Direct measurement of the top-quark width with the ATLAS experiment

In this thesis a measurement of the total decay width of the top quark, Г$_{top}$ is presented using selected semi-leptonic ${t¯t}$ event candidates, recorded from protonproton collisions at a centre-of-mass energy of $\sqrt{s}$ = 8 TeV with the ATLAS experiment at CERN in Geneva, Switzerland. The total recorded integrated luminosity that was used for this measurement equals to $\int$Ldt = 20.3 fb$^{−1}$. The analysis includes the two event channels: $e$ + jets and $μ$ + jets. The reconstruction of the ${t¯t}$ system is achieved by using a per-event $X$2 minimisation technique. Official Monte Carlo samples have been used to simulate the t¯t signal and background contributions in order to perform simulated experiments to obtain the statistical and systematic uncertainties. The results obtained from the measurement of the top parameter are: Г$_{top}$ = 1.65 GeV for the $μ$ + jets channel and Г$_{top}$ = 0.81 GeV for the $e$ + jets channel. The upper limits obtained from the measured values and the analysis total uncertainties are: Г$_{top}$ < 4.60 GeV at 68 % C.L. and Г$_{top}$ < 7.16 GeV at 95 % C.L. for the $μ$ + jets channel, and Г$_{top}$ < 4.40 GeV at 68 % C.L. and Г$_{top}$ < 7.51 GeV at 95 % C.L. for the $e$ + jets channel. These results are consistent with the expected SM value Г$_{top}$ ≈ 1.33 GeV

Los sistemas de clasificación profesional y la valoración de puestos de trabajo

Concisa y certera exposición acerca de la transición acaecida en los sistemas de clasificación profesional, de los modelos basados en las «categorías» a los asentados en los «grupos», y sobre la relación existente entre estos sistemas y la valoración de puestos de trabajo. El autor consigue conjugar con acierto puntuales referencias de tal modo que dejen de ser meros fragmentos aislados

Enhanced Fluoride Over-Coated Al Mirrors for FUV Astronomy

Astronomical observations in the Far Ultraviolet (FUV) spectral region are some of the more challenging due to the very distant and faint objects that are typically searched for in cosmic origin studies such as origin of large scale structure, the formation, evolution, and age of galaxies and the origin of stellar and planetary systems. These challenges are driving the need to improve the performance of optical coatings over a wide spectral range that would increase reflectance in mirrors and reduced absorption in dielectric filters used in optical telescope for FUV observations. This paper will present recent advances in reflectance performance for Al+MgF2 mirrors optimized for Lyman-alpha wavelength by performing the deposition of the MgF2 overcoat at elevated substrate temperatures. We will also present optical characterization of little studied rare-earth fluorides such as GdF3 and LuF3 that exhibit low-absorption over a wide wavelength range and could therefore be used as high refractive index alternatives for dielectric coatings at FUV wavelengths

Post-funcionalización de polianilina con grupos precursores de la función vinilsulfona

Resumen de la comunicación presentada en la XXXI Reunión Bienal de la RSEQ, Toledo, 9-14 septiembre 2007En este trabajo se describe la obtención de polianilina modificada con grupos precursores de la función vinilsulfónica, bien conocida por su reactividad específica a fibras celulósicas (algodón, lino...) y proteicas (lana, seda...). Las cadenas modificadas se obtuvieron mediante un procedimiento de post-funcionalización mediante la reacción de acoplamiento con sales de diazonio, que ha demostrado ser una ruta útil y versátil de incorporación de grupos funcionales en polímeros conductores.Generalitat Valenciana (proyecto GV06-106) Ministerio de Educación y Ciencia (proyecto MAT2004-01479

Novedades corológicas para la flora de la provincia de Córdoba

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Nonlinear Optical Response of a Plasmonic Nanoantenna to Circularly Polarized Light: Rotation of Multipolar Charge Density and Near-Field Spin Angular Momentum Inversion

The spin and orbital angular momentum carried by electromagnetic pulses open new perspectives to control nonlinear processes in light–matter interactions, with a wealth of potential applications. In this work, we use time-dependent density functional theory (TDDFT) to study the nonlinear optical response of a free-electron plasmonic nanowire to an intense, circularly polarized electromagnetic pulse. In contrast to the well-studied case of the linear polarization, we find that the nth harmonic optical response to circularly polarized light is determined by the multipole moment of order n of the induced nonlinear charge density that rotates around the nanowire axis at the fundamental frequency. As a consequence, the frequency conversion in the far field is suppressed, whereas electric near fields at all harmonic frequencies are induced in the proximity of the nanowire surface. These near fields are circularly polarized with handedness opposite to that of the incident pulse, thus producing an inversion of the spin angular momentum. An analytical approach based on general symmetry constraints nicely explains our numerical findings and allows for generalization of the TDDFT results. This work thus offers new insights into nonlinear optical processes in nanoscale plasmonic nanostructures that allow for the manipulation of the angular momentum of light at harmonic frequencies.We acknowledge financial support from project IT1526–22 of the Department of Education of the Basque Government, and projects PID2019–107432GB-I00 and PID2022–139579NB-I00, funded by MCIN/AEI/10.13039/501100011033 and “FEDER Una manera de hacer Europa”

Impact of COVID-19 pandemic in surgical training of Junior Residents in general surgery

Background: The pandemic caused by SARS-CoV2 has had a huge impact on our health system. Due to both cancellation of elective surgery and restructuring in departments at most medical centers, surgical residents face a potential training deficit in their specialty. This study aims to objectively analyze and quantify the impact of the pandemic on the surgical activity of residents, in the setting of emergency and elective surgery, to assess whether this period has really supposed a training deficit. Material and methods: A descriptive analysis is proposed, comparing the number of procedures performed by residents of our department during the year prior to the pandemic and during the pandemic, clustering them into different subgroups. Results: The results give an optimistic outlook. In the first place, in elective surgery, despite the lower procedures performed in absolute numbers, the proportional participation of residents in the scheduled surgeries increased in all the subgroups analyzed, finding statistically significant differences and finally approaching the total number of procedures in both periods, without relevant differences in the comparison. As for emergency surgery, residents also increased their proportional participation in most subgroups, in this case reaching more total procedures, even in absolute numbers. Conclusion: Therefore, the results seem to indicate that the teaching effort made by staff surgeons of the department has managed to palliate, in most of the subgroups analyzed, the decrease in surgical activity that the pandemic has produced, so, at least in the area of surgical practice, the impact of the pandemic has probably been reduced comparing to previous expectations

Twelve tips to make successful medical infographics

In the health sciences, professionals must keep up to date to conduct their evidence-based practise. Hence, there is a growing need to share medical knowledge efficiently among healthcare professionals, patients, and undergraduate health science students. Infographics (text and image) are a hybrid element that serves to represent information in an attractive and meaningful visual format. Actually, with the use of the Internet and social networks, infographics have become a popular format for sharing medical information around the world. On the basis of a published literature review, we provide 12 tips in this article to make a successfully health-related infographic with the aim of assisting clinicians, educators, and researchers in their task of communicating and transforming complex information into a visual, attractive, didactic and shareable format. By following these basic recommendations, it is possible to improve the dissemination of scientific and health-related knowledge to different audiences who can benefit from infographics