Automated large-scale tornado treefall detection and directional analysis using machine learning

Abstract In many regions of the world, tornadoes travel through forested areas with low population densities, making downed trees the only observable damage indicator. Current methods in the EF scale for analyzing tree damage may not reflect the true intensity of some tornadoes. However, new methods have been developed that use the number of trees downed or treefall directions from high-resolution aerial imagery to provide an estimate of maximum wind speed. Treefall Identification and Direction Analysis (TrIDA) maps are used to identify areas of treefall damage and treefall directions along the damage path. Currently, TrIDA maps are generated manually, but this is labor-intensive, often taking several days or weeks. To solve this, this paper describes a machine learning– and image-processing-based model that automatically extracts fallen trees from large-scale aerial imagery, assesses their fall directions, and produces an area-averaged treefall vector map with minimal initial human interaction. The automated model achieves a median tree direction difference of 13.3° when compared to the manual tree directions from the Alonsa, Manitoba, tornado, demonstrating the viability of the automated model compared to manual assessment. Overall, the automated production of treefall vector maps from large-scale aerial imagery significantly speeds up and reduces the labor required to create a Treefall Identification and Direction Analysis map from a matter of days or weeks to a matter of hours. Significance Statement The automation of treefall detection and direction is significant to the analyses of tornado paths and intensities. Previously, it would have taken a researcher multiple days to weeks to manually count and assess the directions of fallen trees in large-scale aerial photography of tornado damage. Through automation, analysis takes a matter of hours, with minimal initial human interaction. Tornado researchers will be able to use this automated process to help analyze and assess tornadoes and their enhanced Fujita–scale rating around the world

Co-delivery of Adipose-derived Stromal Cells and Endothelial Colony Forming Cells in Novel Cell-assembled Scaffolds as a Pro-angiogenic Cell Therapy Platform

Cellular therapies involving the co-delivery of pro-regenerative cell types that have complementary pro-vascular functionality hold promise as a strategy to promote the healing of chronic wounds. In particular, the co-delivery of human adipose‑derived stromal cells (ASCs) and endothelial colony forming cells (ECFCs) has shown promise for regenerating stable blood vessels in vivo, addressing a major barrier within the chronic wound microenvironment. The current study focused on developing novel “cell-assembled” scaffolds for co-delivering ASCs and ECFCs within a supportive matrix composed of decellularized adipose tissue (DAT), with the objective of enhancing their localized retention and augmenting their capacity to stimulate vascular regeneration. Stable scaffolds were constructed containing both cell types alone or in combination, with ECFC tubule formation observed in vitro. In vivo assessment in athymic nu/nu mice showed that co­‑delivery enhanced ECFC retention compared to ECFC alone scaffolds, supporting the further investigation of this novel platform for wound healing applications

Control potential chemically

This presentation develops the research made in collaboration with McMaster University to identify the repassivation potential of SS304L and test the control of its OCP using ferric chloride. Experiments are done in deaerated water with 3g/L of NaCl at 90 °C

Development and validation of the Pain Resilience and Optimism Scale (PROS)

Numerous self-report questionnaires have been used in pain research to explore patients\u27 experiences. However, these questionnaires often employ negatively worded items that can potentially worsen patients\u27 distress. In response to the emergence of positive psychology, this thesis aimed to develop a new questionnaire that adopts a positive and strengths-focused approach, incorporating resilience, to replace the negative items found in existing tools such as the Pain Catastrophizing Scale (PCS). First, the effectiveness of the Connor-Davidson Resilience Scale (CD-RISC) in measuring resilience following trauma was assessed through a systematic review using the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. The review revealed that the CD-RISC may not adequately capture resilience in the context of trauma. Consequently, a new tool called the Post-traumatic Resilience Scale was theorized and developed to address these limitations. In line with the potential benefits of positive psychological factors such as optimism in mitigating the effects of trauma, the 2nd and 3rd studies of this thesis aimed to explore these factors within the framework of Post-traumatic Resilience and Optimism (PTRO). In developing the initial items for the prototype Pain Resilience and Optimism Scale (PROS), researchers reversed the polarity of 13 items from the widely used PCS, transforming them into positively worded items. Feedback from three patients with chronic pain contributed to the creation of the 13-item test version of the PROS. Validation of the PROS involved a sample of Canadian military veterans with chronic pain. The refined version of the scale consisted of eight items categorized into two subfactors: Pain Optimism (5 items) and Pain Resilience (3 items). The reduction in items aligns with previous findings that a shorter version of the PCS adequately measures pain catastrophizing. In conclusion, this thesis proposes the PROS as a new measurement tool for research and clinical use. The validation analyses demonstrate promising psychometric properties, although further research is needed for replication. Incorporating advanced measurement models such as Item Response Theory may enhance the reliability and validity of the PROS in evaluating pain resilience and optimism

