Nadell, Pamela S. and Kate Haulman (Eds.). Making Women’s Histories. Beyond National Perspectives, New York University Press. 2013

Fil: Vásquez, María Gabriela. Universidad Nacional de Cuyo. Facultad de Filosofía y LetrasFil: Riggio, Carla Andrea. Universidad Nacional de Cuyo. Facultad de Filosofía y Letra

Discovery of hard phase lags in the pulsed emission of GRO J1744-28

We report on the discovery and energy dependence of hard phase lags in the 2.14 Hz pulsed profiles of GRO J1744-28. We used data from XMM-Newton and NuSTAR. We were able to well constrain the lag spectrum with respect to the softest (0.3--2.3 keV) band: the delay shows increasing lag values reaching a maximum delay of $\sim$ 12 ms, between 6 and 6.4 keV. After this maximum, the value of the hard lag drops to 7 ms, followed by a recovery to a plateau at 9 ms for energies above 8 keV. NuSTAR data confirm this trend up to 30 keV, but the measurements are statistically poorer, and therefore, less constraining. The lag-energy pattern up to the discontinuity is well described by a logarithmic function. Assuming this is due to a Compton reverberation mechanism, we derive a size for the Compton cloud $R_{\rm{cc}}$ $\sim$ 120 $R_{\rm g}$, consistent with previous estimates on the magnetospheric radius. In this scenario, the sharp discontinuity at $\sim$ 6.5 keV appears difficult to interpret and suggests the possible influence of the reflected component in this energy range. We therefore propose the possible coexistence of both Compton and disk reverberation to explain the scale of the lags and its energy dependence.Comment: Accepted for publication in MNRAS Letters on 2016 June 0

La Fiesta Nacional de la Vendimia (Mendoza, Argentina): patrimonio inmaterial. : Abordaje historiográfico desde la historia pública

Indeed, the community of Mendoza enjoys the National Harvest Festival since 1936, when it was institutionalized by a Decree of Governor Guillermo Cano. From there and except on rare occasions, the celebration is held between the end of February and March, each year. However, in the decade of ’10, a provincial deputy presented to the Legislature a project to carry out Fiesta but did not prosper. It was used in 1913 on the occasion of receiving and entertaining the government delegation that visited Mendoza on the occasion of the Congress of Commerce. The way in which that party was organized and the great influx of the public places this event in the direct antecedent of the institutionalized party. The interest is centered in the first place, in making a description of some constituent elements of the historiographic perspective of the New cultural history and the Public History approach; secondly, to address the harvest stories as harvest festivals from two well-defined aspects: as intangible cultural heritage and as a space for identity construction; Finally, to examine this enriching confluence with the specific purpose of identifying and describing the constituent elements of these approaches by applying them to the historiographic approach of the representations in some harvest festivals in the province of Mendoza.Efectivamente, la comunidad mendocina disfruta de la Fiesta Nacional de la Vendimia desde 1936, cuando fue institucionalizada por un Decreto del Gobernador Guillermo Cano. A partir de allí y excepto en contadas ocasiones, se realiza el festejo entre fines de febrero y marzo, de cada año. Sin embargo, en la década del ’10, un diputado provincial presentó a la Legislatura un proyecto de realización de Fiesta pero no prosperó. Fue utilizado en 1913 con motivo de recibir y agasajar la comitiva gubernamental que visitara Mendoza con motivo de la realización del Congreso de Comercio. La forma en que se organizó esa fiesta y la gran afluencia del público coloca este evento en el antecedente directo de la fiesta institucionalizada. En primer lugar, se realiza una descripción de algunos elementos constitutivos de la perspectiva historiográfica de la Nueva historia cultural y el enfoque de Historia Pública; en segundo término, se aborda los relatos vendimiales como festivales de cosecha desde dos aspectos bien definidos: como patrimonio inmaterial cultural y como espacio de construcción de identidad; por último, se examina dicha enriquecedora confluencia con el propósito específico de identificar y describir los elementos constitutivos de estos enfoques aplicándolos al abordaje historiográfico de las representaciones en algunas fiestas vendimiales de la provincia de Mendoza

Zinc oxide nanoparticles as selective killers of proliferating cells

Background: It has recently been demonstrated that zinc oxide nanoparticles (ZnO NPs) induce death of cancerous cells whilst having no cytotoxic effect on normal cells. However, there are several issues which need to be resolved before translation of zinc oxide nanoparticles into medical use, including lack of suitable biocompatible dispersion protocols and a better understanding being needed of the mechanism of their selective cytotoxic action. Methods: Nanoparticle dose affecting cell viability was evaluated in a model of proliferating cells both experimentally and mathematically. The key issue of selective toxicity of ZnO NPs toward proliferating cells was addressed by experiments using a biological model of noncancerous cells, ie, mesenchymal stem cells before and after cell differentiation to the osteogenic lineage. Results: In this paper, we report a biocompatible protocol for preparation of stable aqueous solutions of monodispersed zinc oxide nanoparticles. We found that the threshold of intracellular ZnO NP concentration required to induce cell death in proliferating cells is 0.4 ± 0.02 mM. Finally, flow cytometry analysis revealed that the threshold dose of zinc oxide nanoparticles was lethal to proliferating pluripotent mesenchymal stem cells but exhibited negligible cytotoxic effects to osteogenically differentiated mesenchymal stem cells. Conclusion: Results confirm the ZnO NP selective cytotoxic action on rapidly proliferating cells, whether benign or malignant

