84 research outputs found
Broad-band X-ray spectral evolution of GX 339-4 during a state transition
We report on X-ray and soft gamma-ray observations of the black-hole
candidate GX 339-4 during its 2007 outburst, performed with the RXTE and
INTEGRAL satellites. The hardness-intensity diagram of all RXTE/PCA data
combined shows a q-shaped track similar to that observed in previous
outbursts.The evolution in the diagram suggested that a transition from
hard-intermediate state to soft-intermediate state occurred, simultaneously
with INTEGRAL observations performed in March. The transition is confirmed by
the timing analysis presented in this work, which reveals that a weak type-A
quasi-periodic oscillation (QPO) replaces a strong type-C QPO. At the same
time, spectral analysis shows that the flux of the high-energy component shows
a significant decrease in its flux. However, we observe a delay (roughly one
day) between variations of the spectral parameters of the high-energy component
and changes in the flux and timing properties. The changes in the high-energy
component can be explained either in terms the high-energy cut-off or in terms
of a variations in the reflection component. We compare our results with those
from a similar transition during the 2004 outburst of GX 339-4.Comment: 8 pages, 6 figures, accepted for publication in MNRAS Main Journa
Nivel sérico de la Beta 2- microglobulina en pacientes con tuberculosis pulmonar activa
Introducción: La tuberculosis pulmonar es una enfermedad inflamatoria crónica del pulmón y esendémica en Paraguay. Niveles elevados de beta-2 microglobulina (b2-m) son utilizados comomarcadores de pronóstico en patologías como la leucemia linfocítica crónica, linfomas, mieloma múltiple,osteoartritis, artritis, enfermedades renales y SIDA, pero su utilidad en la tuberculosis aún necesita deevaluaciones. Objetivo: Evaluar si el nivel de b2-m permitiría determinar el grado de actividad de lainfección sirviendo como marcador de evolución y seguimiento terapéutico de la tuberculosis pulmonar.Metodología: La primera parte fue un estudio descriptivo, de muestreo consecutivo y la segunda unestudio de cohorte, prospectivo. Se determinó el nivel sérico de b2-m por el método de ELISA en 22pacientes con TBC pulmonar activa antes de iniciar el tratamiento y después de 6 meses. Además sedeterminó el nivel sérico de b2-m en 22 individuos aparentemente sanos como controles. Resultados: Seobservó una disminución estadísticamente significativa de los niveles séricos de ß2-m en los 22 pacientesdespués de los 6 meses de tratamiento con respecto a los niveles anteriores al tratamiento (2,2 ± 1,0 vs 4,3± 2,7 μg/mL, p<0,0001). Sin embargo, la disminución de los valores de ß2-m en los 22 pacientes tratadosno descendieron a los niveles de los 22 controles normales (0,98 ± 0,22 μg/mL, p<0,0000001). En el 23% (n=5) de los pacientes con TBC los niveles disminuyeron hasta llegar por debajo del punto de corte alos 6 meses después del tratamiento. Conclusiones: Todos los pacientes con TBC presentaron nivelesaumentados de ß2-m antes del tratamiento y en todos ellos se observó una disminución después deltratamiento, aún sin llegar al valor de los controles. Un seguimiento posterior de por lo menos un añopostratamiento nos permitiría determinar si el nivel de ß2-m podría ser utilizado como un marcador de laactividad de la infección e indirectamente un marcador de eficacia del tratamiento
States and transitions in black-hole binaries
With the availability of the large database of black-hole transients from the
Rossi X-Ray Timing Explorer, the observed phenomenology has become very
complex. The original classification of the properties of these systems in a
series of static states sorted by mass accretion rate proved not to be able to
encompass the new picture. I outline here a summary of the current situation
and show that a coherent picture emerges when simple properties such as X-ray
spectral hardness and fractional variability are considered. In particular,
fast transition in the properties of the fast time variability appear to be
crucial to describe the evolution of black-hole transients. Based on this
picture, I present a state-classification which takes into account the observed
transitions. I show that, in addition to transients systems, other black-hole
binaries and Active Galactic Nuclei can be interpreted within this framework.
