Benefits and Drawbacks of Collaborative Writing for Young Foreign Language Learners: A Case Study on Teachers' Perspective

38 p. : il. -- Bibliogr.: p. 28-34Collaborative Writing (CW) and its benefits and drawbacks for language learning have been studied by many scholars, mainly concerning adult learners (ALs). Nevertheless, its potential applications to young learners (YLs) of a foreign language (FL) are yet to be examined in depth. The collaborative method is based on such theories as Vygotsky’s Sociocultural Theory (1978) which emphasizes that learning is a social process, Krashen’s Input Hypothesis (1985) which explains that language learning is achieved via comprehensible input obtained from other learners, Long’s Interaction Hypothesis (1996) that underlines the significance of the interaction and negotiation of meaning among learners that makes the input more comprehensible and Swain’s Output Hypothesis (1995) which highlights the importance of the production of L2 (output) from which students are conscious of their own knowledge. It is also nurtured by the claims made by Swain (2000), who considers that Languaging, and especially Collaborative Dialogue, may help students to solve their problems by means of interaction. It is important to take into account that writing is considered an arduous skill to acquire, a skill that becomes more challenging when dealing with a FL (Williams, 2012, p. 322; Sheerin, 2008, p. 345; Verspoor & Smiskova, 2012, p. 41). For this reason, working collaboratively on a writing task may help YLs to acquire FL writing skills. Nevertheless, regarding classroom practices with YLs, teachers’ beliefs concerning collaborative work come into play, since their point of view on whether a FL teaching approach or method results beneficial for their pupils is crucial. This dissertation aims to explore teachers' perspective on whether CW is beneficial also for YLs by means of a case study, in which three teachers of diverse stages of a Primary school took part. Semistructured interviews were conducted with the teachers, audio-recorded and transcribed. Then, the data was examined in search of recurrent themes mentioned by the three teachers. The results of this case study show that CW is generally considered favorable for young FL learners, which is in line with the theoretical underpinnings of collaborative learning and the existing body of research. However, more investigation is needed in this field. Overall, the present study supports claims in favor of CW’s benefits for YLs, which enables us to advocate for its more widespread implementation in FL Primary classrooms

Cardiomyogenic potentiality of somatic and stem cells when cultured in the three-dimensional peptide scaffold RAD16-I

