Rivers State University of Science and Technology

About: Rivers State University of Science and Technology is a education organization based out in Port Harcourt, Rivers, Nigeria. It is known for research contribution in the topics: Population & Threatened species. The organization has 1826 authors who have published 1833 publications receiving 15183 citations.

The susceptibility of pepper fruits (Capsicum species) to oviposition by the pepper fruitfly, Atherigona orientalis (Schiner) in Port Harcourt, Nigeria

Abstract: Atherigona orientalis (Schin.) is a dipterous pest of pepper fruit in Nigeria. Field and laboratory observations showed that available local varieties of pepper were infested by the developmental stages during the rainy season in Port Harcourt. The fruits were contaminated with pupae and larval frass. The population of the various stages are primarily related to the availability of susceptible pepper fruits, itself determined by rainfall. Of four local varieties, Nsukka Yellow (Capsicum annum) was most preferred and Bird's eye chilli (C. frutescens) the least preferred by A. orientalis.

Production, organoleptic assessment and nutritional properties of akara from cowpea/maize flour blends

Abstract: The proximate composition, acceptability and nutritional properties of akara produced from cowpeas (Vigna unguiculata) and white maize (Zea mays) flour blends in the ratios 100:0 (Sample A, control), 85:15 (sample B), 75:25 (sample C), 65:35 (sample D), 50:50 (sample E), 40:60 (sample F), and 30:70 (sample G), respectively, were investigated. Protein quality was evaluated by feeding 28 day-old weanling albino rats with 10% protein diets formulated with samples A to G, with casein as the control diet. Crude protein, fat and moisture contents of the all-cowpea akara, were 20.7%, 22.4% and 38.9%, respectively, but decreased to 15.8%, 16.5% and 17.5%, respectively, when the level of maize flour in the blend increased to 70%. Up to 35% maize flour in the blend produced acceptable akara, with ball shape, color and flavor similar to the control. There were no significant (p > 0.05) differences between the values obtained for protein efficiency ratio, net protein ratio, and apparent and true digestibilities of diet G and casein when fed to rats, suggesting an improvement in the protein quality of akara prepared from cowpea: maize (30:70 w/w) flour blend, but at the expense of acceptability.

Preference and palatability of indigenous and exotic acid soil-tolerant multipurpose trees and shrubs by West African Dwarf sheep.

Abstract: Eleven acid soil-tolerant multipurpose trees and shrubs (MPTS) were assessed for preference and palatability with mature West African Dwarf (WAD) sheep using the cafeteria method. About 500 g each of the MPTS were weighed in triplicates into plastic feeding troughs and randomly placed around the perimeter of a Panicum maximum paddock (25 m × 25 m). Five ewes averaging 25.24 ± 0.69 kg were allowed 4 h access to the browse species daily for 12 d. Dry matter intake differed (p A. cordifolia > L. leucoephala > B. monandra > D. guineensis > H. madagascariensis > T. tetraptera > T. africana > A. bella > B. grandiflora > C. calothyrsus.

Degree of Operating Leverage, Contribution Margin and the Risk-Return Profile of Emerging Companies: Evidence from Nigeria

Abstract: This article investigates the effects of degree of operating leverage and contribution margin on profitability and risk of Nigeria’s emerging companies. Emerging companies were described in this study as small and medium-sized enterprises that are high-potential and high-growth in character listed in the Nigerian Stock Exchange’s Alternative Investment Market. Cross-sectional and time series data were collected from Nigerian Stock Exchange for the top ten emerging companies listed in the market. Additional restricted-access data about internal management accounting decisions were retrieved directly from these firms. Data were sought to estimate values for operating profit, operating risk, degree of operating leverage, and contribution margin. Since data were collected for ten years in each case, a ten-by-ten panel study involving two models was designed. The probability of both f-test and t-test was 0.05. First, the study shows that degree of operating leverage (DOL) contributes less to profit before interest and tax (PBIT) of emerging companies than contribution margin (CM), yet DOL contributes more to their operating risk profile than CM does. Second, only CM was found to have caused significantly positive changes in operating risk. It was, therefore, concluded that emerging companies face challenges in recovering fixed costs or take unusually longer period to breakeven.

Macro-habitat preferences by the African manatee and crocodiles – ecological and conservation implications

Abstract: . African manatees (Trichechus senegalensis) and crocodiles are threatened species in parts of their range. In West Africa, crocodiles may constitute the main predators for manatees apart from humans. Here, we explore the macro-habitat selection of manatees and two species of crocodiles (West African crocodiles Crocodylus suchus and dwarf crocodile Osteolaemus tetraspis) in the Niger Delta (Nigeria), testing the hypotheses that (i) manatees may avoid crocodiles in order to minimize risks of predation, and (ii) the two crocodile species do compete. The study was carried out between 1994 and 2010 with a suite of different field techniques. We observed that the main macro-habitat types were freshwater rivers and coastal lagoons for manatees, mangroves for West African crocodiles, and rivers and creeks for dwarf crocodiles, with (i) the three species differing significantly in terms of their macro-habitat type selection, and (ii) significant seasonal influence on habitat selection of each species. Null models for niche overlap showed a significantly lower overlap in macro-habitat type use between manatee and crocodiles, whereas the two crocodiles were relatively similar. Null model analyses did not indicate any competitive interactions between crocodiles. On the other hand, manatees avoided macro-habitats where crocodiles, and especially West African crocodiles, are abundant.