Dosimetry in mixed radiation fields

Imperial Users onl

Mechanisms Affecting Recruitment of Yellow Perch in Lake Michigan

Report issued on: August 2001INHS Technical Report prepared for Great Lakes Fishery Trus

Vitamin D in Australia : issues and recommendations

BACKGROUND A significant number of Australians and people from specific groups within the community are suffering from vitamin D deficiency. It is no longer acceptable to assume that all people in Australia receive adequate vitamin D from casual exposure to sunlight.OBJECTIVE This article provides information on causes, consequences, treatment and prevention of vitamin D deficiency in Australia. DISCUSSION People at high risk of vitamin D deficiency include the elderly, those with skin conditions where avoidance of sunlight is required, dark skinned people (particularly women during pregnancy or if veiled) and patients with malabsorption, eg. coeliac disease. For most people, deficiency can be prevented by 5&ndash;15 minutes exposure of face and upper limbs to sunlight 4&ndash;6 times per week. If this is not possible then a vitamin D supplement of at least 400 IU* per day is recommended. In cases of established vitamin D deficiency, supplementation with 3000-5000 IU per day for at least 1 month is required to replete body stores. Increased availability of larger dose preparations of cholecalciferol would be a useful therapy in the case of severe deficiencies. * 40 IU (international units) = 1 &micro;g<br /

Randomised, controlled trial of alternating pressure mattresses compared with alternating pressure overlays for the prevention of pressure ulcers : PRESSURE (pressure relieving support surfaces) trial

Objective To compare whether differences exist between alternating pressure overlays and alternating pressure mattresses in the development of new pressure ulcers, healing of existing pressure ulcers, and patient acceptability. Design Pragmatic, open, multicentre, randomised controlled trial. Setting 11 hospitals in six NHS trusts. Participants 1972 people admitted to hospital as acute or elective patients. Interventions Participants were randomised to an alternating pressure mattress (n = 982) of- an alternating pressure overlay (n = 990). Main outcome measures The proportion of participants developing a new pressure ulcer of grade 2 or worse; time to development of new pressure ulcers; proportions of participants developing a new ulcer within 30 days; healing of existing pressure ulcers; and patient acceptability Results Intention to treat analysis found no difference in the proportions of participants developing a new pressure ulcer of grade 2 or worse (10.7% overlay patients, 10.3% mattress patients; difference 0.4%, 95% confidence interval - 23% to 3.1%, P = 0.75). More overlay patients requested change owing to dissatisfaction (23.3%) than mattress patients (18.9%, P = 0.02). Conclusion No difference was found between alternating pressure mattresses and alternating pressure overlays in the proportion of people who develop a pressure ulcer

Counter Chemotactic Flow in Quasi-One-Dimensional Path

Quasi-one-dimensional bidirectional particle flow including the effect of chemotaxis is investigated through a modification of the John-Schadschneider-Chowdhury-Nishinari model. Specifically, we permit multiple lanes to be shared by both directionally traveling particles. The relation between particle density and flux is studied for several evaporation rates of pheromone, and the following results are obtained: i) in the low-particle-density range, the flux is enlarged by pheromone if the pheromone evaporation rate is sufficiently low, ii) in the high particle-density range, the flux is largest at a reasonably high evaporation rate and, iii) if the evaporation rate is at the level intermediate between the above two cases, the flux is kept small in the entire range of particle densities. The mechanism of these behaviors is investigated by observing the spatial-temporal evolution of particles and the average cluster size in the system.Comment: 4 pages, 9 figure

Mobilization, Strategy, and Global Apparel Production Networks: Systemic Advantages for Student Antisweatshop Activism

The U.S. antisweatshop movement is a major branch of Global North labor rights activism. We focus on the movement’s college student sector, which has been active and moderately effective since its 1997 birth. Using principles from social movement theory and global political economy, we examine (1) these student labor rights groups’ campus context, (2) global production networks (GPNs), and (3) how campus context and GPNs intersect to facilitate student antisweatshop activity and effectiveness in ways distinct from the non-campus U.S. movement. U.S. college campuses are places of pre-existing collective identity and dense interaction, facilitating antisweatshop mobilization. Collegiate apparel GPNs that source from the Global South contain both the student sector’s largest grievance and an opportunity structure of power relations that this sector seeks to engage. An on-campus movement opportunity also exists: a college administration which is beholden and accessible to students and is simultaneously a gatekeeper in licensed collegiate apparel GPNs – a spatially commensurate point of strategic leverage for a student antisweatshop group as it coordinates with production workers and their local allies. Thus, the student sector possesses certain advantages within a field of power relations permeating the larger network linking it to administrations and firms. Recognizing these distinct advantages and the synergy among them should usefully inform student antisweatshop activists and their allies as they mobilize support and formulate strategies

Mobilization, Strategy, and Global Apparel Production Networks: Systemic Advantages for Student Antisweatshop Activism

The U.S. antisweatshop movement is a major branch of Global North labor rights activism. We focus on the movement’s college student sector, which has been active and moderately effective since its 1997 birth. Using principles from social movement theory and global political economy, we examine (1) these student labor rights groups’ campus context, (2) global production networks (GPNs), and (3) how campus context and GPNs intersect to facilitate student antisweatshop activity and effectiveness in ways distinct from the non-campus U.S. movement. U.S. college campuses are places of pre-existing collective identity and dense interaction, facilitating antisweatshop mobilization. Collegiate apparel GPNs that source from the Global South contain both the student sector’s largest grievance and an opportunity structure of power relations that this sector seeks to engage. An on-campus movement opportunity also exists: a college administration which is beholden and accessible to students and is simultaneously a gatekeeper in licensed collegiate apparel GPNs – a spatially commensurate point of strategic leverage for a student antisweatshop group as it coordinates with production workers and their local allies. Thus, the student sector possesses certain advantages within a field of power relations permeating the larger network linking it to administrations and firms. Recognizing these distinct advantages and the synergy among them should usefully inform student antisweatshop activists and their allies as they mobilize support and formulate strategies