McGill Science undergraduate research journal : MSURJ最新文献_第4页

Hochschild Cohomology of the Cohomology Algebra of Closed Orientable Three- Manifolds 闭可定向三流形上同调代数的Hochschild上同调

McGill Science undergraduate research journal : MSURJ Pub Date : 2021-04-15 DOI: 10.26443/msurj.v16i1.61

Qiufen Wang

引用次数: 0

Effects of adolescent cannabinoid administration in mice on behavioural inhibition and susceptibility to stress during adulthood 青少年大麻素对成年期小鼠行为抑制和应激易感性的影响

McGill Science undergraduate research journal : MSURJ Pub Date : 2021-04-15 DOI: 10.26443/msurj.v16i1.57

Armaan Fallahi, Giovanni Hernandez, Jose-Maria Restrepo Lozano, Cecilia Flores

{"title":"Effects of adolescent cannabinoid administration in mice on behavioural inhibition and susceptibility to stress during adulthood","authors":"Armaan Fallahi, Giovanni Hernandez, Jose-Maria Restrepo Lozano, Cecilia Flores","doi":"10.26443/msurj.v16i1.57","DOIUrl":"https://doi.org/10.26443/msurj.v16i1.57","url":null,"abstract":"Background: Cannabis is one of the most frequently used substances by adolescents. Early exposure to psychoactive compounds has been shown to alter normal brain development and has consequences for psychiatric illness and behaviour in adulthood. In this study, we explored the effects of adolescent synthetic cannabinoid exposure on susceptibility to stress in adulthood, in addition to changes in impulsive behaviour.\u0000Methods: Chronic treatment with synthetic cannabinoid WIN55,212-2 (WIN) at various doses in adolescent mice was followed by the chronic social defeat stress paradigm in adulthood to assay changes in susceptibility to stress. We then employed the operant Go/No-Go task to investigate changes in impulsivity.\u0000Results: No changes in susceptibility to stress were identified (χ2(3)=0.585, p=0.900). Strikingly, we demonstrated a dose dependent decrease in impulsivity of adolescent WIN-treated subjects as measured using the Go/No-Go task (F(3, 20)=5.743, p=0.0053).\u0000Limitations: The main limitation of our findings is the small sample size, particularly for assaying changes in susceptibility to stress using the chronic social defeat stress paradigm. Furthermore, the single housing of animals and suboptimal performance of controls may have affected our findings in the Go/No-Go task.\u0000Conclusion: Overall, this study presents a novel behavioural finding consequent to adolescent exposure to cannabinoids. Further research into the long-term effects of cannabinoid use in adolescence is needed, especially in light of its prevalent use and legalization in Canada.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49263554","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}

引用次数: 0

Molecular Dynamical Investigation of the 7,8-dihydro-8-oxoguanine Mutation in dsDNA dsDNA中7,8-二氢-8-氧鸟嘌呤突变的分子动力学研究

McGill Science undergraduate research journal : MSURJ Pub Date : 2021-04-15 DOI: 10.26443/msurj.v16i1.56

