214 research outputs found

    Représenter l'espace des objets physiques: La thèse de la dépendance réciproque entre l'identification des objets et celle des lieux

    Get PDF
    Cet article a pour but de réfléchir à nouveaux frais à une thèse philosophique traditionnelle qui a une portée fondamentale pour toute étude de la cognition spatiale. Cette thèse articule les relations, au niveau de la pensée conceptuelle, entre nos représentations des objets physiques et celles des lieux qu'ils occupent, et établit l'existence d'une dépendance réciproque entre ces deux ensembles de représentations. Nous tenterons d'établir dans quelle mesure des recherches récentes en sciences cognitives permettent de réviser et de préciser cette thèse (que nous appellerons la ‘thèse de la dépendance réciproque'). Pour cela, nous commencerons par présenter son sens philosophique. Ensuite, nous examinerons des travaux théoriques et empiriques qui semblent pouvoir la remettre en cause, issus des recherches sur les capacités de représentation topographique de lieux et de référence déictique à des objets physiques. Notre conclusion est qu'en dépit du problème de circularité qu'elle pose au niveau conceptuel (l'identification des objets dépendant de celle des lieux, qui à son tour dépendrait de celle des objets), la thèse de la dépendance réciproque reste valable à ce même niveau. Les difficultés posées par la circularité sont surmontées dans la mesure où la représentation des objets et la représentation des lieux reposent sur la fonction d'accessibilité propre aux capacités déictiques et topographiques

    Sounding objects

    Get PDF
    Taxonomy of philosophical theories of Sound: proximal theories; medial theories; distal theories. A distal theory: The Located Event Theory (LET) of sound. Understanding sound and the cognition of sounding objects; ontology of sound according to the LET; epistemology of the perception of sound and sounding objects; auditory images according to the LET; conceptual revisions entailed by distal theories and the LET; replies to objections

    Art et cognition: deux théories

    Get PDF
    Dans ce texte nous proposons, sous la forme d'une série de thèses, deux théories opposées de l'art, que nous appelons respectivement ‘théorie structurelle' et ‘théorie individualiste'. Ces deux théories sont relativement idéalisées par rapport aux positions effectivement occupées dans l'espace logique des débats théoriques sur l'art et la cognition. Elles représentent deux extrêmes parmi un spectre de positions possibles. Elles pourraient être tenues pour des pôles autour desquels organiser la discussion sur les rapports complexes entre les phénomènes artistiques et les sciences cognitives. Généralement, chaque thèse particulière garde un degré relativement important d'indépendance à l'égard des autres thèses et de la théorie à laquelle elle a été associée

    Metacognition as Evidence for Evidentialism

    Get PDF
    Metacognition is the monitoring and controlling of cognitive processes. I examine the role of metacognition in ‘ordinary retrieval cases’, cases in which it is intuitive that via recollection the subject has a justified belief. Drawing on psychological research on metacognition, I argue that evidentialism has a unique, accurate prediction in each ordinary retrieval case: the subject has evidence for the proposition she justifiedly believes. But, I argue, process reliabilism has no unique, accurate predictions in these cases. I conclude that ordinary retrieval cases better support evidentialism than process reliabilism. This conclusion challenges several common assumptions. One is that non-evidentialism alone allows for a naturalized epistemology, i.e., an epistemology that is fully in accordance with scientific research and methodology. Another is that process reliabilism fares much better than evidentialism in the epistemology of memory

