McGill Science undergraduate research journal : MSURJ最新文献

{"title":"Effectiveness of Behavioural Intervention as Treatment for the Vasovagal Response in Blood Donation","authors":"K. Wade, B. Ditto","doi":"10.26443/msurj.v13i1.28","DOIUrl":"https://doi.org/10.26443/msurj.v13i1.28","url":null,"abstract":"Background: The experience of a vasovagal reaction during blood donation, with symptoms such as dizziness, weakness, and fainting, contributes to a more negative donation experience and significantly decreases the likelihood of blood donor return. This study investigates the effects of two behavioural interventions on reducing the occurrence of such reactions, applied muscle tension and respiration control, and possible moderation of these effects by sex, BMI, and medical fear.\u0000Methods: Six hundred and eleven participants were recruited from Héma-Québec blood drives across Montreal and randomly assigned one of four conditions: applied muscle tension, an anti-hyperventilation respiration control procedure, both techniques, or neither. Following their donation, participants completed the Blood Donations Reactions Inventory and Medical Fears Survey. Analysis focuses on the respiration control and applied tension groups.\u0000Results: While donor sex and BMI did not predict the effectiveness of applied muscle tension intervention, results showed that the largest benefit was seen in donors who reported lower levels of medical fears in the respiration control condition group.\u0000Limitations/Conclusions: The results are promising in that they suggest that intervention can decrease the risk for vasovagal symptoms in blood donation, though it may not be sufficient to reduce symptoms in donors with high levels of medical fear.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2018-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45264732","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ecosystem Service Benefits of Lab-cultured and Insect Meat","authors":"Annie Dahan, Lucas Paulson, B. Beauséjour","doi":"10.26443/msurj.v12i1.38","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.38","url":null,"abstract":"Background: Population and income growth are expected to augment meat demand, and consequently, the conversion of natural ecosystems into pasture. Promising alternatives to livestock, particularly lab-cultured and insect meats, use about 1% as much land. Utilizing these technologies could reduce pasture expansion and maintain natural ecosystem service values. This paper investigates: what is the value of the ecosystem services potentially maintained by reducing agricultural expansion through the adoption of cultured and insect meat?\u0000Methods: Total global livestock-associated agricultural expansion by 2050 was predicted using FAO livestock projections (1) multiplied by the average land-use per kilogram of meat (2) yielding 194Mha. This expansion was partitioned among ecosystems according to threat scores derived from past expansion (3). Changes to annual ecosystem service values were calculated using average global values from Costanza et al. (4) multiplied by predicted expansion per ecosystem.\u0000Results & Conclusion: Tropical forests and east-Asia were the most threatened ecosystem and region, respectively, by both area and value. The net loss in annual ecosystem service values in 2050 due to predicted livestock-associated agricultural expansion was calculated to be $732bn/yr, translating to a NPV of $6.62tn to 2050. The potential to save such large ecosystem services value justifies increased research and promotion of these protein production methods.\u0000Limitations: This research does not identify exact ecosystems that are both targeted by agricultural meat expansion and that yield large ecosystem benefits because it is not sufficiently spatially explicit. Thus, it should not be used as a reference for new ecosystem conservation zones.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46459319","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Similar but Different: RBR E3 Ligases and their Domains that are Crucial for Function","authors":"George Sung","doi":"10.26443/msurj.v12i1.45","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.45","url":null,"abstract":"Background: The E3 ubiquitin ligases can be subdivided into four distinct types (RING, HECT, U-box, and RBR type) based on their domain architecture and ubiquitin transfer mechanism. Recent structures of different RBR E3 ligases have been solved showing enzymes in their autoinhibited state. The only exception is HOIP/ HOIL-1L which was recently solved in its “active” conformation. This review discusses the structural and functional characteristics of three different members of the RBR E3 ubiquitin ligase family: Parkin, HOIP/HOIL-1L, and HHARI.\u0000Methods: Searches were performed using PubMed. Search term includes “RBR E3 Ligase”, “Parkin”, “HOIP/ HOIL-1L”, “HHARI”, “UbcH7”, and “E2”. In the end, 25 journal articles were selected as the foundation of this review. The structural coordinates of Parkin, HOIP, and HHARI were accessed from the PDB (www.rcsb.org) with the PDB IDs 4ZYN, 5EDV, and 4KBL, respectively.