868 research outputs found

    Gravity Wave Ducting Observed in the Mesosphere Over Jicamarca, Peru

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    Short-period gravity waves are ubiquitous in the mesosphere, but the vertical structures of their perturbations are difficult to observe. The Jicamarca 50-MHz very high frequency radar allows observations of winds and turbulent scatter with high temporal and vertical resolution. We present a case of a quasi-monochromatic gravity wave with period 520 (±40) s that is likely ducted below a southward wind jet between 68 and 74 km. Above this layer of evanescence, a northward wind enables it to emerge into a more stable layer, where it is refracted to a short vertical wavelength of 2.2 (±0.2) km; data show evidence of weak nonlinearity, and possible overturning or partial reflection from higher altitudes, above the observable region, in the form of a standing wave structure in vertical velocity at approximately 75 km. Based on the dispersion relation, and with help of a two-dimensional model, we determine that most likely the wave is propagating northward and is being ducted below and tunneling through the regions of evanescence created by the wind flow and typical mesospheric thermal structure. This is the first time that such an event has been identified in the Jicamarca mesospheric echoes, and it is distinct from Kelvin-Helmholtz billows also commonly seen with this sensitive radar—instead apparently revealing tunneling of the gravity wave through ambient winds

    Treatment of signs and symptoms of the common cold using EPs 7630 - results of a meta-analysis

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    © 2019 The Author(s) The efficacy of Pelargonium sidoides preparation EPs 7630 in the common cold (CC) was assessed by performing meta-analyses of randomized, double-blind, placebo-controlled trials. Mean differences (MD) and risk ratios (RR) with their 95% confidence intervals (CI) were computed. Five trials with a total of 833 patients were included. All trials had a treatment period of ten days with visits at days 3, 5, and 10 after baseline and used a ten-symptom Cold Intensity Score (CIS) as the primary outcome. Significant differences favoring EPs 7630 were observed for total CIS reduction (day 5: MD = -2·30; 95%CI = -4·12,-0·49; day 10: MD = -1·16; 95%CI = -2·22,-0·10), proportion of patients with substantial improvement (day 5: RR = 1·73; day 10: RR = 1·06) and complete remission (day 5: RR = 2·52; day 10: RR = 2·13). Subjects treated with EPs 7630 missed fewer days at work, used less paracetamol and had an improved sleep quality. No serious adverse reactions to EPs 7630 were reported. The results support the efficacy of EPs 7630 in adults with CC

    Estimates of vertical eddy diffusivity in the upper mesosphere in the presence of a mesospheric inversion layer

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    Rayleigh and resonance lidar observations were made during the Turbopause experiment at Poker Flat Research Range, Chatanika Alaska (65° N, 147° W) over a 10 h period on the night of 17–18 February 2009. The lidar observations revealed the presence of a strong mesospheric inversion layer (MIL) at 74 km that formed during the observations and was present for over 6 h. The MIL had a maximum temperature of 251 K, amplitude of 27 ± 7 K, a depth of 3.0 km, and overlying lapse rate of 9.4 ± 0.3 K km−1. The MIL was located at the lower edge of the mesospheric sodium layer. During this coincidence the lower edge of the sodium layer was lowered by 2 km to 74 km and the bottomside scale height of the sodium increased from 1 km to 15 km. The structure of the MIL and sodium are analyzed in terms of vertical diffusive transport. The analysis yields a lower bound for the eddy diffusion coefficient of 430 m2 s−1 and the energy dissipation rate of 2.2 mW kg−1 at 76–77 km. This value of the eddy diffusion coefficient, determined from naturally occurring variations in mesospheric temperatures and the sodium layer, is significantly larger than those reported for mean winter values in the Arctic but similar to individual values reported in regions of convective instability by other techniques

    Home parenteral nutrition with an omega-3-fatty-acid-enriched MCT/LCT lipid emulsion in patients with chronic intestinal failure (the HOME study):study protocol for a randomized, controlled, multicenter, international clinical trial

