Modeling the broadband persistent emission of magnetars

In this paper, we discuss our first attempts to model the broadband persistent emission of magnetars within a self consistent, physical scenario. We present the predictions of a synthetic model that we calculated with a new Monte Carlo 3-D radiative code. The basic idea is that soft thermal photons (e.g. emitted by the star surface) can experience resonant cyclotron upscattering by a population of relativistic electrons threated in the twisted magnetosphere. Our code is specifically tailored to work in the ultra-magnetized regime; polarization and QED effects are consistently accounted for, as well different configurations for the magnetosphere. We discuss the predicted spectral properties in the 0.1-1000 keV range, the polarization properties, and we present the model application to a sample of magnetars soft X-ray spectra.Comment: 14 pages, 7 figures, to be published in Advances in Space Research. Proceedings of the conference "Frontieres of Space Astrophysics, Neutron Stars & Gamma Ray Bursts", Cairo/Alexandria, 30 March- 4 April 200

Magnetars' Giant Flares: the case of SGR 1806-20

We first review on the peculiar characteristics of the bursting and flaring activity of the Soft Gamma-ray Repeaters and Anomalous X-ray Pulsars. We then report on the properties of the SGR 1806-20's Giant Flare occurred on 2004 December 27th, with particular interest on the pre and post flare intensity/hardness correlated variability. We show that these findings are consistent with the picture of a twisted internal magnetic field which stresses the star solid crust that finally cracks causing the giant flare (and the observed torsional oscillations). This crustal fracturing is accompanied by a simplification of the external magnetic field with a (partial) untwisting of the magnetosphere.Comment: 6 pages, 2 figures; accepted for publication in the Chinese Journal for Astronomy and Astrophysics (Vulcano conference - 2005

Our distorted view of magnetars: application of the Resonant Cyclotron Scattering model

The X-ray spectra of the magnetar candidates are customarily fitted with an empirical, two component model: an absorbed blackbody and a power-law. However, the physical interpretation of these two spectral components is rarely discussed. It has been recently proposed that the presence of a hot plasma in the magnetosphere of highly magnetized neutron stars might distort, through efficient resonant cyclotron scattering, the thermal emission from the neutron star surface, resulting in the production of non-thermal spectra. Here we discuss the Resonant Cyclotron Scattering (RCS) model, and present its XSPEC implementation, as well as preliminary results of its application to Anomalous X-ray Pulsars and Soft Gamma-ray Repeaters.Comment: 5 pages, 5 color figures; Astrophysics & Space Science, in press ("Isolated Neutron Stars"; London, UK

A variable absorption feature in the X-ray spectrum of a magnetar

Soft gamma-ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) are slowly rotating, isolated neutron stars that sporadically undergo episodes of long-term flux enhancement (outbursts) generally accompanied by the emission of short bursts of hard X-rays. This behaviour can be understood in the magnetar model, according to which these sources are mainly powered by their own magnetic energy. This is supported by the fact that the magnetic fields inferred from several observed properties of AXPs and SGRs are greater than - or at the high end of the range of - those of radio pulsars. In the peculiar case of SGR 0418+5729, a weak dipole magnetic moment is derived from its timing parameters, whereas a strong field has been proposed to reside in the stellar interior and in multipole components on the surface. Here we show that the X-ray spectrum of SGR 0418+5729 has an absorption line, the properties of which depend strongly on the star's rotational phase. This line is interpreted as a proton cyclotron feature and its energy implies a magnetic field ranging from 2E14 gauss to more than 1E15 gauss.Comment: Nature, 500, 312 (including Supplementary Information

Peptide functionalization of silicon for detection and classification of prostatic cells

The development of simple, rapid, and low costmethods for early detection, identification, andmeasurement ofmultiple biomarkers remains a challenge to improve diagnosis, treatment monitoring, and prognosis of cancer. Biosensing technology, combining the properties of biological systems with functional advanced materials, guarantees rapid, reproducible, and highly sensitive cell detection. In this study, we developed silicon-based biochips for prostate cancer PC3 cells detection by using cytokeratin 8/18 and Urotensin Receptor (UTR) as markers in order to obtain a biochip-based diagnostic system. Spectroscopic ellipsometry and fluorescence microscopy were used to characterize surface homogeneity and chemical properties. Cell detection was investigated by optical microscopy.Moreover, synthetic fluorescently labeled peptides were prepared and used for developing faster and lowercost identification assay compared with classic ELISA immunoassay. Results showed an effective immobilization of PC3 cells on silicon surface and the specific recognition of these cells by fluorescent Urotensin II (4-11). In conclusion, this strategy could be really useful as diagnostic system for prostate cancer

Pulse phase-coherent timing and spectroscopy of CXOU J164710.2−45521 outbursts

We present a long-term phase-coherent timing analysis and pulse-phase resolved spectroscopy for the two outbursts observed from the transient anomalous X-ray pulsar CXOU J164710.2−455216. For the first outburst we used 11 Chandra and XMM–Newton observations between 2006 September and 2009 August, the longest baseline yet for this source. We obtain a coherent timing solution with P = 10.61065583(4) s, Ṗ = 9.72(1) × 10−13 s s−1 and P̈ = –1.05(5) × 10−20 s s−2. Under the standard assumptions this implies a surface dipolar magnetic field of ∼1014 G, confirming this source as a standard B magnetar. We also study the evolution of the pulse profile (shape, intensity and pulsed fraction) as a function of time and energy. Using the phase-coherent timing solution we perform a phase-resolved spectroscopy analysis, following the spectral evolution of pulse-phase features, which hints at the physical processes taking place on the star. The results are discussed from the perspective of magnetothermal evolution models and the untwisting magnetosphere model. Finally, we present similar analysis for the second, less intense, 2011 outburst. For the timing analysis we used Swift data together with 2 XMM–Newton and Chandra pointings. The results inferred for both outbursts are compared and briefly discussed in a more general framework.DV was supported by the grants AYA 2010-21097-C03-02, ACOMP/2012/135, AYA 2012-39303 and SGR 2009-811. NR was supported by a Vidi NWO grant, Ramon y Cajal Fellowship, AYA 2012-39303 and SGR 2009-811

