Discussions of Diaspora: Cultural Production and Identity in Contemporary Chinese Canadian Literature

This thesis explores modes of cultural production and identity in three Chinese Canadian works of fiction: Disappearing Moon Café, The End of East, and The Better Mother. This research discusses the position of Chinese Canadian literature in relation to the institutional framework of Asian Canadian Studies. Within current academic circles, there exists varied discussions on the many aspects of Asian Canadian’s, this thesis seeks to explore the position of literature written by and about Chinese Canadian’s within the larger framework of Canadian literature and its representations of culture, identity and ethnic enclaves such as Chinatown’s. More specifically, this research explores literary representations of Vancouver’s Chinatown and its links to time, place, cultural identity and sense of family. In doing so, this research aims to add to current discussions of Chinese Canadian literature and theory, while attempting to situate the genre itself among the many other minority genres within Canadian literature

The impact of axial length on retinal tamponade for gas, silicone oil, and heavy silicone oil, using an in vitro model

Background: To investigate whether ocular axial length influences the tamponade efficacy of three commonly used agents: gas, silicone oil, and heavy silicone oil. Methods: A series of filling experiments was conducted using 19-mm and 25-mm surface-modified spherical model eye chambers to mimic the vitreous cavity. For each agent, tamponade efficacy was assessed across a range of percentage fills, and comparison was made between the two model eye chambers. The behavior of each tamponade agent was quantified by measuring (1) the maximum height of the tamponade bubble, and calculating (2) the arc of retinal contact subtended by the tamponade bubble. Results: Polynomial regression analysis found no statistically significant difference between the regression models for the different-sized model eye chambers for bubble height or arc of retinal contact subtended. This applied to all of the tamponade agents under investigation. Conclusions: Across the range of cavity sizes under investigation, no significant difference in tamponade efficacy (as reflected by the measured dimensions of the tamponade bubble) was identified. © 2010 The Author(s).published_or_final_versionSpringer Open Choice, 21 Feb 201

Flow Behavior of Heavy Silicone Oil During Eye Movements

PURPOSE. Currently there are various heavy silicone oil (HSO) tamponade agents available for treating inferior retinal diseases. Most of these HSO agents are either homogeneous liquids or a mixture of two components. Variations in their emulsification rates in vivo have been reported. In this study, we investigated their flow behaviors during eye-like movements. METHODS. A model eye chamber filled with various HSO agents was driven to perform eye-like movements. Five types of HSOs with different formulations together with 2 other tamponade agents were tested. Movements of various HSOs inside the chamber were captured by video recording and analyzed. RESULTS. Oxane HD has a larger movement and higher velocity relative to the eye chamber than the less viscous Densiron 68. The behavior of Densiron 68 is similar to that of homogeneous HSO 1.07 and HSO 1.20. Both Oxane HD and 11% silica fluid show very different behaviors compared to the other HSO agents. In addition, 11% silica fluid shows behavior similar to that of F6H8, a low-viscosity tamponade agent. CONCLUSIONS. The viscosity of HSO is not the sole parameter with which to determine the behavior of HSO during eye movements. Various HSOs that are manufactured by mixing different types of base SO and ''heavy'' additives show distinct flow behaviors. The solubility and stability of the heavy additives in the base SO alter its flow when subjected to eye movements, which may contribute to in vivo emulsification. Keywords: emulsification, eye movements, heavy silicone oil, tamponade S ilicone oil (SO) has been used in vitreoretinal surgery for a long time to repair complicated retinal detachment. 1 Conventional SO has a specific gravity lower than water and thus provides a good tamponade effect for breaks or holes in the superior retina. There is also a group of SO that has a specific gravity higher than water. That type of SO is designed initially for treating proliferative vitreoretinopathy, which has a propensity to affect the inferior part of the retina. 2 Those types are commonly called heavy silicone oil (HSO). The first generation of HSO was made by substituting a few methylated groups of conventional SO to fluorinated groups in order to increase its specific gravity. 3 However, that type of fluorosilicone oil was found to be toxic to ocular tissues

Adenosine 2A receptor and TIM3 suppress cytolytic killing of tumor cells via cytoskeletal polarization

