bluuebunny/crossref_metadata_2025 huggingface dataset:
Facilitating Hydrogen Dissociation over Dilute Nanoporous Ti-Cu Catalysts
Authors: Lee Jennifer , Qi Zhen , Foucher Alexandre , Ngan Hio Tong , Dennis Kevin , Cui Jun , Sadykov Ilia , Crumlin Ethan , Sautet Philippe , Stach Eric , Friend Cynthia , Madix Robert , Biener Juergen
Published: July 2022

The dissociation of H2 is an essential elementary step in many industrial chemical transformations, typically requiring precious metals. Here, we report a hierarchical nanoporous Cu catalyst doped with small amounts of Ti (npTiCu) that increases the rate of H2-D2 exchange by approximately one order of magnitude compared to the undoped nanoporous Cu (npCu) catalyst. The catalysts were prepared by dealloying of bulk alloys, Al80Cu20 and Al80Cu19Ti1, to produce the npCu and npTiCu catalysts, respectively. The promotional effect of Ti was measured via steady-state H2-D2 exchange reaction experiments under atmospheric pressure flow conditions in the temperature range of 300─523 K. Pretreatment with flowing H2 is required for stable catalytic performance. Two pretreatment temperatures, 573 K and 673 K, were investigated for both the undoped and Ti-doped npCu catalysts. The experimentally-determined H2-D2 exchange rate is 5-7 times greater for npTiCu vs. the undoped material under optimized pretreatment and reaction temperatures. The H2 pretreatment leads to full reduction of Cu oxide and partial reduction of surface Ti oxide species present in the as-prepared catalyst as demonstrated using in-situ ambient pressure X-ray photoelectron spectroscopy and X-ray absorption spectroscopy. Both catalysts also contained similar, small amounts of residual aluminum from the dealloying which is present in the form of alumina nanoparticles that did not contribute to the differences in catalytic activity. The apparent activation energy and pre-exponential factors measured for H2-D2 exchange are substantially different for Ti-doped vs. undoped npCu catalysts. DFT calculations suggest that isolated, metallic Ti atoms on the surface of the Cu host can act as the active surface sites for hydrogen recombination. The increase in the rate of exchange above that of pure Cu is caused primarily by a shift in the rate-determining step from dissociative adsorption starting from gas phase H2 or D2 on Cu to H/D atom recombination towards chemisorbed H2/HD/D2 on Ti-doped Cu, with the corresponding decrease in activation entropy that it produces.
Chemoinformatics and Artificial Intelligence Colloquium: Progress and Challenges to Develop Bioactive Compounds
Authors: Bajorath Jürgen , Chávez-Hernández Ana L. , Duran-Frigola Miquel , Fernández-de Gortari Eli , Gasteiger Johann , López-López Edgar , Medina-Franco José L. , Méndez-Lucio Oscar , Mestres Jordi , Miranda-Quintana Ramón Alain , Plisson Fabien , Prieto-Martínez Fernando D. , Rodríguez-Pérez Raquel , Rondón-Villarreal Paola , Saldívar-Gonzalez Fernanda I. , Sánchez-Cruz Norberto , Valli Marilia
Published: July 2022

We report the main conclusions of the first Chemoinformatics and Artificial Intelligence Colloquium, Mexico City (virtual), June 15-17, 2022. Fifteen lectures were presented during a virtual and public event with speakers from industry, academia, and non-for-profit organizations. 1,290 participants, including students and academics from more than 60 countries, had registered. During the meeting, applications, challenges, and opportunities in drug discovery, de novo drug design, ADME-Tox (Absorption, Distribution, Metabolism, Excretion and Toxicity) property predictions, organic chemistry and peptides, and antibiotic resistance were discussed. The program, along with the recordings of all sessions, is freely available at https://www.difacquim.com/english/events/2022-colloquium/
Closed-loop automatic gradient design for liquid chromatography using Bayesian optimization
Authors: Boelrijk Jim , Ensing Bernd , Forré Patrick , Pirok Bob
Published: July 2022

