Modelling Effects of Process Variables During Fermentation of Pineapple Peels Using Yeast for Ethanol Production Using a Second Order Optimal Rotatable Design in Four Dimensions.

The need for a cleaner environment in urban areas and the high cost of petroleum products which are becoming scarce due to unbalanced relation between supply and demand besides air pollution of sources has led to the research for other fuels to replace fossil fuels. Ethanol from biomass waste is such an alternative to petroleum products. Most studies on optimization of process variables using Response Surface Methodology apply Central Composite Designs yet other designs exist. Optimal designs have fewer trials employed with the aim of obtaining efficient designs for fitting reduced quadratic or higher order models. Coded values of a second order optimal rotatable design in four dimensions constructed using balanced incomplete block designs (BIBD) was fit into experimental data in order to study the effects of four process variables namely; time, PH, temperature and substrate concentration on fermentation of pineapples peels using Saccharomyces cerevisiae for ethanol production. Normal probability plots and Multiple R-squared of 0.9323 and Adjusted R-squared of 0.8944 which measure model fitting reliability indicated aptness of the model. Most values of Probability F were less than 0.05, confirming that the model terms were significant and only 6.8% of the total variation could not be explained by the model ensuring good adjustment of the model to experimental data. Model adequacy was also confirmed by the good agreement between the experimental data and predicted values. The design was found reliable in modeling, and studying the effects of the four factors to the processes of fermentation of pineapples peels as substrate for ethanol production using Saccharomyces cerevisiae Keywords: Ethanol, Pineapple Peels, Response Surface Methodology and Rotatable Designs

Feature Extraction using Histogram of Oriented Gradients for Image Classification in Maize Leaf Diseases

The paper presents feature extraction methods and classification algorithms used to classify maize leaf disease images. From maize disease images, features are extracted and passed to the machine learning classification algorithm to identify the possible disease based on the features detected using the feature extraction method. The maize disease images used include images of common rust, leaf spot, and northern leaf blight and healthy images. An evaluation was done for the feature extraction method to see which feature extraction method performs best with image classification algorithms. Based on the evaluation, the outcomes revealed Histogram of Oriented Gradients performed best with classifiers compared to KAZE and Oriented FAST and rotated BRIEF. The random forest classifier emerged the best in terms of image classification, based on four performance metrics which are accuracy, precision, recall, and F1-score. The experimental outcome indicated that the random forest had 0.74 accuracy, 0.77 precision, 0.77 recall, and 0.75 F1-score

Feature Extraction using Histogram of Oriented Gradients for Image Classification in Maize Leaf Diseases

The paper presents feature extraction methods and classification algorithms used to classify maize leaf disease images. From maize disease images, features are extracted and passed to the machine learning classification algorithm to identify the possible disease based on the features detected using the feature extraction method. The maize disease images used include images of common rust, leaf spot, and northern leaf blight and healthy images. An evaluation was done for the feature extraction method to see which feature extraction method performs best with image classification algorithms. Based on the evaluation, the outcomes revealed Histogram of Oriented Gradients performed best with classifiers compared to KAZE and Oriented FAST and rotated BRIEF. The random forest classifier emerged the best in terms of image classification, based on four performance metrics which are accuracy, precision, recall, and F1-score. The experimental outcome indicated that the random forest had 0.74 accuracy, 0.77 precision, 0.77 recall, and 0.75 F1-score

Pitting of malaria parasites and spherocyte formation

BACKGROUND: A high prevalence of spherocytes was detected in blood smears of children enrolled in a case control study conducted in the malaria holoendemic Lake Victoria basin. It was speculated that the spherocytes reflect intraerythrocytic removal of malarial parasites with a concurrent removal of RBC membrane through a process analogous to pitting of intraerythrocytic inclusion bodies. Pitting and re-circulation of RBCs devoid of malaria parasites could be a host mechanism for parasite clearance while minimizing the anaemia that would occur were the entire parasitized RBC removed. The prior demonstration of RBCs containing ring-infected erythrocyte surface antigen (pf 155 or RESA) but no intracellular parasites, support the idea of pitting. METHODS: An in vitro model was developed to examine the phenomenon of pitting and spherocyte formation in Plasmodium falciparum infected RBCs (iRBC) co-incubated with human macrophages. In vivo application of this model was evaluated using blood specimens from patients attending Kisumu Ditrict Hospital. RBCs were probed with anti-RESA monoclonal antibody and a DNA stain (propidium iodide). Flow cytometry and fluorescent microscopy was used to compare RBCs containing both the antigen and the parasites to those that were only RESA positive. RESULTS: Co-incubation of iRBC and tumor necrosis factor-alpha activated macrophages led to pitting (14% ± 1.31% macrophages with engulfed trophozoites) as opposed to erythrophagocytosis (5.33% ± 0.95%) (P < 0.01). Following the interaction, 26.9% ± 8.1% of the RBCs were spherocytes as determined by flow cytometric reduction in eosin-5-maleimide binding which detects RBC membrane band 3. The median of patient RBCs with pitted parasites (RESA+, PI-) was more than 3 times (95,275/μL) that of RESA+, PI+ RBCs (28,365/μL) (P < 0.01). RBCs with pitted parasites showed other morphological abnormalities, including spherocyte formation. CONCLUSION: It is proposed that in malaria holoendemic areas where prevalence of asexual stage parasites approaches 100% in children, RBCs with pitted parasites are re-circulated and pitting may produce spherocytes

