradiometer), para monitorar a dinâmica da área cultivada para a produção de grãos. A variação da área cultivada com duas safras mostrou haver um acréscimo importante na área referente à safrinha, enquanto a área total utilizada para a produção se manteve relativamente estável no mesmo período. Considerando-se os dados obtidos, não há como negar a existência de processos de intensificação agropecuária, tanto pela adoção de boas práticas de manejo quanto pelo desenvolvimento de novas tecnologias, e continuar defendendo, intuitivamente, a tese de que o crescente desempenho da atividade agrícola brasileira ocorre em função, prioritária ou exclusiva, da degradação ambiental

Report of the panel on plate motion and deformation, section 2

Given here is a panel report on the goals and objectives, requirements and recommendations for the investigation of plate motion and deformation. The goals are to refine our knowledge of plate motions, study regional and local deformation, and contribute to the solution of important societal problems. The requirements include basic space-positioning measurements, the use of global and regional data sets obtained with space-based techniques, topographic and geoid data to help characterize the internal processes that shape the planet, gravity data to study the density structure at depth and help determine the driving mechanisms for plate tectonics, and satellite images to map lithology, structure and morphology. The most important recommendation of the panel is for the implementation of a world-wide space-geodetic fiducial network to provide a systematic and uniform measure of global strain

Dinâmica da agricultura na Bacia do Alto Paraguai.

Resumo. A Bacia do Alto Paraguai-BAP possui aproximadamente 60% do seu território em terras brasileiras e inclui uma das mais importantes áreas naturais alagadas do planeta - bioma Pantanal. Apesar da planície pantaneira representar aproximadamente 40% da área total da BAP, o fato de toda sua superfície contribuir com as águas que sustentam e inundam sazonalmente o Pantanal, atribui ao monitoramento total da BAP uma importância estratégica para a definição de ações e políticas públicas que visem garantir a qualidade de todos seus ecossistemas. A porção da BAP situada no planalto e, portanto, fora dos limites da planície pantaneira, tem sofrido transformações na paisagem, em função das pressões pelo aumento da produção de alimentos e energia. Considerando que os sistemas produtivos relacionados à agricultura intensiva promovem alterações significativas nos sistemas naturais, é fundamental promover seu monitoramento para embasar ações e políticas públicas, cujo foco principal seja garantir a qualidade de recursos hídricos que suportam o bioma Pantanal. Assim, este trabalho teve o objetivo de mapear a dinâmica das áreas de agricultura anual e das áreas de produção de cana-de-açúcar na BAP, no período compreendido entre os anos safra de 2001 e 2013, para identificar os principais polos produtores e sua evolução ao longo deste período, através da classificação digital de séries históricas de imagens do índice de vegetação do sensor MODIS. Os resultados obtidos mostraram que a agricultura intensiva cresceu aproximadamente 40% no período e se difundiu para outras regiões do planalto.GeoPantanal 2016

After LUX: The LZ Program

The LZ program consists of two stages of direct dark matter searches using liquid Xe detectors. The first stage will be a 1.5-3 tonne detector, while the last stage will be a 20 tonne detector. Both devices will benefit tremendously from research and development performed for the LUX experiment, a 350 kg liquid Xe dark matter detector currently operating at the Sanford Underground Laboratory. In particular, the technology used for cryogenics and electrical feedthroughs, circulation and purification, low-background materials and shielding techniques, electronics, calibrations, and automated control and recovery systems are all directly scalable from LUX to the LZ detectors. Extensive searches for potential background sources have been performed, with an emphasis on previously undiscovered background sources that may have a significant impact on tonne-scale detectors. The LZ detectors will probe spin-independent interaction cross sections as low as 5E-49 cm2 for 100 GeV WIMPs, which represents the ultimate limit for dark matter detection with liquid xenon technology.Comment: Conference proceedings from APS DPF 2011. 9 pages, 6 figure

Ethanol plant location and intensification vs. extensification of corn cropping in Kansas

This is the author final draft. Copyright 2014 Elsevier.Farmers' cropping decisions are a product of a complex mix of socio-economic, cultural, and natural environments in which factors operating at a number of different spatial scales affect how farmers ultimately decide to use their land in any given year or over a set of years. Some environmentalists are concerned that increased demand for corn driven by ethanol production is leading to conversion of non-cropland into corn production (which we label as “extensification”). Ethanol industry advocates counter that more than enough corn supply comes from crop switching to corn and increased yields (which we label as “intensification”). In this study, we determine whether either response to corn demand – intensification or extensification – is supported. This is determined through an analysis of land-use/land-cover (LULC) data that covers the state of Kansas and a measure of a corn demand shifter related to ethanol production – distance to the closest ethanol plant – between 2007 and 2009