38 research outputs found
The Inverse Amplitude Method in Scattering in Chiral Perturbation Theory to Two Loops
The inverse amplitude method is used to unitarize the two loop
scattering amplitudes of SU(2) Chiral Perturbation Theory in the ,
and channels. An error analysis in terms of the low energy
one-loop parameters and existing experimental data is
undertaken. A comparison to standard resonance saturation values for the two
loop coefficients is also carried out. Crossing
violations are quantified and the convergence of the expansion is discussed.Comment: (Latex, epsfig) 30 pages, 13 figures, 8 table
Economics of mental well-being: a prospective study estimating associated health care costs and sickness benefit transfers in Denmark
Background: Previous literature has examined the societal costs of mental illness, but few studies have estimated the costs associated with mental well-being. In this study, a prospective analysis was conducted on Danish data to determine 1) the association between mental well-being (measured in 2016) and government expenditure in 2017, specifially healthcare costs and sickness benefit transfers. Methods: Data stem from a Danish population-based survey of 3,508 adults (aged 16 + years) in 2016, which was linked to Danish registry data. A validated scale (WEMWBS) was used for the assessment of mental well-being. Costs are expressed in USD PPP. A two-part model was applied to predict costs in 2017, adjusting for sociodemographics, health status (including psychiatric morbidity and health behaviour), as well as costs in the previous year (2016). Results: Each point increase in mental well-being (measured in 2016) was associated with lower healthcare costs (− 78.7, − 23.1, 95% CI = − 4.3) per person in 2017. Conclusions: Estimated reductions in costs related to mental well-being add to what is already known about potential savings related to the prevention of mental illness. It does so by illustrating the savings that could be made by moving from lower to higher levels of mental well-being both within and beyond the clinical range. Our estimates pertain to costs associated with those health-related outcomes that were included in the study, but excluding other social and economic outcomes and benefits. They cover immediate cost estimates (costs generated the year following mental well-being measurement) and not those that could follow improved mental well-being over the longer term. They may therefore be considered conservative from a societal perspective. Population approaches to mental health promotion are necessary, not only to potentiate disease prevention strategies, but also to reduce costs related to lower levels of mental well-being in the non-mental illness population. Our results suggest that useful reductions in both health care resource use and costs, as well as in costs due to sick leave from the workplace, could be achieved from investment in mental well-being promotion within a year
Roy-Steiner-equation analysis of pion-nucleon scattering
We review the structure of Roy-Steiner equations for pion-nucleon scattering,
the solution for the partial waves of the t-channel process , as well as the high-accuracy extraction of the pion-nucleon S-wave
scattering lengths from data on pionic hydrogen and deuterium. We then proceed
to construct solutions for the lowest partial waves of the s-channel process
and demonstrate that accurate solutions can be found if the
scattering lengths are imposed as constraints. Detailed error estimates of all
input quantities in the solution procedure are performed and explicit
parameterizations for the resulting low-energy phase shifts as well as results
for subthreshold parameters and higher threshold parameters are presented.
Furthermore, we discuss the extraction of the pion-nucleon -term via
the Cheng-Dashen low-energy theorem, including the role of isospin-breaking
corrections, to obtain a precision determination consistent with all
constraints from analyticity, unitarity, crossing symmetry, and pionic-atom
data. We perform the matching to chiral perturbation theory in the subthreshold
region and detail the consequences for the chiral convergence of the threshold
parameters and the nucleon mass.Comment: 101 pages, 28 figures; journal versio
QCD and strongly coupled gauge theories : challenges and perspectives
We highlight the progress, current status, and open challenges of QCD-driven physics, in theory and in experiment. We discuss how the strong interaction is intimately connected to a broad sweep of physical problems, in settings ranging from astrophysics and cosmology to strongly coupled, complex systems in particle and condensed-matter physics, as well as to searches for physics beyond the Standard Model. We also discuss how success in describing the strong interaction impacts other fields, and, in turn, how such subjects can impact studies of the strong interaction. In the course of the work we offer a perspective on the many research streams which flow into and out of QCD, as well as a vision for future developments.Peer reviewe
'Excellence' and exclusion:the individual costs of institutional competitiveness
A performance-based funding system like the United Kingdom’s ‘Research Excellence Framework’ (REF) symbolizes the re-rationalization of higher education according to neoliberal ideology and New Public Management technologies. The REF is also significant for disclosing the kinds of behaviour that characterize universities’ response to government demands for research auditability. In this paper, we consider the casualties of what Henry Giroux (2014) calls “neoliberalism’s war on higher education” or more precisely the deleterious consequences of non-participation in the REF. We also discuss the ways with which higher education’s competition fetish, embodied within the REF, affects the instrumentalization of academic research and the diminution of academic freedom, autonomy and criticality
Economics of Well-being and Mental Health: A cost-of-illness analysis on Mental Health in Denmark.
