370 research outputs found

    Typologies and Multidimensional Nature of Computer Use for Classroom Instruction in Secondary Education

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    Computer technology has proved essential in all sectors of human endeavours such as in industry and business. As a consequence, education has been the main beneficiary of the emergence of the microcomputer being used in financial management, administration and progressively in the classroom for instruction. The experimental phase on the benefits of computer technology for instruction is maturing. This paper explores through reviewing literature the various ways computers have been used in the classroom for instruction and through a pilot study, determine the dimensions of computer use with the help of factor analysis. In the pilot study, a sample of 71 respondents provided usable data. This paper helps us to understand: (a) what is meant by “technology/computer use” in the context of classroom instruction, the view that underpins a user’s actual use of technology; (b) the “evident” or “actual usage” of technology in the classroom for instruction; and (c) the possible dimensions of this use. It is deemed important to bring a common understanding of computer use with respect to information and communication technology integration in pedagogy

    An Inventory of Medicinal Plants used to Treat Gynaecological-Obstetric-Urino-Genital Disorders in South Nandi Sub County in Kenya

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    This survey aims at identifying plants that may contribute to the identification and development of new drugs.An ethnomedicinal survey was conducted among the communities in Aldai Division, South Nandi Sub County, Kenya. A total of 56 plants were documented with 30 families are included. The majority of species belong to the families namely Euphorbiaceae, Lamiaceae, Apocynaceae and Fabaceae. Over half of all plants recorded are used treat infections, while ¼ for used labour-child birth and copulation disorders. Keywords: Ethnomedicine, gynaecological-obstetric-urinary, medicinal plants, Nandi

    An effective electrical isolation scheme by iron implantation at different substrate temperatures

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    High-energy implantation of iron in n-type doped InP epilayers at different substrate temperatures: 77K, room temperature (RT), 100degreesC and 200degreesC was investigated to study the electrical isolation of n-type InP. Iron isolation implants were performed at 1MeV with a fluence of 5 x 10(14) /cm(2). This isolation scheme was chosen to place most of the iron atoms well inside the n-type doped layer. The sheet resistivity (R,), sheet carrier concentration (n(S)) and sheet mobility (p) were measured as a function of substrate temperature and post-implantation annealing temperature (100 - 800degreesC). Samples implanted at 77K, RT and 100degreesC show more or less the same trend of postimplant annealing characteristics. A maximum sheet resistivity of similar to1 x 10(7) Omega/rectangle was achieved for samples implanted at 77K, RT and 100degreesC after annealing at 400degreesC. A lower resistivity of similar to1 x 10(6) Omega/rectangle was obtained for a 200degreesC implant after annealing at 4000C. Lower damage accumulation due to enhanced dynamic annealing is observed for the highest implantation temperature. For 200degreesC substrate temperature, annealing above 4000C resulted in a gradual decrease in sheet resistivity to a value close to that of the starting material. But this is not the case for the lower substrate temperatures. The sheet resistivity was increased again for 77K, RT and 100()C implant after annealing at 600degreesC. We infer that for 77K, RT and 100degreesC implantation temperatures, the electrical isolation is due to a product of both damage related centers and defects related to the presence of Fe whereas for 200degreesC substrate temperature, we infer that only damage induced compensation removes the carriers. These results show the importance of iron implants as a device isolation scheme.</p

    Operational Research Project Management, Experiences, Challenges and Lessons Learnt

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    Introduction: Effective project management revolves around Strategic Management. Logistics seem simple and straight forward but, often the role&nbsp; it plays in scientific undertakings is overlooked. It is usually assumed that research starts and ends in the laboratory. It is a fact that, for research activities to be successful, it requires exceptional planning to ensure that, resources are available as per the approved work-plan. This entails&nbsp; determination of what, when, who, why and how it is to be done. Recent studies indicate that, logistics-related activities' impact on research&nbsp; undertakings significantly. Objective: To document the project management experiences and lessons learnt in coordinating and implementation of East Africa Public Health Laboratories Networking Project –Operational Research (EAPHLNP-OR) activities in five East African countries, namely: Kenya, Rwanda, Burundi, Uganda and Tanzania. Methodology: The operational research component of the EAPHLNP, KEMRI established an OR Secretariat to coordinate the project activities in&nbsp; Kenya and provide leadership to regional principal investigators. In consultation with the project Secretariat, the role of the administrator involved Work plan and budget preparation, planning, organizing, communicating, coordinating local and regional meetings, linking KEMRI research team with the study site (Hospital Administration) and Research Teams in the various counties. The site Teams obtained informed consent, recruited respondents, collected specimens, analyzed the specimens and shipped a portion of the same together with the results to KEMRI. Key Activities Of The Project: Managing financial aspects (budget and financial report preparations), logistical coordination, and procurement of training materials, organizing for meeting venues, taking minutes, travel arrangements and participation in scientific report writing. Control mechanism such as dairies, ledger books, work plan charts and schedules, managing and monitoring the progress of the project activities. Lesson Learnt &amp; Challenges: Interpersonal skills were essential at all stages of the project. The critical stage was the forming, storming, and&nbsp; norming stages. Here, group dynamics and conflicts took center stage. This threatened to stall the OR Project. Timely and constant communication with the study site coordinators, prioritization of scheduled project activities, was essential. Ensuring all parties are kept informed on the progress of the OR activities. The information in user-friendly format dairies and schedules provided the necessary feedback at administrative level, on project performance and at research findings. Key challenges included fluctuating funding, group dynamic conflicts and staff transfers. Discussion: EAPHLNP-OR was a Seven (7) years project undertaking, which for effective management involved understanding of the operating environment, strategic planning for short and long term goals, constant communication, review of priorities, documentation and practise of goodinterpersonal skills. Conclusion: Successful project management in OR required an administrator to coordinate the utilization of the available resources both capital and human. This is the second supplement in this issue only aspects on findings from TB and Enteric studies done in Kenya have been addressed.Three regional policy briefs on TB Enteric and malaria have been included

