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

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

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

SEARCH FOR THE t AND b-prime QUARKS IN HADRONIC DECAYS OF THE Z0 BOSON

We present a search for the third generation up type quark t and a possible fourth down type quark b' in hadronic Z0 decays observed in DELPHI at the LEP collider. For any scenario with a decay through the charged current or into a charged Higgs with a mass at least 6 GeV/c2 below the t and 3 GeVc2 below the b' mass, we set a lower limit for the t quark mass at 44.0 GeV/c2 and for the b' mass at 44.5 GeV/c2. For specific scenarios the mass limits are slightly higher, e.g. for charged current decays the limits are 44.5 and 45.0 GeV/c2 respectively, where all limits are given at a 95% confidence level. © 1990.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Search for low mass Higgs bosons produced in Z0 decays

A search for light Higgs bosons was performed using the data sample collected in 1990 by the DELPHI detector at LEP, at centre of mass energies between 88.2 and 94.2 GeV. Using the process e+e-→H0+Z0*, Z0*→ff, it is possible to exclude the existence of the standard model Higgs particle with a mass between 0 and 210 MeV/c2 at the 99% confidence level. Extending this analysis to the minimal supersymmetric standard model restricts the lightest neutral Higgs boson to masses above 28 GeV/c2 irrespective of the value of the mixing angle. © 1991 Springer-Verlag

Experimental study of the triple gluon vertex

In four-jet events from e+e-→Z0→multihadrons one can separate the three principal contributions from the triple-gluon vertex, double gluon-bremsstrahlung and the secondary quark-antiquark production, using the shape of the two-dimensional angular distributions in the generalized Nachtmann-Reiter angle 0NR* and the opening angle of the secondary jets. Thus one can identify directly the contribution from the triple-gluon vertex without comparison with a specific non-QCD model. Applying this new method to events taken with the DELPHI-detector we get for the ratio of the colour factor NC to the fermionic Casimir operator CF: NC/C F=2.55±0.55(stat.)±0.4(fragm.+models)±0.2(error in bias) in agreement with the value 2.25 expected in QCD from NC=3 and CF=4/3.0SCOPUS: ar.jinfo:eu-repo/semantics/publishe