The ionosphere is a highly dynamic medium that exhibits weather disturbances at all latitudes, longitudes, and altitudes, and these disturbances can have detrimental effects on both military and ...civilian systems. In an effort to mitigate the adverse effects, we are developing a physics‐based data assimilation model of the ionosphere and neutral atmosphere called the Global Assimilation of Ionospheric Measurements (GAIM). GAIM will use a physics‐based ionosphere‐plasmasphere model and a Kalman filter as a basis for assimilating a diverse set of real‐time (or near real‐time) measurements. Some of the data to be assimilated include in situ density measurements from satellites, ionosonde electron density profiles, occultation data, ground‐based GPS total electron contents (TECs), two‐dimensional ionospheric density distributions from tomography chains, and line‐of‐sight UV emissions from selected satellites. When completed, GAIM will provide specifications and forecasts on a spatial grid that can be global, regional, or local. The primary output of GAIM will be a continuous reconstruction of the three‐dimensional electron density distribution from 90 km to geosynchronous altitude (35,000 km). GAIM also outputs auxiliary parameters, including NmF2, hmF2, NmE, hmE, and slant and vertical TEC. Furthermore, GAIM provides global distributions for the ionospheric drivers (neutral winds and densities, magnetospheric and equatorial electric fields, and electron precipitation patterns). In its specification mode, GAIM yields quantitative estimates for the accuracy of the reconstructed ionospheric densities.
The relative roles of anthropogenic nitrogen (N) deposition and climate change in causing ecological change in remote Arctic ecosystems, especially lakes, have been the subject of debate over the ...last decade. Some palaeoecological studies have cited isotopic signals (δ(15N)) preserved in lake sediments as evidence linking N deposition with ecological change, but a key limitation has been the lack of co-located data on both deposition input fluxes and isotopic composition of deposited nitrate (NO3−). In Arctic lakes, including those in western Greenland, previous palaeolimnological studies have indicated a spatial variation in δ(15N) trends in lake sediments but data are lacking for deposition chemistry, input fluxes and stable isotope composition of NO3−. In the present study, snowpack chemistry, NO3− stable isotopes and net deposition fluxes for the largest ice-free region in Greenland were investigated to determine whether there are spatial gradients from the ice sheet margin to the coast linked to a gradient in precipitation. Late-season snowpack was sampled in March 2011 at eight locations within three lake catchments in each of three regions (ice sheet margin in the east, the central area near Kelly Ville and the coastal zone to the west). At the coast, snowpack accumulation averaged 181 mm snow water equivalent (SWE) compared with 36 mm SWE by the ice sheet. Coastal snowpack showed significantly greater concentrations of marine salts (Na+, Cl−, other major cations), ammonium (NH4+; regional means 1.4–2.7 µmol L−1), total and non-sea-salt sulfate (SO42−; total 1.8–7.7, non-sea-salt 1.0–1.8 µmol L−1) than the two inland regions. Nitrate (1.5–2.4 µmol L−1) showed significantly lower concentrations at the coast. Despite lower concentrations, higher precipitation at the coast results in greater net deposition for NO3− as well as NH4+ and non-sea-salt sulfate (nss-SO42−) relative to the inland regions (lowest at Kelly Ville 6, 4 and 3; highest at coast 9, 17 and 11 mol ha−1 a−1 of NO3−, NH4+ and nss-SO42− respectively). The δ(15N) of snowpack NO3− shows a significant decrease from inland regions (−5.7 ‰ at Kelly Ville) to the coast (−11.3 ‰). We attribute the spatial patterns of δ(15N) in western Greenland to post-depositional processing rather than differing sources because of (1) spatial relationships with precipitation and sublimation, (2) within-catchment isotopic differences between terrestrial snowpack and lake ice snowpack, and (3) similarities between fresh snow (rather than accumulated snowpack) at Kelly Ville and the coast. Hence the δ(15N) of coastal snowpack is most representative of snowfall in western Greenland, but after deposition the effects of photolysis, volatilization and sublimation lead to enrichment of the remaining snowpack with the greatest effect in inland areas of low precipitation and high sublimation losses.
