East African Journal Of Science, Technology and Innovation
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Development and Evaluation of Wild-Derived Rats as Potential Experimental Models for Research
Get PDFWild rodents have been used as animal models in experimental studies of cellular aging, cerebral malaria, schistosomiasis, and leishmaniasis. Since they are the reservoirs of these diseases, recent studies have shown that research involving wild rodents is more efficient in giving a mirror image of the disease progression outside the laboratory setting. The study design was an analytic experimental study where observations were made between two groups of animals i.e. the wild-derived and lab-bred rats. The outcome of the intervention was obtained by comparing the two groups. This study sought to determine the usability of wild-derived rats as potential experimental animal models for biomedical research. Wild rats were randomly captured in areas with high transmission of Schistosoma mansoni and Leishmania donovani in Kisumu and Kitui counties, in Kenya and maintained in the animal house at Kenya Medical Research Institute (KEMRI) in Nairobi. Breeding was carried out, and the subsequent generations were used to assess schistosomiasis and leishmaniasis disease progression between the wild-derived, and laboratory-bred rats. We further monitored behavior patterns and food consumption rate for 3 months in a total of 6 experimental trials. The results on feed consumption capacity indicated that consumption was significantly higher in laboratory-bred groups (p=0.001) compared to wild-derived rats. Overall, laboratory-bred rats were significantly heavier than wild rats. In the use of rats to assess schistosomiasis and leishmaniasis disease progression, the wild-derived rats were more susceptible to leishmaniasis and may be considered for S. mansoni compared to wild (worms recovered p=0.031). In conclusion, the study indicated that wild rats are potential reservoir hosts for both schistosomiasis and leishmaniasis and have the potential to maintain cycles of infection until after successful chemotherapeutic intervention. Therefore, wild rats may provide natural means for parasites like S. mansoni and L. donovani to re-infect humans in endemic areas.
The Effect of Thickness and Deposition Angle on Optical Transmittance of ZnS/Ag Nanostructures
No full textThis paper presents the optical transmittance properties of thermally evaporated coatings of ZnS/Ag nanostructures as a function of film thickness and deposition angle designed to mitigate the challenges of indoor heating and their effects on low temperature storage facilities. The nanostructures were deposited on glass by varying the film thickness and deposition angle of both silver and zinc sulphide nanofilms at a pressure of 2.5×10-5 mBars in the diffusion pump microprocessor vacuum coater (Edwards AUTO 306). The optical transmittance of the coatings was measured at normal incidence in the wavelength range of 250-2500 nm of the incident electromagnetic radiation. Spectral studies showed that the transmittance decreased with increase in the film thickness of the ZnS/Ag nanostructures and the optical transmittance increased with increase in deposition angle of zinc sulphide in the infrared region. The transmittance of (4 nm)ZnS/Ag, (7 nm)ZnS/Ag, (10 nm)ZnS/Ag and (15 nm)ZnS/Ag samples deposited at normal angle in the visible region had peaks at 61.7%, 66.3%, 54.9%, and 18.0% respectively. The transmittance of the nanostructures increased with the increase in deposition angle of silver nanoparticles. Thus optical transmittance measured at 1800 nm wavelengths for ZnS(0o)/Ag(0o), ZnS(0o)/Ag(30o) and ZnS(0o)/Ag(60o) were 2.8%, 21.7% and 22.1% respectively. The coating of ZnS at high deposition angle decreased transmittance in the visible wavelength. The transmittance peak values in the visible region measured up to 51.1%, 53.5%, and 45.1% for (4 nm)ZnS(0o)/Ag(0o) and (4 nm)ZnS(0o)/Ag(30o) and (4 nm)ZnS(0o)/Ag(60o) samples respectively. However, increase in deposition angle of (10nm)ZnS/Ag nanostructures measured at 1000 nm; ZnS(0o)/Ag(30o), ZnS(30o)/Ag(30o) and ZnS(60o)/Ag(30o) increased transmittance in the infrared wavelengths from 9% to 12% and 34% respectively. Therefore, to increase transmittance in the visible region, the Zinc sulphide nanoparticles should be coated on silver at low deposition angles.
