1,863 research outputs found

    Impacts of the REACH candidate list of substances subject to authorisation:the reputation mechanism and empirical results on behavioral adaptations of German supply chain actors

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    The candidate list of substances subject to authorisation is an instrument provided by the EU chemicals regulation (REACH) to publicly  announce and prioritize chemical substances of very high concern (SVHC) as a first step of imposing an obligation of authorisation on them, i.e. including them into the authorisation list (Annex XIV of REACH). As a consequence of inclusion into the “candidate list”, a variety of obligations concerned with intensifying risk communication apply. Article producers, importers and distributors of articles have to communicate information about SVHCs contained in articles and necessary risk management measures to the recipients of the articles and provide this information to consumers on request (Art. 33 REACH). This research paper analyzes the reputational mechanism of the candidate list showing a potential to stigmatize not only the substances as such but also various actors of the supply chain associated with these substances and their brands. Drawing on behavioral psychology theories, hypotheses on the reputational impacts of the candidate list on substance manufacturers, downstream users (including formulators and manufacturers of articles) and distributors are derived. These are discussed on the basis of current empirical data surveyed by the European Commission

    Suppression of biodynamic interference in head-tracked teleoperation

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    The utility of helmet-tracked sights to provide pointing commands for teleoperation of cameras, lasers, or antennas in aircraft is degraded by the presence of uncommanded, involuntary heat motion, referred to as biodynamic interference. This interference limits the achievable precision required in pointing tasks. The noise contributions due to biodynamic interference consists of an additive component which is correlated with aircraft vibration and an uncorrelated, nonadditive component, referred to as remnant. An experimental simulation study is described which investigated the improvements achievable in pointing and tracking precision using dynamic display shifting in the helmet-mounted display. The experiment was conducted in a six degree of freedom motion base simulator with an emulated helmet-mounted display. Highly experienced pilot subjects performed precision head-pointing tasks while manually flying a visual flight-path tracking task. Four schemes using adaptive and low-pass filtering of the head motion were evaluated to determine their effects on task performance and pilot workload in the presence of whole-body vibration characteristic of helicopter flight. The results indicate that, for tracking tasks involving continuously moving targets, improvements of up to 70 percent can be achieved in percent on-target dwelling time and of up to 35 percent in rms tracking error, with the adaptive plus low-pass filter configuration. The results with the same filter configuration for the task of capturing randomly-positioned, stationary targets show an increase of up to 340 percent in the number of targets captured and an improvement of up to 24 percent in the average capture time. The adaptive plus low-pass filter combination was considered to exhibit the best overall display dynamics by each of the subjects

    Theoretische Untersuchungen zur Fluid-Struktur-Wechselwirkung in zweiphasig durchströmten Schwingungsmodellen

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    Kurzfassung Ausgehend von den Grundgleichungen für Kontinuität, Impuls und Energie einer Zweiphasenströmung werden Beziehungen für ein Ersatzfluid des Gas- Flüssigkeits- Gemisches mit orts- und zeitabhängiger Dichte und Geschwindigkeit aufgestellt und anhand eines Siedemodells geprüft. Es folgen Anwendungen auf ein 1D- und ein 2D- Schwingungsmodell (Pendel im Zweiphasenstrom) unter Berücksichtigung der Fluid-Struktur- Wechselwirkung und die Berechnung von Eigenfrequenzen und Dämpfungen

    Internet and Democracy. Summary

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    Pathological regional blood flow in opiate-dependent patients during withdrawal: A HMPAO-SPECT study

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    The aims of the present study were to investigate regional cerebral blood flow (rCBF) in heroin-dependent patients during withdrawal and to assess the relation between these changes and duration of heroin consumption and withdrawal data. The rCBF was measured using brain SPECT with Tc-99m-HMPAO in 16 heroin-dependent patients during heroin withdrawal. Thirteen patients received levomethadone at the time of the SPECT scans. The images were analyzed both visually and quantitatively, a total of 21 hypoperfused brain regions were observed in 11 of the 16 patients. The temporal lobes were the most affected area, hypoperfusions of the right and left temporal lobe were observed in 5 and 5 patients, respectively. Three of the patients had a hypoperfusion of the right frontal lobe, 2 patients showed perfusion defects in the left frontal lobe, right parietal lobe and left parietal lobe. The results of the quantitative assessments of the rCBF were consistent with the results of the qualitative findings. The stepwise regression analysis showed a significant positive correlation (r = 0.54) between the dose of levomethadone at the time of the SPECT scan and the rCBF of the right parietal lobe. Other significant correlations between clinical data and rCBF were not found. The present results suggest brain perfusion abnormalities during heroin withdrawal in heroin-dependent patients, which are not due to the conditions of withdrawal

