7,366 research outputs found

    Radio Spectral Index Analysis and Classes of Ejection in LS I +61 303

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    LS I +61303 is a gamma-ray binary with periodic radio outbursts coincident with the orbital period of P=26.5 d. The origin of the radio emission is unclear,it could be due either to a jet, as in microquasars, or to the shock boundary between the Be star and a possible pulsar wind. We here analyze the radio spectral index over 6.7 yr from Green Bank Interferometer data at 2.2 GHz and 8.3 GHz. We find two new characteristics in the radio emission. The first characteristic is that the periodic outbursts indeed consist of two consecutive outbursts; the first outburst is optically thick, whereas the second outburst is optically thin. The spectrum of LS I +61 303 is well reproduced by the shock-in-jet model commonly used in the context of microquasars and AGNs: the optically thin spectrum is due to shocks caused by relativistic plasma ("transient jet") traveling through a pre-existing much slower steady flow ("steady jet"). This steady flow is responsible for the preceding optically thick spectrum. The second characteristic we find is that the observed spectral evolution, from optically thick to optically thin emission, occurs twice during the orbital period. We observed this occurrence at the orbital phase of the main 26.5 d outburst and also at an earlier phase, shifted by ΔΦ\Delta \Phi \sim 0.3 (i.e almost 8 days before). We show that this result qualitatively and quantitatively agrees with the two-peak accretion/ejection model proposed in the past for LS I +61303. We conclude that the radio emission in LS I +61303 originates from a jet and suggest that the variable TeV emission comes from the usual Compton losses expected as an important by-product in the shock-in-jet theory.Comment: 27 pages, 7 figures, accepted for publication in Ap

    The dust-enshrouded microquasar candidate AX J1639.0-4642 = IGR J16393-4643

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    We present a multiwavelength study of the field containing the unidentified X-ray source AX J1639.0-4642, discovered with the ASCA observatory and recently detected with the IBIS telescope, onboard the INTEGRAL satellite, dubbed IGR J16393-4643. The huge hydrogen column density towards the source, the hard spectral index in the 0.7-10 keV band and its flux variability suggest that the source is a High Mass X-ray Binary (HMXB) enshrouded by dust. Our search reveals the presence of a non-thermal radio counterpart within the X-ray error box. After a study of the broadband emission from X-rays to the radio domain, we propose that AX J1639.0-4642 is a dust-enshrouded Microquasar (MQ) candidate. In addition, the X-ray source is well within the 95% location contour of the unidentified gamma-ray source 3EG J1639-4702. The main properties of AX J1639.0-4642/3EG J1639-4702 are consistent with those of two other MQs previously proposed to display high-energy gamma-ray emission.Comment: 7 pages, 5 figures. Accepted for publication in A&A. Title and discussion on the possible NIR counterpart have been modifie

    Proyecto para la creación de una nueva extensión del negocio: manufacturas fernandino en la linea de trajes sastres para mujeres en la ciudad de Guayaquil

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    EXPONEMOS EN EL PRESENTE TRABAJO LOS CONSEJOS ES MUY CIERTO TAMBIEN QUE LA EXPERIENCIA OBTENIDA A TRAVES DE LOS AÑOS POR LOS DIRETIVOS DE LA EMPRESA JUEGA UN PAPEL PREPONDERANTE PARA INICIAR PROCESOS DE REINGENIERIA QUE MOTIVEN AL DESARROLLO DE LA EMPRESA Y DEL SECTOR TEXTIL Y DE CONFECCIONES

    Proyecto para la creación de una nueva extensión del negocio: manufacturas fernandino, en la línea de trajes sastre para mujeres, en la ciudad de Guayaquil

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    El tema: “Proyecto para la creación de una nueva extensión del Negocio: “Manufacturas Fernandino”, en la Línea de Trajes Sastre para Mujeres, en la ciudad de Guayaquil”, ofrece una propuesta inmejorable para el autodiagnóstico de la empresa y establece una base de información sólida estadística y analítica para el desarrollo del proyecto en un futuro ampliando su línea de producto trajes sastre; también identifica contemporáneas estrategias de marketing al detalle que responden a los cambios y tendencias que están revolucionando el mercado textil y de confecciones especializadas en el Ecuador y el mundo. Se expone en primer lugar la historia del traje sastre, se presenta un análisis general sobre el entorno macro y micro económico del sector textil y de confecciones, y se analiza de forma interna a la empresa, se profundiza en la propuesta del producto y se analiza las preferencias del mercado objetivo. El planeamiento estratégico se desarrolla y se muestra la dirección de mercadeo adecuada para la propuesta, se cuenta con información financiera relevante para el proyecto finalizando con las conclusiones y recomendaciones

    Neonatal hearing screening in high-risk patients with otoacoustic emissions: evaluation of results

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    Resumen Objetivo: evaluar la efectividad del programa de tamizaje auditivo del Homic en pacientes de alto riesgo de hipoacusia neurosensorial, el cual está basado en la realización de otoemisiones acústicas Diseño: estudio de cohorte retrospectiva, en el que se incluirán a los pacientes mayores de 12 meses de edad nacidos en el Hospital Militar central (HMC) entre enero de 2009 y diciembre de 2012; a quienes por condiciones de alto riesgo de hipoacusia neurosensorial se les realizó antes de los 6 meses de edad otoemisiones acústicas como prueba de tamizaje auditivo. A esta población, se le realizara diagnostico auditivo por medio del método diagnostico Gold Standart el cual es el “cross cheking”. Resultados: Se estudiaron los factores de riesgo para hipoacusia neurosensorial encontrando que el peso al nacer ≤1500 gr. Se relacionó con hipoacusia en un 16%. El 5.6% tiene antecedente familiar de hipoacusia neurosensorial en primer y segundo grado de consanguinidad. La infección congénita (TORCHS: toxoplasmosis, sífilis, rubéola, citomegalovirus, o herpes) como factor de riesgo se presentó en el 2.4% únicamente con la presencia de Toxoplasmosis, de los cuales 2 oídos presentaron cofosis. Conclusiones: La sensibilidad de las Otoemisiones acusticas para sospechar hipoacusia neurosensorial fue del 82.5%. La especificidad estimada en nuestro estudio fue de 90.9%Hospital Militar CentralObjective: To evaluate the effectiveness of auditory screening program Central Military Hospital in patients at high risk of sensorineural hearing loss, which is based on the realization of otoacoustic emissions. Design: Retrospective cohort study, in which over 12 months of age born patients in the Central Military Hospital (HOMIC) between January 2009 and December 2012 were included; who by conditions of high risk of sensorineural hearing loss was performed before 6 months of age otoacoustic emissions and hearing screening test. Total population was 125 patients. We evaluated each ear separately for a total of 250 measurements, this population was conducted auditory diagnosis through cross cheking diagnosis method were analyzed. Results: Risk factors for sensorineural hearing loss were studied. We found that birth weight ≤1500 g. It was associated with hearing loss by 16%. 5.6% have a family history of sensorineural hearing loss in first and second degree of consanguinity. Congenital infection (TORCHS: toxoplasmosis, syphilis, rubella, cytomegalovirus, or herpes) as a risk factor occurred in 2.4% only in the presence of Toxoplasmosis, of which 2 ears presented deafness. Conclusions: The otoacoustic emissions are effective as hearing screening test in Military Central Hospital in patients at high risk of Sensorineural hearing loss. The sensitivity of otoacoustic emissions to suspect sensorineural hearing loss was 82.5%. The estimated specificity in our study was 90.9
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