553 research outputs found

    Regimes of operations of semiconductor ring lasers under optical injection and applications to optical signal processing

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    We present a detailed characterization of the semiconductor ring-laser operating regimes with special emphasis on the response to optical injection. Applications to an optical set/reset bistable memory and four-wave-mixing tunable THz signals generation are demonstrated.</p

    Coping styles relate to health and work environment of Norwegian and Dutch hospital nurses:A comparative study

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    Nurses exposed to high nursing stress report no health complaints as long as they have high coping abilities. The purpose of this study was to investigate coping styles in relation to the health status and work environment of Norwegian and Dutch hospital nurses. This comparative study included a random sample of 5400 Norwegian nurses and a convenience sample of 588 Dutch nurses. Coping, health, and work environment were assessed by questionnaire in both samples and associations were investigated bivariately and multi-variately. We found that active problem-solving coping was associated with the health and work environment of Norwegian nurses but not with the health and work environment of Dutch. Passive coping (avoiding problems or waiting to see what happens) was found to relate to poor general health, poor mental health, low job control, and low job support in both Norwegian and Dutch nurses. Improvements in the nursing work environment may not only result in better mental health, but may also reduce passive coping

    mTORC2 and AMPK differentially regulate muscle triglyceride content via Perilipin 3.

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    OBJECTIVE: We have recently shown that acute inhibition of both mTOR complexes (mTORC1 and mTORC2) increases whole-body lipid utilization, while mTORC1 inhibition had no effect. Therefore, we tested the hypothesis that mTORC2 regulates lipid metabolism in skeletal muscle. METHODS: Body composition, substrate utilization and muscle lipid storage were measured in mice lacking mTORC2 activity in skeletal muscle (specific knockout of RICTOR (Ric mKO)). We further examined the RICTOR/mTORC2-controlled muscle metabolome and proteome; and performed follow-up studies in other genetic mouse models and in cell culture. RESULTS: Ric mKO mice exhibited a greater reliance on fat as an energy substrate, a re-partitioning of lean to fat mass and an increase in intramyocellular triglyceride (IMTG) content, along with increases in several lipid metabolites in muscle. Unbiased proteomics revealed an increase in the expression of the lipid droplet binding protein Perilipin 3 (PLIN3) in muscle from Ric mKO mice. This was associated with increased AMPK activity in Ric mKO muscle. Reducing AMPK kinase activity decreased muscle PLIN3 expression and IMTG content. AMPK agonism, in turn, increased PLIN3 expression in a FoxO1 dependent manner. PLIN3 overexpression was sufficient to increase triglyceride content in muscle cells. CONCLUSIONS: We identified a novel link between mTORC2 and PLIN3, which regulates lipid storage in muscle. While mTORC2 is a negative regulator, we further identified AMPK as a positive regulator of PLIN3, which impacts whole-body substrate utilization and nutrient partitioning

    Observation of the Early Structural Changes Leading to the Formation of Protein Superstructures.

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    Formation of superstructures in protein aggregation processes has been indicated as a general pathway for several proteins, possibly playing a role in human pathologies. There is a severe lack of knowledge on the origin of such species in terms of both mechanisms of formation and structural features. We use equine lysozyme as a model protein, and by combining spectroscopic techniques and microscopy with X-ray fiber diffraction and ab initio modeling of Small Angle X-ray Scattering data, we isolate the partially unfolded state from which one of these superstructures (i.e., particulate) originates. We reveal the low-resolution structure of the unfolded state and its mechanism of formation, highlighting the physicochemical features and the possible pathway of formation of the particulate structure. Our findings provide a novel detailed knowledge of such a general and alternative aggregation pathway for proteins, this being crucial for a basic and broader understanding of the aggregation phenomena.This is the author's accepted manuscript and will be under embargo until the 3rd of September 2015. The final version is published by ACS in The Journal of Physical Chemistry Letters here: http://pubs.acs.org/doi/abs/10.1021/jz501614e

    Lung function reduction and chronic respiratory symptoms among workers in the cement industry: a follow up study

