579 research outputs found
Prendre en compte la santé mentale des publics en bibliothèque universitaire
Mémoire d\u27étude de DCB de la promotion 2022/2023
Dynamics of co-orbital exoplanets in a first order resonance chain with tidal dissipation
Co-orbital planets (in a mean motion resonance) can be formed within a
Laplace resonance chain. Here, we develop a secular model to study the dynamics
of the resonance chain , where the co-orbital pair is in a first-order
mean motion resonance with the outermost third planet. Our model takes into
account tidal dissipation through the use of a Hamiltonian version of the
constant time-lag model, which extends the Hamiltonian formalism of the
point-mass case. We show the existence of several families of equilibria, and
how these equilibria extend to the complete system. In one family, which we
call the main branch, a secular resonance between the libration frequency of
the co-orbitals and the precession frequency of the pericentres has unexpected
dynamical consequences when tidal dissipation is added. We report the existence
of two distinct mechanisms that make co-orbital planets much more stable within
the resonance chain rather than outside it. The first one is due to
negative real parts of the eigenvalues of the linearised system with tides, in
the region of the secular resonance mentioned above. The second one comes from
non-linear contributions of the vector field and it is due to eccentricity
damping. These two stabilising mechanisms increase the chances of a
still-to-come detection of exoplanets in the co-orbital configuration
The effect of radio-collar weight on survival of migratory caribou
Radio transmitters are widely used in wildlife management; therefore, it is essential to assess
any effects that they may have on animal survival. We compared the survival of 269 randomly selected adult
migratory caribou (Rangifer tarandus) fitted with either light very high frequency or heavy Argos satellite
collars during the same period. Heavy collars reduced annual survival of caribou in a declining population
with generally poor body condition by about 18%. Accurate estimates of survival are crucial for management
decisions and possible effects of collars should be considered when calculating estimates
ALTA: Asynchronous Loss Tolerant Algorithms for Grid Computing
International audienceThis paper describes an environment dedicated to the building of efficient scientific applications for the Grid on top of unreliable communication networks. Nowadays, scientific computing appli-cations are usually built on top of reliable communication proto-cols (such as TCP). Nevertheless, the additional cost introduced by the reliability layer is not negligible in wide area network-based grid environments. On the other hand, data loss in communications may have a dramatic impact over the performance – if not over the correctness – of classical parallel algorithms. However, a particular class of parallel iterative algorithms hap-pens to be tolerant to such losses. This is the class of asynchronous iterative algorithms, which are commonly used in large scientific applications. They are particularly prone to a good communica-tion/computation overlap since processors are no more synchro-nized. In this study, we aim at proposing a new architecture suit-able for the development of asynchronous iterative algorithms tolerant to message losses
aPKC-mediated displacement and actomyosin-mediated retention polarize Miranda in <i>Drosophila</i> neuroblasts
QUARITE (quality of care, risk management and technology in obstetrics): a cluster-randomized trial of a multifaceted intervention to improve emergency obstetric care in Senegal and Mali
<p>Abstract</p> <p>Background</p> <p>Maternal and perinatal mortality are major problems for which progress in sub-Saharan Africa has been inadequate, even though childbirth services are available, even in the poorest countries. Reducing them is the aim of two of the main Millennium Development Goals. Many initiatives have been undertaken to remedy this situation, such as the Advances in Labour and Risk Management (ALARM) International Program, whose purpose is to improve the quality of obstetric services in low-income countries. However, few interventions have been evaluated, in this context, using rigorous methods for analyzing effectiveness in terms of health outcomes. The objective of this trial is to evaluate the effectiveness of the ALARM International Program (AIP) in reducing maternal mortality in referral hospitals in Senegal and Mali. Secondary goals include evaluation of the relationships between effectiveness and resource availability, service organization, medical practices, and satisfaction among health personnel.</p> <p>Methods/Design</p> <p>This is an international, multi-centre, controlled cluster-randomized trial of a complex intervention. The intervention is based on the concept of evidence-based practice and on a combination of two approaches aimed at improving the performance of health personnel: 1) Educational outreach visits; and 2) the implementation of facility-based maternal death reviews.</p> <p>The unit of intervention is the public health facility equipped with a functional operating room. On the basis of consent provided by hospital authorities, 46 centres out of 49 eligible were selected in Mali and Senegal. Using randomization stratified by country and by level of care, 23 centres will be allocated to the intervention group and 23 to the control group. The intervention will last two years. It will be preceded by a pre-intervention one-year period for baseline data collection. A continuous clinical data collection system has been set up in all participating centres. This, along with the inventory of resources and the satisfaction surveys administered to the health personnel, will allow us to measure results before, during, and after the intervention. The overall rate of maternal mortality measured in hospitals during the post-intervention period (Year 4) is the primary outcome. The evaluation will also include cost-effectiveness.</p> <p>Trial Registration</p> <p>The QUARITE trial is registered on the Current Controlled Trials website under the number ISRCTN46950658 <url>http://www.controlled-trials.com/</url>.</p
Multidifferential study of identified charged hadron distributions in -tagged jets in proton-proton collisions at 13 TeV
Jet fragmentation functions are measured for the first time in proton-proton
collisions for charged pions, kaons, and protons within jets recoiling against
a boson. The charged-hadron distributions are studied longitudinally and
transversely to the jet direction for jets with transverse momentum 20 GeV and in the pseudorapidity range . The
data sample was collected with the LHCb experiment at a center-of-mass energy
of 13 TeV, corresponding to an integrated luminosity of 1.64 fb. Triple
differential distributions as a function of the hadron longitudinal momentum
fraction, hadron transverse momentum, and jet transverse momentum are also
measured for the first time. This helps constrain transverse-momentum-dependent
fragmentation functions. Differences in the shapes and magnitudes of the
measured distributions for the different hadron species provide insights into
the hadronization process for jets predominantly initiated by light quarks.Comment: All figures and tables, along with machine-readable versions and any
supplementary material and additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-013.html (LHCb
public pages
Study of the decay
The decay is studied
in proton-proton collisions at a center-of-mass energy of TeV
using data corresponding to an integrated luminosity of 5
collected by the LHCb experiment. In the system, the
state observed at the BaBar and Belle experiments is
resolved into two narrower states, and ,
whose masses and widths are measured to be where the first uncertainties are statistical and the second
systematic. The results are consistent with a previous LHCb measurement using a
prompt sample. Evidence of a new
state is found with a local significance of , whose mass and width
are measured to be and , respectively. In addition, evidence of a new decay mode
is found with a significance of
. The relative branching fraction of with respect to the
decay is measured to be , where the first
uncertainty is statistical, the second systematic and the third originates from
the branching fractions of charm hadron decays.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-028.html (LHCb
public pages
Measurement of the ratios of branching fractions and
The ratios of branching fractions
and are measured, assuming isospin symmetry, using a
sample of proton-proton collision data corresponding to 3.0 fb of
integrated luminosity recorded by the LHCb experiment during 2011 and 2012. The
tau lepton is identified in the decay mode
. The measured values are
and
, where the first uncertainty is
statistical and the second is systematic. The correlation between these
measurements is . Results are consistent with the current average
of these quantities and are at a combined 1.9 standard deviations from the
predictions based on lepton flavor universality in the Standard Model.Comment: All figures and tables, along with any supplementary material and
additional information, are available at
https://cern.ch/lhcbproject/Publications/p/LHCb-PAPER-2022-039.html (LHCb
public pages
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