bluuebunny/crossref_metadata_2025 huggingface dataset:
Feminist march of 8M and COVID-19
Authors: Galarza Fernández Emelina , Sosa Valcarcel Aimiris , Quintana Pujalte Andrea Leticia
Published: July 2022

ABSTRACT – The research examines the methods in which social protest is criminalized through the media, as symbolic systems for the construction of reality that favor the control and reproduction of the social order. Based on the case study of the feminist demonstration on March 8, 2020, in Spain, the framing made by the newspapers El País, El Mundo, La Vanguardia, ABC and La Razón in their informative productions are analyzed. The observation period is between March 7 and June 21, 2020, when the first alarm state declared by the Spanish Government to fight the Covid-19 pandemic ended. The results show that beyond the editorial and ideological lines of these media, the feminist protest was mainly demonized by the framing identified in the texts, through the construction of a general idea of responsibility in the spread of the virus.
RESUMO – A pesquisa examina os métodos de criminalização do protesto social que se exercem por meio da mídia, como sistemas simbólicos de construção da realidade que favorecem o controle e a reprodução da ordem social. A partir do estudo de caso da marcha feminista de 8 de março de 2020 na Espanha são analisados os enquadramentos feitos pelos jornais El País, El Mundo, La Vanguardia, ABC e La Razón em suas produções informativas. O período de observação vai de 7 de março a 21 de junho de 2020, quando terminou o primeiro estado de alarme declarado pelo governo espanhol para o combate à pandemia de Covid-19. Os resultados mostram que para além das linhas editoriais e ideológicas desses meios de comunicação, o protesto feminista foi demonizado principalmente pelo enquadramento identificado nos textos, por meio da construção de uma ideia geral de responsabilidade na disseminação do vírus.
RESUMEN – La investigación examina los métodos de criminalización de la protesta social que se ejercen a través de los medios de comunicación, como sistemas simbólicos de construcción de la realidad que favorecen el control y reproducción del orden social. A partir del caso de estudio de la marcha feminista del 8 de marzo de 2020 en España, se analiza el encuadre realizado por los diarios El País, El Mundo, La Vanguardia, ABC y La Razón en sus producciones informativas. El período de observación es entre el 7 de marzo y el 21 de junio de 2020, cuando finalizó el primer estado de alarma declarado por el Gobierno español para combatir la pandemia de Covid-19. Los resultados muestran que más allá de las líneas editoriales e ideológicas de estos medios, la protesta feminista fue principalmente demonizada por el encuadre identificado en los textos, a través de la construcción de una idea general de responsabilidad en la propagación del virus.
Invisalign treatment with mandibular advancement: A retrospective cohort cephalometric appraisal
Authors: Sabouni Waddah , Hansa Ismaeel , Al Ali Shuaib Mohamed , Adel Samar M. , Vaid Nikhilesh
Published: July 2022

Objective

To examine the skeletal, dental, and soft-tissue cephalometric effects of class II correction using Invisalign’s mandibular advancement feature in growing patients.

Materials and Methods

A retrospective cohort clinical study was performed on cases that were started between 2017 and 2019. A total of 32 patients (13 females, 19 males), with an average age of 13 years old (9.9-14.8 years) had undergone Invisalign treatment (Align Technology, Inc., San Jose, CA) wherein the mandibular advancement phase was completed were included. Photos, digital study models, and cephalograms were taken once during the patients’ initial visit and again upon completing the mandibular advancement phase of treatment. The number of aligners worn and the time of treatment in months was recorded for each subject. Cephalometric analysis was performed and overjet and overbite were measured. Statistical analysis was performed using SPSS statistical software (version 25; SPSS, Chicago, Ill) and the level of significance was set at P <0.05. Descriptive statistics were performed to generate means and differences for each cephalometric measurement as well as patient data including age, treatment time, and aligner number. Differences between measurements from patients before treatment (T1) and after treatment (T2) with the mandibular advancement feature were evaluated using a paired t -test.

Results

All 32 patients had multiple jumps staged for the precision wings, i.e., incremental advancement. The average length of treatment for the MA phase was 9.2 months (7.5-13.8 months) and the average number of aligners used during this time was 37 (30-55). Statistically significant differences between T1 and T2, in favor of class II correction, were observed in the ANB angle, WITS appraisal, facial convexity, and mandibular length. The nasolabial angle, overjet, and overbite also showed statistically significant changes between T1 and T2.

