Efficacy of diatomaceous earth and botanical powders against the maize weevil, Sitophilus zeamais Motschulsky (Coleoptera: Curculionidae) on maize

The effectiveness of the diatomaceous earth SilicoSec, neem seed powder and Plectranthus glandulosus leaf powder, applied at four different rates with four exposure intervals (1, 3, 7 and 14 d) for the control of maize weevil, Sitophilus zeamais Motschulsky, on maize in the laboratory was determined. Treatment with SilicoSec was the most effective followed by neem seed powder and P. glandulosus powder. The highest tested content (2 g/kg) of SilicoSec caused 81.1% and 100% mortality of S. zeamais within 3 and 14 days of exposure, respectively. The application of the highest content (40 g/kg) for neem seed powder and P. glandulosus powder resulted in 86.8% and 59.5% mortality, respectively 14 days after exposure. Seven-day LC50-values were 0.56 g/kg for SilicoSec, 19.7 g/kg for neem seed powder and 45.24 g/kg for P. glandulosus powder. The treatments reduced progeny emergence, percentage of grain damage, percentage of weight loss and percentage of germination loss, although P. glandulosus powder was less active for these parameters. Results suggest that SilicoSec can be considered as a potential component of an integrated pest management strategy against the maize weevil. However, in the poor tropical countries were the plant powders are widely available and food production dominated by subsistence agriculture, neem seed powder and P. glandulosus powder could be adopted also for the protection of stored maize against the infestation of S. zeamais. Keywords: Diatomaceous earth, Botanical powders, Maize, Integrated weevil management, Sitophilus zeamai

Hadron Spectra and QGP Hadronization in Au+Au Collisions at RHIC

The transverse mass spectra of Omega hyperons and phi mesons measured recently by STAR Collaboration in Au+Au collisions at sqrt(s_NN) = 130 GeV are described within a hydrodynamic model of the quark gluon plasma expansion and hadronization. The flow parameters at the plasma hadronization extracted by fitting these data are used to predict the transverse mass spectra of J/psi and psi' mesons.Comment: 4 pages, 4 figures, Fig. 3 correcte

Particle dependence of elliptic flow in Au+Au collisions at sNN=\sqrt{s_{NN}}= 200 GeV

The elliptic flow parameter ($v_2$) for $K_S^0$ and $\Lambda+\bar{\Lambda}$ has been measured at mid-rapidity in Au + Au collisions at $\sqrt{s_{_{NN}}}=200$ GeV by the STAR collaboration. The $v_2$ values for both $K_S^{0}$ and $\Lambda+\bar{\Lambda}$ saturate at moderate $p_T$, deviating from the hydrodynamic behavior observed in the lower $p_T$ region. The saturated $v_2$ values and the $p_T$ scales where the deviation begins are particle dependent. The particle-type dependence of $v_2$ shows features expected from the hadronization of a partonic ellipsoid by coalescence of co-moving quarks. These results will be discussed in relation to the nuclear modification factor ($R_{CP}$) which has also been measured for $K_S^0$ and $\Lambda+\bar{\Lambda}$ by the STAR collaboration.Comment: 6 pages, 3 figures, Strange Quark Matter 2003 Conference (SQM 2003): updated with 2 figures from original talk that did not appear in the journa

Quaternionic Electroweak Theory

We explicitly develop a quaternionic version of the electroweak theory, based on the local gauge group $U(1, q)_{L}\mid U(1, c)_{Y}$. The need of a complex projection for our Lagrangian and the physical significance of the anomalous scalar solutions are also discussed.Comment: 12 pages, Revtex, submitted to J. Phys.

Differential Dynamic Microscopy of Bacterial Motility

We demonstrate 'differential dynamic microscopy' (DDM) for the fast, high throughput characterization of the dynamics of active particles. Specifically, we characterize the swimming speed distribution and the fraction of motile cells in suspensions of Escherichia coli bacteria. By averaging over ~10^4 cells, our results are highly accurate compared to conventional tracking. The diffusivity of non-motile cells is enhanced by an amount proportional to the concentration of motile cells.Comment: 4 pages, 4 figures. In this updated version we have added simulations to support our interpretation, and changed the model for the swimming speed probability distribution from log-normal to a Schulz distribution. Neither modification significantly changes our conclusion

Continuous slice functional calculus in quaternionic Hilbert spaces

The aim of this work is to define a continuous functional calculus in quaternionic Hilbert spaces, starting from basic issues regarding the notion of spherical spectrum of a normal operator. As properties of the spherical spectrum suggest, the class of continuous functions to consider in this setting is the one of slice quaternionic functions. Slice functions generalize the concept of slice regular function, which comprises power series with quaternionic coefficients on one side and that can be seen as an effective generalization to quaternions of holomorphic functions of one complex variable. The notion of slice function allows to introduce suitable classes of real, complex and quaternionic $C^*$--algebras and to define, on each of these $C^*$--algebras, a functional calculus for quaternionic normal operators. In particular, we establish several versions of the spectral map theorem. Some of the results are proved also for unbounded operators. However, the mentioned continuous functional calculi are defined only for bounded normal operators. Some comments on the physical significance of our work are included.Comment: 71 pages, some references added. Accepted for publication in Reviews in Mathematical Physic

Backlund transformations for the sl(2) Gaudin magnet

Elementary, one- and two-point, Backlund transformations are constructed for the generic case of the sl(2) Gaudin magnet. The spectrality property is used to construct these explicitly given, Poisson integrable maps which are time-discretizations of the continuous flows with any Hamiltonian from the spectral curve of the 2x2 Lax matrix.Comment: 17 pages, LaTeX, refs adde

Pion Interferometry for Hydrodynamical Expanding Source with a Finite Baryon Density

We calculate the two-pion correlation function for an expanding hadron source with a finite baryon density. The space-time evolution of the source is described by relativistic hydrodynamics and the Hanbury-Brown-Twiss (HBT) radius is extracted after effects of collective expansion and multiple scattering on the HBT interferometry have been taken into account, using quantum probability amplitudes in a path-integral formalism. We find that this radius is substantially smaller than the HBT radius extracted from the freeze-out configuration.Comment: 4 pages, 2 figure

Quantum Holonomy in Three-dimensional General Covariant Field Theory and Link Invariant

We consider quantum holonomy of some three-dimensional general covariant non-Abelian field theory in Landau gauge and confirm a previous result partially proven. We show that quantum holonomy retains metric independence after explicit gauge fixing and hence possesses the topological property of a link invariant. We examine the generalized quantum holonomy defined on a multi-component link and discuss its relation to a polynomial for the link.Comment: RevTex, 12 pages. The metric independence of path integral measure is justified and the case of multi-component link is discussed in detail. To be published in Physical Review

More about orbitally excited hadrons from lattice QCD

This is a second paper describing the calculation of spectroscopy for orbitally excited states from lattice simulations of Quantum Chromodynamics. New features include higher statistics for P-wave systems and first results for the spectroscopy of D-wave mesons and baryons, for relatively heavy quark masses. We parameterize the Coulomb gauge wave functions for P-wave and D-wave systems and compare them to those of their corresponding S-wave states.Comment: 21 pages plus 14 figs, 3 include