306 research outputs found

    Study of ³He Rabi nutations by optically-pumped cesium magnetometers

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    We describe a method for recording the Rabi nutation of nuclear spin polarized ³He by optically pumped cesium magnetometers. The measurement is performed by detecting the time-dependent magnetic field produced by the 3He magnetization. The observed signals are compared to theoretical models and the results are used to precisely trace the evolution of the magnetization. This procedure represents a convenient way to control and measure the Rabi flip angle and the degree of spin polarization in experiments using 3He magnetometers. The method requires only very coarse knowledge of the applied magnetic field’s magnitude

    Design and performance of an absolute 3He/Cs magnetometer

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    We report on the design and performance of a highly sensitive combined ³He/Cs magnetometer for the absolute measurement of magnetic fields. The magnetometer relies on the magnetometric detection of the free spin precession of nuclear spin polarized ³He gas by optically pumped cesium magnetometers. We plan to deploy this type of combined magnetometer in an experiment searching for a permanent electric dipole moment of ultracold neutrons at the Paul-Scherrer Institute (Switzerland). A prototype magnetometer was built at the University of Fribourg (Switzerland) and tested at Physikalisch-Technische Bundesanstalt (Berlin, Germany). We demonstrate that the combined magnetometer allows Cramér-Rao-limited field determinations with recording times in the range of, measurements above being limited by the stability of the applied magnetic field. With a recording time we were able to perform an absolute measurement of a magnetic field of ≈ with a standard uncertainty of, corresponding to ΔB/B < 6 ×10⁻⁸

    Investigation of the intrinsic sensitivity of a ³He/Cs magnetometer

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    We report on extensive studies on the intrinsic sensitivity of a combined ³He/Cs magnetometer. The magnetometer relies on the detection of the free spin precession of nuclear spin polarized ³He by optically pumped cesium magnetometers. We characterize the relevant processes involved in the detection and quantify their impact on the total sensitivity of the magnetometer. An expression is derived that predicts the sensitivity of this magnetometer scheme and the results are compared to experiments. Excellent agreement is found between theory and experiments, and implications for an application of a ³He/Cs magnetometer in an experiment searching for a permanent neutron electric dipole moment are discussed

    Possibilities and limits of questionaire based soft skills evaluation as admission criteria for medical schools

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    Mit der Neuregelung der Studienplatzverteilung von 2005 haben die Universitäten in Deutschland die Möglichkeit, bis zu 60% der Studienplätze nach universitätseigenen Kriterien zu vergeben. Implizit wird vom Gesetzgeber und der öffentlichen Meinung gefordert, nicht-leistungsbezogene Kriterien und Persönlichkeitsmerkmale verstärkt zur Bewerberauswahl einzusetzen (Motivation, Identifikation, Vermeidung von Fehlvorstellungen). Da in Anbetracht der Bewerberzahlen mündliche Auswahlgespräche als ungeeignet erscheinen, wurde vom Fachbereich Medizin der Johann Wolfgang Goethe Universität ein Fragebogen entworfen, um nichtschulische Leistungen zu erfassen. Dieser Fragebogen wurde am Beginn des Wintersemesters 2005/2006 von allen Studienanfängern der JWG-Universität Frankfurt und der Medizinischen Universität Innsbruck ausgefüllt. Entgegen der initialen Erwartungen der Verfasser gaben nur etwa 15% Prozent Medizin-spezifische berufliche Vorerfahrungen an (Rettungsdienst, Ausbildung als Krankenschwester/pfleger oder ähnliches); dagegen wurden von etwa 60% angegeben, mindestens ein Musikinstrument zu spielen oder länger sportlich aktiv gewesen zu sein. Die Zusammenstellung der Selbstangaben zeigt, dass Medizin-relevante Vorkenntnisse nur bei einem kleinen Anteil der Studienbewerber in größerem Umfang vorhanden sind. Aufgrund der großen Streuung in der Art und Dauer der angegebenen Vorleistungen sollte die Erhebung von Parametern zur Beurteilung von soft skills, z.B. durch Online-Fragebogen, als (Vor)Selektionsinstrument nur sehr vorsichtig eingesetzt werden.Due to a reorganization in the admission procedure for German medical students in 2005 Medical Faculties may admit up to 60% of their students according to specific university criteria. Both legislation and public opinion implicitly require nonacademic criteria and personality traits to be included into the selection criteria (motivation, identification, avoidance of misconceptions). Since interviews appear to be not suitable for the high number of applicants the Medical Faculty of the Johann Wolfgang Goethe University in Frankfurt/Main has developed a questionnaire covering extracurricular achievements. This questionnaire has be answered by first year students of the JWG university Frankfurt and the Medical University Innsbruck at the begin of the winter term 2005/2006. Contrary to initial expectations, only 15% of the students stated specific job experience in a medically related field (emergency service, nurse or similar occupations), whereas more than 60% indicated to play at least one instrument and/or being engaged in sports activities. The summary of these self experiences indicate that only a minority of admitted students have medically related experience to a larger degree. The wide variation in time and duration given for the activities indicate that (online) questionnaires should be treated carefully as a preselection method for medical studies admission

