33 research outputs found

    Survey context and question wording affects self reported annoyance due to road traffic noise: a comparison between two cross-sectional studies

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    <p>Abstract</p> <p>Background</p> <p>Surveys are a common way to measure annoyance due to road traffic noise, but the method has some draw-backs. Survey context, question wording and answer alternatives could affect participation and answers and could have implications when comparing studies and/or performing pooled analyses. The aim of this study was to investigate the difference in annoyance reporting due to road traffic noise in two types of surveys of which one was introduced broadly and the other with the clearly stated aim of investigating noise and health.</p> <p>Methods</p> <p>Data was collected from two surveys carried out in the municipality of Malmö, southern Sweden in 2007 and 2008 (n = 2612 and n = 3810). The first survey stated an aim of investigating residential environmental exposure, especially noise and health. The second survey was a broad public health survey stating a broader aim. The two surveys had comparable questions regarding noise annoyance, although one used a 5-point scale and the other a 4-point scale. We used geographic information systems (GIS) to assess the average road and railway noise (L<sub>Aeq,24h</sub>) at the participants' residential address. Logistic regression was used to calculate odds ratios for annoyance in relation to noise exposure.</p> <p>Results</p> <p>Annoyance at least once a week due to road traffic noise was significantly more prevalent in the survey investigating environment and health compared to the public health survey at levels > 45 dB(A), but not at lower exposure levels. However no differences in annoyance were found when comparing the extreme alternatives "never" and "every day". In the study investigating environment and health, "Noise sensitive" persons were more likely to readily respond to the survey and were more annoyed by road traffic noise compared to the other participants in that survey.</p> <p>Conclusions</p> <p>The differences in annoyance reporting between the two surveys were mainly due to different scales, suggesting that extreme alternatives are to prefer before dichotomization when comparing results between the two. Although some findings suggested that noise-sensitive individuals were more likely to respond to the survey investigating noise and health, we could not find convincing evidence that contextual differences affected either answers or participation.</p

    Kernel Architecture of the Genetic Circuitry of the Arabidopsis Circadian System

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    A wide range of organisms features molecular machines, circadian clocks, which generate endogenous oscillations with ~24 h periodicity and thereby synchronize biological processes to diurnal environmental fluctuations. Recently, it has become clear that plants harbor more complex gene regulatory circuits within the core circadian clocks than other organisms, inspiring a fundamental question: are all these regulatory interactions between clock genes equally crucial for the establishment and maintenance of circadian rhythms? Our mechanistic simulation for Arabidopsis thaliana demonstrates that at least half of the total regulatory interactions must be present to express the circadian molecular profiles observed in wild-type plants. A set of those essential interactions is called herein a kernel of the circadian system. The kernel structure unbiasedly reveals four interlocked negative feedback loops contributing to circadian rhythms, and three feedback loops among them drive the autonomous oscillation itself. Strikingly, the kernel structure, as well as the whole clock circuitry, is overwhelmingly composed of inhibitory, rather than activating, interactions between genes. We found that this tendency underlies plant circadian molecular profiles which often exhibit sharply-shaped, cuspidate waveforms. Through the generation of these cuspidate profiles, inhibitory interactions may facilitate the global coordination of temporally-distant clock events that are markedly peaked at very specific times of day. Our systematic approach resulting in experimentally-testable predictions provides insights into a design principle of biological clockwork, with implications for synthetic biology.Comment: Supplementary material is available at the journal websit

    Revised Morning Loops of the Arabidopsis Circadian Clock Based on Analyses of Direct Regulatory Interactions

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    The network structure of the plant circadian clock is complex and direct regulatory interactions between individual components have proven particularly difficult to predict from genetic analyses. Here, we systematically investigate in vivo binding interactions between the morning-specific transcription factor, LATE ELONGATED HYPOCOTYL (LHY) and the promoters of other components of the network. We then demonstrate the functionality of these interactions by testing the responsiveness of the target gene to an ethanol-induced change in expression level of the LHY protein. We uncover novel, negative autoregulatory feedback loops from LHY and the closely related CIRCADIAN CLOCK ASSOCIATED-1 (CCA1) onto their own and each other’s expression. Furthermore we show that LHY acts as a repressor of all other clock components, including PSEUDO-RESPONSE REGULATORs (PRRs) 9 and 7, which were previously thought to be positive regulatory targets. These experimental results lead to a substantial revision of the morning loops of the clock

    Circadian regulation of hormone signaling and plant physiology

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    The survival and reproduction of plants depend on their ability to cope with a wide range of daily and seasonal environmental fluctuations during their life cycle. Phytohormones are plant growth regulators that are involved in almost every aspect of growth and development as well as plant adaptation to myriad abiotic and biotic conditions. The circadian clock, an endogenous and cell-autonomous biological timekeeper that produces rhythmic outputs with close to 24-h rhythms, provides an adaptive advantage by synchronizing plant physiological and metabolic processes to the external environment. The circadian clock regulates phytohormone biosynthesis and signaling pathways to generate daily rhythms in hormone activity that fine-tune a range of plant processes, enhancing adaptation to local conditions. This review explores our current understanding of the interplay between the circadian clock and hormone signaling pathways

    Organisation

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    Le management des technologies, six conditions de succĂšs - JosĂ©e Morin et Jacques GrisĂ© La prise de dĂ©cision : ĂȘtre rationnel ou raisonnable? L'exemple du banquier - Luc Robitaille L'entreprenariat beauceron : les ingrĂ©dients du succĂšs - Mario Carrier et AndrĂ© Billette Il est impĂ©ratif de dĂ©velopper une culture entrepreneuriale intĂ©grĂ©e en Ă©ducation - Jean-Marie Toulouse L'ENTREPRENEURSHIP AU QUÉBEC Nouvelles de la Fondation de l'entrepreneurship - Paul-Arthur Fortin INTERVIEW Propos d'actualitĂ© de J.K. Galbraith - AndrĂ© Briand ÉTAT DE LA RECHERCHE Les pratiques de gestion des ressources humaines (GRH) en PME - Denis J. Garand et Bruno Fab

    Enzyme-Linked Immunosorbent Assay Specific for (1→6) Branched, (1→3)-ÎČ-d-Glucan Detection in Environmental Samples

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    (1→3)-ÎČ-d-Glucans have been recognized as a potential causative agent responsible for bioaerosol-induced respiratory symptoms observed in both indoor and occupational environments. A specific enzyme immunoassay was developed to quantify (1→6) branched, (1→3)-ÎČ-d-glucans in environmental samples. The assay was based on the use of a high-affinity receptor (galactosyl ceramide) specific for (1→3)-ÎČ-d-glucans as a capture reagent and a monoclonal antibody specific for fungal cell wall ÎČ-d-glucans as a detector reagent. The assay was highly specific for (1→6) branched, (1→3)-ÎČ-d-glucans (such as that from Saccharomyces cerevisiae) and did not show any response at 200 ng/ml to curdlan, laminarin, pustulan, dextran, mannan, carboxymethyl cellulose, and endotoxins. The detection level was 0.8 ng/ml for baker's yeast glucan and Betafectin. A coefficient of variation of 7.8% was obtained for (1→3)-ÎČ-d-glucans in house dust samples. Metal working fluids spiked with (1→3)-ÎČ-d-glucans inhibited the glucan assay. Because the assay is specific for (1→6) branched, (1→3)-ÎČ-d-glucans and is sensitive and reproducible, it will be useful for the investigation of health effects from exposure to this class of biologically active molecules
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