Predicting revision risk for aseptic loosening of femoral components in total flip arthroplasty in individual patients - A finite element study

Advances in surgical procedure, prosthesis design, and biomaterials performance have considerably increased the longevity of total joint replacements. Preoperative planning is another step in joint replacement that may have the potential to improve clinical outcome for the individual patient, but has remained relatively consistent for a longtime. One means of advancing this aspect of joint replacement surgery may be to include predictive computer simulation into the planning process. In this article, the potential of patient-specific finite element analysis in preoperative assessment is investigated. Seventeen patient-specific finite element models of cemented Charnley reconstructions were created, of which six were early (

Translating policy into practice: A case study in the secondary prevention of coronary heart disease

Background: This paper focuses on the relationships between health ‘policy’ as it is embodied in official documentation, and health ‘practice’ as reported and reflected on in the talk of policy makers, health professionals and patients. The specific context for the study involves a comparison of policies relating to the secondary prevention of coronary heart disease (CHD) in the two jurisdictions of Ireland – involving as they do a predominantly state funded (National Health Service) system in the north and a mixed healthcare economy in the south. The key question is to determine how the rhetoric of health policy as contained in policy documents connects to, and gets translated into practice and action.

Methods: The data sources for the study include relevant healthcare policy documents (N=5) and progress reports (N=6) in the two Irish jurisdictions, and semi-structured interviews with a range of policy-makers (N=28), practice nurses (14), general practitioners (12) and patients (13) to explore their awareness of the documents’ contents and how they saw the impact of ‘policy’ on primary care practice.

Results: The findings suggest that although strategic policy documents can be useful for highlighting and channelling attention to health issues that require concerted action, they have little impact on what either professionals or lay people do.

Conclusion: To influence the latter and to encourage a systematic approach to the delivery of health care it seems likely that contractual arrangements – specifying tasks to be undertaken and methods for monitoring and reporting on activity - are required.

The effect of month of birth on the attainments of primary and secondary school pupils

Background: Previous research has produced conflicting results regarding the effects of season of birth and age-position on cognitive attainments. In Northern Ireland the school year divides the summer season into two providing an opportunity to evaluate the relative contribution of season of birth and age-position effects. Aims: To investigate the relationship between attainment in literacy skills and month of birth for primary and secondary school pupils and to determine the relationship between motor skills and month of birth in primary school pupils. Sample: One thousand one hundred and twenty four primary school pupils participated, and results for key stage 3 (KS3) English and GCSE English Language, for 3,493 Year 10 and 3,697 Year 12 secondary school pupils, respectively, were obtained. Method: Primary school pupils were individually assessed using standardised reading and spelling tests, as well as tests of motor skill. They were also assessed using a standardised group reading test in their class groups. For the secondary school pupils, the results for two year cohorts, in KS3 English and GCSE English language, respectively, were analysed. Results: For the primary school pupils there was evidence of both a season of birth and an age-position effect on all of the cognitive measures, particularly in the early years of schooling. There was, also, evidence of a significant age-position effect at both KS3 and GCSE in favour of the older pupils. For the younger primary school pupils there was evidence of significant age-position effects on both motor measures. Conclusions: The findings from the present study suggest that month of birth may be related to both season of birth and age-position effects. These effects may be compounded, particularly in the early years of primary school, when summer born children are youngest in their year, as in England. In Northern Ireland, age-position effects are also evident in secondary school public examination results, which may have implications for long-term life choices. © 2009 The British Psychological Society.

Predator diversity enhances secondary production and decreases the likelihood of trophic cascades

We manipulated the diversity of top predators in a three trophic level marine food web. The food web included four top benthic marine fish predators (black goby, rock goby, sea scorpion and shore rockling), an intermediate trophic level of small fish, and a lower trophic level of benthic invertebrates. We kept predator density constant and monitored the response of the lower trophic levels. As top predator diversity increased, secondary production increased. We also observed that in the presence of the manipulated fish predators, the density of small gobiid fish (intermediate consumers) was suppressed, releasing certain groups of benthic invertebrates (caprellid amphipods, copepods, nematodes and spirorbid worms) from heavy intermediate predation pressure. We attribute the mechanism responsible for this trophic cascade to a trait-mediated indirect interaction, with the small gobiid fish changing their use of space in response to altered predator diversity. In the absence of top fish predators, a full-blown trophic cascade occurs. Therefore the diversity of predators reduces the likelihood of trophic cascades occurring and hence provides insurance against the loss of an important ecosystem function (i.e. secondary production).

ON THE MOLECULAR COMPLEXITY OF THE HOT CORES IN ORION-A - GRAIN SURFACE-CHEMISTRY AS THE LAST REFUGE OF THE SCOUNDREL

We have modeled the gas phase chemistry of warm molecular material around protostars that is seeded with evaporating grain mantles. We show that the release of simple molecules into the gas drives ion-molecule and neutral chemistries which can account for many of the complex 0-bearing and N-bearing molecules observed in hot cores. Initial grain mantle components and secondary product molecules are identified, and the observational consequences are discussed.

Alcohol and the affluence paradox: A secondary analysis exploring the health disparities surrounding adolescent alcohol use and alcohol related harm in adulthood

Several studies have shown social differences in alcohol consumption, and social inequalities of harm related to alcohol use and abuse. However, relationships between the position in the socio-economic spectrum, alcohol use, and alcohol-related health problems are not clear cut. While there is some evidence of social gradients or associations between indicators of deprivation and some adolescence outcomes (e.g. externalising behaviour), the evidence regarding associations between socio-economic status and alcohol-related problems in adolescence is more conflicting. A major problem in studying socio-economic inequalities in adolescent health is related to the paucity of measures of socio-economic status in adolescence that are both conceptually and methodologically sound.
The aims of this study were to investigate socio-economic differences in pathways from onset to establishment of drinking patterns in adolescence, assess the consequences of these pathways in terms of alcohol related harm, and to consider the causal mechanisms that may contribute to socio-economic differences in drinking pathways and outcomes