85 research outputs found
Die Vermessung der Dynamik: eine rollierende Panelstudie im Vorfeld der baden-wĂĽrttembergischen Landtagswahl 2011
"Eine rollierende Panelstudie vereint die Vorzüge des Rolling Cross-Section (RCS) Designs mit denen eines Panels. Wie das RCS-Design erlaubt es eine rollierende Panelstudie, tagesgenaue Veränderungen in den Einstellungen und Verhaltensmustern der Bevölkerung zu entdecken. Zugleich bleibt die paneltypische Möglichkeit, Prädiktoren von Veränderungen auf der individuellen Ebene zu analysieren, erhalten. Im vorliegenden Beitrag werden zunächst die jeweiligen Vor- und Nachteile der beiden klassischen Forschungsdesigns - RCS und Panel - skizziert, um daraus die Möglichkeit einer Kombination beider Ansätze abzuleiten. Anschließend wird die 'Wahlstudie Baden-Württemberg 2011' als konkreter Versuch, eine solche Studie zu realisieren, beschrieben: Dies schließt sowohl eine Diskussion der Qualität der Daten als auch von spezifischen Analysepotenzialen ein." (Autorenreferat)"The rolling panel study combines the advantages of rolling cross-section designs with those of classic panel designs. Using a rolling panel, it is possible to scrutinize aggregate changes of attitudes and behavioral intentions on a day-by-day basis, as is the case for rolling cross-section studies. But the design also allows us to analyze individual changes and their causes - typical features of panel studies. The present article starts with a discussion of the advantages and disadvantages of the two classic designs - panel and RCS. Based on that, the authors will deduce a solution to merge both approaches into a single integrated design. Following that, the 'Election Study Baden-Wuerttemberg 2011' will be presented as an attempt to actually realize such a merged design. The discussion will exemplify possible analyses based on such data, but also an evaluation of data quality." (author's abstract
A mycotoxin-deactivating feed additive counteracts the adverse effects of regular levels of Fusarium mycotoxins in dairy cows.
Little is known about the effects of commonly found levels of Fusarium mycotoxins on the performance, metabolism, and immunity of dairy cattle. We investigated the effects of regular contamination levels, meaning contamination levels that can be commonly detected in dairy feeds, of deoxynivalenol (DON) and fumonisins (FB) in total mixed ration (TMR) on the performance, diet digestibility, milk quality, and plasma liver enzymes in dairy cows. This trial examined 12 lactating Holstein dairy cows using a 3-period × 3-treatment Latin square design. The experimental period was 21 d of mycotoxin exposure followed by 14 d of washout. During treatment periods, cows received one of 3 diets: (1) CTR (control) diet of TMR contaminated with 340.5 µg of DON/kg of dry matter (DM) and 127.9 µg FB/kg of DM; (2) MTX diet of TMR contaminated with Fusarium mycotoxins at levels higher than CTR but below US and European Union guidelines (i.e., 733.0 µg of DON/kg of DM and 994.4 µg of FB/kg of DM); or (3) MDP diet, which was MTX diet supplemented with a mycotoxin deactivator product (i.e., 897.3 µg of DON/kg of DM and 1,247.1 µg of FB/kg of DM; Mycofix, 35 g/animal per day). During washout, all animals were fed the same CTR diet. Body weight, body condition score, DM intake, dietary nutrient digestibility, milk production, milk composition and rennet coagulation properties, somatic cell count, blood serum chemistry, hematology, serum immunoglobulin concentrations, and expression of multiple genes in circulating leucocytes were measured. Milk production was significantly greater in the CTR group (37.73 kg/d) than in the MTX (36.39 kg/d) and the MDP (36.55 kg/d) groups. Curd firmness and curd firming time were negatively affected by the MTX diet compared with the other 2 diets. Furthermore, DM and neutral detergent fiber digestibility were lower after the MTX diet than after the CTR diet (67.3 vs. 71.0% and 42.8 vs. 52.3%). The MDP diet had the highest digestibility coefficients for DM (72.4%) and neutral detergent fiber (53.6%) compared with the other 2 diets. The activities of plasma liver transaminases were higher after the MTX diet than after the CTR and MDP diets. Compared with the CTR diet, the MTX diet led to slightly lower expression of genes related to immune and inflammatory functions, indicating that Fusarium mycotoxins had an immunosuppressive effect. Our results indicated that feed contaminated with regular levels of Fusarium mycotoxins adversely affected the performance, milk quality, diet digestibility, metabolic variables, and immunity of dairy cows, and that supplementation with mycotoxin deactivator product counteracted most of these negative effects
Progress in Micro Joule-Thomson Cooling at Twente University
