100 research outputs found
Enhancing enrollment, retention and completion of pastoralist children in primary education at Balangdalalu and Mingenyi villages in Hanang district, Manyara Region
No full textThis project paper addresses the problem of poor accessibility of pastoral children to Primary Education. Special attention is given to the pastoral Barbaig community in Hanang District as the case study.
The central idea here is to inculcate the importance of education to pastoral communities. Poor accessibility of children to primary education is a major concern. Survey findings indicate low enrolment, high dropout and low retention in the localities visited. It is an indisputable fact that the problem of low enrolment and retention and high dropout is growing with increasing poverty in the area where the survey was conducted. Overall, the persistence of the problem is caused by general poverty status of the majority of parents. Other equally contributing factors were low awareness on the importance of education among parents, non conducive schooling environment, long distance to schools and migration of parents in search of pastures and grazing and associated negative culture and traditions of pastoral communities.
Basing on these findings, GET CBO addressed the primary gaps hindering pastoralist children to access primary education by putting strategies to enhance enrolment and retention and address dropouts. It was also recommended for the government to put in place strategies which respond to the needs and living conditions of children from the marginalized communities, especially the pastoralists in particular in relation to primary education. (Author abstract)Malima, R. C. (2007). Enhancing enrolment, retention and completion of pastoralist children in primary education at Balangdalalu and Mingenyivhxages in Hanang district, Manyara region. Retrieved from http://academicarchive.snhu.eduMaster of Science (M.S.)School of Community Economic Developmen
Modeling and Design of Material Separation Systems with Applications to Recycling
No full textThesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2011.This electronic version was submitted by the student author. The certified thesis is available in the Institute Archives and Special Collections.Cataloged from student-submitted PDF version of thesis.Includes bibliographical references (p. 179-193).Material separation technology is critical to the success of the material recycling industry. End-of-life products, post-consumer waste, industrial excess, or otherwise collected materials for reuse are typically mixed with other incompatible materials. These materials must be segregated using material separation processes. This thesis investigates the performance and design of material separation systems for recycling through modeling material flows within these systems. The material separation system models developed here are suited to material recycling because they encompass all types of separation process and any configuration of those processes as well as treat binary and multi-material streams. These models capture the material behavior of separation systems through mass ow balance equations constructed using system configuration and process performance data. The Bayesian material separation model is used to capture the performance of separation stages processing a binary material mixture, while the material separation matrix model, developed here, captures the performance of stages processing multi-material mixtures. A network routing model is used to describe the links between processes within a separation system. The governing mass ow balance equations constructed from the process performance and routing data form systems of linear equations. These equations can be generated and solved programatically. Separation performance can be captured through experimental methods or through physical modeling, but an investigation with either suggests that performance can vary under differing material input conditions and operational settings. Techniques for coping with these effects and potentially using them to tailor system behavior are discussed in a case study on the magnetic roller separation of beverage container shreds. Two case studies use tailored economic metrics to evaluate decisions in the design of separation systems. The effects of operating decisions on an existing plastic container separating line are quantified by evaluating the additional profit from plastics-capture decisions. The second case study investigates the economics of installing a plastics separating line at an energy from waste facility. Modeling suggests several possible configurations for a plastics separating line that outperform configurations suggested by industry experts, showing that the material separation system models developed in this work can provide design guidance in the recycling industry.by Malima Isabelle Wolf.Ph.D
A comparative analysis of four (4) schools in the Limpopo Department of Education (Sekhukhune and Capricorn Districts) in order to understand service delivery.
Get PDFM. Com. University of KwaZulu-Natal, Durban 2014.The purpose of the study was to make a comparative analysis of four (4) schools in two Districts (Sekhukhune and Capricorn) in order to understand service delivery as expressed in good or poor performance of schools in the Limpopo Province. The schools that were used as research sites are Tshebela, Mosego, Lephenye and Setlakalana Secondary Schools. Respondents were District Directors, Circuit Managers, School Principals, School Management Team Members and Learners who were sampled randomly from the target population. Ethical considerations were not bypassed as formal approvals were available.
The study focused primarily on ascertaining the reasons for the varying performances of schools that are located within the same circuits and districts. In addition, the study aimed at investigating how the different role-players contributed to the success and or failure of the schools. Objectives that are within the context of Systems Thinking are highlighted in order to use them as the bottom - line in the schooling framework. International and local literature addressing issues around the objectives were used to contextualize the area of investigation.
