342 research outputs found

    Radiological risk from thoron, a case study: The particularly radon-prone area of Bolsena, and the lesson learned

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    Abstract The contribution of 220 Rn is usually negligible compared to that of 222 Rn: its very short half-life makes escape from its source site within the rock very unlikely and it never has time enough to filtrate through the ground and through cracks in the floors or cellar walls to reach living quarters. This however becomes untrue if walls built with 232 Th-rich materials are present: then sizeable amounts of thoron may be detected in the closed areas bounded by those walls. This is the case for many dwellings in central Italy, and the town of Bolsena (northern Latium) is presented as a case study. A typical building of the area, entirely constructed with tuff blocks, is investigated and the annual dose rates calculated for varying distances from the wall. Thoron concentration was found to decrease with a relaxation length of 13 cm. Thoron was found to pose a significant risk. The rate of air exchange was found to produce little effect. Wall plastering acts as a filter: thoron diffuses through it but a HVL of less than 1 cm was found to prevail

    Applying Adverse Outcome Pathways (AOPs) to support Integrated Approaches to Testing and Assessment (IATA)

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    Chemical regulation is challenged by the large number of chemicals requiring assessment for potential human health and environmental impacts. Current approaches are too resource intensive in terms of time, money and animal use to evaluate all chemicals under development or already on the market. The need for timely and robust decision making demands that regulatory toxicity testing becomes more cost-effective and efficient. One way to realize this goal is by being more strategic in directing testing resources; focusing on chemicals of highest concern, limiting testing to the most probable hazards, or targeting the most vulnerable species. Hypothesis driven Integrated Approaches to Testing and Assessment (IATA) have been proposed as practical solutions to such strategic testing. In parallel, the development of the Adverse Outcome Pathway (AOP) framework, which provides information on the causal links between a molecular initiating event (MIE), intermediate key events (KEs) and an adverse outcome (AO) of regulatory concern, offers the biological context to facilitate development of IATA for regulatory decision making. This manuscript summarizes discussions at the Workshop entitled “Advancing AOPs for Integrated Toxicology and Regulatory Applications” with particular focus on the role AOPs play in informing the development of IATA for different regulatory purposes.publishedVersio

    Migrant participation in Norwegian health care. A qualitative study using key informants

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    Background Little is known about how migrants adapt to first-world public health systems. In Norway, patients are assigned a registered general practitioner (RGP) to provide basic care and serve as gatekeeper for other medical services. Objectives: To explore determinants of migrant compliance with the RGP scheme and obstacles that migrants may experience. Methods: Individuals in leadership positions within migrant organizations for the 13 largest migrant populations in Norway in 2008 participated in this qualitative study. Semi-structured interviews, with migrants serving as key informants, were used to elucidate possible challenges migrant patients face in navigating the local primary health-care system. Conversations were structured using an interview guide covering the range of challenges that migrant patients meet in the health-care system. Results: According to informants, integration into the RGP scheme and adequacy of patient-physician communication varies according to duration of stay in Norway, the patient's country of origin, the reason for migration, health literacy, intention to establish permanent residence in Norway, language proficiency, and comprehension of information received about the health system. Informants noted as obstacles: doctor-patient interaction patterns, conflicting ideas about the role of the doctor, and language and cultural differences. In addressing noted obstacles, one strategy would be to combine direct intervention by migrant associations with indirect intervention via the public-health system

    Extended Knowledge-How

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    According to reductive intellectualists about knowledge-how :147–190, 2008; Philos Phenomenol Res 78:439–467, 2009) knowledge-how is a kind of knowledge-that. To the extent that this is right, then insofar as we might conceive of ways knowledge could be extended with reference to active externalist :7–19, 1998; Clark in Supersizing the mind: embodiment, action, and cognitive extension: embodiment, action, and cognitive extension. Oxford University Press, Oxford, 2008) approaches in the philosophy of mind, we should expect no interesting difference between the two. However, insofar as anti-intellectualist approaches to knowledge-how are a viable option, there is an overlooked issue of how knowledge-how might be extended, via active externalism, in ways very differently from knowledge-that. This paper explores this overlooked space, and in doing so, illustrates how a novel form of extended knowledge-how emerges from a pairing of active externalism in the philosophy of mind with anti-intellectualism in the theory of knowledge. Crucial to our argument will be a new way of thinking about the extended mind thesis, as it pertains to the kinds of state one is in when one knows how to do something, and how this state connects with non-accidentally successful performanc

    Isolation and characterization of a novel 2-sec-butylphenol-degrading bacterium Pseudomonas sp. strain MS-1

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    A novel bacterium capable of utilizing 2-sec-butylphenol as the sole carbon and energy source, Pseudomonas sp. strain MS-1, was isolated from freshwater sediment. Within 30 h, strain MS-1 completely degraded 1.5 mM 2-sec-butylphenol in basal salt medium, with concomitant cell growth. A pathway for the metabolism of 2-sec-butylphenol by strain MS-1 was proposed on the basis of the identification of 3 internal metabolites—3-sec-butylcatechol, 2-hydroxy-6-oxo-7-methylnona-2,4-dienoic acid, and 2-methylbutyric acid—by gas chromatography-mass spectrometry analysis. Strain MS-1 degraded 2-sec-butylphenol through 3-sec-butylcatechol along a meta-cleavage pathway. Degradation experiments with various alkylphenols showed that the degradability of alkylphenols by strain MS-1 depended strongly on the position (ortho ≫ meta = para) of the alkyl substitute, and that strain MS-1 could degrade 2-alkylphenols with various sized and branched alkyl chain (o-cresol, 2-ethylphenol, 2-n-propylphenol, 2-isopropylphenol, 2-sec-butylphenol, and 2-tert-butylphenol), as well as a dialkylphenol (namely, 6-tert-butyl-m-cresol)
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