Clearing the Path to Unemployment Insurance for Low-Wage Workers

Unemployment Insurance is a necessary and beneficial stimulus program for part-time workers. However, the current rules for eligibility often leave eligible workers behind. This study analyzes the alternative base period (ABP), a policy reform that makes it easier for low-wage workers to qualify for UI benefits.

Development of a Hybrid Hydrogel Bio-ink for 3D Printing of Biomimetic Tissue Constructs

Colorectal cancer is the 2nd most common form of cancer in Canada. Most colorectal cancer deaths are caused by complications that stem from the metastasis of colorectal cancer to other organs such as the liver. During metastasis, the extravasation step of the metastasis cascade involves the attachment of circulating tumour cells to the endothelial cell layer that coats the inside of human blood vessels and the eventual migration of the cells past this layer. Current tumour extravasation models, used for drug and mechanistic studies, do not accurately reflect the microenvironments found in the human body. Three dimensional bioprinting has become an attractive method to produce extravasation models. This thesis explores the development of a hybrid hydrogel bio-ink consisting of alginate, GelMA and cellulose nanocrystals to create cell scaffolds that can support the growth of a monolayer of endothelial cells. A bio-ink consisting of 2 wt% alginate, 4 wt% GelMA and 6 wt% cellulose nanocrystals was chosen for printability studies and cellular studies for its high shear thinning and low hysteresis in viscosity recovery. Scaffolds designed to mimic a human blood vessel and villi structures in a healthy colon were printed and EA-hy 926 cells were seeded on top. After six days and an additional seeding of cells it was found that the bio-ink could not sustain the growth of a complete mono-layer of EA-hy 926 cells. The high electrostatic repulsion between the negatively charged cell membrane and the negatively charged alginate and cellulose nanocrystals is thought to play a role in the ability of the cells to attach to the scaffold surface. Scaffold treated with poly(L-lysine) were made and EA-hy-926 cells were again seeded on top. This resulted in better cell distribution, but increased instances of cellular elongation suggested a decrease in cellular adhesion. In both poly(L-lysine) treated and un-treated scaffolds the cells were able to attach and proliferate on top of the scaffolds suggesting that with some changes in either the bio-ink’s formula, cell seeding densities or post printing treatments a mono layer of cells could be formed to be used in the production of extravasation models of colorectal cancer

Prospectus, March 3, 1999

https://spark.parkland.edu/prospectus_1999/1007/thumbnail.jp

3D bioprinting of liver-mimetic construct with alginate/cellulose nanocrystal hybrid bioink

The final publication is available at Elsevier via http://dx.doi.org/10.1016/j.bprint.2017.12.001 © 2018. This manuscript version is made available under the CC-BY-NC-ND 4.0 license http://creativecommons.org/licenses/by-nc-nd/4.0/3D bioprinting is a novel platform for engineering complex, three-dimensional (3D) tissues that mimic real ones. The development of hybrid bioinks is a viable strategy that integrates the desirable properties of the constituents. In this work, we present a hybrid bioink composed of alginate and cellulose nanocrystals (CNCs) and explore its suitability for extrusion-based bioprinting. This bioink possesses excellent shear-thinning property, can be easily extruded through the nozzle, and provides good initial shape fidelity. It has been demonstrated that the viscosities during extrusion were at least two orders of magnitude lower than those at small shear rates, enabling the bioinks to be extruded through the nozzle (100µm inner diameter) readily without clogging. This bioink was then used to print a liver-mimetic honeycomb 3D structure containing fibroblast and hepatoma cells. The structures were crosslinked with CaCl2 and incubated and cultured for 3 days. It was found that the bioprinting process resulted in minimal cell damage making the alginate/CNC hybrid bioink an attractive bioprinting material.Natural Sciences and Engineering Research Council (NSERC) of Canada (grant no. RGPIN-2016-04398

Prospectus, February 17, 1999

https://spark.parkland.edu/prospectus_1999/1005/thumbnail.jp

Photochemistry of 2-butenedial and 4-oxo-2-pentenal under atmospheric boundary layer conditions

