A new lateral trench-gate conductivity modulated power transistor

In this paper, a new conductivity modulated power transistor called the Lateral Trench-Gate Bipolar Transistor (LTGBT) is presented. This structure incorporates a trench-gate in which the locations of the channel and source in conventional LIGBT have been interchanged. This channel and source arrangement results in significant improvement in latch-up current density. Experimental results indicate that the static and dynamic latch-up current densities are improved by 2.3 and 4.2 times, respectively, compared to those of the LIGBT at a n+ cathode length of 5 μm. Dependence of the latch-up current density of the LTGBT on the design of the n+ and p+ cathode regions is examined both numerically and experimentally. The maximum controllable current density is found to be increased when the space between the trench-gate and the p+ cathode is reduced. Specifically, as the space is decreased to 2 μm, no latch-up phenomenon was observed. This nonlatch-up characteristic is obtained at the expense of a slight increase (0.8 V) in threshold voltage.published_or_final_versio

Clinical and patient-reported outcomes of Chinese patients undergoing haemodialysis in hospital or in the community: A 1-year longitudinal study

Aim: Little is known about the effect of haemodialysis (HD) setting on outcomes of patients with end stage renal disease (ESRD). The study aimed at comparing clinical outcomes and patient-reported outcomes (PRO) of patients on community-based (CBHD) and hospital- based haemodialysis (HBHD). Methods: A prospective cohort of Chinese ESRD patients receiving HBHD (n=89) or CBHD (n=117) in Hong Kong were followed up for 12 months. Subjects were assessed on clinical outcomes of dialysis adequacy (Kt/V) and blood haemoglobin and PRO of health-related quality of life (SF-12v2), general health condition (Global Rating Scale (GRS)) and confidence to cope with their illness (Patient Enablement Instrument (PEI)). Differences between groups were analysed by independent t-tests for the SF-12v2, GRS and PEI scores. Chi-square tests were used to analyse the difference in proportion of patients reaching the targets of Kt/V and blood haemoglobin and with GRS>0 and PEI>0. Multiple linear and logistic regressions were performed to assess the adjusted difference-in-difference estimation. Results: The mean PEI and GRS scores of CBHD patients at 12 months were significantly higher than those of HBHD patients. CBHD patients had significantly greater improvement in self-efficacy and were more likely to be enabled after 12 months than the HBHD patients. Conclusion: The study showed similar clinical outcomes and PRO between CBHD and HBHD but CBHD was more effective than HBHD in promoting patient enablement over a 12-month period. The results suggest added value for patients receiving CBHD and support the transfer of HD care from the hospital to the community.published_or_final_versio

Enhanced survival and regeneration of axotomized retinal ganglion cells by a mixture of herbal extracts

The aim of this study is to investigate the effects of Panax quinquefolius L. extract (PQE), Ginkgo biloba extract (GBE), and Hypericum perforatum extract (HPE), in combination or alone, on the survival and regeneration of axotomized retinal ganglion cells (RGCs) in an optic nerve transection model in adult hamsters. Unilateral transection of the optic nerve was performed to evaluate the effects of herbal extracts on the survival of axotomized RGCs. Effects of the herbal extracts on axonal regeneration of axotomized RGCs, on the other hand, were studied by attaching a peripheral nerve graft onto the transected ocular stump to induce regeneration. Operated animals received daily oral administration of vehicle or herbal extracts (PQE, GBE, and HPE), alone or in combination, for 7 and 21 days, respectively, in the survival and regeneration experiments. Surviving and regenerating RGCs were retrogradely labeled with Fluoro-Gold. The eyes were then enucleated and the retinas were flat-mounted for the counting of the labeled RGCs. Treatment with PQE, GBE and HPE alone failed to offer neuroprotection to injured RGCs. However, treatment with Menta-FX, a mixture of PQE, GBE, and HPE, significantly augmented RGC survival 7 days postaxotomy. Treatment with Menta-FX also induced a significant (87%) increase in the number of regenerating RGCs 21 days after optic nerve transection. This study demonstrates that herbs can act as a potential neuroprotective agent for damaged RGCs. It also suggests that the therapeutic value of herbal remedies can be maximized by the use of mixtures of appropriate herbs.published_or_final_versio

Incentives for wetlands conservation in the Mufindi wetlands of the Great Ruaha River Tanzania

