639 research outputs found

    Examining the impact of heterogeneous nitryl chloride production on air quality across the United States

    Get PDF
    The heterogeneous hydrolysis of dinitrogen pentoxide (N<sub>2</sub>O<sub>5</sub>) has typically been modeled as only producing nitric acid. However, recent field studies have confirmed that the presence of particulate chloride alters the reaction product to produce nitryl chloride (ClNO<sub>2</sub>) which undergoes photolysis to generate chlorine atoms and nitrogen dioxide (NO<sub>2</sub>). Both chlorine and NO<sub>2</sub> affect atmospheric chemistry and air quality. We present an updated gas-phase chlorine mechanism that can be combined with the Carbon Bond 05 mechanism and incorporate the combined mechanism into the Community Multiscale Air Quality (CMAQ) modeling system. We then update the current model treatment of heterogeneous hydrolysis of N<sub>2</sub>O<sub>5</sub> to include ClNO<sub>2</sub> as a product. The model, in combination with a comprehensive inventory of chlorine compounds, reactive nitrogen, particulate matter, and organic compounds, is used to evaluate the impact of the heterogeneous ClNO<sub>2</sub> production on air quality across the United States for the months of February and September in 2006. The heterogeneous production increases ClNO<sub>2</sub> in coastal as well as many in-land areas in the United States. Particulate chloride derived from sea-salts, anthropogenic sources, and forest fires activates the heterogeneous production of ClNO<sub>2</sub>. With current estimates of tropospheric emissions, it modestly enhances monthly mean 8-h ozone (up to 1–2 ppbv or 3–4%) but causes large increases (up to 13 ppbv) in isolated episodes. This chemistry also substantially reduces the mean total nitrate by up to 0.8–2.0 μg m<sup>−3</sup> or 11–21%. Modeled ClNO<sub>2</sub> accounts for up to 6% of the monthly mean total reactive nitrogen. Sensitivity results of the model suggest that heterogeneous production of ClNO<sub>2</sub> can further increase O<sub>3</sub> and reduce TNO<sub>3</sub> if elevated particulate-chloride levels are present in the atmosphere

    UK parents' attitudes towards meningococcal group B (MenB) vaccination: a qualitative analysis

    Get PDF
    OBJECTIVES: (1) To explore existing knowledge of, and attitudes, to group B meningococcal disease and serogroup B meningococcal (MenB) vaccine among parents of young children. (2) To seek views on their information needs. DESIGN: Cross-sectional qualitative study using individual and group interviews conducted in February and March 2015, prior to the introduction of MenB vaccine (Bexsero) into the UK childhood immunisation schedule. SETTING: Community centres, mother and toddler groups, parents’ homes and workplaces in London and Yorkshire. PARTICIPANTS: 60 parents of children under 2 years of age recruited via mother and baby groups and via an advert posted to a midwife-led Facebook group. RESULTS: Although recognising the severity of meningitis and septicaemia, parents’ knowledge of group B meningococcal disease and MenB vaccine was poor. While nervous about fever, most said they would take their child for MenB vaccination despite its link to fever. Most parents had liquid paracetamol at home. Many were willing to administer it after MenB vaccination as a preventive measure, although some had concerns. There were mixed views on the acceptability of four vaccinations at the 12-month booster visit; some preferred one visit, while others favoured spreading the vaccines over two visits. Parents were clear on the information they required before attending the immunisation appointment. CONCLUSIONS: The successful implementation of the MenB vaccination programme depends on its acceptance by parents. In view of parents’ recognition of the severity of meningitis and septicaemia, and successful introduction of other vaccines to prevent bacterial meningitis and septicaemia, the MenB vaccination programme is likely to be successful. However, the need for additional injections, the likelihood of post-immunisation fever and its management are issues about which parents will need information and reassurance from healthcare professionals. Public Health England has developed written information for parents, informed by these findings

    Desulfovibrio idahonensis sp. nov., sulfatereducing bacteria isolated from a metal(loid)-contaminated freshwater sediment