Narrative Based Medicine as a tool for needs assessment of patients undergoing hematopoietic stem cell transplantation

Background and aim: In the last years we have seen an ever increasing number of patients with haematologic disorders who need hematopoietic stem cell transplantation (HSCT). The whole sector of HSCT results, infact to be in a continous scientific and technological clinical progress, offering a very advanced care. Despite this, some aspects are underconsidered, some of which could be fundamental to determine the success of the care pathway, such as the experience of the illness by the patient. Using a Narrative Based Medicine approach we wanted to investigate clinical, psychosocial and organizational aspects of the patient\u2019s journey whilst undergoing HSCT. Method: Various narrative interviews were conducted using non-structured approach. Results were analysed by thematic contents. Results: Psycological dimension is the most compromised: above all emerged sentiments of oppression linked to the isolation period in the Low Bacterial Load (LBL) room. To note are also the different dynamics with which the patients perceive the organisation and hospital structures, and how much these factors can influence their care experience. Conclusions: Results suggest the need in clinical practice of an integration between qualitative and clinical approach, so as to permit the psychosocial and relational necessities to emerge, often unexpressed by patients undergoing HSCT

Antibacterial Effect of Stainless Steel Surfaces Treated with a Nanotechnological Coating Approved for Food Contact

Stainless steel, widely present in the food industry, is frequently exposed to bacterial colonization with possible consequences on consumers’ health. 288 stainless steel disks with different roughness (0.25, 0.5 and 1 μm) were challenged with four Gram-negative (Escherichia coli ATCC 25922, Salmonella typhimurium ATCC 1402, Yersinia enterocolitica ATCC 9610 and Pseudomonas aeruginosa ATCC 27588) and four Gram-positive bacteria (Staphylococcus aureus ATCC 6538, Enterococcus faecalis ATCC 29212, Bacillus cereus ATCC 14579 and Listeria monocytogenes NCTT 10888) and underwent three different sanitizing treatments (UVC, alcohol 70% v/v and Gold lotion). Moreover, the same procedure was carried out onto the same surfaces after a nanotechnological surface coating (nanoXHAM® D). A significant bactericidal effect was exerted by all of the sanitizing treatments against all bacterial strains regardless of roughness and surface coating. The nanoXHAM® D coating itself induced an overall bactericidal effect as well as in synergy with all sanitizing treatments regardless of roughness. Stainless steel surface roughness is poorly correlated with bacterial adhesion and only sanitizing treatments can exert significant bactericidal effects. Most of sanitizing treatments are toxic and corrosive causing the onset of crevices that are able to facilitate bacterial nesting and growth. This nanotechnological coating can reduce surface adhesion with consequent reduction of bacterial adhesion, nesting, and growth

Análisis del proceso de acogida e incorporación del personal docente en los institutos tecnológicos del Ecuador

The process of welcoming and incorporating teaching staff in the technological institutes of Ecuador has been one of the weaknesses in the field of human resources that has not been addressed for improvement. The study aimed to establish a teacher welcoming and incorporation process that allows for the strengthening of the technological institutes of Ecuador. It used a mixed quantitative and qualitative approach through project management research, where research techniques such as surveys were applied to gather information from the main stakeholders, including teachers and authorities. Interviews were also conducted to obtain qualitative information, as well as complementary evaluation techniques (focus groups) to understand the needs of different interest groups from the beginning, so that it was possible to plan what needs to be done, when, by whom, and under what standards of direction guidelines. Inductive, deductive, analytical, and bibliographic methods were used. It was found that the technological institutes of Ecuador lack knowledge about the comprehensive process of incorporating their employees from the first moment. It was concluded that most of the incoming teachers do not receive the adaptation or socialization phase that would allow them to truly incorporate into their job positions, the organizational culture, and the institution's objectives.El proceso de acogida e incorporación del personal docente en los institutos tecnológicos del Ecuador, ha sido una de las debilidades en el ámbito de los recursos humanos de los institutos que no se ha intervenido para mejorarlo. El estudio tuvo como objetivo principal establecer un proceso de acogida e incorporación docente que permita el fortalecimiento de los institutos tecnológicos del Ecuador; partió de un enfoque mixto cuantitativo y cualitativo, mediante la investigación de gestión por proyectos, donde se aplicó técnicas de investigación como: la encuesta para recabar información proveniente de los actores principales docentes y autoridades, la entrevista para obtener información de orden cualitativa como también la técnica complementaria de evaluación (focus group) la cual conllevó a comprender las necesidades de los diferentes grupos de interés desde un inicio, de manera que se pudo planificar qué se necesita hacer, cuándo, por quién y bajo qué estándares de lineamientos de dirección; se recurrió a los métodos inductivo, deductivo, analítico y bibliográfico. Se pudo determinar que los institutos tecnológicos del Ecuador carecen de conocimiento en cuanto al proceso integral para incorporar desde el primer momento a sus colaboradores. Se concluyó que la mayor parte de los docentes que ingresan no reciben la fase de adaptación o socialización que les permita la auténtica incorporación a su puesto de trabajo, a la cultura organizativa y a los objetivos que persigue la institución