Unsaturated 1,4-dicarbonyl compounds, such as 2-butenedial and 4-oxo-2-pentenal are produced in the atmospheric boundary layer from the oxidation of aromatic compounds and furans. These species are expected to undergo rapid photochemical processing, affecting atmospheric composition. In this study, the photochemistry of (E)-2-butenedial and both E and Z isomers of 4-oxo-2- pentenal was investigated under natural sunlight conditions at the large outdoor atmospheric simulation chamber EUPHORE. Photochemical loss rates, relative to j(NO2), are determined to be j((E)-2-butenedial)/j(NO2) = 0.14 (0.02), j((E)-4-oxo-2-pentenal)/j(NO2) = 0.18 (0.01), and j((Z)-4-oxo-2-pentenal)/j(NO2) = 0.20 (0.03). The major products detected for both species are a furanone (30 – 42%) and, for (E)-2-butenedial, maleic anhydride (2,5-furandione) (12 – 14%). The mechanism appears to proceed predominantly via photoisomerization to a ketene- enol species following -H abstraction. The lifetimes of the ketene-enol species in the dark from 2-butenedial and 4-oxo-2-pentenal are determined to be 465 s and 235 s, respectively. The ketene-enol can undergo ring closure to yield the corresponding furanone, or further unimolecular rearrangement which can subsequently form maleic anhydride. A minor channel (10 – 15%) also appears to form CO directly. This is presumed to be via a molecular elimination route of an initial biradical intermediate formed in photolysis, with an unsaturated carbonyl (detected here but not quantified) as co-product. -dicarbonyl and radical yields are very low, which has implications for ozone production from the photo-oxidation of unsaturated 1,4-dicarbonyls in the boundary layer. Photochemical removal is determined to be the major loss process for these species in the boundary layer with lifetimes of the order of 10 – 15 minutes, compared to > 3 hours for reaction with OH

Prospectus, February 10, 1999

https://spark.parkland.edu/prospectus_1999/1004/thumbnail.jp

A prospective ascertainment of cancer incidence in sub-Saharan Africa: The case of Kaposi sarcoma.

In resource-limited areas, such as sub-Saharan Africa, problems in accurate cancer case ascertainment and enumeration of the at-risk population make it difficult to estimate cancer incidence. We took advantage of a large well-enumerated healthcare system to estimate the incidence of Kaposi sarcoma (KS), a cancer which has become prominent in the HIV era and whose incidence may be changing with the rollout of antiretroviral therapy (ART). To achieve this, we evaluated HIV-infected adults receiving care between 2007 and 2012 at any of three medical centers in Kenya and Uganda that participate in the East Africa International Epidemiologic Databases to Evaluate AIDS (IeDEA) Consortium. Through IeDEA, clinicians received training in KS recognition and biopsy equipment. We found that the overall prevalence of KS among 102,945 HIV-infected adults upon clinic enrollment was 1.4%; it declined over time at the largest site. Among 140,552 patients followed for 319,632 person-years, the age-standardized incidence rate was 334/100,000 person-years (95% CI: 314-354/100,000 person-years). Incidence decreased over time and was lower in women, persons on ART, and those with higher CD4 counts. The incidence rate among patients on ART with a CD4 count >350 cells/mm(3) was 32/100,000 person-years (95% CI: 14-70/100,000 person-years). Despite reductions over time coincident with the expansion of ART, KS incidence among HIV-infected adults in East Africa equals or exceeds the most common cancers in resource-replete settings. In resource-limited settings, strategic efforts to improve cancer diagnosis in combination with already well-enumerated at-risk denominators can make healthcare systems attractive platforms for estimating cancer incidence

What are communities of practice? A comparative review of four seminal works

This paper is a comparative review of four seminal works on communities of practice. It is argued that the ambiguities of the terms community and practice are a source of the concept's reusability allowing it to be reappropriated for different purposes, academic and practical. However, it is potentially confusing that the works differ so markedly in their conceptualizations of community, learning, power and change, diversity and informality. The three earlier works are underpinned by a common epistemological view, but Lave and Wenger's 1991 short monograph is often read as primarily about the socialization of newcomers into knowledge by a form of apprenticeship, while the focus in Brown and Duguid's article of the same year is, in contrast, on improvising new knowledge in an interstitial group that forms in resistance to management. Wenger's 1998 book treats communities of practice as the informal relations and understandings that develop in mutual engagement on an appropriated joint enterprise, but his focus is the impact on individual identity. The applicability of the concept to the heavily individualized and tightly managed work of the twenty-first century is questionable. The most recent work by Wenger – this time with McDermott and Snyder as coauthors – marks a distinct shift towards a managerialist stance. The proposition that managers should foster informal horizontal groups across organizational boundaries is in fact a fundamental redefinition of the concept. However it does identify a plausible, if limited, knowledge management (KM) tool. This paper discusses different interpretations of the idea of 'co-ordinating' communities of practice as a management ideology of empowerment