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Evaporation or freezing of water-rich fluids with dilute concentrations of dissolved salts can produce brines, as observed in closed basins on Earth 1 and detected by remote sensing on icy bodies in the outer Solar System 2 , 3 . The mineralogical evolution of these brines is well understood in regard to terrestrial environments 4 , but poorly constrained for extraterrestrial systems owing to a lack of direct sampling. Here we report the occurrence of salt minerals in samples of the asteroid (101955) Bennu returned by the OSIRIS-REx mission 5 . These include sodium-bearing phosphates and sodium-rich carbonates, sulfates, chlorides and fluorides formed during evaporation of a late-stage brine that existed early in the history of Bennu’s parent body. Discovery of diverse salts would not be possible without mission sample return and careful curation and storage, because these decompose with prolonged exposure to Earth’s atmosphere. Similar brines probably still occur in the interior of icy bodies Ceres and Enceladus, as indicated by spectra or measurement of sodium carbonate on the surface or in plumes 2 , 3 . Samples from the asteroid (101955) Bennu, returned by the OSIRIS-REx mission, include sodium-bearing phosphates and sodium-rich carbonates, sulfates, chlorides and fluorides formed during evaporation of a late-stage brine.

This paper reviews the phosphate phases in meteorites and those measured by landed spacecraft, what they reveal about past igneous and aqueous conditions on Mars, and important implications for potential prebiotic chemistry, past habitability, and potential biosignatures that could be detected in samples returned from Mars. A review of the 378 martian meteorites as of 2023 indicate that of the two most common phosphate minerals in Mars meteorites, merrillite and apatites, the apatite composition is largely F- and Cl-rich, with shergottites containing more OH. The phosphate concentrations examined across multiple missions show a relatively narrow range of phosphate, with higher concentrations observed in the Mount Sharp Group in Gale crater and Wishstone at Gusev crater and lower concentrations observed at Jezero crater floor and Jezero fan. Possible secondary phosphates detected on Mars, including Fe phosphates at Jezero crater and Gusev crater and Ca- and Al-bearing secondary phosphates, temperatures of formation of secondary phases and their dissolution rates and solubilities are reviewed and summarized. Despite this wealth of information about phosphates on Mars, due to their fine scale and relatively low concentrations, Mars Sample Return is needed to better understand phosphate and its implications for the igneous, aqueous, and astrobiological history of Mars.

In this paper, we examine the hybrid optical fiber (OF)/free-space optics (FSO) architecture for a backhaul downlink over a wavelength-division multiplexing passive optical network (WDM-PON). The hybrid backhaul architecture is able to provide not only high-data-rate but also flexibility and quick deployment. The performance analysis is carried out for the hybrid OF/FSO backhaul downlink over a four-wavelength WDM-PON under the effect of four-wave mixing (FWM). The impact of atmospheric turbulence-induced fading and major noise components, including amplifier’s noise, shot noise, beat noise, background noise, and thermal noise, is also taken into account. The numerical results show that, although high transmitted power and amplifier’s gain at the transmitter side help to mitigate the impact of noise and fading, they should be limited to a specific value to avoid the influence of FWM. Therefore, the use of amplifier or avalanche photodiode at the receiver side would be a better solution to keep the bit-error rate (BER) at the low levels.

Heart failure remains a substantial cause of morbidity and mortality in women. We examined the sex differences in heart failure incidence, mortality and hospital admission in a population-based cohort. All Ontario residents who were diagnosed with heart failure in an ambulatory setting between Apr. 1, 2009, and Mar. 31, 2014, were included in this study. Incident cases of heart failure were captured through physician billing using a validated algorithm. Outcomes were mortality and hospital admission for heart failure within 1 year of the diagnosis. Probability of death and hospital admission were calculated using the Kaplan–Meier method. The hazard of death was assessed using a multivariable Cox proportional hazard model. A total of 90 707 diagnoses of heart failure were made in an ambulatory setting during the study period (47% women). Women were more likely to be older and more frail, and had different comorbidities than men. The incidence of heart failure decreased during the study period in both sexes. The mortality rate decreased in both sexes, but remained higher in women than men. The female age-standardized mortality rate was 89 (95% confidence interval [CI] 80–100) per 1000 in 2009 and 85 (95% CI 75–95) in 2013, versus male age-standardized mortality rates of 88 (95% CI 80–97) in 2009 and 83 (95% CI 75–91) in 2013. Conversely, the rates of incident heart failure hospital admissions after heart failure diagnosis decreased in men and increased in women. Despite decreases in overall heart failure incidence and mortality in ambulatory patients, mortality rates remain higher in women than in men, and rates of hospital admission for heart failure increased in women and declined in men. Further studies should focus on sex differences in health-seeking behaviour, medical therapy and response to therapy to provide guidance for personalized care.

