An epistatic mini-circuitry between the transcription factors Snail and HNF4a controls liver stem cell and hepatocyte features exhorting opposite regulation on stemness-inhibiting microRNAs

Preservation of the epithelial state involves the stable repression of EMT program while maintenance of the stem compartment requires the inhibition of differentiation processes. A simple and direct molecular mini-circuitry between master elements of these biological processes, may provide the best device to keep balanced such complex phenomena. In this work, we show that in hepatic stem cell Snail, a transcriptional repressor of the hepatocyte differentiation master gene HNF4, directly represses the expression of the epithelial microRNAs-200c and -34a, which in turn target several stem cell genes. Notably, in differentiated hepatocytes HNF4, previously identified as a transcriptional repressor of Snail, induces the microRNAs-34a and -200a, b, c that, when silenced, causes epithelial dedifferentiation and reacquisition of stem traits. Altogether these data unveiled Snail, HNF4 and microRNAs -200a, b, c and -34a as epistatic elements controlling hepatic stem cell maintenance/differentiation

"Non-retinotopic processing" in Ternus motion displays modeled by spatiotemporal filters

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Different reaction-times for subitizing, estimation, and texture

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Pupillometry correlates of visual priming, and their dependency on autistic traits

In paradigms of visual search where the search feature (say color) can change from trial to trials, responses are faster for trials where the search color is repeated than when it changes. This is a clear example of "priming" of attention. Here we test whether the priming effects can be revealed by pupillometry, and also whether they are related to autistic-like personality traits, as measured by the Autism-Spectrum Quotient (AQ). We repeated Maljkovic and Nakayama's (1994) classic priming experiment, asking subjects to identify rapidly the shape of a singleton target defined by color. As expected, reaction times were faster when target color repeated, and the effect accumulated over several trials; but the magnitude of the effect did not correlate with AQ. Reaction times were also faster when target position was repeated, again independent of AQ. Presentation of stimuli caused the pupil to dilate, and the magnitude of dilation was greater for switched than repeated trials. This effect did not accumulate over trials, and did not correlate with the reaction times difference, suggesting that the two indexes measure independent aspects of the priming phenomenon. Importantly, the amplitude of pupil modulation correlated negatively with AQ, and was significant only for those participants with low AQ. The results confirm that pupillometry can track perceptual and attentional processes, and furnish useful information unobtainable from standard psychophysics, including interesting dependencies on personality traits

spatiotemporal filtering and motion illusions

We are perplexed by Clarke et al.'s (2013) criticisms on our recent contribution to Journal of Vision (Pooresmaeili, Cicchini, Morrone, & Burr, 2012). Our group has long championed the idea that perceptual processing of information can be anchored in a dynamic coordinate system that need not correspond to the instantaneous retinal representation. Our recent evidence shows that temporal duration (Burr, Tozzi, & Morrone, 2007; Morrone, Cicchini, & Burr, 2010), orientation (Zimmermann, Morrone, Fink, & Burr, 2013), motion (Melcher & Morrone, 2003; Turi & Burr, 2012) and saccadic error-correction (Zimmermann, Burr, & Morrone, 2011) are all processed to some extent in spatiotopic coordinates. Imaging studies reinforce these studies (d'Avossa et al., 2007; Crespi et al., 2011). Much earlier, we showed that the processing of smoothly moving objects was not anchored in instantaneous, retinotopic coordinates, but in the reference frame given by the trajectory of motion. There is an effective interpolation along the trajectory, so temporal offsets in spatially collinear stimuli causes them to appear spatially offset, corresponding to the physical reality of stimuli moving over large regions of space, behind occluders (Burr, 1979; Burr & Ross, 1979). Our explanation for this surprising effect was that it could be a direct consequence of the spatiotemporal orientation of the impulsive response of motion detectors, providing the spatiotemporal reference frame needed to account for the interactions between time and space (Burr & Ross, 1986; Burr, Ross, & Morrone, 1986; Burr & Ross, 2004; Nishida, 2004). Recently, we have applied the concept of spatiotemporal oriented receptive fields to account for ''predictive remapping,'' the ''nonretinotopic'' effects that occur on each saccadic eye-movement (Burr & Morrone, 2010; Burr & Morrone, 2012; Cicchini, Binda, Burr, & Morrone, 2012). We were most impressed by the compelling demonstrations of Herzog's group, clearly showing that the reference frame of processing is not the instantaneous retinal position, but is flexible, depending not only on real physical motion, but on an illusory apparent motion where the stimuli do not actually move (Boi, Ogmen, Krummenacher, Otto, & Herzog, 2009). This seemed to us important, worthy of quantitative measurement and modeling, particularly to see whether these new effects may fall within the framework that so successfully explained previous demonstrations, such as spatiotemporal interpolation. It is reassuring that Clarke et al. (2013) confirm our results, albeit with some variability between subjects. But more importantly add a very nice result in showing that our simplified version of the ''litmus test'' can be enhanced by attending to the motion. This is an excellent point that we overlooked. The strength of this type of motion is well known to depend on attention (Cavanagh, 1992), and it is indeed interesting that the strength of motion-induced effects depends not only on the physical conditions, but on internal states such as attention. Perhaps attention may also provide the flexibility in choosing the most appropriate scale for analysis, which in this case would be lower, given that attention is diverted to the periphery. This would add strength to our model, and an idea worth following up

