Mount Allison University Digital Repository
Not a member yet
368 research outputs found
Sort by
Designing and simulating wavelength shifting geometry in an active helium target
Get PDFScalar polarizabilities are fundamental characteristics closely related to the internal structure of nucleons. While the polarizabilities of the proton have been well studied, the neutron remains elusive due to the lack of a free-neutron target. Based at the Institute for Nuclear Physics in Germany, the A2 Collaboration has proposed a new active helium target filled with helium isotopes that would allow better access to the neutron. This design would allow for the collection of scintillation light within the active volume, which would reduce backgrounds. The blast of photons emitted from each collision are in the vacuum ultraviolet, while the silicon photomultipliers used only detect in the 200 { 900 nm range. Thus, a wavelength shifting material is needed. This research examines potential configurations of wavelength shifting fibers to be placed within the target and simulates the light collection and output of each design. Monte Carlo and Geant4 simulations were carried out to compare scintillation light collection between potential wavelength shifter geometries. The results of this work, along with future analysis, will provide integral insight for building the next prototype. Once the target is built, the neutron scalar polarizabilities can be applied
to help explain quantum chromodynamics in the non-perturbative region
The effects of hypoxia on ketone body metabolism and cardiac function in the shortnose sturgeon (Acipenser brevirostrum)
Get PDFThe goal of this study is to understand the effects of chronic hypoxia on ketone body metabolism and cardiac function in shortnose sturgeon (Acipenser brevirostrum) by comparing three different treatment groups: control, chronic hypoxia and starved. Sturgeon will be exposed to either normoxic conditions, DO saturation of 2.75 mg/L, or will be deprived of food as a positive control for ketogenesis (Furné et al., 2012) for 10 days (Secor and Gunderson, 1998). In all 3 treatment groups, ketone body production in the liver, circulating ketones in plasma, and ketone oxidation in cardiac and skeletal muscle will be measured to determine if there is a ketogenic response. In addition, cardiac muscle force production will be measured using either ketone bodies or glucose as a supplemental fuel to determine if ketone bodies can support force production in hearts from each treatment group.
I hypothesize that chronic hypoxia will elicit a ketogenic response in shortnose sturgeon. I predict that (1) ketone production in the liver will increase after being exposed to the hypoxic environment for 10 days in comparison to the starved group and (2) that there will be an increase ketolytic enzyme activity in the heart after the hypoxic exposure, which will help maintain cardiac contractility. The results obtained from this experiment will help lead to an understanding as to how vertebrates respond to environmental stress through changes in substrate use and mitochondrial function
Di kale: The bride
Get PDFQueer Jewish politics has utilized a depressive framework of moral injury as well as an
understanding of the past that is rooted in nostalgia. This has bound queer Jewishness to the
heterosexual and cisgender structures that harm it. Simultaneously, academic work on queer
Jews has either been ethnographic or confined to the queering of Jewish history. In this
multimedia work that is both written and quilted, I turn to the marginalized practices of the
past, contemporary queer theory, and Jewish mysticism in order to find a reparative praxis for
today. That practice is craft. Craft not only has its roots in queer and Jewish tradition but
creates a space outside of time under which liberation becomes imaginable
Dangerous worlds seen from 2021: American science fiction literature and the Vietnam War
Get PDFThis thesis analyzes the unique militarism within Vietnam War era American science fiction literature. Science fiction is a powerful lens to observe American militarism because science fiction spoke the same language as American politicians and military leaders during the Vietnam war period. Many of the themes, character tropes, symbols, and narrative structures that society generally regards as singularly belonging to the pages of science fiction are actually part of America’s mythology during the Vietnam war. In many respects, the stories of American science fiction are as important as the “city upon a hill” and Manifest Destiny myths to understanding America as an nation, project, and idea. There are so many ideas shared between American science fiction authors and the politicians and military leaders of the United States during the Vietnam War. Because there was so much scientific advancement that occurred between WWII and the start of the Cold War, traditional narrative techniques like journalism that spoke in terms of realism often inadequately addressed topics like technology, warfare and international conflicts. American science fiction literature, whether it supported the Vietnam war or found it immoral and expensive, almost never underestimated America’s actual technological abilities or aggressive foreign policy. During the Vietnam war, American science fiction culture either served as propaganda for the U.S. State, reflecting and cultivating support for America’s doctrine of conquest, or it was politically aware, and stood in opposition to the American war machine. Broadly speaking, American science fiction of the Vietnam war period era articulated either criticism or adulation for America’s techno-fetishism, its cults of the superweapon and the super-soldier, and its resolution to expand its economic influence and geographic jurisdiction
Is the Colavita effect replicable in an online study?
