Spiral Density Waves in a Young Protoplanetary Disk

Gravitational forces are expected to excite spiral density waves in protoplanetary disks, disks of gas and dust orbiting young stars. However, previous observations that showed spiral structure were not able to probe disk midplanes, where most of the mass is concentrated and where planet formation takes place. Using the Atacama Large Millimeter/submillimeter Array we detected a pair of trailing symmetric spiral arms in the protoplanetary disk surrounding the young star Elias 2-27. The arms extend to the disk outer regions and can be traced down to the midplane. These millimeter-wave observations also reveal an emission gap closer to the star than the spiral arms. We argue that the observed spirals trace shocks of spiral density waves in the midplane of this young disk.Comment: This is our own version of the manuscript, the definitive version was published in Science (DOI: 10.1126/science.aaf8296) on September 30, 2016. Posted to the arxiv for non-commercial us

Low-dose spironolactone and cardiovascular outcomes in moderate stage Chronic Kidney Disease:a randomised controlled trial

Chronic kidney disease (CKD) is associated with substantial risk of progression to end stage renal disease and vascular events. The non-steroidal mineralocorticoid receptor antagonist (MRA), finerenone, offers cardio-renal protection for people with CKD and diabetes, but there is uncertainty if the steroidal MRA, spironolactone, provides the same protection. In this prospective, randomised, open, blinded endpoint (PROBE) trial we assessed the effectiveness of 25mg spironolactone in addition to usual care or usual care alone for reducing cardiovascular outcomes in stage 3b CKD among an older community cohort (mean age 74.8 years, standard deviation 8.1). We recruited 1,434 adults from English primary care, of whom 1,372 (96%) were included in the primary analysis. The primary outcome was time from randomisation until the first occurrence of; death, hospitalisation for heart disease, stroke, heart failure, transient ischaemic attack or peripheral arterial disease, or first onset of any condition listed not present at baseline. Across three years of follow-up, the primary endpoint occurred in 113/677 participants randomised to spironolactone (16.7%) and 111/695 randomised to usual care (16.0%) with no significant difference between groups (hazard ratio 1.05, 95%CI:0.81-1.37). Two-thirds of participants randomised to spironolactone stopped treatment within six months, predominantly because they met pre-specified safety stop criteria. The most common reason for stopping spironolactone was a decrease in the estimated glomerular filtration rate that met pre-specified stop criteria (n=239, 35.4%), followed by participants being withdrawn due to treatment side-effects (n=128, 18.9%) and hyperkalaemia (n=54, 8.0%). In conclusion, we found that spironolactone was frequently discontinued due to safety concerns, with no evidence that it reduced cardiovascular outcomes in people with stage 3b CKD. Spironolactone should not be used for people with stage 3b CKD without another explicit treatment indication. ClinicalTrials.gov registration: ISRCTN44522369.<br/

Low-dose spironolactone and cardiovascular outcomes in moderate stage Chronic Kidney Disease:a randomised controlled trial

Chronic kidney disease (CKD) is associated with substantial risk of progression to end stage renal disease and vascular events. The non-steroidal mineralocorticoid receptor antagonist (MRA), finerenone, offers cardio-renal protection for people with CKD and diabetes, but there is uncertainty if the steroidal MRA, spironolactone, provides the same protection. In this prospective, randomised, open, blinded endpoint (PROBE) trial we assessed the effectiveness of 25mg spironolactone in addition to usual care or usual care alone for reducing cardiovascular outcomes in stage 3b CKD among an older community cohort (mean age 74.8 years, standard deviation 8.1). We recruited 1,434 adults from English primary care, of whom 1,372 (96%) were included in the primary analysis. The primary outcome was time from randomisation until the first occurrence of; death, hospitalisation for heart disease, stroke, heart failure, transient ischaemic attack or peripheral arterial disease, or first onset of any condition listed not present at baseline. Across three years of follow-up, the primary endpoint occurred in 113/677 participants randomised to spironolactone (16.7%) and 111/695 randomised to usual care (16.0%) with no significant difference between groups (hazard ratio 1.05, 95%CI:0.81-1.37). Two-thirds of participants randomised to spironolactone stopped treatment within six months, predominantly because they met pre-specified safety stop criteria. The most common reason for stopping spironolactone was a decrease in the estimated glomerular filtration rate that met pre-specified stop criteria (n=239, 35.4%), followed by participants being withdrawn due to treatment side-effects (n=128, 18.9%) and hyperkalaemia (n=54, 8.0%). In conclusion, we found that spironolactone was frequently discontinued due to safety concerns, with no evidence that it reduced cardiovascular outcomes in people with stage 3b CKD. Spironolactone should not be used for people with stage 3b CKD without another explicit treatment indication. ClinicalTrials.gov registration: ISRCTN44522369.<br/

