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Enforcement of socio-economic rights of head porters in the advent of the COVID-19 pandemic in Ghana
Full text linkThe world was plunged into a global panic when the novel coronavirus (COVID-19) was declared a global pandemic in 2020, with scathing effects on all spheres of life. Its effects proved to be more devastating on vulnerable groups, such as the female migrant head porters in Ghana, locally known as ‘Kayaye’. This research examines the enforcement of the socio-economic rights of head porters during the pandemic. Central to the inquiry is whether government responses to the pandemic, particularly lockdowns, social protection measures, and public health directives, safeguarded or undermined the socio-economic rights to health and housing of this vulnerable group. The study examines the extent to which international and national legal frameworks protect these rights, as well as the effectiveness of their enforcement mechanisms. Policy responses, including the Coronavirus Alleviation Programme (CAP) and the Ghana Alleviation and Revitalization of Enterprises Support (GCARES), provided some food and personal protective aid but failed to address structural inequities. Healthcare policies did not offer direct initiatives to safeguard the head porters during this period. This study argues that the Ghanaian government's poor and incompetent crisis management has undermined the rights of head porters to the highest attainable standard of health and to adequate housing, exacerbated by preexisting gender-based disparities. It calls for a rights-based framework prioritizing inclusive social protection and participatory policymaking to safeguard marginalized groups during crises. The findings underscore the need to reconcile public health objectives with the socio-economic realities of informal workers in the post-pandemic recovery efforts and any future health emergencies.February 202
Evaluating the relationship between blubber lipids and fatty acids across blubber thickness in beluga whales (Delphinapterus leucas) harvested for subsistence in the Inuvialuit Settlement Region
Full text linkBlubber is an adapted fat layer common to marine mammals that is used for buoyancy, thermoregulation, and energy storage. Its thickness ranges widely between species, from 2.5 cm in harbour porpoises (Phocoena phocoena), up to 50 cm in bowhead whales (Balaena mysticetus). Blubber is composed of various lipids and fatty acids and is not homogenous in structure or function throughout its depth. Depletion of energy stores from environmental or nutritional stress affects blubber thickness and thus decreases its functionality and the fitness and survival of the animal. Recently, beluga whales (Delphinapterus leucas) from the Eastern Beaufort Sea (EBS) population have been observed with thinner blubber. Changes in blubber thickness and composition may reflect changes in prey availability and quality, or infection/injury of an individual, which may impact individual growth and reproduction rates, and overall population health. The composition and stratification of fatty acids and total lipid percent of EBS beluga blubber was examined and compared between individuals of differing blubber thicknesses. The influence of environmental temperature on fatty acid composition, as well as how biological covariates influence total lipid percent in the blubber and muscle tissue was also explored. Stratification of fatty acids was present, and the inner, middle, and outer blubber layers contained different proportions of fatty acid types as a function of blubber thickness. The innermost blubber layer contained more dietary fatty acids and fatty acids with higher melting points such as polyunsaturated fatty acids (PUFAs) and long-chain monounsaturated fatty acids (LCMUFAs), while the outermost blubber layer contained non-dietary fatty acids and fatty acids with lower melting points such as the short-chain monounsaturated fatty acids (SCMUFAs). The outer layers of blubber contained greater delta-9 desaturation values, demonstrating the impact that environmental temperature has on the fatty acid composition of the blubber. Whales with thinner blubber contained more SCMUFAs and fewer LCMUFAs than whales with thicker blubber, providing evidence of lower feeding rates in this subset of whales and demonstrating the altered distribution of fatty acids with lower melting points in thinner blubber in order to address environmental temperature effects. Total lipid percent was not influenced by body length, harvest location, standardized blubber thickness (body condition), or age, and was greatest in the middle layer of blubber. A significant, negative relationship was found between total lipid percent in the muscle tissue and outer blubber lipid percent, and a positive, significant relationship was found between total lipid percent in the muscle and total protein percent in the muscle. A shift in prey species distributions due to climate change is occurring in the Arctic, and thus a greater occurrence of thin beluga blubber and loss of the lipid-rich middle layer may occur. An overall reduction in thickness may render belugas vulnerable to increases in energy expenditure to maintain core body temperatures. Knowledge of beluga blubber, what factors affect its composition, and what compositional changes occur in thinner blubber is necessary to best inform conservation and management practices.February 202
Investigation of loss of synchronism phenomenon in synchronous machines and protection using trajectory of relative speed
Full text linkThe "loss of synchronism" condition in a synchronous machine is a critical state where the rotor fails to stay synchronized with the stator magnetic field. This can be caused by various factors, including system disturbances and power system instabilities. A machine undergoing a loss of synchronism may experiences torsional stresses, increased rotor iron currents and winding stresses in their mechanical systems. Synchronous machine loss of synchronism protection is employed to promptly disconnect a machine operating asynchronously to avoid damage or degradation.
