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Evaluating Soil Quality and Productivity of Different Clusters in Kabanon-Kapkamak Irrigation Scheme, Kenya
Get PDFThis study investigated soil conditions with an objective of differentiating the area into different clusters on the basis of topographical characteristics, hydrological processes, and degree of erosion, soil surface characteristics, soil colour, depth, texture, structure and consistence across the rolling uplands into the valley bottom. Within each cluster, five composite (replicate) samples were collected at the depth of 0-20 cm and subjected to laboratory determination of soil quality attributes such as pH, soil organic carbon, macro- and micro-nutrients. The adequacy of soils for plant growth was assessed, using semi-quantitative land evaluation methods, where ranges of numerical values of the selected soil quality indicators were rated and assigned fractional values (in percentage). The functional relationships between the measured soil quality attributes and relative crop yields were applied to determine the soil quality and productivity index for describing the biophysical production potential of each of the clusters. All the soil data and land evaluation processes were subjected to analysis of variance (ANOVA) at 95% confidence level, using Genstat Computer Software. Six clusters were identified and the major differences between them were found to be the degree of erosion, stratification and compactness, with an important bearing on the planning and designing of the irrigation layout. The soil pH for all the clusters fell between 6.0 and 7.6, an appropriate pH for most crops. The variations of soil pH between different clusters were found to be insignificant (P>0.05). The most limiting factors were found to be nitrogen and soil organic carbon, with percentage deficiency levels ranging from 51 to 76 in all the six clusters. These deficiencies called for blanket fertilizer recommendation across the six clusters with respect to all soil quality indicators with exception of phosphorous and potassium. Since phosphorous and potassium levels varied widely between the six clusters, the fertilizer types and levels required to enhance the availability of these nutrients to plants should be cluster-specific
The Use of Trichoderma Viride C. in the Management of Chilli Root Knot Disease in Nakuru County, Kenya
Get PDFChilli (Capsicum annum L.) is a sub-tropical crop grown for its pungent tasting fruits and sour leaves. Kenya is among the largest exporters of chilli. Chilli yields are largely reduced by sedentary nematodes (Meloidogyne spp). Chillis are prone to root knot nematodes which reduce the quality and yields. This study focused on the use of Trichoderma viride as a potential biocontrol agent against root knot nematodes. Investigation was done on the effect of Trichoderma viride at different concentrations on the plant height, leaf number, stem diameter, number of galls, nitrogen and phosphorous levels in chilli infected with root knot nematodes. Four dilutions of Trichoderma viride were obtained through serial dilution (100%, 50%, 25% and 12.5%). Bio-control efficacy of Trichoderma viride against the root knot nematodes was tested under glasshouse and field conditions. Evaluation after treatment of plants with T. viride isolates showed that there was no significant effect on plant heights, number of galls, stem diameter or leaf number in chilli. There was significant difference in the nitrogen and phosphorous levels when different treatments of Trichoderma viride were applied on chilli with root knot nematodes
A comparison in Diel Organic Matter Drift in two Great Rift Valley Streams, Kenya
No full textRiparian plant litter serve as the main energy source for low order streams where opportunities for photosynthesis are limited by the canopy cover shading. Transport, retention and breakdown of this matter is crucial for stream metabolism. Drifting organic matter was collected over a 24 hr period between 7th and 8th February 2012 in the Njoro (disturbed) and 17th to 18th February 2012 in the Ellegirini (less disturbed) streams. Two drift samplers (mesh size 100 µm) were emptied every 15 minutes. It was hypothesized that the quantity of organic matter drifting from both streams is not the same. Significantly, more organic matter (pooled data) drifted in Ellegirini than in the Njoro River (t = 9.200, d.f = 150, p < 0.001). Organic matter that drifted during the day was significantly higher than during the night (t = 2.812, d.f = 70, p < 0.01) in the Njoro River. This was not the case in the Ellegirini River (t = 0.751, d.f = 76 p > 0.05). Leaves dominated other plant categories in both streams. It is concluded that organic matter drift in large quantities in less disturbed than disturbed rivers and as a consequence can support diverse communities. It is advisable to link organic matter drift with benthos in future studies for better understanding of organic matter dynamics in tropical streams
Line-of-Sight-Polarized Wide-Band Mimo Measurements at 2-5 GHz
Get PDFA short- range line of sight (LOS) multiple-input multiple-output (MIMO) channel transfer function was measured for a 4x4 system between 2.0 and 5.0 GHz. Measurements were made for a fixed antenna spacing of 2? for all the four antenna polarizations in an indoor environment. Capacity and spatial correlation were investigated and the maximum mean capacity loss of 7.18% was realized when the orientation of the receiving and the transmitting antenna arrays were transformed from co-polar to cross-polar configuration. Furthermore, a validity test was conducted and the empirical distribution was found to be the same and within the theoretical values
Influence of Maternal High Protein Intake on Daily Energy Expenditure and Lactation Performance in the Laboratory Mouse
