Scintillator-based ion beam profiler for diagnosing laser-accelerated ion beams

Next generation intense, short-pulse laser facilities require new high repetition rate diagnostics for the detection of ionizing radiation. We have designed a new scintillator-based ion beam profiler capable of measuring the ion beam transverse profile for a number of discrete energy ranges. The optical response and emission characteristics of four common plastic scintillators has been investigated for a range of proton energies and fluxes. The scintillator light output (for 1 MeV > Ep < 28 MeV) was found to have a non-linear scaling with proton energy but a linear response to incident flux. Initial measurements with a prototype diagnostic have been successful, although further calibration work is required to characterize the total system response and limitations under the high flux, short pulse duration conditions of a typical high intensity laser-plasma interaction

The Effects of Patient Characteristics on Clinician’s Adherence to Preventive Practice Guidelines

ABSTRACT BACKGROUND: The existence of health disparities confirms that not all patients, regardless of differences in patient demographics, are provided quality healthcare (Agency of Health Care Research and Quality, 2003). Moreover, research suggests that health disparities may be present due to the inadequate delivery of medical services (S. Haist, J. Wilson, M. Lineberry, & C. Griffith, 2007; Van Ryn, Burgess, Malat, & Griffin, 2006). The differences in the delivery of care and services to ethnic minorities and those of low socioeconomic status warrant examining the role healthcare providers play in the causation of these health disparities (Smedley, Stith, & Nelson, 2003). OBJECTIVE: The purpose of the study is to identify differences in routine screening practices of Physician Assistants and determine if such differences are associated with patients’ race and socioeconomic status. DESIGN: One hundred and twelve (N = 112) practicing Physician Assistants (N = 142) in Kentucky were surveyed and randomly assigned to receive one of four clinical vignettes. The likelihood of offering different routine screening recommendations was examined based on patient race and socioeconomic status. MAIN MEASURES: We investigated the mean differences of selected preventative care recommendation options for vignette patients as a function of patient race and socioeconomic status. KEY RESULTS: A multivariate analysis revealed that the race of a patient had a statistically significant multivariate effect on differences in screening recommendation, (p =.017) for hypertension (HTN), p=.017, immunization, p=.002. Univariate analysis showed statistically significant differences, with the African American patient were significantly less likely to receive screening for hypertension (HTN), (M = 3.42), 95% CI [3.24, 3.59], or immunizations (M = 2.45), 95% CI [2.21, 2.69] when compared to Caucasian women (M = 3.71, 2.98), 95% CIs [3.55, 3.88], [2.76, 3.23], respectively. CONCULSION: The findings suggest that the race of the patient in the vignette influenced the likelihood of receiving screening recommendations. The findings show that care delivered by Physician Assistants (PAs), are a possible source of healthcare disparities between patients from racial/ethnic minority backgrounds and their Caucasian counterparts. Keywords: disparities, health education, race & ethnicity, socioeconomic, preventive car

Determinants of board composition in Australia and the impact of corporate governance regulation

This study investigates the relation between firm characteristics and board composition in Australia for a sample of the same 432 listed firms in 2001 and 2007 and the impact of the Principles of Good Corporate Governance and Best Practice issued by the Australian Stock Exchange in 2003. Two feature of this regulation were (a) it recommended independent boards for all firms, without regard to firm characteristics (an approach commonly described as `one size fits all) and (b) it allowed non-compliance through `if not why not reporting. Using various designations of independence and firm size subsamples we find for `Top 100 firms in 2001 up to 49% (Adjusted R2 48.8) of variation in board independence may be explained by firm characteristics, but generally the explanatory power was much lower. Evidence is provided that although more firms had majority independent boards the relation between board composition and firm characteristics may have weakened over the period. This highlights a potential concern that the regulation has imposed unnecessary costs or inappropriate governance mechanisms on Australian firms

Vitellogenesis as a biomarker for estrogenic contamination of the aquatic environment

