14589 research outputs found
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Exploring an innovative fabric-based plasmonic sensor for point-of-care diagnostics
No full text1 online resource (xiii, 136 pages) : illustrations (some colour), charts (some colour), graphs (some colour)Includes abstract and appendix.Includes bibliographical references (pages 102-124).Biomarker detection at clinically relevant concentrations at the patient point-of-need remains a challenge for personalized medicine and modern diagnostics. In this thesis work, fabric-based plasmonic electrode sensors were developed and explored for the detection of sweat-based biomarkers, specifically cortisol and uric acid. Cortisol is a potential biomarker for early
identification of post-traumatic stress disorder, while elevated uric acid levels can indicate
medical conditions such as gout. In this work, Electrochemical Surface-Enhanced Raman
Spectroscopy (EC-SERS) was explored as a spectroelectrochemical tool to provide both
qualitative and quantitative results from the fabric-based sensor platform. A scalable inkjet
printing method was explored for large scale production of these sensors, and important
analytical figures of merit were determined. Finally, the launderability of these fabric-based
sensors was also assessed. Future work for this research will explore the wearability of the
devices, as well as the extension of the detectable concentration range
Nonnegative matrices and applications on stochastic process
No full textThis thesis investigates the mathematical foundations underpinning the existence of
stationary states in stochastic processes, with a focus on the role of nonnegative matrices and the Perron–Frobenius theorem. The formal study of stochastic processes began in the early 20th century, notably with Andrey Markov’s work on Markov chains, which laid the groundwork for analyzing systems that evolve probabilistically over time. The transition matrices associated with Markov chains are nonnegative and often stochastic, linking the study of stochastic processes directly to the theory of nonnegative matrices. The Perron–Frobenius theorem, which provides conditions for the existence of a dominant positive eigenvalue and a corresponding positive eigenvector for irreducible nonnegative matrices, became a central tool in proving the existence and uniqueness of stationary distributions. Originally developed in the early 1900s by Oskar Perron (1907) and later extended by Georg Frobenius (1912), this theorem has since become foundational in the mathematical analysis of long-term behavior in stochastic systems. This thesis focuses on proving the Perron–Frobenius theorem in the context of semigroups and examines how these linear algebraic tools are used to establish the existence of stationary states, highlighting their significance in modern stochastic modeling
Investigation of Resonance States in <sup>11</sup>Li
No full text1 online resource (163 pages) : colour illustrations, charts (some colour), graphs (some colour)Includes abstract and appendix.Includes bibliographical references (pages 151-163).Abstract: Halo nuclei, such as 11Li, exhibit a unique structure characterized by a few neutrons that extend far from the core, forming a diffuse neutron halo. Understanding the resonance states in 11Li is essential for exploring its exotic structure and the dynamics of its weakly bound neutrons. This thesis investigates the resonance states of 11Li using deuteron inelastic scattering experiments conducted at the IRIS facility at TRIUMF. A high-purity 11Li beam, produced via the ISOL technique, was incident on a novel solid deuterium target, and the resulting reactions were analyzed using advanced silicon and CsI(Tl) detectors to measure the energies and scattering angles of the reaction products.The analysis employed the missing mass technique, complemented by Monte Carlo simulations to model the experimental setup and suppress background contributions. This approach enabled the reliable identification of resonance states in 11Li, particularly focusing on its low-energy excitations. The enhanced resolution and precision achieved in this study address limitations of prior experiments, providing robust measurements of resonance properties. This work represents a significant contribution to understanding the structural and dynamic properties of 11Li, advancing experimental nuclear physics studies of halo nuclei.</p
A continental ichnological study across Romer’s Gap (Mississippian Period) in Southern New Brunswick: implications for the colonization of Lacustrine and Alluvial continental environments
No full textVertebrate fossils from continental environments are rare in the Misssippian Period. This
includes the interval spanning the Tournaisian and Visean stages historically known as ‘Romer’s Gap’, where the few known sites represent paleoenvironments close to open water rather than inland continental conditions. This thesis uses ichnofossils from the Mississippian-aged strata of southern New Brunswick, Canada as a proxy for biodiversity. Examination of the Horton, Sussex, and Mabou groups in the Martimes Basin has yielded diverse footprint ichnoassemblages representing the earliest-known Carboniferous tetrapods. Additionally, the latest Visean to Serpukhovian Mabou Group has yielded the oldest-known tetrapod burrows.
