EFFECTS OF PORT USER FEES ON EXPORT GRAIN FLOW PATTERNS

The purpose of this paper is to evaluate the effect of the proposed deep draft port user fee on export grain flow patterns and provide insight into potential marketing system adjustment costs which may result from diverted flows. A multiperiod, network flow model is used to conduct the analysis. Analyses show grain flow patterns to be affected most by a port specific fee which is based on weight. The annual variation in flows generated by imposition of port user charges in generally less than the historical year-to-year variation and, in most cases, the altered port area flows can be accommodated by existing infrastructure.International Relations/Trade,

HOUSEHOLD SIZE AND COMPOSITION IMPACTS ON MEAT DEMAND IN MEXICO: A CENSORED DEMAND SYSTEM APPROACH

The proposed paper adopts the censored demand system approach of Lee and Pitt (1986) to examine the structure of Mexican food demand. This approach uses the concept of virtual prices to explain specific purchase patterns. The contribution of our selected paper is the incorporation of the endogenous equivalence scale function proposed by Phlipps (1998) within this censored system. The contribution of this analysis is not only in terms of the use of an endogenous scaling function within a censored demand system, but we also will be use simulated maximum likelihood techniques which allows for the specification and estimation of significantly larger sized demand systems without the imposition of restrictive distributional assumptions on the equation error terms. We use a Gibbs sampling techniques to evaluate higher order truncated distributions required to implement the Lee and Pitt (1986) model specification.Demand and Price Analysis,

A note on the likelihood and moments of the skew-normal distribution

In this paper an alternative approach to the one in Henze (1986) is proposed for deriving the odd moments of the skew-normal distribution considered in Azzalini (1985). The approach is based on a Pascal type triangle, which seems to greatly simplify moments computation. Moreover, it is shown that the likelihood equation for estimating the asymmetry parameter in such model is generated as orthogonal functions to the sample vector. As a consequence, conditions for a unique solution of the likelihood equation are established, which seem to hold in more general setting

Electrodeposition from supercritical fluids

Recent studies have shown that it is possible to electrodeposit a range of materials, such as Cu, Ag and Ge, from various supercritical fluids, including hydrofluorocarbons and mixtures of CO2 with suitable co-solvents. In this perspective we discuss the relatively new field of electrodeposition from supercritical fluids. The perspective focuses on some of the underlying physical chemistry and covers both practical and scientific aspects of electrodeposition from supercritical fluids. We also discuss possible applications for supercritical fluid electrodeposition and suggest some key developments that are required to take the field to the next stage

The COMPLETE Survey of Outflows in Perseus

We present a study on the impact of molecular outflows in the Perseus molecular cloud complex using the COMPLETE survey large-scale 12CO(1-0) and 13CO(1-0) maps. We used three-dimensional isosurface models generated in RA-DEC-Velocity space to visualize the maps. This rendering of the molecular line data allowed for a rapid and efficient way to search for molecular outflows over a large (~ 16 sq. deg.) area. Our outflow-searching technique detected previously known molecular outflows as well as new candidate outflows. Most of these new outflow-related high-velocity features lie in regions that have been poorly studied before. These new outflow candidates more than double the amount of outflow mass, momentum, and kinetic energy in the Perseus cloud complex. Our results indicate that outflows have significant impact on the environment immediately surrounding localized regions of active star formation, but lack the energy needed to feed the observed turbulence in the entire Perseus complex. This implies that other energy sources, in addition to protostellar outflows, are responsible for turbulence on a global cloud scale in Perseus. We studied the impact of outflows in six regions with active star formation within Perseus of sizes in the range of 1 to 4 pc. We find that outflows have enough power to maintain the turbulence in these regions and enough momentum to disperse and unbind some mass from them. We found no correlation between outflow strength and star formation efficiency for the six different regions we studied, contrary to results of recent numerical simulations. The low fraction of gas that potentially could be ejected due to outflows suggests that additional mechanisms other than cloud dispersal by outflows are needed to explain low star formation efficiencies in clusters.Comment: Published in The Astrophysical Journa

Cu/Ag EAM Potential Optimized for Heteroepitaxial Diffusion from ab initio Data

A binary embedded-atom method (EAM) potential is optimized for Cu on Ag(111) by fitting to ab initio data. The fitting database consists of DFT calculations of Cu monomers and dimers on Ag(111), specifically their relative energies, adatom heights, and dimer separations. We start from the Mishin Cu-Ag EAM potential and first modify the Cu-Ag pair potential to match the FCC/HCP site energy difference then include Cu-Cu pair potential optimization for the entire database. The optimized EAM potential reproduce DFT monomer and dimer relative energies and geometries correctly. In trimer calculations, the potential produces the DFT relative energy between FCC and HCP trimers, though a different ground state is predicted. We use the optimized potential to calculate diffusion barriers for Cu monomers, dimers, and trimers. The predicted monomer barrier is the same as DFT, while experimental barriers for monomers and dimers are both lower than predicted here. We attribute the difference with experiment to the overestimation of surface adsorption energies by DFT and a simple correction is presented. Our results show that the optimized Cu-Ag EAM can be applied in the study of larger Cu islands on Ag(111).Comment: 15 pages, 7 figure

An Extinction Study of the Taurus Dark Cloud Complex

We present a study of the detailed distribution of extinction in a region of the Taurus dark cloud complex. Our study uses new BVR images of the region, spectral classification data for 95 stars, and IRAS Sky Survey Atlas (ISSA) 60 and 100 micron images. We study the extinction of the region in four different ways, and we present the first inter-comparison of all these methods, which are: 1) using the color excess of background stars for which spectral types are known; 2) using the ISSA 60 and 100 micron images; 3) using star counts; and 4) using an optical (V and R) version of the average color excess method used by Lada et al. (1994). We find that all four methods give generally similar results, with important exceptions. To study the structure in the dust distribution, we compare the ISSA extinction and the extinction measured for individual stars. From the comparison, we conclude that in the relatively low extinction regions studied, with 0.9 < A_V < 3.0 mag (away from filamentary dark clouds and IRAS cores), there are no fluctuations in the dust column density greater than 45% (at the 99.7% confidence level), on scales smaller than 0.2 pc. We also report the discovery of a previously unknown stellar cluster behind the Taurus dark cloud near R.A 4h19m00s, Dec. 27:30:00 (B1950)Comment: 49 pages (which include 6 pages of tables and 6 pages of figures

Cerebrospinal fluid levels of extracellular heat shock protein 72: A potential biomarker for bacterial meningitis in children

Extracellular heat shock protein 72 (Hsp72) is an endogenous danger signal and potential biomarker for critical illness in children. We hypothesized that elevated levels of extracellular Hsp72 in the cerebrospinal fluid (CSF) of children with suspected meningitis could predict bacterial meningitis. We measured extracellular Hsp72 levels in the CSF of 31 critically ill children with suspected meningitis via a commercially available enzyme-linked immunosorbent assay. Fourteen had bacterial meningitis based on CSF pleocytosis and bacterial growth in either blood or CSF culture. Seventeen children with negative cultures comprised the control group. CSF Hsp72 was significantly elevated in children with bacterial meningitis compared to controls. Importantly, CSF Hsp72 levels did not correlate with the CSF white blood cell count. On receiver operator characteristic analysis, using a cut-off of 8.1 ng/mL, CSF Hsp72 has a sensitivity of 79% and a specificity of 94% for predicting bacterial meningitis. We therefore conclude that CSF extracellular Hsp72 levels are elevated in critically ill children with bacterial meningitis versus controls. Hsp72 potentially offers clinicians improved diagnostic information in distinguishing bacterial meningitis from other processes