Experimental investigation of the effect of reflectors on thermal performance of box type solar cooker.

Cooking consumes a tremendous amount of energy on a regular basis. Solar energy is a very versatile and free energy source that could be used for different applications, including solar cooking. The aim this study is intended to experimentally investigate the effect of different reflectors on the performance of solar box cookers. Box-type solar cooker has been produced and tested with no reflector, aluminum foil reflectors, and mirror glass reflectors cases. Load and no-load tests have been conducted for all three reflector cases and the performances of cookers for each cases reflector have been determined. Several cooking tests was conducted in the outdoors, to investigate the thermal performance of the cooker using water as the absorbing medium. The results of the experimental demonstrate that, the cooker with three side mirror glass reflectors could reach a reasonably high temperature with better efficiency. 1.5 kg of water boiled in 51 min and its second figure of merit was found as 0.533 using mirror glass reflectors. The mirror glass reflector increases the efficiency of the experimental box-type solar cooker by 134% as compared with the cooker having no reflector. The experimental cooker with no reflector did not boil water during the testing period, so it is not recommended for cooking applications; whereas the cooker with the mirror glass reflector has been confirmed to cook most Ethiopian dishes with reasonable performance.

'Restoring the person's life': a qualitative study to inform development of care for people with severe mental disorders in rural Ethiopia.

AIMS: In low-income countries, care for people with severe mental disorders (SMDs) who manage to access treatment is usually emergency-based, intermittent or narrowly biomedical. The aim of this study was to inform development of a scalable district-level mental health care plan to meet the long-term care needs of people with SMD in rural Ethiopia. METHODS: The present study was carried out as formative work for the Programme for Improving Mental health CarE which seeks to develop, implement and evaluate a district level model of integrating mental health care into primary care. Six focus group discussions and 25 in-depth interviews were conducted with service planners, primary care providers, traditional and religious healers, mental health service users, caregivers and community representatives. Framework analysis was used, with findings mapped onto the domains of the Innovative Care for Chronic Conditions (ICCC) framework. RESULTS: Three main themes were identified. (1) Focused on 'Restoring the person's life', including the need for interventions to address basic needs for food, shelter and livelihoods, as well as spiritual recovery and reintegration into society. All respondents considered this to be important, but service users gave particular emphasis to this aspect of care. (2) Engaging with families, addressed the essential role of families, their need for practical and emotional support, and the importance of equipping families to provide a therapeutic environment. (3) Delivering collaborative, long-term care, focused on enhancing accessibility to biomedical mental health care, utilising community-based health workers and volunteers as an untapped resource to support adherence and engagement with services, learning from experience of service models for chronic communicable diseases (HIV and tuberculosis) and integrating the role of traditional and religious healers alongside biomedical care. Biomedical approaches were more strongly endorsed by health workers, with traditional healers, religious leaders and service users more inclined to see medication as but one component of care. The salience of poverty to service planning was cross-cutting. CONCLUSIONS: Stakeholders prioritised interventions to meet basic needs for survival and endorsed a multi-faceted approach to promoting recovery from SMD, including social recovery. However, sole reliance on this over-stretched community to mobilise the necessary resources may not be feasible. An adapted form of the ICCC framework appeared highly applicable to planning an acceptable, feasible and sustainable model of care.

cAMP modulates cGMP-mediated cerebral arteriolar relaxation in vivo.

No studies have specifically addressed whether cAMP can influence nitric oxide (NO)/cGMP-induced cerebral vasodilation. In this study, we examined whether cAMP can enhance or reduce NO-induced cerebral vasodilation in vivo via interfering with cGMP efflux or through potentiating phosphodiesterase 5 (PDE5)-mediated cGMP breakdown, respectively, in cerebral vascular smooth muscle cells (CVSMCs). To that end, we evaluated, in male rats, the effects of knockdown [via antisense oligodeoxynucleotide (ODN) applications] of the cGMP efflux protein multidrug resistance protein 5 (MRP5) and PDE5 inhibition on pial arteriolar NO donor [S-nitroso-N-acetyl penicillamine (SNAP)]-induced dilations in the absence and presence of cAMP elevations via forskolin. Pial arteriolar diameter changes were measured using well-established protocols in anesthetized rats. In control (missense ODN treated) rats, forskolin elicited a leftward shift in the SNAP dose-response curves (approximately 50% reduction in SNAP EC50). However, in MRP5 knockdown rats, cAMP increases were associated with a substantial reduction in SNAP-induced vasodilations (reflected as a significant 35-50% lower maximal response). In the presence of the PDE5 inhibitor MY-5445, the repression of the NO donor response accompanying forskolin was prevented. These findings suggest that cAMP has opposing effects on NO-stimulated cGMP increases. On the one hand, cAMP limits CVSMC cGMP loss by restricting cGMP efflux. On the other, cAMP appears to enhance PDE5-mediated cGMP breakdown. However, because increased endogenous cAMP seems to potentiate NO/cGMP-induced arteriolar relaxation when MRP5 expression is normal, the effect of cAMP to reduce cGMP efflux appears to predominate over cAMP stimulation of cGMP hydrolysis.

Regulation of rat pial arteriolar smooth muscle relaxation in vivo through multidrug resistance protein 5-mediated cGMP efflux.

Multidrug resistance protein 5 (MRP5) has been linked to cGMP cellular export in peripheral vascular smooth muscle cells (VSMCs) and is widely expressed in brain vascular tissue. In the present study, we examined whether knockdown of MRP5 in pial arterioles [via antisense oligodeoxynucleotide (ODN) applications] affected nitric oxide (NO)/cGMP-induced dilations. The antisense or (as a control) missense ODN was applied to the cortical surface approximately 24 h before study via closed cranial windows. The efficacy of the antisense vs. missense ODN in eliciting selective reductions in MRP5 expression was confirmed by analysis of MRP5 mRNA in pial tissue. Unexpectedly, in initial studies, a significantly lower maximal pial arteriolar diameter increase in the presence of the NO donor S-nitrosoacetylpenicillamine (SNAP) was seen in the antisense vs. missense ODN-treated rats (35 vs. 48% diameter increase, respectively). It was suspected that this related to a reduced vascular smooth muscle cell sensitivity to cGMP due to prolonged exposure to increased intracellular cGMP levels elevated by overnight restriction of cGMP efflux. That postulate was supported by a finding of a diminished vasodilating response to the cGMP-dependent protein kinase-activating cGMP analog 8-p-chlorophenylthio-cGMP in antisense vs. missense ODN-treated rats. To prevent desensitization, additional rats were studied in the presence of chronic NOS inhibition via Nomega-nitro-L-arginine. In the NO synthase (NOS)-inhibited rats, the maximal SNAP response was much higher in the antisense (62% increase) vs. the missense ODN (40% increase) group. A similar result was obtained when monitoring responses to the soluble guanylyl cyclase-activating drugs YC-1 and BAY 41-2272. Moreover, in the presence of NOS inhibition, the normal SNAP-induced rise in periarachnoid cerebrospinal fluid cGMP levels, which reflects cGMP efflux, was absent in the antisense ODN-treated rats, a finding consistent with loss of MRP5 function. In conclusion, if one minimizes the confounding effects of basal cGMP production, a clearer picture emerges, one that indicates an important role for MRP5-mediated cGMP efflux in the regulation of NO-induced cerebral arteriolar relaxation.