This thesis explores the loss of synchronism phenomenon in synchronous generators and introduces a novel loss of synchronism detection method based on the estimated relative speed of the rotor. The proposed algorithm utilizes readily available terminal voltage, current and machine parameters to estimate the rotor speed following a disturbance. It identifies loss of synchronism condition if the estimated relative speed tends to increase during a swing cycle. This method is computationally simple, easy to implement, and faster than impedance-based techniques under certain conditions. The sensitivity and security of this method is evaluated through time-domain simulations under various power system conditions. The performance of the proposed method is also compared against well established loss of synchronism protection schemes.
The occurrence of loss of synchronism in synchronous condensers has not been extensively studied, primarily due to its rarity in traditional power systems. However, with the increasing integration of inverter-based resources and associated grid issues, synchronous condensers have become more common. The literature indicates a considerable gap in understanding the loss of synchronism phenomenon in synchronous condensers, particularly under conditions where inverter-based resources dominate the power grid. This thesis examines the loss of synchronism phenomenon in synchronous condensers, including theoretical analysis using phasor diagrams of realistic scenarios. It also investigates the distinction between loss of synchronism and the pole slipping phenomenon, which has led to failures in traditional impedance-based schemes. The proposed relative speed-based method is applied to synchronous condensers and its effectiveness is demonstrated in situations where traditional schemes have failed.
Additionally, effectiveness of the proposed method in weak grids with a high penetration of inverter-based resources is analysed using a modified IEEE 39 bus system.February 202
Advancing spatiotemporal individual-level modeling of infectious disease transmission dynamics
Full text linkThis thesis advances spatiotemporal modeling of infectious disease transmission dynamics by addressing key limitations of the Geographically Dependent Individual-Level Model (GD-ILM) framework. These limitations include reinfection, seasonal transmission, and computational inefficiency for large-scale epidemics. This work is further supported by development of two R packages. In addition, spatiotemporal analyses of Gonorrhea data from Manitoba identify persistent hotspots for targeted interventions.
First, the GD-ILM is extended within a Susceptible-Exposed-Infectious-Recovered-Susceptible framework to capture reinfection dynamics, enabling the model to estimate susceptibility to both primary infection and reinfection while preserving spatially explicit transmission patterns. Application to individual-level Tuberculosis data from Manitoba reveals significant regional and individual-level risk factors and produces fine-scale infection probability maps, providing actionable insights for public health intervention.
Second, the GD-ILM is extended to incorporate seasonally varying transmission, capturing temporal fluctuations in infection risk due to environmental, behavioral, and pathogen-driven factors. Applied to Influenza data from Manitoba, the seasonal GD-ILM identifies high-risk regions and periods, demonstrating the importance of integrating temporal dynamics into spatial models, with simulations confirming the ability to recover spatiotemporal patterns. Parameter estimation in both extensions is performed using a likelihood-based Monte Carlo Expectation Conditional Maximization algorithm.
Third, to overcome computational challenges posed by large-scale epidemics when using the GD-ILM framework, a stratified temporally-weighted Kernel Density Estimation-based Probability Proportional to Size sampling approach, combined with Stochastic Approximation Expectation Conditional Maximization, is developed, enabling efficient parameter estimation and real-time application, and is illustrated through simulations and COVID-19 data from Manitoba.
Fourth, two R packages, "GDILM.SEIRS" and "SeasEpi", are developed and made publicly available on the Comprehensive R Archive Network (CRAN) to facilitate reproducibility and practical adoption of the proposed frameworks in future spatiotemporal individual-level modeling of infectious disease transmission dynamics.
