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Great Lakes Focus on Water Quality: vol.4 iss.3
No full textIn October and November the Pollution from Land Use Activities Reference Group (PLUARG) will sponsor information meetings throughout the Great Lakes Basin. The purposes of the sessions are to present the PLUARG final report, Environmental Management Strategy for the Great Lakes System, with its conclusions and recomendations (See PLUARG write up, page 6), explain the IJC's hearing process, and encourage people to present their views on the report to the Commission on Public Hearings
Elucidating the Dynamics and Equilibrium Asymmetric Organization of Lipids in Biomimetic Model Membranes
Get PDFBiological membranes are a defining component of cellular life. These structures, mainly composed of proteins dispersed in a lipid bilayer, separate cells from the external world, compartmentalize organelles and enable various biological processes. Although these membranes appear to have a rather simple construction, upon closer inspection they possess a diverse array of constituent molecules in constant flux. At the heart of this diversity are the lipids, which not only have countless structural forms but a unique spatial and temporal distribution. With this in mind, we employ small angle neutron scattering, to explore the equilibrium bilayer asymmetry and dynamics of lipids in synthetic biomimetic model membranes. The use of this probe-free technique enables us to study lipids in a native, un-perturbed state and apply this information to enhance our understanding of the distribution and movement of lipids in a biological context. This thesis is divided into four chapters: The first chapter serves as an introduction to biomembrane research. It provides a historical review of the cell membrane and more recent scientific developments in the field. Additionally, the use of synthetic liposomes as biological membrane mimics and various biophysical techniques used to study membrane structure and dynamics are discussed. The second chapter examines the transverse asymmetric bilayer organization of lipids in biomimetic liposomes. Often assumed to form symmetric bilayers under equilibrium conditions, small angle neutron scattering, a custom data fitting model and a specialized contrast match scheme are used to show that this is not always the case. Chapter three uses time-resolved small angle neutron scattering to study vitamin E's dynamics in saturated model membranes. The rates of intervesicular exchange (kex) and intrabilayer flip-flop (kf) are assessed in a few conditions, such as different liposome concentrations and the presence of various cyclodextrins. These results provide potential insights into vitamin E's antioxidative role within membranes. Chapter four serves to conclude the work presented herein. It explains how these results enhance our current knowledge of biomembranes and outlines future work that can be performed to extend our understanding of lipid organization and dynamics
Staff Management of a Call Center
No full textHow to optimize the cost of running an information system
Designing and screening altered peptide ligands for the treatment of HLA type II autoimmune disorders using computational chemistry.
Get PDFViable, Healthy and Safe CommunitiesHLA type II autoimmune disorders (e.g. Rheumatoid Arthritis, Diabetes, Celiac), affect a significant portion of the population and are becoming more common. These diseases result from the misrecognition of small peptides by mutated human leukocyte antigen (HLA) receptors which present these peptides to T cell receptors (TCR) of the immune system, initiating an incorrect immune response. Currently, no drug exists capable of stopping or reversing the disease. A proposed solution is the use of altered peptide ligands (APLs), which are peptidomimetics capable of binding the HLA in place of the misrecognized peptide, potentially halting or even reversing disease progression by preventing immune system activation. The problem with the design of APLs is that it is extremely difficult to screen or predict their activity without costly in vitro testing, coupled with an often long and challenging synthesis of non-natural amino acids and subsequent peptide. Our objective is the high throughput screening of APLs using computational chemistry techniques consisting of three steps: 1) Docking 2) Molecular Dynamics Simulations (MD) 3) Molecular Mechanics-generalized Born and surface area continuum solvation (MM-GBSA) calculations. Docking of a set of peptides to HLA-DQ2 with known affinities shows good correlation to experimental IC50 values and is an effective initial screening step, with low cost allowing for high throughput screening. Several APLs based on the Rheumatoid Arthritis HLA-DR4 binding motif were examined using this process. These ligands were docked, then 50 short molecular dynamics simulations were performed per peptide which was then used to calculate their binding affinity using MM-GBSA. Binding affinities show large standard deviations which highlights the need for many simulations in order to obtain statistically converged results. Predicted binding affinities agree with observed binding trends of these peptides to the DR4 receptor showing that this approach can be used to screen and rank APLs
Literacy in Early Childhood Education: Incorporating literacy through Play Based Learning utilizing an English Language Learner lens
No full textCanada has seen a steady regression in literacy skills, evidenced most recently in the Progress in International Reading Literacy Study (PIRLS) assessment, which saw Canada drop from a global ranking of 12th to 18th. Canadian children continue to enter the school system with weak literacy skills. Specifically, English Language Learners (ELL), have struggled in Ontario to achieve provincial baselines; coupled with their unique learning needs, ELLs make up a large percentage of Ontario student composition. One evidence-based method for supporting the learning needs of ELL students in the primary grades is through Play-Based Learning (PBL). This approach allows students to explore language, develop vocabulary, and enhance their comprehension skills, all of which are essential components of literacy. This three-year tri-funded project is conducting a feasibility study, in collaboration with a local school board, to evaluate the viability of an in-school PBL program that is tailored to the learning needs of ELL students. To address the need for relevant, meaningful PBL material, the research team will take a novel approach by utilizing LEGO, a common manipulative in a kindergarten classroom with a high ELL population. Researchers will measure the impact on student literacy development using evidence-based methods and evaluate educators' understandings of and confidence implementing PBL pre- and post-test. The overall goal is to advocate for elements of the program to be embedded on a provincial and national scale through ELL literacy educator training, resource sourcing and allocation, and impact measurement/assessment
