3,316 research outputs found
Symptoms in Swiss adolescents in relation to exposure from fixed site transmitters : a prospective cohort study
There is public concern regarding potential health effects of radiofrequency electromagnetic fields (RF-EMF) emitted by fixed site transmitters. We therefore investigated whether self-reported general well-being in adolescents is affected by RF-EMF exposure from mobile phone base stations (downlink) and broadcast transmitters (TV and radio).; In a prospective cohort study, 439 study participants aged 12-17 years, completed questionnaires about their self-reported well-being and possible confounding factors at baseline and one year later. Exposure from fixed site transmitters at home and school was calculated by using a geospatial propagation model. Data were analysed using a mixed-logistic cross-sectional model of a combined dataset consisting of baseline and follow-up data and a longitudinal approach where we investigated whether exposure at baseline (cohort analysis) or changes in exposure between baseline and follow-up (change analysis) were related to a new onset of a symptom between baseline and follow-up. All analyses were adjusted for relevant confounders.; Mean exposure (median; 75(th)) for broadcast transmitters, downlink and total exposure at baseline were 1.9Â ÎŒW/m(2) (1.0Â ÎŒW/m(2); 2.8Â ÎŒW/m(2)), 14.4Â ÎŒW/m(2) (3.8Â ÎŒW/m(2); 11.0Â ÎŒW/m(2)) and 16.3Â ÎŒW/m(2) (5.8Â ÎŒW/m(2); 13.4Â ÎŒW/m(2)), respectively. In cross-sectional analyses no associations were observed between any symptom and RF-EMF exposure from fixed site transmitters. In the cohort and change analyses only a few significant associations were observed including an increased OR for tiredness (2.94, 95%CI: 1.43 to 6.05) for participants in the top 25(th) percentile of total RF-EMF exposure from fixed site transmitters at baseline, in comparison to participants exposed below the median and a decreased OR for exhaustibility (0.50, 95%CI: 0.27 to 0.93) for participants with an exposure increase between baseline and follow-up.; In this cohort study, using a geospatial propagation model, RF-EMF exposure from fixed site transmitters was not consistently associated with self-reported symptoms in Swiss adolescents. The few observed associations have to be interpreted with caution and might represent chance findings
Das neue UNI/PHZ-GebÀude in Luzern
Das neue UNI/PHZ-GebĂ€ude in Luzern ist fĂŒr die Zentalschweiz ein Novum. Es besticht durch sein prĂ€gnantes Ăusseres. Im Innern erfĂŒllt es ein anspruchsvolles Raumprogramm fĂŒr drei Institutionen. Mit dem Neubau ist die Hochschule Luzern der PĂ€dagogischen Hochschule Zentralschweiz im urbanen Umfeld an zentralster Lage in der Stadt Luzern auch baulich prĂ€sent und der Raum Zentralschweiz um ein bemerkenswert multifunktionales BildungsgebĂ€ude reicher geworden.Located next to the station and the famous KKL, the new building of the University of Lucerne and the University of Teacher Education Central Switzerland (PHZ) Lucerne reactiÂvates an urban area. Its defensively expressive facade gives it an appropriate presence. It offers teacher education a variety of different learning spaces, and it is a remarkably multifunctional study and knowledge building in Central Switzerland.nKeywords architecture â buildings for education â learning
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Influences of the use of management systems on the moral attitudes and behaviours of small and medium sized enterprises : measuring the dynamic interplay of morality, environment and managing systems
The author designs a comprehensive model to characterise and optimise sustainable performance of small and medium sized enterprises SMEs - in the overall context of physical environment, society, economy and business. This model embraces issues of morality, management system, and environment and uses a corresponding measurement tool to discuss the interplay of these issues with the intention of leading SMEs to continuous improvement. For the design, issues of system thinking have been applied to cope with the complexity of the interplay of the elements.
The model and the measurement tool are tested by a longitudinal survey of 27 SMEs in Switzerland and Germany. An outstanding issue of this survey is the interviewing of people from different hierarchical levels and departments of the companies (total: 212 individuals); it provides a comprehensive view of companies' attitudes and behaviours. The survey illustrates that a standardised management system is not decisive for the implementation of an increasingly dynamic and circular system with intensive integration of people. The implementation merely depends on the (moral) attitudes and behaviours of owners or top managers and employees. But SMEs with standardised (especially environmental) management systems generally demonstrate more outcomes towards embedded morality, circularity and integration as well as effectiveness and sustainable performance.
