Replicating a seventeenth century sword: the Storta Project

Making a good “copy” of an ancient weapon means to reach different targets, not only regarding the final product of the making process but also the process itself. This means that to make a sword like this, it is necessary to initially study all the material regarding swords and blades from the same period and geographic area. This process involves not only their style, design, geometry, weights and balance, but also the cultural background of the period, the use and symbolism of the weapon and finally the original production techniques used. This article reviews and documents the “Storta project” in the context of a museum exhibition in Minsk (European Martial Arts: From Vulcan’s Forge to the Arts of Mars, 01.05-30.09.2019)

Reach-To-Grasp Movements: A Multimodal Techniques Study

The aim of the present study was to investigate the correlation between corticospinal activity, kinematics, and electromyography (EMG) associated with the execution of precision and whole-hand grasps (WHGs). To this end, motor-evoked potentials (MEPs) induced by transcranial magnetic stimulation (TMS), EMG, and 3-D motion capture data have been simultaneously recorded during the planning and the execution of prehensile actions toward either a small or a large object. Differences in the considered measures were expected to distinguish between the two types of grasping actions both in terms of action preparation and execution. The results indicate that the index finger (FDI) and the little finger (ADM) muscles showed different activation patterns during grasping execution, but only the FDI appeared to distinguish between the two types of actions during motor preparation. Kinematics analysis showed that precision grips differed from WHGs in terms of displayed fingers distance when shaping before object\u2019s contact, and in terms of timing and velocity patterns. Moreover, significant correlations suggest a relationship between the muscular activation and the temporal aspects concerned with the index finger\u2019s extension during whole-hand actions. Overall, the present data seem to suggest a crucial role played by index finger as an early \u201cmarker\u201d of differential motor preparation for different types of grasps and as a \u201cnavigator\u201d in guiding whole-hand prehensile actions. Aside from the novelty of the methodological approach characterizing the present study, the data provide new insights regarding the level of crosstalk among different levels concerned with the neuro-behavioral organization of reach-to-grasp movements

Integral foliated simplicial volume and ergodic decomposition

We establish an integration formula for integral foliated simplicial volume along ergodic decompositions. This is analogous to the ergodic decomposition formula for the cost of groups.Comment: 15 pages; v2: corrected the main proof and improved the exposition; to appear in Annales Math\'ematiques Blaise Pasca

Look at Me: Early Gaze Engagement Enhances Corticospinal Excitability During Action Observation

Direct gaze is a powerful social cue able to capture the onlooker's attention. Beside gaze, head and limb movements as well can provide relevant sources of information for social interaction. This study investigated the joint role of direct gaze and hand gestures on onlookers corticospinal excitability (CE). In two experiments we manipulated the temporal and spatial aspects of observed gaze and hand behavior to assess their role in affecting motor preparation. To do this, transcranial magnetic stimulation (TMS) on the primary motor cortex (M1) coupled with electromyography (EMG) recording was used in two experiments. In the crucial manipulation, we showed to participants four video clips of an actor who initially displayed eye contact while starting a social request gesture, and then completed the action while directing his gaze toward a salient object for the interaction. This way, the observed gaze potentially expressed the intention to interact. Eye tracking data confirmed that gaze manipulation was effective in drawing observers' attention to the actor's hand gesture. In the attempt to reveal possible time-locked modulations, we tracked CE at the onset and offset of the request gesture. Neurophysiological results showed an early CE modulation when the actor was about to start the request gesture looking straight to the participants, compared to when his gaze was averted from the gesture. This effect was time-locked to the kinematics of the actor's arm movement. Overall, data from the two experiments seem to indicate that the joint contribution of direct gaze and precocious kinematic information, gained while a request gesture is on the verge of beginning, increases the subjective experience of involvement and allows observers to prepare for an appropriate social interaction. On the contrary, the separation of gaze cues and body kinematics can have adverse effects on social motor preparation. CE is highly susceptible to biological cues, such as averted gaze, which is able to automatically capture and divert observer's attention. This point to the existence of heuristics based on early action and gaze cues that would allow observers to interact appropriately

¿Hacia dónde va la ciencia política?

