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-(Morpho-anatomical effects of sodium azide and nitrous acid on Citrullus lanatus (Thunb.) Matsum. & Nakai (Cucurbitaceae) and Moringa oleifera Lam. (Moringaceae) ). Chemical mutagens (e.g. sodium azide and nitrous acid) are important tools in crop improvements because they produce resistance against pathogens in crops to improve their yield and quality traits. This study investigates the morphological and anatomical effects of sodium azide and nitrous acid on Citrullus lanatus and Moringa olefeira at various concentrations (1 mM, 2 mM, 3 mM and 4 mM) for 4 hours, and planted in plastic pots for 12 weeks observations. Results showed that sodium azide and nitrous acid have differential infl uenced on morphological features (stem height, leaf number and root length) in C. lanatus and M. olefeira respectively. Anatomical features (stomatal density, index and size) are more infl uenced by the sodium azide-treated plants in both plants than in the nitrous acid-treated plants. Both mutagens are more effective in the two plants than the control. Keywords: chemical mutagens, leaf, leaf anatomy, morphology, root, stem RESUMO -(Efeitos morfo-anatômicos da azida sódica e ácido nitroso em Citrullus lanatus (Thunb.) Matsum. & Nakai (Cucurbitaceae) e Moringa oleifera Lam. (Moringaceae)). Os agentes mutagénicos químicos (por exemplo, azida de sódio e ácido nitroso) são ferramentas importantes na melhoria das culturas porque produzem resistência contra patogénios nas culturas para melhorar as suas características de rendimento e qualidade. Este estudo investiga os efeitos morfológicos e anatômicos da azida sódica e do ácido nitroso em Citrullus lanatus e Moringa olefeira em várias concentrações (1 mM, 2 mM, 3 mM e 4 mM) por 4 horas, e plantados em vasos plásticos para observações de 12 semanas. Os resultados mostraram que a azida sódica e o ácido nitroso têm infl uência diferencial nas características morfológicas (altura do caule, número de folhas e comprimento da raiz) em C. lanatus e M. olefeira, respectivamente. Características anatômicas (densidade, índice e tamanho dos estômatos) são mais infl uenciadas pelas plantas tratadas com azida de sódio em ambas as plantas do que nas plantas tratadas com ácido nitroso. Ambos os mutagênicos são mais efi cazes nas duas plantas que o controle.

This paper reports the outcome of a study on the resilient modulus of hot mix asphalt characterised under different environmental conditions and testing methods with the intention of establishing the effects of climate and testing procedure for appropriate standardisation of laboratory and field quality control/assurance of pavement works. Destructive (DT) and non-destructive (NDT) tests were carried out on laboratory Marshall Specimens of an asphalt mix prepared for a specified pavement wearing course in Nigeria at three temperatures: 4, 25 (in dry air), 25 (soaked in water) and 508C. The DT was achieved with the Marshall Stability apparatus for the indirect tensile strength while the non-destructive was accomplished with the portable ultrasonic non-destructive digital indicating tester. Sixty-four test specimens were conditioned to the three temperatures before conducting the strength characterisation exercise alongside the effect of delayed test for a few hours and 3 months. The moisture susceptibility damage of the hot mix asphalt was also assessed with the specimens at the prevailing laboratory room temperature of 258C. Statistical analysis of variance test was carried out on the resilient modulus data base developed to establish the effects of the temperature and other treatments. The resilient modulus of hot mix asphalt decreased as the temperature increased, irrespective of the test method adopted, while the NDT method gave a more consistent result than the destructive, thereby recommended as a better quality control scheme during the construction of bituminous flexible pavement. The 3-month delay in testing the strength of asphalt does not significantly affect the value at 5% level of confidence.

Borassus aethiopum extract as a biological extender was evaluated on semen quality, fertility and hatchability in chickens under conditions of warm preservation at 37 o C. The extenders were prepared in 1:5 and 1:10 ratios (extract to normal saline) and preserved for 0, 1, 2, 3 and 4 hours respectively in a factorial design layout. There was no significant (p>0.05) effect of the extender on semen characteristics within 2 hours of preservation. However, motility (%) was significantly (p<0.05) reduced when the semen was preserved for more than 2 hours. Interactions between the extender ratios and the period of preservation were significant (p<0.05) for motility (%), dead and abnormal cells. Motility (%) was insignificantly (p>0.05) higher in the extender of 1:10 than in the extender of 1:5 and it was above 70%. Using the extender of 1:10 in the fertility and hatchability trial in a completely randomized design layout showed that fertility decreased, 95% in the 0hour treatment to 73% in the 4-hour treatment while hatchability decreased from 71.4% in the 0-hour treatment to 61.5% in the 4-hour treatment. It may be concluded that the Borassus aethiopum extract could be used to extend and preserve the semen of chickens for 3 hours providing good fertility and hatchability of eggs.