Reduction of Yield and Income Risk Under Alternative Crop Insurance and Disaster Assistance Plans

This study compares the effectiveness of five crop insurance/disaster assistance plans: an individual farm yield insurance plan similar to the current FCIC multi-peril program ; two area yield insurance plans; a farm yield disaster assistance plan; and an area yield disaster assistance plan. These methods are examined for reduction in yield and gross income variability with and without participation in the government deficiency payment programs using farm-level yield data from 98 dryland wheat farms and 38 dryland corn farms in Kansas . Although individual farm yield insurance is complex, suffers from moral hazard and adverse selection problems, and is likely to be the most expensive to administer , it provides more yield and gross income risk reduction than any of the alternative insurance/disaster assistance plans.Crop Insurance, Crop Disaster Assistance, Risk, Wheat, Corn, Risk and Uncertainty,

Transcriptomes of parents identify parenting strategies and sexual conflict in a subsocial beetle

This work was funded by UK NERC grants to M.G.R. and A.J.M. an NERC studentship to D.J.P. the University of Georgia and a US NSF grant to A.J.M. and M.G.R.Parenting in the burying beetle Nicrophorus vespilloides is complex and, unusually, the sex and number of parents that can be present is flexible. Such flexibility is expected to involve specialized behaviour by the two sexes under biparental conditions. Here, we show that offspring fare equally well regardless of the sex or number of parents present. Comparing transcriptomes, we find a largely overlapping set of differentially expressed genes in both uniparental and biparental females and in uniparental males including vitellogenin, associated with reproduction, and takeout, influencing sex-specific mating and feeding behaviour. Gene expression in biparental males is similar to that in non-caring states. Thus, being ‘biparental’ in N. vespilloides describes the family social organization rather than the number of directly parenting individuals. There was no specialization; instead, in biparental families, direct male parental care appears to be limited with female behaviour unchanged. This should lead to strong sexual conflict.Publisher PDFPeer reviewe

GaAs Enhancement-Mode NMOSFETs Enabled by Atomic Layer Epitaxial La1.8Y0.2O3La_{1.8}Y_{0.2}O_3 as Dielectric

We demonstrate high performance enhancement-mode (E-mode) GaAs NMOSFETs with an epitaxial gate dielectric layer of $La_{1.8}Y_{0.2}O_3$ grown by atomic layer epitaxy (ALE) on GaAs(111)A substrates. A $0.5-\mu m$-gate-length device has a record-high maximum drain current of 336 mA/mm for surface-channel E-mode GaAs NMOSFETs, a peak intrinsic transconductance of 210 mS/mm, a subthreshold swing of 97 mV/dec and an $I_{ON}/I_{OFF}$ ratio larger than $10^7$. Thermal stability of the single crystalline $La_{1.8}Y_{0.2}O_3$-single crystalline GaAs interface is investigated by capacitance-voltage (C-V) and conductance-voltage (G-V) analysis. High temperature annealing is found to be effective to reduce the $D_{it}$.Chemistry and Chemical Biolog

Density perturbations in the brane-world

In Randall-Sundrum-type brane-world cosmologies, density perturbations generate Weyl curvature in the bulk, which in turn backreacts on the brane via stress-energy perturbations. On large scales, the perturbation equations contain a closed system on the brane, which may be solved without solving for the bulk perturbations. Bulk effects produce a non-adiabatic mode, even when the matter perturbations are adiabatic, and alter the background dynamics. As a consequence, the standard evolution of large-scale fluctuations in general relativity is modified. The metric perturbation on large-scales is not constant during high-energy inflation. It is constant during the radiation era, except at most during the very beginning, if the energy is high enough.Comment: Additional arguments and minor corrections; version accepted by Phys. Rev.

Restoring the sting to metric preheating

The relative growth of field and metric perturbations during preheating is sensitive to initial conditions set in the preceding inflationary phase. Recent work suggests this may protect super-Hubble metric perturbations from resonant amplification during preheating. We show that this possibility is fragile and sensitive to the specific form of the interactions between the inflaton and other fields. The suppression is naturally absent in two classes of preheating in which either (1) the vacua of the non-inflaton fields during inflation are deformed away from the origin, or (2) the effective masses of non-inflaton fields during inflation are small but during preheating are large. Unlike the simple toy model of a $g^2 \phi^2 \chi^2$ coupling, most realistic particle physics models contain these other features. Moreover, they generically lead to both adiabatic and isocurvature modes and non-Gaussian scars on super-Hubble scales. Large-scale coherent magnetic fields may also appear naturally.Comment: 6 pages, 3 ps figures, RevTex, revised discussion of backreaction and new figure. To appear Phys. Rev. D (Rapid Communication

Surface alloying and iron selenide formation in Fe/Bi2Se3(0001) observed by x-ray absorption fine structure experiments

The atomic structure of ultrathin iron films deposited on the (0001) surface of the topological insulator Bi2Se3 is analyzed by surface x-ray absorption spectroscopy. Iron atoms deposited on a Bi2Se3 (0001) surface kept at 160 K substitute bismuth atoms within the first quintuple layer. Iron atoms are neighbored by six selenium atoms at a distance in the 2.4 Å range indicating substantial atomic relaxations. Mild annealing up to 520 K leads to the formation of α-FeSe, characterized by a local order extending up to the sixth shell (5.80 Å). Ab initio calculations predict a noncollinear magnetic ordering with a transition temperature of 3.5–10 K depending on the iron concentration and the number of the layers in which Fe is located