Tumors generate an immune-suppressive environment that prevents effective killing of tumor cells by CD8(+) cytotoxic T cells (CTL). It remains largely unclear upon which cell type and at which stage of the anti-tumor response mediators of suppression act. We have combined an in vivo tumor model with a matching in vitro reconstruction of the tumor microenvironment based on tumor spheroids to identify suppressors of anti-tumor immunity that directly act on interaction between CTL and tumor cells and to determine mechanisms of action. An adenosine 2A receptor antagonist, as enhanced by blockade of TIM3, slowed tumor growth in vivo. Engagement of the adenosine 2A receptor and TIM3 reduced tumor cell killing in spheroids, impaired CTL cytoskeletal polarization ex vivo and in vitro and inhibited CTL infiltration into tumors and spheroids. With this role in CTL killing, blocking A(2A)R and TIM3 may complement therapies that enhance T cell priming, e.g. anti-PD-1 and anti-CTLA-4

Structural Variation among Wild and Industrial Strains of Penicillium chrysogenum

Strain selection and strain improvement are the first, and arguably most important, steps in the industrial production of biological compounds by microorganisms. While traditional methods of mutagenesis and selection have been effective in improving production of compounds at a commercial scale, the genetic changes underpinning the altered phenotypes have remained largely unclear. We utilized high-throughput Illumina short read sequencing of a wild Penicillium chrysogenum strain in order to make whole genome comparisons to a sequenced improved strain (WIS 54–1255). We developed an assembly-free method of identifying chromosomal rearrangements and validated the in silico predictions with a PCR-based assay and Sanger sequencing. Despite many rounds of mutagen treatment and artificial selection, WIS 54–1255 differs from its wild progenitor at only one of the identified rearrangements. We suggest that natural variants predisposed for high penicillin production were instrumental in the success of WIS 54–1255 as an industrial strain. In addition to finding a previously published inversion in the penicillin biosynthesis cluster, we located several genes related to penicillin production associated with these rearrangements. By comparing the configuration of rearrangement events among several historically important strains known to be high penicillin producers to a collection of recently isolated wild strains, we suggest that wild strains with rearrangements similar to those in known high penicillin producers may be viable candidates for further improvement efforts

Use and awareness of and willingness to self-test for HIV: an analysis of cross-sectional population-based surveys in Malawi and Zimbabwe.

BACKGROUND: Many southern African countries are nearing the global goal of diagnosing 90% of people with HIV by 2020. In 2016, 84 and 86% of people with HIV knew their status in Malawi and Zimbabwe, respectively. However, gaps remain, particularly among men. We investigated awareness and use of, and willingness to self-test for HIV and explored sociodemographic associations before large-scale implementation. METHODS: We pooled responses from two of the first cross-sectional Demographic and Health Surveys to include HIV self-testing (HIVST) questions in Malawi and Zimbabwe in 2015-16. We investigated sociodemographic factors and sexual risk behaviours associated with previously testing for HIV, and past use, awareness of, and future willingness to self-test using univariable and multivariable logistic regression, adjusting for the sample design and limiting analysis to participants with a completed questionnaire and valid HIV test result. We restricted analysis of willingness to self-test to Zimbabwean men, as women and Malawians were not systematically asked this question. RESULTS: Of 31,385 individuals, 31.2% of men had never tested compared with 16.5% of women (p < 0.001). For men, the likelihood of having ever tested increased with age. Past use and awareness of HIVST was very low, 1.2 and 12.6%, respectively. Awareness was lower among women than men (9.1% vs 15.3%, adjusted odds ratio [aOR] = 1.55; 95% confidence interval [CI]: 1.37-1.75), and at younger ages, and lower education and literacy levels. Willingness to self-test among Zimbabwean men was high (84.5%), with greater willingness associated with having previously tested for HIV, being at high sexual risk (highest willingness [aOR = 3.74; 95%CI: 1.39-10.03, p < 0.009]), and being ≥25 years old. Wealthier men had greater awareness of HIVST than poorer men (p < 0.001). The highest willingness to self-test (aOR = 3.74; 95%CI: 1.39-10.03, p < 0.009) was among men at high HIV-related sexual risk. CONCLUSIONS: In 2015-16, many Malawian and Zimbabwean men had never tested for HIV. Despite low awareness and minimal HIVST experience, willingness to self-test was high among Zimbabwean men, especially older men with moderate-to-high HIV-related sexual risk. These data provide a valuable baseline against which to investigate population-level uptake of HIVST as programmes scale up. Programmes introducing, or planning to introduce, HIVST should consider including relevant questions in population-based surveys

