Bidens pilosa is a member of the Asteraceae family that is widely distributed across the tropics. It has been utilized by different communities both as food and medicinal herb. This plant and its polyacetylenic compou...Bidens pilosa is a member of the Asteraceae family that is widely distributed across the tropics. It has been utilized by different communities both as food and medicinal herb. This plant and its polyacetylenic compounds hold potential as a natural antidiabetic intervention that can be used to combat this global public health problem. Bioactive compounds found in this plant constitute promising interventions for combating obesity which is a major risk factor for the development of type 2 diabetes. These phytocompounds can work independently or synergistically to modulate appetite, lipase activity, adipogenesis and adipocyte apoptosis. However, the efficacy, mode of action and scope of management of diabetes by these compounds remains elusive. The current review aims to summarize data on efficacy in the management of diabetes, an antidiabetic candidate polyacetylenic compound and possible biological activities as an antidiabetic agent from the available literature. Much emphasis has been directed to cytopiloyne as a representative of polyacetylenic compounds extracted from Bidens pilosa and its activity on diabetic animal models. The majority of the studies conducted on animal models described antidiabetic mechanisms that range from hypoglycemic to secretagogue activity of cytopiloyne in a dose-dependent manner. A clinical trial pilot indicated improved glycemic control of Bidens pilosa formulation among diabetic patients in the study. Bidens pilosa and its compounds are highly potent antidiabetic agent(s) that should be graduated to an intervention for management of diabetes through pre-clinical and clinical trials to elucidate its efficacy and safety.展开更多
Identification and deployment of high-yielding and stress-tolerant maize hybrids adapted to stress-prone agro-ecologies is important for improving the food security and livelihoods of smallholder farmers in eastern Af...Identification and deployment of high-yielding and stress-tolerant maize hybrids adapted to stress-prone agro-ecologies is important for improving the food security and livelihoods of smallholder farmers in eastern Africa.The objectives of this study were to(i)assess the performance of maize hybrids under well-watered and drought stress conditions;(ii)evaluate grain yield stability of 65 intermediate-maturing and 55 early-maturing hybrids in 24 well-watered locations and seven drought stress locations;and(iii)identify representative and/or discriminative testing locations for increasing genetic gains for the target traits.There were significant differences for grain yield among early-and intermediatematuring hybrids tested under well-watered and drought stress environments.Among the early-maturing hybrids,the top 10 hybrids produced 46.8%–73.9%and 31.2%–42.1%higher mean grain yields than the best commercial check under drought and well-watered conditions,respectively.Among the intermediate-maturing hybrids,the top 10 hybrids produced 25.2%–47.7%and 8.5%–13.5%higher grain yield than commercial checks under drought stress and well-watered conditions,respectively,suggesting improvement in the levels of drought tolerance in both early-and intermediate-maturing hybrids.GGE biplot analysis and a bi-segmented regression linear method identified specific early-maturing and intermediate-maturing hybrids that performed well under both well-watered and drought stress conditions.These hybrids could be recommended for commercial production in eastern Africa.Kakamega in Kenya was found to be the most representative and highly discriminating site among well-watered testing locations,while Kabuku in Tanzania was the least representative of test locations.For testing under drought stress conditions,Kiboko in Kenya was identified as the most representative location.This information could be useful for allocating resources and streamlining CIMMYT maize hybrid testing in eastern Africa.展开更多
Background: Screening for cancer of the cervix at Kenyatta National Hospital (KNH), follows the recommended three-step strategy;Papanicolaou (Pap) smear, colposcopy/biopsy and loop electrosurgical excision procedure (...Background: Screening for cancer of the cervix at Kenyatta National Hospital (KNH), follows the recommended three-step strategy;Papanicolaou (Pap) smear, colposcopy/biopsy and loop electrosurgical excision procedure (LEEP)/biopsy. This approach poses the following challenges: multiple clinic visits, costly, time consuming, long turnaround time to treatment, non-compliance and loss-to-follow-up. Objective: To determine the agreement between histologies following colposcopy and LEEP amongst women in KNH as a forerunner for opportunity to shift from the three-step approach to the two-step “see and treat” (same-day colposcopy and LEEP) approach. Methods: This was a retrospective descriptive cohort of Women who underwent LEEP procedure between January 2008 and 31st December 2010 following the three-step approach at KNH, Kenya. Results: A total of 124 patients out of the 132 patients who underwent LEEP were included in the analysis. The 8 patients excluded had missing files. HIV infected, uninfected or unknown women are similar socio-demographically. The mean (SD) age for the HIV infected, uninfected and unknown is 37 (6), 33 (10) and 35 (9) years respectively. Colposcopic and LEEP biopsy histology within patients demonstrated a high weighted kappa statistics agreement of 84%. LEEP increased diagnosis of invasive cancer. Patients had a median (IQR) 5 (4 - 6) clinic visits from Pap smear to LEEP treatment. It took median (IQR) 55 (27 - 116) days between Pap smear to colposcopy result and 167 (101 - 276) days between Pap smear results to LEEP treatment. If a LEEP procedure were to be performed in this cohort of women on the same day of the colposcopy biopsy a median (IQR) 77 (55 - 137) days could have been saved. Conclusion: There is a high agreement between colposcopy and LEEP biopsies in our setting offering a window of opportunity to perform “See and Treat” same-day colposcopy and LEEP treatment procedure, skipping the colposcopy biopsy stage.展开更多
