5,413 research outputs found
Clathrin Heavy Chain subunits coordinate endo- and exocytic traffic and affect stomatal movement
The current model for vesicular traffic to and from the plasma membrane is accepted but the molecular requirements for this coordination are not well defined. We have identified the has1 mutant, which has a stomatal function defect, as a clathrin heavy chain 1 (CHC1) mutant allele and show that it has a decreased rate of endocytosis and growth defects that are shared with other chc1 mutant alleles. We used chc1 alleles and the related chc2 mutant as tools to investigate the effects clathrin defects have on secretion pathways and plant growth. We show that secretion and endocytosis at the plasma membrane is sensitive to CHC1 and CHC2 function in seedling roots, and that chc mutants have physiological defects in stomatal function and plant growth that have not been previously described. These findings suggest that clathrin supports specific functions of multiple cell types. Stomata movement and gas exchange is altered in chc mutants, indicating clathrin is important for stomatal regulation. The aberrant function of chc mutant stomata is consistent with the growth phenotypes observed under different water and light conditions, which are also similar to those of the secretory SNARE mutant, syp121. The syp121 and chc mutants have impaired endo- and exocytosis compared to wild type, indicating a link between SYP121-dependent secretion and clathrin-dependent endocytosis at the plasma membrane. Our findings provide evidence that clathrin and SYP121 functions are important for the coordination of endo- and exocytosis, and have an impact on stomatal function, gas exchange, and vegetative growth in Arabidopsis
Satisfaction and annoyance of residents in neighbourhoods situated near industrial activity. Analysis of telephone survey data on the residential environment
In many of the Dutch national policy plans, environmental quality is a strong guiding principle. From an environmental science and policy perspective, environmental quality at the local level is affected by sound, odour and air pollution, as well as external safety risks. This study examines the relationship between people's perception of sound and odour (noise and odour annoyance) and the perceived environmental quality, represented as residential satisfaction (RS). Data from 19 telephone surveys (TLO) were compiled in a large TLO database. In the present study data from 17 TLOs performed in 86 locations, covering 18,000 respondents were analysed. Typically, TLOs are used for policy or maintenance purposes to assess the RS of people living in the vicinity of industrial plants or factories. Data on (individual) exposure levels were not available for these analyses. A remarkeble finding is the observed dispersion of correlations between annoyance and satisfaction per location (n=84, correlations for sound and satisfaction: -0,57 en 0,07; for odour and satisfaction between: -0,57 en 0,37). For this reason a multi-level analysis (MLA) was performed. This finding indicates location specific differences, probably due to differences in exposure levels. Furthermore, tenure and type of dwelling appeared to be relatively strong predictors of residential satisfaction. Homeowners appeared to be more satisfied than tenants. People in flats were more dissatisfied than people living in (semi-)detached houses. Annoyance from noise and (offensive) odours was another, relatively strong, predictor of RS. In general, residents reporting more annoyance were less satisfied with their residential situation. Other predictors of RS were age, gender, and the number of facilities in the dwelling. Older people and women were more satisfied with their residential situation than younger people and men, respectively. The more facilities present in the dwelling, the more satisfied residents appeared to be. Residential satisfaction is determined by a combination of subjective (e.g. annoyance), objective (e.g. number of facilities) and personal factors (e.g. age, gender). Annoyance appears to be a relatively important factor of residential satisfaction but tenure and dwelling type appear to be, relatively, more important. It is strongly recommended to add sound and odour exposure data to the TLO-database.Het begrip 'kwaliteit' speelt in steeds meer beleidsvoornemens van de (rijks)overheid een krachtig sturende rol. Voor de lokale omgeving, de leefomgeving, is de algemene beleidsdoelstelling van VROM het verbeteren en in stand houden van de woonkwaliteit. Belangrijke determinanten van de ervaren kwaliteit van de leefomgeving zijn (hinder van) geluid, geur, luchtverontreiniging en externe veiligheid. In dit onderzoek wordt de invloed van hinder van geluid en geur op de ervaren kwaliteit (tevredenheid) van de leefomgeving onderzocht. De belangrijkste vragen waren a) wat is de invloed van hinder op de woontevredenheid en b) welke