The association between these states and the physics of the accretion flow
around black holes will be possible only through modeling of the full time
evolution of galactic transient systems.Comment: 30 pages, 11 figures, To appear in Belloni, T. (ed.): The Jet
Paradigm - From Microquasars to Quasars, Lect. Notes Phys. 794 (2009
Organogenesis relies on SoxC transcription factors for the survival of neural and mesenchymal progenitors
During organogenesis, neural and mesenchymal progenitor cells give rise to many cell lineages, but their molecular requirements for self-renewal and lineage decisions are incompletely understood. In this study, we show that their survival critically relies on the redundantly acting SoxC transcription factors Sox4, Sox11 and Sox12. The more SoxC alleles that are deleted in mouse embryos, the more severe and widespread organ hypoplasia is. SoxC triple-null embryos die at midgestation unturned and tiny, with normal patterning and lineage specification, but with massively dying neural and mesenchymal progenitor cells. Specific inactivation of SoxC genes in neural and mesenchymal cells leads to selective apoptosis of these cells, suggesting SoxC cell-autonomous roles. Tead2 functionally interacts with SoxC genes in embryonic development, and is a direct target of SoxC proteins. SoxC genes therefore ensure neural and mesenchymal progenitor cell survival, and function in part by activating this transcriptional mediator of the Hippo signalling pathway
Guía de práctica clínica para el diagnóstico y tratamiento de la distrofia muscular de Duchenne. Sociedad Peruana de Neurología. Versión Corta
Objetivo: Elaborar una guía de práctica clínica peruana para el diagnóstico y tratamiento de la Distrofia Muscular de Duchenne y Becker (DMD). Materiales y métodos: Se conformó un grupo elaborador de la guía (GEG) que incluyó médicos especialistas en neurología, neuropediatría, genética y metodología. El GEG formuló ocho preguntas para desarrollar las recomendaciones de la Guía de Práctica Clínica (GPC). Se realizó una búsqueda sistemática en Medline, Scopus y CCRT durante el periodo enero-abril 2021 para responder a las preguntas PICO. La certeza de la evidencia fue evaluada usando la metodología Grading of Recommendations Assessment, Development, and Evaluation (GRADE). Resultados: Las preguntas PICO, se orientaron para explorar el tamizaje, diagnóstico y tratamiento de la DMD. Se formularon 15 recomendaciones (10 fuertes, 5 condicionales) y 11 puntos de buena práctica clínica Conclusión: Se presenta la guía para el diagnóstico y tratamiento de la DMD, elaborada bajo una metodología basada en las evidencias actuales.
Study protocol for a pragmatic randomised controlled trial in general practice investigating the effectiveness of acupuncture against migraine
<p>Abstract</p> <p>Background</p> <p>Migraine is a chronic neurologic disease that can severely affect the patient's quality of life. Although in recent years many randomised studies have been carried out to investigate the effectiveness of acupuncture as a treatment for migraine, it remains a controversial issue. Our aim is to determine whether acupuncture, applied under real conditions of clinical practice in the area of primary healthcare, is more effective than conventional treatment.</p> <p>Methods/Design</p> <p>The design consists of a pragmatic multi-centre, three-armed randomised controlled trial, complemented with an economic evaluation of the results achieved, comparing the effectiveness of verum acupuncture with sham acupuncture, and with a control group receiving normal care only.</p> <p>Patients eligible for inclusion will be those presenting in general practice with migraine and for whom their General Practitioner (GP) is considering referral for acupuncture. Sampling will be by consecutive selection, and by randomised allocation to the three branches of the study, in a centralised way following a 1:1:1 distribution (verum acupuncture; sham acupuncture; conventional treatment). Secondly, one patient in three will be randomly selected from each of the acupuncture (verum or sham) groups for a brain perfusion study (by single photon emission tomography). The treatment with verum acupuncture will consist of 8 treatment sessions, once a week, at points selected individually by the acupuncturist. The sham acupuncture group will receive 8 sessions, one per week, with treatment being applied at non-acupuncture points in the dorsal and lumbar regions, using the minimal puncture technique. The control group will be given conventional treatment, as will the other two groups.</p> <p>Discussion</p> <p>This trial will contribute to available evidence on acupuncture for the treatment of migraine. The primary endpoint is the difference in the number of days with migraine among the three groups, between the baseline period (the 4 weeks prior to the start of treatment) and the period from weeks 9 to 12. As a secondary aspect, we shall record the index of laterality and the percentage of change in the mean count per pixel in each region of interest measured by the brain perfusion tomography, performed on a subsample of the patients within the real and sham acupuncture groups.</p> <p>Trial registration</p> <p>Current Controlled Trials ISRCTN98703707.</p
Cultural significance of wild mammals in mayan and mestizo communities of the Lacandon Rainforest, Chiapas, Mexico
Role of age and comorbidities in mortality of patients with infective endocarditis
Purpose: The aim of this study was to analyse the characteristics of patients with IE in three groups of age and to assess the ability of age and the Charlson Comorbidity Index (CCI) to predict mortality.