Yushania alpina is the only bamboo species native to Kenya and covers about 150,000 ha growing in pure or mixed stands in the montane forests. The Aberdare forest is one of the natural habitats for Y. alpine occupying...Yushania alpina is the only bamboo species native to Kenya and covers about 150,000 ha growing in pure or mixed stands in the montane forests. The Aberdare forest is one of the natural habitats for Y. alpine occupying an area of 6419 ha mainly in the water catchment areas. The growing human population and depletion of other forest resources have necessitated the exploration of Y. alpine as a source of energy. This paper assessed the quantity of Y. alpine available for biomass energy and its potential for sustainable exploitation. Plots were laid on area maps to cater for altitude and distance from farms. The study area was stratified into three altitudinal zones: A (2220 - 2330 m), B (2331 - 2440 m) and C (2441 - 2550 m). The initial sampling plot of 10 m × 10 m was located randomly 500 m from the edge of the forest while the subsequent plots were laid out systematically at intervals of 500 m. In each plot, a total enumeration and biomass estimation of bamboo clumps were done using Muchiri and Muga (2013) [1] method. Bamboo samples and those of commonly used biomass energy sources were analysed for calorific value using bomb calorimeter. In addition, data for quantities of biomass energy used by some local industries were used to estimate the amount of bamboo required. The mean stocking was 19,981 (20,000) culms ha-1, and varied significantly among altitude strata and distance from adjacent farms. The mean biomass density and energy content were 86 tons/ha and 380,893 Kca/ha respectively with the higher altitudinal stratum (zone C) having the highest means (114 tons/ha) while the lower stratum (zone A) had the lowest (65 tons/ha). The energy needed by sampled local industries was 416,276,266 Kcal per year against 2.4 billion Kcal available in the bamboo forest. This implies that the bamboo forest in its present stocking can provide biomass energy for these local industries for more than five years. With bamboo maturing with less than five years, the forest can sustainably provide the required energy while still 展开更多
The distribution of key diseases of coffee particularly the Coffee berry disease （CBD） and Coffee leaf rust （CLR） in Kenya depended on coffee growing agro-ecological zones, which have varied climatic conditions. U...The distribution of key diseases of coffee particularly the Coffee berry disease （CBD） and Coffee leaf rust （CLR） in Kenya depended on coffee growing agro-ecological zones, which have varied climatic conditions. Under the changing climate, there has been an observed shift in their altitudinal distribution. To ascertain whether these diseases have shifted in their distribution, an extensive field survey covering 120 coffee farmers/households in all the coffee growing agro ecological zones was conducted. The survey established four coffee diseases; -viz. Coffee berry disease, Coffee leaf rust, Fusarium root disease （FRD） and Bacterial blight of coffee （BBC） as of economic importance to the farming community. The CBD, CLR and FRD were widely distributed in all coffee growing agro ecological zones. Of the four diseases, the CBD （65%） and CLR （63.3%） were most common as reported by the farmers, however these diseases dominated in their respective agro ecological zones; CBD （72.2%） in Upper Midland 1 （UM1） and CLR （75.0%） in Upper Midland 2 （UM2）. Both diseases equally infected coffee farms （69.2%） in main coffee zone （UM2）. According to the survey said diseases have increased their altitudinal range, a trend that will increase diseases pressure in coffee growing areas.展开更多
Background: Knowledge of factors associated with seroprevalence of Hepatitis B in pregnancy is important in informing policies towards prevention of vertical transmission of Hepatitis B Virus (HBV) infection, since in...Background: Knowledge of factors associated with seroprevalence of Hepatitis B in pregnancy is important in informing policies towards prevention of vertical transmission of Hepatitis B Virus (HBV) infection, since in-utero and perinatal infection lead to chronic carrier state with severe long-term sequela. In addition, adequate and timely immunization plays a major role in the prevention of transmission. Objective: To determine the factors associated with HBs Ag seroprevalence in pregnant women from various geographical regions in Kenya. Methods and Subjects: This was a cross-sectional survey amongst all pregnant women attending antenatal clinics in Kenyatta National Hospital and 8 other hospitals from different regions of Kenya in their third trimester of pregnancy among June 2001 to June 2002. For each pregnant woman, age, history of intravenous drug use, sexually transmitted disease (STD), liver diseases, alcohol intake, blood transfusion (BT) and presence of traditional scarification were documented. HBs Ag serology was assayed at the Kenya Medical Research Institute (KEMRI) laboratory. Results: A total of 2241 pregnant women were enrolled in the study, 2196 consented, of whom 205 (9.3%) tested positive for HBs Ag. A significant association was found between HBs Ag seroprevalence and traditional scarification (p = 0.029), history of blood transfusion (p = 0.0024) and alcohol intake (p = 0.05). There was no significant association between Hbs Ag seroprevalence and sexually transmitted disease (p = 0.64). It was not possible to evaluate the association of HBs Ag seroprevalence with history of hospitalization for any liver disease including Hepatitis A, B or C, history of intravenous drug use or contact with sex partners previously hospitalised for any liver disease including Hepatitis A, B or C as the numbers with these attributes were small. Conclusions: We found 9.3% of pregnant women were HBs Ag positive, significantly higher than previously observed. The high seropositivity was associated with traditional 展开更多
The most prevalent way of disposing solid waste in most of the developing countries is open dumping which is the easiest and considered to be the cheapest method of removing waste from the immediate environment. The i...The most prevalent way of disposing solid waste in most of the developing countries is open dumping which is the easiest and considered to be the cheapest method of removing waste from the immediate environment. The increasing awareness on public health and environment quality concerns are expected to provide the impetus that is needed to develop and implement a sustainable approach to manage solids. An inventory of these locations, the types of waste handled and management processes for waste products will aid in the assessment of the polluting capability of such sites. This paper discusses research experiences gathered during a study that was undertaken in three Kenya dumpsites to explore the potential for utilising the waste for energy generation in a low-income economy and at the same time, address worsening disposal challenges.展开更多
