186 research outputs found
Multisystem recovery after sport-related concussion in adolescent rugby players:a prospective study protocol
The role of concussion history and biological sex on pupillary light reflex metrics in adolescent rugby players: a cross-sectional study.
Abstract: Background: Concussion examination is based primarily on clinical evaluation and symptomatic reporting. Pupillary light reflex (PLR) metrics may provide an objective physiological marker to inform concussion diagnosis and recovery, but few studies have assessed PLR, and normative data are lacking, particularly for adolescents. Aim: To capture PLR data in adolescent rugby players and examine the effects of concussion history and biological sex. Design: Crossâsectional. Methods: Male and female adolescent rugby union players aged 16 to 18 years were recruited at the start of the 2022â2023 playing season. PLR was recorded using a handheld pupillometer which provided seven different metrics relating to pupil diameter, constriction/dilation latency, and velocity. Data were analysed using a series of 2 Ă 2 ANOVAs to examine the main effects of independent variables: biological sex, concussion history, and their interactions, using adjusted pâvalues (p < 0.05). Results: 149 participants (75% male) were included. A total of 42% reported at least one previous concussion. Most metrics were unaffected by the independent variables. There were however significant main effects for concussion history (F = 4.11 (1); p = 0.05) and sex (F = 5.42(1); p = 0.02) in end pupil diameters, and a main effect for sex in initial pupil diameters (F = 4.45 (1); p = 0.04). Although no significant interaction effects were found, on average, females with a concussion history presented with greater pupillary diameters and velocity metrics, with many pairwise comparisons showing large effects (SMD > 0.8). Conclusions: Pupillary diameters in adolescent athletes were significantly affected by concussion history and sex. The most extreme PLRmetrics were recorded in females with a history of concussion (higher pupillary diameters and velocities). This highlights the importance of establishing baseline PLR metrics prior to interpretation of the PLR postâconcussion. Longâstanding PLR abnormalities postâconcussion may reflect ongoing autonomic nervous system dysfunction. This warrants further investigation in longitudinal studies
The role of concussion history and biological sex on baseline concussion clinical profile symptoms in adolescent rugby players
BackgroundAccurate concussion monitoring requires access to preinjury baseline data. This is particularly important in adolescent athletes who have a high risk of concussion and are prone to prolonged recovery. As Rugby Union is governed by similar laws for men and women, it is also an ideal population to rigorously examine the impact of biological sex on concussion symptoms.AimsTo evaluate self-reported concussion symptoms at baseline in adolescent rugby union players, and examine if subtype-specific symptoms are affected by concussion history and biological sex.MethodsAdolescent rugby union players aged 16â18 years were recruited during the 2022â2023 playing season. Participants completed a series of questionnaires covering post-concussion symptoms, concussion clinical profiles, anxiety, depression and fear avoidance behaviours. Independent variables of interest in analysis were biological sex and concussion history.Results149 participants (75% male) were included. 42% (63/149) reported at least one previous concussion (average time since concussion: 18.7 months, range 1â72). Adolescents with a concussion history reported significantly higher scores than those with no history, across two clinical profiles (ocular and sleep), concussion symptom severity, and depression, all based on medium effect sizes (SMD 0.3â0.5). Females had significantly higher scores across cognitive/fatigue, ocular and sleep clinical profiles, concussion symptoms, anxiety and depression, each with large effect sizes (SMDâ>â0.5).ConclusionsConcussion history and sex are associated with higher baseline scores on specific concussion clinical profile, concussion symptom severity, and anxiety symptoms. These findings highlight the importance of considering baseline differences when interpreting post-injury clinical profile symptoms in adolescent rugby players. (Trial registration: ACTRN12622000931774)
Improved determination of particulate absorption from combined filter pad and PSICAM measurements
Filter pad light absorption measurements are subject to two major sources of experimental uncertainty: the so-called pathlength amplification factor, ÎČ, and scattering offsets, o, for which previous null-correction approaches are limited by recent observations of non-zero absorption in the near infrared (NIR). A new filter pad absorption correction method is presented here which uses linear regression against point-source integrating cavity absorption meter (PSICAM) absorption data to simultaneously resolve both ÎČ and the scattering offset. The PSICAM has previously been shown to provide accurate absorption data, even in highly scattering waters. Comparisons of PSICAM and filter pad particulate absorption data reveal linear relationships that vary on a sample by sample basis. This regression approach provides significantly improved agreement with PSICAM data (3.2% RMS%E) than previously published filter pad absorption corrections. Results show that direct transmittance (T-method) filter pad absorption measurements perform effectively at the same level as more complex geometrical configurations based on integrating cavity measurements (IS-method and QFT-ICAM) because the linear regression correction compensates for the sensitivity to scattering errors in the T-method. This approach produces accurate filter pad particulate absorption data for wavelengths in the blue/UV and in the NIR where sensitivity issues with PSICAM measurements limit performance. The combination of the filter pad absorption and PSICAM is therefore recommended for generating full spectral, best quality particulate absorption data as it enables correction of multiple errors sources across both measurements
Measurement and physical interpretation of the mean motion of turbulent density patterns detected by the BES system on MAST
The mean motion of turbulent patterns detected by a two-dimensional (2D) beam
emission spectroscopy (BES) diagnostic on the Mega Amp Spherical Tokamak (MAST)
is determined using a cross-correlation time delay (CCTD) method. Statistical
reliability of the method is studied by means of synthetic data analysis. The
experimental measurements on MAST indicate that the apparent mean poloidal
motion of the turbulent density patterns in the lab frame arises because the
longest correlation direction of the patterns (parallel to the local background
magnetic fields) is not parallel to the direction of the fastest mean plasma
flows (usually toroidal when strong neutral beam injection is present). The
experimental measurements are consistent with the mean motion of plasma being
toroidal. The sum of all other contributions (mean poloidal plasma flow, phase
velocity of the density patterns in the plasma frame, non-linear effects, etc.)