\u0000Summary: Currently, most solved RBR E3 ligase structures are only in their inactive forms, except for HOIP/ HOIL-1L, and these inactive forms provide valuable information on how these proteins are regulated in vivo. All the RBR E3 ligases have common domains, but their structures and functions are heavily dependent on their accessory domains, which serve as regulators that orchestrate certain ubiquitin chain syntheses and play a role in the autoinhibition of RBR E3 ligases. Although these domains are structurally different, they use distinct molecular interactions to achieve the same goal. While the regulation of most RBR E3 ligases has been extensively studied, more structural studies are required to further characterize the mechanism that these enzymes use to build different ubiquitin chains. Understanding the mechanisms underlying the formation of each type of ubiquitin chain could help elucidate their functions and related pathways.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45251876","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Role of Ubiquitin in the Survival of Legionella pneumophila in Eukaryotic Host Cells","authors":"Siwei Wang","doi":"10.26443/msurj.v12i1.44","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.44","url":null,"abstract":"Background: Eukaryotic cells use essential ubiquitin-mediated pathways in their defense against pathogenic bacteria, such as Legionella pneumophila, the intracellular pathogen of Legionnaire’s disease. Despite the protective role of these pathways, L. pneumophila virulence has evolved to secrete numerous effector proteins involved in co-opting host ubiquitin-mediated processes to facilitate their survival. Many of these effector proteins are of great research interest in the quest to demystify the molecular mechanisms underlying L. pneumophila pathogenesis as the bacterium has a vast repertoire of effector proteins.\u0000Methods: Articles were obtained from scientific literature databases such as PubMed and the McGill library. Selected articles provided an overview of the ubiquitination pathway, eukaryotic autophagy, L. pneumophila pathogenesis, and structural and functional analysis of L. pneumophila and other bacterial effectors involved in subverting host ubiquitin systems.\u0000Summary: This review discusses the current structural and functional characterization of L. pneumophila protein effectors involved in exploiting host ubiquitin machinery to facilitate intracellular bacterial survival. These protein effectors include those with E3 ubiquitin ligase activity, LubX, AnkB, and SidC, which respectively mediate bacterial nutrient acquisition, temporal regulation of other effectors, and remodelling of the L. pneumophila replicative niche; the SidE family of effectors, which mediates the first novel, single-enzyme ubiquitination pathway and deubiquitination; and ravZ, a protease promoting evasion of host autophagy. However, the exact molecular functions and biological consequences of these effectors as well as the full repertoire of L. pneumophila effectors facilitating ubiquitin-mediated survival still require further investigation.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45311680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Urban Biodiversity Through Sustainable Architecture and Urban Planning","authors":"Jacob Garrah, Katherine Berton, S. Chen","doi":"10.26443/msurj.v12i1.40","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.40","url":null,"abstract":"Background: In recent years, ecologists, architects, urban planners and decision makers, and citizens have become more aware of the importance of biodiversity in cities, creating a renewed effort to make cities and new developments better suited towards natural habitats. Sustainable architecture and design practices have offered ground to significant discovery and innovation in the art of city-building.\u0000Methods: A literature review of current practices in the Western world of the last twenty years and two case studies will be used to illustrate current efforts and future directions of biodiversity preservation.\u0000Summary: Integrating building strategies and holistic urban ecosystem development, compounded by encouraging interdisciplinary approaches that promote collaborative and bottom-up urban planning through community activism are the main trends in current sustainable city-building. The literature review is far from exhaustive and requires a historical perspective to better understand implications of past and present sustainability efforts. The paper serves as introduction to a promising field. Relationships between biodiversity preservation and urban planning and design need to be reinforced in order to build a more connected, healthy, and resilient community.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47668192","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Dirty Turtles: Examining the Effects of Persistent Pollutants on Embryonic Turtle Development","authors":"Jessica H. Ford","doi":"10.26443/msurj.v12i1.41","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.41","url":null,"abstract":"Background: In an anthropogenically-altered world, it is common to find pollutants such as plastics, pesticides, fertilizers, and heavy metals in waterways and soil. Many plastics, such as BPAs; organic chemicals that can absorb plastics, such as PCBs; and pesticides, such as atrazine, are known to be endocrine disrupting chemicals (EDCs). Many EDCs act as xenoestrogens and can affect the sexual development of numerous organisms, from mammals, such as humans; to reptiles, such as turtles. Turtles are long-living organisms that often have an omnivorous diet and demonstrate site fidelity, thus they are useful subjects in which to study the effect of EDCs on organismal development.