72 research outputs found

    Deep brain stimulation for obsessive-compulsive disorder: A systematic review of randomised controlled clinical trials.

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    38 p.Introducción: Existe un porcentaje de pacientes diagnosticados de trastorno obsesivo compulsivo (TOC) refractarios al tratamiento psicofarmacológico. La estimulación cerebral profunda (ECP) se presenta como una técnica neuroquirúrgica para este grupo de pacientes como alternativa a la neurocirugía no reversible. El objetivo de este artículo consiste en la revisión sistemática de la evidencia científica en la eficacia y aplicabilidad de esta técnica en los pacientes con TOC resistente. Métodos: Se ha realizado una búsqueda de bibliografía en las bases de datos PubMed/MedLine, PsycInfo, Scielo y Scopus con los términos *Deep brain stimulation* OR *DBS* AND *obsessive compulsive disorder * OR *OCD*, para identificar y, en su caso, seleccionar el metanálisis más reciente que recoja la evidencia publicada hasta el momento: Alonso et al. (PloS One. 2015, Jul 24; 10 (7))1 .Partiendo de él, se ha realizado una revisión sistemática de la literatura en las bases de datos PubMed/MedLine, PsycInfo, Scielo y Scopus con los términos utilizados en la búsqueda previa, pero esta vez de ensayos clínicos aleatorizados publicados a partir del metanálisis seleccionado. Resultados: El análisis señala la eficacia de la ECP para tratamiento del TOC refractario, aunque con determinados efectos adversos. Sin embargo, aún no se ha establecido una diana cerebral ideal para la ECP, abriendo las puertas al inicio de la individualización de la diana en cada paciente. Conclusiones: La mayoría de estudios publicados señalan una mejoría significativa de los síntomas y la calidad de vida con la ECP. Es necesario realizar más estudios aleatorizados y controlados para comprobar su efectividad a largo plazoIntroduction: There is a percentage of patients diagnosed with obsessive compulsive disorder (OCD) refractory to psychopharmacological treatment. Deep brain stimulation (DBS) is presented as a neurosurgical technique for this group of patients as an alternative to non-reversible neurosurgery. The objective of this article is the systematic review of the scientific evidence on the efficacy and applicability of this technique in patients with resistant OCD. Methods: A systematic and retrospective review of the literature has been performed in the PubMed / MedLine databases with the terms * Deep brain stimulation * OR * DBS * AND * obsessive compulsive disorder * OR * OCD *, selecting the most recent meta analysis that collect the summary of clinical trials and evidence published so far: Alonso et al. 1 Based on this, another systematic review of the literature has been performed in the PubMed / MedLine, PsycInfo, Scielo and Scopus databases with the terms used in the previous search, but this time searching randomized clinical trials published sfter the selected meta-analysis was published. Results: The analysis indicates the efficacy of ECP for the treatment of refractory OCD, although with certain adverse effects. However, an ideal brain target for ECP has not yet been established, opening the doors to the start of target individualization in each patient. Conclusions: Most published studies indicate a significant improvement in symptoms and quality of life with DBS. Further randomized controlled trials are needed to verify its long-term effectivenessGrado en Medicin

    Fundamentos de Control Automático de Sistemas Continuos y Muestreados

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    La Ingeniería de Control versa sobre el diseño de leyes matemáticas que gobiernen sistemas físicos conforme a una serie de especificaciones. Esta disciplina es, por tanto, esencial para la automatización de sistemas o procesos industriales. Este manual presenta, en un primer gran bloque, los métodos tradicionales de análisis y diseño de controladores de sistemas continuos (o analógicos). La segunda parte describe las mismas herramientas para sistemas muestreados (o digitales)

    A very massive spectroscopic binary in the LH 54 OB association in the LMC

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    We announce the discovery of a new early-type, double-lined spectroscopic binary in the LH 54 OB association in the LMC. We present a V light curve and radial velocities. We investigate the possible configurations of the system, concluding that it probably contains the most massive star measured at the present, with a mass (in solar units) of the order of 100, while its companion has approximately 50.Comment: 7 pages, 5 figures. MNRAS, accepte

