Asteroseismology of delta Scuti stars in open clusters: Praesepe

The present paper provides a general overview of the asteroseismic potential of delta Scuti stars in clusters, in particular focusing on convection diagnostics. We give a summarise of the last results obtained by the authors for the Praesepe cluster of which five delta Scuti stars are analysed. In that work, linear analysis is confronted with observations, using refined descriptions for the effects of rotation on the determination of the global stellar parameters and on the adiabatic oscillation frequency computations. A single, complete, and coherent solution for all the selected stars is found, which lead the authors to find important restrictions to the convection description for a certain range of effective temperatures. Furthermore, the method used allowed to give an estimate of the global parameters of the selected stars and constrain the cluster.Comment: 6 pages, 1 figure. Accepted for publication in Communications in Asteroseismolog

Validation of potentiometric method to determine the degree of deacetylation of chitosan

Un método potenciométrico para la determinación del grado de desacetilación de muestras de quitosanas derivadas de quitina de langosta se validó según las exigencias internacionales actuales. Para garantizar que ocurriera la reacción completa entre el analito y la disolución de HCl se aplicó calentamiento de las muestras a temperatura inferior a 60ºC. Auxiliarmente a los cambios de pH, para la detección del primer punto de infl exión, se utilizó el anaranjado de metilo como indicador visual cuyo intervalo de transición está en un rango estrecho de pH ácido, entre 2 a 4. No se registraron interferencias desde el punto de vista analítico en la zona de interés de la curva potenciométrica en ausencia del analito, por lo que el método fue selectivo. Se demostró que el método fue lineal en el rango de 10.0 a 15.0 mg/mL, además fue preciso y exacto para la determinación del porcentaje de grupos aminos libres.The purpose of this study was to validate, in accordance with international standards, a potentiometric method to determine the degree of deacetylation of chitosan samples derived from lobster chitin. To ensure a complete reaction between the analyte and the HCl solution, the samples were heated to temperatures of up to 60ºC. The change in pH and the methyl orange method, as a visual indicator were used to detect the fi rst infl ection point. The transition interval fell within the narrow pH acid range of 2 to 4. From an analytical point of view, no interference was observed on the potentiometric curve in the absence of the analyte, thus showing that the method was suffi ciently selective. For the determination of the percentage of free amino groups, the method proved to be linear within the 10.0 to 15.0 mg/mL range, as well as precise and exact

Osteitis condensante de clavícula

La osteítis condensante de clavícula es una lesión ósea infrecuente, benigna y de etiología desconocida. Se caracteriza por esclerosis densa y homogénea de la porción infero-medial clavicular con obliteración de la cavidad medular sin afectación de la articulación esternoclavicular. Hasta ahora sólo se había descrito en mujeres, en el presente trabajo presentamos un caso en un paciente varón. Se discute el diagnóstico diferencial con otras entidades que producen afectación similar y proponemos la TC como método diagnóstico de elección, defendiendo el tratamiento conservador.Condensing osteitis of the clavicle is a benign and uncommon bone lesion of unknown cause, characterized by homogeneously dense sclerotic patch with obliteration of the marrow cavity at the medial end of the clavicle without involvement of the sternoclavicular joint. To date it had been described only in women. In this work we report a case in a male patient. The differential diagnosis with other disorders of similar findings is discussed. We propose CT-scan as the elective diagnostic test and we defend the conservative treatment

Characterisation of Medipix3 Silicon Detectors in a Charged-Particle Beam

While designed primarily for X-ray imaging applications, the Medipix3 ASIC can also be used for charged-particle tracking. In this work, results from a beam test at the CERN SPS with irradiated and non-irradiated sensors are presented and shown to be in agreement with simulation, demonstrating the suitability of the Medipix3 ASIC as a tool for characterising pixel sensors.Comment: 16 pages, 13 figure

