We characterize the occurrence rate of planets, ranging in size from 0.5 to 16 R⊕, orbiting FGK stars with orbital periods from 0.5 to 500 days. Our analysis is based on results from the "DR25" ...catalog of planet candidates produced by NASA's Kepler mission and stellar radii from Gaia "DR2." We incorporate additional Kepler data products to accurately characterize the efficiency of planets being recognized as "threshold crossing events" by Kepler's Transiting Planet Search pipeline and labeled as planet candidates by the robovetter. Using a hierarchical Bayesian model, we derive planet occurrence rates for a wide range of planet sizes and orbital periods. For planets with sizes 0.75-1.5 R⊕ and orbital periods of 237-500 days, we find a rate of planets per FGK star of <0.27 (84.13th percentile). While the true rate of such planets could be lower by a factor of ∼2 (primarily due to potential contamination of planet candidates by false alarms), the upper limits on the occurrence rate of such planets are robust to ∼10%. We recommend that mission concepts aiming to characterize potentially rocky planets in or near the habitable zone of Sun-like stars prepare compelling science programs that would be robust for a true rate in the range fR,P = 0.03-0.40 for 0.75-1.5 R⊕ planets with orbital periods in 237-500 days, or a differential rate of 0.06-0.76.
Low carbohydrate diets, which restrict carbohydrate in favour of increased protein or fat intake, or both, are a popular weight-loss strategy. However, the long-term effect of carbohydrate ...restriction on mortality is controversial and could depend on whether dietary carbohydrate is replaced by plant-based or animal-based fat and protein. We aimed to investigate the association between carbohydrate intake and mortality.
We studied 15 428 adults aged 45–64 years, in four US communities, who completed a dietary questionnaire at enrolment in the Atherosclerosis Risk in Communities (ARIC) study (between 1987 and 1989), and who did not report extreme caloric intake (<600 kcal or >4200 kcal per day for men and <500 kcal or >3600 kcal per day for women). The primary outcome was all-cause mortality. We investigated the association between the percentage of energy from carbohydrate intake and all-cause mortality, accounting for possible non-linear relationships in this cohort. We further examined this association, combining ARIC data with data for carbohydrate intake reported from seven multinational prospective studies in a meta-analysis. Finally, we assessed whether the substitution of animal or plant sources of fat and protein for carbohydrate affected mortality.
During a median follow-up of 25 years there were 6283 deaths in the ARIC cohort, and there were 40 181 deaths across all cohort studies. In the ARIC cohort, after multivariable adjustment, there was a U-shaped association between the percentage of energy consumed from carbohydrate (mean 48·9%, SD 9·4) and mortality: a percentage of 50–55% energy from carbohydrate was associated with the lowest risk of mortality. In the meta-analysis of all cohorts (432 179 participants), both low carbohydrate consumption (<40%) and high carbohydrate consumption (>70%) conferred greater mortality risk than did moderate intake, which was consistent with a U-shaped association (pooled hazard ratio 1·20, 95% CI 1·09–1·32 for low carbohydrate consumption; 1·23, 1·11–1·36 for high carbohydrate consumption). However, results varied by the source of macronutrients: mortality increased when carbohydrates were exchanged for animal-derived fat or protein (1·18, 1·08–1·29) and mortality decreased when the substitutions were plant-based (0·82, 0·78–0·87).
Both high and low percentages of carbohydrate diets were associated with increased mortality, with minimal risk observed at 50–55% carbohydrate intake. Low carbohydrate dietary patterns favouring animal-derived protein and fat sources, from sources such as lamb, beef, pork, and chicken, were associated with higher mortality, whereas those that favoured plant-derived protein and fat intake, from sources such as vegetables, nuts, peanut butter, and whole-grain breads, were associated with lower mortality, suggesting that the source of food notably modifies the association between carbohydrate intake and mortality.
National Institutes of Health.
