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.
{"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":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":"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}
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.
{"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":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":"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}
Background: Ethnocentrism is defined as an individual’s tendency to favor in-group members at the expense of out-group members. Recent computer simulations have studied its evolution by modelling cooperative and defective behaviours in a Prisoner’s Dilemma framework. Methods: This paper introduces reciprocity to the study of ethnocentrism and extends Hammond and Axelrod’s agent-based model by simulating the effects of five new genotypic strategies. (1) Results: In stable-state outcomes, although ethnocentrism still dominates, moderate ethnocentrism (in-group cooperation and out-group reciprocity) is more frequent than humanitarianism and is by far the most adaptive out of all reciprocal strategies. Because it is the only reciprocal strategy that cooperates with in-group members, we conclude that it is thanks to in-group cooperation that moderate ethnocentrism is successful, which confirms previous research findings. Additionally, throughout early and late evolutionary patterns, we see that moderate ethnocentrism benefits and suffers from the characteristics of both ethnocentrism and humanitarianism, which may explain why ethnocentrism still emerges as the dominant strategy overall. Conclusion: The strengths of the present model lie in its ability to abstractly model reciprocal behaviours in the study of ethnocentrism and may be more externally valid than Hammond and Axelrod’s original agent-based model. (1) However, this model does not take in account other factors that play a role in human decision-making, such as social context, learning, or development, which could be topics of future computational simulations on ethnocentrism.
{"title":"Implications of Reciprocity in the Evolution of Ethnocentrism and Cooperation","authors":"R. Feng","doi":"10.26443/msurj.v15i1.6","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.6","url":null,"abstract":"Background: Ethnocentrism is defined as an individual’s tendency to favor in-group members at the expense of out-group members. Recent computer simulations have studied its evolution by modelling cooperative and defective behaviours in a Prisoner’s Dilemma framework. Methods: This paper introduces reciprocity to the study of ethnocentrism and extends Hammond and Axelrod’s agent-based model by simulating the effects of five new genotypic strategies. (1) Results: In stable-state outcomes, although ethnocentrism still dominates, moderate ethnocentrism (in-group cooperation and out-group reciprocity) is more frequent than humanitarianism and is by far the most adaptive out of all reciprocal strategies. Because it is the only reciprocal strategy that cooperates with in-group members, we conclude that it is thanks to in-group cooperation that moderate ethnocentrism is successful, which confirms previous research findings. Additionally, throughout early and late evolutionary patterns, we see that moderate ethnocentrism benefits and suffers from the characteristics of both ethnocentrism and humanitarianism, which may explain why ethnocentrism still emerges as the dominant strategy overall. Conclusion: The strengths of the present model lie in its ability to abstractly model reciprocal behaviours in the study of ethnocentrism and may be more externally valid than Hammond and Axelrod’s original agent-based model. (1) However, this model does not take in account other factors that play a role in human decision-making, such as social context, learning, or development, which could be topics of future computational simulations on ethnocentrism.","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":"44260265","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}
Alexandra Machalani, Amanda Gallant, Victoria Orha, N. Ostbo, Eric Hehman
Background: Cognitive misers are no happy fools. Earlier findings (1) came to this conclusion by assessing people’s sensitivity to attribute substitution, which they defined as the situation that occurs when we are confronted with a problem that demands greater cognitive effort, for which we rely on automatic and intuitive processes that substitute the complex situation for an easier one. Methods: Through the exploration of the “bat-and-ball” problem, (2) De Neys, Rossi, and Houdé (1) found that participants were indeed sensitive to the substitution bias. Specifically, participants who incorrectly answered the question that gave rise to the substitution bias were significantly less confident in their answer relative to their answer on a control problem that did not give rise to the substitution. Using the same methods, we conducted a direct replication study on a sample of 264 undergraduate psychology students. Results and Conclusion: Our results suggest that we successfully replicated the original conclusions; participants who answered by substituting the difficult question for an easier one significantly (p<.0001) decreased their confidence ratings on the version of the problem that gave rise to the substitution bias, relative to the problem that did not. Limitations: Though there may have been limitations, it seems that we are sensitive to attribute substitution.