Conclusion

Invisalign aligners with the mandibular advancement feature took approximately 9 months for 1.5 mm of overjet correction. The lower incisor angulation was maintained during class II correction. The minimal skeletal changes are in favor of class II correction.
Topiramate-induced acute angle-closure glaucoma: A case report and review of literature
Authors: Sharma Rishi , Kaushik Jaya
Published: July 2022

Drug-induced angle-closure glaucoma is an emergency associated with potentially vision threatening side effects. There are various classes of drugs which induce acute angle-closure glaucoma. Topiramate is an oral sulfa-based drug used for seizure, migraine, and neuropathic pain. There are published case reports of topiramate-induced angle-closure which can mimic acute angle-closure glaucoma. We present a case of a 32-year-old female who developed bilateral angle-closure glaucoma secondary to topiramate.
Unruptured aneurysm at bifurcation of super short middle cerebral artery mimicking duplicated middle cerebral artery aneurysm
Authors: Michiwaki Yuhei , Kawashima Masatou , Tanaka Tatsuya , Sashida Ryohei , Hirokawa Yu , Wakamiya Tomihiro , Shimoji Kazuaki , Suehiro Eiichi , Onoda Keisuke , Yamane Fumitaka , Matsuno Akira
Published: July 2022

Background:

Duplicated middle cerebral artery (DMCA) is a normal variation of the middle cerebral artery (MCA), and distinguishing DMCA from other arteries based only on the angiographical findings is sometimes difficult.

Case Description:

Preoperative angiography of a 60-year-old woman revealed two MCAs originating near the top of the right internal carotid artery and a 6-mm-sized aneurysm located between these two MCAs. The ipsilateral A1 segment of the anterior cerebral artery was not visualized due to hypoplasia. The patient was diagnosed with an unruptured aneurysm at the bifurcation between MCA and DMCA, preoperatively. However, during clipping surgery, the hypoplastic A1 segment was observed at approximately 2 mm proximal to the bifurcation of the MCA, indicating that these two MCAs were not “true” MCA and DMCA, but rather two normal MCA trunks bifurcated from the very short prebifurcation segment of M1. This difference in interpretation was due to the fact that the hypoplastic A1 was not visualized on preoperative examinations. The patient was discharged following the surgery without any neurological deficits.

Conclusion:

The distinction between DMCA and MCA trunks from the very short prebifurcation segment of MCA might be difficult, especially when the ipsilateral A1 segment is hypoplastic. Such an M1 with a length of 2–3 mm might be named super short M1. Thus, it is necessary to confirm the anatomy during aneurysm surgery.
Yeni Mezun Hemşirelerin Mesleki Açıdan Kendilerini Yeterli Hissetme Durumları
Authors: TERKEŞ Nurten
Published: July 2022

Giriş: Hemşirelik mesleğinden hasta merkezli ve kanıta dayalı araştırmaların içerdiği bütüncül bir bakımın sağlaması beklenmektedir. Bunun için hemşirelerin mesleki yeterliliğe/yetkinliğe sahip olarak mezun olması gerekmektedir. Amaç: Çalışmamızın amacı yeni mezun olan hemşirelerin mesleki açıdan kendilerini ne kadar yeterli gördüklerini belirlemektir. Gereç ve Yöntemler: Araştırma 25 Nisan-15 Haziran 2021 tarihleri arasında yürütülmüş olup, bir sağlık yüksekokulu hemşirelik bölümünden mezun olan 115 hemşire ile yapılmıştır. Veri toplama formu olarak; hemşirelere kişisel bilgi formu ve Bütüncül Hemşirelik Yeterlik Ölçeği kullanılmıştır. İstatistiksel analizler SPSS 21 paket programı ile yapılmıştır. Bulgular: Araştırmaya katılan yeni mezun hemşirelerin %54.8’inin erkek, %47.1’inin 24 yaş ve üzeri, %78.3’ünün Anadolu Lisesi mezunu, %69.6’sının çalıştığı görülmektedir. Ayrıca kendini mesleki açıdan yeterli hissettiğini ifade edenlerin oranı %36.5 ve yetersiz hissedenlerin oranı %30.5’dir. Pandemi nedeniyle mesleki yeterliliklerinin etkilendiğini düşünenlerin oranı %58.2 olarak tespit edilmiştir. olduğu bulunmuştur. Çalışmamızda bütüncül hemşirelik yeterlilik ölçeğinden alınan puan ortalamasının 5,78±0,86 olduğu bulunmuştur. Araştırmamızda yeni mezun hemşirelerin tanıtıcı özelliklerine göre Bütüncül Hemşirelik Yeterlilikleri Ölçek’ten alınan puan ortalamaları karşılaştırıldığında, cinsiyet, yaş, mezun olduğu lise, lisans mezuniyet notu ve kendini mesleki acıdan yeterli hissetme durumu ile ölçek puan ortalamaları arasında istatistiksel olarak anlamlı fark olduğu görülmektedir (p
Promoting Halogen-Bonding Catalyzed Living Radical Polymerization through Ion-Pair Strain
Authors: Huang Shiwen , Su Xinjian , Wu Yanzhen , Xiong Xiao-Gen , Liu Yiliu
Published: July 2022

