« Bon, qui connaît la règle ? » Aspects communautaire et situé de la transmission orale des règles de jeu chez les joueurs passionnés

La règle du jeu est souvent reconnue ou identifiée par les joueurs comme l’un des critères permettant de déterminer si une activité est un jeu ou non. Les jeux d’édition sont ainsi définis par (2021 [1979]) par l’association de la règle du jeu au matériel ludique. Pour autant, la transmission des règles se fait rarement par l’écrit lors des soirées et clubs de jeux de société où se rassemblent les joueurs passionnés. Avec la prolifération des vidéos d’explications de règles de jeux, certains joueurs cherchent dorénavant les tutoriels des versions numériques des jeux de société pour apprendre et perfectionner leur pratique. Cet article se propose d’étudier l’enjeu posé par l’apprentissage des règles chez les joueurs passionnés. En effet la légitimité sociale autour de la maîtrise des règles, la capacité à les restituer, à les communiquer efficacement ou à les apprendre rapidement entre en conflit avec l’effort individuel à fournir, véritable porte d’entrée du loisir.Rules are often recognized or identified by players as one of the criteria for identifying whether an activity is a game or not. Edited boardgames are also defined by Brougère (2021 [1979]) by the association of game rules with game elements. However, we observe that this transmission of rules by reading them is only partial. Indeed, during games evenings or club activity we observe that oral transmission is favored by the core gamers. Thus, with the proliferation of game rules explanation videos, we can observe that some players are now looking for tutorials of digital versions of boardgames to learn and improve their practice. This paper intends to study the issue posed by the transmission of the rules among the core gamers. Since the social legitimacy around the mastery of the rules, the ability to transmit them, to communicate them effectively or to learn them quickly conflicts with the effort to provide a real gateway to the practice of boardgames

Evaluation of kernel low-rank compressed sensing in preclinical diffusion magnetic resonance imaging

Compressed sensing (CS) is widely used to accelerate clinical diffusion MRI acquisitions, but it is not widely used in preclinical settings yet. In this study, we optimized and compared several CS reconstruction methods for diffusion imaging. Different undersampling patterns and two reconstruction approaches were evaluated: conventional CS, based on Berkeley Advanced Reconstruction Toolbox (BART-CS) toolbox, and a new kernel low-rank (KLR)-CS, based on kernel principal component analysis and low-resolution-phase (LRP) maps. 3D CS acquisitions were performed at 9.4T using a 4-element cryocoil on mice (wild type and a MAP6 knockout). Comparison metrics were error and structural similarity index measure (SSIM) on fractional anisotropy (FA) and mean diffusivity (MD), as well as reconstructions of the anterior commissure and fornix. Acceleration factors (AF) up to 6 were considered. In the case of retrospective undersampling, the proposed KLR-CS outperformed BART-CS up to AF = 6 for FA and MD maps and tractography. For instance, for AF = 4, the maximum errors were, respectively, 8.0% for BART-CS and 4.9% for KLR-CS, considering both FA and MD in the corpus callosum. Regarding undersampled acquisitions, these maximum errors became, respectively, 10.5% for BART-CS and 7.0% for KLR-CS. This difference between simulations and acquisitions arose mainly from repetition noise, but also from differences in resonance frequency drift, signal-to-noise ratio, and in reconstruction noise. Despite this increased error, fully sampled and AF = 2 yielded comparable results for FA, MD and tractography, and AF = 4 showed minor faults. Altogether, KLR-CS based on LRP maps seems a robust approach to accelerate preclinical diffusion MRI and thereby limit the effect of the frequency drift

Usefulness of PKH fluorescent labelling to study leukemic cell proliferation with various cytostatic drugs or acetyl tetrapeptide – AcSDKP