Finally, spatial, temporal, and spatiotemporal cluster detection analyses of Gonorrhea data from Manitoba identify persistent high-risk areas and time periods, guiding targeted public health interventions.May 202
The design, construction, and testing of a tuned VHF amplifier
Full text linkThis thesis deals with the design and construction of a tuned VHF amplifier. The main requirements are that optimum transducer gain must be attempted with a bandwidth of 6 MHz. Theoretical considerations such as stability, determination of optimum terminations and matching networks will be considered. The design will be carried out using a Fairchild 2N4122 bipolar transistor operating on channel 2 into a 50 olim coaxial system. We shall try to include enough qualitative discussion with a minimum of theory so that a reader with only an elementary background in electronics will be able to apply the concepts to a design of his own
Distribution of petrogenic aromatic hydrocarbons across the seawater-ice-atmosphere interface
Full text linkThe Arctic is experiencing rapid changes due to global warming, making it possible for enhanced industrial activities in the region. The increasing maritime shipping, oil and gas exploration and extraction activities, and other developments increase the risk of oil spills in ice-covered Arctic waters. Among the oil components, aromatic hydrocarbons are of particular concern due to their widely known toxic effects on marine ecosystems. The transport and fate of petrogenic aromatic hydrocarbons in Arctic sea ice are largely controlled by their physicochemical properties and sea ice dynamics. Yet, the interplay of those properties and changing sea ice conditions in the distribution of petrogenic aromatic hydrocarbons across the seawater-ice-atmosphere interface remains poorly understood. This thesis investigates the mechanisms governing the distribution of petrogenic aromatic hydrocarbons in sea ice and across the seawater-ice-atmosphere interface through a series of outdoor microcosm and mesocosm experiments. The distribution of aromatic hydrocarbons across the ice column from an encapsulated oil lens, as well as their exchange with the atmosphere and the underlying seawater, differ depending on the compound. Specifically, low-molecular-weight aromatic hydrocarbons, such as alkylbenzenes and less-substituted alkylnaphthalenes, are found to partition to air inclusions in sea ice and subsequently follow air bubble dynamics, resulting in substantial losses to the atmosphere. Moderate-molecular-weight aromatic hydrocarbons, including more-substituted alkylnaphthalenes and three-ring polycyclic aromatic hydrocarbons, preferentially dissolve in sea ice brine and subsequently migrate downward to the water column. High-molecular-weight four- to five-ring polycyclic aromatic hydrocarbons tend to interact with particulate organic matter immobilized in brine channels, resulting in their accumulation and retention in sea ice. Furthermore, it is shown that the effects of temperature and salinity on the partitioning behaviour of polycyclic aromatic hydrocarbons in sea ice and freezing seawater are substantially more complex than those at temperatures above 0℃. Overall, this thesis provides new and in-depth insights into the mechanisms and distribution pathways of petrogenic aromatic hydrocarbons with varying physicochemical properties in the sea ice environment. These results will advance and improve oil spill weathering modelling and toxicity assessment, therefore contributing to the development of a suitable oil spill response strategy in the rapidly changing Arctic Ocean.Natural Sciences and Engineering Research Council of Canada
Canada Research Chairs Program
Genome Canada
Genome PrairieFebruary 202
Freshwater influence on the hydrography and dissolved CO2 of the Northeast
Full text linkThe Northeast Greenland shelf and the associated fjords are an extremely dynamic Arctic environment. It is influenced by Arctic Ocean processes, the Greenland Ice Sheet, and the North Atlantic. In turn, any modifications that occur in the region are exported south, back into the North Atlantic. This thesis addresses some of the open questions in the region regarding regional water mass distribution, carbon
dynamics, and fjord processes.
The first research chapter presents an updated hydrography for the Northeast Greenland shelf, including observations from latitudes that were not included in previous work. We look at the sources for the water masses identified and find a clear link between the Polar Surface Water found on the Northeast Greenland shelf and the Laptev Sea region in the Siberian Arctic using geochemical tracers.
The second research chapter is an investigation of the effect of the hydrographical configuration identified in the previous chapter on the carbon system. We determine that the region can act as a source of CO2 to the atmosphere rather than a sink, challenging the prior understanding of the Northeast Greenland shelf as a strong atmospheric CO2 sink.
The third and last research chapter focuses on a mooring and novel automated stable water isotope sampler deployed, with a weather station, in a fjord linked to the Northeast Greenland shelf. After the maximum discharge occurs in autumn, driven by a change from along-shelf winds to piteraq, the salinity increases steadily.
Nonetheless, the fjord remains stratified throughout winter between depths of 11 m and 50 m, even recovering after two high salinity events. This very stably stratified water column will be exported onto the shelf, where it will add to an already highly stratified surface water identified in the first research chapter.February 202
The Global Hypophosphatasia Registry: lessons learned from a decade of real-world data
Full text linkIntroduction: Hypophosphatasia (HPP) is an inherited, metabolic, rare disease characterized by a high level of clinical heterogeneity. In response to this robust heterogeneity, the Global HPP Registry was formed to characterize the types of manifestations that patients may experience, as well as to compile information on genetic underpinnings of the disease, overall impact on patient quality of life, and safety and effectiveness of enzyme replacement therapy. The objective of this review was to synthesize key learnings gained from the Global HPP Registry, which is now in its tenth year of enrolling patients.
Methods: Registry data were analyzed to provide up-to-date information on age at diagnosis of HPP and alkaline phosphatase substrate testing. Published articles and abstracts reporting results from the registry were reviewed and summarized.