Discovering efficient catalysts is highly desired in expanding the application of halogen-bonding catalysis. We herein report our findings on applying triaminocyclopropenium (TAC) iodides as highly potent catalysts for halogen-bonding catalyzed living radical polymerization. Promoted by the unique effect of ion-pair strain between the TAC cation and the iodide anion, the TAC iodides showed high catalytic efficiency in the halogen-bonding catalysis toward radical generation, and surpassed the previously reported organic iodide catalysts. With the TAC iodide as catalyst, radical polymerization with a living feature was successfully realized, which shows general applicability with a variety of monomers and produced block copolymers. In addition, the TAC-iodides also showed promising feasibility in catalyzing the radical depolymerization of iodo-terminated polymethacrylates. Noteworthily, the catalytic capacity of the TAC iodides is demonstrated to be closely related to the electronic properties of the TAC cation, which offers a molecular platform for further catalyst screening and optimization.
Cu-Catalysed Coupling of Aliphatic Amines with Alkylboronic Esters
Authors: Dennis Francesca , Romero Arenas Antonio , Rodgers George , Andrews Jonathan , Peralta-Arriaga Samantha , Partridge Benjamin
Published: July 2022

We report a Cu-catalysed oxidative coupling of aliphatic amines with alkylboronic esters to give high value alkyl amines, products found widely in applications from medicinal chemistry to materials science. This operationally simple reaction, which can be performed on gram scale, runs under mild conditions and exhibits excellent functional group tolerance. The terminal oxidant of the reaction is O2 from the air, avoiding the need for additional chemical oxidants. Investigation into the reaction mechanism suggests the intermediacy of an alkyl radical, generated from the boronic ester upon activation through an amino radical transfer process. To demonstrate its utility and potential for late-stage functionalization, we showcase the method as the final step in the total synthesis of a TRPV 1 antagonist.
Structure-based computational approaches for characterization and functional elucidation of the fusion protein from Nipah henipavirus
Authors: Saikat Abu Saim Mohammad
Published: July 2022

Many epidemics of varying severity have triggered panic and devastation in the past. The Nipah virus has one of the world's highest fatality rates. The encephalitis resulting from acute respiratory distress has been fatal in some instances. Many factors influence the virus's genesis and spread. Developing new methods has improved personal hygiene awareness and surveillance over the contaminated area. An unidentified protein from Nipah henipavirus was the focus of this investigation. The secondary structure of the protein consists of a helix, a sheet, a turn, and a coil. Furthermore, the Ramachandran plot and the Z-score-based and local model quality assessment processes revealed the quality of the modeled protein structure. The protein can be used as a target for developing prospective antiviral medication and vaccine candidates.
Graph neural networks predict energetic and mechanical properties for models of solid solution metal alloy phases
Authors: Lupo Pasini Massimiliano , Jung GS , Irle Stephan
Published: July 2022

We developed a graph convolutional neural network (GCNN) to predict the formation energy and the bulk modulus for models of solid solution alloys for various atomic crystal structures and relaxed volumes. We trained the GCNN model on a dataset for nickel-niobium (NiNb) that was generated for simplicity with the embedded atom model (EAM) empirical interatomic potential. The dataset has been generated by calculating the formation energy and the bulk modulus as a prototypical elastic property for optimized geometries starting from initial body-centered cubic (BCC), face-centered cubic (FCC), and hexagonal compact packed (HCP) crystal structures, with configurations spanning the possible compositional range for each of the three types of initial crystal structure. Numerical results show that the GCNN model effectively predicts both the formation energy and the bulk modulus as functions of the optimized crystal structure, relaxed volume, and configurational entropy of the model structures for solid solution alloys.
Optimisation of a Holographic Microscope for Microbial Study
Authors: Niraula Bimochan , Nadeau Jay
Published: July 2022

Background: Tracking of microbial organisms over a volume requires images at multiple focal planes along the orthogonal direction. With most conventional microscopes, this requires repeated readjustments; using Digital Holographic Microscopy (DHM), it is possible to use a set of interference patterns to reconstruct at various distances, thereby creating a 3D stack based off a single image.

Methods: We used an off-axis Mach-Zehnder DHM for imaging and tracking bacterial movement. We describe the algorithm employed for tracking, as well as our improvement of trackability by testing differences in image contrast with the use of Quantum Dots.

Results: We show that the use of Quantum Dots resulted in an increase in contrast of approximately 11%.

Conclusion: We suggest this as a method of increasing resolvability of individual microbes. With a more compact design, the microscope will be applicable in various fields, and can be used remotely for studies of microbial organisms.
Melatonin and its Receptors
Authors: Min Seung Hyun , Gobbi Gabriella , Posa Luca
Published: July 2022

Background: Melatonin (5-methoxy-N-acetyltryptamine) is a hormone that has numerous physiological functions. Synthesized and released during nighttime, melatonin exerts its physiological effects in a circadian manner. Melatonin acts by binding to its different types of receptors. The purpose of this systematic review is to summarize recent findings about melatonin, its receptors, and the differential functionalities of the most characterized melatonin receptors MT1 and MT2.
Methods: We searched PubMed and Google Scholar for studies that reported melatonin receptor subtypes, their differential functionalities, biochemical structures, signal transductions, and various functions of melatonin such as pain, sleep, temperature, and antioxidative effects. We chose seventy articles for this systematic review.
Summary: These studies highlight melatonin’s range of physiological functions and the differential functionalities of the melatonin receptors MT1 and MT2; they characterize the receptors’ signal transduction cascades and their biochemical structures. More studies assessing melatonin receptors’ functions would help patients with disorders in sleep, pain, and circadian rhythm.
Effectiveness of Behavioural Intervention as Treatment for the Vasovagal Response in Blood Donation
Authors: Wade Kristina , Ditto Blaine
Published: July 2022