The purpose of this thesis was to conduct a cross-sectional cost-of-suboptimal mental well-being analysis which estimates additional healthcare and non-healthcare costs of low and moderate compared to high mental well-being for the Danish society in 2017. Methods from conventional cost-of-illness studies were applied as well as an OLS regression. Necessary data came from a Danish survey on Mental Health and Well-being which was linked to Danish registries. Total healthcare and non-healthcare costs for low and moderate compared to high mental well-being were estimated to be € 1,552.6 million in 2017. Estimated additional costs suggest that it is not enough to merely measure the economic costs of classified mental disorders. Implications for the field of promotion in mental health and well-being were described. Another study has to be carried out to include more cost components.The purpose of this thesis was to conduct a cross-sectional cost-of-suboptimal mental well-being analysis which estimates additional healthcare and non-healthcare costs of low and moderate compared to high mental well-being for the Danish society in 2017. Methods from conventional cost-of-illness studies were applied as well as an OLS regression. Necessary data came from a Danish survey on Mental Health and Well-being which was linked to Danish registries. Total healthcare and non-healthcare costs for low and moderate compared to high mental well-being were estimated to be € 1,552.6 million in 2017. Estimated additional costs suggest that it is not enough to merely measure the economic costs of classified mental disorders. Implications for the field of promotion in mental health and well-being were described. Another study has to be carried out to include more cost components
Is mechanical power an under-recognised entity within the preterm lung?
Abstract Background Mechanical power is a major contributor to lung injury and mortality in adults receiving mechanical ventilation. Recent advances in our understanding of mechanical power have allowed the different mechanical components to be isolated. The preterm lung shares many of the same similarities that would indicate mechanical power may be relevant in this group. To date, the role of mechanical power in neonatal lung injury is unknown. We hypothesise that mechanical power maybe useful in expanding our understanding of preterm lung disease. Specifically, that mechanical power measures may account for gaps in knowledge in how lung injury is initiated. Hypothesis-generating data set To provide a justification for our hypothesis, data in a repository at the Murdoch Children’s Research Institute, Melbourne (Australia) were re-analysed. 16 preterm lambs 124–127d gestation (term 145d) who received 90 min of standardised positive pressure ventilation from birth via a cuffed endotracheal tube were chosen as each was exposed to three distinct and clinically relevant respiratory states with unique mechanics. These were (1) the respiratory transition to air-breathing from an entirely fluid-filled lung (rapid aeration and fall in resistance); (2) commencement of tidal ventilation in an acutely surfactant-deficient state (low compliance) and (3) exogenous surfactant therapy (improved aeration and compliance). Total, tidal, resistive and elastic-dynamic mechanical power were calculated from the flow, pressure and volume signals (200 Hz) for each inflation. Results All components of mechanical power behaved as expected for each state. Mechanical power increased during lung aeration from birth to 5 min, before again falling immediately after surfactant therapy. Before surfactant therapy tidal power contributed 70% of total mechanical power, and 53.7% after. The contribution of resistive power was greatest at birth, demonstrating the initial high respiratory system resistance at birth. Conclusions In our hypothesis-generating dataset, changes in mechanical power were evident during clinically important states for the preterm lung, specifically transition to air-breathing, changes in aeration and surfactant administration. Future preclinical studies using ventilation strategies designed to highlight different types of lung injury, including volu-, baro- and ergotrauma, are needed to test our hypothesis
Prognostic significance of the get with the guidelines-heart failure (GWTG-HF) risk score in patients undergoing trans-catheter tricuspid valve repair (TTVR)
The Get-With-The-Guidelines-Heart-Failure (GWTG-HF) score is a risk assessment tool to predict mortality in patients with heart-failure (HF). We aimed to evaluate the GWTG-HF score for risk stratification in HF patients with tricuspid regurgitation undergoing trans-catheter tricuspid valve repair (TTVR). In total, 181 patients who underwent TTVR via edge-to-edge repair (86%) or annuloplasty (14%) were enrolled. Patients were categorized into a low- (≤ 43 points), intermediate- (44-53 points) and high-risk score groups (≥ 54 points). TTVR led to an improvement of TR (p < 0.0001) and NYHA (p < 0.0001). Kaplan-Meier analysis and log-rank test revealed that higher GWTG-HF scores were associated with reduced rates of event-free survival regarding mortality (96% vs 89% vs 73%, respectively, p = 0.001) and hospitalization for heart failure (HHF) (89% vs 86% vs 74%, respectively, p = 0.026). After adjusting for important variables like renal function, left ventricular ejection fraction and mitral regurgitation, the GWTG-HF score remained an independent predictor of the composite endpoint of HHF or mortality (hazard ratio 1.04 per 1-point increase, p = 0.029). Other remaining predictors were renal function and mitral regurgitation. The GWTG-HF score used as a risk stratification tool of mortality and HHF maintains its prognostic value in a HF population with severe TR undergoing TTVR
Faster in Women?
