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Web Scraping Methods to Assess Injury and Illness Trends in the National Hockey League
No full textReturning to play following an abrupt cessation of activity is a known risk factor for athletic injury (Sclafani & Davis, 2016). The National Hockey League (NHL) saw an unprecedented disruption to the competitive calendar due to the COVID-19 pandemic in March of 2020 (Zucker, 2020) and the impact of said disruption on injury and illness in the NHL is largely unknown. Given the nature of competition, where athletes are exposed to the highest risk sporting exposures (McKay et al., 2014), and the public interest in player health, injury data from internet-based public sources are an attractive option for sports-medicine-based research (Blond, Blond, & Loscalzo, 2021; Cahill et al., 2022). Significant variability in methodology, and thus results, exists between studies that use publicly obtained data (POD) (Inclan et al., 2024; Krüger et al., 2023), suggesting a need to standardize and operationalize methodology for its use. One potential source of variable results could stem from the NHL’s flexible injury disclosure policy that affords teams discretion if they feel disclosure may negatively impact a player’s physical wellbeing when they return to play (National Hockey League & National Hockey League Players' Association, 2013; Strong, 2024). Undisclosed events that result in time loss are rarely considered in sports-medicine research that use POD. The purpose of this thesis project was to i.) investigate the impact of an abrupt cessation of play in the NHL on injury and illness, ii.) to operationalize data scraping methods in a sports-medicine context, and iii.) quantify the bias introduced through the inclusion (or exclusion) of undisclosed events on time loss in the NHL.
Strengths and limitations of web scraping methods were described in addition to providing step by step instructions in Python version 3.10.4 for how to access data pertaining to time loss in professional sports in a replicable fashion. Using a retrospective cohort of all NHL players between the 2016-17 and 2023-24 seasons, public access data of events resulting in time loss were collected. All data was collected using custom built replicable methods in Python. Burden of events was assessed through incidence and severity outcomes, and events were broken down into regional categories (upper body, lower body, head, core, non-game related injuries, illness and undisclosed). Inter- and intra-seasonal trends were investigated by adjusting for season, stage of season completion, player profile, playoff-competitive team or not, and pre- or post-pandemic seasons. Statistical analysis included Poisson and Negative Binomial Regression, with significance set at P < .05.
Undisclosed events were more likely to be reported in the last fifth of the season (P < .001) and more common for higher profile players (P < .001), regardless of the stage of the season. Severity of undisclosed events was highly variable between seasons and did not show any significant trends over season duration. Exclusion of undisclosed events has the potential to significantly under-report incidence of injury and illness (P < .001). Incidence rate ratio (IRR) for illness peaked in December 2021 (IRR = 62.46; 95% CI 13.65 to 285.91). Incidence of upper body injuries was significantly higher in 2020-21 (IRR = 1.70, P = .001) and 2021-22 (IRR = 1.40, P = .044) compared to pre-pandemic seasons (Incidence = 17.58 injuries / 1000 player-hours). Injury incidence increased as the 2022-23 season progressed (P = .004); injury incidence was stable across all other seasons
Numerical Simulation of Proppant Transport in Hydraulic Fractures and Gel Particle Transport in Porous Media
No full textParticle-fluid multiphase flow processes are frequently encountered in petroleum energy applications. For example, proppants, typically sand or ceramic beads, are injected into hydraulic fractures to keep them open, allowing for increased fluid flow and improved hydrocarbon extraction. The successful placement and transport of proppants within the fractures directly influence the efficiency and productivity of the hydraulic fracturing process. One objective of this research focuses on the development and application of a coupling method that integrates the Computational Fluid Dynamic (CFD) method and the Discrete Element Method (DEM) for simulating proppant transport in fractures. Besides, gel particle treatment after waterflooding can improve sweep efficiency and increase final oil production by plugging high-permeability channels and modifying water injection profiles. Particle transport and retention in porous media is also a typical particle-fluid multiphase flow. Another objective of this research is to develop a numerical model to simulate the injection of particle slugs and investigate how gel particles move and get retained in porous media.
