172 research outputs found

    Reexamining Metallgesellschaft’s Hedging Policy: Does Anything Beat a One-For-One Hedge Ratio?

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    There has been significant debate surrounding Metallgesellschaft\u27s derivatives based fixed-price marketing strategy. Most of this debate relates to Metallgesellschaft\u27s choice to use a one-for-one hedge ratio instead of an alternative hedge ratio optimized for risk management. I contribute to this discussion by reexamining the hedging strategy of Metallgesellschaft and use the Test for Superior Predictive Ability to determine whether any hedge ratio less than one outperforms the one-for-one hedge utilized by Metallgesellschaft

    Health Disparities Among Racial and Ethnic Minority Firefighters

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    ABSTRACT Background: Racial/ethnic minorities are substantially underrepresented in the fire service and this situation is unique when compared to similarly mentally and physically demanding and hazardous occupations such as the military and law enforcement. There is little systematic research to provide greater clarity about this significant disparity. The purpose of this study is to examine physical and behavioral health issues of racial/ethnic minority firefighters when compared to their white, non-Hispanic counterparts and potentially identify areas for future research that might assist in improving their substantial underrepresentation. Materials and Methods: We report the results of a secondary analysis of data combining the baseline evaluations of two different firefighter health studies, the Firefighter Injury and Risk Evaluation (FIRE) and Fuel 2 Fight (F2F) studies. Male career firefighters (N=1,404) were from 31 fire departments across the US and its territories. White, non-Hispanic firefighters comprised 72.5% of the sample (n=1,018) and 27.5% classified themselves as a racial/ethnic minority. Firefighters who agreed to participate comprised 94% (F2F) and 97% (FIRE) of those available and all underwent assessments including body composition, fitness, and general/behavioral health, and job satisfaction. Results: We examined differences in health and job status between minority and non-minority firefighters and between firefighters in minority- (MDCs) and white-dominated communities (WDCs). After adjusting for potential confounds, there were significant main effects for the individual minority status vs. non-minority status on both BMI and BF%, indicating that minority firefighters had significantly higher average BMI (28.8±0.3kg/m2) and BF% (24.7± 0.7%) when compared to their white, non-Hispanic colleagues (27.7±0.2kg/m2and 23.1±0.6% for BMI and BF%, respectively). Minority firefighters also were 59% more likely to be obese (adjusted [A]OR=1.59; 95% CI=1.16-2.18). Firefighters serving in MDCs reported significantly more poor health days (Mean±SE; 3.2±0.2 days) than firefighters serving in WDCs (2.8±0.2 days; p=0.038). In addition, minority firefighters reported significantly more poor health days (3.6±0.4 days) than their non-minority colleagues (2.8±0.2 days; p=0.003), while the interaction indicates that minority firefighters in MDCs reported more poor health days than the other groups (p Conclusions: Individual and community minority status (i.e., ethnic density effect) were both significantly associated with a number of important health status indicators, with racial/ethnic minority firefighters demonstrating greater risk for unfavorable body composition and more poor physical health days. In addition, minority firefighters in WDCs reported the highest prevalence of lifetime diagnosis of depression by a physician, while minority firefighters in MDCs had the lowest. Many of these health status indicators have recently been studied within the context of experiences with discrimination, demonstrating that racial discrimination is associated with greater risk for obesity, depression, and poor physical and mental health and could be contributing to health disparities and potentially negatively impacting racial/ethnic minority firefighter health, safety, and retention

