Symmetric Rotating Wave Approximation for the Generalized Single-Mode Spin-Boson System

The single-mode spin-boson model exhibits behavior not included in the rotating wave approximation (RWA) in the ultra and deep-strong coupling regimes, where counter-rotating contributions become important. We introduce a symmetric rotating wave approximation that treats rotating and counter-rotating terms equally, preserves the invariances of the Hamiltonian with respect to its parameters, and reproduces several qualitative features of the spin-boson spectrum not present in the original rotating wave approximation both off-resonance and at deep strong coupling. The symmetric rotating wave approximation allows for the treatment of certain ultra and deep-strong coupling regimes with similar accuracy and mathematical simplicity as does the RWA in the weak coupling regime. Additionally, we symmetrize the generalized form of the rotating wave approximation to obtain the same qualitative correspondence with the addition of improved quantitative agreement with the exact numerical results. The method is readily extended to higher accuracy if needed. Finally, we introduce the two-photon parity operator for the two-photon Rabi Hamiltonian and obtain its generalized symmetric rotating wave approximation. The existence of this operator reveals a parity symmetry similar to that in the Rabi Hamiltonian as well as another symmetry that is unique to the two-photon case, providing insight into the mathematical structure of the two-photon spectrum, significantly simplifying the numerics, and revealing some interesting dynamical properties.Comment: 11 pages, 5 figure

Socioeconomic inequalities in blood pressure: co-ordinated analysis of 147,775 participants from repeated birth cohort and cross-sectional datasets, 1989 to 2016

Background: High blood pressure (BP) is a key modifiable determinant of cardiovascular disease and a likely determinant of other adverse health outcomes. While socioeconomic inequalities in BP are well documented, it remains unclear (1) how these inequalities have changed across time, given improvements over time in the detection and treatment of high BP (hypertension); (2) whether BP inequalities are present below and above hypertension treatment thresholds; and (3) whether socioeconomic position (SEP) across life has cumulative effects on BP. We sought to address these gaps using evidence from two complementary sources: birth cohort and repeated cross-sectional datasets. Methods: We used three British birth cohort studies—born in 1946, 1958, and 1970—with BP measured at 43–46 years (in 1989, 2003, and 2016), and 21 repeated cross-sectional datasets—the Health Survey for England (HSE), with BP measured among adults aged ≥ 25 years (1994–2016). Adult education attainment was used as an indicator of SEP in both datasets; childhood father’s social class was used as an alternative indicator of (early life) SEP in cohorts. Adjusting for the expected average effects of antihypertensive medication use, we used linear regression to quantify SEP differences in mean systolic BP (SBP), and quantile regression to investigate whether inequalities differed across SBP distributions—below and above hypertension treatment thresholds. Results: In both datasets, lower educational attainment was associated with higher SBP, with similar absolute magnitudes of inequality across the studied period. Differences in SBP by education (Slope Index of Inequality) based on HSE data were 3.0 mmHg (95% CI 1.8, 4.2) in 1994 and 4.3 mmHg (2.3, 6.3) in 2016. Findings were similar for diastolic BP (DBP) and survey-defined hypertension. Inequalities were found across the SBP distribution in both datasets—below and above the hypertension threshold—yet were larger at the upper tail; in HSE, median SBP differences were 2.8 mmHg (1.7, 3.9) yet 5.6 mmHg (4.9, 6.4) at the 90th quantile. Adjustment for antihypertensive medication use had little impact on the magnitude of inequalities; in contrast, associations were largely attenuated after adjustment for body mass index. Finally, cohort data suggested that disadvantage in early and adult life had cumulative independent associations with BP: cohort-pooled differences in SBP were 5.0 mmHg (3.8, 6.1) in a score combining early life social class and own education, yet were 3.4 mmHg (2.4, 4.4) for education alone. Conclusion: Socioeconomic inequalities in BP have persisted from 1989 to 2016 in Britain/England, despite improved detection and treatment of high BP. To achieve future reductions in BP inequalities, policies addressing the wider structural determinants of high BP levels are likely required, particularly those curtailing the obesogenic environment—targeting detection and treatment alone is unlikely to be sufficient

Do depressive symptoms link chronic diseases to cognition among older adults? Evidence from the Health and Retirement Study in the United States

