473 research outputs found

    Risk assessment of adding Gasodor S-Free to natural gas

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    Om te herkennen wanneer te veel aardgas vrijkomt, en zo explosies te voorkomen, wordt er een geurstof aan toegevoegd. De huidige geurstof (tetrahydrothiofeen) bevat zwavel. Om de uitstoot van zwavel naar het milieu verder te verminderen onderzoekt Gasunie Transport Services de mogelijkheid om een andere, zwavelvrije geurstof, toe te voegen: Gasodor S-Free. Vanwege het omvangrijke gebruik van aardgas is het van belang voldoende zicht te hebben op mogelijke risico's van dit product. Het RIVM heeft onvoldoende informatie kunnen vinden om vast te stellen of het gebruik van Gasodor S-Free als geurstof in aardgas veilig is. De zorg bestaat dat dit product allergische reacties kan veroorzaken als het wordt ingeademd. Het gebruik van Gasodor S-Free wordt afgeraden totdat meer duidelijk is over het mogelijke risico op allergische reacties. Het RIVM geeft aanbevelingen voor vervolgonderzoek om het risico op deze reacties beter te kunnen beoordelen. Gasodor S-Free is een mengsel van drie stoffen, voornamelijk ethylacrylaat en methylacrylaat (samen 95 procent of meer), en een kleine fractie 2-ethyl-3-methylpyrazine. Mogelijke gevolgen van de twee hoofdbestanddelen zijn op basis van de huidige kennis niet goed te beoordelen. Bekend is dat ethylacrylaat en methylacrylaat de luchtwegen kunnen irriteren, maar door de lage concentraties worden geen normen overschreden. Ook zijn ze niet kankerverwekkend. Het is bekend dat beide stoffen allergische reacties kunnen veroorzaken bij huidcontact. Vergelijkbare effecten zouden ook kunnen optreden als de stof wordt ingeademd, maar dit kan op basis van de beschikbare informatie niet worden beoordeeld. Over nadelige effecten van de derde stof (2-ethyl-3-methylpyrazine) is onvoldoende informatie beschikbaar om een uitspraak te kunnen doen over mogelijke effecten op mens en milieu.As natural gas is odourless, an odorant is added to detect the release of gas and prevent explosions. The odorant (tetrahydrothiophene) that is currently used contains sulphur. So as not to add to current levels of sulphur in the environment, Gasunie Transport Services has investigated the possibility of adding another sulphur-free fragrance: Gasodor S-Free. Because of the extensive use of natural gas, it is important that the potential risks of this product are thoroughly evaluated. RIVM has not been able to find sufficient information to determine whether the use of Gasodor S-Free as an odorant in natural gas is safe. There is a concern that this product can cause allergic reactions if inhaled. Any application of Gasodor S-Free, therefore, should be discouraged until the possible risk of allergic reactions has been clarified. RIVM provides recommendations about which investigations could be conducted to assess the risk of these reactions more comprehensively. Gasodor S-Free is a mixture of three substances, mainly ethyl acrylate and methyl acrylate (together 95 percent or more), and a small percent of 2-ethyl-3-methylpyrazine. The possible consequences of the two main components cannot be judged properly based on current knowledge. Ethyl acrylate and methyl acrylate are known to irritate the respiratory tract, but the low concentrations in intended use of Gasodor S-Free do not exceed standards. Nor are they carcinogenic. However, it is known that both substances can cause allergic contact dermatitis. Allergic effects could also occur if the substance is inhaled, but this cannot be evaluated based on the available information. There is also insufficient information available on the adverse effects of the third substance (2-ethyl-3-methylpyrazine) for an assessment of the possible effects on humans and the environment to be madeSod

    Search for rare quark-annihilation decays, B --> Ds(*) Phi

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    We report on searches for B- --> Ds- Phi and B- --> Ds*- Phi. In the context of the Standard Model, these decays are expected to be highly suppressed since they proceed through annihilation of the b and u-bar quarks in the B- meson. Our results are based on 234 million Upsilon(4S) --> B Bbar decays collected with the BABAR detector at SLAC. We find no evidence for these decays, and we set Bayesian 90% confidence level upper limits on the branching fractions BF(B- --> Ds- Phi) Ds*- Phi)<1.2x10^(-5). These results are consistent with Standard Model expectations.Comment: 8 pages, 3 postscript figues, submitted to Phys. Rev. D (Rapid Communications

    Health care and societal costs of the management of children and adolescents with attention-deficit/hyperactivity disorder in Spain: a descriptive analysis.