Optimisation of the eccentricity of the pyriform diagram for balancing electrical power systems loading
Get PDFElectricity is a vital resource need in any modern society for an enhanced lifestyle. Furthermore, electricity load management covers optimal power generation, transmission, distribution, and utilisation. Also, demand-side management is electricity consumption beyond the meter, and the ever-increasing electricity demand because of rising population and higher standards of living place a limitation and a constraint on its accessibility to all the citizens in any community. The eccentricity of the pyriform scatter diagram data shape was used to characterise the statistical distribution of the electricity consumption data points around a common axis. The Markov process, the Jordan Canonical transformation, and the Martingales were used to generalise the independent electricity consumption to depend only on the outcome preceding it and not after it. The results show a balanced light loading of 50.0%. The pyriform was symmetrical, convex, and even about the midpoint, which served as the globally optimised solution of the electricity consumption balanced loading problem. A balanced electrical power systems loading enables utilities to supply more customers, increases operational efficiencies, and places less stress on electricity generators, transmission, and distribution networks. It is recommended that optimisation of electrical power systems loading will lead to energy efficiency, energy savings, lower-cost operations for reliable and sustainable supply, growth, and development. Balanced light loading of electrical power systems components facilitates optimal unit commitment at lower economic and social costs. Whenever service taxes are reduced because of cheaper electricity prices, utilities witness flatter load curves and avoided production costs across power systems operations. This further, lessens blackouts and extends life of utility facilities
Cross-sectional study of cow comfort and management factors associated with subclinical mastitis in smallholder dairy farms in Kenya
Get PDFA number of environmental and contagious factors have been associated with subclinical mastitis (SCM), which is a common and costly problem for smallholder dairy farmers (SDF). We conducted a cross-sectional study on 118 cows in their first two months post-calving on 109 SDF in Kenya. The study objective was to investigate the relationships among various cow and farm management parameters and SCM specific to SDF. The stall floor comfort level was assessed through knee impact and wetness tests, and cleanliness on the leg and udder were also scored. Various mastitis prevention measures were also assessed (e.g., milking protocols, and use of teat dip and dry cow therapy). Individual quarter SCM was assessed on each cow using California Mastitis Test (CMT). Univariable and multivariable logistic regression models were fit to determine management factors associated with cow-level SCM. Farm-level, cow-level and quarter-level prevalence of SCM was 45.9% (50/109), 43.2% (51/118) and 21.9 % (103/471), respectively. The proportion of stalls scored as dirty was 33.1% while 49.1% of cows had dirty legs. Only 10.1% of farms were using either disinfectant teat dip or dry cow therapy (or both) to prevent mastitis. Low parity and poor stall hygiene were significantly associated with occurrence of SCM. At high daily milk yield, the probability of having SCM was higher in cows housed in a shed with a dirty versus clean alleyway, with no significant difference at low daily milk yield. From the study findings, we concluded that certain cow characteristics and comfort measures were associated with SCM and need to be incorporated in education plans for farmers in SDF
Effect of ecotype and age on semen characteristics of three Tanzanian native chickens
Get PDFSeveral findings on the semen characteristics of domestic chickens have revealed that ecotype and age significantly affect semen quality. There is, however, lack of data on effects of ecotype and age on semen characteristics of Tanzanian native roosters. This study evaluated the effect of ecotypes (Ching’wekwe, Morogoro-medium and Kuchi) and ages (11-15 and 24-28 months) on semen quality. A total of 192 semen samples were collected from 12 roosters (four from each ecotype) using the abdominal massage technique at weekly interval for four consecutive months. Semen characteristics of individual samples were evaluated. The semen volume, pH, sperm motility, sperm concentration, proportion of spermatozoa with normal morphology and proportion of live spermatozoa among the ecotypes varied from 0.42±0.04 to 0.52±0.03mL, 7.01±0.00 to 7.02±0.00, 72.81±1.27 to 76.63±1.35%, 3.90±0.98 to 4.12±1.96 x 109/mL, 86.16±0.55 to 89.38±0.80% and 88.06±1.13 to 90.97±0.81% respectively. However, only the variations in proportion of spermatozoa with normal morphology and proportion of live spermatozoa among the ecotypes were significant (P<0.05). The semen volume, pH, sperm motility, sperm concentration, proportion of spermatozoa with normal morphology and proportion of live spermatozoa among the two age groups varied from 0.44±0.03 to 0.52±0.03mL, 7.01±0.00 to 7.02±0.00, 73.88±1.13 to75.92±0.99%, 3.80±0.45 to 4.28±0.32 x 109/mL, 87.02±0.58 to 88.15±0.64%, 88.27±0.77 to 89.83±0.77% respectively. However, only the variations in semen volume among the two age groups were significant (P<0.05). The Pearson correlation coefficients between semen volume and other semen quality characteristics were mostly low to medium with positive values ranging from 0.01-0.51 between semen volume and sperm motility and between morphological normal spermatozoa and proportion of live spermatozoa, respectively. Although there is minimal variation in semen quality among ecotypes and age groups, all the ecotypes might still be used in breeding purposes to maintain native chickens, because the results found were within the reference range for chickens
