Software defined radio (SDR) introduces endless possibilities for future communication technologies. Instead of being limited to a static segment of the radio spectrum, SDR allows RF front-ends to be more flexible by using digital signal processing (DSP) and cognitive techniques to integrate adaptive hardware with dynamic software. We present the design and implementation of an innovative RF front-end transceiver architecture for application into a SDR test-bed platform. System-level requirements were extracted from the Space Network User Guide (SNUG). Initial system characterization demonstrated image leakage due to poor filtering and mixer isolation issues. Hence, the RF front-end design was re-implemented using the Weaver architecture for improved image rejection performance.

Darbe analizuojama Blackfin procesorių sparta vaizdo apdorojime akių žvilgsnio sekimui. / New Blackfin media processors perfomance was analyzed for video preprocessing in eye gaze tracking.

Over 80% of colorectal cancers (CRCs) are sporadic/randomly arising tumors. Interval CRCs represent a subset of sporadic tumors that develop within 6-36 months after a negative colonoscopy. Interval CRCs are suggested to exhibit altered biological properties that contribute to rapid growth and proliferation. We hypothesize that chromosomal instability (CIN), or aberrant chromosome numbers, contributes to the etiology of Interval CRCs. We have assembled a Manitoban cohort of Interval and sporadic (control) CRC tumor samples, and established a fluorescence in situ hybridization approach to characterize CIN by enumerating specific chromosomes. The results of this study indicate that 75% of Interval CRCs exhibit a CIN phenotype, making CIN the most prevalent contributor to genomic instability in Interval CRCs. Only once we grasp a better understanding of the tumorigenic pathways through which Interval CRCs develop, can we tailor screening strategies and treatment options to specifically identify and combat this subset of sporadic CRC.

A variety of genes that influence aging have been identified in a broad selection of organisms including Saccharomyces cerevisiae (yeast), Caenorhabditis elegans (worms), Drosophila (fruit flies), Macaca Mulatta (rhesus monkeys), and even Homo sapiens. Many of these genes, such the TOR’s, FOXO’s, AKT’s, and S6K’s are conserved across different organisms. All of these genes participate in nutrient sensing networks. Other conserved genetic networks may similarly affect lifespan. In this thesis, I explored genes from an iron metabolism family and a heat shock protein (HSP) gene family that have been identified, but not confirmed, to influence lifespan. Yeast is a reliable model for mitotic (replicative) aging. Using yeast, I tested whether the FET-genes, encoding a family of iron importer-related genes, are required for mitotic lifespan. I also tested whether another family of genes, the yeast SSA HSP70- encoding genes, related to mammalian HSP70s, influence mitotic aging. I primarily used the replicative lifespan (RLS) assay, in which I measured the mitotic capacity of multiple FET and SSA yeast mutants. I hypothesize that aging occurs when iron transport is misregulated, which may lead to an over-reliance on HSPs for lifespan maintenance. The results presented in this thesis support the hypothesis. First, FET3 was primarily involved in lifespan maintenance under normal conditions (2% glucose), while FET5 was primarily involved in the cellular lifespan extension characteristic of caloric restriction (0.01% glucose), a known anti-aging intervention. In addition, SSA2 appeared to facilitate lifespan maintenance in the absence of FET4, while the presence of SSA1 limited lifespan length. That the aging genes identified in this study are involved in iron metabolism or heat stress suggests that protein aggregation or reactive oxidative species production are common processes through which these genes interact.

