Perfomance do transverso do abdómen : recurso à ecografia como informação de retorno extrínseca

RESUMO: Desenho do estudo: Estudo quantitativo, experimental prospectivo de factor único, desenho pré-teste, pós-teste. Objectivos: Determinar a efectividade da ecografia em tempo real, como Informação de Retorno Extrínseca Visual Ecográfica (IRE-VE) na performance do transverso do abdómen (TrA), em sujeitos saudáveis; analisar eventuais diferenças entre a IRE-VE e a Informação de Retorno Extrínseca Verbal Clínica (IRE-VC); medir a performance da musculatura abdominal, através das diferenças na espessura dos músculos TrA e oblíquo interno (OI) e deslizamento do TrA, em repouso e em contracção. Enquadramento: A maioria dos indivíduos não tem conhecimentos nem consciência do contributo de uma boa performance do TrA para a estabilidade da coluna lombar. Vários estudos recentes se têm dedicado a este assunto, tendo sido mostrado o importante contributo da ecografia como Informação de Retorno Extrínseca (IRE). Uma vez que o TrA e o OI contribuem para a estabilidade lombo pélvica, e que a aprendizagem do seu controlo motor é essencial para a recuperação da função, torna-se relevante clarificar o contributo da informação de retorno na primeira fase da aprendizagem da performance desses músculos, bem como encontrar as melhores estratégias para a sua realização. A ecografia foi o instrumento escolhido para servir esse objectivo. Métodos: Participaram no estudo 75 sujeitos, sem queixas lombares, com idades compreendidas entre os 18 e os 38 anos com um valor médio de 21,9 anos (±4,03), divididos aleatoriamente em três grupos com uma tarefa comum: a “Manobra do Transverso”, em que um grupo não recebeu IRE (GC), outro recebeu IRE verbal clínica e palpatória (GIRE-VC) e ooutro recebeu IRE visual ecográfica (GIRE-VE). Para efeitos de análise da contracção da musculatura abdominal, foram estudadas a espessura dos músculos TrA e OI e o deslizamento do TrA, visualizados em imagens ecográficas em tempo real, e congeladas para medição em diferido. Estes procedimentos foram apurados num estudo piloto de fidedignidade das medições em causa. Quanto à abordagem estatística das variáveis de performance muscular foi realizada uma análise da variância simples paramétrica para amostras independentes e um teste para a diferença de médias para amostras emparelhadas. Resultados: Observamos que no GC, a ausência de IRE cursou com uma performance idêntica nos dois momentos de avaliação e que nos dois grupos com IRE, das variáveis de performance, é significativamente diferente a contracção do TrA, para uma diferença de 1,95 mm no GIRE-VE (p=0,000) e de 0,84 mm no GIRE-VC (p=0,000). Ao comparar os grupos entre si houve diferenças no limiar da significância (p=0,056) para uma melhor contracção do TrA no GIRE-VE. As outras variáveis, contracção do OI e deslizamento do TrA, não revelaram efeito relacionado com a IRE em nenhum dos grupos. Conclusão: Dos resultados obtidos, podemos concluir que a IRE-VE, quando usada isoladamente, na Manobra do Transverso provoca um maior aumento na espessura do TrA, quando comparada com a IRE-VC . O uso da ecografia mostrou ser efectivo na facilitação da performance da Manobra do Transverso em sujeitos saudáveis.---------------------ABSTRACT: Study Design: Single Factor Experimental Design: Pre-Test Post-test Control Group Design. Objectives: To measure the contribution of different types of biofeedack on Transversus Abdominis (TrA) and Internal Oblique (IO) performance through changes in thickness and lateral slide of TrA anterior fascia during abdominal hollowing exercise (AHE). Background: Increasingly clinicians are using real-time ultrasound imaging as a form of supplementing feedback when teaching trunk stabilization exercises to patients; however, there has been no evidence of its effectiveness when used alone. Material and Methods: Seventy-five healthy subjects were divided randomly into 3 groups that received: group 1, no feedback; group 2, verbal and palpatory feedback, and group 3, realtime ultrasound feedback. The TrA and IO performance of each subject was twice assessed (before and after receiving feedback) when performing the AHE in a supine hook-lying position. Analysis of variance and T-test were used for the independent and paired samples, respectively, to determine significant changes in the performance of TrA and IO, based on intra and inter group analysis. Results: Group 1 had no differences between moments; group 2 had significant differences concerning TrA thickness (p=0,000) to a 0,84 mm thickness difference; group 3 had significant differences concerning TrA thickness (p=0,000) to a 1,94 mm difference; The ability to perform the AHE differed only among group 3 and group 1 (p=0.056), and only for changes in thickness of TrA muscle. No differences among groups were found neither for the lateral slide of TrA anterior fascia, nor for the internal oblique thickness. Conclusion: From the results of this study we conclude that real-time ultrasound feedback, when used alone during an AHE, can have a larger increase in TrA thickness when compared to verbal and palpatory feedback. The use of real time ultrasound showed to be effective as a feedback tool to facilitate the performance of the AHE in a supine hook-lying position in healthy subjects.

