Per aprendre anglès, quan abans millor? L'aprenentatge de l'anglès com a llengua estrangera. When Learning English, is it a case of 'The earlier the better?' Learning English as a foreign Language

En contra del que molts pares i mestres pensen, i en contra del que s'ha trobat en contextos d'adquisició natural de segones llengües i d'immersió, començar al més aviat possible l'aprenentatge d'idiomes, sobretot pel que fa a les tasques cognitivament més exigents, com l'escriptura, no sembla l'opció més eficaç. Els resultats del Grup de Recerca en Adquisició de Llengües (GRAL) estudià aprenents d'anglès que començaren als vuit i onze anys i trobaren, sistemàticament, que a llarg termini, després de les mateixes hores d'instrucció, eren els més grans, que havien començat als onze anys, els que obtenien millors resultats en totes les proves orals i escrites d'anglès excepte en alguna de prova de reconeixement fonètic. La maduresa cognitiva dels alumnes més grans i els diferents mecanismes d¿aprenentatge implícit i explícit entre els nens més petits i els adults ajuden a explicar per què només començar abans l'aprenentatge d'idiomes no sembla suficient per obtenir millors resultats.

Psychometric evaluation of the IWQOL-Lite (Spanish version) when applied to a sample of obese patients awaiting bariatric surgery

Background Obesity may have an impact on key aspects of health-related quality of life (HRQOL). In this context, the Impact of Weight Quality of Life (IWQOL) questionnaire was the first scale designed to assess HRQOL. The aim of the present study was twofold: to assess HRQOL in a sample of Spanish patients awaiting bariatric surgery and to determine the psychometric properties of the IWQOL-Lite and its sensitivity to detect differences in HRQOL across groups. Methods Participants were 109 obese adult patients (BMI¿ 35 kg/m2) from Barcelona, to whom the following measurement instruments were applied: IWQOL-Lite, Depression Anxiety Stress Scales, Brief Symptom Inventory, and self-perception items. Results Descriptive data regarding the IWQOL-Lite scores obtained by these patients are reported. Principal components analysis revealed a five-factor model accounting for 72.05% of the total variance, with factor loadings being adequate for all items. Corrected itemtotal correlations were acceptable for all items. Cronbach"s alpha coefficients were excellent both for the subscales (0.880.93) and the total scale (0.95). The relationship between the IWQOLLite and other variables supports the construct validity of the scale. Finally, sensitivity analysis revealed large effect sizes when comparing scores obtained by extreme BMI groups. Conclusions This is the first study to report the application of the IWQOL-Lite to a sample of Spanish patients awaiting bariatric surgery and to confirm that the Spanish version of the instrument has adequate psychometric properties.

The Conservativeness of the Central Bank when Institutional Quality is Poor

We propose an extension of Alesina and Tabellini 's model (1987) to include corruption, which is understood as the presence of weak institutions collecting revenue through formal tax channels. This paper analyses how conservative should an independent central bank be when the institutional quality is poor. When there are no political distortions, we show that the central bank has to be more conservative than the government, except with complete corruption. In this particular case, the central bank should be as conservative as the government. Further, we obtain that the relationship between the optimal relative degree of conservativeness of the central bank and the degree of corruption is affected by supply shocks. Concretely, when these shocks are not important, the central bank should be less conservative if the degree of corruption increases. However, this result may not hold when the shocks are relevant. JEL classi fication: D6, D73, E52, E58, E62, E63. Keywords: Central Bank Conservativeness; Corruption; Fiscal Policy; Monetary Policy; Seigniorage.

The number of planar central configurations for the 4-body problem is finite when 3 mass positions are fixed

In the n{body problem a central con guration is formed when the position vector of each particle with respect to the center of mass is a common scalar multiple of its acceleration vector. Lindstrom showed for n = 3 and for n > 4 that if n ? 1 masses are located at xed points in the plane, then there are only a nite number of ways to position the remaining nth mass in such a way that they de ne a central con guration. Lindstrom leaves open the case n = 4. In this paper we prove the case n = 4 using as variables the mutual distances between the particles.