At the University of Twente, research on the development of a sorption-based micro cooler is in progress. Because of the absence of moving parts, such a cooler is virtually vibration free and highly durable, which potentially results in a long lifetime. A miniature cryogenic cooler with these properties would be appealing in a wide variety of applications including the cooling of vibration-sensitive detectors in space missions, low-noise amplifiers and semi- and superconducting circuitry. The objective of the present project is to scale down a Joule-Thomson (JT) cold stage to a total volume of a few hundredths of a cm3. This size reduction introduces many problems. The proposed cold stage volume results in a restriction cross-sectional area of about a thousandth of a mm2 which may cause clogging problems. Flow channels with a cross-sectional area of a few hundredths of a mm2 will produce high pressure drops influencing the JT cycle. Furthermore, the micro channels must be capable of withstanding high pressures and maintaining a large temperature gradient over a relatively short length. The project aim is to develop a reliable micro JT cold stage that is fabricated out of one material with a relatively simple and reproducible fabrication method. The length of the cold stage is calculated at about 20 mm with a width of 1.7 mm and height of about 0.3 mm. The mass flow is in the order of one mg per second to create a net cooling power of 10 mW at 96 K. The final objective of the project is to integrate the cold stage, vacuum chamber and device into one compact design. This paper discusses possible solutions to the problems mentioned and presents a concept design of such a miniature JT cold stage
Digitalisierung und Demokratie
Die Digitalisierung spielt bei den Prozessen und Entwicklungen in einer Demokratie eine immer größere Rolle. Denn Digitalisierung erweitert die Möglichkeiten der Information, Kommunikation und Partizipation. Gleichzeitig können digitale Technologien zu einer schnellen Verbreitung von Falschinformationen beitragen und bergen ein Potenzial für Meinungsmanipulation, zum Beispiel vor Wahlen. Dieses Spannungsfeld ist Thema der Stellungnahme "Digitalisierung und Demokratie". Darin analysieren die Autorinnen und Autoren Aspekte des Zusammenspiels von Digitalisierung und Demokratie. Darauf aufbauend formulieren sie Handlungsempfehlungen zur Gestaltung künftiger Entwicklungen durch Politik, Recht und Zivilgesellschaft
Multidisciplinary outpatient care program for patients with chronic low back pain: design of a randomized controlled trial and cost-effectiveness study [ISRCTN28478651]
<p>Abstract</p> <p>Background</p> <p>Chronic low back pain (LBP) is a major public and occupational health problem, which is associated with very high costs. Although medical costs for chronic LBP are high, most costs are related to productivity losses due to sick leave. In general, the prognosis for return to work (RTW) is good but a minority of patients will be absent long-term from work. Research shows that work related problems are associated with an increase in seeking medical care and sick leave. Usual medical care of patients is however, not specifically aimed at RTW.</p> <p>The objective is to present the design of a randomized controlled trial, i.e. the BRIDGE-study, evaluating the effectiveness in improving RTW and cost-effectiveness of a multidisciplinary outpatient care program situated in both primary and outpatient care setting compared with usual clinical medical care for patients with chronic LBP.</p> <p>Methods/Design</p> <p>The design is a randomized controlled trial with an economic evaluation alongside. The study population consists of patients with chronic LBP who are completely or partially sick listed and visit an outpatient clinic of one of the participating hospitals in Amsterdam (the Netherlands). Two interventions will be compared. 1. a multidisciplinary outpatient care program consisting of a workplace intervention based on participatory ergonomics, and a graded activity program using cognitive behavioural principles. 2. usual care provided by the medical specialist, the occupational physician, the patient's general practitioner and allied health professionals. The primary outcome measure is sick leave duration until full RTW. Sick leave duration is measured monthly by self-report during one year. Data on sick leave during one-year follow-up are also requested form the employers. Secondary outcome measures are pain intensity, functional status, pain coping, patient satisfaction and quality of life. Outcome measures are assessed before randomization and 3, 6, and 12 months later. All statistical analysis will be performed according to the intension-to-treat principle.</p> <p>Discussion</p> <p>Usual care of primary and outpatient health services isn't directly aimed at RTW, therefor it is desirable to look for care which is aimed at RTW. Research shows that several occupational interventions in primary care are aimed at RTW. They have shown a significant reduction of sick leave for employee with LBP. If a comparable reduction of sick leave duration of patients with chronic LBP of who attend an outpatient clinic can be achieved, such reductions will be obviously substantial for the Netherlands and will have a considerable impact.</p> <p>Trial registration</p> <p>ISRCTN28478651</p
Cost effectiveness of a multi-stage return to work program for workers on sick leave due to low back pain, design of a population based controlled trial [ISRCTN60233560]
