1,521 research outputs found
Dirac Cat States in Relativistic Landau Levels
We show that a relativistic version of Schrodinger cat states, here called
Dirac cat states, can be built in relativistic Landau levels when an external
magnetic field couples to a relativistic spin 1/2 charged particle. Under
suitable initial conditions, the associated Dirac equation produces unitarily
Dirac cat states involving the orbital quanta of the particle in a well defined
mesoscopic regime. We demonstrate that the proposed Dirac cat states have a
purely relativistic origin and cease to exist in the non-relativistic limit. In
this manner, we expect to open relativistic quantum mechanics to the rich
structures of quantum optics and quantum information.Comment: Revtex4, color figures, submitted for publicatio
The Impact of Emotional Intelligence on Conditions of Trust among Leaders at the Kentucky Department for Public Health
There has been limited leadership research on emotional intelligence and trust in governmental public health settings. The purpose of this study was to identify and seek to understand the relationship between trust and elements of emotional intelligence, including stress management, at the Kentucky Department for Public Health (KDPH). The KDPH serves as Kentucky’s state governmental health department. KDPH is led by a Commissioner and composed of seven primary divisions and 25 branches within those divisions. The study was a non-randomized cross-sectional study utilizing electronic surveys that evaluated conditions of trust among staff members and emotional intelligence among supervisors. Pearson correlation coefficients and corresponding p-values are presented to provide the association between emotional intelligence scales and the conditions of trust. Significant positive correlations were observed between supervisors’ stress management and the staff members’ trust or perception of supervisors’ loyalty (r = 0.6, p = 0.01), integrity (r = 0.5, p = 0.03), receptivity (r = 0.6, p = 0.02), promise fulfillment (r = 0.6, p = 0.02), and availability (r= 0.5, p = 0.07). This research lays the foundation for emotional intelligence and trust research and leadership training in other governmental public health settings, such as local, other state, national, or international organizations. This original research provides metrics to assess the public health workforce with attention to organizational management and leadership constructs. The survey tools could be used in other governmental public health settings in order to develop tailored training opportunities related to emotional intelligence and trust organizations
Two-Loop Calculations with Vertex Corrections in the Walecka Model
Two-loop corrections with scalar and vector form factors are calculated for
nuclear matter in the Walecka model. The on-shell form factors are derived from
vertex corrections within the framework of the model and are highly damped at
large spacelike momenta. The two-loop corrections are evaluated first by using
the one-loop parameters and mean fields and then by refitting the total
energy/baryon to empirical nuclear matter saturation properties. The modified
two-loop corrections are significantly smaller than those computed with bare
vertices. Contributions from the anomalous isoscalar form factor of the nucleon
are included for the first time. The effects of the implicit density dependence
of the form factors, which arise from the shift in the baryon mass, are also
considered. Finally, necessary extensions of these calculations are discussed.Comment: 29 pages in REVTeX, 18 figures, preprint IU/NTC 94-02 //OSU--94-11
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Concurrent Stress and Depressive Symptoms Increase Risk of Myocardial Infarction or Death
BACKGROUND: Depression and stress have each been found to be associated with poor prognosis in patients with coronary heart disease. A recently offered psychosocial perfect storm conceptual model hypothesizes amplified risk will occur in those with concurrent stress and depressive symptoms. We tested this hypothesis in a large sample of US adults with coronary heart disease. METHODS AND RESULTS: Participants included 4487 adults with coronary heart disease from the Reasons for Geographic and Racial Differences in Stroke study, a prospective cohort study of 30,239 black and white adults. We conducted Cox proportional hazards regression with the composite outcome of myocardial infarction or death and adjustment for demographic, clinical, and behavioral factors. Overall, 6.1% reported concurrent high stress and high depressive symptoms at baseline. During a median 5.95 years of follow-up, 1337 events occurred. In the first 2.5 years of follow-up, participants with concurrent high stress and high depressive symptoms had increased risk for myocardial infarction or death (adjusted hazard ratio, 1.48 [95% confidence interval, 1.08-2.02]) relative to those with low stress and low depressive symptoms. Those with low stress and high depressive symptoms (hazard ratio, 0.92 [95% confidence interval, 0.66-1.28]) or high stress and low depressive symptoms (hazard ratio, 0.86 [95% confidence interval, 0.57-1.29]) were not at increased risk. The association on myocardial infarction or death was not significant after the initial 2.5 years of follow-up (hazard ratio, 0.89 [95% confidence interval, 0.65-1.22]). CONCLUSIONS: Our results provide initial support for a psychosocial perfect storm conceptual model; the confluence of depressive symptoms and stress on medical prognosis in adults with coronary heart disease may be particularly destructive in the shorter term
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Effects of Concurrent Depressive Symptoms and Perceived Stress on Cardiovascular Risk in Low‐ and High‐Income Participants: ...
Background: Psychosocial risk for cardiovascular disease (CVD) may be especially deleterious in persons with low socioeconomic status. Most work has focused on psychosocial factors individually, but emerging research suggests that the confluence of psychosocial risk may be particularly harmful. Using data from the Reasons for Geographical and Racial Differences in Stroke (REGARDS) study, we examined associations among depressive symptoms and stress, alone and in combination, and incident CVD and all‐cause mortality as a function of socioeconomic status.