BACKGROUND: PKH67 labelling was compared for classical proliferation assessment (using S phase evaluation) to analyse the cell proliferation of 29 AML patients treated or not with various drugs. Among these drugs, the effect of tetrapeptide AcSDKP or AcSDKP-NH2 on AML cells, stimulated or not by cytokines, was also evaluated in order to determine (i) if AcSDKP was able to inhibit blast cell proliferation as it inhibits haematopoietic progenitors (ii) if AcSDKP-NH2 was more stable than AcSDKP with FBS. METHODS: For PKH labeling, cells were suspended in Diluent C, and rapidly admixed with PKH67 solution at 20 μM PKH67. Staining was stopped by addition of FBS. RESULTS: A good correlation between PKH67 labelling and bromodeoxyuridine incorporation was obtained first with 6/9 patients for control cells, then for 11/17 AML patients treated with classical antileukemic drugs (among whom 4 were also treated with AcSDKP). The effect of AcSDKP was also studied on 7 patients. The discrepancy between both methods was essentially due to an accumulation of cells into different cycle phases measured by BrdUrd incorporation secondary to drug action and PKH67 labelling which measured the dynamic proliferation. This last method allows identifying resistant cells which still proliferate. AcSDKP or AcSDKP-NH2 induced a decrease of leukemic cell proliferation in 5/7 patients when cytokines were added (in order to stimulate proliferation) one day after tetrapeptide AcSDKP or AcSDKP-NH2. No effect on proliferation was noted when cytokines were added to AcSDKP-NH2. CONCLUSION: PKH67 labelling method is a powerful tool for cell proliferation assessment in patients with AML, even in cells treated by various drugs

Contribution of CT-Scan Analysis by Artificial Intelligence to the Clinical Care of TBI Patients

The gold standard to diagnose intracerebral lesions after traumatic brain injury (TBI) is computed tomography (CT) scan, and due to its accessibility and improved quality of images, the global burden of CT scan for TBI patients is increasing. The recent developments of automated determination of traumatic brain lesions and medical-decision process using artificial intelligence (AI) represent opportunities to help clinicians in screening more patients, identifying the nature and volume of lesions and estimating the patient outcome. This short review will summarize what is ongoing with the use of AI and CT scan for patients with TBI

High-Precision Radiosurgical Dose Delivery by Interlaced Microbeam Arrays of High-Flux Low-Energy Synchrotron X-Rays

Microbeam Radiation Therapy (MRT) is a preclinical form of radiosurgery dedicated to brain tumor treatment. It uses micrometer-wide synchrotron-generated X-ray beams on the basis of spatial beam fractionation. Due to the radioresistance of normal brain vasculature to MRT, a continuous blood supply can be maintained which would in part explain the surprising tolerance of normal tissues to very high radiation doses (hundreds of Gy). Based on this well described normal tissue sparing effect of microplanar beams, we developed a new irradiation geometry which allows the delivery of a high uniform dose deposition at a given brain target whereas surrounding normal tissues are irradiated by well tolerated parallel microbeams only. Normal rat brains were exposed to 4 focally interlaced arrays of 10 microplanar beams (52 µm wide, spaced 200 µm on-center, 50 to 350 keV in energy range), targeted from 4 different ports, with a peak entrance dose of 200Gy each, to deliver an homogenous dose to a target volume of 7 mm3 in the caudate nucleus. Magnetic resonance imaging follow-up of rats showed a highly localized increase in blood vessel permeability, starting 1 week after irradiation. Contrast agent diffusion was confined to the target volume and was still observed 1 month after irradiation, along with histopathological changes, including damaged blood vessels. No changes in vessel permeability were detected in the normal brain tissue surrounding the target. The interlacing radiation-induced reduction of spontaneous seizures of epileptic rats illustrated the potential pre-clinical applications of this new irradiation geometry. Finally, Monte Carlo simulations performed on a human-sized head phantom suggested that synchrotron photons can be used for human radiosurgical applications. Our data show that interlaced microbeam irradiation allows a high homogeneous dose deposition in a brain target and leads to a confined tissue necrosis while sparing surrounding tissues. The use of synchrotron-generated X-rays enables delivery of high doses for destruction of small focal regions in human brains, with sharper dose fall-offs than those described in any other conventional radiation therapy