    Mitochondria Regulate Proliferation in Adult Cardiac Myocytes

    Get PDF
    Newborn mammalian cardiomyocytes quickly transition from a fetal to an adult phenotype that utilizes mitochondrial oxidative phosphorylation but loses mitotic capacity. We tested whether forced reversal of adult cardiomyocytes back to a fetal glycolytic phenotype would restore proliferative capacity. We deleted Uqcrfs1 (mitochondrial Rieske iron-sulfur protein, RISP) in hearts of adult mice. As RISP protein decreased, heart mitochondrial function declined, and glucose utilization increased. Simultaneously, the hearts underwent hyperplastic remodeling during which cardiomyocyte number doubled without cellular hypertrophy. Cellular energy supply was preserved, AMPK activation was absent, and mTOR activation was evident. In ischemic hearts with RISP deletion, new cardiomyocytes migrated into the infarcted region, suggesting the potential for therapeutic cardiac regeneration. RNA sequencing revealed upregulation of genes associated with cardiac development and proliferation. Metabolomic analysis revealed a decrease in α-ketoglutarate (required for TET-mediated demethylation) and an increase in S-adenosylmethionine (required for methyltransferase activity). Analysis revealed an increase in methylated CpGs near gene transcriptional start sites. Genes that were both differentially expressed and differentially methylated were linked to upregulated cardiac developmental pathways. We conclude that decreased mitochondrial function and increased glucose utilization can restore mitotic capacity in adult cardiomyocytes, resulting in the generation of new heart cells, potentially through the modification of substrates that regulate epigenetic modification of genes required for proliferation

    Differentiation of COVID-19 signs and symptoms from allergic rhinitis and common cold: An ARIA-EAACI-GA2LEN consensus

    Get PDF
    Background: Although there are many asymptomatic patients, one of the problems of COVID-19 is early recognition of the disease. COVID-19 symptoms are polymorphic and may include upper respiratory symptoms. However, COVID-19 symptoms may be mistaken with the common cold or allergic rhinitis. An ARIA-EAACI study group attempted to differentiate upper respiratory symptoms between the three diseases. Methods: A modified Delphi process was used. The ARIA members who were seeing COVID-19 patients were asked to fill in a questionnaire on the upper airway symptoms of COVID-19, common cold and allergic rhinitis. Results: Among the 192 ARIA members who were invited to respond to the questionnaire, 89 responded and 87 questionnaires were analysed. The consensus was then reported. A two-way ANOVA revealed significant differences in the symptom intensity between the three diseases (p <.001). Conclusions: This modified Delphi approach enabled the differentiation of upper respiratory symptoms between COVID-19, the common cold and allergic rhinitis. An electronic algorithm will be devised using the questionnaire

    Intricate macrophage-colorectal cancer cell communication in response to radiation

    Get PDF
    Both cancer and tumour-associated host cells are exposed to ionizing radiation when a tumour is subjected to radiotherapy. Macrophages frequently constitute the most abundant tumour-associated immune population, playing a role in tumour progression and response to therapy. The present work aimed to evaluate the importance of macrophage-cancer cell communication in the cellular response to radiation. To address this question, we established monocultures and indirect co-cultures of human monocyte-derived macrophages with RKO or SW1463 colorectal cancer cells, which exhibit higher and lower radiation sensitivity, respectively. Mono- and co-cultures were then irradiated with 5 cumulative doses, in a similar fractionated scheme to that used during cancer patients' treatment (2 Gy/fraction/day). Our results demonstrated that macrophages sensitize RKO to radiation-induced apoptosis, while protecting SW1463 cells. Additionally, the co-culture with macrophages increased the mRNA expression of metabolism- and survival-related genes more in SW1463 than in RKO. The presence of macrophages also upregulated glucose transporter 1 expression in irradiated SW1463, but not in RKO cells. In addition, the influence of cancer cells on the expression of pro- and anti-inflammatory macrophage markers, upon radiation exposure, was also evaluated. In the presence of RKO or SW1463, irradiated macrophages exhibit higher levels of pro-inflammatory TNF, IL6, CCL2 and CCR7, and of anti-inflammatory CCL18. However, RKO cells induce an increase of macrophage pro-inflammatory IL1B, while SW1463 cells promote higher pro-inflammatory CXCL8 and CD80, and also anti-inflammatory VCAN and IL10 levels. Thus, our data demonstrated that macrophages and cancer cells mutually influence their response to radiation. Notably, conditioned medium from irradiated co-cultures increased non-irradiated RKO cell migration and invasion and did not impact on angiogenesis in a chicken embryo chorioallantoic membrane assay. Overall, the establishment of primary human macrophage-cancer cell co-cultures revealed an intricate cell communication in response to ionizing radiation, which should be considered when developing therapies adjuvant to radiotherapy

