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Understanding the efficiency of hydraulic actuation systems using the concept of cyclic performance index
Get PDFThis research develops and applies a new approach for evaluating the performance of hydraulic systems, with particular emphasis on those incorporating Energy Storage and Reutilization (ESR) circuits. Hydraulic systems are widely used in industry for their high-power density and versatility. Yet, current performance evaluation methods, such as energy-saving ratios, relative efficiency, and Sankey flow diagrams, are limited. These methods do not adequately account for stored and reutilized energy, making it difficult to fairly compare systems or accurately assess the benefits of energy recovery. To address this problem, the study applies the Cyclic Performance Index (CPI), a metric introduced by Costa and Sepehri [1], which evaluates all energy flows in the system. The CPI incorporates input energy from the prime mover, recoverable energy from the load, and energy losses during operation, thereby providing a more comprehensive framework for performance assessment.
The CPI methodology is validated through MATLAB simulations of Electro-Hydrostatic Actuators (EHA) configured with and without Energy Storage and Reutilization (ESR) circuits. This approach allows direct comparison between standard configurations and those equipped with energy recovery capability. The results show that, when ESR circuits are integrated, overall energy performance improved by approximately 40%, with CPI values increasing from 0.15 to 0.21. These results confirm the practical utility of CPI for capturing the impact of energy storage and reuse. The study also identifies limitations, especially where some stored energy is not fully reutilized due to system losses. This highlights the need for further optimization of ESR circuit design to enhance recovery efficiency.
In conclusion, the CPI offers a standardized and reliable tool for evaluating hydraulic systems with or without energy recovery. By measuring the balance of energy consumption, storage, and reuse, it allows for more precise comparisons between different system configurations. This research supports the development of energy-efficient and sustainable hydraulic technologies by illustrating both the advantages of ESR integration and the value of CPI as a performance evaluation metric.February 202
What actually happens in partnered health research? A concordance analysis of agreement on partnership practices in funded Canadian projects between academic and knowledge user investigators
Get PDFBackground: Collaborations involving partnerships between academic researchers and knowledge users can improve the relevance and potential adoption of evidence in health care practices and decision-making. However, descriptions of partnering practice characteristics are often limited to self-report from the lead academic researcher, with no comparison among team members. The primary objective of this study was to determine the extent to which nominated principal investigator (NPI) respondents of a questionnaire about funded Canadian partnered health research projects agreed with other team researchers and knowledge users (KU) on partnership practices.
Methods: We conducted secondary analysis of a subset of data from 106 respondents from 53 partnered Canadian health research projects funded between 2011 and 2019. We organized projects into NPI-researcher and NPI-KU dyads, and analyzed 23 binary variables about types of knowledge users involved and approaches for involving knowledge users in the project. We calculated Kappa scores and examined if agreement varied by dyad type and time across three blocks of years of project funding using a two-way ANOVA. We also explored how agreement varied by question type (independent t-test) and by variable (Pearson Chi-Square).
Results: Overall agreement on partnership practices was minimal (mean Kappa = 0.38, SD 0.27). NPI- researcher dyads had higher Kappa scores than NPI-KU dyads (p = 0.03). There were no significant differences across funding year blocks (p > 0.05). Agreement on the types of knowledge users engaged in the project was weak (mean Kappa = 0.43, SD 0.32), and there was no difference by dyad type. Agreement was minimal on the approaches for involving knowledge users the project (mean Kappa = 0.28, SD 0.31), and NPI-researcher dyads had significantly higher Kappa scores than NPI-KU dyads (p = 0.03). Variable-level agreement ranged between 47 and 98%.