Contemporary complex samples require sophisticated methods for full analysis. This work describes the development of a Bayesian optimization algorithm for the automated and unsupervised development of gradient programs. The algorithm was tailored to LC using a Gaussian process model with a novel covariance kernel. To facilitate unsupervised learning, the algorithm was designed to interface directly with the chromatographic system. Single-objective and multi-objective Bayesian optimization strategies were investigated for the separation of a complex (n>80) dye mixture. The multi-objective strategy was found to be very powerful and flexible in terms of exploring the Pareto front. The single-objective strategy was found to be slightly faster in finding a satisfactory optimum. One additional advantage of the multi-objective approach was that it allows a trade-off to be made between multiple objectives. In general, the Bayesian optimization strategy was found to be particularly suitable, but not limited to, cases where retention modelling is not possible, although its scalability might be limited in terms of the number of parameters that can be simultaneously optimized.
Immune Response Regulation has Therapeutic Potential in the Treatment of Cancer
Authors: Festa Maria
Published: July 2022

Background: Depending on their path of differentiation, immune cells can have opposing roles in tumour progression. As a result, during growth, tumours undergo selective pressure to produce immunosuppressive factors that contribute to tumour growth, angiogenesis, and metastasis. This review discusses the contribution of different macrophages and T cells to tumour progression, as well as their role in current cancer immunotherapies.

Methods: We searched for articles online through McGill Library with search terms including the names of different immune cells along with “polarity”, “tumour progression”, or “cancer immunotherapy”. Cancer therapies “CTLA-4 blockade”, “Ipilimumab”, “adoptive cell transfer”, and “PD1 inhibition” were also used as search terms.

Summary: Depending on the cell types involved, crosstalk between different immune cells in the tumour stroma can contribute to either the development or the inhibition of tumour growth. Certain therapies such as adoptive cytotoxic T lymphocyte (CTLs) transfer and CTLA-4 & PD1 inhibition work by enhancing CTL tumoricidal responses, and have produced durable responses in a small but significant group of patients. Other therapies work by skewing the phenotype of tumour associated macrophages from pro-tumorigenic to anti-tumorigenic. However, disrupting the balance between immune cell functions risks triggering inflammatory disorders such as autoimmunity. Therefore, future directions in cancer immunotherapy include targeting potential responders and restricting therapeutic mechanisms to the tumour microenvironment.
Dementia With Lewy Bodies: An Overview
Authors: Hovendon Bridget , Kaufman Michelle
Published: July 2022

Background: Dementia is a neurocognitive disorder that involves multiple cognitive deficits, including memory impairment. Dementia occurs in a variety of disease processes, including Alzheimer disease (AD) and dementia with Lewy bodies, the two most prevalent neurocognitive diseases. This paper reviews the signs and symptoms, neuropathology, diagnosis, prognosis, and treatment of Dementia with Lewy bodies (DLB).

Methods: Terms searched included “Lewy body dementia,” “Lewy body disease,” “cognitive disorders,” and “neurodegenerative diseases.” Priority was given to peer-reviewed sources published within the last five years.

Summary: In addition to standard neurocognitive disorder symptoms, patients with DLB present clinically fluctuating cognition, visual hallucinations, and Parkinsonism as well as a variety of other symptoms with lower diagnostic sensitivity. Clinical signs, cognitive assessments, and radiologic imaging are used to diagnose DLB as being distinct from disorders like AD, Parkinson disease dementia (PDD), delirium, and normal aging changes. Interventions for this disease may be pharmacological or non-pharmacological. Pharmacological treatments include cholinesterase inhibitors, Levadopa, and selective serotonin reuptake inhibitors or serotonin-norepinephrine reuptake inhibitors. Non-pharmacological interventions include occupational therapy, cognitive stimulation, and physical activity.
Promise of Mindfulness-Based Interventions as Therapies to Prevent Cognitive Decline
Authors: Sapozhnikov Daniel
Published: July 2022

Background: Alzheimer’s disease (AD) is a neurodegenerative disorder that affects 5 million United States citizens. Many authors have proposed that mindfulness-based interventions (MBIs) have the potential to effectively prevent AD-associated pathology and symptomology. However, the fact that both meditation and AD are complex processes that involve a great number of biological pathways has made these phenomena particularly challenging to dissect. This review advocates the use of gene expression to investigate the mechanisms by which MBIs combat AD pathology.

