285 research outputs found

    Hypersonic and Supersonic Static Aerodynamics of Mars Science Laboratory Entry Vehicle

    Get PDF
    This paper describes the analysis of continuum static aerodynamics of Mars Science Laboratory (MSL) entry vehicle (EV). The method is derived from earlier work for Mars Exploration Rover (MER) and Mars Path Finder (MPF) and the appropriate additions are made in the areas where physics are different from what the prior entry systems would encounter. These additions include the considerations for the high angle of attack of MSL EV, ablation of the heatshield during entry, turbulent boundary layer, and other aspects relevant to the flight performance of MSL. Details of the work, the supporting data and conclusions of the investigation are presented

    Comparison of office, home and ambulatory blood pressure measurements in hypertensive and suspected hypertensive SWICOS participants.

    Get PDF
    PURPOSE Hypertension should be confirmed with the use of home BP measurement (HBPM) or 24h ambulatory BP measurement (ABPM). The aim of our study was to compare measurements obtained by OBPM, HBPM and ABPM in individuals with elevated OBPM participating in the population-based Swiss Longitudinal Cohort Study (SWICOS). MATERIAL AND METHODS Participants with OBPM ≥140/90 mmHg assessed their BP using HBPM and ABPM. The cut-off for hypertension was ≥135/85 mmHg for HBPM, ≥130/80 mmHg for ABPM. White-coat hypertension (WCH) was defined as normal HPBM and ABPM in participants not taking antihypertensive drugs. Uncontrolled hypertension was defined as hypertension in HBPM or ABPM despite antihypertensive treatment. RESULTS Of 72 hypertensive subjects with office BP ≥140/90 mmHg and valid measurements of HBPM and ABPM, 39 were males (aged 62.8 ± 11.8y), 33 were females (aged 57.4 ± 14.2y). Hypertension was confirmed with HBPM and ABPM in 17 participants (24%), with ABPM only in 24 further participants (33%), and with HBPM only in 2 further participants (3%). Participants who had hypertension according to ABPM but not HBPM were younger (59 ± 11 y versus 67 ± 16 y; p < 0.001) and more frequently still working (83% versus 23%; p < 0.001). The prevalence of WCH was 28%. Among the 32 subjects taking antihypertensive drugs, uncontrolled hypertension was found in 49%. CONCLUSION This population-based study found a high prevalence of WCH and potential uncontrolled hypertension among individuals with elevated OBPM. This study, therefore, supports the ESH recommendations of complementing OBPM by ABPM or HBPM. The use of HBPM instead of ABPM for the confirmation of hypertension in individuals with elevated OBPM might lead to underdiagnosis and uncontrolled hypertension, in particular in the younger working population. In these individuals, this study suggests using ABPM instead of HBPM

    Comparison of office, home and ambulatory blood pressure measurements in hypertensive and suspected hypertensive SWICOS participants

    Full text link
    PURPOSE Hypertension should be confirmed with the use of home BP measurement (HBPM) or 24h ambulatory BP measurement (ABPM). The aim of our study was to compare measurements obtained by OBPM, HBPM and ABPM in individuals with elevated OBPM participating in the population-based Swiss Longitudinal Cohort Study (SWICOS). MATERIAL AND METHODS Participants with OBPM ≥140/90 mmHg assessed their BP using HBPM and ABPM. The cut-off for hypertension was ≥135/85 mmHg for HBPM, ≥130/80 mmHg for ABPM. White-coat hypertension (WCH) was defined as normal HPBM and ABPM in participants not taking antihypertensive drugs. Uncontrolled hypertension was defined as hypertension in HBPM or ABPM despite antihypertensive treatment. RESULTS Of 72 hypertensive subjects with office BP ≥140/90 mmHg and valid measurements of HBPM and ABPM, 39 were males (aged 62.8 ± 11.8y), 33 were females (aged 57.4 ± 14.2y). Hypertension was confirmed with HBPM and ABPM in 17 participants (24%), with ABPM only in 24 further participants (33%), and with HBPM only in 2 further participants (3%). Participants who had hypertension according to ABPM but not HBPM were younger (59 ± 11 y versus 67 ± 16 y; p < 0.001) and more frequently still working (83% versus 23%; p < 0.001). The prevalence of WCH was 28%. Among the 32 subjects taking antihypertensive drugs, uncontrolled hypertension was found in 49%. CONCLUSION This population-based study found a high prevalence of WCH and potential uncontrolled hypertension among individuals with elevated OBPM. This study, therefore, supports the ESH recommendations of complementing OBPM by ABPM or HBPM. The use of HBPM instead of ABPM for the confirmation of hypertension in individuals with elevated OBPM might lead to underdiagnosis and uncontrolled hypertension, in particular in the younger working population. In these individuals, this study suggests using ABPM instead of HBPM