Petrov G, Regitz-Zagrosek V, Lehmkuhl E, et al. Regression of Myocardial Hypertrophy After Aortic Valve Replacement. Circulation. 2010;122(11_suppl_1):S23-S28.Background—In patients with aortic stenosis, pressure overload induces cardiac hypertrophy and fibrosis. Female sex and estrogens influence cardiac remodeling and fibrosis in animal models and in men. Sex differences and their molecular mechanisms in hypertrophy regression after aortic valve replacement have not yet been studied.
Methods and Results—We prospectively obtained preoperative and early postoperative echocardiography in 92 patients, 53 women and 39 men, undergoing aortic valve replacement for isolated aortic stenosis. We analyzed in a subgroup of 10 patients matrix gene expression in left ventricular (LV) biopsies. In addition, we determined the effect of 17β-estradiol on collagen synthesis in isolated rat cardiac fibroblasts. Preoperatively, women and men had similar ejection fraction. Similar percentages of women and men had increased LV diameters (37% and 38%). Women more frequently exhibited LV hypertrophy than men (women: 86%; men: 56%; P<0.01). Postoperatively, increased LV diameters persisted in 34% of men but only in 12% of women (P<0.023). LV hypertrophy reversed more frequently in women than in men, leading to a similar prevalence of LV hypertrophy after surgery (women: 45%; men: 36%). In surgical biopsies, men had significantly higher collagen I and III and matrix metalloproteinase 2 gene expression than women. In isolated rat cardiac fibroblasts, 17β-estradiol significantly increased collagen I and III gene expressions in male cells but decreased it in female cells.
Conclusion—Women adapt to pressure overload differently from men. Less fibrosis before surgery may enable faster regression after surgery
Regression of Myocardial Hypertrophy After Aortic Valve Replacement
Petrov G, Regitz-Zagrosek V, Lehmkuhl E, et al. Regression of Myocardial Hypertrophy After Aortic Valve Replacement. Circulation. 2010;122(11_suppl_1):S23-S28.Background—In patients with aortic stenosis, pressure overload induces cardiac hypertrophy and fibrosis. Female sex and estrogens influence cardiac remodeling and fibrosis in animal models and in men. Sex differences and their molecular mechanisms in hypertrophy regression after aortic valve replacement have not yet been studied.
Methods and Results—We prospectively obtained preoperative and early postoperative echocardiography in 92 patients, 53 women and 39 men, undergoing aortic valve replacement for isolated aortic stenosis. We analyzed in a subgroup of 10 patients matrix gene expression in left ventricular (LV) biopsies. In addition, we determined the effect of 17β-estradiol on collagen synthesis in isolated rat cardiac fibroblasts. Preoperatively, women and men had similar ejection fraction. Similar percentages of women and men had increased LV diameters (37% and 38%). Women more frequently exhibited LV hypertrophy than men (women: 86%; men: 56%; P<0.01). Postoperatively, increased LV diameters persisted in 34% of men but only in 12% of women (P<0.023). LV hypertrophy reversed more frequently in women than in men, leading to a similar prevalence of LV hypertrophy after surgery (women: 45%; men: 36%). In surgical biopsies, men had significantly higher collagen I and III and matrix metalloproteinase 2 gene expression than women. In isolated rat cardiac fibroblasts, 17β-estradiol significantly increased collagen I and III gene expressions in male cells but decreased it in female cells.
Conclusion—Women adapt to pressure overload differently from men. Less fibrosis before surgery may enable faster regression after surgery