1,340 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,
Calibrated Stochastic Dynamic Models for Resource Management
In this paper we develop a positive calibrated approach to stochastic dynamic programming. Risk aversion, discount rate, and intertemporal substitution preferences of the decision-maker are calibrated by a procedure that minimizes the mean squared error from data on past decisions. We apply this framework to managing stochastic water supplies from Oroville Reservoir, located in Northern California. The calibrated positive SDP closely reproduces the historical storage and releases from the dam and shows sensitivity of optimal decisions to a decision-maker's risk aversion and intertemporal preferences. The calibrated model has average prediction errors that are substantially lower than those from the model with an expected net present value objective.Resource /Energy Economics and Policy,
A call for high quality early childhood education in the early years of school in Western Australia
This paper has been written in response to the growing concerns from educators of children in the early years of school (kindergarten to year 2) and university teacher educators who are experiencing first-hand a rapid increase in the formalisation of the early years of schooling in many classrooms in Western Australia (The West Australian, 2013). Concerns for the general and long term health and wellbeing of young children have surfaced in the early childhood profession as we witness increased pressure placed on improving school achievement in national literacy and numeracy tests (King & Janson, 2009; Wescombe-Down, 2013)
A call for a WA Play Strategy in Early Childhood Education and Care
In 2013, ECA WA members were invited to contribute to the development of a strategic plan that would set priorities, focus energy and resources, and work toward the core function of Early Childhood Australia: to advocate for the rights and well-being of children in early childhood education and care (ECEC). Members identified the diminishing opportunities for children (aged birth to eight years) to access quality play in these environments as a major concern necessitating it as a key priority in future planning. The vision that child-initiated and self-directed play be reinstated as a fundamental right in early education and care settings, including the early years of schooling, was similarly shared by members of other leading early childhood advocacy organisations in WA (OMEP, ECTA, EYES and the SSTUWA). Moreover, the demise of play in ECEC was considered by key stakeholder representatives (of Playgroup WA, CareWest, Family Day Care WA, Meerilinga, and Childcare Association of WA) at the ECA WA AGM (2014) during a Panel Discussion on Play. Shortly thereafter, ECA WA pledged its commitment to developing a play strategy initiative
The prevalence of peripheral neuropathy severe enough to cause a loss of protective sensation in a population-based sample of people with known and newly detected diabetes in Barbados: a cross-sectional study.
AIMS: To determine the prevalence and potential risk factors for diabetic peripheral neuropathy with a loss of protective sensation in Barbados. METHODS: A representative population sample aged > 25 years with previously diagnosed diabetes or a fasting blood glucose ≥ 7 mmol/l or HbA1c ≥ 48 mmol/mol (6.5%) was tested by 10 g monofilament at four plantar sites per foot and a 28 Hz tuning fork and neurothesiometer at the hallux. Data were adjusted to the age structure of people with diabetes in Barbados. Multivariable logistic regression assessed associations with peripheral neuropathy with a loss of protective sensation. RESULTS: Of 236 participants [74% response rate, 33% men, 91% black, median age 58.6 years, mean BMI 30.1 kg/m2 , mean HbA1c 54 mmol/mol (7.1%)], 51% had previously diagnosed diabetes. Foot examination demonstrated that 25.8% (95% CI 20.2 to 31.5) had at least one insensate site with monofilament testing, 14.8% (95% CI 10.2 to 19.4) had an abnormal tuning fork test and 10.9% (95% CI 6.9 to 14.9) had a vibration perception threshold > 25 V. Peripheral neuropathy with a loss of protective sensation prevalence was 28.5% (95% CI 22.7 to 34.4) as indicated by monofilament with ≥ 1 insensate site and/or vibration perception threshold > 25 V. With previously diagnosed diabetes the prevalence was 36.4% (95% CI 27.7 to 45.2) with 98.4% of cases identified by monofilament testing. Increasing age, previously diagnosed diabetes, male sex and abdominal obesity were independently associated with peripheral neuropathy with a loss of protective sensation. CONCLUSIONS: Over a third of people with previously diagnosed diabetes had evidence of peripheral neuropathy with a loss of protective sensation. Monofilament testing alone may be adequate to rule out peripheral neuropathy with a loss of protective sensation. Monofilament and neurothesiometer stimuli are reproducible but dependent on participant response
