Karl Popper's Philosophical Breakthrough

Despite his well-known deductivism, in his early (unpublished) writings, Popper held an inductivist position. Up to 1929 epistemology entered Popper's reflections only as far as the problem was that of the justification of the scientific character of these fields of research. However, in that year, while surveying the history of non-Euclidean geometries, Popper explicitly discussed the cognitive status of geometry without referring to psycho-pedagogical aspects, thus turning from cognitive psychology to the logic and methodology of science. As a consequence of his reflections on the problematic relationship between geometrical-mathematical constructions and physical reality Popper was able to get over a too direct notion of such a relationship, cast doubts on inductive inference and started conceiving in a new (strictly non-inductivist) manner the relationship between theoretical and observational propositions

Sraffa come “classico”: un esercizio congetturale

La congettura che qui si propone è che in Produzione di merci Sraffa abbia inteso ripristinare il programma analitico, proprio degli economisti classici, di una teoria del valore-lavoro, superando il fallimento provocato dalla esplicita considerazione dei beni-capitali che ha reso impossibile la “riduzione” dei prezzi di produzione a valori-lavoro mediante misura del “lavoro morto” in essi contenuto. La congettura è condotta in tre momenti successivi. Anzitutto si ricostruisce il paradigma del valore-lavoro dei classici per mostrare come esso fosse rigorosamente esatto nel caso di una produzione “a solo lavoro”. In seguito si mostra come Sraffa avrebbe potuto operare per fondare un’analisi altrettanto rigorosa del valore-lavoro nonostante la presenza dei beni-capitali sulla base del punto di vista del prodotto netto complessivo per imputare al valore monetario di questo il solo “lavoro vivo” (equazione di neo-valore). Infine si suggerisce che Sraffa potrebbe essersi mosso proprio nella direzione di cui sopra, come sembrano alludere i suoi appunti di lavoro che progressivamente vengono alla luce. La conclusione della congettura è che, comunque giudicasse Sraffa (cosa che, al momento, è argomento opinabile), Produzione di merci può essere letta anche come la diretta prosecuzione della teoria del valore-lavoro degli economisti classici che risolve la difficoltà provocata dalla presenza dei beni-capitali impossibili a ridursi rigorosamente a quantità di “lavoro morto”

Rethinking First Language–Second Language Similarities and Differences in English Proficiency: Insights From the ENglish Reading Online (ENRO) Project

This article presents the ENglish Reading Online (ENRO) project that offers data on English reading and listening comprehension from 7,338 university-level advanced learners and native speakers of English representing 19 countries. The database also includes estimates of reading rate and seven component skills of English, including vocabulary, spelling, and grammar, as well as rich demographic and language background data. We first demonstrate high reliability for ENRO tests and their convergent validity with existing meta-analyses.We then provide a bird’s-eye view of first (L1) and second (L2) language comparisons and examine the relative role of various predictors of reading and listening comprehension and reading speed. Across analyses, we found substantially more overlap than differences between L1 and L2 speakers, suggesting that English reading proficiency is best considered across a continuum of skill, ability, and experiences spanning L1 and L2 speakers alike. We end by providing pointers for how researchers can mine ENRO data for future studies.Este artículo se encuentra publicado en Language Learning, 73(1)

Text reading in English as a second language: Evidence from the Multilingual Eye-Movements Corpus

Research into second language (L2) reading is an exponentially growing field. Yet, it still has a relatively short supply of comparable, ecologically valid data from readers representing a variety of first languages (L1). This article addresses this need by presenting a new data resource called MECO L2 (Multilingual Eye Movements Corpus), a rich behavioral eye-tracking record of text reading in English as an L2 among 543 university student speakers of 12 different L1s.MECO L2 includes a test battery of component skills of reading and allows for a comparison of the participants’ reading performance in their L1 and L2. This data resource enables innovative large-scale cross-sample analyses of predictors of L2 reading fluency and comprehension. We first introduce the design and structure of the MECO L2 resource, along with reliability estimates and basic descriptive analyses. Then, we illustrate the utility of MECO L2 by quantifying contributions of four sources to variability in L2 reading proficiency proposed in prior literature: reading fluency and comprehension in L1, proficiency in L2 component skills of reading, extralinguistic factors, and the L1 of the readers. Major findings included (a) a fundamental contrast between the determinants of L2 reading fluency versus comprehension accuracy, and (b) high within-participant consistency in the real-time strategy of reading in L1 and L2.We conclude by reviewing the implications of these findings to theories of L2 acquisition and outline further directions in which the new data resourcemay support L2 reading research.Este artículo se encuentra publicado en Studies in Second Language Acquisition, 45(1), 3-37

