Purpose: The purpose of the paper is to assess the effectiveness of the practical SPSS training t... more Purpose: The purpose of the paper is to assess the effectiveness of the practical SPSS training to students’ research competency among postgraduate students in JKUAT CBD Campus.Methodology: An explanatory research design was used to establish the relationship between practical SPSS training and research competence of students. The population was 173 students and a census of the full population was taken. A questionnaire was administered at the end of the training to capture the pre and post training experience and test the effectiveness of the training. The analysis of the data was conducted through descriptive and inferential statistics. In particular, frequencies, means, standard deviations and paired t-test were used.Results: The post training evaluation results reveal that majority of the respondents had low knowledge in data entry, descriptive statistics, regression and correlation analysis, parametric and non-parametric analysis, and journal article extraction and publication...
Cold tolerance of New Rice for Africa (NERICA) and their parent varieties was evaluated under nat... more Cold tolerance of New Rice for Africa (NERICA) and their parent varieties was evaluated under natural air temperature conditions of Kenyan tropical highlands using the multiple-sown field evaluation method. Rice varieties were cultivated 10 times to expose them to a shift in temperature during 20-day periods before heading (critical period), measuring the average daily mean temperature during the critical period (T mean) for each variety and filled grain ratio, which was used as an indicator of cold tolerance. T mean of each variety was low in 6 out of 10 experiments. In the remaining four high-temperature experiments, there were no significant varietal differences in filled grain ratio. In the six low-temperature experiments, all varieties experienced 20.1−21.5°C T mean. After comparison under virtually the same cold stress, NERICA 1, 3, 4, 7−10, 12, 17, 18, and WAB 56-104 were judged as cold-tolerant; NERICA 2, 5, 11, 13, and 14, and WAB 56-50 and 181-18 were moderately tolerant, and NERICA 6, 15, and 16 were cold-susceptible varieties. These evaluations generally corresponded with previous experimental results under temperature-controlled environments, showing the practicality of multiple-sown field cold tolerance evaluation in Kenya. It also indicated that NERICA varieties, which recorded different levels of cold tolerance and whose average number of days to heading in all experiments were 66−78, are suitable as a set of standard check varieties in this region to evaluate cold tolerance of rice varieties with this range of days to heading.
The growth of 20 rice varieties, including both lowland and upland varieties, was evaluated in Ke... more The growth of 20 rice varieties, including both lowland and upland varieties, was evaluated in Kenya under well-watered and water-deficit conditions in four different soil types (black cotton, red clay, volcanic ash, and sandy clay) to compare the adaptability of these varieties to the two water regimes. Under water-deficit condition, after terminating irrigation, the reduction in soil water potential differed markedly according to soil type. The rice varieties tested were classified into four groups, which were largely consistent with differences in rice variety ecotype. We confirmed that lowland varieties such as Basmati 370 should not be considered as a candidate for cultivation under rain-fed upland conditions in Kenya. Furthermore, the results revealed that even potentially high-yielding varieties may not attain their yield potential if the cultivation environment is unsuitable. Although we found that five upland varieties (Dular, IRAT109, NERICA 1, NERICA 4, and Yumenohatamoch...
Inappropriate seed packaging and seed dormancy affects seed quality and consequently leads to red... more Inappropriate seed packaging and seed dormancy affects seed quality and consequently leads to reduced crop stand, low seedling vigour and reduced yields. The objective of the study was to determine the effect of seed packaging material and seed treatment on viability and dormancy in rice seeds. Effect of packaging material was evaluated by storing freshly harvested seeds of Basmati 370 and BW 196 varieties in polythene, khaki, cheese cloth, polypropylene (Pp) sack and gunny bag sat room temperature and at 6 oC for six months. Effect of seed treatment on dormancy was determined by pre-treatment of seeds with nitric acid at 0.1 M, 0.2 M, 0.5 M, 1 M and 2 M, gibberellic acid (GA3) at 1000 ppm, 2000 ppm and 5000 ppm, and hydrogen peroxide at 0.5 M, 1 M, 2 M, 3 M, 5 M and dry heat at 50 oC for 48 hours. The seeds were subjected to germination test on moist paper and data on percentage germination, seedling length and seedling dry weight were taken. Packaging material had a significant (P...