The Ubiquitin Ligase Adaptor NDFIP1 Selectively Enforces a CD8<sup>+</sup> T Cell Tolerance Checkpoint to High-Dose Antigen
Escape from peripheral tolerance checkpoints that control cytotoxic CD8+ T cells is important for cancer immunotherapy and autoimmunity, but pathways enforcing these checkpoints are mostly uncharted. We reveal that the HECT-type ubiquitin ligase activator, NDFIP1, enforces a cell-intrinsic CD8+ T cell checkpoint that desensitizes TCR signaling during in vivo exposure to high antigen levels. Ndfip1-deficient OT-I CD8+ T cells responding to high exogenous tolerogenic antigen doses that normally induce anergy aberrantly expanded and differentiated into effector cells that could precipitate autoimmune diabetes in RIP-OVAhi mice. In contrast, NDFIP1 was dispensable for peripheral deletion to low-dose exogenous or pancreatic islet-derived antigen and had little impact upon effector responses to Listeria or acute LCMV infection. These data provide evidence that NDFIP1 mediates a CD8+ T cell tolerance checkpoint, with a different mechanism to CD4+ T cells, and indicates that CD8+ T cell deletion and anergy are molecularly separable checkpoints.This work
was funded by NIH grant U19-AI100627, by an Australian Government
Research Training Program Domestic Scholarship (to M.V.W.), by a Sydney
Parker Smith Postdoctoral Research Fellowship from the Cancer Council of
Victoria (to J.M.M.), and by the National Health and Medical Research Council
(NHMRC) through Program Grants 1016953, 1113904, and 1054925, Australia
Fellowship 585490 (to C.C.G.), Senior Principal Research Fellowship 1081858
(to C.C.G.), CJ Martin Early Career Fellowship 585518 (to I.A.P.), and Independent
Research Institutes Infrastructure Support Scheme Grant 361646. Florey
Institute of Neuroscience and Mental Health and WEHI acknowledge the
strong support from the Victorian Government and in particular funding from
the Operational Infrastructure Support Grant
Recommended from our members
ADENOVIRUS INTERACTION WITH ITS CELLULAR RECEPTOR CAR.
The mechanism of adenovirus attachment to the host cell plasma membrane has been revealed in detail by research over the past 10 years. It has long been known that receptor binding activity is associated with the viral fibers, trimeric spike proteins that protrude radially from the vertices of the icosahedral capsid (Philipson et al. 1968). In some adenovirus serotypes, fiber and other virus structural proteins are synthesized in excess and accumulate in the cell nucleus during late stages of infection. Fiber protein can be readily purified from lysates of cells infected with subgroup C viruses, for example Ad2 and Ad5 (Boulanger and Puvion 1973). Addition of purified fiber protein to virus suspensions during adsorption strongly inhibits infection, indicating that fiber and intact virus particles compete for binding sites on host cells (Philipson et al. 1968; Hautala et al. 1998). Cell binding studies using purified radiolabeled fiber demonstrated that fiber binds specifically and with high affinity to the cell plasma membrane, and that cell lines typically used for laboratory propagation of adenovirus have approximately 10{sup 4} high-affinity receptor sites per cell (Persson et al. 1985; Freimuth 1996). Similar numbers of high-affinity binding sites for radiolabeled intact virus particles also were observed (Seth et al. 1994)
The role of the exit in the initial screening of investment opportunities: The case of business angel syndicate gatekeepers
The exit process has been largely ignored in business angel research.. The practitioner community identifies the difficulty in achieving exits as the most pressing problem for investors. This has been attributed to the failure of investors to adopt an exit-centric approach to investing. The validity of this claim is examined via a study of the investment approach of 21 ‘gatekeepers’ (managers) of angel groups in Scotland and Northern Ireland. Most gatekeepers say that they do consider the exit when they invest. However, this is contradicted by a verbal protocol analysis which indicates that the exit is not a significant consideration in their initial screening process. The small number of exits achieved by the groups is consistent with the general lack of an exit-centric approach to investing. Only three groups exhibit evidence of a strong exit-centric approach to investing. The lack of exits may have a negative impact on the level of future angel investment activity
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