Methods: Searches were performed using Thomson Reuters Web of Science. Ultimately, 85 journal articles were selected for their content as it pertains to the purpose of this review.

Summary: Peripheral blood mononuclear cells (PBMCs) may provide reliable measures of cerebral gene expression. Profiling their gene expression has demonstrated that MBIs may produce gene expression changes in many of the same pathways (inflammation, cellular stress, proliferation, synaptic function) and often in the opposite direction of disease-related deregulation. While AD is marked by shortened telomeres resulting in genetic turmoil, meditation has been documented to exhibit a positive effect on telomere maintenance. A comprehensive gene expression investigation is invaluable to reveal relevant molecular mechanisms and provide the foundation for exploring the interaction between MBI and AD.
The Relationship between Large Herbivore Abundance and Algal Cover on Coral Reefs on West Coast Barbados
Authors: Caron Vanessa , Greiner Ariel , Ransier Krista , Cameron-Steinke Bryna
Published: July 2022

Background: Over the past few decades, climate change and the intensification of coastal development significantly contributed to the degradation of coral reefs across the Caribbean Sea. Widespread increase in algal cover on coral reefs since the 1970s has made it difficult for the corals to recover. Thus, algae regulating factors, such as herbivorous grazers and groundwater nutrient concentrations, have important implications for the conservation of coral reefs. In this study we conducted a small-scale assessment of the relationship between the abundance of two families of herbivorous fishes, Scaridae and Acanthuridae, and algal cover on the coral reefs of West Coast Barbados was conducted, and we hypothesized that a direct negative correlation exists between them.

Methods: Herbivorous fish abundance and percent algal cover were quantified for three different coral reefs, and the data was analyzed using linear regressions and analyses of variance.

Results: We found that although there were no significant relationship between herbivorous fish abundance and algal cover, there was a significant difference between them across the three reefs studied. These results suggest the presence of other factors influencing algal cover. One such factor could potentially be ground- water input levels, which was found to differ at each of the three sites studied.

Limitations: The limited timeframe of this study did not allow for extensive sampling.

Conclusion: In order to effectively protect the coral reefs in Western Barbados, Further studies are needed to increase the understanding of the relationship between herbivory and algal cover in Western Barbados as well as to further investigate the role of groundwater seepage on algal growth.
Preserved Vestibular Function in Mice with Loss of α-9 Subunit of the α-9/10 Nicotinic Acetylcholine Receptor (α-9/10 nAChR)
Authors: Mendoza Jesse , Grafton Francis , Shan Wong Amy , Cullen Kathleen
Published: July 2022

Background: The α-9/10 nicotinic acetylcholine receptor is known to be the primary channel through which both vestibular and auditory efferents mediate the inhibition of their respective peripheral hair cells and afferents. With respect to the auditory system, the deletion of the α-9 subunit results in abnormalities in the development of properly functioning cochlear hair cells. Given the high degree of similarity between the au- ditory and the vestibular systems, we hypothesize that α-9 knockout mice should have impaired vestibular hair cell development and consequently compromised vestibular-mediated functions.

Methods: In order to characterize vestibular function in α-9 knockout alert mice, we quantified the vestibu- lo-ocular reflex (VOR) through both gain and phase. Additionally, the optokinetic nystagmus (OKN) was sim- ilarly assessed as a control. VOR in light (VORl) was also quantified to further evaluate VOR and OKN efficacy. Furthermore, as information from the vestibular system mediates postural regulation and head stabilization, we assessed these properties through rotor rod and balance beam paradigms.

Results: Surprisingly, the loss of the α-9 subunit in knockout mice did not result in any attenuation in VOR gain nor deviations in phase compared to wild type. OKN and VORl’s gain and phase values remain similarly unchanged, confirming preserved function within the vestibular nucleus. Descending vestibulospinal infor- mation seems to be unaltered as well, as no significant difference was observed in postural testing.

Limitations: The α-9 knockout mice used specifically had exon 1 and exon 2 of the α-9 gene targeted, which could potentially limit generalizability. Also, frequencies greater than 3Hz were not tested.