Get PDFLaboratory mouse (strain MF1) was used as a model to investigate the effects of high protein intake on daily energy expenditure and lactation performance. The specific dynamic action (SDA) for high protein (HP: 60% energy as protein) and high carbohydrate (HC: 70% energy as carbohydrate) diets was measured using open-flow respirometry at 9.4% and 6.1%, respectively. The same two diets were fed ad libitum to mice during lactation. Mice fed on HP and HC diets at 21 ºC reached an asymptote in their daily food intake at 12.29±0.2 g day-1 and 16.57±0.2 g day-1, respectively between days 12-17 of lactation. HP-fed mice had a significantly higher daily energy expenditure (DEE) measured by doubly labelled water (133.4±4.8 kJ day-1) and higher water turnover (41.1±6.2 g day-1) than HC-fed mice (DEE: 102.1 ±14.2 kJ day-1 and water turnover: 26.7±6.5 g day-1) but the energy they exported as milk was significantly lower (84.2±31.4 kJ day-1) than that of HC-fed mice (164.6±30.5 kJ day-1) and therefore resulted in poor growth rate of their offspring. The urea production of HP-fed mice from their daily protein intake of 7.1 g was estimated at 1994 mg which required 10.2 ml of water per day to be cleared. The mice increased their urine production by 14.4 ml probably to eliminate this urea. In conclusion, the MF1 mice fed HP diet at 21 ºC and the HC-fed mice reached an asymptote in their daily food intake at 12.29 g day-1 and 16.57 g day-1 respectively, between days 12-17 of lactation. HP diet had negative effects on lactation performance at 21 ºC when compared with the HC diet. The negative effects of the HP diet were due to the higher DEE which resulted from the heat production consequent of digestion and milk production by the HP-fed mice. Therefore, the higher DEE greatly reduced the energy available for milk production. This probably explains the reduction in growth of the pups/offspring from the HP-fed mothers because they did not get sufficient energy for growth. 
Rescheduling Lengthy Downloads on Bottleneck Links
Get PDFTCP’s ability to share bottleneck bandwidth fairly and efficiently dwindles when faced with an increase in the number of competing flows. Indeed studies have shown that long TCP flows consume more than 90% of the available bandwidth, with short flows consuming a very small portion. It is also known that out of these, a very small percentage of the largest flows carry the majority of the bytes. The utilization pattern of bottleneck links exacerbates this situation. During the daytime (peak period), the network utilization is characteristically high whereas at night (off-peak period), the link is virtually idle. At peak periods, TCP’s congestion control mechanisms highly favour long-lived flows at the expense of their short-lived counterparts. We discuss the design and implementation of a flow rescheduling tool. The tool identifies, blocks and reschedules long flows to reconnect during the off-peak period. Network bottlenecks are a commonplace phenomenon in many IP networks just as much as they are unavoidable. TCP’s ability to share bottleneck bandwidth fairly and efficiently dwindles when faced with an increase in the number of competing flows. Indeed recent studies have shown that long TCP flows consume more than 90% of the available bandwidth, with short flows consuming a very small portion. It has also been realized that out of these, a very small percentage of the largest flows carry the majority of the bytes. The utilization pattern of bottleneck links does not make matters any better. During the day, the utilization pattern is characteristically high whereas at night, the link is virtually idle. We refer to these times as the peak and offpeak periods respectively. At peak time, TCP’s congestion control mechanisms highly favor long-lived flows at the expense of their short-lived counterparts. This work discusses the design and implementation of a flow rescheduling tool, specifically illustrating the techniques used to achieve accuracy and robustness. The tool works by identifying and rescheduling long flows to reconnect during the off-peak period, when link utilization is very low. We present validation results for the tool which demonstrate its reliability in the face of actual Internet conditions
Effects of Macrobends on the Attenuation of Optical Signals in Multi-Mode Graded Index 62.5/125 µm Cable at 850 nm Wavelength
Get PDFIn fibre optic transmissions, macrobend is a large visible bend in the optical fiber that can cause attenuation, a reduction of optical power in the glass. A relatively large- radius bend in an optical fibre may results to the degradation of the optical signal. In this paper, different magnitudes of circular macrobends in graded index 62.5/125 cable at 850 nm wavelength were used to determine the effect of macrobends on attenuation of signals. A special bending jig was used to produce circular bends ranging from 3mm to 200mm. The insertion method was used while attenuation (signal power loss) was measured in decibels (dB). Statistical analysis software (SAS) at a significant level of 5 per cent (and least significant difference
(LSD) ranking method were used for data analysis. The findings showed that large magnitude of macrobend radii (above 40.0 mm) resulted in low attenuation (about 9.0 dB) of signals, while small size bend radii (about 3.0 mm) produced very high (about 40.0 dB ) of signal losses. The research findings indicate that macrobends have significant effects on the attenuation of optical signals
Design and Application of Bio-economic Modelling in Livestock Genetic Improvement in Kenya: A Review