    Assessment of the Reconstructed Aerodynamics of the Mars Science Laboratory Entry Vehicle

    Get PDF
    On August 5, 2012, the Mars Science Laboratory entry vehicle successfully entered Mars atmosphere, flying a guided entry until parachute deploy. The Curiosity rover landed safely in Gale crater upon completion of the Entry Descent and Landing sequence. This paper compares the aerodynamics of the entry capsule extracted from onboard flight data, including Inertial Measurement Unit (IMU) accelerometer and rate gyro information, and heatshield surface pressure measurements. From the onboard data, static force and moment data has been extracted. This data is compared to preflight predictions. The information collected by MSL represents the most complete set of information collected during Mars entry to date. It allows the separation of aerodynamic performance from atmospheric conditions. The comparisons show the MSL aerodynamic characteristics have been identified and resolved to an accuracy better than the aerodynamic database uncertainties used in preflight simulations. A number of small anomalies have been identified and are discussed. This data will help revise aerodynamic databases for future missions and will guide computational fluid dynamics (CFD) development to improved prediction codes

    Aerodynamic Interference Due to MSL Reaction Control System

    Get PDF
    An investigation of effectiveness of the reaction control system (RCS) of Mars Science Laboratory (MSL) entry capsule during atmospheric flight has been conducted. The reason for the investigation is that MSL is designed to fly a lifting actively guided entry with hypersonic bank maneuvers, therefore an understanding of RCS effectiveness is required. In the course of the study several jet configurations were evaluated using Langley Aerothermal Upwind Relaxation Algorithm (LAURA) code, Data Parallel Line Relaxation (DPLR) code, Fully Unstructured 3D (FUN3D) code and an Overset Grid Flowsolver (OVERFLOW) code. Computations indicated that some of the proposed configurations might induce aero-RCS interactions, sufficient to impede and even overwhelm the intended control torques. It was found that the maximum potential for aero-RCS interference exists around peak dynamic pressure along the trajectory. Present analysis largely relies on computational methods. Ground testing, flight data and computational analyses are required to fully understand the problem. At the time of this writing some experimental work spanning range of Mach number 2.5 through 4.5 has been completed and used to establish preliminary levels of confidence for computations. As a result of the present work a final RCS configuration has been designed such as to minimize aero-interference effects and it is a design baseline for MSL entry capsule

    Impact of Cardiovascular Risk Factors on Arterial Stiffness in a Countryside Area of Switzerland: Insights from the Swiss Longitudinal Cohort Study.