Firstly, it is challenging to simulate the proppant transport phenomena in rough fractures due to the roughness effect as well as the complex nature of the coupled particle-fluid flow. This study addresses the critical challenge of accurately predicting the movement of proppant particles within rough fractures based on the resolved CFD-DEM method. By resolving the flow field and accounting for the particle-liquid and particle-bubble interactions, the proposed method overcomes the limitations of previous empirical or simplified models.
Secondly, the established resolved CFD-DEM coupling model is used to study proppant aggregating and bridging occurring in the fractures and determine the critical ratio of the fracture width to the particle diameter leading to proppant bridging. This study numerically replicates the proppant bridging phenomenon reported in previous experiments and further reveals the underlying mechanisms leading to proppant aggregating and bridging.
Besides, a numerical study is conducted to investigate proppant transport in a large-scale rough fracture. The key component of this study is the adoption of the unresolved CFD-DEM coupling method. The unresolved method, which adopts a large mesh compared to the resolved CFD, could increase computational efficiency and could be used in a relatively large fracture model. Additionally, the effects of various factors, such as fracture inclination, proppant size, and fracturing fluid viscosity, on proppant transport are also analyzed based on this model.
Finally, a numerical study based on the modified filtration method is conducted to gain a comprehensive understanding of gel particle transport and retention in porous media. Instead of tracking the movement of each particle in the CFD-DEM method, the modified filtration method treats gel particles as a suspension component in the water phase and could be used in the field-scale simulations of particle-fluid flow. The established model accurately reproduces experimental pressure dynamics during the injection of multiple slugs. Then, we apply this model to a field-scale reservoir model, and simulation results demonstrate the potential of the proposed model for analyzing and optimizing particle migration and injection at the field scale
Air Flow Dynamics Driven by Water Flow and Pressure in a Partially Full Pipe
No full textUnderstanding airflow movement in sanitary sewer headspaces is crucial due to the transport of hazardous gases like hydrogen sulfide. These gases are released into the air headspace, posing health risks and contributing to odour complaints in urban areas. Existing models for predicting bulk sewer airflow rely on a limited set of uncontrolled experiments without direct measurement of pressure gradients, resulting in uncertain water drag and friction coefficients.
This research addresses these challenges by conducting a set of experiments in a confined water-driven air cavity. Additional experiments are added to study airflow in a partially filled circular pipe with controlled air pressure gradients. Additionally, a numerical model is developed to extend the range of experimental results and examine the influence of water drag and headspace air pressure on airflow.
Water surface drag and wall friction coefficients are the main parameters used to calibrate airflow system models, and they should be determined accurately for better model efficiency. The key dimensionless parameters influencing these coefficients are identified and listed as the nominal Froude and Reynolds numbers, a dimensionless pressure gradient term, headspace height to diameter ratio, and relative roughness height of the wall and water surface, calculated based on the water surface velocity and pipe diameter. A three-dimensional Computational Fluid Dynamics (CFD) model is developed to explore the effect of those parameters, assuming the air-water interface as a moving boundary in Couette flows. The resulting airflow regimes are analyzed using the produced air velocity profiles. The value of the water drag coefficient is between 0.002 and 0.01, while the wall friction coefficient ranges from 0.015 to 0.045 for typical sewer conditions. This study provides a new way to determine average air velocity, water drag and wall friction coefficients in practical cases which covers the most affecting parameters on air movement in sewers.
Experiments are performed to study a water-driven air cavity flow in a closed pipe. The pipe is 16 m long, 0.3 m in diameter and the headspace height-to-diameter ratio ranges from 0.3 to 0.6 with a water surface velocity around 0.6 m/s. Air velocity profiles are captured using Particle Image Velocimetry (PIV) using injected smoke. Local flow structures show Kelvin-Helmholtz instabilities due to the circulation flow pattern with opposite directions one positive with water flow and the other negative against water flow. Numerical modelling using Reynolds-Averaged Navier-Stokes (RANS) and Large Eddy Simulation (LES) models is developed to be validated and to extend the analysis for different water surface velocities and cavity lengths. The experimental and numerical velocity profiles show reasonable agreement. The height of the negative region is approximately double that of the positive region. The average air velocity relative to the water surface velocity ranges from 50% to 18% for positive velocity and from -22% to -8% for negative velocity as the water surface velocity increases from 0.05 to 3 m/s. The airflow discharge in each region increases from 1.1 to 1.6 L/s with the cavity length till the length-to-height ratio reaches 32. Beyond this ratio, the discharge approaches a constant.