Conclusions: Our findings demonstrate that α-9 knockout mice still maintain normal vestibular function.
Understanding the 2013-2015 Ebola Outbreak
Authors: Shapiro Janna
Published: July 2022

Background: The 2013-2015 Ebola outbreak caused severe human suffering and a global health crisis. Ebola Virus (EBOV) is a naturally zoonotic RNA virus that has several immune-evasion mechanisms and can cause serious disease and death in humans. The massive impact of the recent epidemic is unique in the 40-year history of this pathogen. Scientists and public health officials around the world are researching the factors that may have contributed to the scale and devastating nature of the 2013-2015 outbreak.

Methods: Terms searched online through the McGill library and Medline Ovid included “Ebola”, “immune evasion”, “sequencing”, “Ebola glycoprotein” and “zoonotic transmission”. Only articles published since 2014 were selected.

Summary: In this review article, we will provide discussion on the principal factors contributing to the un- usually destructive nature of the 2013-2015 Ebola outbreak. Interestingly, although several nonsynony- mous mutations have been observed in the recently circulating strains, they were not the principal cause of the unusually devastating nature of the outbreak. Instead, the high rate of transmission was likely caused by sociological factors, such as population dynamics and late detection of the outbreak. However, there is evidence to suggest that once the high rate of transmission in humans was established there was selective pressure on the virus to evade the human immune system. This selective pressure may have exacerbated an already deadly outbreak. Ongoing research efforts indicate that there is still much to be discovered about the virus and the control of outbreak management.
Dead but not gone: The case for PRL as a pseudophosphatase
Authors: Wu Howie
Published: July 2022

Background: Protein phosphorylation and dephosphorylation is an integral component of many cellular signaling pathways and regulatory mechanisms. Phosphatases are enzymes that catalyze the removal of phosphate groups from proteins. The phosphatases of regenerating liver (PRLs) are a family of phosphatases which have been correlated with cancer development and metastasis. However, they appear to have weak phosphatase activity and little is known about their physiological substrates. This review discusses PRL from a structural and functional perspective, including recent findings on its interaction with another family of proteins, cyclin M (CNNM).
Methods: Articles were obtained from the scientific literature using databases like PubMed and McGill University’s open access institutional repository. This paper specifically focuses on those articles that provided an overview of phosphatases, PRLs, CNNMs, and structural and functional studies of PRLs and CNNMs. In total, 40 articles were selected for the purpose of this review.
Summary: Although PRLs retain many of the structural features of other protein tyrosine phosphatases (PTPs) including the phosphatase catalytic motif and regulation via oxidation, other structural features such as mutation of a conserved serine/threonine residue to alanine in the active site disfavor catalytic activity. Moreover, PRL interaction with CNNM appears to be responsible for its oncogenic potential, yet this inter- action does not appear to require PRL phosphatase activity. Thus, PRL may be best classified as a pseudo-phosphatase, which are phosphatase-like proteins that are structurally similar to phosphatases but have acquired a dominant function that does not require phosphatase activity.
Interactions between Mercury and Biogeochemical Features of Aquatic Ecosystems: A Critical Review
Authors: Beaumont-Courteau Sandrine
Published: July 2022

Background: Mercury (Hg) is a pollutant known to affect the nervous system. The most threatening form of Hg is methylmercury (MeHg), which can biomagnify in aquatic biota. This critique summarizes our current understanding of the major relationships between mercury speciation in aquatic environments and various environmental factors to determine the most suitable indicators of MeHg pollution.
Methods: Searches were performed using Web of Science. Ultimately, 33 studies were chosen and reviewed. Priority was given to recent studies as this review focused on the current state of our knowledge.
Summary: The total amount of Hg (THg) alone cannot be used as an indicator of MeHg since the relationship between THg and MeHg is poorly correlated. Microbial DNA is often used in research to give insight into the mercury cycle and fate in aquatic systems, but further studies are needed to accurately assess MeHg concentration using DNA. Based on an early study, it was thought that water colour could indicate the amount of Hg in aquatic biota. However, subsequent work has shown this to not be the case since dissolved organic matter (DOM) can help or hinder Hg bioavailability and bioaccumulation. There is a nonlinear relationship between dissolved organic carbon (DOC) and MeHg bioaccumulation where there is a threshold concentration (~8.5 mg C L-1 DOC) above which mercury bioaccumulation is hindered. A recent study found that the methylation rate of an aquatic system was correlated to the type of organic matter present in the sediments, although it could not predict the amount of MeHg present in the water since runoff brings Hg from the catchment to the downstream aquatic system. Recent advancements have been made to understand components of the mercury cycle (e.g. land-water interactions, microbial methylation, water-sediment interactions), but a model encompassing all components has yet to be constructed.
Historical Perspectives on the Bacterium Vibrio natriegens and its Potential to Revolutionize Bioengineering
Authors: Williams Jonah M.
Published: July 2022

