54 research outputs found

    Digital receivers for low-frequency radio telescopes UTR-2, URAN, GURT

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    This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. This paper describes digital radio astronomical receivers used for decameter and meter wavelength observations. Since 1998, digital receivers performing on-the-fly dynamic spectrum calculations or waveform data recording without data loss have been used at the UTR-2 radio telescope, the URAN VLBI system, and the GURT new generation radio telescope. Here we detail these receivers developed for operation in the strong interference environment that prevails in the decameter wavelength range. Data collected with these receivers allowed us to discover numerous radio astronomical objects and phenomena at low frequencies, a summary of which is also presented.Comment: 24 pages, 15 figure

    miRNAs are essential for the regulation of the PI3K/AKT/FOXO pathway and receptor editing during B cell maturation

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    B cell development is a tightly regulated process dependent on sequential rearrangements of immunoglobulin loci that encode the antigen receptor. To elucidate the role of microRNAs (miRNAs) in the orchestration of B cell development, we ablated all miRNAs at the earliest stage of B cell development by conditionally targeting the enzymes critical for RNAi in early B cell precursors. Absence of any one of these enzymes led to a block at the pro- to pre-B cell transition due to increased apoptosis and a failure of pre-B cells to proliferate. Expression of a Bcl2 transgene allowed for partial rescue of B cell development, however, the majority of the rescued B cells had low surface immunoglobulin expression with evidence of ongoing light chain editing. Our analysis revealed that miRNAs are critical for the regulation of the PTEN-AKT-FOXO1 pathway that in turn controls Rag expression during B cell development

    Evaluation of 16S rRNA gene PCR sensitivity and specificity for diagnosis of prosthetic joint infection: a prospective multicenter cross-sectional study

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    There is no standard method for the diagnosis of prosthetic joint infection (PJI). The contribution of 16S rRNA gene PCR sequencing on a routine basis remains to be defined. We performed a prospective multicenter study to assess the contributions of 16S rRNA gene assays in PJI diagnosis. Over a 2-year period, all patients suspected to have PJIs and a few uninfected patients undergoing primary arthroplasty (control group) were included. Five perioperative samples per patient were collected for culture and 16S rRNA gene PCR sequencing and one for histological examination. Three multicenter quality control assays were performed with both DNA extracts and crushed samples. The diagnosis of PJI was based on clinical, bacteriological, and histological criteria, according to Infectious Diseases Society of America guidelines. A molecular diagnosis was modeled on the bacteriological criterion (≥ 1 positive sample for strict pathogens and ≥ 2 for commensal skin flora). Molecular data were analyzed according to the diagnosis of PJI. Between December 2010 and March 2012, 264 suspected cases of PJI and 35 control cases were included. PJI was confirmed in 215/264 suspected cases, 192 (89%) with a bacteriological criterion. The PJIs were monomicrobial (163 cases [85%]; staphylococci, n = 108; streptococci, n = 22; Gram-negative bacilli, n = 16; anaerobes, n = 13; others, n = 4) or polymicrobial (29 cases [15%]). The molecular diagnosis was positive in 151/215 confirmed cases of PJI (143 cases with bacteriological PJI documentation and 8 treated cases without bacteriological documentation) and in 2/49 cases without confirmed PJI (sensitivity, 73.3%; specificity, 95.5%). The 16S rRNA gene PCR assay showed a lack of sensitivity in the diagnosis of PJI on a multicenter routine basis

    El rol de enfermería en la atención de adultos mayores con fractura de cadera

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    El rol de enfermería en la atención de adultos mayores con fracturas de cadera se basa es la prestación de nuestros conocimientos. Se desarrolló una investigación de enfoque cuantitativo, cualitativo, de campo descriptivo observacional en el área de traumatología del Hospital Luis Vernaza el cual es considerado uno de los mejores establecimiento de salud en cuanto a la atención al adulto del Ecuador. Como objetivo se observó cuanto conoce el personal de enfermería sobre la atención en Adultos mayores con fractura de cadera e identificar sus causas y complicaciones. Nuestra muestra fue de 32 personas que corresponde al 100% del personal de enfermería que labora en el área de traumatología. Entre los resultados más notable que se obtuvieron, EL 75% del personal (24 personas) manifiesta tener buenos conocimientos en manejo de fractura de cadera. En cuanto a un protocolo o guía de atención el 92% del personal dice conocerlo, el 71,8% del personal tiene como preparación cursos de auxiliar de enfermería el 28.2 %restante es de profesión licenciado/a en enfermería. El proceso de Atención de Enfermería lo desconoce el 62,5% del personal. Durante nuestra investigación se llegó a la conclusión que el personal auxiliar de enfermería tiene pocos conocimientos sobre los cuidados a brindar a pacientes que sufren este tipo de patología

    Statistical analysis of 26 yr of observations of decametric radio emissions from Jupiter

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    Jupiter is a complex and at the same time very powerful radio source in the decameter wavelength range. The emission is anisotropic, intrinsically variable at millisecond to hour timescales, and also modulated by various external processes at much longer periods, ranging from ~10 h to months or years (including Jovian day and year, solar activity and solar wind variations, and for ground-based observations, terrestrial day and year). As a consequence, long-term observations and their statistical study have proved to be necessary for disentangling and understanding the observed phenomena. We have built a database from the available 26 yr of systematic, daily observations conducted at the Nançay Decameter Array and recorded in digital format. This database contains all observed Jovian decametric emissions, classified with respect to the time-frequency morphology, their dominant circular polarization, and maximum frequency. We present the results of the first statistical analysis of this database. We confirm the earlier classification of Jovian decameter emissions in Io-A, -A′, -B, -C, -D and non-Io-A, -B, -C types, but we also introduce new emission types (Io-A′′ and Io-B′) and precise and characterize the non-Io-D type. We determine the contours of all emission types in the CML− ΦIo plane (Central Meridian Longitude in Jupiter’s System III coordinates versus Io Phase), provide representative examples of their typical time-frequency patterns, and the distribution of emission’s maximum frequency as a function of ΛIo (Io’s Longitude). Finally, we present a statistical analysis of the distributions of the occurrence rate, duration, intensity and polarization for each emission type. non-Io-DAM appears to be related to small-scale, possibly bursty auroral structures
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