1,600 research outputs found
Apoptosis Modulation as a Promising Target for Treatment of Systemic Sclerosis
Diffuse systemic sclerosis (SSc) is a fatal autoimmune disease characterized by an excessive ECM deposition inducing a loss of function of skin and internal organs. Apoptosis is a key mechanism involved in all the stages of the disease: vascular damage, immune dysfunction, and fibrosis. The purpose of this paper is to gather new findings in apoptosis related to SSc, to highlight relations between apoptosis and fibrosis, and to identify new therapeutic targets
Quatre après les inondations, dans le département de l'Aude : la création du Syndicat mixte des milieux aquatiques et des rivières.
Le département de l'Aude. a été durement touché par les crues de 1999, et quatre ans après, le retour d'expérience est instructif. Jacques Chabaud, après un rappel des événements de 1999, décrit le dispositif mis en place dans le cadre du programme de prévention des inondations, et notamment la création d'un Syndicat regroupant le Département et la plupart des établissements publics concernés
Using LDGM Codes and Sparse Syndromes to Achieve Digital Signatures
In this paper, we address the problem of achieving efficient code-based
digital signatures with small public keys. The solution we propose exploits
sparse syndromes and randomly designed low-density generator matrix codes.
Based on our evaluations, the proposed scheme is able to outperform existing
solutions, permitting to achieve considerable security levels with very small
public keys.Comment: 16 pages. The final publication is available at springerlink.co
Weighted complex projective 2-designs from bases: optimal state determination by orthogonal measurements
We introduce the problem of constructing weighted complex projective
2-designs from the union of a family of orthonormal bases. If the weight
remains constant across elements of the same basis, then such designs can be
interpreted as generalizations of complete sets of mutually unbiased bases,
being equivalent whenever the design is composed of d+1 bases in dimension d.
We show that, for the purpose of quantum state determination, these designs
specify an optimal collection of orthogonal measurements. Using highly
nonlinear functions on abelian groups, we construct explicit examples from d+2
orthonormal bases whenever d+1 is a prime power, covering dimensions d=6, 10,
and 12, for example, where no complete sets of mutually unbiased bases have
thus far been found.Comment: 28 pages, to appear in J. Math. Phy
Continuous-variable sampling from photon-added or photon-subtracted squeezed states
We introduce a new family of quantum circuits in Continuous Variables and we
show that, relying on the widely accepted conjecture that the polynomial
hierarchy of complexity classes does not collapse, their output probability
distribution cannot be efficiently simulated by a classical computer. These
circuits are composed of input photon-subtracted (or photon-added) squeezed
states, passive linear optics evolution, and eight-port homodyne detection. We
address the proof of hardness for the exact probability distribution of these
quantum circuits by exploiting mappings onto different architectures of
sub-universal quantum computers. We obtain both a worst-case and an
average-case hardness result. Hardness of Boson Sampling with eight-port
homodyne detection is obtained as the zero squeezing limit of our model. We
conclude with a discussion on the relevance and interest of the present model
in connection to experimental applications and classical simulations.Comment: 11 pages, 6 figure
On the universality of small scale turbulence
The proposed universality of small scale turbulence is investigated for a set
of measurements in a cryogenic free jet with a variation of the Reynolds number
(Re) from 8500 to 10^6. The traditional analysis of the statistics of velocity
increments by means of structure functions or probability density functions is
replaced by a new method which is based on the theory of stochastic Markovian
processes. It gives access to a more complete characterization by means of
joint probabilities of finding velocity increments at several scales. Based on
this more precise method our results call in question the concept of
universality.Comment: 4 pages, 4 figure
A role for the mevalonate pathway in early plant symbiotic signaling
Rhizobia and arbuscular mycorrhizal fungi produce signals that are perceived by host legume receptors at the plasma membrane and trigger sustained oscillations of the nuclear and perinuclear Ca(2+) concentration (Ca(2+) spiking), which in turn leads to gene expression and downstream symbiotic responses. The activation of Ca(2+) spiking requires the plasma membrane-localized receptor-like kinase Does not Make Infections 2 (DMI2) as well as the nuclear cation channel DMI1. A key enzyme regulating the mevalonate (MVA) pathway, 3-Hydroxy-3-Methylglutaryl CoA Reductase 1 (HMGR1), interacts with DMI2 and is required for the legume-rhizobium symbiosis. Here, we show that HMGR1 is required to initiate Ca(2+) spiking and symbiotic gene expression in Medicago truncatula roots in response to rhizobial and arbuscular mycorrhizal fungal signals. Furthermore, MVA, the direct product of HMGR1 activity, is sufficient to induce nuclear-associated Ca(2+) spiking and symbiotic gene expression in both wild-type plants and dmi2 mutants, but interestingly not in dmi1 mutants. Finally, MVA induced Ca(2+) spiking in Human Embryonic Kidney 293 cells expressing DMI1. This demonstrates that the nuclear cation channel DMI1 is sufficient to support MVA-induced Ca(2+) spiking in this heterologous system
Size limiting in Tsallis statistics
Power law scaling is observed in many physical, biological and
socio-economical complex systems and is now considered as an important property
of these systems. In general, power law exists in the central part of the
distribution. It has deviations from power law for very small and very large
step sizes. Tsallis, through non-extensive thermodynamics, explained power law
distribution in many cases including deviation from the power law, both for
small and very large steps. In case of very large steps, they used heuristic
crossover approach. In real systems, the size is limited and thus, the size
limiting factor is important. In the present work, we present an alternative
model in which we consider that the entropy factor q decreases with step size
due to the softening of long range interactions or memory. This explains the
deviation of power law for very large step sizes. Finally, we apply this model
for distribution of citation index of scientists and examination scores and are
able to explain the entire distribution including deviations from power law.Comment: 22 pages, 8 figure
The European Photon Imaging Camera on XMM-Newton: The MOS Cameras
The EPIC focal plane imaging spectrometers on XMM-Newton use CCDs to record
the images and spectra of celestial X-ray sources focused by the three X-ray
mirrors. There is one camera at the focus of each mirror; two of the cameras
contain seven MOS CCDs, while the third uses twelve PN CCDs, defining a
circular field of view of 30 arcmin diameter in each case. The CCDs were
specially developed for EPIC, and combine high quality imaging with spectral
resolution close to the Fano limit. A filter wheel carrying three kinds of
X-ray transparent light blocking filter, a fully closed, and a fully open
position, is fitted to each EPIC instrument. The CCDs are cooled passively and
are under full closed loop thermal control. A radio-active source is fitted for
internal calibration. Data are processed on-board to save telemetry by removing
cosmic ray tracks, and generating X-ray event files; a variety of different
instrument modes are available to increase the dynamic range of the instrument
and to enable fast timing. The instruments were calibrated using laboratory
X-ray beams, and synchrotron generated monochromatic X-ray beams before launch;
in-orbit calibration makes use of a variety of celestial X-ray targets. The
current calibration is better than 10% over the entire energy range of 0.2 to
10 keV. All three instruments survived launch and are performing nominally in
orbit. In particular full field-of-view coverage is available, all electronic
modes work, and the energy resolution is close to pre-launch values. Radiation
damage is well within pre-launch predictions and does not yet impact on the
energy resolution. The scientific results from EPIC amply fulfil pre-launch
expectations.Comment: 9 pages, 11 figures, accepted for publication in the A&A Special
Issue on XMM-Newto
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