I. Dementyev, Ashkan Karimi

{"title":"Molecular Dynamical Investigation of the 7,8-dihydro-8-oxoguanine Mutation in dsDNA","authors":"I. Dementyev, Ashkan Karimi","doi":"10.26443/msurj.v16i1.56","DOIUrl":"https://doi.org/10.26443/msurj.v16i1.56","url":null,"abstract":"Background: The oxidization of a Guanine (G) base pair to 7,8-dihydro-8-oxoguanine (OG) is one of the most common DNA mutations. OG mutations can undergo a regular Watson-Crick base-pairing, or a reverse Hoogsteen (HG) base-pairing, especially in OG:A mismatches. While the causes of these mutations are well-understood, the kinetic and energetic characteristics of this new pseudo-base have never been fully investigated, especially at temperatures around biological function (17-37°C).\u0000Methods: We created a simulation to derive the Free Energy Surface (FES) of OG:C and OG:A Hoogsteen to Watson-Crick base-pair (bp) transitions under multiple temperatures, relative to 2 collective geometric variables: the dihedral Chi and the pseudo-dihedral CPD angle. To make the simulation, we used the relatively recent Metadynamics algorithms in conjunction with GROMACS 2020.2.\u0000Results: The lowest free energy increased linearly with increasing temperatures (17-37°C). Major Chi and CPD rotations at these minima varied heavily for 27°C and 32°C (the largest was seen in the former), but stayed relatively similar for other temperatures, indicating a highly sensitive relationship to temperature, likely due to DNA flexibility, quantum mechanical (QM) effects, and hydrogen bonding. Free energies had a weak negative linear relationship, and free energy hypersurfaces were given for studied temperatures of 17-37°C. Human body temperature (37°C) results were also included and explained. The simulations showed why OG:A Hoogsteen bps often occur in organisms and are energetically preferable to standard Watson-Crick. OG:C HG base pairings are determined to likely be not as common as OG:A HG.\u0000Limitations: Future investigations must focus on discovering rate constants of these base-pairs, as time constraints did not permit them to be done here, as well as more QM-focused simulations.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2021-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47042751","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}

引用次数: 1

EPR Paradox, Einstein-Rosen bridges and teleportation EPR悖论，爱因斯坦-罗森桥和瞬间传送

McGill Science undergraduate research journal : MSURJ Pub Date : 2021-04-15 DOI: 10.26443/msurj.v16i1.64

Florian Seefeld

引用次数: 0

The Effects of Psychosocial Stress and Sex Differences on Cognitive Effort Avoidance 心理社会压力和性别差异对认知努力回避的影响

McGill Science undergraduate research journal : MSURJ Pub Date : 2020-04-13 DOI: 10.26443/msurj.v15i1.7

Noa Givon

{"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":null,"pages":null},"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}

引用次数: 0

An Evaluation of Microplastics in Lac Hertel Sediment Over Time 赫特尔湖沉积物中微塑料随时间变化的评价

McGill Science undergraduate research journal : MSURJ Pub Date : 2020-04-13 DOI: 10.26443/msurj.v15i1.8

E. Brown, Laura Mackey, Libby Rothberg, M. Burnett, Noel B. Bergeron, Yael Lewis

{"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":null,"pages":null},"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}

引用次数: 0

Leukemia Inhibitory Factor (LIF) Modulation: a Novel, Non-Hormonal Contraceptive Method 白血病抑制因子（LIF）调节：一种新的非激素避孕方法

McGill Science undergraduate research journal : MSURJ Pub Date : 2020-04-13 DOI: 10.26443/msurj.v15i1.13

Hannah Dolin

引用次数: 1

Correlations of Fundamental Social Motives with Personality Measures and Life History Variables 基本社会动机与人格测量和生活史变量的相关性

McGill Science undergraduate research journal : MSURJ Pub Date : 2020-04-13 DOI: 10.26443/msurj.v15i1.10

Mana Moshkforoush

{"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":null,"pages":null},"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}

引用次数: 0

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 妊娠期和产后早期暴露于加拿大房屋粉尘中发现的有机磷酸酯阻燃剂混合物对出生后第4天大鼠后肢骨骼发育的影响

McGill Science undergraduate research journal : MSURJ Pub Date : 2020-04-13 DOI: 10.26443/msurj.v15i1.5

Charlise Xinyi Chen, Han Yan, B. Hales

{"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":null,"pages":null},"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}

引用次数: 0

Emergency Rainwater Harvesting, Water Storage, and Distribution System for an Affordable Housing Development in Barbados 巴巴多斯经济适用房开发的应急雨水收集、储水和分配系统

McGill Science undergraduate research journal : MSURJ Pub Date : 2020-04-13 DOI: 10.26443/msurj.v15i1.11

Laura Vanderweyen, X. Zhang, Vladislav Zasmolin

{"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":null,"pages":null},"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}

引用次数: 0