72 research outputs found

    Crop- and Location-Specific Drought Index for Agricultural Water Management: Development, Evaluation, and Forecasting

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    Severe droughts have plagued the United States over the last few years. The 2011 Texas drought, the 2012 U.S. drought, and the current California drought have greatly impacted the nation’s economy and agricultural production. Different crops vary in their response to water stress. Despite this, commonly used drought indices, such as the Palmer Drought Severity Index, do not consider crop specific factors. The goal of this project was to create a methodology to produce crop and location specific drought and yield trend forecasts to help agricultural producers make more informed water management decisions. To achieve this, a drought index was developed and analyzed, weather forecasts were used in a hydrology/crop model to predict hydrologic conditions and crop yields, and an example interactive map interface were created to convey this information to water stakeholders. The drought index uses five parameters that affect or are affected by drought. These parameters include precipitation, temperature, cumulative biomass, soil moisture, and transpiration. Soil moisture and temperature are ranked against crop-specific threshold values, while precipitation and cumulative biomass are ranked against location-specific normal values. Transpiration is ranked against the location-specific potential transpiration. A case study was performed in the Upper Colorado River Basin located in West Texas using this drought index. Cotton is the primary crop grown in the watershed and was used in this study. The Soil and Water Assessment Tool (SWAT) was used to estimate the cumulative biomass, soil moisture, and transpiration. A multiple linear regression model was developed for each week of the growing season based on the significant parameters during that stage of the growing season. These models were used to predict yield trends and drought severity. Two week forecasts for each drought parameter, yield trends, and the drought index were generated for 2010 through 2013 by using forecasted precipitation and temperature data as inputs for the hydrologic and crop model. This provided forecasted soil moisture, transpiration, and cumulative biomass production. Parameter rankings, yield trends, and the drought index were compared for those calculated with actual precipitation and temperature data as well as forecasted precipitation and temperature data. The precipitation ranking, temperature ranking, cumulative biomass ranking, transpiration ranking, estimated yield trends, and drought index indicated satisfactory forecast results. The soil moisture forecast did not result in satisfactory forecast. The final step in the project was to create an example interface for agricultural producers and water managers to view drought related stresses. ArcGIS online was used to create maps which show graphs of the weekly drought index and soil moisture ranking. Maps were created at the county scale. These maps provide agricultural producers readily accessible information that can be used for decision making related to water management

    Water in South Dakota Stakeholder Guided Strategies for Moving Forward

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    The 2017 Eastern South Dakota Water Conference included a stakeholder working session that resulted in over 350 comments. This paper reflects the challenges, goals and action items pertaining to South Dakota’s water resources as identified by the state’s diverse stakeholders

    Crop- and Location-Specific Drought Index for Agricultural Water Management: Development, Evaluation, and Forecasting

    Get PDF
    Severe droughts have plagued the United States over the last few years. The 2011 Texas drought, the 2012 U.S. drought, and the current California drought have greatly impacted the nation’s economy and agricultural production. Different crops vary in their response to water stress. Despite this, commonly used drought indices, such as the Palmer Drought Severity Index, do not consider crop specific factors. The goal of this project was to create a methodology to produce crop and location specific drought and yield trend forecasts to help agricultural producers make more informed water management decisions. To achieve this, a drought index was developed and analyzed, weather forecasts were used in a hydrology/crop model to predict hydrologic conditions and crop yields, and an example interactive map interface were created to convey this information to water stakeholders. The drought index uses five parameters that affect or are affected by drought. These parameters include precipitation, temperature, cumulative biomass, soil moisture, and transpiration. Soil moisture and temperature are ranked against crop-specific threshold values, while precipitation and cumulative biomass are ranked against location-specific normal values. Transpiration is ranked against the location-specific potential transpiration. A case study was performed in the Upper Colorado River Basin located in West Texas using this drought index. Cotton is the primary crop grown in the watershed and was used in this study. The Soil and Water Assessment Tool (SWAT) was used to estimate the cumulative biomass, soil moisture, and transpiration. A multiple linear regression model was developed for each week of the growing season based on the significant parameters during that stage of the growing season. These models were used to predict yield trends and drought severity. Two week forecasts for each drought parameter, yield trends, and the drought index were generated for 2010 through 2013 by using forecasted precipitation and temperature data as inputs for the hydrologic and crop model. This provided forecasted soil moisture, transpiration, and cumulative biomass production. Parameter rankings, yield trends, and the drought index were compared for those calculated with actual precipitation and temperature data as well as forecasted precipitation and temperature data. The precipitation ranking, temperature ranking, cumulative biomass ranking, transpiration ranking, estimated yield trends, and drought index indicated satisfactory forecast results. The soil moisture forecast did not result in satisfactory forecast. The final step in the project was to create an example interface for agricultural producers and water managers to view drought related stresses. ArcGIS online was used to create maps which show graphs of the weekly drought index and soil moisture ranking. Maps were created at the county scale. These maps provide agricultural producers readily accessible information that can be used for decision making related to water management