Three transducers for one photodetector: essays for optical communications

Dissertation presented to obtain the PhD degree in Electrical and Computer Engineering - Electronics

Projecto e implementação de uma fonte de alta tensão para produção de descargas eléctricas

O objetivo deste trabalho consistiu em projetar, construir e testar um protótipo em laboratório de uma fonte de alimentação de alta tensão que permita descargas elétricas {estáveis e de dimensões reduzidas}, de modo a que possa ser utilizada, dada a sua essencialidade, na fabricação de redes de período longo (LPG) em fibra ótica nos chamados turning points. Estes são pontos de elevada sensibilidade, fundamentais no desenvolvimento tecnológico de sensores em fibra ótica, em particular, de sensores refractométricos. O protótipo da fonte de alimentação é composto por um regulador do tipo BUCK, um inversor para alimentação do transformador de alta tensão, o circuito de realimentação e controlo PWM e um microcontrolador para o comando da fonte. Posteriormente procedeu-se à otimização dos parâmetros de descarga, o que conduziu a fabricação de redes de período longo com períodos inferiores a 150 micrómetros. Este é um resultado sem paralelo a nível internacional no que concerne ao uso da técnica do arco elétrico.

Critical events in mechanically ventilated patients

Mechanical Ventilation is an artificial way to help a Patient to breathe. This procedure is used to support patients with respiratory diseases however in many cases it can provoke lung damages, Acute Respiratory Diseases or organ failure. With the goal to early detect possible patient breath problems a set of limit values was defined to some variables monitored by the ventilator (Average Ventilation Pressure, Compliance Dynamic, Flow, Peak, Plateau and Support Pressure, Positive end-expiratory pressure, Respiratory Rate) in order to create critical events. A critical event is verified when a patient has a value higher or lower than the normal range defined for a certain period of time. The values were defined after elaborate a literature review and meeting with physicians specialized in the area. This work uses data streaming and intelligent agents to process the values collected in real-time and classify them as critical or not. Real data provided by an Intensive Care Unit were used to design and test the solution. In this study it was possible to understand the importance of introduce critical events for Mechanically Ventilated Patients. In some cases a value is considered critical (can trigger an alarm) however it is a single event (instantaneous) and it has not a clinical significance for the patient. The introduction of critical events which crosses a range of values and a pre-defined duration contributes to improve the decision-making process by decreasing the number of false positives and having a better comprehension of the patient condition.

Decentralization and the Gains from Monitoring

This paper analyzes the delegation of contracting capacity in a moral hazard environment with sequential production in a project which involves a principal and two agents. The agent in charge of the …nal production can obtain soft information about the other agent's effort choice by investing in monitoring. I investigate the circumstances under which it is optimal for the principal to use a centralized organization in which she designs the contracts with both agents or to use a decentralized organization in which she contracts only one agent, and delegates the power to contract the other agent. It is shown that in this setting a decentralized organization can be superior to a centralized organization. This is because the principal is better off under monitoring and the incentives for an agent to invest in monitoring can be higher in a decentralized organization. The circumstances under which this is true are related to the monitoring costs and the importance of each agent for production. The results explain the recent application of the design-build method in public procurement. Journal of Economic Literature Classi…cation Numbers: D23, D82, L14, L22. Keywords: Decentralization of Contracting, Monitoring, Moral Hazard.