Rates of death from cardiovascular and cerebrovascular diseases have been steadily declining over the past few decades. Whether such declines are occurring to a similar degree for common disorders such as acute myocardial infarction, heart failure and stroke is uncertain. We examined recent national trends in mortality and rates of hospital admission for these 3 conditions. We analyzed mortality data from Statistic Canada's Canadian Mortality Database and data on hospital admissions from the Canadian Institute for Health Information's Hospital Morbidity Database for the period 1994–2004. We determined age- and sex-standardized rates of death and hospital admissions per 100 000 population aged 20 years and over as well as in-hospital case-fatality rates. The overall age- and sex-standardized rate of death from cardiovascular disease in Canada declined 30.0%, from 360.6 per 100 000 in 1994 to 252.5 per 100 000 in 2004. During the same period, the rate fell 38.1% for acute myocardial infarction, 23.5% for heart failure and 28.2% for stroke, with improvements observed across most age and sex groups. The age- and sex-standardized rate of hospital admissions decreased 27.6% for stroke and 27.2% for heart failure. The rate for acute myocardial infarction fell only 9.2%. In contrast, the relative decline in the in-hospital case-fatality rate was greatest for acute myocardial infarction (33.1%; p < 0.001). Much smaller relative improvements in case-fatality rates were noted for heart failure (8.1%) and stroke (8.9%). The rates of death and hospital admissions for acute myocardial infarction, heart failure and stroke in Canada changed at different rates over the 10-year study period. Awareness of these trends may guide future efforts for health promotion and health care planning and help to determine priorities for research and treatment. Une version française de ce résumé est disponible à l'adresse www.cmaj.ca/cgi/content/full/cmaj.081197/DC2

Routinely collected data from large population health surveys linked to chronic disease outcomes create an opportunity to develop more complex risk-prediction algorithms. We developed a predictive algorithm to estimate 5-year risk of incident cardiovascular disease in the community setting. We derived the Cardiovascular Disease Population Risk Tool (CVDPoRT) using prospectively collected data from Ontario respondents of the Canadian Community Health Surveys, representing 98% of the Ontario population (survey years 2001 to 2007; follow-up from 2001 to 2012) linked to hospital admission and vital statistics databases. Predictors included body mass index, hypertension, diabetes, and multiple behavioural, demographic and general health risk factors. The primary outcome was the first major cardiovascular event resulting in hospital admission or death. Death from a noncardiovascular cause was considered a competing risk. We included 104 219 respondents aged 20 to 105 years. There were 3709 cardiovascular events and 818 478 person-years follow-up in the combined derivation and validation cohorts (5-year cumulative incidence function, men: 0.026, 95% confidence interval [CI] 0.025–0.028; women: 0.018, 95% 0.017–0.019). The final CVDPoRT algorithm contained 12 variables, was discriminating (men: C statistic 0.82, 95% CI 0.81–0.83; women: 0.86, 95% CI 0.85–0.87) and was well-calibrated in the overall population (5-year observed cumulative incidence function v. predicted risk, men: 0.28%; women: 0.38%) and in nearly all predefined policy-relevant subgroups (206 of 208 groups). The CVDPoRT algorithm can accurately discriminate cardiovascular disease risk for a wide range of health profiles without the aid of clinical measures. Such algorithms hold potential to support precision medicine for individual or population uses. Study registration: ClinicalTrials.gov, no. NCT02267447

Rates of cardiovascular disease among people with diabetes have declined over the last 20–30 years. To determine whether First Nations people have experienced similar declines, we compared time trends in rates of cardiac event and disease management among First Nations people with diabetes and other people with diabetes in Ontario, Canada. We conducted a retrospective cohort study of patients aged 20 to 105 years with diabetes between 1996 and 2015, using linked health administrative databases. Outcomes compared were the annual incidence of each admission to hospital for myocardial infarction and heart failure, and death owing to ischemic heart disease. Management indicators were coronary revascularization and prescription rates for cardioprotective medications. Overall rates and annual percent changes were compared using Poisson regression. Incidence rates for all cardiac outcomes decreased over the study period. The greatest relative annual decline among First Nations men and women were observed in ischemic heart disease death (4.4%, 95% confidence interval [CI] 3.0 to 5.9) and heart failure (5.4%, 95% CI 4.5 to 6.4), respectively. Among other men and women, the greatest annual declines were seen in ischemic heart disease death (6.3%, 95% CI 6.1 to 6.5 and 7.3%, 95% CI 7.1 to 7.6, respectively). However, all absolute cardiac event rates were higher among First Nations people (p < 0.001). Coronary artery revascularization procedures and prescriptions for cardioprotective medications increased among First Nations people, while only prescriptions increased among other people. Over the last 20 years, the incidence of cardiac events has declined among First Nations people with diabetes, but remains higher than other people with diabetes in Ontario. For continued reductions in incidence, future efforts need to recognize First Nations people’s unique social and cultural determinants of health.

