Search

In this research work, the extraction, characterization, device fabrication, and theoretical investigation of Hibiscus sabdariffa plant extract, for possible application in solid DSSCs, are reported. The plant extract was analyzed using FT-IR and UV–Vis spectrophotometry. Polyaniline on graphene was used as the counter electrode whereas titanium (IV) oxide was used as the photo anode for the fabricated DSSCs. The experimental results obtained for the open circuit voltage, short circuit current density, field factor, maximum power and conversion efficiency are 0.925 V, 0.073 A/cm2, 1.43, 1.04 W, and 0.044 % respectively. The excited states of anthocyanin (delphinidin) and quercetin, the most stable structures of Hibiscus sabdariffa plant extract, were studied using density functional theory method. In addition, the theoretical open circuit voltage, light harvesting efficiency, coupling constant, free energy change, and HOMO–LUMO energy gap were predicted for the photovoltaic properties. The theoretical results suggest that quercetin has relatively better photovoltaic properties and, hence, potentially a better dye for solar cell application.

EGGS of Haemonchus contortus and Oesophagostomum columbianum exposed to a constant temperature of 13.8°C at 100% relative humidity developed to the infective third stage larvae within 15 and 18 days respectively. Exposure of eggs for nine hours at 40.6°C and 100% relative humidity was lethal but development to the infective stage was achieved by culturing at 27°C after six hours of exposure at 400C and 100% relative humidity. The normal Nigerian temperature range of 13.8°C [lowest minimum for Obudu Cattle Ranch] to 40.6°C (maximum for Maiduguri) is therefore suitable for survival and development of these stronglyle eggs to the infective stages at any season in the country.

In a survey at the Maiduguri metropolitan abattoir in northeastern Nigeria, between August and November 2009, Oesophagostomum columbianum nodules were found on the intestines of 702 (71.3 %) Sahel goats out of 984 examined. The nodules were predominantly located in the large intestines of most of the goats (96.4 %), but in heavy infections (3.6 %), the nodules extended into the small intestines and the omentum. The presence of nodules did not significantly (P > 0.05) increase the weight of the intestines of infected goats. Grossly the nodules were young (60 %), purulent (30 %) or calcified (10 %). Histologically the nodules appeared as granulomas with one or multiple necrotic foci. The infiltrating cells associated with the granulomas were eosinophils, neutrophils, macrophages, epithelioid macrophages and lymphocytes, but no multinucleated giant cell was found. The intestinal epithelium adjacent to the granuloma had intense lymphocytic infiltration into the lamina propria, necrosis and sloughing of the epithelial cells, stunting of the expanded villi and fewer intestinal glands. It was concluded that natural O. columbianum infection of Sahel goats was prevalent in the area and the infection caused non-suppurative enteritis associated with submucosal nodules which were granulomas lacking giant cells.

This paper describes a study on the oestrous and ovarian activity and responses to prostaglandin F2 alpha (PGF2 alpha) administration and artificial insemination in zebu heifers. Four cycling heifers were artificially infected with 5 x 10(6) Trypanosoma vivax organisms. Two heifers served as controls. Two injections of PGF2 alpha were given 11 days apart, commencing at the peak of parasitaemia in the infected animals, followed by artificial insemination 72 and 96 h after the second administration of PGF2 alpha. Sera were analysed for progesterone by radioimmunoassay, while ovarian activity and oestrus were determined by rectal palpation and visual observation, respectively. All the infected heifers developed the clinical disease. All control and infected heifers had progesterone profiles consistent with luteolysis and the occurrence of oestrus following the second administration of PGF2 alpha. Progesterone levels did not return to normal luteal values in infected animals, however, whilst they did so in control animals. No control or infected heifers became pregnant. The findings suggest that PGF2 alpha will induce a non-fertile oestrus in zebu heifers acutely infected with T. vivax. Re-ovulation is also inhibited within 22 days in a majority of infected animals.

The development and survival of the eggs of Haemonchus contortus on pasture at Ibadan were studied by spreading faeces containing eggs on grass plots from October 1973 to October 1974. Development of the eggs to the infective larvae took place within one week in May, June, July, September and October. Larvae were not recovered in the other months. Their survival times were 28, 42, 42, 35, 63 and 49 days respectively in October 1973. May, June, July, September and October 1974. Rainfall was the most important epizootiological factor which influenced the development and survival of the infective larvae. Development of the eggs to the infective larvae took place when the mean daily rainfall for the first 7 days was 3 mm or more. The survival time of the larvae appeared to be prolonged when rain fell evenly throughout the periods the larvae were on pasture.

During the dry season (January to March) in Calabar, strongyloid eggs in cattle faeces hatched within 24 h and developed to infective larvae within 7 days on pasture. The larvae survived 6 weeks in January, 4 weeks in February, 8 weeks in March and 10 weeks in April. Rainfall rather than temperature played the major role in the development and survival of the larvae on pasture during this period. There results show that the hatching of the eggs and the development of the larvae can take place at any time of the year in Calabar.

Oral administration of solutions of pyrantel tartrate at 50, 75, 100 and 125 mg/kg body weight gave 43.9, 82.1, 92.8 and 99.1 per cent efficacy respecively. None of the chicks given 100 and 125 mg/kg body weight showed any sign of toxicity.

At a dose of 15 mg/kg body weight, pyrantel tartrate was 18-51, 99-63, 100 and 100 per cent effective in chickens treated at 10, 20, 30 and 40 days respectively after infection with Ascaridia galli. Similarly, 25 mg/kg was 14-44, 100, 100 and 99-63 per cent effective.