On the sensitivity reach of LQ production with preferential couplings to third generation fermions at the LHC

Leptoquarks (LQs) are hypothetical particles that appear in various extensions of the Standard Model (SM) that can explain observed differences between SM theory predictions and experimental results. The production of these particles has been widely studied at various experiments, most recently at the Large Hadron Collider (LHC), and stringent bounds have been placed on their masses and couplings, assuming the simplest beyond-SM (BSM) hypotheses. However, the limits are significantly weaker for LQ models with family non-universal couplings containing enhanced couplings to third-generation fermions. We present a new study on the production of a LQ at the LHC, with preferential couplings to third-generation fermions, considering proton-proton collisions at $\sqrt{s} = 13$ $\mathrm{TeV}$ and $\sqrt{s} = 13.6$ $\mathrm{TeV}$. Such a hypothesis is well motivated theoretically and it can explain the recent anomalies in the precision measurements of $\mathrm{B}$-meson decay rates, specifically the $R_{D^{(*)}}$ ratios. Under a simplified model where the LQ masses and couplings are free parameters, we focus on cases where the LQ decays to a $\tau$ lepton and a $\mathrm{b}$ quark, and study how the results are affected by different assumptions about chiral currents and interference effects with other BSM processes with the same final states, such as diagrams with a heavy vector boson, $\mathrm{Z}^{'}$. The analysis is performed using machine learning techniques, resulting in an increased discovery reach at the LHC and allowing us to probe the entirety of the new physics phase space which addresses the $\mathrm{B}$-meson anomalies, for LQ masses up to 2.25 $\mathrm{TeV}$.Comment: 26 pages, 13 figure

Prótesis de pirocarbono en fracturas complejas de cabeza de radio.

Presentamos los resultados de un estudio observacional retrospectivo sobre 23 casos de fracturas complejas de cabeza de radio tratadas mediante la implantación de una prótesis cabeza radio de pircocarbono (Mo - Pyc). La distribución por sexos fue 10 hombres y 13 mujeres, y la edad media de 54 años. El seguimiento medio fue de 70 meses (48-93 meses). La principal causa fue una fractura de cabeza de radio no reconstruible con inestabilidad asociada de codo. La evaluación clínica se realizó con la Mayo Elbow Performance Score (MEPS). Radiográficamen - te se valoró la congruencia articular, el tamaño de la prótesis, la radiolucencia periprotésica, la osificación heterotópica y la osteoartritis. Al final del seguimiento la media de la escale MEPS fue 82/100, con 84 % resultados de excelentes y buenos. La flexión media fue de 130º, extensión -30º, pronación 76º y supinación 77º. La estabilidad del codo fue buena en todos los casos y no observamos migración proximal del radio. Observamos radiolucencia alrededor del vástago en 5 pacientes, pero sin aparente repercusión clínica. Las complicaciones fueron una paresia del nervio interóseo posterior con recuperación funcional al cabo de 11 semanas, 2 pacientes presentaron "overstuffing" con subluxación posterior asociada que necesitó realizar exéresis de la cabeza y una osificación heterotópica con repercu - sión sobre el balance articular que necesitó 2 cirugías, todos ellos con resultados clínicos aceptables. Los resultados son alentadores.The authors present the results of a retrospective observational study of 23 cases of a complex radial head fractures treated by pyrocarbon radial head prosthesis (MoPyc). This modular radial head prosthesis is compo - sed of a cementless titanium stem and a 15º angulated neck. The gender distribution was 10 men and 13 women, ave - rage age 54 years. The mean follow-up was 70 months (48-93 months). The main etiology was a radial head fracture with elbow instability. Clinical evaluation was performed using the Mayo Elbow Performance Score (MEPS). Was assessed radiographically joint congruity, the size of the prosthesis, periprosthetic radiolucency, heterotopic ossifica - tion and osteoarthritis. At follow-up, the MEPS average was 82/100, with 84% of good and excellent results. Elbow flexion averaged 130º, extension -30º, pronation 76º and supination 77º. Elbow stability was good in all the cases, and no proximal migration of the radius occurred. Asymptomatic bone lucencies were found in five cases around the stem. Complications included paresis of the posterior interosseous nerve with functional recovery after 11 weeks, 2 patients had "overstuffing" associated with posterior subluxation and they need to perform excision of the head and one heterotopic ossification with articular impact on balance that needs two surgeries, all of them with acceptable clinical results. The preliminary results are encouragin

Continent-wide analysis of how urbanization affects bird-window collision mortality in North America

