Biology subjects

De Beaumont, L.

Publications and source records attributed to De Beaumont, L..

5 recordsLinked to original sources

bioRxiv2026

Approaching the limit: Modeling the physiological bounds of playable space in football

AO_SCPLOWBSTRACTC_SCPLOWPitch control models quantify spatial dominance in football by estimating which player can arrive first at each pitch location, but they treat all players as equivalently capable regardless of preceding effort. We introduce physiology-aware pitch control (Phys-PC), a model-agnostic time-to-arrive correction that imposes two physiological capacity channels calibrated from tracking data: a transient recoverable burden capturing incomplete recovery from recent high-intensity efforts, and a cumulative non-recoverable drain accumulating across match play. Both channels reduce a bounded access scale that modulates kinematic TTA before any downstream pitch-control computation. All parameters are anchored to exercise-physiology benchmarks; no laboratory measurements are assumed. Applied to a 64-match international tournament, Phys-PC reveals structure that kinematic models cannot detect. In head-to-head races, the dominant burden channel shifts from transient to cumulative over the course of a match, with a transient resurgence in the final 15 minutes. These physiological asymmetries predict match outcomes: relative reserve advantage is associated with higher odds of winning ground challenges (OR = 1.20, p = 0.006; +4.2 pp), completing over-the-top passes past recovering defenders (OR = 1.45, p = 0.034; +8.3 pp), and progressing possession sequences into the final third (OR = 1.31, p = 0.013; +5.1 pp). At the player-profile level, an acute-cumulative decomposition of contested space access separates roles and individuals whose territorial reach is maintained through sustained positioning from those whose access is rebuilt through repeated high-intensity actions, providing a physiological lens on team tactical structure.

bioengineering↗

bioRxiv2021

TractoInferno: A large-scale, open-source, multi-site database for machine learning dMRI tractography

TractoInferno is the worlds largest open-source multi-site tractography database, including both research- and clinical-like human acquisitions, aimed specifically at machine learning tractography approaches and related ML algorithms. It provides 284 datasets acquired from 3T scanners across 6 different sites. Available data includes T1-weighted images, single-shell diffusion MRI (dMRI) acquisitions, spherical harmonics fitted to the dMRI signal, fiber ODFs, and reference streamlines for 30 delineated bundles generated using 4 tractography algorithms, as well as masks needed to run tractography algorithms. Manual quality control was additionally performed at multiple steps of the pipeline. We showcase TractoInferno by benchmarking the learn2track algorithm and 5 variations of the same recurrent neural network architecture. Creating the TractoInferno database required approximately 20,000 CPU-hours of processing power, 200 man-hours of manual QC, 3,000 GPU-hours of training baseline models, and 4 Tb of storage, to produce a final database of 350 Gb. By providing a standardized training dataset and evaluation protocol, TractoInferno is an excellent tool to address common issues in machine learning tractography.

neuroscience↗

bioRxiv2021

The calcium sensor synaptotagmin-1 is critical for phasic axonal dopamine release in the striatum and mesencephalon, but is dispensable for basic motor behaviors in mice

In Parkinsons disease (PD), motor dysfunctions only become apparent after extensive loss of DA innervation. This resilience has been hypothesized to be due to the ability of many motor behaviors to be sustained through a diffuse basal tone of DA; but experimental evidence for this is limited. Here we show that conditional deletion of the calcium sensor synaptotagmin-1 (Syt1) in DA neurons (Syt1 cKODA mice) abrogates most activity-dependent axonal DA release in the striatum and mesencephalon, leaving somatodendritic (STD) DA release intact. Strikingly, Syt1 cKODA mice showed intact performance in multiple unconditioned DA-dependent motor tasks and even in a task evaluating conditioned motivation for food. Considering that basal extracellular DA levels in the striatum were unchanged, our findings suggest that activity-dependent DA release is dispensable for such tasks and that they can be sustained by a basal tone of extracellular DA. Taken together, our findings reveal the striking resilience of DA-dependent motor functions in the context of a near-abolition of phasic DA release, shedding new light on why extensive loss of DA innervation is required to reveal motor dysfunctions in PD.

neuroscience↗

bioRxiv2019

Clinically significant acute pain disturbs motor cortex intracortical inhibition and facilitation in orthopedic trauma patients: A TMS study

ObjectivePrimary motor (M1) cortical excitability alterations are involved in the development and maintenance of chronic pain. Less is known about M1-cortical excitability implications in the acute phase of an orthopedic trauma. This study aims to assess acute M1-cortical excitability in patients with an isolated upper limb fracture (IULF) in relation to pain intensity. MethodsEighty-four (56 IULF patients <14 days post-trauma and 28 healthy controls) performed a single transcranial magnetic stimulation (TMS) session over M1 (resting motor threshold (rMT); short-intracortical inhibition (SICI); intracortical facilitation (ICF); long-interval cortical inhibition (LICI)). IULF patients were divided into two subgroups according to pain intensity (mild versus moderate to severe pain). ResultsReduced SICI and ICF were found in IULF patients with moderate to severe pain, whereas mild pain was not associated with M1 alterations. Age, sex, and time since the accident had no influence on TMS measures. DiscussionThese findings show altered M1 in the context of acute moderate to severe pain, suggesting early signs of altered GABAergic inhibitory and glutamatergic facilitatory activities.

neuroscience↗

bioRxiv2018

In vivo cerebral microdialysis validation of the acute central glutamate response in a translational rat model of concussion combining force and rotation

Concussions/mild traumatic brain injury (mTBI) represent a major public health concern due to persistent behavioral and neurological effects. The mechanisms by which concussions lead to such effects are partly attributable to an hyperacute indiscriminate glutamate release. Cerebral microdialysis studies in rodents reported a peak of extracellular glutamate 10 minutes after injury. Microdialysis has the advantage of being one of the few techniques allowing the quantification of neurotransmitters in vivo and at different time points following injury. In addition to the clear advantages afforded by microdialysis, the Wayne State weight-drop model induces an impact on the skull of a subject unrestrained by the fall of a weight. The latter model allows rapid acceleration and deceleration of the head and torso, an essential feature in human craniocerebral trauma and a factor that is missing from many existing animal concussion models. In the present study, we applied the Wayne State procedure and microdialysis to document, in awake rats, the acute changes in extracellular hippocampal glutamate and GABA levels resulting from concussive trauma. We studied the dorsal CA1 hippocampal region as it contains a high density of glutamatergic terminal and receptors, thus making it vulnerable to excitotoxic insult. Using HPLC, dialysate levels of hippocampal glutamate and GABA were measured in adult male Sprague-Dawley rats in 10 min increments for 60 min prior to, during and for 90 min following concussive trauma induced by the Wayne State weight-drop procedure. Sham control animals were treated in the same manner but without receiving the concussive trauma procedure. Our results show that concussive trauma is followed, within 10 min, by a robust, transient 3-fold increase in hippocampal glutamate levels; such changes were not seen in controls. In contrast, GABA levels were unaffected by the concussive trauma procedure. The findings derived from the approach used here are generally consistent with those of previous other studies. They also provide a crucial in vivo validation of the Wayne State procedure as a model with promising translational potential for pre-clinical studies on early therapeutic responses to concussion.

neuroscience↗