A mixed methods approach of research was used to strengthen data collection. Questionnaires were designed for different categories of respondents to relate their experiences and roles in promoting or defeating principles of good performance. Interviews with select individuals and with Focus Groups, together with direct observation was undertaken at a place and time convenient to the respondents. All responses were written down on the questionnaires. The response rate and a synopsis of the responses is outlined in accordance with the themes while the results analysis is congruent with the objectives of the study. The analysis of the results reflected that there was a positive relationship between the identified themes, their categories and sub – categories with either good or poor performance in some schools while the opposite was true in other schools. Recommendations for future research, learning and adopting best strategies were made
Co-occurrence and distribution of East (L1014S) and West (L1014F) African knock-down resistance in Anopheles gambiae sensu lato population of Tanzania.
Get PDFOBJECTIVE: Insecticide resistance molecular markers can provide sensitive indicators of resistance development in Anopheles vector populations. Assaying these makers is of paramount importance in the resistance monitoring programme. We investigated the presence and distribution of knock-down resistance (kdr) mutations in Anopheles gambiae s.l. in Tanzania. METHODS: Indoor-resting Anopheles mosquitoes were collected from 10 sites and tested for insecticide resistance using the standard WHO protocol. Polymerase chain reaction-based molecular diagnostics were used to genotype mosquitoes and detect kdr mutations. RESULTS: The An. gambiae tested were resistance to lambdacyhalothrin in Muheza, Arumeru and Muleba. Out of 350 An. gambiae s.l. genotyped, 35% were An. gambiae s.s. and 65% An. arabiensis. L1014S and L1014F mutations were detected in both An. gambiae s.s. and An. arabiensis. L1014S point mutation was found at the allelic frequency of 4-33%, while L1014F was at the allelic frequency 6-41%. The L1014S mutation was much associated with An. gambiae s.s. (χ(2) = 23.41; P < 0.0001) and L1014F associated with An. arabiensis (χ(2) = 11.21; P = 0.0008). The occurrence of the L1014S allele was significantly associated with lambdacyhalothrin resistance mosquitoes (Fisher exact P < 0.001). CONCLUSION: The observed co-occurrence of L1014S and L1014F mutations coupled with reports of insecticide resistance in the country suggest that pyrethroid resistance is becoming a widespread phenomenon among our malaria vector populations. The presence of L1014F mutation in this East African mosquito population indicates the spreading of this gene across Africa. The potential operational implications of these findings on malaria control need further exploration
Evaluation of the Long-Lasting Insecticidal Net Interceptor LN: Laboratory and Experimental Hut Studies against Anopheline and Culicine Mosquitoes in Northeastern Tanzania
Get PDFLong lasting insecticidal nets (LN) are a primary method of malaria prevention. Before new types of LN are approved they need to meet quality and efficacy standards set by the WHO Pesticide Evaluation Scheme. The process of evaluation has three phases. In Phase I the candidate LN must meet threshold bioassay criteria after 20 standardized washes. In Phase II washed and unwashed LNs are evaluated in experimental huts against wild, free flying anopheline mosquitoes. In Phase III the LN are distributed to households in malaria endemic areas, sampled over three years of use and tested for continuing insecticidal efficacy. Interceptor® LN (BASF Corporation, Germany) is made of polyester netting coated with a wash resistant formulation of alpha-cypermethrin. Interceptor LN was subjected to bioassay evaluation and then to experimental hut trial against pyrethroid-susceptible Anopheles gambiae and An. funestus and resistant Culex quinquefasciatus. Mosquito mortality, blood feeding inhibition and personal protection were compared between untreated nets, conventional alpha-cypermethrin treated nets (CTN) washed 20 times and LNs washed 0, 20 and 30 times. In Phase I Interceptor LN demonstrated superior wash resistance and efficacy to the CTN. In the Phase II hut trial the LN killed 92% of female An. gambiae when unwashed and 76% when washed 20 times; the CTN washed 20 times killed 44%. The LN out-performed the CTN in personal protection and blood-feeding inhibition. The trend for An. funestus was similar to An. gambiae for all outcomes. Few pyrethroid-resistant Cx. quinquefasciatus were killed and yet the level of personal protection (75-90%) against Culex was similar to that of susceptible An. gambiae (76-80%) even after 20 washes. This protection is relevant because Cx. quinquefasciatus is a vector of lymphatic filariasis in East Africa. After 20 washes and 60 nights’ use the LN retained 27% of its initial insecticide dose. Interceptor LN meets the approval criteria set by WHO and is recommended for use in disease control against East African vectors of malaria and filariasis. Some constraints associated with the phase II evaluation criteria, in particular the washing procedure, are critically reviewed
Species shifts in the Anopheles gambiae complex: do LLINs successfully control Anopheles arabiensis?
