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Unveiling Gender Disparities in Urban Pakistan’s Higher Education
No full textThis literature review examines persistent gender disparities in urban Pakistan’s higher education, highlighting socio-cultural, economic, and institutional barriers restricting women’s academic and professional mobility. Despite increased female enrollment, patriarchal norms, mobility constraints, financial dependence, and discriminatory structures hinder full participation in education and the workforce. Using frameworks of distributive and recognition-based justice (Hennessy, 1999; Höffe, 2013; Young & Allen, 2011) and intersectionality (Crenshaw et al., 2021; Collins, 2019), the paper explores how systemic exclusions intersect with class, gendered expectations, and policy inefficiencies.
Findings reveal although Pakistan’s National Education Policy promotes gender equity, implementation remains weak due to systemic neglect and resistance. Women employ diverse strategies—from negotiation to activism—to navigate constraints, but resilience alone cannot counter structural inequities. The review calls for targeted reforms, including policy interventions for gender equity in higher education, gender-sensitive institutional reforms, economic incentives and support mechanisms and bridging the policy-practice gap. Without dismantling entrenched barriers, higher education will remain an incomplete path to empowerment rather than a transformative force for equity and mobility
Harnessing Ultraviolet Light to Generate Virtual Histopathology
No full textCancer is one of the leading causes of death worldwide. In dealing with solid cancers, the recommended treatment is often surgery, where the cancerous tissue is surgically resected from the patient while conserving as much healthy tissue as possible. During tumor resection operations, surgeons are currently unable to assess the extent of tumor outside of visual or tactile feedback. Consequently, postoperative analysis of resected specimens is required to ensure the complete removal of the tumor. The gold standard for tissue analysis involves formalin-fixation, paraffin-embedding, and sectioning of tissues before being stained with hematoxylin and eosin (H&E) and then imaged using white light brightfield microscopy. Unfortunately, these tissue processing steps are both time consuming and labor intensive and thus cannot be performed intraoperatively to provide direct feedback to surgeons. Hence, in cases where can- cerous tissues are missed, patients must undergo secondary surgeries which leads to unnecessary emotional and physical trauma for the patients, as well as higher risks of worsened prognosis, in addition to a greater economic burden on the healthcare system. Accordingly, there is an unmet need to develop technologies that are capable of providing tissue analysis, comparable to the gold standard, within intraoperative time frames. Here we report the progress of developing such technologies starting from first better characterizing photoacoustic remote sensing (PARS) mechanisms and generating a more reliable ultraviolet source for PARS microscopy. Next, PARS microscopy is utilized in conjunction with ultraviolet (UV) scattering microscopy to generate virtual H&E histology. By introducing deep learning, this work is then expanded to convert two-channel PARS and UV scattering images into a single maximally realistic H&E virtual histology image that is best suited to pathologist interpretation. Through pathologist reader studies, this approach was found to achieve sensitivity and specificity values of 0.96 and 0.91 in breast tissues and 0.87 and 0.94 in prostate tissues, respectively, while also being preferred overall in comparison to frozen section analysis. Moreover, quantitative metric analysis showed strong agreement between this virtual histology technique and the gold standard. This deep learning-enabled virtual histology approach is then extended to generating additional structural and metabolic contrast in tissues by collecting inherent autofluorescence emission generated by the UV excitation. Optical redox ratio (ORR) is measured in tissue samples, supplementing virtual histology with key insights into tissue metabolism. ORR measurements are validated in both cell cultures and tissues, and in consultation with pathologists are found to provide useful diagnostic guidance. Lastly, deep learning is utilized in conjunction with UV excited autofluorescence, DRAQ5 fluorescence and UV reflectance contrast to focus on generating virtual histology label-free in freshly excised tissues using only a single UV excitation wavelength. Overall, given the rapid image acquisition times, high resolution, tight depth sectioning, capability in imaging freshly excised tissues, and realistic virtual histology output generated, this work has a real potential to find a place in providing intraoperative guidance to surgeons during tumor resection surgeries
