82 research outputs found
Opposing prognostic relevance of junction plakoglobin in distinct prostate cancer patient subsets
Both oncogenic and tumor suppressor functions have been described for junction plakoglobin (JUP), also known as Îł-catenin. To clarify the role of JUP in prostate cancer, JUP protein expression was immunohistochemically detected in a tissue microarray containing 11Â 267 individual prostatectomy specimens. Considering all patients, high JUP expression was associated with adverse tumor stage (PÂ =Â 0.0002), high Gleason grade (PÂ <Â 0.0001), and lymph node metastases (PÂ =Â 0.011). These associations were driven mainly by the subset without TMPRSS2:ERG fusion, in which high JUP expression was an independent predictor of poor prognosis (multivariate analyses, PÂ =Â 0.0054) and early biochemical recurrence (PÂ =Â 0.0003). High JUP expression was further linked to strong androgen receptor expression (PÂ <Â 0.0001), high cell proliferation, and PTEN and FOXP1 deletion (PÂ <Â 0.0001). In the ERG-negative subset, high JUP expression was additionally linked to MAP3K7 (PÂ =Â 0.0007) and CHD1 deletion (PÂ =Â 0.0021). Contrasting the overall prognostic effect of JUP, low JUP expression indicated poor prognosis in the fraction of CHD1-deleted patients (PÂ =Â 0.039). In this subset, the association of high JUP and high cell proliferation was specifically absent. In conclusion, the controversial biological roles of JUP are reflected by antagonistic prognostic effects in distinct prostate cancer patient subsets
A Collider Signature of the Supersymmetric Golden Region
Null results of experimental searches for the Higgs boson and the
superpartners imply a certain amount of fine-tuning in the electroweak sector
of the Minimal Supersymmetric Standard Model (MSSM). The "golden region" in the
MSSM parameter space is the region where the experimental constraints are
satisfied and the amount of fine-tuning is minimized. In this region, the stop
trilinear soft term is large, leading to a significant mass splitting between
the two stop mass eigenstates. As a result, the decay of the heavier stop into
the lighter stop and a Z boson is kinematically allowed throughout the golden
region. We propose that the experiments at the Large Hadron Collider (LHC) can
search for this decay through an inclusive signature, Z+2jb+missing Et+X. We
evaluate the Standard Model backgrounds for this channel, and identify a set of
cuts that would allow detection of the supersymmetric contribution at the LHC
for the MSSM parameters typical of the golden region. We also discuss other
possible interpretations of a signal for new physics in the Z+2jb+missing Et+X
channel, and suggest further measurements that could be used to distinguish
among these interpretations.Comment: 23 pages, 5 figures. New in v4: an error fixed in Eq. (13); results
unaffecte
Two Simple W' Models for the Early LHC
W' gauge bosons are good candidates for early LHC discovery. We define two
reference models, one containing a W'_R and one containing a W'_L, which may
serve as ``simplified models'' for presenting experimental results of W'
searches at the LHC. We present the Tevatron bounds on each model and compute
the constraints from precision electroweak observables. We find that indirect
low-energy constraints on the W'_L are quite strong. However, for a W'_R
coupling to right-handed fermions there exists a sizeable region in parameter
space beyond the bounds from the Tevatron and low-energy precision measurements
where even 50 inverse picobarns of integrated LHC luminosity are sufficient to
discover the W'_R. The most promising final states are two leptons and two
jets, or one lepton recoiling against a ``neutrino jet''. A neutrino jet is a
collimated object consisting of a hard lepton and two jets arising from the
decay of a highly boosted massive neutrino.Comment: 20 pages, 8 figures. v2: references adde
Inserting single Cs atoms into an ultracold Rb gas
We report on the controlled insertion of individual Cs atoms into an
ultracold Rb gas at about 400 nK. This requires to combine the techniques
necessary for cooling, trapping and manipulating single laser cooled atoms
around the Doppler temperature with an experiment to produce ultracold
degenerate quantum gases. In our approach, both systems are prepared in
separated traps and then combined. Our results pave the way for coherent
interaction between a quantum gas and a single or few neutral atoms of another
species
Defining the optimal dose of radiation in leukemic patients with extramedullary lesions
<p>Abstract</p> <p>Background</p> <p>Analysis of the clinical response of extramedullary lesions in leukemic patients treated with radiation therapy (RT) and defining the optimal dose of radiation.</p> <p>Methods</p> <p>Forty-two extramedullary lesions found in 24 leukemic patients treated with RT were reviewed. The radiation was delivered usually 2 Gy/day, up to a median of 20 Gy (range: 18.0-40.8). The clinical response and symptom palliation effect were analyzed. The factors affecting the response were also included in the analysis.</p> <p>Results</p> <p>After a median time of 7.9 weeks, the overall response rate was 76.2%. A complete response (CR) was achieved in 35.7%, a partial response in 40.5%. The symptom was relieved in 85.7% sites. The overall response rate was better in patients whose initial tumor size was smaller than 10 cm<sup>2 </sup>(<it>p = 0.010</it>) or who were treated with more than 25 Gy (<it>p = 0.031</it>). The overall CR rate was also higher in those who had smaller tumors (smaller than 6 cm or 30 cm<sup>2</sup>) (<it>p = 0.015)</it>, or when the tumor was located in soft tissue (<it>p = 0.029</it>).</p> <p>Conclusions</p> <p>Extramedullary lesions in leukemic patients can be successfully treated with RT. The tumor response rate was excellent and symptom relief was achieved in almost all patients. There was a better response to treatment when the tumor was small or it was located in soft tissue. Although, there was no definite correlation between volume reduction and total dose, it seems that higher total dose more of than 25 Gy is needed for better response.</p
