Improving the Quality of Care in Developing Countries

Although the quantity rather than quality of health services has been the focus historically in developing countries, ample evidence suggests that quality of care (or the lack of it) must be at the center of every discussion about better health. This paper discusses the cost effectiveness of various interventions to improve the quality of care in developing countries.health economics, quality of care, cost effectiveness

Improving the Quality of Care in Developing Countries

Although the quantity rather than quality of health services has been the focus historically in developing countries, ample evidence suggests that quality of care (or the lack of it) must be at the center of every discussion about better health. This paper discusses the cost effectiveness of various interventions to improve the quality of care in developing countries

Hydrodynamical simulations of merging galaxy clusters: giant dark matter particle colliders, powered by gravity

Terrestrial particle accelerators collide charged particles, then watch the trajectory of outgoing debris – but they cannot manipulate dark matter. Fortunately, dark matter is the main component of galaxy clusters, which are continuously pulled together by gravity. We show that galaxy cluster mergers can be exploited as enormous, natural dark matter colliders. We analyse hydrodynamical simulations of a universe containing self-interacting dark matter (SIDM) in which all particles interact via gravity, and dark matter particles can also scatter off each other via a massive mediator. During cluster collisions, SIDM spreads out and lags behind cluster member galaxies. Individual systems can have quirky dynamics that makes them difficult to interpret. Statistically, however, we find that the mean or median of dark matter’s spatial offset in many collisions can be robustly modelled, and is independent of our viewing angle and halo mass even in collisions between unequal-mass systems. If the SIDM cross-section were σ/m = 0.1 cm2 g−1 = 0.18 barn GeV−1, the ‘bulleticity’ lag would be ∼5 per cent that of gas due to ram pressure, and could be detected at 95 per cent confidence level in weak lensing observations of ∼100 well-chosen clusters

Improving the Quality of Care in Developing Countries

Although the quantity rather than quality of health services has been the focus historically in developing countries, ample evidence suggests that quality of care (or the lack of it) must be at the center of every discussion about better health. This paper discusses the cost effectiveness of various interventions to improve the quality of care in developing countries

Cosmology Using Cluster Internal Velocity Dispersions

We compare the distribution of internal velocity dispersions of galaxy clusters for an observational sample to those obtained from a set of N-body simulations of seven COBE-normalised cosmological scenarios: the standard CDM (SCDM) and a tilted (n=0.85) CDM (TCDM) model, a CHDM model with 25% of massive neutrinos, two low-density LCDM models with Omega_0=0.3 and 0.5, two open OCDM models with Omega_0=0.4 and 0.6. Simulated clusters are observed in projection so as to reproduce the main observational biases and are analysed by applying the same algorithm for interlopers removal and velocity dispersion estimate as for the reference observational sample. Velocity dispersions for individual clusters can be largely affected by observational biases in a model-dependent way: models in which clusters had less time to virialize show larger discrepancies between 3D and projected velocity dispersions. From the comparison with real clusters we find that both SCDM and TCDM largely overproduce clusters. The CHDM model marginally overproduces clusters and requires a somewhat larger sigma_8 than a purely CDM model in order to produce the same cluster abundance. The LCDM model with Omega_0=0.3 agrees with data, while the open model with Omega_0=0.4 and 0.6 underproduces and marginally overproduces clusters, respectively.Comment: 28 pages, LaTeX uses Elsevier style file, 7 postscript figures (3 bitmapped to lower res.) included. Submitted to New Astronom

Understanding the Astrophysics of Galaxy Evolution: the role of spectroscopic surveys in the next decade

Over the last decade optical spectroscopic surveys have characterized the low redshift galaxy population and uncovered populations of star-forming galaxies back to z ~ 7. This work has shown that the primary epoch of galaxy building and black hole growth occurs at redshifts of 2 to 3. The establishment of the concordance LCDM cosmology shifted the focus of galaxy population studies from constraining cosmological parameters to characterizing the processes which regulate the formation and evolution of galaxies.In the next decade, high redshift observers will attempt to formulate a coherent evolutionary picture connecting galaxies in the high redshift Universe to galaxies today. In order to link galaxy populations at different redshifts, we must not only characterize their evolution in a systematic way, we must establish which physical processes are responsible for it. Considerable progress has already been made in understanding how galaxies evolved from z ~ 1 to the present day. Large spectroscopic surveys in the near infrared are required to push these studies back towards the main epoch of galaxy building. Only then will we understand the full story of the formation of L* galaxies like our own Milky Way. A large near-IR spectroscopic survey will also provide the calibration needed to avoid systematics in the large photometric programs proposed to study the nature of dark matter and dark energy. We provide an outline design for a multi-object 0.4 to 1.8 micron spectrograph, which could be placed on an existing telescope, and which would allow a full characterization of the galaxy population out to z ~ 2. We strongly recommend a serious further study to design a real instrument, which will be required for galaxy formation studies to advance to the next frontier.Comment: White paper, primary author J.E. Gunn, submitted to Astro2010 Decadal Survey, see http://www7.nationalacademies.org/bpa/Astro2010_SWP_byTitle.htm

