Debate: Do all patients with heart failure require implantable defibrillators to prevent sudden death?

Sudden death is a major cause of mortality in patients with ventricular dysfunction. The highest risk occurs among patients with less severe functional impairment. Current methods of risk stratification are inadequate, and a rational therapy for prevention of sudden death is not available. The implantable cardioverter-defibrillator (ICD) has proven to be more effective than drugs in reducing sudden-death risk in some subsets of patients. Empiric ICD therapy, targeting the general population with mild to moderate heart failure, will maximize the impact of such a strategy to prevent sudden death and improve long-term survival

Detection and characterization of Io's atmosphere from high-resolution 4-{\mu}m spectroscopy

We report on high-resolution and spatially-resolved spectra of Io in the 4.0 {\mu}m region, recorded with the VLT/CRIRES instrument in 2008 and 2010, which provide the first detection of the {\nu}1 + {\nu}3 band of SO2 in Io's atmosphere. Data are analyzed to constrain the latitudinal, longitudinal, and diurnal distribution of Io's SO2 atmosphere as well as its characteristic temperature. equatorial SO2 column densities clearly show longitudinal asymmetry, but with a maximum of around 1.5e17 cm-2 at central meridian longitude L = 200-220 and a minimum of around 3e16 cm-2 at L = 285-300, the longitudinal pattern somewhat differs from earlier inferences from Ly {\alpha} and thermal IR measurements. Within the accuracy of the measurements, no evolution of the atmospheric density from mid-2008 to mid-2010 can be distinguished. The decrease of the SO2 column density towards high latitude is apparent, and the typical latitudinal extent of the atmosphere found to be (+-) 40{\deg} at half-maximum. The data show moderate diurnal variations of the equatorial atmosphere, which is evidence for a partially sublimation-supported atmospheric component. Compared to local noon, factor of 2 lower densities are observed around 40{\deg} before and 80{\deg} after noon. Best-fit gas temperatures range from 150 to 220 K, with a weighted mean value of 170 (+-) 20 K, which should represent the column-weighted mean kinetic temperature of Io's atmosphere. Finally, although the data include clear thermal emission due to Pillan (in outburst in July 2008) and Loki, no detectable enhancements in the SO2 atmosphere above these volcanic regions are found, with an upper limit of 4e16 cm-2 at Pillan and 1e17 cm-2 at Loki.Comment: Accepted for publication in Icaru

An efficient parallel termination detection algorithm

Information local to any one processor is insufficient to monitor the overall progress of most distributed computations. Typically, a second distributed computation for detecting termination of the main computation is necessary. In order to be a useful computational tool, the termination detection routine must operate concurrently with the main computation, adding minimal overhead, and it must promptly and correctly detect termination when it occurs. In this paper, we present a new algorithm for detecting the termination of a parallel computation on distributed-memory MIMD computers that satisfies all of those criteria. A variety of termination detection algorithms have been devised. Of these, the algorithm presented by Sinha, Kale, and Ramkumar (henceforth, the SKR algorithm) is unique in its ability to adapt to the load conditions of the system on which it runs, thereby minimizing the impact of termination detection on performance. Because their algorithm also detects termination quickly, we consider it to be the most efficient practical algorithm presently available. The termination detection algorithm presented here was developed for use in the PMESC programming library for distributed-memory MIMD computers. Like the SKR algorithm, our algorithm adapts to system loads and imposes little overhead. Also like the SKR algorithm, ours is tree-based, and it does not depend on any assumptions about the physical interconnection topology of the processors or the specifics of the distributed computation. In addition, our algorithm is easier to implement and requires only half as many tree traverses as does the SKR algorithm. This paper is organized as follows. In section 2, we define our computational model. In section 3, we review the SKR algorithm. We introduce our new algorithm in section 4, and prove its correctness in section 5. We discuss its efficiency and present experimental results in section 6

