Neutron-diffraction studies of amorphous CNx materials

The results of neutron-diffraction experiments performed on two samples of amorphous CNx, with nitrogen concentrations of 5 and 30 at. %, prepared by a combination of filtered cathodic are and Kaufman-type ion source, are presented. Increasing the N content of the samples is seen to cause a decrease of the average bond length and the first coordination number. An increase in the average bond angle from 113 degrees to 121 degrees is also observed. The pair-distribution functions indicate that N incorporation results in some transformation of sp(3) C sites to sp(2) sites, but there is no evidence for N inducing the formation of crystalline graphitic clusters, and the overall structure remains amorphous. A direct subtraction of the two data sets emphasizes the loss of sp(3) bonds and the increasing sp(2) character of the higher-N-content sample, and shows the occurrence of a variety of bonding environments for N. More limited information on second neighbor correlations involving N is also revealed

The reporting of theoretical health risks by the media: Canadian newspaper reporting of potential blood transmission of Creutzfeldt-Jakob disease

BACKGROUND: The media play an important role at the interface of science and policy by communicating scientific information to the public and policy makers. In issues of theoretical risk, in which there is scientific uncertainty, the media's role as disseminators of information is particularly important due to the potential to influence public perception of the severity of the risk. In this article we describe how the Canadian print media reported the theoretical risk of blood transmission of Creutzfeldt-Jakob disease (CJD). METHODS: We searched 3 newspaper databases for articles published by 6 major Canadian daily newspapers between January 1990 and December 1999. We identified all articles relating to blood transmission of CJD. In duplicate we extracted information from the articles and entered the information into a qualitative software program. We compared the observations obtained from this content analysis with information obtained from a previous policy analysis examining the Canadian blood system's decision-making concerning the potential transfusion transmission of CJD. RESULTS: Our search identified 245 relevant articles. We observed that newspapers in one instance accelerated a policy decision, which had important resource and health implication, by communicating information on risk to the public. We also observed that newspapers primarily relied upon expert opinion (47 articles) as opposed to published medical evidence (28 articles) when communicating risk information. Journalists we interviewed described the challenges of balancing their responsibility to raise awareness of potential health threats with not unnecessarily arousing fear amongst the public. CONCLUSIONS: Based on our findings we recommend that journalists report information from both expert opinion sources and from published studies when communicating information on risk. We also recommend researchers work more closely with journalists to assist them in identifying and appraising relevant scientific information on risk

Novel method of estimating volume of distribution of a drug obeying Michaelis-Menten elimination kinetics

The novel method of estimating the volume of distribution involves (a) administering an appropriate bolus intravenous dose of the drug, (b) starting a constant-rate intravenous infusion of the drug at the same time, (c) maintaining the infusion for a given number of hours, (a) measuring the drug concentration over the entire time course, (e) computer-fitting the post-infusion data to obtain estimates of V m and K m , (f) estimating the total area under the concentration-time curve from zero time to infinity, and (g) iteratively solving a cubic equation to obtain the estimate of the volume of distribution. The method was applied to ethanol in the cat and yielded an average value of 635ml/kg (63.5% of body weight) with a coefficient of variation of 23.0%. This is equivalent to total body water in the cat.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45074/1/10928_2005_Article_BF01312262.pd

Opties voor een klimaatbestendige zoetwatervoorziening in Laag Nederland, tussentijds integratierapport

Dit rapport geeft een tussentijds overzicht van ‘state of the art’ kennis uit lopend onderzoek van het consortium ‘Climate Proof Fresh Water Supply’ (CPFWS) dat in het kader van het onderzoeksprogramma Kennis voor Klimaat wordt uitgevoerd. De focus van dit onderzoek naar een klimaatbestendige zoetwatervoorziening ligt op lokale en regionale oplossingen in Laag Nederland voor land- en tuinbouw en natuur. De zoetwatervoorziening van dit gebied wordt naast droogte vooral bedreigd door verzilting van grond- en oppervlaktewater. In zes samenhangende werkpakketten wordt geanalyseerd hoe dit gebied meer zelfvoorzienend kan worden én hoe aanpassingen in het (hoofd)watersysteem kunnen bijdragen aan de watervoorziening van het gebied. Centraal in de aanpak zijn een 3-tal casestudies in de Hotspots Haaglanden, Rotterdam Regio en Zuidwestelijke delta

Balancing supply and demand of fresh water under increasing drought and salinisation in the Netherlands

The latest climate impact assessments show that climate change will cause an increasing mismatch between demand and supply of fresh water in many densely populated deltas around the world. Recent studies for the Netherlands show that the current water supply strategy is not climate proof in the long-run. Therefore, a future ‘climate proof’ fresh water supply is national priority on the Dutch water policy agend

Individual, family and offence characteristics of high risk childhood offenders: comparing non-offending, one-time offending and re-offending Dutch-Moroccan migrant children in the Netherlands

<p>Abstract</p> <p>Background</p> <p>Childhood offenders are at an increased risk for developing mental health, social and educational problems later in life. An early onset of offending is a strong predictor for future persistent offending. Childhood offenders from ethnic minority groups are a vulnerable at-risk group. However, up until now, no studies have focused on them.</p> <p>Aims</p> <p>To investigate which risk factors are associated with (re-)offending of childhood offenders from an ethnic minority.</p> <p>Method</p> <p>Dutch-Moroccan boys, who were registered by the police in the year 2006-2007, and their parents as well as a control group (n = 40) were interviewed regarding their individual and family characteristics. Two years later a follow-up analysis of police data was conducted to identify one-time offenders (n = 65) and re-offenders (n = 35).</p> <p>Results</p> <p>All groups, including the controls, showed substantial problems. Single parenthood (OR 6.0) and financial problems (OR 3.9) distinguished one-time offenders from controls. Reading problems (OR 3.8), having an older brother (OR 5.5) and a parent having Dutch friends (OR 4.3) distinguished re-offenders from one-time offenders. First offence characteristics were not predictive for re-offending. The control group reported high levels of emotional problems (33.3%). Parents reported not needing help for their children but half of the re-offender's families were known to the Child Welfare Agency, mostly in a juridical framework.</p> <p>Conclusion</p> <p>The Moroccan subgroup of childhood offenders has substantial problems that might hamper healthy development. Interventions should focus on reaching these families tailored to their needs and expectations using a multi-system approach.</p