Methods: Prospective cohort study of all patients with IE included in the GAMES Spanish database between 2008 and 2015. Patients were stratified into three age groups:<65 years, 65 to 80 years, and = 80 years.The area under the receiver-operating characteristic (AUROC) curve was calculated to quantify the diagnostic accuracy of the CCI to predict mortality risk.
Results: A total of 3120 patients with IE (1327 < 65 years;1291 65-80 years;502 = 80 years) were enrolled.Fever and heart failure were the most common presentations of IE, with no differences among age groups.Patients =80 years who underwent surgery were significantly lower compared with other age groups (14.3%, 65 years; 20.5%, 65-79 years; 31.3%, =80 years). In-hospital mortality was lower in the <65-year group (20.3%, <65 years;30.1%, 65-79 years;34.7%, =80 years;p < 0.001) as well as 1-year mortality (3.2%, <65 years; 5.5%, 65-80 years;7.6%, =80 years; p = 0.003).Independent predictors of mortality were age = 80 years (hazard ratio [HR]:2.78;95% confidence interval [CI]:2.32–3.34), CCI = 3 (HR:1.62; 95% CI:1.39–1.88), and non-performed surgery (HR:1.64;95% CI:11.16–1.58).When the three age groups were compared, the AUROC curve for CCI was significantly larger for patients aged <65 years(p < 0.001) for both in-hospital and 1-year mortality.
Conclusion: There were no differences in the clinical presentation of IE between the groups. Age = 80 years, high comorbidity (measured by CCI), and non-performance of surgery were independent predictors of mortality in patients with IE.CCI could help to identify those patients with IE and surgical indication who present a lower risk of in-hospital and 1-year mortality after surgery, especially in the <65-year group
CIBERER : Spanish national network for research on rare diseases: A highly productive collaborative initiative
Altres ajuts: Instituto de Salud Carlos III (ISCIII); Ministerio de Ciencia e Innovación.CIBER (Center for Biomedical Network Research; Centro de Investigación Biomédica En Red) is a public national consortium created in 2006 under the umbrella of the Spanish National Institute of Health Carlos III (ISCIII). This innovative research structure comprises 11 different specific areas dedicated to the main public health priorities in the National Health System. CIBERER, the thematic area of CIBER focused on rare diseases (RDs) currently consists of 75 research groups belonging to universities, research centers, and hospitals of the entire country. CIBERER's mission is to be a center prioritizing and favoring collaboration and cooperation between biomedical and clinical research groups, with special emphasis on the aspects of genetic, molecular, biochemical, and cellular research of RDs. This research is the basis for providing new tools for the diagnosis and therapy of low-prevalence diseases, in line with the International Rare Diseases Research Consortium (IRDiRC) objectives, thus favoring translational research between the scientific environment of the laboratory and the clinical setting of health centers. In this article, we intend to review CIBERER's 15-year journey and summarize the main results obtained in terms of internationalization, scientific production, contributions toward the discovery of new therapies and novel genes associated to diseases, cooperation with patients' associations and many other topics related to RD research
The wide-field, multiplexed, spectroscopic facility WEAVE: Survey design, overview, and simulated implementation
WEAVE, the new wide-field, massively multiplexed spectroscopic survey
facility for the William Herschel Telescope, will see first light in late 2022.
WEAVE comprises a new 2-degree field-of-view prime-focus corrector system, a
nearly 1000-multiplex fibre positioner, 20 individually deployable 'mini'
integral field units (IFUs), and a single large IFU. These fibre systems feed a
dual-beam spectrograph covering the wavelength range 366959\,nm at
, or two shorter ranges at . After summarising the
design and implementation of WEAVE and its data systems, we present the
organisation, science drivers and design of a five- to seven-year programme of
eight individual surveys to: (i) study our Galaxy's origins by completing
Gaia's phase-space information, providing metallicities to its limiting
magnitude for 3 million stars and detailed abundances for
million brighter field and open-cluster stars; (ii) survey million
Galactic-plane OBA stars, young stellar objects and nearby gas to understand
the evolution of young stars and their environments; (iii) perform an extensive
spectral survey of white dwarfs; (iv) survey
neutral-hydrogen-selected galaxies with the IFUs; (v) study properties and
kinematics of stellar populations and ionised gas in cluster galaxies;
(vi) survey stellar populations and kinematics in field galaxies
at ; (vii) study the cosmic evolution of accretion
and star formation using million spectra of LOFAR-selected radio sources;
(viii) trace structures using intergalactic/circumgalactic gas at .
Finally, we describe the WEAVE Operational Rehearsals using the WEAVE
Simulator.Comment: 41 pages, 27 figures, accepted for publication by MNRA
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