Reacciones de los candidatos ante el uso de las redes sociales en selección y evaluación de personal

Human Resource (HR) professionals are increasingly using Social Networking Websites (SNWs) for personnel recruitment and selection processes. However, evidence is required regarding their psychometric properties and their impact on applicant reactions. In this paper we present and discuss the results of exploring applicant reactions to either the use of a professional SNW (such as LinkedIn) or a non-professional SNW (such as Facebook). A scale for assessing applicant reactions was applied to 124 professionals. The results showed more positive attitudes to the use of professional SNWs compared with non-professional SNWs. Both gender and age moderated these results, with females and young applicants having a less positive attitude than males and older participants towards the use of non-professional SNW

Cambios en el uso del preservativo en una cohorte de prostitutas

ResumenObjetivoDescribir los cambios en el uso del preservativo en una cohorte de mujeres que ejercen la prostitución en Alicante y analizar los factores que se relacionan con los cambios en esta práctica preventiva.MétodosSe han usado los datos de un estudio prospectivo que incluyó a las mujeres dedicadas a la prostitución que acudieron al Centro de Información y Prevención de Sida (CIPS) de Alicante desde 1986 a 1996. Se estimó la frecuencia en el uso del preservativo con los clientes en la primera y última visita al centro, se valoró el cambio entre las dos visitas y los factores asociados a ellos. Se realizaron dos análisis de regresión logística para determinar la asociación entre el cambio positivo o negativo y las variables explicativas.ResultadosLa prevalencia de uso del preservativo en la última visita fue mayor que en la primera (83,9% frente al 69,2%; p < 0,001). Entre las prostitutas que trabajan en contactos se incrementa más de cinco veces el uso del preservativo que entre las que lo hacen en los clubs y en la calle. Las que tienen mayor tiempo de seguimiento son las que tienen una mayor prevalencia en el uso del preservativo al final del seguimiento (odds ratio ajustada > 6 años frente a < de un año = 7,61; intervalo de confianza [IC] del 95%: 2,2-26,0).ConclusiónEste estudio ha puesto en evidencia un incremento en la frecuencia del uso del preservativo y la baja frecuencia de su abandono en una cohorte de prostitutas a lo largo de 10 años. En un futuro será necesario adaptar esta estrategia preventiva a las nuevas formas de prostitución menos estables y al incremento de inmigrantes, factores que motivan una menor asistencia y adhesión a centros de prevención.SummaryObjetiveTo describe changes in condom use among prostitutes enrolled in a prospective cohort study in Alicante (Spain), and to identify those factors associated with changes in this behaviour.MethodsData from this study come from a prospective cohort study of women working at prostitution enrolled in a center for AIDS preventive at Alicante from 1986 to 1996. The proportion of condom use by prostitutes with their clients was recorded during the first visit and the last one, and changes in condom use were estimated as the difference between them. Two logistic regression analyses were done to identify those factors associated with positive or negative changes in condom use.ResultsA statistically significant increase in the prevalence of condom use was observed between the first, 69,2%, and the last visit, 83,9% (p < 0,001). Prostitutes working private increased the condom use more than five time than those working in clubs or at the street. The higher the follow-up time the higher the prevalence of condom user, OR > 6 years = 7,6 (95% CI: 2,2-26,0). No variable was associated with a negative change in condom use.ConclusionThis study shows an overall increase of condom use in a cohort of prostitutes after 10 years of follow-up. Relapse in risk behavior has been infrequent. In the future, preventive strategies to increase the use of condoms among prostitutes should be adapted to the new forms of sexual commerce

Continuous 3-year outdoor operation of a flat-panel membrane photobioreactor to treat effluent from an anaerobic membrane bioreactor

