McGill Science undergraduate research journal : MSURJ最新文献

{"title":"Hochschild Cohomology of the Cohomology Algebra of Closed Orientable Three- Manifolds","authors":"Qiufen Wang","doi":"10.26443/msurj.v16i1.61","DOIUrl":"https://doi.org/10.26443/msurj.v16i1.61","url":null,"abstract":"Let F be a field of characteristic other than 2. We show that the zeroth Hochschild cohomology vector space HH0(A) of a degree 3 graded commutative Frobenius F-algebra A = iAi, where we will always assume A0 = F, is isomorphic to the direct sum of the degree 0, 2 and 3 graded components and the kernel of a certain natural evaluation map ιμ : A1 Λ2(A1). In particular, this holds forA = H∗(M; F) the cohomology algebra of a closed orientable 3-manifoldM. In Theorem A of [1], Charette proves the vanishing of a certain discriminantΔassociated to a closed orientable 3-manifold L with vanishing cup product 3-form. It turns out that if we could show that HH2,−2(A) = 0for A = H∗(L;C), we would have found a more elementary proof of this part of Charette’s theorem. We show that for any β 3, the degree 3 graded commutative Frobenius algebra A with μA = 0and dim(A1) = β satisfiesHH2,−2(A) = 0. Thus Charette’s theorem is not simplified.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"44935093","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":"EPR Paradox, Einstein-Rosen bridges and teleportation","authors":"Florian Seefeld","doi":"10.26443/msurj.v16i1.64","DOIUrl":"https://doi.org/10.26443/msurj.v16i1.64","url":null,"abstract":"In this review, we go over the bases of quantum teleportation, ER bridges in General relativity, and the foundational work on the hypothesis ER=EPR and summarize the resulting wormhole teleportation protocol. We then discuss that − resulting from ER=EPR − certain wormholes have to be either traversable or at the very least let information permeate, resulting in the exploration of the possibility that incoming matter might change the metric outside of wormhole throats. In this study, made in the Schwarzschild metric with the original coordinate system, we managed to find a non-zero energy-momentum tensor produced by a particular solution of the electromagnetic wave equation in curved spacetime, implying a change in the overall metric by Einstein’s Equation.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2021-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45559721","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":"The Effects of Psychosocial Stress and Sex Differences on Cognitive Effort Avoidance","authors":"Noa Givon","doi":"10.26443/msurj.v15i1.7","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.7","url":null,"abstract":"Background: Recent research suggests stress may affect cognitive performance including memory, executive functioning, decision-making, and task-switching. However, it is unknown whether these effects are aversive or advantageous for effort exertion. This experiment aimed to evaluate the effects of acute psychosocial stress on willingness to exert cognitive control processes in a cognitive-effort-based decision-making task.Methods: To test this, 40 participants (20 female) in a within-subject, fully crossed, randomized design, were exposed to both a psychosocial stress induction condition (the Trier Social Stress Test; TSST) and a control condition. Subsequently, they underwent the Demand Selection Task (DST) that tests for participants’ effort aversion by manipulating switch probabilities in a task-switching paradigm. Results and Conclusion: The induction of stress did not lead to significant error or accuracy rates, or significant differences in cognitive effort avoidance. Previous research indicated sex differences in response to stress. However, there is a lack of data on sex differences in the avoidance of demanding cognitive processes. Therefore, we assessed sex differences in the DST and found that women were more likely to avoid cognitive effort, choosing the less cognitively demanding cue more often than men. Limitations: A limitation of this study is the small sample size. Future research should increase the sample size and take individual differences in stress responders, type of stressor, and biases on effort exertion into account.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"42464705","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":"An Evaluation of Microplastics in Lac Hertel Sediment Over Time","authors":"E. Brown, Laura Mackey, Libby Rothberg, M. Burnett, Noel B. Bergeron, Yael Lewis","doi":"10.26443/msurj.v15i1.8","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.8","url":null,"abstract":"Background: Microplastics, defined as plastic smaller than 5 mm, are pervasive in both marine and freshwater ecosystems. Humans, zooplankton, and fish have been shown to ingest microplastics, which could have detrimental health impacts. Consequently, this project investigated the question: are there microplastics in the sediment of Lac Hertel, located in the Mont Saint Hilaire Biosphere Reserve in Quebec, and if so, how has the amount of microplastics changed over time?Methods: One sediment core was obtained from the centre of the lake and one was obtained from the edge near the mesocosm dock. Next, one section from the top, middle, and bottom of each core was collected. Afterwards, the microplastics were extracted from the sediments, counted with a dissecting microscope under regular light, and a subset of fragments were tested with a hot needle to confirm that they were plastic.Results: A generalized linear model indicated that the number of microplastics in our samples increased significantly over time and that the sediment samples from the mesocosm dock had significantly fewer microplastics than the lake’s centre. Similarly, a Pearson correlation test revealed that an increasing sediment depth had a significantly negative relationship with the number of microplastics at the lake’s centre. However, another Pearson correlation test determined that this trend was not reflected at the mesocosm dock, potentially because of sediment focusing.Limitations: Due to resource and time constraints, we had a small sample size, only analyzed microplastics larger than 250 µm, and counted microplastics instead of weighing them.Conclusion: Our results suggest that there has been a significant increase in microplastics in Lac Hertel sediment over time. Ultimately, our results emphasize the need to mitigate plastic pollution.