70 research outputs found

    A tutorial for analyzing human reaction times: How to filter data, manage missing values, and choose a statistical model

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    This tutorial for the statistical processing of reaction times collected through a repeated-measure design is addressed to researchers in psychology. It aims at making explicit some important methodological issues, at orienting researchers to the existing solutions, and at providing them some evaluation tools for choosing the most robust and precise way to analyze their data. The methodological issues we tackle concern data filtering, missing values management, and statistical modeling (F1, F2, F1 + F2, quasi-F, mixed-effects models with hierarchical, or with crossed factors). For each issue, references and remedy suggestions are given. In addition, modeling techniques are compared on real data and a benchmark is given for estimating the precision and robustness of each techniqu

    Les effets perturbateurs liés au scintillement subliminal des écrans cathodiques sur le contrôle oculomoteur lors du déplacement saccadique des yeux

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    Les écrans cathodiques, dont l'usage s'est généralisé à la grande majorité de la population occidentale, sont responsables de troubles variés (maux de tête, fatigue visuelle, chute des performances cognitives, etc.), dont la gravité peut aller jusqu'au syndrome neurologique chez les sujets prédisposés (déclenchement de crises d'épilepsie). Si les radiations imputables au canon à électrons peuvent être en cause dans une certaine mesure, ce sont surtout les caractéristiques physiques du stimulus lumineux qui induisent un « stress visuel ». À la différence des objets visuels du monde réel, stables et permanents, l'image générée par un écran cathodique est intermittente, avec une variation subliminale de luminance (« scintillement ») qui dépend de la fréquence de rafraîchissement utilisée. Ce scintillement subliminal est susceptible, par l'intermédiaire des processus sensoriels de la vision, d'altérer les processus perceptifs, cognitifs, mais aussi oculomoteurs. L'étude présentée dans ce document s'attache, à partir d'observations antérieures sur la variabilité des positions de première fixation (PPF) de l'oeil dans une chaîne de caractères en fonction de la fréquence de rafraîchissement de l'écran, à comprendre quels mécanismes du contrôle oculomoteur de la saccade sont modulés, et pourquoi il en est ainsi

    INITIAL EMBEDDED WORDS CAN FACILITATE THE RECOGNITION OF THEIR CARRIER WORD, BUT NOT ACCORDING TO TRACE-LIKE MODELS

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    Présentation de simulations d'un modèle mathématiqueThis theoretical article explores how initial embedded words can facilitate the recognition of their carrier, first in simulations with TRACE, second in exposing new conceptions of word recognition. Simulations with TRACE were used for testing if lexical resonance implemented in TRACE, and if activation transfer from the embedded word to the carrier, suggested by Luce and Lyons (1999), could be candidate mechanisms. These simulations proved that none of these two mechanisms explain the facilitation phenomenon. Therefore, two alternative models of word recognition were developed, LML and LEXSS. LEXSS was tested in simulations and its predictions were confronted to human behavior measurements. Results show that LEXSS predicts adequately human behavior, implying that it has some psychological validity.Cet article théorique explore comment la présence d'un mot enchâssé initial peut faciliter la reconnaissance de son porteur, premièrement à travers une série de simulations, deuxièmement en proposant de nouvelles conceptions pour la reconnaissance des mots.Les simulations ont été réalisées avec TRACE pour tester si la résonance lexicale, implémentée dans TRACE, et si le transfert d'activation du mot enchâssé à son porteur, suggéré par Luce et Lyons (1999), pouvaient être des mécanismes explicatifs.Ces simulations ont démontré qu'aucun de ces deux mécanismes ne pouvaient rendre compte du phénomène de facilitation.Par conséquent, deux modèles alternatifs ont été élaborés, LML et LEXSS. LEXSS a pu être testé dans des simulations; ses prédictions ont été confrontées à des mesures comportementementales humaines. Les résultats montrent que LEXSS prédit correctement le comportement humain, apportant crédit à sa validité psychologique

