Letter-similarity effects in braille word recognition

Letter-similarity effects are elusive with common words in lexical decision experiments: viotin and viocin (base word: violin) produce similar error rates and rejection latencies. However, they are robust for stimuli often presented with the same appearance (e.g., misspelled logotypes such as anazon [base word: amazon] produce more errors and longer latencies than atazon). Here, we examine whether letter-similarity effects occur in reading braille. The rationale is that braille is a writing system in which the sensory information is processed in qualitatively different ways than in visual reading: the form of the word’s letters is highly stable due to the standardisation of braille and the sensing of characters is transient and somewhat serial. Hence, we hypothesised that the letter similarity effect would be sizable with misspelled common words in braille, unlike the visual modality. To test this hypothesis, we conducted a lexical decision experiment with blind adult braille readers. Pseudowords were created by replacing one letter of a word with a tactually similar or dissimilar letter in braille following a tactile similarity matrix (e.g., [ausor] vs [aucor]; baseword: [autor]). Bayesian linear mixed-effects models showed that the responses to tactually similar pseudowords were less accurate than to tactually dissimilar pseudowords—the response times (RTs) showed a parallel trend. This finding supports the idea that, when reading braille, the mapping of input information onto abstract letter representations is done through a noisy channel

Four-cell stage mouse blastomeres have different developmental properties

Blastomeres of the early mouse embryo are thought to be equivalent in their developmental properties at least until the eight-cell stage. However, the experiments that have led to this conclusion could not have taken into account either the spatial origin of individual blastomeres or the spatial allocation and fate of their progeny. We have therefore readdressed this issue having defined cell lineages in mouse embryos undergoing different patterns of cleavage in their second division cycle. This has enabled us to identify a major group of embryos in which we can predict not only the spatial origin of each given four-cell blastomeres, but also which region of the blastocyst is most likely to be occupied by its progeny. We show that a pattern of second cleavage divisions in which a meridional division is followed by one that is equatorial or oblique allows us to identify blastomeres that differ in their fate and in their developmental properties both from each other and from their cousins. We find that one of these four-cell stage blastomeres that inherits some vegetal membrane marked in the previous cleavage cycle tends to contribute to mural trophectoderm. The progeny of its sister tend to donate cells to part of the ICM lining the blastocyst cavity and its associated trophectoderm. Chimaeras made entirely of these equatorially or obliquely derived blastomeres show developmental abnormalities in both late preimplantation and early postimplantation development. By contrast, chimaeras made from four-cell stage blastomeres from early meridional divisions develop normally. The developmental defects of chimaeras made from the most vegetal blastomeres that result from later second cleavages are the most severe and following transplantation into foster mothers they fail to develop to term. However, when such individual four-cell blastomeres are surrounded by blastomeres from random positions, they are able to contribute to all embryonic lineages. In conclusion, this study shows that while all four-cell blastomeres can have full developmental potential, they differ in their individual developmental properties according to their origin in the embryo from as early as the four-cell stage

Absence of Nodal signaling promotes precocious neural differentiation in the mouse embryo

AbstractAfter implantation, mouse embryos deficient for the activity of the transforming growth factor-β member Nodal fail to form both the mesoderm and the definitive endoderm. They also fail to specify the anterior visceral endoderm, a specialized signaling center which has been shown to be required for the establishment of anterior identity in the epiblast. Our study reveals that Nodal−/− epiblast cells nevertheless express prematurely and ectopically molecular markers specific of anterior fate. Our analysis shows that neural specification occurs and regional identities characteristic of the forebrain are established precociously in the Nodal−/− mutant with a sequential progression equivalent to that of wild-type embryo. When explanted and cultured in vitro, Nodal−/− epiblast cells readily differentiate into neurons. Genes normally transcribed in organizer-derived tissues, such as Gsc and Foxa2, are also expressed in Nodal−/− epiblast. The analysis of Nodal−/−;Gsc−/− compound mutant embryos shows that Gsc activity plays no critical role in the acquisition of forebrain characters by Nodal-deficient cells. This study suggests that the initial steps of neural specification and forebrain development may take place well before gastrulation in the mouse and highlights a possible role for Nodal, at pregastrula stages, in the inhibition of anterior and neural fate determination

Do diacritics entail an early processing cost in the absence of abstract representations? Evidence from masked priming in English