Aprendre a Ensenyar a Resoldre Problemes

La finalitat general del projecte és la millora de la formació dels estudiants de magisteri i de professorat, pel que fa a la seva visió i els seus coneixements sobre l'ensenyament i aprenentatge de les matemàtiques, a partir d'una redefinició de les diferents assignatures de didàctica de les matemàtiques. Es pren l'aprenentatge de l'ensenyament de la resolució de problemes com a eix vertebrador de les assignatures, introduint la realitat de l'aula per mitjà de la interpretació de casos professionals gravats en videoclips. El projecte pretén elaborar materials docents així com dissenyar i experimentar noves metodologies, tant en l'àmbit presencial com virtual, i al mateix temps fomentar la coordinació del professorat que imparteix les assignatures de didàctica. Tot el material es recollirà en una base de dades en l'ADRE, que permetrà la consulta tant presencial com virtual dels materials docents i casos professionals recollits per parts de l'alumnat i professorat. Els objectius a assolits responen a la finalitat del projecte i estan relacionats amb moltes de les prioritats de la convocatòria, ja que impliquen, entre altres coses, la producció de material docent, l’experimentació de noves metodologies i la interrelació entre teoria i pràctica professional.

Tapiola-ryhmän Yhtiökokousjärjestelmä-ohjelmiston määrittely ja suunnittelu

Tässä insinöörityössä selvitettiin mahdollisuuksia parantaa Tapiola-ryhmän Yhtiökokousjärjestelmä-ohjelmiston ominaisuuksia ja tietoturvallisuutta. Järjestelmää käytetään Tapiola-ryhmän vakuutusyhtiöiden yhtiökokouksiin osallistuvien osakkaiden kirjaamiseen ja heidän äänten laskentaan. Tutkimuksen perusteella tehtiin järjestelmän määrittely ja suunnittelu, joiden tuloksena syntyivät toiminnallinen ja tekninen määrittelydokumentaatio, jotka toimivat pohjana uuden Yhtiökokousjärjestelmän toteutukselle. Työ tehtiin Tapiola-ryhmälle Tieto-Tapiola Oy:n tilauksesta. Työn alussa tutkittiin erilaisia mahdollisuuksia toteuttaa järjestelmän ohjelmisto- ja tietokanta-arkkitehtuuri, joiden perusteella määrittelyä ja suunnittelua alettiin toteuttaa. Tutkimuksen perusteella päädyttiin käyttämään Java SE -arkkitehtuuria sovelluksen toteutukseen ja SQL Server -tietokantaa järjestelmän tietovarastona. Valittuihin ratkaisuihin päädyttiin niiden hyvien tietoturvallisuus- ja kertakirjausominaisuuksien takia. Toiminnallisessa määrittelydokumentissa käydään läpi järjestelmälle asetettuja vaatimuksia ja kuvataan sen toiminnot, liiketoimintaluokkamalli, käyttöliittymä ja tulosteet. Lisäksi siinä otetaan kantaa järjestelmän käyttöympäristöön, ulkoisiin tietokantaliittymiin, käyttäjän tunnistautumiseen ja tietoturvallisuuteen sekä käydään läpi sen toiminta käyttäjien näkökulmasta. Toiminnallisen määrittelydokumentin pohjalta luotiin tekninen määrittelydokumentti. Siinä kuvataan järjestelmän ympäristö ja ohjelmisto- sekä tietokanta-arkkitehtuuri yleisellä tasolla. Tämän lisäksi järjestelmän arkkitehtuuria käydään myös tarkemmin läpi sekä kuvataan moduulit ja toiminnot niin tarkasti, että niiden perusteella voidaan toteuttaa koko järjestelmä. Työn tuloksena syntyivät kattava toiminnallinen ja tekninen määrittelydokumentaatio, joissa käydään läpi kaikki järjestelmän toteuttamiseen tarvittavat elementit sillä tarkkuudella, että järjestelmän toteuttaminen voidaan aloittaa.