    BD+36 3317: An algol type eclipsing binary in Delta Lyrae cluster

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    In this paper, we present standard Johnson UBV photometry of the eclipsing binary BD+36 3317 which is known as a member of Delta Lyrae (Stephenson 1) cluster. We determined colors and brightness of the system, calculated E(B - V) color excess. We discovered that the system shows total eclipse in secondary minimum. Using this advantage, we found that the primary component of the system has B9 - A0 spectral type. Although there is no published orbital solution, we tried to estimate the physical properties of the system from simultaneous analysis of UBV light curves with 2003 version of Wilson-Devinney code. Then we considered photometric solution results together with evolutionary models and estimated the masses of the components as M1 = 2.5 Msun and M2 = 1.6 Msun. Those estimations gave the distance of the system as 353 pc. Considering the uncertainties in distance estimation, resulting distance is in agreement with the distance of Delta Lyrae cluster.Comment: 18 pages, 4 figures, 5 table

    On stellar limb darkening and exoplanetary transits

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    This paper examines how to compare stellar limb-darkening coefficients evaluated from model atmospheres with those derived from photometry. Different characterizations of a given model atmosphere can give quite different numerical results (even for a given limb-darkening `law'), while light-curve analyses yield limb-darkening coefficients that are dependent on system geometry, and that are not directly comparable to any model-atmosphere representation. These issues are examined in the context of exoplanetary transits, which offer significant advantages over traditional binary-star eclipsing systems in the study of stellar limb darkening. `Like for like' comparisons between light-curve analyses and new model-atmosphere results, mediated by synthetic photometry, are conducted for a small sample of stars. Agreement between the resulting synthetic-photometry/atmosphere-model (SPAM) limb-darkening coefficients and empirical values ranges from very good to quite poor, even though the targets investigated show only a small dispersion in fundamental stellar parameters.Comment: Accepted, MNRAS, 4/8/201

    Mode identification for Balloon 090100001 using combined multicolour photometry and spectroscopy

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    In this paper, we show that method of mode identification using combined multicolour photometry and spectroscopy can be successfully applied to the pulsating subdwarf B star Balloon 090100001. The method constrains the spherical degree, l.We confirm that the dominant mode is radial and we show that for some other modes the method provides values of l consistent with the observed rotationally split triplet. Moreover, we derive a radius variation of 1.7 per cent for the dominant mode. The identification opens the possibility for constraining the internal structure of the star by means of seismic methods.Comment: MNRAS, in press, already at the online-early stag

    A photometric and spectroscopic study of NSVS 14256825: the second sdOB+dM eclipsing binary

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    We present an analysis of UBVRC_{\rm C}IC_{\rm C}JH photometry and phase-resolved optical spectroscopy of NSVS 14256825, an HW Vir type binary. The members of this class consist of a hot subdwarf and a main-sequence low-mass star in a close orbit (Porb 0.1P_{\rm orb} ~ 0.1 d). Using the primary-eclipse timings, we refine the ephemeris for the system, which has an orbital period of 0.11037 d. From the spectroscopic data analysis, we derive the effective temperature, T1=40000±500T_1 = 40000 \pm 500 K, the surface gravity, logg1=5.50±0.05\log g_1 = 5.50\pm0.05, and the helium abundance, n(He)/n(H)=0.003±0.001n(\rm He)/n(\rm H)=0.003\pm0.001, for the hot component. Simultaneously modelling the photometric and spectroscopic data using the Wilson-Devinney code, we obtain the geometrical and physical parameters of NSVS 14256825. Using the fitted orbital inclination and mass ratio (i = 82\fdg5\pm0\fdg3 and q=M2/M1=0.260±0.012q = M_2/M_1 = 0.260\pm0.012, respectively), the components of the system have M1=0.419±0.070MM_1 = 0.419 \pm 0.070 M_{\odot}, R1=0.188±0.010RR_1 = 0.188 \pm 0.010 R_{\odot}, M2=0.109±0.023MM_2 = 0.109 \pm 0.023 M_{\odot}, and R2=0.162±0.008RR_2 = 0.162 \pm 0.008 R_{\odot}. From its spectral characteristics, the hot star is classified as an sdOB star.Comment: 8 pages, 7 figures, accepted for publication in MNRA