Despite the availability of several acute coronary syndrome (ACS) prognostic risk scores, there is no appropriate score for early-risk stratification at the time of the first medical contact with patients with ACS. The primary objective of this study is to develop a simple risk score that can be used for early-risk stratification of patients with ACS. We derived the risk score from the Acute Myocardial Infarction in Quebec and Canada ACS-1 registries and validated the risk score in 4 other large data sets of patients with ACS (Canada ACS-2 registry, Canada-GRACE, EFFECT-1, and the FAST-MI registries). The final risk score is named the Canada Acute Coronary Syndrome Risk Score (C-ACS) and ranged from 0 to 4, with 1 point assigned for the presence of each of these variables: age ≥75 years, Killip >1, systolic blood pressure <100 mm Hg, and heart rate >100 beats/min. The primary end points were short-term (inhospital or 30-day) and long-term (1- or 5-year) all-cause mortality. The C-ACS has good predictive values for short- and long-term mortality of patients with ST-segment elevation myocardial infarction and non–ST-segment elevation ACS. The negative predictive value of a C-ACS score ≥1 is excellent at ≥98% (95% CI 0.97-0.99) for short-term mortality and ≥93% (95% CI 0.91-0.96) for long-term mortality. In other words, a C-ACS score of 0 can potentially identify correctly ≥97% short-term survivors and ≥91% long-term survivors. The C-ACS risk score permits rapid stratification of patients with ACS. Because this risk score is simple and easy to memorize and calculate, it can be rapidly applied by health care professionals without advanced medical training.

The ratio of percutaneous coronary interventions to coronary artery bypass graft surgeries (PCI:CABG ratio) varies considerably across hospitals. We conducted a comprehensive study to identify clinical and nonclinical factors associated with variations in the ratio across 17 cardiac centres in the province of Ontario. In this retrospective cohort study, we selected a population-based sample of 8972 patients who underwent an index cardiac catheterization between April 2006 and March 2007 at any of 17 hospitals that perform invasive cardiac procedures in the province. We classified the hospitals into four groups by PCI:CABG ratio (low [< 2.0], low–medium [2.0–2.7], medium–high [2.8–3.2] and high [> 3.2]). We explored the relative contribution of patient, physician and hospital factors to variations in the likelihood of patients receiving PCI or CABG surgery within 90 days after the index catheterization. The mean PCI:CABG ratio was 2.7 overall. We observed a threefold variation in the ratios across the four hospital ratio groups, from a mean of 1.6 in the lowest ratio group to a mean of 4.6 in the highest ratio group. Patients with single-vessel disease usually received PCI (88.4%–99.0%) and those with left main artery disease usually underwent CABG (80.8%–94.2%), regardless of the hospital's procedure ratio. Variation in the management of patients with non-emergent multivessel disease accounted for most of the variation in the ratios across hospitals. The mode of revascularization largely reflected the recommendation of the physician performing the diagnostic catheterization and was also influenced by the revascularization “culture” at the treating hospital. The physician performing the diagnostic catheterization and the treating hospital were strong independent predictors of the mode of revascularization. Opportunities exist to improve transparency and consistency around the decision-making process for coronary revascularization, most notably among patients with non-emergent multivessel disease.

The array of outcomes according to longitudinal furosemide doses in heart failure (HF) have not been evaluated. We examined the relationship of dynamic furosemide dose with mortality and hospitalizations for cardiovascular disease and renal dysfunction. Among elderly patients with HF (≥65 years) newly discharged from hospital, dynamic furosemide exposure was determined by examining dose fluctuations up to 5 years of follow-up using the Ontario Drug Benefit pharmacare database. Dynamic furosemide exposures were classified as low dose (LD; 1-59 mg/d), medium dose (MD; 60-119 mg/d), or high dose (HD; ≥120 mg/d). Outcomes were assessed by modeling furosemide exposure as a time-dependent covariate. Among 4,406 patients (78.4 ± 7.0 years; 50.5% male), 46% changed furosemide dose categories within 1 year, and 63% changed dose categories over the follow-up period. High-dose furosemide patients were younger, were mostly male, and exhibited more ischemic or valvular disease, diabetes, atrial fibrillation, hypotension, hyponatremia, and higher baseline creatinine than LD. Compared with LD, MD exposure was associated with increased mortality with adjusted hazard ratio 1.96 (95% CI 1.79-2.15), whereas HD exposure conferred greater mortality risk with hazard ratio 3.00 (95% CI 2.72-3.31) after multiple covariate adjustment (both P < .001). Adjusted risks of hospitalization for HF (MD: 1.24 [95% CI 1.12-1.38] and HD: 1.43 [95% CI 1.26-1.63]), renal dysfunction (MD: 1.56 [95% CI 1.38-1.76] and HD: 2.16 [95% CI 1.88-2.49]), and arrhythmias (MD: 1.15 [95% CI 1.03-1.30] and HD: 1.45 [95% CI 1.27-1.66]) were also higher with increasing furosemide exposure. Exposure to higher furosemide doses is associated with worsened outcomes and is broadly predictive of death and morbidity.