    Demonstration Project for Asphalt Performance Engineered Mixture Design Testing

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    The asphalt industry is moving towards performance-based methods for asphalt mixture design. The Federal Highway Administration (FHWA) is supportive of state departments of transportations (DOT) adopting index and predictive performance tests, especially those making use of the Asphalt Mixture Performance Tester (AMPT). The FHWA is therefore encouraging state DOTs to gain experience with the requirements of the procedures and analysis tools for Balanced Mixture Design (BMD). The main objective of this study is to evaluate fatigue cracking on three INDOT mainline pavement projects that have asphalt mixtures designed by the Superpave 5 mixture design, and to better understand the fundamental engineering testing capabilities of the AMPT. A total of four Superpave 5 asphalt mixtures were collected and tested from the three projects. The viscoelastic characteristics and fatigue behavior of plant-mixed, laboratory compacted (PMLC), laboratory-mixed, laboratory compacted (LMLC), and plant-mixed, field compacted (PMFC) specimens were assessed according to the AASHTO TP-132 and AASHTO TP-133 test methods. Two AMPT machines (IPC Controls and PaveTest) were used to conduct the dynamic modulus tests, while all fatigue tests were performed using a PaveTest AMPT. The raw data were analyzed using the FlexMAT software. The dynamic modulus and cyclic fatigue test results indicate that AMPT testing can be used to effectively evaluate INDOT asphalt mixtures during the mixture design and production phases. However, to do so, detailed planning and effective training are needed to help ensure the successful completion of AMPT testing

    iMAgery focused psychological therapy for persecutory delusions in PSychosis (iMAPS):A novel treatment approach

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    Intrusive mental imagery and negative beliefs about self and others are frequently reported problems for individuals who experience psychosis, but there are few treatment approaches that have specifically targeted these. Intrusive mental images and negative schema have been identified as potential maintaining factors for persecutory delusions. These can range from paranoia-related recurrent intrusive images (e.g., being attacked by others, being followed by unknown figures who mean you harm) from the past or “flash-forward” future paranoia related intrusive mental images. In this article we outline clinical issues and adaptations of an imagery-focused approach for persecutory delusions. Drawing on a number of sources including a systematic literature review, a qualitative study exploring core beliefs, an experience sampling study and techniques from existing manuals and approaches, we adapted these imagery approaches to work with images and schema. The close links between imagery and core beliefs highlighted an opportunity to also use imagery rescripting approaches to transform negative schema and reduce persecutory delusions. Individuals with psychosis often want help with intrusive mental images and negative beliefs; adapted evidence-based imagery focused interventions can be used and the interventions may also help to reduce persecutory delusions

    Measurement of the total neutron scattering cross section ratios of noble gases of natural isotopic composition using a pulsed neutron beam

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    Precision measurements of slow neutron cross sections with atoms have several scientific applications. In particular the n-4^{4}He s-wave scattering length is important to know both for helping to constrain the nuclear three-body interaction and for the proper interpretation of several ongoing slow neutron experiments searching for other types of neutron-atom interactions. We present new measurements of the ratios of the neutron differential scattering cross sections for natural isotopic-abundance mixtures of the noble gases He, Ar, Kr, and Xe to natural isotopic abundance Ne. These measurements were performed using a recently developed neutron scattering apparatus for gas samples located on a pulsed slow neutron beamline which was designed to search for possible exotic neutron-atom interactions and employs both neutron time of flight information and a position-sensitive neutron detector for scattering event reconstruction. We found agreement with the literature values of scattering cross sections inferred from Ar/Ne, Kr/Ne and Xe/Ne differential cross section ratios over the qq range of 171 - 7 nm1^{-1}. However for the case of He/Ne we find that the cross section inferred differs by 11.3% (7.6 σ\sigma) from previously-reported values inferred from neutron phase shift measurements, but is in reasonable agreement with values from other measurements. The very large discrepancy in the He/Ne ratio calls for a new precision measurement of the n-4^{4}He scattering length using neutron interferometry

    The validity of self-rated health as a measure of health status among young military personnel: evidence from a cross-sectional survey

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    Abstract Background Single item questions about self ratings of overall health status are widely used in both military and civilian surveys. Limited information is available to date that examines what relationships exist between self-rated health, health status and health related behaviors among relatively young, healthy individuals. Methods The current study uses the population of active duty United States Air Force recruits (N = 31,108). Participants completed surveys that asked about health behaviors and health states and were rated their health on a continuum from poor to excellent. Results Ratings of health were consistently lower for those who used tobacco (F = 241.7, p < .001), reported binge drinking (F = 69.0, p < .001), reported drinking and driving (F = 19.4, p < .001), reported taking health risks (F = 109.4, p < .001), were depressed (F = 256.1, p < .001) and were overweight (F = 39.5, p < .001). Conclusion Given the consistent relationship between self-rated overall health and factors important to military health and fitness, self-rated health appears to be a valid measure of health status among young military troops.Peer Reviewe