The sedimentological record suggests the tetrapods responsible for trackways lived within
forested wetlands on the margins of freshwater lakes and alluvial plains, thus representing the earliest colonization of continental paleoenvironments by tetrapods. Tetrapod burrowing
represents the earliest known behavioral response of the group to climate change. Trace fossils demonstrate that diverse tetrapods were already adapted for continental ecosystems earlier in the Mississippian than previously recorded, representing the oldest known
evidence for temnospondyls, anthracosaurs, and recumbirostran ‘microsaur’ lineages. Relic
Devonian-grade polydactyl tetrapods similar to whatcheerids remained within the alluvial
Kennebecasis Formation. The dryland, strongly seasonal alluvial settings of the Stilesville and Enrage formations preserve sparse tetrapod ichnofossils interpreted to have been made by anthracosaurs and recumbirostran microsaurs that were likely better-adapted to continental conditions. This study tests and mostly agrees with recently-established ichnobiochronological models for the Mississippian Period, with evidence of Valentian ichnobiochronological elements extending into the Mississippian Bluebeachian ichnobiochron, suggesting an overlap between them. The present research extends the known chronological distribution of several ichnogenera (Hylopus, Batrachichnus, Limnopus) earlier into the Tournaisian. This study also informally recognizes new tetrapod ichnofossil morphotypes that will be published as new ichnotaxa, including new trackways (‘Brachydactylopus’ and a new polydactyl trackway) and burrows (Reniformichnus ‘stringeri’ and Katarrhedrites ‘peekabooensis’)
An analysis of coastal lagoons and barriers along the Atlantic Coast of Nova Scotia, Canada
Get PDF1 online resource (vii, 66 pages) : colour illustrations, colour maps, charts (some colour), graphs (some colour)Includes abstract and appendix.Includes bibliographical references (pages 61-63).The province of Nova Scotia, Canada, is abundant with coastal landscapes and diverse
terrain; and is the chosen study area because of the coastal lagoons that exist on the Atlantic
coast. Coastal lagoons, inland waterbodies separated from the ocean by only a barrier beach, are productive and valued wetland environments for their ecosystem services and protection against shoreline erosion. This study involved the creation of an ArcGIS inventory of 873 coastal lagoons along the Atlantic coast of Nova Scotia that have intact barrier beaches. Additionally, time change analyses and cross-sectional profiles were completed for a select number of sites within the study area, to demonstrate how coastal lagoons are affected by ocean water levels rising at Nova Scotia’s rate of approximately 32 cm per century, and coastal change over time.
Results show that while many coastal lagoons exhibit sensitivity to environmental change, their rates of change vary, with some lagoons remaining relatively stable over several decades. Notably, lagoons with longer barrier beaches displayed more pronounced changes over time, particularly in response to storm surges. The study found no direct relationship between barrier beach structure (as measured by topographic profiles) and overwash frequency. However, climate-driven coastal stressors such as erosion and storm activity remain critical drivers of coastal change. This research highlights the importance of identifying and classifying coastal lagoons for land-use planning and hazard assessment. The use of historical imagery proved effective in visualizing coastal change, with room for more research as extended temporal analysis could reveal different trends. Overall, this study provides a spatial framework for understanding Nova Scotia’s coastal lagoons and why they matter in a changing climate
The role of millisecond pulsars in constraining black hole populations in globular clusters : new insights from mock data
Get PDF1 online resource (ix, 65 pages) : colour illustrations, charts (some colour), graphs (some colour)Includes abstract and appendices.Includes bibliographical references (pages 61-65).Millisecond pulsars (MSPs) are rapidly rotating neutron stars with extremely stable spin periods, which can be used to analyze the central dynamics and mass distribution of globular clusters (GCs). This thesis discusses generating mock MSP data within a simulated GC and integrating multimass equilibrium dynamical models with pulsar timing data along with traditional observables to analyze the mass distribution and remnant populations in GCs. The simulated MSP observations are drawn from a selected Cluster Monte Carlo (CMC) model, with pulsar positions sampled based on the distribution of neutron stars. By analyzing the contributions from the GC’s gravitational potential to MSP spin and orbital period derivatives, we aim to quantify how pulsar timing observations can influence the precision and accuracy of inferred populations of stellar-mass black holes (BHs) at the cluster core. We include different realizations of mock datasets with an increasing number of pulsars in the core of the cluster in a simulated GC. As the number of pulsars in the mock dataset increases, the population of black holes (BHs) becomes better constrained and uncertainies are more reliable. Using 25 mock pulsar realizations, we constrain the mass fraction of BHs in the cluster to 0.61%-0.90%, with reduced uncertainty. This range is closely aligned with the value
derived from the CMC snapshot (0.89%), demonstrating the consistency of the process. We also investigated the real globular cluster M62 with its pulsar timing data, where we fit multimass models under different assumptions about the cluster’s heliocentric distance, evaluating fits both with and without pulsar data. The results are compared to assess how effectively pulsar timing data constrain the BH population in the cluster. Given the large number of new pulsars expected to be discovered in GCs with upcoming radio telescopes and surveys, our tests with fitting dynamical models to data that includes pulsar timing measurements for constraining BH populations in GCs will help future studies of GCs