Background: The experience of a vasovagal reaction during blood donation, with symptoms such as dizziness, weakness, and fainting, contributes to a more negative donation experience and significantly decreases the likelihood of blood donor return. This study investigates the effects of two behavioural interventions on reducing the occurrence of such reactions, applied muscle tension and respiration control, and possible moderation of these effects by sex, BMI, and medical fear.
Methods: Six hundred and eleven participants were recruited from Héma-Québec blood drives across Montreal and randomly assigned one of four conditions: applied muscle tension, an anti-hyperventilation respiration control procedure, both techniques, or neither. Following their donation, participants completed the Blood Donations Reactions Inventory and Medical Fears Survey. Analysis focuses on the respiration control and applied tension groups.
Results: While donor sex and BMI did not predict the effectiveness of applied muscle tension intervention, results showed that the largest benefit was seen in donors who reported lower levels of medical fears in the respiration control condition group.
Limitations/Conclusions: The results are promising in that they suggest that intervention can decrease the risk for vasovagal symptoms in blood donation, though it may not be sufficient to reduce symptoms in donors with high levels of medical fear.
Delivering the “Living Drug”: T Cell Immunotherapy
Authors: Rendon Laura
Published: July 2022

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.
Implications of Reciprocity in the Evolution of Ethnocentrism and Cooperation
Authors: Feng Ruo Ying
Published: July 2022

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.
Eco-Audit of MOFs as H₂ Storage Materials for Vehicle Applications, Using Novel Refueling Model
Authors: Andraos Elias , Merino Guido , Ritter Maximilian
Published: July 2022

Metal-organic frameworks (MOFs) are a heavily researched candidate for fuel-cell electric vehicle (FCEV) hydrogen storage. However, little analysis has been done on the environmental impact of potential MOF vehicles compared to established alternative vehicles, such as compressed hydrogen or battery-electric vehicles. In this work, a preliminary eco-audit was conducted for a FCEV using an MOF hydrogen storage system based the best current MOF Ni₂(m-dobdc) (Ni-MOF-74). (1) Cost and environmental impact analyses were performed for both the production and use phases of an MOF-FCEV. The cost and environmental impact of MOF production was compared to that of Lithium Nickel Manganese Cobalt Oxide (LiNMCO) batteries, the current state-of-the-art for BEVs. (2) Environmental impact was assessed using embodied energy estimates based on reported values for LiNMCO BEVs. These highlighted MOF vehicles as a competitor to current renewable energy vehicle technologies. For the use phase, a hydrogen refueling station that produces hydrogen onsite by proton exchange membrane (PEM) electrolysis from grid electricity was compared to an equivalent population of battery electric vehicles (BEVs) charged at distributed recharging stations. FCEVs using the proposed refueling model were able to compete with BEVs both in terms of electricity CO₂ footprint and cost in the simulated solar-dominated Californian grid, but not in the hydro- and nuclear-heavy Ontario grid.
Molecular Dynamical Investigation of the 7,8-dihydro-8-oxoguanine Mutation in dsDNA
Authors: Dementyev Ilya , Karimi Ashkan
Published: July 2022

Background: The oxidization of a Guanine (G) base pair to 7,8-dihydro-8-oxoguanine (OG) is one of the most common DNA mutations. OG mutations can undergo a regular Watson-Crick base-pairing, or a reverse Hoogsteen (HG) base-pairing, especially in OG:A mismatches. While the causes of these mutations are well-understood, the kinetic and energetic characteristics of this new pseudo-base have never been fully investigated, especially at temperatures around biological function (17-37°C).
Methods: We created a simulation to derive the Free Energy Surface (FES) of OG:C and OG:A Hoogsteen to Watson-Crick base-pair (bp) transitions under multiple temperatures, relative to 2 collective geometric variables: the dihedral Chi and the pseudo-dihedral CPD angle. To make the simulation, we used the relatively recent Metadynamics algorithms in conjunction with GROMACS 2020.2.
Results: The lowest free energy increased linearly with increasing temperatures (17-37°C). Major Chi and CPD rotations at these minima varied heavily for 27°C and 32°C (the largest was seen in the former), but stayed relatively similar for other temperatures, indicating a highly sensitive relationship to temperature, likely due to DNA flexibility, quantum mechanical (QM) effects, and hydrogen bonding. Free energies had a weak negative linear relationship, and free energy hypersurfaces were given for studied temperatures of 17-37°C. Human body temperature (37°C) results were also included and explained. The simulations showed why OG:A Hoogsteen bps often occur in organisms and are energetically preferable to standard Watson-Crick. OG:C HG base pairings are determined to likely be not as common as OG:A HG.
Limitations: Future investigations must focus on discovering rate constants of these base-pairs, as time constraints did not permit them to be done here, as well as more QM-focused simulations.
Micro-Urban Heat Islands in the City of Montreal
Authors: Aucoin Samuel , Briand Alex , Duval Béatrice , Qudsi Zoya
Published: July 2022