{"title":"Substitution Sensitivity and the Bat-and-Ball Problem: A Direct Replication of De Neys et al. (2013)","authors":"Alexandra Machalani, Amanda Gallant, Victoria Orha, N. Ostbo, Eric Hehman","doi":"10.26443/msurj.v15i1.9","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.9","url":null,"abstract":"Background: Cognitive misers are no happy fools. Earlier findings (1) came to this conclusion by assessing people’s sensitivity to attribute substitution, which they defined as the situation that occurs when we are confronted with a problem that demands greater cognitive effort, for which we rely on automatic and intuitive processes that substitute the complex situation for an easier one. Methods: Through the exploration of the “bat-and-ball” problem, (2) De Neys, Rossi, and Houdé (1) found that participants were indeed sensitive to the substitution bias. Specifically, participants who incorrectly answered the question that gave rise to the substitution bias were significantly less confident in their answer relative to their answer on a control problem that did not give rise to the substitution. Using the same methods, we conducted a direct replication study on a sample of 264 undergraduate psychology students. Results and Conclusion: Our results suggest that we successfully replicated the original conclusions; participants who answered by substituting the difficult question for an easier one significantly (p<.0001) decreased their confidence ratings on the version of the problem that gave rise to the substitution bias, relative to the problem that did not. Limitations: Though there may have been limitations, it seems that we are sensitive to attribute substitution.","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":"47689347","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}
Introduction: Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a rare genetic disorder etiologically stemming from mutations in the FH gene. This disorder has been reported in 300 families worldwide. We were presented with the following case as part of the Rare Disease Interdepartmental Science Case Competition (RISCC) in order to successfully diagnose the patient and examine the pathophysiology, socioeconomics, and treatment strategy of this disorder.Case Presentation: A 27-year-old woman presented to the emergency room with a two-week history of hematuria. Her medical history included a single benign skin lesion. She did not report a family history of cancer but stated that her mother underwent a hysterectomy for unknown reasons.Clinical Investigations: An abdominal ultrasound revealed an isoechoic nodular formation on the right kidney, and CT scans confirmed the presence of a 7-cm renal tumour and extensive leiomyomas in the patient’s uterus. Genetic testing revealed a mutation in the fumarate hydratase (FH) gene, leading to the diagnosis of hereditary leiomyomatosis and renal cell carcinoma.Pathophysiology: HLRCC is a condition caused by an autosomal dominant germline mutation in the FH gene, characterized by skin lesions, uterine leiomyomas, and aggressive renal cell carcinoma. FH acts as a tumour suppressor gene and encodes the fumarase protein. HLRCC arises from a variety of missense mutations in the FH gene that prevent the formation of a full fumarase tetramer. The disease is likely related to the dosage of the gene, rather than the site of mutation. Consequently, there is no known genotype/phenotype correlation. Fumarate inhibits HIF-α hydroxylases, so loss of the FH gene causes fumarate accumulation within cells and prevents the degradation of HIF-α. This induces a state of pseudohypoxia and leads to upregulation of genes involved in cell growth and tumorigenesis. Fumarate accumulation also modulates the Keap1-Nrf2 pathway by inducing activation of Nrf2 and allows for the protection of cancer cells from oxidative and electrophilic stressors. Furthermore, deficiency of fumarase prevents oxidative phosphorylation, thus promoting aerobic glycolysis, the most common method of metabolism used by cancer cells.Socioeconomics: The risk of infertility and developing an aggressive cancer makes it essential to have frequent and thorough screening procedures early in life for children with a family history of HLRCC. Medical costs, infertility risk, and frequent hospital visits breed anxiety and stress for patients and family members. Fortunately, organizations like HLRCC Family Alliance exist to provide accessible information and represent a welcoming support community.Treatment Strategy: To treat the patient’s renal tumour, we suggest a radical nephrectomy with wide margins due to the aggressive nature of renal cell carcinoma. Additional imaging should be performed to identify and excise any metastatic tumours. The patient should als
