Multi-wavelength observations of the transitional millisecond pulsar binary XSSJ12270-4859

We present an analysis of X-ray, Ultraviolet and optical/near-IR photometric data of the transitional millisecond pulsar binary XSSJ12270-4859, obtained at different epochs after the transition to a rotation-powered radio pulsar state. The observations, while confirming the large-amplitude orbital modulation found in previous studies after the state change, also reveal an energy dependence of the amplitudes as well as variations on time scale of months. The amplitude variations are anti-correlated in the X-ray and the UV/optical bands. The average X-ray spectrum is described by a power law with \Gamma index of 1.07(8) without requiring an additional thermal component. The power law index \Gamma varies from 1.2 to 1.0 between superior and inferior conjunction of the neutron star. We interpret the observed X-ray behaviour in terms of synchrotron radiation emitted in an extended intrabinary shock, located between the pulsar and the donor star, which is eclipsed due to the companion orbital motion. The G5 type donor dominates the UV/optical and near-IR emission and is similarly found to be heated up to ? 6500K as in the disc state. The analysis of optical light curves gives a binary inclination 46 < i < 65deg and a mass ratio 0.11 < q <0.26. The donor mass is found to be 0.15 < M2 < 0.36Msun for a neutron star mass of 1.4Msun. The variations in the amplitude of the orbital modulation are interpreted in terms of small changes in the mass flow rate from the donor star. The spectral energy distribution from radio to gamma-rays is composed by multiple contributions that are different from those observed during the accretion-powered state.Comment: 10 pages, 8 figures, 1 table Accepted for publication in Monthly Notices Royal Astronomical Society, Main Journa

Highly oscillatory solutions of a Neumann problem for a pp-laplacian equation

We deal with a boundary value problem of the form $-\epsilon(\phi_p(\epsilon u'))'+a(x)W'(u)=0,\quad u'(0)=0=u'(1),$ where $\phi_p(s) = \vert s \vert^{p-2} s$ for $s \in \mathbb{R}$ and $p>1$, and $W:[-1,1] \to {\mathbb R}$ is a double-well potential. We study the limit profile of solutions when $\epsilon \to 0^+$ and, conversely, we prove the existence of nodal solutions associated with any admissible limit profile when $\epsilon$ is small enough

Observation of B⁰s - B⁻⁰s oscillations and the development and application of same-side-kaon flavor tagging

Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Physics, 2007.Includes bibliographical references (p. 201-209).The search for flavor oscillations in the neutral Bs - B meson system constitutes a flagship analysis of the Tevatron proton-anti-proton collider physics program and an important probe for effects due to new physics beyond the Standard Model of particles and interactions. In particular, the precise measurement of a process such as Boscillations sets a strong constraint on the parameters of quark-flavor mixing in the Standard Model. This dissertation reports the analysis which, for the first time, observed B- Bs oscillations, using data collected with the CDF detector. The sub-percent precision of the measurement is also noteworthy. The data sample used for this analysis includes fully and partially reconstructed Bdecays: ... The focus of this thesis is the algorithm of same-side-kaon tagging which provides _-0 a large fraction of the flavor-tagging power available to this analysis of B- B8 oscillations. Flavor tagging consists in assessing whether a B, meson is creates as a B_--0 or a B, state, and constitutes an important ingredient in the analysis presented in this document. The algorithm which is here described combines particle identification information and kinematic characteristics of the Bevent in an artificial neural network to provide improved tagging power E'2 of about 4.0 - 4.8%, depending on the data sample to which the algorithm is applied. The search for B1 oscillations is performed using an amplitude method based on a frequency scanning procedure. Applying a neural network-based combination of lepton, kaon and jet charge opposite-side tagging algorithms, with a total tagging power of ED2 = 1.8%, and the same-side-kaon tagging algorithm to a data sample of 1 fb-1, a signal of B- B_ oscillations with a significance greater than 5 standard deviations is found ...by Alberto Belloni.Ph.D

Is the plateau state in GRS 1915+105 equivalent to canonical hard states?