Cultivar mixtures for the management of Plasmodiophora brassicae in canola
No full textClubroot, caused by the obligate parasite Plasmodiophora brassicae, is a major soilborne disease affecting canola (Brassica napus, oilseed rape) and other brassicas in Canada and worldwide. Disease management largely depends on the use of clubroot-resistant canola cultivars. However, the extensive cultivation of resistant varieties has led to the emergence of resistance-breaking pathotypes of P. brassicae. In this study, mixtures of the susceptible (S) canola cultivar ‘Westar’ and the resistant (R) cultivar ‘P501L’ in various ratios (R monocrop, 1S:9R, 1S:3R, 1S:1R, 3S:1R, and S monocrop) were evaluated for their effects on P. brassicae virulence, pathotype composition, and resting spore production over multiple cultivation cycles. Briefly, the cultivar mixtures were grown in a potting medium inoculated with either a field isolate representing P. brassicae pathotype 3H or a combination of single-spore isolates of pathotypes 3D and 3H in a 1:9 ratio, over three consecutive 7-week cycles under greenhouse conditions. Clubroot severity was assessed at the end of each cycle, and in planta P. brassicae resting spore production was quantified using microscopy. The concentration of resting spores remaining in the potting medium was determined through quantitative PCR analysis. The virulence of P. brassicae populations recovered from each treatment was evaluated on selected hosts of the Canadian Clubroot Differential (CCD) after the first two cultivation cycles, while pathotype designation and full virulence assessments were conducted on the complete CCD set after the third cycle. The cultivar mixtures showed lower clubroot severity and resting spore production compared to susceptible monocrops but were less effective compared to a resistant monocrop. No interactions were observed between the resistant and susceptible cultivars, with each cultivar behaving independently as either a resistant or susceptible monocrop. Assessment of P. brassicae virulence and pathotype designations revealed shifts in most mixtures, typically toward more aggressive pathogen strains. Based on these findings, binary mixtures of resistant and susceptible canola cultivars cannot be recommended as a substitute for a resistant monocrop. However, further testing with additional cultivars and cultivation cycles, along with field studies, is needed to draw definitive conclusions
Comparative Analyses of Molecular Responses in Pines to Infection by Cronartium harknessii
No full textWestern gall rust (WGR) is a disease affecting pine species caused by the fungal pathogen Cronartium harknessii (J. P. Moore) E. Meinecke (formerly Endocronartium harknessii). Young trees are particularly susceptible to C. harknessii, which negatively impacts forest regeneration and health. C. harknessii affects lodgepole (Pinus contorta Douglas ex Loudon var. latifolia Engelm.) and jack pine (P. banksiana A. B. Lambert), two environmentally and economically important forest tree species with ranges that cover much of Canada’s forested land. Quantitative resistance to C. harknessii has been documented in both lodgepole and jack pine, with jack pine demonstrating more resistance than lodgepole pine.
In my thesis, I examined how molecular responses to C. harknessii differ between these sister species, and how molecular responses differ between more resistant (MR) and more susceptible (MS) families of lodgepole and jack pine. C. harknessii is presumed to be a biotrophic pathogen, given that other rust species in Order Pucciniales are biotrophs. I tested the hypotheses that (1) molecular mechanisms conferring interspecies host differences in quantitative resistance to C. harknessii are not the same as the mechanisms that confer intraspecies differences in quantitative resistance to C. harknessii, and (2) interspecies and intraspecies differences in C. harknessii resistance involves components of the biotrophic signaling network, including hormones, pathogen-associated molecular pattern triggered immunity (PTI) and effector-triggered immunity (ETI). These components of plant defense are well described in angiosperms, but are far less understood in conifers like lodgepole and jack pine.
