525 research outputs found
Lithosphere Structure and upper mantle characteristics below the Bay of Bengal
The oceanic lithosphere in the Bay of Bengal (BOB) formed 80–120 Ma following the breakup of eastern Gondwanaland. Since its formation, it has been affected by the emplacement of two long N-S trending linear aseismic ridges (85oE and Ninetyeast) and by the loading of ca. 20-km of sediments of the Bengal Fan. Here, we present the results of a combined spatial and spectral domain analysis of residual geoid, bathymetry and gravity data constrained by seismic reflection and refraction data. Self-consistent geoid and gravity modeling defined by temperature-dependent mantle densities along a N-S transect in the BOB region revealed that the depth to the Lithosphere-Asthenosphere boundary (LAB) deepens steeply from 77 km in the south to 127 km in north, with the greater thickness being anomalously thick compared to the lithosphere of similar-age beneath the Pacific Ocean. The Geoid-Topography Ratio (GTR) analysis of the 85°E and Ninetyeast ridges indicate that they are compensated at shallow depths. Effective elastic thickness (Te) estimates obtained through admittance/ coherence analysis as well as the flexural modeling along these ridges led to the conclusions: i) 85°E Ridge was emplaced in off-ridge environment (Te = 10–15 km); ii) the higher Te values of ?25 km over the Afanasy Nikitin Seamount (ANS) reflect the secondary emplacement of the seamount peaks in off-ridge environment, iii) that the emplacement of the Ninetyeast Ridge north of 2°N occurred in an off-ridge environment as indicated by higher Te values (25-30 km). Furthermore, the admittance analysis of geoid and bathymetry revealed that the admittance signatures at wavelengths >800 km are compensated by processes related to upper mantle convection
Bianchi Type I Cosmology in Generalized Saez-Ballester Theory via Noether Gauge Symmetry
In this paper, we investigate the generalized Saez-Ballester scalar-tensor
theory of gravity via Noether gauge symmetry (NGS) in the background of Bianchi
type I cosmological spacetime. We start with the Lagrangian of our model and
calculate its gauge symmetries and corresponding invariant quantities. We
obtain the potential function for the scalar field in the exponential form. For
all the symmetries obtained, we determine the gauge functions corresponding to
each gauge symmmetry which include constant and dynamic gauge. We discuss
cosmological implications of our model and show that it is compatible with the
observational data.Comment: 13 pages, 2 figures, accepted for publication in 'European Physical
Journal C
Theranostic nanoparticles enhance the response of glioblastomas to radiation
YesDespite considerable progress with our understanding of glioblastoma multiforme (GBM) and the precise
delivery of radiotherapy, the prognosis for GBM patients is still unfavorable with tumor recurrence due
to radioresistance being a major concern. We recently developed a cross-linked iron oxide nanoparticle
conjugated to azademethylcolchicine (CLIO-ICT) to target and eradicate a subpopulation of quiescent
cells, glioblastoma initiating cells (GICs), which could be a reason for radioresistance and tumor relapse.
The purpose of our study was to investigate if CLIO-ICT has an additive therapeutic effect to enhance the
response of GBMs to ionizing radiation.
Methods: NSG™ mice bearing human GBMs and C57BL/6J mice bearing murine GBMs received
CLIO-ICT, radiation, or combination treatment. The mice underwent pre- and post-treatment magnetic
resonance imaging (MRI) scans, bioluminescence imaging (BLI), and histological analysis. Tumor
nanoparticle enhancement, tumor flux, microvessel density, GIC, and apoptosis markers were compared
between different groups using a one-way ANOVA and two-tailed Mann-Whitney test. Additional NSG™
mice underwent survival analyses with Kaplan–Meier curves and a log rank (Mantel–Cox) test.
Results: At 2 weeks post-treatment, BLI and MRI scans revealed significant reduction in tumor size for
CLIO-ICT plus radiation treated tumors compared to monotherapy or vehicle-treated tumors.
Combining CLIO-ICT with radiation therapy significantly decreased microvessel density, decreased
GICs, increased caspase-3 expression, and prolonged the survival of GBM-bearing mice. CLIO-ICT
delivery to GBM could be monitored with MRI. and was not significantly different before and after
radiation. There was no significant caspase-3 expression in normal brain at therapeutic doses of
CLIO-ICT administered.
