5,570 research outputs found

    Vertically Air Lifted High Altitude Light Launch Apparatus (VALHALLA)

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    Project VALHALLA aims to get collegiate level rockets to reach higher altitudes by providing a launch platform that shall allow them to be launched from 100,000 ft. This shall allow researchers to pass ninety percent of Earth\u27s dense atmosphere when launching their rockets and shall allow for research at altitude. VALHALLA’s design consists of using multiple high-altitude balloons arranged around a launch platform to reach the target altitude with the rocket. The project shall consist of the following subsystems: policy, structure and design, helium recovery system, and electronics. The policy team shall be responsible for ensuring that this platform conforms to all US regulations. The structures team shall be responsible for designing and building the design. VALHALLA will be reusable, being an economical option, with the development of a system to recycle the helium in the balloons. All coding, wiring, and communications shall be completed by the electronics team. VALHALLA has contacted the Federal Aviation Administration, is continuing research, and has started building the first prototype which shall be tested in Fall 2021. The group has been providing our team with practical business and scientific experience that shall prepare them for leadership roles in their professional careers

    Setting targets leads to greater long-term weight losses and ‘unrealistic’ targets increase the effect in a large community-based commercial weight management group

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    Background. Setting personal targets is an important behavioural component in weight management programmes. Normal practice is to encourage ‘realistic’ weight loss but the under-pinning evidence base for this is limited and controversial. This study investigates the effect of number and size of weight loss targets on long-term weight loss in a large community sample of adults. Methods. Weight change, attendance and target weight data for all new UK members, joining January to March 2012 was extracted from a commercial slimming organisation’s electronic database. Results. Of the 35 380 members who had weight data available at 12 months after joining, 69.1% (n=24 447)had a starting BMI≄30kg/m2. Their mean weight loss was 12.9±7.8% and for both sexes, weight loss at 12 months was greater for those who set targets (p25% was 7.6±4.0 kg/m2. A higher percentage of obese members did not set targets (p<0.001) compared to those with a BMI below 30kg/m2. Conclusions. Much of the variance in achieved weight loss in this population was explained by the number of targets set and the size of the first target. Whilst obese people were less likely to set targets, doing so increased the likelihood of achieving clinically significant weight loss and for some ‘unrealistic’ targets improved results

    Intravitreal Anti-VEGF Drugs and Signals of Dementia and Parkinson-Like Events: Analysis of the VigiBase Database of Spontaneous Reports

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    Introduction: Since vascular endothelial growth factor (VEGF) regulates several aspects of the central nervous system, particularly in dopaminergic neurons, VEGF inhibitors may be linked to Parkinson-like events and dementia, or variants of these diseases. Two recent case reports have found a potential link between intravitreal anti-VEGF use and Parkinson’s disease (PD) and dementia. Aim: To evaluate disproportionality in a large spontaneous reporting database concerning intravitreal anti-VEGF drugs and PD or dementia, and related conditions. Methods: Using VigiBase, individual case safety reports (ICSRs) attributed to intravitreal ranibizumab, aflibercept, pegaptanib, and bevacizumab were identified from 2010 to 2016. Within Standardised Narrow Medical Dictionary for Regulatory Activities (MedDRAÂź) Queries (SMQs) for “Parkinson-like events” and “Dementia,” suspected events were identified using preferred terms (PTs). The Proportional Reporting Ratio (PRR) was estimated with the lower 95% confidence intervals (CIs) for all drug-event pairs with ≄3 suspected events. The vigiGrade completeness score was reported for the ICSRs. The analyses were repeated, including only persons aged 65 and over. Results: Out of 18.9 million ICSRs, 7,945 (0.004%) concerned intravitreal anti-VEGF drugs. Of these, 27 (0.34%) were identified concerning the SMQs “Dementia” (N = 17, 62.96%) and “Parkinson-like events” (N = 10, 37.94%) in persons of all ages. Among persons age 65 and over, 4,758 (59.88% of relevant ICSRs) ICSRs were identified for anti-VEGF drugs. When restricting disproportionality analysis to persons aged 65 and over, no disproportionality was seen for any of the drug-event pairs at the level of SMQ. However, on analysing disproportionality by PT, a potential signal emerged for intravitreal ranibizumab and Parkinson’s disease [N = 6 ICSRs; PRR: 3.05 (95% CI: 1.36-6.81)]. In general, the vigiGrade completeness score was low for all the ICSRs of interest, as no ICSR had a score >0.8. Conclusion: Present findings suggest a potential signal for Parkinson’s disease related to intravitreal ranibizumab. This is supported by several biologically plausible mechanisms but requires confirmation through pharmacoepidemiological studies, especially because of the low number of cases