Get PDFINTRODUCTION: High coverage of conventional and long-lasting insecticide treated nets (ITNs and LLINs) in parts of E Africa are associated with reductions in local malaria burdens. Shifts in malaria vector species ratio have coincided with the scale-up suggesting that some species are being controlled by ITNs/LLINs better than others. METHODS: Between 2005-2006 six experimental hut trials of ITNs and LLINs were conducted in parallel at two field stations in northeastern Tanzania; the first station was in Lower Moshi Rice Irrigation Zone, an area where An. arabiensis predominates, and the second was in coastal Muheza, where An. gambiae and An. funestus predominate. Five pyrethroids and one carbamate insecticide were evaluated on nets in terms of insecticide-induced mortality, blood-feeding inhibition and exiting rates. RESULTS: In the experimental hut trials mortality of An. arabiensis was consistently lower than that of An. gambiae and An. funestus. The mortality rates in trials with pyrethroid-treated nets ranged from 25-52% for An. arabiensis, 63-88% for An. gambiae s.s. and 53-78% for An. funestus. All pyrethroid-treated nets provided considerable protection for the occupants, despite being deliberately holed, with blood-feeding inhibition (percentage reduction in biting rates) being consistent between species. Veranda exiting rates did not differ between species. Percentage mortality of mosquitoes tested in cone bioassays on netting was similar for An. gambiae and An. arabiensis. CONCLUSIONS: LLINs and ITNs treated with pyrethroids were more effective at killing An. gambiae and An. funestus than An. arabiensis. This could be a major contributing factor to the species shifts observed in East Africa following scale up of LLINs. With continued expansion of LLIN coverage in Africa An. arabiensis is likely to remain responsible for residual malaria transmission, and species shifts might be reported over larger areas. Supplementary control measures to LLINs may be necessary to control this vector species
An experimental hut evaluation of Olyset nets against anopheline mosquitoes after seven years use in Tanzanian villages.
Get PDFBACKGROUND: Long-lasting insecticidal nets (LLINs) are advocated by WHO for protection against malaria. Of the three brands of LLINs currently approved by WHO, Olyset(R) is the only one currently granted full recommendation. With this type of LLIN, the insecticide (permethrin) is incorporated into the polyethylene fibre during manufacture and diffuses from the core to the surface, thereby maintaining surface concentrations. It has not been determined for how long Olyset nets remain protective against mosquitoes in household use. METHODS: Examples of Olyset nets, which had been in use in Tanzanian villages for seven years, were tested in experimental huts against naturally entering Anopheles gambiae and Anopheles funestus mosquitoes. Performance was compared with new Olyset nets, conventionally treated ITNs (either newly treated with alphacypermethrin or taken from local villages after 1.5 years of use) and untreated nets. All nets were artificially holed except for the seven-year Olyset nets, which had developed holes during prolonged domestic use. RESULTS: Anopheles funestus and An. gambiae in NE Tanzania are susceptible to pyrethroids. The new Olyset nets caused high mortality against An. funestus (73.9%) and An. gambiae (62.7%) in experimental huts. The seven-year Olyset nets caused 58.9% mortality against An. funestus and 40.0% mortality against An. gambiae. The freshly treated alphacypermethrin nets also caused high mortality against An. funestus (70.6%) and An. gambiae (72.0%); this decreased to 58.4% and 69.6% respectively after 1.5 years of use. The new Olyset nets inhibited blood-feeding by 40-50%. The 7 year Olyset nets showed no feeding inhibition over that shown by the untreated nets. The alphacypermethrin treated nets failed to inhibit blood-feeding after 1.5 years of use. However iHhhdn laboratory tunnel tests samples of all types of treated net including the 7 year Olyset inhibited blood-feeding by more than 95%. CONCLUSION: After seven years of use Olyset nets were still strongly insecticidal. Mosquito mortality decreased by only 20-35% over this period. However, Olyset would not provide personal protection after seven years unless it was in good condition and all holes fully repaired
Susceptibility Status of Malaria Vectors to Insecticides Commonly used for Malaria Control in Tanzania.