Methods and Results At baseline, 22 658 participants without a history of CVD (58.8% female, 41.7% black, mean age 63.9±9.3 years) reported on depressive symptoms, stress, annual household income, and education. Participants were classified into 1 of 3 psychosocial risk groups at baseline: (1) neither depressive symptoms nor stress, (2) either depressive symptoms or stress, or (3) both depressive symptoms and stress. Cox proportional hazards models were used to predict physician‐adjudicated incident total CVD events (nonfatal myocardial infarction, nonfatal stroke, and cardiovascular death) and all‐cause mortality over a median of 7.0 years (interquartile range 5.4–8.3 years) of follow‐up. In fully adjusted models, participants with both depressive symptoms and stress had the greatest elevation in risk of developing total CVD (hazard ratio 1.48, 95% CI 1.21–1.81) and all‐cause mortality (hazard ratio 1.33, 95% CI 1.13–1.56) but only for those with low income (< 35 000) income. This pattern of results was not observed in models stratified by education.
Conclusions Findings suggest that screening for a combination of elevated depressive symptoms and stress in low‐income persons may help identify those at increased risk of incident CVD and mortality
Speciation control during Suzuki-Miyaura cross-coupling of haloaryl and haloalkenyl MIDA boronic esters
Boronic acid solution speciation can be controlled during the Suzuki-Miyaura cross-coupling of haloaryl MIDA boronic esters to enable the formal homologation of boronic acid derivatives. The reaction is contingent upon control of the basic biphase and is thermodynamically driven: temperature control provides highly chemoselective access to either BMIDA adducts at room temperature or BPin products at elevated temperature. Control experiments and solubility analyses have provided some insight into the mechanistic operation of the formal homologation process
CDC Botswana : sharing another partnership success
CDC Botswana, in partnership with the Ministry of Health since 1995--for a safer, healthier Botswana.Publication date from document properties.CDCBotswanaSharesSuccess_19_07_12.pd
Quantifying the impact of climate change on drought regimes using the Standardised Precipitation Index
The study presents a methodology to characterise short- or long-term drought events, designed to aid understanding of how climate change may affect future risk. An indicator of drought magnitude, combining parameters of duration, spatial extent and intensity, is presented based on the Standardised Precipitation Index (SPI). The SPI is applied to observed (1955–2003) and projected (2003–2050) precipitation data from the Community Integrated Assessment System (CIAS). Potential consequences of climate change on drought regimes in Australia, Brazil, China, Ethiopia, India, Spain, Portugal and the USA are quantified. Uncertainty is assessed by emulating a range of global circulation models to project climate change. Further uncertainty is addressed through the use of a high-emission scenario and a low stabilisation scenario representing a stringent mitigation policy. Climate change was shown to have a larger effect on the duration and magnitude of long-term droughts, and Australia, Brazil, Spain, Portugal and the USA were highlighted as being particularly vulnerable to multi-year drought events, with the potential for drought magnitude to exceed historical experience. The study highlights the characteristics of drought which may be more sensitive under climate change. For example, on average, short-term droughts in the USA do not become more intense but are projected to increase in duration. Importantly, the stringent mitigation scenario had limited effect on drought regimes in the first half of the twenty-first century, showing that adaptation to drought risk will be vital in these regions
Investigations of Aerobic Methane Oxidation in Two Marine Seep Environments: Part 1—Chemical Kinetics
Microbial aerobic oxidation is known to be a significant sink of marine methane (CH4), contributing to the relatively minor atmospheric release of this greenhouse gas over vast stretches of the ocean. However, the chemical kinetics of aerobic CH4 oxidation are not well established, making it difficult to predict and assess the extent that CH4 is oxidized in seawater following seafloor release. Here we investigate the kinetics of aerobic CH4 oxidation using mesocosm incubations of fresh seawater samples collected from seep fields in Hudson Canyon, U.S. Atlantic Margin and MC118, Gulf of Mexico to gain a fundamental chemical understanding of this CH4 sink. The goals of this investigation were to determine the response or lag time following CH4 release until more rapid oxidation begins, the reaction order, and the stoichiometry of reactants utilized (i.e., CH4, oxygen, nitrate, phosphate, trace metals) during CH4 oxidation. The results for both Hudson Canyon and MC118 environments show that CH4 oxidation rates sharply increased within less than one month following the CH4 inoculation of seawater. However, the exact temporal characteristics of this more rapid CH4 oxidation varied based on location, possibly dependent on the local circulation and biogeochemical conditions at the point of seawater collection. The data further suggest that methane oxidation behaves as a first‐order kinetic process and that the reaction rate constant remains constant once rapid CH4 oxidation begins
Investigations of Aerobic Methane Oxidation in Two Marine Seep Environments: Part 2—Isotopic Kinetics
During aerobic oxidation of methane (CH4) in seawater, a process which mitigates atmospheric emissions, the 12C‐isotopologue reacts with a slightly greater rate constant than the 13C‐isotopologue, leaving the residual CH4 isotopically fractionated. Prior studies have attempted to exploit this systematic isotopic fractionation from methane oxidation to quantify the extent that a CH4 pool has been oxidized in seawater. However, cultivation‐based studies have suggested that isotopic fractionation fundamentally changes as a microbial population blooms in response to an influx of reactive substrates. Using a systematic mesocosm incubation study with recently collected seawater, here we investigate the fundamental isotopic kinetics of aerobic CH4 oxidation during a microbial bloom. As detailed in a companion paper, seawater samples were collected from seep fields in Hudson Canyon, U.S. Atlantic Margin, and atop Woolsey Mound (also known as Sleeping Dragon) which is part of lease block MC118 in the northern Gulf of Mexico, and used in these investigations. The results from both Hudson Canyon and MC118 show that in these natural environments isotopic fraction for CH4 oxidation follows a first‐order kinetic process. The results also show that the isotopic fractionation factor remains constant during this methanotrophic bloom once rapid CH4 oxidation begins and that the magnitude of the fractionation factor appears correlated with the first‐order reaction rate constant. These findings greatly simplify the use of natural stable isotope changes in CH4 to assess the extent that CH4 is oxidized in seawater following seafloor release
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