    The Evolution of Cloud Cores and the Formation of Stars

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    For a number of starless cores, self-absorbed molecular line and column density observations have implied the presence of large-amplitude oscillations. We examine the consequences of these oscillations on the evolution of the cores and the interpretation of their observations. We find that the pulsation energy helps support the cores and that the dissipation of this energy can lead toward instability and star formation. In this picture, the core lifetimes are limited by the pulsation decay timescales, dominated by non-linear mode-mode coupling, and on the order of ~few x 10^5--10^6 yr. Notably, this is similar to what is required to explain the relatively low rate of conversion of cores into stars. For cores with large-amplitude oscillations, dust continuum observations may appear asymmetric or irregular. As a consequence, some of the cores that would be classified as supercritical may be dynamically stable when oscillations are taken into account. Thus, our investigation motivates a simple hydrodynamic picture, capable of reproducing many of the features of the progenitors of stars without the inclusion of additional physical processes, such as large-scale magnetic fields.Comment: 12 pages, 7 figures, submitted to Ap

    Outcome of carotid stent-assisted angioplasty versus open surgical repair of recurrent carotid stenosis

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    AbstractPurposeWe compared outcome and durability of carotid stent-assisted angioplasty (CAS) with open surgical repair (ie, repeat carotid endarterectomy [CEA]) to treat recurrent carotid stenosis (RCS).MethodsA retrospective review of anatomic and neurologic outcomes was carried out after 27 repeat CEA procedures (1993-2002) and 52 CAS procedures (1997-2002) performed to treat high-grade internal carotid artery (ICA) RCS after CEA. The incidence of intervention because of symptomatic RCS was similar (repeat CEA, 63%; CAS, 60%), but the interval from primary CEA to repeat intervention was greater (P < .05) in the repeat CEA group (83 ± 15 months) compared with the CAS group (50 ± 8 months). In the CAS group, 17 of 52 arteries (33%) were judged not to be surgical candidates because of surgically inaccessible high lesions (n = 8), medical comorbid conditions (n = 4), neck irradiation (n = 3), or previous surgery with cranial nerve deficit or stroke (n = 2). Three patients who underwent repeat CEA had lesions not appropriate for treatment with CAS.ResultsOverall 30-day morbidity was similar after CAS (12%; death due to ipsilateral intracranial hemorrhage, 1; nondisabling stroke, 1; reversible neurologic deficits or transient ischemic attack, 2; access site complication, 2) and repeat CEA (11%; no death; nondisabling stroke, 1; reversible cranial nerve injury, 1; cervical hematoma, 1). Combined stroke and death rate was 3.7% for repeat CEA and 5.7% for CAS (P > .1). All duplex ultrasound scans obtained within 3 months after CEA and CAS demonstrated patent ICA and velocity spectra of less than 50% stenosis. During follow-up, no repeat CEA (mean, 39 months) or CAS (mean, 26 months) repair demonstrated ICA occlusion, but two patients (8%) who underwent repeat CEA and 4 patients (8%) who underwent CAS required balloon or stent angioplasty because of 80% RCS. At last follow-up, no patient had ipsilateral stroke and all ICA remain patent. At duplex scanning, stenosis-free (<50% diameter reduction) ICA patency at 36 months was 75% after repeat CEA and 57% after CAS (P = .26, log-rank test).ConclusionsCarotid angioplasty for treatment of high-grade stenotic ICA after CEA resulted in similar anatomic and neurologic outcomes compared with open surgical repair. Most lesions are amenable to endovascular therapy, and CAS enabled treatment in patients judged not to be suitable surgical candidates. Duplex scanning surveillance after repeat CEA or CAS is recommended, because stenosis can recur after either secondary procedure

    On the internal structure of starless cores. II. A molecular survey of L1498 and L1517B