Through the design and development of a comprehensive SME model and measuring tool, the author broadens the gap of narrowing SME research concerning optimised performance on individual issues and positions of individual companies to an overall context of society, economy, business and physical environment
Risk aggregation, dependence structure and diversification benefit
Insurance and reinsurance live and die from the diversification benefits or lack of it in their risk portfolio. The new solvency regulations allow companies to include them in their computation of risk-based capital (RBC). The question is how to really evaluate those benefits. To compute the total risk of a portfolio, it is important to establish the rules for aggregating the various risks that compose it. This can only be done through modelling of their dependence. It is a well known fact among traders in financial markets that "diversification works the worst when one needs it the most''. In other words, in times of crisis the dependence between risks increases. Experience has shown that very large loss events almost always affect multiple lines of business simultaneously. September 11, 2001, is an example of such an event: when the claims originated simultaneously from lines of business which are usually uncorrelated, such as property and life, at the same time that the assets of the company were depreciated due to the crisis on the stock markets. In this paper, we explore various methods of modelling dependence and their influence on diversification benefits. We show that the latter strongly depend on the chosen method and that rank correlation grossly overestimates diversification. This has consequences on the RBC for the whole portfolio, which is smaller than it should be when correctly accounting for tail correlation. However, the problem remains to calibrate the dependence for extreme events, which are rare by definition. We analyze and propose possible ways to get out of this dilemma and come up with reasonable estimates.Risk-Based Capital, Hierarchical Copula, Dependence, Calibration
Studies on DNA, complexed by surfactants or modified with pyrene
This work consists of several parts. It was initiated by Gieseâs electon or hole transfer
through DNA using a modified thymidine as a photon triggered radical injector. Taken
the gained knowlegde, that has been collected over years from the series of Tstar
experiments in DNA fragments (oligonucleotides) in solution in account, this work
describes in the first part the changing of the surrounding media. By complexing the
polyanionic backbone of DNA or oligonucleotides with amphiphilic, cationic surfactants
(Surfactant-DNA complex, SDC), water as media could be exchanged by alcohols such
es methanol or propanol. DNA can thereby be dissolved in organic solvents. Surfactants
like dimethylditetradecylammonium chloride (DMDTAB) were used for experiments on
the T star.
During gathering the knowlegde of how to handle the complexes, we started to complex
salmon DNA with a hole series of surfactants of aliphatic as well as aromatic and
polyaromatic nature. Cationic surfactants (trimethylammonim heads) were synthesisied
containing moieties like pyrene, anthracene and substituted derivatives, naphthalimide,
carbazole, umbelliferone, phthalimide and coumarin to change the physical and spectral
properties of the resulting DNA complexes.
The complex of DNA and cetylammonium bromide (CTAB) was spun into fibres with
diameters of 300 - 500 nm by electrospinning. In this way stable, self-assembling
nanomaterials have been produced.
An other part of this work deals with the photophysical and photochemical properties of
DNA, modifed with pyrene. Pyrene has been incorporated as pyrene deoxyribose
nucleoside, replacing only one nucleobase as well as a diamide, replacing the nucleobase
and a sugar moiety into oligomers. This pyrene modified strands have been irradiated
with UV light and the degradation has been analysed using HPLC and Maldi-ToF
Bootstrapping the economy -- a non-parametric method of generating consistent future scenarios
The fortune and the risk of a business venture depends on the future course of the economy. There is a strong demand for economic forecasts and scenarios that can be applied to planning and modeling. While there is an ongoing debate on modeling economic scenarios, the bootstrapping (or resampling) approach presented here has several advantages. As a non-parametric method, it directly relies on past market behaviors rather than debatable assumptions on models and parameters. Simultaneous dependencies between economic variables are automatically captured. Some aspects of the bootstrapping method require additional modeling: choice and ransformation of the economic variables, arbitrage-free consistency, heavy tails of distributions, serial dependence, trends and mean reversion. Results of a complete economic scenario generator are presented, tested and discussed.economic scenario generator (ESG); asset-liability management (ALM); bootstrapping; resampling; simulation; Monte-Carlo simulation; non-parametric model; yield curve model