Semantic errors in children’s narratives: The problem of reference

El objetivo de este trabajo es desarrollar un conjunto de categorías que nos permita describir los errores semánticos de la producción oral de narrativas en niños de 5 años. El enfoque teórico desde el cual se analizan los casos es la lingüística cognitiva funcional ya que se estudia la relación lenguaje – cognición en función de una actividad comunicativa, la lengua en un uso particular: narrar un estímulo visual dinámico. Este estudio se encuadra dentro del programa de investigación denominado ‘Gramática de interfaces’. El análisis es cualitativo y de alcance descriptivo; se les presentó a los niños dos estímulos visuales de un minuto y medio en dos ocasiones y luego se los invitó a que contaran oralmente lo que vieron en cada video. Las narrativas fueron grabadas, luego se transcribieron. En este trabajo en particular identificamos trece errores semánticos, los analizamos y los categorizamos. En un primer paso, contrastamos el significado del verbo utilizado por el niño con el segmento del estímulo potencialmente referido por esa expresión. Identificamos la información en el estímulo que no era referida por la expresión lingüística. Justificamos nuestra interpretación de la expresión como referencia fallida en la relevancia de la información omitida. El resultado son seis categorías que nos permiten empezar a clasificar problemas de la referencia en el discurso infantil.The aim of this paper is to develop a set of categories able to describe semantic slips of the tongue in oral production of narratives by five years old children. The analysis is framed within Cognitive Linguistics since it studies the relation between language and cognition in the context of a communicative situation, language in a particular context of use: the narration of a dynamic visual stimuli. In particular, this study is part of a research program called 'Interface Grammar'. We undertook a qualitative and descriptive analysis. Children were presented twice with two visual stimuli and asked to narrate them. The narratives were transcribed and analyzed. We identified thirteen semantic slips, which were described and classified. First, we contrasted the meaning of the verb used by the child with the segment of the stimuli intended to be referred to by the expression. We identified the information in the stimuli that was not covered by the verb meaning. Then, we justify our interpretation of the use of that expression as a 'failed reference' by the relevance of the omitted information. The result consists of six categories that allow us to start to classify reference problems in children's discourse.Fil: Seno, Vanesa Nancy. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentina. Universidad Nacional de Cuyo; ArgentinaFil: Gattei, Carolina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Ciudad Universitaria. Instituto de Física de Buenos Aires. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales. Instituto de Física de Buenos Aires; Argentina. Universidad Torcuato Di Tella; ArgentinaFil: Paris, Luis Alberto. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; Argentina. Universidad Nacional de Cuyo; Argentin

When High-Capacity Readers Slow Down and Low-Capacity Readers Speed Up: Working Memory and Locality Effects

We examined the effects of argument-head distance in SVO and SOV languages (Spanish and German), while taking into account readers´ working memory capacity and controlling for expectation (Levy, 2008) and other factors. We predicted only locality effects, that is, a slowdown produced by increased dependency distance (Gibson, 2000; Lewis and Vasishth, 2005). Furthermore, we expected stronger locality effects for readers with low working memory capacity. Contrary to our predictions, low-capacity readers showed faster reading with increased distance, while high-capacity readers showed locality effects. We suggest that while the locality effects are compatible with memory-based explanations, the speedup of low-capacity readers can be explained by an increased probability of retrieval failure. We present a computational model based on ACT-R built under the previous assumptions, which is able to give a qualitative account for the present data and can be tested in future research. Our results suggest that in some cases, interpreting longer RTs as indexing increased processing difficulty and shorter RTs as facilitation may be too simplistic: The same increase in processing difficulty may lead to slowdowns in high-capacity readers and speedups in low-capacity ones. Ignoring individual level capacity differences when investigating locality effects may lead to misleading conclusions.Fil: Nicenboim, Bruno. Universitat Potsdam; AlemaniaFil: Logacev, Pavel. Universitat Potsdam; AlemaniaFil: Gattei, Carolina Andrea. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mendoza. Instituto de Ciencias Humanas, Sociales y Ambientales; ArgentinaFil: Vasishth, Shravan. Universitat Potsdam; Alemani

Glial cell line-derived neurotrophic factor influences proliferation of osteoblastic cells

Little is known about the role of neurotrophic growth factors in bone metabolism. This study investigated the short-term effects of glial cell line-derived neurotrophic factor (GDNF) on calvarial-derived MC3T3-E1 osteoblasts. MC3T3-E1 expressed GDNF as well as its canonical receptors, GFRα1 and RET. Addition of recombinant GDNF to cultures in serum-containing medium modestly inhibited cell growth at high concentrations; however, under serum-free culture conditions GDNF dose-dependently increased cell proliferation. GDNF effects on cell growth were inversely correlated with its effect on alkaline phosphatase (ALP) activity showing a significant dose-dependent inhibition of relative ALP activity with increasing concentrations of GDNF in serum-free culture medium. Live/dead and lactate dehydrogenase assays demonstrated GDNF did not significantly affect cell death or survival under serum-containing and serum-free conditions. The effect of GDNF on cell growth was abolished in the presence of inhibitors to GFR α 1 and RET indicating that GDNF stimulated calvarial osteoblasts via its canonical receptors. Finally, this study found that GDNF synergistically increased tumor necrosis factor-α (TNF-α)-stimulated MC3T3-E1 cell growth suggesting that GDNF interacted with TNF-α-induced signaling in osteoblastic cells. In conclusion, this study provides evidence for a direct, receptor-mediated effect of GDNF on osteoblasts highlighting a novel role for GDNF in bone physiology. \ud \u