    In vitro epithelial-to-mesenchymal transformation in human adult epicardial cells is regulated by TGFβ-signaling and WT1

    Get PDF
    Adult epicardial cells are required for endogenous cardiac repair. After myocardial injury, they are reactivated, undergo epithelial-to-mesenchymal transformation (EMT) and migrate into the injured myocardium where they generate various cell types, including coronary smooth muscle cells and cardiac interstitial fibroblasts, which contribute to cardiac repair. To understand what drives epicardial EMT, we used an in vitro model for human adult epicardial cells. These cells have an epithelium-like morphology and markedly express the cell surface marker vascular cell adhesion marker (VCAM-1). In culture, epicardial cells spontaneously undergo EMT after which the spindle-shaped cells now express endoglin. Both epicardial cells before and after EMT express the epicardial marker, Wilms tumor 1 (WT1). Adding transforming growth factor beta (TGFβ) induces loss of epithelial character and initiates the onset of mesenchymal differentiation in human adult epicardial cells. In this study, we show that TGFβ-induced EMT is dependent on type-1 TGFβ receptor activity and can be inhibited by soluble VCAM-1. We also show that epicardial-specific knockdown of Wilms tumor-1 (WT1) induces the process of EMT in human adult epicardial cells, through transcriptional regulation of platelet-derived growth factor receptor alpha (Pdgfrα), Snai1 and VCAM-1. These data provide new insights into the process of EMT in human adult epicardial cells, which might provide opportunities to develop new strategies for endogenous cell-based cardiac repair

    The limits of selflessness: semantic relativism and the epistemology of de se thoughts

    Get PDF
    The final publication is available at link.springer.com. URL: http://link.springer.com/article/10.1007/s11229-013-0262-8It has recently been proposed that the framework of semantic relativism be put to use to describe mental content, as deployed in some of the fundamental operations of the mind. This programme has inspired in particular a novel strategy of accounting for the essential egocentricity of first-personal or de se thoughts in relativist terms, with the advantage of dispensing with a notion of self-representation. This paper is a critical discussion of this strategy. While it is based on a plausible appeal to cognitive economy, the relativist theory does not fully account for the epistemic profile that distinguishes de se thinking, as some of its proponents hope to do. A deeper worry concerns the reliance of the theory on a primitive notion of "centre" that hasn't yet received enough critical attention, and is ambiguous between a thin and a rich reading. I argue that while the rich reading is required if the relativist analysis of the de se is to achieve its most ambitious aims, it also deprives the theory of much of its explanatory power

    BUILDING BRIDGES FOR INNOVATION IN AGEING : SYNERGIES BETWEEN ACTION GROUPS OF THE EIP ON AHA

    Get PDF
    The Strategic Implementation Plan of the European Innovation Partnership on Active and Healthy Ageing (EIP on AHA) proposed six Action Groups. After almost three years of activity, many achievements have been obtained through commitments or collaborative work of the Action Groups. However, they have often worked in silos and, consequently, synergies between Action Groups have been proposed to strengthen the triple win of the EIP on AHA. The paper presents the methodology and current status of the Task Force on EIP on AHA synergies. Synergies are in line with the Action Groups' new Renovated Action Plan (2016-2018) to ensure that their future objectives are coherent and fully connected. The outcomes and impact of synergies are using the Monitoring and Assessment Framework for the EIP on AHA (MAFEIP). Eight proposals for synergies have been approved by the Task Force: Five cross-cutting synergies which can be used for all current and future synergies as they consider overarching domains (appropriate polypharmacy, citizen empowerment, teaching and coaching on AHA, deployment of synergies to EU regions, Responsible Research and Innovation), and three cross-cutting synergies focussing on current Action Group activities (falls, frailty, integrated care and chronic respiratory diseases).Peer reviewe
    corecore