Frames of War: When is Life Grievable?

La tesis principal de Butler en Frames of War es que los marcos interpretativos por medio de los cuales nos es posible entender la violencia son parte material y esencial del propio acto de librar una guerra. Del mismo modo que un contenido y su envoltorio a veces no pueden separarse, lo que entendemos como"contenido" (el hecho bélico) está necesariamente enmarcado y no es posible aproximarse a él ajeno a los marcos que lo vehiculan. El marco es una estrategia activa de contención que no sólo contiene lo que es sino también su justificación y su interpretación, y en un contexto de guerra el marco dictamina, además de la justificación, la distinción entre las vidas que merecen ser preservadas y lloradas, y las que no.

Goal setting and monetary incentives: when large stakes are not enough

The aim of this paper is to test the effectiveness of wage-irrelevant goal setting policies in a laboratory environment. In our design, managers can assign a goal to their workers by setting a certain level of performance on the work task. We establish our theoretical conjectures by developing a model where assigned goals act as reference points to workers’ intrinsic motivation. Consistent with our model, we find that managers set goals which are challenging but attainable for an average-ability worker. Workers respond to these goals by increasing effort, performance and by decreasing on-the-job leisure activities with respect to the no-goal setting baseline. Finally, we study the interaction between goal setting and monetary rewards and find that goal setting is most effective when monetary incentives are strong. These results suggest that goal setting may produce intrinsic motivation and increase workers’ performance beyond what is achieved using solely monetary incentives.

Threading libraries performance when applied to image acquisition and processing in a forensic application

Peer-reviewed

When supply travels far beyond demand: Causes of oversupply in Spain’s transport infrastructure

Spain’s transport infrastructure policy has become a paradigmatic case of oversupply and of mismatch with demand. The massive expansion of the country’s transport infrastructure over the last decade has not been a response to demand bottlenecks or previously identified needs. For this reason, the intensity of use today on all interurban modes of transport in Spain falls well below that of other EU countries. This paper analyzes the institutional and regulatory factors that have permitted this policy, allowing us to draw lessons from the Spanish case that should help other countries avoid the pitfalls and shortcomings of Spanish policy.

When supply travels far beyond demand: Causes of oversupply in Spain’s transport infrastructure

Spain’s transport infrastructure policy has become a paradigmatic case of oversupply and of mismatch with demand. The massive expansion of the country’s transport infrastructure over the last decade has not been a response to demand bottlenecks or previously identified needs. For this reason, the intensity of use today on all interurban modes of transport in Spain falls well below that of other EU countries. This paper analyzes the institutional and regulatory factors that have permitted this policy, allowing us to draw lessons from the Spanish case that should help other countries avoid the pitfalls and shortcomings of Spanish policy.

Secure many-to-one communications in wireless sensor networks

Wireless Sensor Networks (WSN) are formed by nodes with limited computational and power resources. WSNs are finding an increasing number of applications, both civilian and military, most of which require security for the sensed data being collected by the base station from remote sensor nodes. In addition, when many sensor nodes transmit to the base station, the implosion problem arises. Providing security measures and implosion-resistance in a resource-limited environment is a real challenge. This article reviews the aggregation strategies proposed in the literature to handle the bandwidth and security problems related to many-to-one transmission in WSNs. Recent contributions to secure lossless many-to-one communication developed by the authors in the context of several Spanish-funded projects are surveyed. Ongoing work on the secure lossy many-to-one communication is also sketched.