    Get PDF
    INTRODUCTION Cardiovascular disease is the leading cause of morbidity and mortality. Besides traditional cardiovascular risk factors, arterial stiffness is a recognized predictor of cardiovascular risk. METHODS We investigated the relationship between traditional cardiovascular risk factors, sex, and aortic pulse wave velocity in subjects living in a countryside area of Southern Switzerland. For this aim, we performed a cross-sectional analysis of data from adult participants of the Swiss Longitudinal Cohort Study, which, initiated in 2015, follows health status and disease risk factors in a Swiss countryside cohort at least 6 years of age. RESULTS A total of 387 people (205 women and 182 men) were included. Hyperlipidemia, overweight, and obesity were more common (p ≤ 0.001) and LDL-cholesterol, triglycerides, and hemoglobin A1c were higher (p < 0.03) in men than women. Systolic and diastolic brachial and aortic blood pressures were higher in men (p < 0.02), whereas aortic pulse wave velocity and aortic pulse pressure were higher in women (p < 0.05). The aortic pulse wave velocity was significantly higher in subjects with hypertension, hyperlipidemia, diabetes, and obesity, and significantly increased with age (p < 0.0001). Multiple linear regression analysis showed a significant correlation between pulse wave velocity and age, female sex, brachial systolic blood pressure, and heart rate (p < 0.005). CONCLUSION Also in a countryside area, the aortic pulse wave velocity is higher in subjects with hypertension, hyperlipidemia, diabetes and obesity, and significantly increases with age. Furthermore, with advancing age, aortic pulse wave velocity is higher in women than men. TRIAL REGISTRATION ClinicalTrials.gov identifier, NCT02282748

    MEDPass versus conventional administration of oral nutritional supplements - A randomized controlled trial comparing coverage of energy and protein requirements.

    Get PDF
    BACKGROUND & AIMS The use of oral nutritional supplements (ONS) in the hospital setting is important to reach individual protein and energy goals in patients at risk for malnutrition. Compliance with ONS can be challenging but may be improved by prescribing ONS in smaller portions with medication rounds (MEDPass). We compared the likelihood of meeting energy and protein requirements in patients receiving ONS with MEDPass versus conventional ONS administration. METHODS The MEDPass Trial is a randomized, controlled, open-label superiority trial conducted on medical and geriatric wards in a University Hospital in Switzerland. The MEDPass group was allocated to receive 50 ml of ONS four times per day with the medication rounds. The control group received ONS per conventional care between the meals. The primary outcome was the percentage of energy in relation to the individual requirement. Secondary outcomes included the coverage of protein intake in relation to the individual requirement, the amount of daily consumed ONS, the course of handgrip strength (HGS), body weight appetite and nausea. Furthermore, we compared 30-day mortality and hospital length of stay (LOS) was studied in medical patients. RESULTS From November 22nd, 2018 until November 30th, 2021, 204 patients were included in the trial (MEDPass group n = 100, control group n = 104). A total of 203 patients at nutritional risk were analyzed in the intention-to-treat analysis (ITT). Regarding the primary endpoint, there was no difference in the coverage of energy requirement between the MEDPass and control group (82 vs. 85% (Δ -3%, 95%CI -11 to 4%), p = 0.38). Similarly, no differences were found for the secondary outcomes including coverage of protein requirement (101 vs. 104% (Δ -3%, 95% CI -12 -7%), p = 0.57, average daily intake of ONS (170 vs 173 ml (Δ - 3 ml, 95% CI -14 to 8 ml), p = 0.58) and 30-day mortality (3 vs. 8 patients, OR 0.4 (95% CI 0.1-1.4), p = 0.15). The course of HGS, body weight, appetite and nausea did not differ between the groups (p = 0.29, p = 0.14, p = 0.65 and p = 0.94, respectively). The per protocol analysis including 178 patients showed similar results. CONCLUSION Within this controlled trial setting, we found a high compliance for ONS intake and high coverage of protein requirements but no further improvement when ONS was administered using MEDPass compared to conventional care. MEDPass administration may provide an alternative that is easy to integrate into nursing routines, which may lead to lower workload with cost benefits and reduction of food waste. TRIAL REGISTRATION ClinicalTrials.gov: NCT03761680

    Quantum noise in the position measurement of a cavity mirror undergoing Brownian motion

    Get PDF
    We perform a quantum theoretical calculation of the noise power spectrum for a phase measurement of the light output from a coherently driven optical cavity with a freely moving rear mirror. We examine how the noise resulting from the quantum back action appears among the various contributions from other noise sources. We do not assume an ideal (homodyne) phase measurement, but rather consider phase modulation detection, which we show has a different shot noise level. We also take into account the effects of thermal damping of the mirror, losses within the cavity, and classical laser noise. We relate our theoretical results to experimental parameters, so as to make direct comparisons with current experiments simple. We also show that in this situation, the standard Brownian motion master equation is inadequate for describing the thermal damping of the mirror, as it produces a spurious term in the steady-state phase fluctuation spectrum. The corrected Brownian motion master equation [L. Diosi, Europhys. Lett. {\bf 22}, 1 (1993)] rectifies this inadequacy.Comment: 12 pages revtex, 2 figure