Background: Few studies have assessed psychological pathways that connect the association between non-psychotropic chronic disease and cognition. We assessed the extent to which the association between the two was mediated by depressive symptoms in older adults. / Methods: Data came from waves 10-13 (2010-2016) of the Health and Retirement Study in the United States (7,651 men and 10,248 women). Multilevel path analysis, allowing for random intercepts and slopes, was employed to estimate the extent to which depressive symptoms mediated the total effect of a chronic disease on cognition. / Results: We found that the presence of stroke, high blood pressure, diabetes, heart problems, and comorbidity, in both men and women, and lung disease in women, was associated with lower levels of cognition. The total effects of chronic diseases on cognition were partially mediated through depressive symptoms. Depressive symptoms mediated approximately 19%–39% and 23%–54% of the total effects of chronic diseases on cognition in men and women, respectively. This mediation effect of depressive symptoms was more consequential for older women than their male counterparts in all statistically significant associations between chronic diseases and cognition, except for diabetes. / Limitations: We relied on self-reported diagnoses of diseases and depressive symptoms. Our use of a multilevel path analysis with random slopes precluded the inclusion of binary/categorical dependent variables, and the estimation of standardized beta values. / Conclusions: To understand the cognitive challenges that chronically ill older adults face, practitioners and policymakers should consider not just the direct symptoms related to chronic diseases, but also the often overlooked psychological conditions faced by older adults

Physical activity in adolescence: cross-national comparisons of levels, distributions and disparities across 52 countries

Introduction: Despite global concerns regarding physical inactivity, limited cross-national evidence exists to compare adolescents’ physical activity participation. We analysed 52 high- and low-middle income countries, with activity undertaken inside and outside of school in 2015. We investigated gender- and socioeconomic-disparities, and additionally examined correlations with country-level indices of physical education (PE) curriculum time allocation, wealth, and income inequality. / Methods: We used the Programme for International Student Assessment (PISA), a nationally representative cross-sectional survey of 15-year-olds (N=347,935). Students reported average attendance (days/week) in PE classes, and the days/week engaged in moderate activity (MPA) and vigorous activity (VPA) outside of school. Both the mean and distributions of outcomes were evaluated, as were gender- and socioeconomic-disparities. Pearson’s correlations (r) between the physical activity outcomes and PE curriculum time allocation, wealth (indexed by GDP) and income inequality (indexed by the Gini coefficient) were calculated. / Results: Activity levels inside and outside of school were higher in Eastern Europe than Western Europe, the Americas, and the Middle East/North Africa. Comparisons of average levels masked potentially important differences in distributions. For example, activity levels inside school showed a bimodal distribution in the US (mean PE class attendance 2.4 days/week; 41.3%, 6.3% and 33.1% of students attended PE classes on 0, 2 and 5 days/week respectively). In contrast, most other countries exhibited more centrally shaped distributions. Pro-male and pro-high socioeconomic disparities were modest for participation inside school, but higher for MPA and VPA outside of school. The magnitude of these also differed markedly by country. Activity in school was weakly positively correlated with PE curriculum time allocation (r=0.33); activity outside of school was strongly negatively correlated with income inequality (e.g. r=-0.69 for MPA). / Conclusion: Our findings reveal extensive cross-country differences in adolescents’ physical activity; in turn, these highlight policy areas that could ultimately improve global adolescent health, such as the incorporation of minimum country-level PE classes, and the targeting of gender- and socioeconomic- disparities in activity conducted outside of school. Our findings also highlight the utility of educational databases such as PISA for use in global population health research

Ab-Initio Calculation of Molecular Aggregation Effects: a Coumarin-343 Case Study

We present time-dependent density functional theory (TDDFT) calculations for single and dimerized Coumarin-343 molecules in order to investigate the quantum mechanical effects of chromophore aggregation in extended systems designed to function as a new generation of sensors and light-harvesting devices. Using the single-chromophore results, we describe the construction of effective Hamiltonians to predict the excitonic properties of aggregate systems. We compare the electronic coupling properties predicted by such effective Hamiltonians to those obtained from TDDFT calculations of dimers, and to the coupling predicted by the transition density cube (TDC) method. We determine the accuracy of the dipole-dipole approximation and TDC with respect to the separation distance and orientation of the dimers. In particular, we investigate the effects of including Coulomb coupling terms ignored in the typical tight-binding effective Hamiltonian. We also examine effects of orbital relaxation which cannot be captured by either of these models

