1,796 research outputs found
CP Phases in Supersymmetric Tri-lepton Signals at the Tevatron
We have analyzed the supersymmetric tri-lepton signals for sparticle searches
at the Tevatron in the minimal supersymmetric standard model with general CP
phases without generational mixing. The CP phases may affect very strongly the
chargino and neutralino mass spectrums and
as well as and . Even under the stringent
constraints from the electron electric dipole moment the CP phases can lead to
a minimum of the tri-lepton event rate for their non-trivial values.Comment: 10 pages, 3 eps figures, largely revised by including the electron
EDM constraint
FE implementation of HAH model using FDM-based stress update algorithm for springback prediction of AHSS sheets
The homogeneous anisotropic hardening (HAH) model was implemented into a finite element (FE) code in order to predict springback for an advanced high strength steel (AHSS) sheet sample after double-stage U-draw bending. The finite difference method (FDM) was utilized as an alternative way to calculate the derivatives of this advanced distortional plasticity model allowing the update of the equivalent plastic strain and stress tensor at each time step in the user-material subroutines (UMAT and VUMAT). The FDM makes it easier to derive the stress gradient of complex yield surfaces. The proposed FDM-based stress update algorithm was verified by comparing the springback profiles after the single- and double-stage U-draw bending tests for a DP980 sheet sample predicted with analytical and numerical approaches. In addition, the springback measurement parameters and computational efficiencies depending on both approaches were also compared. The results indicate that the computational efficiency and accuracy of the FE simulations with the FDM-based stress update algorithm were similar to those of the analytical method. © 2018 Institute of Physics Publishing. All rights reserved.11Ysciescopu
Is Cosmic Parity Violation Responsible for the Anomalies in the WMAP Data?
This research demonstrates that parity violation in general relativity can
simultaneously explain the observed loss in power and alignment at a preferred
axis ('Axis of Evil')in the low multipole moments of the WMAP data. This
observational possibility also provides an experimental window for an
inflationary leptogenesis mechanism arising from large-scale parity violation.
A velocity dependent potential is induced from gravitational backreaction,
which modifies the primordial scalar angular power spectrum of density
perturbations in the CMB. This modification suppresses power of odd parity
multipoles on large scales which can be associated with the scale of a massive
right-handed neutrino.Comment: 5 pages, included new references, expanded on some calculation
β-lapachone induces growth inhibition and apoptosis in bladder cancer cells by modulation of BCL-2 family and activation of caspases
Aim: To study in vitro the molecular mechanism of apoptosis caused by b-lapachone, a quinone obtained from the bark of the lapacho tree (Tabebuia avellanedae). Materials and Methods: The study was carried out on human bladder carcinoma T24 cell line. Determination of cell viability was done using trypan blue exclusion method, apoptosis quantitative estimation — by DAPI staining and agarose gel electrophoresis for DNA fragmentation. Flow cytometry analysis, RT-PCR and Western blot analysis, colorimetric assay of caspase activity were applied as well. Results: It was found that in micromolar range of concentrations b-lapachone inhibited the viability of T24 cells by inducing apoptosis, which could be proved by formation of apoptotic bodies and DNA fragmentation. Treatment of T24 cells with b-lapachone resulted in a down-regulation of Bcl-2 expression and up-regulation of Bax expression. b-lapachone-induced apoptosis was also associated with activation of caspase-3 and caspase-9, inhibition of IAP expression, and degradation of poly (ADP-ribose) polymerase, phospholipase C-g1 and b-catenin proteins. At the same time Fas and FasL levels were inhibited upon treatment with b-lapachone in a concentration-dependent manner. Conclusion: b-lapachone-induced apoptosis in T24 cells is mediated, at least in part, by the mitochondrial-signaling pathway.Цель: изучить механизмы апоптоза клеток карциномы мочевого пузыря человека Т24 при действии β-лапакона, хинона
