Showing papers by "University of Winnipeg published in 2023"

Completely dark matter from rapid-turn multifield inflation

Abstract: We study cosmological gravitational particle production as applied to "rapid-turn" models of inflation involving two scalar fields. We are interested in the production of massive spin-0 particles that only interact gravitationally and provide a candidate for the dark matter. Specifically, we study two models of rapid-turn multifield inflation, motivated in part by the de Sitter swampland conjecture, that are distinguished by the curvature of field space and the presence or absence of field space 'angular momentum' conservation. We find that one of these models leads to insufficient particle production and cannot explain the observed dark matter relic abundance. The second model is able to explain the origin of spin-0 dark matter via gravitational production, and we identify the relevant region of parameter space that is consistent with measurements of the dark-matter relic abundance, the dark-matter-photon isocurvature perturbations, and the spectrum of curvature perturbations that is probed by cosmological observations. Our work demonstrates the compatibility of the de Sitter swampland conjecture with completely dark matter.

Chalcogen-Substituted Carbenes: A Density Functional Study of Structure, Stability, and Donor Ability

Abstract: Chalcogen-substituted carbenes are examined computationally using density functional theory. Several approaches are used to assess the stability and reactivity of chalcogenazol-2-ylidene carbenes (NEHCs; E = O, S, Se, Te). The known unsaturated species 1,3-dimethylimidazol-2-ylidene is studied at the same level of theory as the NEHC molecules, as a reference. Electronic structures, stability towards dimerization, and ligand properties are discussed. The results highlight the NEHCs as potentially valuable ancillary ligands for stabilizing low-valent metals or paramagnetic main group molecules. A simple, effective computational method for evaluating sigma donor ability and pi acidity of carbenes is presented.

Paramedic perspectives on sex and gender equity in prehospital electrocardiogram acquisition

Abstract: Acute coronary syndrome (ACS) makes up a substantial healthcare burden. Previous research has demonstrated that women fare worse than men across a range of hospital-based ACS processes and outcomes. In the prehospital setting, the 12-lead electrocardiogram (ECG) can identify critical ACS cases and speed access to definitive treatment. However, studies on rates of ECG acquisition among patients at risk of ACS in the prehospital setting have shown that women receive the test less frequently than men. The purpose of this study was to investigate the reasons for observed gender differences in rates of ECG acquisition in the prehospital setting. This is a cross-sectional study of paramedics in an urban emergency medical service agency. An experienced qualitative researcher conducted 26 semi-structured interviews. Using a subjectivist inductive approach, the study team analyzed interview transcripts following the six-step process described by Braun and Clarke (2006). Qualitative rigor was maintained through consistent review, discussion, and revision at each stage. Four themes were identified among diverse views around the 12-lead acquisition. (1) Safety (feelings of physical comfort and psychological safety related to administering a 12-lead). (2) Knowledge (subject-matter knowledge involving the protocols and procedures as well as self-knowledge of participants’ own practice). (3) Training and learning (perceptions of foundational training and on-the-job learning, and how those have influenced their perceptions of how to care for patients experiencing ACS). (4) Professionalism (perceptions of behavior and attitudes and how they influence patient care). These four interrelated themes were integrated to represent a model of prehospital cardiac care. This study addressed a gap in the literature by documenting prehospital providers’ attitudes and beliefs around cardiac care. The resulting model of prehospital cardiac care offers both a template for evaluating the equity of current treatment and a road map for improvement.

Dyck Words, Pattern Avoidance, and Automatic Sequences

Abstract: We study various aspects of Dyck words appearing in binary sequences, where 0 is treated as a left parenthesis and 1 as a right parenthesis. We show that binary words that are 7/3-power-free have bounded nesting level, but this no longer holds for larger repetition exponents. We give an explicit characterization of the factors of the Thue-Morse word that are Dyck, and show how to count them. We also prove tight upper and lower bounds on f(n), the number of Dyck factors of Thue-Morse of length 2n.

Chalcogen-Substituted Carbenes: A Density Functional Study of Structure, Stability, and Donor Ability

Abstract: Chalcogen-substituted carbenes are examined computationally using density functional theory. Several approaches are used to assess the stability and reactivity of chalcogenazol-2-ylidene carbenes (NEHCs; E = O, S, Se, Te). The known unsaturated species 1,3-dimethylimidazol-2-ylidene is studied at the same level of theory as the NEHC molecules, as a reference. Electronic structures, stability towards dimerization, and ligand properties are discussed. The results highlight the NEHCs as potentially valuable ancillary ligands for stabilizing low-valent metals or paramagnetic main group molecules. A simple, effective computational method for evaluating sigma donor ability and pi acidity of carbenes is presented.