Study of the reflection spectrum of the accreting neutron star GX 3+1 using XMM-Newton and INTEGRAL

Broad emission features of abundant chemical elements, such as Iron, are commonly seen in the X-ray spectra of accreting compact objects and their studies can provide useful information about the geometry of the accretion processes. In this work, we focus our attention on GX 3+1, a bright, persistent accreting low mass X-ray binary, classified as an atoll source. Its spectrum is well described by an accretion disc plus a stable comptonizing, optically thick corona which dominates the X-ray emission in the 0.3-20 keV energy band. In addition, four broad emission lines are found and we associate them with reflection of hard photons from the inner regions of the accretion disc where doppler and relativistic effects are important. We used self-consistent reflection models to fit the spectra of the 2010 XMM-Newton observation and the stacking of the whole datasets of 2010 INTEGRAL observations. We conclude that the spectra are consistent with reflection produced at ~10 gravitational radii by an accretion disc with an ionization parameter of xi~600 erg cm/s and viewed under an inclination angle of the system of ~35{\deg}. Furthermore, we detected for the first time for GX 3+1, the presence of a powerlaw component dominant at energies higher than 20 keV, possibly associated with an optically thin component of non-thermal electrons.Comment: Accepted to appear on MNRAS, 9 pages, 5 figur

Broad-band spectral analysis of the accreting millisecond X-ray pulsar SAX J1748.9-2021

We analyzed a 115 ks XMM-Newton observation and the stacking of 8 days of INTEGRAL observations, taken during the raise of the 2015 outburst of the accreting millisecond X-ray pulsar SAX J1748.9-2021. The source showed numerous type-I burst episodes during the XMM-Newton observation, and for this reason we studied separately the persistent and burst epochs. We described the persistent emission with a combination of two soft thermal components, a cold thermal Comptonization component (~2 keV) and an additional hard X-ray emission described by a power-law (photon index ~2.3). The continuum components can be associated with an accretion disc, the neutron star (NS) surface and a thermal Comptonization emission coming out of an optically thick plasma region, while the origin of the high energy tail is still under debate. In addition, a number of broad (~0.1-0.4 keV) emission features likely associated to reflection processes have been observed in the XMM-Newton data. The estimated 1.0-50 keV unabsorbed luminosity of the source is ~5x10^37 erg/s, about 25% of the Eddington limit assuming a 1.4 solar mass NS. We suggest that the spectral properties of SAX J1748.9-2021 are consistent with a soft state, differently from many other accreting X-ray millisecond pulsars which are usually found in the hard state. Moreover, none of the observed type-I burst reached the Eddington luminosity. Assuming that the burst ignition and emission are produced above the whole NS surface, we estimate a neutron star radius of ~7-8 km, consistent with previous results.Comment: Accepted for publication in MNRAS; 12 pages, 9 figures, 2 table

A Concept of Assessment of LIV Tests with THESEUS Using the Gamma-Ray Bursts Detected by Fermi/GBM

According to Einstein's special relativity theory, the speed of light in a vacuum is constant for all observers. However, quantum gravity effects could introduce its dispersion depending on the energy of photons. The investigation of the spectral lags between the gamma-ray burst (GRB) light curves recorded in distinct energy ranges could shed light on this phenomenon: the lags could reflect the variation of the speed of light if it is linearly dependent on the photon energy and a function of the GRB redshift. We propose a methodology to start investigating the dispersion law of light propagation in a vacuum using GRB light curves. This technique is intended to be fully exploited using the GRB data collected with THESEUS

Constructed wetlands for the reuse of industrial wastewater: a case-study

The use of phytoremediation systems to enhance the treatment of industrial wastewater coming from a standard depuration process in order to allow their reuse can potentially lead to several interesting benefits (costs savings for depuration processes, freshwater and energy supply with a consequent reduction of the overall environmental impact of the industrial sites). In this work the case study of a large automotive plant (FCA plant in Verrone, Piedmont, NW Italy) was analysed, with the aim of evaluating the possible application of a phytoremediation system (constructed wetland, CW) to treat the effluents of its existing wastewater treatment plant (WWTP, currently discharged into a watercourse) and reuse them in the industrial processes. For this purpose, a pilot CW system was set up with two different configurations horizontal and vertical. Experiments were carried out to identify the one characterized by the best abatement rate of the pollutant concentrations of the plant effluents. Results showed that the horizontal submerged flow system (HF) was the most efficient phytoremediation system suitable for the aging of the effluents of the existing WWTP in view of their possible reuse in the industrial processes. Furthermore, costs related to its scaling-up for a real application demonstrated that the CW can be the cheaper option compared to a traditional treatment process for wastewater reuse. The amount of treated water which may be reused can range from 55% to 80% of the effluents from the existing WWTP, with a consequent reduction of more than 80% in the current water supply from aquifers