Transcatheter aortic valve implantation was developed to mitigate the mortality and morbidity associated with high-risk traditional aortic valve replacement. The Edwards SAPIEN valve was approved for ...transcatheter aortic valve implantation transfemoral delivery in the European Union in November 2007 and for transapical delivery in January 2008.
The SAPIEN Aortic Bioprosthesis European Outcome (SOURCE) Registry was designed to assess the initial clinical results of the Edwards SAPIEN valve in consecutive patients in Europe after commercialization. Cohort 1 consists of 1038 patients enrolled at 32 centers. Patients who were treated with the transapical approach (n=575) suffered more comorbidities than the transfemoral patients (n=463), resulting in a significantly higher logistic EuroSCORE (29.1% versus 25.7%; P<0.001). Therefore, these groups are considered different, and outcomes cannot be compared. Overall short-term procedural success was observed in 93.8%. The incidence of valve embolization was 0.3% (n=3), and coronary obstruction was reported for 0.6% (n=6 cases). Incidence of stroke was 2.5% and similar for both procedural approaches. Thirty-day mortality was 6.3% in transfemoral patients and 10.3% in transapical patients. The occurrence of vascular complications was not a predictor of <30-day mortality in the transfemoral population.
Technical proficiency can be learned and adapted readily as demonstrated by the short-term procedural success rate and low 30-day mortality rates reported in the SOURCE Registry. Specific complication management and refinement of patient selection are needed to further improve outcomes.
As a part of ongoing efforts of the NCI-FDA Interagency Oncology Task Force subcommittee on molecular diagnostics, members of the Clinical Proteomic Technology Assessment for Cancer program of the ...National Cancer Institute have submitted 2 protein-based multiplex assay descriptions to the Office of In Vitro Diagnostic Device Evaluation and Safety, US Food and Drug Administration. The objective was to evaluate the analytical measurement criteria and studies needed to validate protein-based multiplex assays. Each submission described a different protein-based platform: a multiplex immunoaffinity mass spectrometry platform for protein quantification, and an immunological array platform quantifying glycoprotein isoforms. Submissions provided a mutually beneficial way for members of the proteomics and regulatory communities to identify the analytical issues that the field should address when developing protein-based multiplex clinical assays.
Pregnant women are increasingly using mobile apps as a source of supplemental information. These pregnancy-related mobile apps present women with contradictory risk recommendations without the ...medical research to support their claims. The content analysis describes a sample of the pregnancy-tracking mobile application environment open to pregnant mothers and uses the social amplification of risk framework. Within this framework, written recommendations and the presence or absence of corresponding citations on controversial topics in pregnancy were recorded and risk was coded as received contradictory information. Of the 48 pregnancy-tracking mobile apps downloaded, 11 (22.9%) were associated with either a seller or a developer with a medical background. Only 24 of 48 (50.0%) of the apps cited a source, such as a health professional agency or peer-reviewed research journal for health recommendations. In our results, we show a sampling of contradictory risk recommendations made by mobile apps that cite or do not cite their source for that recommendation on 8 controversial topics in pregnancy. Findings suggest providers treating pregnant women must be aware of the complex information environment and help them navigate the risk information they encounter on some of the most popular pregnancy-tracking mobile apps.
The effects of excess cortisol secretion on blood pressure and fat deposition are well documented, but the importance of this glucocorticoid in controlling these processes in normal individuals is ...less clear. We studied the relationship between cortisol excretion rate (tetrahydrocortisol THF+allo-THF+tetrahydrocortisone THE) and a range of important cardiovascular risk factors in 439 normal subjects (238 male) sampled from the North of Glasgow (Scotland) population. There were marked gender differences: female subjects were lighter and had lower blood pressures and cortisol levels, whereas HDL cholesterol was higher. The pattern of cortisol metabolism was also different; the index of 11beta-hydroxysteroid dehydrogenase activity (THF+allo-THF/THE) was lower and that of 5alpha-reductase (allo-THF/THF) was higher. There was a strong correlation of blood pressure (positive), cholesterol (positive), and HDL cholesterol (negative in women, positive in men) with age. Cortisol excretion rate did not correlate with blood pressure but correlated strongly with parameters of body habitus (body mass index and waist and hip measurements positive) and HDL cholesterol (negative). With multiple regression analysis, there remained a significant association of cortisol excretion rate with HDL cholesterol in men and women and with body mass index in men. These results suggest that glucocorticoids regulate key components of cardiovascular risk.
