13 research outputs found
The effect of scaffold structure and biologic factors on bone regeneration in cap-based scaffolds measured using machine learning
No full textBone regeneration conduits are necessary in critically large defects. Hydroxyapatite (HAp) scaffolds are osteoconductive, synthetic grafts that provide an alternative to natural grafts, which have limitations. We and others have fabricated HAp scaffolds with a hierarchical structure that has macropores between orthogonal rods - into which bone can grow, and micropores within those rods. Our previous research has shown that these micropores create a capillary effect and, with the macropores, pull in fluid from the defect at implantation, encouraging bone regeneration. There is a limited understanding in the effect of different components of the defect fluid (cells and serum) and extracellular vesicles (EVs) on bone regeneration. In addition, the effect of relaxing HAp scaffold rod orthogonality has not been experimentally studied. This work aims to understand the effect of these structural and biological factors on bone regeneration in HAp scaffolds.
We investigate the effect of scaffold structure (control rectilinear, optimized rectilinear, and optimized curvilinear), biologic treatments (control-dry, cells, serum, EVs), implantation site (anterior, middle, and posterior), and dry vs. wet implantation conditions (to further explore the capillary effect) on bone regeneration. Bone regeneration is measured using segmented micro-computed tomography (Micro-CT) images of implanted scaffolds, a challenging segmentation problem because of the similar mineral composition, and thus attenuation, between scaffold and ingrown bone.
Convolutional U-Net models are increasingly used for segmentation of biomedical images as they do not require large training sets. Model segmentation performance is typically reported using aggregate metrics such as dice similarity coefficient (DSC), precision, and recall. These metrics, while useful, are reported as mean ± standard deviation without consideration of the context. As a result, these common metrics may not reflect the key results that are relevant to the application. Here, the key result is in accurately quantifying bone regeneration and in characterizing spatial variations in bone regeneration in HAp scaffolds.
We implement a U-Net model trained with three loss functions—Cross-Entropy loss (widely used), Soft Dice loss (to address class imbalance) and Accuracy-based loss. We consider the parameter ΔBGF, the difference in bone growth fraction (BGF) between predicted output and ground truth images, and its correlations of the more standard metrics with |ΔBGF| for the models using the three loss functions. Accuracy is the most representative metric of performance relative to our outcome of interest, measuring ingrown bone. We show that the model is robust to changes in orientation, and resolution, and contrast – representing different imaging micro-CT conditions - supporting its potential for broader application.
Using the results from the U-Net segmentation, we quantify bone regeneration in the scaffolds considering the treatments above and compare the outcomes in order to understand what factors contribute most to bone regeneration. The analysis considers both anatomic factors (implantation site (A, M, P), depth of scaffold in the defect (Hb/s)) and geometric factors created by the surgical procedures (defect to scaffold diameter ratio (∅d/s) – or the gap between scaffold and defect - and scaffold tilt (tan(θ))). The quantitative analysis shows that scaffolds implanted in the middle implantation site had significantly higher BGF than scaffolds in the anterior implantation site (p < 0.05). BGF variation is caused by other factors like bone contact fraction (BCF), defect to scaffold diameter ratio (∅d/s), the fraction of the scaffold height within the defect (Hb/s), and the tilt (tan(θ)) within the defect. When we isolate the BGF from BCF, ∅d/s, Hb/s, and tan(θ), we observe that all dry scaffolds (control rectilinear - dry, optimized rectilinear, optimized curvilinear) had significantly higher BGF than all wet scaffolds (cells, serum, EVs) (p < 0.05). This result is important because it supports our previous findings: fluid in the defect acts synergistically with these HAp scaffolds with multiscale porosity, through their capillarity, in enhancing bone regeneration [1,2]. The current study shows that this capillary effect is prominent after accounting for other factors like those caused by bone anatomy or geometry of the defect. The results further show that the combination of endogenous biologic components in the defect fluid is also synergistic compared to the individual components (cells, serum, EVs). All together, this study provides guidance for implant design at the scale of the defect and scaffold size and shape, as well as at the scale of the microstructural features of the scaffold that can generate the capillary forces to draw in fluid.Submission published under a 24 month embargo labeled 'U of I Access', the embargo will last until 2027-12-01The student, Sohaila Aboutaleb, accepted the attached license on 2025-11-25 at 13:04.The student, Sohaila Aboutaleb, submitted this Dissertation for approval on 2025-11-25 at 13:11.This Dissertation was approved for publication on 2025-11-30 at 11:46.DSpace SAF Submission Ingestion Package generated from Vireo submission #22950 on 2026-02-19 at 18:45:5
Factors Affecting Metformin Plasma Concentrations
No full textThe attached document may provide the author's accepted version of a published work. See Citation for details of the published work
Nesfatin-1 Improve Spatial Memory Impairment Following Transient Global Cerebral Ischemia/Reperfusion via Inhibiting Microglial and Caspase-3 Activation
