The data sample of Λ0b→J/ψpK− decays acquired with the LHCb detector from 7 and 8 TeV pp collisions, corresponding to an integrated luminosity of 3 fb−1, is inspected for the presence of J/ψp or ...J/ψK− contributions with minimal assumptions about K−p contributions. It is demonstrated at more than nine standard deviations that Λ0b→J/ψpK− decays cannot be described with K−p contributions alone, and that J/ψp contributions play a dominant role in this incompatibility. These model-independent results support the previously obtained model-dependent evidence for P+c→J/ψp charmonium-pentaquark states in the same data sample.
La fréquence des récidives thrombotiques dans le SAPL et les facteurs associés à ces récidives sont variables dans la littérature. L’objectif de ce travail était de déterminer le taux de récidive ...thrombotique dans une population de patients atteints de SAPL thrombotique suivie au sein de notre CHU et d’identifier les facteurs de risque associés à ces récidives.
Nous avons réalisé une étude rétrospective d’une cohorte de patients suivis entre le 1er janvier 2000 et le 31 décembre 2019. Nous avons recueilli les caractéristiques du SAPL, le traitement, le risque cardiovasculaire artériel et veineux ainsi que les caractéristiques des récidives et l’évolution du statut immunologique au cours du suivi. Une analyse univariée des facteurs associés à la récidive était réalisée par le test du Log-rank. Une analyse multivariée avec un modèle de Cox était réalisée sur les variables sélectionnées précédemment ou considérées d’intérêt.
Cent-quatorze (114) patients répondaient aux critères de SAPL thrombotique selon la classification de Sydney. L’âge moyen était de 42 ans 26–58 avec un sex-ratio F/H de 2,2 et un suivi médian de 8 ans 4–12. Trente patients (26 %) avaient récidivé au moins un fois avec un délai médian de 6 ans 3–11 soit une incidence approchée de 1,5 pour 100 patients-années. La majorité des patients (20) (67 %) récidivait une seule fois; 10 (33 %) récidivaient au moins deux fois. Au moment de la récidive, 20 patients (46 %) étaient sous AVK seul ou en association à un antiagrégant plaquettaire. L’INR était dans la cible chez 8 patients (40 %), hors cible chez 5 patients (25 %) et non retrouvé chez 7 patients (35 %). En analyse univariée avec le test du Log-rank, le statut triple positif (36 % vs 29 %) (p=0,033), l’antécédent de lupus érythémateux systémique (27 % vs 11 %) (p=0,023), un antécédent personnel de maladie cardiovasculaire (10 % vs 14 %) (p=0,007), d’hypertension artérielle (43 % vs 22 %) (p=0,029), d’hypercholestérolémie (23 % vs 8 %) (p=0,035), d’obésité (30 % vs 8 %) (p=0,001) étaient significativement associés à la récidive. Le seul facteur indépendamment associé à une récidive en analyse multivariée avec le modèle de Cox était l’antécédent d’obésité au diagnostic avec un risque moyen trois fois plus élevé de récidiver (HR=3,97 1,17–13,49, p=0,028).
Le taux de récidive thrombotique de notre série semble inférieure à ceux de la littérature (31 % dans la cohorte Europhospholipide, 44 % dans l’étude rétrospective prolongée sur 18 ans de Taraborrelli et al. avec une incidence annuelle de 3,5 %). De manière intéressante et sous réserve des limites liées au caractère rétrospectif de cette étude et du nombre de patient inclus, les facteurs de risque cardio vasculaire et l’obésité semblent également être associés à la récidive thrombotique en plus du statut immunologique. Ces données soulignent la nécessité d’un contrôle plus strict des facteurs de risque cardiovasculaire.
A search for ultra-high energy photons with energies above 1 EeV is performed using nine years of data collected by the Pierre Auger Observatory in hybrid operation mode. An unprecedented separation ...power between photon and hadron primaries is achieved by combining measurements of the longitudinal air-shower development with the particle content at ground measured by the fluorescence and surface detectors, respectively. Only three photon candidates at energies 1–2 EeV are found, which is compatible with the expected hadron-induced background. Upper limits on the integral flux of ultra-high energy photons of 0.027, 0.009, 0.008, 0.008 and 0.007 km{sup −2} sr{sup −1} yr{sup −1} are derived at 95% C.L. for energy thresholds of 1, 2, 3, 5 and 10 EeV. These limits bound the fractions of photons in the all-particle integral flux below 0.1%, 0.15%, 0.33%, 0.85% and 2.7%. For the first time the photon fraction at EeV energies is constrained at the sub-percent level. The improved limits are below the flux of diffuse photons predicted by some astrophysical scenarios for cosmogenic photon production. The new results rule-out the early top-down models − in which ultra-high energy cosmic rays are produced by, e.g., the decay of super-massive particles − and challenge the most recent super-heavy dark matter models.
The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the ...surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30-80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy-corrected for geometrical effects-is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.
On September 14, 2015 the Advanced LIGO detectors observed their first gravitational wave (GW) transient GW150914. This was followed by a second GW event observed on December 26, 2015. Both events ...were inferred to have arisen from the merger of black holes in binary systems. Such a system may emit neutrinos if there are magnetic fields and disk debris remaining from the formation of the two black holes. With the surface detector array of the Pierre Auger Observatory we can search for neutrinos with energy Eν above 100 PeV from pointlike sources across the sky with equatorial declination from about −65° to +60°, and, in particular, from a fraction of the 90% confidence-level inferred positions in the sky of GW150914 and GW151226. A targeted search for highly inclined extensive air showers, produced either by interactions of downward-going neutrinos of all flavors in the atmosphere or by the decays of tau leptons originating from tau-neutrino interactions in the Earth’s crust (Earth-skimming neutrinos), yielded no candidates in the Auger data collected within ±500 s around or 1 day after the coordinated universal time (UTC) of GW150914 and GW151226, as well as in the same search periods relative to the UTC time of the GW candidate event LVT151012. From the nonobservation we constrain the amount of energy radiated in ultrahigh-energy neutrinos from such remarkable events.
