USING CHOICE EXPERIMENTS TO ELICIT FARMERS PREFERENCES? FOR CROP AND HEALTH INSURANCE

A random utility discrete choice experiments is used to determine farmers' preferences for health insurance, crop insurance, and a product that switches some portion of crop insurance subsidy to health insurance premium subsidy with access to large-pool risk groups.Risk and Uncertainty,

Morphological phylogeny of Megachilini and the evolution of leaf-cutter behavior in bees (Hymenoptera: Megachilidae): Evolution of leaf-cutter behavior in bees

A unique feature among bees is the ability of some species of Megachile Latreille s.l. to cut and process fresh leaves for nest construction. The presence of a razor between the female mandibular teeth (interdental laminae) to facilitate leaf-cutting (LC) is a morphological novelty that might have triggered a subsequent diversification in this group. However, we have a limited understanding of the phylogeny of this group despite the large number of described species and the origins and patterns of variations of this mandibular structure are unknown. Herein, using a cladistic analysis of adult external morphological characters, we explored the relationships of all genera of Megachilini and the more than 50 subgenera of Megachile s.l. We coded 272 characters for 8 outgroups and 114 ingroup species. Depending on the weighting scheme (equal or implied weighting), our parsimony analyses suggested the monophyly of Megachile s.l. and that either Noteriades Cockerell or the clade Coelioxys Latreille + Radoszkowskiana Popov is the extant sister group of all other Megachilini. In addition, we conducted Bayesian total-evidence tip-dating analyses to examine other possible hypotheses of relationships and patterns of variation of the interdental lamina. Our analyses suggest that interdental laminae developed asynchronicaly from two different structures in the mandible, and differ in their phenotypic plasticity. Character correlation tests using phylogenetic pairwise comparisons indicated that the presence of interdental lamina is not associated with head size, mandible size and shape, and pubescence on the adductor interspace. We discuss the implications of our findings for the classification of Megachilini and the development of novel evolutionary, ecological, and functional hypotheses on this behavior. New taxa established are Pseudoheriadini Gonzalez & Engel, new tribe, Ochreriadini Gonzalez & Engel, new tribe, Cremnomegachile Gonzalez & Engel, new genus, Rozenapis Gonzalez & Engel, new genus, and Saucrochile Gonzalez & Engel, new genus, along with the following new combinations: Cremnomegachile dolichosoma (Benoist), new combination, Rozenapis ignita (Smith), new combination, and Saucrochile heriadiformis (Smith), new combination

Matrix-Element Corrections to Parton Shower Algorithms

We discuss two ways in which parton shower algorithms can be supplemented by matrix-element corrections to ensure the correct hard limit: by using complementary phase-space regions, or by modifying the shower itself. In the former case, existing algorithms are self-consistent only if the total correction is small. In the latter case, existing algorithms are never self-consistent, a problem that is particularly severe for angular-ordered parton shower algorithms. We show how to construct self-consistent algorithms in both cases. The postscript file for this paper can also be obtained by anonymous ftp from thep.lu.se in the file pub/Preprints/lu_tp_94_17.psComment: 11 pages, LU TP 94-1

Multilateral inversion of A_r, C_r and D_r basic hypergeometric series

In [Electron. J. Combin. 10 (2003), #R10], the author presented a new basic hypergeometric matrix inverse with applications to bilateral basic hypergeometric series. This matrix inversion result was directly extracted from an instance of Bailey's very-well-poised 6-psi-6 summation theorem, and involves two infinite matrices which are not lower-triangular. The present paper features three different multivariable generalizations of the above result. These are extracted from Gustafson's A_r and C_r extensions and of the author's recent A_r extension of Bailey's 6-psi-6 summation formula. By combining these new multidimensional matrix inverses with A_r and D_r extensions of Jackson's 8-phi-7 summation theorem three balanced very-well-poised 8-psi-8 summation theorems associated with the root systems A_r and C_r are derived.Comment: 24 page

Predicting death over 8 years in a prospective cohort of HIV-infected women: the Women's Interagency HIV Study.