Background: Vibrio natriegens is an aquatic bacterium that has the fastest doubling time of any currently known organism at approximate 9.8 min. This review delves into the early categorization of V. natriegens, its phylogeny and physiology, and the efforts aimed at studying its potential to enhance both micro- and macro-scale biotechnology.
Methods: Twenty-eight research papers from scientific literature databases including PubMED (US National Library of Medicine), National Center for Biotechnology Information (NCBI), and the American Society for Microbiology Journals were used in this study.
Summary: Almost sixty years after the original isolate, microbiologists and bioengineers alike are expressing a renewed interest in V. natriegens as a possible replacement for Escherichia coli. Recent biotechnological efforts have been successful in developing the necessary genetic systems for such a transition. The productivity of V. natriegens suggests that the organism can also be used in large scale bio-refineries producing nutraceuticals and other bio-products.
Winter Mid-Tropospheric Weather Regimes in the Eastern North Pacific
Authors: Low Yeechian , Atallah Eyad , Gyakum John
Published: July 2022

Background: The eastern North Pacific (ENPac) is a region of climatologically significant cyclone activity, often associated with extreme weather in North America. Regions of high (ridges) and low (troughs) 500- hPa height typically drive this activity. We identify 500-hPa height time variability extremes as “regimes.” Our objectives are to determine the regimes’ characteristics, predictability, and relationships to North American extreme weather.
Methods: We define weather regimes, separating them into two types based on whether the 500-hPa height variance is extremely low or high. We analyze their general characteristics during the winter (December, January, and February) and relationships to extreme North American weather. To analyze the regimes’ predictability, we define forecast discontinuities as significantly improved extreme 500-hPa height variability model forecasts compared with model forecasts verifying at the same time, but initialized 24 hours earlier. We analyze their effects on anticipated weather.
Results: ENPac low variance regimes are usually dominated by one or two large, slow-moving features, usually a trough with an associated surface cyclone 200-700 km to the west and a ridge with an associated surface anticyclone 200-700 km to the east. This pattern leads to anomalous southerly winds and moisture transport. Low variance regimes are generally associated with anomalous wetness in northwestern Canada, warmth in western North America, and dryness in the southwest U.S. High variance regimes are usually dominated by smaller, faster-moving features that alter the 500-hPa heights substantially. These regimes are more varied, but there is a tendency to have a ridge 200-700 km to the west and a trough 200-700 km to the east, leading to anomalous northerly winds and transport of drier polar air into the ENPac region. High variance regimes are generally associated with anomalously cold air in western North America and wetness in the western U.S. Some forecast discontinuities are associated with changes in anticipated weather locally in the ENPac region, while other discontinuities are associated with changes in anticipated weather on a much larger scale, extending to North America.
Limitations: Limitations include the small sample of regimes found during the period of record (18 low variance and 10 high variance), the metric being limited to the 500-hPa level, and the study of only the ENPac winter.
Conclusion: Low and high variance regimes generally lead to different ENPac weather patterns and North American extreme weather. Forecast discontinuities differ significantly from each other in their spatial extents. Further work is necessary to identify their causes and characteristics.
Examining the Transition from a perennial to a seasonal sea ice cover in the Arctic Ocean: A Lagrangian Approach
Authors: Hart Jamie , Tremblay Bruno , Brunette Charles , Dufour Carolina , Newton Robert
Published: July 2022