ABSTRACT The Kepler Mission has discovered thousands of planets with radii <4 , paving the way for the first statistical studies of the dynamics, formation, and evolution of these sub-Neptunes and ...super-Earths. Planetary masses are an important physical property for these studies, and yet the vast majority of Kepler planet candidates do not have theirs measured. A key concern is therefore how to map the measured radii to mass estimates in this Earth-to-Neptune size range where there are no Solar System analogs. Previous works have derived deterministic, one-to-one relationships between radius and mass. However, if these planets span a range of compositions as expected, then an intrinsic scatter about this relationship must exist in the population. Here we present the first probabilistic mass-radius relationship (M-R relation) evaluated within a Bayesian framework, which both quantifies this intrinsic dispersion and the uncertainties on the M-R relation parameters. We analyze how the results depend on the radius range of the sample, and on how the masses were measured. Assuming that the M-R relation can be described as a power law with a dispersion that is constant and normally distributed, we find that , a scatter in mass of , and a mass constraint to physically plausible densities, is the "best-fit" probabilistic M-R relation for the sample of RV-measured transiting sub-Neptunes (Rpl < 4 ). More broadly, this work provides a framework for further analyses of the M-R relation and its probable dependencies on period and stellar properties.
The quantification of membrane-associated biomolecular interactions is crucial to our understanding of various cellular processes. State-of-the-art single-molecule approaches rely largely on the ...addition of fluorescent labels, which complicates the quantification of the involved stoichiometries and dynamics because of low temporal resolution and the inherent limitations associated with labeling efficiency, photoblinking and photobleaching. Here, we demonstrate dynamic mass photometry, a method for label-free imaging, tracking and mass measurement of individual membrane-associated proteins diffusing on supported lipid bilayers. Application of this method to the membrane remodeling GTPase, dynamin-1, reveals heterogeneous mixtures of dimer-based oligomers, oligomer-dependent mobilities, membrane affinities and (dis)association of individual complexes. These capabilities, together with assay-based advances for studying integral membrane proteins, will enable the elucidation of biomolecular mechanisms in and on lipid bilayers.
The current Dietary Guidelines for Americans recommend multiple healthy eating patterns. However, few studies have examined the associations of adherence to different dietary patterns with long-term ...risk of total and cause-specific mortality.
To examine the associations of dietary scores for 4 healthy eating patterns with risk of total and cause-specific mortality.
This prospective cohort study included initially healthy women from the Nurses' Health Study (NHS; 1984-2020) and men from the Health Professionals Follow-up Study (HPFS; 1986-2020).
Healthy Eating Index 2015 (HEI-2015), Alternate Mediterranean Diet (AMED) score, Healthful Plant-based Diet Index (HPDI), and Alternate Healthy Eating Index (AHEI).
The main outcomes were total and cause-specific mortality overall and stratified by race and ethnicity and other potential risk factors.
The final study sample included 75 230 women from the NHS (mean SD baseline age, 50.2 7.2 years) and 44 085 men from the HPFS (mean SD baseline age, 53.3 9.6 years). During a total of 3 559 056 person-years of follow-up, 31 263 women and 22 900 men died. When comparing the highest with the lowest quintiles, the pooled multivariable-adjusted HRs of total mortality were 0.81 (95% CI, 0.79-0.84) for HEI-2015, 0.82 (95% CI, 0.79-0.84) for AMED score, 0.86 (95% CI, 0.83-0.89) for HPDI, and 0.80 (95% CI, 0.77-0.82) for AHEI (P < .001 for trend for all). All dietary scores were significantly inversely associated with death from cardiovascular disease, cancer, and respiratory disease. The AMED score and AHEI were inversely associated with mortality from neurodegenerative disease. The inverse associations between these scores and risk of mortality were consistent in different racial and ethnic groups, including Hispanic, non-Hispanic Black, and non-Hispanic White individuals.
In this cohort study of 2 large prospective cohorts with up to 36 years of follow-up, greater adherence to various healthy eating patterns was consistently associated with lower risk of total and cause-specific mortality. These findings support the recommendations of Dietary Guidelines for Americans that multiple healthy eating patterns can be adapted to individual food traditions and preferences.
AbstractObjectiveTo examine how a healthy lifestyle is related to life expectancy that is free from major chronic diseases.DesignProspective cohort study.Setting and participantsThe Nurses’ Health ...Study (1980-2014; n=73 196) and the Health Professionals Follow-Up Study (1986-2014; n=38 366).Main exposuresFive low risk lifestyle factors: never smoking, body mass index 18.5-24.9, moderate to vigorous physical activity (≥30 minutes/day), moderate alcohol intake (women: 5-15 g/day; men 5-30 g/day), and a higher diet quality score (upper 40%).Main outcomeLife expectancy free of diabetes, cardiovascular diseases, and cancer.ResultsThe life expectancy free of diabetes, cardiovascular diseases, and cancer at age 50 was 23.7 years (95% confidence interval 22.6 to 24.7) for women who adopted no low risk lifestyle factors, in contrast to 34.4 years (33.1 to 35.5) for women who adopted four or five low risk factors. At age 50, the life expectancy free of any of these chronic diseases was 23.5 (22.3 to 24.7) years among men who adopted no low risk lifestyle factors and 31.1 (29.5 to 32.5) years in men who adopted four or five low risk lifestyle factors. For current male smokers who smoked heavily (≥15 cigarettes/day) or obese men and women (body mass index ≥30), their disease-free life expectancies accounted for the lowest proportion (≤75%) of total life expectancy at age 50.ConclusionAdherence to a healthy lifestyle at mid-life is associated with a longer life expectancy free of major chronic diseases.