Desenvolupament d'una aplicació per a la creació de pressupostos on-line

En aquests moments, el mercat no es troba en una bona situació, per aquest motiu les empreses han de buscar noves maneres de créixer, expandir-se i noves formes d’interactuar amb els clients. La idea original d’aquest projecte sorgeix de la necessitat de disposar d’una manera diferent de promocionar-se i oferir nous serveis a través d’internet mitjançant una pàgina web. Degut a la situació actual, el preu és un aspecte molt important i influent a l’hora de realitzar una obra. Per aquest motiu es va pensar que seria molt interessant que el client pogués demanar de forma fàcil i ràpida un pressupost, i a l’instant tingués un preu orientatiu del que li pot costar la obra. D’aquesta manera l’interessat s’estalvia i agilitza molts passos previs abans de començar una obra. Després d’analitzar quina era la millor manera de portar a terme el projecte informàtic, s’ha determinat que la pàgina web es desenvoluparà utilitzant els llenguatges HTML i PHP combinant-lo amb el framework CodeIgniter. El disseny de la web es realitzarà mitjançant fulles d’estil CSS conjuntament amb el framework BootStrap. Per realitzar l’aplicació web que realitza els pressupostos s’utilitzarà AJAX i jQuery perquè d’aquesta manera el procés sigui dinàmic. L’entorn de desenvolupament escollit és el NetBeans i per provar el projecte s’utilitza el XAMPP. Un usuari només necessitarà un navegador i connexió a internet per fer servir totes les funcions de la web. Podrà realitzar pressupostos, concertar visites, contactar i per suposat veure tota la part informativa de la pàgina.

En torno a los efectos de la edad en el aprendizaje escolar de una lengua extrangera

The purpose of this article is to treat a currently much debated issue, the effects of age on second language learning. To do so, we contrast data collected by our research team from over one thousand seven hundred young and adult learners with four popular beliefs or generalizations, which, while deeply rooted in this society, are not always corroborated by our data.Two of these generalizations about Second Language Acquisition (languages spoken in the social context) seem to be widely accepted: a) older children, adolescents and adults are quicker and more efficient at the first stages of learning than are younger learners; b) in a natural context children with an early start are more liable to attain higher levels of proficiency. However, in the context of Foreign Language Acquisition, the context in which we collect the data, this second generalization is difficult to verify due to the low number of instructional hours (a maximum of some 800 hours) and the lower levels of language exposure time provided. The design of our research project has allowed us to study differences observed with respect to the age of onset (ranging from 2 to 18+), but in this article we focus on students who began English instruction at the age of 8 (LOGSE Educational System) and those who began at the age of 11 (EGB). We have collected data from both groups after a period of 200 (Time 1) and 416 instructional hours (Time 2), and we are currently collecting data after a period of 726 instructional hours (Time 3). We have designed and administered a variety of tests: tests on English production and reception, both oral and written, and within both academic and communicative oriented approaches, on the learners' L1 (Spanish and Catalan), as well as a questionnaire eliciting personal and sociolinguistic information. The questions we address and the relevant empirical evidence are as follows: 1. "For young children, learning languages is a game. They enjoy it more than adults."Our data demonstrate that the situation is not quite so. Firstly, both at the levels of Primary and Secondary education (ranging from 70.5% in 11-year-olds to 89% in 14-year-olds) students have a positive attitude towards learning English. Secondly, there is a difference between the two groups with respect to the factors they cite as responsible for their motivation to learn English: the younger students cite intrinsic factors, such as the games they play, the methodology used and the teacher, whereas the older students cite extrinsic factors, such as the role of their knowledge of English in the achievement of their future professional goals. 2 ."Young children have more resources to learn languages." Here our data suggest just the opposite. The ability to employ learning strategies (actions or steps used) increases with age. Older learners' strategies are more varied and cognitively more complex. In contrast, younger learners depend more on their interlocutor and external resources and therefore have a lower level of autonomy in their learning. 3. "Young children don't talk much but understand a lot"This third generalization does seem to be confirmed, at least to a certain extent, by our data in relation to the analysis of differences due to the age factor and productive use of the target language. As seen above, the comparably slower progress of the younger learners is confirmed. Our analysis of interpersonal receptive abilities demonstrates as well the advantage of the older learners. Nevertheless, with respect to passive receptive activities (for example, simple recognition of words or sentences) no great differences are observed. Statistical analyses suggest that in this test, in contrast to the others analyzed, the dominance of the subjects' L1s (reflecting a cognitive capacity that grows with age) has no significant influence on the learning process. 4. "The sooner they begin, the better their results will be in written language"This is not either completely confirmed in our research. First of all, we perceive that certain compensatory strategies disappear only with age, but not with the number of instructional hours. Secondly, given an identical number of instructional hours, the older subjects obtain better results. With respect to our analysis of data from subjects of the same age (12 years old) but with a different number of instructional hours (200 and 416 respectively, as they began at the ages of 11 and 8), we observe that those who began earlier excel only in the area of lexical fluency. In conclusion, the superior rate of older learners appears to be due to their higher level of cognitive development, a factor which allows them to benefit more from formal or explicit instruction in the school context. Younger learners, however, do not benefit from the quantity and quality of linguistic exposure typical of a natural acquisition context in which they would be allowed to make use of implicit learning abilities. It seems clear, then, that the initiative in this country to begin foreign language instruction earlier will have positive effects only if it occurs in combination with either higher levels of exposure time to the foreign language, or, alternatively, with its use as the language of instruction in other areas of the curriculum.

