A Time-Predictable Memory Network-on-Chip

To derive safe bounds on worst-case execution times (WCETs), all components of a computer system need to be time-predictable: the processor pipeline, the caches, the memory controller, and memory arbitration on a multicore processor. This paper presents a solution for time-predictable memory arbitration and access for chip-multiprocessors. The memory network-on-chip is organized as a tree with time-division multiplexing (TDM) of accesses to the shared memory. The TDM based arbitration completely decouples processor cores and allows WCET analysis of the memory accesses on individual cores without considering the tasks on the other cores. Furthermore, we perform local, distributed arbitration according to the global TDM schedule. This solution avoids a central arbiter and scales to a large number of processors

A Time-predictable Memory Network-on-Chip

To derive safe bounds on worst-case execution times (WCETs), all components of a computer system need to be time-predictable: the processor pipeline, the caches, the memory controller, and memory arbitration on a multicore processor. This paper presents a solution for time-predictable memory arbitration and access for chip-multiprocessors. The memory network-on-chip is organized as a tree with time-division multiplexing (TDM) of accesses to the shared memory. The TDM based arbitration completely decouples processor cores and allows WCET analysis of the memory accesses on individual cores without considering the tasks on the other cores. Furthermore, we perform local, distributed arbitration according to the global TDM schedule. This solution avoids a central arbiter and scales to a large number of processors

Reflecting strategic and conforming gendered experiences of community health workers using photovoice in rural Wakiso district, Uganda

BACKGROUND: Community health workers (CHWs) are an important human resource in Uganda as they are the first contact of the population with the health system. Understanding gendered roles of CHWs is important in establishing how they influence their performance and relationships in communities. This paper explores the differential roles of male and female CHWs in rural Wakiso district, Uganda, using photovoice, an innovative community-based participatory research approach. METHODS: We trained ten CHWs (five males and five females) on key concepts about gender and photovoice. The CHWs took photographs for 5 months on their gender-related roles which were discussed in monthly meetings. The discussions from the meetings were recorded, transcribed, and translated to English, and emerging data were analysed using content analysis in Atlas ti version 6.0.15. RESULTS: Although responsibilities were the same for both male and female CHWs, they reported that in practice, CHWs were predominantly involved in different types of work depending on their gender. Social norms led to men being more comfortable seeking care from male CHWs and females turning to female CHWs. Due to their privileged ownership and access to motorcycles, male CHWs were noted to be able to assist patients faster with referrals to facilities during health emergencies, cover larger geographic distances during community mobilization activities, and take up supervisory responsibilities. Due to the gendered division of labour in communities, male CHWs were also observed to be more involved in manual work such as cleaning wells. The gendered division of labour also reinforced female caregiving roles related to child care, and also made female CHWs more available to address local problems. CONCLUSIONS: CHWs reflected both strategic and conformist gendered implications of their community work. The differing roles and perspectives about the nature of male and female CHWs while performing their roles should be considered while designing and implementing CHW programmes, without further retrenching gender inequalities or norms

Iron Behaving Badly: Inappropriate Iron Chelation as a Major Contributor to the Aetiology of Vascular and Other Progressive Inflammatory and Degenerative Diseases

The production of peroxide and superoxide is an inevitable consequence of aerobic metabolism, and while these particular "reactive oxygen species" (ROSs) can exhibit a number of biological effects, they are not of themselves excessively reactive and thus they are not especially damaging at physiological concentrations. However, their reactions with poorly liganded iron species can lead to the catalytic production of the very reactive and dangerous hydroxyl radical, which is exceptionally damaging, and a major cause of chronic inflammation. We review the considerable and wide-ranging evidence for the involvement of this combination of (su)peroxide and poorly liganded iron in a large number of physiological and indeed pathological processes and inflammatory disorders, especially those involving the progressive degradation of cellular and organismal performance. These diseases share a great many similarities and thus might be considered to have a common cause (i.e. iron-catalysed free radical and especially hydroxyl radical generation). The studies reviewed include those focused on a series of cardiovascular, metabolic and neurological diseases, where iron can be found at the sites of plaques and lesions, as well as studies showing the significance of iron to aging and longevity. The effective chelation of iron by natural or synthetic ligands is thus of major physiological (and potentially therapeutic) importance. As systems properties, we need to recognise that physiological observables have multiple molecular causes, and studying them in isolation leads to inconsistent patterns of apparent causality when it is the simultaneous combination of multiple factors that is responsible. This explains, for instance, the decidedly mixed effects of antioxidants that have been observed, etc...Comment: 159 pages, including 9 Figs and 2184 reference