This study provides an air velocity dataset under water drag and forced air injection in a 16 m long, 0.3 m diameter pipe connected between two tanks in a confined air system. The tanks are linked by a 100 mm air pipe equipped with an air fan and a regulating valve to control the forced airflow. The headspace height-to-diameter ratio is varied at 0.25, 0.5, and 0.75 and forced airflow is injected in both directions, aligned with and opposing the water flow, at rates between 3 to 50 L/s. A RANS model is developed assuming the water surface is a moving solid boundary as in Couette flows. Water drag created an adverse pressure gradient of approximately 0.02, 0.01 and 0.004 Pa/m at headspace height-to-diameter ratios of 0.25, 0.5, and 0.75 respectively. Forced airflow produced pressure gradients ranging from -0.8 to 0.85, -0.1 to 0.15, and -0.03 to 0.06 Pa/m for the same ratios. The comparison between experimental and numerical air velocity profiles shows good agreement in general proving that the numerical model is reliable. Force balance analysis showed that friction was negligible in water-drag-only cases but became dominant with pressure force in favourable cases, while drag force was reduced
Accumulation of snow on plants: domestic roses
No full textRose hips or rose haws, are the fruit of rose plants. They often persist through the winter and are used in traditional medicines
Investigating the Impact of Radiation Induced Fibrosis on Tongue Biomechanics Using a Virtual Tongue Model
No full textThe overall goal of this thesis was to understand how radiation-induced fibrosis impacts tongue function. Radiation induced fibrosis is a common, late side-effect of radiation treatment that is clinically characterized by hardening, loss of elasticity and muscle tissue atrophy. This altered muscle tissue is hypothesized to impact the tongue’s function by altering its biomechanics (velocity, position, shape and forces). This work used computer simulation to understand the relationship between fibrosis and tongue biomechanics. Two primary questions related to the relationship are investigated using a virtual model of the tongue:
1) How does the location and severity of fibrosis impact tongue function? In study 1 (Ch.3), fibrosis was simulated by systematically increasing the stiffness of the element materials of the tongue. To systematically manipulate the stiffness, three parameters, namely density (high, low), area (large, small) and location, were used. The average change in tongue tip position was used to characterize the target protrusion motion. Compared to baseline, the density and area of fibrosis led to reductions in tongue protrusion (i.e., reduced anterior-posterior direction), increases in tongue height (superior-inferior tip position direction), and ipsilateral deviations (lateral-medial direction). The location of fibrosis modulated the effects of density and area by either amplifying or minimizing the main effects. The comprehensive investigation of the density, area and location of fibrosis led to the main conclusion that every lesion location on the tongue can compromise the tongue’s movement. This highlights the complex interaction between the tongue’s anatomy, soft tissue biomechanics and changes in muscle tissue properties.
2) Is a muscle length-based compensatory mechanism capable of recovering fibrosis induced impairments in tongue function? In study 2 (Ch.4), recovery from a single lesion of fibrosis resulting in ipsilateral deviation of the tongue was investigated. The same parameters from study 1 were used to generate the lesion and its consequences on the virtual tongue. The recovery mechanism involved a stretch reflex that included shortening outstretched muscle bundle lengths in the tongue. Partial recovery for both the high- and low-density fibrosis case was observed. The findings of the study demonstrated that recovery from fibrosis using a simple mechanism of muscle length shortening is plausible.
