21 Works

Data from: Long term persistence of experimental populations beyond a species’ natural range

Regan Cross & Christopher Eckert
Ecological experiments usually infer long-term processes from short-term data, and the analysis of geographic range limits is a good example. Species’ geographic ranges may be limited by low fitness due to niche constraints, a hypothesis most directly tested by comparing the fitness of populations transplanted within and beyond the range. Such studies often fail to find beyond-range fitness declines strong enough to conclude that geographic range limits are solely imposed by niche limits. However, almost...

Data from: Partitioning resources through the seasons: abundance and phenology of carrion beetles (Silphidae) in southeastern Ontario

Jillian Wettlaufer, Kevin Burke, David Beresford & Paul Martin
The coexistence of ecologically similar species is thought to require resource partitioning to minimize competition. Phenological, seasonal differences in activity may provide an important axis for resource partitioning. Here, we test for evidence of seasonal differences in activity within a diverse guild of carrion beetles (Silphidae) in a habitat preserve on the Frontenac Arch, southeastern Ontario, Canada using a large-scale survey during their active seasons (April to October). We then used generalized additive models to...

Adoption Costs of Financial Innovation: Evidence from Italian ATM Cards

Kim Huynh, Philipp Schmidt-Dengler, Gregor W. Smith & Angelika Welte
The discrete choice to adopt a financial innovation affects a household’s exposure to inflation and transactions costs. We model this adoption decision as being subject to an unobserved cost. Estimating the cost requires a dynamic structural model, to which we apply a conditional choice simulation estimator. A novel feature of our method is that preference parameters are estimated separately, from the Euler equations of a shopping-time model, to aid statistical efficiency. We apply this method...

A Benchmark Data Set for Hydrogen Combustion

Akshaya Das, Christopher J. Stein, Farnaz Heidar-Zadeh, Luke Bertels, Meili Liu, Xingyi Guan, Mojtaba Haghighatlari, Jie Li, Oufan Zhang, Hongxia Hao, Itai Leven, Martin Head-Gordon & Teresa Head-Gordon

Trading Dynamics with Adverse Selection and Search: Market Freeze, Intervention and Recovery

Jonathan Chiu & Thorsten V. Koeppl
We study the trading dynamics in an asset market where the quality of assets is private information of the owner and finding a counterparty takes time. When trading of a financial asset ceases in equilibrium as a response to an adverse shock to asset quality, a large player can resurrect the market by buying up lemons which involves assuming financial losses. The equilibrium response to such a policy is intricate as it creates an announcement...

International Borrowing, Specialization and Unemployment in a Small, Open Economy

Patrick N. Osakwe & Shouyong Shi
Empirical evidence suggests that the unemployment rate and the export/GNP ratio are positively correlated with external debt across developing countries. This paper develops a dynamic model that provides an explanation for the aforementioned relationships. The central idea of our paper is that international borrowing affects unemployment and specialization patterns by unevenly changing the risk-sharing structure—across sectors—between firms and workers. The economy produces a domestic good and an export good and faces uncertainty in its terms...

Increasing stimulus similarity drives nonmonotonic representational change in hippocampus

Jeffrey Wammes
Studies of hippocampal learning have obtained seemingly contradictory results, with manipulations that increase coactivation of memories sometimes leading to differentiation of these memories, but sometimes not. These results could potentially be reconciled using the nonmonotonic plasticity hypothesis, which posits that representational change (memories moving apart or together) is a U-shaped function of the coactivation of these memories during learning. Testing this hypothesis requires manipulating coactivation over a wide enough range to reveal the full U-shape....

Knee extension moment arm variations relate to mechanical function in walking and running

Mitchell Wheatley
The patellofemoral joint plays a crucial mechanical role during walking and running. It increases the knee extensor mechanism’s moment arm and reduces required knee extension muscle forces to generate the extension moment that supports body weight, prevents knee buckling and propels the centre-of-mass. However, the mechanical implications of moment arm variation caused by patellofemoral and tibiofemoral motion remain unclear. We used a data-driven musculoskeletal model with a 12-degree-of freedom knee to simulate the knee extension...

Chronic selection for early reproductive phenology in an annual plant across a steep, elevational gradient of growing season length

David J. Ensing, Dylan M. D. H. Sora & Christopher G. Eckert
Colonisation along ubiquitous gradients of growing season length should require adaptation of phenological traits, driven by natural selection. While phenology often varies with season length and genetic differentiation in phenological traits sometimes seems adaptive, few studies test whether natural selection is responsible for these patterns. The annual plant Rhinanthus minor is genetically differentiated for phenology across a 1000-m elevational gradient of growing season length in the Canadian Rocky Mountains. We estimated phenotypic selection on five...

