Behavioural and olfactory responses of Sitophilus zeamais (Coleoptera: Curculionidae) to Aframomum melegueta and Zingiber officinale oleoresins.

The oleoresins extracted from the seeds of alligator pepper, Aframomum melegueta and ginger, Zingiber officinale rhizome using methanol, was evaluated for bioactivity against the maize weevil, Sitophilus zeamais in the laboratory. Using a 4-arm olfactometer, solutions of the oleoresins at a concentration of 1 mg/ml exhibited significant olfactory repellent activity against male and female S. zeamais when tested alone, and in combination with maize seeds. These findings provide a scientific basis for the observed repellent properties of the oleoresins and demonstrate the need for their development in stored product pest protection in Africa where these plants are readily available.KEYWORDS: Oleoresin, Aframomum melegueta, Zingiber officinale, Sitophilus zeamais, Olfactometer

Pathogenicity of Meloidogyne Incognita Race 1 on Tomato as Influenced by Different Arbuscular Mycorrhizal Fungi and Bioformulated Paecilomyces Lilacinus in a Dysteric Cambisol Soil

A greenhouse experiment was conducted to investigate the single and combined effects of different arbuscular mycorrhizal fungi (AMF) and bioformulated Paecilomyces lilacinus against M. incognita race 1 on tomato. Dysteric Cambisol soil was used. The experiment took place in Calabar, Cross River State, Nigeria. The experiment was laid out as a 3x6 factorial in a completely randomized design (CRD) with three replications. Three applications of the bionematicide were combined with five species of AMF plus an uninoculated control. The results indicated that AMF species differed significantly (p ≤ 0.05) in their efficacy of gall and egg mass inhibition, tomato root colonization rate as well as growth and fresh fruit yield enhancement. Glomus etunicatum and G. deserticola were the most efficient species. Two applications of the bionematicide more significantly (p ≤ 0.05) reduced galling and egg production than a single application. Individual combinations of two AMF (G. etunicatum and G. deserticola) with a double application of the bionematicide, resulted in the greatest gall and egg mass inhibition and consequently the greatest growth and fresh fruit yield enhancement

Influence of soil fertility status on host response to black Sigatoka and yield of plantain (<i>Musa AAB</i>) in southern Nigeria

The severity of black Sigatoka disease on the first and second cycle plantains managed under varying soil fertility status was assessed using Zero fertilizer and mulch as control, Sawdust mulch (SDM) applied at 20 t/ ha, and 50,100, and 150 kg NPK 20-10-10 /ha, applied sole and in combination with each fertilizer rate in a randomized complete block with three replications. Data were collected on number of functional leaves retained on the plant during the dry season, leaf longevity, number of functional leaves on the plant at flowering (NFLF) and at harvest (NFLH), number of leaves with black leaf streak at stage 5 on the modified Stover Scale (Gauhl, 1994) at the flower stage (NLSF) and at harvest (NLSH) and bunch yield per hectare. Mean number of functional leaves per plant during the dry season and the mean leaf life span were significantly (p< 0.05) higher in mulched + fertilizer treated plantains with 8 to 10 functional leaves per plant compared with 5 to 7 leaves retained on plantains in control/bare plots. Mulched and mulched + fertilizer treated plants had longer mean leaf life span of 10 to 12 weeks in the first generation and 9 to 11 weeks in the second generation. Black sigatoka infection severity on plantains were significantly (p< 0.05) high in nonmulched plantains. Plantains grown under optimum soil fertility management (150 kg NPK 20-10-10/ha + 20 tonnes of sawdust mulch/ha) showed high tolerance to black sigatoka infection and produced the highest bunch yield of 15.7 tonnes/ha.Key words: Black sigatoka, severity, plantain, soil fertility

Real-time simulations and experiments on ultrahigh frequency surface waves in micro-structured phononic crystals

We investigate experimentally and by numerical simulation the interaction between ultrahigh frequency surface acoustic waves (SAW) and periodic microstructures. We use both one-dimensional (1D) phononic crystals consisting of copper lines embedded in silicon oxide and 2D phononic crystals consisting of air-filled holes etched as a square lattice in a silicon substrate. Experimental results obtained by ultrashort pulsed optical excitation and interferometric detection are compared to time-domain finite element (FEM) simulations of the propagating ultrahigh frequency SAW with frequency components up to ~1 GHz in these phononic crystals, allowing the investigation of SAW scattering and phononic band structure. Good agreement was obtained between simulation and experiment

Analytic Hierarchy Process Model for the Diagnosis of Typhoid Fever

Abstract Typhoid fever is a global health problem, which seems neglected, but is responsible for significant levels of morbidity in many regions of the world, with about 12 million cases annually, and about 600,000 fatalities. Diagnosis of typhoid poses a great deal of challenge because its clinical presentation is confused with those of many other febrile infections such as malaria, yellow fever, etc. In addition, most developing countries do not have adequate bacteriology laboratories for further investigations. Decision support systems have been known to increase the efficiency and effectiveness of the diagnosis process, in addition to improving access; however, most existing decision support models for diagnosis of diseases have largely focused on ‘non-tropical’ conditions. An effective decision support model for diagnosis of tropical diseases can only be developed though the engineering of experiential knowledge of physicians who are experts in the management of such conditions. In this study, we mined experiential knowledge of twenty-five tropical disease specialist physicians to develop a decision support system based on the Analytic Hierarchy Process (AHP). The resulting model was tested based on 2044 patient data. Our model successfully determined the occurrence (or otherwise) of typhoid fever in 78.91% of the cases, demonstrating the utility of AHP in the diagnosis of typhoid fever.</jats:p

Measurement of the deuteron polarization in a large target

Adeva B, Ahmad S, Arvidson A, et al. Measurement of the deuteron polarization in a large target. Nucl.Instrum.Meth. A. 1994;349(2-3):334-344