    Resuspension of E. coli from Direct Fecal Deposits in Stream

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    Direct fecal deposits from cattle provide a significant source of E. coli to streams and therefore pose a threat to human health in agricultural watersheds. Experiments were conducted in a flume (9.1 m long, 0.6 m wide, and 0.6 m deep) with flow of 0.0106 m3 s-1 , an average velocity of 11.4 cm s-1 ,and water depth of 15.24 cm to measure the resuspension and deposition of E. coli from an undisturbed standard cowpat. Water samples were collected 1.22 m and 3.66 m downstream of the deposited cowpat, and at each downstream cross-section nine samples were collected to characterize the bacterial movement. E. coli in water samples were separated into the attached and unattached phases by filtration to assess the mechanism of transport. The cumulative load contribution from a single deposited cowpat after one hour was 2.49×10 9 cfu 3.66 m downstream. The composite E. coli concentrations at all sampling points and times exceeded the federal standards for primary contact in the United States of 126 cfu/100 ml. Between 77.2 and 99.5% of all E. coli downstream of the direct deposit were associated with particulates. The resuspension rate was 5.91×107 and 9.52×104 cfu m-2 s-1 0.5 min and 60 minutes after deposition, respectively, 1.22 m downstream of the deposit and 2.19×106 and 3.14×103 cfu m-2 s-1 0.5 min and 60 min after deposition, respectively, 3.66 m downstream of the deposit. Results from this study are useful to improve modeling techniques to predict in-stream E. coli concentrations from direct fecal deposits and emphasize the need to implement management practices to reduce livestock access to streams

    Securing Cloud File Systems using Shielded Execution

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    Cloud file systems offer organizations a scalable and reliable file storage solution. However, cloud file systems have become prime targets for adversaries, and traditional designs are not equipped to protect organizations against the myriad of attacks that may be initiated by a malicious cloud provider, co-tenant, or end-client. Recently proposed designs leveraging cryptographic techniques and trusted execution environments (TEEs) still force organizations to make undesirable trade-offs, consequently leading to either security, functional, or performance limitations. In this paper, we introduce TFS, a cloud file system that leverages the security capabilities provided by TEEs to bootstrap new security protocols that meet real-world security, functional, and performance requirements. Through extensive security and performance analyses, we show that TFS can ensure stronger security guarantees while still providing practical utility and performance w.r.t. state-of-the-art systems; compared to the widely-used NFS, TFS achieves up to 2.1X speedups across micro-benchmarks and incurs <1X overhead for most macro-benchmark workloads. TFS demonstrates that organizations need not sacrifice file system security to embrace the functional and performance advantages of outsourcing

    Effectiveness of Denitrifying Bioreactors on Water Pollutant Reduction from Agricultural Areas

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    HighlightsDenitrifying woodchip bioreactors treat nitrate-N in a variety of applications and geographies.This review focuses on subsurface drainage bioreactors and bed-style designs (including in-ditch).Monitoring and reporting recommendations are provided to advance bioreactor science and engineering. Denitrifying bioreactors enhance the natural process of denitrification in a practical way to treat nitrate-nitrogen (N) in a variety of N-laden water matrices. The design and construction of bioreactors for treatment of subsurface drainage in the U.S. is guided by USDA-NRCS Conservation Practice Standard 605. This review consolidates the state of the science for denitrifying bioreactors using case studies from across the globe with an emphasis on full-size bioreactor nitrate-N removal and cost-effectiveness. The focus is on bed-style bioreactors (including in-ditch modifications), although there is mention of denitrifying walls, which broaden the applicability of bioreactor technology in some areas. Subsurface drainage denitrifying bioreactors have been assessed as removing 20% to 40% of annual nitrate-N loss in the Midwest, and an evaluation across the peer-reviewed literature published over the past three years showed that bioreactors around the world have been generally consistent with that (N load reduction median: 46%; mean ±SD: 40% ±26%; n = 15). Reported N removal rates were on the order of 5.1 g N m-3 d-1 (median; mean ±SD: 7.2 ±9.6 g N m-3 d-1; n = 27). Subsurface drainage bioreactor installation costs have ranged from less than 5,000to5,000 to 27,000, with estimated cost efficiencies ranging from less than 2.50kg1Nyear1toroughly2.50 kg-1 N year-1 to roughly 20 kg-1 N year-1 (although they can be as high as $48 kg-1 N year-1). A suggested monitoring setup is described primarily for the context of conservation practitioners and watershed groups for assessing annual nitrate-N load removal performance of subsurface drainage denitrifying bioreactors. Recommended minimum reporting measures for assessing and comparing annual N removal performance include: bioreactor dimensions and installation date; fill media size, porosity, and type; nitrate-N concentrations and water temperatures; bioreactor flow treatment details; basic drainage system and bioreactor design characteristics; and N removal rate and efficiency

