Karatina University

Abstract Volatile terpenes constitute a predominant class of floral scent emitted by Paeonia lactiflora. Despite their ecological and economical significance, the genetic blueprint of the underlying biosynthetic pathway remains poorly elucidated. Although a few terpene synthase (TPS) genes have been reported, the broader network of genes orchestrating terpene production in P. lactiflora is still largely unresolved. In this study, we attempted to address this gap by exploring the terpene biosynthetic pathway genes in P. lactiflora ‘Zifengyu’. β-caryophyllene, geraniol, citronellol and 1, 8-cineole were identified as the dominant floral terpenes, and catalytic functions of key proteins- terpene synthase (PlTPS), Nudix hydrolase (PlNUDX) and prenyltransferase (PlPT) were comprehensively characterized. Briefly, biochemical analyses revealed that six of the nine identified PlTPS proteins utilized diverse prenyl diphosphates to generate both monoterpenes and sesquiterpenes, while their products specificity were determined by plastidic or cytosolic localizations in planta. In particular, PlTPS4, PlTPS5 and PlTPS9 catalyzed the production of β-caryophyllene, 1, 8-cineole and geraniol, respectively. Besides, two amino acid residues were found to drive catalytic activity and product profiles in PlTPS4 and PlTPS5. Markedly, PlNUDX hydrolyzed GPP and NPP to yield geraniol and nerol thereby providing a plastid-independent pathway for monoterpene biosynthesis, and prenyltransferases were further functionally characterized to clarify the supply of prenyl diphosphates feeding into volatile terpenes. Collectively, these findings not only provide a mechanistic framework for understanding floral terpene biosynthesis in P. lactiflora but also reveal alternative metabolic routes that enrich its volatile profiles which could be utilized in scent improvement of ornamental plants.

Background: The clinical profile of patients is crucial in emergency departments to determine their severity and the urgency of their condition. Globally, early ED mortality is driven by non-communicable diseases, trauma, and cardiovascular disorders, often worsened by comorbidities and delayed care. Kenya’s emergency department (ED) mortality rate is estimated to be 10-15%, with 1.9% of deaths within 72 hours.

<p>Theoretical investigation of the effect of the polarization angle on high-order harmonic generation in an inhomogeneous two-color field is reported. The results show that the use of two-color fields greatly enhanced the harmonic cutoff point in comparison with the one-color field from 70th to 90th orders in a homogeneous field. In addition, the introduction of an inhomogeneity parameter of 0.003 generated a broad supercontinuum of approximately 270 orders. However, an increase in the polarization angle adversely affected the harmonic cutoff.</p>

Career decision making is crucial among people all over the world and choosing a career is challenging to those who do not have a wide life experience. Despite the high school completion rates, there is a noticeable trend in Kiambu County that majority of students find it difficult to choose a career after completion. The purpose of this study was to determine the influence of parent’s level of education on students’ career decision self-efficacy of students in public secondary schools in Kiambu County, Kenya. The study was guided by the Social Cognitive Career theory and the Systems theory. This study used a combination of descriptive and correlational research design. Data was collected using self-administered questionnaires. The target population consisted of 29,682 form three students in Kiambu county. The sample size consisted of 380 form three students who were selected using stratified sampling techniques from the 285 secondary schools in Kiambu County, Kenya. Questionnaires were used for data collection. The questionnaires were pilot tested with 30 students from three secondary schools. The Reliability of the instrument was tested using Cronbach’s Alpha reliability coefficient (r=0.79). Content validity was tested using content validity index (CVI=0.84). The data was analyzed using descriptive statistics which included percentages, means, and frequencies. The hypothesis was tested using t-test, Simple Regression and Analysis of Variance at 0.05 level of significance. The research found out that parents level of education (F (4, 375) = 11.663, p = .000) has statistically significant influence on students’ career decision self-efficacy in public secondary schools in Kiambu County, Kenya. Findings of this study informs the Ministry of Education, policy makers, career guidance teachers and also parents on the influence of parents level of education on the students while making career decisions. This study contributes to the body of knowledge as it provides a model for predicting students’ career decision self-efficacy given the parents level education. Based on the findings of the study, it was concluded that parent’s level of education has statistically significant influence on career decision self-efficacy among students in public secondary schools in Kiambu County, Kenya. The study recommended that the career teachers should consider parent’s level of education in career guidance as it statistically influence career decision self-efficacy among students in public secondary schools.

Background and Purpose: Plants contain complex bioactive compounds with insecticide properties.The present study was designed to characterize and determine the larvicidal potency of crude methanol and hexane extracts of Urtica massaica against laboratory-cultured Anopheles gambiae larvae. Materials and Methods:This research was a laboratory-based experiment.Bioactive compounds were extracted using methanol and hexane, while larvae for bioassay were laboratory stock.The effectiveness of the extracts was evaluated using the World Health Organisation (WHO) >80% mortality threshold and methods, respectively.The extract dose was taken as the independent variable, while observed mortalities were the dependent variable.Dimethyl sulfoxide and distilled water were used as negative controls.Descriptive statistics and one-way analysis of variance were performed for statistical justifications of bioactive quantities and insecticidal properties of the extracts.Significant level was set at P<0.05.Results: Five groups of chemical compounds were extracted: Phenolic > amino acids and nitrogen derivatives>steroids and terpenoids > flavonoids, nitrogen derivatives, and others.Nineteen compounds were from roots, 17 from leaves, and 12 from stems.-Sitosterol, 3,4-diferuloylquinic, and catechin were more while benzoic acid, L-leucine, N-(m-anisoyl)-, methyl ester, and myricetin were the least abundant in leaves, stem, and roots, respectively.Extracts from the stem killed more than 80% of exposed larvae for doses of 10 mL/100 cm 3 (e/w) than those of the other parts (root and leaves).The observed mortalities, however, were not significantly different (P>0.05),irrespective of the dose or control used. Conclusion:U. massaica contains diverse bioactive compounds potent against A. gambiae larvae.

