As rare as common sense

An anthology of short fiction by Jose Luis Llerena

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

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

SDN-DMM for intelligent mobility management in heterogeneous mobile IP networks

[EN] Mobility management applied to the traditional architecture of the Internet has become a great challenge because of the exponential growth in the number of devices that can connect to the network. This article proposes a Software-Defined Networking (SDN)-based architecture, called SDN-DMM (SDN-Distributed Mobility Management), that deals with the distributed mode of mobility management in heterogeneous access networks in a simplified and efficient way, ensuring mainly the continuity of IP sessions. Intent-based mobility management with an IP mapping schema for mobile node identification offers optimized routing without tunneling techniques, hence, an efficient use of the network infrastructure. The simplified mobility control API reduces both signaling and handover latency costs and provides a better scalability and performance in comparison with traditional and SDN-based DMM approaches. An analytical evaluation of such costs demonstrated the better performance of SDN-DMM, and a proof of concept of the proposal was implemented in a real environment.CAPES (Coordenacao de Aperfeicoamento de Pessoal de Nivel Superior) - Brasil; Secretaria de Estado de Investigacion, Desarrollo e Innovacion, Grant/Award Number: TIN2017-84802-C2-1-P; "Convocatoria 2017 - Proyectos I+D+I Programa Estatal de Investigacion, Desarrollo e Innovacion, convocatoria excelencia", Grant/Award Number: TIN2017-84802-C2-1-P; FAP-DF ("Fundacao de Apoio a Pesquisa do Distrito Federal")-BrazilTorres Cordova, R.; Gondim, PRL.; Llerena, YP.; Lloret, J. (2019). SDN-DMM for intelligent mobility management in heterogeneous mobile IP networks. International Journal of Communication Systems. 32(17):1-31. https://doi.org/10.1002/dac.4140131321

Molecular recognition of an acyl–enzyme intermediate on the lipase B from <i>Candida antarctica</i>

This investigation provides evidence of the acyl enzyme species involved in the interaction of R/Sketoprofen with the lipase B from Candida antarctica. The interaction between the profen and the enzyme was studied by in situ time-resolved ATR-FTIR under both static and transient conditions. Particularly, modulation excitation spectroscopy (MES) with phase sensitive detection (PSD) allowed us to univocally distinguish the signals belonging to the interaction between ketoprofen and the enzyme from the strong background signals. These experimental tools coupled with theoretical DFT analysis allowed us to propose various species derived from the interaction of ketoprofen with serine through H bonding (without reaction) and the acyl enzyme species (ester bond formation) which are the intermediates in the biocatalytic assisted esterification and hydrolysis using lipases.Centro de Investigación y Desarrollo en Ciencias AplicadasFacultad de Ciencias Exacta

Ionized gas kinematics and chemical abundances of low-mass star-forming galaxies at z∼3z\sim 3

We selected 35 low-mass SFGs (7.9<log(M$_*$/M$_{\odot}$)<10.3) from deep spectroscopic surveys based on their CIII]1908 emission. We used follow-up NIR observations to examine their rest-optical emission lines and identify ionized outflow signatures through broad emission wings detected after Gaussian modeling of [OIII]4959,5007 profiles. We characterized the galaxies' gas-phase metallicity and carbon-to-oxygen (C/O) abundance using a Te-based method via the OIII]1666/[OIII]5007 ratio and photoionization models. We find line ratios and rest-frame EWs characteristic of high-ionization conditions powered by massive stars. Our sample displays mean rest-frame EW([OIII]5007)~560\r{A} while 15% of them show EW([OIII]4959,5007)>1000\r{A} and EW(CIII])>5\r{A}, closely resembling those now seen in EoR galaxies with JWST. We find low gas-phase metallicities 12+log(O/H)~7.5-8.5 and C/O abundances from 23%-128% solar, with no apparent increasing trend with metallicity. From our [OIII]4959,5007 profile modeling, we find that 65% of our sample shows an outflow component, which is shifted relative to the ionized gas systemic velocity, with mean $v_{max}$~280 km/s which correlates with the $\Sigma_{SFR}$. We find that the mass-loading factor $\mu$ of our sample is typically lower than in more massive galaxies from literature but higher than in typical local dwarf galaxies. In the stellar mass range covered, we find that $\mu$ increases with $\Sigma_{SFR}$ thus suggesting that for a given stellar mass, denser starbursts in low-mass galaxies produce stronger outflows. Our results complement the picture drawn by similar studies at lower redshift, suggesting that the removal of ionized gas in low-mass SFGs driven by stellar feedback is regulated by their stellar mass and by the strength and concentration of their star formation, i.e. $\Sigma_{\rm SFR}$.Comment: Accepted for publication in A&A. We updated the manuscript following referee's suggestions. We updated the estimations of C/O by not including CIV flux since it is not detected in most of our sample. No major changes in our results compared with previous versio

Insights into the reionization epoch from cosmic-noon-CIV emitters in the VANDELS survey

Recently, intense emission from nebular C III] and C IV emission lines have been observed in galaxies in the epoch of reionization ($z>6$) and have been proposed as the prime way of measuring their redshift and studying their stellar populations. These galaxies might represent the best examples of cosmic reionizers, as suggested by recent low-z observations of Lyman Continuum emitting galaxies, but it is hard to directly study the production and escape of ionizing photons at such high redshifts. The ESO spectroscopic public survey VANDELS offers the unique opportunity to find rare examples of such galaxies at cosmic noon ($z\sim 3$), thanks to the ultra deep observations available. We have selected a sample of 39 galaxies showing C IV emission, whose origin (after a careful comparison to photoionization models) can be ascribed to star formation and not to AGN. By using a multi-wavelength approach, we determine their physical properties including metallicity and ionization parameter and compare them to the properties of the parent population to understand what are the ingredients that could characterize the analogs of the cosmic reionizers. We find that C IV emitters are galaxies with high photons production efficiency and there are strong indications that they might have also large escape fraction: given the visibility of C IV in the epoch of reionization this could become the best tool to pinpoint the cosmic reioinzers.Comment: 15 pages, 10 figures, resubmitted to A&A after addressing the referee comment

No strong dependence of Lyman continuum leakage on physical properties of star-forming galaxies at 3.1 ≲ z ≲ 3.5

We present Lyman continuum (LyC) radiation escape fraction (fesc) measurements for 183 spectroscopically confirmed star-forming galaxies in the redshift range 3.11 300 Å. For candidate LyC leakers, we find a weak negative correlation between fesc and galaxy stellar masses, no correlation between fesc and specific star-formation rates (sSFRs) and a positive correlation between fesc and EW0([O III] + Hβ). The weak/no correlations between stellar mass and sSFRs may be explained by misaligned viewing angles and/or non-coincident timescales of starburst activity and periods of high fesc. Alternatively, escaping radiation may predominantly occur in highly localised star-forming regions, or fesc measurements may be impacted by stochasticity of the intervening neutral medium, obscuring any global trends with galaxy properties. These hypotheses have important consequences for models of reionisation