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    BACKGROUND: Home parenteral nutrition (HPN) is a life-preserving therapy for patients with chronic intestinal failure (CIF) indicated for patients who cannot achieve their nutritional requirements by enteral intake. Intravenously administered lipid emulsions (ILEs) are an essential component of HPN, providing energy and essential fatty acids, but can become a risk factor for intestinal-failure-associated liver disease (IFALD). In HPN patients, major effort is taken in the prevention of IFALD. Novel ILEs containing a proportion of omega-3 polyunsaturated fatty acids (n-3 PUFA) could be of benefit, but the data on the use of n-3 PUFA in HPN patients are still limited. METHODS/DESIGN: The HOME study is a prospective, randomized, controlled, double-blind, multicenter, international clinical trial conducted in European hospitals that treat HPN patients. A total of 160 patients (80 per group) will be randomly assigned to receive the n-3 PUFA-enriched medium/long-chain triglyceride (MCT/LCT) ILE (Lipidem/Lipoplus® 200 mg/ml, B. Braun Melsungen AG) or the MCT/LCT ILE (Lipofundin® MCT/LCT/Medialipide® 20%, B. Braun Melsungen AG) for a projected period of 8 weeks. The primary endpoint is the combined change of liver function parameters (total bilirubin, aspartate transaminase and alanine transaminase) from baseline to final visit. Secondary objectives are the further evaluation of the safety and tolerability as well as the efficacy of the ILEs. DISCUSSION: Currently, there are only very few randomized controlled trials (RCTs) investigating the use of ILEs in HPN, and there are very few data at all on the use of n-3 PUFAs. The working hypothesis is that n-3 PUFA-enriched ILE is safe and well-tolerated especially with regard to liver function in patients requiring HPN. The expected outcome is to provide reliable data to support this thesis thanks to a considerable number of CIF patients, consequently to broaden the present evidence on the use of ILEs in HPN. TRIAL REGISTRATION: ClinicalTrials.gov, ID: NCT03282955. Registered on 14 September 2017

    Hard Habits to Break: Investigating Coastal Resource Utilisations and Management Systems in Sulawesi, Indonesia.

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    This research investigates the paradox that many coastal communities in developing countries are resource rich but income poor. Another aspect of this paradox is the belief that local communities possess traditional knowledge that respects nature. This belief contrasts the fact that major tropical coastal ecosystems, namely coral reefs and mangroves, are being destroyed at rapid and increasing rates, in many cases by the people whose livelihoods depend on them. These paradoxical circumstances lead to a central question: if the sustainability of coastal resources is vital for the livelihood of local communities, why are these resources being degraded, often to the point of complete destruction? This study explores the motives and consequences of destructive methods of coastal resource utilisation and examines the potential for sustainable livelihoods based on coastal resources currently under threat from destructive use patterns. The analysis is based on a field study conducted in 2006 and 2008 in eleven sites around the island of Sulawesi, Indonesia. This area is characterised by great biodiversity, including one of the highest marine biodiversities in the Asia-Pacific region. Coral and mangrove ecosystem resource use was found to be driven by different processes and activities; hence the destructive practices impacting both ecosystems were also different. Blast and poison fishing were the most widespread destructive resource use methods found for coral reefs whereas large-scale habitat conversion was responsible for mangrove ecosystem reduction. In the field both resources were found to be under enormous anthropogenic pressures, with published data suggesting that only 5.8% of Indonesian coral reefs are currently in excellent condition and only 38% of mangrove cover remaining in Sulawesi relative to that of 25 years ago. The dynamics of these coastal resources, and of their destruction, are classic examples of the ’tragedy of the commons’. Research findings further indicate that formal institutions tasked with managing these resources have not been able to promote their effective conservation. An array of competing demands and conflicting interests, coupled with inefficient institutional arrangements and under-investment, have rendered inadequate many resource management efforts, including the externally-imposed concepts, allowing destructive patterns of resource utilization to persist. Local communities are disempowered when confronted with (1) the intricate network of destructive-fishing actors targeting coral reefs, or (2) large company-government bureaucracy collusions allowing mangrove conversion. The existence of this collusive network must be considered in any effort to address problems of effective management. Empirical insights suggest that conservation at local level has to face the challenges of market-driven resource extraction at a global scale. Only when a coastal community manages to overcome the dilemma in managing common-pool resource, conservation measures can be implemented and a degree of sustainability attained. Findings from this research have important implications for the discourses on coastal resource policy and research. This research advances the discussions to the area where the core of conflict of interests among stakeholders took place, and yet has rarely been addressed previously. The synthesis from this study provides a strong basis to understand the nature of asymmetric relations amongst the resource stakeholders, and therefore will help in generating effective policies for a fairer coastal resource management regime

    On the short-term variability of turbulence and temperature in the winter mesosphere