Heat within a city is not evenly distributed, giving rise to regions of relatively warm and cold temperatures. Regions of very high heat are referred to as micro-urban heat islands (MUHIs) and can be severe enough to harm human health. Despite MUHIs being an important factor in urban health, they are extremely underresearched. In this study we mapped the locations of MUHIs on the island of Montréal and compared them with the locations of vegetation on three clear, sunny days: August 10th, 2021; July 6th, 2020; and June 20th, 2020 using Landsat 8 thermal images with 30 m resolution. We compared two criteria for MUHIs and quantified their composition based on unsupervised classification done on ENVI 5.6.1, and Normalized Difference Vegetation Index (NDVI) calculations. Our results show that MUHIs are mainly associated with the presence of asphalt and concrete, and the absence of dense vegetation. The presence of these materials is not, however, a strong predictor of the formation of MUHIs in themselves. Though variability in unsupervised classifications between images introduces uncertainty in MUHI composition, these results suggest that increasing dense vegetation coverage in Montréal could prevent MUHI development during the summer.
Exploring Differing Host Cutaneous Microbiome and Immune Responses Contributing to Chytridiomycosis Susceptibility in Amphibians
Authors: Corbin Connie
Published: July 2022

Chytridiomycosis is an emerging infectious disease caused by Batrachochytrium dendrobatidis, a fungal pathogen affecting the skin of amphibians. Chytridiomycosis is differentially affecting amphibian species and populations across the world, causing severe declines and extinctions. It is spread by contact or zoospores travelling in water sources. It is not yet fully understood why susceptibility is so variable. Understanding differing susceptibility is crucial for realising any successful conservation efforts. Multiple factors appear responsible for the differing susceptibility. The two factors being examined in this literature review are ineffective immune responses and the limitations of the cutaneous microbiome. Relevant papers’ significance and limitations are discussed with their provenance and objectivity taken into consideration. The immune system of amphibians comprises innate and acquired defences. The innate immune system has been found to be counterproductive in some cases, much like how an allergic reaction in humans can be detrimental to health. An adaptive immune response has yet to be confirmed in previously exposed individuals. The cutaneous microbiome plays an initial role in the defence against harmful zoospores by making the environment unsuitable or by producing deadly secretions; this consequently prevents colonization by the zoospores. Differing levels of secretions have been measured in response to disease. Most amphibian immune systems and microbiomes are not adapted to deal with chytridiomycosis, and the fungi are adapted to exploit this weakness. There are many difficulties in studying this disease, such as recreating a natural habitat in laboratory conditions, which is vital to get accurate microbiome data. The variety of species and global spread of this disease is incredibly wide ranging with many factors to consider. Many studies are only focused on one aspect of the disease, so a holistic and global approach would be more beneficial.
Mercury Determination: A Hair Raising Experiment
Authors: Duford David , Lafleur Josiane P. , Lam Rebecca , Skinner Cameron D. , Salin Eric D.
Published: July 2022

A novel, fast, low-cost portable system for the total analysis of mercury (Hg) in human hair is presented by induction heating-electrothermal vaporization, gold amalgamation, atomic absorption spectrometry (IH-ETV-GA-AAS). Using this innovative technique a detection limit of 1 ng (or 1.5 mg/g based on a 0.6 mg sample) was achieved.
Variations in the electrocommunication behaviour of the weakly electric fish Apteronotus Leptorhynchus
Authors: Tamburello Natascia , Krahe Rudiger
Published: July 2022

Apteronotus leptorhynchus (Gymnotiformes) is a weakly electric fish which produces wave-like electric organ discharges as well as brief modulations in the frequency of these discharges, termed chirps. Thought to be used for communicating, this study explores variations in previously described chirp types by investigating fish chirping behaviour through recordings of external electric field modulations, and several novel phenomena were characterized. An alternative form of the type 1 chirp was discovered that is preceded by a gradual rise in frequency lasting 8-10 ms. Two sub-categories of type 2 chirps emerged, distinguished by frequency excursions of 23-86 Hz and 86-183 Hz respectively, and individual fish chirp almost exclusively within a single subgroup. Type 3 chirps occupied a much lower range of durations (10-60 ms) than those previously described, and no type 4, 5 or 6 chirps were observed. Finally, a single unusual chirp characterized by an extreme frequency and amplitude modulation raises interesting questions about chirp production mechanisms. While we cannot exclude that the differences observed across chirping studies are a consequence of subtle differences in methodology, we propose that geographical variation in electrocommunication behaviour should be investigated as an alternative explanation with possible implications for speciation.
Density-dependent succession in Caribbean seagrass communities
Authors: Binning Sandra , Mavromatis Charalampos , Guichard Frédéric
Published: July 2022

