Natural & Applied Sciences

Natural & Applied Sciences Research Papers/Topics

Diversity and structure of prokaryotic communities within organic and conventional farming systems in central highlands of Kenya

Abstract Management practices such as tillage, crop rotation, irrigation, organic and inorganic inputs application are known to influence diversity and function of soil microbial populations. In this study, we investigated the effect of conventional versus organic farming systems at low and high input levels on structure and diversity of prokaryotic microbial communities. Soil samples were collected from the ongoing long-term farming system comparison trials established in 2007 at Chuka and ...

Diversity of Termitomyces Associated with Fungus- Farming Termites Assessed by Cultural and Culture- Independent Methods

Abstract Background: Fungus-cultivating termites make use of an obligate mutualism with fungi from the genus Termitomyces, which are acquired through either vertical transmission via reproductive alates or horizontally transmitted during the formation of new mounds. Termitomyces taxonomy, and thus estimating diversity and host specificity of these fungi, is challenging because fruiting bodies are rarely found. Molecular techniques can be applied but need not necessarily yield the same outcom...

Mutations and Epidemiology of SARS-CoV-2 Compared to Selected Corona Viruses during the First Six Months of the COVID-19 Pandemic: A Review

Abstract Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative agent of coronavirus (CoV) disease 2019 (COVID-19). This study compared the genome, mutations, and infectivity/ transmissibility of SARS-CoV-2 with selected betacoronaviruses (beta-CoVs). This study further examined the origin, risk factors, and outbreaks caused by beta-CoVs. We searched the following databases for relevant studies: PubMed, Google Scholar, and the World Health Organization COVID-19 databas...

On Centre Properties of Irreducible Subalgebras of Compact Elementary Operators

Abstract/Overview In this paper, we characterize the centre of dense irreducible subalgebras of compact elementary operators that are spectrally bounded. We show that the centre is a unital, irreducible and commutative C∗ -subalgebra. Furthermore, the supports from the centre are orthogonal and the intersection of a nonzero ideal with the centre is non-zero.

Properties of Spectrally Bounded Compact Elementary Operators

Abstract/Overview Spectrally bounded compact elementary operators on dense irreducible subalgebras of C ∗ -algebras are characterized. Also, it is shown that left multiplications, right multiplications, generalized derivations and basic elementary operators are spec trally bounded compact elementary operators. Furthermore, several properties of spectrally bounded compact elementary operators such as completeness, convergence, continuity and total boundedness in a general Banach setting ...

Norm-Attainability and Range-Kernel Orthogonality of Elementary Operators

Abstract/Overview Various aspects of elementary operators have been characterized by many mathematicians. In this paper, we consider norm-attainability and orthogonality of these operators in Banach spaces. Characterizations and generalizations of norm-attainability and orthogonality are given in details. We first give necessary and sufficient conditions for norm-attainability of Hilbert space operators then we give results on orthogonality of the range and the kernel of elementary operat...

Lie Symmetry Analysis of Modified Diffusive Predator-prey Competition System of Equations

Abstract/Overview In this paper, a nonlinear fourth order evolution equation is investigated by the Lie symmetry analysis approach. All the geometric vector fields and the Lie groups of the evolution equation are obtained. Finally, the symmetry reduction and the exact solutions of the equation are obtained by means of power series method.

Geomorphic and Climatic Drivers Are Key Determinants of Structural Variability of Mangrove Forests along the Kenyan Coast

Abstract Mangrove forests occur across a diversity of coastal landforms that influence their structural development and productivity. Preliminary studies in Kenya indicate that mangroves growing in the region north and south of Tana River delta have different structural attributes. We hypothesise a close relationship between mangrove distribution, climate and landform types. Floristic composition of mangroves along the coast of Kenya was characterised and differences illustrated using non-m...

