4,409 research outputs found
Implementing Options Markets in California To Manage Water Supply Uncertainty
In California, the tremendous spatial and temporal variation in precipitation suggests that flexible contractual arrangements, such as option contracts, would increase allocative efficiency of water over time and space. Under such arrangements, a water agency pays an option premium for the right to purchase water at some point in the future, if water conditions turn out to be dry. The premium represents the value of the flexibility gained by the buyer from postponing its decision whether to purchase water. In California, the seller of existing option arrangements is often an agricultural producer who can fallow land, in the event that a water option is exercised. In this simulation-optimization approach, we seek to determine the value of transferring water uncertainty from one party to another at several locations in California, given current water prices and the spatial and temporal distribution of water year types in the state. (Preliminary analysis covers northern California; future analysis will incorporate southern California.) We analyze within a mathematical programming framework whether increased trading among water agencies across time as well as space would result in significant gains from trade. We use output from CALVIN, an economic-engineering optimization model of the California water system which runs the current configuration of the California water system over historical hydrological conditions, to generate water's imputed price at different locations during different seasons. We also explore reasons why previous theoretical calculations of option value in the western United States have far exceeded option premia on existing bilateral contracts.Risk and Uncertainty,
Liposomes with diverse compositions are protected during desiccation by LEA proteins from Artemia franciscana and trehalose
© 2015 Published by Elsevier B.V. Intracellular accumulation of Late Embryogenesis Abundant (LEA) proteins and the disaccharide trehalose is associated with cellular desiccation tolerance in a number of animal species. Two LEA proteins from anhydrobiotic embryos of the brine shrimp Artemia franciscana were tested for the ability to protect liposomes of various compositions against desiccation-induced damage in the presence and absence of trehalose. Damage was assessed by carboxyfluorescein leakage after drying and rehydration. Further, using a cytoplasmic-localized (AfrLEA2) and a mitochondrial-targeted (AfrLEA3m) LEA protein allowed us to evaluate whether each may preferentially stabilize membranes of a particular lipid composition based on the protein\u27s subcellular location. Both LEA proteins were able to offset damage during drying of liposomes that mimicked the lipid compositions of the inner mitochondrial membrane (with cardiolipin), outer mitochondrial membrane, and the inner leaflet of the plasma membrane. Thus liposome stabilization by AfrLEA3m or AfrLEA2 was not dependent on lipid composition, provided physiological amounts of bilayer and non-bilayer-forming lipids were present (liposomes with a non-biological composition of 100% phosphatidylcholine were not protected by either protein). Additive protection by LEA proteins plus trehalose was dependent on the lipid composition of the target membrane. Minimal additional damage occurred to liposomes stored at room temperature in the dried state for one week compared to liposomes rehydrated after 24 h. Consistent with the ability to stabilize lipid bilayers, molecular modeling of the secondary structures for AfrLEA2 and AfrLEA3m revealed bands of charged amino acids similar to other amphipathic proteins that interact directly with membranes
How to Manage Stored Grain
Spoilage, shrinkage and contamination in farm-stored grains are all costly to the owner. They result in weight losses, heavy market discounts when the grain is sold and loss in palatability as a livestock feed. When these losses occur, the discounts may be anywhere from a few cents to more than a dollar a bushel even for grain that looks all right without close inspection
The Effects of tDCS Across the Spatial Frequencies and Orientations that Comprise the Contrast Sensitivity Function
Richard B, Johnson AP, Thompson B and Hansen BC (2015) The Effects of tDCS Across the Spatial Frequencies and Orientations that Comprise the Contrast Sensitivity Function. Front. Psychol. 6:1784. doi: 10.3389/fpsyg.2015.01784Transcranial Direct Current Stimulation (tDCS) has recently been employed in traditional psychophysical paradigms in an effort to measure direct manipulations on spatial frequency channel operations in the early visual system. However, the effects of tDCS on contrast sensitivity have only been measured at a single spatial frequency and orientation. Since contrast sensitivity is known to depend on spatial frequency and orientation, we ask how the effects of anodal and cathodal tDCS may vary according to these dimensions. We measured contrast sensitivity with sinusoidal gratings at four different spatial frequencies (0.5, 4, 8, and 12 cycles/°), two orientations (45° Oblique and Horizontal), and for two stimulus size conditions [fixed size (3°) and fixed period (1.5 cycles)]. Only contrast sensitivity measured with a 45° oblique grating with a spatial frequency of 8 cycles/° (period = 1.5 cycles) demonstrated clear polarity specific effects of tDCS, whereby