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A comparison of autoencoders and variational autoencoders for anomaly detection in dermoscopic images
No full textEarly detection and diagnosis of skin abnormalities are crucial for effective treatment and management of skin diseases. This paper explores the application of deep learning techniques for skin tissue analysis, focusing on the detection of abnormalities from dermoscopic images. Unsupervised learning methods such as Autoencoders (AE) and Variational Autoencoders (VAE) save resources by eliminating the need for labeled data, making them more efficient and scalable than supervised learning. We compare the performance of AE and VAE architectures in developing a robust model capable of distinguishing between benign and malignant skin lesions.This study uses the HAM10000 dataset of 10,015 dermoscopic images, divided into seven classes that represent benign and malignant diagnostic categories. The dataset was split into benign (normal) and malignant (anomalous) cases. The models were trained to learn features of the normal data and generate reconstructions of these images. The reconstruction error indicates how accurately the model interprets the image features. An optimal decision boundary is chosen to classify images as benign or malignant based on their reconstruction error.The AE and VAE models were evaluated using accuracy, F1-score, and False Negative Rate (FNR). Minimizing FNR is crucial in healthcare as it indicates missed malignant cases. Experimental results, averaged over 30 training runs, demonstrate that the AE outperforms the VAE in accuracy (71.84% vs. 67.79%), F1-score (73.03% vs. 67.33%), and FNR (23.76% vs. 33.58%). These findings suggest that the AE architecture is promising for automated skin cancer detection, which can lead to more accurate and timely diagnoses and improved patient outcomes.</p
Sexuality education: the experiences of teachers, grades 5-9, when instructing sexual health curriculum to youth in PEI
No full textThe aim of this interpretive study is to understand the experiences of school-based sexuality educators in Prince Edward Island when teaching sexual health curriculum to youth, grades 5-9. Specifically, this study explores teachers’ affective experiences when instructing the sexual health curriculum to students, including the responses from students to the curriculum, as well as the supports and hindrances teachers encountered within the provincial setting and school system. The central research focus of this research is to examine the experiences of educators when teaching sexuality education within the current political and social context and school system of Prince Edward Island. Data were collected from twelve educators who had previously instructed the sexual health curriculum to grades five to nine students through the use of semi-structured interviews, a focus group, and reflective written responses to meet the aims of this research inquiry. Participants commonly observed a marked increase in openness to sexual and gender diversity among their students and noted how important they perceive sexuality education to be in their students’ lives. Several participants shared the perception that increased mentorship and professional learning are important for teachers who are new to the subject; those with experience generally expressed feeling comfortable discussing sexuality and gender with students. The data in this study demonstrate that while intermediate (Grades 7, 8, 9) educators deem the new integrated sexual and health curriculum to be appropriate for their students, they also identify gaps and oversights, as well as a general sense of an under-valuing of sexuality education within the broader school curriculum. Implications of the study’s findings are addressed, and practical recommendations offered for ways to strengthen sexuality education programs in the future.</p
Arthropods in mature eastern hemlock forests: assessing the non-target effects of basal bark imidacloprid application for control of hemlock woolly adelgid on forest floor and canopy arthropod fauna in southwestern Nova Scotia
No full textAs the invasive and highly destructive hemlock woolly adelgid (Adelges tsugae) continues its spread northwards into Nova Scotia, the province’s stands of eastern hemlock (Tsuga canadensis) face an ever-mounting threat to their long-term survival. As one of the largest and longest-lived trees occurring in the Canadian Maritimes, eastern hemlock stands comprise a foundational component of one of the region’s climax forest types, providing crucial ecosystem services for innumerable forest flora and fauna. Given the tree’s significance to local ecology, conservation practitioners in the province are implementing measures to control populations of A. tsugae, including application of neonicotinoid insecticides, like imidacloprid. Until recently, imidacloprid treatments to control hemlock woolly adelgid in Nova Scotia were limited to stem injection. To achieve faster and more economical control of A. tsugae, however, some local conservation practitioners are pivoting to basal bark application of the chemical. Spray application of imidacloprid raises concerns about potential harmful impacts to non-target arthropods inhabiting local treated hemlock stands. To address these concerns, we sampled a diverse range of arthropods inhabiting the forest floor and the subcanopy and canopy layers both before and after localized basal bark application of imidacloprid, as well as in nearby untreated stands. For our sampling, we used both passive pitfall trapping and baited Lindgren funnel trapping to sample terrestrial and canopy biodiversity. For both trap types, the most abundant taxa captured (representing 33 arthropod clades) were identified and analyzed for changes in their abundance that were characterised by a treatment and year interaction. While we identified a significant decline in the abundance of one of our target groups linked to imidacloprid treatment, spine-waisted