Conclusions: The overall low level of agreement among team members responding about the same project has implications for the continued study and practice of partnered health research. These findings highlight the caution that must be used in interpreting retrospectively assessed self-report practices. Moving forward, prospective documentation of partnered research practices offers the greatest potential to overcome the limitations of recall-based retrospective analyses
Application of immunomodulatory biomaterials for cardiovascular repair
No full textCardiovascular diseases are the leading cause of death worldwide. Coronary artery disease, in particular, accounts for over 7 million deaths annually. Improvements in medical management has reduced the mortality of an acute myocardial infarction but simultaneously increased the prevalence of chronic heart failure. Currently available therapies for end-stage heart failure are limited, and novel therapies in functional myocardial regeneration are needed to address the irreversible loss of functional cardiomyocytes. This thesis focused on using biomaterials to tackle inflammation in the pathogenesis of heart failure to reduce myocardial injury and improve cardiac function. Inflammation plays a key role in cardiomyocyte loss, adverse remodeling, and failure of existing regenerative therapies. Biomaterials have emerged as promising tools to mediate the crosstalk between immune cells, stem and/or progenitor cells, and injured tissues to drive favourable pro-reparative immune responses. Chapter II is a literature review that highlighted the role of the immune system in cardiac injury, identified key signaling molecules that can be targeted for immunomodulation, and explored the role of mesenchymal stem cells in paracrine mediation of cardiac repair. Chapter III presented the development of a novel rosuvastatin-chitosan hydrogel that facilitated the delivery, survival, and immunomodulatory activity of allogeneic mesenchymal stem cells delivered to an acutely infarcted area of the myocardium. Chapter IV described the application and mechanistic characterization of novel two-dimensional transition metal carbides (MXenes) for targeted immunomodulation in a model of transplant vasculopathy. Finally, Chapter V described further rational design and improvements to the overall biocompatibility and function of the immunomodulatory MXene materials. Together, the work presented in this thesis represents several new biomaterials-based immunomodulatory platforms that can be used to facilitate cardiac repair after injury.February 202
Family and friend survey
No full textThe Centre on Aging conducted a study of COVID-19 vaccination decision-making in personal care homes (PCH) in Manitoba. This research project focused on residents who were not able to make their own decisions about being vaccinated, and the aim of this study was to learn more about the perspectives and experiences of employees, volunteers, and families and friends of residents regarding vaccination decision-making specifically related to the COVID-19 pandemic. Eligible participants had to be 18 years of age or older, someone who either worked or volunteered at a PCH during the pandemic, and/or a family member or friend of a PCH resident in Manitoba during the pandemic who was not able to provide their own consent to be vaccinated against COVID-19
The safety and long-term outcomes of opioid exposures in pregnancy
No full textBackground: The use of opioids during pregnancy has increased in North America. Opioids can cross the placenta and produce signs of withdrawal known as Neonatal Abstinence Syndrome (NAS). In this project, I described the trends of opioid prescriptions among pregnant people and the incidence of NAS in Manitoba, examined factors associated with the development and severity of NAS and investigated the neurodevelopmental outcomes following exposure to prescription opioids during pregnancy.
Methods: A population-based cohort study was conducted using the population data repository of the Manitoba Center for Health Policy. Poisson regression models were used to describe the time trends of opioid prescriptions utilization during pregnancy and describe the incidence of NAS (Chapter 2). Multivariable logistic regression models were used to examine factors associated with the development and severity of NAS (Chapter 3) and to investigate neurodevelopmental outcomes following exposure to prescription opioids during pregnancy (Chapter 4). Early Development Instrument (EDI) was used to assess developmental vulnerability in kindergarteners.
Results: The proportion of live births exposed to opioid prescriptions during pregnancy increased from 3.7% in 1995 to 7.4% in 2017; however, there has been a reduction in recent years. The incidence of NAS in Manitoba more than tripled between 1995 and 2021 (2.0-7.6 per 1,000 live births). Female sex, normal birth weight, and breastfeeding were protective factors against the diagnosis of NAS. Breastfeeding initiation was the only protective factor against the need for pharmacological treatment.
Of the 103,905 eligible children, 51% of the exposed group (n=973) were developmentally vulnerable in 1 or more domains, compared with 32% of the matched control group (n=3,814) (Adjusted Odds Ratio [AOR] 1.46; 95% CI 1.23-1.71). Children in the exposed group had a significantly higher likelihood of being vulnerable in all domains: physical health and well-being (AOR 1.31; 95%CI 1.08-1.59), communication skills and general knowledge (AOR 1.53;95%CI 1.25-1.88), language and cognitive development (AOR 1.53;95%CI 1.25-1.86), social competence (AOR 1.60;95%CI 1.32-1.95); emotional maturity domain was the least affected (AOR 1.25;95%CI 1.01-1.55). There was a higher risk of developmental vulnerability in children exposed to opioids in early pregnancy, longer durations, and higher opioid doses.
