Comparing Five and Lower-Dimensional Grain Boundary Character and Energy Distributions in Copper: Experiment and Molecular Statics Simulation

Metallurgical and Materials Transactions A - The misorientation of 515 grain boundaries has been determined using electron backscatter diffraction data from an 18 μm thick copper foil with...     

Proton acceleration using 50 fs, high intensity ASTRA-Gemini laser pulses

We report on experimental investigations of proton acceleration from thin foil targets irradiated with ultra-short (∼50 fs), high contrast (∼10¹⁰) and ultra-intense (up to 10²¹ W/cm²) laser pulses. These measurements provided for the first time the opportunity to extend the scaling laws for the acceleration process in the ultra-short regime beyond the 10²⁰ W/cm² threshold. The scaling of accelerated proton energies was investigated by varying the thickness of Al targets (down to 50 nm) under 35° angle of laser incidence and with p-polarised light.     

Computer modelling and analysis of the photodegradation effect in a-Si:H p-i-n solar cell

Using a previous model, which was developed to describe the light-induced creation of the defect density in the a-Si:H gap states, we present in this work a numerical modelling of the photodegradation effect in the a-Si:H p-i-n solar cell under continuous illumination. We first considered the simple case of a monochromatic light beam with a wavelength λ between 530-540 nm non uniformly absorbed, then the global standard solar spectrum (AM 1.5) illumination is taken into account. The photodegradation is analysed on the basis of the resulting changes in the free carrier's densities, recombination rate, band structure, electrical potential and field, space charge, and current densities. Changes in the cell's external parameters: the open circuit voltage V_oc, the short circuit current density J_sc, the fill factor FF and the maximum power density P_max are also presented.     

Measuring errors and violations on the road: A bifactor modeling approach to the Driver Behavior Questionnaire

The Driver Behavior Questionnaire (DBQ) is a self-report measure of driving behavior that has been widely used over more than 20 years. Despite this wealth of evidence a number of questions remain, including understanding the correlation between its violations and errors sub-components, identifying how these components are related to crash involvement, and testing whether a DBQ based on a reduced number of items can be effective. We address these issues using a bifactor modeling approach to data drawn from the UK Cohort II longitudinal study of novice drivers. This dataset provides observations on 12,012 drivers with DBQ data collected at .5, 1, 2 and 3 years after passing their test. A bifactor model, including a general factor onto which all items loaded, and specific factors for ordinary violations, aggressive violations, slips and errors fitted the data better than correlated factors and second-order factor structures. A model based on only 12 items replicated this structure and produced factor scores that were highly correlated with the full model. The ordinary violations and general factor were significant independent predictors of crash involvement at 6 months after starting independent driving. The discussion considers the role of the general and specific factors in crash involvement.     

Structure of CheA, a signal-transducing histidine kinase

BACKGROUND/AIMS: After liver transplantation for autoimmune hepatitis, the long-term results and the incidence of recurrence of primary disease are unknown. METHODS: In this retrospective study we reviewed the clinical course of 25 patients transplanted for autoimmune hepatitis and followed for a mean of 5.3 years (2-8.5 years). RESULTS: The actuarial 5-year patient and graft survival rates were 91% (+/-6%) and 83% (+/-8%). The actuarial 1-year rate of acute rejection was 50% (+/-10.2%), which was comparable to that of patients transplanted for primary biliary cirrhosis and primary sclerosing cholangitis. Autoantibodies persisted in 77% of patients, at a lower titer than before liver transplantation. Ten patients were excluded from the study of autoimmune hepatitis recurrence, one because of an early postoperative death and nine because of hepatitis C virus infection acquired before or after liver transplantation. In the remaining 15 patients, who were free of hepatitis C virus infection, 5-year patient and graft survivals were 100% and 87%, respectively. Despite triple immunosuppressive therapy, three patients (20%) developed chronic hepatitis with histological and serological features of autoimmune hepatitis in the absence of any other identifiable cause. The disease was severe in two patients, leading to graft failure and asymptomatic in another, despite marked histological abnormalities. In one of these three patients, autoimmune hepatitis recurred on the second liver graft as well. CONCLUSIONS: Patients undergoing liver transplantation for autoimmune hepatitis have an excellent survival rate although severe primary disease may recur, suggesting the need for stronger post-operative immunosuppressive therapy.     

Application of pbp1A PCR in identification of penicillin-resistant Streptococcus pneumoniae

A seminested PCR assay, based on the amplification of the pneumococcal pbp1A gene, was developed for the detection of penicillin resistance in clinical isolates of Streptococcus pneumoniae. The assay was able to differentiate between intermediate (MICs = 0.25 to 0.5 microgram/ml) and higher-level (MICs = >/=1 microgram/ml) resistance. Two species-specific primers, 1A-1 and 1A-2, which amplified a 1,043-bp region of the pbp1A penicillin-binding region, were used for pneumococcal detection. Two resistance primers, 1A-R1 and 1A-R2, were designed to bind to altered areas of the pbp1A gene which, together with the downstream primer 1A-2, amplify DNA from isolates with penicillin MICs of >/=0.25 and >/=1 microgram/ml, respectively. A total of 183 clinical isolates were tested with the pbp1A assay. For 98.3% (180 of 183) of these isolates, the PCR results obtained were in agreement with the MIC data. The positive and negative predictive values of the assay were 100 and 91%, respectively, for detecting strains for which the MICs were >/=0.25 microgram/ml and were both 100% for strains for which the MICs were >/=1 microgram/ml.     

Effects of novelty and pain on behavior and hippocampal extracellular ACh levels in male and female rats

In vivo microdialysis was used to assess the effects of novelty and pain on hippocampal ACh release in male and female rats. Experiments were carried out during the dark phase and consisted of 2 days of tests: on Day 1, after Baseline 1, animals were exposed to a new cage (Novelty) to which, 30 min later, a plastic cylinder (Object) was introduced. On Day 2, after Baseline 2, the Formalin test (50 microl of formalin 10%, s.c. injected in the dorsal hindpaw) was carried out in the animal's home cage. All behaviors were recorded. The extracellular levels of ACh in the dorsal hippocampus were estimated, in 10-min samples, by assay of ACh in the dialysates by HPLC. On Day 1 the raw values of ACh were higher in females than in males, but no sex difference was present when the percentage of change was considered. In both sexes the Novelty and Object tests induced an increase in ACh levels with respect to Baseline. Higher levels of exploration were present in females than males during the first 10 min of Novelty. On Day 2, ACh release increased in both sexes during the Formalin test. No sex difference in either ACh raw values or the percentages of change were found. Females showed higher levels of licking and lower levels of activity than males. The present study shows that novelty and pain induce similar hippocampal cholinergic activation in male and female rats but different behaviors. The results are discussed in light of the several anatomical and functional sex differences present in the hippocampus.