2,882 research outputs found
Probing elastic and inelastic breakup contributions to intermediate-energy two-proton removal reactions
The two-proton removal reaction from 28Mg projectiles has been studied at 93
MeV/u at the NSCL. First coincidence measurements of the heavy 26Ne projectile
residues, the removed protons and other light charged particles enabled the
relative cross sections from each of the three possible elastic and inelastic
proton removal mechanisms to be determined. These more final-state-exclusive
measurements are key for further interrogation of these reaction mechanisms and
use of the reaction channel for quantitative spectroscopy of very neutron-rich
nuclei. The relative and absolute yields of the three contributing mechanisms
are compared to reaction model expectations - based on the use of eikonal
dynamics and sd-shell-model structure amplitudes.Comment: Accepted for publication in Physical Review C (Rapid Communication
Elastic breakup cross sections of well-bound nucleons
The 9Be(28Mg,27Na) one-proton removal reaction with a large proton separation
energy of Sp(28Mg)=16.79 MeV is studied at intermediate beam energy.
Coincidences of the bound 27Na residues with protons and other light charged
particles are measured. These data are analyzed to determine the percentage
contributions to the proton removal cross section from the elastic and
inelastic nucleon removal mechanisms. These deduced contributions are compared
with the eikonal reaction model predictions and with the previously measured
data for reactions involving the re- moval of more weakly-bound protons from
lighter nuclei. The role of transitions of the proton between different bound
single-particle configurations upon the elastic breakup cross section is also
quantified in this well-bound case. The measured and calculated elastic breakup
fractions are found to be in good agreement.Comment: Phys. Rev. C 2014 (accepted
Coherent motion of stereocilia assures the concerted gating of hair-cell transduction channels
The hair cell's mechanoreceptive organelle, the hair bundle, is highly
sensitive because its transduction channels open over a very narrow range of
displacements. The synchronous gating of transduction channels also underlies
the active hair-bundle motility that amplifies and tunes responsiveness. The
extent to which the gating of independent transduction channels is coordinated
depends on how tightly individual stereocilia are constrained to move as a
unit. Using dual-beam interferometry in the bullfrog's sacculus, we found that
thermal movements of stereocilia located as far apart as a bundle's opposite
edges display high coherence and negligible phase lag. Because the mechanical
degrees of freedom of stereocilia are strongly constrained, a force applied
anywhere in the hair bundle deflects the structure as a unit. This feature
assures the concerted gating of transduction channels that maximizes the
sensitivity of mechanoelectrical transduction and enhances the hair bundle's
capacity to amplify its inputs.Comment: 24 pages, including 6 figures, published in 200
Controlled interfacial assembly of 2D curved colloidal crystals and jammed shells
Assembly of colloidal particles on fluid interfaces is a promising technique
for synthesizing two-dimensional micro-crystalline materials useful in fields
as diverse as biomedicine1, materials science2, mineral flotation3 and food
processing4. Current approaches rely on bulk emulsification methods, require
further chemical and thermal treatments, and are restrictive with respect to
the materials employed5-9. The development of methods that exploit the great
potential of interfacial assembly for producing tailored materials have been
hampered by the lack of understanding of the assembly process. Here we report a
microfluidic method that allows direct visualization and understanding of the
dynamics of colloidal crystal growth on curved interfaces. The crystals are
periodically ejected to form stable jammed shells, which we refer to as
colloidal armour. We propose that the energetic barriers to interfacial crystal
growth and organization can be overcome by targeted delivery of colloidal
particles through hydrodynamic flows. Our method allows an unprecedented degree
of control over armour composition, size and stability.Comment: 18 pages, 5 figure
Skin Lesion Analyser: An Efficient Seven-Way Multi-Class Skin Cancer Classification Using MobileNet
Skin cancer, a major form of cancer, is a critical public health problem with
