955 research outputs found
Interactive effect of cowpea variety, dose and exposure time on bruchid tolerance to botanical pesticides
Callosobruchus maculatus has for years remained a serious menace in cowpea in Sub-Sahara Africa. The objective of this study was to investigate the effect of genotypic cowpea (Vigna unguiculata (L.) Walp) varieties, time and dose on C. maculatus exposed to powders of Piper guineense and Eugenia aromatica. Irrespective of duration and botanicals, bruchid reared on KDV showed the highest tolerance to both plant materials; while their counterparts from IAR48V were the most susceptible. Median lethal time (LT50) also varied according to the
plant materials; with the highest in KDV reared bruchid [P. guineense: KDV (18.31), IAR48V (9.27), IFBV
(13.17); E. aromatica: KDV (76.01), IAR48V (5.59), IFBV (6.49)]. There was a significant impact of cowpea
variety (V), exposure time (T) and dose (D) on the tolerance of C. maculatus to both plant materials. The effect of all two-way (VxT, VxD, DxT) and three way interactions (VĂ—TĂ—D) on the tolerance of C. maculatus to both plant materials was also significant. Varietal effect was more pronounced in bruchids exposed to E. aromatica; while exposure time was more pronounced in bruchids exposed to P. guineense
Integrated stratigraphy of the Kimmeridge Clay Formation (Upper Jurassic) based on exposures and boreholes in south Dorset, UK
For the purposes of a high-resolution multi-disciplinary study of the Upper Jurassic Kimmeridge Clay Formation, two boreholes were drilled at Swanworth Quarry and one at Metherhills, south Dorset, UK. Together, the cores represent the first complete section through the entire formation close to the type section. We present graphic logs that record the stratigraphy of the cores, and outline the complementary geophysical and analytical data sets (gamma ray, magnetic susceptibility, total organic carbon, carbonate, [delta]13Corg). Of particular note are the new borehole data from the lowermost part of the formation which does not crop out in the type area. Detailed logs are available for download from the Kimmeridge Drilling Project web-site at http://kimmeridge.earth.ox.ac.uk/. Of further interest is a mid-eudoxus Zone positive shift in the [delta]13Corg record, a feature that is also registered in Tethyan carbonate successions, suggesting that it is a regional event and may therefore be useful for correlation. The lithostratigraphy of the cores has been precisely correlated with the nearby cliff section, which has also been examined and re-described. Magnetic-susceptibility and spectral gamma-ray measurements were made at a regular spacing through the succession, and facilitate core-to-exposure correlation. The strata of the exposure and core have been subdivided into four main mudrock lithological types: (a) medium-dark–dark-grey marl; (b) medium-dark–dark grey–greenish black shale; (c) dark-grey–olive-black laminated shale; (d) greyish-black–brownish-black mudstone. The sections also contain subordinate amounts of siltstone, limestone and dolostone. Comparison of the type section with the cores reveals slight lithological variation and notable thickness differences between the coeval strata. The proximity of the boreholes and different parts of the type section to the Purbeck–Isle of Wight Disturbance is proposed as a likely control on the thickness changes
Management of the palatally displaced canine
The maxillary permanent canine is a common tooth to deviate from its normal path of eruption and become displaced, usually into the roof of the mouth or palate. This article outlines the assessment, diagnosis and potential early management options for a palatally displaced permanent canine tooth (PDC). Some adverse consequences of a PDC are discussed
Gamma Ray Lines from a Universal Extra Dimension
Indirect Dark Matter searches are based on the observation of secondary
particles produced by the annihilation or decay of Dark Matter. Among them,
gamma-rays are perhaps the most promising messengers, as they do not suffer
deflection or absorption on Galactic scales, so their observation would
directly reveal the position and the energy spectrum of the emitting source.
Here, we study the detailed gamma-ray energy spectrum of Kaluza--Klein Dark
Matter in a theory with 5 Universal Extra Dimensions. We focus in particular on
the two body annihilation of Dark Matter particles into a photon and another
particle, which produces monochromatic photons, resulting in a line in the
energy spectrum of gamma rays. Previous calculations in the context of the five
dimensional UED model have computed the line signal from annihilations into
\gamma \gamma, but we extend these results to include \gamma Z and \gamma H
final states. We find that these spectral lines are subdominant compared to the
predicted \gamma \gamma signal, but they would be important as follow-up
signals in the event of the observation of the \gamma \gamma line, in order to
distinguish the 5d UED model from other theoretical scenarios.Comment: 21 pages, 6 figure
Condensate fluctuations in finite Bose-Einstein condensates at finite temperature
A Langevin equation for the complex amplitude of a single-mode Bose-Einstein
condensate is derived. The equation is first formulated phenomenologically,
defining three transport parameters. It is then also derived microscopically.