Get PDFBio-economic modelling in livestock production systems presents the opportunity for incorporating some elements of human decision making and simulates the impact of such decisions using mathematical relationships produced from biological and economic parameters. This paper has reviewed the processes of bio-economic modelling as applied to livestock genetic improvement especially in simulating profitability of alternative enterprises as well as estimation of biological and economic weights. A collection of country specific bio-economic models developed for different species of livestock have been critically analysed in describing their design and application. Participation of target group farmers in design and implementation of the models with respect to their reliability has been presented. It is found that most models were generated from animal lifecycle on farm while considering animal age groups, biological and economic parameters influencing revenues and costs. The differences in the level of participation closely related to the production system of target farmers. Bioeconomic models have remained a tool for professional animal breeders with little extension of the technique to fit farmers’ preferences. In most cases, livestock farmers had very little control of the estimates of parameters generated from bio-economic modelling. Farmer-based option (accounting for risks) of bio-economic modelling could increase acceptability and utilisation of estimates derived from them. Therefore design and application of bio-economic models for livestock genetic improvement could greatly benefit from participation of target groups and incorporation of sensitive systemic variables to improve repackaging of information that enhance sustainable adoption by actors in the livestock industry
Determination of the Bending Strength and Hardness Values of Sisal Fiber Reinforced Polyester Composites
Get PDFSchistosomiasis and geohelminthic infections are major public health problems in developing countries and exert a heavy burden on morbidity when they occur singly or concurrently. Chemotherapeutic approach has been adopted in many endemic areas, using praziquantel and albendazole, based on World Health Organization (WHO) recommendations for control. The need for cost-effectiveness considerations in control strategies requires that greater emphasis be placed on further research to understand the factors that determine their occurrence and response to chemotherapy when they occur singly or concurrently. Towards this, a longitudinal survey in Kisumu and Siaya counties, Kenya, was conducted to assess the post-treatment prevalence of Schistosoma mansoni, Trichuris trichiura, Ascaris lumbricoides and hookworms in school children (9–12 years) and adults over a 9-month period (September 2008 – May 2009). Adults were followed up monthly, while children were followed up every two months. Baseline prevalence of schistosomiasis was 52.0% + 2.5% in adults, and 38.5% + 1.8% in children while that of geohelminthiasis was 22.5% + 3.9% and 55.6% + 4.1% in adults and school children respectively. The difference in prevalence between the adults and children for both schistosomiasis and geohelmithes was not significant (P=0.9302), After 9 and 5 treatments in adults and children respectively, there was reduction in prevalence of schistosomiasis to 28.9% + 2.3% and 24.0% + 3.1% in adults and children respectively, while in geohelminthiasis prevalence reduced to 4.3% + 1.5% in adults and 27.0% + 2.5% in school children. These difference in prevalence among adults and children was not significant (P=0.8717). This study shows the differential occurrence of schistosomiasis and geohelmiths in children and adults. It also shows that frequent and consistent treatment decreases the prevalence of helminths in endemic areas and is effective both in adults and children. There’s however need for further studies to determine the most cost-effective strategies for mass drug administration, that will impact morbidity caused by helminths to sustainable levels in vulnerable groups
Determination of Triumfetta tomentosa B. Growth Parameters and Fibre Properties in Kenya
Get PDFTriumfetta tomentosa B. (Fam. Tiliaceae) is an indigenous perennial shrub growing naturally in moist habitats. It is a multipurpose plant traditionally used by many communities in Kenya as a source of fodder, fiber for baskets and ropes and wood for winnowing trays. However, as population increases, the suitable habitat for the shrub is being converted into agricultural and settlement sites making T. tomentosa an endangered species. Kenya needs a cheap source of vegetable fiber in order to revive its textile industries and make industrialization a reality by the year 2030. Currently Kenya spends about Ksh 20M in imported vegetable fibres. The aim of this study was to investigate methods of cultivating T. tomentosa and processing its fibres. Seeds and cuttings were collected from Mt. Kenya and Karura forests. These were raised in nurseries at Muguga (Kenya Forestry Research Institute - KEFRI). The seedlings were transplanted after attaining about 25-40 cm in height. Three experimental sites including Embu, Meru and Muguga were used for cultivation of T. tomentosa. Random Block Design method was used at spacing of 30 cm X 30 cm and 45 cm X 45 cm in 3 replicates for each plant material. Growth in height and diameter at breath (dbh) was measured after every month until about 50% of all the plants had formed flowers. Others were subjected to retting at Egerton University to release fibres. Fiber properties were tested at Kenya Bureau of Standards (KEBS) in Nairobi, Kenya. Descriptive statistics, Chi-square test of independence and Mann-Whitney U test of significance models were used. Cuttings from Karura had a higher shooting percentage (70%) than those from Mt. Kenya forest (40%). Plants from Embu plot gave the highest fiber yield among the three plots, while tenacity tests showed significant difference between fibres from cuttings and those from seeds. The results showed that it was easier to cultivate T. tomentosa from cuttings. Its fibres were close to those of Jute in tenacity and therefore good for making sacks, ropes and mats