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Seeing objects usually grasped with a power or a precision grip (e.g., an apple vs a cherry) potentiates power- and precision-grip responses, respectively. An embodied account suggests that this effect occurs because object conceptual representations would lie on a motor simulation process. A new account, named the size-coding account, argues that this effect could be rather due to an overlapping of size codes used to represent both manipulable objects and response options. In this article, we investigate whether this potentiation effect could be merely due to a low-level visual feature that favours a size-coding of stimuli: the visual size in which objects are presented. Accordingly, we conducted two experiments in which we presented highly elementary and non-graspable stimuli (i.e., ink spots) either large or small rather than graspable objects. Our results showed that the mere visual size automatically potentiates power- and precision-grip responses that are in line with the size-coding account of the potentiation effect of grasping behaviours. Moreover, these results appeal to improve the methodological control of the size of stimuli especially when researchers try to support the embodied account. [ABSTRACT FROM AUTHOR]

Vasopressin and its receptors modulate several gut functions, but their role in intestinal inflammation is unknown. Our aims were to determine 1) the localization of V1b receptors in human and rodent colon, 2) the role of vasopressin and V1b receptors in experimental colitis using two approaches: [V1b.sup.-/-] mice and a selective V1b receptor antagonist, SSR149415, and 3) the mechanisms involved. V1b receptors were localized in normal and inflamed colon from humans and rats. Experimental colitis was induced in rats and mice and some groups were treated before or after colitis induction with oral SSR149415 (3-30 mg/kg). Other groups of mice were submitted to dehydration to increase vasopressin plasma levels, prior to colitis induction. Body weight, damage scores, MPO, and TNF-[alpha] tissue levels were determined. Finally, colonic segments of wild-type (WT) and [V1b.sup.-/-] mice were mounted in Ussing chambers and paracellular permeability in response to vasopressin was studied. V1b receptors were expressed in enterocytes and ganglia cells of the enteric nervous system of human and rat intestine. Expression levels were independent from inflammatory status. Colitis was less severe in rodents treated by either preventive or curative SSR149415 and in [V1b.sup.-/-] mice. 2,4,6-Trinitrobenzene sulfonic acid induced a strong mortality in dehydrated animals that was reversed by preventive SSR149415 or mast cell stabilizer. Vasopressin significantly increased paracellular permeability in WT, but not in [V1b.sup.-/-] mice. Preincubation of colon tissues with SSR149415 abolished the vasopressin effect. Similarly, vasopressin had no effect in colonic preparations from WT mice pretreated with mast cell stabilizers. Vasopressin, through V1b receptor interaction, has proinflammatory properties linked to mast cell activation and downstream alterations of the colonic epithelial barrier. These findings underline the potential interest of V1b receptor blockers in gut inflammatory diseases. epithelial barrier; inflammatory bowel disease doi: 10.1152/ajpgi.00022.2010.

Cet article porte sur l'influence de la taille typique dans une tache de categorisation. L'originalite de notre travail repose sur l'homogeneite de la taille graphique des stimuli. Nous avons commence par construire une norme de taille typique des stimuli, celle-ci porte sur la taille reelle des objets representes par les dessins de tailles homogenes. Ensuite, une experience d'amorcage a ete realisee dans laquelle les dessins amorces et cibles entretiennent deux types de relations : une relation de taille typique et une relation categorielle. Lors de la passation, l'existence d'un lien de taille typique entre amorce et cible n'est pas mentionnee aux participants. Les resultats obtenus montrent un effet d'amorcage positif de la taille typique mais pas d'effet de la categorie. Les resultats sont discutes en regard de l'approche theorique developpee par Barsalou et son equipe (1999, 2003). Dans ce cadre theorique, la taille typique peut &re assimilable a une connaissance perceptive. De cette facon, la taille typique pourrait etre automatiquement simulee par les participants lors de la perception de stimuli connus dans des tailles egalisees. This study explores the influence of typical size during a categorization task. The specificity of this experimental work is based on the homogeneity of the graphic stimuli size. We have created a typical size standard of our stimuli, that concerns the real size of the objects represented by the drawings of homogeneous sizes. Then, a priming experiment was performed in which the prime and target drawings had two types of relations: a typical size, and a categorial. The participants are naive as to the typical size relation between prime and target. The results show a positive priming effect of the typical size but not of the category. The results are discussed in term of theoretical approach developed by Barsalou and his colleagues (1999, 2003). In this theoretical framework, the typical size can be considered as a perceptual knowledge. In that way, we propose that participants could automatically simulate the typical size as soon as they perceived the drawings of objects with homegenous sizes.