The rapid increase in population in Thika has led to increase in municipal solid waste generation, which has posed challenges in the waste disposal and management. This study was carried out to quantify and characteri...The rapid increase in population in Thika has led to increase in municipal solid waste generation, which has posed challenges in the waste disposal and management. This study was carried out to quantify and characterize the waste generated within Thika municipality. Six months data （between March 2014 and August 2014） of waste stream at the dumpsite was reviewed and analyzed. The survey indicated that 66.95% ± 0.34% of the total waste dumped originated from the municipal council ofThika （MCT）. It constitutes of domestic, commercial and institutional waste. 33.05% is industrial waste. Sixty eight percent （68%） of the waste consisted primarily of four components： paper, plastic, organics and food. Food accounted for 15.51% ± 0.95%, paper 18.31% ± 1.7%, plastics 17.89% ± 0.81% and organics other than food 16.51% ±1.01%, respectively obtained at 95% confidence level. Each of the components has some level of recovery. Some of the reusable and recyclable materials were being recovered, food waste had the highest recovery rate of 23% ± 1.7% and was used as animal feed, while plastic （soft plastic） 17% ± 0.93% was sold to recyclers. Recovery of materials for recycling and composting was estimated at 10.21 tonnes or 11.35% of daily generation, leaving 76.44 tonnes per day that can be converted into useful energy. The study shows waste in this dumpsite can be exploited to by converting it to energy thus a good solution for waste management.展开更多
This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat ...This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat Division of the Baringo District, Kenya. A survey methodology was employed using a random sample of 25 Farmer Field School （FFS） members and 5 non=FFS members from each of the five locations of Marigat Division. In total, 100 FFS members and 25 non-FFS members participated in the study; addi- tional supplementary data were collected from the Kenya Forestry Research Institute （KEFRI）, a major facilitator and trainer of the identified FFS activities and practices in the study area since 2004. More than 80% of the local community never undertook any form of prosopis management practice; however, this changed after FFS training, indicating an acquisition and retention of knowledge which probably diffused to the non-FFS counterparts, through either formal or informal ways. Harvesting was the most preferred （100%） and stump burning the least preferred （46%） practice of managing the spread of prosopis. The success and preference of any prosopis management practice was attributed to wood and non-wood benefits derived from prosopis and growing of animal fodder and food crops on rehabilitated land. More than 80% of respondents attributed ineffectiveness of any prosopis management practice to coppicing and viable seed banks of the tree, while 50% highlighted a lack of consistency and integration in carrying out manage- ment practices. The reported negative attitude towards prosopis changed after training with none of the view to eradicate it. Labor intensity and frequent regeneration of seedlings were identified as the major challenges faced during the implementation of proso- pis management practices. In conclusion, the study shows that harvesting, uprooting, stump burning, pruning and thinning realized through consistent holistic integration contribute to containing the spread of prosopis tr展开更多
The degradation of Escherichia coli bacteria by treatment with cold, weakly ionised, highly dissociated oxygen plasma, with an electron temperature of 3 eV, a plasma density of 8 × 10^15 m^-3 and a neutral oxygen...The degradation of Escherichia coli bacteria by treatment with cold, weakly ionised, highly dissociated oxygen plasma, with an electron temperature of 3 eV, a plasma density of 8 × 10^15 m^-3 and a neutral oxygen atom density of 3.5 × 10^21 m^-3 was studied. To determine the ＇real＇ plasma effects, two methods were used for evaluation and determination, as well as a comparison of the number of bacteria that had survived： the standard plate count technique （PCT） and advanced fluorescence-activated cell sorting （FACS）. Bacteria were deposited onto glass substrates and kept below 50 ℃ during the experiments with oxygen plasma. The results showed that the bacteria had fully degraded after about 2 min of plasma treatment, depending slightly on the amount of bacteria that had been deposited on the substrates. The very precise determination of the O flux on the substrates and the two-method comparison allowed for the determination of the critical dose of oxygen atoms required for the destruction of a bacterial cell wall--about 6 × 10^24 m^-2--as well as deactivation of the substrates--about 8 × 10^25 m^-2. These results were taken in order to discuss other results obtained by comparable studies and scientific method evaluations in the determination of plasma effects on bacteria.展开更多
A simulation trial to assess losses in crib and in-house maize storage practices was conducted. Three cribs were constructed and 180 kg maize in two bags treated with 1.6% pirimiphos methyl and 0.3% permethrin stored ...A simulation trial to assess losses in crib and in-house maize storage practices was conducted. Three cribs were constructed and 180 kg maize in two bags treated with 1.6% pirimiphos methyl and 0.3% permethrin stored in one. In the other, a similar quantity of untreated maize in two bags was stored while in the third crib, 4 bags of cob maize were placed. Another four bags, two treated and two untreated were placed on dunnage separated by a 2-meter path in the living house. Samples were analysed at 4-week interval for 24 weeks and pest damage was used to calculate percent weight loss. Grain from selected farmers was also analysed for comparison. Crib trial had 53% and 20% pest damage in untreated and treated maize compared with 56% and 16% for in-house storage after six months. Cumulative weight loss averaged 20.6% and 9.7% for untreated and treated maize. The figures are markedly higher than 5% criterion for effective pest control measures. Weight loss on farmer stocks compared well with untreated maize and grain damage varied from 5.4% to 27%, translating to 0.5% and 16.8% cumulative loss. These results suggest ineffective pest control measures by Bungoma farmers. The results contrast with Kitui ones in an earlier study where Prostephanus truncatus is endemic and contributed to 10% cumulative loss above the Bungoma level. Efforts should be made to reduce grain damage to below 5% to realise food security at farm level.展开更多
