27 research outputs found

    Microbial redox processes in deep subsurface environments and the potential application of (per)chlorate in oil reservoirs

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    The ability of microorganisms to thrive under oxygen-free conditions in subsurface environments relies on the enzymatic reduction of oxidized elements, such as sulfate, ferric iron, or CO2, coupled to the oxidation of inorganic or organic compounds. A broad phylogenetic and functional diversity of microorganisms from subsurface environments has been described using isolation-based and advanced molecular ecological techniques. The physiological groups reviewed here comprise iron-, manganese-, and nitrate-reducing microorganisms. In the context of recent findings also the potential of chlorate and perchlorate [jointly termed (per)chlorate] reduction in oil reservoirs will be discussed. Special attention is given to elevated temperatures that are predominant in the deep subsurface. Microbial reduction of (per)chlorate is a thermodynamically favorable redox process, also at high temperature. However, knowledge about (per)chlorate reduction at elevated temperatures is still scarce and restricted to members of the Firmicutes and the archaeon Archaeoglobus fulgidus. By analyzing the diversity and phylogenetic distribution of functional genes in (meta)genome databases and combining this knowledge with extrapolations to earlier-made physiological observations we speculate on the potential of (per)chlorate reduction in the subsurface and more precisely oil fields. In addition, the application of (per)chlorate for bioremediation, souring control, and microbial enhanced oil recovery are addressed.This research was funded by Shell Global Solutions International BV. Research of Alfons J. M. Stams is funded by ERC (project 323009) and Gravitation grant (project 024.002.002) of the Dutch Ministry of Education, Culture and Science and the Netherlands Science Foundation

    THE MICROBIOLOGY OF COAL I

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    It is not always gut-feelings and regulations link together : A qualitative studyabout the social worker's assessment of adequately good parenthood.

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    SocialtjÀnsten Àr den samhÀllsinstans som bÀr det yttersta ansvaret för att göra nÄgot som tillgodoser barnets behov av skydd och familjens behov av stöd. Forskning pÄvisar att det finns dilemman i bedömningen av vad som kan rÀknas som barns godtagbara eller oacceptabla hemförhÄllanden. Det rÄder till viss del oenighet mellan socialsekreterarna var grÀnsen för acceptabel förÀldraomsorg ligger, dÄ bedömningen ofta utgörs av egna personliga och professionella erfarenheter. Detta kan utgöra en risk att barnets utveckling och hÀlsa tar skada dÄ bedömningen till viss del beror pÄ vilken socialsekreterare som gör utredningen.Mot bakgrund av ovanstÄende problemomrÄde synes det angelÀget att uppmÀrksamma socialsekreterarens tankar kring sin bedömning av ett tillrÀckligt bra förÀldraskap och var grÀnsen gÄr för acceptabla förÀldrabeteenden. För att skapa en djupare förstÄelse för hur socialsekreteraren tolkar och resonerar kring ett tillrÀckligt bra förÀldraskap har en kvalitativ ansats med halvstrukturerade intervjuer anvÀnts. Studiens teoretiska referensram utgÄr frÄn Objektsrelationsteorin, Donald W Winnicotts begrepp TillrÀckligt bra, Kari Killéns definitioner av förÀldraförmÄgor samt begreppet Fronesis. Datamaterialet har kodats,kategoriserats, tematiserats och analyserats utifrÄn ovan nÀmnda teoretiska perspektiv och tidigare forskning inom omrÄdet. Studiens resultat visar att socialsekreterarnas tankar om ett tillrÀckligt bra förÀldraskap delvis gÄr i linje med tidigare forskning. DÄ de anser att bedömningen Àr komplex och grundar sig bÄde i kunskap, personliga referensramar samt regelverkets ramar. Viktiga aspekter i bedömningen anser socialsekreterarna vara förÀldrars förmÄga till att upprÀtthÄlla kontinuitet och stabilitet över tid, samt att vara kÀnslomÀssigt tillgÀnglig för sitt barn. Andra viktiga aspekter Àr förÀldrars förmÄga att sÀtta barnets behov frÀmst och att inse sina begrÀnsningar.FörmÄgan att ha insikt genomsyras i alla aspekter av förÀldraskapet.Social Services is the section of society that has main responsibility for making sure children's needs of protection and the family's need of support are seen and met. Research shows that there is a dilemma in the assessment of what can be counted as children's acceptable or unacceptable home situation, but also to some extent there is disagreement between socialworkers about where boundaries for what acceptable parenting is lie. This may constitute a risk detrimental to the child's development and health partly due to which social worker carries out the investigation. In view of the problem area illustrated above, it is important to draw attention to the thoughts of the social worker when assessing adequately good parenthood and where boundaries lie for acceptable parental behaviour. To attain a deeper understanding of how social workers interpret and reason about adequately good parenthood, a qualitative approach with semistructured interviews was used. The study's theoretical reference is based on the object relations theory, Donald W Winnicotts concept 'Good Enough', Kari Killéns definition of parental ability and the concept Phronesis. The information data was coded, categorised,themed and analysed by using the above mentioned theoretical perspectives and earlier research on the subject. Results show that social workers thoughts on adequately good parenting partly are in line with earlier research. They consider that assessments are complex, basing them on knowledge,personal points of reference and regulatory framework. Social workers view parents' ability to maintain continuity and stability over time as an important aspect in making assessments, and also being emotionally available for their child. Other important aspects are parents' ability to put their child's needs before their own and to recognise their own limitations. The ability to have insight permeates all aspects of parenthood

    The breakdown of benzyl compounds by a soil micrococcus

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