Get PDFThe aim of the study was to monitor the insecticide susceptibility status of malaria vectors in 12 sentinel districts of Tanzania. WHO standard methods were used to detect knock-down and mortality in the wild female Anopheles mosquitoes collected in sentinel districts. The WHO diagnostic doses of 0.05% deltamethrin, 0.05% lambdacyhalothrin, 0.75% permethrin and 4% DDT were used. The major malaria vectors in Tanzania, Anopheles gambiae s.l., were susceptible (mortality rate of 98-100%) to permethrin, deltamethrin, lambdacyhalothrin and DDT in most of the surveyed sites. However, some sites recorded marginal susceptibility (mortality rate of 80-97%); Ilala showed resistance to DDT (mortality rate of 65% [95% CI, 54-74]), and Moshi showed resistance to lambdacyhalothrin (mortality rate of 73% [95% CI, 69-76]) and permethrin (mortality rate of 77% [95% CI, 73-80]). The sustained susceptibility of malaria vectors to pyrethroid in Tanzania is encouraging for successful malaria control with Insecticide-treated nets and IRS. However, the emergency of focal points with insecticide resistance is alarming. Continued monitoring is essential to ensure early containment of resistance, particularly in areas that recorded resistance or marginal susceptibility and those with heavy agricultural and public health use of insecticides
Evaluation of PermaNet 3.0 a deltamethrin-PBO combination net against Anopheles gambiae and pyrethroid resistant Culex quinquefasciatus mosquitoes: an experimental hut trial in Tanzania.
Get PDFBACKGROUND: Combination mosquito nets incorporating two unrelated insecticides or insecticide plus synergist are designed to control insecticide resistant mosquitoes. PermaNet 3.0 is a long-lasting combination net incorporating deltamethrin on the side panels and a mixture of deltamethrin and synergist piperonyl butoxide (PBO) on the top panel. PBO is an inhibitor of mixed function oxidases implicated in pyrethroid resistance. METHOD: An experimental hut trial comparing PermaNet 3.0, PermaNet 2.0 and a conventional deltamethrin-treated net was conducted in NE Tanzania using standard WHOPES procedures. The PermaNet arms included unwashed nets and nets washed 20 times. PermaNet 2.0 is a long-lasting insecticidal net incorporating deltamethrin as a single active. RESULTS: Against pyrethroid susceptible Anopheles gambiae the unwashed PermaNet 3.0 showed no difference to unwashed PermaNet 2.0 in terms of mortality (95% killed), but showed differences in blood-feeding rate (3% blood-fed with PermaNet 3.0 versus 10% with PermaNet 2.0). After 20 washes the two products showed no difference in feeding rate (10% with 3.0 and 9% with 2.0) but showed small differences in mortality (95% with 3.0 and 87% with 2.0). Against pyrethroid resistant Culex quinquefasciatus, mediated by elevated oxidase and kdr mechanisms, the unwashed PermaNet 3.0 killed 48% and PermaNet 2.0 killed 32% but after 20 washes there was no significant difference in mortality between the two products (32% killed by 3.0 and 30% by 2.0). For protecting against Culex PermaNet 3.0 showed no difference to PermaNet 2.0 when either unwashed or after 20 washes; both products were highly protective against biting. Laboratory tunnel bioassays confirmed the loss of biological activity of the PBO/deltamethrin-treated panel after washing. CONCLUSION: Both PermaNet products were highly effective against susceptible Anopheles gambiae. As a long-lasting net to control or protect against pyrethroid resistant mosquitoes PermaNet 3.0 showed limited improvement over PermaNet 2.0 against Culex quinquefasciatus
Evaluation of Malaria Vector Susceptibility to Insecticide in After Indoor Residual Spraying in Muleba District Kagera Region
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