Artificial light and its effect on bird migration: insights from concurrent acoustic and radar monitoring
No full textFor birds that migrate nocturnally, starlight plays a critical role in navigation; however, light from anthropomorphic sources can disrupt navigation. These disruptions could result in losses of biodiversity if anthropogenic lights have detrimental effects on migrating birds. In order to prevent continued biodiversity losses of migratory animals, careful analyses of artificial light disruptions are required. Radar tracking and acoustic monitoring have been used previously in the study of avian migration, but these techniques have yet to be used concurrently in studying migratory disruption by artificial light. In this study, I used a combination of acoustic and radar techniques to understand whether avian migration is disrupted by anthropogenic light. I used NEXRAD radar to estimate bird traffic rates and altitudinal positioning of migrating birds, and acoustic monitoring to identify the species of those migrants. I used these techniques in tandem to study birds passing over sites with artificial light and nearby dark control sites. NEXRAD data provided evidence of birds passing over artificially lit areas in greater numbers and altitudinal changes in migrating flocks. Acoustic data provided evidence of increased call rates and changes in flock composition, suggesting increased disorientation and reduced cohesion of natural mixed species flocks near artificial light. I conclude that artificial light changes migratory behaviour of birds, imposing greater energetic costs to migration. This research, and parallel studies of anthropogenic light, highlight the importance of understanding the effect of anthropogenic light, as expanding urbanization removes remaining unaltered refugia and natural biological processes become increasingly disrupted by human influences
Identifying a Genetic Signature that Predicts the Progression of Non-Muscle Invasive Urothelial Carcinoma to Muscle-Invasive Cancer.
No full textBladder cancer (BC) is Canada's fifth most commonly diagnosed cancer, with two distinct types: non-muscle invasive (NMIBC) and muscle-invasive (MIBC). The objectives of this study are to find molecular biomarkers that lead to the progression of MIBC from NMIBC to provide a targeted treatment approach therefore, also using early detection to decrease cases of MIBC and to predict the biomarkers which aid in the transition of high-grade NMIBC to MIBC. The hypothesis states that if molecular biomarkers are identified and predict the progression of MIBC from NMIBC, they can be implemented for clinical use. This study divided 22 BC patients from the Windsor Regional Hospital into two cohorts. The first cohort included NMIBC samples; the second included MIBC samples. Three STAR patient samples began with NMBIC diagnosis and progressed to MIBC during this study. Data sequencing and analysis were conducted to identify sequencing depth, allele frequency and non-synonymous mutations. The results indicated a higher allele frequency and mutational change in MIBC samples. Cell line studies were also conducted, showing increased proliferation rates. Retrospective data was collected from patients’ charts, indicating that 100% of MIBC patients' deaths were related to bladder cancer. This ongoing study brings significant value to the oncology and translational health field
Design of High Stability Superhydrophobic Surfaces
Get PDFIn the recent two decades, superhydrophobic surfaces' properties and their potential applications have attracted much attention. With the main advantages of self-cleaning, anti-icing, and drag-reduction, the superhydrophobic surfaces can be applied to many industry fields. But the traditional fabrication methods developed in the last twenty years for the superhydrophobic surfaces were focusing on mimicking nature. Specifically, most of the fabrication methods were based on the micro, and nano-scale structure of plants and animals, which came with the problems that such weeny structure on the surfaces would be damaged easily in the practical application without the self-healing capability like the creatures in nature and they are always with a high cost and strict requirements. Thus, people need to find another approach to fabricate superhydrophobic surfaces. The re-entrant angle model, which is basically wider on top and narrower at the bottom, and the most important thing is that this is a general structure that can be more durable in practical application. In this major research paper, we will emphasize the development of the fabrication of superhydrophobic surfaces and the newer design based on the re-entrant angle model
Changes in Lake State: Major state changes in an ancient tropical lake through geological time
No full textEarth has been changing for millions of years, and these changes can even be felt in our freshwater systems, a vital resource influencing all forms of life, from algae to terrestrial mammals. Lake Towuti, Indonesia is one of very few lakes that have the potential to record changes over such long time spans. The pristine nature of this lake, with its low algal biomass and its ability to support a multitude of rare and endemic species, has led this lake to international interest. This study investigates whether the state of Lake Towuti has always been the same by studying the fossil record of deep sediment cores from two sites within Lake Towuti. We hypothesized that the composition of the fossilized algal diatom communities is the same throughout the cores, as it is unlikely that pristine lakes have encountered any major changes. Our methods include identifying diatom species and counting their abundance through microscopy, and measuring the concentrations and of select elements through spectroscopy. Our results to date show: (1) an array of novel endemic diatom species not yet described anywhere else; and (2) major long-term switches in the state of the lake. The complete shift in a lake's algal community, dominated with species not seen today, shows the potential for lakes to continuously change between different algal states. This study also provides the identification of novel, endemic, and extinct diatom species. And lastly, the disappearance of a more algal lake state highlights the capacity for lakes to recover from extended periods of high productivity, an important finding in a time where we are struggling with harmful algal blooms in our own Great Lakes