to the apparent mean poloidal velocity of the density patterns is found to be
negligible. These results hold in all investigated L-mode, H-mode and internal
transport barrier (ITB) discharges. The one exception is a high-poloidal-beta
(the ratio of the plasma pressure to the poloidal magnetic field energy
density) discharge, where a large magnetic island exists. In this case BES
detects very little motion. This effect is currently theoretically unexplained.Comment: 28 pages, 15 figures, submitted to PPC
Perforated Meckel's diverticulitis complicating active Crohn's ileitis: a case report
<p>Abstract</p> <p>Introduction</p> <p>In Crohn's disease, the extension of active terminal ileitis into a Meckel's diverticulum is possible, but usually has no impact on clinical decision-making. We describe an original surgical approach in a young woman presenting with a combination of perforated Meckel's diverticulitis and active Crohn's ileitis.</p> <p>Case presentation</p> <p>We report the case of a 22-year-old woman with Crohn's disease, who was admitted for abdominal pain, fever and diarrhoea. CT scan demonstrated active inflammation of the terminal ileum, as well as a fluid collection in the right iliac fossa, suggesting intestinal perforation. Laparoscopy was performed and revealed, in addition to extensive ileitis, a 3 Ă 3 cm abscess in connection with perforated Meckel's diverticulitis. It was therefore possible to avoid ileocaecal resection by only performing Meckel's diverticulectomy; pathological examination of the surgical specimen revealed the presence of transmural inflammation with granulomas and perforation of the diverticulum at its extremity.</p> <p>Conclusion</p> <p>Crohn's disease of the ileum may be responsible for Meckel's diverticulitis and cause perforation which, in this case, proved to be a blessing in disguise and spared the patient an extensive small bowel resection.</p
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Simulation of NPLWR environment in the ATR Loop-1 test
An irradiation test of high-temperature, light water reactor, tritium targets was conducted in the ATR that simulated the neutronic, thermal-hydraulic and chemical conditions in an NPLWR for the production of tritium. Requirements for water chemistry, temperature, pressure, spectrum and fluence were met for essentially all of the 217 days of irradiation. The loop test facilities in the ATR provide excellent capabilities for conducting long term, well controlled, in situ tests to simulate degradation of the materials, components and systems used in LWR`s and should be considered for testing other components
A Happy Abundance : Tales, Memoirs and More Past and Present in Wayne, Maine
https://digitalmaine.com/wayne_books/1002/thumbnail.jp
Developing, Evaluating and Scaling Learning Agents in Multi-Agent Environments
The Game Theory & Multi-Agent team at DeepMind studies several aspects of
multi-agent learning ranging from computing approximations to fundamental
concepts in game theory to simulating social dilemmas in rich spatial
environments and training 3-d humanoids in difficult team coordination tasks. A
signature aim of our group is to use the resources and expertise made available
to us at DeepMind in deep reinforcement learning to explore multi-agent systems
in complex environments and use these benchmarks to advance our understanding.
Here, we summarise the recent work of our team and present a taxonomy that we
feel highlights many important open challenges in multi-agent research.Comment: Published in AI Communications 202
SeaWiFS Postlaunch Technical Report Series
This report documents the scientific activities on board the Royal Research Ship (RRS) James Clark Ross (JCR) during the fifth Atlantic Meridional Transect (AMT-5), 14 September to 17 October 1997. There are three objectives of the AMT Program. The first is to derive an improved understanding of the links between biogeochemical processes, biogenic gas exchange, air-sea interactions, and the effects on, and responses of, oceanic ecosystems to climate change. The second is to investigate the functional roles of biological particles and processes that influence ocean color in ecosystem dynamics. The Program relates directly to algorithm development and the validation of remotely-sensed observations of ocean color. Because the Sea-viewing Wide Field-of-view Sensor (SeaWiFS) instrument achieved operational status during the cruise (on 18 September), AMT-5 was designated the SeaWiFS Atlantic Characterization Experiment (SeaACE) and was the only major research cruise involved in the validation of SeaWiFS data during the first 100 days of operations. The third objective involved the near-real time reporting of in situ light and pigment observations to the SeaWiFS Project, so the performance of the satellite sensor could be determined
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