Comparison between species using RNA-Seq showed that jack pine mounted a faster, more intense response to C. harknessii by 21 days post inoculation (dpi) compared to lodgepole pine. These transcriptome results suggest an earlier perception of the pathogen in jack pine, coupled with greater activation of defense strategies such as cell wall modifications, induction of pathogenesis-related (PR) genes and synthesis of chemical defense metabolites. On the other hand, the response of lodgepole pine was of a lower magnitude, which could be attributed to delayed or impaired perception of C. harknessii, leading to weaker downstream signalling. Defense trade-offs were suggested by downregulation of photosynthesis-related genes primarily in lodgepole pine, but not in jack pine, suggesting a potential reduction in photosynthetic capacity. Interestingly, the defense response to C. harknessii invoked jasmonic acid (JA) rather than salicylic acid (SA), as measured by hormone analysis, which was unexpected.
Our findings from the transcriptomic comparison between MR and MS lodgepole pine indicate a robust defense response in MR families compared to MS families, characterized by upregulation of genes involved in phytohormone signaling, cell wall modification, redox homeostasis, and secondary metabolism. Additionally, neither MR nor MS lodgepole pine showed enrichment of pathogen perception genes in response to C. harknessii, as observed previously in jack pine, highlighting a distinct resistance mechanism between the two species in response to C. harknessii infection.
Unlike lodgepole pine, molecular responses to C. harknessii in MR and MS jack pine were not substantively different. Jack pine MR and MS families showed an overrepresentation of genes associated with pathogen perception, which likely contributed to the strong defense responses as earlier described for jack pine compared to lodgepole pine.
This study also highlighted that pine responses to C. harknessii differ from those observed in angiosperm models of biotrophic pathogen defense, with JA being induced rather than SA. Although SA defense responsive PR genes were induced, SA itself was not upregulated in either lodgepole or jack pine following C. harknessii infection. In jack pine, not only was SA not induced, but levels were downregulated following inoculation with C. harknessii. Gene expression profiling suggests that this downregulation may be associated with the activity of SA-hydroxylase (SAH), though further research is needed to fully understand the role of SAH in the C. harknessii-pine pathosystem. Alternative hypotheses for JA induction in response to C. harknessii include the possibility of a C. harknessii virulence mechanism mediated by JA, a JA-mediated defense response, and a JA response related to a potentially hemibiotrophic nature of C. harknessii.
In Alberta, breeding for resistance to C. harknessii is a key focus in tree improvement programs. The findings from this study provide novel insights into the molecular mechanisms of pine defense responses to C. harknessii that may inform future resistance breeding efforts
Evolution of density, magnetic field, and ion temperature in ion-Weibel unstable counter-streaming plasma
Get PDFLaser-driven, counter-streaming plasmas are susceptible to filamentation due to the
nonlinear ion-Weibel instability. Such behaviour is hypothesized to be a source of
some large magnetic fields in astrophysical plasmas. This phenomenon has been
investigated in multiple simulations and experiments spanning over a decade. Experiments
conducted on the OMEGA laser facility leveraged novel optical Thomson
scattering techniques to measure these filaments and their associated magnetic fields
by examining local intensity fluctuations in ion acoustic waves. This project incorporates
analyses of the electron plasma wave (EPW) measurements. The EPW data
shows large, rapid fluctuations in plasma density. By measuring the density fluctuations,
we can infer the size of the filaments to be ∼80 μm.
Additionally, we can leverage our measurements of plasma parameters such as density,
temperature, and flow velocity to infer the strength of the B-field in multiple ways.