Using the masked priming technique, word recognition experiments in various languages have shown slower response times for a target word like NEVEU (nephew, in French) when preceded by a diacritical prime like néveu than by the identity prime neveu. The most common account of this effect is linguistic: diacritical and non-diacritical vowels (e.g., é and e) activate different letter representations (e.g., compare neveu /nə.vø/ vs. néveu /ne.vø/). However, another explanation is that the reduced effectiveness of the diacritical primes is merely due to the perceptual salience of accent marks in the first moments of word processing. Here, we designed a masked priming experiment that tested this perceptual salience account by comparing the effectiveness of diacritical versus non-diacritical primes in a language where diacritics have no linguistic value, namely, English (e.g., nórth-NORTH vs. north-NORTH). We found a small but reliable cost due to the diacritical primes, thus revealing that perceptual salience reduced the effectiveness of the primes. However, the effect sizes were substantially smaller than in the experiments in languages with diacritical marks, thus suggesting that the néveu-NEVEU versus neveu-NEVEU difference relies on both linguistic and perceptual sources

The anterior-posterior axis emerges respecting the morphology of the mouse embryo that changes and aligns with the uterus before gastrulation

Background: When the anterior-posterior axis of the mouse embryo becomes explicit at gastrulation, it is almost perpendicular to the long uterine axis. This led to the belief that the uterus could play a key role in positioning this future body axis. Results: Here, we demonstrate that when the anterior-posterior axis first emerges it does not respect the axes of the uterus but, rather, the morphology of the embryo. Unexpectedly, the emerging anterior-posterior axis is initially aligned not with the long, but the short axis of the embryo. Then whether the embryo develops in vitro or in utero, the anterior-posterior axis becomes aligned with the long axis of embryo just prior to gastrulation. Of three mechanisms that could account for this apparent shift in anterior-posterior axis orientation-cell migration, spatial change of gene expression, or change in embryo shape-lineage tracing studies favor a shape change accompanied by restriction of the expression domain of anterior markers. This property of the embryo must be modulated by interactions with the uterus as ultimately the anterior-posterior and long axes of the embryo align with the left-right uterine axis. Conclusions: The emerging anterior-posterior axis relates to embryo morphology rather than that of the uterus. The apparent shift in its orientation to align with the long embryonic axis and with the uterus is associated with a change in embryo shape and a refinement of anterior gene expression pattern. This suggests an interdependence between anterior-posterior gene expression, the shape of the embryo, and the uterus.Wellcome Trust [064421]info:eu-repo/semantics/publishedVersio

Regionalization of the mouse visceral endoderm as the blastocyst transforms into the egg cylinder.

BACKGROUND: Reciprocal interactions between two extra-embryonic tissues, the extra-embryonic ectoderm and the visceral endoderm, and the pluripotent epiblast, are required for the establishment of anterior-posterior polarity in the mouse. After implantation, two visceral endoderm cell types can be distinguished, in the embryonic and extra-embryonic regions of the egg cylinder. In the embryonic region, the specification of the anterior visceral endoderm (AVE) is central to the process of anterior-posterior patterning. Despite recent advances in our understanding of the molecular interactions underlying the differentiation of the visceral endoderm, little is known about how cells colonise the three regions of the tissue. RESULTS: As a first step, we performed morphological observations to understand how the extra-embryonic region of the egg cylinder forms from the blastocyst. Our analysis suggests a new model for the formation of this region involving cell rearrangements such as folding of the extra-embryonic ectoderm at the early egg cylinder stage. To trace visceral endoderm cells, we microinjected mRNAs encoding fluorescent proteins into single surface cells of the inner cell mass of the blastocyst and analysed the distribution of labelled cells at E5.0, E5.5 and E6.5. We found that at E5.0 the embryonic and extra-embryonic regions of the visceral endoderm do not correspond to distinct cellular compartments. Clusters of labelled cells may span the junction between the two regions even after the appearance of histological and molecular differences at E5.5. We show that in the embryonic region cell dispersion increases after the migration of the AVE. At this time, visceral endoderm cell clusters tend to become oriented parallel to the junction between the embryonic and extra-embryonic regions. Finally we investigated the origin of the AVE and demonstrated that this anterior signalling centre arises from more than a single precursor between E3.5 and E5.5. CONCLUSION: We propose a new model for the formation of the extra-embryonic region of the egg cylinder involving a folding of the extra-embryonic ectoderm. Our analyses of the pattern of labelled visceral endoderm cells indicate that distinct cell behaviour in the embryonic and extra-embryonic regions is most apparent upon AVE migration. We also demonstrate the polyclonal origin of the AVE. Taken together, these studies lead to further insights into the formation of the extra-embryonic tissues as they first develop after implantation.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are

Is The Iberian-African plates boundary well defined in the Alboran Basin of the Westernmost Mediterranean?