persoons- en/of woonkenmerken zijn van invloed op de woontevredenheid? De gegevens zijn verzameld met behulp van Telefonische Leefsituatie Onderzoeken (TLO's) bij mensen die in de buurt van (industriele) bedrijvigheid wonen. Verschillende TLO's (n=19) zijn in een groot TLO-bestand samengevoegd. In deze analyse is gebruik gemaakt van 17 TLO's met daarin in totaal 86 onderzoekslocaties en ongeveer 18.000 respondenten. Vanwege de gelaagde structuur van de gegevens is uitgevoerd. Gegevens over (individuele) blootstellingniveaus waren voor deze analyses niet beschikbaar. Een opmerkelijk bevinding is de grote spreiding in de (cor)relatie tussen woontevredenheid en hinder per locatie (n=84, correlaties voor geluid tussen: -0,57 en 0,07; voor geur tussen -0,57 en 0,37). Dit is de reden waarom in afwijking van eerder onderzoek een multi-level analyse (MLA) is uitgevoerd. Deze bevinding duidt op locatie-specifieke verschillen die van invloed kunnen zijn op de relatie woontevredenheid en hinder. Verschillen in blootstellingsnivo's zouden hieraan ten grondslag kunnen liggen. De andere bevindingen zijn in overeenstemming met resultaten van soortgelijk onderzoek. De bezitsvorm van de woning (eigenaar-huurder) en het type woning blijken relatief belangrijke voorspellers van tevredenheid met de leefomgeving. In het algemeen zijn huurders minder tevreden dan eigenaren. Flatbewoners zijn minder tevreden dan mensen in (half)vrijstaande huizen. Daarnaast blijkt hinder (van lawaai en stank) een relatief belangrijke voorspeller van woontevredenheid te zijn. Naarmate respondenten meer hinder ondervinden zijn ze minder tevreden met hun leefomgeving. De leeftijd, het geslacht, en het aantal voorzieningen in de woning van de respondent zijn eveneens voorspellers van woontevredenheid, zij het in mindere mate. Vrouwen en oudere mensen zijn meer tevreden met hun leefomgeving dan mannen respectievelijk jongere mensen. Naarmate in een woning meer voorzieningen aanwezig zijn tonen de bewoners zich meer tevreden. De tevredenheid met de leefomgeving in woongebieden nabij industriele activiteit wordt bepaald door een mix van persoons-, belevings- en omgevingsgebonden kenmerken. De mate van hinder is een relatief belangrijke determinant van woontevredenheid maar is niet de belangrijkste. Bezitsvorm van de woning en type woning zijn, relatief gezien, belangrijker. Het is aan te bevelen de, mede op basis van de variatie in de relatie tussen hinder en woontevredenheid de TLO-data uit te breiden met (vergelijkbare) blootstellingsgegevens
Exposure-response relationship for noise annoyance and sleep disturbance. An analysis of national data
Blootstelling-responsrelaties voor verkeersgeluid en hinder lijken schaalspecifiek te zijn: relaties opgesteld op internationaal niveau wijken soms af van relaties op nationaal niveau die op hun buurt weer afwijken van relaties op regionaal niveau. Voor beleid betekent dit dat bij toepassing van (inter-)nationale blootstelling-responsrelaties op lokale situaties terdege rekening dient te worden gehouden met de beperkingen en 'vertaalbaarheid' van de relatie naar de lokale situatie. Daarnaast blijkt dat ondanks het gebruik van standaardvragen voor hinder en slaapverstoring, vastgelegd in een ISO-norm, de wijze van operationaliseren van hinder en slaapverstoring van invloed is op de blootstelling-responsrelatie. Dit zijn de belangrijkste bevindingen uit een onderzoek naar de relatie tussen geluid van wegverkeer en hinder en slaapverstoring op basis van gegevens uit het EMPARA-geluidsmodel en de Hinderinventarisatie 2003. In Nederland en binnen de Europese Unie is de verstoring van de leefomgeving door geluid een belangrijk aandachtspunt van beleid, omdat blootstelling aan hoge geluidsniveaus kan leiden tot negatieve effecten op welbevinden en gezondheid, waaronder hinder en slaapverstoring. In het rapport is onderzocht of het mogelijk is om met bestaande Nederlandse onderzoeksgegevens relaties vast te stellen tussen blootstelling aan verkeersgeluid en het optreden van hinder en slaapverstoring. De resultaten zijn vergeleken met de voorstellen voor relaties die in Europees verband zijn gedaan en de uitkomsten van de Gezondheidskundige Evaluatie Schiphol. Hierbij traden belangrijke verschillen aan het licht. Een belangrijke kanttekening bij de resultaten is dat slechts een beperkt aantal deelnemers aan het onderzoek is blootgesteld aan hogere geluidbelastingniveaus waardoor de betrouwbaarheidsintervallen voor hoge blootstellingen groot zijn. Dit is het gevolg van de scheve (min of meer log-normale) verdeling van geluidblootstelling in de Nederlandse bevolking.Exposure-response relations for traffic sound and annoyance appear to be scale-specific: relationships established at international levels sometimes deviate from national relationships; in turn these relations can deviate from regional ones. For policy, this means that due consideration should be given to the limitations and