Phytoplankton community structure and environment in the Kenyan waters of Lake Victoria

1. Phytoplankton species composition, numerical abundance, spatial distribution and total biomass measured as chlorophyll a concentration were studied in relation to environmental factors in September 1994 (dry season) and March 1995 (rainy season), respectively, in the Kenyan waters of Lake Victoria; 103 species were recorded. 2. Blue-green algae (Cyanophyceae) were most diverse, followed by diatoms (Bacillariophyceae), green algae (Chlorophyceae) and dinoflagellates (Dinophyceae). 3. Twinspan separated the phytoplankton communities in the Nyanza Gulf and those in the open lake during both seasons. During the dry season, the Nyanza Gulf was strongly dominated by blue-greens, while diatoms dominated in the open lake. During the rainy season, blue-greens remained dominant in the Nyanza Gulf although the number of species found was lower than during the dry season; in the open lake, blue-greens replaced diatoms as the dominant group and there were more species than in the dry season. 4. Canonical correspondence analysis indicated that the phytoplankton species distribution was significantly correlated with turbidity during the dry season and with SiO2 during the rainy season. Chlorophyll a concentrations ranging from 2.0 to 71.5 mg m-3 in the dry season and 2.0-17.2 mg m-3 in the rainy season confirm earlier reports of increasing phytoplankton biomass in Lake Victoria since the 1960s

Role of Bryophytes And Tree Canopy In Mist Trapping In Mt. Marsabit Forest

Mt. Marsabit forest, is an isolated Tropical Rain Forest, oasis, located 560 Km north of Nairobi, Kenya; and surrounded by deserts of Chalbi, Kaisut and Bubisa. The forest is under threat mainly by anthropogenic effects before the forest biota is studied. This research was to investigate the role of bryophytes and forest canopy in trapping mist water, for supporting Mt. Marsabit forest community development. The experiments were located 1450 m. asl windward of Mt. Marsabit. Stem simulates of varying circumferences were dressed with bryophytes and bryophytes mounted mist traps were located on same site. The water retention capacity was 6 times own dry weight with a hygroscopic capacity of 13%. The mist water trapped by bryophytes was 8 liters of water / m ²/ mist day translating to 196 mm of rainfall per year. The stem simulates of 20 cm circumference, 50 cm long trapped 30 ml of water per mist day using surface area of 0.05 m² translating to 914 ml of water per m² per mist day equivalent to 65 mm of rainfall per year. The study revealed that vegetation is an important catchments area surface (attract rain) whose loss leads to reduced water resource for plant and animal use; climate moderation. Further, mist water is the compensation factor that supports the forest ecosystem. The cooling effect of water is lost with the loss of vegetation. The loss of water leads to drier environment with climate change as the ripple effect. The change in river regimes and the general hydrologic cycle is due to loss in vegetation, where mist water was not accounted for by science. The mist water resource is renewable water resource that can be used to recharge ground water, conserve and rehabilitate forest and provide water for domestic, agricultural and industrial use

Water Hyacinth Eichhornia crassipes (Mart.) Solms-Laubach Dynamics and Succession in the Nyanza Gulf of Lake Victoria (East Africa): Implications for Water Quality and Biodiversity Conservation

This study, conducted in Nyanza Gulf of Lake Victoria, assessed ecological succession and dynamic status of water hyacinth. Results show that water hyacinth is the genesis of macrophyte succession. On establishment, water hyacinth mats are first invaded by native emergent macrophytes, Ipomoea aquatica Forsk., and Enydra fluctuans Lour., during early stages of succession. This is followed by hippo grass Vossia cuspidata (Roxb.) Griff. in mid- and late stages whose population peaks during climax stages of succession with concomitant decrease in water hyacinth biomass. Hippo grass depends on water hyacinth for buoyancy, anchorage, and nutrients. The study concludes that macrophyte succession alters aquatic biodiversity and that, since water hyacinth infestation and attendant succession are a symptom of broader watershed management and pollution problems, aquatic macrophyte control should include reduction of nutrient loads and implementing multifaceted approach that incorporates biological agents, mechanical/manual control with utilization of harvested weed for cottage industry by local communities

<i>Trypanosoma brucei rhodesiense</i> transmitted by a single tsetse fly bite in vervet monkeys as a model of human African trypanosomiasis

Sleeping sickness is caused by a species of trypanosome blood parasite that is transmitted by tsetse flies. To understand better how infection with this parasite leads to disease, we provide here the most detailed description yet of the course of infection and disease onset in vervet monkeys. One infected tsetse fly was allowed to feed on each host individual, and in all cases infections were successful. The characteristics of infection and disease were similar in all hosts, but the rate of progression varied considerably. Parasites were first detected in the blood 4-10 days after infection, showing that migration of parasites from the site of fly bite was very rapid. Anaemia was a key feature of disease, with a reduction in the numbers and average size of red blood cells and associated decline in numbers of platelets and white blood cells. One to six weeks after infection, parasites were observed in the cerebrospinal fluid (CSF), indicating that they had moved from the blood into the brain; this was associated with a white cell infiltration. This study shows that fly-transmitted infection in vervets accurately mimics human disease and provides a robust model to understand better how sleeping sickness develops