    Demonstration Project for Asphalt Performance Engineered Mixture Design Testing

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    SPR-4452The asphalt industry is moving towards performance-based methods for asphalt mixture design. The Federal Highway Administration (FHWA) is supportive of state departments of transportations (DOT) adopting index and predictive performance tests, especially those making use of the Asphalt Mixture Performance Tester (AMPT). The FHWA is therefore encouraging state DOTs to gain experience with the requirements of the procedures and analysis tools for Balanced Mixture Design (BMD). The main objective of this study is to evaluate fatigue cracking on three INDOT mainline pavement projects that have asphalt mixtures designed by the Superpave 5 mixture design, and to better understand the fundamental engineering testing capabilities of the AMPT. A total of four Superpave 5 asphalt mixtures were collected and tested from the three projects. The viscoelastic characteristics and fatigue behavior of plant-mixed, laboratory compacted (PMLC), laboratory-mixed, laboratory compacted (LMLC), and plant-mixed, field compacted (PMFC) specimens were assessed according to the AASHTO TP-132 and AASHTO TP-133 test methods. Two AMPT machines (IPC Controls and PaveTest) were used to conduct the dynamic modulus tests, while all fatigue tests were performed using a PaveTest AMPT. The raw data were analyzed using the FlexMAT software. The dynamic modulus and cyclic fatigue test results indicate that AMPT testing can be used to effectively evaluate INDOT asphalt mixtures during the mixture design and production phases. However, to do so, detailed planning and effective training are needed to help ensure the successful completion of AMPT testing

    Evaluating laser-driven Bremsstrahlung radiation sources for imaging and analysis of nuclear waste packages

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    A small scale sample nuclear waste package, consisting of a 28 mm diameter uranium penny encased in grout, was imaged by absorption contrast radiography using a single pulse exposure from an X-ray source driven by a high-power laser. The Vulcan laser was used to deliver a focused pulse of photons to a tantalum foil, in order to generate a bright burst of highly penetrating X-rays (with energy >500 keV), with a source size of <0.5 mm. BAS-TR and BAS-SR image plates were used for image capture, alongside a newly developed Thalium doped Caesium Iodide scintillator-based detector coupled to CCD chips. The uranium penny was clearly resolved to sub-mm accuracy over a 30 cm2 scan area from a single shot acquisition. In addition, neutron generation was demonstrated in situ with the X-ray beam, with a single shot, thus demonstrating the potential for multi-modal criticality testing of waste materials. This feasibility study successfully demonstrated non-destructive radiography of encapsulated, high density, nuclear material. With recent developments of high-power laser systems, to 10 Hz operation, a laser-driven multi-modal beamline for waste monitoring applications is envisioned

    Risk Factors for Overweight and Obesity among Thai Adults: Results of the National Thai Food Consumption Survey

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    We evaluated the associations between overweight and obesity and socio-economic status (SES), behavioral factors, and dietary intake in Thai adults. A nationally representative sample of 6,445 Thais adults (18-70 years) was surveyed during 2004-2005. Information including demographics, SES characteristics, dietary intake, and anthropometrics were obtained. Overall, 35.0% of men, and 44.9% of women were overweight or obese (BMI ≥ 23 kg/m2) using the Asian cut-points. Regression models demonstrated that age was positively associated with being overweight in both genders. In gender-stratified analyses, male respondents who were older, lived in urban areas, had higher annual household income, and did not smoke were more likely to be classified as overweight and obese. Women who were older, had higher education, were not in a marriage-like relationship and were in semi-professional occupation were at greater risk for being overweight and obese. High carbohydrate and protein intake were found to be positively associated with BMI whereas the frequent use of dairy foods was found to be negatively associated with BMI among men. The present study found that SES factors are associated with being classified as overweight and obese in Thai adults, but associations were different between genders. Health promotion strategies regarding obesity and its related co-morbidity are necessary
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