Fast technological evolution and intensity of competition oblige companies to constantly seek for new ways to differentiate and offer added value to their customers. With the increasing popularity of social media, companies have started to consider this means as a new way to communicate with their customers and increase their brand reputation. One of the most notable phenomena of new media is how it has increased and created new forms of social interaction.In Kenya, despite the critical role played by the Small and Medium Enterprises (SMEs) in the country, research has shown that 90% business startups fail in their third year and especially those owned by the youths The general purpose of the study was to establish the influence of social media marketing on performance of small and medium businesses in Nairobi’s industrial area. This study adopted a descriptive research design. Official records of AGPO as at December 2023 showed that there are 13,011 youth-owned businesses registered in the county of Nairobi with the Youth Access to Government Procurement Opportunities Program (YAGPO). The study used the 10-30% Mugenda Sampling principle to calculate the sample size of 130 SMEs. The first specific objective was to establish the extent Social Media Platforms Influence the Performance of Small and Medium Enterprises. A Pearson correlation analysis was done to establish the relationship between social media platform on performance of SMEs and the result established a significant positive relationship between social media platform used and the performance of SMEs (r=.811, p value =0.000). The second specific objective was to establish the extent bloggers influence the performance of Small and Medium Enterprises. A Pearson correlation analysis was done to establish the relationship between blogger influence on performance of SMEs and the result established a significant positive relationship between blogger influence and the performance of SMEs (r=.730, p value =0.000). The third objective was to establish the extent social media messaging factors influence the performance of Small and Medium Enterprises. A Pearson correlation analysis was done to establish the relationship between messaging factors on performance of SMEs and the result established a significant positive relationship between social media messaging factors used and the performance of SMEs (r=.359, p value =0.000). The study concluded that use of social media marketing has a positive influence on performance of SMEs and recommended that there is need for SMEs to embrace the use of social media to market their products and that the government should support SMEs by providing affordable internet services.

This study sought to investigate the intellectual wellness programmes on service delivery in faith-based hospitals in the Nairobi metropolitan area. In the modern competitive business environment, organisations and their management have realised that their survival and competitiveness lie in the quality of the services and by extension the service providers. The study adopted descriptive survey and correlational research designs. The study targeted the employees in faith-based hospitals in the Nairobi metropolitan area. A stratified random sampling approach was used in selecting the respondents. The study sample size was 297 respondents. Of the 297 questionnaires distributed to the target respondents, 244 of the questionnaires were filled and returned. Thus, there was a response rate of 82 per cent. The study obtained primary data using a questionnaire. Descriptive and inferential statistics were used to analyse data. Descriptive statistics included frequencies, mean, standard deviation and percentage. Correlational analysis was used to determine the relationship between the independent and dependent variables. The study also carried out a regression analysis to determine the level of association of the study variables. Results were presented in tables. The study established that there were employees' intellectual wellness programmes in the faith-based hospitals in the Nairobi metropolitan area. Correlation analysis results showed that a significant moderate positive correlation existed between service delivery and intellectual wellness programmes. The study also determined that intellectual wellness had a significant influence on service delivery in faith-based hospitals in the Nairobi metropolitan area. The study thus concluded that intellectual employee wellness programmes had a significant influence on service delivery in faith-based hospitals in the Nairobi metropolitan area.

Abstract Fire and herbivory interact to alter ecosystems and carbon cycling. In savannas, herbivores can reduce fire activity by removing grass biomass, but the size of these effects and what regulates them remain uncertain. To examine grazing effects on fuels and fire regimes across African savannas, we combined data from herbivore exclosure experiments with remotely sensed data on fire activity and herbivore density. We show that, broadly across African savannas, grazing herbivores substantially reduce both herbaceous biomass and fire activity. The size of these effects was strongly associated with grazing herbivore densities, and surprisingly, was mostly consistent across different environments. A one‐zebra increase in herbivore biomass density (~100 kg/km 2 of metabolic biomass) resulted in a ~53 kg/ha reduction in standing herbaceous biomass and a ~0.43 percentage point reduction in burned area. Our results indicate that fire models can be improved by incorporating grazing effects on grass biomass.

Abstract In the 1980s, Artemia franciscana from San Francisco Bay (SFB) was introduced into Kenyan saltworks, where it has colonized and established stable populations. However, little is known about its biology, particularly with respect to its parental SFB population. This study compared the salinity tolerances of Kenyan (KEN) population, their SFB progenitors and those of Great Salt Lake (GSL) populations. Growth and survival of these A. franciscana populations were evaluated under varying salinity levels in a laboratory set up. A. franciscana nauplii were cultured at a rate of 1 nauplii/mL in 36 Erlenmeyer flasks and fed microalgae (Chaetoceros sp.) at 1.5 × 106 cells/animal/day for 8 days. Survival was evaluated daily and survivors were fixed in individual vials with Lugol solution. The total length of each fixed A. franciscana nauplii specimen was measured under a compound microscope. All populations were susceptible to salinities greater than 100 g/L. Compared with the parental SFB population, the KEN population exhibited significantly reduced survival and growth at 140 g/L, suggesting a narrower salinity tolerance range. These findings underscore the need for further studies focusing on other physiological parameters, abiotic factors and genetic characterization to confirm whether the KEN population is experiencing ecological adaptation. This will contribute to the optimization of Artemia practices in various salinity environments as a result of climate change.