A membrane photobioreactor (MPBR) plant was operated continuously for 3 years to evaluate the separate effects of different factors, including: biomass and hydraulic retention times (BRT, HRT), light path (Lp), nitrification rate (NOxR) and nutrient loading rates (NLR, PLR). The overall effect of all these parameters, which influence MPBR performance had not previously been assessed. The multivariate projection approach chosen for this study provided a good description of the collected data and facilitated their visualization and interpretation. Forty variables used to control and assess MPBR performance were evaluated during three years of continuous outdoor operation by means of principal component analysis (PCA) and partial least squares (PLS) analysis. The PCA identified the photobioreactor light path as the factor with the largest influence on data variability. Other important factors were: air flow rate (Fair), nitrogen and phosphorus recovery rates (NRR, PRR), biomass productivity (BP),optical density at 680 nm (OD680), ammonium and phosphorus effluent concentration (NH4, P), HRT, BRT, and nitrogen and phosphorus loading rates (NLR and PLR). The MPBR performance could be adequately estimated by a PLS model based on all the recorded variables, but this estimation worsened appreciably when only the controllable variables (Lp, Fair, HRT and BRT) were used as predictors, which underlines the importance of the non-controlled variables on MPBR performance. The microalgae cultivation process could thus only be partially controlled by the design and operating variables. As effluent nitrate concentration was shown to be the key factor in the nitrification rate, it can be used as an indirect measurement of nitrifying bacteria activity. A high nitrification rate was found to be inadvisable, since it showed an inverse correlation with NRR. In this respect, temperature appeared to be the main ambient/controlling factor in nitrifying bacteria activity

Algoritmo mixto mínima entropía-máxima información para la selección de ítems en un test adaptativo informatizado

El objetivo del estudio que presentamos es comparar la eficacia como estrategia de selección de ítems de tres algoritmos diferentes: a) basado en máxima información; b) basado en mínima entropía; y c) mixto mínima entropía en los ítems iniciales y máxima información en el resto; bajo la hipótesis de que el algoritmo mixto, puede dotar al TAI de mayor eficacia. Las simulaciones de procesos TAI se realizaron sobre un banco de 28 ítems de respuesta graduada calibrado según el modelo de Samejima, tomando como respuesta al TAI la respuesta original de los sujetos que fueron utilizados para la calibración. Los resultados iniciales muestran cómo el criterio mixto es más eficaz que cualquiera de los otros dos tomados independientemente. Dicha eficacia se maximiza cuando el algoritmo de mínima entropía se restringe a la selección de los primeros ítems del TAI, ya que con las respuestas a estos primeros ítems la estimación de θ comienza a ser relevante y el algoritmo de máxima información se optimiza.Item selection algorithms in computerized adaptive testing. The aim of this paper is to compare the efficacy of three different item selection algorithms in computerized adaptive testing (CAT). These algorithms are based as follows: the first one is based on Item Information, the second one on Entropy, and the last algorithm is a mixture of the two previous ones. The CAT process was simulated using an emotional adjustment item bank. This item bank contains 28 graded items in six categories, calibrated using Samejima (1969) Graded Response Model. The initial results show that the mixed criterium algorithm performs better than the other ones

Psychometric properties of an emotional adjustment computerized adaptive test

En el presente trabajo se describen las propiedades psicométricas de un Test Adaptativo Informatizado para la medición del ajuste emocional de las personas. La revisión de la literatura acerca de la aplicación de los modelos de la teoría de la respuesta a los ítems (TRI) muestra que ésta se ha utilizado más en el trabajo con variables aptitudinales que para la medición de variables de personalidad, sin embargo diversos estudios han mostrado la eficacia de la TRI para la descripción psicométrica de dichas variables. Aun así, pocos trabajos han explorado las características de un Test Adaptativo informatizado, basado en la TRI, para la medición de una variable de personalidad como es el ajuste emocional. Nuestros resultados muestran la eficiencia del TAI para la evaluación del ajuste emocional, proporcionando una medición válida y precisa, utilizando menor número de elementos de medida en comparación con las escalas de ajuste emocional de instrumentos fuertemente implantadosIn the present work it was described the psychometric properties of an emotional adjustment computerized adaptive test. An examination of Item Response Theory (IRT) research literature indicates that IRT has been mainly used for assessing achievements and ability rather than personality factors. Nevertheless last years have shown several studies wich have successfully used IRT to personality assessment instruments. Even so, a few amount of works has inquired the computerized adaptative test features, based on IRT, for the measurement of a personality traits as it’s the emotional adjustment. Our results show the CAT efficiency for the emotional adjustment assessment so this provides a valid and accurate measurement; by using a less number of items in comparison with the emotional adjustment scales from the most strongly established questionnaire