STIP1/HOP Regulates the Actin Cytoskeleton through Interactions with Actin and Changes in Actin-Binding Proteins Cofilin and Profilin

Abstract Cell migration plays a vital role in both health and disease. It is driven by reorganization of the actin cytoskeleton, which is regulated by actin-binding proteins cofilin and profilin. Stress-inducible phosphoprotein 1 (STIP1) is a well-described co-chaperone of the Hsp90 chaperone system, and our findings identify a potential regulatory role of STIP1 in actin dynamics. We show that STIP1 can be isolated in complex with actin and Hsp90 from HEK293T cells and directly interacts wit...

Isolation and characterisation of bacteria from the haloalkaline Lake Elmenteita, Kenya

Abstract Culture-independent studies show that soda lake environments harbour diverse groups of bacteria and archaea. In this study different enrichment and isolation media were used in an attempt to isolate novel groups of bacteria from Lake Elmenteita. Different media were prepared using filter-sterilised water from the lake. The isolates recovered were purified on tryptic soy agar supplemented with 1% sodium carbonate and 4% sodium chloride. Phylogenetic analysis of 181 partial 16S rRNA g...

Complete genome sequence of the thermophilic sulfur-reducer Desulfurobacterium thermolithotrophum type strain (BSAT) from a deep-sea hydrothermal vent

Abstract Desulfurobacterium thermolithotrophum L'Haridon et al. 1998 is the type species of the ge-nus Desulfurobacterium which belongs to the family Desulfurobacteriaceae. The species is of interest because it represents the first thermophilic bacterium that can act as a primary pro-ducer in the temperature range of 45-75 °C (optimum 70°C) and is incapable of growing un-der microaerophilic conditions. Strain BSAT preferentially synthesizes high-melting-point fatty acids (C18 and C20) whic...

Complete genome sequence of the gliding freshwater bacterium Fluviicola taffensis type strain (RW262T)

Abstract Fluviicola taffensis O'Sullivan et al. 2005 belongs to the monotypic genus Fluviicola within the family Cryomorphaceae. The species is of interest because of its isolated phylogenetic lo-cation in the genome-sequenced fraction of the tree of life. Strain RW262T forms a monophy-letic lineage with uncultivated bacteria represented in freshwater 16S rRNA gene libraries. A similar phylogenetic differentiation occurs between freshwater and marine bacteria in the family Flavobacteriaceae,...

Complete genome sequence of Oceanithermus profundus type strain (506T)

Abstract Oceanithermus profundus Miroshnichenko et al. 2003 is the type species of the genus Ocea-nithermus, which belongs to the family Thermaceae. The genus currently comprises two spe-cies whose members are thermophilic and are able to reduce sulfur compounds and nitrite. The organism is adapted to the salinity of sea water, is able to utilize a broad range of carbo-hydrates, some proteinaceous substrates, organic acids and alcohols. This is the first com-pleted genome sequence of a membe...

Assessment of Four Commercial Watermelon Cultivars and one Local Landrace for Their Response to Naturally Occurring Diseases Pests and Non-Pathogenic Disorders in Sub-Humid Tropical Condition

Abstract Four commercial watermelon cultivars available in Kenya and one local landrace were evaluated for their susceptibility/resistance to naturally occurring diseases, pests and non-pathogenic disorders. The accessions included three most common commercial watermelon cultivars in Kenya namely ‘Sugarbaby’, ‘Crimson Sweet’ and ‘Charleston Gray’; one newly introduced cultivar from United States namely ‘Yellow Crimson’; and one local landrace (GBK-043014) from Kakamega distri...

Genetic diversity and population structure of wild and cultivated Crotalaria species based on genotyping-by-sequencing

Abstract Crotalaria is a plant genus that is found all over the world, with over 700 species of herbs and shrubs. The species are potential alternative food and industrial crops due to their adaptability to different environments. Currently, information on the genetic diversity and population structure of these species is scanty. Genotyping-by-sequencing (GBS) is a costeffective high-throughput technique in diversity evaluation of plant species that have not been fully sequenced. In the curr...


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