6,434 research outputs found

    Service organisation for the secondary prevention of ischaemic heart disease in primary care.

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    BACKGROUND: Ischaemic heart disease (IHD) is a major cause of mortality and morbidity and its prevalence is set to increase. Secondary prevention aims to prevent subsequent acute events in people with established IHD. While the benefits of individual medical and lifestyle interventions is established, the effectiveness of interventions which seek to improve the way secondary preventive care is delivered in primary care or community settings is less so. OBJECTIVES: To assess the effectiveness of service organisation interventions, identifying which types and elements of service change are associated with most improvement in clinician and patient adherence to secondary prevention recommendations relating to risk factor levels and monitoring (blood pressure, cholesterol and lifestyle factors such as diet, exercise, smoking and obesity) and appropriate prophylactic medication. SEARCH STRATEGY: We searched the Cochrane Central Register of Controlled Trials (CENTRAL, The Cochrane Library 2007, Issue 4), MEDLINE (1966 to Feb 2008), EMBASE (1980 to Feb 2008), and CINAHL (1981 to Feb 2008). Bibliographies were checked. No language restrictions were applied. SELECTION CRITERIA: Randomised or quasi-randomised controlled trials of service organisation interventions in primary care or community settings in populations with established IHD. DATA COLLECTION AND ANALYSIS: Analyses were conducted according to Cochrane recommendations and Odds Ratios (with 95% confidence intervals) reported for dichotomous outcomes, mean differences (with 95% CIs) for continuous outcomes. MAIN RESULTS: Eleven studies involving 12,074 people with IHD were included. Increased proportions of patients with total cholesterol levels within recommended levels at 12 months, OR 1.90 (1.04 to 3.48), were associated with interventions that included regular planned appointments, patient education and structured monitoring of medication and risk factors, but significant heterogeneity was apparent. Results relating to blood pressure within target levels bordered on statistical significance. There were no significant effects of interventions on mean blood pressure or cholesterol levels, prescribing, smoking status or body mass index. Few data were available on the effect on diet. There was some suggestion of a \u22ceiling effect\u22 whereby interventions have a diminishing beneficial effect once certain levels of risk factor management are reached. AUTHORS\u27 CONCLUSIONS: There is weak evidence that regular planned recall of patients for appointments, structured monitoring of risk factors and prescribing, and education for patients can be effective in increasing the proportions of patients within target levels for cholesterol control and blood pressure. Further research in this area would benefit from greater standardisation of the outcomes measured

    Orion Exploration Flight Test-1 Contingency Drogue Deploy Velocity Trigger

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    As a backup to the GPS-aided Kalman filter and the Barometric altimeter, an "adjusted" velocity trigger is used during entry to trigger the chain of events that leads to drogue chute deploy for the Orion Multi-Purpose Crew Vehicle (MPCV) Exploration Flight Test-1 (EFT-1). Even though this scenario is multiple failures deep, the Orion Guidance, Navigation, and Control (GN&C) software makes use of a clever technique that was taken from the Mars Science Laboratory (MSL) program, which recently successfully landing the Curiosity rover on Mars. MSL used this technique to jettison the heat shield at the proper time during descent. Originally, Orion use the un-adjusted navigated velocity, but the removal of the Star Tracker to save costs for EFT-1, increased attitude errors which increased inertial propagation errors to the point where the un-adjusted velocity caused altitude dispersions at drogue deploy to be too large. Thus, to reduce dispersions, the velocity vector is projected onto a "reference" vector that represents the nominal "truth" vector at the desired point in the trajectory. Because the navigation errors are largely perpendicular to the truth vector, this projection significantly reduces dispersions in the velocity magnitude. This paper will detail the evolution of this trigger method for the Orion project and cover the various methods tested to determine the reference "truth" vector; and at what point in the trajectory it should be computed

    Maternal thyroid function and child educational attainment: prospective cohort study