Yield determination of maize hybrids under limited irrigation

Hybrid adoption, irrigation, and planting density are important factors for maize (Zea mays L.) production in semiarid regions. For this study, a 2-yr field experiment was conducted in the Texas High Plains to investigate maize yield determination, seasonal evapotranspiration (ETc), and water-use efficiency (WUE) under limited irrigation. Two hybrids (N74R, a conventional hybrid, and N75H, a drought-tolerant (DT) hybrid) were planted at three water regimes (I100, I75, and I50, referring to 100%, 75%, and 50% of the evapotranspiration requirement) and three planting densities (PD 6, PD 8, and PD 10, referring to 6, 8, and 10 seeds m−2). At I50, drought stress reduced grain yield by 4.78 t/ha for the conventional hybrid but only 4.22 t/ha for the DT hybrid, when compared to I100. Although ETc decreased at I75 and I50, the highest WUE was found at I75. The DT hybrid did not yield more than the conventional hybrid but had greater yield stability at lower water regimes and extracted less soil water. Drought decreased biomass, harvest index, and kernel weight but did not affect kernel number. Higher planting densities increased biomass and kernel number but decreased kernel weight. Kernel number and kernel weight of the conventional hybrid were more sensitive to planting density than the DT hybrid. These data demonstrated that limited irrigation at I75 is an effective way to save water and maintain the maize yield in semiarid areas, and that DT hybrid shows a greater yield stability to plant density under water stress

Models of the SL9 Impacts II. Radiative-hydrodynamic Modeling of the Plume Splashback

We model the plume "splashback" phase of the SL9 collisions with Jupiter using the ZEUS-3D hydrodynamic code. We modified the Zeus code to include gray radiative transport, and we present validation tests. We couple the infalling mass and momentum fluxes of SL9 plume material (from paper I) to a jovian atmospheric model. A strong and complex shock structure results. The modeled shock temperatures agree well with observations, and the structure and evolution of the modeled shocks account for the appearance of high excitation molecular line emission after the peak of the continuum light curve. The splashback region cools by radial expansion as well as by radiation. The morphology of our synthetic continuum light curves agree with observations over a broad wavelength range (0.9 to 12 microns). A feature of our ballistic plume is a shell of mass at the highest velocities, which we term the "vanguard". Portions of the vanguard ejected on shallow trajectories produce a lateral shock front, whose initial expansion accounts for the "third precursors" seen in the 2-micron light curves of the larger impacts, and for hot methane emission at early times. Continued propagation of this lateral shock approximately reproduces the radii, propagation speed, and centroid positions of the large rings observed at 3-4 microns by McGregor et al. The portion of the vanguard ejected closer to the vertical falls back with high z-component velocities just after maximum light, producing CO emission and the "flare" seen at 0.9 microns. The model also produces secondary maxima ("bounces") whose amplitudes and periods are in agreement with observations.Comment: 13 pages, 9 figures (figs 3 and 4 in color), accepted for Ap.J. latex, version including full figures at: http://oobleck.tn.cornell.edu/jh/ast/papers/slplume2-20.ps.g

Health literacy of recently hospitalised patients: a cross-sectional survey using the Health Literacy Questionnaire (HLQ)

BackgroundHealth literacy is simply defined as an individual&rsquo;s ability to access, understand and use information in ways that promote and maintain good health. Lower health literacy has been found to be associated with increased emergency department presentations and potentially avoidable hospitalisations. This study aimed to determine the health literacy of hospital inpatients, and to examine if associations exist between different dimensions of their health literacy, sociodemographic characteristics and hospital services use.MethodsA written survey was sent to 3,252 people aged &ge;18 years in English, Arabic, Chinese, Vietnamese, Italian or Greek. The survey included demographic and health questions, and the Health Literacy Questionnaire (HLQ). The HLQ is a multidimensional instrument comprising nine independent scales. Use of hospital services was measured by length of stay, number of admissions in 12 months and number of emergency department presentations. Effect size (ES) for standardised differences in means described the magnitude of differences in HLQ scale scores between demographic and socioeconomic groups.Results385 questionnaires were returned (13%); mean age 64 years (SD 17), 49% female. Aged &ge;65 years (55%), using the Internet&thinsp;&lt;&thinsp;once a month (37%), failure to complete high school (67%), low household income (39%), receiving means-tested government benefits (61%) and being from a culturally and linguistically diverse (CALD) background (24%), were all associated with lower scores in some health literacy scales. Being aged &ge;65 years, not currently employed, receiving government benefits, and being from a CALD background were also associated with increased use of some hospital services. There was no association between lower scores on any HLQ scale and greater use of hospital services.ConclusionWe found no association between lower health literacy and greater use of hospital health services. However increased age, having a CALD background and not speaking English at home were all associated with having the most health literacy challenges Strategies to address these are needed to reduce health inequalities.<br /