ants (Aphaenogaster spp.), we also identified a significant decline in the abundance of two groups (the ground beetle Synuchus impunctatus and the striped ambrosia beetle Trypodendron lineatum) in plots that did not receive imidacloprid treatment. At a broader family level, several interannual and inter-site differences in taxon diversity and composition not related to imidacloprid treatment were also identified, particularly for the ground beetles (Carabidae), longhorn beetles (Cerambycidae) and true weevils (Curculioindae). While the drivers of this treatment-independent variation are unknown, they may correlate with advanced hemlock canopy decline caused by hemlock woolly adelgid. Further investigation into imidacloprid’s potential to yield non-target effects on local arthropods is warranted, particularly on spine-waisted ants. Further study is also warranted to better understand the ecological implications of eastern hemlock decline and canopy loss driven by hemlock woolly adelgid infestation, especially in a Nova Scotian context.</p
Formulations to deliver cannabidiol and psilocybin for the treatment of neuropsychiatric disorders
No full textAnxiety and depression are the two most common neuropsychiatric disorders worldwide, affecting an estimated 284- and 264-million people, respectively, per year as of 2018. The current medications available to treat these disorders (e.g., benzodiazepines, selective serotonin reuptake inhibitors) have a low rate of response with numerous unpleasant side effects (i.e., heart problems, suicidal ideation, insomnia, memory loss). Despite this, very few new treatment options have come to the market in the last twenty years.Cannabidiol (CBD) and psilocybin have both recently been investigated as potential treatment agents. CBD and psilocybin are both natural products of which research has shown promise for their use to treat several diseases. This project, developed in partnership with Halucenex Life Sciences Inc. (Windsor, NS, CA), aimed to formulate a drug delivery vehicle containing CBD, psilocybin, and a combination of the two using several emulsification and encapsulation techniques. It is hypothesized that combining CBD and psilocybin will allow them to work synergistically, enhancing their effects. The encapsulation of active ingredients in a suitable wall material allows for protection from degradation, enhances adsorption in the body, increases the stability and shelf-life of the product, and allows for a controlled release of the active pharmaceutical ingredients.Progesterone was used in preliminary experiments as a proxy for CBD, whereas 5-hydroxytryptophan (5-HTP) or tryptophan were used as proxies for psilocybin. The techniques explored included inverse gelation and external gelation, as well as powder complexes and Pickering emulsions. The original inverse gelation method was not successful, and thus no data is reported. A second version of the inverse gelation method, as well as the external gelation method, were successful and yielded gel-like spheres loaded with the active ingredient. The emulsions were analyzed to determine their zeta potential, size, and polydispersity index (PDI). The active ingredient was re-extracted from the gels and analyzed with High Performance Liquid Chromatography (HPLC) to determine their encapsulation efficiencies.The most promising methods for each active pharmaceutical ingredient were determined to be (1) External Gelation for progesterone (EE% = 33 ± 5), (2) Physical Mixture/External Gelation for CBD (EE% = 48 ± 10), (3) UV for 5-HTP (EE% = 42), (4) UV for tryptophan (EE% = 1.4 ± 0.3), and (5) [5:5] [EMULSION:ALGINATE] for the double encapsulation of CBD and tryptophan (EE% = 61 ± 8). These results suggest that the combination of the tested active ingredients may be enhancing their effects and allowing them to work synergistically. However, more studies must be done (specifically with CBD:psilocybin) to confirm.</p
Further observations and preliminary modeling of the eclipsing binary star V552 Cassiopeia
No full textV552 Cassiopeia is an eclipsing binary star system located in the constellation Cassiopeia that, prior to the work presented in this thesis, had not been extensively studied. This thesis outlines the work done to make further observations of the system, and determine the absolute magnitude, luminosity, radii, and semimajor axis of the system for the first time. In addition to Acadia observations, data from the ASAS-SN, TESS, and Gaia missions were used to find the inclination, temperature ratio, and radius ratio using an optimization program written in Python. The components of the star system were placed on a Hertzsprung–Russel diagram, along the subgiants branch, and a mesh model was produced using Binary Maker 3.</p
A pilot study of physical literacy programming for individuals with disabilities
No full textIndividuals with disabilities do not engage in sufficient physical activity due, in part, to decreased opportunities and barriers to participation. Physical activity is theorized to be positively connected to physical literacy, yet individuals with disabilities are often excluded from current research surrounding physical literacy. To help fill this gap, the current pilot study examined the impact of the Acadia University S.M.I.L.E. program on the subjective and objective physical literacy scores of its’ participants. The feasibility of implementing these assessments during a program day was also explored. Physical literacy was assessed at pre- and post-assessment using the PLAYbasic (completed by the participant) and the PL-C Quest (completed by the participant and their caregiver). The study included 32 participants (age range = 6-39 years, mean age = 17 years; 62.5% male) with a range of developmental, physical, and sensory disabilities. Paired samples t-test were used to examine changes from pre- to postassessment. The results indicated statistically significant improvements (p < .05) with large effect sizes in overall PLAYbasic scores, as well as in the five item scores. No significant changes (p > .05) were noted in the PL-C Quest scores of either the participants or their caregivers. The implementation of these assessments throughout the programming day was shown to be feasible with large percentages of participation in all assessments. Further work will include this pilot study in a three-year longitudinal study that will assess the strength and directionality of the relationships between physical literacy, physical activity, and health among the participants.</p