из коры дерева Tabebuia avellanedae. Материалы и методы: для определения жизнеспособности клеток использовали
окраску трипановым синим; окрашивание DAPI и электрофоретический анализ фрагментации ДНК в агарозном геле,
метод проточной цитометрии (для количественной оценки апоптоза); полимеразную цепную реакцию в режиме реального
времени (РВ-ПЦР) и Вестерн блот-анализ (для оценки уровня экспрессии генов и белков), а также колориметрический
анализ активности каспаз. Результаты: выявлено, что в микромолярных концентрациях β-лапакон понижает жизне-
способность клеток линии Т24 путем активации апоптоза, что подтверждается формированием апоптотических тел и
фрагментацией ДНК. Результаты РВ-ПЦР и иммуноблоттинга указывают на то, что обработка клеток β-лапаконом
приводит к снижению экспрессии Bcl-2 и к активации Bax. Апоптоз, индуцированный β-лапаконом, также сопровож-
дается активацией каспаз -3 и -9, ингибированием экспрессии семейства IAP, а также деградацией поли-(ADP-рибозо)
полимеразы, фосфатазы C-γ1 и β-катенина. Тем не менее, уровень экспрессии Fas и FasL снижался при увеличении
концентрации β-лапакона. Выводы: апоптоз, индуцированный при действии β-лапакона в клетках Т24, может быть час-
тично опосредован митохондриальным сигнальным каскадом
Time and Amplitude of Afterpulse Measured with a Large Size Photomultiplier Tube
We have studied the afterpulse of a hemispherical photomultiplier tube for an
upcoming reactor neutrino experiment. The timing, the amplitude, and the rate
of the afterpulse for a 10 inch photomultiplier tube were measured with a 400
MHz FADC up to 16 \ms time window after the initial signal generated by an LED
light pulse. The time and amplitude correlation of the afterpulse shows several
distinctive groups. We describe the dependencies of the afterpulse on the
applied high voltage and the amplitude of the main light pulse. The present
data could shed light upon the general mechanism of the afterpulse.Comment: 11 figure
Neutron beam test of CsI crystal for dark matter search
We have studied the response of Tl-doped and Na-doped CsI crystals to nuclear
recoils and 's below 10 keV. The response of CsI crystals to nuclear
recoil was studied with mono-energetic neutrons produced by the
H(p,n)He reaction. This was compared to the response to Compton
electrons scattered by 662 keV -ray. Pulse shape discrimination between
the response to these 's and nuclear recoils was studied, and quality
factors were estimated. The quenching factors for nuclear recoils were derived
for both CsI(Na) and CsI(Tl) crystals.Comment: 21pages, 14figures, submitted to NIM
Model of correlated sequential adsorption of colloidal particles
We present results of a new model of sequential adsorption in which the
adsorbing particles are correlated with the particles attached to the
substrate. The strength of the correlations is measured by a tunable parameter
. The model interpolates between free ballistic adsorption in the limit
and a strongly correlated phase, appearing for
and characterized by the emergence of highly ordered structures. The phenomenon
is manifested through the analysis of several magnitudes, as the jamming limit
and the particle-particle correlation function. The effect of correlations in
one dimension manifests in the increased tendency to particle chaining in the
substrate. In two dimensions the correlations induce a percolation transition,
in which a spanning cluster of connected particles appears at a certain
critical value . Our study could be applicable to more general
situations in which the coupling between correlations and disorder is relevant,
as for example, in the presence of strong interparticle interactions.Comment: 6 pages, 8 EPS figures. Phys. Rev. E (in press
Muon anomalous magnetic moment and the stabilized Randall-Sundrum scenario
We study the effects of extra dimension on the muon anomalous magnetic moment
in the stabilized Randall-Sundrum scenario. The effects of the Kaluza-Klein
states heavier than the cut-off scale expected to be of order are
neglected. Contribution from the spin-2 Kaluza-Klein states dominates over that
from the spin-0 radion. The recent BNL E821 results impose a strict constraint
on the parameter space of the model: TeV with
. Small is preferred if
is TeV scale.Comment: 9 pages, ReVTeX, reference added, version to appear in PL
- …