Natural & Applied Sciences

Research Papers/Topics Natural & Applied Sciences

Application of the geological streamflow and Muskingum Cunge models in the Yala River Basin, Kenya

Abstract The nature of surface runoff and its effects in the watershed can be represented by the application of hydrologic and hydraulic models. In this study, the Geological Streamflow Model (GeoSFM) and the Muskingum Cunge (M-C) model were used to model the hydrologic processes of the Yala river network. The objective was to develop a flood early warning system to mitigate potential flood hazard risk exposed to the downstream inhabitants. Historical hydro]metric datasets of 1975] 2005 were...

Phytochemical Composition and Antibacterial Activity of Fruit Extract of Solanum incanum L. against Ralstonia solanacearum

Abstract Aims: To determine the phytochemical composition and antibacterial activity of Solanum incanum fruits against Ralstonia solanacearum. Study Design: Experimental design involving completely randomized design Place and Duration of Study: The study was conducted at department of Chemistry and Biochemistry, School of Sciences and Aerospace studies, Moi University, Kenya, between January and June 2021. Original Research Article Karanja et al.; AJACR, 9(4): 1-16, 2021; Article no.AJACR.75...

Erythrocyte indices, anaemia levels and types in Kenyan injection and non-injection substance users

Abstract The impact of injection and non-injection substance use in HIV infections is an area of great public importance especially with respect to hematologic and immune profiles. Evaluations of hematologic and immune status are critical for better disease classification and clinical management especially of HIV positive substance users. However, not much information is known about the hematologic and immune derangements in HIV infected injection and non-injection substance users. This stud...

TEMPORAL TRENDS OF HIV PREVALENCE IN SUB-SAHARAN AFRICA

Abstract Background. The HIV epidemic varies significantly across different groups in the SSA region, and complicates designing effective general interventions. We aim at uncovering temporal trends in HIV prevalence disaggregated by age, sex, and country. Method. We determined HIV prevalence trends among males and females aged 15-49 years for surveys conducted from the years 2003-2007 (period 1) and 2013-2018 (period 2) in SSA. Countries were divided into three clusters based on their socio-...

Volatile aroma chemical constituents of fruit pulp of some Kenyan varieties of mango (Mangifera indica L.)

Abstract Volatiles are key constituents of mango fruit aroma and vital in defining fruit quality besides influencing consumer preferences. In this paper, volatiles of eight Kenyan mango varieties: Ngowe, Apple, Keitt, Boribo, Tommy Atkins, Van Dyke, Sabre and Kent were collected on porapak Q adsorbent filters (mesh 40-80μm) using air entrainment kit and analyzed by Gas Chromatography (GC) and GC coupled to a Mass Spectrometer. Fifty-eight compounds, representing monoterpenes (66.1%), esters...

Ovicidal Activity of 2-Hydroxy-4-Methoxybenzaldehyde, Derivatives and Structural Analogues on Anopheles gambiae eggs

Abstract Background Effective remedies for disrupting Anopheles gambiae metamorphosis at the egg stage are crucial in suppression of the malaria vector populations that result in the reduction of disease burden. 2-Hydroxy-4-methoxybenzaldehyde (the major component of Mondia whytei roots), its derivatives, structural analogues and their blends were evaluated against the eggs of An. gambiae in the search for ovicidal compounds with potential use in mosquito control programs. Methods Mature roo...

SARS-CoV-2 Detection in Fecal Samples in Sym-asymptotic Patients with Typical Findings of COVID-19 on Ag-RDT and SARS-CoV-2 RT-PCR Tests

Abstract Coronavirus is a disease caused by a severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) which emerged as a global pandemic in 2019 from Wuhan, China. Since its emergence, it has caused immense suffering to human life, 6.27 million lives have been lost, movement curtailed and social dynamics disrupted. The golden standard for getting samples for SARS-CoV-2 detection is through oral- nasopharyngeal swab, this method of sample collection is invasive and uncomfortable, thus st...

Field Evaluation of a Push-Pull System to Reduce Malaria Transmission

Abstract/Overview Malaria continues to place a disease burden on millions of people throughout the tropics, especially in sub-Saharan Africa. Although efforts to control mosquito populations and reduce human-vector contact, such as long-lasting insecticidal nets and indoor residual spraying, have led to significant decreases in malaria incidence, further progress is now threatened by the widespread development of physiological and behavioural insecticide-resistance as well as changes in t...