Spectral analysis and classification of ore and ore-adjacent rocks of the Windsor Group at Walton, Nova Scotia
No full textThe Maritimes Basin, a vast sedimentary basement extending from the Gulf of Maine to the Grand Banks of Newfoundland, has been the focus of geological research due to its complex geological history. Within this basin lies the structurally complex Windsor-Kennetcook subbasin, characterized by sedimentary successions later deformed during tectonism. The Windsor-Kennetcook subbasin is where the historic Walton barite mine, the area of interest for this thesis, is located. The Walton mine was operational from 1941 to 1978 and produced significant quantities of valuable commodities such as barite, copper, zinc, lead, and silver. The Walton deposit is characterized by a barite orebody with a mineralized sulphide halo.This thesis aims to investigate the mineralogical variability of the Walton deposit and its surrounding rocks using hyperspectral imaging. Hyperspectral imaging was used to analyze select drill core from the mine area, with a focus on identifying minerals of interest. This methodology aims to complement existing drill core logging techniques and improve the understanding of hydrothermal type deposits.</p
The default body in Frances Hodgson Burnett's The Secret Garden (1911) and Jean Little's Mine for Keeps (1962)
No full textThis research examines the representation of children with disabilities in Frances Hodgson Burnett’s The Secret Garden (1911) and Jean Little’s Mine for Keeps (1962) to determine how both books perpetuate the concept of the default body. In doing so, I demonstrate how, despite being more modern, Mine for Keeps perpetuates the default body through its preferential depiction of whiteness, thinness, and ability. By “default body,” I am referring to aspects of the characters' bodies that are treated as the “norm,” such as whiteness, thinness, and non-disabled-ness. While The Secret Garden and Mine for Keeps each portray a disabled character, the representation of disability works to emphasize those characters’ differences rather than to normalize them. For instance, Mine for Keeps develops the concept of the default body through its representation of Sal, her family, and her friends as white, thin, conventionally attractive characters even as it centres Sal’s experience of cerebral palsy. These representations of the body in Mine for Keeps mirror those in The Secret Garden, since all non-disabled characters are white, thin, English-speaking, and non-disabled. The similarities in the representation of bodies in The Secret Garden and Mine for Keeps works to undermine the ostensible goal of achieving non-disabled-ness in The Secret Garden and of normalization of disability in Mine for Keeps. I focus on The Secret Garden and Mine for Keeps and how, despite visibility and some improvements in disability representation from The Secret Garden, Little’s novel still prioritizes the default body in the same way Burnett’s does.</p
Expression of MMP and TIMP genes in the common sea star, Asterias rubens, congruent with the onset of sea star wasting syndrome
No full textSea stars are a keystone predator species, filling an essential niche in ecosystems across the globe. Sea Star Wasting Syndrome (SSWS)- a suite of loosely defined characteristics which lead to changes in behaviour, followed by the development of a ‘melting’ phenotype. SSWS has been documented in numerous populations and has been observed occurring over the past century. The 2013 event was the most extreme. Both sub-tidal and benthic sea star populations in the North American Pacific coast have been decimated by the current epidemic. The causative agent of SSWS is unknown, as are the future implications of SSWS on marine ecosystems. This paper proposes a potential mechanism by which sea stars may be self-digesting Mutable collagenous tissue (MCT) via matrix metalloproteinase (MMP) activity. In this study, sixteen sea stars of A. rubens were collected and housed in saltwater aquaria, where they were exposed to a shock event in which the salinity was lowered to 5PSU, drastically lower than the preferred salinity of 25-30PSU. Endpoint PCR was used to determine the presence/absence of MMPs and their inhibitors (TIMPs) within the coelomic fluid before and after the stressful event. Results indicate that wasting has little effect on the expression of MMPs 2 and 13. There was a statistically significant reduction in the number of individuals expressing the MMP inhibitor, TIMP 2, in concert with the emergence of the wasting phenotype. These results demonstrate the importance of TIMP and MMP gene regulation in SSWS.</p
Synthesis of a series of novel γ- and δ- Ketoanilides
No full textKetoanilides have the potential to serve as valuable starting materials to make many structurally complex heterocyclic systems owing to their ability to form cyclic N-acyliminium ions and tertiary enamides.The goal of this research was to synthesize several γ- and δ- ketoanilides from appropriate keto acids and anilines. As stated before, the purpose of their synthesis is to explore novel chemical transformations leading to interesting polyheterocyclic skeletons in separate endeavors. Through a condensation reaction with a keto acid such as levunic acid and substituted anilines enabled by a carbodiimide, ketoanilides can be formed. Following this protocol, fourteen ketoanilide analogs were synthesized. These compounds were purified, and thoroughly characterized via spectroscopic means.</p