1,759 research outputs found

    Risk of low birth weight near EUROHAZCON hazardous waste landfill sites in England.

    No full text
    Few studies have investigated the occurrence of both low birth weight (LBW) and congenital anomalies in populations living near hazardous waste landfill sites. The authors investigated the risk of LBW near 10 English hazardous waste landfill sites included in a previous European study, which reported an increased risk of congenital anomalies. Odds ratios, adjusted for sex, deprivation, year of birth, and study area (pooled ORs), were estimated for LBW (< 2500 gm) within 0-3 km compared with 3-7 km zones around the landfill sites. The authors found a small and not statistically significant increase in risk of LBW (OR = 1.03, 95% confidence interval = 0.98-1.08) within 3 km of hazardous waste landfill sites. Their findings suggest that previously reported results for congenital anomalies should not be extrapolated to a wider range of pregnancy outcomes but should be evaluated separately for each

    Stabilisering av biogasprocessen vid höga ammoniaknivÄer : effekten av acetatpulsning pÄ den mikrobiella populationen

    Get PDF
    This study investigated the problem of ammonia inhibition in biogas reactors, commonly occurring when protein rich substrates are used in anaerobic digestion processes. Ammonia inhibition is one of the foremost causes of failure in anaerobic digestion, leading to process instability, with symptoms commonly expressed as; reduction in biogas produced, decreased methane content in the gas and accumulation of volatile fatty acids. Increasing ammonia concentrations lead to a shift in the dominant pathways for methane production, from acetoclastic methanogens to syntrophic acetate-oxidizing bacteria, working with hydrogenotrophic methanogens. This shift occurs as the acetoclastic methanogens are sensitive to increasing ammonia concentrations. Both pathways utilize acetate, which apart from ammonia, is one of the factors that also is believed to regulate the level of the different pathways. The aim of this study was to evaluate the impact of subjecting anaerobic digestion processes in biogas reactors to increasing levels of ammonia and to study the performance of the reactors as well as the potential microbial changes that occur when reactors are supplemented with acetate simultaneous with the ammonia increases. The total ammonium-nitrogen was successfully increased in the reactors to concentrations known to cause ammonia inhibition towards the end of one hydraulic retention time. The increase in total ammonium-nitrogen correlated with increased H2S concentrations in the reactors and an accumulation of volatile fatty acids. Acetate addition resulted in higher acetate concentration in the reactors, but without accumulation. The acetate addition possibly caused an increase in the gene abundance of hydrogenotrophic methanogenic order Methanomicrobiales and the genus Methanoculleus. No significant change in gene abundance of acetoclastic methanogens or syntrophic acetate-oxidising bacteria occurred in response to the increase in ammonia and acetate in this study. The lack of microbial compositional changes could have been due time of the study, being too short for changes in the microbial composition to happen. Moreover, the acetate-enrichment was possibly too low to stimulate growth of syntrophic acetate-oxidising bacteria when compared to concentrations in other studies.Biogas bestÄr till största delen av metan, men ocksÄ av koldioxid, och mindre nivÄer av svavelvÀte och andra gaser. Biogas kan framstÀllas frÄn en mÀngd olika Àmnen sÄsom hushÄllsavfall, slaktavfall och rester frÄn t.ex. livsmedelsindustrin. Biogasprocessen Àr attraktiv dÄ den medger möjligheten att framstÀlla förnybar energi frÄn mÄnga olika avfallsmaterial och Àr anvÀndbar som ett alternativ till fossila brÀnslen. Biogas kan anvÀndas för elproduktion, uppvÀrmning eller matlagning i stÀder eller uppgraderas för att ta bort andra gaser Àn metan och dÀrefter anvÀndas som fordonsbrÀnsle av bilar och bussar. FrÄn resterna av biogasprocessen bildas det Àven en nÀringsrik nedbrytningsrest (rötrest) som kan anvÀndas inom jordbruket som gödningsmedel. Bildning av biogas frÄn olika material sker i en rötningsprocess som Àr anaerob (fri frÄn syre till största grad). Det kan dÄ uppstÄ vissa problem om man anvÀnder proteinrikt material i sin process, som i övrigt Àr eftertraktade pÄ grund av sin höga metanpotential. Under nedbrytning av protein frigörs ammoniak, som kan hÀmma processen. Problemen kan vara sÄ allvarliga att processen inte lÀngre fungerar som den ska. Syftet med den hÀr studien var att se om det gÄr att förbÀttra biogasprocessen vid anvÀndning av proteinrikt material. Vissa av de mikroorganismer som Àr delaktiga i processen blir lÀttare inhiberade av höga ammoniak-nivÄer Àn andra mikroorganismer, vilket leder till ett skifte i vilka grupper som dominerar och hur metanbildningen sker. Exjobbet genomfördes vid Sveriges Lantbruksuniversitet under hösten 2019. I studien höjdes ammoniaknivÄerna medvetet i fem reaktorer i labskala (nedskalade reaktorer för biogasproduktion). Samtidigt som ammoniaknivÄn höjdes tillsattes ocksÄ Àttiksyra. De höjda nivÄerna av Àttiksyra syftade till att frÀmja tillvÀxten av en av mikroorganismgrupperna som Àr tÄliga vid höjda ammoniakkoncentrationer. PÄ sÄ sÀtt var mÄlet att se om vissa av de problem som vanligtvis uppstÄr kan motverkas. Data frÄn reaktorerna samlades in för att se om prestandan förÀndrades under studien, och för att se om nÄgra förÀndringar i den mikrobiella sammansÀttningen skedde. Resultatet frÄn studien visar att den medvetna höjningen av ammoniak-nivÄerna lyckades, men att tillsatsen av Àttiksyra inte var tillrÀckligt hög för att den tÄligare gruppen skulle tillvÀxa signifikant. I studien uppvisade reaktorerna vissa av de dokumenterade problem som uppstÄr i samband med höjda ammoniaknivÄer