Summary Background Percutaneous coronary intervention (PCI) is most commonly guided by angiography alone. Intravascular ultrasound (IVUS) guidance has been shown to reduce major adverse ...cardiovascular events (MACE) after PCI, principally by resulting in a larger postprocedure lumen than with angiographic guidance. Optical coherence tomography (OCT) provides higher resolution imaging than does IVUS, although findings from some studies suggest that it might lead to smaller luminal diameters after stent implantation. We sought to establish whether or not a novel OCT-based stent sizing strategy would result in a minimum stent area similar to or better than that achieved with IVUS guidance and better than that achieved with angiography guidance alone. Methods In this randomised controlled trial, we recruited patients aged 18 years or older undergoing PCI from 29 hospitals in eight countries. Eligible patients had one or more target lesions located in a native coronary artery with a visually estimated reference vessel diameter of 2·25–3·50 mm and a length of less than 40 mm. We excluded patients with left main or ostial right coronary artery stenoses, bypass graft stenoses, chronic total occlusions, planned two-stent bifurcations, and in-stent restenosis. Participants were randomly assigned (1:1:1; with use of an interactive web-based system in block sizes of three, stratified by site) to OCT guidance, IVUS guidance, or angiography-guided stent implantation. We did OCT-guided PCI using a specific protocol to establish stent length, diameter, and expansion according to reference segment external elastic lamina measurements. All patients underwent final OCT imaging (operators in the IVUS and angiography groups were masked to the OCT images). The primary efficacy endpoint was post-PCI minimum stent area, measured by OCT at a masked independent core laboratory at completion of enrolment, in all randomly allocated participants who had primary outcome data. The primary safety endpoint was procedural MACE. We tested non-inferiority of OCT guidance to IVUS guidance (with a non-inferiority margin of 1·0 mm2 ), superiority of OCT guidance to angiography guidance, and superiority of OCT guidance to IVUS guidance, in a hierarchical manner. This trial is registered with ClinicalTrials.gov , number NCT02471586. Findings Between May 13, 2015, and April 5, 2016, we randomly allocated 450 patients (158 35% to OCT, 146 32% to IVUS, and 146 32% to angiography), with 415 final OCT acquisitions analysed for the primary endpoint (140 34% in the OCT group, 135 33% in the IVUS group, and 140 34% in the angiography group). The final median minimum stent area was 5·79 mm2 (IQR 4·54–7·34) with OCT guidance, 5·89 mm2 (4·67–7·80) with IVUS guidance, and 5·49 mm2 (4·39–6·59) with angiography guidance. OCT guidance was non-inferior to IVUS guidance (one-sided 97·5% lower CI −0·70 mm2 ; p=0·001), but not superior (p=0·42). OCT guidance was also not superior to angiography guidance (p=0·12). We noted procedural MACE in four (3%) of 158 patients in the OCT group, one (1%) of 146 in the IVUS group, and one (1%) of 146 in the angiography group (OCT vs IVUS p=0·37; OCT vs angiography p=0·37). Interpretation OCT-guided PCI using a specific reference segment external elastic lamina-based stent optimisation strategy was safe and resulted in similar minimum stent area to that of IVUS-guided PCI. These data warrant a large-scale randomised trial to establish whether or not OCT guidance results in superior clinical outcomes to angiography guidance. Funding St Jude Medical.
The aging of the US population is expected to lead to a large increase in the number of adults with dementia, but some recent studies in the United States and other high-income countries suggest that ...the age-specific risk of dementia may have declined over the past 25 years. Clarifying current and future population trends in dementia prevalence and risk has important implications for patients, families, and government programs.
To compare the prevalence of dementia in the United States in 2000 and 2012.