Connecting Children to Nature Through Scientific Inquiry: The Impact on Children’s Well-Being

Abstract: This chapter discusses an approach to teaching science that aims to support student well-being through local experiences with nature. Referred to here as the Capabilities-Development-with-Nature (CDWN) approach, this model is a blend of the inquiry-based Reggio Emilia philosophy and outdoor education. Through the lens of a capabilities approach, the study highlights an outdoor learning practice that provides opportunities for students to develop needs-linked capabilities necessary for well-being. To establish the focus of the study, human needs and corresponding capabilities were selected by stakeholders. The findings, gathered through semi-structured interviews as well as classroom and outdoor observations, indicate how the evaluated outdoor education approach provides opportunities for students to develop and enact the identified capabilities. This innovative approach to teaching science may provide a loose framework for consideration in other contexts by teachers and theorists who are concerned with the well-being of students.

Smallest and Largest Block Palindrome Factorizations

Abstract: A palindrome is a word that reads the same forwards and backwards. A block palindrome factorization (or BP-factorization) is a factorization of a word into blocks that becomes palindrome if each identical block is replaced by a distinct symbol. We call the number of blocks in a BP-factorization the width of the BP-factorization. The largest BP-factorization of a word w is the BP-factorization of w with the maximum width. We study words with certain BP-factorizations. First, we give a recurrence for the number of length-n words with largest BP-factorization of width t. Second, we show that the expected width of the largest BP-factorization of a word tends to a constant. Third, we give some results on another extremal variation of BP-factorization, the smallest BP-factorization. A border of a word w is a non-empty word that is both a proper prefix and suffix of w. Finally, we conclude by showing a connection between words with a unique border and words whose smallest and largest BP-factorizations coincide.

Neurodiversity is Human Diversity, an Equity Imperative for Education

Abstract: This article discusses historical system structures in education that have impeded on inclusion and present pertinent historical challenges, pedagogy and beliefs that are foundational in cultivating inclusive environments today. It explores Neurodiversity, an equity imperative, as critical to shifting the culture of teaching and learning by offering a potential framework for overcoming historical systemic barriers to inclusion. Next, it discusses shared attributes of epidemiology of teacher beliefs, neuroscience and Teacher self-study as potential foundational components, complimenting Neurodiversity paradigms. Lastly, a proposed theoretical framework and suggested future research which could lead to the development of an inclusive pedagogy. Education is the cornerstone to fostering talent and creativity of each individual and it is only when the system is truly inclusive of all human diversity, can individuals flourish developing their talents.

Alum reduced phosphorus release from flooded soils under cold spring weather conditions

Abstract: The effectiveness of amendments such as alum [Al2 (SO4 )3 ·18H2 O] in reducing phosphorus (P) loss to floodwater has been reported under summer conditions and laboratory-controlled environments, but not under actual spring weather conditions in cold climate regions with high diurnal temperature variations when potential for P losses is high. The effectiveness of alum in reducing P release under Manitoba spring weather conditions was evaluated in a 42-day experiment using 15-cm soil monoliths from eight agricultural soils, which were unamended or alum-amended (5 Mg ha-1 ) and flooded to a 10-cm head. Dissolved reactive P (DRP) concentrations and pH of porewater and floodwater were determined on flooding day and every 7 days after flooding (DAF). Porewater and floodwater DRP concentrations in unamended soils increased 1.4- to 4.5-fold, and 1.8- to 15.3-fold, respectively, from 7 to 42 DAF. In alum-amended soils, DRP concentrations averaged across soils was 43%-73% (1.0-2.0 mg L-1 ) lower in porewater, and 27%-64% (0.1-1.2 mg L-1 ) lower in floodwater than unamended soils during the flooding period. The reduction of DRP by alum was more pronounced under high fluctuating diurnal spring air temperature than with controlled air temperature (4°C) in a previous similar study. Acidic pH in porewater and floodwater due to alum did not persist over 7 days. This study showed that alum application is a viable option in reducing P released to floodwater in agricultural soils of cold regions where flooding-induced P loss is prevalent in the spring.