Fatality rates associated with driving and cycling for all road users in Great Britain 2005–2013

Fatality rates based on deaths only to the drivers themselves do not accurately portray the impact of driving on road traffic deaths. We characterised more fully the impact of driving and cycling on road traffic fatalities by including deaths to all the other road users in fatal car or cycle crashes. We used crash data from the Great Britain National Road Accident Database (STATS19) and exposure data from the National Travel Survey. Rates were estimated as the ratio of fatalities to the amount of time travelled: fatalities per million hours’ use (f/mhu). Rates in 2005-07, 2008-10, and 2011-13 were calculated based on deaths to: (1) the drivers or cyclists themselves (persons ‘in charge’ of vehicles), (2) other, i.e. ‘third-party’, road users (e.g. passengers, drivers or riders of other vehicles, and pedestrians), and (3) both of these groups combined, i.e. all road users. Rates were stratified by the sex and age of the drivers or cyclists involved in the fatal crashes. Rates based on deaths to persons in charge of vehicles were higher for cyclists than for drivers, whereas those based on deaths to third-party road users showed the opposite. The inclusion of third-party deaths increased the overall rates considerably more for drivers than for cyclists. Nevertheless, the overall rate for male cyclists (2011-13: 0.425 f/mhu; 95% Confidence Interval (CI): 0.377–0.478) exceeded that for male drivers (0.257 f/mhu; 95% CI: 0.248–0.267). A similar pattern was observed for females (cycling: 0.216 f/mhu; 95% CI: 0.158–0.287; driving: 0.127 f/mhu; 95% CI: 0.120–0.135). These differences between cars and cycles were overestimated as the safer travel on motorways could not be disaggregated in the estimates for driving. The higher rates for cycling - mainly borne by the cyclists themselves - need to be balanced against the substantially lower risks to other road users

Long non-coding RNA profiling of human lymphoid progenitor cells reveals transcriptional divergence of B cell and T cell lineages.

To elucidate the transcriptional 'landscape' that regulates human lymphoid commitment during postnatal life, we used RNA sequencing to assemble the long non-coding transcriptome across human bone marrow and thymic progenitor cells spanning the earliest stages of B lymphoid and T lymphoid specification. Over 3,000 genes encoding previously unknown long non-coding RNAs (lncRNAs) were revealed through the analysis of these rare populations. Lymphoid commitment was characterized by lncRNA expression patterns that were highly stage specific and were more lineage specific than those of protein-coding genes. Protein-coding genes co-expressed with neighboring lncRNA genes showed enrichment for ontologies related to lymphoid differentiation. The exquisite cell-type specificity of global lncRNA expression patterns independently revealed new developmental relationships among the earliest progenitor cells in the human bone marrow and thymus

Projection of the health and economic impacts of Chronic kidney disease in the Chilean population

Background: Chronic Kidney Disease (CKD) is a leading public health problem, with substantial burden and economic implications for healthcare systems, mainly due to renal replacement treatment (RRT) for end-stage kidney disease (ESKD). The aim of this study is to develop a multistate predictive model to estimate the future burden of CKD in Chile, given the high and rising RRT rates, population ageing, and prevalence of comorbidities contributing to CKD. // Methods: A dynamic stock and flow model was developed to simulate CKD progression in the Chilean population aged 40 years and older, up to the year 2041, adopting the perspective of the Chilean public healthcare system. The model included six states replicating progression of CKD, which was assumed in 1-year cycles and was categorised as slow, medium or fast progression, based on the underlying conditions. We simulated two different treatment scenarios. Only direct costs of treatment were included, and a 3% per year discount rate was applied after the first year. We calibrated the model based on international evidence; the exploration of uncertainty (95% credibility intervals) was undertaken with probabilistic sensitivity analysis. // Results: By the year 2041, there is an expected increase in cases of CKD stages 3a to ESKD, ceteris paribus, from 442,265 (95% UI 441,808–442,722) in 2021 to 735,513 (734,455–736,570) individuals. Direct costs of CKD stages 3a to ESKD would rise from 322.4M GBP (321.7–323.1) in 2021 to 1,038.6M GBP (1,035.5–1,041.8) in 2041. A reduction in the progression rates of the disease by the inclusion of SGLT2 inhibitors and pre-dialysis treatment would decrease the number of individuals worsening to stages 5 and ESKD, thus reducing the total costs of CKD by 214.6M GBP in 2041 to 824.0M GBP (822.7–825.3). // Conclusions: This model can be a useful tool for healthcare planning, with development of preventive or treatment plans to reduce and delay the progression of the disease and thus the anticipated increase in the healthcare costs of CKD

