CMD: A Multi-Channel Coordination Scheme for Emergency Message Dissemination in IEEE 1609.4

In the IEEE 1609.4 legacy standard for multi-channel communications in vehicular ad hoc networks(VANETs), the control channel (CCH) is dedicated to broadcast safety messages while the service channels (SCH's) are dedicated to transmit infotainment service content. However, the SCH can be used as an alternative to transmit high priority safety messages in the event that they are invoked during the service channel interval (SCHI). This implies that there is a need to transmit safety messages across multiple available utilized channels to ensure that all vehicles receive the safety message. Transmission across multiple SCH's using the legacy IEEE 1609.4 requires multiple channel switching and therefore introduces further end-to-end delays. Given that safety messaging is a life critical application, it is important that optimal end-to-end delay performance is derived in multi-channel VANET scenarios to ensure reliable safety message dissemination. To tackle this challenge, three primary contributions are in this article: first, a channel coordinator selection approach based on the least average separation distance (LAD) to the vehicles that expect to tune to other SCH's and operates during the control channel interval (CCHI) is proposed. Second, a model to determine the optimal time intervals in which CMD operates during the CCHI is proposed. Third, a contention back-off mechanism for safety message transmission during the SCHI is proposed. Computer simulations and mathematical analysis show that CMD performs better than the legacy IEEE 1609.4 and a selected state-of-the-art multi-channel message dissemination schemes in terms of end-to-end delay and packet reception ratio.Comment: 15 pages, 10 figures, 7 table

Supply chain performance and satisfaction : investigating the perceptions of relationship quality in the Ugandan maize supply chain

This PhD research assessed the perception of supply chain relationship quality and how it influences supply chain performance and satisfaction. The study was conducted in a triadic agribusiness (maize) supply chain in Uganda. Maize is an important economic crop due to the fact that Uganda has a competitive advantage in the production segment of the maize supply chain. These strategic advantages means that improvements in maize marketing systems have the potential to increase household income and hence contribute to poverty reduction for the predominantly smallholder maize farmers. To succeed and remain competitive, maize supply chain members needs to improve on their collaborative behaviours through establishing and maintaining long-term relationships. Using a triad as a unit of theory and analysis, primary data was collected from 150 maize supply chain members i.e. supplier, focal firms, customers. We find that good relationship quality was perceived to positively influence performance. Improvements in supply chain performance was positively associated with economic satisfaction, but not with social satisfaction. Further, we found that relationship duration and firm size did not influence the perceptions performance and satisfaction. On power relations, use of coercive power was perceived to negatively influence performance, while the use of non-coercive power was perceived to positively influence performance. In each of the examined relationships, supply chain members differed in their perceptions of relationship quality. The observed differences in perceptions revealed the different mechanisms through which the supply chain manages its downstream and upstream segments. While the formal downstream was managed based on contracts and trust, the informal upstream was managed based on power-dependency and trust relationships. Basing on transaction cost economics, the balance theory and the structural-hole concept, this study illustrates how a supply chain is capable of managing its formal and informal segments to ensure success of the entire supply chain. We conclude that engaging in good supply chain relationships has potentials to improve the performance of individual supply chain members, as well as the performance of the entire supply chain. However, for it to succeed, these relationships have to be tailor-made to fit the respective supply chain partners’ perspectives, interests and characteristics

Lending Terms and Financial Performance Of Small Medium Enterprises In Uganda: Case of Soroti District

The rate of improvement on SMEs performance in developing countries was significantly lower than in the developed world as a result of weak clients’ financial performance linked to high lending terms. A cross sectional survey and descriptive research design was used and questionnaire administered to the SMEs. Findings reveal that there was insufficient liquidity, effective financial efficiency of resource utilization, high risk of solvency leading to financial distress and that lending terms of financial institutions are linearly related to the financial performance of SMEs with the lending terms explaining 26.6% variations of the performance of SMEs that borrowed. Thus lending terms of financial institutions had a low influence in performance than other factors. Keywords: Lending terms, Financial Performance, SMEs, Financial institutions

Validation of an improved isolation and detection method for Campylobacter jejuni in various foods

Scope and Method of Study:The Food and Agricultural Products Center (FAPC) method, an improved method for the detection and isolation of Campylobacter in food, was compared to the Food and Drug Administration/Bacteriological Analytical Method (FDA/BAM) method in the recovery of Campylobacter jejuni inoculated in food samples. Beef, chicken skin, milk and ground beef samples were kept at 4°C for 10 days and the effects of enrichment time storage period, blood supplementation of the enrichment broth and detection method on the recovery of Campylobacter inoculated in the food samples were investigated over the storage period. The abilities of the two methods to recover two strains of Campylobacter jejuni ATCC 29428 and 33560, inoculated in the food samples over the storage period were compared.Findings and Conclusions:The results from FDA and FAPC methods for detection of Campylobacter jejuni from food samples were found not to be statistically different from each other. Blood supplementation of the enrichment broth had no effect on the recovery of Campylobacter from food in either method. Although the counts of Campylobacter cells recovered after 48 hours of enrichment were higher than those recovered after 24 hours, counts recovered after 24 hours served the purpose of enrichment and thus, there is no need for a 48-hour enrichment period. The growth curves of Campylobacter cultured at 37°C and 42°C demonstrated that it can grow well at either temperature and therefore it is not necessary to grow Campylobacter at 42°C as required by the FDA protocol. One incubation temperature at 37°C was adequate to recover Campylobacter cells from the food matrices tested