Medición del flujo de neutrones a 10,6 Gv

Se analizan los registros obtenidos en una serie de cuatro vuelos con globos dilatables, que alcanzaron una altura máxima equivalente a una presión de 12 mb. Los lanzamientos fueron realizados en Buenos Aires. Los equipos transportados constaban de un contador enriquecido y otro normal, rodeados de 2,5 cm de parafina y 0,5 mm de Cd.; sistema sensible a neutrones en el rango de energías de aproximadamente 0,01 a 1 Mev. La posición del máximo de transición, a 10,6 Gv, fue 98 ± 3 mb; valor que concuerda con el esperado, de acuerdo con la variación en latitud predicha por Lingenfelter y con los resultados experimentales obtenidos por Holt, Mendell y Korff. El contaje al tope de la atmósfera fue estimado por extrapolación, representando aproximadamente un 33 °/o del contaje máximo; valor muy alto si se compara con el obtenido en otros trabajos.This paper presents an analysis of the records obtained during a series of four flights, carried out by means of expandible balloons, which reached a maximum altitude equivalent to a 12 mb pressure. The launching took place at Buenos Aires. The transported equipment was constituted by one enriched counter and one normal surrounded by 2,5 cm of paraffin and 0,5 mm of. Cd. The system was sensitive to neutrons within the energy range of 0,01 to 1 Mev. The position of the maximum transition at 10,6 Gv was 98 ± 3 mb., value which agrees with the one expected according to the variation in latitude predicted by Lingelfelter and with the experimental results obtained by Holt, Mendell and Korff. The counting on top of the atmosphere was estimated trough extrapolation, representing roughly a 33°/o of the maximum counting. This is a very high value compared to the ones obtained in other works.Asociación Argentina de Geofísicos y Geodesta

Medición del flujo de neutrones a 10,6 Gv

Se analizan los registros obtenidos en una serie de cuatro vuelos con globos dilatables, que alcanzaron una altura máxima equivalente a una presión de 12 mb. Los lanzamientos fueron realizados en Buenos Aires. Los equipos transportados constaban de un contador enriquecido y otro normal, rodeados de 2,5 cm de parafina y 0,5 mm de Cd.; sistema sensible a neutrones en el rango de energías de aproximadamente 0,01 a 1 Mev. La posición del máximo de transición, a 10,6 Gv, fue 98 ± 3 mb; valor que concuerda con el esperado, de acuerdo con la variación en latitud predicha por Lingenfelter y con los resultados experimentales obtenidos por Holt, Mendell y Korff. El contaje al tope de la atmósfera fue estimado por extrapolación, representando aproximadamente un 33 °/o del contaje máximo; valor muy alto si se compara con el obtenido en otros trabajos.This paper presents an analysis of the records obtained during a series of four flights, carried out by means of expandible balloons, which reached a maximum altitude equivalent to a 12 mb pressure. The launching took place at Buenos Aires. The transported equipment was constituted by one enriched counter and one normal surrounded by 2,5 cm of paraffin and 0,5 mm of. Cd. The system was sensitive to neutrons within the energy range of 0,01 to 1 Mev. The position of the maximum transition at 10,6 Gv was 98 ± 3 mb., value which agrees with the one expected according to the variation in latitude predicted by Lingelfelter and with the experimental results obtained by Holt, Mendell and Korff. The counting on top of the atmosphere was estimated trough extrapolation, representing roughly a 33°/o of the maximum counting. This is a very high value compared to the ones obtained in other works.Asociación Argentina de Geofísicos y Geodesta

Adaptation to hand-tapping affects sensory processing of numerosity directly: evidence from reaction times and confidence

Each file contains a matrix called “MatriceRisultati”. Each row of the matrix “MatriceRisultati” is a trial. The columns contain the following information: 1st: Number of trial 2nd: Test numerosity 3rd: Subject response on numerosity 4th: Subject response on their confidence level 5th: Response time 6th: 0 if the test numerosity 1

Visualización de la geometría algebraica

En esta comunicación se presenta una experiencia realizada mediante el empleo de un simulador para introducir la noción de cuádricas en la asignatura Álgebra y Geometría Analítica correspondiente al primer año de la carrera de ingeniería. El uso de simuladores permite pasar rápidamente del registro algebraico al gráfico al ir variando los parámetros y va introduciendo al estudiante en situaciones simples que más adelante en la carrera se irán ampliando con simulaciones más complejas. Este tipo de experiencias propician la autogestión de los aprendizajes, por cuanto cada alumno puede utilizar el software a su ritmo de aprendizaje, y motiva a los estudiantes al estudio del tema mediante el empleo de una herramienta que le resulta familiar

Carnets de bord en sciences humaines : genèse, dynamique et fin d'une revue

Ce dernier numéro est l'occasion de faire un bilan et d'analyser les raisons qui nous ont conduits à décider de mettre un terme à l'existence d'une revue que nous avons animée pendant près de dix ans. Fidèles à la ligne éditoriale, nous dévoilons les coulisses de la production de Carnets de bord. Chemin faisant, nous nous livrons à un exercice d'auto-analyse susceptible d'éclairer la fragilité de ce genre d'initiatives intellectuelles dans un contexte universitaire où les critères managériaux d'évaluation ont largement gagné du terrain