It is important to understand the patterns of succession and competition in seagrass beds as a way of explaining recovery processes after disturbances. This project studies macroalgae-seagrass succession dynamics in the Caribbean, and tests the importance of interspecific density-dependence (competition) in predicting the successional sequence of species in a wave-disturbed ecosystem. Competition and gap disturbances seem to be the dominant factors influencing species coexistence in offshore regions whereas habitat partitioning driven by differences in depth, disturbance and wave action creates distinct zones of macroalgae and seagrass inshore. In general, density dependent processes across our study site were influenced by major physical gradients. This study has important consequences for predicting dramatic shifts in large-scale seagrass ecosystems, which act as ecological engineers and provide many ecosystem services.
Using CloudSat data to look at the cloud and precipitation structure in the Arctic
Authors: Gagné Marie-Ève , Laplante Alexandre , Stewart Ronald , Hanesiak John
Published: July 2022

Clouds and precipitation are fundamental determinates of the Arctic climate. Despite the presence of clouds and storm systems, very few precipitations reach the ground. In fact, polar precipitation patterns are characterized by frequent sublimation of the water particles during their descent. This discrepancy between cloud coverage and storm systems and the amount of precipitation on the ground is not explained because relatively little is known about these features due partly to the lack of available data. Recently, CloudSat, a polar-orbiting satellite, was launched in order to provide unique information about the cloud and precipitation structure of the Arctic, which cannot be measured using current weather instruments. The data is used in the context of the Storm Studies in the Arctic, a field experiment that started in Fall 2007 in the Canadian Arctic, aims at describing the extreme weather occurring over Baffin Island and Iqaluit. The present study focuses on the Southern Baffin Island using data from CloudSat for the area covered by the Storm Studies in the Arctic field experiment. We analyzed 37 passes of CloudSat over Iqaluit and examined cloud altitude and type, environmental conditions like temperature and relative humidity, as well as the precipitation type, size, and rate. Our analysis shows that the cloud structure is characterized by formations that are mostly stratiform, composed of one to two cloud-layers at low- and mid-level, and mostly thin individual clouds. A low cloud base and a large cloud thickness seem to be requirements for precipitation over the region. Although these results do not give satisfying answers regarding what triggers sublimation , they provide general information about the macrostructure of the clouds. This is a first step in understanding why in the Arctic very little precipitation reaches the ground. We believe further information about cloud microstructure can be garnered using data from CloudSat. Our data therefore provides recommendation for the Storm Studies in the Arctic experiment that started after this study was conducted.
Viability of renewable technologies from marine derived energy as global sources of electricity
Authors: Dubois Shawn , Klein Kerry , Villemure Marlène
Published: July 2022

Due to dwindling natural resources and continually increasing energy demands, renewable energy may be the solution to the world’s future energy needs. The oceans represent a large reservoir of energy and marine derived renewable energy may in turn represent a significant source of global electricity. In particular, the marine renewables reviewed in this study are ocean thermal energy conversion and wave energy. Unlike more mainstream renewables, little research has been undertaken to determine the capabilities of these technologies. However, the authors believe that these technologies have the potential to contribute significantly to the global energy market. Global potential maps for each technology were constructed using analysis of data sets provided by the International Research Institute for Climate and Society (Columbia University) and a Geographic Information System. These show the best viability of OTEC to be concentrated around the Equator, where the vertical ocean temperature gradients are at least 20°C/km, and that the most suitable areas for wave power are concentrated between the latitudes of roughly 40 to 60° N and S, where surface wind speeds average at least 8 m/s. Given these areas, gross potential outputs were calculated to be 605 TW for OTEC and 3368 TW for wave power, 1% of which is still greater than the global electricity demand (13.2 PWh, or 1.51 TW of power, in 2000 (EIA, 2007)). These results are promising, but they do not reflect technological, sociological and economical limitations. The environmental impacts of these technologies may range from local effects on ecosystems and biodiversity to long-term global climate and oceanic implications. Compared to modern non-renewable energy sources, these technologies have no significant greenhouse gas emissions. Given the globally significant potential outputs and limited environmental impacts of OTEC and wave energy, it is clear that marine renewable energy technologies are viable as future sources of electricity.
Fabrication of optical fiber probes for scanning near-field optical microscopy
Authors: Guo Si , LeDue Jeffrey , Grütter Peter
Published: July 2022

Many areas of cell biology have remained unexplored due to the limitations of conventional optical microscopy for image structures smaller than the diffraction limit of light. Scanning near-field optical microscopy (SNOM) is an emerging technique which allows sub-diffraction limit optical resolution and hence access to nanoscale structures such as those in biological cells. Since the success of a scanning probe microscopy techniques depend on the tip, we present a method for the fabrication of SNOM aperture probes and antenna probes capable of high resolution imaging of delicate liquid based samples such as neurons. The procedure includes thinning and tapering optical fibers by chemical etching, followed by the deposition of a thin aluminium film, and micromaching using focused ion beam (FIB). Tip geometry, antenna resonances, excitation conditions, and field localizations have been examined. The probes have a resonant frequency of 18-28 kHz, a Q of 200-400 in air and up to 100 in water, and a spring constant of on the orders of 140 N/m. Successful optical and topographical imaging up to a resolution of 250 nm was achieved with the probes. Together with adjustments in equipment and instrumentation, the probe’s optical and mechanical properties allow for a low imaging force and high tip sensitivity which are necessary conditions for the imaging of biological cells.
Food temptations spontaneously elicit compensatory beliefs in dieters
Authors: Monson Eva , Knäuper Bärbel , Knonick Ilana
Published: July 2022

