Measuring the principal Hugoniot of inertial-confinement-fusion-relevant TMPTA plastic foams

Wetted-foam layers are of significant interest for inertial-confinement-fusion capsules, due to the control they provide over the convergence ratio of the implosion and the opportunity this affords to minimize hydrodynamic instability growth. However, the equation of state for fusion-relevant foams are not well characterized, and many simulations rely on modeling such foams as a homogeneous medium with the foam average density. To address this issue, an experiment was performed using the VULCAN Nd:glass laser at the Central Laser Facility. The aim was to measure the principal Hugoniot of TMPTA plastic foams at 260mg/cm3, corresponding to the density of liquid DT-wetted-foam layers, and their “hydrodynamic equivalent” capsules. A VISAR was used to obtain the shock velocity of both the foam and an α-quartz reference layer, while streaked optical pyrometry provided the temperature of the shocked material. The measurements confirm that, for the 20–120 GPa pressure range accessed, this material can indeed be well described using the equation of state of the homogeneous medium at the foam density

Engineering the Redox Potential over a Wide Range within a New Class of FeS Proteins

Abstract: MitoNEET is a newly discovered mitochondrial protein and a target of the TZD class of antidiabetes drugs. MitoNEET is homodimeric with each protomer binding a [2Fe-2S] center through a rare 3-Cys and 1-His coordination geometry. Both the fold and the coordination of the [2Fe-2S] centers suggest that it could have novel properties compared to other known [2Fe-2S] proteins. We tested the robustness of mitoNEET to mutation and the range over which the redox potential (EM) could be tuned. We found that the protein could tolerate an array of mutations that modified the EM of the [2Fe-2S] center over a range of ∼700 mV, which is the largest EM range engineered in an FeS protein and, importantly, spans the cellular redox range (+200 to-300 mV). These properties make mitoNEET potentially useful for both physiological studies and industrial applications as a stable, water-soluble, redox agent

Transmission of Methicillin‐Resistant Staphylococcus aureus Infection Through Solid Organ Transplantation: Confirmation Via Whole Genome Sequencing

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109324/1/ajt12898.pd

A Hedged Monte Carlo Approach to Real Option Pricing

In this work we are concerned with valuing optionalities associated to invest or to delay investment in a project when the available information provided to the manager comes from simulated data of cash flows under historical (or subjective) measure in a possibly incomplete market. Our approach is suitable also to incorporating subjective views from management or market experts and to stochastic investment costs. It is based on the Hedged Monte Carlo strategy proposed by Potters et al (2001) where options are priced simultaneously with the determination of the corresponding hedging. The approach is particularly well-suited to the evaluation of commodity related projects whereby the availability of pricing formulae is very rare, the scenario simulations are usually available only in the historical measure, and the cash flows can be highly nonlinear functions of the prices.Comment: 25 pages, 14 figure

Linking Scottish vital event records using family groups

Funding: This work was supported by ESRC Grants ES/K00574X/2 “Digitising Scotland” and ES/L007487/1 “Administrative Data Research Centre – Scotland.”The reconstitution of populations through linkage of historical records is a powerful approach to generate longitudinal historical microdata resources of interest to researchers in various fields. Here we consider automated linking of the vital events recorded in the civil registers of birth, death and marriage compiled in Scotland, to bring together the various records associated with the demographic events in the life course of each individual in the population. From the histories, the genealogical structure of the population can then be built up. Rather than apply standard linkage techniques to link the individuals on the available certificates, we explore an alternative approach, inspired by the family reconstitution techniques adopted by historical demographers, in which the births of siblings are first linked to form family groups, after which intergenerational links between families can be established. We report a small-scale evaluation of this approach, using two district-level data sets from Scotland in the late nineteenth century, for which sibling links have already been created by demographers. We show that quality measures of up to 83% can be achieved on these data sets (using F-Measure, a combination of precision and recall). In the future, we intend to compare the results with a standard linkage approach and to investigate how these various methods may be used in a project which aims to link the entire Scottish population from 1856 to 1973.PostprintPeer reviewe

Ehrlichia ewingii Infection in White-Tailed Deer (Odocoileus virginianus)

Two closely related zoonotic ehrlichiae, Ehrlichia chaffeensis and E. ewingii, are transmitted by Amblyomma americanum, the lone star tick. Because white-tailed deer (Odocoileus virginianus) are critical hosts for all mobile stages of A. americanum and are important vertebrate reservoirs of E. chaffeensis, we investigated whether deer may be infected with E. ewingii, a cause of granulocytotropic ehrlichiosis in humans and dogs. To test for E. ewingii infection, we used polymerase chain reaction and inoculation of fawns with whole blood from wild deer. Of 110 deer tested from 20 locations in 8 U.S. states, 6 (5.5%) were positive for E. ewingii. In addition, natural E. ewingii infection was confirmed through infection of captive fawns. These findings expand the geographic distribution of E. ewingii, along with risk for human infection, to include areas of Kentucky, Georgia, and South Carolina. These data suggest that white-tailed deer may be an important reservoir for E. ewingii

Slow Dissociation of a Charged Ligand: Analysis of the Primary Quinone QA Site of Photosynthetic Bacterial Reaction Centers

Reaction centers (RCs) are integral membrane proteins that undergo a series of electron transfer reactions during the process of photosynthesis. In the QA site of RCs from Rhodobacter sphaeroides, ubiquinone-10 is reduced, by a single electron transfer, to its semiquinone. The neutral quinone and anionic semiquinone have similar affinities, which is required for correct in situ reaction thermodynamics. A previous study showed that despite similar affinities, anionic quinones associate and dissociate from the QA site at rates ≈104 times slower than neutral quinones indicating that anionic quinones encounter larger binding barriers (Madeo, J.; Gunner, M. R. Modeling binding kinetics at the QA site in bacterial reaction centers. Biochemistry2005, 44, 10994–11004). The present study investigates these barriers computationally, using steered molecular dynamics (SMD) to model the unbinding of neutral ground state ubiquinone (UQ) and its reduced anionic semiquinone (SQ–) from the QA site. In agreement with experiment, the SMD unbinding barrier for SQ– is larger than for UQ. Multi Conformational Continuum Electrostatics (MCCE), used here to calculate the binding energy, shows that SQ– and UQ have comparable affinities. In the QA site, there are stronger binding interactions for SQ– compared to UQ, especially electrostatic attraction to a bound non-heme Fe2+. These interactions compensate for the higher SQ– desolvation penalty, allowing both redox states to have similar affinities. These additional interactions also increase the dissociation barrier for SQ– relative to UQ. Thus, the slower SQ– dissociation rate is a direct physical consequence of the additional binding interactions required to achieve a QA site affinity similar to that of UQ. By a similar mechanism, the slower association rate is caused by stronger interactions between SQ– and the polar solvent. Thus, stronger interactions for both the unbound and bound states of charged and highly polar ligands can slow their binding kinetics without a conformational gate. Implications of this for other systems are discussed