    Computations of Viking Lander Capsule Hypersonic Aerodynamics with Comparisons to Ground and Flight Data

    Get PDF
    Comparisons are made between the LAURA Navier-Stokes code and Viking Lander Capsule hypersonic aerodynamics data from ground and flight measurements. Wind tunnel data are available for a 3.48 percent scale model at Mach 6 and a 2.75 percent scale model at Mach 10.35, both under perfect gas air conditions. Viking Lander 1 aerodynamics flight data also exist from on-board instrumentation for velocities between 2900 and 4400 m/sec (Mach 14 to 23.3). LAURA flowfield solutions are obtained for the geometry as tested or flown, including sting effects at tunnel conditions and finite-rate chemistry effects in flight. Using the flight vehicle center-of-gravity location (trim angle approx. equals -11.1 deg), the computed trim angle at tunnel conditions is within 0.31 degrees of the angle derived from Mach 6 data and 0.13 degrees from the Mach 10.35 trim angle. LAURA Mach 6 trim lift and drag force coefficients are within 2 percent of measured data, and computed trim lift-to-drag ratio is within 4 percent of the data. Computed trim lift and drag force coefficients at Mach 10.35 are within 5 percent and 3 percent, respectively, of wind tunnel data. Computed trim lift-to-drag ratio is within 2 percent of the Mach 10.35 data. Using the nominal density profile and center-of-gravity location, LAURA trim angle at flight conditions is within 0.5 degrees of the total angle measured from on-board instrumentation. LAURA trim lift and drag force coefficients at flight conditions are within 7 and 5 percent, respectively, of the flight data. Computed trim lift-to-drag ratio is within 4 percent of the data. Computed aerodynamics sensitivities to center-of-gravity location, atmospheric density, and grid refinement are generally small. The results will enable a better estimate of aerodynamics uncertainties for future Mars entry vehicles where non-zero angle-of-attack is required

    Neuronal Profilin Isoforms Are Addressed by Different Signalling Pathways

    Get PDF
    Profilins are prominent regulators of actin dynamics. While most mammalian cells express only one profilin, two isoforms, PFN1 and PFN2a are present in the CNS. To challenge the hypothesis that the expression of two profilin isoforms is linked to the complex shape of neurons and to the activity-dependent structural plasticity, we analysed how PFN1 and PFN2a respond to changes of neuronal activity. Simultaneous labelling of rodent embryonic neurons with isoform-specific monoclonal antibodies revealed both isoforms in the same synapse. Immunoelectron microscopy on brain sections demonstrated both profilins in synapses of the mature rodent cortex, hippocampus and cerebellum. Both isoforms were significantly more abundant in postsynaptic than in presynaptic structures. Immunofluorescence showed PFN2a associated with gephyrin clusters of the postsynaptic active zone in inhibitory synapses of embryonic neurons. When cultures were stimulated in order to change their activity level, active synapses that were identified by the uptake of synaptotagmin antibodies, displayed significantly higher amounts of both isoforms than non-stimulated controls. Specific inhibition of NMDA receptors by the antagonist APV in cultured rat hippocampal neurons resulted in a decrease of PFN2a but left PFN1 unaffected. Stimulation by the brain derived neurotrophic factor (BDNF), on the other hand, led to a significant increase in both synaptic PFN1 and PFN2a. Analogous results were obtained for neuronal nuclei: both isoforms were localized in the same nucleus, and their levels rose significantly in response to KCl stimulation, whereas BDNF caused here a higher increase in PFN1 than in PFN2a. Our results strongly support the notion of an isoform specific role for profilins as regulators of actin dynamics in different signalling pathways, in excitatory as well as in inhibitory synapses. Furthermore, they suggest a functional role for both profilins in neuronal nuclei
    corecore