Through various self-regulatory strategies, individuals attempt to strike a balance between the satisfaction of immediate desires and fulfillment of long term goals. One such strategy is described by the compensatory beliefs model, which suggests that individuals rationalize their surrender to an immediate desire or temptation. This model is indirectly supported by earlier studies where compensatory beliefs were induced by the experimental context. The current pilot study examines whether compensatory beliefs can be self-initiated i.e. are spontaneously generated as a response to temptation. We recruited ten female McGill students currently on a weight loss diet and assigned them randomly to a temptation and a control group. We presented all participants with a choice between two identical cookies, differently described for the temptation and control groups: for the temptation condition one cookie was labeled as high in fat and sugar and the other as low in fat and sugar while for the control condition both cookies were labeled as low in fat and sugar. Participants listed compensatory thoughts in both a closed and an open response format. Our pilot data show that dieters indeed spontaneously generate compensatory beliefs in response to temptation. Compensatory beliefs should be considered a factor in unsuccessful self-regulation and more specifically in failed dieting attempts.
HM: A Legacy in Neuroscience
Authors: Eckbo Erik
Published: July 2022

“The problem of neurology is to understand man him- self.” Walking by the Montreal Neurological Institute (MNI) and Hospital, one might give brief regard to these words coined by Wilder Penfield and prominently displayed on the edifice of the building. It is unlikely, however, that most pas- sersby would have an accurate grasp of the groundbreaking work that has been undertaken by scientists at this institute – research that has delved into the inner workings of the human mind. During the 1930s, Penfield developed the surgical treatment of epilepsy by means of temporal lobe resection, and this procedure became a standard among many neurosurgical centres (Greenblatt, Dagi, et al. 1997). The MNI is also where Brenda Milner began her groundbreaking work in the field of neuropsychology, most notably with a patient who until recently was simply known as HM.
Investigation of the role of heme oxygenase-1 in β-thalassemia pathophysiology
Authors: Mendel Arielle , Santos Daniel , Ponka Prem
Published: July 2022

β -thalassemia is an inherited disorder characterized by impaired hemoglobin synthesis in developing erythrocytes due to unbalanced globin chain production, resulting in severe oxidative damage to cells. Heme oxygenase-1 (HO-1) has been shown to have antioxidant benefits and is upregulated in response to oxidative stress; thus increased HO-1 levels could serve as an indicator of β-thalassemia pathophysiology. To test this hypothesis, we created a cell culture model of β-thalassemia by decreasing β globin expression in murine erythroleukemic (MEL) cells using short interfering RNA (siRNA). An increase in HO-1 protein expression, along with a decrease in heme levels was observed in cells where β globin reduction was sustained for 96 hours. Further investigation is needed to determine the role that HO-1 plays in normal erythroid development and confirm the observed relationship between β globin reduction and increased HO-1 expression, however, our results provide evidence that this method serves as an effective and novel cell model of β thalassemia.
Differential Effects of Estrogen on Memory Processes and Learning Strategies: A Selective Review of Animal Studies
Authors: Khorashadi Mina
Published: July 2022

estrogen has differential effects on learning and memory. The direction of these effects depends on a variety of factors including the type of memory process, task specific demands, dose and time course of treatment. While some processes, including working memory, spatial memory and place learning, are improved in high estrogen conditions, other processes such as amygdala-dependent associative memory, reference memory and response learning are impaired. Furthermore, learning strategy is sensitive to the effects of estrogen. specifically, high estrogen conditions promote the use of a hippocampus-dependent strategy, while low estrogen levels bias learning towards a response strategy. In humans, the evidence for effects of estrogen on cognitive function is controversial and the mechanisms of action are not fully understood. This review will discuss major findings from animal studies, highlighting the modulatory effects of estrogen on learning and memory, possible neurobiological mechanisms underlying these effects and the implications of these findings for future investigations of the cognitive effects of estrogen in humans.
Scanning the Cosmos: the Search for life in the Universe
Authors: Berg Anne-Sophie
Published: July 2022

The utter vastness of the universe makes it seem possible, perhaps even very probable, that there is life thriving on other planets. The cosmos, governed everywhere by the same laws of nature, are teeming with the very material that composes the sun, the earth and human beings. Could there be other worlds like our own? Might life exist beyond this planet? To answer these questions, we must consider the specific environments and distinctive circumstances necessary for life to arise. With this information, the detection methods and tools able to scour the great expanse for signatures of life can be determined. They, in turn, can be utilized to gather further data, potentially leading to the discovery of new worlds and new beings.
Neuronal spiking is better than bursting at predicting motion detection in area MT
Authors: Ravishankar Mathura , McKenzie Erica
Published: July 2022

Background: The middle temporal visual area (MT) is widely studied in visual processing and in integration of motion signals to form general perceptions. The objective of this study is to determine whether neuronal bursting in area MT of monkeys is more predictive of motion detection than neuronal spiking.