\u0000Methods: In this study, the effects of plastics, pesticides, flame retardants, and heavy metals on developing turtle embryos were examined across a variety of both freshwater and marine turtles. A search of existing relevant literature was carried out in November of 2016 using the database Web Of Science and Google Scholar by looking for the keywords “turtles” AND “sex-reversal” AND “endocrine disrupting chemicals (EDCs)”, with no restrictions used on the years in which these studies were published. Web of Science returned 42 articles and Google scholar returned 3870 articles. Of these, 13 studies were deemed relevant and examined, encompassing 35 cases, and consisting of data from eight different species of turtles.\u0000Summary: It was found that plastics and PCBs, even in low doses, had the greatest effects on sex reversal across turtle species, and could affect their behavior later in life as well. Pesticides showed an ability to alter the sex of the turtle, and also caused developmental defects. Flame-retardants and heavy metals were shown to be maternally transferred to offspring, but studies did not find obvious cases of sex reversal or developmental defects at low doses. Many turtle species are endangered, and thus understanding threats to their health and development is critical to their future survival.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46257990","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Examining the Effects of Covered Landfills on Gas Emissions in Parc Baldwin, Montreal","authors":"Kathryn Elmer, Melanie B. Greenwald, Erik E. Johnson","doi":"10.26443/msurj.v12i1.39","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.39","url":null,"abstract":"Background: Within recent years, parks built on top of former landfills have come under scrutiny for their effectiveness at mitigating the effects of the landfill underneath. The purpose of this study is to identify the biogas emissions of converted landfills nearly a century after landfill closure.\u0000Methods: Soil and air emissions for methane and carbon dioxide were collected at 112 sites within the North and South portions of Parc Baldwin in Montreal, Quebec, as well as the presumed boundaries of the former landfill.\u0000Results: Overall, it was found that South Baldwin and the immediate area (previously a landfill) had a higher mean average methane concentration, as well as a greater number of sites with methane present than North Baldwin. Particular raised areas in South Baldwin showed anomalously high carbon dioxide concentrations. There was a large degree of heterogeneity between emissions at different sites.\u0000Limitations: The Eagle 2 machine is limited to measuring only up to 5,000 ppm or 0.5% volume. Another difficulty with the variation in collection of the data is the differences in collection dates.\u0000Conclusions: Ultimately, while South Baldwin did have higher CO2 and methane emissions compared to its counterpart, it is inconclusive whether or not this phenomenon is related to the landfill or other factors. Gas concentrations were significantly below the lower explosive limit in both parks.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49372496","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Melatonin and its Receptors","authors":"Seung Hyun Min, G. Gobbi, L. Posa","doi":"10.26443/msurj.v12i1.43","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.43","url":null,"abstract":"Background: Melatonin (5-methoxy-N-acetyltryptamine) is a hormone that has numerous physiological functions. Synthesized and released during nighttime, melatonin exerts its physiological effects in a circadian manner. Melatonin acts by binding to its different types of receptors. The purpose of this systematic review is to summarize recent findings about melatonin, its receptors, and the differential functionalities of the most characterized melatonin receptors MT1 and MT2.\u0000Methods: We searched PubMed and Google Scholar for studies that reported melatonin receptor subtypes, their differential functionalities, biochemical structures, signal transductions, and various functions of melatonin such as pain, sleep, temperature, and antioxidative effects. We chose seventy articles for this systematic review.\u0000Summary: These studies highlight melatonin’s range of physiological functions and the differential functionalities of the melatonin receptors MT1 and MT2; they characterize the receptors’ signal transduction cascades and their biochemical structures. More studies assessing melatonin receptors’ functions would help patients with disorders in sleep, pain, and circadian rhythm.