Philosophiae Doctor - PhD / Bionomics of vector-borne pathogens (VBPs) is a complex phenomenon that involves understanding the ecology of arthropod borne pathogens and vertebrate hosts potentially involved in their transmission cycles. Investigations into the bionomics of viral and bacterial VBPs circulating in Baringo and Homa Bay Counties of Kenya were carried out. Specifically, vertebrate hosts represented in mosquito bloodmeals, presence of arboviruses in blood fed mosquitoes and patients presenting with acute undiagnosed febrile illnesses in rural health facilities, and tick borne pathogens (TBPs) diversity in ticks of animals were identified. Mosquitoes were trapped by BG sentinel and CDC light traps, while ticks were sampled directly from domestic animals and tortoises close to human habitation along the shores and adjacent islands of Lakes Victoria and Baringo in Kenya. Blood and sera were also sampled from patients presenting with acute febrile illnesses visiting four rural health facilities in Homa Bay County. Mosquitoes and ticks were sorted and identified to species using standard morphological taxonomic keys. All the biological samples (blood-fed mosquitoes, ticks and blood/sera) were processed using molecular and culture procedures for detection of VBPs (arboviruses, Ehrlichia, Anaplasma, Rickettsia and protozoa). Among 445 blood-fed Aedeomyia, Aedes, Anopheles, Culex, Mansonia, and Mimomyia mosquitoes, 33 bloodmeal hosts were identified including humans, eight domestic animal species, six peridomestic animal species and 18 wildlife species. Further detection of Sindbis and Bunyamwera viruses was done on blood-fed mosquito homogenates by Vero cell culture and RTPCR in Culex, Aedeomyia, Anopheles and Mansonia mosquitoes from Baringo that had fed on humans and livestock. In TBPs assay, 585 tick pools were analysed consisting of 4,126 ticks collected in both study areas. More ticks were sampled in Baringo (80.5%), compared to Homa Bay (19.5%). In Baringo, agents of ehrlichiosis were detected from Amblyomma and Rhipicephalus ticks including Ehrlichia ruminantium (12.3%), Ehrichia canis (10.5%) and Paracoccus sp. (4.4%). Agents of anaplasmosis included Anaplasma ovis (7.2%), Anaplasma platys (4.4%) and Anaplasma bovis (4.0%), all from Hyalomma, Amblyomma and Rhipicephalus ticks, as well as agents of rickettsiosis, including Rickettsia africae, Rickettsia aeschlimannii, Rickettsia rhipicephali, Rickettsia montanensis and a Rickettsia sp. that was not conclusively characterized. Babesia caballi, Theileria sp. and Hepatozoon fitzsimonsi were also detected from both Rhipicephalus ticks and Amblyomma ticks. In Homa Bay, Ehrichia ruminantium (17.5%) and Ehrichia canis (9.3%) were isolated from Amblyomma latum and Rhipicephalus pulchellus, as well as Anaplasma platys (14.4%) and Anaplasma ovis (14.4%) from Amblyomma and Rhipicephalus species. In determination of the occurrence of arboviruses among patients presenting with acute febrile illnesses, acute Bunyamwera 3 (0.9%) and Sindbis 2 (0.6%) infections were detected by RT-PCR and cell culture and Sindbis seroprevalence was determined by plaque assay. Though a significant proportion of these patients tested positive for low Plasmodium parasitemia, none were co-infected with Plasmodium parasites and arboviruses. This study highlights the presence and relative importance of zoonotic VBPs in both study areas.