Recent researches have shown that a food security strategy that dependent entirely on exotic crop... more Recent researches have shown that a food security strategy that dependent entirely on exotic crops, which are greatly affected by sporadic rainfall, is not sustainable. There is a need to shift to indigenous crops that are more tolerant to unpredictable weather patterns. Little shareable knowledge exists on the production of these crops; the production knowledge is passed by word of mouth and demonstration across generations, and sometimes lost in the process. This research seeks to show how this gap can be addressed using a knowledge management system (KMS). One of the key factors that distinguishes the intelligent production process of the 21st century is the emphasis on data, information and ultimately knowledge. The importance of KMS in agriculture cannot be over emphasized. This research started with an exploratory pre-study to identify the key functionality that needed to be captured by the KMS. The pre-study brought to the fore the need for the use of technology information in improving the sorghum production process. Three key themes emerged from the pre-study, namely identification of best practices, convenient way of disseminating information to stakeholders, and finally enhancement of research processes through use of information technology. These functional needs formed the basis for the development of the KMS. Further works can be undertaken to expand the solution to include more weather tolerant crops patterns, in order to provide a wider crops option to smallholder farmers.
Sensitive high-frequency microwave devices hold great promise for biosensor design. These devices... more Sensitive high-frequency microwave devices hold great promise for biosensor design. These devices include GaAs field effect transistors (FETs), which can serve as transducers for biochemical reactions, providing a platform for label-free biosensing. In this study, a two-dimensional numerical model of a GaAs FET-based nucleic acid biosensor is proposed and simulated. The electronic band structure, space charge density, and current-voltage relationships of the biosensor device are calculated. The intrinsic small signal parameters for the device are derived from simulated DC characteristics and used to predict AC behavior at high frequencies. The biosensor model is based on GaAs field-effect device physics, semiconductor transport equations, and a DNA charge model. Immobilization of DNA molecules onto the GaAs sensor surface results in an increase in charge density at the gate region, resulting from negatively-charged DNA molecules. In modeling this charge effect on device electrical characteristics, we take into account the pre-existing surface charge, the orientation of DNA molecules on the sensor surface, and the distance of the negative molecular charges from the sensor surface. Hybridization with complementary molecules results in a further increase in charge density, which further
Why mammals have poor regenerative ability has remained a long-standing question in biology. In r... more Why mammals have poor regenerative ability has remained a long-standing question in biology. In regenerating vertebrates, injury can induce a process known as epimorphic regeneration to replace damaged structures. Using a 4-mm ear punch assay across multiple mammalian species, here we show that several Acomys spp. (spiny mice) and Oryctolagus cuniculus completely regenerate tissue, whereas other rodents including MRL/MpJ 'healer' mice heal similar injuries by scarring. We demonstrate ear-hole closure is independent of ear size, and closure rate can be modelled with a cubic function. Cellular and genetic analyses reveal that injury induces blastema formation in Acomys cahirinus. Despite cell cycle re-entry in Mus musculus and A. cahirinus, efficient cell cycle progression and proliferation only occurs in spiny mice. Together, our data unite blastema-mediated regeneration in spiny mice with regeneration in other vertebrates such as salamanders, newts and zebrafish, where all healthy adults regenerate in response to injury.
Integration of high-frequency solid-state microelectronic devices into biomedical applications is... more Integration of high-frequency solid-state microelectronic devices into biomedical applications is becoming increasingly attractive. The high sensitivity of microwave devices to local changes in electromagnetic fields makes them a logical choice for an impedimetric biosensor, for example; furthermore, incorporation of a biomolecule as a biorecognition element results in high diagnostic specificity. Integration of organic biomolecules into a solid-state sensing platform can be accomplished by various immobilization schemes. The present work describes a general approach by which organic molecules can be immobilized onto a thin-film gate metallization of a Schottky metal-semiconductor field-effect transistor (MESFET), permitting attachment of proteins or nucleic acids.
2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008
Microelectronic biosensors hold great promise for rapid, sensitive and specific in vitro point-of... more Microelectronic biosensors hold great promise for rapid, sensitive and specific in vitro point-of-care immunodiagnostics. In particular, sensors fabricated using organic semiconductors have attractive advantages-such as ease of manufacture and low cost-in the design and implementation of such devices. Furthermore, immobilization of an antibody or protein antigen as a biorecognition element onto an organic semiconducting film allows for direct transduction of biomolecular binding events into an electronic signal which is readily measured and processed. In previous work, we have demonstrated that an antigen can be bound to organic semiconducting films while retaining enzymatic activity after immobilization. The present work considers organic semiconducting films which are spin-cast onto an interdigitated electrode; antibodies labeled with gold-nanoparticles are applied to the organic semiconducting film and serve as a biorecognition element. The sensor geometry includes a high-frequency coplanar waveguide contact metallization to facilitate direct measurement using microwave wafer probes. Equivalent circuit models are derived from microwave measurements over the frequency range 0.3 MHz to 8.5 GHz.