Investigating the velocity dependence correction for charge determination of isotopes
Get PDF1 online resource (x, 57 pages) : colour illustrations, charts (some colour), graphs (some colour)Includes abstract.Includes bibliographical references (pages 55-57).Neutron-rich nuclei are reshaping our understanding of the nucleus and provide information on neutron-rich matter in our universe. As more neutrons are added to a nucleus, exotic features such as neutron skins and halos emerge, challenging the standard nuclear shell model. These phenomena have led to gaps in knowledge surrounding the shell model for neutron-rich nuclei with appearances, and disappearances, of traditional shell closures, known as magic numbers. Calcium isotopes provide a unique insight when studying the nuclear shell model and its evolution in neutron-rich nuclei. Two of its stable isotopes, 40Ca and 48Ca, are doubly magic nuclei, while its more exotic isotopes have sparked interest with potential new shell closures in 52Ca and 54Ca. To investigate these nuclei, 48Ca - 55Ca were studied at RIKEN Radioactive Beam Facility, where a 70Zn beam was fragmented at 345 MeV/nucleon on a 9Be target, the nuclei then underwent in-flight selection and identification using the BigRIPS separator and ZeroDegree spectrometer. Properly identifying these nuclei is crucial for accurate analysis. Within the field, di!erent functional dependences of velocity are used to determine a nucleus’s proton number. This work examines iii these di!erent functional dependences of velocity and determines which provides the most accurate atomic number identification translation from a stable Ca isotope to neutron-rich ones, as well as for other elements.</p
Fourth downs decoded : a predictive and causal analysis of player impact and decision making in the NFL
Get PDF1 online resource (37 pages) : colour illustrations, charts (some colour), graphs (some colour)Includes abstract.Includes bibliographical references (pages 35-37).This research breaks down fourth downs in the NFL by identifying crucial player positions and evaluating how coaches incorporate different factors in their decision-making process. Using a newly engineered dataset that incorporated detailed player statistics from 2017-2023, we analyze the causal and predictive factors influencing fourth down decisions and outcomes.
Our Generalized Inverse Mills Ratio reveals coaches factor in unobserved variables during
fourth down decisions that can predict the likelihood of a fourth down conversion. However
certain player archetypes, such as quarterbacks that excel in short passes, are not properly
evaluated. We find significant impacts from other specific player positions, with offensive
linemen showing strong joint significance on conversion but not on coaching decisions. The
findings provide actionable insights for NFL coaches to identify key signals in fourth down
situations and optimize player selection and team build for these critical plays
Creating community : transient denizens of the city that stands for less than 4% of the year
Get PDF1online resource (iii, 61 pages) : illustrations (some colour)Includes abstract and appendices.Includes bibliographical references (pages 48-53).Burning Man, a yearly arts and culture event in the Nevadan desert, has attracted a dedicated community which upholds the event by dedicating volunteer time and maintaining
social connections outside of the event. Its participants come from around the world, bringing
with them a diverse set of experiences, skills, and views, creating participant-run activities which often take on a ritual quality. Additionally, the event itself is centered around the ritual of
burning a large human effigy. I seek to investigate what manner of ritual activities occur at
Burning Man and how those rituals bring people together to form community by drawing on my ethnographic data, Burning Man’s history, and comparisons to community formation among pyrotechnic installments and monumental building, guided by various theoretical models of community, including Erving Goffman’s mutual openness and focused interaction, Victor Turner’s communitas and rites of passage, and Hakim Bey’s transient autonomous zones. By examining Burning Man as a case study of community formation, I explore how group ritual activities at Burning Man generate social bonds among participants as they work together to cocreate the event. This provides insight into the mechanisms which have formed, and continue to form, communities around the world and throughout human history
When to stay and when to go? the determinants and benefits of mate and nestbox retention in an urban population of European Starlings (Sturnus vulgaris)
Get PDF1 online resource (79 pages) : colour graphsIncludes abstracts.Includes bibliographical references (pages 17-20, 38-41, 57-58, 71-73, 78-79).Following the breeding season, individuals must decide if they should they stay with their
partner and stay within their territory in the subsequent season. To test why mate and site
retention occurs and if retention provides any benefits, a population of European Starlings
(Sturnus vulgaris) with over a decade of breeding data (2007 to 2025) was used to examine the frequency of mate and nestbox retention and if condition, and measures of both reproductive success and parental investment were associated with retention. Mate retention frequency was 48.8% and brood condition tended to be higher in broods preceding mate retention. In pairs that bred together for longer periods of time saw no significant benefits from doing so. Nestbox retention frequency was 43.8% and females tended to retain their nestboxes more frequently than males, and nestbox retention was positively correlated with mate retention