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    [Abridged] We present a molecular survey of the starless cores L1498 and L1517B. These cores have been selected for their relative isolation and close-to-round shape, and they have been observed in a number of lines of 13 molecular species (4 already presented in the first part of this series): CO, CS, N2H+, NH3, CH3OH, SO, C3H2, HC3N, C2S, HCN, H2CO, HCO+, and DCO+. Using a physical model of core structure and a Monte Carlo radiative transfer code, we determine for each core a self-consistent set abundances that fits simultaneously the observed radial profile of integrated intensity and the emergent spectrum towards the core center (for abundant species, optically thin isopologues are used). From this work, we find that L1498 and L1517B have similar abundance patterns, with most species suffering a significant drop toward the core center. This occurs for CO, CS, CH3OH, SO, C3H2, HC3N, C2S, HCN, H2CO, HCO+, and DCO+, which we fit with profiles having a sharp central hole. The size of this hole varies with molecule: DCO+, HCN, and HC3N have the smallest holes while SO, C2S and CO have the largest holes. Only N2H+ and NH3 are present in the gas phase at the core centers. From the different behavior of molecules, we select SO, C2S, and CH3OH as the most sensitive tracers of molecular depletion. Comparing our abundance determinations with the predictions from current chemical models we find order of magnitude discrepancies. Finally, we show how the ``contribution function'' can be used to study the formation of line profiles from the different regions of a core.Comment: 22 pages, 12 figures, A&A accepte

    Sources of unsafe primary care for older adults: a mixed-methods analysis of patient safety incident reports

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    Background: Older adults are frequent users of primary healthcare services, but are at increased risk of healthcare-related harm in this setting. Objectives: To describe the factors associated with actual or potential harm to patients aged 65 years and older, treated in primary care, to identify action to produce safer care. Design and Setting: A cross-sectional mixed-methods analysis of a national (England and Wales) database of patient safety incident reports from 2005 to 2013. Subjects: 1,591 primary care patient safety incident reports regarding patients aged 65 years and older. Methods: We developed a classification system for the analysis of patient safety incident reports to describe: the incident and preceding chain of incidents; other contributory factors; and patient harm outcome. We combined findings from exploratory descriptive and thematic analyses to identify key sources of unsafe care. Results: The main sources of unsafe care in our weighted sample were due to: medication-related incidents e.g. prescribing, dispensing and administering (n = 486, 31%; 15% serious patient harm); communication-related incidents e.g. incomplete or non-transfer of information across care boundaries (n = 390, 25%; 12% serious patient harm); and clinical decision-making incidents which led to the most serious patient harm outcomes (n = 203, 13%; 41% serious patient harm). Conclusion: Priority areas for further research to determine the burden and preventability of unsafe primary care for older adults, include: the timely electronic tools for prescribing, dispensing and administering medication in the community; electronic transfer of information between healthcare settings; and, better clinical decision-making support and guidance

    Vascular Health in American Football Players: Cardiovascular Risk Increased in Division III Players

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    Studies report that football players have high blood pressure (BP) and increased cardiovascular risk. There are over 70,000 NCAA football players and 450 Division III schools sponsor football programs, yet limited research exists on vascular health of athletes. This study aimed to compare vascular and cardiovascular health measures between football players and nonathlete controls. Twenty-three athletes and 19 nonathletes participated. Vascular health measures included flow-mediated dilation (FMD) and carotid artery intima-media thickness (IMT). Cardiovascular measures included clinic and 24 hr BP levels, body composition, VO2 max, and fasting glucose/cholesterol levels. Compared to controls, football players had a worse vascular and cardiovascular profile. Football players had thicker carotid artery IMT (0.49 ± 0.06 mm versus 0.46 ± 0.07 mm) and larger brachial artery diameter during FMD (4.3 ± 0.5 mm versus 3.7 ± 0.6 mm), but no difference in percent FMD. Systolic BP was significantly higher in football players at all measurements: resting (128.2 ± 6.4 mmHg versus 122.4 ± 6.8 mmHg), submaximal exercise (150.4 ± 18.8 mmHg versus 137.3 ± 9.5 mmHg), maximal exercise (211.3 ± 25.9 mmHg versus 191.4 ± 19.2 mmHg), and 24-hour BP (124.9 ± 6.3 mmHg versus 109.8 ± 3.7 mmHg). Football players also had higher fasting glucose (91.6 ± 6.5 mg/dL versus 86.6 ± 5.8 mg/dL), lower HDL (36.5±11.2 mg/dL versus 47.1±14.8 mg/dL), and higher body fat percentage (29.2±7.9% versus 23.2±7.0%). Division III collegiate football players remain an understudied population and may be at increased cardiovascular risk
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