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    Four mesosphere–lower thermosphere temperature and turbulence profiles were obtained in situ within  ∼ 30&thinsp;min and over an area of about 100 by 100&thinsp;km during a sounding rocket experiment conducted on 26 January 2015 at Poker Flat Research Range in Alaska. In this paper we examine the spatial and temporal variability of mesospheric turbulence in relationship to the static stability of the background atmosphere. Using active payload attitude control, neutral density fluctuations, a tracer for turbulence, were observed with very little interference from the payload spin motion, and with high precision ( &lt; 0.01 %) at sub-meter resolution. The large-scale vertical temperature structure was very consistent between the four soundings. The mesosphere was almost isothermal, which means more stratified, between 60 and 80&thinsp;km, and again between 88 and 95&thinsp;km. The stratified regions adjoined quasi-adiabatic regions assumed to be well mixed. Additional evidence of vertical transport and convective activity comes from sodium densities and trimethyl aluminum trail development, respectively, which were both observed simultaneously with the in situ measurements. We found considerable kilometer-scale temperature variability with amplitudes of 20&thinsp;K in the stratified region below 80&thinsp;km. Several thin turbulent layers were embedded in this region, differing in width and altitude for each profile. Energy dissipation rates varied between 0.1 and 10&thinsp;mW&thinsp;kg−1, which is typical for the winter mesosphere. Very little turbulence was observed above 82&thinsp;km, consistent with very weak small-scale gravity wave activity in the upper mesosphere during the launch night. On the other hand, above the cold and prominent mesopause at 102&thinsp;km, large temperature excursions of +40 to +70&thinsp;K were observed. Simultaneous wind measurements revealed extreme wind shears near 108&thinsp;km, and combined with the observed temperature gradient, isolated regions of unstable Richardson numbers (0 &lt; Ri &lt; 0.25) were detected in the lower thermosphere. The experiment was launched into a bright auroral arc under moderately disturbed conditions (Kp ∼ 5).</p

    Household Contamination with Salmonella enterica1

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    Household contamination with Salmonella enterica increases when occupational exposure exists (cattle farms with known salmonellosis in cattle, a salmonella research laboratory, or a veterinary clinic experiencing an outbreak of salmonellosis). Fifteen of 55 (27.2%) vacuum cleaner bags from households with occupational exposure to S. enterica were positive versus 1 of 24 (4.2% without known exposure. Use of a carpet cleaner and several cleaners/disinfectants reduced, but failed to eliminate, S. enterica from artificially contaminated carpet

    Performance of the ESC 0/1-h and 0/3-h Algorithm for the Rapid Identification of Myocardial Infarction Without ST-Elevation in Patients With Diabetes

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    Patients with diabetes mellitus (DM) have elevated levels of high-sensitivity cardiac troponin (hs-cTn). We investigated the diagnostic performance of the European Society of Cardiology (ESC) algorithms to rule out or rule in acute myocardial infarction (AMI) without ST-elevation in patients with DM.; We prospectively enrolled 3,681 patients with suspected AMI and stratified those by the presence of DM. The ESC 0/1-h and 0/3-h algorithms were used to calculate negative and positive predictive values (NPV, PPV). In addition, alternative cutoffs were calculated and externally validated in 2,895 patients.; In total, 563 patients (15.3%) had DM, and 137 (24.3%) of these had AMI. When the ESC 0/1-h algorithm was used, the NPV was comparable in patients with and without DM (absolute difference [AD] -1.50 [95% CI -5.95, 2.96]). In contrast, the ESC 0/3-h algorithm resulted in a significantly lower NPV in patients with DM (AD -2.27 [95% CI -4.47, -0.07]). The diagnostic performance for rule-in of AMI (PPV) was comparable in both groups: 0/1-h (AD 6.59 [95% CI -19.53, 6.35]) and 0/3-h (AD 1.03 [95% CI -7.63, 9.7]). Alternative cutoffs increased the PPV in both algorithms significantly, while improvements in NPV were only subtle.; Application of the ESC 0/1-h algorithm revealed comparable safety to rule out AMI comparing patients with and without DM, while this was not observed with the ESC 0/3-h algorithm. Although alternative cutoffs might be helpful, patients with DM remain a high-risk population in whom identification of AMI is challenging and who require careful clinical evaluation

    Single hadron response measurement and calorimeter jet energy scale uncertainty with the ATLAS detector at the LHC

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    The uncertainty on the calorimeter energy response to jets of particles is derived for the ATLAS experiment at the Large Hadron Collider (LHC). First, the calorimeter response to single isolated charged hadrons is measured and compared to the Monte Carlo simulation using proton-proton collisions at centre-of-mass energies of sqrt(s) = 900 GeV and 7 TeV collected during 2009 and 2010. Then, using the decay of K_s and Lambda particles, the calorimeter response to specific types of particles (positively and negatively charged pions, protons, and anti-protons) is measured and compared to the Monte Carlo predictions. Finally, the jet energy scale uncertainty is determined by propagating the response uncertainty for single charged and neutral particles to jets. The response uncertainty is 2-5% for central isolated hadrons and 1-3% for the final calorimeter jet energy scale.Comment: 24 pages plus author list (36 pages total), 23 figures, 1 table, submitted to European Physical Journal
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