Sustainable wetland management has to some extent become a high  priority for world’s environmentalists. Achieving sustainable wetland  management may require an increase in the voluntary adoption of best  management practices by both local communities and the government. This may be preceded by more tailored suite of incentive measures which  are effective in encouraging local people to adopt proper management practices. This study presents results from a study done in the Little Ruaha catchment of the Great Ruaha River Basin. Household surveys were done to assess the relevant incentives for wetlands management and how local  communities perceived the incentive and incentive mechanisms for sustainable wetland management. It was revealed that not every member of the community was motivated to conserve wetland and thus the  perceived wetland conservation incentives also vary greatly. Among  preferred incentives were; joint management, privatization, alternativeincome generating activities and land use rights/legal land ownership. Government policies and regulations were not perceived as real incentives. This study recommends a ‘tool-box’ of incentives which will encourage a range of local people in different situations to conserve wetlands. However, the tool box of incentives and their programs should be implemented with extra cautions as it may result into perverse incentives and consequently lead into unequal benefit sharing becoming disincentives to conservation and further degradation of wetlands.Key Words: Incentives; Disincentives; Wetlands; Great Ruaha Rive

The Fall of the Tragic Hero: A Critique of the “Hubristic Principle”

The idea of attaching moral depravity to the fall of the tragic heroes (according to Aristotle, those men who enjoy prosperity and high reputation like Oedipus and Thyestes etc.) did not start with the three tragic poets, namely; Aeschylus, Sophocles and Euripides, but rather it dates back even to Homer. This idea is, of course, influenced by the old Greek tradition of Koros, Hubris, Nemesis and Ate. The totality of this traditional view and its application is equated to the phrase ‘hubristic principle’, in the scheme of this work. The hubristic principle makes specific that the fall of the herois as a result of a sin or wrong that he committed. The commission of this wrong must not go unpunished. In effect, the hand of Justice, what they call nemesis, no matter how delayed must fall on the hero. The problem is how then do you reconcile situations where the fall of the hero is not hismaking? In other words, where do you place undeserved misfortune that befalls the hero? Apparently, it is this inadequacy of the hubristic syndrome that Aristotle proposes hamartia (Greek, for error) as the appropriate means in accounting for the fall of the tragic hero. This paperdiscusses first, the hubristic principle and its application and second, assesses the reliability of the theory in accounting for the fall of the tragic hero

Woody vegetation stocking, composition and diversity in Miombo Woodlands in Tanzania: A case study of Mgori forest reserve in Singida District

Participatory forest management (PFM) model is aimed at improving both forest resources conservation and livelihoods of local communities. In Tanzania, PFM is widely spread in forest reserves bearing the names of joint forest management, co forest management and community based forest management. However, despite the wide spread, less so far has been done to assess its contribution to conservation of the forest resources and livelihoods of local communities. The study, however, majored on assessment of forest resources by describing woody stocking, and species composition and diversity at Mgori Forest Reserve, in Tanzania. Mgori forest reserve (MFR) is one of the reserves in Tanzania, which are under the model. MFR is within miombo woodlands of Tanzania allocated along the western side of the country. Inventory data were collected from four village forest reserves, which are part of MFR. Atotal of 136 plots of the size 20 x 50 m (0.1ha) were laid in different clusters. The study enumerated a total number of 79 tree/shrub species. DBH distribution followed an inverse ‘J’ shape. Stem density in the study ranged between 494 and 885 N ha-1, while basal area and woody volumedistribution followed a ‘J’ shape. The basal area varied from 9.65 to 18.50 m2 ha-1, while the woody volume was averaged to 65.99 m3 ha-1 with a range of 54.49 to 104.47 m3 ha-1. The most dominant tree species in the study were Brachistigia spiciformis and Jubernadia globifolia. Importantvalue index of tree species ranged between 4.29 and 10.00, while Shannon Weiner index was between 2.54 and 3.04. Index of dominance in this study was between 0.03 and 0.11, while species diversity index ranged from 38.46 to 89.36 and species richness and evenness ranged between 9.65 and 21.04 and 1.55 and 1.81 respectively. The study concludes that woody stocking parameters as well as tree/shrub species composition and diversity indices are normal and similar to any other reserved forests in miombo woodlands.Key words: miombo woodland, stem density, basal area, woody volume, species composition, diversity, participatory forest management, village forest reserve

Acute Kidney Injury: Global Health Alert

Acute kidney injury (AKI) is increasingly prevalent in developing and developed countries and is associated with severe morbidity and mortality. Most etiologies of AKI can be prevented by interventions at the individual, community, regional and in-hospital levels. Effective measures must include community-wide efforts to increase an awareness of the devastating effects of AKI and provide guidance on preventive strategies, as well as early recognition and management. Efforts should be focused on minimizing causes of AKI, increasing awareness of the importance of serial measurements of serum creatinine in high risk patients, and documenting urine volume in acutely ill people to achieve early diagnosis; there is as yet no definitive role for alternative biomarkers. Protocols need to be developed to systematically manage prerenal conditions and specific infections. More accurate data about the true incidence and clinical impact of AKI will help to raise the importance of the disease in the community, increase awareness of AKI by governments, the public, general and family physicians and other health care professionals to help prevent the disease. Prevention is the key to avoid the heavy burden of mortality and morbidity associated with AKI