Get PDFProper functioning in a multimodal environment requires us to be able to bind our senses into a coherent perception of the world. The Colavita effect is an instance of multisensory competition whereby we prioritize visual information over auditory information when they are presented simultaneously. Past research has shown the Colavita effect to be a robust phenomenon through resistance to several experimental manipulations. In recent years, researchers have opted to migrate many psychological
studies to online platforms. However, studies of cognitive phenomena present a particular challenge due to their reliance on strict environmental controls. I aimed to examine if the Colavita visual dominance effect would be replicable in an online study. Participants completed a Colavita protocol online and remotely where they were asked to respond to the modality of unimodal (auditory, visual) and bimodal (audiovisual)
stimuli. Bayesian analyses revealed that participants did not respond preferentially to the visual component of audiovisual stimuli, and thus did not show evidence for a Colavita effect. Given past success in finding evidence for visual dominance in traditional laboratory settings and robustness in the literature, the absence of the Colavita effect is likely attributable to both the change in environment and variation in environment between participants
Development of xenotransplantation models for sturgeon germplasm: Zebrafish (danio rerio)
Get PDFSturgeon are the most endangered vertebrate group in the world (IUCN 2016). Sturgeon are endangered due to anthropogenic factors such as overfishing, industrial activity, and harvesting for their caviar (Pikitch et al. 2005). Xenotransplantation is a model for conservation of endangered sturgeon species, but has not yet been performed between a sturgeon donor and a teleost recipient. The goal of this study was to create sterile triploid surrogates. Zebrafish (Danio rerio) were used as model organisms to lay the foundation for the xenotransplantation process for shortnose sturgeon (Acipenser brevirostrum) germplasm to blue tilapia (Oreochromis aureus) surrogates. Triploid induction was tested using a heat shock method. Indicators of ploidy were examined using erythrocyte imaging and larval morphology analysis. A linear discriminant analysis was run on larval morphology traits to discriminate between 14-day old heat shock and non-heat shock larvae. As well, reanimated cryopreserved sturgeon gonad tissue was dissociated and run through a Percoll gradient to determine gonad cell isolation. A t-test revealed a significant difference in survival between heat shock and non heat shock zebrafish embryos at 24 hours post fertilization (t = 15.649, df = 4, p-value = 9.739e-05). Survival was significantly greater for the non-heat shock group compared to the heat shock group. The linear discriminant analysis reported discrimination between the heat shock versus non heat shock zebrafish embryos with an accuracy of 80%. Sturgeon cells were dissociated and colonized the top three Percoll gradient layers. The methodology employed in this study is essential to the research on sturgeon germline chimerism. More specifically, my study contributes to the production of triploid surrogates for transplantation of sturgeon oogonial cells in order to preserve valuable genetic information that is at risk of extinction
The robot cleaning problem: A graphical representation
Get PDFSuppose there is a building with many different hallways and a robot vacuum that cleans the building. Each hallway has a time stamp with the last time the hallway was cleaned. The robot cleans the hallways using a greedy algorithm: at each step, the robot looks at the neighbouring hallways and traverses the dirtiest (i.e. the one that hasn't been cleaned in the longest time). We will find the bounds for the minimum number of steps, s(G), the robot takes to clean every edge of a graph G such as: bipartite, tripartite, and multipartite graphs. We will define what it means for a graph to be weakly self-stabilizing, and show that by connecting two weakly/self-stabilizing graphs may result in a weakly self-stabilizing graph. Lastly,
we will introduce throttling: the trade-off in cost between adding more robots to a graph and reducing the number of steps to clean the graph
"Am I normal?" An analysis of adult sex education through interviews with sex educators
Get PDFResearch and discussion about sex education almost exclusively focused on sex education of children and teens; however, there is an increasing amount of sex education aimed at adults. Despite its growing popularity, few studies have explored adult sex education from a pedagogical perspective. With educators ranging from Instagram sex ed influencers to dominatrix-led kink workshops to church-based sex education courses, adult sex education has solidified its place in modern society. The current study sought to investigate adult sex education from the perspective of the educators in order to better understand the work that they do, as well as the clients they serve. Seventeen sex educators from Canada, the United States, and the United Kingdom participated in this study. Five themes were identified as part of this
sample. This included normalcy, communication, shame, past sex education, sex education beyond heteronormativity, and empowerment. The results of this study help to outline the information sought from adult sex education, as well as inform gaps in mainstream sex education
Nocturnal and diurnal feeding behaviour of migratory shorebirds at a Northumberland Strait stopover site
Get PDFNocturnal feeding is known to occur in several species of shorebirds, particularly in tidal environments. This behaviour is thought to be done either out of necessity – because energy from food cannot be sufficiently gained at other times of day – or out of preference – because it is advantageous to feed at night compared to other times of day. In Atlantic Canada, Semipalmated Sandpipers (Calidris pusilla)
feed nocturnally in the Bay of Fundy, a stopover site used during their summer migration. These nocturnally feeding birds are known to make use of a tactile feeding behaviour known as skimming, common amongst sandpiper species. While the Bay of Fundy is known to host hundreds of thousands of Semipalmated Sandpipers each year, other stopover sites in Atlantic Canada host more diverse shorebird populations. Several species of shorebird are known to feed during stopover in the Northumberland
Strait, however, there is a lack of research how these birds feed at night. We examined feeding behaviour, including foraging (pecking and probing) and skimming, of Semipalmated Sandpipers, White-Rumped Sandpipers (Calidris fusciocollis), and Semipalmated Plovers (Charadrius semipalmatus) during the day, evening, and night at Petit-Cap Beach, New Brunswick. We compared foraging rates and skim times
across species and time periods, and determined the predictors behind these behaviours, to understand what drives nocturnal feeding. At night, we found that Semipalmated Sandpipers skimmed more than White-Rumped Sandpipers, and seemed to switch from foraging to skimming more quickly. Both species foraged more and skimmed less when moon illumination was high, though White-Rumped Sandpiper foraging and skimming were more influenced by polychaete abundance. Semipalmated Plovers did
not feed at night, and had the lowest foraging rates during the day and evening. We found that birds that are capable of skimming will feed at night and make use of this behaviour, meaning that skimming ability of individual species likely plays some role in driving nocturnal feeding. As these skimming birds were also longer-distance migrants, we cannot rule out the energetic demand of migration as a driving force
behind nocturnal feeding as well. These findings suggest birds may feed nocturnally for both necessary and preferential reasons, broadening our understanding of the drivers behind nocturnal feeding in the Northumberland Strai