Feasibility Study of Hydrogen Production from Wind Energy in Narvik

The use of renewable energy sources is gaining momentum globally as possible replacements for fossil fuels which have proven to be serial contributors to global warming. Hydrogen is one such environmentally friendly fuel with zero carbon emission proven to be reliable for use in the transport sector. Since hydrogen is an energy carrier, its mode of production has for a long time relied on high carbon emission fuels that negate its authority as emission-free fuel. Therefore, this study investigates a green hydrogen production method based on water electrolysis using electrical energy from wind power. The project entails a detailed wind resource assessment around Narvik region through historical meteorological data analysis, and CFD simulations using Windographer and WindSim software programs to ascertain the viability of the wind power potential of the area. Thereafter, the project establishes suitable location(s) for appropriate wind turbine siting to generate optimal net AEP for use in the electrolysers. Subsequently, a detailed analytical calculation is conducted on the possible amount of hydrogen that can be produced when a water electrolyser system is installed at the Djupvik site based on the net AEP values obtained. Finally, there is determination of the probable cost estimates for such a venture

Impact of introducing human immunodeficiency virus testing, treatment and care in a tuberculosis clinic in rural Kenya

SETTING: In July 2005, Médecins Sans Frontières and the Ministry of Health, Kenya, implemented an integrated tuberculosis-human immunodeficiency virus (TB-HIV) programme in western Kenya. OBJECTIVE: To evaluate the impact of an integrated TB-HIV programme on patient care and TB programme outcomes. DESIGN: Retrospective evaluation of three time periods: before (January-June 2005), shortly after (January-June 2006) and medium term after (January-December 2007) the implementation of the integrated programme. RESULTS: Respectively 79% and 91% of TB patients were HIV tested shortly and at medium term after service integration. The HIV-positive rate varied from 96% before the intervention to respectively 88% (305/347) and 74% (301/405) after. The estimated number of HIV-positive cases was respectively 303, 323 and 331 in the three periods. The proportion of patients receiving cotrimoxazole prophylaxis increased significantly from 47% (142/303) to 94% (303/323) and 86% (285/331, P < 0.05). Before the intervention, 87% (171/197) of the TB-HIV patients would have been missed when initiating antiretroviral treatment, compared to respectively 29% (60/210) and 36% (78/215) after the integration. The TB programme success rate increased from 56% (230/409) to 71% (319/447) in the third period (P < 0.05); however, there was no significant decrease in the default rate: 20% to 22% (P = 0.66) and 18% (P = 0.37). CONCLUSION: Integrated TB-HIV care has a very positive impact on the management of TB-HIV patients and on TB treatment outcomes

Value chain and marketing margins of cassava: An assessment of cassava marketing in northern Uganda

Cassava is one of the emerging market oriented agricultural commodities with potential to contribute to improved livelihoods of smallholder farmers in Uganda. Besides being a food crop, cassava is attracting more attention as a commercial commodity. The rise in the commercial orientation of cassava is due to the fact that cassava products have important industrial applications for plywood, textile, bakery, pharmaceutical, paper, alcohol, and food industries. However, this commercial potential of cassava has not been fully realized in Uganda, with cassava being largely produced and consumed domestically. There is need to understand the factors hindering the commercialization of cassava and its products if it’s full potential are to be realized. This paper assessed the market potentials of cassava and its products in northern Uganda with the aim of improving its commercialization. Data was collected through a quantitative survey of 110 cassava producers and traders in Lira District between 2012 and 2013. Analysis was done using SPSS and Excel. Results show that fresh tubers dominated the marketed products by both producers and retailers (50 %). Among the three cassava marketing channels, the producer – retailer channel had the highest gross margins; sold as a bag at the farm gate price of $12, the retailer realizes a markup price of$ 8 per bag. Selling cassava as a “heap” on the street was even more valuable as the price is pegged at an average 50% above the farm gate price. Processing of cassava increased the gross margins by at least 40% compared to fresh tubers. Producers realized gross margins that were 112% above those for fresh tubers, suggesting that producers can benefit from processing cassava into chips. Wholesalers had advantage only when they marketed cassava flour (US$0.32) second to retailers at US$0.56. These findings suggest that cassava has good market potential to improve the incomes and livelihoods of households in northern Uganda. This, however, can only be realized if cassava can be processed into value added products such as starch and high quality cassava flour which have high commercial values.Key words: Cassava, cassava products, value chain, marketing  margin, northern Ugand