Microfinance Institutions (MFIs) in sub-Saharan Africa (SSA) and the developing world have over the years attracted and received billions of US dollars (valued at over US$4 billion annually worldwide) in subsidies and concessionary funds. These subsidies are used to capitalize, promote growth, and help improve efficiency, operations and performance of newly established MFIs. At face value these interventions seem positive, yet studies have shown that they can be counterproductive in terms of their effect on the performance, efficiency and self-sustainability of the MFIs. This research addresses this issue by identifying four determinants of MFI’s performance and analysing the effect that subsidies have on them. A quantitative approach was used in the analysis in which the financial data of 92 MFIs were estimated using panel data estimation. The method of variable selection was based on the procedure used by Nawaz (2010). This method of determining the relationship between selected performance and sustainability indicators and subsidy was modelled on the Subsidy Dependant Index (SDI) method of analysis developed by Yaron (1992a) and the Return on Asset (ROA), Operational Self-Sufficiency (OSS) and Financial Self-Sufficiency (FSS) methods of analysis developed by the SEEP Network (2005). The summary results of the analysis showed that the majority of MFIs (90.22%) were not sustainable nor were they found to be profitable. However, the results show that all the institutions were operationally self-sufficient and that, on average, MFIs in SSA charged higher interest rates than MFIs in other parts of the world. The average OSS was 136.01% showing that MFIs are operationally self-sufficient. However, the average FSS value was 74.32% reflecting that the MFIs are not able to raise enough revenue to cover their capital and indirect costs which would ultimately result in them running out of equity funds. The inclusion of subsidies in the sustainability regressions resulted in a decline in the ability of the MFIs to attain operational and financial self-sufficiency, thus showing the negative effect subsidies have on the sustainability of MFIs. Inflation and interest rates charged on loans also had a negative effect on sustainability as they resulted in an increase in costs and a decline in the number of low income clients. MFIs located in wealthier countries were found to be more efficient because of the lower costs associated with having wealthier clients who have larger loan sizes. MFIs in lower income countries have to overcome limitations of weak infrastructures, low population densities and rural markets which increase operating costs. Older institutions were found to more likely be sustainable than new and young MFIs as expected because of their improved efficiency and productivity and also because they have more experience and are therefore better equipped to overcome challenges. However, by adding subsidy in the analysis the results show that the level of efficiency of MFIs is reduced. The results also show that with increased maturity MFIs are found to be more productive, however, when subsidies are included in the finances the levels of productivity will decline as costs increase. NBFIs are the most suitable business model to practice in MFIs in Africa according to the findings which reflect that NBFIs are more profitable and efficient than any of the other business models in the sample. However, cooperatives were found to be the most productive business model as they have a stronger borrower to staff ratio than the other institutional types. Furthermore, cooperatives and NBFIs tend to have clients who are better off and therefore can afford to take larger sized loans, unlike clients of NGOs who are poor who struggle to have a stable income. Copyright / Dissertation (MSc(Agric))--University of Pretoria, 2012. / Agricultural Economics, Extension and Rural Development / unrestricted

Gender inequalities are still widely pervasive and deeply institutionalised, particularly in Africa, where the burden of disease is highly gendered. The public health sector has been slow in responding to and addressing gender as a determinant of health. The purpose of this inquiry was to gain a deeper insight into the different ways in which gender was represented in the public health curriculum in sub-Saharan Africa. A qualitative inquiry was undertaken on gender in the curriculum in nine autonomous schools of public health in sub-Saharan Africa. Official curriculum documents were analysed and in-depth interviews were held with fourteen staff members of two schools that served as case studies. A content analysis of the data was carried out, followed by discourse analysis. A poststructuralist theoretical framework was used as the ‘lens’ for interpreting the findings. Most of the official curricula were ‘layered’, with gender not appearing on the surface. Gender was represented mainly as an implicit discourse and appeared explicitly in only one core course and a few elective modules. The overwhelmingly dominant discourse in the official curricula was the ‘woman’ discourse, with a strong emphasis on the reproductive and maternal roles of women, while discourses on men, sexuality and power relations seemed to be marginalised. Gender discourses that emerged from the in-depth interviews with participants were lodged in biological, social and academic discourses on gender. The dominant discourses revolved around sexual difference and role differences based on sex. Participants drew on societal discourses (family, culture and religion), academic discourses and their lived experiences to explain their understandings of gender. Their narratives on the teaching of gender showed that gender was not taught or received a low priority and that it was insufficiently addressed in the public health curriculum. Barriers to teaching gender were: lack of knowledge, resources and commitment; resistance; and competing priorities. From this study it emerged that curriculum and the production of gender knowledge are sites of struggle that result in multiple understandings of gender that are manifest in dominant and marginalised discourses. Prevailing institutional power relations mirror dominant societal and political discourses that have a fundamental effect on curriculum decisions and resource allocations. This interplay between dominant discourses and power relations, underpinned by a strong biomedical paradigm, could explain the positioning of gender as an implicit representation in the curriculum, with a more explicit focus on gender in the elective modules than in the compulsory or core courses. Being implicitly represented, gender does not compete with other priorities for additional resources. It is recommended that the public health curriculum be reconceptualised by: accommodating multiple understandings of gender; questioning constructed dominant gender discourses; considering broader, varied and complex social, cultural, economic, historical and political contexts in which gender is constructed and experienced; and moving from curriculum technicalities to understanding the curriculum as a process and not a product. / Thesis (PhD)--University of Pretoria, 2010. / School of Health Systems and Public Health (SHSPH) / Unrestricted