Air Pollution Monitoring System Using Wireless Sensor Networks and Cloud Computing
Get PDFAir pollution is the availability of pollutants and other particles in the air which affect its quality. The common sources of air pollution include vehicle and industrial emissions, bushfire and volatile organic compounds. Over 80% of the urban dwellers are exposed to air pollution especially in low and middle-income countries. With most African countries embracing industrialization coupled with rapid urbanization, air pollution is swiftly becoming a serious concern due to the associated health risks. Globally, about 4.2 million people die annually from diseases attributed to air pollution. This paper presents a mechanism of using sensors to remotely monitor air pollution. The monitored data are then sent to the cloud database in real time using an internet connection. The materials used include an Arduino Uno, ESP8266 module, carbon monoxide and smoke sensors. The approach involves connecting an ESP8266 wireless module, smoke and carbon monoxide sensors to the Arduino board using jumpers. Results revealed that data is collected by the sensors, processed by Arduino and sent to the cloud for storage and analysis. The cloud service visualizes the received data in a graphical format for easy analysis whereas a spreadsheet document can also be extracted for offline analysis. In conclusion, a system capable of monitoring smoke and carbon monoxide pollutants has been proposed. This system is effective in sending the monitored data to a cloud database in real time. Policy makers, governments, and different stakeholders such as environment authorities should embrace such systems and also sensitize the citizens on the dangers of air pollution
Effects of poultry litter and inorganic fertilizer on growth and productivity of Rhizobia inoculated and non-inoculated beans
Get PDFAgriculture has been the most contributing sector towards Uganda’s economy. However, its output has always been hampered by declining soil fertility leading to reduced yields, increased agricultural losses, and malnourishment among low-income earners. In Uganda, there is scanty research about the effectiveness of either organic or inorganic fertilizers in crop production. Therefore, there was a need to establish the effectiveness of inorganic fertilizer (N: P: K; 17:17:17) and organic fertilizer (poultry manure/litter) on the growth, and productivity of rhizobia inoculated and non-inoculated bio-fortified NAROBEAN 2 variety, which is rich in iron and zinc, high yielding and drought resistant. A randomized complete block design experiment was conducted at Mbarara Zonal Agricultural Research and Development Institute (MBAZARDI). Poultry litter was applied at the rate of (10t/ha), N: P: K 17:17:17 at 20.3 kg ha-1, and Rhizobia at 250g per 15 kg of beans. Treatments were; Rhizobia + N: P: K 17:17:17 (M 1), Rhizobia + Poultry litter (M 2), Rhizobia only (M 3), Poultry litter only (M 4), N: P: K 17:17:17 only (M 5) and the control (M 6). Growth parameters included the number of leaves, branches, and shoot height; and productivity parameters included the number of pods produced per plant and economic yield. Statistical analyses were done at 5% level of significance. The growth parameters showed no significant difference (P > 0.05) while the bean grain yield and productivity were significantly different (p < 0.05) under the various treatments. Rhizobia + Poultry litter and N: P: K 17:17:17 only, produced the highest effect on both growth and productivity as compared to other treatments. Application of rhizobia with poultry manure was the best soil treatment for increasing the growth and productivity of NAROBEAN 2. This will increase production, food security, abate malnutrition, and sustainably improve soil quality
Exploring Infant Feeding Beliefs and Practices among Mothers in Major Urban Informal Settlements in Kenya
Get PDFAppropriate infant feeding is a proxy indicator for the good health and nutritional status of infants. The objective of this qualitative study was to explore mother’s beliefs and practices of infant feeding practices up to two years of age or beyond in major urban informal settlements in Kenya. A total of nine focus groups were conducted in three randomly selected sites, namely: Kaptembwo in Nakuru, Manyatta ‘A’ in Kisumu, and Kibera in Nairobi. Sixty-four mothers of children aged 6-24 months were chosen purposively, and the results were thematically analyzed. Results showed that most mothers still breast-fed their children, but they intended to stop breastfeeding when the child is 18 months old. Generally, the mothers reported the benefits of breastfeeding for two years of age or beyond, such as protection against diseases, improving health, and making the child strong. They perceived barriers to breastfeeding up to two years or beyond such as child illness, child’s decision, return to work, baby addiction to breast milk, and inconvenience brought about by breastfeeding. The foods perceived by mothers as good for the baby included yogurt, groundnuts, pumpkins, bananas, pawpaw, watermelon, oranges, spinach, and traditional vegetables. While the foods perceived as not good for the baby were processed milk, eggs, and sweet foods such as sodas, biscuits, cakes. Participants had a positive attitude towards water treatment and handwashing practices. The most commonly reported method of treating water was boiling. The perceived barriers to water treatment and handwashing practices included lack of fuel and water, forgetfulness, inadequate money, not able to control children. The findings indicate that increasing awareness on the duration of breastfeeding may motivate more mothers to breastfeed for two years and beyond.