transferability of (inter-) national exposure-response relationships used in local situations. The definition and operationalisation of the terms 'annoyance' and 'sleep disturbance' can have a profound impact on the results. Although survey questions on annoyance conform to the ISO standard, the different interpretations of annoyance found in the literature can result in differences between exposure-response relationships. These are the main findings from a study investigating the relation between traffic sound and annoyance and sleep disturbance on the basis of the EMPARA noise model and a periodic national Annoyance survey (2003). Disturbance of the living environment through noise exposure is of concern, both in the Netherlands and the European Union. Exposure to high levels of noise can have adverse effects (annoyance and sleep disturbance) on health and well-being. The study described used existing Dutch data for determining the relationship between exposure to transport noise, and annoyance and sleep disturbance. The results from the Annoyance survey and EMPARA were compared with the proposals of the EU Noise Expert Network and the outcome of the monitoring programme, Health Impact Assessment - Schiphol Airport. The comparison revealed significant differences. In the Annoyance survey only few respondents experienced relatively high exposure levels. This resulted in large confidence intervals at high exposures.MN
Microbial growth response to substrate complexity under different temperature regimes
Soil microbial communities mediate soil feedbacks to climate change and a thorough understanding of their response to increasing temperatures is central for predicting climate-induced changes in carbon fluxes. However, it is still unclear how microbial communities will change their structure and functions in response to temperature change and availability of organic carbon of varying complexity. Here, we present results from a lab-based study where soil microbial communities were exposed to different temperatures and organic C of different stability. Soil samples were collected from vegetated and bare fallow plots located in two regions in southwest Germany varying in climatic and edaphic conditions. Soils amended with cellobiose (CB), xylan or coniferyl alcohol (CA, lignin precursor) were incubated at 5, 15 and 25 °C. We generally found highest cumulative respiration (CO2-C) at 25 °C in all substrate treatments even though total microbial growth (measured as total extracted DNA) was higher at 15 °C. Fungal biomass (measured from ergosterol content and fungal PLFAs) responded significantly to added substrate and incubation temperature, with higher fungal biomass at 5 or 15 °C than 25 °C in all substrate amendments. Xylan addition resulted in significantly higher ergosterol contents than for CB and CA. Within region, land-use significantly affected fungal biomass response to added substrate; however, the temperature response was similar between fallow and vegetated plots. Bacterial community response was also significantly affected by substrate quality. In contrast to fungi, the growth response of Gram+ and Gram- bacteria declined in the order CB > xylan > CA. Currently, we are analyzing the qPCR data understand the response of different bacterial taxa to temperature and substrate complexity. Our results demonstrate the importance of the interaction between soil temperature and substrate quality for soil microbial community functions and growth strategies
A Survey of Health Management User Objectives Related to Diagnostic and Prognostic Metrics
One of the most prominent technical challenges to effective deployment of health management systems is the vast difference in user objectives with respect to engineering development. In this paper, a detailed survey on the objectives of different users of health management systems is presented. These user objectives are then mapped to the metrics typically encountered in the development and testing of two main systems health management functions: diagnosis and prognosis. Using this mapping, the gaps between user goals and the metrics associated with diagnostics and prognostics are identified and presented with a collection of lessons learned from previous studies that include both industrial and military aerospace applications
Interaction and observation: categorical semantics of reactive systems trough dialgebras
We use dialgebras, generalising both algebras and coalgebras, as a complement
of the standard coalgebraic framework, aimed at describing the semantics of an
interactive system by the means of reaction rules. In this model, interaction
is built-in, and semantic equivalence arises from it, instead of being
determined by a (possibly difficult) understanding of the side effects of a
component in isolation. Behavioural equivalence in dialgebras is determined by
how a given process interacts with the others, and the obtained observations.
