Una evaluación de usabilidad a productos de software: caso de estudio práctico

Internet facilita el acceso a la información, diversas son las fuentes y los dispositivos para accederla, permitiendo a los usuarios finales abandonarlos si alguno no satisface totalmente sus necesidades. Orientando la labor de la industria de software a crear productos de mayor calidad, más usables y brindar una mejor experiencia a los usuarios finales. Durante los últimos años la caracterí­stica de calidad, usabilidad, ha adquirido mayor relevancia, probando su influencia en la aceptación y el éxito del software. Introducida durante el proceso de desarrollo del software, la usabilidad, solo será percibida por los usuarios finales utilizando el software concluido; realzando la importancia de asegurarla desde etapas tempranas del desarrollo. La percepción abstracta de esta caracterí­stica impone la búsqueda constante de nuevos métodos para asegurarla y satisfacer así­ las crecientes exigencias de los usuarios finales. La presente investigación evalúa la usabilidad de Sitios Web a través de un caso de estudio y pretende demostrar si estos satisfacen todas las necesidades de usabilidad de los usuarios finales. La estrategia de evaluación se divide en 3 fases: la primera, la caracterización del proceso de desarrollo seguido para la creación de los Sitios Web, desde el tratamiento a la caracterí­stica usabilidad él. La segunda fase, evalúa la usabilidad en los Sitios Web siguiendo las pautas internacionales. Finalmente, en la tercera fase se realizaron las pruebas con usuarios finales. Las conclusiones del presente trabajo constituyen medidas que tributan a la mejora del proceso de aseguramiento de la usabilidad para crear una mejor experiencia de usuario

Impacto ambiental del vial de distribución principal de Cayo Cruz, Camagüey / Environmental impacts of main distribution road of Cayo Cruz, Camagüey

The article aims to expose the results of the environmental impact assessment carried out to the main distribution road project in the tourist pole Cayo Cruz, Camagüey. A total of 32 impacts between positive and negative were identified. The facilitation of tourism development is the most important of the positive impacts. The potential negative impacts of greater range are biological / ecological, such as those related to the possible effects on species of special interest for biological diversity and can be mitigated with the implementation of a group of measures that are suggested in this work.El artículo persigue exponer los resultados de la evaluación de impacto ambiental realizada al proyecto del vial principal de distribución en el polo turístico Cayo Cruz, Camagüey. Se identificaron un total de 32 impactos entre positivos y negativos. La facilitación del desarrollo turístico es el más importante de los impactos positivos. Los impactos negativos potenciales de mayor rango son los biológicos/ecológicos, como los relacionados con las posibles afectaciones a las especies de especial interés para la diversidad biológica y pueden ser mitigados con la implementación de un grupo de medidas que son sugeridas en el presente trabajo. / The article aims to expose the results of the environmental impact assessment carried out to the main distribution road project in the tourist pole Cayo Cruz, Camagüey. A total of 32 impacts between positive and negative were identified. The facilitation of tourism development is the most important of the positive impacts. The potential negative impacts of greater range are biological / ecological, such as those related to the possible effects on species of special interest for biological diversity and can be mitigated with the implementation of a group of measures that are suggested in this work

Early-type objects in NGC6611 and Eagle Nebula

An important question about Be stars is whether Be stars are born as Be stars or not. It is necessary to observe young clusters to answer this question. Observations of stars in NGC6611 and the star-formation region of Eagle Nebula have been carried out with the ESO-WFI in slitless spectroscopic mode and at the VLT-GIRAFFE. The targets for the GIRAFFE observations were pre-selected from the literature and our catalogue of emission-line stars (ELS) based on the WFI study. GIRAFFE observations allowed us to study accurately the population of the early-type stars with and without emission lines. For this study, we determined the fundamental parameters of OBA stars. We also studied the status of the objects (main sequence or pre-main sequence stars) by using IR data, membership probabilities, and location in HR diagrams. The nature of the early-type ELS in M16 is derived. The slitless observations with the WFI clearly indicate a small number of ELS in M16. We observed with GIRAFFE 101 OBA stars, among them 9 are ELS with circumstellar emission in Halpha. We found that: W080 could be a new He-strong star, like W601. W301 is a possible classical Be star, W503 is a mass-transfer eclipsing binary with an accretion disk, and the other ones are possible Herbig Ae/Be stars. We also found that the rotational velocities of main sequence B stars are 18% lower than those of pre-main sequence B stars, in good agreement with theory about the evolution of rotational velocities. Combining different indications and technics, we found that 27% of the B-type stars are binaries. We also redetermined the age of NGC6611 found equal to 1.2--1.8 Myears in good agreement with the most recent determinations.Comment: Accepted by A&A, english not yet correcte