Purpose: The purpose of the paper is to assess the effectiveness of the practical SPSS training t... more Purpose: The purpose of the paper is to assess the effectiveness of the practical SPSS training to students’ research competency among postgraduate students in JKUAT CBD Campus.Methodology: An explanatory research design was used to establish the relationship between practical SPSS training and research competence of students. The population was 173 students and a census of the full population was taken. A questionnaire was administered at the end of the training to capture the pre and post training experience and test the effectiveness of the training. The analysis of the data was conducted through descriptive and inferential statistics. In particular, frequencies, means, standard deviations and paired t-test were used.Results: The post training evaluation results reveal that majority of the respondents had low knowledge in data entry, descriptive statistics, regression and correlation analysis, parametric and non-parametric analysis, and journal article extraction and publication...
Cold tolerance of New Rice for Africa (NERICA) and their parent varieties was evaluated under nat... more Cold tolerance of New Rice for Africa (NERICA) and their parent varieties was evaluated under natural air temperature conditions of Kenyan tropical highlands using the multiple-sown field evaluation method. Rice varieties were cultivated 10 times to expose them to a shift in temperature during 20-day periods before heading (critical period), measuring the average daily mean temperature during the critical period (T mean) for each variety and filled grain ratio, which was used as an indicator of cold tolerance. T mean of each variety was low in 6 out of 10 experiments. In the remaining four high-temperature experiments, there were no significant varietal differences in filled grain ratio. In the six low-temperature experiments, all varieties experienced 20.1−21.5°C T mean. After comparison under virtually the same cold stress, NERICA 1, 3, 4, 7−10, 12, 17, 18, and WAB 56-104 were judged as cold-tolerant; NERICA 2, 5, 11, 13, and 14, and WAB 56-50 and 181-18 were moderately tolerant, and NERICA 6, 15, and 16 were cold-susceptible varieties. These evaluations generally corresponded with previous experimental results under temperature-controlled environments, showing the practicality of multiple-sown field cold tolerance evaluation in Kenya. It also indicated that NERICA varieties, which recorded different levels of cold tolerance and whose average number of days to heading in all experiments were 66−78, are suitable as a set of standard check varieties in this region to evaluate cold tolerance of rice varieties with this range of days to heading.
The growth of 20 rice varieties, including both lowland and upland varieties, was evaluated in Ke... more The growth of 20 rice varieties, including both lowland and upland varieties, was evaluated in Kenya under well-watered and water-deficit conditions in four different soil types (black cotton, red clay, volcanic ash, and sandy clay) to compare the adaptability of these varieties to the two water regimes. Under water-deficit condition, after terminating irrigation, the reduction in soil water potential differed markedly according to soil type. The rice varieties tested were classified into four groups, which were largely consistent with differences in rice variety ecotype. We confirmed that lowland varieties such as Basmati 370 should not be considered as a candidate for cultivation under rain-fed upland conditions in Kenya. Furthermore, the results revealed that even potentially high-yielding varieties may not attain their yield potential if the cultivation environment is unsuitable. Although we found that five upland varieties (Dular, IRAT109, NERICA 1, NERICA 4, and Yumenohatamoch...
Inappropriate seed packaging and seed dormancy affects seed quality and consequently leads to red... more Inappropriate seed packaging and seed dormancy affects seed quality and consequently leads to reduced crop stand, low seedling vigour and reduced yields. The objective of the study was to determine the effect of seed packaging material and seed treatment on viability and dormancy in rice seeds. Effect of packaging material was evaluated by storing freshly harvested seeds of Basmati 370 and BW 196 varieties in polythene, khaki, cheese cloth, polypropylene (Pp) sack and gunny bag sat room temperature and at 6 oC for six months. Effect of seed treatment on dormancy was determined by pre-treatment of seeds with nitric acid at 0.1 M, 0.2 M, 0.5 M, 1 M and 2 M, gibberellic acid (GA3) at 1000 ppm, 2000 ppm and 5000 ppm, and hydrogen peroxide at 0.5 M, 1 M, 2 M, 3 M, 5 M and dry heat at 50 oC for 48 hours. The seeds were subjected to germination test on moist paper and data on percentage germination, seedling length and seedling dry weight were taken. Packaging material had a significant (P...