European Geosciences Union (EGU) General Assembly 2018, 8-13 April 2018, Vienna, Austria.-- 1 pageThe Alboran Basin (Westernmost Mediterranean) hosts the boundary between the Iberian and African plates. Traditionally, this boundary has been described as a wide deformation zone, in which the convergence is accommodated by several onshore-offshore tectonic structures. Extensional processes that led to the Alboran Basin formation took place from the Early to the Late Miocene, led by slab roll-back and slab tearing. During the Plio-Quaternary, the basin has been deformed due to the Iberia – Africa tectonic plates convergence, producing the contractive reorganization of some structures at the basin. In this study, we estimate the total slip accommodated by the most prominent tectonic structures in the area of Ear-liest Pliocene in age. We use Pre-Stack Depth Migrated sections of the crustal structure, that allow us to analyzed the real geometry of these structures at depth and to measure strain. We use the deformation-related geometry of strata and faults to estimate slip on the main faults. Results show that estimated total slip accommodated by the main fault system may be similar (with error bounds) to the estimated plate convergence value since the Messinian time (∼24 km). Thus, slip on that faults may have accommodated most of the Iberian – African plate convergence during the Plio-Quaternary, revealing that the contractive reorganization of the Alboran basin is focused on a few first-order structures that act as lithospheric boundaries, rather than widespread and diffuse along the entire basinPeer Reviewe

CIGB-300, a proapoptotic peptide, inhibits angiogenesis in vitro and in vivo

We have previously demonstrated that a proapoptotic cyclic peptide CIGB-300, formerly known as P15-Tat delivered into the cells by the cell-penetrating peptide Tat, was able to abrogate the CK2-mediated phosphorylation and induce tumor regression when injected directly into solid tumors in mice or by systemic administration. In this work, we studied the role of CIGB-300 on the main events that take place in angiogenesis. At non-cytotoxic doses, CIGB-300 was able to inhibit adhesion, migration, and tubular network formation induced by human umbilical vein endothelial cells (HUVEC) growing upon Matrigel in vitro. Likewise, we evaluated the cellular penetration and localization into the HUVEC cells of CIGB-300. Our results confirmed a quick cellular penetration and a cytoplasmic accumulation in the early minutes of incubation and a translocation into the nuclei beginning at 12h of treatment, with a strong presence in the perinuclear area. A microarray analysis was used to determine the genes affected by the treatment. We observed that CIGB-300 significantly decreased four genes strongly associated with tubulogenesis, growth, and differentiation of endothelial cells. The CIGB-300 was tested in vivo on chicken embryo chorioallantoic membranes (CAM), and a large number of newly formed blood vessels were significantly regressed. The results suggested that CIGB-300 has a potential as an antiangiogenic treatment. The mechanism of action may be associated with partial inhibition of VEGF and Notch pathways.Fil: Farina, Hernán Gabriel. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Benavent Acero, Fernando Rodrigo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Perera, Yasser. Center for Genetic Engineering and Biotechnology; CubaFil: Rodríguez, Arielis. Center for Genetic Engineering and Biotechnology; CubaFil: Perea, Silvio E.. Center for Genetic Engineering and Biotechnology; CubaFil: Acevedo Castro, Boris. Center for Genetic Engineering and Biotechnology; CubaFil: Gomez, Roberto. No especifíca;Fil: Alonso, Daniel F.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Gomez, Daniel Eduardo. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Letter-similarity effects in braille word recognition.

Letter-similarity effects are elusive with common words in lexical decision experiments: viotin and viocin (base word: violin) produce similar error rates and rejection latencies. However, they are robust for stimuli often presented with the same appearance (e.g., misspelled logotypes such as anazon [base word: amazon] produce more errors and longer latencies than atazon). Here, we examine whether letter-similarity effects occur in reading braille. The rationale is that braille is a writing system in which the sensory information is processed in qualitatively different ways than in visual reading: the form of the word's letters is highly stable due to the standardization of braille and the sensing of characters is transient and somewhat serial. Hence, we hypothesized that the letter similarity effect would be sizeable with misspelled common words in braille, unlike the visual modality. To test this hypothesis, we conducted a lexical decision experiment with blind adult braille readers. Pseudowords were created by replacing one letter of a word with a tactually-similar or dissimilar letter in braille following a tactile similarity matrix (Baciero et al., 2021a; e.g., [ausor] vs. [aucor]; baseword: [autor]). Bayesian linear mixed-effects models showed that the responses to tactually-similar pseudowords were less accurate than to tactually-dissimilar pseudowords-the RTs showed a parallel trend. This finding supports the idea that, when reading braille, the mapping of input information onto abstract letter representations is done through a noisy channel (Norris & Kinoshita, 2012)