{"title":"Clinical Manifestations of Hereditary Leiomyomatosis and Renal Cell Carcinoma: a Case Report","authors":"Jude Balit, Aanya Bhagrath, Marina Nysten, F. Rahman, Joyce Wu, Kejin Zhu","doi":"10.26443/msurj.v15i1.15","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.15","url":null,"abstract":"Introduction: Hereditary leiomyomatosis and renal cell carcinoma (HLRCC) is a rare genetic disorder etiologically stemming from mutations in the FH gene. This disorder has been reported in 300 families worldwide. We were presented with the following case as part of the Rare Disease Interdepartmental Science Case Competition (RISCC) in order to successfully diagnose the patient and examine the pathophysiology, socioeconomics, and treatment strategy of this disorder.Case Presentation: A 27-year-old woman presented to the emergency room with a two-week history of hematuria. Her medical history included a single benign skin lesion. She did not report a family history of cancer but stated that her mother underwent a hysterectomy for unknown reasons.Clinical Investigations: An abdominal ultrasound revealed an isoechoic nodular formation on the right kidney, and CT scans confirmed the presence of a 7-cm renal tumour and extensive leiomyomas in the patient’s uterus. Genetic testing revealed a mutation in the fumarate hydratase (FH) gene, leading to the diagnosis of hereditary leiomyomatosis and renal cell carcinoma.Pathophysiology: HLRCC is a condition caused by an autosomal dominant germline mutation in the FH gene, characterized by skin lesions, uterine leiomyomas, and aggressive renal cell carcinoma. FH acts as a tumour suppressor gene and encodes the fumarase protein. HLRCC arises from a variety of missense mutations in the FH gene that prevent the formation of a full fumarase tetramer. The disease is likely related to the dosage of the gene, rather than the site of mutation. Consequently, there is no known genotype/phenotype correlation. Fumarate inhibits HIF-α hydroxylases, so loss of the FH gene causes fumarate accumulation within cells and prevents the degradation of HIF-α. This induces a state of pseudohypoxia and leads to upregulation of genes involved in cell growth and tumorigenesis. Fumarate accumulation also modulates the Keap1-Nrf2 pathway by inducing activation of Nrf2 and allows for the protection of cancer cells from oxidative and electrophilic stressors. Furthermore, deficiency of fumarase prevents oxidative phosphorylation, thus promoting aerobic glycolysis, the most common method of metabolism used by cancer cells.Socioeconomics: The risk of infertility and developing an aggressive cancer makes it essential to have frequent and thorough screening procedures early in life for children with a family history of HLRCC. Medical costs, infertility risk, and frequent hospital visits breed anxiety and stress for patients and family members. Fortunately, organizations like HLRCC Family Alliance exist to provide accessible information and represent a welcoming support community.Treatment Strategy: To treat the patient’s renal tumour, we suggest a radical nephrectomy with wide margins due to the aggressive nature of renal cell carcinoma. Additional imaging should be performed to identify and excise any metastatic tumours. The patient should als","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":"41941657","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}
Background: Excitable media are spatially distributed systems that propagate signals without damping. Examples include fire propagating through a forest, the Belousov-Zhabotinsky reaction, and cardiac tissue. (1) Excitable media generate waves which synchronize cardiac muscle contraction with each heartbeat. Spatiotemporal patterns formed by excitation waves distinguish healthy heart tissues from diseased ones. (3) Discrete Greenberg-Hastings Cellular- Automaton (CA) (1) and the continuous FitzHugh- Nagumo (FHN) model (7) are two methods used to simulate cardiac wave propagation. However, previous observations have shown that these models are not accurately predictive of experimental results as a function of time. We hypothesize that cardiac simulations deviate from the experimental data at a rate that depends on the complexity of the experimental data’s initial conditions (I.C.).Methods: To test this hypothesis, we investigated two types of propagating waves with different complexities: a planar (i.e. simple) and a spiral wave (i.e. complex). With the same I.C., we first compared simulation results of a Greenberg-Hastings Cellular Automaton (GH-CA) model to that a FitzHugh-Nagumo (FHN) continuous model which we used as a surrogate for experimental data. We then used median-filtered real-time cardiac tissue experimental data to initialize the GH-CA model and observe the divergence of wave propagation in the simulation and the experiment.Results: The alignment between the CA model of a planar wave and the FHN model remains constant, while the degree of overlap between the CA and FHN models decreases for a spiral wave as a function of time. CA simulation initialized by a planar wave real-time cardiac tissue data propagates like the experimental data, however, this is not the case for the spiral wave experimental data.Conclusion: We were able to confirm our hypothesis that the divergence between the two models is due to initial condition (I.C.) complexity.Discussion: We discuss a promising strategy to represent a GH-CA model as a Convolutional Neural Network (CNN) to enhance predictability of the model when an initial condition is given by the experimental data with a higher level of complexity.
