Joseph K. Byaruhanga

Characterization of Chemical Composition and Microstructure of Natural Iron Ore from Muko Deposits

The study aimed at investigating the chemical composition and microstructure of raw iron ore from the deposits in Muko area (south-western Uganda). The quality of this iron ore was evaluated to establish its suitability to serve as a raw material for iron production. Samples were taken from the six hills of Muko ore deposits and tests carried out to establish their composition and properties. X-ray diffraction and scanning electron microscopy were employed in the investigation and chemical analysis performed to determine the compounds constituting the ore. The quality of this ore was compared to generalized world market standards and ores from other nations. It was found that Muko ore is a rich hematite grade with Fe content above 65%. It has little gangue (<6% SiO2 and 3-4% Al2O3) and low contents of the deleterious elements (% and %), which correspond to acceptable levels for commercial iron ores.

Genetic mutations in sodium channel domain II and carboxylesterase genes associated with phenotypic resistance against synthetic pyrethroids by Rhipicephalus (Boophilus) decoloratus ticks in Uganda

We previously reported emergence of super synthetic pyrethroid (SP) resistant Rhipicephalus (Boophilus) decoloratus ticks in Uganda. This study investigated the genetic basis of phenotypic resistance against SP in R. (B.) decoloratus and sought to identify novel diagnostic mutations for rapid detection of SP resistance in the above tick species. Genomic DNA was extracted from pooled larvae of 20 tick populations (19 of known SP susceptibility and 1 unknown susceptibility). The voltage sensitive sodium channel (VSSC) domain II S4-5 linker (SP target) and partial carboxylesterase (SP metabolizing enzyme) genes were amplified by PCR, cloned and sequenced. The resultant sequences were analyzed to determine single nucleotide polymorphisms (SNPs) associated with phenotypic resistance in the various tick populations investigated. Novel SNPs that introduced Eco RI and Eco RII restriction sites in carboxylesterase gene were identified in silco and validated with restriction fragment length polymorphism (RFLP) against 18 tick populations of known SP susceptibility. The study identified a super knock down resistance (kdr) mutation T58C in R. (B.) decoloratus VSSC associated with stable SP resistance. We further identified multiple nonsynonymous mutations in carboxylesterase of SP resistant ticks; one of which conferred novel EcoRII (G195C) restriction site for PCR-RFLP detection of SP resistance. In conclusion, this study is the first to report super kdr mutation in sodium channel domain II and multiple mutations in carboxylesterase genes that may concurrently mediate stable resistance against synthetic pyrethroids in R. (B.) decoloratus ticks from Uganda. The Eco RII based PCR-RFLP is a useful tool for rapid detection of stable SP resistant R. (B.) decoloratus ticks.

Retrospective study on cattle and poultry diseases in Uganda

Abstract Cattle and poultry enterprises are among the major contributors to food security and socioeconomic empowerment of households in Uganda. However, various diseases constrain their productivity. A two-year retrospective study between April 2012 and March 2014 was conducted using records for cattle and poultry diseases diagnosed at the Central Diagnostic Laboratory (CDL) to determine prevalent diseases in Uganda. The laboratory received 836 samples from poultry (36.3%) and cattle (63.7%). Of the 836 samples, 47.5% had a definitive diagnosis of disease causation. Most of the cattle and poultry diseases diagnosed were protozoan diseases (39.3%) followed by bacterial (21.4%), viral (17.1%), helminthiasis (11.1%), nutritional diseases (4%) and others (7.1%). For poultry, viral diseases (29.5%) and protozoan diseases (27.1%) especially newcastle disease (44.3%) and coccidiosis (100%) respectively, were the most diagnosed. While for cattle, hemo-protozoan parasites (52.1%) were the most prevalent, of which 92.9% were east coast fever infection. Bacterial infection (20.5%) in cattle were the second most diagnosed diseases and mastitis was the most diagnosed (46.2%). In summary, coccidioisis, collibacillosis, newcastle disease, gumboro disease, and avian helminthiasis were the most prevalent poultry diseases while in cattle, east coast fever, helminthiasis, mastitis, brucellosis and rabies were the most frequently diagnosed diseases. This study has identified the major diseases that hinder poultry and cattle production in Uganda. The data generated by CDL could be used for surveillance, monitoring and designing strategic interventions for control of poultry and cattle diseases in Uganda.

Prevalence of endometritis and its associated risk factors in dairy cattle of Central Uganda.