We used data from the Health and Retirement Study (HRS), a nationally representative, population-based longitudinal survey of individuals in the United States 65 years or older from the 2000 (n = 10 546) and 2012 (n = 10 511) waves of the HRS.
Dementia was identified in each year using HRS cognitive measures and validated methods for classifying self-respondents, as well as those represented by a proxy. Logistic regression was used to identify socioeconomic and health variables associated with change in dementia prevalence between 2000 and 2012.
The study cohorts had an average age of 75.0 years (95% CI, 74.8-75.2 years) in 2000 and 74.8 years (95% CI, 74.5-75.1 years) in 2012 (P = .24); 58.4% (95% CI, 57.3%-59.4%) of the 2000 cohort was female compared with 56.3% (95% CI, 55.5%-57.0%) of the 2012 cohort (P < .001). Dementia prevalence among those 65 years or older decreased from 11.6% (95% CI, 10.7%-12.7%) in 2000 to 8.8% (95% CI, 8.2%-9.4%) (8.6% with age- and sex-standardization) in 2012 (P < .001). More years of education was associated with a lower risk for dementia, and average years of education increased significantly (from 11.8 years 95% CI, 11.6-11.9 years to 12.7 years 95% CI, 12.6-12.9 years; P < .001) between 2000 and 2012. The decline in dementia prevalence occurred even though there was a significant age- and sex-adjusted increase between years in the cardiovascular risk profile (eg, prevalence of hypertension, diabetes, and obesity) among older US adults.
The prevalence of dementia in the United States declined significantly between 2000 and 2012. An increase in educational attainment was associated with some of the decline in dementia prevalence, but the full set of social, behavioral, and medical factors contributing to the decline is still uncertain. Continued monitoring of trends in dementia incidence and prevalence will be important for better gauging the full future societal impact of dementia as the number of older adults increases in the decades ahead.
The angular momentum deficit (AMD) of a planetary system is a measure of its orbital excitation and a predictor of long-term stability. We adopt the AMD-stability criterion to constrain the orbital ...architectures for exoplanetary systems. Previously, He et al. showed through forward modeling (SysSim) that the observed multiplicity distribution can be well reproduced by two populations consisting of a low and a high mutual inclination component. Here, we show that a broad distribution of mutual inclinations arising from systems at the AMD-stability limit can also match the observed Kepler population. We show that distributing a planetary system's maximum AMD among its planets results in a multiplicity-dependent distribution of eccentricities and mutual inclinations. Systems with intrinsically more planets have lower median eccentricities and mutual inclinations, and this trend is well described by power-law functions of the intrinsic planet multiplicity (n): and , where and are the medians of the eccentricity and inclination distributions. We also find that intrinsic single planets have higher eccentricities ( e,1 ∼ 0.25) than multiplanet systems and that the trends with multiplicity appear in the observed distributions of period-normalized transit duration ratios. We show that the observed preferences for planet-size orderings and uniform spacings are more extreme than what can be produced by the detection biases of the Kepler mission alone. Finally, we find that for systems with detected transiting planets between 5 and 10 days, there is another planet with a greater radial velocity signal 53% of the time.
ABSTRACT An intriguing trend among Kepler's multi-planet systems is an overabundance of planet pairs with period ratios just wide of a mean motion resonance (MMR) and a dearth of systems just narrow ...of them. Traditional planet formation models are at odds with these observations. They are also in contrast with the period ratios of radial-velocity-discovered multi-planet systems which tend to pile up at MMR. We propose that gas-disk migration traps planets in an MMR. After gas dispersal, orbits of these trapped planets are altered through interaction with a residual planetesimal disk. We study the effects of planetesimal disk interactions on planet pairs trapped in MMR using planets of mass typical of the Kepler planet candidates and explore large ranges for the mass, and density profile of the planetesimal disk. We find that planet-planetesimal disk interactions naturally create the observed asymmetry in period-ratio distribution for large ranges of planetesimal disk and planet properties. If the planetesimal disk mass is above a threshold of 0.2× the planet mass, these interactions typically disrupt MMR. Afterwards, the planets migrate in such a way that the final period-ratio is slightly higher than the integer ratio corresponding to the initial MMR. Below this threshold these interactions typically cannot disrupt the resonance and the period ratio stays close to the integer ratio. The threshold explains why the more massive planet pairs found by RV surveys are still in resonance. We encourage future research to explore how significantly the associated accretion would change the planets' atmospheric and surface properties.
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