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    Background: Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental condition in childhood (5.3% to 7.1% worldwide prevalence), with substantial overall financial burden to children/adolescents, their families, and society. The aims of this study were to describe the clinical characteristics of children and adolescents with ADHD in Spain, estimate the associated direct/indirect costs of the disorder, and assess whether the characteristics and financial costs differed between children/adolescents adequately responding to currently available pharmacotherapies compared with children/adolescents for whom pharmacotherapies failed. Methods: This was a multicenter, cross-sectional, descriptive analysis conducted in 15 health units representative of the overall Spanish population. Data on demographic characteristics, socio-occupational status, social relationships, clinical variables of the disease, and pharmacological and non-pharmacological treatments received were collected in 321 children and adolescents with ADHD. Direct and indirect costs were estimated over one year from both a health care system and a societal perspective. Results: The estimated average cost of ADHD per year per child/adolescent was ΒΏ5733 in 2012 prices; direct costs accounted for 60.2% of the total costs (ΒΏ3450). Support from a psychologist/educational psychologist represented 45.2% of direct costs and 27.2% of total costs. Pharmacotherapy accounted for 25.8% of direct costs and 15.5% of total costs. Among indirect costs (ΒΏ2283), 65.2% was due to caregiver expenses. The total annual costs were significantly higher for children/adolescents who responded poorly to pharmacological treatment (ΒΏ7654 versus ΒΏ5517; P = 0.024), the difference being mainly due to significantly higher direct costs, particularly with larger expenses for non-pharmacological treatment (P = 0.012). Conclusions: ADHD has a significant personal, familial, and financial impact on the Spanish health system and society. Successful pharmacological intervention was associated with lower overall expenses in the management of the disorder

    State-of-the-art management of locally advanced head and neck cancer

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    During the past 20 years, treatments for head and neck squamous cell carcinoma (HNSCC) have changed dramatically owing largely to the advent of novel approaches such as combined modality therapy as well as improvements in surgical and radiotherapeutic techniques. Locally advanced disease in particular, which engendered very high recurrence and mortality rates, is now associated with long-term disease-free survival in the majority of cases. This article will focus on locally advanced HNSCC, which frequently remains a clinical challenge, review state-of-the-art therapy, and introduce promising novel therapies. The field continues to evolve rapidly with new evidence during the past year clearly establishing the benefit of adjuvant chemoradiotherapy (CRT), as well as early evidence showing improved survival with the use of an epidermal growth factor receptor inhibitor in combination with radiotherapy. There are varied regimens in use for patients with locally advanced disease, but at the same time the multitude of options can plague the clinician when trying to select the most appropriate one. This article will attempt to put the various approaches into perspective and propose an evidence-based treatment algorithm

    Increasing vegetable intakes: rationale and systematic review of published interventions

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    Purpose While the health benefits of a high fruit and vegetable consumption are well known and considerable work has attempted to improve intakes, increasing evidence also recognises a distinction between fruit and vegetables, both in their impacts on health and in consumption patterns. Increasing work suggests health benefits from a high consumption specifically of vegetables, yet intakes remain low, and barriers to increasing intakes are prevalent making intervention difficult. A systematic review was undertaken to identify from the published literature all studies reporting an intervention to increase intakes of vegetables as a distinct food group. Methods Databasesβ€”PubMed, PsychInfo and Medlineβ€”were searched over all years of records until April 2015 using pre-specified terms. Results Our searches identified 77 studies, detailing 140 interventions, of which 133 (81 %) interventions were conducted in children. Interventions aimed to use or change hedonic factors, such as taste, liking and familiarity (n = 72), use or change environmental factors (n = 39), use or change cognitive factors (n = 19), or a combination of strategies (n = 10). Increased vegetable acceptance, selection and/or consumption were reported to some degree in 116 (83 %) interventions, but the majority of effects seem small and inconsistent. Conclusions Greater percent success is currently found from environmental, educational and multi-component interventions, but publication bias is likely, and long-term effects and cost-effectiveness are rarely considered. A focus on long-term benefits and sustained behaviour change is required. Certain population groups are also noticeably absent from the current list of tried interventions

    Elevated Levels of the Polo Kinase Cdc5 Override the Mec1/ATR Checkpoint in Budding Yeast by Acting at Different Steps of the Signaling Pathway