A search for CP violation in D-0 -> K-K+ and D-0 -> pi(-)pi(+) decays is performed using pp collision data, corresponding to an integrated luminosity of 3 fb(-1), collected using the LHCb detector at ...center-of-mass energies of 7 and 8 TeV. The flavor of the charm meson is inferred from the charge of the pion in D*(+) -> D-0 pi(+) and D*(-) -> (D) over bar (0)pi(-) decays. The difference between the CP asymmetries in D-0 -> K-K+ and D-0 -> pi(-)pi(+) decays, Delta A(CP) A(CP)(K-K+) - A(CP)(pi(-)pi(+)), is measured to be -0.10 +/- 0.08(stat) +/- 0.03(syst)%. This is the most precise measurement of a time-integrated CP asymmetry in the charm sector from a single experiment.
We describe the Hybrid seeding, a stand-alone pattern recognition algorithm aiming at finding charged particle trajectories for the LHCb upgrade. A significant improvement to the charged particle ...reconstruction efficiency is accomplished by exploiting the knowledge of the LHCb magnetic field and the position of energy deposits in the scintillating fibre tracker detector. Moreover, we achieve a low fake rate and a small contribution to the overall timing budget of the LHCb real-time data processing.
The emission of radio waves from air showers has been attributed to the so-called geomagnetic emission process. At frequencies around 50 MHz this process leads to coherent radiation which can be ...observed with rather simple setups. The direction of the electric field induced by this emission process depends only on the local magnetic field vector and on the incoming direction of the air shower. We report on measurements of the electric field vector where, in addition to this geomagnetic component, another component has been observed that cannot be described by the geomagnetic emission process. The data provide strong evidence that the other electric field component is polarized radially with respect to the shower axis, in agreement with predictions made by Askaryan who described radio emission from particle showers due to a negative charge excess in the front of the shower. Our results are compared to calculations which include the radiation mechanism induced by this charge-excess process.
A
bstract
Associated production of bottomonia and open charm hadrons in pp collisions at
s
=
7
and 8 TeV is observed using data corresponding to an integrated luminosity of 3 fb
−1
accumulated with ...the LHCb detector. The observation of five combinations, Y(1S)D
0
, Y(2S)D
0
, Y(1S)D
+
, Y(2S)D
+
and Y(1S)D
s
+
, is reported. Production crosssections are measured for Y(1S)D
0
and Y(1S)D
+
pairs in the forward region. The measured cross-sections and the differential distributions indicate the dominance of double parton scattering as the main production mechanism.
Le test de génération de thrombine (TGT) évalue l’initiation, la propagation et l’inhibition de la coagulation. Ce test global permet d’évaluer le risque hémorragique chez les patients hémophiles, ...mais il peut aussi être utilisé pour étudier les états hypercoagulables. L’intérêt de ce test serait de dépister le risque cardiovasculaire, régulièrement associé aux maladies auto-immunes (MAI). Le syndrome des antiphospholipides (SAPL) a été étudié par cette technique pour prédire le risque thrombotique des patients. Dans les autres maladies auto-immunes sans évènement thrombotique, le TGT est retrouvé augmenté, principalement dans la polyarthrite rhumatoïde (PR), le lupus érythémateux systémique et la maladie de Behçet. Ces résultats dans la PR sont corrélés avec l’activité inflammatoire de la maladie. Dans le lupus érythémateux systémique et la maladie de Behçet, le TGT semble être le reflet de l’activité de la maladie. En conclusion, le TGT reste relativement peu utilisé dans l’évaluation clinique des MAI, mais son rôle futur dans le choix de certains traitements potentiellement thrombogènes pourrait devenir important. Enfin, le lien franc entre coagulation et inflammation, synonyme de maladie active, peut être appréhendé par l’utilisation du TGT avec encore certaines limites d’interprétation principalement liées à l’absence de standardisation.
Thrombin generation assay (TGA) is a useful tool to evaluate the initiation, propagation and inhibition of coagulation. TGA is a global test that is used to assess hemorrhagic risk in hemophilia patients, but it can also be used to study hypercoagulable states. The interest of TGA is to screen for cardiovascular risk, which is regularly associated with autoimmune disease (AID) such as antiphospholipid syndrome. Indeed, TGA has been used to evaluate hypercoagulability in patients with antiphospholipid syndrome treated with rivaroxaban versus warfarin. In other AIDs without thrombotic events, TGA measurement is elevated, mainly in rheumatoid arthritis (RA), systemic lupus erythematosus and Behçet's disease. These findings in RA are correlated with the inflammatory activity of the disease. In systemic lupus erythematosus and Behçet's disease, TGA appears to reflect disease activity. In conclusion, TGA remains relatively under used in the clinical evaluation of AID, but it could play a greater role in the evaluation of certain potentially thrombogenic treatments in AID. Finally, TGA helps measuring AID activity, due to the clearlink between coagulation and inflammation, despite some limitations of interpretation mainly due to a lack of standardization.
PDF