Aims: Endometritis is a major postpartum disease that affects dairy cattle productivity which is accompanied by heavy economic losses to the farmer. The status of Clinical endometritis (CE) and Sub-Clinical Endometritis (SCE) in sub-Saharan Africa is poorly understood, thus the study was carried out to provide information on the prevalence and associated risk factors that are responsible for the occurrence of SCE and CE in dairy cattle of Central Uganda. Study Design: This was a prospective study involving 140 dairy cattle within 60 days postpartum from 35 commercial dairy farms in Central Uganda. The dairy herds were visited in both the dry (n=90) and wet season (n=50) and subsequent visits were conducted after 3 months and 5 months to collect data for reproductive performance Original Research Article Tayebwa et al.; AJEA, 7(3): xxx-xxx, 2015; Article no.AJEA.2015.115 155 Methodology: A metricheck® device was used to collect the cervico-vaginal discharge which was examined for color, odor, texture, and measurement of its pH during the postpartum period for diagnosis of endometritis. Further examination of the reproductive tract was carried out using a vaginal speculum and subsequently rectal palpations were performed. The objectives of the study were to determine the prevalence of CE and SCE in the Central Uganda and assess the risk factors involved. Results: In this study, the prevalence of CE and SCE was established at 3.6% and 18.6% respectively, this burden was slightly higher in the wet than in the dry season but with no statistical significance P=0.126. Dairy cattle that had calved more than three times were shown to be associated with a higher body appearance (BCS > 3) than those that had calved down fewer times. Dystocia, Retained After Birth and Abortion were identified as associated risk factors (P = 0.00) to SCE and CE whereas infertility and Prolonged days calving to conception (>90 d) were postpartum implications (P=0.00) associated with SCE and CE in this study. This would be attributed to the poor management of postpartum dairy cattle in the farms visited as no farm was found with a maternity pen. SCE caused infertility in 65.5% of the dairy cattle whereas the CE is a major influencing factor to long calving to first AI and calving to conception interval (306d±90.6), On basis of reproduction, there was no major difference towards use of AI or Natural service. Conclusion: Management of endometritis in the region should address pre-partum and postpartum dairy herd management through improved extension service delivery and technical farm support to construct maternity pens, Endometritis is a multifactorial disease that requires a multidisciplinary approach to boost nutrition and health thus reducing incidence of risk factors such as dystocia and Retained fetal birth) .subsequent studies should be carried out to explore the national burden of SCE and ascertain the cause of the abortion.

Characterisation of the Physical and Metallurgical Properties of Natural Iron Ore for Iron Production

The blast furnace is still the dominant form of iron production, but over the years, direct reduction methods have increased due to a number of reasons. Overall, iron production methods have optimal requirements with respect to the feed materials especially iron ore. In this study, tests were carried out on Muko iron ore from Uganda to analyse its suitability to meet the feed requirements of todays dominant iron production methods. More specifically, the Tumbler, Abrasion, and Shatter Indices of the ore were determined. In addition, porosity, thermoanalysis, and reducibility tests were performed. Overall, the Muko ore was found to have good mechanical properties exemplified with tumble and shatter index data >89.0 wt% and <2.5 wt%, respectively. Furthermore, its reducibility at 0.87%/min is within the acceptable range as a natural material feed for blast furnace and direct reduction furnaces. Also, the energy requirement for heating the ore to 1100°C was found to be higher in the samples containing a wider size range of irregular grains and the largest contaminations. In summary, it is concluded that the Muko iron ore has good physical and metallurgical properties to serve as a natural material for the blast furnace and direct reduction furnaces.

C190A knockdown mutation in sodium channel domain II of pyrethroid-resistant Rhipicephalus appendiculatus

This study investigated the target site mutations in the partial sequence of voltage-sensitive sodium channel (VSSC) domain II of synthetic pyrethroid (SP)-resistant Rhipicephalus appendiculatus. Genomic DNA was extracted from seven tick populations (two susceptible and five resistant) collected from central, eastern and southwestern Uganda. The PCR amplicons of the VSSC domain II were cloned and sequenced to determine novel single nucleotide polymorphisms (SNP). A non-synonymous mutation C78 A corresponding to C190 A was found in all the five SP-resistant ticks. The C78 A mutation led to amino acid substitution from leucine to isoleucine (L21I) which was previously reported to confer knockdown (kdr) mutation in R. (Boophilus) microplus. The genetic confirmation of SP-resistant R. appendiculatus in central and southwestern Uganda calls for an urgent strategy for controlling the ticks.

A Quantitative Evaluation of the Quality of Recycled Steel in Uganda

All steel made in Uganda is currently manufactured from scrap. Such steel has often been characterized by unpredictable performance in consonance with its inconsistent raw material inputs. This study evaluates and relates the mechanical, metallurgical and geometrical properties of these bars in order to identify the factors underlying the performance of the products from this steel and examine the relationship with their scrap content. In order to study the steels, tensile, torsion and micrographic tests have been carried out together with spark emission spectrometry on samples collected from different plants. The test results generally indicate impressive steel resilience, strength and metallographic properties in spite of relatively high and irregular carbon content. Limited weldability, uniaxiality of properties, uneven scatter of microelements and substantial non-uniformity of longitudinal mechanical properties have been observed. Rolling and post rolling defects have been noted. The geometric reliability of the bars has also been found generally low. Improvement of secondary refinement, use of direct reduced iron (DRI) diluent and more diligent sorting have suggested as solutions.Copyright

Electroporcelains from Raw Materials in Uganda: A Review

Porcelains are vitrified and fine grained ceramic whitewares, used either glazed or unglazed. Electrical porcelains are widely used as insulators in electrical power transmission systems due to the high stability of their electrical, mechanical and thermal properties in the presence of harsh environments. They are primarily composed of clay, feldspar and a filler material, usually quartz or alumina. These materials are widely available in Uganda, but little research has been carried out on them in relation to technical porcelains let alone their use for the same. Based on the abundance of the requisite materials and the corresponding demand for insulation materials, this paper reviews the current and traditional methods of manufacturing electrical porcelains. The major objective is to review the processes for production of electric porcelains from the basic raw materials including material characterisation methods.