Results: Analyses showed peaks in age at diagnosis of HPP in early childhood and middle adulthood. Pyridoxal 5′-phosphate testing was performed in 18% to 61% of registry patients across geographic regions, and phosphoethanolamine testing was performed in 5% to 48% of registry patients. Published reports demonstrate that nonskeletal manifestations of HPP are an important disease feature that can affect functional outcomes. The review also reports recent findings on the genetics of HPP across a broad patient population, including heterozygous patients, and integrated literature showing that patients with HPP can have high levels of disease burden regardless of whether they present with overt skeletal manifestations or if the disease first presents in childhood or adulthood. Based on the collective findings of this review, an updated classification system for patients with HPP is proposed that incorporates a more recent understanding of the spectrum of this condition. Outcomes showing the effectiveness of enzyme replacement therapy among children and adults treated in a real-world setting are also included.
Conclusions: In summary, learnings from the past decade of the registry have improved the overall understanding of HPP in a wide patient population and may play an important role in improving disease recognition and diagnosis
From field to craft: Maya people’s gendered relations with the jipijapa palm in San Jose Village, Belize
Full text linkSeeking to create new foundations for life, the Maya of Belize continue to create economies that allow their ways of living to persist and thrive within a globalized world. The Maya have relied on their surrounding natural resources to ensure their socio-economic and cultural well-being. One natural resource that has been vital for the Maya is the jipijapa palm (Carludovica palmata). Although the jipijapa palm is commonly used as a food source, men’s and women’s interaction with it differs. Men utilize the palm for farm work, whereas women utilize it within their household work as well as for craft creation to sell on the tourism market. Although jipijapa has always had cultural value, the advent of tourism gave it monetary value, causing a shift in how Maya relate to the plant.
Tourism, the COVID-19 pandemic, and climate change are significant globalized changes that have impacted the Maya’s relationship with the jipijapa palm. Partaking in the tourism industry led to the hyper-consumption of jipijapa palms and scarcity in some villages, pressuring the remaining source in San Jose, Belize. The pandemic stagnated the jipijapa craft production, revealing its fragility and hyper-dependency on the local tourism industry. Due to climate change, in May 2024, the Toledo District experienced intense wildfires that burned for weeks, destroying numerous farms and acres of jipijapa palms.
Learning from the year’s perils, the Maya of San Jose Village seek to build a more resilient future. They aspired to engage in the international exportation of their crafts, alleviating the dependency on local tourism markets. They also aim to restore burnt farms, replant jipijapa palms, and adopt sustainable farming techniques, such as agroforestry, to protect their farmlands and the broader environment, ensuring the longevity of their natural resources in a constantly shifting world.February 202
Seasonal and under-ice dynamics of the La Grande River plume and their influence on eelgrass habitats in northeastern James Bay
Full text linkA river plume is a buoyant, freshened surface layer often turbid or colored formed by mixing river discharge with saline coastal waters. Its structure and extent are shaped by wind, tides, ice cover, and discharge variability, though plume dynamics remain less understood in seasonally ice-covered environments. Under continuous landfast ice, plumes may expand further than in open water due to reduced wind mixing but can be constrained by ice bottom topography. This thesis investigates the seasonal dynamics and short-term variability of the La Grande River (LGR) plume in relation to discharge regulation, ice conditions, and their combined influence on coastal plume extent and key ecological properties within eelgrass (Zostera marina) habitats. The LGR plume is the primary freshwater source in James Bay (subarctic Canada) during winter, and its discharge has increased due to hydroelectric development. Observations from 2016–2017 showed the under-ice plume did not expand significantly despite rising discharge since 1987. Narrowing landfast ice and coastal topography limited northward spread, while bottom-mounted moorings confirmed southward expansion despite prevailing northward currents. Persistent westerly winds lowered salinity in eelgrass embayments, indicating wind affects plume extent even when direct wind forcing is blocked by landfast ice. Two locations CH4 (north) and CH33 (south of the LGR), named after local hunting traplines, were studied for seasonal ice breakup effects on eelgrass habitat conditions. During ice cover, high discharge lowered salinity at both sites, with tidal salinity oscillations of 15 PSU at CH33 and more stable brackish conditions (1–2 PSU variation) at CH4. Ice breakup in late May–early June caused brief salinity drops and temperature increases. During open water, salinity stabilized, and temperature and photosynthetically active radiation (PAR) levels rose, initiating eelgrass growth. Site-specific differences persisted: CH33 exceeded the optimal salinity for growth (>15 PSU) 44% (ice-covered) and 89% (open water) of the time, compared to 25% and 82% at CH4. Open-water PAR exceeded the eelgrass compensation point 26% of the time at CH33 and 15% at CH4. However, CH33’s higher PAR was offset by suboptimal salinity and temperature, potentially limiting growth relative to CH4’s more stable conditions.February 202