Spiral density waves in a young protoplanetary disk

Gravitational forces are expected to excite spiral density waves in protoplanetary disks, disks of gas and dust orbiting young stars. However, previous observations that showed spiral structure were not able to probe disk midplanes, where most of the mass is concentrated and where planet formation takes place. Using the Atacama Large Millimeter/submillimeter Array, we detected a pair of trailing symmetric spiral arms in the protoplanetary disk surrounding the young star Elias 2-27. The arms extend to the disk outer regions and can be traced down to the midplane. These millimeter-wave observations also reveal an emission gap closer to the star than the spiral arms. We argue that the observed spirals trace shocks of spiral density waves in the midplane of this young disk

Grain Growth in the Circumstellar Disks of the Young Stars CY Tau and DoAr 25

We present new results from the Disks@EVLA program for two young stars: CY Tau and DoAr 25. We trace continuum emission arising from their circusmtellar disks from spatially resolved observations, down to tens of AU scales, at λ = 0.9, 2.8, 8.0, 9.8 mm for DoAr 25 and at λ = 1.3, 2.8, 7.1 mm for CY Tau. Additionally, we constrain the amount of emission whose origin is different from thermal dust emission from 5 cm observations. Directly from interferometric data, we find that observations at 7 mm and 1 cm trace emission from a compact disk while millimeter-wave observations trace an extended disk structure. From a physical disk model, where we characterize the disk structure of CY Tau and DoAr 25 at wavelengths shorter than 5 cm, we find that (1) dust continuum emission is optically thin at the observed wavelengths and over the spatial scales studied, (2) a constant value of the dust opacity is not warranted by our observations, and (3) a high-significance radial gradient of the dust opacity spectral index, β, is consistent with the observed dust emission in both disks, with low-β in the inner disk and high-β in the outer disk. Assuming that changes in dust properties arise solely due to changes in the maximum particle size (a_(max)), we constrain radial variations of a_(max) in both disks, from cm-sized particles in the inner disk (R 80 AU). These observational constraints agree with theoretical predictions of the radial-drift barrier, however, fragmentation of dust grains could explain our a_(max)(R) constraints if these disks have lower turbulence and/or if dust can survive high-velocity collisions

Rare Decays of the η′\eta^{'}

We have searched for the rare decays of the eta prime meson to e+ e- eta, e+ e- pizero, e+ e- gamma, and e mu in hadronic events at the CLEO II detector. The search is conducted on 4.80 fb^-1 of e+ e- collisions at the Cornell Electron Storage Ring. We find no signal in any of these modes, and set 90% confidence level upper limits on their branching fractions of 2.4 X 10^-3, 1.4 X 10^-3, 0.9 X 10^-3, and 4.7 X 10^-4, respectively. We also investigate the Dalitz plot of the common decay of the eta prime to pi+ pi- eta. We fit the matrix element with the Particle Data Group parameterization and find Re(alpha) = -0.021 +- 0.025, where alpha is a linear function of the kinetic energy of the eta.Comment: 12 pages postscript, also available through http://w4.lns.cornell.edu/public/CLN

Cross-National Differences in Victimization : Disentangling the Impact of Composition and Context

Varying rates of criminal victimization across countries are assumed to be the outcome of countrylevel structural constraints that determine the supply ofmotivated o¡enders, as well as the differential composition within countries of suitable targets and capable guardianship. However, previous empirical tests of these ‘compositional’ and ‘contextual’ explanations of cross-national di¡erences have been performed upon macro-level crime data due to the unavailability of comparable individual-level data across countries. This limitation has had two important consequences for cross-national crime research. First, micro-/meso-level mechanisms underlying cross-national differences cannot be truly inferred from macro-level data. Secondly, the e¡ects of contextual measures (e.g. income inequality) on crime are uncontrolled for compositional heterogeneity. In this paper, these limitations are overcome by analysing individual-level victimization data across 18 countries from the International CrimeVictims Survey. Results from multi-level analyses on theft and violent victimization indicate that the national level of income inequality is positively related to risk, independent of compositional (i.e. micro- and meso-level) di¡erences. Furthermore, crossnational variation in victimization rates is not only shaped by di¡erences in national context, but also by varying composition. More speci¢cally, countries had higher crime rates the more they consisted of urban residents and regions with lowaverage social cohesion.