En torno a los efectos de la edad en el aprendizaje escolar de una lengua extrangera

The purpose of this article is to treat a currently much debated issue, the effects of age on second language learning. To do so, we contrast data collected by our research team from over one thousand seven hundred young and adult learners with four popular beliefs or generalizations, which, while deeply rooted in this society, are not always corroborated by our data.Two of these generalizations about Second Language Acquisition (languages spoken in the social context) seem to be widely accepted: a) older children, adolescents and adults are quicker and more efficient at the first stages of learning than are younger learners; b) in a natural context children with an early start are more liable to attain higher levels of proficiency. However, in the context of Foreign Language Acquisition, the context in which we collect the data, this second generalization is difficult to verify due to the low number of instructional hours (a maximum of some 800 hours) and the lower levels of language exposure time provided. The design of our research project has allowed us to study differences observed with respect to the age of onset (ranging from 2 to 18+), but in this article we focus on students who began English instruction at the age of 8 (LOGSE Educational System) and those who began at the age of 11 (EGB). We have collected data from both groups after a period of 200 (Time 1) and 416 instructional hours (Time 2), and we are currently collecting data after a period of 726 instructional hours (Time 3). We have designed and administered a variety of tests: tests on English production and reception, both oral and written, and within both academic and communicative oriented approaches, on the learners' L1 (Spanish and Catalan), as well as a questionnaire eliciting personal and sociolinguistic information. The questions we address and the relevant empirical evidence are as follows: 1. "For young children, learning languages is a game. They enjoy it more than adults."Our data demonstrate that the situation is not quite so. Firstly, both at the levels of Primary and Secondary education (ranging from 70.5% in 11-year-olds to 89% in 14-year-olds) students have a positive attitude towards learning English. Secondly, there is a difference between the two groups with respect to the factors they cite as responsible for their motivation to learn English: the younger students cite intrinsic factors, such as the games they play, the methodology used and the teacher, whereas the older students cite extrinsic factors, such as the role of their knowledge of English in the achievement of their future professional goals. 2 ."Young children have more resources to learn languages." Here our data suggest just the opposite. The ability to employ learning strategies (actions or steps used) increases with age. Older learners' strategies are more varied and cognitively more complex. In contrast, younger learners depend more on their interlocutor and external resources and therefore have a lower level of autonomy in their learning. 3. "Young children don't talk much but understand a lot"This third generalization does seem to be confirmed, at least to a certain extent, by our data in relation to the analysis of differences due to the age factor and productive use of the target language. As seen above, the comparably slower progress of the younger learners is confirmed. Our analysis of interpersonal receptive abilities demonstrates as well the advantage of the older learners. Nevertheless, with respect to passive receptive activities (for example, simple recognition of words or sentences) no great differences are observed. Statistical analyses suggest that in this test, in contrast to the others analyzed, the dominance of the subjects' L1s (reflecting a cognitive capacity that grows with age) has no significant influence on the learning process. 4. "The sooner they begin, the better their results will be in written language"This is not either completely confirmed in our research. First of all, we perceive that certain compensatory strategies disappear only with age, but not with the number of instructional hours. Secondly, given an identical number of instructional hours, the older subjects obtain better results. With respect to our analysis of data from subjects of the same age (12 years old) but with a different number of instructional hours (200 and 416 respectively, as they began at the ages of 11 and 8), we observe that those who began earlier excel only in the area of lexical fluency. In conclusion, the superior rate of older learners appears to be due to their higher level of cognitive development, a factor which allows them to benefit more from formal or explicit instruction in the school context. Younger learners, however, do not benefit from the quantity and quality of linguistic exposure typical of a natural acquisition context in which they would be allowed to make use of implicit learning abilities. It seems clear, then, that the initiative in this country to begin foreign language instruction earlier will have positive effects only if it occurs in combination with either higher levels of exposure time to the foreign language, or, alternatively, with its use as the language of instruction in other areas of the curriculum.