Expressions for the transport parameters in the form of Green-Kubo formulas are
thereby derived and evaluated for simple trap geometries, a cubic box with
cyclic boundary conditions and an isotropic parabolic trap. The number
fluctuations in the condensate, their correlation time, and the
temperature-dependent collapse-time of the order parameter as well as its
phase-diffusion coefficient are calculated.Comment: 29 pages, Revtex, to appear in Phys.Rev.
Direct Constraints on Minimal Supersymmetry from Fermi-LAT Observations of the Dwarf Galaxy Segue 1
The dwarf galaxy Segue 1 is one of the most promising targets for the
indirect detection of dark matter. Here we examine what constraints 9 months of
Fermi-LAT gamma-ray observations of Segue 1 place upon the Constrained Minimal
Supersymmetric Standard Model (CMSSM), with the lightest neutralino as the dark
matter particle. We use nested sampling to explore the CMSSM parameter space,
simultaneously fitting other relevant constraints from accelerator bounds, the
relic density, electroweak precision observables, the anomalous magnetic moment
of the muon and B-physics. We include spectral and spatial fits to the Fermi
observations, a full treatment of the instrumental response and its related
uncertainty, and detailed background models. We also perform an extrapolation
to 5 years of observations, assuming no signal is observed from Segue 1 in that
time. Results marginally disfavour models with low neutralino masses and high
annihilation cross-sections. Virtually all of these models are however already
disfavoured by existing experimental or relic density constraints.Comment: 22 pages, 5 figures; added extra scans with extreme halo parameters,
expanded introduction and discussion in response to referee's comment
Barrier effects on the collective excitations of split Bose-Einstein condensates
We investigate the collective excitations of a single-species Bose gas at T=0
in a harmonic trap where the confinement undergoes some splitting along one
spatial direction. We mostly consider onedimensional potentials consisting of
two harmonic wells separated a distance 2 z_0, since they essentially contain
all the barrier effects that one may visualize in the 3D situation. We find,
within a hydrodynamic approximation, that regardless the dimensionality of the
system, pairs of levels in the excitation spectrum, corresponding to
neighbouring even and odd excitations, merge together as one increases the
barrier height up to the current value of the chemical potential. The
excitation spectra computed in the hydrodynamical or Thomas-Fermi limit are
compared with the results of exactly solving the time-dependent
Gross-Pitaevskii equation. We analyze as well the characteristics of the
spatial pattern of excitations of threedimensional boson systems according to
the amount of splitting of the condensate.Comment: RevTeX, 12 pages, 13 ps figure
Popular attitudes to memory, the body, and social identity : the rise of external commemoration in Britain, Ireland, and New England
A comparative analysis of samples of external memorials from burial grounds in Britain, Ireland and New England reveals a widespread pattern of change in monument style and content, and exponential growth in the number of permanent memorials from the 18th century onwards. Although manifested in regionally distinctive styles on which most academic attention has so far been directed, the expansion reflects global changes in social relationships and concepts of memory and the body. An archaeological perspective reveals the importance of external memorials in articulating these changing attitudes in a world of increasing material consumption
Quantum Kinetic Theory V: Quantum kinetic master equation for mutual interaction of condensate and noncondensate
A detailed quantum kinetic master equation is developed which couples the
kinetics of a trapped condensate to the vapor of non-condensed particles. This
generalizes previous work which treated the vapor as being undepleted.Comment: RevTeX, 26 pages and 5 eps figure
A Bayesian view of the current status of dark matter direct searches
Bayesian statistical methods offer a simple and consistent framework for
incorporating uncertainties into a multi-parameter inference problem. In this
work we apply these methods to a selection of current direct dark matter
searches. We consider the simplest scenario of spin-independent elastic WIMP
scattering, and infer the WIMP mass and cross-section from the experimental
data with the essential systematic uncertainties folded into the analysis. We
find that when uncertainties in the scintillation efficiency of Xenon100 have
been accounted for, the resulting exclusion limit is not sufficiently
constraining to rule out the CoGeNT preferred parameter region, contrary to
previous claims. In the same vein, we also investigate the impact of
astrophysical uncertainties on the preferred WIMP parameters. We find that
within the class of smooth and isotropic WIMP velocity distributions, it is
difficult to reconcile the DAMA and the CoGeNT preferred regions by tweaking
the astrophysics parameters alone. If we demand compatibility between these
experiments, then the inference process naturally concludes that a high value
for the sodium quenching factor for DAMA is preferred.Comment: 37 pages, 14 figures and 7 tables. Replacement for matching the
version accepted for publicatio
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