6,007 research outputs found

    Economic Analysis of Water Conservation Policies in the Texas Panhandle

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    Due to declining water availability from the Ogallala Aquifer, management policy alternatives for extending the life of the aquifer to sustain rural economies in the Texas Panhandle are evaluated. The study concludes that water conservation policies for the region significantly impact crop mix, resource usage, and net present value of farm profits over a sixty-year planning horizon.Ogallala Aquifer, Groundwater Conservation, Water Management Policy, Texas Panhandle, Resource /Energy Economics and Policy,

    Assessment and Impact of Water Conservation Policies in Texas High Plains

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    The availability of water in the Texas Panhandle is a major concern. The top twenty-six counties of West Texas have a semi-arid climate, with little surface water available for consumption. The majority of the water used in the region for agriculture comes from the Ogallala Aquifer, which provides groundwater for Kansas, Oklahoma, and Nebraska as well. The southern portion of the aquifer has a very slow recharge rate, which strengthens the need for conservation practices. Due to the limited availability of water from the Ogallala Aquifer, water conservation plans need to be developed and implemented. The irrigation of crops accounts for 95% of the groundwater use in the Texas Panhandle. New technologies such as drip and lowenergy pivot irrigation systems would ordinarily provide for increased water conservation, but the increased production of crops requiring irrigation in the semi-arid region has led to greater water consumption rather than conservation. The objectives of this study are to first, determine the actual economic benefit that irrigation provides over non-irrigation, and second, to assess possible conservation policies given the economic benefit from irrigation. To meet the first objective, we plan to use existing production and water use models to show the actual difference in revenue of irrigation versus non-irrigation in an effort to assess the cost to producers in terms of lost revenue per acre by switching to non-irrigated crops. We will then address the policy implications surrounding this decrease in revenue, including policies that will encourage water conservation, to address the second objective

    Panel Resource Management (PRM) Implementation and Effects within Safety Review Panel Settings and Dynamics

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    While technical training and advanced degree's assure proficiency at specific tasks within engineering disciplines, they fail to address the potential for communication breakdown and decision making errors familiar to multicultural environments where language barriers, intimidating personalities and interdisciplinary misconceptions exist. In an effort to minimize these pitfalls to effective panel review, NASA's lead safety engineers to the ISS Safety Review Panel (SRP), and Payload Safety Review Panel (PSRP) initiated training with their engineers, in conjunction with the panel chairs, and began a Panel Resource Management (PRM) program. The intent of this program focuses on the ability to reduce the barriers inhibiting effective participation from all panel attendees by bolstering participants confidence levels through increased communication skills, situational awareness, debriefing, and a better technical understanding of requirements and systems

    Sulfites

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    Key Concepts Sulfites are frequently used food and drug additives. Ingestion of sulfite residues has been documented to trigger asthmatic reactions in sensitive individuals. Sulfite-induced asthma occurs in less than 5% of asthmatic individuals, and those with severe, persistent asthma are at greatest risk. The diagnosis of sulfite-induced asthma is best made by blinded oral challenge with assessment of lung function. Labeling regulations in the United States alert sulfite-sensitive individuals to the presence of sulfites in foods, which must then be avoided

    Strong exciton-photon coupling with colloidal nanoplatelets in an open microcavity

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    Colloidal semiconductor nanoplatelets exhibit quantum size effects due to their thickness of only few monolayers, together with strong optical band-edge transitions facilitated by large lateral extensions. In this article we demonstrate room temperature strong coupling of the light and heavy hole exciton transitions of CdSe nanoplatelets with the photonic modes of an open planar microcavity. Vacuum Rabi splittings of 66±166 \pm 1 meV and 58±158 \pm 1 meV are observed for the heavy and light hole excitons respectively, together with a polariton-mediated hybridisation of both transitions. By measuring the concentration of platelets in the film we compute the transition dipole moment of a nanoplatelet exciton to be μ=(575±110)\mu = (575 \pm 110) D. The large oscillator strength and fluorescence quantum yield of semiconductor nanoplatelets provide a perspective towards novel photonic devices, combining polaritonic and spinoptronic effects.Comment: 9 pages, 4 figure

    Two successive calcium-dependent transitions mediate membrane binding and oligomerization of daptomycin and the related antibiotic A54145

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    The final publication is available at Elsevier via http://doi.org/10.1016/j.bbamem.2016.05.020 © 2016. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/Daptomycin and A54145 are homologous lipopeptide antibiotics that permeabilize the cell membranes of Gram-positive bacteria. Membrane permeabilization depends on the presence of both phosphatidylglycerol (PG) and calcium, and it involves the formation of oligomeric transmembrane pores that consist of approximately 6-8 subunits. We here show that each lipopeptide molecule binds two calcium ions in separable, successive steps. The first calcium ion causes the lipopeptide molecule to bind to the target membrane, and likely to form a loosely associated oligomer. Higher calcium concentrations induce binding of a second ion, which produces the more tightly associated and more deeply membrane-inserted final, functional form of the oligomer. Both calcium dependent steps are accompanied by fluorescence signals that indicate transition of specific amino acid residues into less polar environments, suggestive of insertion into the target membrane. Our findings agree with the earlier observation that two of the four acidic amino acid residues in the daptomycin molecule are essential for antibacterial activity. (C) 2016 Elsevier B.V. All rights reserved.This study was supported by operating grants by NSERC to Scott Taylor (155283-2012) and Michael Palmer (250265-2013)

    Soybean Oil Is Not Allergenic to Soybean-Sensitive Individuals

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    We have previously demonstrated that peanut oil is not allergenic to peanut-sensitive individuals. Seven soybean-sensitive patients were enrolled in a double-blind crossover study to determine whether ingestion of soybean oil can induce adverse reactions in such patients. All subjects had histories of systemic allergic reactions (urticaria, angioedema, wheezing, dyspnea, and/or vomiting) after soybean ingestion and had positive puncture skin tests with a 1:20 w/v glycerinated-saline whole soybean extract. Sera from six of the seven subjects were tested by RAST assay for the presence of specific IgE antibodies to soybean allergens. All patients had elevated levels of serum IgE antibodies to the crude soybean extract; binding values ranged from 2.3 to 28.1 times that of a negative control serum. Before the oral challenges, all patients demonstrated negative puncture skin tests to three commercially available soybean oils and to olive oil (control). On four separate days, patients were challenged with the individual soybean oils and to olive oil in random sequence. At 30-minute intervals, under constant observation, patients ingested 2, 5, and 8 ml of one of the soybean oils or olive oil contained in 1 ml capsules. No untoward reactions were observed with either the commercially available soybean oils or olive oil. Soybean oil ingestion does not appear to pose a risk to soybean-sensitive individuals
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