Investigating the neuroprotective effects of pharmacological Bax inhibition

Apoptosis is a highly regulated mode of cell death in the development and progression of neurodegenerative diseases and neuronal injuries. The Bcl-2 protein family are key regulators of the intrinsic mitochondrial apoptotic pathway. Our lab and others have demonstrated that the pro-apoptotic Bcl-2 family member Bax plays a prominent role in regulating neuronal apoptosis. Eltrombopag has been identified as an inhibitor of Bax in in vitro non-neuronal cells. We hypothesized that Eltrombopag would provide neuroprotection against Bax-mediated apoptosis in neurons. Specifically, we investigated whether Eltrombopag could inhibit apoptosis induced by ER-stress using Thapsigargin and oxidative stress using 6OHDA, both of which we have previously shown to be Bax-mediated. In both models of neuronal apoptosis, Eltrombopag administration prevented cytochrome-3 release, inhibited caspase-3 activation, and attenuated neuronal death. Our findings suggest that utilizing Eltrombopag as an inhibitor of the Bcl-2 family protein Bax may be therapeutic in attenuating disease and injury-associated neuronal apoptosis

Development of pH-Weighted Magnetic Resonance Imaging in the Spinal Cord: Application in Degenerative Cervical Myelopathy

Degenerative cervical myelopathy (DCM) is a degenerative disease of the spinal cord that can lead to neurological dysfunction. It has been hypothesized that ischemia and hypoxia in the spinal cord at the site of compression could impact functional recovery after decompression surgery. Unfortunately, direct in-vivo quantification of hypoxia and ischemia in the spine has been limited in humans. Magnetic resonance imaging (MRI) can be utilized to measure hypoxia indirectly in soft tissue. Specifically, chemical exchange saturation transfer (CEST) is an MRI contrast that can be derived from the transfer of magnetization from selectively excited endogenous protons to bulk water protons. This exchange process is pH-dependent and can be exploited to produce a pH-weighted CEST contrast called amine/amide concentration independent detection (AACID). Hypoxia can decrease the pH of tissue. For the first time in DCM patients, the severity of spinal cord compression was correlated with functional brain activity changes, suggesting that hypoxic injury in the spinal cord may contribute to cortical reorganization in the motor areas of the brain. The results from this study provided the motivation for this thesis to develop three-dimensional (3D) AACID CEST pH-weighted MRI at the clinically relevant field strength of 3.0T in the healthy brain and spinal cord and then to demonstrate the feasibility of pH-weighted imaging in the spinal cord of DCM patients. Furthermore, the reproducibility of spinal cord AACID CEST MRI was quantified and found to have the greatest reproducibility at the center of the 3D volume when incorporating a B1-inhomogeneity correction. In conclusion, this dissertation demonstrates the process of developing a 3D pH-weighted CEST MRI contrast at the clinically relevant field strength of 3.0T in the cervical spinal cord. This work includes initially exploring how the severity of cord compression affects brain functional activity, optimizing the CEST sequence at 3.0T, evaluating the reproducibility of the AACID measurement in both the healthy brain and cervical spinal cord and initial utilization in the spinal cord of people with DCM. This dissertation lays the groundwork to determine if hypoxia is occurring in the spinal cord of DCM patients and if it is a measure of neurological outcome

The Spatial Risk of Assault on Police Officers in Toronto, Ontario

Since September 12th, 2022, nine police officers in Canada have been fatally assaulted in the line of duty. These officer deaths raise important questions concerning the nature of risks police face on duty, as well as the ways we can better understand those risks. Utilizing a Risk Terrain Modelling (RTM) approach, this study examined the risk of assault to police officers in Toronto, Ontario using Assault to Peace Officer data from January 1st, 2022, to December 31st, 2022. This study revealed that the risk of assault to police varies by the physical features present in each Division of the Toronto Police Service. Specifically, 7 features of the physical environment were found to increase risk of assault to police, with locations with high previous rates of robbery posing the most consistent risk. The resulting output provides The Toronto Police Service and policymakers with information and suggestions on how to utilize RTM methods to improve the safety of officers on-duty