Mixed Models with n>1 and Large Scale Structure constraints

Recent data on CBR anisotropies show a Doppler peak higher than expected in CDM cosmological models, if the spectral index $n=1$. However, CDM and LCDM models with n>1 can hardly be consistent with LSS data. Mixed models, instead, whose transfer function is naturally steeper because of free--streaming in the hot component, may become consistent with data if n>1, when Omega_h is large. This is confirmed by our detailed analysis, extended both to models with a hot component whose momentum space distribution had a thermal origin (like massive neutrinos), and to models with a non--cold component arising from heavier particle decay. In this work we systematically search models which fulfill all constraints which can be implemented at the linear level. We find that a stringent linear constraint arises from fitting the extra-power parameter Gamma. Other significant constraints arise comparing the expected abundances of galaxy clusters and high-z systems with observational data. Keeping to models with Gamma \geq 0.13, a suitable part of the space parameter still allows up to \sim 30% of hot component (it is worth outlining that our stringent criteria allow only models with 0.10 \mincir Omega_h \mincir 0.16, if n \leq 1). We also outline that models with such large non--cold component would ease the solution of the so--called baryon catastrophe in galaxy clusters.Comment: 28 pages + 9 figures, uses elsart.sty, to be published in New Astronom

Effects of SARS-COV-2 infection on outcomes in patients hospitalized for acute cardiac conditions. A prospective, multicenter cohort study (Swiss Cardiovascular SARS-CoV-2 Consortium).

BACKGROUND Although the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) causing coronavirus disease 2019 (COVID-19) primarily affects the respiratory system, the disease entity has been associated with cardiovascular complications. This study sought to assess the effect of concomitant SARS-COV-2 infection on clinical outcomes of patients hospitalized primarily for acute cardiac conditions on cardiology wards in Switzerland. METHODS In this prospective, observational study conducted in 5 Swiss cardiology centers during the COVID-19 pandemic, patients hospitalized due to acute cardiac conditions underwent a reverse-transcriptase polymerase chain reaction test at the time of admission and were categorized as SARS-COV-2 positive (cases) or negative (controls). Patients hospitalized on cardiology wards underwent treatment for the principal acute cardiac condition according to local practice. Clinical outcomes were recorded in-hospital, at 30 days, and after 1 year and compared between cases and controls. To adjust for imbalanced baseline characteristics, a subgroup of patients derived by propensity matching was analyzed. RESULTS Between March 2020 and February 2022, 538 patients were enrolled including 122 cases and 416 controls. Mean age was 68.0 ± 14.7 years, and 75% were men. Compared with controls, SARS-COV-2-positive patients more commonly presented with acute heart failure (35% vs. 17%) or major arrhythmia (31% vs. 9%), but less commonly with acute coronary syndrome (26% vs. 53%) or severe aortic stenosis (4% vs. 18%). Mortality was significantly higher in cases vs. controls in-hospital (16% vs. 1%), at 30 days (19.0% vs. 2.2%), and at 1 year (28.7% vs. 7.6%: p < 0.001 for all); this was driven primarily (up to 30 days) and exclusively (at one-year follow-up) by higher non-cardiovascular mortality, and was accompanied by a greater incidence of worsening renal function in cases vs. controls. These findings were maintained in a propensity-matched subgroup of 186 patients (93 cases and 93 controls) with balanced clinical presentation and baseline characteristics. CONCLUSIONS In this observational study of patients hospitalized for acute cardiac conditions, SARS-COV-2 infection at index hospitalization was associated with markedly higher all-cause and non-cardiovascular mortality throughout one-year follow-up. These findings highlight the need for effective, multifaceted management of both cardiac and non-cardiac morbidities and prolonged surveillance in patients with acute cardiac conditions complicated by SARS-COV-2 infection

