MULTIPAC, a multiple pool processor and computer for a spacecraft central data system, phase 2 Final report

MULTIPAC, multiple pool processor and computer for deep space probe central data syste

A discrete slug population model determined by egg production

Slugs are significant pests in agriculture (as well as a nuisance to gardeners), and it is therefore important to understand their population dynamics for the construction of efficient and effective control measures. Differential equation models of slug populations require the inclusion of large (variable) temporal delays, and strong seasonal forcing results in a non-autonomous system. This renders such models open to only a limited amount of rigorous analysis. In this paper, we derive a novel batch model based purely upon the quantity of eggs produced at different times of the year. This model is open to considerable reduction; from the resulting two variable discrete-time system it is possible to reconstruct the dynamics of the full population across the year and give conditions for extinction or global stability and persistence. Furthermore, the steady state temporal population distribution displays qualitatively different behavior with only small changes in the survival probability of slugs. The model demonstrates how small variations in the favorability of different years may result in widely different slug population fluctuations between consecutive years, and is in good agreement with field data

The burden of disease attributable to sexually transmitted infections in South Africa in 2000

Objectives. To estimate the burden of disease attributable to sexually transmitted infections (STIs) in South Africa, to identify the factors contributing to this burden, and to review successes and failures in reducing this burden. Design. Years of life lost (YLL) and years lived with disability (YLD) were estimated using different approaches for HIV/ AIDS, other STIs and cervical cancer. Burden in respect of HIV/ AIDS was estimated using the ASSA2002 model, and for the other diseases the revised national burden of disease estimates for 2000 based on 1996 cause-of-death data were used. The ASSA2002 model was used to estimate numbers of AIDS deaths under different prevention and treatment scenarios. Setting. South Africa. Outcome measures. Deaths, YLL and disability-adjusted life years (DALYs) associated with HIV/AIDS, other STIs and cervical cancer. Results. STIs accounted for more than 26% of all deaths and over 5 million DALYs in 2000 and over 98% of this burden was due to HIV/AIDS. A combination of social, behavioural and biological conditions contribute to this burden. HIV/AIDS mortality and morbidity are estimated to have increased significantly since 2000, and the future change in this burden is largely dependent on the extent to which antiretroviral treatment and HIV prevention programmes are introduced. 2.5 million AIDS deaths could be prevented by 2015 if high levels of access to antiretroviral treatment are achieved. Conclusion. South Africa faces one of the largest STI epidemics in the world. A multifaceted strategy to prevent and treat STIs is needed, and burden of disease assessments should look beyond the role of ‘unsafe sex' when attributing this disease burden to risk factors. South African Medical Journal Vol. 97 (8) Part 2 2007: pp. 658-66

Can health trainers make a difference with difficult-to-engage clients? A multisite case study

A political attempt in the United Kingdom to address health inequalities in the past decade has been the government’s initiative to employ local health trainers (HTs) or health trainer champions (HTCs) to support disadvantaged individuals with aspects of their health-related behaviors. HT/HTCs provide health-related information and support to individuals with healthy eating, physical activity, and smoking cessation. They undertake community engagement and direct individuals to relevant health services. They differ in that HTs are trained to provide health interventions to individuals or groups and to make referrals to specialist health care services when necessary. This article provides an evaluation of HT/HTCs interventions across three sites, including one prison, one probation service (three teams), and one mental health center. An evaluation framework combining process and outcome measures was employed that used mixed methods to capture data relating to the implementation of the service, including the context of the HT/HTCs interventions, the reactions of their clients, and the outcomes reported. It was found that HT/HTCs interventions were more effective in the prison and mental health center compared with the probation site largely as a result of contextual factors

Conformational activation of ADAMTS13

A disintegrin and metalloprotease with thrombospondin motifs 13 (ADAMTS13) is a metalloprotease that regulates von Willebrand factor (VWF) function. ADAMTS13-mediated proteolysis is determined by conformational changes in VWF, but also may depend on its own conformational activation. Kinetic analysis of WT ADAMTS13 revealed ∼2.5-fold reduced activity compared with ADAMTS13 lacking its C-terminal tail (MDTCS) or its CUB1-2 domains (WTΔCUB1-2), suggesting that the CUB domains naturally limit ADAMTS13 function. Consistent with this suggestion, WT ADAMTS13 activity was enhanced ∼2.5-fold by preincubation with either an anti-CUB mAb (20E9) or VWF D4CK (the natural binding partner for the CUB domains). Furthermore, the isolated CUB1-2 domains not only bound MDTCS, but also inhibited activity by up to 2.5-fold. Interestingly, a gain-of-function (GoF) ADAMTS13 spacer domain variant (R568K/F592Y/R660K/Y661F/Y665F) was ∼2.5-fold more active than WT ADAMTS13, but could not be further activated by 20E9 mAb or VWF D4CK and was unable to bind or to be inhibited by the CUB1-2 domains, suggesting that the inhibitory effects of the CUB domains involve an interaction with the spacer domain that is disrupted in GoF ADAMTS13. Electron microscopy demonstrated a “closed” conformation of WT ADAMTS13 and suggested a more “open” conformation for GoF ADAMTS13. The cryptic spacer domain epitope revealed by conformational unfolding also represents the core antigenic target for autoantibodies in thrombotic thrombocytopenic purpura. We propose that ADAMTS13 circulates in a closed conformation, which is maintained by a CUB–spacer domain binding interaction. ADAMTS13 becomes conformationally activated on demand through interaction of its C-terminal CUB domains with VWF, making it susceptible to immune recognition

Fragmented participation in management of the fishery for small pelagic fish in South Africa – inclusion of small-rights holders is a complex matter

The reasons why most small-rights holders do not participate in management of the fishery for small pelagic fish (‘small pelagics’) in South Africa, despite legislation and policy encouraging their participation, were analysed. Membership of the Small Pelagics Management Working Group (SPMWG), the main participatory governance organ, is limited to representatives of recognised stakeholder associations. Rights holders therefore have to belong to a stakeholder association, which then selects a member or members to represent them on the SPMWG. Small quotas and the difficulties of sourcing capital mean that small-rights holders are not able to invest in infrastructure. Besides, most of the small-rights holders and their companies lack experience and management skills to survive independently in this highly competitive industry, which is based on high volume and low profit margins. As a result, most of the small-rights holders have no option but to enter into complex catching and processing agreements with vessel- and factory owners belonging to the existing recognised stakeholder associations. For the small-rights holders, it does not make sense to join these associations or even to form their own if they cannot actively participate in the industry independently. Greater participation by small-rights holders should start with their genuine integration into the industry through improved ability to invest in infrastructure and through management skills development. Most likely, this will require an interventionist approach by government.Department of HE and Training approved lis