{"title":"Comparison of Complexity and Predictability of a Cellular Automaton Model in Excitable Media Cardiac Wave Propagation Compared with a FitzHugh-Nagumo Model","authors":"Yujing Zou, G. Bub","doi":"10.26443/msurj.v15i1.12","DOIUrl":"https://doi.org/10.26443/msurj.v15i1.12","url":null,"abstract":"Background: Excitable media are spatially distributed systems that propagate signals without damping. Examples include fire propagating through a forest, the Belousov-Zhabotinsky reaction, and cardiac tissue. (1) Excitable media generate waves which synchronize cardiac muscle contraction with each heartbeat. Spatiotemporal patterns formed by excitation waves distinguish healthy heart tissues from diseased ones. (3) Discrete Greenberg-Hastings Cellular- Automaton (CA) (1) and the continuous FitzHugh- Nagumo (FHN) model (7) are two methods used to simulate cardiac wave propagation. However, previous observations have shown that these models are not accurately predictive of experimental results as a function of time. We hypothesize that cardiac simulations deviate from the experimental data at a rate that depends on the complexity of the experimental data’s initial conditions (I.C.).Methods: To test this hypothesis, we investigated two types of propagating waves with different complexities: a planar (i.e. simple) and a spiral wave (i.e. complex). With the same I.C., we first compared simulation results of a Greenberg-Hastings Cellular Automaton (GH-CA) model to that a FitzHugh-Nagumo (FHN) continuous model which we used as a surrogate for experimental data. We then used median-filtered real-time cardiac tissue experimental data to initialize the GH-CA model and observe the divergence of wave propagation in the simulation and the experiment.Results: The alignment between the CA model of a planar wave and the FHN model remains constant, while the degree of overlap between the CA and FHN models decreases for a spiral wave as a function of time. CA simulation initialized by a planar wave real-time cardiac tissue data propagates like the experimental data, however, this is not the case for the spiral wave experimental data.Conclusion: We were able to confirm our hypothesis that the divergence between the two models is due to initial condition (I.C.) complexity.Discussion: We discuss a promising strategy to represent a GH-CA model as a Convolutional Neural Network (CNN) to enhance predictability of the model when an initial condition is given by the experimental data with a higher level of complexity.","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":"49114806","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}
Background: This study examines the monthly, seasonal, and interannual variations in Pacific Ocean heat transport entering the Arctic Ocean through the Bering Strait, and its influence on sea ice extent in the Arctic Ocean. Methods: Monthly ocean heat transport is calculated using temperature and volumetric transport data from moorings deployed in the Bering Strait. Pearson correlations are calculated between the observed detrended monthly cumulative Bering Strait ocean heat transport and the detrended monthly sea ice extent time series from May through September. Results: An increase in the spring variability of the Bering Strait ocean heat transport is found since 2010, associated with both increased volume flux and water temperatures in May and June. A significant negative correlation between the Bering Strait ocean heat transport and Arctic sea ice extent in the Pacific sector is observed for May, June, and July, both within and outside the marginal ice zone, with a sharp decline in predictability for August and September. Conclusion: The Bering Strait ocean heat transport is a skillful predictor for early melt season sea ice extent in the Pacific sector but loses predictive skills later in the summer in August and September due to changes in ice dynamics, in accordance with the loss of predictive skill in Global Climate Models.