No full textExercise preconditioning exhibits neuroprotective effects on hippocampal CA1 neuronal damage after cerebral ischemia
No full textRecent evidence has suggested the neuroprotective effects of physical exercise on cerebral ischemic injury. However, the role of physical exercise in cerebral ischemia-induced hippocampal damage remains controversial. The aim of the present study was to evaluate the effects of pre-ischemia treadmill training on hippocampal CA1 neuronal damage after cerebral ischemia. Male adult rats were randomly divided into control, ischemia and exercise + ischemia groups. In the exercise + ischemia group, rats were subjected to running on a treadmill in a designated time schedule (5 days per week for 4 weeks). Then rats underwent cerebral ischemia induction through occlusion of common carotids followed by reperfusion. At 4 days after cerebral ischemia, rat learning and memory abilities were evaluated using passive avoidance memory test and rat hippocampal neuronal damage was detected using Nissl and TUNEL staining. Pre-ischemic exercise significantly reduced the number of TUNEL-positive cells and necrotic cell death in the hippocampal CA1 region as compared to the ischemia group. Moreover, pre-ischemic exercise significantly prevented ischemia-induced memory dysfunction. Pre-ischemic exercise mighct prevent memory deficits after cerebral ischemia through rescuing hippocampal CA1 neurons from ischemia-induced degeneration
Gender, Trauma, and the Use of Trauma, Diversity and Inclusivity Principles During Probation and Parole Supervision
No full textMartinson (1974) argued that Nothing Works in the rehabilitation of justice impacted individuals. In response, Andrews and Kiesling (1980) developed a set of core correctional practices (CCPs) that could be used by probation and parole officers to enhance correctional outcomes for justice impacted individuals. More recently, trauma responsive approaches have emerged as another hypothesized effective strategy for dealing with justice impacted individuals who experience high levels of trauma (Miller & Najavits, 2012). This study investigates the nature and prevalence of probable traumatic experiences among justice impacted individuals on probation with a focus on gender differences (N ≈ 329). The study also investigates if probation and parole officers who were recently trained in a model of community supervision that blends trauma responsiveness with core correctional practices—the Ontario Ministry of the Solicitor General’s Made-in-Ontario Core Correctional Practices (CCP) Model of Community Supervision- are more likely to apply trauma, diversity and inclusivity (TDI) principles in their interactions with clients after the training. The study uses client case notes prepared by probation and parole officers. Results showed that despite women reporting significantly higher probable trauma, trauma-informed approaches were applied similarly across gender groups. In addition, TDI implementation was consistent regardless of trauma status in the context of CCP. This highlights the need for more targeted trauma-informed approaches based on individual needs rather than a generalized application of trauma-informed intervention.
The opinions and views expressed in this report reflect those of the author and not the Ontario Ministry of the Solicitor General. Sohaila Abdelhadi contributed intellectually to the research, prepared the poster from their thesis work, and managed its submission. All authors contributed to data collection and coding
EU PREFERIA TER PERDIDO UM OLHO: A REPRESENTAÇÃO DO ESTUPRO, NA CRÔNICA DE PALOMA FRANCA AMORIM (2017)
No full textThis article aims to analyze the chronicle written by Paloma Franca Amorim (2017), entitled Eu preferia ter perdido um olho, primarily published in the newspaper O Liberal, in the state of Pará. The author offers a sensitive linguistic fabric when dealing with one of the violences against a woman and thematizes rape. She uses the chronicle’s resources to represent the social and historical problem and transport the discourse to the dimension that permeates literature and journalism. The study is based on the point of view of Nádia Battella Gotlib (1998), about literature written by women in Brazil, intertwined with the reports collected by Sohaila Abdulali (2019), who confronts the rape culture and culminates with Monique Wittig’s conceptions (2019) about what it means to be a woman in a sexist society.O presente artigo investiga a representação do estupro, na crônica de Paloma Franca Amorim (2017), intitulada Eu preferia ter perdido um olho, publicada primariamente no Jornal O Liberal, do estado do Pará. A autora oferece um tecido linguístico sensível ao representar uma das violências mais recorrentes contra as mulheres ao rememorar dois desses episódios traumáticos pelos quais a própria autora viveu e entrelaça a uma notícia sobre o tema, que estava em voga na época. Ela escolhe a crônica como narrativa do problema social e histórico, transportando o discurso para esta dimensão que permeia a Literatura e o Jornalismo. O estudo toma por base as discussões de Nádia Battella Gotlib (1998), a respeito da literatura feita por mulheres no Brasil, entrelaçadas aos relatos coletados por Sohaila Abdulali (2019), que faz frente à cultura do estupro e culmina nas concepções de Monique Wittig (2019) a respeito do que é ser mulher em uma sociedade sexista
Graphene and Its Nanocomposites Derivatives: Synthesis, Properties, and Their Applications in Water Treatment, Gas Sensor, and Solar Cell Fields