123,000 newly diagnosed melanoma cases and between 2 and 3 million non-melanoma
cases worldwide each year. The leading cause of skin cancer is high exposure of
skin cells to UV radiation, which can damage the DNA inside skin cells leading
to uncontrolled growth of skin cells. Skin cancer is primarily diagnosed
visually employing clinical screening, a biopsy, dermoscopic analysis, and
histopathological examination. It has been demonstrated that the dermoscopic
analysis in the hands of inexperienced dermatologists may cause a reduction in
diagnostic accuracy. Early detection and screening of skin cancer have the
potential to reduce mortality and morbidity. Previous studies have shown Deep
Learning ability to perform better than human experts in several visual
recognition tasks. In this paper, we propose an efficient seven-way automated
multi-class skin cancer classification system having performance comparable
with expert dermatologists. We used a pretrained MobileNet model to train over
HAM10000 dataset using transfer learning. The model classifies skin lesion
image with a categorical accuracy of 83.1 percent, top2 accuracy of 91.36
percent and top3 accuracy of 95.34 percent. The weighted average of precision,
recall, and f1-score were found to be 0.89, 0.83, and 0.83 respectively. The
model has been deployed as a web application for public use at
(https://saketchaturvedi.github.io). This fast, expansible method holds the
potential for substantial clinical impact, including broadening the scope of
primary care practice and augmenting clinical decision-making for dermatology
specialists.Comment: This is a pre-copyedited version of a contribution published in
Advances in Intelligent Systems and Computing, Hassanien A., Bhatnagar R.,
Darwish A. (eds) published by Chaturvedi S.S., Gupta K., Prasad P.S. The
definitive authentication version is available online via
https://doi.org/10.1007/978-981-15-3383-9_1
Testing Yukawa-unified SUSY during year 1 of LHC: the role of multiple b-jets, dileptons and missing E_T
We examine the prospects for testing SO(10) Yukawa-unified supersymmetric
models during the first year of LHC running at \sqrt{s}= 7 TeV, assuming
integrated luminosity values of 0.1 to 1 fb^-1. We consider two cases: the
Higgs splitting (HS) and the D-term splitting (DR3) models. Each generically
predicts light gluinos and heavy squarks, with an inverted scalar mass
hierarchy. We hence expect large rates for gluino pair production followed by
decays to final states with large b-jet multiplicity. For 0.2 fb^-1 of
integrated luminosity, we find a 5 sigma discovery reach of m(gluino) ~ 400 GeV
even if missing transverse energy, E_T^miss, is not a viable cut variable, by
examining the multi-b-jet final state. A corroborating signal should stand out
in the opposite-sign (OS) dimuon channel in the case of the HS model; the DR3
model will require higher integrated luminosity to yield a signal in the OS
dimuon channel. This region may also be probed by the Tevatron with 5-10 fb^-1
of data, if a corresponding search in the multi-b+ E_T^miss channel is
performed. With higher integrated luminosities of ~1 fb^-1, using E_T^miss plus
a large multiplicity of b-jets, LHC should be able to discover Yukawa-unified
SUSY with m(gluino) up to about 630 GeV. Thus, the year 1 LHC reach for
Yukawa-unified SUSY should be enough to either claim a discovery of the gluino,
or to very nearly rule out this class of models, since higher values of
m(gluino) lead to rather poor Yukawa unification.Comment: 32 pages including 31 EPS figure
Localization-delocalization transition of a reaction-diffusion front near a semipermeable wall
The A+B --> C reaction-diffusion process is studied in a system where the
reagents are separated by a semipermeable wall. We use reaction-diffusion
equations to describe the process and to derive a scaling description for the
long-time behavior of the reaction front. Furthermore, we show that a critical
localization-delocalization transition takes place as a control parameter which
depends on the initial densities and on the diffusion constants is varied. The
transition is between a reaction front of finite width that is localized at the
wall and a front which is detached and moves away from the wall. At the
critical point, the reaction front remains at the wall but its width diverges
with time [as t^(1/6) in mean-field approximation].Comment: 7 pages, PS fil
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