Scaling law for topologically ordered systems at finite temperature

Understanding the behaviour of topologically ordered lattice systems at finite temperature is a way of assessing their potential as fault-tolerant quantum memories. We compute the natural extension of the topological entanglement entropy for T > 0, namely the subleading correction $I_{\textrm{topo}}$ to the area law for mutual information. Its dependence on T can be written, for Abelian Kitaev models, in terms of information-theoretic functions and readily identifiable scaling behaviour, from which the interplay between volume, temperature, and topological order, can be read. These arguments are extended to non-Abelian quantum double models, and numerical results are given for the $D(S_3)$ model, showing qualitative agreement with the Abelian case.Comment: 4 pages, 2 figure

Understanding the performance of an AnMBR treating urban wastewater and food waste via model simulation and characterization of the microbial population dynamics

[EN] An anaerobic membrane bioreactor (AnMBR) pilot plant treating kitchen food waste (FW) jointly with urban wastewater was run for 536 days. Different operational conditions were tested varying the sludge retention time (SRT), the hydraulic retention time (HRT) and the penetration factor (PF) of food waste disposers. COD removal efficiency exceeded 90% in all tested conditions. The joint treatment resulted in an almost 3-fold increase in methane production (at 70 days of SRT, 24 h HRT and 80% PF) in comparison with the treatment of urban wastewater only. Mathematical model simulations and Illumina technology were used to obtain in-depth information of this outstanding process performance. Both the PF and SRT factors increased influent biodegradability. The experimental results were accurately reproduced via model simulations modifying only the influent biodegradability. The high SRT and the presence of ground FW in the influent resulted in higher hydrolytic activity. Not only did the Archaea population increase 3-fold but Levilinea genera was also significantly raised. Three new genera characterised by anaerobic fermentation of amino acids (Leptolinea, Aminomonas and Aminobacterium) were among the ten most abundant of the total sequences identified during the joint treatment, indicating an improvement in the hydrolysis step of anaerobic degradation. Influent biodegradability remained at high values when FW addition stopped.This research work has been financially supported by the Generalitat Valenciana (PROMETEO/2012/029 PROJECT), which is gratefully acknowledged.Durán Pinzón, F.; Zamorano -López, N.; Barat, R.; Ferrer, J.; Aguado García, D. (2018). Understanding the performance of an AnMBR treating urban wastewater and food waste via model simulation and characterization of the microbial population dynamics. Process Biochemistry. 67:139-146. https://doi.org/10.1016/j.procbio.2018.02.010S1391466

PLS-based soft-sensor to predict ammonium concentration evolution in hollow fibre membrane contactors for nitrogen recovery

[EN] Hollow fibre membrane contactors (HFMC) have emerged as a promising technology for nitrogen-recovery that can be implemented in wastewater treatment plants (WWTPs) to promote circular economy. In this process, a hydrophobic membrane allows the transference of free-ammonia across the hollow fibres. During its operation, the ammonium concentration decreases, and real-time measurements would be of great value for process monitoring, optimization and control. Ammonium probes exist, but they are expensive and present noticeably maintenance costs. In this work, results from eight N-recovery experiments performed at different pH values using real supernatant of a full-scale anaerobic digester were analysed in terms of the time-evolution profiles of pH and total ammonium nitrogen (TAN). The pH revealed to carry relevant information related to the TAN concentration, as it decreased in the feed solution due to free ammonia stripping. The pH is an inexpensive-to measure process variable that can be routinely acquired in any WWTP. Therefore, a data-driven soft-sensor has been developed. It uses the pH, its derivative, and the pH increments after each reagent dosing as input signals, to estimate the TAN concentration via PLS. An extended PLS-model incorporating interaction terms, quadratic and cubic forms of the three input variables improved the TAN concentration estimation. The developed soft-sensor was able to accurately reproduce the evolution of TAN concentration (in the range 0-1000 mgNH(4)(+)-N/L with R-2 > 0.97 and RMSE < 40 mg/L) during the HFMC process operation, thus making it possible to monitor the process as well as enabling future development of different control and optimization strategies.This research was financially supported by the Spanish Ministry of Economy and Competitiveness (MINECO projects CTM2014-54980-C2-1/2-R and CTM2017-86751-C2-1/2-R) with the European Regional Development Fund (ERDF) as well as the Universitat Polite`cnica de Vale`ncia via a pre-doctoral FPI fellowship to Guillermo Noriega.Aguado García, D.; Noriega-Hevia, G.; Ferrer, J.; Seco, A.; Serralta Sevilla, J. (2022). PLS-based soft-sensor to predict ammonium concentration evolution in hollow fibre membrane contactors for nitrogen recovery. Journal of Water Process Engineering. 47:1-7. https://doi.org/10.1016/j.jwpe.2022.102735174