Rail transport has a crucial role in shaping the transportation system in a country.For instance,rail transport has played a significant role in movement of goods and people in Kenya and in Africa as whole for almost ...Rail transport has a crucial role in shaping the transportation system in a country.For instance,rail transport has played a significant role in movement of goods and people in Kenya and in Africa as whole for almost a century.By 1990,however,the industry started to decline due to competition from more reliable and efficient means of transportation(buses and trucks).Passenger services had almost disappeared(accounting for less than 1%of total traffic).Against this background,this research paper analyses consideration factors for sustainability of the SGR(Standard Gauge Railway)infrastructure in Kenya.A case study method was selected and mainly used the desk top research approach to collect secondary data that were drawn from railway institution records,railway journals,railway magazines,internet and other secondary sources from projects,contract documents and government reports.The research results were used to formulate a roadmap for sustainable railway infrastructure projects.The research also discusses the outcomes and makes some recommendations for railway transportation infrastructure projects sustainability.展开更多
<p align="justify"> <span style="font-family:Verdana;">This study sought to determine the spatial and temporal variability of rainfall under past and future climate scenarios. The data ...<p align="justify"> <span style="font-family:Verdana;">This study sought to determine the spatial and temporal variability of rainfall under past and future climate scenarios. The data used comprised station-based monthly gridded rainfall data sourced from the Climate Research </span><span style="font-family:Verdana;">Unit (CRU) and monthly model outputs from the Fourth Edition of the Rossby Centre (RCA4) Regional Climate Model (RCM), which has scaled-down </span><span style="font-family:Verdana;">nine GCMs for Africa. Although the 9 Global Climate Models (GCMs) downscaled by the RCA4 model was not very good at simulating rainfall in Kenya, the ensemble of the 9 models performed better and could be used for further studies. The ensemble of the models was thus bias-corrected using the scaling method to reduce the error;lower values of bias and Normalized Root Mean Square Error (NRMSE) w</span></span><span style="font-family:Verdana;">ere</span><span style="font-family:'Minion Pro Capt','serif';"><span style="font-family:Verdana;"> recorded when compared to the uncorrected models. The bias-corrected ensemble was used to study the spatial and temporal behaviour of rainfall under baseline (1971 to 2000) and future RCP 4.5 and 8.5 scenarios (2021 to 2050). An insignificant trend was noted under the </span><span style="font-family:Verdana;">baseline condition during the March-May (MAM) and October-December</span> <span style="font-family:Verdana;">(OND) rainfall seasons. A positive significant trend at 5% level was noted</span><span style="font-family:Verdana;"> under RCP 4.5 and 8.5 scenarios in some stations during both MAM and OND seasons. The increase in rainfall was attributed to global warming due to increased anthropogenic emissions of greenhouse gases. Results on the spatial variability of rainfall indicate the spatial extent of rainfall will increase under both RCP 4.5 and RCP 8.5 scenario when compared to the baseline;the increase is higher under the RCP 8.5 scenario. Overall rainfall was found to be highly v展开更多
Green gram is considered as one of the legumes suitable for cultivation in the Arid and Semi-Arid Lands (ASALs) of Kenya. However, climate change may alter the areas suitable for green gram production. This study soug...Green gram is considered as one of the legumes suitable for cultivation in the Arid and Semi-Arid Lands (ASALs) of Kenya. However, climate change may alter the areas suitable for green gram production. This study sought to model green gram suitability in Kenya under present and future conditions using bias-corrected RCA4 models data. The datasets used were: maps of soil parameters extracted from Kenya Soil Survey map;present and future rainfall and temperature data from an ensemble of nine models from the Fourth Edition of the Rossby Centre (RCA4) Regional Climate Model (RCM);and altitude from the Digital elevation model (DEM) of the USGS. The maps were first reclassified into four classes of suitability as Highly Suitable (S1), Moderately Suitable (S2), Marginally Suitable (S3), and Not Suitable (N). The classes represent the different levels of influence of a factor on the growth and yield of green grams. The reclassified maps were then assigned a weight generated using the Analytical Hierarchy Process (AHP). A weighted overlay of climate characteristics (past and future rainfall and temperature), soil properties (depth, pH, texture, CEC, and drainage) and altitude found most of Kenya as moderately suitable for green gram production during the March to May (MAM) and October to December (OND) seasons under the baseline, RCP 4.5 and RCP 8.5 scenarios with highly suitable areas being found in Counties like Kitui, Makueni, and West Pokot among others. During the MAM season, the area currently highly suitable for green gram production (67,842.62 km<sup>2</sup>) will increase slightly to 68,600.4 km<sup>2</sup> (1.1%) during the RCP 4.5 and reduce to 61,307.8 km<sup>2</sup> (<span style="white-space:nowrap;">−</span>9.6%) under the RCP 8.5 scenario. During the OND season, the area currently highly suitable (49,633.4 km<sup>2</sup>) will increase under both RCP 4.5 (22.2%) and RCP 8.5 (58.5%) scenarios. This increase is as a result of favourable rainfall and temperature conditions in the future.展开更多