Background: Declining Arctic sea ice extent has been accompanied by a large loss in multiyear ice (MYI). The dynamic and thermodynamic processes which affect this transition include promotion of first year ice (FYI) to MYI, demotion (melting) of MYI to open water, and ice export through Fram Strait. In this study we quantify the relative importance of these three processes.
Methods: We use the Lagrangian Ice Tracking System which employs satellite-derived sea ice drift vectors combined with sea ice concentrations to find annual areas of promotion, demotion, and export.
Results: Over the satellite record (1989-2015), we quantify the total contributions to sea ice extent loss from promotion (+30 million km2), demotion (-19.7 million km2), and export of MYI (-18.6 million km2). The result is a total net loss of 8.3 million km2 of MYI. We find that all three processes are positively correlated with minimum sea ice extent and are increasing with rates of +0.165 million km2/decade, -0.146 million km2/ decade, and -0.096 million km2/decade for promotion, demotion, and export respectively. We also compute the negative ice growth feedback at 0.59 (with r2=0.27). This indicates that ice pack recovers, on average, 59% of the MYI area lost to demotion/export through promotion of FYI the following winter.
Limitations: Uncertainties in the drift speed are compounded by the weekly temporal resolution of the model, which affects the resulting estimates of demotion and promotion area.
Conclusion: Demotion and export combined are increasing faster than promotion and represent a larger area contribution. This imbalance accounts for the observed loss of MYI area.
Correlations of Fundamental Social Motives with Personality Measures and Life History Variables
Authors: Moshkforoush Mana
Published: July 2022

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.
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: Chen Charlise Xinyi , Yan Han , Hales Barbara
Published: July 2022

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).
The Effects of Psychosocial Stress and Sex Differences on Cognitive Effort Avoidance
Authors: Givon Noa
Published: July 2022

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.
Substitution Sensitivity and the Bat-and-Ball Problem: A Direct Replication of De Neys et al. (2013)
Authors: Machalani Alexandra , Gallant Amanda , Orha Victoria , Ostbo Nora , Hehman Eric
Published: July 2022

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.
Imagine All the People: Investigating People’s Perceptual Biases as They Pertain to Age, Race, and Gender
Authors: Audet Marion
Published: July 2022

Typically, perceptual biases are studied by investigating how people respond to written scenarios, without considering the mental representations people form while reading these descriptions. This paper provides a novel approach to face perception research by looking at people’s mental representations of strangers and aims to determine whether current ways of classifying people into definite race, age, and gender categories were accurate or needed to be rethought. Specifically, participants digitally reproduced the faces they imagined while reading different scenarios where strangers were described only by race, age, and gender (N = 76). Subsequently, a different set of participants rated these faces on various traits (N = 1024). In the first part of the study, participants created 9 faces from written descriptions of strangers, the last of which included information about criminal history. In the second part, participants rated these faces on dimensions of attractiveness, trustworthiness, intelligence, and physical strength for faces in the non-crime condition, and on dimensions of threat, criminality, and attractiveness for the crime condition. Linear regression models showed that age, race, and gender had various effects on scores on different dimensions, as well as on within-group variance. For instance, older faces were awarded lower attractiveness ratings than younger faces overall, an effect which was also moderated by race, with older age being less predictive of attractiveness ratings for Black faces. Furthermore, there was significantly less variability in attractiveness ratings for Black faces than White faces. Overall, this study revealed that stereotypes do not always adhere to clear-cut categories of race, age, and gender, suggesting that they may be applied somewhat dimensionally rather than categorically.
Effects of adolescent cannabinoid administration in mice on behavioural inhibition and susceptibility to stress during adulthood
Authors: Fallahi Armaan , Hernandez Giovanni , Restrepo Lozano Jose-Maria , Flores Cecilia
Published: July 2022

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.
Methods: 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.
Results: 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).
Limitations: 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.
Conclusion: 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.
What is the Best Music for Neurofeedback Training?
Authors: Hawari Lyla , Singer Neomi , Rabinowitz Arielle , Zatorre Robert
Published: July 2022

The nucleus accumbens (NAc) is widely known for its role in reward seeking behavior which is heavily reliant on dopamine signaling. Dopamine plays an important role in reward seeking behavior and motivation and its dysregulation is shown to cause symptoms of depression such as apathy, a lack of motivation, and anhedonia, a loss of pleasure. Studying the NAc, specifically the ventral striatum in this case, is critical in understanding the underlying mechanisms of this dysregulation. Music neurofeedback is a biofeedback technique that provides feedback on brain activity through the audio quality of the music, with lower quality sounding more muffled. This study uses this technique to train participants to increase the activity of their ventral striatum in an attempt to upregulate the activity of the reward system.