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    Checkpoints are surveillance mechanisms that constitute a barrier to oncogenesis by preserving genome integrity. Loss of checkpoint function is an early event in tumorigenesis. Polo kinases (Plks) are fundamental regulators of cell cycle progression in all eukaryotes and are frequently overexpressed in tumors. Through their polo box domain, Plks target multiple substrates previously phosphorylated by CDKs and MAPKs. In response to DNA damage, Plks are temporally inhibited in order to maintain the checkpoint-dependent cell cycle block while their activity is required to silence the checkpoint response and resume cell cycle progression. Here, we report that, in budding yeast, overproduction of the Cdc5 polo kinase overrides the checkpoint signaling induced by double strand DNA breaks (DSBs), preventing the phosphorylation of several Mec1/ATR targets, including Ddc2/ATRIP, the checkpoint mediator Rad9, and the transducer kinase Rad53/CHK2. We also show that high levels of Cdc5 slow down DSB processing in a Rad9-dependent manner, but do not prevent the binding of checkpoint factors to a single DSB. Finally, we provide evidence that Sae2, the functional ortholog of human CtIP, which regulates DSB processing and inhibits checkpoint signaling, is regulated by Cdc5. We propose that Cdc5 interferes with the checkpoint response to DSBs acting at multiple levels in the signal transduction pathway and at an early step required to resect DSB ends

    Stretching Actin Filaments within Cells Enhances their Affinity for the Myosin II Motor Domain

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    To test the hypothesis that the myosin II motor domain (S1) preferentially binds to specific subsets of actin filaments in vivo, we expressed GFP-fused S1 with mutations that enhanced its affinity for actin in Dictyostelium cells. Consistent with the hypothesis, the GFP-S1 mutants were localized along specific portions of the cell cortex. Comparison with rhodamine-phalloidin staining in fixed cells demonstrated that the GFP-S1 probes preferentially bound to actin filaments in the rear cortex and cleavage furrows, where actin filaments are stretched by interaction with endogenous myosin II filaments. The GFP-S1 probes were similarly enriched in the cortex stretched passively by traction forces in the absence of myosin II or by external forces using a microcapillary. The preferential binding of GFP-S1 mutants to stretched actin filaments did not depend on cortexillin I or PTEN, two proteins previously implicated in the recruitment of myosin II filaments to stretched cortex. These results suggested that it is the stretching of the actin filaments itself that increases their affinity for the myosin II motor domain. In contrast, the GFP-fused myosin I motor domain did not localize to stretched actin filaments, which suggests different preferences of the motor domains for different structures of actin filaments play a role in distinct intracellular localizations of myosin I and II. We propose a scheme in which the stretching of actin filaments, the preferential binding of myosin II filaments to stretched actin filaments, and myosin II-dependent contraction form a positive feedback loop that contributes to the stabilization of cell polarity and to the responsiveness of the cells to external mechanical stimuli

    Functional Analysis of Host Factors that Mediate the Intracellular Lifestyle of Cryptococcus neoformans

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    Cryptococcus neoformans (Cn), the major causative agent of human fungal meningoencephalitis, replicates within phagolysosomes of infected host cells. Despite more than a half-century of investigation into host-Cn interactions, host factors that mediate infection by this fungal pathogen remain obscure. Here, we describe the development of a system that employs Drosophila S2 cells and RNA interference (RNAi) to define and characterize Cn host factors. The system recapitulated salient aspects of fungal interactions with mammalian cells, including phagocytosis, intracellular trafficking, replication, cell-to-cell spread and escape of the pathogen from host cells. Fifty-seven evolutionarily conserved host factors were identified using this system, including 29 factors that had not been previously implicated in mediating fungal pathogenesis. Subsequent analysis indicated that Cn exploits host actin cytoskeletal elements, cell surface signaling molecules, and vesicle-mediated transport proteins to establish a replicative niche. Several host molecules known to be associated with autophagy (Atg), including Atg2, Atg5, Atg9 and Pi3K59F (a class III PI3-kinase) were also uncovered in our screen. Small interfering RNA (siRNA) mediated depletion of these autophagy proteins in murine RAW264.7 macrophages demonstrated their requirement during Cn infection, thereby validating findings obtained using the Drosophila S2 cell system. Immunofluorescence confocal microscopy analyses demonstrated that Atg5, LC3, Atg9a were recruited to the vicinity of Cn containing vacuoles (CnCvs) in the early stages of Cn infection. Pharmacological inhibition of autophagy and/or PI3-kinase activity further demonstrated a requirement for autophagy associated host proteins in supporting infection of mammalian cells by Cn. Finally, systematic trafficking studies indicated that CnCVs associated with Atg proteins, including Atg5, Atg9a and LC3, during trafficking to a terminal intracellular compartment that was decorated with the lysosomal markers LAMP-1 and cathepsin D. Our findings validate the utility of the Drosophila S2 cell system as a functional genomic platform for identifying and characterizing host factors that mediate fungal intracellular replication. Our results also support a model in which host Atg proteins mediate Cn intracellular trafficking and replication
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