{"title":"Variability and Predictability of the Bering Strait Ocean Heat Transport and Arctic Ocean Sea Ice Extent","authors":"Jed E. Lenetsky, B. Tremblay, Charles Brunette","doi":"10.26443/msurj.v14i1.48","DOIUrl":"https://doi.org/10.26443/msurj.v14i1.48","url":null,"abstract":"Background: This study examines the monthly, seasonal, and interannual variations in Pacific Ocean heat transport entering the Arctic Ocean through the Bering Strait, and its influence on sea ice extent in the Arctic Ocean.\u0000Methods: Monthly ocean heat transport is calculated using temperature and volumetric transport data from moorings deployed in the Bering Strait. Pearson correlations are calculated between the observed detrended monthly cumulative Bering Strait ocean heat transport and the detrended monthly sea ice extent time series from May through September.\u0000Results: An increase in the spring variability of the Bering Strait ocean heat transport is found since 2010, associated with both increased volume flux and water temperatures in May and June. A significant negative correlation between the Bering Strait ocean heat transport and Arctic sea ice extent in the Pacific sector is observed for May, June, and July, both within and outside the marginal ice zone, with a sharp decline in predictability for August and September.\u0000Conclusion: The Bering Strait ocean heat transport is a skillful predictor for early melt season sea ice extent in the Pacific sector but loses predictive skills later in the summer in August and September due to changes in ice dynamics, in accordance with the loss of predictive skill in Global Climate Models.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"49369875","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}
Background: Research on the evolution of traits in regard to predator-prey relationships can illuminate the effects of migrating species and invasive species on native populations, which is increasingly relevant with heightened anthropogenic environmental disturbances shifting territories of native species. Methods: We used a replicated field experiment to test the effects that predators have on the phenotype of Anolis smaragdinus in the Bahamas. It was predicted that A. smaragdinus would rapidly evolve over six generations to have shorter fore and hind limb lengths due to the presence of the predator, Leiocephalus carinatus, driving A. sagrei and A. smaragdinus into higher habitats, which selects for shorter limb lengths. Results: ANCOVAs were performed for male and female A. smaragdinus, where only two of the thirteen measured traits, ulna length and third toe length in females, were found to have a significant year by treatment interaction between 2011 and 2017. We observed a general reduction in mean trait size when predators are present. Therefore, predators may be driving A. smaragdinus to higher perching sites which selects for smaller limb length. Also, it was found that populations of A. smaragdinus may be able to evolve in as little as six generations when predators and competitors are present. Limitations: A longer study is needed to see if other trait changes would become significant over time, since the residual means are trending in one direction. Another suggestion is to do a study with fewer experimental islands and larger founder populations. This would violate the meaning of a true founder population; however, it may allow A. smaragdinus to become fully integrated within the new environment and lead to a smaller chance of extinction. Conclusion: The study showed that the introduction of predators may cause significant phenotypic changes in female A. smaragdinus’ ulna and third toe length, while also showing a general reduction in mean trait size when predators are present. Therefore, predators may be driving A. smaragdinus to higher perching sites which selects for smaller limb length. However, the study did not show a significant change in either the fore limb length or the hind limb length between 2011 and 2017 which was predicted originally.
{"title":"Predator Driven Trait Changes in Anolis smaragdinus","authors":"S. Wunderlich","doi":"10.26443/msurj.v14i1.49","DOIUrl":"https://doi.org/10.26443/msurj.v14i1.49","url":null,"abstract":"Background: Research on the evolution of traits in regard to predator-prey relationships can illuminate the effects of migrating species and invasive species on native populations, which is increasingly relevant with heightened anthropogenic environmental disturbances shifting territories of native species.\u0000Methods: We used a replicated field experiment to test the effects that predators have on the phenotype of Anolis smaragdinus in the Bahamas. It was predicted that A. smaragdinus would rapidly evolve over six generations to have shorter fore and hind limb lengths due to the presence of the predator, Leiocephalus carinatus, driving A. sagrei and A. smaragdinus into higher habitats, which selects for shorter limb lengths.\u0000Results: ANCOVAs were performed for male and female A. smaragdinus, where only two of the thirteen measured traits, ulna length and third toe length in females, were found to have a significant year by treatment interaction between 2011 and 2017. We observed a general reduction in mean trait size when predators are present. Therefore, predators may be driving A. smaragdinus to higher perching sites which selects for smaller limb length. Also, it was found that populations of A. smaragdinus may be able to evolve in as little as six generations when predators and competitors are present.\u0000Limitations: A longer study is needed to see if other trait changes would become significant over time, since the residual means are trending in one direction. Another suggestion is to do a study with fewer experimental islands and larger founder populations. This would violate the meaning of a true founder population; however, it may allow A. smaragdinus to become fully integrated within the new environment and lead to a smaller chance of extinction.\u0000Conclusion: The study showed that the introduction of predators may cause significant phenotypic changes in female A. smaragdinus’ ulna and third toe length, while also showing a general reduction in mean trait size when predators are present. Therefore, predators may be driving A. smaragdinus to higher perching sites which selects for smaller limb length. However, the study did not show a significant change in either the fore limb length or the hind limb length between 2011 and 2017 which was predicted originally.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47653729","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}