This paper aims to investigate what the most effective music choices are in terms of genre, key, valence (positive or negative emotions) and energy (pertaining to levels of arousal) to maximize the improvement on neurofeedback training. These musical attributes were identified by the Spotify “Organize Your Music” categorization tool. Participants underwent six EEG music neurofeedback training sessions with individually tailored pleasurable music as the source of feedback. The participants either received real feedback in the neurofeedback group (NF) or sham feedback in the control group. The results of this study showed that neurofeedback performance was negatively correlated with valence whereby songs that led to the greatest performance, measured as increase in ventral striatum activity from baseline, were those low in valence. Participants that had the greatest improvement in their neurofeedback training selected songs that were in a minor key and belonged to the pop genre. Although this study is based on a small sample, it takes the first step towards the overarching goal of using music to manage dysregulation in the reward system.
Convective Rolls in a Compressible Fluid
Authors: Simzer Katherine J. , Lewis Gregory M.
Published: July 2022

Rayleigh-Bénard convection occurs between two horizontally infinite plates when the lower plate is heated with respect to the upper one. The temperature gradient between the two plates causes convective rolls to form as the warmer fluid below becomes more buoyant than the cooler fluid above it. The standard (classical) analysis uses the Boussinesq approximation, which neglects the variations of fluid density except in relation to buoyancy forces. This approximation is not accurate for some real-world applications. This project is inspired by the atmosphere, so we will consider the onset of convection in a vertically stratified layer of fluid which we model using the anelastic equations. The standard analysis is presented in many textbooks and is used as a comparison to the analysis for the compressible fluid presented here. Using linear stability analysis, we compute the critical temperature differences required to induce convection. It is not possible to find analytical solutions, and therefore, numerical methods implemented in Python using LAPACK subroutines are used. Results of the critical Rayleigh number at the half-height of the fluid for a range of plate separation distances are computed. For all the cases that are considered, the solution for the compressible problem follows the standard solution for plate separation distances smaller than some viscosity-dependent value that increases with the viscosity of the fluid. For larger d, it is observed that the stratification inhibits the onset of convection. Our solution is far more idealized than any actual convection happening in the atmosphere. However, it does demonstrate, in this context, the limits of the Boussinesq approximation.
Comparative analysis of delivery methods for stem cell therapy in liver diseases
Authors: Zhu Zhiyue
Published: July 2022

Background: Mesenchymal stem cell transplantation is an emerging therapy for treating acute and chronic liver diseases as an alternative for patients who are not transplant candidates. The potential of this treatment depends on its therapeutic efficiency and safety, which have been investigated and evaluated in both preclinical and clinical settings. However, there are still some risks associated with the delivery methods, such as low long-term retention rate and the possibility of arousing cancer or rejection.
Methods: During the review process, previous papers mentioning “stem cell treatment” and “liver diseases” were searched. We described different up-to-date approaches for stem cells from various origins to be delivered to the liver and compared respectively their pros and cons for clinical applications. We also proposed several potential techniques for future studies.
Summary: An efficient and safe stem cell delivery could be enabled via Alginate-Polylysine-Alginate (APA) microencapsulation, lipid-conjugated coating or the use of nanoparticles. Their efficacy will be improved through tissue engineering and microrobots as the delivery is sustained and targeted with fewer rejection responses.
Molecular Mechanisms Controlling the Differentiation of Germ Cells in mammals: Divergent expression patterns of SLBP in male and female meiotic cells and their developmental consequences
Authors: Martin Kyle J. , Clarke Hugh J.
Published: July 2022