Both these studies demonstrated how computer simulation can be used as a tool to understand the impact of fibrosis on tongue protrusion. The combination of simulation techniques, biomechanics and knowledge from the field of motor learning provides a foundation for future studies to further understand the impact of fibrosis and work towards targeted interventions
The Assessment of Ex-situ Organ Perfusion (ESOP) Platforms as Reliable Delivery Mechanisms for Novel Therapeutic Agents to Donor Organs to Improve Transplantation Outcomes
Get PDFThe quality of a donor organ degrades over a few hours post-mortem, and soon it becomes unavailable for transplantation. Cold static preservation (CSP) of organs can acceptably preserve the lung for a maximum of 6 hours and about 9 hours for a donor liver. Ex-situ organ perfusion (ESOP) allows organ assessment during preservation in a physiologic state, extending the preservation time and giving a window of opportunity to custom-fit organs towards achieving a ‘transplant for life.’
This thesis aims to explore lung and liver ESOP models as valuable delivery channels for novel therapeutics to solve organ-specific transplantation challenges. Lung immunomodulation using viral gene therapy to mitigate ischemia-reperfusion injury (IRI), thus decreasing the likelihood of chronic lung allograft rejection (CLAD). The successful cryopreservation of liver allografts will increase donor organ availability and improve organ allocation, reducing waitlist mortality for end-stage liver patients. We aim to highlight and assess the invaluable role of ESOP platforms in providing feasible delivery routes, necessary therapeutic time, and close organ monitoring while averting toxicity and unforeseeable risks to recipients.
The manuscript has seven chapters. After a digested review of the relevant literature, the next four chapters cover the assessment of ex-situ lung perfusion's (ESLP) role in adenoviral-adiponectin gene therapy. This is followed by a chapter dedicated to the evaluation of ice recrystallization inhibitors in liver cryopreservation using liver machine perfusion (LMP). Lastly, the conclusion reiterates the main outcomes and peaks into the future of ESOP research.
The first hypothesis is that ESLP-assisted delivery of adiponectin (APN) protein to donor lungs to be expressed or released during reperfusion and throughout the early period post-lung transplantation will confer protection to the organ and lessen early graft dysfunction from ischemia-reperfusion injury. In chapter one, rat ESLP was used to evaluate the benefit of airway administration of the synthetic adiponectin receptor agonist, AdipoRon, to rat lungs after 6 h of cold ischemia. Rat lung physiology and function were evaluated during 4 h normothermic ESLP; inflammatory cytokine secretion was measured in perfusate samples and compared to control lungs without AdipoRon. Interestingly, our results showed that lung edema was significantly reduced with AdipoRon. The second chapter compared adenovirus gene therapy techniques and delivery routes during 12 h porcine normothermic ESLP. Porcine lungs were transduced during ESLP with recombinant adenovirus-mCherry (Ad-mCherry) to compare adenovirus safety and transduction efficiency following vascular or tracheal delivery transduction. Successful Ad-mCherry expression was achieved using vascular and bronchial routes. Both routes showed stable and comparable lung function and inflammation during perfusion. Then, the third chapter was set to evaluate the feasibility and benefit of adenovirus-adiponectin (Ad-APN) gene therapy to porcine lungs during 12 h normothermic ESLP. Adiponectin expression significantly attenuated interleukin-8 (IL-8) secretion which is considered an early marker of graft failure during lung reperfusion. Chapter four investigated the benefit of expressed adiponectin protein to rat lung recipients after in-vivo Ad-APN gene delivery donor rats. Male Lewis (LEW) rats were recovered for 24 h after in-vivo tracheal transduction with recombinant Ad-APN; next, their left lungs were orthotopically transplanted to Sprague Dawley (SD) recipients and assessed for 2 h. Oxygen saturation, blood gas analysis, plasma cytokine profile, and lung tissue peroxidation were analyzed to compare ischemia-reperfusion severity with and without Ad-APN. After 2 h of reperfusion, levels of the M1 macrophage marker, monocyte chemoattractant protein-1 (MCP-1) were significantly lower in the plasma samples of Ad-APN rat lung recipients compared to controls. Thus, APN expression induced the polarization of macrophages to the anti-inflammatory (M2) phenotype.