文摘Bidens pilosa is a member of the Asteraceae family that is widely distributed across the tropics. It has been utilized by different communities both as food and medicinal herb. This plant and its polyacetylenic compounds hold potential as a natural antidiabetic intervention that can be used to combat this global public health problem. Bioactive compounds found in this plant constitute promising interventions for combating obesity which is a major risk factor for the development of type 2 diabetes. These phytocompounds can work independently or synergistically to modulate appetite, lipase activity, adipogenesis and adipocyte apoptosis. However, the efficacy, mode of action and scope of management of diabetes by these compounds remains elusive. The current review aims to summarize data on efficacy in the management of diabetes, an antidiabetic candidate polyacetylenic compound and possible biological activities as an antidiabetic agent from the available literature. Much emphasis has been directed to cytopiloyne as a representative of polyacetylenic compounds extracted from Bidens pilosa and its activity on diabetic animal models. The majority of the studies conducted on animal models described antidiabetic mechanisms that range from hypoglycemic to secretagogue activity of cytopiloyne in a dose-dependent manner. A clinical trial pilot indicated improved glycemic control of Bidens pilosa formulation among diabetic patients in the study. Bidens pilosa and its compounds are highly potent antidiabetic agent(s) that should be graduated to an intervention for management of diabetes through pre-clinical and clinical trials to elucidate its efficacy and safety.
基金supported by the Bill and Melinda Gates Foundationthe Howard G.Buffett Foundation+4 种基金the United States Agency for International Development(USAID)through the Water Efficient Maize for Africa(WEMA)projectthe Stress Tolerant Maize for Africa(STMA)projectthe CGIAR Research Program MAIZEThe CGIAR Research Program MAIZE receives W1&W2 support from the Governments of Australia,Belgium,Canada,China,France,India,Japan,the Republic of Korea,Mexico,the Netherlands,New Zealand,Norway,Sweden,Switzerland,United Kingdom,the United States,and the World BankBrazilian Coordination for the Improvement of Higher Education Personnel(CAPES)for a scholarship supporting Wender Rezende
文摘Identification and deployment of high-yielding and stress-tolerant maize hybrids adapted to stress-prone agro-ecologies is important for improving the food security and livelihoods of smallholder farmers in eastern Africa.The objectives of this study were to(i)assess the performance of maize hybrids under well-watered and drought stress conditions;(ii)evaluate grain yield stability of 65 intermediate-maturing and 55 early-maturing hybrids in 24 well-watered locations and seven drought stress locations;and(iii)identify representative and/or discriminative testing locations for increasing genetic gains for the target traits.There were significant differences for grain yield among early-and intermediatematuring hybrids tested under well-watered and drought stress environments.Among the early-maturing hybrids,the top 10 hybrids produced 46.8%–73.9%and 31.2%–42.1%higher mean grain yields than the best commercial check under drought and well-watered conditions,respectively.Among the intermediate-maturing hybrids,the top 10 hybrids produced 25.2%–47.7%and 8.5%–13.5%higher grain yield than commercial checks under drought stress and well-watered conditions,respectively,suggesting improvement in the levels of drought tolerance in both early-and intermediate-maturing hybrids.GGE biplot analysis and a bi-segmented regression linear method identified specific early-maturing and intermediate-maturing hybrids that performed well under both well-watered and drought stress conditions.These hybrids could be recommended for commercial production in eastern Africa.Kakamega in Kenya was found to be the most representative and highly discriminating site among well-watered testing locations,while Kabuku in Tanzania was the least representative of test locations.For testing under drought stress conditions,Kiboko in Kenya was identified as the most representative location.This information could be useful for allocating resources and streamlining CIMMYT maize hybrid testing in eastern Africa.
文摘Background: Screening for cancer of the cervix at Kenyatta National Hospital (KNH), follows the recommended three-step strategy;Papanicolaou (Pap) smear, colposcopy/biopsy and loop electrosurgical excision procedure (LEEP)/biopsy. This approach poses the following challenges: multiple clinic visits, costly, time consuming, long turnaround time to treatment, non-compliance and loss-to-follow-up. Objective: To determine the agreement between histologies following colposcopy and LEEP amongst women in KNH as a forerunner for opportunity to shift from the three-step approach to the two-step “see and treat” (same-day colposcopy and LEEP) approach. Methods: This was a retrospective descriptive cohort of Women who underwent LEEP procedure between January 2008 and 31st December 2010 following the three-step approach at KNH, Kenya. Results: A total of 124 patients out of the 132 patients who underwent LEEP were included in the analysis. The 8 patients excluded had missing files. HIV infected, uninfected or unknown women are similar socio-demographically. The mean (SD) age for the HIV infected, uninfected and unknown is 37 (6), 33 (10) and 35 (9) years respectively. Colposcopic and LEEP biopsy histology within patients demonstrated a high weighted kappa statistics agreement of 84%. LEEP increased diagnosis of invasive cancer. Patients had a median (IQR) 5 (4 - 6) clinic visits from Pap smear to LEEP treatment. It took median (IQR) 55 (27 - 116) days between Pap smear to colposcopy result and 167 (101 - 276) days between Pap smear results to LEEP treatment. If a LEEP procedure were to be performed in this cohort of women on the same day of the colposcopy biopsy a median (IQR) 77 (55 - 137) days could have been saved. Conclusion: There is a high agreement between colposcopy and LEEP biopsies in our setting offering a window of opportunity to perform “See and Treat” same-day colposcopy and LEEP treatment procedure, skipping the colposcopy biopsy stage.