Differences in health literacy profiles of patients admitted to a public and a private hospital in Melbourne, Australia

BackgroundHealth literacy refers to an individual&rsquo;s ability to find, understand and use health information in order to promote and maintain health. An individual&rsquo;s health literacy may also be influenced by the way health care organisations deliver care. The aim of this study was to investigate the influence of hospital service type (public versus private) on individual health literacy.MethodsTwo cross-sectional surveys were conducted using the Health Literacy Questionnaire (HLQ), a multi-dimensional self-report instrument covering nine health literacy domains. Recently discharged private patients (n&thinsp;=&thinsp;3121) were sent the survey in English, public patients (n&thinsp;=&thinsp;384) were sent the survey in English, Arabic, Chinese, Vietnamese, Italian or Greek. Eligibility included hospitalisation &ge;24 h in last 30 days, aged &ge;18 years, no cognitive impairment. Odds ratios were used to assess differences between hospital sociodemographic and health related variables. ANOVA and Cohen&rsquo;s effect sizes compared HLQ scores between hospitals. Chi square and multiple logistic regression were used to determine whether differences between private and public hospital HLQ scores was independent of hospital population sociodemographic differences. ANOVA was used to review associations between HLQ scores and subgroups of demographic, health behaviour and health conditions and these were then compared across the two hospital populations.ResultsPublic hospital participants scored lower than private hospital participants on eight of the nine health literacy domains of the HLQ (scores for Active Appraisal did not differ between the two samples). Six domains, five of which in part measure the impact of how care is delivered on health literacy, remained lower among public hospital participants after controlling for age, education, language and income. Across both hospital populations, participants who were smokers, those who had low physical activity, those with depression and/or anxiety and those with 3 or more chronic conditions reported lower scores on some HLQ domains.ConclusionsOur finding of lower health literacy among patients who had received care at a public hospital in comparison to a private hospital, even after adjustment for sociodemographic and language differences, suggests that private hospitals may possess organisational attributes (environment, structure, values, practices and/or workforce competencies) that result in improved health literacy responsiveness.<br /

Health literacy of recently hospitalised patients: a cross-sectional survey using the Health Literacy Questionnaire (HLQ)

BackgroundHealth literacy is simply defined as an individual&rsquo;s ability to access, understand and use information in ways that promote and maintain good health. Lower health literacy has been found to be associated with increased emergency department presentations and potentially avoidable hospitalisations. This study aimed to determine the health literacy of hospital inpatients, and to examine if associations exist between different dimensions of their health literacy, sociodemographic characteristics and hospital services use.MethodsA written survey was sent to 3,252 people aged &ge;18 years in English, Arabic, Chinese, Vietnamese, Italian or Greek. The survey included demographic and health questions, and the Health Literacy Questionnaire (HLQ). The HLQ is a multidimensional instrument comprising nine independent scales. Use of hospital services was measured by length of stay, number of admissions in 12 months and number of emergency department presentations. Effect size (ES) for standardised differences in means described the magnitude of differences in HLQ scale scores between demographic and socioeconomic groups.Results385 questionnaires were returned (13%); mean age 64 years (SD 17), 49% female. Aged &ge;65 years (55%), using the Internet&thinsp;&lt;&thinsp;once a month (37%), failure to complete high school (67%), low household income (39%), receiving means-tested government benefits (61%) and being from a culturally and linguistically diverse (CALD) background (24%), were all associated with lower scores in some health literacy scales. Being aged &ge;65 years, not currently employed, receiving government benefits, and being from a CALD background were also associated with increased use of some hospital services. There was no association between lower scores on any HLQ scale and greater use of hospital services.ConclusionWe found no association between lower health literacy and greater use of hospital health services. However increased age, having a CALD background and not speaking English at home were all associated with having the most health literacy challenges Strategies to address these are needed to reduce health inequalities.<br /