Experimental Project No. 621, Pavement Instrumentation, HR-293, 1992

This document contains a discussion of the reasons why the project did not succeed. A detailed discussion of the steps taken by the Iowa Department of Transportation to make the experiment work are contained in this document, along with recommendations for future projects.

Blanket Curing to Promote Early Strength Concrete, MLR-87-7, 1989

Fast Track concrete has proven to be successful in obtaining high early strengths. This benefit does not come without cost. Special Type III cement and insulating blankets to accelerate the cure add to its expense when compared to conventional paving. This research was intended to determine the benefit derived from the use of insulating blankets to accelerate strength gain in three concrete mixes using Type I cement. The goal was to determine mixes and curing procedures that would result in a range of opening times. This determination would allow the most economical design for a particular project by tailoring it to a specific time restraint. Three mixes of various cement content were tested in the field. Flexural beams were cast for each mix and tested at various ages. Two test sections were placed for each mix, one section being cured with the addition of insulating blankets and the other being cured with only conventional curing compound. Iowa Department of Transportation specifications require 500 psi flexural strength before a pavement can be opened to traffic. Concrete with Fast Track proportions (nominal 7 1/2 bag), Type I cement, and insulating blankets reached that strength in approximately 36 hr, a standard mix (nominal 6 1/2 bag) using the blankets in approximately 48 hr, and the Fast Track proportions with Type I cement without blankets in about 60 hr. The results showed a significant improvement in early strength gain with the use of insulating blankets.

Demonstration Project using Railroad Flatcars for Low-Volume Road Bridges, TR-444, 2003

The use of Railroad Flatcars (RRFCs) as the superstructure on low-volume county bridges has been investigated in a research project conducted by the Bridge Engineering Center at Iowa State University. These bridges enable county engineers to replace old, inadequate county bridge superstructures for less than half the cost and in a shorter construction time than required for a conventional bridge. To illustrate their constructability, adequacy, and economy, two RRFC demonstration bridges were designed, constructed, and tested: one in Buchanan County and the other in Winnebago County. The Buchanan County Bridge was constructed as a single span with 56-ft-long flatcars supported at their ends by new, concrete abutments. The use of concrete in the substructure allowed for an integral abutment at one end of the bridge with an expansion joint at the other end. Reinforced concrete beams (serving as longitudinal connections between the three adjacent flatcars) were installed to distribute live loads among the RRFCs. Guardrails and an asphalt milling driving surface completed the bridge. The Winnebago County Bridge was constructed using 89-ft-long flatcars. Preliminary calculations determined that they were not adequate to span 89 ft as a simple span. Therefore, the flatcars were supported by new, steel-capped piers and abutments at the RRFCs' bolsters and ends, resulting in a 66-ft main span and two 10-ft end spans. Due to the RRFC geometry, the longitudinal connections between adjacent RRFCs were inadequate to support significant loads; therefore, transverse, recycled timber planks were utilized to effectively distribute live loads to all three RRFCs. A gravel driving surface was placed on top of the timber planks, and a guardrail system was installed to complete the bridge. Bridge behavior predicted by grillage models for each bridge was validated by strain and deflection data from field tests; it was found that the engineered RRFC bridges have live load stresses significantly below the AASHTO Bridge Design Specification limits. To assist in future RRFC bridge projects, RRFC selection criteria were established for visual inspection and selection of structurally adequate RRFCs. In addition, design recommendations have been developed to simplify live load distribution calculations for the design of the bridges. Based on the results of this research, it has been determined that through proper RRFC selection, construction, and engineering, RRFC bridges are a viable, economic replacement system for low-volume road bridges.