A rapidly increasing number of chemicals, or their degradation products, are being recognized as possessing estrogenic activity, albeit usually weak. We have found that effluent from sewage treatment works contains a chemical, or mixture of chemicals, that induces vitellogenin synthesis in male fish maintained in the effluent, thus indicating that the effluent is estrogenic. The effect was extremely pronounced and occurred at all sewage treatment works tested. The nature of the chemical or chemicals causing the effect is presently not known. However, we have tested a number of chemicals known to be estrogenic to mammals and have shown that they are also estrogenic to fish; that is, no species specificity was apparent. Many of these weakly estrogenic chemicals are known to be present in effluents. Further, a mixture of different estrogenic chemicals was considerably more potent than each of the chemicals when tested individually, suggesting that enhanced effects could occur when fish are exposed simultaneously to various estrogenic chemicals (as is likely to occur in rivers receiving effluent). Subsequent work should determine whether exposure to these chemicals at the concentrations present in the environment leads to any deleterious physiological effects

「ダロウ」と「吧(ba)」の確認要求用法の比較

日本語の「ダロウ」には、推量の用法と確認要求の用法がある。一方、中国語の文末語気詞「吧(ba)」にも日本語の「ダロウ」と対応する用法がある。この論文では、対話にしか現れない日本語の確認要求の用法がどういう場合に中国語の「吧(ba)」と対応し、またどういう場合に対応しないのかを考察する

Practice area and work demands in nurses' aides: a cross-sectional study

BACKGROUND: Knowledge of how work demands vary between different practice areas could give us a better understanding of the factors that influence the working conditions in the health services, and could help identify specific work-related challenges and problems in the different practice areas. In turn, this may help politicians, and healthcare administrators and managers to develop healthy work units. The aim of this study was to find out how nurses' aides' perception of demands and control at work vary with the practice area in which the aides are working. METHODS: In 1999, 12 000 nurses' aides were drawn randomly from the member list of the Norwegian Union of Health – and Social Workers, and were mailed a questionnaire. 7478 (62.3 %) filled in the questionnaire. The sample of the present study comprised the 6485 nurses' aides who were not on leave. Respondents working in one practice area were compared with respondents not working in this area (all together). Because of multiple comparisons, 0.01 was chosen as statistical significance level. RESULTS: Total quantitative work demands were highest in somatic hospital departments, nursing homes, and community nurse units. Physical demands were highest in somatic hospital departments and nursing homes. Level of positive challenges was highest in hospital departments and community nurses units, and lowest in nursing homes and homes or apartment units for the aged. Exposure to role conflicts was most frequent in nursing homes, homes or apartment units for the aged, and community nurse units. Exposure to threats and violence was most frequent in psychiatric departments, nursing homes, and institutions for mentally handicapped. Control of work pace was highest in psychiatric departments and institutions for mentally handicapped, and was lowest in somatic hospital departments and nursing homes. Participation in decisions at work was highest in psychiatric departments and community nurse units, and was lowest in somatic hospital departments and nursing homes. CONCLUSION: The demands and control experienced by Norwegian nurses' aides at work vary strongly with the practice area. Preventive workplace interventions should be tailored each area

When light hurts: Comparative Morphometry of Human Brainstem in Traumatic Photalgia

Traumatic brain injury is an increasingly common affliction, although many of its serious repercussions are still underappreciated. A frequent consequence is the development of light-induced pain, or ‘photalgia’, which can often lead to prolonged debilitation. The mechanism underlying the sensitivity to light, however, remains unresolved. Since tissue oedema (swelling) is a common feature of traumatic brain injury, we propose that the brainstem oedema, in particular, might sensitize the brainstem trigeminal complex to signals from ocular mechanisms activated in bright light. To assess this hypothesis, we ran high-resolution Magnetic Resonance Imaging of the brainstems of concussion groups with mild and severe photalgia, without photalgia, and healthy controls. The 3D configuration of the brainstem was determined by Tensor-Based Morphometry (TBM) for each participant. The TBM revealed significant deviations in the brainstem morphology of all concussion groups, with a characteristic signature for each group. In particular, concussion without photalgia showed bilateral expansion at the pontine/medulla junction, whereas concussion with photalgia showed mid-pontine shrinkage, consistent with degeneration of nuclei of the trigeminal complex. These results support the hypothesis that brainstem shrinkage/degeneration represents a morphological substrate of the photalgic sensitization of the trigeminal pathway

Exploration of the Mid-Cayman Rise

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