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42637604","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Are species largely redundant? Testing the reliability of increasingly complex trait-based classifications in understanding Canadian Arctic ecosystems","authors":"G. Y. Haage","doi":"10.26443/msurj.v12i1.37","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.37","url":null,"abstract":"Background: In recent years, some ecologists have advocated the use of functional groups instead of direct species in linking site composition to the environment. They could potentially reveal connections between distant sites and aid in the formation of widely-applicable environmental policies. Several studies have compared the efficiency of using functional groups, in which species are grouped based on functional traits, like feeding method or size, to using species directly. However, few have looked at the effect of varying the complexity of functional groups when compared to species data. This study compares functional group classes of varying complexity, with complexity defined as the number of traits considered, to species data. The hypothesis that more complex functional group classes, compared to less complex classes, tend to approach the results obtained when using taxonomy, is tested.\u0000Methods: In testing this hypothesis, this study uses site composition data from aquatic floor (benthic) ecosystems in the Canadian Arctic. Four functional traits were considered important to describe these species: Bioturbation (sediment disturbance), body size, feeding habit and mobility. These traits were used to segregate species into functional groups of varying complexity, with complexity level determined by the number of traits (out of four) being used. Four environmental characteristics were considered for each site: Chlorophyll a, phaeopigments, depth and salinity. In order to test how similar functional group data is to species data, we sought to determine whether the same environmental variables were important in explaining site composition. This was determined by BIO-ENV analyses and Spearman Rank correlations. Mantel permutation tests then determined whether the correlations were significant.\u0000Results: While all levels of complexity, from one to four functional traits, showed some significant correlations (Spearman Rank ≥0.5, p≤ 0.05) between site composition and environmental variables, there was no general trend suggesting functional group complexity correlates with greater similarity to taxonomic data. For presence/absence data, all functional results, regardless of complexity, pinpointed only phaeopigments as important, while presence/absence species data also included chlorophyll a and depth. All results with strong and significant correlations (r≥0.5 p≤ 0.05), regardless of data type or complexity, maintained a measure of food supply (Chlorophyll a or phaeopigments), demonstrating its importance in determining ecosystem composition at these sites.\u0000Limitations: Potential improvements include measuring traits directly from the organisms, considering more environmental variables and increasing the number of functional traits considered. Which traits are considered also vary with each study.\u0000Conclusions: The hypothesis was not validated by the results. When pinpointing the most complex functional group class (the most important variable), rath","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48763670","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CBS Domain: Its Structure, Ligand Binding, and Emerging Role in Regulation","authors":"David A. Scarlata","doi":"10.26443/msurj.v12i1.42","DOIUrl":"https://doi.org/10.26443/msurj.v12i1.42","url":null,"abstract":"Background: Cystathionine β-synthase (CBS) domains are structurally conserved motifs that are present in the proteomes of species from all kingdoms of life. Signifying their importance are the hereditary diseases resulting from mutations within the CBS sequence. They are usually encoded in tandem within a plethora of non-functionally related cytosolic or transmembrane proteins, often intramolecularly dimerizing to afford what is known as a CBS pair or Bateman module. It is also known that these CBS pairs can further multimerize to form higher-order assemblies, which have functions that remain to be elucidated. Moreover, a wide range of adenosyl ligands, divalent cations and nucleic acids have been documented to bind CBS domains and induce conformational changes to the larger protein in which they reside, thus suggesting their involvement in protein regulation in response to intracellular energy status.\u0000Methods: This review was written based on the existing data currently available in the literature and included findings from 44 papers. Selection of papers was based on those that provided up-to-date information on the structural characteristics of CBS domains and their involvement in protein regulation.\u0000Summary: This review aims to conceptualize the architectural characteristics of CBS domains, the structural basis of ligand binding, and its involvement in the regulation of protein function.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2017-04-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44208007","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}