A seismological analysis of Delta Scuti stars in the Pleiades cluster

A comparison between the oscillation frequencies of six multi-periodic Delta Scuti stars of the Pleiades cluster and the eigenfrequencies of rotating stellar models that match the corresponding stellar parameters has been carried out. The assumption that all the stars considered have some common parameters, such as metallicity, distance or age, is imposed as a constraint. As a result, we have a best fit solution associated with a cluster metallicity of [Fe/H] ~ 0.067, an age between 70x10^6 and 100x10^6 yr and a distance modulus of mv-Mv=5.60-5.70 mag. All the stars were found to oscillate mainly in non-radial, low degree, low order p modes. Estimates of mass and rotation rates for each star are also obtainedComment: 10 pages, 7 figure

Development and validation of enzymatic method for the determination of alcohol in immunoglobulin and albumin

Se desarrolló y validó un método enzimático para la cuantificación del contenido de alcohol en los IFAs de Inmunoglobulina y Albúmina. En ambos casos el procedimiento analítico resultó lineal, exacto, preciso y específico para el control de calidad. Se demostró que el método fue lineal en el rango de 6.0 a 19.0 mg de alcohol/g de proteína para la albúmina y de 9.2 a 27.6 mg de alcohol/g de proteína para la inmunoglobulina, respectivamente. El método sugerido se aplicó con éxito en la determinación del contenido de alcohol como impureza en lotes industriales.An enzymatic method for the quantification of alcohol content in immunoglobulin and albumin was developed and validated. In both materials, the analytical procedure was linear, accurate, precise and specific. The method was linear in the range from 6.0 to 19.0 mg of alcohol/g of protein to albumin and to immunoglobulin from 9.2 to 27.6 mg of alcohol/g of protein, respectively. The proposed method was applied successfully in industrial batches for the determination of the alcohol content as impurity

Dynamics of Coronal Bright Points as seen by Sun Watcher using Active Pixel System detector and Image Processing (SWAP), Atmospheric Imaging Assembly AIA), and Helioseismic and Magnetic Imager (HMI)

The \textit{Sun Watcher using Active Pixel system detector and Image Processing}(SWAP) on board the \textit{PRoject for OnBoard Autonomy\todash 2} (PROBA\todash 2) spacecraft provides images of the solar corona in EUV channel centered at 174 \AA. These data, together with \textit{Atmospheric Imaging Assembly} (AIA) and the \textit{Helioseismic and Magnetic Imager} (HMI) on board \textit{Solar Dynamics Observatory} (SDO), are used to study the dynamics of coronal bright points. The evolution of the magnetic polarities and associated changes in morphology are studied using magnetograms and multi-wavelength imaging. The morphology of the bright points seen in low-resolution SWAP images and high-resolution AIA images show different structures, whereas the intensity variations with time show similar trends in both SWAP 174 and AIA 171 channels. We observe that bright points are seen in EUV channels corresponding to a magnetic-flux of the order of $10^{18}$ Mx. We find that there exists a good correlation between total emission from the bright point in several UV\todash EUV channels and total unsigned photospheric magnetic flux above certain thresholds. The bright points also show periodic brightenings and we have attempted to find the oscillation periods in bright points and their connection to magnetic flux changes. The observed periods are generally long (10\todash 25 minutes) and there is an indication that the intensity oscillations may be generated by repeated magnetic reconnection

The bright optical afterglow of the long GRB 001007

We present optical follow up observations of the long GRB 001007 between 6.14 hours and ~468 days after the event. An unusually bright optical afterglow (OA) was seen to decline following a steep power law decay with index alpha = -2.03 +/- 0.11, possibly indicating a break in the light curve at t - to < 3.5 days, as found in other bursts. Upper limits imposed by the LOTIS alerting system 6.14 hours after the gamma ray event provide tentative (1.2 sigma) evidence for a break in the optical light curve. The spectral index beta of the OA yields -1.24 +/- 0.57. These values may be explained both by several fireball jet models and by the cannonball model. Fireball spherical expansion models are not favoured. Late epoch deep imaging revealed the presence of a complex host galaxy system, composed of at least two objects located 1.2" (1.7 sigma) and 1.9" (2.7 sigma) from the afterglow position.Comment: 7 pages, 5 figures, published in A&