    Oral diabetes medication monotherapy and short-term mortality in individuals with type 2 diabetes and coronary artery disease

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    Objective To determine whether sulfonylurea use, compared with non-sulfonylurea oral diabetes medication use, was associated with 2-year mortality in individuals with well-controlled diabetes and coronary artery disease (CAD). Research design and methods We studied 5352 US veterans with type 2 diabetes, obstructive CAD on coronary angiography, hemoglobin A1c ≤7.5% at the time of catheterization, and taking zero or one oral diabetes medication (categorized as no medications, non-sulfonylurea medication, or sulfonylurea). We estimated the association between medication category and 2-year mortality using inverse probability of treatment-weighted (IPW) standardized mortality differences and IPW multivariable Cox proportional hazards regression. Results 49%, 35%, and 16% of the participants were on no diabetes medications, non-sulfonylurea medications, and sulfonylureas, respectively. In individuals on no medications, non-sulfonylurea medications, and sulfonylureas, the unadjusted mortality rates were 6.6%, 5.2%, and 11.9%, respectively, and the IPW-standardized mortality rates were 5.9%, 6.5%, and 9.7%, respectively. The standardized absolute 2-year mortality difference between non-sulfonylurea and sulfonylurea groups was 3.2% (95% CI 0.7 to 5.7) (p=0.01). In Cox proportional hazards models, the point estimate suggested that sulfonylurea use might be associated with greater hazard of mortality than non-sulfonylurea medication use, but this finding was not statistically significant (HR 1.38 (95% CI 1.00 to 1.93), p=0.05). We did not observe significant mortality differences between individuals on no diabetes medications and non-sulfonylurea users. Conclusions Sulfonylurea use was common (nearly one-third of those taking medications) and was associated with increased 2-year mortality in individuals with obstructive CAD. The significance of the association between sulfonylurea use and mortality was attenuated in fully adjusted survival models. Caution with sulfonylurea use may be warranted for patients with well-controlled diabetes and CAD, and metformin or newer diabetes medications with cardiovascular safety data could be considered as alternatives when individualizing therapy

    Lumenal sites and C terminus accessibility of the skeletal muscle calcium release channel (ryanodine receptor)

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    The membrane topology of the skeletal muscle ryanodine receptor (RyR1) was investigated using site-directed antibodies directed against amino acid sequences 2804-2930, 4581-4640, 4860-4886, and 4941-5037. Ab(2804-2930) bound with identical affinity to either closed or permeabilized sarcoplasmic reticulum vesicles, confirming the cytoplasmic location of this segment. Ab(4581-4640) did not bind to closed vesicles but bound well to permeabilized vesicles, supporting a lumenal location for this segment. Ab(4860-4886) did not bind to closed vesicles but exhibited weak binding to the permeabilized vesicles, suggesting that a portion of the epitope may be exposed on the lumenal surface. The C-terminal antibody (Ab(4941-5037)) bound weakly to closed vesicles, and binding was not significantly enhanced by permeabilizing vesicles with low concentrations of non-denaturing detergent. However, the C-terminal antibodies bound efficiently to vesicles which were transiently incubated at alkaline pH or subjected to trypsinolysis, conditions where few of the vesicles were permeabilized. These results support a model for the membrane topology of the ryanodine receptor as proposed by Takeshima et al. (Takeshima, H., Nishimura, S., Matsumoto, T., Ishida, H., Kangawa, K., Minamino, N., Matsuo, H., Ueda, M., Hanaoka, M., Hirose, T., and Numa, S. (1989) Nature 339, 439-445). The results also suggest that the native conformation of the C terminus is inaccessible to antibodies
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