Google Searches as a Means of Improving the Nowcasts of Key Macroeconomic Variables
The Google Insights data are a collection of recorded Internet searches for a huge number of the keywords, which are available since January 2004. These searches represent a kind of revealed perceptions of Internet users, which are a (possibly not entirely representative) sample of the general public. These data can be used to improve the short-term forecasts or nowcasts of various macroeconomic variables. In this paper, we compare the nowcasts of the growth rates of the real US private consumption based on both the conventional consumer confidence indicators and the Google indicators. The latter are extracted from the Google searches using the principal component analysis. It is shown that the Google indicators are especially successful at predicting private consumption in times of economic trouble, for they are 20% more accurate than the best alternative during the 2008m1-2009m5 forecast period. In addition, Google indicators are available at weekly frequency and not subject to revisions. This makes them an excellent source of information for the macroeconomic forecasting.Google indicators, forecasting, principal components, US private consumption
Control of the plasmonic resonance of a graphene coated plasmonic nanoparticle array combined with a nematic liquid crystal
We report on the fabrication and characterization of a switchable plasmonic device based on a conductive graphene oxide (cGO) coated plasmonic nanoparticle (NP) array, layered with nematic liquid crystal (NLC) as an active medium. A monolayer of NPs has been immobilized on a glass substrate through electrostatic interaction, and then grown in place using nanochemistry. This monolayer is then coated with a thin (less then 100nm) cGO film which acts simultaneously as both an electro-conductive and active medium. The combination of the conductive NP array with a separate top cover substrate having both cGO and a standard LC alignment layer is used for aligning a NLC film in a hybrid configuration. The system is analysed in terms of morphological and electro-optical properties. The spectral response of the sample characterized after each element is added (air, cGO, NLC) reveals a red-shift of the localized plasmonic resonance (LPR) frequency of approximately 62nm with respect to the NP array surrounded by air. The application of an external voltage (8Vpp) is suitable to modulate (blue shift) the LPR frequency by approximately 22nm
Belastungsstabile Subtalararthrodesemit I.CO.SÂź-Schrauben
Zusammenfassung. : Operationsziel: : Belastungsstabile Arthrodese des unteren Sprunggelenks (USG, Articulatio talocalcanearis). Indikationen: : Symptomatische Arthrose des unteren Sprunggelenks. Symptomatische Coalitio talocalcanearis. Fixierte Fehlstellung des RĂŒckfuĂes. Neurogene Fehlstellung des RĂŒckfuĂes. LigamentĂ€r nicht stabilisierbarer RĂŒckfuĂ. Kontraindikationen: : Akuter Gelenkinfekt. Diabetische Neuroarthropathie. Operationstechnik: : Lateraler LĂ€ngsschnitt und Eröffnen des Sinus tarsi, AusrĂ€umen desselben und Arthrotomie des unteren Sprunggelenks. Aufspreizen des Gelenks und Entknorpeln der GelenkflĂ€chen von lateral nach medial, zunĂ€chst der hinteren, dann der mittleren und vorderen Gelenkanteile. Reposition und temporĂ€re Transfixation des Gelenks mit zwei perkutanen Kirschner-DrĂ€hten: 1. von plantar-posterior durch den Kalkaneus in den Taluskörper und 2. von plantar-lateral schrĂ€g nach dorsomedial in den Taluskopf. Kontrolle unter dem Röntgenbildwandler, Ăberbohren der Kirschner-DrĂ€hte und Einbringen von zwei 6,5-mm- I.CO.SÂź-Schrauben (Ideal Compression Screws). AuffĂŒllen des Sinus tarsi mit autogenem oder homologem Knochenspan. Weiterbehandlung: : Bei abgeschwollenen Weichteilen freie Mobilisation mit Belastung nach MaĂgabe der Schmerzen, beginnend mit zwei UnterarmgehstĂŒtzen. Ergebnisse: : Von den im Jahr 2000 im Kantonsspital Basel (OrthopĂ€disch- traumatologische Abteilung, OrthopĂ€dische UniversitĂ€tsklinik) operierten 13 Patienten (drei Frauen, zehn MĂ€nner; Durchschnittsalter 49 Jahre) waren zwölf nach 16,5 (12-22) Monaten mit dem Resultat der Arthrodese des unteren Sprunggelenks zufrieden, und diese war in allen 13 FĂ€llen in regelrechter Stellung konsolidiert. Nach knöcherner Durchbauung wurden insgesamt vier Patienten, alle nach einer initial posttraumatischen Arthrose und verschiedenen Voroperationen, wegen Restbeschwerden erneut operiert: In allen vier FĂ€llen wurden die möglicherweise störenden Schrauben entfernt, in einem Fall erfolgte zusĂ€tzlich eine Revision der Narbe und des Tarsaltunnels. Im Kitaoka-Hindfoot-Score erreichten neun Patienten zwischen 88 und 92 Punkte und drei Patienten zwischen 65 und 77 Punkte. Ein Patient erreichte nur 56 Punkte und war wegen persistierender Schmerzen sowie der bereits vor der Operation bestehenden generellen Einsteifung des RĂŒckfuĂes nicht zufrieden. In keinem Fall lieĂen sich eine SekundĂ€rdislokation der Fragmente, ein Implantatversagen und/oder eine Knochendemineralisation beobachte
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