Artisanal Fishing Supports Breeding of Malaria Mosquitoes in Western Kenya

Abstract/Overview Background: Everyday hundreds of people, mainly men, set out to take part in a vibrant artisanal capture fshing (ACF) industry on Lake Victoria. It is not known whether actions of artisanal fshers, in their unrelenting quest for exist ence, surpass ecosystems’ sustainability thresholds with potentially negative repercussions on human health with respect to malaria transmission potential. This article sought to fll this information gap. Methods: This study used an ecosy...

Short communication: Efficacy of two commercial disinfectants on Paenibacillus larvae spores

Abstract Paenibacillus larvae is a spore-forming bacterium causing American foulbrood (AFB) in honey bee larvae. The remains of a diseased larva contains billions of extremely resilient P. larvae spores viable for decades. Burning clinically symptomatic colonies is widely considered the only workable strategy to prevent further spread of the disease, and the management practices used for decontamination requires high concentrations of chemicals or special equipment. The aim of this study was...

Knockdown of Cytochrome P450 Genes Gh_D07G1197 and Gh_A13G2057 on Chromosomes D07 and A13 Reveals Their Putative Role in Enhancing Drought and Salt Stress Tolerance in Gossypium Hirsutum

Abstract/Overview We identified 672, 374, and 379 CYPs proteins encoded by the CYPs genes in Gossypium hirsutum, Gossypium raimondii, and Gossypium arboreum, respectively. The genes were found to be distributed in all 26 chromosomes of the tetraploid cotton, with chrA05, chrA12, and their homeolog chromosomes harboring the highest number of genes. The physiochemical properties of the proteins encoded by the CYP450 genes varied in terms of their protein lengths, molecular weight, isoelectr...

Anti-inflammatory norhopanes from the root bark of Fagaropsis angolensis (Engl.) H.M.Gardner

Abstract Two new norhopane derivatives namely 3β,6β,22-trihydroxy-7β,11α-di[(4-hydroxybenzoyl)oxy]-21αH-24- norhopa-4(23)-ene (1) and 3β,6β,22-trihydroxy-7β-[(4-hydroxybenzoyl)oxy]-21αH-24-norhopa-4(23)-ene (2) together with two previously reported compounds, including a norhopane, 3β,6β,11α-trihydroxy-7β-[(4-hydroxybenzoyl) oxy]-24-norhopa-4(23),17(21)-diene (3) and a norneohopane, (21αH)-24-norneohopa-4(23), 22(29)-diene-3β,6β,7β-triol 7-caffeate (4) were isolated from the...

Low foristic richness of afro‐alpine vegetation of Mount Kenya is related to its small area

Abstract Diversity patterns of tropical alpine vegetation is poorly studied. We estimated vascular plant floristic richness for two typical afro-alpine communities in Mount Kenya using a series of nested plots sized from 25 to 100 m2. The α-diversity was low for all plot sizes (4.8–7.8 and 12.8 species per one and 100 m2, respectively). Comparative analysis of α-, β- and γ-diversity across 22 plant communities from five Mountain regions (Mount Kenya, European Alps, Caucasus, Tibet, New...

Serological evidence of single and mixed infections of Rift Valley fever virus, Brucella spp. and Coxiella burnetii in dromedary camels in Kenya

Abstract Camels are increasingly becoming the livestock of choice for pastoralists reeling from effects of climate change in semi-arid and arid parts of Kenya. As the population of camels rises, better understanding of their role in the epidemiology of zoonotic diseases in Kenya is a public health priority. Rift Valley fever (RVF), brucellosis and Q fever are three of the top priority diseases in the country but the involvement of camels in the transmission dynamics of these diseases is poor...

Fixed Points Approximation for Non Expansive Operators in Hilbert Spaces

Abstract/Overview Approximations of fixed points have been done in different space and classes. However, characterizations in norm attainable classes remain interesting. This paper discusses approximation of nonexpansive operators in Hilbert spaces in terms of fixed points. In particular, we prove that for an invariant subspace H0 of a complex Hilbert space H; there exists a unique nonexpansive retraction R of H0 onto _(Q) and x 2 H0 such that the sequence f_ng generated by _n =_nf(_n)+(1...


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