Les malalties cardiovasculars són una de les majors causes de mortalitat a escala mundial. L’infart de miocardi és el principal responsable de les cardiopaties isquèmiques. La irrigació sanguínia al cor es veu bloquejada degut a una oclusió en un capil•lar sanguini provocant mort cel•lular massiva que genera una zona miocardíaca necròtica. En la última dècada, la medicina cardíaca regenerativa s’ha focalitzat en estratègies fonamentades en l’enginyeria de teixits i la teràpia cel•lular basada en cèl•lules mare. En aquest treball, hem caracteritzat el potencial cardíac de diferents tipus cel•lulars cultivats en bastides tri-dimensionals (3D) generades a partir de l’hidrogel peptídic RAD16-I. En primer lloc, hem estudiat l’adquisició de potencial mesenquimàtic de fibroblasts humans de dermis (hNDFs) en cultius 3D i la seva diferenciació subseqüent a llinatges adipogènic i cardiogènic. Únicament els hNDFs cultivats en hidrogels de RAD16-I adquireixen una potenciació mesenquimàtica. Les cèl•lules adopten espontàniament propietats semblants a les cèl•lules mare mesenquimàtiques mentre que la diferenciació a adipogènesis i cardiogènesis requereix medi d’inducció. En segon lloc, hem comparat el grau de diferenciació cardíaca de cèl•lules mare humanes pluripotents induïdes (hiPSCs) cultivades en ambients 2D versus 3D i hem avaluat l’efecte de l’àcid ascòrbic (AA) en el procés. En el nostre treball i com ja s’havia demostrat en publicacions prèvies, l’AA va resultar accelerar i millorar la diferenciació cardíaca de hiPSCs en cultius 2D. A més, els resultats presentats suggereixen que les hiPSCs cultivades en 3D augmenten el seu grau de diferenciació i adquireixen un potencial cardiogènic 105 vegades més elevat que en els cultius 2D. En tercer lloc, hem dissenyat un pegat cardíac basat en cultius 3D de cèl•lules adultes porcines progenitores del teixit adipós del mediastí (pMATPCs) injectats en matrius naturals (pericardi humà descel•lularitzat). Hem implantat la bio-pròtesis miocardíaca in vivo i hem determinat que la bio-bastida afavoreix la migració cel•lular i la regeneració de la zona infartada en el model porcí. En conclusió, hem analitzat el potencial cardiogènic de cèl•lules adultes somàtiques (hNDFs), cèl•lules mare adultes (pMATPCs) i cèl•lules mare pluripotents (hiPSCs) en cultius 3D basats en hidrogels de RAD16-I per a futures aplicacions en el tractament de malalties cardíaques.Las enfermedades cardiovasculares son una de las mayores causas de mortalidad a escala mundial. El infarto de miocardio es el principal responsable de las cardiopatías isquémicas. La irrigación sanguínea al corazón se ve bloqueada debido a una oclusión en un capilar sanguíneo provocando muerte celular masiva que genera una zona miocárdica necrótica. En la última década, la medicina cardíaca regenerativa se ha focalizado en estrategias fundamentadas en la ingeniería de tejidos y la terapia celular basada en células madre. Es este trabajo, hemos caracterizado el potencial cardíaco de distintos tipos celulares cultivados en andamios tridimensionales (3D) generados a partir del hidrogel peptídico RAD16-I. En primer lugar, hemos estudiado la adquisición de potencial mesenquimático de fibroblastos humanos de dermis (hNDFs) en cultivos 3D y su diferenciación subsecuente a linajes adipogénico y cardiogénico. Únicamente los hNDFs cultivados en hidrogeles de RAD16-I adquieren una potenciación mesenquimática. Las células adoptan espontáneamente propiedades parecidas a las células madre mesenquimáticas mientras que la diferenciación a adipogénesis y cardiogénesis requiere medio de inducción. En segundo lugar, hemos comparado el grado de diferenciación cardíaca de células madre humanas pluripotentes inducidas (hiPSCs) cultivadas en ambientes 2D versus 3D y hemos evaluado el efecto del ácido ascórbico (AA) en el proceso. En nuestro trabajo y como ya se había demostrado en publicaciones previas, el AA resultó acelerar y mejorar la diferenciación cardíaca de hiPSCs en cultivos 2D. A demás, los resultados presentados sugieren que las hiPSCs cultivadas en 3D aumentan su grado de diferenciación y adquieren un potencial cardiogénico 105 veces más elevado que en los cultivos 2D. En tercer lugar, hemos diseñado un parche cardíaco basado en cultivos 3D de células adultas porcinas progenitoras del tejido adiposo del mediastino (pMATPCs) inyectados en matrices naturales (pericardio humano descelularizado). Hemos implantado la bio-prótesis miocárdica in vivo y hemos determinado que el bio-andamio favorece la migración celular y la regeneración de la zona infartada en el modelo porcino. En conclusión, hemos analizado el potencial cardiogénico de células adultas somáticas (hNDFs), células madre adultas (pMATPCs) y células madre pluripotentes (hiPSCs) en cultivos 3D basados en hidrogeles de RAD16-I para futuras aplicaciones en el tratamiento de enfermedades cardíacas.Cardiac failure is the primary cause of mortality throughout the world. One of the leading causes of heart failure is myocardial infarction, which results from a reduced flow of blood to a part of the heart. This leads to cardiomyocyte death and myocardial necrosis. In the past decade, various strategies for cardiac reparative medicine have been investigated, from tissue engineering to stem cell-based therapy. Herein, we characterized the cardiac potential of different cell types cultured in three-dimensional (3D) scaffolds based on the peptide hydrogel RAD16-I. Firstly, we studied the mesenchymal potential acquisition of human Normal Dermal Fibroblasts (hNDFs) in 3D cultures and further commitment into adipogenic and cardiogenic lineages. We suggest that only hNDFs cultured in RAD16-I hydrogels undergo a mesenchymal potentiation. Cells spontaneously acquired mesenchymal stem cell-like properties whereas they required induction media to differentiate into adipogenic- and cardiogenic-like lineages. Secondly, we compared the degree of cardiac commitment of human induced Pluripotent Stem Cells (hiPSCs) when cultured in 2D versus 3D and the effect of ascorbic acid (AA), which has been proven to promote cardiac differentiation, on the process. In fact, AA seemed to accelerate and improve the cardiac commitment of hiPSCs in 2D cultures. Results suggested that hiPSCs in 3D cultures displayed an increased level of differentiation and acquired 105-fold more cardiogenic potential than cells cultured in 2D. Thirdly, we designed a cardiac patch based on 3D cultures of adult porcine Mediastinal Adipose Tissue Progenitor Cells (pMATPCs) injected into natural matrices (decellularized human pericardium). We implanted the myocardial bioprosthesis in vivo and determined that the bioscaffold supported cell migration and regeneration into the infarcted area in swine. In summary, we studied the cardiogenic potential of adult somatic cells (hNDFs), adult stem cells (pMATPCs) and pluripotent stem cells (hiPSCs) in 3D cultures based on RAD16-I hydrogels for potential future applications in the treatment of heart disease

Benefits and Drawbacks of Collaborative Writing for Young Foreign Language Learners: A Case Study on Teachers' Perspective