Socioeconomic inequalities in the prevalence and management of hypertension: analyses of the Chilean National Health Surveys 2003, 2010 and 2017

Hypertension is the highest attributable risk of death worldwide, causing 7.1million deaths annually, and it is the primary cause of cardiovascular morbidity and mortality. In Chile, around one-in-three adults are living with this chronic health condition. Chilean evidence has shown inequalities in hypertension prevalence by various measures of socioeconomic position (SEP). However, information on SEP inequalities in the three key aspects of hypertension management (awareness, treatment, and control of high blood pressure), is only partially known. / Purpose: To assess SEP inequalities in hypertension prevalence and management in Chilean adults. / Methods: Data came from the Chilean National Health Surveys (ENS) 2003, 2010 and 2017. Years of formal education was used as the SEP measure. Age-and gender-specific Slope and Relative Indices of Inequalities (SII and RII) were calculated for the prevalence of hypertension (mean SBP ≥140mmHg, DBP ≥90mmHg, or current medication use to lower blood pressure) and for each management outcome. / Results: Analytical sample comprised 3,426; 4,838 and 5,373 participants aged ≥17y with blood pressure measurements for years 2003, 2010 and 2017, respectively. Prevalence of hypertension was 32.4%, 32.2% and 30.8% for the years 2003, 2010 and 2017, respectively. According to the SII and RII, males and females aged <65y showed higher hypertension prevalence among those with fewer years of education in 2003, 2010 and 2017. Among those classed as hypertensive, levels of awareness increased from 59.4% in 2003 to 65.9% in 2017. Over the same time period, levels of treatment increased from 39.0% to 65.2%, and levels of control increased from 14.1% to 23.9%. SEP inequalities in hypertension management – with better outcomes for the most educated – were highest among females aged ≥65y. / Conclusion: Introduction of universal access to care for hypertension in Chile in 2005 accounted partly for the rise of hypertension management levels since 2003. According to local and international strategies for the prevention and control of noncommunicable diseases, there is room for improvement. However, improvements should have a specific focus on SEP inequalities. / Acknowledgement/Funding: Chilean Ministry of Health

Community severance and health: measuring community severance and examining its impact on the health of adults in Great Britain

BACKGROUND Aspects of community severance (the separation of people from goods, services, and each other by busy roads or other transport infrastructure) have been linked to poor health and wellbeing, but few studies have examined this relationship. We created a novel index for community severance and estimated its association with the self-rated health of adults in Great Britain. METHODS Data were collected from a nationally representative online panel survey of 4,111 participants, February-July 2016. To construct an index, polychoric factor analysis (suitable for ordinal variables), was conducted on four survey items related to the perceived impact of roads on ability to walk locally. Community severance index (CSI) scores were negatively skewed, so were categorised into four groups (lowest 40%, second, third, highest). We examined the association of community severance with self-rated health (‘good’ (very good/good) vs. ‘poor’ (fair/bad/very bad)) using logistic regression, adjusting for potential confounders (age, income, employment status). MAIN RESULTS Polychoric factor analysis confirmed that it was appropriate to combine the four survey items into a single index (Cronbach’s Alpha=0.86; Keiser-Meyer-Olkin measure of sampling adequacy= 0.76, factor loadings >0.74). After controlling for confounding factors, being in the highest CSI group was associated with higher odds of reporting poor self-rated health (Odds Ratio: 1.79, 95% Confidence Interval: 1.48-2.17) compared with the lowest CSI group. There was a dose-response gradient, with those in the second and third highest CSI groups having increased odds of reporting poor self-rated health, though of lower magnitude ((1.21, 1.01-1.45) and (1.41, 1.16-1.71) respectively). CONCLUSIONS We found an inverse association between CSI and self-rated health. This suggests that to improve health, local governments and road authorities should take steps to reduce community severance through traffic reduction and calming, pedestrian prioritisation, and the installation of well-designed crossing points