This paper examined the nexus between health care expenditure and economic growth in Sub-Saharan Africa. It is widely acknowledged that health is a type of human capital and a critical factor in the process of economic growth. Health production, in turn, is a major determinant of health outcomes. While the former relationship has been extensively researched in developed countries, very few studies have attempted to investigate this relationship in developing countries, particularly Sub-Saharan Africa (SSA). Furthermore, very few studies have been conducted in SSA to investigate the relationship between health determinants, health outcomes, and economic growth. This study takes on the challenge of investigating this three-way relationship for SSA countries. Different variables like population, saving and foreign direct investment were found to be statistically significant determinants of economic growth using the Arellano-Bond Dynamic GMM technique for 26 SSA countries, while food availability were found to be significant determinants of life expectancy. On the other hand, none of the health indicators are significant determinants of economic growth in the region, implying that health outcomes must be improved in order to have a significant impact on growth. The findings should prompt immediate policy changes to harmful indicators in order to better stimulate health-led economic growth in SSA.

<p>  This dissertation has two essays that are focused on understanding the effects of technology adoption decisions made by smallholder farmers who have incomplete information. The first essay employed a clustered randomized control trial (RCT) with factorial design in upper Eastern Kenya to estimate the impact of three different interventions at improving credence attributes of smallholder farmers’ maize. This essay also utilized a Becker DeGroot Marschak auction method to determine if farmers were willing to adopt a credence technology, and if yes, if their willingness to pay varied based on having previous experience with this agricultural technology. The second essay used the 2018/19 Ethiopia Socio-economic Survey to analyze the impacts of three sources of measurement error caused by farmers’ misperceptions on maize yields. Moreover, this essay explored how farmers’ incomplete information about adoption of one agricultural input led to misallocation of other complementary inputs. </p>

The following thesis regards the use of small aperture telescopes for space domain awareness efforts. The rapidly populating space domain was motivation for the development of a new operation scheme to conduct space domain awareness feasibility studies using small telescopes. Two 14-inch Schmidt-Cassegrain Telescopes at the California Polytechnic State University and the Air Force Research Lab in Kirtland AFB, NM, in conjunction with a dedicated CCD camera and a commercial DSLR camera, were utilized to conduct optical observations on satellites in Earth orbit. Satellites were imaged during August 2019, and from January 2020 to March 2020, resulting in the collection of 77 valid images of 16 unique satellites. These images were used to obtain celestial spherical coordinates, which were used in Gauss and Double-R angles-only initial orbit determination methods. Initial orbit determination methods successfully produced valid results, reaffirming the feasibility of using small aperture telescopes for such methods. These orbit determinations were used to propagate orbit states forward in time to determine the feasibility of future imaging of the targets with the same apparatus. Propagation results demonstrated that initial orbit determinations rapidly decayed in accuracy over distant times and are most accurate for immediate satellite passes. In addition, an attempt to combine multiple initial orbit determinations using Lambert’s problem solutions was made. Combination of these multiple initial orbit determinations resulted in either no orbit state accuracy improvement compared to individual initial orbit determinations, or a decrease in accuracy compared to these methods. Ultimately, efforts demonstrated that small telescope usage is feasible for orbit determination operations, however there may be a need for hardware and operational revisions to improve the ability of the apparatus.