文摘Yushania alpina is the only bamboo species native to Kenya and covers about 150,000 ha growing in pure or mixed stands in the montane forests. The Aberdare forest is one of the natural habitats for Y. alpine occupying an area of 6419 ha mainly in the water catchment areas. The growing human population and depletion of other forest resources have necessitated the exploration of Y. alpine as a source of energy. This paper assessed the quantity of Y. alpine available for biomass energy and its potential for sustainable exploitation. Plots were laid on area maps to cater for altitude and distance from farms. The study area was stratified into three altitudinal zones: A (2220 - 2330 m), B (2331 - 2440 m) and C (2441 - 2550 m). The initial sampling plot of 10 m × 10 m was located randomly 500 m from the edge of the forest while the subsequent plots were laid out systematically at intervals of 500 m. In each plot, a total enumeration and biomass estimation of bamboo clumps were done using Muchiri and Muga (2013) [1] method. Bamboo samples and those of commonly used biomass energy sources were analysed for calorific value using bomb calorimeter. In addition, data for quantities of biomass energy used by some local industries were used to estimate the amount of bamboo required. The mean stocking was 19,981 (20,000) culms ha-1, and varied significantly among altitude strata and distance from adjacent farms. The mean biomass density and energy content were 86 tons/ha and 380,893 Kca/ha respectively with the higher altitudinal stratum (zone C) having the highest means (114 tons/ha) while the lower stratum (zone A) had the lowest (65 tons/ha). The energy needed by sampled local industries was 416,276,266 Kcal per year against 2.4 billion Kcal available in the bamboo forest. This implies that the bamboo forest in its present stocking can provide biomass energy for these local industries for more than five years. With bamboo maturing with less than five years, the forest can sustainably provide the required energy while still
文摘The distribution of key diseases of coffee particularly the Coffee berry disease （CBD） and Coffee leaf rust （CLR） in Kenya depended on coffee growing agro-ecological zones, which have varied climatic conditions. Under the changing climate, there has been an observed shift in their altitudinal distribution. To ascertain whether these diseases have shifted in their distribution, an extensive field survey covering 120 coffee farmers/households in all the coffee growing agro ecological zones was conducted. The survey established four coffee diseases; -viz. Coffee berry disease, Coffee leaf rust, Fusarium root disease （FRD） and Bacterial blight of coffee （BBC） as of economic importance to the farming community. The CBD, CLR and FRD were widely distributed in all coffee growing agro ecological zones. Of the four diseases, the CBD （65%） and CLR （63.3%） were most common as reported by the farmers, however these diseases dominated in their respective agro ecological zones; CBD （72.2%） in Upper Midland 1 （UM1） and CLR （75.0%） in Upper Midland 2 （UM2）. Both diseases equally infected coffee farms （69.2%） in main coffee zone （UM2）. According to the survey said diseases have increased their altitudinal range, a trend that will increase diseases pressure in coffee growing areas.
文摘Background: Knowledge of factors associated with seroprevalence of Hepatitis B in pregnancy is important in informing policies towards prevention of vertical transmission of Hepatitis B Virus (HBV) infection, since in-utero and perinatal infection lead to chronic carrier state with severe long-term sequela. In addition, adequate and timely immunization plays a major role in the prevention of transmission. Objective: To determine the factors associated with HBs Ag seroprevalence in pregnant women from various geographical regions in Kenya. Methods and Subjects: This was a cross-sectional survey amongst all pregnant women attending antenatal clinics in Kenyatta National Hospital and 8 other hospitals from different regions of Kenya in their third trimester of pregnancy among June 2001 to June 2002. For each pregnant woman, age, history of intravenous drug use, sexually transmitted disease (STD), liver diseases, alcohol intake, blood transfusion (BT) and presence of traditional scarification were documented. HBs Ag serology was assayed at the Kenya Medical Research Institute (KEMRI) laboratory. Results: A total of 2241 pregnant women were enrolled in the study, 2196 consented, of whom 205 (9.3%) tested positive for HBs Ag. A significant association was found between HBs Ag seroprevalence and traditional scarification (p = 0.029), history of blood transfusion (p = 0.0024) and alcohol intake (p = 0.05). There was no significant association between Hbs Ag seroprevalence and sexually transmitted disease (p = 0.64). It was not possible to evaluate the association of HBs Ag seroprevalence with history of hospitalization for any liver disease including Hepatitis A, B or C, history of intravenous drug use or contact with sex partners previously hospitalised for any liver disease including Hepatitis A, B or C as the numbers with these attributes were small. Conclusions: We found 9.3% of pregnant women were HBs Ag positive, significantly higher than previously observed. The high seropositivity was associated with traditional
文摘The most prevalent way of disposing solid waste in most of the developing countries is open dumping which is the easiest and considered to be the cheapest method of removing waste from the immediate environment. The increasing awareness on public health and environment quality concerns are expected to provide the impetus that is needed to develop and implement a sustainable approach to manage solids. An inventory of these locations, the types of waste handled and management processes for waste products will aid in the assessment of the polluting capability of such sites. This paper discusses research experiences gathered during a study that was undertaken in three Kenya dumpsites to explore the potential for utilising the waste for energy generation in a low-income economy and at the same time, address worsening disposal challenges.
