Natural & Applied Sciences

Natural & Applied Sciences Research Papers/Topics

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...

The Contribution of Subtidal Seagrass Meadows to the Total Carbon Stocks of Gazi Bay, Kenya

Abstract Seagrass beds occur globally in both intertidal and subtidal zones within shallow marine environments, such as bays and estuaries. These important ecosystems support fisheries production, attenuate strong wave energies, support human livelihoods and sequester large amounts of CO2 that may help mitigate the effects of climate change. At present, there is increased global interest in understanding how these ecosystems could help alleviate the challenges likely to face humanity and the...

Vertical Distribution of Plant-Parasitic Nematodes in Sweet Potato

Abstract Plant-parasitic nematodes (PPN) are harmful pests that have become a severe threat to crop production worldwide. Diversity of PPN at horizontal and spatial scales influence the effectiveness of control strategies. This study evaluated the vertical distribution of PPN genera at 0 cm to 30 cm and 30 cm to 60 cm in sweet potato fields in Central, Manyatta, and Nembure regions of Embu County, Kenya. A significant region × depth interaction was observed for Tylenchus. For all the other ...

Nematode assemblages, food web indices and metabolic footprints in maize-pigeon pea agro-ecosystems

Abstract Pigeon pea (Cajanus cajan L.) and maize (Zea mays L.) are important food crops in developing countries due to their multiple benefits. However, their production is constrained by plant-parasitic nematodes (PPN) which cause significant yield losses. Understanding the nematode-based soil food web structure in maize-pigeon pea agroecosystems will allow sustainable PPN management by improving soil health. This study explored nematode community assemblages, indices and metabolic footprin...

Genetic Diversity of African Nightshade (Solanum nigrum L.) Complex Accessions from Western Kenya

Abstract Kenya. Despite its importance as a nutritious vegetable and having inherent medicinal value, African nightshade has been neglected, few farmers are growing it, there is potential reduction of food supply and these may be as a result of few studies carried out to improve the crop. Recently, growing demand is necessary for the development of improved, high yielding varieties, intensify diversity studies of interest, conservation and utilization of genetic resources especially in Weste...

Formulating Black Scholes Equation Using a Jump Diffusion Heston’s Model

Abstract/Overview In modern financial mathematics, accurate values are obtained by taking into account a considerable number of more realistic assumptions in logistic Black Scholes equation. The aspects considered here are cost of transactions in trading, perfect illiquid markets and risks that occur from non – protected portfolio or large investments that have a lot of impact on price of the assets, volatility, the percentage drift and the life of the portfolio itself. In modern world ...

Derivation of Black Scholes Equation Using Heston’s Model with Dividend Yielding Asset

Abstract/Overview Black Scholes formula is crucial in modern applied finance. Since the introduction of Black – Scholes concept model that assumes volatility is constant; several studies have proposed models that address the shortcomings of Black – Scholes model. Heston’s models stands out amongst most volatility models because the process of volatility is positive and is a process that obeys mean reversion and this is what is observed in the real market world. One of the shortcomin...

Simulation of the charge ratio of cosmic ray muons in extensive air showers using corsika

Abstract/Overview The interaction of primary cosmic rays in the atmosphere produces, among other particles, pions and kaons. They decay to muons, which form an important component of extensive air showers, which can be measured on the Earth's surface. The ratio of positively to negatively charged muons, called the muon charge ratio, provides important information about the cosmic ray interactions in the atmosphere. In this study, the theoretical hadronic interaction models in the cosmic r...


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