38 p. : il. -- Bibliogr.: p. 28-34Collaborative Writing (CW) and its benefits and drawbacks for language learning have been studied by many scholars, mainly concerning adult learners (ALs). Nevertheless, its potential applications to young learners (YLs) of a foreign language (FL) are yet to be examined in depth. The collaborative method is based on such theories as Vygotsky’s Sociocultural Theory (1978) which emphasizes that learning is a social process, Krashen’s Input Hypothesis (1985) which explains that language learning is achieved via comprehensible input obtained from other learners, Long’s Interaction Hypothesis (1996) that underlines the significance of the interaction and negotiation of meaning among learners that makes the input more comprehensible and Swain’s Output Hypothesis (1995) which highlights the importance of the production of L2 (output) from which students are conscious of their own knowledge. It is also nurtured by the claims made by Swain (2000), who considers that Languaging, and especially Collaborative Dialogue, may help students to solve their problems by means of interaction. It is important to take into account that writing is considered an arduous skill to acquire, a skill that becomes more challenging when dealing with a FL (Williams, 2012, p. 322; Sheerin, 2008, p. 345; Verspoor & Smiskova, 2012, p. 41). For this reason, working collaboratively on a writing task may help YLs to acquire FL writing skills. Nevertheless, regarding classroom practices with YLs, teachers’ beliefs concerning collaborative work come into play, since their point of view on whether a FL teaching approach or method results beneficial for their pupils is crucial. This dissertation aims to explore teachers' perspective on whether CW is beneficial also for YLs by means of a case study, in which three teachers of diverse stages of a Primary school took part. Semistructured interviews were conducted with the teachers, audio-recorded and transcribed. Then, the data was examined in search of recurrent themes mentioned by the three teachers. The results of this case study show that CW is generally considered favorable for young FL learners, which is in line with the theoretical underpinnings of collaborative learning and the existing body of research. However, more investigation is needed in this field. Overall, the present study supports claims in favor of CW’s benefits for YLs, which enables us to advocate for its more widespread implementation in FL Primary classrooms

Neuropatías ópticas y tratornos oculomotories periféricos en pacientes con SIDA

La prevalencia de las alteraciones neuroftalmológicas en los pacientes con el síndrome de inmunodefwiencia adquirida (SIDA) es de alrededor del 8%. Las alteraciones neuroftalmológicas más frecuentes son: 1. Las paresias de nervios craneales. 2. Neuropatías ópticas, y 3. Trastornos pupilares. Las paresias de nervios craneales suelen ser combinadas más que aisladas y deberse a lesiones intraparenquimatosas (toxoplasmosis o linfoma) o meningitis (tuberculosis o linfoma). Las alteraciones del r>ei-vio óptico suelen serpapilitis por CMV, neuropatía óptica por sífilis o meningitis criptococócica. Dentro de las alteraciones pupilares se han descrito síndromes de Bernard-Horner por afectación simpática, pupilas de Argyll-Robertson por lesiones tectales mesencefálicas y midriasis asociadas a lesiones del nervio motor ocular común

Determination of 2,4,6-trichloroanisole by cyclic voltammetry

The electrochemical reduction of 2,4,6-trichloroanisole (TCA), a chlorinated arene with electron-donating substituents, was evaluated by cyclic voltammetry (CV). TCA is a major concern for the winery industry since it is related with “cork taint”, a wine defect. The results obtained showed that CV could be used to detect and quantify TCA in standard solutions. Linear relationships could be set between the current amplitude and TCA concentrations (R>0.990) with detection and quantification limits of 0.08 and 0.26 ppm. Although, these preliminary limits are higher than the human sensory threshold (5 ppt in wine), the simplicity of the methodology confers this study a possible role in the development of more efficient and less expensive process for TCA detection in the industry.This work was partially supported by project PEst-C/EQB/LA0020/2011, financed by FEDER through COMPETE - Programa Operacional Factores de Competitividade and by FCT - Fundacao para a Ciencia e a Tecnologia

Detection of pathogenic Bacteria by Electrochemical Impedance Spectroscopy: Influence of the immobilization strategies on the sensor performance

Electrochemical impedance spectroscopy (EIS) is applied to detect pathogenic E. coli O157:H7 bacteria via a label free immunoassay-based detection method. Polyclonal anti-E.coli antibodies (PAb) are immobilized onto gold electrodes following two different strategies, via chemical bond formation between antibody amino groups and a carboxylic acid containing self-assembled molecular monolayer (SAM) and alternatively by linking a biotinylated anti-E. coli to Neutravidin on a mixed-SAM. Impedance spectra for sensors of both designs for increasing concentrations of E. coli are recorded in phosphate buffered saline (PBS). The Nyquist plots can be modeled with a Randle equivalent circuit, identifying the charge transfer resistance RCT as the relevant concentration dependent parameter. Sensors fabricated from both designs are able to detect very low concentration of E. coli with limits of detection as low as 10-100 cfu/ml. The influence of the different immobilization protocols on the sensor performance is evaluated in terms of sensitivity, dynamic range and resistance against nonspecific absorption