Effects of gravitational darkening on the determination of fundamental parameters in fast rotating B-type stars

In this paper we develop a calculation code to account for the effects carried by fast rotation on the observed spectra of early-type stars. Stars are assumed to be in rigid rotation and the grid of plane-parallel model atmospheres used to represent the gravitational darkening are calculated by means of a non-LTE approach. Attention is paid on the relation between the apparent and parent non-rotating counterpart stellar fundamental parameters and apparent and true vsini parameters as a function of the rotation rate Omega/Omega_c, stellar mass and inclination angle. It is shown that omission of gravitational darkening in the analysis of chemical abundances of CNO elements can produce systematic overestimation or underestimation, depending on the lines used, rotational rate and inclination angle. The proximity of Be stars to the critical rotation is re-discussed by correcting not only the vsini of 130 Be stars, but also their effective temperature and gravity to account for stellar rotationally induced geometrical distortion and for the concomitant gravitational darkening effect. We concluded that the increase of the vsini estimate is accompanied by an even higher value of the stellar equatorial critical velocity, so that the most probable average rate of angular velocity of Be stars attains Omega/Omega_c ~ 0.88.Comment: 20 pages, 16 figures. Submitted for publication in A&

Spitzer/IRAC view of Sh 2-284: Searching for evidence of triggered star formation in an isolated region in the outer Milky Way

Using Spitzer/IRAC observations of a region to be observed by the CoRoT satellite, we have unraveled a new complex star-forming region at low metallicity in the outer Galaxy. We perform a study of S284 in order to outline the chain of events in this star-forming region. We used four-band Spitzer/IRAC photometry as well as Halpha imaging obtained with INT/WFC. Combining these data with the optical photometry obtained in the frame of CoRoTs preparation and the 2MASS catalog we analysed the properties and distribution of young stellar objects (YSOs) associated with point-like sources. We also studied the SEDs of regions of extended emission, complementing our dataset with IRAS and MSX data. We find that S284 is unique in several ways: it is very isolated at the end of a spiral arm and both the diffuse dust and ionized emission are remarkably symmetric. We have partially resolved the central clusters of the three bubbles present in this region. Despite the different scales present in its multiple-bubble morphology, our study points to a very narrow spread of ages among the powering high-mass clusters. In contrast, the particular sawtooth structure of the extended emission at the rim of each ionized bubble harbours either small lower-mass clusters with a younger stellar population or individual young reddened protostars. In particular, triggered star formation is considered to be at work in these regions.Comment: Accepted by A&A. 13 pages, 10 figures, 2 Table

Lower ototoxicity and absence of hidden hearing loss point to gentamicin C1a and apramycin as promising antibiotics for clinical use

Trabajo presentado en el 42nd Annual MidWinter Meeting of the Association of Otorhinolaryngology, celebrado en Baltimore (Estados Unidos) del 9 al 13 de febrero de 2019.[Background]: Spread of antimicrobial resistance and shortage of novel antibiotics have led to an urgent need for new antibacterials (Maura et al. 2016, Curr Opin Microbiol 33: 41-46; Tacconelli et al. 2018, Lancet Infect Dis 18: 318-327). Although aminoglycoside antibiotics (AGs) exhibit potent antimicrobial activity, their use has been largely restricted due to serious sideeffects, mainly nephrotoxicity and ototoxicity (Forge and Schacht 2000, Audiol Neurootol 5: 3-22; Huth et al. 2011, Int J Otolaryngol 2011: 937861). It is therefore of great importance to identify AGs of strong antibacterial activity that lack their most harmful side effects.[Methods]: A large number of AGs were tested against a series of multidrug-resistant clinical isolates of the ESKAPE panel; of these, five AGs showing strong antibacterial activity were selected to evaluate their ototoxicity. A stepwise approach was followed, aiming at setting up a protocol that could be used in future high-throughput screenings. In vitro tests were initially conducted by assessing the viability of two established otic cell lines following AG treatment, and subsequently on murine cochlear organotypic cultures, by analysing hair cell survival. In vivo work was then carried out on a guinea pig model, following local round window application of the AGs.[Results]: Commercial gentamicin mixture (GM), the GM congener gentamicin C1a (GM C1a), apramycin (Apra), paromomycin (Paro) and neomycin (Neo) were selected for ototoxicity testing. In vitro analyses confirmed GM and Neo as the most toxic of the tested AGs, and Apra and Paro as those with the lowest toxicity; interestingly, GM C1a appeared to be less toxic than GM. Regarding the in vivo work, a dose-dependent effect of AGs on outer hair cell (OHC) survival and compound action potentials (CAPs) showed that GM C1a and Apra were the least toxic. Strikingly, although no changes were observed in CAP thresholds and OHC survival following treatment with low concentrations of Neo, GM and Paro, the number of inner hair cell (IHC) synaptic ribbons and the CAP amplitudes were reduced. This indication of hidden hearing loss was not observed with GM C1a or Apra at such concentrations.[Conclusion]: These findings have: (a) validated our screening approach, approach that will now be used for high-throughput testing of newly isolated AG congeners, (b) revealed the IHCs as the inner ear’;s most vulnerable element to AG treatment, and (c) identified GM C1a and Apra as promising bases for the development of clinically useful antibiotics

