2,405 research outputs found

    Remote sensing of cloud liquid water during ICE'89

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    The cloud liquid water path, LWP, over the North Sea during the International Cirrus Experiment 1989 (ICE'89) is derived from measurements of the microwave radiometer SSM/I on board.of the polar orbiting satellite DMSP and from measurements of a ground-based 33-GHz-radiometer operating on board of the German research vessel 'Poseldon'. Comparisons of maps of LWP compiled from the SSM/I data with time series computed from the ground-based system show no significant bias and agree within the range of uncertainty caused by the different sampling characteristics of the observing systems. Using a combination of SSM/I data and almost simultaneously recorded METEOSAT-IR data offers the possibility to identify different cloud types, e.g. to seperate cirrus clouds and cirrus with underlying water clouds. Both types may have the same IR-brightness temperature but different microwave brightness temperature because ice clouds have a negligible influence on the microwave radiances

    Universal dephasing in a chiral 1D interacting fermion system

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    We consider dephasing by interactions in a one-dimensional chiral fermion system (e.g. a Quantum Hall edge state). For finite-range interactions, we calculate the spatial decay of the Green's function at fixed energy, which sets the contrast in a Mach-Zehnder interferometer. Using a physically transparent semiclassical ansatz, we find a power-law decay of the coherence at high energies and zero temperature (T=0), with a universal asymptotic exponent of 1, independent of the interaction strength. We obtain the dephasing rate at T>0 and the fluctuation spectrum acting on an electron.Comment: 5 pages, 3 figures; minor changes, version as published

    Renaissance der Angebotspolitik

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    Von der europäischen Schulden- und Wirtschaftskrise scheint Deutschland unbeeindruckt. Doch die derzeitige wirtschaftliche Stärke bedeutet nicht, dass das deutsche Reformmodell auch zukünftigen Herausforderungen, wie der demografischen Entwicklung und den Belastungen durch Schulden- und Finanzkrise, gewachsen ist. Wenn der bestehende Reformbedarf nicht ernst genommen wird, kann Deutschland sehr schnell wieder zum "kranken Mann Europas" werden. Der Kronberger Kreis empfiehlt der neuen Bundesregierung, sich auf die Angebotspolitik zu konzentrieren und so die deutsche Wettbewerbsfähigkeit zu stärken. In dieser Studie finden sich sorgfältig konzipierte Politikvorschläge für die Gestaltung der öffentlichen Finanzen, der Steuer- und Arbeitsmarktpolitik, der Renten-, Kranken- und Pflegeversicherung, der Energiewende sowie der Privatisierung und Deregulierung. Die Analyse der deutschen Probleme und das Aufzeigen der Lösungskonzepte erfolgen grundsätzlich im europäischen Kontext

    Relaxation of Josephson qubits due to strong coupling to two-level systems

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    We investigate the energy relaxation (T1) process of a qubit coupled to a bath of dissipative two-level fluctuators (TLF). We consider the fluctuators strongly coupled to the qubit both in the limit of spectrally separated single TLF's as well as in the limit of spectrally dense TLF's. We conclude that the avoided level crossings, usually attributed to very strongly coupled single TLF's, could also be caused by many weakly coupled spectrally dense fluctuators.Comment: 11+ pages, 10 figures, citations added, discussion extende

    Neustart in der Energiepolitik jetzt!

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    Der Kronberger Kreis, wissenschaftlicher Beirat der Stiftung Marktwirtschaft, fordert einen energiepolitischen Neustart in Deutschland. Bei Fortführung des Status quo drohen ansonsten die drei energiepolitischen Oberziele - Umwelt- und Klimaschutz, Versorgungssicherheit sowie Kosteneffizienz - weit verfehlt zu werden. Damit aber wäre der deutsche Sonderweg in der Energiepolitik eher abschreckendes Beispiel als internationales Vorbild im Kampf gegen den Klimawandel. Als überlegenes klimapolitisches Instrument empfiehlt der Kronberger Kreis eine Stärkung und Ausweitung des internationalen CO2-Emissionshandels und die Abschaffung des EEG. Sollte die Politik dazu die Kraft nicht finden, müssen angesichts der systemimmanenten Mängel des EEG alternative, marktkonforme Reformen angegangen werden. Hierfür empfiehlt der Kronberger Kreis ein zertifikatebasiertes Grünstrom-Quotenmodell nach schwedischem Vorbild. Um effiziente Standortentscheidungen für Kraftwerke zu induzieren sowie einen effizienten Netzausbau zu befördern, sollten zudem geographisch differenzierte Preise im Stromgroßhandel oder aber geographisch differenzierte Netzentgelte auf der Erzeugerseite eingeführt werden. Aus heutiger Sicht nicht erforderlich ist hingegen die - immer wieder geforderte - Einführung eines Kapazitätsmechanismus für konventionelle Kraftwerke

    Production and properties of thin film materials sol-gel by method based on TiO[2]-MxOy, where M-Ni, Cu, Zn

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    The physical-chemical, morphological, and structural properties of thin-film TiO[2]-MxOy obtained by sol-gel method were investigated. Titanium sol is formed by controlled hydrolysis of tetrabutoxy titanium in acidic media. The effect of synthesis and calcination temperature on the phase, crystal size was studied using Xray phase analysis (XRD), scanning electron microscopy (SEM). XRD observations confirmed the nanocrystalline nature of TiO[2]

    Efficacy of tooth splinting and occlusal adjustment in patients with periodontitis exhibiting masticatory dysfunction: A systematic review