Chapter six covered the second hypothesis which is that the ice control agents (ICAs), N-(2-fluorophenyl)-C6-azido-D-gluconamide (2FA) and N-(2-chlorophenyl)-D-gluconamide (4CLA) are non-toxic to rat liver during LMP and can improve the recovery of cryopreserved liver by controlling ice nucleation and recrystallization. A model of rat liver subnormothermic machine perfusion (SNMP) for 4 h was used to deliver the ICAs, 2FA or 4CLA and determine their toxicity to donor livers. Next, liver slices were obtained and snap-frozen in liquid nitrogen, and then freeze-substitution techniques were used to visualize ice-grain size and distribution. ICA-perfused livers had comparable function, liver enzyme secretion and histology injury scores compared to controls. Both ICAs permeated successfully during 4 h SNMP and significantly controlled ice-grain size in zone-1 of the liver acini
The use of uterine horn resection surgery to optimize non-surgical embryo collection in gilts and sows
No full textNon-surgical embryo collection (nsEC) and transfer have proven to be financially beneficial practices across a multitude of livestock sectors, justifying their demand in the swine industry. Currently, the conventional methods for collecting pig embryos involve either a costly and invasive surgical procedure or a terminal post-slaughter collection. Over the last several decades, the pursuit to standardize the techniques of swine nsEC has encountered significant challenges. The impediments limiting the widespread adoption of nsEC include the narrow cervical canal and convoluted structure of uterine horns (UHs), as well as the requirement for a specialized catheter to traverse through the uterus.
The objectives of this study were to explore a transitional surgical model involving an ipsilateral, otherwise known as a ‘single-sided’ resection, to enhance access to the utero-tubal junction and better facilitate embryo retrieval upon implementing a transcervical catheter procedure. A contralateral ovariectomy was performed to evaluate the ovarian response of a single ovary. Optimizing nsEC would support the evaluation of embryo survival, quality, and interactions within the uterus. When combined with embryo transfer, these methods would offer a superior and cost-effective means of disseminating swine genetics and safeguarding herd health from pathological agents while concurrently addressing animal welfare concerns associated with live animal transport by reducing the use of this convention.
During this research investigation, purebred dam- and sire-line gilts (parity zero; n = 15) and sows (parities one through five; n = 8) underwent a multi-step UH resection surgery to shorten the UH tissue, excise the contralateral ovary, and ligate the contralateral horn to produce an ipsilateral 40 cm UH. The three subsequent estrous cycles following the surgical procedure were reserved for uterine healing and recovery. After the recovery period, a series of nsECs involving uterine flushing were conducted between days 4 and 8 of the estrous cycle, following the onset of estrus (day 0) and cervical artificial insemination. In the gilt group, across 50 nsECs, the mean embryo media recovery was 57.8 ± 26.8% (mean ± sd), while in the sow group, across 49 nsECs, it was 76.0 ± 17.0%. Collectively, between the gilts and sows, 140 oocytes and embryos were retrieved using transcervical catheterization, gleaning that the application of non-surgical techniques is a feasible approach to harvesting embryos in pigs. Additionally, superovulatory ovarian hypertrophy was observed between the surgical procedure and post-slaughter assessment in the dam- and sire-line pigs. This was demonstrated by an increase in the number of corpora lutea (13.4 and 3.0 vs 27.2 and 12.0, P < 0.05) and intact ovary weight (11.9 and 7.7 vs 25.9 and 38.7 g, P < 0.05), respectively.
Our efforts focused on attaining consistently elevated embryo media recovery rates and potential embryos using nsEC procedures. We envision that a refined catheter design and the use of second parity maternal breed sows will serve as pivotal components in streamlining embryo recovery procedures, representing a noteworthy advancement in the quest to improve the efficiency of swine reproduction. This pioneering approach is anticipated to be fundamental in propelling the broader field of assisted reproductive technologies within swine breeding and the industry as a whole