3,536 research outputs found

    Adoption of the personas technique in the open source software development process

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    The growth in the number of non-developer open source software (OSS) application users and the escalating use of these applications have led to the need and interest in developing usable OSS. OSS communities do not generally know how to apply usability techniques and are unclear about which techniques to use in each activity of the development process. The aim of our research is to adopt the Personas usability technique in the PSeInt OSS project and determine the feasibility of adapting the technique for application. To do this, we participated as volunteers in the project. We used the case study research method during technique application and participation in the community. As a result, we identified adverse conditions that were an obstacle to technique application and modified the technique to make it applicable. We can conclude from our experience that these changes were helpful for applying the technique, although it was not easy to recruit OSS users to participate in usability technique applicationThis research has been partly funded by several organizations, including the Government of Ecuador’s Secretariat of Higher Education, Science, Technology and Innovation (SENESCYT) through a scholarship and the State Technical University of Quevedo through doctoral training scholarships for university professors. Also this research was funded by the Spanish Ministry of Education, Culture and Sports FLEXOR and “Realizando Experimentos en la Industria del Software: Comprensión del Paso de Laboratorio a la Realidad” projects (TIN2014-52129-R and TIN2014-60490-P, respectively) and the eMadrid-CM “Investi-gación y Desarrollo de Tecnologías Educativas en la Comunidad de Madrid” project (S2013/ICE-2715

    Diabetes and atypical presentations of patients hospitalized for an acute myocardial infarction in Puerto Rico

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    Introduction: Diabetes mellitus is one of the fastest growing health issues concerning the world today with an estimated 382 million individuals aïŹ€ected as of 2013 and a projected increase in number to 592 million by 2035. Diabetes mellitus is a condition aïŹ€ecting 12-15% of the population or around 400,000 people in Puerto Rico. The most common presenting complaint of diabetics who are hospitalized for an acute myocardial infarction (AMI) is chest pain. However, the pervasiveness of atypical symptoms in diabetic patients is yet unclear. The aim of this study is to determine if there is an association between diabetes and the presentation of atypical symptoms in the emergency room in those suïŹ€ering from an AMI in Puerto Rico. Methods: We conducted a secondary data analysis of data from participants from the 2007, 2009 and 2011 Puerto Rico Cardiovascular Disease Surveillance system (PRCDS), an observational, non-concurrent, cross-sectional study. The main independent variable was presence of diabetes mellitus (Type I and Type II). The outcome was the presence of atypical symptoms at the time of presentation, deïŹned as the absence of chest pain on admission. The prevalence of atypical symptoms in diabetic patients and non-diabetic patients was compared. Binary logistic regression was used to test for independent association. Statistical signiïŹcance was considered for p-values ≀0.05 for a two-tailed test. Analysis was conducted using SPSS software. Results: We found no association between atypical presentation of an AMI and diabetes, before or after adjustment for age, gender, congestive heart failure, stroke history and BMI. (unadjusted OR= 1.0, 95%CI=0.7-1.4 and adjusted OR=1.0, 95% CI=0.6-1.5). Other independent associations identiïŹed were that patients older than 75 were 3.5 times more likely to present atypically than people younger than 55 (OR= 3.5, 95% CI=1.6-7.6), and those with CHF and stroke were more likely to present with atypical symptoms (OR=3.2, 95% CI=1.7-6.1 and OR=4.2 95% CI=2.1-8.4, respectively). Lastly, overweight patients were 3.3 times more likely to present atypically than healthy weight patients (OR=2.0, 95% CI=0.6-7.0). Conclusion: We found no evidence of an association between diabetes and the presentation of atypical symptoms in patients hospitalized for AMI in Puerto Rico

    Peritoneal protein transport during the baseline peritoneal equilibration test is an accurate predictor of the outcome of peritoneal dialysis patients

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    [Abstract] Background: Peritoneal protein excretion (PPE) is a potential marker of the outcome in peritoneal dialysis (PD) patients. Method: Observational study of a cohort of 269 patients starting PD in a single unit. Study variables: total PPE during a baseline peritoneal equilibration test (PET; PET-PPE) and 24-hour PPE. Control variables: essential baseline demographic, laboratory and adequacy markers. Main outcomes: mortality, cardiovascular events and risk of peritonitis. We applied univariate and multivariate strategies of survival analysis. Main Results: PET-PPE sustained a significant, yet limited correlation with 24-hour PPE (r = 0.46, p < 0.0005). At baseline, the main study variables showed an independent correlation with peritoneal transport characteristics (D/P240’ creatinine) and cardiovascular comorbidity. PET-PPE (p < 0.0005, model global χ2 59.4) was a more accurate predictor of overall mortality than 24-hour PPE (p = 0.04, χ2 50.5). Moreover, PPE during PET, but not 24-hour PPE, was an independent predictor of the risks of cardiovascular and infectious mortality, and of peritonitis. Conclusions: Baseline PPE represents a strong independent marker of survival of PD patients. Estimation of PPE during PET is more accurate than 24-hour PPE for this purpose, sustains a definite independent association with cardiovascular and infectious mortality, and shows a significant correlation with the risk of peritonitis