We develop a technique to inter-define categories of dialgebras of different
functors, that in particular permits us to compare a standard coalgebraic
semantics and its dialgebraic counterpart. We exemplify the framework using the
CCS and the pi-calculus. Remarkably, the dialgebra giving semantics to the
pi-calculus does not require the use of presheaf categories
Ecological factors controlling biodiversity in the British countryside (ECOFACT). Module 6 - The causes of change in biodiversity. Interim report
Evaluation of coagulation activation after Rhinovirus infection in patients with asthma and healthy control subjects: an observational study
Background Asthma exacerbations are frequently triggered by rhinovirus infections. Both asthma and respiratory tract infection can activate haemostasis. Therefore we hypothesized that experimental rhinovirus-16 infection and asthmatic airway inflammation act in synergy on the haemostatic balance. Methods 28 patients (14 patients with mild allergic asthma and 14 healthy non-allergic controls) were infected with low-dose rhinovirus type 16. Venous plasma and bronchoalveolar lavage fluid (BAL fluid) were obtained before and 6 days after infection to evaluate markers of coagulation activation, thrombin-antithrombin complexes, von Willebrand factor, plasmin-antiplasmin complexes, plasminogen activator inhibitor type-1, endogenous thrombin potential and tissue factor-exposing microparticles by fibrin generation test, in plasma and/or BAL fluid. Data were analysed by nonparametric tests (Wilcoxon, Mann Whitney and Spearman correlation). Results 13 patients with mild asthma (6 females, 19-29 y) and 11 healthy controls (10 females, 19-31 y) had a documented Rhinovirus-16 infection. Rhinovirus-16 challenge resulted in a shortening of the fibrin generation test in BAL fluid of asthma patients (t = -1: 706 s vs. t = 6: 498 s; p = 0.02), but not of controls (t = -1: 693 s vs. t = 6: 636 s; p = 0.65). The fold change in tissue factor-exposing microparticles in BAL fluid inversely correlated with the fold changes in eosinophil cationic protein and myeloperoxidase in BAL fluid after virus infection (r = -0.517 and -0.528 resp., both p = 0.01). Rhinovirus-16 challenge led to increased plasminogen activator inhibitor type-1 levels in plasma in patients with asthma (26.0 ng/mL vs. 11.5 ng/mL in healthy controls, p = 0.04). Rhinovirus-16 load in BAL showed a linear correlation with the fold change in endogenous thrombin potential, plasmin-antiplasmin complexes and plasminogen activator inhibitor type-1. Conclusions Experimental rhinovirus infection induces procoagulant changes in the airways of patients with asthma through increased activity of tissue factor-exposing microparticles. These microparticle-associated procoagulant changes are associated with both neutrophilic and eosinophilic inflammation. Systemic activation of haemostasis increases with Rhinoviral load
A mechanosensory receptor required for food texture detection in Drosophila.
Textural properties provide information on the ingestibility, digestibility and state of ripeness or decay of sources of nutrition. Compared with our understanding of the chemosensory assessment of food, little is known about the mechanisms of texture detection. Here we show that Drosophila melanogaster can discriminate food texture, avoiding substrates that are either too hard or too soft. Manipulations of food substrate properties and flies' chemosensory inputs indicate that texture preferences are revealed only in the presence of an appetitive stimulus, but are not because of changes in nutrient accessibility, suggesting that animals discriminate the substrates' mechanical characteristics. We show that texture preference requires NOMPC, a TRP-family mechanosensory channel. NOMPC localizes to the sensory dendrites of neurons housed within gustatory sensilla, and is essential for their mechanosensory-evoked responses. Our results identify a sensory pathway for texture detection and reveal the behavioural integration of chemical and physical qualities of food
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