A study was conducted to investigate the colonic motor effect of short-chain fatty acids (SCFAs) and their mechanisms in rats. Colonic motility and transit time were measured in conscious rats while SCFAs were infused into the colon, either alone or after administration of neural antagonists or immunoneutralization of circulating polypeptide YY. Findings indicated that SCFAs restrict colonic myolectrical activity in a dose-dependent manner. The effect is dependent on the chemical nature of SCFAs and seems to be mediated through a neuroendocrine mechanism involving the circulating polypeptide YY.

Olive oil consumption is beneficial for health as it is associated with a decreased prevalence of cancer and cardiovascular diseases. Oleic acid is, by far, the most abundant component of olive oil. Since it can be made through de novo synthesis in animals, it is not an essential fatty acid. While it has become clear that dietary oleic acid regulates many biological processes, the signaling pathway involved in these regulations remains poorly defined. In this work we tested the impact of an oleic acid-rich diet on hepatic gene expression. We were particularly interested in addressing the contribution of Liver X Receptors (LXR) in the control of genes involved in hepatic lipogenesis, an essential process in whole body energy homeostasis. We used wild-type mice and transgenic mice deficient for both α and β Liver X Receptor isoforms (LXR-/-) fed a control or an oleate enriched diet. We observed that hepatic-lipid accumulation was enhanced as well as the expression of lipogenic genes in the liver of wild-type mice fed the oleate enriched diet. In contrast, none of these changes occurred in the liver of LXR-/- mice. Strikingly, oleate-rich diet reduced cholesterolemia in wild-type mice and induced signs of liver inflammation and damage in LXR-/- mice but not in wild-type mice. This work suggests that dietary oleic acid reduces cholesterolemia while promoting LXR-dependent hepatic lipogenesis without detrimental effects to the liver. [ABSTRACT FROM AUTHOR]

Despite well-known intestinal epithelial barrier impairment and visceral hypersensitivity in irritable bowel syndrome (IBS) patients and IBS-like models, structural and physical changes in the mucus layer remain poorly understood. Using a water avoidance stress (WAS) model, we aimed at evaluating whether 1) WAS modified gut permeability, visceral sensitivity, mucin expression, biochemical structure of O-glycans, and related mucus physical properties, and 2) whether Lactobacillus farciminis treatment prevented these alterations. Wistar rats received orally L. farciminis or vehicle for 14 days; at day 10, they were submitted to either sham or 4-day WAS. Intestinal paracellular permeability and visceral sensitivity were measured in vivo. The number of goblet cells and Muc2 expression were evaluated by histology and immunohistochemistry, respectively. Mucosal adhesion of L. farciminis was determined ex situ. The mucin O-glycosylation profile was obtained by mass spectrometry. Surface imaging of intestinal mucus was performed at nanoscale by atomic force microscopy. WAS induced gut hyperpermeability and visceral hypersensitivity but did not modify either the number of intestinal goblet cells or Muc2 expression. In contrast, O-glycosylation of mucins was strongly affected, with the appearance of elongated polylactosaminic chain containing O-glycan structures, associated with flattening and loss of the mucus layer cohesive properties. L. farciminis bound to intestinal Muc2 and prevented WAS-induced functional alterations and changes in mucin O-glycosylation and mucus physical properties. WAS-induced functional changes were associated with mucus alterations resulting from a shift in O-glycosylation rather than from changes in mucin expression. L. farciminis treatment prevented these alterations, conferring epithelial and mucus barrier strengthening. [ABSTRACT FROM AUTHOR]

Proinflammatory cytokines produced by immune cells play a central role in the increased intestinal epithelial permeability during inflammation. Expansion of visceral adipose tissue (VAT) is currently considered a consequence of intestinal inflammation. Whether VAT per se plays a role in early modifications of intestinal barrier remains unknown. The aim of this study was to demonstrate the direct role of adipocytes in regulating paracellular permeability of colonic epithelial cells (CECs). We show in adult rats born with intrauterine growth retardation, a model of VAT hypertrophy, and in rats with VAT graft on the colon, that colonic permeability was increased without any inflammation. This effect was associated with altered expression of tight junction (TJ) proteins occludin and ZO-1. In coculture experiments, adipocytes decreased transepithelial resistance (TER) of Caco-2 CECs and induced a disorganization of ZO-1 on TJs. Intraperitoneal administration of leptin to lean rats increased colonic epithelial permeability and altered ZO-1 expression and organization. Treatment of HT29-19A CECs with leptin, but not adiponectin, dose-dependently decreased TER and altered TJ and F-actin cytoskeleton organization through a RhoA-ROCK-dependent pathway. Our data show that adipocytes and leptin directly alter TJ function in CECs and suggest that VAT could impair colonic epithelial barrier. [ABSTRACT FROM AUTHOR]