Structural brain network abnormalities and the probability of seizure recurrence after epilepsy surgery: supplementary material

Nishant Sinha, Yujiang Wang, Nádia Moreira Da Silva, Anna Miserocchi, Andrew McEvoy, Jane De Tisi, Sjoerd Vos, Gavin Winston, John Duncan & Peter Taylor
Objective: We assessed pre-operative structural brain networks and clinical characteristics of patients with drug resistant temporal lobe epilepsy (TLE) to identify correlates of post-surgical seizure recurrences. Methods: We examined data from 51 TLE patients who underwent anterior temporal lobe resection (ATLR) and 29 healthy controls. For each patient, using the preoperative structural, diffusion, and post-operative structural MRI, we generated two networks: ‘pre-surgery’ network and ‘surgically-spared’ network. Standardising these networks with respect to controls, we determined...

DNA metabarcoding marker choice skews perception of marine eukaryotic biodiversity

Jordan M Casey, Emma Ransome, Allen G Collins, Angka Mahardini, Eka M Kurniasih, Andrianus Sembiring, Nina M D Schiettekatte, Ni Kadek Dita Cahyani, Aji Wahyu Anggoro, Mikaela Moore, Abby Uehling, Mahdi Belcaid, Paul H Barber, Jonathan B Geller & Christopher P Meyer
DNA metabarcoding is an increasingly popular technique to investigate biodiversity; however, many methodological unknowns remain, especially concerning the biases resulting from marker choice. Regions of the cytochrome c oxidase subunit I (COI) and 18S rDNA (18S) genes are commonly employed “universal” markers for eukaryotes, but the extent of taxonomic biases introduced by these markers and how such biases may impact metabarcoding performance is not well quantified. Here, focusing on macro-eukaryotes, we use standardized sampling from...

Supplemental material for: Validation of intraluminal filling defect length to identify carotid free-floating thrombus in patients with stroke/TIA

Carlos Torres, Cheemun Lum, Grant Stotts, Michel Shamy, Dylan Blacquiere, Ronda Lun, Prasham Dave, Aditya Bharatha, Rebecca Thornhill, Franco Momoli, Bijoy Menon, Paulo Puac & Dar Dowlatshahi
Objective: To validate a previously proposed filling defect length threshold of >3.8 mm on CT-angiography (CTA) to discriminate between free-floating thrombus (FFT) and plaque of atheroma. Materials and Methods: Prospective multicenter observational study of 100 participants presenting with TIA/stroke symptoms and a carotid intraluminal filling defect on initial CTA. Follow-up CTA was obtained within one week, and at weeks 2 and 4 if the intraluminal filling defect was unchanged in length. Resolution or decreased length...

Dataset for: Effects of chloride and nutrients on freshwater plankton communities

Danielle Greco, Shelley Arnott, Isabelle Fournier & Brandon Schamp
Increasing chloride concentrations threaten freshwater zooplankton. We questioned the protectiveness of the Canadian Water Quality Guideline for chloride because it is based on individual species studied under laboratory conditions and does not account for potential interactive factors, such as nutrient concentration. We exposed plankton communities to thirty chloride concentration increments for six weeks, crossed with either ambient or high nutrient treatments. Total zooplankton abundance, biomass, and richness declined with increasing chloride, with losses observed below...

Progression of clinical features in Lewy body dementia can be detected over six months

Elie Matar, Elie Matar, Simon R. White, John-Paul Taylor, Alan Thomas, Ian G. McKeith, Joseph P. M. Kane, Ajenthan Surendranathan, Glenda M. Halliday, Simon J. G. Lewis & John T. O'Brien
Objective: This study aimed to quantify the trajectory and magnitude of change of the key clinical features and corresponding symptom domains of Dementia with Lewy bodies (DLB) and Parkinson’s disease dementia (PDD) including global cognition, parkinsonism, recurrent visual hallucinations, cognitive fluctuations and sleep disturbance. Methods: 116 patients with Lewy body dementia (DLB=72, PDD=44) underwent assessment at baseline, 3 and 6 months as part of a prospective multi-centre randomized control trial. Linear mixed models were constructed...

Experimental tests of selection against heterospecific aggression as a driver of avian color pattern divergence

Haley Kenyon & Paul Martin
Signal divergence is thought to reduce the costs of co-occurrence for closely related species and may thereby be important in the generation and maintenance of new biodiversity. In birds, closely related, sympatric species are more divergent in their color patterns than those that live apart, but the selective pressures driving sympatric divergence in color pattern are not well understood. Here, we conducted field experiments on naïve birds using spectrometer-matched, painted 3D-printed models to test whether...