The impact of a new class of automated digital patient engagement (DPE) platforms on potentially avoidable costs, hospital admissions, and complications after discharge following hip and knee ...arthroplasties has not been established.
We conducted a multicenter observational cohort study comparing claims data for potentially avoidable costs, hospital admissions, and complications for 90 days after discharge following hip and knee arthroplasties at 10 practice sites in CA and NV. One hundred eighty-six patients, enrolled between 2014 and 2016 on an automated DPE platform receiving guidance and remote monitoring perioperatively, were compared with 372 patients who underwent the same procedures from the same physicians within 3 years immediately preceding platform implementation. The primary end point was the proportion of patients with $0.00 in 90-day target costs because of potentially avoidable utilization within the platform's influence. Secondary end points included rates of potentially avoidable 90-day hospital admissions and composite complications.
Ninety-three percent and 84.7% of the study and baseline cohorts, respectively, had $0.00 in target costs (P = .004), with a mean savings of $656.52/patient (P = .006). The baseline and study cohorts had 3.0% and 1.6% 90-day hospital admission rates (relative risk 0.545; 0.154, 1.931, P = .40), and 15.3% and 7.0% composite complication rates, respectively (relative risk 0.456; 0.256, 0.812, P = .004).
Patients enrolled on an automated DPE platform after hip and knee arthroplasties demonstrated a significant reduction in potentially avoidable 90-day costs, a 45.4% nonsignificant relative reduction in 90-day hospital admissions, and a 54.4% significant relative reduction in 90-day complications.
Hippocrates recognized the importance of asking about sleep as long ago as 400 BC when he wrote "
". Disrupted sleep for any reason has immediate and long term consequences on physical and mental ...health. Insomnia disorder ("immoderate watchfulness") remains the commonest sleep disorder in primary and secondary care with an estimated 5-10% of the adult population affected. While it is commonly comorbid with other physical and mental health problems, the new diagnostic classification has been helpfully simplified such that it is considered a disorder in itself. If it is the patient's main concern, it warrants treatment. Patients and health professionals have often had limited teaching about effective strategies for insomnia which leaves many untreated and insomnia can be unfairly perceived as a challenging symptom to manage. The first line treatment is now well established as insomnia-specific cognitive behavioural therapy (CBTi) in the most recent US and European treatment guidelines. Over 25 years of high quality research have shown evidence for sustained improvements in sleep in those with insomnia alone or insomnia comorbid with other conditions. This is a simple CBT to deliver with better and safer outcomes than prescription hypnotics. Therefore, this review will cover the initial assessment of insomnia, including insomnia mimics, the selection of patients for treatment and the key components of CBT therapy. Finally, the review will cover evidence for different modes of delivery (online, self, help, group or individual face to face) in a variety of clinical settings.
Abstract Objective: To assess whether a raised serum troponin T concentration would be an independent predictor of death in patients with an acute ischaemic stroke. Design: Observational study. ...Setting: Auckland Hospital, Auckland, New Zealand. Subjects: All 181 patients with an acute ischaemic stroke admitted over nine months in 1997-8, from a total of 8057 patients admitted to the acute medical service. Main outcome measures: Blood samples for measuring troponin T concentration were collected 12-72 hours after admission; other variables previously associated with severity of stroke were also recorded and assessed as independent predictors of inpatient mortality. Results: Troponin T concentration was raised (>0.1 μg/l) in 17% (30) of patients admitted with an acute ischaemic stroke. Thirty one patients died in hospital (12/30 (40%) patients with a raised troponin T concentration v 19/151 (13%) patients with a normal concentration (relative risk 3.2 (95% confidence 1.7 to 5.8; P=0.0025)). Of 17 possible predictors of death, assessed in a multivariate stepwise model, only a raised troponin T concentration (P=0.0002), age (P=0.0008), and an altered level of consciousness at presentation (P=0.0074) independently predicted an adverse outcome. Conclusions: Serum troponin T concentration at hospital admission is a powerful predictor of mortality in patients admitted with an acute ischaemic stroke.
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