Effects of SARS-COV-2 infection on outcomes in patients hospitalized for acute cardiac conditions. A prospective, multicenter cohort study (Swiss Cardiovascular SARS-CoV-2 Consortium)

BACKGROUND Although the severe acute respiratory syndrome coronavirus 2 (SARS-COV-2) causing coronavirus disease 2019 (COVID-19) primarily affects the respiratory system, the disease entity has been associated with cardiovascular complications. This study sought to assess the effect of concomitant SARS-COV-2 infection on clinical outcomes of patients hospitalized primarily for acute cardiac conditions on cardiology wards in Switzerland. METHODS In this prospective, observational study conducted in 5 Swiss cardiology centers during the COVID-19 pandemic, patients hospitalized due to acute cardiac conditions underwent a reverse-transcriptase polymerase chain reaction test at the time of admission and were categorized as SARS-COV-2 positive (cases) or negative (controls). Patients hospitalized on cardiology wards underwent treatment for the principal acute cardiac condition according to local practice. Clinical outcomes were recorded in-hospital, at 30 days, and after 1 year and compared between cases and controls. To adjust for imbalanced baseline characteristics, a subgroup of patients derived by propensity matching was analyzed. RESULTS Between March 2020 and February 2022, 538 patients were enrolled including 122 cases and 416 controls. Mean age was 68.0 ± 14.7 years, and 75% were men. Compared with controls, SARS-COV-2-positive patients more commonly presented with acute heart failure (35% vs. 17%) or major arrhythmia (31% vs. 9%), but less commonly with acute coronary syndrome (26% vs. 53%) or severe aortic stenosis (4% vs. 18%). Mortality was significantly higher in cases vs. controls in-hospital (16% vs. 1%), at 30 days (19.0% vs. 2.2%), and at 1 year (28.7% vs. 7.6%: p < 0.001 for all); this was driven primarily (up to 30 days) and exclusively (at one-year follow-up) by higher non-cardiovascular mortality, and was accompanied by a greater incidence of worsening renal function in cases vs. controls. These findings were maintained in a propensity-matched subgroup of 186 patients (93 cases and 93 controls) with balanced clinical presentation and baseline characteristics. CONCLUSIONS In this observational study of patients hospitalized for acute cardiac conditions, SARS-COV-2 infection at index hospitalization was associated with markedly higher all-cause and non-cardiovascular mortality throughout one-year follow-up. These findings highlight the need for effective, multifaceted management of both cardiac and non-cardiac morbidities and prolonged surveillance in patients with acute cardiac conditions complicated by SARS-COV-2 infection

Multicolor Photometry Study of the Galaxy Cluster A2589: Dynamics, Luminosity Function and Star Formation History

In this paper we present a multicolor photometry for A2589 ($z=0.0414$) with 15 intermediate bands in the Beijing-Arizona-Taiwan-Connecticut (BATC) system which covers an optical wavelength range from 3000 \AA\ to 10000 \AA. The spectral energy distributions (SEDs) for more than 5000 sources are achieved down to {\it V} $\sim$ 20 mag in about 1 deg$^{2}$ field. A2589 has been also covered by the Sloan Digital Sky Survey (SDSS) in photometric mode only. A cross-identification of the BATC-detected galaxies with the SDSS photometric catalog achieves 1199 galaxies brighter than $i=19.5$ mag, among which 68 member galaxies with known spectroscopic redshifts are found. After combining the SDSS five-band photometric data and the BATC SEDs, the technique of photometric redshift is applied to these galaxies for selecting faint member galaxies. The color-magnitude relation is taken as a further restriction of early-type cluster galaxies. As a result, 106 galaxies are newly selected as member galaxies. Spatial distribution of member galaxies shows a north-south elongation which agrees with the X-ray brightness profile and the orientation of central cD galaxy, NGC 7647. No substructures are detected on the basis of positions and radial velocities of cluster galaxies, indicating that A2589 is a well-relaxed system. The luminosity function of A2589 exhibits a peak at $M_{R} \sim -20$ mag and a dip at $M_{R} \sim -19$ mag. The low-density outer regions are the preferred habitat of faint galaxies. With the evolutionary population synthesis model, PEGASE, the environmental effect on the star formation properties for 68 spectroscopically confirmed member galaxies is studied. The outlier faint galaxies tend to have longer time scales of star formation, shorter mean stellar ages, and lower metallicities of interstellar medium, which can be interpreted in the context of hierarchical cosmological scenario.Comment: 2011 Accepted to A