    Diagnosis, Treatment and Follow Up of Acute Pulmonary Embolism: Consensus Practice from the PERT Consortium

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    Pulmonary embolism (PE) is a life-threatening condition and a leading cause of morbidity and mortality. There have been many advances in the field of PE in the last few years, requiring a careful assessment of their impact on patient care. However, variations in recommendations by different clinical guidelines, as well as lack of robust clinical trials, make clinical decisions challenging. The Pulmonary Embolism Response Team Consortium is an international association created to advance the diagnosis, treatment, and outcomes of patients with PE. In this consensus practice document, we provide a comprehensive review of the diagnosis, treatment, and follow-up of acute PE, including both clinical data and consensus opinion to provide guidance for clinicians caring for these patients

    Does the Establishment of Sustainable Use Reserves Affect Fire Management in the Humid Tropics?

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    Tropical forests are experiencing a growing fire problem driven by climatic change, agricultural expansion and forest degradation. Protected areas are an important feature of forest protection strategies, and sustainable use reserves (SURs) may be reducing fire prevalence since they promote sustainable livelihoods and resource management. However, the use of fire in swidden agriculture, and other forms of land management, may be undermining the effectiveness of SURs in meeting their conservation and sustainable development goals. We analyse MODIS derived hot pixels, TRMM rainfall data, Terra-Class land cover data, socio-ecological data from the Brazilian agro-census and the spatial extent of rivers and roads to evaluate whether the designation of SURs reduces fire occurrence in the Brazilian Amazon. Specifically, we ask (1) a. Is SUR location (i.e., de facto) or (1) b. designation (i.e. de jure) the driving factor affecting performance in terms of the spatial density of fires?, and (2), Does SUR creation affect fire management (i.e., the timing of fires in relation to previous rainfall)? We demonstrate that pre-protection baselines are crucial for understanding reserve performance. We show that reserve creation had no discernible impact on fire density, and that fires were less prevalent in SURs due to their characteristics of sparser human settlement and remoteness, rather than their status de jure. In addition, the timing of fires in relation to rainfall, indicative of local fire management and adherence to environmental law, did not improve following SUR creation. These results challenge the notion that SURs promote environmentally sensitive fire-management, and suggest that SURs in Amazonia will require special attention if they are to curtail future accidental wildfires, particularly as plans to expand the road infrastructure throughout the region are realised. Greater investment to support improved fire management by farmers living in reserves, in addition to other fire users, will be necessary to help ameliorate these threats

    Differential Brain Development with Low and High IQ in Attention-Deficit/Hyperactivity Disorder

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    Attention-Deficit/Hyperactivity Disorder (ADHD) and intelligence (IQ) are both heritable phenotypes. Overlapping genetic effects have been suggested to influence both, with neuroimaging work suggesting similar overlap in terms of morphometric properties of the brain. Together, this evidence suggests that the brain changes characteristic of ADHD may vary as a function of IQ. This study investigated this hypothesis in a sample of 108 children with ADHD and 106 typically developing controls, who participated in a cross-sectional anatomical MRI study. A subgroup of 64 children also participated in a diffusion tensor imaging scan. Brain volumes, local cortical thickness and average cerebral white matter microstructure were analyzed in relation to diagnostic group and IQ. Dimensional analyses investigated possible group differences in the relationship between anatomical measures and IQ. Second, the groups were split into above and below median IQ subgroups to investigate possible differences in the trajectories of cortical development. Dimensionally, cerebral gray matter volume and cerebral white matter microstructure were positively associated with IQ for controls, but not for ADHD. In the analyses of the below and above median IQ subgroups, we found no differences from controls in cerebral gray matter volume in ADHD with below-median IQ, but a delay of cortical development in a number of regions, including prefrontal areas. Conversely, in ADHD with above-median IQ, there were significant reductions from controls in cerebral gray matter volume, but no local differences in the trajectories of cortical development
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