OBJECTIVES:Luminal serine-proteases lead to increased colonic paracellular permeability and visceral hypersensitivity in patients with diarrhea-predominant irritable bowel syndrome (IBS-D). Other proteases, namely cysteine-proteases (CPs), increase airway permeability by digesting epithelial tight junction proteins. In this study, we focused on constipation-predominant IBS (IBS-C) and we aimed to (i) evaluate CP levels in two cohorts of IBS patients, (ii) test if IBS-C fecal supernatant (FSN) affects permeability, and visceral sensitivity after repeated administrations in mice, and (iii) evaluate occludin expression in IBS-C colonic biopsies.METHODS:Fecal CP activity was determined using selective substrate and inhibitor (E64). The effect of papain, as positive control, and IBS-C FSN administrations were evaluated on colonic paracellular permeability and mucosal occludin levels in mice and T84 monolayers. Occludin protein levels were evaluated in IBS-C colonic biopsies. Sensitivity to colorectal distension (CRD) was measured after repeated administrations of IBS-C FSN.RESULTS:We found in a subset of IBS-C patients an enhanced fecal CP activity, in comparison with healthy controls and IBS-D patients. CP activity levels positively correlated with disease severity and abdominal pain scoring. This association was confirmed by receiver operating characteristic curve analysis. In mice, repeated application of IBS-C FSN into colon triggered increased permeability, linked to the enzymatic degradation of occludin, and was associated with enhanced visceral sensitivity to CRD. Finally, occludin levels were found decreased in colonic biopsies from IBS-C patients, and IBS-C FSNs were able to degrade recombinant human occludin in vitro. All these effects were abolished by preincubation of IBS-C FSN with a CP inhibitor, E64.CONCLUSIONS:These data suggest that luminal CPs may represent a new factor contributing to the genesis of symptoms in IBS. [ABSTRACT FROM AUTHOR]

"How can perception be altered by language?" is the fundamental question of this article. Indeed, various studies have pointed out the influence of colour-related knowledge on object and colour perception, evoked by linguistic stimuli. Here the relevance of the simulationist approach is assumed in order to explain this influence, where the understanding of colour-related words or sentences involves a process of colour simulation that is supported by a neuronal network partially similar to the network involved in colour perception. Consequently, colour-related knowledge and colour perception can interact through a process of pattern interference. In support of this idea, studies are discussed showing priming effects between colour simulation and colour perception, but two limitations are also raised. Firstly, these works all used between-category colour discrimination tasks that allow the intervention of lexical processes that can also explain priming. Secondly, these works control the congruency link between prime and target at the level of 'colour category', and no demonstration is made of an influence at the level of specific hues. Consequently, the simulationist view of language/perception interactions seems an interesting way to thinking but more experimens are needed in order to overcome some limitations. [ABSTRACT FROM AUTHOR]

Activation of colonic proteinase-activated receptor-2 (PAR2) caused inflammation and increased mucosal permeability in mouse colon. The present study was aimed at characterizing the possible links between these two phenomena. We evaluated the effects of intracolonic infusion of PAR2-activating peptide, SLIGRL, on colonic paracellular permeability and inflammation at two different doses, 5 and 100 µg per mouse, in an attempt to discriminate between both PAR2-mediated effects. We further investigated the possible involvement of interferon γ (IFN-γ) and calmodulin-dependent activation of myosin light chain kinase (MLCK), and alterations of zonula occludens-1 (ZO-1) localization in PAR2-induced responses. Thus, at the lower dose, SLIGRL increased colonic permeability without causing inflammation. Western blotting showed phosphorylation of mucosal myosin light chain (MLC) expression after both doses of SLIGRL. Moreover, while the MLCK inhibitor, ML-7, abolished the permeability effects of the low dose of SLIGRL, it only partially inhibited that of the high dose. In IFN-γ-deficient mice (B6 ifng-/-), the increases in permeability were similar for both doses of SLIGRL and prevented by ML-7. In addition, MLCK immunoprecipitation revealed an increase of calmodulin binding to MLCK in the mucosa of mice treated with either dose of SLIGRL. Finally, we have shown that direct activation of PARE on enterocytes is responsible for increased permeability and ZO-1 disruption. Moreover, SLIGRL at a dose that does not produce inflammation increases permeability via calmodulin activation, which binds and activates MLCK. The resulting tight junction opening does not depend upon IFN-γ secretion, while the increased permeability in response to the high dose of PAR2 agonist involves IFN-γ secretion. [ABSTRACT FROM AUTHOR]

