137 research outputs found
The expression of growth hormone releasing hormone (GHRH) and its receptors in breast carcinomas with apocrine differentiation - further evidence of the presence of a GHRH pathway in these tumors
Finite-Size Effects and Scaling for the Thermal QCD Deconfinement Phase Transition within the Exact Color-Singlet Partition Function
We study the finite-size effects for the thermal QCD Deconfinement Phase
Transition (DPT), and use a numerical finite size scaling analysis to extract
the scaling exponents characterizing its scaling behavior when approaching the
thermodynamic limit. For this, we use a simple model of coexistence of hadronic
gas and color-singlet Quark Gluon Plasma (QGP) phases in a finite volume. The
Color-Singlet Partition Function (CSPF) of the QGP cannot be exactly calculated
and is usually derived within the saddle point approximation. When we try to do
calculations with such an approximate CSPF, a problem arises in the limit of
small temperatures and/or volumes (VT3<<1), requiring then additional
approximations if we want to carry out calculations. We propose in this work a
new method for an accurate calculation of any quantity of the finite system,
without explicitly calculating the CSPF itself and without any approximation.
By probing the behavior of some useful thermodynamic response functions on the
hole range of temperature, it turns out that in a finite size system, all
singularities in the thermodynamic limit are smeared out and the transition
point is shifted away. A numerical finite size scaling analysis of the obtained
data allows us to determine the scaling exponents of the QCD DPT. Our results
expressing the equality between their values and the space dimensionality is a
consequence of the singularity characterizing a first order phase transition
and agree very well with the predictions of other FSS theoretical approaches
and with the results of both lattice QCD and Monte Carlo models calculations.Comment: 09 pages, 11 Postscript figure
Three-party qutrit-state sharing
A three-party scheme for securely sharing an arbitrary unknown single-qutrit
state is presented. Using a general Greenberger-Horne-Zeilinger (GHZ) state as
the quantum channel among the three parties, the quantum information (i.e., the
qutrit state) from the sender can be split in such a way that the information
can be recovered if and only if both receivers collaborate. Moreover, the
generation of the scheme to multi-party case is also sketched.Comment: 7 page
Relationship between structural changes, hydrogen content and annealing in stacks of ultrathin Si/Ge amorphous layers
Amorphous Si, Ge and SiGe alloys are often doped with H in order to passivate the dangling bonds. However, H is not stable against light soaking and heat treatments yielding degradation of the electrical-optical properties. We present results on the structural instability, as a function of annealing, caused by H in multilayers (MLs) of alternating 3 nm thick a-Si and a-Ge layers deposited by sputtering. H was added at flow rates of 0.4, 0.8, 1.5, 3 and 6 ml/min. By ERDA it was seen that for flow rates ≥1.5 ml/min the effective H content incorporated in the samples saturates at ∼16 at. %. IR optical absorbance shows that mostly Si and Ge monohydrides form. Annealing was done at 673 K for times of 1 to 10 h. The evolution of the properties of the MLs as a function of annealing and H content was followed by IR optical absorbance, TEM, AFM, ERDA. With increasing annealing time/temperature and H content the surface morphology degrades with formation of bubbles and craters whose size and density increase up to 9 μm and 6.7x105 cm-2 for a H flow rate of 6 ml/min. The signal of Ge-H and Si-H complexes almost completely vanish in the IR absorbance spectra upon annealing indicating that H is released to the lattice. This supports the conclusion that it is the released H that produces the bubbles and the craters when the H bubbles blow up because of a too high internal pressure. ERDA experiments performed on single layers of a-Si and a-Ge, showing a faster H released from a-Si than from a-Ge, and energy filtered TEM (EFTEM) maps, showing larger broadening of the a-Si layers in the ML structure, suggest that upon annealing H is first released from a-Si layers. This is in agreement with published data reporting on the lower binding energy of Si-H with respect to Ge-H in amorphous materials
Near-threshold production of omega mesons in the pn -> d omega reaction
The first measurement of the p n -> d omega total cross section has been
achieved at mean excess energies of Q = 28 and 57 MeV by using a deuterium
cluster-jet target. The momentum of the fast deuteron was measured in the ANKE
spectrometer at COSY-Juelich and that of the slow "spectator" proton p(sp) from
the p d -> p(sp) d omega reaction in a silicon telescope placed close to the
target. The cross sections lie above those measured for p p -> p p omega but
seem to be below theoretical predictions.Comment: 7 pages, 8 figures; second approach to describe the background has
been added; results changed insignificantly, EPJ in pres
Is Regression after Neoadjuvant Chemotherapy for Locally Advanced Breast Cancer Different in Sentinel and Non-sentinel Nodes?
Proton driver optimization for new generation neutrino superbeams to search for sub-leading numu->nue oscillations ( angle)
We perform a systematic study of particle production and neutrino yields for
different incident proton energies and baselines , with the aim of
optimizing the parameters of a neutrino beam for the investigation of
-driven neutrino oscillations in the range allowed by
Superkamiokande results. We study the neutrino energy spectra in the
``relevant'' region of the first maximum of the oscillation at a given baseline
. We find that to each baseline corresponds an ``optimal'' proton energy
which minimizes the required integrated proton intensity needed to
observe a fixed number of oscillated events. In addition, we find that the
neutrino event rate in the relevant region scales approximately linearly with
the proton energy. Hence, baselines and proton energies can be
adjusted and the performance for neutrino oscillation searches will remain
approximately unchanged provided that the product of the proton energy times
the number of protons on target remains constant. We apply these ideas to the
specific cases of 2.2, 4.4, 20, 50 and 400 GeV protons. We simulate focusing
systems that are designed to best capture the secondary pions of the
``optimal'' energy. We compute the expected sensitivities to
for the various configurations by assuming the existence
of new generation accelerators able to deliver integrated proton intensities on
target times the proton energy of the order of ${\cal O}(5\times 10^{23})\rm\
GeV\times\rm pot/year$.Comment: 39 pages, 17 figure
The negatively charged amino acids in the lumenal loop influence the pigment binding and conformation of the major light-harvesting chlorophyll a/b complex of photosystem II
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Dempster Hwy - km 217spruce meadowPicea mariana, Ledum palustre, Eriophorum scheuzeri, Saussurea angustifoli
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