Emission-line stars discovered in the UKST H-alpha survey of the Large Magellanic Cloud; Part 1: Hot stars

We present new, accurate positions, spectral classifications, radial and rotational velocities, H-alpha fluxes, equivalent widths and B,V,I,R magnitudes for 579 hot emission-line stars (classes B0 - F9) in the Large Magellanic Cloud which include 469 new discoveries. Candidate emission line stars were discovered using a deep, high resolution H-alpha map of the central 25 deg2 of the LMC obtained by median stacking a dozen 2 hour H-alpha exposures taken with the UK Schmidt Telescope. Spectroscopic follow-up observations on the AAT, UKST, VLT, the SAAO 1.9m and the MSSSO 2.3m telescope have established the identity of these faint sources down to magnitude R~23 for H-alpha (4.5 x 10^-17 ergs cm^2 s^-1 Ang). Confirmed emission-line stars have been assigned an underlying spectral classification through cross-correlation against 131 absorption line template spectra covering the range O1 to F8. We confirm 111 previously identified emission line stars and 64 previously known variable stars with spectral types hotter than F8. The majority of hot stars identified (518 stars or 89%) are class B. Of all the hot emission-line stars in classes B-F, 130 or 22% are type B[e], characterised by the presence of forbidden emission lines such as [SII], [NII] and [OII]. We report on the physical location of these stars with reference to possible contamination from ambient HII emission. Along with flux calibration of the H-alpha emission we provide the first H-alpha luminosity function for selected sub-samples after correction for any possible nebula or ambient contamination. We find a moderate correlation between the intensity of H-alpha emission and the V magnitude of the central star based on SuperCOSMOS magnitudes and OGLE-II photometry where possible. Cool stars from classes G-S, with and without strong H-alpha emission, will be the focus of part 2 in this series.Comment: 24 pages (main paper) 36 figures, 6 tables; Appendix Tables: 22 pages, MNRAS, 201

Expression Patterns of Glutathione Transferase Gene (GstI) in Maize Seedlings Under Juglone-Induced Oxidative Stress

Juglone (5-hydroxy-1,4-naphthoquinone) has been identified in organs of many plant species within Juglandaceae family. This secondary metabolite is considered as a highly bioactive substance that functions as direct oxidant stimulating the production of reactive oxygen species (ROS) in acceptor plants. Glutathione transferases (GSTs, E.C.2.5.1.18) represent an important group of cytoprotective enzymes participating in detoxification of xenobiotics and limiting oxidative damages of cellular macromolecules. The purpose of this study was to investigate the impact of tested allelochemical on growth and development of maize (Zea mays L.) seedlings. Furthermore, the effect of juglone-induced oxidative stress on glutathione transferase (GstI) gene expression patterns in maize seedlings was recorded. It was revealed that 4-day juglone treatment significantly stimulated the transcriptional activity of GstI in maize seedlings compared to control plants. By contrast, at the 6th and 8th day of experiments the expression gene responses were slightly lower as compared with non-stressed seedlings. Additionally, the specific gene expression profiles, as well as the inhibition of primary roots and coleoptile elongation were proportional to juglone concentrations. In conclusion, the results provide strong molecular evidence that allelopathic influence of juglone on growth and development of maize seedlings may be relevant with an induction of oxidative stress in acceptor plants