The stem-loop binding protein (SLBP) binds to replication-dependent histone mRNA and participates in its processing, stabilization and translation. It has previously been shown that SLBP expression in somatic cells is regulated by the cell cycle. Our work demonstrates that male and female germ line cell expression patterns differ dramatically both from the somatic cell-cycle regulated pattern, and from each other. Using immunofluorescence on a post-natal series of male and female gonads, SLBP was shown to translocate from the cytoplasm of non-growing oocytes to the nucleus upon initiation of growth, followed by re-entry into the cytoplasm upon entry into metaphase II. In contrast, developing male germ cells initially express SLBP at high levels both in the nucleus and the cytoplasm, followed by cytoplasmic segregation and finally complete absence of expression by maturation. We believe that these divergent expression patterns in male and female germ cells reflect the different requirements for SLBP in cell differentiation and early embryogenesis, respectively.
Unwinding the universe: a brief look at String Theory
Authors: Dascal Michael
Published: July 2022

“String Theory” has been a buzz-word in contemporary physics for years. It is at the very edge of theoretical ontology, predicting bizarre qualities of the universe – even claiming we exist in 11-dimensional space-time. These predictions may be strange, but the Theory can account for many of the laws of the universe if we put aside our preconceptions and accept the strange possibilities the Theory suggests.
A recipe for laboratory-grown crystals
Authors: Deakin Michelle , Paquette Jeanne , Baker Don
Published: July 2022

Clinopyroxenes are among the first minerals to crystallize out of a ferromagnesian silicate magma. They commonly exhibit “sectorzoning”, a phenomenon whereby the crystal incorporates elements in different proportions on non-equivalent crystal faces. By growing clinopyroxene crystals in the laboratory, it is possible to investigate controls on compositional variation, which provides insight on magmatic processes. The goal of this research was to develop an experimental method for growing synthetic clinopyroxene (a silicate mineral) in a carbonate melt rather than in a silicate one. This is advantageous since silicate residue on the clinopyroxene crystal may damage crystal faces, which contain important information on growth features, unlike carbonate residue which is easily dissolved leaving crystal faces intact. The carbonate melt was modeled after the alkali-rich carbonatite lavas erupting at Oldoinyo Lengai, Tanzania by using powdered clinopyroxene, magnetite and alkali carbonates containing up to 5% wt. water as starting materials, and running the experiment at conditions of 800∞C and 10 kbars. Clinopyroxene crystals in a carbonate crystalline matrix were retrieved from the experiment capsules, and cleaned for imaging and analysis with the atomic force microscope (AFM), scanning electron microscope (SEM) and electron microprobe (EMP). This experimental approach provides well-preserved crystal faces whose surfaces can be examined at nanoscale resolution. This technique could be applied to a wide range of synthetic silicate minerals, and the resulting observations help to better understand the relationship between crystal surface structure and trace element uptake during crystal growth.
While the molecular basis receives attention, development of a molecular-based diagnosis is still in a deficit: understanding Attention Deficit Hyperactivity Disorder
Authors: Behrmann Jason
Published: July 2022

Attention deficit hyperactivity disorder is the most prevalent childhood-onset behavioral disorder, affecting approximately 8% of the population, where a disproportionate amount of males are afflicted. Common symptoms of the disorder include inattentiveness, hyperactivity, and impulsivity. Genomewide linkage analyses have demonstrated that the disorder is likely due to several genetic factors, whereby the dopaminergic, serotonergic, and noradrenergic neurotransmitter systems are highly implicated through various observations. Genetic screens of afflicted individuals have implicated the presence of specific genetic polymorphisms with ADHD, examples being the 10-repeat-40-base-pair allele of the dopamine transporter, DAT-1, and the silent-G861C-substitution allele of the serotonin receptor, 5-HT1B. Evidence is emerging that proteins involved in the release of neurotransmitters from synaptic vesicles, like SNAP-25, may also be involved in the pathology of ADHD. The most common method of treatment is the administration of psychostimulants, like amphetamine derivatives and methylphenidate (Ritalin®), drugs which target the dopaminergic system. New therapies that target other neurotransmitter systems, like the selective noradrenaline transport inhibitor, atomoxetine, are gaining recognition as effective treatments. Common methods to diagnose ADHD reside in psychological assessments. As more insight is gained into the genetic basis for the disorder, it appears likely that a clinical diagnostic test based on genetic screening for these factors, such as specific genetic polymorphisms, could serve as an additional means of diagnosis.