Annual Research & Review in Biology

Aim: Sugarcane (Saccharum officinarum L.) which is mostly cultivated in tropical and subtropical regions of the world is an important source of sucrose. This crop which was originally grown in South Eastern Asia and the Pacific for the sole purpose of chewing is mainly used nowadays for the production of sugar, bio-fuels, medicine etc. In spite of its numerous uses, the production of sugarcane in Buea, South West region of Cameroon is hampered by many factors including the incidence of disease. It is possible that some varieties are no longer cultivated because of their susceptibility to fungal diseases. It was for these reasons that we decided to survey the sugarcane farms in this area, to evaluate the presence of diseased symptoms due to activity of fungi.

Study Design: Random sampling.

Place and Duration of Study: Buea and its environs, Rubber Pathology Laboratory IRAD Ekona, and Life Sciences Laboratory, University of Buea, between June 2016 and July 2017.

Methodology: During the survey, sugarcane farms in five villages in Buea and its environments were visited. The leaves and stems of the plants were observed for any symptoms of fungal activity. The incidence, severity and prevalence of the symptoms were noted. Leaf samples were collected from diseased sugarcane plants and transported to the laboratory for the isolation of fungi on Potato Dextrose Agar growth medium. The isolates were identified based on their cultural and micro-morphological characteristics.

Results: Sugarcane plants with fungal disease symptoms were seen in all the farms visited during the survey, thus a prevalence of 100%. The disease incidence varied from 54- 100%, while the severity ranged from 20- 55%. Two genera of fungi were isolated from the diseased plants viz: Chaetomium sp. and Bipolaris sp.

Conclusion: Chaetomium and Bipolaris are associated with fungal symptoms in diseased sugarcanes hence any management plans geared towards the improvement of sugarcane production in this area must include control measures for these fungi.

We investigated the biology and ecology of the tanaidacean Sinelobus stanfordi from the littoral water of Martín García Island at five sites along the coast chosen for their substrate characteristics, and classified the individuals according to size (mm) and ectosomatic characterinalysisstics as: manca III (0.60-1.19), juvenile male and female I (0.90-1.49), juvenile female II and copulatory male I (1.2-1.79), preparatory female I (1.8-2.39), preparatory female II (2.40-2.99), copulatory female I (2.40-2.69), copulatory female II (2.99-4.19), ovigerous female (1.80-3.59), copulatory male II (1.5-1.79), copulatory male III (2.10-2.69) and copulatory male IV (2.40-3.89). The smallest female with rudimentary ovisacs measured 1.84 mm. The tanaid density ranged from 0 to 10,548 ind.m^-2. The average female-to-male sex ratio was 3.04:1. An abundance analysis indicated no significant differences among the sampling sites (X² =4.037, p>0.001), while the fecundity (number of eggs) did not vary significantly with female size (r² =0.2164, n = 19). The almost permanent presence of all developmental stages during every season of the year suggested a likely continuous year-long reproduction of S. stanfordi. Relationship between the water variables and S. stanfordi populations: The lower than optimal average electrical conductivity (160.24 μS.cm^-1) for the species did not seem to limit the population-growth kinetics. The postmarsupial development throughout almost all the stages evidenced a significant positive correlation with pH. The soluble-reactive-phosphorus levels were within the low tolerance values as well as the NO^-3 and the NH₄ ⁺ and both close to optimal along with the near-optimal percent saturation of oxygen.

Analyzing progression of diseases is vital to monitor patient's traversal over time through a disease. Clinical study settings present modeling challenges, as patients' disease trajectories are only partially observed, and patients' disease statuses are only assessed at clinic visit times. HIV disease is a continuum of progressive damage to the immune system from the time of infection to the manifestation of severe immunologic damage. We proposed a semi-Markov model and collected data at Yirgalem General Hospital. Our study found that for an HIV/AIDS patient the transition probability from a given state to the next worse state increases within the good states as time gets optimum and then decreases with increasing time during a follow up. In a specific state of the disease a patient will stay in that state with a non- zero probability in good states and a patient will transit to the next state either to the worst or to the good state with a non-zero probability. The probability of being in same state decreases over time.  With the good or alive states, the probability of being in a better state is non-zero, but less than the probability of being in worst states.  The survival probabilities are decreasing with increasing time. Therefore, we recommend that increased clinical care for patients on ART services should be strengthen and patients need to regularly check their CD4 T cell count in the appropriate day based on physician order to timely know and monitor their disease status to improve the survival probability and to reduce mortality.

The experiment was conducted with 2 replications and 54 genotypes of wheat consisting 10 lines, 4 testers and their 40 crosses made in line X tester mating fashion in randomized block design during growing seasons 2014-2015. Spike length recorded the highest value of broad sense heritability while Canopy temperature index reported the highest value of genetic advance as a percent of mean and also reported highest phenotypic and genotypic coefficient of variation. Genotypic path analysis revealed that test weight and weight of grain/spike exhibited positive and strong association with grain yield and highest positive direct effects on grain yield. The selection for yield contributing test weight and weight of grain/spike must be given preference along with grain yield for speedy improvement grain yield.

The study was carried out to determine the prevalence rate of the schistosomiasis in school-aged children of 4 selected primary schools in Ijoun community of Yewa North Local Government Area in Ogun State and to evaluate the distribution of infection in terms of age and gender. A total number of 184 Urine samples were collected from the pupils and examined for the presence of over of Schistosoma haematobium, 89 0f the student were positive, Yewa North local Government School 1 had the highest prevalence with 58.82%, followed by Yewa North local Government School 2 with 50.0%, followed by Ansarudeen Primary School with 48%, and Yewa North local Government School 3 recorded the least with 40.0%. Out of 100 sample collected for male 49 were positive with the rate of 49.0% and 84 samples collected for female 40 were positive with the rate of 47.61%. The prevalence of schistosomiasis in relation to age groups. Age group 10 -12 years recorded the highest prevalence with 54.21% followed by age 7-9 with 52.38%, followed by age 13-15 with 37.73% and age group 16 -18 years had the lowest rate (33.33%). From the stated hypothesis, It can be affirmed that there is a significant difference between age and gender of the children in relation to schistosomiasis. There is a need for health education in the rural areas, designed to discourage the pupil's contact with surface water sources and provision of portable water supply.

Aquaculture is currently playing, and will continue to play, a big part in boosting global fish production and in meeting the rising demand of fishery products. Capture fisheries production has levelled off and is no longer considered capable of sustaining the supply of fisheries products needed to meet the growing global demand. Tilapia is the common name for several species of cichlid fish inhabiting freshwater streams, ponds, rivers and lakes and less commonly in brackish water. Considered as an invasive species, tilapias are now of increasing importance in Aquaculture. Tilapia is the second most farmed fish world-wide and its production has quadrupled over the past decade because of its suitability for aquaculture, marketability and stable market prices. Native to Africa and Middle East, tilapias were introduced into over 90 countries for aquaculture and fisheries. Tilapia continued its rapid increase in global production. Recent production figures reported by various sources, our global production estimate for 2015 is 5,576,800 mt.  Tilapias are now one of the most widely introduced fish globally that has clearly emerged as a very promising group in aquaculture.