BACKGROUND: To describe the design of a population based randomized controlled trial (RCT), including a cost-effectiveness analysis, comparing participative ergonomics interventions between 2–8 weeks of sick leave and Graded Activity after 8 weeks of sick leave with usual care, in occupational back pain management. METHODS: DESIGN: An RCT and cost-effectiveness evaluation in employees sick-listed for a period of 2 to 6 weeks due to low back pain. Interventions used are 1. Communication between general practitioner and occupational physician plus Participative Ergonomics protocol performed by an ergonomist. 2. Graded Activity based on cognitive behavioural principles by a physiotherapist. 3. Usual care, provided by an occupational physician according to the Dutch guidelines for the occupational health management of workers with low back pain. The primary outcome measure is return to work. Secondary outcome measures are pain intensity, functional status and general improvement. Intermediate variables are kinesiophobia and pain coping. The cost-effectiveness analysis includes the direct and indirect costs due to low back pain. The outcome measures are assessed before randomization (after 2–6 weeks on sick leave) and 12 weeks, 26 weeks and 52 weeks after first day of sick leave. DISCUSSION: The combination of these interventions has been subject of earlier research in Canada. The results of the current RCT will: 1. crossvalidate the Canadian findings in an different sociocultural environment; 2. add to the cost-effectiveness on treatment options for workers in the sub acute phase of low back pain. Results might lead to alterations of existing (inter)national guidelines
Cryogenic microcooling : a micromachined cold stage operating with a sorption compressor in a vapor compression cycle
Cryocoolers are refrigerators capable of reaching temperatures below roughly 120 kelvin. Such coolers are used for cooling of, for instance, superconducting electronics and magnets, (infrared) detectors, and cryopumps. Low-temperature applications requiring very little cooling power, such as a single chip with a low noise amplifier or a superconducting magnetometer, would benefit from very small closed-cycle cryocoolers. Such coolers do not yet exist. This thesis is the result of a research project to investigate opportunities for such microcoolers. The project required a high degree of pioneering because the field of subjects and possibilities is vast and largely unexplored. As a result, the contents of this thesis is very divergent and cover various areas of science, such as (micro)mechanics, thermodynamics, fluid mechanics, heat transfer and material science. This divergence occurs especially in chapters 2 and 3, in which a number of cooling cycles are discussed, as well as opportunities for miniaturization of these coolers. The remainder of the thesis describes the development of miniature components for a sorption cooler. This cooling system was chosen because it is suitable to be applied on a small scale
Die Vermessung der Dynamik: eine rollierende Panelstudie im Vorfeld der baden-wĂĽrttembergischen Lantagswahl 2011
Eine rollierende Panelstudie vereint die Vorzüge des Rolling Cross-Section (RCS) Designs mit denen eines Panels. Wie das RCS-Design erlaubt es eine rollierende Panelstudie, tagesgenaue Veränderungen in den Einstellungen und Verhaltensmustern der Bevölkerung zu entdecken. Zugleich bleibt die paneltypische Möglichkeit, Prädiktoren von Veränderungen auf der individuellen Ebene zu analysieren, erhalten. Im vorliegenden Beitrag werden zunächst die jeweiligen Vor- und Nachteile der beiden klassischen Forschungsdesigns – RCS und Panel – skizziert, um daraus die Möglichkeit einer Kombination beider Ansätze abzuleiten. Anschließend wird die „Wahlstudie Baden-Württemberg 2011“ als konkreter Versuch, eine solche Studie zu realisieren, beschrieben: Dies schließt sowohl eine Diskussion der Qualität der Daten als auch von spezifischen Analysepotenzialen ein
Abstimmung gut, alles gut?
Hat die Volksabstimmung am 27. November 2011 zur Befriedung des Konflikts um Stuttgart 21 beigetragen und zu einer breit getragenen Akzeptanz des Projekts in der Bevölkerung geführt? Basierend auf zwei umfangreichen Studien zeigen Johannes Blumenberg und Thorsten Faas, wie sich die Einstellungen der
Bevölkerung, ihre Emotionen zum Projekt
Stuttgart 21, aber auch zum Verfahren
der Volksabstimmung entwickelt und verändert haben. Nannten im November/Dezember 2010 noch 35 Prozent der Teilnehmer Stuttgart 21 als wichtigstes Problem, wurde dieses Thema zwei Wochen vor der Wahl durch die Kernschmelzen in Fukushima zurückgedrängt. Einem
leichten Anstieg der Präsenz von Stuttgart 21 folgte im Anschluss an die Volksabstimmung ein merklicher Abfall der
Wichtigkeit des Themas. Die Volksabstimmung hat – so das Fazit – dazu beigetragen, dass Stuttgart 21 aus dem
Problembewusstsein der BĂĽrgerinnen
und BĂĽrger geraten ist. Ebenso wurden
die Emotionen besänftigt. Die Akzeptanz des Ergebnisses der Volksabstimmung zeigt sich letztlich auch in der
geäußerten Erwartung, dass die Landes-
regierung das Ergebnis akzeptiert und
als politischen Auftrag versteht
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