ObjectivesPredicting mortality in middle-aged HIV-infected (HIV+) women on antiretroviral therapies (ART) is important for understanding the impact of HIV infection. Several health indices have been used to predict mortality in women with HIV infection. We evaluated: (1) an HIV biological index, Veterans Aging Cohort Study (VACS); (2) a physical index, Fried Frailty Index (FFI); and (3) a mental health index, Center for Epidemiologic Studies-Depression (CES-D). Proportional hazards regression analyses were used to predict death and included relevant covariates.DesignProspective, observational cohort.SettingMulticentre, across six sites in the USA.Participants1385 multirace/ethnic ART-experienced HIV+ women in 2005.Primary and secondary outcomesAll deaths, AIDS deaths and non-AIDS deaths up to ~8 years from baseline.ResultsIncluded together in one model, VACS Index was the dominant, significant independent predictor of all deaths within 3 years (HR=2.20, 95% CI 1.83, 2.65, χ2=69.04, p<0.0001), and later than 3 years (HR=1.55, 95% CI 1.30, 1.84, χ2=23.88, p<0.0001); followed by FFI within 3 years (HR=2.06, 95% CI 1.19, 3.57, χ2=6.73, p=0.01) and later than 3 years (HR=2.43, 95% CI 1.58, 3.75, χ2=16.18, p=0.0001). CES-D score was not independently associated with mortality.Conclusions and relevanceThis is the first simultaneous evaluation of three common health indices in HIV+ adults. Indices reflecting physical and biological ageing were associated with death

A new multivariable 6-psi-6 summation formula

By multidimensional matrix inversion, combined with an A_r extension of Jackson's 8-phi-7 summation formula by Milne, a new multivariable 8-phi-7 summation is derived. By a polynomial argument this 8-phi-7 summation is transformed to another multivariable 8-phi-7 summation which, by taking a suitable limit, is reduced to a new multivariable extension of the nonterminating 6-phi-5 summation. The latter is then extended, by analytic continuation, to a new multivariable extension of Bailey's very-well-poised 6-psi-6 summation formula.Comment: 16 page

Receptors and Other Signaling Proteins Required for Serotonin Control of Locomotion in Caenorhabditis elegans

A better understanding of the molecular mechanisms of signaling by the neurotransmitter serotonin is required to assess the hypothesis that defects in serotonin signaling underlie depression in humans. Caenorhabditis elegans uses serotonin as a neurotransmitter to regulate locomotion, providing a genetic system to analyze serotonin signaling. From large-scale genetic screens we identified 36 mutants of C. elegans in which serotonin fails to have its normal effect of slowing locomotion, and we molecularly identified eight genes affected by 19 of the mutations. Two of the genes encode the serotonin-gated ion channel MOD-1 and the G-protein-coupled serotonin receptor SER-4. mod-1 is expressed in the neurons and muscles that directly control locomotion, while ser-4 is expressed in an almost entirely non-overlapping set of sensory and interneurons. The cells expressing the two receptors are largely not direct postsynaptic targets of serotonergic neurons. We analyzed animals lacking or overexpressing the receptors in various combinations using several assays for serotonin response. We found that the two receptors act in parallel to affect locomotion. Our results show that serotonin functions as an extrasynaptic signal that independently activates multiple receptors at a distance from its release sites and identify at least six additional proteins that appear to act with serotonin receptors to mediate serotonin response.National Institutes of Health (U.S.) (Grant GM24663

A Computational Approach to Simulating the Performance of a 24-Hour Solar-Fuel Cell-Hydrogen Electric Power Plant