    An Independent Analysis of Kepler-4b through Kepler-8b

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    We present two independent, homogeneous, global analyses of the transit light curves, radial velocities and spectroscopy of Kepler-4b through Kepler-8b, with numerous differences over the previous methods. These include: 1) improved decorrelated parameter fitting set, 2) new limb darkening coefficients, 3) time-stamps modified to BJD for consistency with RV, 4) two different methods for compensating for the integration-time of Kepler LC-data, 5) best-fit secondary-eclipse depths and excluded upper limits, 6) fitted mid-transit times, durations, depths and baseline fluxes for individual transits. We make several new determinations: 1) We detect a secondary eclipse for Kepler-7b of depth (47+/-14)ppm and significance 3.5-sigma. We conclude reflected light is a more plausible origin than thermal emission and determine a geometric albedo of Ag=(0.38+/-0.12). 2) An eccentric-orbit model for the Neptune-mass planet Kepler-4b is marginally detected to 2-sigma confidence with e=(0.25+/-0.12). If confirmed, this would place Kepler-4b in a similar category as GJ436b and HAT-P-11b as an eccentric, Neptune-mass planet. 3) We find marginal (2-sigma) evidence for Kepler-5b's secondary eclipse of depth (26+/-17)ppm. The most plausible explanation is reflected light caused by a planet with Ag=(0.15+/-0.10). 4) A 2.6-sigma peak in Kepler-6b TTV periodogram is detected and is not easily explained as an aliased frequency. We find that a resonant/non-resonant perturber, Trojan or exomoon all provide inadequate explanations and the most likely source is stellar rotation. 5) We find different impact parameters relative to the discovery papers in most cases, but generally self-consistent. 6) We constrain the presence of resonant planets, exomoons and Trojans using transit timing.Comment: Revised version accepted for publication in ApJ. 34 pages, 26 figures, 12 table

    Spectroscopic and Photometric Study of the Contact Binary BO CVn

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    We present the results of the study of the contact binary system BO CVn. We have obtained physical parameters of the components based on combined analysis of new, multi-color light curves and spectroscopic mass ratio. This is the first time the latter has been determined for this object. We derived the contact configuration for the system with a very high filling factor of about 88 percent. We were able to reproduce the observed light curve, namely the flat bottom of the secondary minimum, only if a third light has been added into the list of free parameters. The resulting third light contribution is significant, about 20-24 percent, while the absolute parameters of components are: M1=1.16, M2=0.39, R1=1.62 and R2=1.00 (in solar units). The O-C diagram shows an upward parabola which, under the conservative mass transfer assumption, would correspond to a mass transfer rate of dM/dt = 6.3 \times 10-8M\odot/yr, matter being transferred from the less massive component to the more massive one. No cyclic, short-period variations have been found in the O-C diagram (but longer-term variations remain a possibility)Comment: 16 pages, 5 figures, 5 tables, accepted for publication by New Astronom

    Multiperiodicity in the newly discovered mid-late Be star V2104 Cygni

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    We obtained the first long, homogenous time-series of V2104Cyg, consisting of 679 datapoints, with the uvbybeta photometers of Sierra Nevada and San Pedro Martir Observatories with the aim to detect and subsequently interpret the intrinsic frequencies of this previously unstudied variable star, which turned out to be a Be star. We try to figure out its place among the variable B stars on the upper Main Sequence. In order to obtain additional information on physical parameters we collected a few spectra with the ELODIE and FIES instruments. We searched for frequencies in the uvby passbands using 2 different frequency analysis methods and used the S/N>4 criterion to select the significant periodicities. We obtained an estimate of the physical parameters of the underlying B star of spectral type between B5 and B7, by correcting for the presence of a circumstellar disk, using a formalism based on the strenght of the Halpha line emission. We detected 3 independent frequencies with amplitudes below 0.01mag, f1 = 4.7126 c/d, f2 = 2.2342 c/d and f3 = 4.671 c/d, and discovered that V2104Cyg is a Be star. The fast rotation (vsini=290+/-10 km/s, and 27<i<45) hampered the investigation of the associated pulsational parameters l. Nevertheless, the most plausible explanation for the observed variability of this mid-late type Be star is a non-radial pulsation model. This paper is based on observations obtained at the Observatorio Astronomico Nacional San Pedro Martir (Mexico), Observatorio de Sierra Nevada (Spain), Observatoire de Haute Provence (France), and on observations made with the Nordic Optical Telescope, Observatorio Roque de los Muchachos, La Palma, Spain.Comment: 7 pages, 4 figures, A&A accepte
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