    Association Behavior of Biotinylated and Non-Biotinylated PolyEthylene Oxide-b-Poly(2-(Diethylamino)Ethyl Methacrylate)

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    Biotinylated and non-biotinylated copolymers of ethylene oxide (EO) and 2-(diethylamino)ethyl methacrylate (DEAEMA) were synthesized by the atom transfer radical polymerization technique (ATRP). The chemical compositions of the copolymers as determined by NMR are represented by PEO₁₁₃PDEAEMA₇₀ and biotin-PEO₁₀₄PDEAEMA₉₃ respectively. The aggregation behavior of these polymers in aqueous solutions at different pHs and ionic strengths was studied using a combination of potentiometric titration, dynamic light scattering (DLS), static light scattering (SLS), and transmission electron microscopy (TEM). Both PEO-b-PDEAEMA and biotin-PEO-b-PDEAEMA diblock copolymers form micelles at high pH with hydrodynamic radii (Rh) of about 19 and 23 nm, respectively. At low pH, the copolymers are dispersed as unimers in solution with Rh of about 6-7 nm. However, at a physiological salt concentration (cs) of about 0.16M NaCl and a pH of 7-8, the copolymers form large loosely packed Guassian chains, which were not present at the low cs of 0.001M NaCl. The critical micelle concentrations (CMC) and the cytotoxicity of the copolymers were investigated to determine a suitable polymer concentration range for future biological applications. Both PEO-b-PDEAEMA and biotin-PEO-b-PDEAEMA diblock copolymers possess identical CMC values of about 0.0023 mg/g, while the cytotoxicity test indicated that the copolymers are not toxic up to 0.05mg/g (> 83% cell survival at this concentration).Singapore-MIT Alliance (SMA

    Lethal Mutagenesis of Poliovirus Mediated by a Mutagenic Pyrimidine Analogue

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    Lethal mutagenesis is the mechanism of action of ribavirin against poliovirus (PV) and numerous other RNA viruses. However, there is still considerable debate regarding the mechanism of action of ribavirin against a variety of RNA viruses. Here we show by using T7 RNA polymerase mediated production of PV genomic RNA, PV polymerase-catalyzed primer extension and cell-free PV synthesis that a pyrimidine ribonucleoside triphosphate analogue (rPTP) with ambiguous basepairing capacity is an efficient mutagen of the PV genome. The in vitro incorporation properties of rPTP are superior to ribavirin triphosphate. We observed a log-linear relationship between virus titer reduction and the number of rPMP molecules incorporated. A PV genome encoding a high-fidelity polymerase was more sensitive to rPMP incorporation, consistent with diminished mutational robustness of high-fidelity PV. The nucleoside (rP) did not exhibit antiviral activity in cell culture owing to the inability of rP to be converted to rPMP by cellular nucleotide kinases. rP was also a poor substrate for herpes simplex virus thymidine kinase. The block to nucleoside phosphorylation could be bypassed by treatment with the P nucleobase, which exhibited both antiviral activity and mutagenesis, presumably a reflection of rP nucleotide formation by a nucleotide salvage pathway. These studies provide additional support for lethal mutagenesis as an antiviral strategy, suggest that rPMP prodrugs may be highly efficacious antiviral agents, and provide a new tool to determine the sensitivity of RNA virus genomes to mutagenesis as well as interrogation of the impact of mutational load on the population dynamics of these viruses

    Lethal Mutagenesis of Picornaviruses with N-6-Modified Purine Nucleoside Analogues

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    RNA viruses exhibit extraordinarily high mutation rates during genome replication. Nonnatural ribonucleosides that can increase the mutation rate of RNA viruses by acting as ambiguous substrates during replication have been explored as antiviral agents acting through lethal mutagenesis. We have synthesized novel N-6-substituted purine analogues with ambiguous incorporation characteristics due to tautomerization of the nucleobase. The most potent of these analogues reduced the titer of poliovirus (PV) and coxsackievirus (CVB3) over 1,000-fold during a single passage in HeLa cell culture, with an increase in transition mutation frequency up to 65-fold. Kinetic analysis of incorporation by the PV polymerase indicated that these analogues were templated ambiguously with increased efficiency compared to the known mutagenic nucleoside ribavirin. Notably, these nucleosides were not efficient substrates for cellular ribonucleotide reductase in vitro, suggesting that conversion to the deoxyriboucleoside may be hindered, potentially limiting genetic damage to the host cell. Furthermore, a high-fidelity PV variant (G64S) displayed resistance to the antiviral effect and mutagenic potential of these analogues. These purine nucleoside analogues represent promising lead compounds in the development of clinically useful antiviral therapies based on the strategy of lethal mutagenesis
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