文摘The rapid increase in population in Thika has led to increase in municipal solid waste generation, which has posed challenges in the waste disposal and management. This study was carried out to quantify and characterize the waste generated within Thika municipality. Six months data （between March 2014 and August 2014） of waste stream at the dumpsite was reviewed and analyzed. The survey indicated that 66.95% ± 0.34% of the total waste dumped originated from the municipal council ofThika （MCT）. It constitutes of domestic, commercial and institutional waste. 33.05% is industrial waste. Sixty eight percent （68%） of the waste consisted primarily of four components： paper, plastic, organics and food. Food accounted for 15.51% ± 0.95%, paper 18.31% ± 1.7%, plastics 17.89% ± 0.81% and organics other than food 16.51% ±1.01%, respectively obtained at 95% confidence level. Each of the components has some level of recovery. Some of the reusable and recyclable materials were being recovered, food waste had the highest recovery rate of 23% ± 1.7% and was used as animal feed, while plastic （soft plastic） 17% ± 0.93% was sold to recyclers. Recovery of materials for recycling and composting was estimated at 10.21 tonnes or 11.35% of daily generation, leaving 76.44 tonnes per day that can be converted into useful energy. The study shows waste in this dumpsite can be exploited to by converting it to energy thus a good solution for waste management.
文摘This research was carried out to evaluate the preference and adoption of harvesting, uprooting, stump burning, pruning and thinning practices for controlling the spread ofProsopisjuliflora （prosopis） within Marigat Division of the Baringo District, Kenya. A survey methodology was employed using a random sample of 25 Farmer Field School （FFS） members and 5 non=FFS members from each of the five locations of Marigat Division. In total, 100 FFS members and 25 non-FFS members participated in the study; addi- tional supplementary data were collected from the Kenya Forestry Research Institute （KEFRI）, a major facilitator and trainer of the identified FFS activities and practices in the study area since 2004. More than 80% of the local community never undertook any form of prosopis management practice; however, this changed after FFS training, indicating an acquisition and retention of knowledge which probably diffused to the non-FFS counterparts, through either formal or informal ways. Harvesting was the most preferred （100%） and stump burning the least preferred （46%） practice of managing the spread of prosopis. The success and preference of any prosopis management practice was attributed to wood and non-wood benefits derived from prosopis and growing of animal fodder and food crops on rehabilitated land. More than 80% of respondents attributed ineffectiveness of any prosopis management practice to coppicing and viable seed banks of the tree, while 50% highlighted a lack of consistency and integration in carrying out manage- ment practices. The reported negative attitude towards prosopis changed after training with none of the view to eradicate it. Labor intensity and frequent regeneration of seedlings were identified as the major challenges faced during the implementation of proso- pis management practices. In conclusion, the study shows that harvesting, uprooting, stump burning, pruning and thinning realized through consistent holistic integration contribute to containing the spread of prosopis tr
基金The financial support from the Slovenian Research Agency (ARRS)NATO CLG/SPS.984555+1 种基金EU COST grant MP1101the MESS 171037 and 41011 projects for partial support
文摘The degradation of Escherichia coli bacteria by treatment with cold, weakly ionised, highly dissociated oxygen plasma, with an electron temperature of 3 eV, a plasma density of 8 × 10^15 m^-3 and a neutral oxygen atom density of 3.5 × 10^21 m^-3 was studied. To determine the ＇real＇ plasma effects, two methods were used for evaluation and determination, as well as a comparison of the number of bacteria that had survived： the standard plate count technique （PCT） and advanced fluorescence-activated cell sorting （FACS）. Bacteria were deposited onto glass substrates and kept below 50 ℃ during the experiments with oxygen plasma. The results showed that the bacteria had fully degraded after about 2 min of plasma treatment, depending slightly on the amount of bacteria that had been deposited on the substrates. The very precise determination of the O flux on the substrates and the two-method comparison allowed for the determination of the critical dose of oxygen atoms required for the destruction of a bacterial cell wall--about 6 × 10^24 m^-2--as well as deactivation of the substrates--about 8 × 10^25 m^-2. These results were taken in order to discuss other results obtained by comparable studies and scientific method evaluations in the determination of plasma effects on bacteria.