Kinematics and EMG to show integration of proprioceptive and visual feedback during online control of reaching

Shoko Kasuga, Frédéric Crevecoeur, Kevin Cross & Stephen Scott
Visual and proprioceptive feedback both contribute to optimal perceptual decisions, but it remains unknown how these feedback signals are integrated together or consider factors such as delays and variance during online control. We investigated this question by having participants reach to a target with randomly applied mechanical and/or visual disturbances. We observed that the presence of visual feedback during a mechanical disturbance did not increase the size of the muscle response significantly but did decrease...

Empirical Likelihood Block Bootstrapping

Jason Allen, Allan W. Gregory & Katsumi Shimotsu
Monte Carlo evidence has made it clear that asymptotic tests based on generalized method of moments (GMM) estimation have disappointing size. The problem is exacerbated when the moment conditions are serially correlated. Several block bootstrap techniques have been proposed to correct the problem, including Hall and Horowitz (1996) and Inoue and Shintani (2006). We propose an empirical likelihood block bootstrap procedure to improve inference where models are characterized by nonlinear moment conditions that are serially...

Debt-Relief Programs and Money Left on the Table: Evidence from Canada's Response to COVID-19

Jason Allen, Robert Clark, Shaoteng Li & Nicolas Vincent
During the COVID-19 pandemic, Canadian financial institutions offered debt-relief programs to help borrowers cope with job losses and economic insecurity. We consider the low take-up rates for these programs and suggest that to be effective, such programs must be visible and easy to use.

Amaranthus palmeri EPSPS copy number and glyphosate resistance variation

Sarah B.
Gene copy number variation (CNV) has been increasingly associated with organismal responses to environmental stress, but we know little about the quantitative relation between CNV and phenotypic variation. In this study we quantify the relation between variation in EPSPS (5-enolpyruvylshikimate-3-phosphate synthase) copy number using digital drop PCR and variation in phenotypic glyphosate resistance in 22 populations of Amaranthus palmeri (Palmer Amaranth), a range-expanding agricultural weed. Overall, we detected a significant positive relation between population mean...

Opposing community assembly patterns for dominant and non-dominant plant species in herbaceous ecosystems globally

Carlos Alberto Arnillas, Elizabeth Borer, Eric Seabloom, Juan Alberti, Selene Baez, Jonathon Bakker, Elizabeth Boughton, Yvonne Buckley, Miguel Bugalho, Ian Donohue, John Dwyer, Jennifer Firn, Riley Gridzak, Nicole Hagenah, Yann Hautier, Aveliina Helm, Anke Jentsch, , Kimberly Komatsu, Lauri Laanisto, Ramesh Laungani, Rebecca McCulley, Joslin Moore, John Morgan, Pablo Peri … & Marc Cadotte
Biotic and abiotic factors interact with dominant plants —the locally most frequent or with the largest coverage— and non-dominant plants differently, partially because dominant plants modify the environment where non-dominant plants grow. For instance, if dominant plants compete strongly, they will deplete most resources, forcing non-dominant plants into a narrower niche space. Conversely, if dominant plants are constrained by the environment, they might not exhaust available resources but instead may ameliorate environmental stressors that usually...

Cucurbit[7]uril host−guest complexations of steroidal neuromuscular blocking agents in aqueous solution

Donal H. Macartney & Mona A. Gamal-Eldin
The complexations of three steroidal neuromuscular blocking agents, rocuronium, vecuronium, and pancuronium, by the cucurbit[7]uril host molecule have been investigated in aqueous solution using 1H NMR spectroscopy and ESI mass spectrometry. The CB[7] binds to each of the two terminal cationic N-heterocyclic groups by means of ion-dipole interactions and hydrophobic effects, with stability constants in the order of vecuronium > pancuronium > rocuronium. This trend is different from those observed for the anionic substituted γ-cyclodextrin...

Registration Year

  • 2021
    21

Resource Types

  • Dataset
    16
  • Text
    5

Affiliations

  • Queen's University
    21
  • Bank of Canada
    5
  • Algoma University
    2
  • Newcastle University
    2
  • University of Toronto
    2
  • Helmholtz Centre for Environmental Research
    1
  • University of Washington
    1
  • University of Pretoria
    1
  • The University of Texas at Austin
    1
  • Archbold Biological Station
    1