Use of rumen microorganisms to boost the anaerobic biodegradability of microalgae

[EN] A laboratory bioreactor using rumen microorganisms to treat Scenedesmus spp. biomass was operated for 190 days. At first the bioreactor operated as a Rumen-like Fermenter (RF) with a Sludge Retention Time (SRT) of 7 days. The RF was subsequently transformed into an anaerobic digestion system including two configurations: continuously-stirred tank reactor and anaerobic membrane bioreactor in which different SRT values of up to 100 days were assessed. Methane production peaked at 214 mL CH4 g&#8722;1 CODIn with a SRT of 100 days. COD removal and BDP peaked at above 70% and 60%, respectively, at the highest SRT, with no pre-treatment prior to microalgae digestion. The waste sludge production dropped to 0.133 mg VSS mg&#8722;1 CODIn after a SRT of 100 days.This work was funded by the Spanish Ministry of Economy and Competitiveness with the support from the European Commission through the European Regional Development Funds (MINECO, CTM2011-28595-C02-01 and CTM2011-28595-C02-02), which are gratefully acknowledged. The authors would also express their gratitude to the Education, Invetigation, Culture and Sports Council from the Valencian Generality for the Post-Doctoral fellowship awarded to Juan Bautista Gimenez Garcia (APOSTD/2016/104). The authors are thankful to Ion Perez Baena (Universitat Politecnica de Valencia, Institut de Ciencia i Tecnologia Animal) for kindly providing the ruminal fluid used in this study.Gimenez, JB.; Aguado García, D.; Bouzas, A.; Ferrer, J.; Seco Torrecillas, A. (2017). Use of rumen microorganisms to boost the anaerobic biodegradability of microalgae. Algal Research. 24:309-316. https://doi.org/10.1016/j.algal.2017.04.0033093162

P-recovery in a pilot-scale struvite crystallisation reactor for source separated urine systems using seawater and magnesium chloride as magnesium sources

[EN] Practical recovery of a non-renewable nutrient, such as phosphorus (P), is essential to support modern agriculture in the near future. The high P content of urine, makes it an attractive source for practicing the recovery of this crucial nutrient. This paper presents the experimental results at pilot-plant scale of struvite crystallisation from a source-separated urine stream using two different magnesium sources, namely magnesium chloride and seawater. The latter was chosen as sustainable option to perform P-recovery in coastal areas. Real seawater was used to assess in a more realistic way its efficiency to precipitate P as struvite, since its composition (with noticeable concentration of ions such as Ca2+, SO42¿, Na+, ¿) could lead to the formation of impurities and other precipitates. 0.99¿g of struvite was obtained per litre of urine irrespective of the operational conditions tested. In all tested conditions, precipitation efficiencies exceeded 90% and recovery efficiencies were higher than 87%, with an average struvite crystal size higher than 110¿¿m (and up to 320¿¿m, depending on the experimental conditions) in the harvested struvite samples. Almost pure struvite was obtained when MgCl2 was used as precipitant, while amorphous calcium phosphate and other impurities appeared in the precipitates using seawater as magnesium source. However, the lower settling velocity of the amorphous precipitates in comparison with the struvite precipitates suggests that their separation at industrial scale could be relatively straightforward.This research work was possible thanks to FCC Aqualia participation in INNPRONTA 2011 IISIS IPT-20111023 project (partially funded by The Centre for Industrial Technological Development (CDTI) and supported by the Spanish Ministry of Economy and Competitiveness).Aguado García, D.; Barat, R.; Bouzas Blanco, A.; Seco Torrecillas, A.; Ferrer, J. (2019). P-recovery in a pilot-scale struvite crystallisation reactor for source separated urine systems using seawater and magnesium chloride as magnesium sources. The Science of The Total Environment. 672:88-96. https://doi.org/10.1016/j.scitotenv.2019.03.485S889667