Each of the resulting B-field estimates are on the order of 100 tesla, or ∼6.7% of the
initial energy of the system, and are in agreement with results of 2D PIC simulations
Bifunctional oxygen electrodes for Unitized Reversible Fuel Cells fabricated by inkjet printing
No full textUnitized regenerative fuel cells (URFCs) have the potential to balance the intermittency of large-scale renewable energy sources, such as solar and wind, by enabling hydrogen production, storage, and utilization for electricity production. URFC systems theoretically provide a higher specific energy density than other energy conversion systems, making them particularly suitable for weight- and space-sensitive applications, such as aerospace and transportation. By combining fuel cell and electrolyzer functions in a single unit, URFCs reduce system weight, space, and overall costs. However, they also face technical challenges that have limited their efficiency and commercial viability. The unitized system must be designed for both processes, requiring trade-offs to balance the fuel cell and electrolyzer performance. One of the main challenges comes from the bifunctional oxygen electrode (BOE), where the lack of a single catalyst for oxygen reduction and the oxygen evolution reactions requires a compromise in material choice, combination method, and electrode fabrication. This thesis aims to advance URFC technology by developing more efficient, durable, and cost-effective proton-exchange membrane (PEM) electrodes. This work will study and optimize the PEM electrode’s composition and structure during fabrication. For this, two different configurations of BOEs were fabricated and studied: 1) a physical mixture of catalysts and 2) a multilayer arrangement. These configurations were studied to understand the effects of catalyst ratio, ionomer content, and overall catalyst loading on cell performance. In the process, inkjet printing was evaluated as a fabrication method to fabricate the low-loading electrodes in both configurations, demonstrating its potential for precise and reproducible electrode fabrication.
The first part of this thesis presents the study of the optimal ionomer, catalyst ratio, and catalyst loading of an inkjet-printed BOE for URFCs. For this, a physical mixture of Pt, IrOx, and Nafion ionomer was inkjet printed directly on a Nafion membrane to fabricate varying loading bifunctional oxygen electrodes for a URFC and characterized via scanning electrode microscopy and cyclic voltammetry. The results show that the two catalysts do not interfere with one another and that an optimal electrode requires low ionomer loading, i.e., 10 wt.%, and a significantly lower amount of the IrOx catalyst compared to platinum, i.e., 3:1 Pt-IrOx ratio. A catalyst loading study showed that the highest round-trip (RT) efficiency is obtained at around 0.67 mgPt+IrOx/cm2, reaching 50% at 500 mA/cm2. Further increasing the amount of catalyst does not result in a significant cell performance improvement either in water electrolysis or fuel cell mode.
Finally, a multilayer electrode is assessed and compared to the mixed BOEs. For this, separate catalyst layers (CLs) of platinum black and IrOx with varying Pt to IrOx ratios were inkjet printed on a PEM in two configurations: (a) PEM/Pt black/IrOx, and (b) PEM/IrOx/Pt black. The electrodes were characterized via scanning electrode microscopy, cyclic voltammetry, and electrochemical impedance spectroscopy. The results show that the performance of the multilayer electrodes is highly dependent on the position of the CLs in the electrode and that the Pt to IrOx ratio is critical for the successful operation of the electrode when the Pt layer is in contact with the PEM. At high catalyst loadings, the poorly conductive IrOx layer, in contact with the GDL, acted as a barrier for the electrons to reach the Pt layer, increasing the high-frequency impedance of the cell and leading to a second semicircle. The catalyst ratio study showed that, at lower IrOx loadings, the multilayer approach outperforms the mixed catalyst BOEs when the Pt CL is in contact with the PEM reaching an RT efficiency of 51.2% at 500 mA/cm2 and 43.8% at 1000 mA/cm2 with a catalyst loading of only 0.56 mg/cm2 and a 9:1 Pt:IrOx ratio.
Overall this thesis contributes to the understanding of URFC electrode design by studying the catalyst interactions and the electrode fabrication method, highlighting the importance of the Pt-to-Ir ratio to achieve high-performance URFC BOEs. With optimized catalyst layer positioning and catalyst ratios, the electrodes developed in this work achieved the highest RT efficiency for any multilayer BOE and one of the highest by the amount of catalysts of any constant gas BOE reported in the literature
Wild roses at the Clifford E. Lee Nature Sanctuary
No full textThe Alberta Wild Rose, floral symbol of the Province of Alberta, grows abundantly at the Clifford E. Lee Nature Sanctuary