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    Objective: To determine if first trimester maternal thyroid dysfunction is a critical determinant of child scholastic performance and overall educational attainment. Design: Prospective cohort study. Setting: Avon Longitudinal Study of Parents and Children cohort in the UK. Participants: 4615 mother-child pairs with an available first trimester sample (median 10 weeks gestation, interquartile range 8-12). Exposures: Free thyroxine, thyroid stimulating hormone, and thyroid peroxidase antibodies assessed as continuous measures and the seven clinical categories of maternal thyroid function. Main outcome measures: Five age-specific national curriculum assessments in 3580 children at entry stage assessment at 54 months, increasing up to 4461 children at their final school assessment at age 15. Results: No strong evidence of clinically meaningful associations of first trimester free thyroxine and thyroid stimulating hormone levels with entry stage assessment score or Standard Assessment Test scores at any of the key stages was found. Associations of maternal free thyroxine or thyroid stimulating hormone with the total number of General Certificates of Secondary Education (GCSEs) passed (range 0-16) were all close to the null: free thyroxine, rate ratio per pmol/L 1.00 (95% confidence interval 1.00 to 1.01); and thyroid stimulating hormone, rate ratio 0.98 (0.94 to 1.02). No important relationship was observed when more detailed capped scores of GCSEs allowing for both the number and grade of pass or when language, mathematics, and science performance were examined individually or when all educational assessments undertaken by an individual from school entry to leaving were considered. 200 (4.3%) mothers were newly identified as having hypothyroidism or subclinical hypothyroidism and 97 (2.1%) subclinical hyperthyroidism or hyperthyroidism. Children of mothers with thyroid dysfunction attained an equivalent number of GCSEs and equivalent grades as children of mothers with euthyroidism. Conclusions: Maternal thyroid dysfunction in early pregnancy does not have a clinically important association with impaired child performance at school or educational achievement

    An Alternative Flight Software Trigger Paradigm: Applying Multivariate Logistic Regression to Sense Trigger Conditions Using Inaccurate or Scarce Information

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    In late 2014, NASA will fly the Orion capsule on a Delta IV-Heavy rocket for the Exploration Flight Test-1 (EFT-1) mission. For EFT-1, the Orion capsule will be flying with a new GPS receiver and new navigation software. Given the experimental nature of the flight, the flight software must be robust to the loss of GPS measurements. Once the high-speed entry is complete, the drogue parachutes must be deployed within the proper conditions to stabilize the vehicle prior to deploying the main parachutes. When GPS is available in nominal operations, the vehicle will deploy the drogue parachutes based on an altitude trigger. However, when GPS is unavailable, the navigated altitude errors become excessively large, driving the need for a backup barometric altimeter to improve altitude knowledge. In order to increase overall robustness, the vehicle also has an alternate method of triggering the parachute deployment sequence based on planet-relative velocity if both the GPS and the barometric altimeter fail. However, this backup trigger results in large altitude errors relative to the targeted altitude. Motivated by this challenge, this paper demonstrates how logistic regression may be employed to semi-automatically generate robust triggers based on statistical analysis. Logistic regression is used as a ground processor pre-flight to develop a statistical classifier. The classifier would then be implemented in flight software and executed in real-time. This technique offers improved performance even in the face of highly inaccurate measurements. Although the logistic regression-based trigger approach will not be implemented within EFT-1 flight software, the methodology can be carried forward for future missions and vehicles

    Behavioral Deficits and Axonal Injury Persistence after Rotational Head Injury Are Direction Dependent

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    Pigs continue to grow in importance as a tool in neuroscience. However, behavioral tests that have been validated in the rodent model do not translate well to pigs because of their very different responses to behavioral stimuli. We refined metrics for assessing porcine open field behavior to detect a wide spectrum of clinically relevant behaviors in the piglet post-traumatic brain injury (TBI). Female neonatal piglets underwent a rapid non-impact head rotation in the sagittal plane (n=8 evaluable) or were instrumented shams (n=7 evaluable). Open field testing was conducted 1 day prior to injury (day −1) in order to establish an individual baseline for analysis, and at days +1 and +4 after injury. Animals were then killed on day +6 after injury for neuropathological assessment of axonal injury. Injured piglets were less interested in interacting with environmental stimuli and had a lower activity level than did shams. These data were compared with previously published data for axial rotational injuries in neonatal piglets. Acute behavioral outcomes post-TBI showed a dependence on the rotational plane of the brain injury, with animals with sagittal injuries demonstrating a greater level of inactivity and less random usage of the open field space than those with axial injuries. The persistence of axonal injury is also dependent on the rotational plane, with sagittal rotations causing more prolonged injuries than axial rotations. These results are consistent with animal studies, finite element models, and studies of concussions in football, which have all demonstrated differences in injury severity depending upon the direction of head impact rotation

    Final report for DOE Grant No. DE-FG02-07ER64404 - Field Investigations of Microbially Facilitated Calcite Precipitation for Immobilization of Strontium-90 and Other Trace Metals in the Subsurface