En torno a los efectos de la edad en el aprendizaje escolar de una lengua extrangera

The purpose of this article is to treat a currently much debated issue, the effects of age on second language learning. To do so, we contrast data collected by our research team from over one thousand seven hundred young and adult learners with four popular beliefs or generalizations, which, while deeply rooted in this society, are not always corroborated by our data.Two of these generalizations about Second Language Acquisition (languages spoken in the social context) seem to be widely accepted: a) older children, adolescents and adults are quicker and more efficient at the first stages of learning than are younger learners; b) in a natural context children with an early start are more liable to attain higher levels of proficiency. However, in the context of Foreign Language Acquisition, the context in which we collect the data, this second generalization is difficult to verify due to the low number of instructional hours (a maximum of some 800 hours) and the lower levels of language exposure time provided. The design of our research project has allowed us to study differences observed with respect to the age of onset (ranging from 2 to 18+), but in this article we focus on students who began English instruction at the age of 8 (LOGSE Educational System) and those who began at the age of 11 (EGB). We have collected data from both groups after a period of 200 (Time 1) and 416 instructional hours (Time 2), and we are currently collecting data after a period of 726 instructional hours (Time 3). We have designed and administered a variety of tests: tests on English production and reception, both oral and written, and within both academic and communicative oriented approaches, on the learners' L1 (Spanish and Catalan), as well as a questionnaire eliciting personal and sociolinguistic information. The questions we address and the relevant empirical evidence are as follows: 1. "For young children, learning languages is a game. They enjoy it more than adults."Our data demonstrate that the situation is not quite so. Firstly, both at the levels of Primary and Secondary education (ranging from 70.5% in 11-year-olds to 89% in 14-year-olds) students have a positive attitude towards learning English. Secondly, there is a difference between the two groups with respect to the factors they cite as responsible for their motivation to learn English: the younger students cite intrinsic factors, such as the games they play, the methodology used and the teacher, whereas the older students cite extrinsic factors, such as the role of their knowledge of English in the achievement of their future professional goals. 2 ."Young children have more resources to learn languages." Here our data suggest just the opposite. The ability to employ learning strategies (actions or steps used) increases with age. Older learners' strategies are more varied and cognitively more complex. In contrast, younger learners depend more on their interlocutor and external resources and therefore have a lower level of autonomy in their learning. 3. "Young children don't talk much but understand a lot"This third generalization does seem to be confirmed, at least to a certain extent, by our data in relation to the analysis of differences due to the age factor and productive use of the target language. As seen above, the comparably slower progress of the younger learners is confirmed. Our analysis of interpersonal receptive abilities demonstrates as well the advantage of the older learners. Nevertheless, with respect to passive receptive activities (for example, simple recognition of words or sentences) no great differences are observed. Statistical analyses suggest that in this test, in contrast to the others analyzed, the dominance of the subjects' L1s (reflecting a cognitive capacity that grows with age) has no significant influence on the learning process. 4. "The sooner they begin, the better their results will be in written language"This is not either completely confirmed in our research. First of all, we perceive that certain compensatory strategies disappear only with age, but not with the number of instructional hours. Secondly, given an identical number of instructional hours, the older subjects obtain better results. With respect to our analysis of data from subjects of the same age (12 years old) but with a different number of instructional hours (200 and 416 respectively, as they began at the ages of 11 and 8), we observe that those who began earlier excel only in the area of lexical fluency. In conclusion, the superior rate of older learners appears to be due to their higher level of cognitive development, a factor which allows them to benefit more from formal or explicit instruction in the school context. Younger learners, however, do not benefit from the quantity and quality of linguistic exposure typical of a natural acquisition context in which they would be allowed to make use of implicit learning abilities. It seems clear, then, that the initiative in this country to begin foreign language instruction earlier will have positive effects only if it occurs in combination with either higher levels of exposure time to the foreign language, or, alternatively, with its use as the language of instruction in other areas of the curriculum.