Physicochemical properties and flour pasting profiles of popular sweet potato varieties from Kenya and Uganda
Get PDFSweet potato varies in physicochemical properties as a result of inherent varietal makeup and agroecological zones where they are grown. Although pasting profiles of sweet potato flour can be used to determine their end-use in food processing, information on systematic evaluation of popular varieties in Kenya and Uganda is limited. Four orange-fleshed sweet potato varieties from Kenya and four common varieties from Uganda were evaluated for their physicochemical properties and for the pasting profiles of their flours. Results indicated significant variations (p< 0.01) in the attributes of the eight varieties. Orange fleshed varieties (OFV) had comparatively higher moisture, beta carotene, fat, and mineral contents but lower pasting profiles than the non-orange fleshed varieties (NOFV). The sodium/Potassium ratio of the eight varieties ranged from 0.16 to 0.5 and within <1 that is recommended. Calcium/magnesium ratios ranged from 1.11 to 2.09 and were above the required value of 1. OFV had calcium/phosphorous values above 2.00 while NOFV had values below 0.1 against the required >0.5. OFV had lower Peak viscosities (124-590cP) and cold paste viscosities (89.5-319cP) compared to 677-1060Cp (peak viscosities) and 438-800cP (cold paste viscosities) for NOFV. Positive correlations were recorded between flour pasting profiles and carbohydrates (r = 0.71 – 0.88), starch (r = 0.26 -0.52), phosphorous (r = 0.05 – 0.37), protein (r = 0.07 – 0.30) and fiber (r = 0.54 – 0.79). Sweet potato consumption can combat hidden hunger since it is rich in various minerals. The shelf life of sweet potato can be prolonged through processing into flour including blended flours for the production of high-quality food products
Revolutionization of Revenue Collection with Government E-Payment Gateway System in Tanzania: A Public Value Creation Perspective
Get PDFThrough the Ministry of Finance and Planning, the Government of Tanzania implemented the Government Electronic Payment Gateway (GePG) system to provide an e-payment gateway platform in order to improve government revenue collection in the country. As of July 2020, the system was implemented in 660 public institutions and is integrated into 28 commercial banks and 6 mobile money operators. While the system has been widely accepted, evaluation of its adequacy and performance is necessary as many similar initiatives implemented in Africa have failed to deliver the desired outcomes. This study evaluated the performance of the system by drawing success measures based on public value: efficiency, effectiveness, and social value. The study adopted a concurrent mixed research design where the questionnaire was integrated within interviews in a single investigation involving 442 respondents from 271 public institutions in 11 regions in Tanzania. The study found that the use of the system increased revenue collection by 44.28% while reducing the cost associated with revenue collection by 27.10% between 2015/2016 and 2019/2020 in the surveyed institutions. Moreover, the use of the system enhanced the trust between citizens and government, increased transparency and traceability in the process of revenue collection. Nonetheless, the lack of integration of the GePG system with institutional billing systems and the lack of self-service facility in some institutions were found to the challenges. The findings from this study contribute to an understanding of the effectiveness of e-government systems based on public value.