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    Objective: To evaluate the efficacy of tooth splinting (TS) and occlusal adjustment (OA) compared to no TS or OA in patients with periodontitis exhibiting masticatory dysfunction. Material: The primary outcome criterion was tooth loss (TL), and the secondary outcome parameters were change in probing pocket depth (PPD), change in clinical attachment level (CAL), tooth mobility (TM), and patient-reported outcome measures (PROMs). Literature search was performed on three electronic databases (from 01/1965 to 04/2021) and focused on clinical studies with at least 12 months follow-up. Results: From a total of 1515 publications, 51 articles were identified for full-text reading, of which 2 retrospective case series on TS with low risk of bias and 1 randomized and 2 prospective studies on OA with unclear risk of bias were included. For TS, synthesis of data showed that in 72 patients, 26 out of 311 teeth (weighted mean incidence of TL 8.4%) and 156 out of 1541 teeth with no TS (weighted mean incidence of TL 10.1%) were lost over 2 years following non-surgical periodontal therapy. The randomized controlled clinical trial (RCT) indicated CAL gain for teeth with OA compared to no OA. For the effect of OA on TL, PPD, and TM, heterogeneous data were retrieved from the included studies. Conclusions: Within the limitations of this review and based on a low level of evidence, it is concluded that TS does not improve survival of mobile teeth in patients with advanced periodontitis. OA on teeth with mobility and/or premature contacts may lead to improved CAL, while the effect of OA on the remaining periodontal parameters remains unclear

    A Population-Based Survey

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    Background: Chronic conditions are an increasing challenge for individuals and the health care system. Smartphones and health apps are potentially promising tools to change health-related behaviors and manage chronic conditions. Objective: The aim of this study was to explore (1) the extent of smartphone and health app use, (2) sociodemographic, medical, and behavioral correlates of smartphone and health app use, and (3) associations of the use of apps and app characteristics with actual health behaviors. Methods: A population-based survey (N=4144) among Germans, aged 35 years and older, was conducted. Sociodemographics, presence of chronic conditions, health behaviors, quality of life, and health literacy, as well as the use of the Internet, smartphone, and health apps were assessed by questionnaire at home visit. Binary logistic regression models were applied. Results: It was found that 61.25% (2538/4144) of participants used a smartphone. Compared with nonusers, smartphone users were younger, did more research on the Internet, were more likely to work full-time and more likely to have a university degree, engaged more in physical activity, and less in low fat diet, and had a higher health-related quality of life and health literacy. Among smartphone users, 20.53% (521/2538) used health apps. App users were younger, less likely to be native German speakers, did more research on the Internet, were more likely to report chronic conditions, engaged more in physical activity, and low fat diet, and were more health literate compared with nonusers who had a smartphone. Health apps focused on smoking cessation (232/521, 44.5%), healthy diet (201/521, 38.6%), and weight loss (121/521, 23.2%). The most common app characteristics were planning (264/521, 50.7%), reminding (188/521, 36.1%), prompting motivation (179/521 34.4%), and the provision of information (175/521, 33.6%). Significant associations were found between planning and the health behavior physical activity, between feedback or monitoring and physical activity, and between feedback or monitoring and adherence to doctor’s advice. Conclusions: Although there were many smartphone and health app users, a substantial proportion of the population was not engaged. Findings suggest age-related, socioeconomic-related, literacy-related, and health-related disparities in the use of mobile technologies. Health app use may reflect a user’s motivation to change or maintain health behaviors. App developers and researchers should take account of the needs of older people, people with low health literacy, and chronic conditions

    Associations of Health App Use and Perceived Effectiveness in People With Cardiovascular Diseases and Diabetes: Population-Based Survey

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    Background: Mobile health apps can help to change health-related behaviors and manage chronic conditions in patients with cardiovascular diseases (CVDs) and diabetes mellitus, but a certain level of health literacy and electronic health (eHealth) literacy may be needed. Objective: The aim of this study was to identify factors associated with mobile health app use in individuals with CVD or diabetes and detect relations with the perceived effectiveness of health apps among app users. Methods: The study used population-based Web-based survey (N=1500) among Germans, aged 35 years and older, with CVD, diabetes, or both. A total of 3 subgroups were examined: (1) Individuals with CVD (n=1325), (2) Individuals with diabetes (n=681), and (3) Individuals with CVD and diabetes (n=524). Sociodemographics, health behaviors, CVD, diabetes, health and eHealth literacy, characteristics of health app use, and characteristics of apps themselves were assessed by questionnaires. Linear and logistic regression models were applied. Results: Overall, patterns of factors associated with health app use were comparable in individuals with CVD or diabetes or both. Across subgroups, about every fourth patient reported using apps for health-related purposes, with physical activity and weight loss being the most prominent target behaviors. Health app users were younger, more likely to be female (except in those with CVD and diabetes combined), better educated, and reported more physical activity. App users had higher eHealth literacy than nonusers. Those users who perceived the app to have a greater effectiveness on their health behaviors tended to be more health and eHealth literate and rated the app to use more behavior change techniques (BCTs). Conclusions: There are health- and literacy-related disparities in the access to health app use among patients with CVD, diabetes, or both, which are relevant to specific health care professionals such as endocrinologists, dieticians, cardiologists, or general practitioners. Apps containing more BCTs had a higher perceived effect on people’s health, and app developers should take the complexity of needs into account. Furthermore, eHealth literacy appears to be a requirement to use health apps successfully, which should be considered in health education strategies to improve health in patients with CVD and diabetes
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