Delay Tolerant Networking over the Metropolitan Public Transportation

We discuss MDTN: a delay tolerant application platform built on top of the Public Transportation System (PTS) and able to provide service access while exploiting opportunistic connectivity. Our solution adopts a carrier-based approach where buses act as data collectors for user requests requiring Internet access. Simulations based on real maps and PTS routes with state-of-the-art routing protocols demonstrate that MDTN represents a viable solution for elastic nonreal-time service delivery. Nevertheless, performance indexes of the considered routing policies show that there is no golden rule for optimal performance and a tailored routing strategy is required for each specific case

Tratamiento de la luxación congénita de cadera inveterada según la técnica de klisic

En este trabajo se valoran retrospectivamente un grupo de 15 pacientes, con edades superiores a los 6 años, afectos de luxación congenita inveterada y que fueron intervenidos (16 caderas) mediante la técnica de Klisic. El tiempo medio de seguimiento fue de 4 años. En 12 caderas se habían realizado previamente distintas técnicas quirúrgicas sin obtener resultados satisfactorios. Tras efectuar la técnica de Klisic, 11 caderas presentaban un centraje coxofemoral satisfactorio. Se objetivos necrosis epifisaria en 6 casos, aunque en 5 de ellos ya existía antes de la intervención. Valorando los resultados con una escala clínico-radiológica (Trevor y cols. 1975), se obtuvieron resultados excelentes o buenos en el 50% de los casos. En el 3 1% de los pacientes el resultado fue pobre desde el punto de vista radiológico y clínico. En conclusión, la técnica de Klisic supone una alternativa recomendable para el tratamiento de la luxación inveterada de cadera. Su indicación más adecuada sería la luxación alta con acetábulo hipoplásico.A group of 15 patients, over 6 years of age, with neglected congenital hip dislocation (16 hips) were operated on using the Klisic''''s technique. The mean follow-up was 4 years. Prior this surgery, 12 hips had undergone different surgical treatments without satisfactory results. At the end of follow-up 11 hips were satisfactory reduced. In 6 cases necrosis of the femoral head was detected, but necrotic signs were seem in the preoperative radiographs of 5 of these cases. According to a clinico-radiographic score (Trevor et al. 1975), either excellent or good results were obtained in 50% of cases. In 3 1% the outcome was poor from both clinical and radiographic point of view. In conclusion, Klisic''''s technique seems to be a suitable alternative for the treatment of reglected congenital dislocation of the hip. The more proper indication would be a high dislocation of the hip with hypoplasic acetabulum

Prospects for multiwavelength polarization observations of GRB afterglows and the case GRB 030329

We explore the prospects for simultaneous, broad-band, multiwavelength polarimetric observations of GRB afterglows. We focus on the role of cosmic dust in GRB host galaxies on the observed percentage polarization of afterglows in the optical/near-infrared bands as a function of redshift. Our driving point is the afterglow of GRB 030329, for which we obtained polarimetric data in the R band and K band simultaneously about 1.5 days after the burst. We argue that polarimetric observations can be very sensitive to dust in a GRB host, because dust can render the polarization of an afterglow wavelength-dependent. We discuss the consequences for the interpretation of observational data and emphasize the important role of very early polarimetric follow-up observations in all bands, when afterglows are still bright, to study the physical properties of dust and magnetic fields in high-z galaxies.Comment: accepted for publication in Astronomy & Astrophysic

Cyclotron lines in X-ray pulsars as a probe of relativistic plasmas in superstrong magnetic fields

The systematic search for the presence of cyclotron lines in the spectra of accreting X-ray pulsars is being carried on with the BeppoSAX satellite since the beginning of the mission. These highly successful observations allowed the detection of cyclotron lines in many of the accreting X-ray pulsars observed. Some correlations between the different measured parameters were found. We present these correlations and discuss them in the framework of the current theoretical scenario for the X-ray emission from these sources.Comment: 5 pages, 2 figures, uses aipproc.sty, to appear in Proceeding of Fifth Compton Symposiu

Alargamiento en agenesia de tibia y peroné

Las displasias o defectos congénitos (parciales o totales) de la pierna pueden a fin didáctico subdividirse en deficiencia congénita de la tibia y en deficiencia congénita del peroné. Los miembros inferiores se originan de la llamada "yema de extremidades" provenientes del mesenquima y apareciendo al final de la cuarta semana, y están opuestas a los segmentos lumbares extendiéndose ventralmente. Los centros primarios de osificación de las diafisis de los huesos aparecen entre las 7 y 12 semanas. Las epífisis aparecen por centros secundarios, siendo los primeros en aparecer aquellos alrededor de la rodilla -distal de fémur y proximal de tibia- al noveno mes. Los músculos se desarrrollan in situ alrededor de los huesos en formación. A la séptima semana existe una rotación de los brazos y piernas, que en las extremidades inferiores rotan medialmente 90° (rodilla hacia adelante) de forma que los músculos externos se colocan hacia adelante. De alli que al haber una interrupción del proceso normal de evolución y rotación la patología congénita de miembros inferiores afecte mayormente las estructuras externas

Radio Monitoring of the January 11, 1997 Gamma-Ray Burst

We report on a comprehensive radio monitoring program of the bright gamma-ray burster GRB970111. These VLA observations were made at a frequency of 1.4 GHz and span a range of post-burst timescales between 28 hours and one month. Despite extensive sampling at sub-milliJansky sensitivities, no radio source was detected above 0.5 mJy in the current best error box (~14 arcmin^2) for GRB970111. A highly unusual radio source, VLA J1528.7+1945, was seen to drop in flux density by a factor of two in our monitoring period but it lies outside the error box and thus it is unlikely to be related to GRB970111. Cosmological fireball models of gamma-ray bursts make predictions of late-time emission occurring at longer wavelengths. The absence of a flaring or fading radio counterpart to GRB970111 provides strong constraints on these models.Comment: ApJ Let (accepted

ASCA and BeppoSAX observations of the peculiar X-ray source 4U1700+24/HD154791

The X-ray source 4U1700+24/HD154791 is one of the few galactic sources whose counterpart is an evolved M star. In X-rays the source shows extreme erratic variability and a complex and variable spectrum. While this strongly suggests accretion onto a compact object, no clear diagnosis of binarity was done up to now. We report on ASCA and BeppoSAX X-ray broad band observations of this source and on ground optical observations from the Loiano 1.5 m telescope.Comment: 5 pages, 4 figures, uses aipproc.sty, to appear in Proceedings of the Fifth Compton Symposiu