    Diffuse Light in Hickson Compact Groups: The Dynamically Young System HCG 44

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    Compact groups are associations of a few galaxies in which the environment plays an important role in galaxy evolution. The low group velocity dispersion favors tidal interactions and mergers, which may bring stars from galaxies to the diffuse intragroup light. Numerical simulations of galaxy clusters in hierarchical cosmologies show that the amount of the diffuse light increases with the dynamical evolution of the cluster. We search for diffuse light in the galaxy group HCG 44 in order to determine its luminosity and luminosity fraction. Combining with literature data, we aim to constrain the dynamical status of Hickson compact groups. We use Intra Group planetary nebulae (IGPNe) as tracers of diffuse light. These are detected by the so-called on band-off band technique. We found 12 emission line objects in HCG 44, none of them associated with the galaxies of the group. 6/12 emission line objects are consistent with being IGPNe in HCG 44, but are also consistent with being Lyα\alpha background galaxies. Thus we derive an upper limit to the diffuse light fraction in HCG 44 of 4.7%. We find a correlation between the fraction of elliptical galaxies and the amount of diffuse light in Hickson compact groups. Those with large fraction of diffuse light are those with large fractions in number and luminosity of E/S0 galaxies. We propose an evolutionary sequence for Hickson compact groups in which the amount of diffuse light increases with the dynamical evolution of the group.Comment: 9 pages, 4 figures, accepted for publication at A&

    Fuzzy-based forest fire prevention and detection by wireless sensor networks

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    Forest fires may cause considerable damages both in ecosystems and lives. This proposal describes the application of Internet of Things and wireless sensor networks jointly with multi-hop routing through a real time and dynamic monitoring system for forest fire prevention. It is based on gathering and analyzing information related to meteorological conditions, concentrations of polluting gases and oxygen level around particular interesting forest areas. Unusual measurements of these environmental variables may help to prevent wildfire incidents and make their detection more efficient. A forest fire risk controller based on fuzzy logic has been implemented in order to activate environmental risk alerts through a Web service and a mobile application. For this purpose, security mechanisms have been proposed for ensuring integrity and confidentiality in the transmission of measured environmental information. Lamport's signature and a block cipher algorithm are used to achieve this objective

    Two-bands superconductivity with intra- and interband pairing for synthetic superlattices

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    We consider a model for superconductivity in a two-band superconductor, having an anisotropic electronic structure made of two partially overlapping bands with a first hole-like and a second electron-like fermi surface. In this pairing scenario, driven by the interplay between interband Vi,jV_{i,j} and intraband Vi,iV_{i,i} pairing terms, we have solved the two gap equations at the critical temperature T=TcT = T_c and calculate TcT_c and the chemical potential Ό\mu as a function of the number of carriers nn for various values of pairing interactions, V1,1V_{1,1}, V2,2V_{2,2}, and V1,2V_{1,2}. The results show the complexity of the physics of condensates with multiple order parameters with the chemical potential near band edges.Comment: 6 pages, 2 figure

    Peculiar emission line spectra of core extremely red BOSS quasars at z ~ 2-3: orientation and/or evolution?

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    Context. Core extremely red quasars (core ERQ) have been proposed to represent an intermediate evolutionary phase in which a heavily obscured quasar blows out the circumnuclear interstellar medium with very energetic outflows before it becomes an optical quasar. Aims. We investigate whether the properties of core ERQ fit the AGN orientation-based unification scenario. Methods. We revised the general UV and optical emission line properties of core ERQ in the context of the orientation-based scenario. We used diagnostic diagrams based on UV emission line ratios and UV-to-optical line kinematic information to compare the physical and kinematic gas properties of core ERQ with those of other luminous narrow- and broad-line AGN. In particular, we provide a revised comparison of the [OIII] kinematics in 21 core ERQ (20 from Perrotta et al. 2019, MNRAS, 488, 4126 and SDSS J171420.38+414815.7, based on GTC EMIR near-infrared spectroscopy) with other samples of quasars with matching luminosity with the aim of evaluating whether core ERQ host the most extreme [OIII] outflows. Results. The UV line ratios suggest that the physical properties (e.g., density and metallicity) of the ionised gas in core ERQ are similar to those observed in the broad-line region of blue nitrogen-loud quasars. The [OIII] outflow velocities of core ERQ are on average consistent with those of very luminous blue type 1 quasars, although extreme outflows are much more frequent in core ERQ. These similarities can be explained in the context of the AGN unification model under the assumption that core ERQ are viewed with an intermediate orientation between type 2 (edge-on) and type 1 (face-on) quasars. Conclusions. We propose that core ERQ are very luminous but otherwise normal quasars viewed at an intermediate orientation. This orientation allows a direct view of the outer part of the large broad-line region from which core ERQ UV line emission originates; the extreme [OIII] outflow velocities are instead a consequence of the very high luminosity of core ERQ

    Limited impact of jet induced feedback in the multi-phase nuclear interstellar medium of 4C12.50

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    Although the ultraluminous infrared radio galaxy 4C12.50 at z=0.12 is a promising candidate to reveal how radio induced feedback may regulate star formation in galaxies, we find no solid evidence for current or past impact of this mechanism on the evolution of this system, neither by clearing out the dusty central cocoon efficiently, nor by suppressing star formation. We study in detail for the first time the hot (>~1500 K) molecular gas in this object. The potential impact of the radio jet on this gas phase, as well as on the star formation activity, are investigated. 4C12.50 hosts (2.1+/-0.4)x1e4 Msun of hot molecular gas. An unusually high rotational temperature T =3020+/-160 K is inferred. The molecular gas mass obeys a power law temperature distribution d(M(H2))/dT ~ T^-5 from T~300 K and up to ~3000 K. Both results support that shocks (probably induced by the radio jet) contribute to the heating and excitation of the hot molecular gas. A molecular outflow is not detected. The coupling of the outflowing ionized and neutral outflows with the hot molecular gas is poor. We find no evidence for star formation supression. NIR and MIR integral field spectroscopy at very high spatial resolution (for instance, with the JWST) would be of key value to further investigate these issues.Comment: Accepted for publication in A&A,18 pages, 13 figure
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