cathodal tDCS increased and anodal tDCS decreased contrast sensitivity. Overall, effects of tDCS were largest for oblique stimuli presented at high spatial frequencies (i.e., 8 and 12 cycles/°), and were small or absent at lower spatial frequencies, other orientations and stimulus size. Thus, the impact of tDCS on contrast sensitivity, and therefore on spatial frequency channel operations, is opposite in direction to other behavioral effects of tDCS, and only measurable in stimuli that generally elicit lower contrast sensitivity (e.g., oblique gratings with period of 1.5 cycles at spatial frequencies above the peak of the contrast sensitivity function).Portions of the current study were funded by a discovery grant from the Natural Sciences and Engineering Research Council (NSERC) to AJ, and by the Colgate Research Council Grant to BH. BR was supported by the Fonds de Recherche du Quebec â Nature et Technologie (FQRNT), and a bursary from the MinistĂšre de lâĂducation, de lâEnseignement supĂ©rieur et de la Recherche (MEESR)
First-Pass Meconium Samples from Healthy Term Vaginally-Delivered Neonates : An Analysis of the Microbiota
Acknowledgments The authors would like to thank the parents who consented to provide samples with limited notice at an emotional and stressful time. This work was supported entirely from personal donations to the neonatal endowments fund at Aberdeen Maternity Hospital and we thank families for their continued generosity, year-on-year. The Rowett Institute of Nutrition and Health receives funding from the Scottish Government (SG-RESAS). Funding: This work was funded from NHS Grampian Neonatal Endowments. The Rowett Institute receives funding from the Rural and Environmental Science and Analytical Services programme of the Scottish Government. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD
Directions for 21st Century Lifelong Learning Institutes: Elucidating Questions from Osher Lifelong Learning Institute Studies
The literature regarding lifelong learning is robust, while the literature on lifelong learning institutions, centers, and programs remain under-researched in comparison. This article draws insights from a specific network of lifelong learning institutes with a rich history and high rapport in the United States: the Osher Lifelong Learning Institute (OLLI) network. Sixty articles regarding OLLIs are catalogued and highlighted to elucidate twelve thematic areas and twelve questions for future research and practice. In particular, these themes are related to adult education, healthy aging, and educational gerontology. The article concludes by reflecting on trends in and needs for institutional research and practice.Les publications portant sur lâĂ©ducation permanente sont nombreuses, contrairement Ă celles touchant les institutions, centres et programmes dâĂ©ducation permanente qui, en comparaison, demeurent gĂ©nĂ©ralement mal connus. Cet article recueille des idĂ©es dâun rĂ©seau dâinstituts dâĂ©ducation permanente ayant un passĂ© riche et de bons rapports aux Ătats-Unis : le rĂ©seau Osher Lifelong Learning Institute (OLLI). Soixante articles portant sur OLLI ont Ă©tĂ© cataloguĂ©s et analysĂ©s pour faire ressortir douze thĂšmes et douze questions pour la recherche et la pratique Ă lâavenir. Ces thĂšmes se rattachent Ă lâĂ©ducation des adultes, le vieillissement sain et la gĂ©rontologie Ă©ducative. Lâarticle se termine par des rĂ©flexions sur des tendances et des besoins relatifs Ă la recherche et la pratique institutionnelles.Mots clĂ©s : recherche institutionnelle, Ă©ducation permanente, ainĂ©s, Ă©ducation des adultes, universitĂ©s adaptĂ©es aux personnes ĂągĂ©e
Theoretical and Experimental Investigation of Heat Conduction in Air, Including Effects of Oxygen Dissociation
Solutions are presented for the conduction of beat through a semi-infinite gas medium having a uniform initial temperature and a constant boundary temperature. The coefficients of thermal conductivity and diffusivity are treated as variables, and the solutions are extended to the case of air at temperatures where oxygen dissociation occurs. These solutions are used together with shock-tube measurements to evaluate the integral of thermal conductivity for air as a function of temperature
The inexorable increase of biological exposure in paediatric Inflammatory Bowel Disease:a Scottish, population-based, longitudinal study
Tropical forcing of the Summer East Atlantic pattern
The Summer East Atlantic (SEA) mode is the second dominant mode of summer low-frequency variability in the Euro-Atlantic region. Using reanalysis data, we show that SEA-related circulation anomalies significantly influence temperatures and precipitation over Europe. We present evidence that part of the interannual SEA variability is forced by diabatic heating anomalies of opposing signs in the tropical Pacific and Caribbean that induce an extratropical Rossby wave train. This precipitation dipole is related to SST anomalies characteristic of the developing ENSO phases. Seasonal hindcast experiments forced with observed sea surface temperatures (SST) exhibit skill at capturing the interannual SEA variability corroborating the proposed mechanism and highlighting the possibility for improved prediction of boreal summer variability. Our results indicate that tropical forcing of the SEA likely played a role in the dynamics of the 2015 European heat wave
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