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    <p>Abstract</p> <p>Background</p> <p>There are only a few follow-up studies of respiratory function among cement workers. The main aims of this study were to measure total dust exposure, to examine chronic respiratory symptoms and changes in lung function among cement factory workers and controls that were followed for one year.</p> <p>Methods</p> <p>The study was conducted in two cement factories in Ethiopia. Totally, 262 personal measurements of total dust among 105 randomly selected workers were performed. Samples of total dust were collected on 37-mm cellulose acetate filters placed in closed faced Millipore-cassettes. Totally 127 workers; 56 cleaners, 44 cement production workers and 27 controls were randomly selected from two factories and examined for lung function and interviewed for chronic respiratory symptoms in 2009. Of these, 91 workers; 38 cement cleaners (mean age 32 years), 33 cement production workers (36 years) and 20 controls (38 years) were examined with the same measurements in 2010.</p> <p>Results</p> <p>Total geometric mean dust exposure among cleaners was 432 mg/m<sup>3</sup>. The fraction of samples exceeding the Threshold Limit Value (TLV) of 10 mg/m<sup>3 </sup>for the cleaners varied from 84-97% in the four departments. The levels were considerably lower among the production workers (GM = 8.2 mg/m<sup>3</sup>), but still 48% exceeded 10 mg/m<sup>3</sup>.</p> <p>The prevalence of all the chronic respiratory symptoms among both cleaners and production workers was significantly higher than among the controls.</p> <p>Forced Expiratory Volume in one second (FEV<sub>1</sub>) and FEV<sub>1</sub>/Forced Vital Capacity (FEV<sub>1</sub>/FVC) were significantly reduced from 2009 to 2010 among the cleaners (p < 0.002 and p < 0.004, respectively) and production workers (p < 0.05 and p < 0.02, respectively), but not among the controls.</p> <p>Conclusions</p> <p>The high prevalence of chronic respiratory symptoms and reduction in lung function is probably associated with high cement dust exposure. Preventive measures are needed to reduce the dust exposure.</p

    Diffusion of an e-learning programme among Danish General Practitioners: A nation-wide prospective survey

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    <p>Abstract</p> <p>Background</p> <p>We were unable to identify studies that have considered the diffusion of an e-learning programme among a large population of general practitioners. The aim of this study was to investigate the uptake of an e-learning programme introduced to General Practitioners as part of a nation-wide disseminated dementia guideline.</p> <p>Methods</p> <p>A prospective study among all 3632 Danish GPs. The GPs were followed from the launching of the e-learning programme in November 2006 and 6 months forward. Main outcome measures: Use of the e-learning programme. A logistic regression model (GEE) was used to identify predictors for use of the e-learning programme.</p> <p>Results</p> <p>In the study period, a total of 192 different GPs (5.3%) were identified as users, and 17% (32) had at least one re-logon. Among responders at first login most have learnt about the e-learning programme from written material (41%) or from the internet (44%). A total of 94% of the users described their ability of conducting a diagnostic evaluation as good or excellent. Most of the respondents used the e-learning programme due to general interest (90%). Predictors for using the e-learning programme were Males (OR = 1.4, 95% CI 1.1; 2.0) and members of Danish College of General Practice (OR = 2.2, 95% CI 1.5; 3.1), whereas age, experience and working place did not seem to be influential.</p> <p>Conclusion</p> <p>Only few Danish GPs used the e-learning programme in the first 6 months after the launching. Those using it were more often males and members of Danish College of General Practice. Based on this study we conclude, that an active implementation is needed, also when considering electronic formats of CME like e-learning.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov Identifier: NCT00392483.</p

    Cement dust exposure and acute lung function: A cross shift study

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    Background: Few studies have been carried out on acute effects of cement dust exposure. This study is conducted to investigate the associations between current "total" dust exposure and acute respiratory symptoms and respiratory function among cement factory workers. Methods: A combined cross-sectional and cross-shift study was conducted in Dire Dawa cement factory in Ethiopia. 40 exposed production workers from the crusher and packing sections and 20 controls from the guards were included. Personal "total" dust was measured in the workers' breathing zone and peak expiratory flow (PEF) was measured for all selected workers before and after the shift. When the day shift ended, the acute respiratory symptoms experienced were scored and recorded on a five-point Likert scale using a modified respiratory symptom score questionnaire. Results: The highest geometric mean dust exposure was found in the crusher section (38.6 mg/m3) followed by the packing section (18.5 mg/m3) and the guards (0.4 mg/m3). The highest prevalence of respiratory symptoms for the high exposed workers was stuffy nose (85%) followed by shortness of breath (47%) and "sneezing" (45%). PEF decreased significantly across the shift in the high exposed group. Multiple linear regression showed a significant negative association between the percentage cross-shift change in PEF and total dust exposure. The number of years of work in high-exposure sections and current smoking were also associated with cross-shift decrease in PEF. Conclusions: Total cement dust exposure was related to acute respiratory symptoms and acute ventilatory effects. Implementing measures to control dust and providing adequate personal respiratory protective equipment for the production workers are highly recommended

    An introduction to InP-based generic integration technology

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    Photonic integrated circuits (PICs) are considered as the way to make photonic systems or subsystems cheap and ubiquitous. PICs still are several orders of magnitude more expensive than their microelectronic counterparts, which has restricted their application to a few niche markets. Recently, a novel approach in photonic integration is emerging which will reduce the R&D and prototyping costs and the throughput time of PICs by more than an order of magnitude. It will bring the application of PICs that integrate complex and advanced photonic functionality on a single chip within reach for a large number of small and larger companies and initiate a breakthrough in the application of Photonic ICs. The paper explains the concept of generic photonic integration technology using the technology developed by the COBRA research institute of TU Eindhoven as an example, and it describes the current status and prospects of generic InP-based integration technology
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