Background: The loss of a limb is a debilitating incident and can leave patients significantly disabled and often unable to perform activities of daily living. Prosthetic limbs can provide some modicum of normalcy back to their lives, and there has been much research over the past few decades into restoration of biomedical and physiological function with the use of externally powered and robotic prostheses. This review aims to explore the various approaches to machine-body interfacing that can be employed to achieve intuitive and meaningful control of these complex devices, and to discuss the individual benefits and drawbacks of each method. Methods: Studies looked at include both primary and secondary sources of research. Identification was via a PubMed search for the terms “prosthetic limb”, “powered prostheses”, “myoelectric prostheses”, “neural interface”, “prosthetic somatosensory feedback”, and “brain-machine interface”, which resulted in a total of 3892 papers retrieved. Of these, 28 were retained as sources for this review. Selection was based on relevance to control of powered prostheses. Summary: Significant strides have been made in expanding the choice of interface sites for bionic prosthesis control. Muscles, nerves, and the brain are all options, each with varying degrees of invasiveness and corresponding resolution of information obtained, and non-muscle interfacing prostheses may soon be commercially available. These advances have allowed for increasingly precise control of prosthetic limbs. However, this is limited by the challenge of returning sensory information from the prosthesis back to the user.
{"title":"Bionic Human: A Review of Interface Modalities for Externally Powered Prosthetic Limbs","authors":"Nipun Mundkur","doi":"10.26443/msurj.v14i1.53","DOIUrl":"https://doi.org/10.26443/msurj.v14i1.53","url":null,"abstract":"Background: The loss of a limb is a debilitating incident and can leave patients significantly disabled and often unable to perform activities of daily living. Prosthetic limbs can provide some modicum of normalcy back to their lives, and there has been much research over the past few decades into restoration of biomedical and physiological function with the use of externally powered and robotic prostheses. This review aims to explore the various approaches to machine-body interfacing that can be employed to achieve intuitive and meaningful control of these complex devices, and to discuss the individual benefits and drawbacks of each method.\u0000Methods: Studies looked at include both primary and secondary sources of research. Identification was via a PubMed search for the terms “prosthetic limb”, “powered prostheses”, “myoelectric prostheses”, “neural interface”, “prosthetic somatosensory feedback”, and “brain-machine interface”, which resulted in a total of 3892 papers retrieved. Of these, 28 were retained as sources for this review. Selection was based on relevance to control of powered prostheses.\u0000Summary: Significant strides have been made in expanding the choice of interface sites for bionic prosthesis control. Muscles, nerves, and the brain are all options, each with varying degrees of invasiveness and corresponding resolution of information obtained, and non-muscle interfacing prostheses may soon be commercially available. These advances have allowed for increasingly precise control of prosthetic limbs. However, this is limited by the challenge of returning sensory information from the prosthesis back to the user.","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43634626","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}
M. Espriella, Tyler Schaper, Alison Atchia, Katherine Rose, V. Lecours
Background: Macrocystis pyrifera, commonly known as giant kelp, is a fast-growing brown alga that typically inhabits temperate waters. In southern California, M. pyrifera provides many ecologically and economically significant ecosystem services. Sargassum horneri, a non-native brown macroalga commonly known as devil weed, often outcompetes M. pyrifera while providing fewer ecological or economical benefits. Examining potential areas of species overlap is key to understanding the invasion potential of S. horneri and essential to the implementation of removal efforts. This study aims to map the suitable habitat of M. pyrifera and invasive S. horneri in the coastal waters of Santa Catalina Island, California, and to quantify any overlapping habitat between the two macroalgae. Methods: Broadly defined potential habitats were characterized around Santa Catalina Island using an unsupervised approach to habitat mapping based on a series of abiotic surrogates mapped at a 2 m spatial resolution. In situ substrate data were then overlaid onto the unsupervised classification to identify spatial associations between substrate type and potential habitats, and to interpret the classes. To predict the distribution of M. pyrifera and S. horneri around Santa Catalina Island based on their respective association with the environment, maximum entropy (MaxEnt) was used to produce species distribution models. The resulting models for M. pyrifera and S. horneri were overlaid to identify potential areas of conflict based on suitable habitat overlap. Results: The unsupervised approach to habitat mapping resulted in a map of four potential habitats around Santa Catalina Island based on substrate cover. Sand was the most dominant type of substrate. The supervised approach using MaxEnt identified 10.27% of the study area as suitable habitat for M. pyrifera and 7.37% as suitable habitat for S. horneri. A total of 33.56% of the suitable habitat for M. pyrifera was found to also be suitable for S. horneri. Limitations: The characterization of habitats and the species distribution modeling were limited to the study of benthic terrain characteristics due to the unavailability of other high-resolution environmental data (e.g., hydrodynamics and chemical data) around Santa Catalina Island. In addition, data were not available for the very shallow waters near the coast, where giant kelp is often found. Given the complexity of this ecosystem, the addition of other variables and data coverage closer to the coast would potentially make the maps and models more representative of the actual distribution of M. pyrifera and S. horneri and provide a more complete understanding of their environmental preferences. Conclusion: This study provides insight into the kelp forest ecosystems found in California’s Channel Islands; it is a vital first step in order to understand the potential areas for invasion of M. pyrifera by S. horneri, thus supporting decision making and efforts to control S.