文摘A simulation trial to assess losses in crib and in-house maize storage practices was conducted. Three cribs were constructed and 180 kg maize in two bags treated with 1.6% pirimiphos methyl and 0.3% permethrin stored in one. In the other, a similar quantity of untreated maize in two bags was stored while in the third crib, 4 bags of cob maize were placed. Another four bags, two treated and two untreated were placed on dunnage separated by a 2-meter path in the living house. Samples were analysed at 4-week interval for 24 weeks and pest damage was used to calculate percent weight loss. Grain from selected farmers was also analysed for comparison. Crib trial had 53% and 20% pest damage in untreated and treated maize compared with 56% and 16% for in-house storage after six months. Cumulative weight loss averaged 20.6% and 9.7% for untreated and treated maize. The figures are markedly higher than 5% criterion for effective pest control measures. Weight loss on farmer stocks compared well with untreated maize and grain damage varied from 5.4% to 27%, translating to 0.5% and 16.8% cumulative loss. These results suggest ineffective pest control measures by Bungoma farmers. The results contrast with Kitui ones in an earlier study where Prostephanus truncatus is endemic and contributed to 10% cumulative loss above the Bungoma level. Efforts should be made to reduce grain damage to below 5% to realise food security at farm level.
文摘Rail transport has a crucial role in shaping the transportation system in a country.For instance,rail transport has played a significant role in movement of goods and people in Kenya and in Africa as whole for almost a century.By 1990,however,the industry started to decline due to competition from more reliable and efficient means of transportation(buses and trucks).Passenger services had almost disappeared(accounting for less than 1%of total traffic).Against this background,this research paper analyses consideration factors for sustainability of the SGR(Standard Gauge Railway)infrastructure in Kenya.A case study method was selected and mainly used the desk top research approach to collect secondary data that were drawn from railway institution records,railway journals,railway magazines,internet and other secondary sources from projects,contract documents and government reports.The research results were used to formulate a roadmap for sustainable railway infrastructure projects.The research also discusses the outcomes and makes some recommendations for railway transportation infrastructure projects sustainability.
文摘<p align="justify"> <span style="font-family:Verdana;">This study sought to determine the spatial and temporal variability of rainfall under past and future climate scenarios. The data used comprised station-based monthly gridded rainfall data sourced from the Climate Research </span><span style="font-family:Verdana;">Unit (CRU) and monthly model outputs from the Fourth Edition of the Rossby Centre (RCA4) Regional Climate Model (RCM), which has scaled-down </span><span style="font-family:Verdana;">nine GCMs for Africa. Although the 9 Global Climate Models (GCMs) downscaled by the RCA4 model was not very good at simulating rainfall in Kenya, the ensemble of the 9 models performed better and could be used for further studies. The ensemble of the models was thus bias-corrected using the scaling method to reduce the error;lower values of bias and Normalized Root Mean Square Error (NRMSE) w</span></span><span style="font-family:Verdana;">ere</span><span style="font-family:'Minion Pro Capt','serif';"><span style="font-family:Verdana;"> recorded when compared to the uncorrected models. The bias-corrected ensemble was used to study the spatial and temporal behaviour of rainfall under baseline (1971 to 2000) and future RCP 4.5 and 8.5 scenarios (2021 to 2050). An insignificant trend was noted under the </span><span style="font-family:Verdana;">baseline condition during the March-May (MAM) and October-December</span> <span style="font-family:Verdana;">(OND) rainfall seasons. A positive significant trend at 5% level was noted</span><span style="font-family:Verdana;"> under RCP 4.5 and 8.5 scenarios in some stations during both MAM and OND seasons. The increase in rainfall was attributed to global warming due to increased anthropogenic emissions of greenhouse gases. Results on the spatial variability of rainfall indicate the spatial extent of rainfall will increase under both RCP 4.5 and RCP 8.5 scenario when compared to the baseline;the increase is higher under the RCP 8.5 scenario. Overall rainfall was found to be highly v
文摘Green gram is considered as one of the legumes suitable for cultivation in the Arid and Semi-Arid Lands (ASALs) of Kenya. However, climate change may alter the areas suitable for green gram production. This study sought to model green gram suitability in Kenya under present and future conditions using bias-corrected RCA4 models data. The datasets used were: maps of soil parameters extracted from Kenya Soil Survey map;present and future rainfall and temperature data from an ensemble of nine models from the Fourth Edition of the Rossby Centre (RCA4) Regional Climate Model (RCM);and altitude from the Digital elevation model (DEM) of the USGS. The maps were first reclassified into four classes of suitability as Highly Suitable (S1), Moderately Suitable (S2), Marginally Suitable (S3), and Not Suitable (N). The classes represent the different levels of influence of a factor on the growth and yield of green grams. The reclassified maps were then assigned a weight generated using the Analytical Hierarchy Process (AHP). A weighted overlay of climate characteristics (past and future rainfall and temperature), soil properties (depth, pH, texture, CEC, and drainage) and altitude found most of Kenya as moderately suitable for green gram production during the March to May (MAM) and October to December (OND) seasons under the baseline, RCP 4.5 and RCP 8.5 scenarios with highly suitable areas being found in Counties like Kitui, Makueni, and West Pokot among others. During the MAM season, the area currently highly suitable for green gram production (67,842.62 km<sup>2</sup>) will increase slightly to 68,600.4 km<sup>2</sup> (1.1%) during the RCP 4.5 and reduce to 61,307.8 km<sup>2</sup> (<span style="white-space:nowrap;">−</span>9.6%) under the RCP 8.5 scenario. During the OND season, the area currently highly suitable (49,633.4 km<sup>2</sup>) will increase under both RCP 4.5 (22.2%) and RCP 8.5 (58.5%) scenarios. This increase is as a result of favourable rainfall and temperature conditions in the future.