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48163121","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":"Leukemia Inhibitory Factor (LIF) Modulation: a Novel, Non-Hormonal Contraceptive Method","authors":"Hannah Dolin","doi":"10.26443/msurj.v15i1.13","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.13","url":null,"abstract":"Background: Numerous studies have demonstrated that Leukemia Inhibitory factor (LIF) plays an essential role in embryonic implantation. Vaginal application of pegylated LIF antagonists can successfully prevent implantation and pregnancy in mice. The development of non-hormonal, female-controlled contraceptives is imperative, as combined oral contraceptives are associated with depression and are not feasible for use in all women.Methods: This paper reviews 44 studies regarding LIF, implantation, hormonal contraceptives and the use of LIF antagonists as a means to inhibit pregnancy.Summary: Current research indicates that LIF-modulation could be effective as a non-hormonal contraceptive method, although researchers should be wary of the negative side effects associated with systemic LIF modulation. Vaginal application of LIF antagonists could decrease the risk of negative side effects.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43804252","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":"Correlations of Fundamental Social Motives with Personality Measures and Life History Variables","authors":"Mana Moshkforoush","doi":"10.26443/msurj.v15i1.10","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.10","url":null,"abstract":"Background: In response to the replication crisis in the field of psychology, the authors conduct a replication of the Neel et al. (2016) (1) study examining individual differences in fundamental social motives. Methods: Using the Fundamental Social Motives Inventory, we explore the relationships of the fundamental social motives to other individual differences and personality measures and the extent to which life history variables (e.g., age, sex, childhood environment) predict individual differences in the fundamental social motives. In addition to the replication study, the authors also incorporate the Behavioral Inhibition/Activation Scale (BIS/BAS) as a new variable to determine this measure of personality’s correlation with all seven fundamental social motives of Self-Protection, Disease Avoidance, Affiliation, Status, Mate Seeking, Mate Retention, and Kin Care. A total of 34 participants are recruited from Amazon Mechanical Turk to complete the measures of personality under question. The replication criteria are set at ±0.15 r/β-units from the original study results and effect sizes greater than or equal to r/β=0.5 have to demonstrate statistical significance at the p<0.05 level.Results: Results demonstrate that between a third and a half of all effect sizes replicate Neel et al.’s (1) findings.Limitations: These results should be considered carefully with respect to the low sample size of our study.Conclusion: The BIS/BAS variable proves to be most informative, indicating that the seven motives cluster under either the BIS or BAS factors with medium to large strengths of correlation. These findings contribute to discussions on considering the most accurate measures of social motivation and the implications of individual differences in psychology’s understanding of such motivational systems.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45858075","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":"Gestational and early postnatal exposure to a mixture of organophosphate ester flame retardants found in Canadian house dust on hindlimb skeletal development in postnatal day 4 rats","authors":"Charlise Xinyi Chen, Han Yan, B. Hales","doi":"10.26443/msurj.v15i1.5","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.5","url":null,"abstract":"Background: Ever since organophosphate esters (OPEs) became the mainstream replacement for organobromine compounds in fire retardants (FRs), numerous studies have explored their potential as endocrine disruptors and developmental toxicants. The purpose of this study is to investigate the impact of gestational and early postnatal exposure of OPE mixtures on the ossification of hindlimb phalangeal in postnatal day 4 (PND4) rat pups, as the amount of OPEs within the diet mixture is relative to its composition in Canadian household dust.Methods: Male and female adult Charles River Sprague-Dawley rats were exposed to OPE mixtures for 70 and 21 days, respectively. The OPE doses were determined to be 10x, 1,000x, and 30,000x the relative human exposure. The progenies were exposed to OPEs both gestationally (~21 days) and lactationally (4 days). At least 2 of each sex from each litter were sacrificed and processed at PND4 for skeletal staining using Alizarin red and Alcian blue. The samples were analyzed and compared against a reference sample to examine any abnormalities in ossification.Results: At PND4, there is no significant effect of OPEs on the number of pups with abnormal ossification between the control and treatment groups. High doses of OPEs, at concentrations 30,000x of relative human exposures, showed a significant increase in the severity of delay of ossification at the middle phalanx of PND4 pups.Limitations: Due to the limitation of small sample sizes (litter n=6-7) and a wide variance in data, there is no clear evidence on whether OPE exposure induces greater incidences of abnormal ossification in the digits of PND4 pups.Conclusion: There is a delay in ossification from OPE exposure at the high dose (30,000x).","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46282414","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":"Emergency Rainwater Harvesting, Water Storage, and Distribution System for an Affordable Housing Development in Barbados","authors":"Laura Vanderweyen, X. Zhang, Vladislav Zasmolin","doi":"10.26443/msurj.v15i1.11","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.11","url":null,"abstract":"Background: To sustain both permanent residents and an intense tourism industry, Barbados overpumps its sole source of natural freshwater—the aquifer. Climate change is projected to increase both storm intensity and drought, further hampering groundwater recharge. These intense rainfalls quickly saturate topsoil and result in extensive surface run-off that causes flooding, erosion, sedimentation, and eutrophication. By providing more water for households and reducing aquifer withdrawal, rainwater harvesting has the potential to both mitigate water scarcity and reduce the amount of harmful run-off. However, rainwater harvesting is not currently practiced in Barbados. This paper proposes a hurricane-resistant rainwater harvest, storage, and distribution system to be implemented in an affordable housing community in St. Thomas, Barbados.Methods: In the creation of the distribution system design, social, economic and environmental concepts need to be considered. We first conducted a field survey within the neighbourhood to understand what the residents felt the local water supply lacked. Afterwards, we performed a detailed rainfall analysis to determine the amount of rainwater that can realistically be captured. Finally, we consulted with various academic experts, local industry members, and supply stores to determine an affordable design.Results: Our findings suggest that an initial household investment of $2790.90 BBD appears adequate to provide a system for rainwater harvesting, dual plumbing, and communal distribution which can withstand and utilize 1/50 years storms.Limitations: Given that rainwater harvesting is not currently practiced in Barbados, government initiatives are needed to encourage its development.Conclusion: Affordable rainwater harvesting, dual plumbing, and community distribution systems can be implemented to possibly reshape life in countries facing water scarcity.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48558450","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":"Delivering the “Living Drug”: T Cell Immunotherapy","authors":"L. Rendon","doi":"10.26443/msurj.v15i1.14","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.14","url":null,"abstract":"Background: Cancer is one of the most lethal diseases worldwide. Traditional approaches such as chemotherapy have toxic side e!ects. New therapies on the rise are more target specific. One such therapy, immunotherapy, has become increasingly attractive in the field. However, to ensure the modulated and controlled manipulation of the immune system, delivery methods for drugs cells and biomaterials must be developed.Methods: In this review, we analyze the literature to discuss the recent advances in T cell immunotherapy as well as four delivery technologies that address the issues of safety and efficacy associated with this treatment.Summary: We conclude that the CAR-T approach could be a step towards overcoming the inaccessibility of poorly vascularized tumors and the evasion mechanisms of tumor cells. Delivery methods such as surface conjugated nanoparticles, DNA nanocarriers, scafolds and artifcial antigen-presenting cells aim for a more tumor-targeted approach rather than a systemic one, making this therapy applicable in the clinic.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"48884862","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":"Seeing the Forest for the Deer: Plant Abundance and Diversity at the Gault Nature Reserve During a Spike in White-Tailed Deer","authors":"Mackenzie Burnett, Imogen Hobbs, Alexa Ripple","doi":"10.26443/msurj.v15i1.4","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.4","url":null,"abstract":"Background: Deer populations have been rising across North America for decades. At the Gault Nature Reserve in Quebec, half of which is open to the public, the population of white-tailed deer (Odocoileus virginianus) has exceeded the region’s carrying capacity, estimated to be 5 deer/km2, since 1996. Given that heavy grazing profoundly impacts forests, the purpose of this paper was to investigate the potential influence of white-tailed deer on plant abundance and diversity at the Gault Nature Reserve. We hypothesized that the abundance of deer, and by extension the effect of deer on vegetation, was negatively correlated with the proximity and frequency of human visitors on pedestrian trails. Our alternative hypothesis was that the effect of deer on vegetation was positively correlated with human disturbance, which is greater on the public side of the reserve.Methods: We recorded the abundance and diversity of vascular plants along 14 transects of increasing distance from pedestrian trails on the public and private sides of the reserve.Results: Contrary to our hypothesis, generalized linear models indicated that overall, plant abundance and diversity declined significantly as the distance from trails increased and that the effect of distance was significantly different on the two sides of the reserve. Pearson correlation tests revealed that there was not a significant correlation between distance and plant abundance and diversity on the public side, although there was a significantly negative correlation between these variables on the private side.Limitations: White-tailed deer were not directly studied, which limited the inferences that could be made about their influence on plant abundance and diversity.Conclusion: The distance from trails was a strong determinant of plant abundance and diversity on the private of the reserve, but not on the public side, possibly because trail edges generally receive more sunlight and because the increased number of trails on the public side may have confounded our results. Although we did not find support for our hypothesis, the influence of trail edges on plant communities was reinforced. Researchers should continue to monitor the influence of white-tailed deer and forest managers should be mindful of edge effects when making decisions.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":" ","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-04-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46991789","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}