{"title":"Habitat mapping of giant kelp (Macrocystis pyrifera) and devil weed (Sargassum horneri) off the coast of Santa Catalina Island, California","authors":"M. Espriella, Tyler Schaper, Alison Atchia, Katherine Rose, V. Lecours","doi":"10.26443/msurj.v14i1.51","DOIUrl":"https://doi.org/10.26443/msurj.v14i1.51","url":null,"abstract":"Background: Macrocystis pyrifera, commonly known as giant kelp, is a fast-growing brown alga that typically inhabits temperate waters. In southern California, M. pyrifera provides many ecologically and economically significant ecosystem services. Sargassum horneri, a non-native brown macroalga commonly known as devil weed, often outcompetes M. pyrifera while providing fewer ecological or economical benefits. Examining potential areas of species overlap is key to understanding the invasion potential of S. horneri and essential to the implementation of removal efforts. This study aims to map the suitable habitat of M. pyrifera and invasive S. horneri in the coastal waters of Santa Catalina Island, California, and to quantify any overlapping habitat between the two macroalgae.\u0000Methods: Broadly defined potential habitats were characterized around Santa Catalina Island using an unsupervised approach to habitat mapping based on a series of abiotic surrogates mapped at a 2 m spatial resolution. In situ substrate data were then overlaid onto the unsupervised classification to identify spatial associations between substrate type and potential habitats, and to interpret the classes. To predict the distribution of M. pyrifera and S. horneri around Santa Catalina Island based on their respective association with the environment, maximum entropy (MaxEnt) was used to produce species distribution models. The resulting models for M. pyrifera and S. horneri were overlaid to identify potential areas of conflict based on suitable habitat overlap.\u0000Results: The unsupervised approach to habitat mapping resulted in a map of four potential habitats around Santa Catalina Island based on substrate cover. Sand was the most dominant type of substrate. The supervised approach using MaxEnt identified 10.27% of the study area as suitable habitat for M. pyrifera and 7.37% as suitable habitat for S. horneri. A total of 33.56% of the suitable habitat for M. pyrifera was found to also be suitable for S. horneri.\u0000Limitations: The characterization of habitats and the species distribution modeling were limited to the study of benthic terrain characteristics due to the unavailability of other high-resolution environmental data (e.g., hydrodynamics and chemical data) around Santa Catalina Island. In addition, data were not available for the very shallow waters near the coast, where giant kelp is often found. Given the complexity of this ecosystem, the addition of other variables and data coverage closer to the coast would potentially make the maps and models more representative of the actual distribution of M. pyrifera and S. horneri and provide a more complete understanding of their environmental preferences.\u0000Conclusion: This study provides insight into the kelp forest ecosystems found in California’s Channel Islands; it is a vital first step in order to understand the potential areas for invasion of M. pyrifera by S. horneri, thus supporting decision making and efforts to control S. ","PeriodicalId":91927,"journal":{"name":"McGill Science undergraduate research journal : MSURJ","volume":null,"pages":null},"PeriodicalIF":0.0,"publicationDate":"2019-04-10","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"43870345","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}
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