1,301 research outputs found
Winterfat, saltbush – forage shrubs for the Canadian prairies
Non-Peer Reviewe
Bacterial viability and biological seed treatment of canola
Non-Peer ReviewedThe use of sulfur-oxidizing plant growth promoting rhizobacteria (PGPR) applied as seed treatment for increasing canola yield has been reported previously (Kloepper et al., 1988; Yesmin and Banerjee, 2000). For consistent plant growth response colonization of the rhizosphere and rhizoplane by the PGPR is essential. In many cases, however, results have been variable or not comparable. Inadequate colonization of the roots by the introduced PGPR strain is considered to be a major reason for sub-optimal results (Schippers et al., 1995). Bacterial viability is one of the most important factors for successful and adequate colonization of the rhizosphere and rhizoplane that ultimately affect the plant yield. Thus, the ability of microbial inoculants to successfully colonize expanding root systems is of major importance in determining the potential success of the biological seed treatments (Parke, 1991). Seed is used as a carrier for inoculum and biologicals should be in a state where it can most effectively colonize the emerging roots. Biological activity, however, may decline rapidly between the time of inoculation and seeding to field. The present study investigates the survivals of PGPR on biologically treated seeds with non-coated (bare), peat coated and fungicide-coated seeds. Mixture of PGPR strains were also examined as that might have greater potential to give a consistent performance under different environmental and growth conditions
Comparison of inoculant media for sulfur-oxidizing plant growth promoting rhizobacteria in canola
Non-Peer ReviewedThe ability of rhizosphere microorganisms to influence plant growth is gaining considerable attention worldwide. Various studies have already proven the beneficial effect of plant growth promoting rhizobacteria (PGPR) on different agricultural crops (Kloepper, 1993; Banerjee, 1995). Canola, like other oil seed crop has high sulfur demand. In recent years, several attempts have been made to utilize S-oxidizing microorganisms to meet plant S requirement and to substitute costly S fertilizer. But the success is variable, as the information on S-oxidizing PGPR is limited and the mechanisms also not yet fully understood. In many cases, no standard methods were followed and different inoculation media were used. The population density and activities of microorganisms could vary with the inoculation media. The aim of the present study was to compare the effects of PGPR if any due to the difference in the commonly used inoculant media like seed, soil and elemental S fertilizer
Noncommuting Electric Fields and Algebraic Consistency in Noncommutative Gauge theories
We show that noncommuting electric fields occur naturally in
-expanded noncommutative gauge theories. Using this noncommutativity,
which is field dependent, and a hamiltonian generalisation of the
Seiberg-Witten Map, the algebraic consistency in the lagrangian and hamiltonian
formulations of these theories, is established. A comparison of results in
different descriptions shows that this generalised map acts as canonical
transformation in the physical subspace only. Finally, we apply the hamiltonian
formulation to derive the gauge symmetries of the action.Comment: 16 pages, LaTex, considerably expanded version with a new section on
`Gauge symmetries'; To appear in Phys. Rev.
Radiation Damage of F8 Lead Glass with 20 MeV Electrons
Using a 20 MeV linear accelerator, we investigate the effects of
electromagnetic radiation on the optical transparency of F8 lead glass.
Specifically, we measure the change in attenuation length as a function of
radiation dose. Comparing our results to similar work that utilized a proton
beam, we conclude that F8 lead glass is more susceptible to proton damage than
electron damage.Comment: 5 pages, 6 figure
Meson-Baryon-Baryon Vertex Function and the Ward-Takahashi Identity
Ohta proposed a solution for the well-known difficulty of satisfying the
Ward-Takahashi identity for a photo-meson-baryon-baryon amplitude (MBB)
when a dressed meson-baryon-baryon (MBB) vertex function is present. He
obtained a form for the MBB amplitude which contained, in addition to
the usual pole terms, longitudinal seagull terms which were determined entirely
by the MBB vertex function. He arrived at his result by using a Lagrangian
which yields the MBB vertex function at tree level. We show that such a
Lagrangian can be neither hermitian nor charge conjugation invariant. We have
been able to reproduce Ohta's result for the MBB amplitude using the
Ward-Takahashi identity and no other assumption, dynamical or otherwise, and
the most general form for the MBB and MBB vertices. However, contrary
to Ohta's finding, we find that the seagull terms are not robust. The seagull
terms extracted from the MBB vertex occur unchanged in tree graphs,
such as in an exchange current amplitude. But the seagull terms which appear in
a loop graph, as in the calculation of an electromagnetic form factor, are, in
general, different. The whole procedure says nothing about the transverse part
of the (MBB) vertex and its contributions to the amplitudes in
question.Comment: A 20 pages Latex file and 16 Postscript figures in an uuencoded
format. Use epsf.sty to include the figures into the Latex fil
Measurement of Magnetic Relaxation in the peak regime of V3Si
Magnetization relaxation measurements are carried out in the Peak effect
regime of superconducting V3Si crystal, using Quantum Design SQUID
magnetometer. Relaxation in the increasing field scan is logarithmic in time,
consistent with the theory of flux creep. The relaxation on the decreasing
field scan however exhibits athermal behavior which is predominantly governed
by the flux avalanches triggered by the small external field perturbation
experienced by the superconductor during measurement scan in an inhomogeneous
field.Comment: PDF, 17 pages including 9 figure
Inferring Multiple Graphical Structures
Gaussian Graphical Models provide a convenient framework for representing
dependencies between variables. Recently, this tool has received a high
interest for the discovery of biological networks. The literature focuses on
the case where a single network is inferred from a set of measurements, but, as
wetlab data is typically scarce, several assays, where the experimental
conditions affect interactions, are usually merged to infer a single network.
In this paper, we propose two approaches for estimating multiple related
graphs, by rendering the closeness assumption into an empirical prior or group
penalties. We provide quantitative results demonstrating the benefits of the
proposed approaches. The methods presented in this paper are embeded in the R
package 'simone' from version 1.0-0 and later
Entropy spectrum of a Kerr anti-de Sitter black hole
The entropy spectrum of a spherically symmetric black hole was derived
without the quasinormal modes in the work of Majhi and Vagenas. Extending this
work to rotating black holes, we quantize the entropy and the horizon area of a
Kerr anti-de Sitter black hole by two methods. The spectra of entropy and area
are obtained via the Bohr-Sommerfeld quantization rule and the adiabatic
invariance in the first way. By addressing the wave function of emitted
(absorbed) particles, the entropy and the area are quantized in the second one.
Both results show that the entropy and the area spectra are equally spaced.Comment: Accepted for publication in The European Physical Journal C, Volume
72, Issue
Black Hole Entropy: From Shannon to Bekenstein
In this note we have applied directly the Shannon formula for information
theory entropy to derive the Black Hole (Bekenstein-Hawking) entropy. Our
analysis is semi-classical in nature since we use the (recently proposed [8])
quantum mechanical near horizon mode functions to compute the tunneling
probability that goes in to the Shannon formula, following the general idea of
[5]. Our framework conforms to the information theoretic origin of Black Hole
entropy, as originally proposed by Bekenstein.Comment: 9 pages Latex, Comments are welcome; Thoroughly revised version,
reference and acknowledgements sections enlarged, numerical error in final
result corrected, no major changes, to appear in IJT
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