Conclusions: Prenatal exposure to opioids is increasing in Manitoba and was associated with an increased risk of developmental vulnerability in children. It is of utmost importance to provide children with POE and their families with early and long-term developmental screening and family centered supports to help achieve optimal educational and family health outcomes.May 202
Immunoglobulin E (IgE)-mediated food allergy
No full textAbstract Food allergy is defined as an adverse immunologic response to a food. Immunoglobulin E (IgE)-mediated reactions to foods are associated with a broad range of signs and symptoms that may involve any of the following body systems: the skin, gastrointestinal tract, respiratory tract, and cardiovascular system. IgE-mediated food allergy is a leading cause of anaphylaxis. Therefore, timely and appropriate diagnosis and treatment are imperative. A diagnosis of food allergy entails a careful history and diagnostic tests, which may include skin prick tests, serum-specific IgE, and oral food challenge. The goal of food allergy care is to empower patients and caregivers to manage the risk of food-allergic reactions, reduce food allergy-related anxiety, and achieve a sense of control over their condition. This can be achieved in different ways for different patients and across different life stages. This article provides an overview of the epidemiology, pathophysiology, diagnosis, and management of IgE-mediated food allergy.Key take-home messages Food allergy is defined as an adverse immunologic response to a food protein. Diagnosis of food allergy requires a detailed history and diagnostic tests, such as SPT and/or food-specific serum IgE measurement, and in some cases, OFCs. Management of food allergy involves avoidance of the culprit food(s) and self-injectable epinephrine for anaphylaxis. For patients with systemic symptoms, the treatment of choice is epinephrine administered by intramuscular injection into the lateral thigh. OIT is indicated as an option for food allergy management, which can be disease-modifying when performed early in the first years of life (see OIT article in this supplement). However, OIT is not readily accessible in many regions
Current perspectives on vaccines and therapeutics for Lassa Fever
No full textAbstract Lassa virus, the cause of deadly Lassa fever, is endemic in West Africa, where thousands of cases occur on an annual basis. Nigeria continues to report increasingly severe outbreaks of Lassa Fever each year and there are currently no approved vaccines or therapeutics for the prevention or treatment of Lassa Fever. Given the high burden of disease coupled with the potential for further escalation due to climate change the WHO has listed Lassa virus as a priority pathogen with the potential to cause widespread outbreaks. Several candidate vaccines have received support and have entered clinical trials with promising early results. This review focuses on the current state of vaccine and therapeutic development for LASV disease and the potential of these interventions to advance through clinical trials. The growing burden of LASV disease in Africa highlights the importance of advancing preclinical and clinical testing of vaccines and therapeutics to respond to the growing threat of LASV disease
A park-based group mobility program for older adults with difficulty walking outdoors: a qualitative process evaluation of the Getting Older Adults Outdoors (GO-OUT) randomized controlled trial
No full textAbstract Background The Getting Older Adults Outdoors (GO-OUT) randomized controlled trial showed that a workshop and 10-week park-based outdoor walk group (OWG) was superior to the workshop and 10 weekly reminders (WR) with increasing walking capacity, but not outdoor walking activity, health-promoting behavior, or successful aging, among older adults with difficulty walking outdoors. The objective of this planned process evaluation was to explore participants’ perceptions of mechanisms of impact of and contextual factors influencing experiences with the interventions to help explain the observed intervention effects on study outcomes. Methods A qualitative descriptive study involving semi-structured interviews conducted at 6-months post-baseline was conducted. A directed content analysis was undertaken. Participants We interviewed 27 adults (52% male, 48% female, mean age 76 years) from the OWG (n = 13) and WR group (n = 14). Results We identified two themes including: “Holding Me Accountable to Walk More Frequently”, and “We Walked Farther, With More Ease and Confidence, and We Felt Better”. Participants in both groups described how the OWG and WR programs provided some degree of structure and accountability to others that increased their motivation to walk outdoors. Participants described how the OWG led to improved walking capacity (e.g., increased walking distance) and confidence. Interacting with people during OWG sessions led to a sense of enjoyment, and well-being. Conclusions Community programs that incorporate structure, accountability, and opportunities for social interaction, can help improve motivation to increase outdoor walking activity and a sense of belonging for older adults with difficulty walking outdoors. Park-based OWG programs appear to convey additional important benefits related to improved physical function and well-being. Trial registration ClinicalTrials.gov NCT03292510 Date of registration: September 25, 2017
Disaster capitalism, settler colonialism, and Indigenous environmental justice in the COVID-19 pandemic
No full textWhile the COVID-19 pandemic was experienced and borne by everyone, the weight of everyone’s burden was not equal; As they have in the past, Indigenous peoples experienced disproportionate impacts during the crisis. This may be largely connected to the ongoing presence of settler colonial ideologies and structures which, among other issues, resulted in a patronizing disregard for Indigenous pandemic decision-making. In conjunction, disaster capitalism ensued throughout the pandemic, a practice defined by Naomi Klein as the exploitation of crises by the powerful to further their own agendas, which worked to further compound and hinder Indigenous efforts to ensure community safety and well-being. However, First Nations nonetheless asserted their self-determination, challenging harmful decision-making and prioritizing community well-being. This project utilizes two cases (Case Study 1: Keeyask Lockdown, Manitoba and Case Study 2: Ring of Fire, Ontario) to examine how the pervasive ideologies of settler colonialism interacted and influenced disaster capitalism during the pandemic, as well as how Indigenous Environmental Justice (IEJ) was then enacted by communities. An analysis of these cases demonstrate that, while disaster capitalism and IEJ were prevalent during COVID-19, the specific circumstances were nonetheless shaped by distinct, place-based histories and relationships among settlers and Indigenous peoples. Moreover, this project explores the narratives surrounding these cases, including how they were presented to the public by various Mainstream, Alternative/Advocacy and Indigenous news outlets by utilizing a media analysis. This analysis notably observed the considerable inclusion of settler narratives/biases by Mainstream sources, while Alternative/Advocacy, and Indigenous sources specifically, highlighted Indigenous voices/experiences and the context of sovereignty. Lastly, the inclusion of a community experience chapter highlights place-based Indigenous experiences and ways of knowing regarding the Keeyask case study; Demonstrating the complexity of Indigenous relationships with industry and settler government, these experiences moreover spoke to a dedication to continue to take action, heal and move forward in a good way. By exploring these subjects of settler colonialism, disaster capitalism and IEJ through various lens’ and by utilizing a two-eyed seeing approach, this project demonstrates the value of employing multiple perspectives and storytelling when striving to formulate contextualized, respectful and meaningful research.February 202
Safety of cannabinoids used for medical purposes in children and adolescents
Get PDFBackground: Over the last two decades, there has been growing interest and research in using cannabinoids for medical purposes in children. The main goal of my doctoral thesis was to examine the safety of cannabinoids used for medical purposes in children to generate data to guide clinical practice and future research.