    EGF-induced adipose tissue mesothelial cells undergo functional vascular smooth muscle differentiation

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    Recent studies suggested that the post-natal mesothelium retain differentiative potential of the embryonic mesothelium, which generates fibroblasts and vascular smooth muscle cells (VSMCs), in developing coelomic organs via epithelial-to-mesenchymal transition (EMT). Whether adult mesothelial cells (MCs) are able to give rise to functional VSMCs in vitro and which are the factors and mechanisms directing this process remain largely unknown. Here, we isolated adipose tissue MCs (ATMCs) from adult mice, and demonstrated that ATMCs cultured in a serum-containing media supplemented with epidermal growth factor (EGF) efficiently increased both their proliferation and EMT above levels found in only serum-containing media cultures. EGF-induced ATMCs gained phosphorylation of the EGF receptor and activated simultaneously ILK/Erk1/2, PI3K/Akt and Smad2/3-dependent pathways. Sequential subculture onto collagen-I surface efficiently improved their vasculogenic EMT towards cells featuring VSMCs (α-SMA, calponin, caldesmon, SM22α, desmin, SM-MHC, smoothelin-B and PDGFR-β) that could actively contract in response to receptor and non-receptor-mediated vasoactive agonists. Overall, our results indentify EGF signalling as a robust vasculogenic inductive pathway for ATMCs, leading to their transdifferentiation into functional VSMC-like cells.Junta de Andalucía Grant PI-0022/2008Junta de Andalucía, Consejería de Innovación Ciencia y Empresa P07-CVI-279

    miR-7 Modulates hESC Differentiation into Insulin-Producing Beta-like Cells and Contributes to Cell Maturation

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    Human pluripotent stem cells retain the extraordinary capacity to differentiate into pancreatic beta cells. For this particular lineage, more effort is still required to stress the importance of developing an efficient, reproducible, easy, and cost-effective differentiation protocol to obtain more mature, homogeneous, and functional insulin-secreting cells. In addition, microRNAs (miRNAs) have emerged as a class of small non-coding RNAs that regulate many cellular processes, including pancreatic differentiation. Some miRNAs are known to be preferentially expressed in islets. Of note, miR-375 and miR-7 are two of the most abundant pancreatic miRNAs, and they are necessary for proper pancreatic islet development. Here we provide new insight into specific miRNAs involved in pancreatic differentiation. We found that miR-7 is differentially expressed during the differentiation of human embryonic stem cells (hESCs) into a beta cell-like phenotype and that its modulation plays an important role in generating mature pancreatic beta cells. This strategy may be exploited to optimize the potential for in vitro differentiation of hESCs into insulin-producing beta-like cells for use in preclinical studies and future clinical applications as well as the prospective uses of miRNAs to improve this process.Spanish Ministry of Economy and Competitiveness BFU2016-74932-C2 BFU2013-45564-C2FEDER Funds PI-0272-2017Andalusian Regional Ministry of Health PI-0272-2017European Cooperation in Science and Technology BM1305Spanish Ministry of Economy, Industry and Competitiveness CD16/00118Spanish Institute of Health Carlos III PI16/00259 PI17/02104 RD16/0011/0034 CD16/0011

    Mesothelial cells: A cellular surrogate for tissue engineering of corneal endothelium