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    Subsurface radionuclide and metal contaminants throughout the U.S. Department of Energy (DOE) complex pose one of DOEâÃÂÃÂs greatest challenges for long-term stewardship. One promising stabilization mechanism for divalent ions, such as the short-lived radionuclide 90Sr, is co-precipitation in calcite. We have previously found that that nutrient addition can stimulate microbial ureolytic activity that this activity accelerates calcite precipitation and co-precipitation of Sr, and that higher calcite precipitation rates can result in increased Sr partitioning. We have conducted integrated field, laboratory, and computational research to evaluate the relationships between ureolysis and calcite precipitation rates and trace metal partitioning under environmentally relevant conditions, and investigated the coupling between flow/flux manipulations and precipitate distribution. A field experimental campaign conducted at the Integrated Field Research Challenge (IFRC) site located at Rifle, CO was based on a continuous recirculation design; water extracted from a down-gradient well was amended with urea and molasses (a carbon and electron donor) and re-injected into an up-gradient well. The goal of the recirculation design and simultaneous injection of urea and molasses was to uniformly accelerate the hydrolysis of urea and calcite precipitation over the entire inter-wellbore zone. The urea-molasses recirculation phase lasted, with brief interruptions for geophysical surveys, for 12 days followed by long-term monitoring which continued for 13 months. Following the recirculation phase we found persistent increases in urease activity (as determined from 14C labeled laboratory urea hydrolysis rates) in the upper portion of the inter-wellbore zone. We also observed an initial increase (approximately 2 weeks) in urea concentration associated with injection activities followed by decreasing urea concentration and associated increases in ammonium and dissolved inorganic carbon (DIC) following the termination of injection. Based on the loss of urea and the appearance of ammonium, a first order rate constant for urea hydrolysis of 0.18 day-1 rate with an associate Rf for ammonium of 11 were estimated. This rate constant is approximately 6 times higher than estimated for previous field experiments conducted in eastern Idaho. Additionally, DIC carbon isotope ratios were measured for the groundwater. Injected urea had a ÃÂô13C of 40.7ÃÂñ0.4 âÃÂð compared to background groundwater DIC of ÃÂô13C of -16.6ÃÂñ0.2âÃÂð. Observed decreases in groundwater DIC ÃÂô13C of up to -19.8âÃÂð followed temporal trends similar to those observed for ammonium and suggest that both the increase in ammonium and the sift in ÃÂô13C are the result of urea hydrolysis. Although direct observation of calcite precipitation was not possible because of the high pre-existing calcite content in the site sediments, an observed ÃÂô13C decrease for solid carbonates from sediment samples collect following urea injection (compared to pre-injection values) is likely the result of the incorporation of inorganic carbon derived from urea hydrolysis into newly formed solid carbonates

    Determination of Caffeine as a Marker for Septic Tank Contamination of Wilgreen Lake

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    Wilgreen Lake in Richmond, Kentucky, has been listed by both the state and the Environmental Protection Agency as an “impaired” lake due to excess nutrients, which may be in part contributed by domestic septic systems. Caffeine can be used as an anthropogenic marker to estimate the contribution of septic tank effluent to the lake. We have modified existing analytical methods to produce a viable method for the determination of caffeine in environmental water samples and applied the method to water samples collected from Wilgreen Lake. The modified method allows determination of caffeine in a concentration range of 75 to 10,000 ng/L in the water samples. Waters Oasis® HLB solid phase extraction cartridges are used to clean up and concentrate the water samples, which are then analyzed by liquid chromatography-tandem mass spectrometry. A Waters XTerra MS C18 column (3.5 µm film thickness, 2.1 x 100 mm column dimensions) is utilized in the separation. Carbon-13 labeled caffeine is added to all samples prior to extraction and serves as an internal standard. The parameters of the optimized method and results of the application of this method to water samples collected from Wilgreen Lake will be presented

    A Comparative Study of Interval Management Control Law Capabilities

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    This paper presents a new tool designed to allow for rapid development and testing of different control algorithms for airborne spacing. This tool, Interval Management Modeling and Spacing Tool (IM MAST), is a fast-time, low-fidelity tool created to model the approach of aircraft to a runway, with a focus on their interactions with each other. Errors can be induced between pairs of aircraft by varying initial positions, winds, speed profiles, and altitude profiles. Results to-date show that only a few of the algorithms tested had poor behavior in the arrival and approach environment. The majority of the algorithms showed only minimal variation in performance under the test conditions. Trajectory-based algorithms showed high susceptibility to wind forecast errors, while performing marginally better than the other algorithms under other conditions. Trajectory-based algorithms have a sizable advantage, however, of being able to perform relative spacing operations between aircraft on different arrival routes and flight profiles without employing ghosting. methods. This comes at the higher cost of substantially increased complexity, however. Additionally, it was shown that earlier initiation of relative spacing operations provided more time for corrections to be made without any significant problems in the spacing operation itself. Initiating spacing farther out, however, would require more of the aircraft to begin spacing before they merge onto a common route
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