Peptide YY (PYY) is involved in the regulation of several gastro-intestinal functions, including motility. The aims of the present study were (i) to characterize the effects of PYY on smooth muscle strips obtained from the different gastro-intestinal segments in rats and in humans and (ii) to realize a map of the Y receptors expression. Contractions of strips were recorded under isometric conditions, using PYY and acetylcholine as control. We observed that PYY induced a contraction of muscle strips from rat proximal colon, but displayed no effect on other gut segments. Using RT-PCR, mRNA encoding the Y1 and Y4 receptors were detected in muscle strips depending on the segment. In humans, the muscle preparations responded to ACh but not to PYY. Moreover, only Y2 receptor mRNA was found in the ileum and the left colon, but not in other segments. Our study shows the heterogeneity in the expression of Y receptors along the gastro-intestinal tract, and reveals great discrepancies between rats and humans both concerning the expression of Y receptor, and the response of smooth muscle strips to PYY. [Copyright &y& Elsevier]

Connected objects are deployed all over the world. Thus, they are contributing to improving communications. In urban areas, technological challenges are gradually being overcome, and advances in this area are exponential. Unfortunately, isolated territories such as northern Quebec do not beneficiate from this technological progress. Yet, northern Quebec relies on abundant natural resources, with notably its huge hydroelectric dams and iron mines, and therefore, the region's economic life revolves essentially around the exploitation of these resources and is heavily reliant on rail transportation. However, according to Transport Canada, 1246 railroad accidents were reported in 2019 to the Transportation Safety Board (TSB). Thirty-eight people described as trespassers lost their lives, and five railroad employees were fatally injured. In this context, we present the implementation of a security system in an isolated environment for employees intervening on the railroad track to warn them of the imminent arrival of a train. Due to the context of the isolated environment, i.e., without an electrical network, without internet, and without an LTE network, a solution for employees has been developed using a Zigbee telecommunication system and a connected watch. A case study on a train operating in a remote and isolated area in northern Quebec is presented to validate the performance of the proposed system based on an open-source and customizable solution. [ABSTRACT FROM AUTHOR]

Smart objects are deployed globally, contributing to improved communications and the growth of industrial systems' performances. Unfortunately, isolated territories are generally excluded from this progress. Remote areas in Canada are no exception. Thus, about two hundred thousand people are living in isolated regions in Canadian territory. The development of these communities is slowed down not only by an outdated energy supply, but they are also dependent on telecommunication systems not fully deployed in those regions, thus contributing to the amplification of those populations' isolation. Furthermore, the magnetic field in some regions of the planet and very often in isolated areas undergoes partial or total absorption, known as white areas, making the propagation of the signal very delicate. As a part of this article, a state of the art of telecommunication solutions available in an isolated environment is applied with a critical analysis based on several criteria. It shows the ability to use an original approach based on a captive balloon. Despite the proposed solution's feasibility, several challenges need to be addressed before formally adopting it. These challenges include: (i) controlling the height of the balloon; (ii) stabilization of the balloon; and (iii) powering the system. The list of references given at the end of the paper should offer aids for the industry and for researchers working in this field. [ABSTRACT FROM AUTHOR]

Objective:Intestinal proteases carry out a variety of functions in the gastrointestinal (GI) tract. Studies have reported that elevated enteric proteases in patients with GI disease can alter intestinal physiology, however the origin (human vs. microbial) of elevated proteases in patients with GI disease is unclear. Aim:The aim of this study was to investigate the association between protease activity and the microbiota in human fecal samples. Design:In order to capture a wide range of fecal protease (FP) activity stool samples were collected from 30 IBS patients and 24 healthy controls. The intestinal microbiota was characterized using 454 high throughput pyro-sequencing of the 16S rRNA gene. The composition and diversity of microbial communities were determined and compared using the Quantitative Insights Into Microbial Ecology (QIIME) pipeline. FP activity levels were determined using an ELISA-based method. FP activity was ranked and top and bottom quartiles (n=13 per quartile) were identified as having high and low FP activity, respectively. Results:The overall diversity of the intestinal microbiota displayed significant clustering separation (p = 0.001) between samples with high vs. low FP activity. The Lactobacillales, Lachnospiraceae, and Streptococcaceae groups were positively associated with FP activity across the entire study population, whilst the Ruminococcaceae family and an unclassified Coriobacteriales family were negatively associated with FP activity. Conclusions:These data demonstrate significant associations between specific intestinal bacterial groups and fecal protease activity and provide a basis for further causative studies investigating the role of enteric microbes and GI diseases. [ABSTRACT FROM AUTHOR]