When cholesterol is not cholesterol: a note on the enzymatic determination of its concentration in model systems containing vegetable extracts

Background: Experimental evidences demonstrate that vegetable derived extracts inhibit cholesterol absorption in the gastrointestinal tract. To further explore the mechanisms behind, we modeled duodenal contents with several vegetable extracts. Results: By employing a widely used cholesterol quantification method based on a cholesterol oxidase-peroxidase coupled reaction we analyzed the effects on cholesterol partition. Evidenced interferences were analyzed by studying specific and unspecific inhibitors of cholesterol oxidase-peroxidase coupled reaction. Cholesterol was also quantified by LC/MS. We found a significant interference of diverse (cocoa and tea-derived) extracts over this method. The interference was strongly dependent on model matrix: while as in phosphate buffered saline, the development of unspecific fluorescence was inhibitable by catalase (but not by heat denaturation), suggesting vegetable extract derived H2O2 production, in bile-containing model systems, this interference also comprised cholesterol-oxidase inhibition. Several strategies, such as cholesterol standard addition and use of suitable blanks containing vegetable extracts were tested. When those failed, the use of a mass-spectrometry based chromatographic assay allowed quantification of cholesterol in models of duodenal contents in the presence of vegetable extracts. Conclusions: We propose that the use of cholesterol-oxidase and/or peroxidase based systems for cholesterol analyses in foodstuffs should be accurately monitored, as important interferences in all the components of the enzymatic chain were evident. The use of adequate controls, standard addition and finally, chromatographic analyses solve these issues.

The relative salience of facial features when differentiating faces based on an interference paradigm

Research on face recognition and social judgment usually addresses the manipulation of facial features (eyes, nose, mouth, etc.). Using a procedure based on a Stroop-like task, Montepare and Opeyo (J Nonverbal Behav 26(1):43-59, 2002) established a hierarchy of the relative salience of cues based on facial attributes when differentiating faces. Using the same perceptual interference task, we established a hierarchy of facial features. Twenty-three participants (13 men and 10 women) volunteered for the experiment to compare pairs of frontal faces. The participants had to judge if the eyes, nose, mouth and chin in the pair of images were the same or different. The factors manipulated were the target-distractive factor (4 face components 9 3 distractive factors), interference (absent vs. present) and correct answer (the same vs. different). The analysis of reaction times and errors showed that the eyes and mouth were processed before the chin and nose, thus highlighting the critical importance of the eyes and mouth, as shown by previous research.

Financing public education when altruistic agents have retirement concerns

[cat]El capital humà i, per tant, l’educació tenen un impacte en el benestar futur de la societat. En aquest treball s’estudia la connexió entre el suport dels votants per una educació pública i les preocupacions sobre la seva jubilació. Mostrem com els votants anticipen els efectes positius que té l’educació sobre les pensions futures. Així, el recolzament a un sistema educatiu públic s’incrementa si el sistema de pensions és més redistributiu, cosa que també es dóna entre els ciutadans que prefereixen una educació privada. També mostrem que el tipus d’equilibri “ends against the middle” pot ocórrer fins i tot quan la taxa impositiva preferida pels votants és decreixent amb la renda.

Financing public education when altruistic agents have retirement concerns

[cat]El capital humà i, per tant, l’educació tenen un impacte en el benestar futur de la societat. En aquest treball s’estudia la connexió entre el suport dels votants per una educació pública i les preocupacions sobre la seva jubilació. Mostrem com els votants anticipen els efectes positius que té l’educació sobre les pensions futures. Així, el recolzament a un sistema educatiu públic s’incrementa si el sistema de pensions és més redistributiu, cosa que també es dóna entre els ciutadans que prefereixen una educació privada. També mostrem que el tipus d’equilibri “ends against the middle” pot ocórrer fins i tot quan la taxa impositiva preferida pels votants és decreixent amb la renda.

Incumbency (dis)advantage when citizens can propose

This paper analyses the problem that an incumbent faces during the legislature when deciding how to react to citizen proposals such as the outcome of referenda or popular initiatives. We argue that these proposals constitute a potential source of electoral disadvantage when citizens factor in their evaluation of the incumbent his reaction to these proposals. This is because an incumbent politician may jeopardize his re-election by implementing policies close to his preferred ones but unpopular among the electorate. We characterize conditions under which this potential disadvantage becomes in fact an electoral advantage for the incumbent. We find that the choices of the incumbent during the legislature will be closest to citizens policy proposals when the intensity of electoral competition is neither too soft nor too tough. Finally, we use our results to discuss some implications of the use of mechanisms such as referenda and popular assemblies on electoral competition and on the incumbency advantage phenomenon.