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    [Purpose]: To evaluate whether mouse adipose tissue mesothelial cells (ATMCs) share morphologic and biochemical characteristics with mouse corneal endothelial cells (CECs) and to evaluate their capacity to adhere to the decellularized basal membrane of human anterior lens capsules (HALCs) as a potential tissue-engineered surrogate for corneal endothelium replacement. [Methods]: Adipose tissue mesothelial cells were isolated from the visceral adipose tissue of adult mice, and their expression of several corneal endothelium markers was determined with quantitative RT-PCR, immunofluorescence, and Western blotting. Adipose tissue mesothelial cells were cultured in a mesothelial retaining phenotype medium (MRPM) and further seeded and cultured on top of the decellularized basal membrane of HALCs. ATMC-HALC composites were evaluated by optical microscopy, immunofluorescence, and transmission electron microscopy. [Results]: Mesothelial retaining phenotype medium-cultured ATMCs express the corneal endothelium markers COL4A2, COL8A2, SLC4A4, CAR2, sodium- and potassium-dependent adenosine triphosphatase (Na+/K+-ATPase), b-catenin, zona occludens-1, and N-cadherin in a pattern similar to that in mouse CECs. Furthermore, ATMCs displayed strong adhesion capacity onto the basal membrane of HALCs and formed a confluent monolayer within 72 hours of culture in MRPM. Ultrastructural morphologic and marker characteristics displayed by ATMC monolayer on HALCs clearly indicated that ATMCs retained their original phenotype of squamous epithelial-like cells. [Conclusions]: Corneal epithelial cells and ATMCs share morphologic (structural) and marker (functional) similarities. The ATMCs adhered and formed structures mimicking focal adhesion complexes with the HALC basal membrane. Monolayer structure and achieved density of ATMCs support the proposal to use adult human mesothelial cells (MCs) as a possible surrogate for damaged corneal endothelium.Supported by Fondos FEDER, Fundación Progreso y Salud, Consejería de Salud, Junta de Andalucía (Grant PI-0022/2008), INNPACTO Program (INP-2011-1615-900000), and SUDOE Program-BIOREG (Intereg SOE3/P1/E750); Consejer´ıa de Innovación Ciencia y Empresa, Junta de Andalucía (Grant CTS-6505); Ministry of Science and Innovation (Red TerCel-FEDER Grant RD12/0019/ 0028); Instituto de Salud Carlos III Grant PI10/00964); the Ministry of Health and Consumer Affairs Advanced Therapies Program Grant TRA-120 (BS); and Corporación Tecnológica de Andalucía CTA (NBT). CIBERDEM is an initiative of the Instituto de Salud Carlos III.Peer Reviewe

    Preconditioning of Microglia by α-Synuclein Strongly Affects the Response Induced by Toll-like Receptor (TLR) Stimulation

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    In recent years, it has become accepted that α-synuclein (αSyn) has a key role in the microglia-mediated neuroinflammation, which accompanies the development of Parkinson's disease and other related disorders, such as Dementia with Lewy Bodies and Alzheimer's disease. Nevertheless, the cellular and molecular mechanisms underlying its pathological actions, especially in the sporadic forms of the diseases, are not completely understood. Intriguingly, several epidemiological and animal model studies have revealed a link between certain microbial infections and the onset or progression of sporadic forms of these neurodegenerative disorders. In this work, we have characterized the effect of toll-like receptor (TLR) stimulation on primary murine microglial cultures and analysed the impact of priming cells with extracellular wild-type (Wt) αSyn on the subsequent TLR stimulation of cells with a set of TLR ligands. By assaying key interleukins and chemokines we report that specific stimuli, in particular Pam3Csk4 (Pam3) and single-stranded RNA40 (ssRNA), can differentially affect the TLR2/1- and TLR7-mediated responses of microglia when pre-conditioned with αSyn by augmenting IL-6, MCP-1/CCL2 or IP-10/CXCL10 secretion levels. Furthermore, we report a skewing of αSyn-primed microglia stimulated with ssRNA (TLR7) or Pam3 (TLR2/1) towards intermediate but at the same time differential, M1/M2 phenotypes. Finally, we show that the levels and intracellular location of activated caspase-3 protein change significantly in αSyn-primed microglia after stimulation with these particular TLR agonists. Overall, we report a remarkable impact of non-aggregated αSyn pre-sensitization of microglia on TLR-mediated immunity, a phenomenon that could contribute to triggering the onset of sporadic α-synuclein-related neuropathologies
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