Simplified Models for LHC New Physics Searches
This document proposes a collection of simplified models relevant to the
design of new-physics searches at the LHC and the characterization of their
results. Both ATLAS and CMS have already presented some results in terms of
simplified models, and we encourage them to continue and expand this effort,
which supplements both signature-based results and benchmark model
interpretations. A simplified model is defined by an effective Lagrangian
describing the interactions of a small number of new particles. Simplified
models can equally well be described by a small number of masses and
cross-sections. These parameters are directly related to collider physics
observables, making simplified models a particularly effective framework for
evaluating searches and a useful starting point for characterizing positive
signals of new physics. This document serves as an official summary of the
results from the "Topologies for Early LHC Searches" workshop, held at SLAC in
September of 2010, the purpose of which was to develop a set of representative
models that can be used to cover all relevant phase space in experimental
searches. Particular emphasis is placed on searches relevant for the first
~50-500 pb-1 of data and those motivated by supersymmetric models. This note
largely summarizes material posted at http://lhcnewphysics.org/, which includes
simplified model definitions, Monte Carlo material, and supporting contacts
within the theory community. We also comment on future developments that may be
useful as more data is gathered and analyzed by the experiments.Comment: 40 pages, 2 figures. This document is the official summary of results
from "Topologies for Early LHC Searches" workshop (SLAC, September 2010).
Supplementary material can be found at http://lhcnewphysics.or
Guidelines for developing optical clocks with fractional frequency uncertainty
There has been tremendous progress in the performance of optical frequency
standards since the first proposals to carry out precision spectroscopy on
trapped, single ions in the 1970s. The estimated fractional frequency
uncertainty of today's leading optical standards is currently in the
range, approximately two orders of magnitude better than that of the best
caesium primary frequency standards. This exceptional accuracy and stability is
resulting in a growing number of research groups developing optical clocks.
While good review papers covering the topic already exist, more practical
guidelines are needed as a complement. The purpose of this document is
therefore to provide technical guidance for researchers starting in the field
of optical clocks. The target audience includes national metrology institutes
(NMIs) wanting to set up optical clocks (or subsystems thereof) and PhD
students and postdocs entering the field. Another potential audience is
academic groups with experience in atomic physics and atom or ion trapping, but
with less experience of time and frequency metrology and optical clock
requirements. These guidelines have arisen from the scope of the EMPIR project
"Optical clocks with uncertainty" (OC18). Therefore, the
examples are from European laboratories even though similar work is carried out
all over the world. The goal of OC18 was to push the development of optical
clocks by improving each of the necessary subsystems: ultrastable lasers,
neutral-atom and single-ion traps, and interrogation techniques. This document
shares the knowledge acquired by the OC18 project consortium and gives
practical guidance on each of these aspects
Shedding Light on the Dark Sector with Direct WIMP Production
A Weakly Interacting Massive Particle (WIMP) provides an attractive dark
matter candidate, and should be within reach of the next generation of
high-energy colliders. We consider the process of direct WIMP pair-production,
accompanied by an initial-state radiation photon, in electron-positron
collisions at the proposed International Linear Collider (ILC). We present a
parametrization of the differential cross section for this process which
conveniently separates the model-independent information provided by cosmology
from the model-dependent inputs from particle physics. As an application, we
consider two simple models, one supersymmetric, and another of the "universal
extra dimensions" (UED) type. The discovery reach of the ILC and the expected
precision of parameter measurements are studied in each model. In addition, for
each of the two examples, we also investigate the ability of the ILC to
distinguish between the two models through a shape-discrimination analysis of
the photon energy spectrum. We show that with sufficient beam polarization the
alternative model interpretation can be ruled out in a large part of the
relevant parameter space.Comment: 21 pages, 9 figure
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