Recent researches have shown that a food security strategy that dependent entirely on exotic crop... more Recent researches have shown that a food security strategy that dependent entirely on exotic crops, which are greatly affected by sporadic rainfall, is not sustainable. There is a need to shift to indigenous crops that are more tolerant to unpredictable weather patterns. Little shareable knowledge exists on the production of these crops; the production knowledge is passed by word of mouth and demonstration across generations, and sometimes lost in the process. This research seeks to show how this gap can be addressed using a knowledge management system (KMS). One of the key factors that distinguishes the intelligent production process of the 21st century is the emphasis on data, information and ultimately knowledge. The importance of KMS in agriculture cannot be over emphasized. This research started with an exploratory pre-study to identify the key functionality that needed to be captured by the KMS. The pre-study brought to the fore the need for the use of technology information in improving the sorghum production process. Three key themes emerged from the pre-study, namely identification of best practices, convenient way of disseminating information to stakeholders, and finally enhancement of research processes through use of information technology. These functional needs formed the basis for the development of the KMS. Further works can be undertaken to expand the solution to include more weather tolerant crops patterns, in order to provide a wider crops option to smallholder farmers.
Sensitive high-frequency microwave devices hold great promise for biosensor design. These devices... more Sensitive high-frequency microwave devices hold great promise for biosensor design. These devices include GaAs field effect transistors (FETs), which can serve as transducers for biochemical reactions, providing a platform for label-free biosensing. In this study, a two-dimensional numerical model of a GaAs FET-based nucleic acid biosensor is proposed and simulated. The electronic band structure, space charge density, and current-voltage relationships of the biosensor device are calculated. The intrinsic small signal parameters for the device are derived from simulated DC characteristics and used to predict AC behavior at high frequencies. The biosensor model is based on GaAs field-effect device physics, semiconductor transport equations, and a DNA charge model. Immobilization of DNA molecules onto the GaAs sensor surface results in an increase in charge density at the gate region, resulting from negatively-charged DNA molecules. In modeling this charge effect on device electrical characteristics, we take into account the pre-existing surface charge, the orientation of DNA molecules on the sensor surface, and the distance of the negative molecular charges from the sensor surface. Hybridization with complementary molecules results in a further increase in charge density, which further
Why mammals have poor regenerative ability has remained a long-standing question in biology. In r... more Why mammals have poor regenerative ability has remained a long-standing question in biology. In regenerating vertebrates, injury can induce a process known as epimorphic regeneration to replace damaged structures. Using a 4-mm ear punch assay across multiple mammalian species, here we show that several Acomys spp. (spiny mice) and Oryctolagus cuniculus completely regenerate tissue, whereas other rodents including MRL/MpJ 'healer' mice heal similar injuries by scarring. We demonstrate ear-hole closure is independent of ear size, and closure rate can be modelled with a cubic function. Cellular and genetic analyses reveal that injury induces blastema formation in Acomys cahirinus. Despite cell cycle re-entry in Mus musculus and A. cahirinus, efficient cell cycle progression and proliferation only occurs in spiny mice. Together, our data unite blastema-mediated regeneration in spiny mice with regeneration in other vertebrates such as salamanders, newts and zebrafish, where all healthy adults regenerate in response to injury.
Integration of high-frequency solid-state microelectronic devices into biomedical applications is... more Integration of high-frequency solid-state microelectronic devices into biomedical applications is becoming increasingly attractive. The high sensitivity of microwave devices to local changes in electromagnetic fields makes them a logical choice for an impedimetric biosensor, for example; furthermore, incorporation of a biomolecule as a biorecognition element results in high diagnostic specificity. Integration of organic biomolecules into a solid-state sensing platform can be accomplished by various immobilization schemes. The present work describes a general approach by which organic molecules can be immobilized onto a thin-film gate metallization of a Schottky metal-semiconductor field-effect transistor (MESFET), permitting attachment of proteins or nucleic acids.
2008 30th Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 2008
Microelectronic biosensors hold great promise for rapid, sensitive and specific in vitro point-of... more Microelectronic biosensors hold great promise for rapid, sensitive and specific in vitro point-of-care immunodiagnostics. In particular, sensors fabricated using organic semiconductors have attractive advantages-such as ease of manufacture and low cost-in the design and implementation of such devices. Furthermore, immobilization of an antibody or protein antigen as a biorecognition element onto an organic semiconducting film allows for direct transduction of biomolecular binding events into an electronic signal which is readily measured and processed. In previous work, we have demonstrated that an antigen can be bound to organic semiconducting films while retaining enzymatic activity after immobilization. The present work considers organic semiconducting films which are spin-cast onto an interdigitated electrode; antibodies labeled with gold-nanoparticles are applied to the organic semiconducting film and serve as a biorecognition element. The sensor geometry includes a high-frequency coplanar waveguide contact metallization to facilitate direct measurement using microwave wafer probes. Equivalent circuit models are derived from microwave measurements over the frequency range 0.3 MHz to 8.5 GHz.
Uploads
Papers by John Kimani