World energy demand has risen from about 375 exajoules (EJ) in 1990 to around 600 EJ today. The Energy Information Administration predicts that by the year 2035, this figure will rise to around 800 EJ. This places large stresses on the electric generation infrastructure. Increasingly this demand is being met by renewable energy sources. There are several reasons this is the case. The prices of renewables are dropping quickly and reaching grid parity in more regions. Utilizing renewable energy generation can help achieve energy security: adverse weather or military conflicts are less likely to impact supply routes when energy is produced closer to home. Furthermore, renewable energy technologies are attractive because they do not adversely affect the environment by releasing greenhouse gases which contribute to global warming. One major problem with the deployment of renewable technologies is their intermittent nature. In order to achieve good market penetration it is likely that some sort of energy storage needs to be employed. Several types exist such as thermal storage, pumped storage, batteries and chemicals. Chemical energy derived from renewables is attractive because it has long storage lifetimes, is easily transportable and can be produced from abundant feedstocks; as in the case of generating hydrogen from water electrolysis. Hydrogen produced from solar energy shows promise because of the abundant feedstock (water) and energy supply (the sun). One way that hydrogen can be used to buffer the intermittent nature of solar energy is by using photovoltaic modules to produce electricity which is used to electrolyze water with a regenerative fuel cell and then storing the hydrogen gas. Small-scale solar-fuel cell-hydrogen power plants have been constructed and tested, but often suffer from poor equipment reliability or improper equipment sizing. More study on the effects of component sizing on the system performance of these power plants must be performed. In this research, a computer program is developed which can simulate the long-term behavior of a solar-fuel cell-hydrogen power plant given any sizing of system components: the number and type of photovoltaic modules, the total power of the regenerative fuel cells and the hydrogen storage capacity. Taking into account the details of the system components, location of the plant, meteorological data and the demand load, this program predicts the behavior of such a power plant for any time period. In particular the program can be used to simulate time periods that eliminate the effect of the plant start-up. In essence this is done by running the program for several years to remove the effects of the initial conditions. The biggest initial condition that affects short term results is the amount of hydrogen in storage at the beginning of the simulation. Another important aspect of this program is that the simulation is done on an hourly basis. This computer program outputs important parameters such as how much of the electricity demand was met, how much excess electricity was produced, the amount of solar resource available, the power output of the photovoltaic array, the power into or out of the regenerative fuel cell, and the amount of hydrogen in storage. From these outputs, the proper sizing of a solar-fuel cell-hydrogen power plant can be determined for any size load from residential to utility-scale

Analysis of meteorology-chemistry interactions during air pollution episodes using online coupled models within AQMEII Phase-2

This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).This study reviews the top ranked meteorology and chemistry interactions in online coupled models recommended by an experts’ survey conducted in COST Action EuMetChem and examines the sensitivity of those interactions during two pollution episodes: the Russian forest fires 25 Jul -15 Aug 2010 and a Saharan dust transport event from 1 Oct -31 Oct 2010 as a part of the AQMEII phase-2 exercise. Three WRF-Chem model simulations were performed for the forest fire case for a baseline without any aerosol feedback on meteorology, a simulation with aerosol direct effects only and a simulation including both direct and indirect effects. For the dust case study, eight WRF-Chem and one WRF-CMAQ simulations were selected from the set of simulations conducted in the framework of AQMEII. Of these two simulations considered no feedbacks, two included direct effects only and five simulations included both direct and indirect effects. The results from both episodes demonstrate that it is important to include the meteorology and chemistry interactions in online-coupled models. Model evaluations using routine observations collected in AQMEII phase-2 and observations from a station in Moscow show that for the fire case the simulation including only aerosol direct effects has better performance than the simulations with no aerosol feedbacks or including both direct and indirect effects. The normalized mean biases are significantly reduced by 10-20% for PM10 when including aerosol direct effects. The analysis for the dust case confirms that models perform better when including aerosol direct effects, but worse when including both aerosol direct and indirect effects, which suggests that the representation of aerosol indirect effects needs to be improved in the model.Peer reviewedFinal Published versio