    Living Long and Well: Prospects for a Personalized Approach to the Medicine of Ageing.

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    Research into ageing and its underlying molecular basis enables us to develop and implement targeted interventions to ameliorate or cure its consequences. However, the efficacy of interventions often differs widely between individuals, suggesting that populations should be stratified or even individualized. Large-scale cohort studies in humans, similar systematic 56 studies in model organisms, and detailed investigations into the biology of ageing can provide individual validated biomarkers and mechanisms, leading to recommendations for targeted interventions. Human cohort studies are already ongoing, and can be supplemented by in silico simulations. Systematic studies in animal models are made possible by the use of inbred strains, or genetic reference populations of mice. Combining both, the comprehensive picture of the various determinants of ageing and healthspan can be studied in detail, and an appreciation of the relevance of results from model organisms to humans emerges. The interactions between genotype and environment, particularly the psychosocial environment, are poorly studied in both humans and model organisms, presenting serious challenges to any approach to a personalized medicine of ageing. To increase success of preventive interventions, we argue that there is a pressing need for an individualized evaluation of interventions such as physical exercise, nutrition, nutraceuticals and calorie restriction mimetics as well as psychosocial and environmental factors, separately and in combination. The expected extension of healthspan enables us to refocus healthcare spending on individual prevention starting in late adulthood, and on the brief period of morbidity at very old age

    Pure Profit for Russia: Benefits of Responsible Finance

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    The purpose of this report is to serve as a post financial crisis handbook that will help both financiers and environmentalists in Russia to cooperate in establishing a ‘greener’ and less risky financial system in a similar manner to which this process is underway in other emerging markets such as China, Brazil and South Africa. The report provides an overview of the evolution of international mechanisms of environmental and social responsibility in the global financial sector, quantifies the scope of exposure of foreign and Russian financial institutions to environment-intensive sectors of the Russian economy, and concludes with recommendations regarding actions that might be implemented by both the Russian government and domestic financial institutions. The report has been prepared within the framework of the project ‘Integration of Environmental and Social Safeguards, Standards and Processes and the Climate Change Agenda in the Russian Finance Sector’ implemented by WWF-Russia and WWF-Germany with the financial assistance of the Federal Agency for the Environment (Umweltbundesamt/UBA) under the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), and with the support of the Russian Ministry of Natural Resources and Ecology, European Bank for Reconstruction and Development (EBRD), in collaboration with the Equator Principles Outreach Group for Russia

    Pure Profit for Russia: Benefits of Responsible Finance

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    The purpose of this report is to serve as a post financial crisis handbook that will help both financiers and environmentalists in Russia to cooperate in establishing a ‘greener’ and less risky financial system in a similar manner to which this process is underway in other emerging markets such as China, Brazil and South Africa. The report provides an overview of the evolution of international mechanisms of environmental and social responsibility in the global financial sector, quantifies the scope of exposure of foreign and Russian financial institutions to environment-intensive sectors of the Russian economy, and concludes with recommendations regarding actions that might be implemented by both the Russian government and domestic financial institutions. The report has been prepared within the framework of the project ‘Integration of Environmental and Social Safeguards, Standards and Processes and the Climate Change Agenda in the Russian Finance Sector’ implemented by WWF-Russia and WWF-Germany with the financial assistance of the Federal Agency for the Environment (Umweltbundesamt/UBA) under the German Federal Ministry for the Environment, Nature Conservation and Nuclear Safety (BMU), and with the support of the Russian Ministry of Natural Resources and Ecology, European Bank for Reconstruction and Development (EBRD), in collaboration with the Equator Principles Outreach Group for Russia
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