    Get PDF
    Two novel sulfate-reducing bacteria, strains CY1 and CY2, were isolated from heavy-metal-contaminated sediments of Lake Coeur d\u27Alene, Idaho, USA. Strains CY1 and CY2 were found to contain c-type cytochromes and to reduce sulfate, sulfite, thiosulfate, elemental sulfur, DMSO, anthraquinone disulfonate and fumarate using lactate as an electron donor. In a comparison of 16S rRNA gene sequences, CY1 and CY2 were found to be 100% identical, but only 97 and 92.4% similar, respectively, to the type strains of Desulfovibrio mexicanus and Desulfovibrio aminophilus. Unlike these species, however, CY1 was neither able to disproportionate thiosulfate nor able to use yeast extract or amino acids as electron donors. These data, considered in conjunction with differences among strain CY1 and the two related type strains in chemotaxonomy, riboprint patterns, temperature and pH optima, support recognition of a distinct and novel species within the genus Desulfovibrio, Desulfovibrio idahonensis sp. nov., with the type strain CY1 (=DSM 15450 =JCM 14124 ). © 2009 IUMS. T T T T T T T

    Membrane type-1 matrix metalloproteinase activity is regulated by the endocytic collagen receptor Endo180.

    Get PDF
    The molecular interactions leading to organised, controlled extracellular matrix degradation are of central importance during growth, development and tissue repair, and when deregulated contribute to disease processes including cancer cell invasion. There are two major pathways for collagen degradation: one dependent on secreted and membrane-bound collagenases, the other on receptor-mediated collagen internalisation and intracellular processing. Despite the established importance of both pathways, the functional interaction between them is largely unknown. We demonstrate here, that the collagen internalisation receptor Endo180 (also known as CD280, uPARAP, MRC2) is a novel regulator of membrane-bound matrix metalloproteinase (MT1-MMP) activity, MT1-MMP-dependent MMP-2 activation and urokinase plasminogen activator (uPA) activity. We show close correlation between Endo180 expression, collagen accumulation and regulation of MT1-MMP cell-surface localisation and activity. We directly demonstrate, using collagen inhibition studies and non-collagen-binding mutants of Endo180, that the molecular mechanism underlying this regulation is the ability of Endo180 to bind and/or internalise collagens, rather than by acting as an interaction partner for pro-uPA and its receptor uPAR. These studies strongly support a functional interaction between two distinct collagen degradation pathways, define a novel mechanism regulating MT1-MMP activity and might have important implications for organised collagen clearance in the pericellular environment

    Teenagers’ understandings of and attitudes towards vaccines and vaccine-preventable diseases: a qualitative study

    Get PDF
    &lt;p&gt;Background: To examine immunisation information needs of teenagers we explored understandings of vaccination and vaccine-preventable diseases, attitudes towards immunisation and experiences of immunisation. Diseases discussed included nine for which vaccines are currently offered in the UK (human papillomavirus, meningitis, tetanus, diphtheria, polio, whooping cough, measles, mumps and rubella), and two not currently included in the routine UK schedule (hepatitis B and chickenpox).&lt;/p&gt; &lt;p&gt;Methods Twelve focus groups conducted between November 2010 and March 2011 with 59 teenagers (29 girls and 30 boys) living in various parts of Scotland.&lt;/p&gt; &lt;p&gt;Results Teenagers exhibited limited knowledge and experience of the diseases, excluding chickenpox. Measles, mumps and rubella were perceived as severe forms of chickenpox-like illness, and rubella was not associated with foetal damage. Boys commonly believed that human papillomavirus only affects girls, and both genders exhibited confusion about its relationship with cancer. Participants considered two key factors when assessing the threat of diseases: their prevalence in the UK, and their potential to cause fatal or long-term harm. Meningitis was seen as a threat, but primarily to babies. Participants explained their limited knowledge as a result of mass immunisation making once-common diseases rare in the UK, and acknowledged immunisation's role in reducing disease prevalence.&lt;/p&gt; &lt;p&gt;Conclusions While it is welcome that fewer teenagers have experienced vaccine-preventable diseases, this presents public health advocates with the challenge of communicating benefits of immunisation when advantages are less visible. The findings are timely in view of the Joint Committee on Vaccination and Immunisation's recommendation that a booster of meningitis C vaccine should be offered to teenagers; that teenagers did not perceive meningitis C as a significant threat should be a key concern of promotional information. While teenagers’ experiences of immunisation in school were not always positive, they seemed enthusiastic at the prospect of introducing more vaccines for their age group.&lt;/p&gt

    The Lore of Low Methane Livestock:Co-Producing Technology and Animals for Reduced Climate Change Impact

