Bacterial populations and their activity in the Benguela upwelling system

Bibliography : pages 267-315.An investigation of variability in hydrological and bacterial parameters at a fixed coastal station (Oudekraal. Cape Peninsula 33°59'S 17°21'E) showed that bacterial populations varied in numbers and biomass on both a short term (daily) and seasonal basis in response to changes in hydrological conditions which were largely wind induced

Goals and Expectations of Continuation High School Students Transitioning to Postsecondary Education

Background: Students at a continuation high school (CHS) attended an occupational therapy program to acquire life skills in preparation for their transition from secondary education. Most of the students who participated in the OT program planned to pursue a postsecondary education (PSE), but the CHS students encountered many barriers in negotiating the requirements of PSE. Discernment of these barriers encountered by the CHS students may enable the occupational therapy practitioners to better prepare the students for PSE. Method: This was a qualitative phenomenological study based on analyses of interview data. Semi-structured one-on-one interviews were conducted with eight CHS senior students and five CHS graduates with the aim to explore the students’ beliefs and knowledge regarding their transition to PSE. Results: The CHS students consistently reported PSE to be essential for successful adulthood but were unable to describe basic PSE entry requirements and processes. The students did not report concerns regarding their intellectual aptitude for PSE but reported entrenched negative behaviors, particularly truancy, as potential barriers to success. The students acknowledged responsibility for their successes and/or failures without blaming either others or the social environment. Conclusion: It is recommended that OT interventions focus on guiding the students to access knowledge of the PSE process and set realistic personal, education, and career goals with incremental action steps leading to goal achievement

Accumulation of Sellafield-derived radiocarbon (14C) in Irish Sea and West of Scotland intertidal shells and sediments

The nuclear energy industry produces radioactive waste at various stages of the fuel cycle. In the United Kingdom, spent fuel is reprocessed at the Sellafield facility in Cumbria on the north west coast of England. Waste generated at the site comprises a wide range of radionuclides including radiocarbon (14C) which is disposed of in various forms including highly soluble inorganic carbon within the low level liquid radioactive effluent, via pipelines into the Irish Sea. This 14C is rapidly incorporated into the dissolved inorganic carbon (DIC) reservoir and marine calcifying organisms, e.g. molluscs, readily utilise DIC for shell formation. This study investigated a number of sites located in Irish Sea and West of Scotland intertidal zones. Results indicate 14C enrichment above ambient background levels in shell material at least as far as Port Appin, 265 km north of Sellafield. Of the commonly found species (blue mussel (Mytilus edulis), common cockle (Cerastoderma edule) and common periwinkle (Littorina littorea)), mussels were found to be the most highly enriched in 14C due to the surface environment they inhabit and their feeding behaviour. Whole mussel shell activities appear to have been decreasing in response to reduced discharge activities since the early 2000s but in contrast, there is evidence of continuing enrichment of the carbonate sediment component due to in-situ shell erosion, as well as indications of particle transport of fine 14C-enriched material close to Sellafield

Temporal trend in the transfer of Sellafield-derived 14C into different size fractions of the carbonate component of NE Irish Sea sediment

From 1994 onwards, 14C discharges from the Sellafield nuclear fuel reprocessing plant have been made largely to the Northeast Irish Sea. They represent the largest contributor to UK and European populations of the collective dose commitment derived from the entire nuclear industry discharges. Consequently, it is important to understand the long-term fate of 14C in the marine environment. Research undertaken in 2000 suggested that the carbonate component of Northeast Irish Sea sediments would increase in 14C activity as mollusc shells, which have become enriched in Sellafield-derived 14C, are broken down by physical processes including wave action and incorporated into intertidal and sub-tidal sediments. The current study, undertaken in 2011, tested this hypothesis. The results demonstrate significant increases in 14C enrichments found in whole mussel shells compared to those measured in 2000. Additionally, in 2000, there was an enrichment above ambient background within only the largest size fraction (>500 μm) of the intertidal inorganic sediment at Nethertown and Flimby (north of Sellafield). In comparison, the present study has demonstrated 14C enrichments above ambient background in most size fractions at sites up to 40 km north of Sellafield, confirming the hypothesis set out more than a decade ago

Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C). Part 1. The Irish Sea

Ecosystem uptake and transfer processes of Sellafield-derived radiocarbon (14C) within the Irish Sea were examined. Highly variable activities in sediment, seawater and biota indicate complex 14C dispersal and uptake dynamics. All east basin biota exhibited 14C enrichments above ambient background while most west basin biota had 14C activities close to background, although four organisms including two slow-moving species were significantly enriched. The western Irish Sea gyre is a suggested pathway for transfer of 14C to the west basin and retention therein. Despite ongoing Sellafield 14C discharges, organic sediments near Sellafield were significantly less enriched than associated benthic organisms. Rapid scavenging of labile, 14C-enriched organic material by organisms and mixing to depth of 14C-enriched detritus arriving at the sediment/water interface are proposed mechanisms to explain this. All commercially important fish, crustaceans and molluscs showed 14C enrichments above background; however, the radiation dose from their consumption is extremely low and radiologically insignificant

Factors influencing community case management and care hours for clients with traumatic brain injury living in the UK

Objective: To investigate the relationship between deficits associated with traumatic brain injury (TBI) and case management (CM) and care/support (CS) in two UK community samples. Research design: Prospective descriptive study. Method: Case managers across the UK and from a single UK CM service contributed client profiles to two data sets (Groups 1 and 2, respectively). Data were entered on demographics, injury severity, functional skills, functional-cognition (including executive functions), behaviour and CM and CS hours. Relationships were explored between areas of disability and service provision. Results: Clients in Group 2 were more severely injured, longer post-injury and had less family support than clients in Group 1. There were few significant differences between Groups 1 and 2 on measures of Functionalskill, Functional-cognition and Behaviour disorder. Deficits in Functionalskills were associated with CS, but not CM. Deficits in measures of executive functions (impulsivity, predictability, response to direction) were related to CM, but not to CS. Insight was related to both CM and CS. Variables related to behaviour disorder were related to CM, but were less often correlated to CS. Conclusions: The need for community support is related not only to Functionalskills (CS), but also to behaviour disorder, self-regulatory skills and impaired insight (CM)

Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C) part 2 : the west of Scotland

Ecosystem uptake and transfer of Sellafield-derived radiocarbon (14C) were examined within the West of Scotland marine environment. The dissolved inorganic carbon component of seawater, enriched in14C, is transported to the West of Scotland where it is transferred through the marine food web. Benthic and pelagic biota with variable life-spans living in the North Channel and Clyde Sea show comparable14C activities. This suggests that mixing of14C within the Irish Sea results in a relatively constant northwards dispersal of activity. Benthic species in the Firth of Lorn have similar14C enrichments, demonstrating that Irish Sea residual water is the dominant source to this area. Measured14C activities in biota show some similarity to western Irish Sea activities, indicating that dispersion to the West of Scotland is significant with respect to the fate of Sellafield14C releases. Activities measured in commercially important species do not pose any significant radiological risk

Modelling marine trophic transfer of radiocarbon (14C) from a nuclear facility

Sellafield marine discharges of 14C are the largest contributor to the global collective dose from the nuclear fuel industry. As such, it is important to understand the fate of these discharges beyond the limitations and scope of empirical analytical investigations for this highly mobile radioactive contaminant. Ecopath with Ecosim (EwE) is widely used to model anthropogenic impacts on ecosystems, such as fishing, although very few EwE studies have modelled the fate of bioavailable contaminants. This work presents, for the first time, a spatial-temporal 14C model utilising recent developments in EwE software to predict the ecological fate of anthropogenic 14C in the marine environment. The model predicted observed trends in 14C activities between different species and through time. It also provided evidence for the integration of Sellafield 14C in species at higher trophic levels through time