Methods: First, we conducted a living systematic review (LSR) to study the available evidence on cannabis products used for medical purposes in children. Second, to learn more about specific indications and safety profiles, we conducted three separate subgroup systematic reviews of studies including children with cancer, autism spectrum disorder (ASD), and a subgroup analysis of randomized controlled trials where adverse event (AEs) profiles were compared between those receiving cannabinoids and control arms. Third, a pharmacovigilance database study was conducted to evaluate the real-world safety reporting on cannabidiol (CBD) and investigate its drug interactions in children.
Results: In the LSR, among identified interventional and observational studies, common indications for cannabinoids in children were refractory epilepsy (n=146 studies, 188,726 participants), followed by cancer and cancer symptom management (n=30 studies, 208,753 participants), and ASD (n=18 studies, 1285 participants). The most common cannabinoids studied in interventional studies were purified CBD (78.6%, n=66 studies, 5235 participants) with dose-range of 2-50 mg/kg/day, tetrahydrocannabinol (THC) (6%, n=5 studies, 148 participants) with dose-range of 2.5-10 mg/day (with a max dose of nabiximols containing 32.4 mg of THC) and nabilone (6%, n=5 studies, 267 participants) with dose-range of 0.5-2 mg/day. In a cancer symptom management systematic review, cannabinoids were commonly used for chemotherapy-induced nausea and vomiting (11/19, 58%) management. In controlled studies, somnolence, dizziness, dry mouth, and withdrawal due to adverse events were more commonly associated with the use of cannabinoids in children with cancer compared to active control group. In the ASD review, the pooled prevalence of AEs across single-arm studies and observational studies was 44.8% (95% CI, 24.1-67.4; I2 = 94%; 9 studies) in children with ASD. Somnolence, changes in appetite, restlessness, and tiredness were the commonly reported AEs (> 10%). Validated efficacy measures were reported inconsistently across studies. Epilepsy, sleep impairment, hyperactivity, concentration impairment, and irritability were the most common symptoms managed with cannabinoids in children with ASD. In a meta-analysis of randomized controlled clinical trials, cannabinoids were associated with an overall increased risk of adverse events (risk ratio [RR], 1.09; 95% CI, 1.02-1.16; I2 = 54%; 12 trials), withdrawals due to adverse events (RR, 3.07; 95% CI, 1.73-5.43; I2 = 0%;14 trials), and serious adverse events (RR, 1.81; 95% CI, 1.21-2.71; I2 = 59%; 11 trials) compared with control group. In real-world pharmacovigilance data, Signals were detected for hospitalization [Proportional Reporting Ratio (PRR) 30.83 (95% CI, 26.03-36.51), 127 reports], sudden unexplained death in epilepsy [PRR 27.64 (95% CI, 10.06-75.91), 4 reports], seizures [PRR 19.77 (95% CI, 18.03-21.66), 328 reports] and death [PRR 14.07 (95% CI, 12.27-16.13), 176 reports]. CBD was commonly reported to interact with clobazam (n=8/19, 42.10%), valproic acid (n=4/19, 21.05%), mTOR inhibitors (everolimus and sirolimus; n=3/19, 15.78%), topiramate (n=2/19, 10.50%), and zonisamide (n=2/19, 10.50%).
Conclusions This thesis's findings identified evidence gaps while synthesizing dosing, safety, and reported benefits of cannabinoid use in children for medical purposes. Long-term safety studies, especially those exploring cannabinoid-related drug interactions and tools that improve adverse event reporting and harmonize cannabis exposure definitions, are needed.May 202