Los textos de Giovanni Sartori y de David D. Laitin son una muestra de que la reflexiónsobre la actualidad y el futuro de la ciencia política están presentes también en la comunidadcientífica internacional. El profesor Sartori hace un balance que abarca sesentaaños de la disciplina y afirma que está sufriendo un proceso de americanización. La cienciapolítica está hoy demasiado obsesionada, a su juicio, por la perfección metodológica yla cuantificación frente a la investigación y a la lógica que él defiende. El profesor Laitinintenta rebatir el análisis de Sartori estudiando las aportaciones de tres subcampos dela ciencia política, como exponentes, según sus propias palabras, de la calidad, el internacionalismoy la importancia de la disciplina en el mundo real. Ambos autores reflexionansobre el núcleo teórico y el método de la ciencia política

Gaze and Body Cues Interplay during Interactive Requests

Although observing other\u2019s gaze and body movements provides a crucial source of information to successfully interact with other people, it remains unclear whether observers weigh differently these cues and whether the convergence of gaze and body\u2019s directions determines facilitation effects. Here we aim to shed more light on this issue by testing the reliance upon these cues from both a behavioral and a neurophysiological perspective in a social interactive context. In Experiment 1, we manipulated the convergence between the direction of an actor\u2019s upper limb movement and gaze direction while he attempts to socially interact with the participants observing the scene. We determined the direction of gaze as well as the duration of participants\u2019 ocular fixations during the observation of the scene. In Experiment 2, we measured and correlated the effect of the body/gaze manipulation on corticospinal excitability and on the readiness to interact\u2014a disposition to engage in social situations. Eye-tracking data revealed that participants fixated chiefly the actor\u2019s head when his hand and gaze directions were divergent. Possibly a strategy to disambiguate the scene. Whereas participants mainly fixated the actor\u2019s hand when he performed an interactive request toward the participants. From a neurophysiological point of view, the more participants felt involved in the interaction, the lower was motor preparation in the muscle potentially needed to fulfill the actor\u2019s request. We contend that social contexts are more likely to elicit motor preparation compared to non-social ones, and that muscular inhibition is a necessary mechanism in order to prevent unwanted overt reactions during action observation tasks

Assessing the effects of tDCS over a delayed response inhibition task by targeting the right inferior frontal gyrus and right dorsolateral prefrontal cortex

Many situations in our everyday life call for a mechanism deputed to outright stop an ongoing course of action. This behavioral inhibition ability, known as response stopping, is often impaired in psychiatric conditions characterized by impulsivity and poor inhibitory control. Transcranial direct current stimulation (tDCS) has recently been proposed as a tool for modulating response stopping in such clinical populations, and previous studies in healthy humans have already shown that this noninvasive brain stimulation technique is effectively able to improve response stopping, as measured in a stop-signal task (SST) administered immediately after the stimulation. So far, the right inferior frontal gyrus (rIFG) has been the main focus of these attempts to modulate response stopping by the means of noninvasive brain stimulation. However, other cortical areas such as the right dorsolateral prefrontal cortex (rDLPFC) have been implicated in inhibitory control with other paradigms. In order to provide new insight about the involvement of these areas in response stopping, in the present study, tDCS was delivered to 115 healthy subjects, using five stimulation setups that differed in terms of target area (rIFG or rDLPFC) and polarity of stimulation (anodal, cathodal, or sham). The SST was performed 15 min after the offset of the stimulation. Consistently with previous studies, only anodal stimulation over rIFG induced a reliable, although weak, improvement in the SST, which was specific for response stopping, as it was not mirrored in more general reaction time measures

Arginine 107 of yeast ATP synthase subunit g mediates sensitivity of the mitochondrial permeability transition to phenylglyoxal

Modification with arginine-specific glyoxals modulates the permeability transition (PT) of rat liver mitochondria, with inhibitory or inducing effects that depend on the net charge of the adduct(s). Here, we show that phenylglyoxal (PGO) affects the PT in a species-specific manner (inhibition in mouse and yeast, induction in human and Drosophila mitochondria). Following the hypotheses (i) that the effects are mediated by conserved arginine(s) and (ii) that the PT is mediated by the F-ATP synthase, we have narrowed the search to 60 arginines. Most of these residues are located in subunits alpha, beta, gamma, epsilon, a, and c and were excluded because PGO modification did not significantly affect enzyme catalysis. On the other hand, yeast mitochondria lacking subunit g or bearing a subunit g R107A mutation were totally resistant to PT inhibition by PGO. Thus, the effect of PGO on the PT is specifically mediated by Arg-107, the only subunit g arginine that has been conserved across species. These findings are evidence that the PT is mediated by F-ATP synthase.Peer reviewe