Impact of Land Use on Water Quality in River Njoro Watershed, Kenya

Water resources within the River Njoro watershed have become degraded due to high population growth rate and change in land use upsetting environmental stability. Land cover classification using Landsat images (Baldyga et al., 2004) shows loss of about 20% of forested areas between 1986 and 2003 in the watershed. The forested and large-scale farm areas have been converted mainly into small-scale mixed agriculture and human settlements. These changes have impacted negatively on the ecological integrity and hydrologic processes in the watershed (Shivoga, 2001) but little is known about the influence of specific land uses on water quality of the river

Records of Arthropod Species Sampled from Avocado Plant (Persea americana Mill) in Smallscale Agro-ecosystems at Taita Hills and Mount Kilimanjaro

Avocado, Persea americana Mill, plays a central role in distribution of both beneficial and detrimental arthropods thereby influencing local species diversity in agro-ecosystems adjacent to Afromontane forests at Mount Kilimanjaro in North-eastern Tanzania and Taita Hills in South-eastern Kenya. However, little is known about arthropod species that inhabit avocado trees in the two study areas despite the fact that the crop forms the major part of agro-ecosystem in the East African highlands. A novel survey was, therefore, carried out for two years between August 2012 and July 2014 to establish arthropod species in avocado orchards along South-eastern slopes of both Mount Kilimanjaro and Taita Hills. A total of sixty one species of arthropods were recorded from the avocado crop through fruit observation and canopy sampling. The present arthropod checklist provides baseline knowledge for scientists in evaluating beneficial and pest status of each species inhabiting avocado plant in the East African agro-ecosystems.Peer reviewe

Datasets on abundance of common blossom thrips and weather variables in small-scale avocado orchards at Taita Hills and Mount Kilimanjaro

Avocado, Persea americana Miller (Lauraceae), is an important fruit crop cultivated by small-holder farmers along Afrotropical highlands of Taita Hills in South-eastern Kenya and Mount Kilimanjaro in Northern Tanzania. The small-holder farmers in these East African regions generate substantial food and cash from avocado fruits. However, the avocado crop is faced with challenges of infestation by insect pests such as the common blossom thrips (Frankliniella schultzei Trybom) which feeds on pollen and floral tissue thereby reducing productivity of the trees. Moreover, there is no information describing distribution patterns of Frankliniella schultzei and associated weather in East African avocado orchards despite the fact that small-scale farming is dependent on rainfall. This article was, therefore, initiated to provide dataset on abundance of Frankliniella schultzei from the avocado plants that relates with monthly rainfall and air temperatures at Taita Hills and Mount Kilimanjaro. Frankliniella schultzei was collected using white coloured beating tray and camel brush whereas air temperatures (°C) and rainfall (mm) was recorded daily using automatic data loggers and rain gauge, respectively. The survey at the two transects commenced during peak flowering season of avocado crop in August up to end of harvesting period in July of the following year. Temporal datasets were generated by Kruskal-Wallis Chi-square test. Current temporal datasets presents strong baseline information specifically for Kenya and Tanzania government agencies to develop further agricultural strategies aimed at improving avocado farming within Taita Hills and Mount Kilimanjaro agro-ecosystems.Peer reviewe

Spatial characterization of common blossom thrips (Frankliniella schultzei) in smallholder avocado orchards along slopes of Taita Hills and Mount Kilimanjaro

Frankliniella schultzei Trybom (Thysanoptera:Thripidae) is an important flower pest of avocado crop (Persea americana Mill) at Taita Hills in South-eastern Kenya and Mount Kilimanjaro in North-eastern Tanzania. However, its geographical distribution is not known in the East African avocado cropping systems. In order to generate the spatial data of the common blossom thrips (Frankliniella schultzei), a survey was carried out in smallholder avocado orchards along altitudinal gradient (900 -1800m.a.s.l.) of Taita Hills and Mount Kilimanjaro using a white coloured beating tray and camel brush. Once the specimens of thrips were taxonomically verified, the abundance data was tabulated into three altitudinal zones, namely; lowland (900-1199m.a.s.l.), sub-montane (1200-1499m.a.s.l.) and montane (1500-1799m.a.s.l.). Frankliniella schultzei was recorded in all altitudinal zones of both transects with mean abundance being highest at Taita Hills (5.4) compared to Mount Kilimanjaro (0.9). However, abundance of the pest was greater in cooler highlands (>1200m.a.s.l.) than warmer lowland areas (<1200m.a.s.l.) of both transects. The findings of this study contributes significantly towards spatial mapping of Frankliniella schultzei in East Africa and this information is important in developing strategies aimed at controling infestation of avocado flowers by the insect pest at the two study transects.Peer reviewe

Type Specimens of the Insect Order Odonata in the Collection of the National Museums of Kenya

Volume: 60Start Page: 89End Page: 9

Characterization of diseased primary human hepatocytes in an all-human cell-based triculture system

Abstract Liver diseases, including NAFLD, are a growing worldwide health concern. Currently, there is a lack of suitable in vitro models that sustain basic primary human hepatocyte (PHH) morphology and functionality while supporting presentation of disease-associated phenotypic characteristics such as lipid accumulation and inflammasome activation. In TruVivo, an all-human triculture system (hTCS), basic metabolic functions were characterized in PHHs isolated from normal or diseased livers during two-weeks of culture. Decreases in albumin and urea levels and CYP3A4 activity were seen in diseased-origin PHHs compared to normal PHHs along with higher CYP2E1 expression. Positive expression of the macrophage markers CD68 and CD163 were seen in the diseased PHH preparations. Elevated levels of the pro-inflammatory cytokines IL-6 and MCP-1 and the fibrotic markers CK-18 and TGF-β were also measured. Gene expression of FASN, PCK1, and G6PC in the diseased PHHs was decreased compared to the normal PHHs. Further characterization revealed differences in lipogenesis and accumulation of intracellular lipids in normal and diseased PHHs when cultured with oleic acid and high glucose. TruVivo represents a promising new platform to study lipogenic mechanisms in normal and diseased populations due to the preservation of phenotypic differences over a prolonged culture period