En torno a los efectos de la edad en el aprendizaje escolar de una lengua extrangera

The purpose of this article is to treat a currently much debated issue, the effects of age on second language learning. To do so, we contrast data collected by our research team from over one thousand seven hundred young and adult learners with four popular beliefs or generalizations, which, while deeply rooted in this society, are not always corroborated by our data.Two of these generalizations about Second Language Acquisition (languages spoken in the social context) seem to be widely accepted: a) older children, adolescents and adults are quicker and more efficient at the first stages of learning than are younger learners; b) in a natural context children with an early start are more liable to attain higher levels of proficiency. However, in the context of Foreign Language Acquisition, the context in which we collect the data, this second generalization is difficult to verify due to the low number of instructional hours (a maximum of some 800 hours) and the lower levels of language exposure time provided. The design of our research project has allowed us to study differences observed with respect to the age of onset (ranging from 2 to 18+), but in this article we focus on students who began English instruction at the age of 8 (LOGSE Educational System) and those who began at the age of 11 (EGB). We have collected data from both groups after a period of 200 (Time 1) and 416 instructional hours (Time 2), and we are currently collecting data after a period of 726 instructional hours (Time 3). We have designed and administered a variety of tests: tests on English production and reception, both oral and written, and within both academic and communicative oriented approaches, on the learners' L1 (Spanish and Catalan), as well as a questionnaire eliciting personal and sociolinguistic information. The questions we address and the relevant empirical evidence are as follows: 1. "For young children, learning languages is a game. They enjoy it more than adults."Our data demonstrate that the situation is not quite so. Firstly, both at the levels of Primary and Secondary education (ranging from 70.5% in 11-year-olds to 89% in 14-year-olds) students have a positive attitude towards learning English. Secondly, there is a difference between the two groups with respect to the factors they cite as responsible for their motivation to learn English: the younger students cite intrinsic factors, such as the games they play, the methodology used and the teacher, whereas the older students cite extrinsic factors, such as the role of their knowledge of English in the achievement of their future professional goals. 2 ."Young children have more resources to learn languages." Here our data suggest just the opposite. The ability to employ learning strategies (actions or steps used) increases with age. Older learners' strategies are more varied and cognitively more complex. In contrast, younger learners depend more on their interlocutor and external resources and therefore have a lower level of autonomy in their learning. 3. "Young children don't talk much but understand a lot"This third generalization does seem to be confirmed, at least to a certain extent, by our data in relation to the analysis of differences due to the age factor and productive use of the target language. As seen above, the comparably slower progress of the younger learners is confirmed. Our analysis of interpersonal receptive abilities demonstrates as well the advantage of the older learners. Nevertheless, with respect to passive receptive activities (for example, simple recognition of words or sentences) no great differences are observed. Statistical analyses suggest that in this test, in contrast to the others analyzed, the dominance of the subjects' L1s (reflecting a cognitive capacity that grows with age) has no significant influence on the learning process. 4. "The sooner they begin, the better their results will be in written language"This is not either completely confirmed in our research. First of all, we perceive that certain compensatory strategies disappear only with age, but not with the number of instructional hours. Secondly, given an identical number of instructional hours, the older subjects obtain better results. With respect to our analysis of data from subjects of the same age (12 years old) but with a different number of instructional hours (200 and 416 respectively, as they began at the ages of 11 and 8), we observe that those who began earlier excel only in the area of lexical fluency. In conclusion, the superior rate of older learners appears to be due to their higher level of cognitive development, a factor which allows them to benefit more from formal or explicit instruction in the school context. Younger learners, however, do not benefit from the quantity and quality of linguistic exposure typical of a natural acquisition context in which they would be allowed to make use of implicit learning abilities. It seems clear, then, that the initiative in this country to begin foreign language instruction earlier will have positive effects only if it occurs in combination with either higher levels of exposure time to the foreign language, or, alternatively, with its use as the language of instruction in other areas of the curriculum.