Methods: Two Macaca mulatta (macaque) monkeys were trained in Dr. Erik Cook’s lab to detect coherent motion while connected to microelectrodes that determined their neuronal spiking activities. Using MatLab, we manipulated the collected data to determine whether spiking or bursting is more predictive of motion detection.

Results: We repeatedly found that neuronal spiking in area MT is better than bursting at predicting motion detection in macaques (p < 0.01).

Conclusions: Therefore, our results suggest that area MT neurons do not fire behaviourally meaningful bursts in response to coherent motion. This finding is useful for learning about the visual processing pathway, and how information is coded in the brain.

Limitations: A key limitation of this study is that we did not exclude any experiments from analysis to control for quality of the collected data, perhaps leading to confounding factors.
Force-fluctuation physics of confined DNA: probing the breakdown of the Marko-Siggia law
Authors: Riaz Haider , Klotz Alex R. , Reisner Dr. Walter W.
Published: July 2022

Introduction: The study of polymers in nanofluidic systems such as nanopores and nanochannels is an important avenue of research in the physical and life sciences today. Complex nanofluidic devices containing varying topography are ideal for quantifying the behaviour of polymers under confinement. This study investigates the Marko-Siggia force-extension relationship under confinement. We measure the transverse fluctuations of deoxyribonucleic acid (DNA) confined between two pits in a nanofluidic slit to measure the potential breakdown of this model.

Methods: We took images of fluorescently tagged single DNA molecules in the nanopit array with video- fluorescence microscopy and analyzed the standard deviation of the peak position along the direction of the molecular extension.

Results: We were able to measure the parabolic relation between position and the strength of transverse fluctuations. By examining the peak variance as a function of slit height, our results indicate that the two dimensional version of the force-fluctuation relationship may be appropriate in the limit of strong confinement. However, we could not consistently measure the absolute length of the DNA stretched between two pits, which prevented us from fully exploring the force-extension and force-fluctuation relationships of confined DNA.

Conclusions: These experiments further demonstrate that nanofluidic confinement serves as a useful tool for testing the extreme properties of polymers, and our results suggest further investigation into the breakdown of the Marko-Siggia force law.
Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS): a once obscure neurodegenerative disease with increasing significance for neurological research
Authors: Li Xinlu (Crystal)
Published: July 2022

Background: Autosomal Recessive Spastic Ataxia of Charlevoix-Saguenay (ARSACS) is a rare cerebellar ataxia occurring in the Charlevoix-Saguenay population in Quebec with high incidence as a result of founder effects. Following the discovery of the gene responsible for the disease, many other patient groups have been identified worldwide and the characterization of the gene product, sacsin, has unveiled similarities between the pathogenic mechanism of ARSACS and those of other major neurodegenerative disease.

Summary: The core symptoms of ARSACS consist of a triad of early-onset cerebellar ataxia, peripheral neuropathy and spasticity, which is accounted by degeneration of Purkinje neurons. The gene responsible for the disease is located on chromosome 13q11 and encodes for the chaperone sacsin. Drp-1, a GTPase crucial for regulating mitochondrial fission/fusion dynamics, has been identified as a potential substrate of sacsin, suggesting a link between the pathogenic mechanisms of ARSACS and prevalent neurodegenerative diseases such as Alzheimer’s, Parkinson’s and Huntington’s diseases.
Moda e cinema em duas perspectivas
Authors: Falcone Giulia , Vigneron Victor Santos
Published: July 2022

Este artigo propõe uma aproximação entre a moda e o cinema a partir de dois autores de destaque no campo acadêmico brasileiro, os críticos Gilda de Mello e Souza e Paulo Emílio Salles Gomes. Embora guardem especializações epistemológicas próprias, Gilda com o estudo da moda e Paulo Emílio com a crítica de cinema, constata-se que nem Gilda e nem Paulo Emílio são estranhos ao objeto originalmente abordado pelo outro, visto que Gilda elabora uma série de análises de filmes nacionais e estrangeiros, enquanto Paulo Emílio não é de todo alheio à questão do figurino, e, consequentemente, da moda, em suas críticas cinematográficas. Assim, ao analisar os escritos de Gilda e de Paulo Emílio sobre moda e cinema, nota-se como as relações de gênero e de sexualidade se sobressaem enquanto questões de relevância na abordagem de ambos os autores, ainda que a perspectiva adotada por cada um seja distinta. Considera-se, enfim, que mesmo se as análises desenvolvidas por eles acerca desses temas não sejam isentas de reservas ou reavaliações, elas oferecem um viés introdutório a suas respectivas obras e a seus métodos críticos.