GRS1915+105 is a very peculiar black hole binary that exhibits accretion-related states that are not observed in any other stellar-mass black hole system. One of these states, however -- referred to as the plateau state -- may be related to the canonical hard state of black hole X-ray binaries. Both the plateau and hard state are associated with steady, relatively lower X-ray emission and flat/inverted radio emission, that is sometimes resolved into compact, self-absorbed jets. However, while generally black hole binaries quench their jets when the luminosity becomes too high, GRS1915+105 seems to sustain them despite the fact that it accretes at near- or super-Eddington rates. In order to investigate the relationship between the plateau and the hard state, we fit two multi-wavelength observations using a steady-state outflow-dominated model, developed for hard state black hole binaries. The data sets consist of quasi-simultaneous observations in radio, near-infrared and X-ray bands. Interestingly, we find both significant differences between the two plateau states, as well as between the best-fit model parameters and those representative of the hard state. We discuss our interpretation of these results, and the possible implications for GRS 1915+105's relationship to canonical black hole candidates.Comment: accepted for publication in MNRA

Enfoque metodológico dirigido por modelos para desarrollos de Internet/Web de las cosas

Se presenta un proyecto de investigación y desarrollo que tiene por objetivo general el de elaborar un enfoque metodológico dirigido por modelos para soportar la generación (semi)automática de aplicaciones en el dominio de Internet/Web de las Cosas.Eje: Ingeniería de Software.Red de Universidades con Carreras en Informátic

Herramienta de calendarización para proyectos desarrollados utilizando XP

En este trabajo se presenta un proyecto de investigación denominado “Simulación como Herramienta para la Mejora de los Procesos de Software Desarrollados con Metodologías Ágiles Utilizando Dinámica de Sistemas”, cuyo objetivo es construir modelos de simulación utilizando la disciplina de dinámica de sistemas y técnicas alternativas, que permitan dar soporte a la gestión de los procesos de desarrollo de software ágiles llevados a cabo utilizando diversas metodologías y prácticas ágiles. Particularmente se presentan los avances realizados hasta ahora en relación a construcción de una herramienta de calendarización para proyectos que utilizan la metodología Extreme Programming (XP).Eje: Ingeniería de Software.Red de Universidades con Carreras en Informática (RedUNCI

Comparing dextrose prolotherapy with other substances in knee osteoarthritis pain relief: A systematic review

The objective of this study is to compare the effectiveness of dextrose-prolotherapy with other substances for pain relief in patients with primary knee osteoarthritis. The literature screening was done in January 2021 through Medline (PubMed), EMBASE, and Database of the National Institute of Health based on the following criteria: randomized clinical trials that subjected patients with primary knee osteoarthritis who underwent treatment with dextrose-prolotherapy and other substances for pain relief. Paired reviewers independently identified 3381 articles and included 8 trials that met the eligibility criteria. According to the findings of this review, participants that underwent dextrose-prolotherapy showed improvements between baseline and posterior assessments and when compared to saline injections, but when compared to other substances, the results were not clear. Although dextrose-prolotherapy is a useful treatment method by itself, it is still not possible to clearly affirm that it is superior or inferior to its counterparts. There is an urgent need for further studies to bring more evidence to the field

Increased expression of interleukin-22 in patients with giant cell arteritis

GCA is characterized by arterial remodelling driven by inflammation. IL-22 is an attractive cytokine which acts at the crosstalk between immune and stromal cells. We hypothesized that IL-22 might be induced in GCA and might be involved in disease pathogenesis

Modelo de simulación dinámico de proyectos de desarrollo de software con scrum

En este trabajo se sintetizan los avances de una línea de investigación, la cual tiene definido por objetivo esencial: la construcción y mejora continua de un modelo de simulación dinámico que de soporte a la metodología de gestión de proyectos desarrollados con Scrum. Concretamente, se describen los subsistemas que componen actualmente el modelo propuesto y construido para simular los componentes esenciales de la gestión de un proyecto desarrollado con Scrum, así como también, se referencian los experimentos realizados con el modelo. El modelo construido resulta de utilidad para administradores de proyectos considerados novatos en la aplicación de la metodología referida, permitiéndoles conocer de antemano las consecuencias de sus decisiones. Adicionalmente, se presentan nuevos objetivos y trabajos futuros para la línea.Eje: Ingeniería de SoftwareRed de Universidades con Carreras en Informática (RedUNCI