Ab-initio investigation of phonon dispersion and anomalies in palladium

In recent years, palladium has proven to be a crucial component for devices ranging from nanotube field effect transistors to advanced hydrogen storage devices. In this work, I examine the phonon dispersion of fcc Pd using first principle calculations based on density functional perturbation theory. While several groups in the past have studied the acoustic properties of palladium, this is the first study to reproduce the phonon dispersion and associated anomaly with high accuracy and no adjustable parameters. In particular, I focus on the Kohn anomaly in the [110] direction.Comment: 19 pages, preprint format, 7 figures, added new figures and discussio

The value of agricultural water rights in agricultural properties in the path of development

This paper estimates the value of water rights in a rapidly urbanizing semi-arid area: Phoenix, Arizona. To do this we use hedonic pricing to explore the impact of water rights on property values in 151 agricultural land transactions that occurred between 2001 and 2005. We test two main hypotheses: (1) that the marginal willingness to pay for water rights is higher in more developed urbanizing areas than in less developed rural areas, and (2) that the marginal willingness to pay for water rights in urban areas is increasing in the value of developed land. We find that the marginal willingness to pay for water rights is highest among properties in urbanized or urbanizing areas where a significant proportion of the land has already been developed. Additionally, we find that the marginal willingness to pay for agricultural water rights is greatest in cities where developed land is most valuable

The STAR Silicon Strip Detector (SSD)

The STAR Silicon Strip Detector (SSD) completes the three layers of the Silicon Vertex Tracker (SVT) to make an inner tracking system located inside the Time Projection Chamber (TPC). This additional fourth layer provides two dimensional hit position and energy loss measurements for charged particles, improving the extrapolation of TPC tracks through SVT hits. To match the high multiplicity of central Au+Au collisions at RHIC the double sided silicon strip technology was chosen which makes the SSD a half million channels detector. Dedicated electronics have been designed for both readout and control. Also a novel technique of bonding, the Tape Automated Bonding (TAB), was used to fullfill the large number of bounds to be done. All aspects of the SSD are shortly described here and test performances of produced detection modules as well as simulated results on hit reconstruction are given.Comment: 11 pages, 8 figures, 1 tabl

Multiplicity distribution and spectra of negatively charged hadrons in Au+Au collisions at sqrt(s_nn) = 130 GeV

The minimum bias multiplicity distribution and the transverse momentum and pseudorapidity distributions for central collisions have been measured for negative hadrons (h-) in Au+Au interactions at sqrt(s_nn) = 130 GeV. The multiplicity density at midrapidity for the 5% most central interactions is dNh-/deta|_{eta = 0} = 280 +- 1(stat)+- 20(syst), an increase per participant of 38% relative to ppbar collisions at the same energy. The mean transverse momentum is 0.508 +- 0.012 GeV/c and is larger than in central Pb+Pb collisions at lower energies. The scaling of the h- yield per participant is a strong function of pt. The pseudorapidity distribution is almost constant within |eta|<1.Comment: 6 pages, 3 figure

Cloning and characterization of the ecto-nucleotidase NTPDase3 from rat brain: Predicted secondary structure and relation to other members of the E-NTPDase family and actin

The protein family of ecto-nucleoside triphosphate diphosphohydrolases (E-NTPDase family) contains multiple members that hydrolyze nucleoside 5’-triphosphates and nucleoside 5’-diphosphates with varying preference for the individual type of nucleotide. We report the cloning and functional expression of rat NTPDase3. The rat brain-derived cDNA has an open reading frame of 1590 bp encoding 529 amino acid residues, a calculated molecular mass of 59.1 kDa and predicted N- and C-terminal hydrophobic sequences. It shares 94.3% and 81.7% amino acid identity with the mouse and human NTPDase3, respectively, and is more closely related to cell surface-located than to the intracellularly located members of the enzyme family. The NTPDase3 gene is allocated to chromosome 8q32 and organized into 11 exons. Rat NTPDase3 expressed in CHO cells hydrolyzed both nucleoside triphosphates and nucleoside diphosphates with hydrolysis ratios of ATP:ADP of 5:1 and UTP:UDP of 8:1. After addition of ATP, ADP is formed as an intermediate product that is further hydrolyzed to AMP. The enzyme is preferentially activated by Ca2+ over Mg2+ and reveals an alkaline pH optimum. Immunocytochemistry confirmed expression of heterologously expressed NTPDase3 to the surface of CHO cells. PC12 cells express endogenous surface-located NTPDase3. An immunoblot analysis detects NTPDase3 in all rat brain regions investigated. An alignment of the secondary structure domains of actin conserved within the actin/HSP70/sugar kinase superfamily to those of all members of the NTPDase family reveals apparent similarity. It infers that NTPDases share the two-domain structure with members of this enzyme superfamily

The analysis of 2-amino-2-thiazoline-4-carboxylic acid in the plasma of smokers and non-smokers

ATCA (2-amino-2-thiazoline-4-carboxylic acid) is a promising marker to assess cyanide exposure because of several advantages of ATCA analysis over direct determination of cyanide and alternative cyanide biomarkers (i.e. stability in biological matrices, consistent recovery, and relatively small endogenous concentrations). Concentrations of ATCA in the plasma of smoking and non-smoking human volunteers were analyzed using gas-chromatography mass-spectrometry to establish the feasibility of using ATCA as a marker for cyanide exposure. The levels of ATCA in plasma of smoking volunteers, 17.2 ng/ml, were found to be significantly (p < 0.001) higher than that of non-smoking volunteers, 11.8 ng/ml. Comparison of ATCA concentrations of smokers relative to non-smokers in both urine and plasma yielded relatively similar results. The concentration ratio of ATCA for smokers versus non-smokers in plasma and urine was compared to similar literature studies of cyanide and thiocyanate, and correlations are discussed. This study supports previous evidence that ATCA can be used to determine past cyanide exposure and indicates that further studies should be pursued to validate the use of ATCA as a marker of cyanide exposure

Protective effect of human amniotic fluid stem cells in an immunodeficient mouse model of acute tubular necrosis.

Acute Tubular Necrosis (ATN) causes severe damage to the kidney epithelial tubular cells and is often associated with severe renal dysfunction. Stem-cell based therapies may provide alternative approaches to treating of ATN. We have previously shown that clonal c-kit(pos) stem cells, derived from human amniotic fluid (hAFSC) can be induced to a renal fate in an ex-vivo system. Herein, we show for the first time the successful therapeutic application of hAFSC in a mouse model with glycerol-induced rhabdomyolysis and ATN. When injected into the damaged kidney, luciferase-labeled hAFSC can be tracked using bioluminescence. Moreover, we show that hAFSC provide a protective effect, ameliorating ATN in the acute injury phase as reflected by decreased creatinine and BUN blood levels and by a decrease in the number of damaged tubules and apoptosis therein, as well as by promoting proliferation of tubular epithelial cells. We show significant immunomodulatory effects of hAFSC, over the course of ATN. We therefore speculate that AFSC could represent a novel source of stem cells that may function to modulate the kidney immune milieu in renal failure caused by ATN