Identifying factors that shape whether digital food marketing appeals to children

Abstract: Abstract Objective: Children are frequently exposed to unhealthy food marketing on digital media. This marketing contains features that often appeal to children, such as cartoons or bold colors. Additional factors can also shape whether marketing appeals to children. In this study, in order to assess the most important predictors of child appeal in digital food marketing, we used machine learning to examine how marketing techniques and children’s sociodemographic characteristics, weight, height, BMI, frequency of screen use, and dietary intake influence whether marketing instances appeal to children. Design: We conducted a pilot study with 39 children. Children were divided into 13 groups, in which they evaluated whether food marketing instances appealed to them. Children’s agreement was measured using Fleiss’ kappa and the S score. Text, labels, objects, and logos extracted from the ads were combined with children’s variables to build four machine learning models to identify the most important predictors of child appeal. Setting: Households in Calgary, Alberta, Canada. Participants: 39 children aged 6-12 years. Results: Agreement between children was low. The models indicated that the most important predictors of child appeal were the text and logos embedded in the food marketing instances. Other important predictors included children’s consumption of vegetables and soda, sex, and weekly hours of television. Conclusions: Text and logos embedded in the food marketing instances were the most important predictors of child appeal. The low agreement among children shows that the extent to which different marketing strategies appeal to children varies.

Rare words in text summarization

Abstract: Automatic text summarization is a difficult task, which involves a good understanding of an input text to produce fluent, brief and vast summary. The usage of text summarization models can vary from legal document summarization to news summarization. The model should be able to understand where important information is located to produce a good summary. However, infrequently used or rare words might limit model’s understanding of an input text, as the model might ignore such words or put less attention on them, especially, when the trained model is tested on the dataset, where the frequency distribution of used words is different. Another issue is that the model accepts only a limited amount of tokens (words) of an input text, which might contain redundant information or not including important information as it is located further in the text. To address the problem of rare words, we have proposed a modification to the attention mechanism of the transformer model with pointer-generator layer, where attention mechanism receives frequency information for each word, which helps to boost rare words. Additionally, our proposed supervised learning model uses the hybrid approach incorporating both extractive and abstractive elements, to include more important information for the abstractive model in a news summarization task. We have designed experiments involving a combination of six different hybrid models with varying input text sizes (measured as tokens) to test our proposed model. Four well-known datasets specific to news articles were used in this work: CNN/DM, XSum, Gigaword and DUC 2004 Task 1. Our results were compared using the well-known ROUGE metric. Our best model achieved R-1 score of 38.22, R-2 score of 15.07 and R-L score of 35.79, outperforming three existing models by several ROUGE points.

We are all Human Beings

Abstract: This article describes a teacher’s journey into prison where she delivers university writing classes. The author explores techniques and strategies that foster empowerment in prison classrooms. Based on the author’s experience and secondary research on critical pedagogy and transformative learning, she explores what it means to treat university writing students in prison like human beings and how to inspire emotionally and socially engaged learning.

Teaching Global Citizenship: A Teacher Reflects on a Learning-Teaching Event and Implications for Global Citizenship Education

Abstract: In narrative style, this paper looks at how a particular teaching-learning event, a meeting in 2003 between Canadian high school students and their Costa Rican host families in Pedrogosso, Costa Rica, unveils pedagogies of global citizenship. By interweaving insights obtained from scholars of education, experiences of students, and reflections by teachers, the author shows how learning for world citizenship often happens in unexpected and unscripted circumstances, when teachers are absent—although, not without responsibility.

Lunar Vertex: A PRISM Science Investigation of the Reiner Gamma Lunar Magnetic Anomaly and Swirl

Abstract: Lunar Vertex is a mission at the intersection of multiple science communities, from planetary geology to space plasma physics. As the first Payloads and Research Investigations on the Surface of the Moon (PRISM1) investigation, scheduled for delivery to the Reiner Gamma (RG) magnetic anomaly in 2024 aboard a commercial lunar lander, Lunar Vertex will unravel the nature of the RG anomaly, the connection to and origin of the associated lunar swirl surface feature, and the structure and impact of the “mini-magnetosphere” in this region. Lunar Vertex includes a suite of magnetometers (Vector Magnetometer – Lander; VML), a fixed-mounted set of cameras (Vertex Camera Array; VCA), and a low-energy ion and electron plasma analyzer (Magnetic Anomaly Plasma Spectrometer; MAPS) on the lander. In addition, a second suite of commercial fluxgate magnetometers (Vector Magnetometer – Rover; VMR) and a multispectral imager (Rover Multispectral Microscope; RMM) are mounted on a dedicated rover that will traverse a distance of at least 500 m from the lander, providing additional multi-point measurements. The combination of magnetic field measurements taken during cruise and descent by VML and during surface operations by both VML and VMR will characterize the surface magnetic field within a strong lunar magnetic anomaly. The combined magnetic field and plasma measurements from VML and MAPS will provide direct observations of plasma populations reaching the lunar surface and the associated local magnetic field configuration. Furthermore, the lunar regolith within the RG magnetic anomaly and over different regions of the associated lunar swirl will be characterized by RMM and VCA to reveal the surface texture, composition, and particle distribution around both the lander and rover locations and the correspondence to potential surface weathering processes.