Characteristics of buildings and land cover surrounding buildings influence the number of bird-window collisions, yet little is known about whether bird-window collisions are associated with urbanization at large spatial scales. We initiated a continent-wide study in North America to assess how bird-window collision mortality is influenced by building characteristics, landscaping around buildings, and regional urbanization. In autumn 2014, researchers at 40 sites (N = 281 buildings) used standardized protocols to document collision mortality of birds, evaluate building characteristics, and measure local land cover and regional urbanization. Overall, 324 bird carcasses were observed (range = 0–34 per site) representing 71 species. Consistent with previous studies, we found that building size had a strong positive effect on bird-window collision mortality, but the strength of the effect on mortality depended on regional urbanization. The positive relationship between collision mortality and building size was greatest at large buildings in regions of low urbanization, locally extensive lawns, and low-density structures. Collision mortality was consistently low for small buildings, regardless of large-scale urbanization. The mechanisms shaping broad-scale variation in collision mortality during seasonal migration may be related to habitat selection at a hierarchy of scales and behavioral divergence between urban and rural bird populations. These results suggest that collision prevention measures should be prioritized at large buildings in regions of low urbanization throughout North America

Memorias. Encuentro de Experiencias en Inventarios y Monitoreo Biológico

Las discusiones temáticas alrededor de la consolidación del Inventario Nacional de Biodiversidad para Colombia y la Red de Monitoreo de Biodiversidad como una estrategia de largo plazo, sin duda temas complejos que requerirán de grandes esfuerzos, coordinación y generosidad institucional y personal, los podrá apreciar el lector a lo largo del presente documento, esperando que pueda entender también la importancia que tienen los resultados y la agenda propuesta si en el futuro queremos tomar decisiones con bases científicas

Biodiversidad 2015. Estado y tendencias de la biodiversidad continental de Colombia

El propósito de este documento es fortalecer la capacidad de agentes públicos y privados para la aplicación de la PNGIBSE, que constituye en sí misma una apuesta de interfaz entre ciencia, política y sociedad en la perspectiva de construir sostenibilidad en el desarrollo. Además de ello, representa un insumo para el seguimiento a los compromisos del país frente a convenios e iniciativas internacionales (CDB, IPBES, OCDE), así como un mecanismo pedagógico para generar interés, conciencia y apropiación de las diferentes dimensiones de la biodiversidad del país.Bogotá, D. C., ColombiaInstituto de Investigación de Recursos Biológicos Alexander von Humboldtreporte.humboldt.org.coreporte.humboldt.org.co/biodiversidad/en

Multi-messenger Observations of a Binary Neutron Star Merger

International audienceOn 2017 August 17 a binary neutron star coalescence candidate (later designated GW170817) with merger time 12:41:04 UTC was observed through gravitational waves by the Advanced LIGO and Advanced Virgo detectors. The Fermi Gamma-ray Burst Monitor independently detected a gamma-ray burst (GRB 170817A) with a time delay of $\sim 1.7\,{\rm{s}}$ with respect to the merger time. From the gravitational-wave signal, the source was initially localized to a sky region of 31 deg(2) at a luminosity distance of ${40}_{-8}^{+8}$ Mpc and with component masses consistent with neutron stars. The component masses were later measured to be in the range 0.86 to 2.26 $\,{M}_{\odot }$. An extensive observing campaign was launched across the electromagnetic spectrum leading to the discovery of a bright optical transient (SSS17a, now with the IAU identification of AT 2017gfo) in NGC 4993 (at $\sim 40\,{\rm{Mpc}}$) less than 11 hours after the merger by the One-Meter, Two Hemisphere (1M2H) team using the 1 m Swope Telescope. The optical transient was independently detected by multiple teams within an hour. Subsequent observations targeted the object and its environment. Early ultraviolet observations revealed a blue transient that faded within 48 hours. Optical and infrared observations showed a redward evolution over ∼10 days. Following early non-detections, X-ray and radio emission were discovered at the transient’s position $\sim 9$ and $\sim 16$ days, respectively, after the merger. Both the X-ray and radio emission likely arise from a physical process that is distinct from the one that generates the UV/optical/near-infrared emission. No ultra-high-energy gamma-rays and no neutrino candidates consistent with the source were found in follow-up searches. These observations support the hypothesis that GW170817 was produced by the merger of two neutron stars in NGC 4993 followed by a short gamma-ray burst (GRB 170817A) and a kilonova/macronova powered by the radioactive decay of r-process nuclei synthesized in the ejecta