    Mixing and switching

    Get PDF

    Determinants of Nordic Stakeholder Bank Performance During and After the Financial Crisis

    Get PDF
    Stakeholder banking is an umbrella terms that is used to describe cooperative and savings banks. They differ from other commercial mainly through their ownership form, as they are owned by their customers. Because of this unique characteristic stakeholder banks are not able to use the capital markets to fund their business. Furthermore, they are often considered to run their business with a focus on stakeholder surplus maximization rather than pure profit maximization. These factors highly affect their business model, business capitalization, and risk taking. Owners, with their simultaneous role as customers, are reluctant to allow the bank to take risky positions in their operations with the fear of losing their savings. This thesis focuses on how stakeholder banks differ from their shareholder bank counterparts in the Nordic countries during and after the period of the most recent financial crisis. The effect of being a stakeholder bank, as well as differences in the micro- and macroeconomic performance determinants of the two groups, is examined through three performance variables: profitability, cost efficiency, and loan quality. This study finds stakeholder banks to be more profitable and cost efficient than shareholder banks during the crisis, as well as having better quality loans in the post-crisis period

    Advocacy coalitions and flood insurance: power and policies in the Australian Natural Disaster Insurance Review

    Get PDF
    Insurance against flooding creates households and places that are protected against financial harm in the form of catastrophic losses. Contested here are questions surrounding the availability and affordability of private insurance cover, significantly affecting the lives of people in at-risk geographies by imposing costs either as insurance premiums or episodic flood damages. Policy choices and decisions (‘political/economic’) about such controversial place-based environmental/risk issues (‘spatial’) are often made “behind closed doors”. A public inquiry opens those doors, albeit briefly, so we can see “what goes on”. The Natural Disaster Insurance Review (NDIR), a public inquiry after the 2010/2011 Australian floods, was a major forum of debate about Australian flood insurance policy. We explore the intricate politics of the key advocacy coalitions involved, to understand NDIR’s role and outcomes. Our case study methodology uses content analysis of c. 100 NDIR submissions and reports, media coverage, and insurance industry and government statements, supported by in-depth interviews with people directly involved. We show that a well-resourced and powerful coalition of insurers was the dominant advocacy coalition in the NDIR and that consumers and their at-risk communities were represented by a relatively under-resourced coalition. The primary role of the inquiry as a problem-solving process was ultimately overridden during the post-inquiry implementation phase, during which the insurance coalition was dominant. Major NDIR recommendations were not implemented, and hence key spatial/political issues that the inquiry was established to address for the benefit of those at risk remained unresolved

    A Conceptual Model for Network Decision Support Systems

    Get PDF
    We introduce the concept of a network DSS (NWDSS) consisting of fluid, heterogeneous nodes of human and machine agents, connected by wireless technology, which may enter and leave the network at unpredictable times, yet must also cooperate in decision-making activities. We describe distinguishing properties of the NWDSS and propose a 3-tier conceptual model comprised of digital infrastructure, transactive memory systems and emergent collaborative decision-making. We suggest a decision loop of Sense-Analyze-Adapt-Memory leveraging TMS as a starting point for addressing the agile collaborative requirements of emergent decision-making. Several examples of innovative NWDSS services are presented from Naval Postgraduate School field experiments

    Chemical spots and their dynamical evolution on HgMn stars

    Full text link
    Our recent studies of late B-type stars with HgMn peculiarity revealed for the first time the presence of fast dynamical evolution of chemical spots on their surfaces. These observations suggest a hitherto unknown physical process operating in the stars with radiative outer envelopes. Furthermore, we have also discovered existence of magnetic fields on these stars that have up to now been thought to be non-magnetic. Here we will discuss the dynamical spot evolution on HD 11753 and our new results on magnetic fields on AR Aur.Comment: 4 pages, 2 figures, to appear in the proceedings of the IAU Symposium 273 "Physics of Sun and Star Spots", Ventura, California 22-26 August 201

    Automated self-service modeling: predictive analytics as a service

    Get PDF
    The article of record as published may be found at https://doi.org/10.1007/s10257-011-0185-1Research into service provision and innovation is becoming progres- sively more important as automated service-provision via the web matures as a technology. We describe a web-based targeting platform that uses advanced dynamic model building techniques to conduct intelligent reporting and modeling. The impact of the automated targeting services is realized through a knowledge base that drives the development of predictive model(s). The knowledge base is comprised of a rules engine that guides and evaluates the development of an automated model-building process. The template defines the model classifier (e.g., logistic regression, multinomial logit, ordinary least squares, etc.) in concert with rules for data filling and transformations. Additionally, the template also defines which variables to test (‘‘include’’ rules) and which variables to retain (‘‘keep’’ rules). The ‘‘final’’ model emerges from the iterative steps undertaken by the rules engine, and is utilized to target, or rank, the best prospects. This automated modeling approach is designed to cost-effectively assist businesses in their tar- geting activities—independent of the firm’s size and targeting needs. We describe how the service has been utilized to provide ‘‘targeting services’’ for a small to medium business direct marketing campaign, and for direct sales-force targeting in a larger firm. Empirical results suggest that the automated modeling approach provides superior ‘‘service’’ in terms of cost and timing compared to more tra- ditional manual service provision
    • 

    corecore