    Get PDF
    Methane emissions from sheep and cattle production have gained increasing profile in the context of climate change. Policy and scientific research communities have suggested a number of technological approaches to mitigate these emissions. This paper uses the concept of co-production as an analytical framework to understand farmers’ evaluation of a 'good animal’. It examines how technology and sheep and beef cattle are co-produced in the context of concerns about the climate change impact of methane. Drawing on 42 semi-structured interviews, this paper demonstrates that methane emissions are viewed as a natural and integral part of sheep and beef cattle by farmers, rather than as a pollutant. Sheep and beef cattle farmers in the UK are found to be an extremely heterogeneous group that need to be understood in their specific social, environmental and consumer contexts. Some are more amenable to appropriating methane reducing measures than others, but largely because animals are already co-constructed from the natural and the technical for reasons of increased production efficiency

    Research on the Geography of Agricultural Change: Redundant or Revitalized?

    Get PDF
    Future research directions for agricultural geography were the subject of debate in Area in the late 1980s. The subsequent application of political economy ideas undoubtedly revived interest in agricultural research. This paper argues that agricultural geography contains greater diversity than the dominant political economy discourse would suggest. It reviews ‘other’ areas of agricultural research on policy, post-productivism, people, culture and animals, presenting future suggestions for research. They should ensure that agricultural research continues revitalized rather than redundant into the next millennium

    Identification of a Novel, Small Molecule Partial Agonist for the Cyclic AMP Sensor, EPAC1

    Get PDF
    Screening of a carefully selected library of 5,195 small molecules identified 34 hit compounds that interact with the regulatory cyclic nucleotide-binding domain (CNB) of the cAMP sensor, EPAC1. Two of these hits (I942 and I178) were selected for their robust and reproducible inhibitory effects within the primary screening assay. Follow-up characterisation by ligand observed nuclear magnetic resonance (NMR) revealed direct interaction of I942 and I178 with EPAC1 and EPAC2-CNBs in vitro. Moreover, in vitro guanine nucleotide exchange factor (GEF) assays revealed that I942 and, to a lesser extent, I178 had partial agonist properties towards EPAC1, leading to activation of EPAC1, in the absence of cAMP, and inhibition of GEF activity in the presence of cAMP. In contrast, there was very little agonist action of I942 towards EPAC2 or protein kinase A (PKA). To our knowledge, this is the first observation of non-cyclic-nucleotide small molecules with agonist properties towards EPAC1. Furthermore, the isoform selective agonist nature of these compounds highlights the potential for the development of small molecule tools that selectively up-regulate EPAC1 activity

    Contributions of domestic sources to PM2.5 in South Korea

    Get PDF
    We use the CAMx (Comprehensive Air Quality Model with Extensions) chemical transport model (CTM) with 4-km horizontal resolution over the Korean Peninsula to investigate source contributions to PM2.5 in Korea from domestic and upwind sources. We modeled 2015 and 2016 to account for meteorological variation with Korean emissions from the Clean Air Policy Supporting System (CAPSS), meteorology from WRF (Weather, Research, and Forecasting) model, and regional boundary concentrations from the GEOS-Chem global CTM. The CAMx particulate source apportionment technology (PSAT) provided PM2.5 source contributions from 5 source sectors and 6 geographic regions within Korea, international sources, and boundary concentrations. PM2.5 contributions from outside Korea are important with boundary concentrations plus the “other” emissions sector (includes marine shipping, agricultural ammonia, and international emissions from North Korea and Japan within the CAMx domain) contributing 67% of annual average PM2.5 in Seoul in 2016 and 71% in 2015. The boundary concentrations contributed between 30% and 50% of PM2.5 at different Korean cities with contributions generally lower in 2016 than in 2015. For Korean sources, PM2.5 contributions from Electric Generating Unit (EGU) emissions were smaller than contributions from mobile and industrial emissions sources although there is considerable day-to-day variation in contributions. On an annual basis in 2016, the “other” category contributed 25% followed by mobile sources at 23%, industrial sources at 6%, and EGU sources at 3%. For 2015, the contributions were similar. Focusing on March when PM2.5 concentrations were higher than other months, the contributions from other, mobile, industrial, and EGUs were 21%, 18%, 4%, and 4%, respectively in 2016. For 2015, contributions from these four categories were 18%, 15%, 3%, and 3%, respectively
    corecore