Conclusion: Our data shows additive anti-tumor effects of CLIO-ICT nanoparticles in combination with
radiotherapy. The combination therapy proposed here could potentially be a clinically translatable
strategy for treating GBMs
Phylogeography of the pharaoh cuttle Sepia pharaonis based on partial mitochondrial 16S sequence data
The pharaoh cuttle Sepia pharaonis Ehrenberg, 1831 (Mollusca: Cephalopoda: Sepiida) is a broadly distributed species of substantial fisheries importance found from east Africa to southern Japan. Little is known about S. pharaonis phylogeography, but evidence from morphology and reproductive biology suggests that Sepia pharaonis is actually a complex of at least three species. To evaluate this possibility, we collected tissue samples from Sepia pharaonis from throughout its range. Phylogenetic analyses of partial mitochondrial 16S sequences from these samples reveal five distinct clades: a Gulf of Aden/Red Sea clade, a northern Australia clade, a Persian Gulf/Arabian Sea clade, a western Pacific clade (Gulf of Thailand and Taiwan) and an India/Andaman Sea clade. Phylogenetic analyses including several Sepia species show that S. pharaonis sensu lato may not be monophyletic. We suggest that "S. pharaonis" may consist of up to five species, but additional data will be required to fully clarify relationships within the S. pharaonis complex
A New Class of Bianchi Type-I Cosmological Models in Scalar-Tensor Theory of Gravitation and Late Time Acceleration
A new class of a spatially homogeneous and anisotropic Bianchi type-I
cosmological models of the universe for perfect fluid distribution within the
framework of scalar-tensor theory of gravitation proposed by Saez and Ballester
(Phys. Lett. 113:467, 1986) is investigated. To prevail the deterministic
solutions we choose the different scale factors which yield time-dependent
deceleration parameters (DP) representing models which generate a transition of
the universe from the early decelerated phase to the recent accelerating phase.
Three different physically viable models of the universe are obtained in which
their anisotropic solutions may enter to some isotropic inflationary era. The
modified Einstein's field equations are solved exactly and the models are found
to be in good concordance with recent observations. Some physical and geometric
properties of the models are also discussed.Comment: 16 pages, 8 figure
Detector Description and Performance for the First Coincidence Observations between LIGO and GEO
For 17 days in August and September 2002, the LIGO and GEO interferometer
gravitational wave detectors were operated in coincidence to produce their
first data for scientific analysis. Although the detectors were still far from
their design sensitivity levels, the data can be used to place better upper
limits on the flux of gravitational waves incident on the earth than previous
direct measurements. This paper describes the instruments and the data in some
detail, as a companion to analysis papers based on the first data.Comment: 41 pages, 9 figures 17 Sept 03: author list amended, minor editorial
change
Measurement of the Bottom-Strange Meson Mixing Phase in the Full CDF Data Set
We report a measurement of the bottom-strange meson mixing phase \beta_s
using the time evolution of B0_s -> J/\psi (->\mu+\mu-) \phi (-> K+ K-) decays
in which the quark-flavor content of the bottom-strange meson is identified at
production. This measurement uses the full data set of proton-antiproton
collisions at sqrt(s)= 1.96 TeV collected by the Collider Detector experiment
at the Fermilab Tevatron, corresponding to 9.6 fb-1 of integrated luminosity.
We report confidence regions in the two-dimensional space of \beta_s and the
B0_s decay-width difference \Delta\Gamma_s, and measure \beta_s in [-\pi/2,
-1.51] U [-0.06, 0.30] U [1.26, \pi/2] at the 68% confidence level, in
agreement with the standard model expectation. Assuming the standard model
value of \beta_s, we also determine \Delta\Gamma_s = 0.068 +- 0.026 (stat) +-
0.009 (syst) ps-1 and the mean B0_s lifetime, \tau_s = 1.528 +- 0.019 (stat) +-
0.009 (syst) ps, which are consistent and competitive with determinations by
other experiments.Comment: 8 pages, 2 figures, Phys. Rev. Lett 109, 171802 (2012
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
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