The role of Bahi swamp wetlands in enhancing household food security and income of adjacent communities

The study was conducted to assess the role of Bahi swamp resources in enhancing household food security and income of adjacent communities. Specifically, the study assessed the socioeconomic activities in the swamp with a potential contribution to local livelihoods, the contribution of the swamp in enhancing household food security and income and the level of local dependence on the swamp. Two villages (Makulu and Nagulo-Bahi)  were involved. Data were collected through questionnaire, PRA techniques(resource mapping, key informant interviews and focused group  discussions) and direct observation. Data were summarized and analysed using Microsoft Excel, SPSS and content analysis. Other data from  discussions were analysed through relative ranking. The socioeconomic activities with potential contribution to food security and income of adjacent communities in order of importance included crop cultivation, fishing,  livestock grazing and collection of thatching grasses. Cultivation of paddy rice contributed significantly to household food security generating 65.4% of total household food crop production compared to other crops grown in drier areas adjacent to the swamp. Fishing played a substantial contribution to household food security through household consumption of 10% of fish caught. For household income, sales of paddy rice from the swamp contributed 59.6% while fish sales contributed 36% of the total annual household income. Multiplier activities emerging during fishing season facilitate income to a wider group of communities. On average, 56.2% of the population depend on the swamp for daily socio-economic activities associated with generation of household food and income. The Bahi swamp and related products play a significant role in enhancing local livelihoods for the adjacent communities. Planning for  wise use of the swamp in respect of the dominant socioeconomic activities will likely improve its  contribution to livelihoods.Key words: Bahi swamps, food security, income, wetland

Influence of hydrological fluctuations on vegetation and Avifauna species composition, abundance and diversity in the Bahi Swamp wetlands Central Tanzania

This study was conducted in Bahi wetlands to assess the influence of  hydrological fluctuations on the vegetation and avifauna species  composition, abundance and diversity. A total of 80 rectangular vegetation plots measuring 2m x 5m were established along transect lines radiating from the core wetland, along eight cardinal directions each transect having a length of 1200m and accommodating 10 sampling points. Avifauna  species were inventoried in 3 points along each transect making a total of 24 sampling points for birds. One-way ANOVA was performed to  test for significant differences in the avifauna species diversity along the  hydrological gradient. A total of 40 avifauna species and 56 plant species belonging to 18 and 7 families respectively were recorded. There were  significant differences (p<0.05) in avifauna and plant species composition, abundance and diversity between distances from the centre of the wetland. Avifauna species abundance and diversity decreased with increasing   distance from centre of the wetland. Likewise, the abundance of plant species decreased with increasing distance from the centre of the wetland. The flora and avifauna species composition, abundance and diversity in theBahi wetlands are influenced by hydrological fluctuations, whereby the  composition, abundance and diversity are higher closer to the wetland than away from the edge of the wetland. The vegetation of wetland is  dominated by Leersia hexandra and other members of the Graminae  family. Bahi wetland is a refuge for migratory avifauna species. It was observed that both distant and African migrants visit the wetland for wintering. The most abundant species were Greater Flamingoes and Red Knobbed Coot. Awareness and education on the biodiversity values of the wetland is needed to influence conservation and sustainable utilization of  the wetland resources

Influence of socio-economic factors on land use and vegetation cover changes in and around Kagoma forest reserve in Tanzania

The Miombo woodland ecosystem has been and continues to face conservation threats. We assessed the socio-economic drivers of land use and vegetation cover changes and the extent of land use/cover change in and around Kagoma Forest Reserve (KFR), Tanzania. Household survey, field observations and focus group discussions were used to obtain socio-economic data that influence land use and vegetation cover changes and logistic regression model was used to establish the relationship between socio-economic drivers and land cover change. Remote sensing and GIStechniques were used to analyze land use and vegetation cover changes over the past 23 years. Landsat imagery of 1988, 1999 and 2010 were used in this study. The perceived drivers for the changes include; overgrazing, demand for forest products, shifting cultivation, agriculturalexpansion, increasing crop prices and lack of land tenure. It was revealed that there has been significant land use and vegetation cover transformation from one class to another. In the period of 12 years (1988-1999) woodland, cultivated land and settlements increased by 5.8%, 5.9% and 0.52% respectively, while forests decreased by 5.64%. During 1999-2010 period woodland decreased by 22.97% and forest by 2.5%, while cultivated land increased by 6.07% and settlements by 9.14%.Enforcement of different laws and regulations relating to natural resources and land use planning to improve land tenure and resource use in villages bordering the forest can substantially reduce the problem of land degradation.Key words: Land use, vegetation, cover changes, Kagoma Forest Reserve, Tanzani