Synaptic convergence patterns onto retinal ganglion cells are preserved despite topographic variation in pre- and postsynaptic territories

Sensory processing can be tuned by a neuron’s integration area, the types of inputs, and the proportion and number of connections with those inputs. Integration areas often vary topographically to sample space differentially across regions. Here, we highlight two visual circuits in which topographic changes in the postsynaptic retinal ganglion cell (RGC) dendritic territories and their presynaptic bipolar cell (BC) axonal territories are either matched or unmatched. Despite this difference, in both circuits, the proportion of inputs from each BC type, i.e., synaptic convergence between specific BCs and RGCs, remained constant across varying dendritic territory sizes. Furthermore, synapse density between BCs and RGCs was invariant across topography. Our results demonstrate a wiring design, likely engaging homotypic axonal tiling of BCs, that ensures consistency in synaptic convergence between specific BC types onto their target RGCs while enabling independent regulation of pre- and postsynaptic territory sizes and synapse number between cell pairs

Moving Beyond the 2018 Minimum International Care Considerations for Osteoporosis Management in Duchenne Muscular Dystrophy (DMD)

Individuals living with Duchenne muscular dystrophy (DMD) are at significant risk of bone fragility due to osteoporosis, with the most potent drivers of fragility fractures in this context stemming from the aggressive myopathy and long term oral glucocorticoid therapy. Young people with DMD have a high fracture burden, with reported total and vertebral fracture rates that are four [1, 2] and 535 times [1] higher than those of healthy growing boys, respectively. Vertebral fractures can occur as early as six months following daily glucocorticoid initiation [3]. Up to 75% of young people with DMD sustain at least one fracture after eight years of glucocorticoid therapy [4]. Fractures in DMD can lead to devastating outcomes, including steeper rates of functional decline, premature and permanent loss of ambulation, chronic pain, and even death from fat embolism syndrome or adrenal crisis following long bone fractures [2, 5–8]. The potential for serious consequences and medical complications linked to fractures has driven efforts to develop effective guidelines for timely bone health surveillance and treatment with more recent efforts to develop fracture prevention strategies.To guide clinicians in the management of DMD and its related co-morbidities (including skeletal health), the first internationally-endorsed, minimum standards of care were published in 2010 under the moniker “Clinical Care Considerations” [9, 10]. This document recommends that osteoporosis monitoring include spine x-rays if back pain or kyphosis is present, followed by initiation of intravenous bisphosphonate therapy if vertebral fractures are identified [10]. In the years following the inaugural 2010 Clinical Care Considerations, studies were published showing that vertebral fractures, a key manifestation of bone fragility among children and adults living with glucorticoid-treated chronic conditions, were frequently asymptomatic, necessitating routine surveillance for early detection [3, 11]. It was also better appreciated that even a single long bone fracture can signal osteoporosis in a persistently high-risk setting such as DMD, and prompt initiation of bone protection therapy is important.With this new knowledge, the latest international, minimum standards of clinical care for DMD published in 2018, known as Care Considerations [12–14], recommended routine, standardized spine imaging for early detection of vertebral fractures, combined with more timely bone-targeted (bisphosphonate) intervention in the presence of vertebral or low trauma long bone fractures [12]. At the same time, the ever-changing therapeutic landscape for the treatment of the underlying condition calls for ongoing examination of the intimate relationship between muscle and bone development in DMD, including the effect of different DMD treatment approaches on the skeletal and endocrine systems. The overall goal of such focus is to harvest discussions about optimal management that will foster bone strength and prevent fractures in this high-risk setting across all underlying disease-targeted treatment paradigms for people with DMD