No full textPublisher Copyright: © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.Graphene and its derivatives have remarkable properties such as high electrical conductivity, mechanical strength, large surface area, excellent hydrophilicity, and significant thermal and barrier properties. Graphene oxides and its composites can be synthesized using simple top-down procedures. Graphene is a 2D material that consists of SP2 carbon atoms arranged in a honeycomb structure. Graphene oxides can be prepared from graphene, which allows functionalizing the material to achieve more significant advantages via controlling the role of the oxygen groups. Moreover, it reveals a desirable ability to form nanocomposites with various materials categories such as metals, semiconductors, metal oxides, and polymers. Graphene and its derivatives nanocomposites have been applied in extensive technological applications in electronic, biological, engineering, energy production, and energy storage. Herein, we will briefly introduce Graphene and its derivatives nanocomposites synthesis techniques, and impressive properties. We will specifically show their promising performance in separated applications such as water treatment gas sensors, and solar cell applications.Peer reviewe
Protection of Hippocampal CA1 Neurons Against Ischemia/Reperfusion Injury by Exercise Preconditioning via Modulation of Bax/ Bcl-2 Ratio and Prevention of Caspase-3 Activation
No full textIntroduction: Ischemia leads to loss of neurons by apoptosis in specific brain regions, especially in the hippocampus. The purpose of this study was investigating the effects of exercise preconditioning on expression of Bax, Bcl-2, and caspase-3 proteins in hippocampal CA1 neurons after induction of cerebral ischemia.
Methods: Male rats weighing 260-300 g were randomly allocated into three groups (sham, exercise, and ischemia). The rats in exercise group were trained to run on a treadmill 5 days a week for 4 weeks. Ischemia was induced by the occlusion of both common carotid arteries (CCAs) for 20 min. Levels of expression of Bax, Bcl-2, and caspase-3 proteins in CA1 area of hippocampus were determined by immunohistochemical staining .
Results: The number of active caspase-3-positive neurons in CA1 area were significantly increased in ischemia group, compared to sham-operated group (P<0.001), and exercise preconditioning significantly reduced the ischemia/reperfusion-induced caspase-3 activation, compared to the ischemia group (P<0.05). Also, results indicated a significant increase in Bax/Bcl-2 ratio in ischemia group, compared to sham-operated group (P<0.001).
Discussion: This study indicated that exercise has a neuroprotective effects against cerebral ischemia when used as preconditioning stimuli
Creating Supportive Spaces: Understanding if Trauma, Diversity, and Inclusivity Training for Probation and Parole Officers Influences Client Behaviour
No full textIndividuals serving community sentences represent a diverse population, with a variety of needs and unique lived experiences. Understanding how to support these clients to promote positive change is an important avenue of research. A new training curriculum—Ontario Ministry of the Solicitor General’s Made-in-Ontario Core Correctional Practices (CCP) Model of Community Supervision- was designed to address this by training probation and parole officers on a set of behaviours described as Trauma Diversity and Inclusivity (TDI) pillars. The study seeks to investigate whether probation and parole officers use of TDI pillars increased post implementation of the ministry’s model. A sample of probation and parole officer case files for clients on probation (pre-training, n = 152, and post-training, n = 134) were coded to compare TDI use. This study also seeks to investigate if TDI skills correlate with client engagement and effort, and positive probation outcomes during supervision.
The opinions and views expressed in this report reflect those of the author and not the Ontario Ministry of the Solicitor General. This project was done with the support of the Ontario Ministry of the Solicitor General
Are Core Correctional Practice Strategies Associated with Positive Change Among Clients on Probation Irrespective of Gender, Indigeneity, or Mental Health and Substance Misuse?
No full textThe intersection of mental health, substance use, and the criminal justice system presents significant challenges for probation and parole officers (PPOs), particularly when supervising justice-impacted persons (JIPs) with complex needs. Grounded in the risk-need-responsivity (RNR) model (Andrews et al., 1990), this research explores the relationship between core correctional strategies (e.g., teaching clients to reframe thinking styles) and client outcomes while on probation (e.g., less substance use, employment stability) and whether gender and Indigeneity moderate these effects. The study also explores if the presence of acute mental health crises and substance misuse influences the relationship between probation and parole officers’ use of Core Correctional Practice (CCP) strategies and client outcomes. The study analyzes 193 probation case notes following the introduction of the Ontario Solicitor General’s Made-in-Ontario Core Correctional Practices (CCP) Model of Community Supervision. A subset of six items from the Client Change Scale (CCS, Serin & Lloyd, 2018) is used to assess behavioural change across key life domains (e.g., employment, substance use, program engagement). Findings will inform evidence-based training enhancements and policy reforms to improve probation outcomes for diverse populations.
The opinions and views expressed in this report reflect those of the author and not the Ontario Ministry of the Solicitor General. This project was done with the support of the Ontario Ministry of the Solicitor General
