51 Works

Clinician-researcher’s perspectives on clinical research during the COVID-19 pandemic

Sarah Silverberg, Lisa Puchalski-Ritchie, Nina Gobat, Alistair Nichol & Srinavas Murthy
Objectives: The outcome of well-performed clinical research is essential for evidence-based patient management during pandemics. However, conducting clinical research amidst a pandemic requires researchers to balance clinical and research demands. We seek to understand the values, experiences, and beliefs of physicians working at the onset of the COVID-19 pandemic in order to inform clinical research planning. We aim to understand whether pandemic settings affect physician comfort with research practices, and how physician experiences shape their...

Rwenzori colobus core unit SNA data - association scans between units, simple association index per dyad, male dispersal events, rainfall and food availability

Julie Teichroeb, Frances Adams, T. Jean Arseneau-Robar & Tyler Bonnell
1. Multi-level societies are complex, nested social systems where basic social groups (i.e., core units) associate in a hierarchical manner, allowing animals to adjust their group sizes in response to variables such as food availability, predation, or conspecific threat. These pressures fluctuate over time and examining the extent to which this variation affects the clustering of core units into different tiers may be instrumental in understanding the evolution of multi-level societies. 2. The goal of...

Progressive neurochemical abnormalities in cognitive and motor subgroups of ALS: a prospective multicentre study

Daniel Ta, Abdullah Ishaque, Ojas Srivastava, Chris Hanstock, Peter Seres, Dean Eurich, Collin Luk, Hannah Briemberg, Richard Frayne, Angela Genge, Simon Graham, Lawrence Korngut, Lorne Zinman & Sanjay Kalra
Objective: To evaluate progressive cerebral degeneration in amyotrophic lateral sclerosis (ALS) by assessing alterations in N-acetylaspartate (NAA) ratios in the motor and prefrontal cortex within clinical subgroups of ALS. Methods: Seventy-six ALS patients and 59 healthy controls were enrolled a prospective, longitudinal, multicenter study in the Canadian ALS Neuroimaging Consortium (CALSNIC). Participants underwent serial clinical evaluations and MRS at baseline, 4 and 8 months using a harmonized protocol across 5 centers. NAA ratios were quantified...

Behavioural, morphological, and life history shifts during invasive spread

Monica Mowery, Cor Vink, Andrew Mason & Maydianne Andrade
Invasive species are common around the world, but we still do not know which traits are most important for successfully establishing in new environments. Different stages of the invasion process, including transport, introduction, establishment, and spread, can act as selective filters for different combinations of phenotypic traits. Theoretical and empirical studies predict that invasive populations should have suites of behaviours that improve dispersal and spread, including higher boldness, dispersal propensity, and activity levels than native...

Dietary and body mass reconstruction of the Miocene neotropical bat Notonycteris magdalenensis (Phyllostomidae) from La Venta, Colombia

Camilo López-Aguirre, Nicholas Czaplewski, Andrés Link, Masanaru Takai & Suzanne Hand
With 14 species recorded, the Miocene La Venta bat fauna is the most diverse bat palaeocommunity in South America. They include the oldest plant-visiting bat in the New World, and some of the earliest representatives of the extant families Phyllostomidae, Thyropteridae and Noctilionidae. La Venta’s Notonycteris magdalenensis is an extinct member of the subfamily Phyllostominae, a group of modern Neotropical animalivorous bats, and is commonly included in studies of the evolution of Neotropical bats, but...

Adaptation across geographic ranges is consistent with strong selection in marginal climates and legacies of range expansion

Megan Bontrager, Takuji Usui, Julie Lee-Yaw, Daniel Anstett, Haley Branch, Anna Hargreaves, Christopher Muir & Amy Angert
Every species experiences limits to its geographic distribution. Some evolutionary models predict that populations at range edges are less well-adapted to their local environments due to drift, expansion load, or swamping gene flow from the range interior. Alternatively, populations near range edges might be uniquely adapted to marginal environments. In this study, we use a database of transplant studies that quantify performance at broad geographic scales to test how local adaptation, site quality, and population...

Ongoing production of low-fitness hybrids limits range overlap between divergent cryptic species

Else Mikkelsen & Darren Irwin
Contact zones between recently-diverged taxa provide opportunities to examine the causes of reproductive isolation and the processes that determine whether two species can coexist over a broad region. The Pacific Wren (Troglodytes pacificus) and Winter Wren (Troglodytes hiemalis) are two morphologically similar songbirds that started diverging about 4 million years ago, older than most sister species pairs of temperate songbirds. The ranges of these species come into narrow contact in western Canada, where the two...

Sex-specific maternal programming of corticosteroid binding globulin by predator odour

Sameera Abuaish, Sophia Lavergne, Benjamin Hing, Sophie St-Cyr, Richard Spinieli, Rudy Boonstra & Patrick McGowan
Predation is a key organizing force in ecosystems. The threat of predation may act to program the endocrine hypothalamic-pituitary-adrenal axis during development to prepare offspring for the environment they are likely to encounter. Such effects are typically investigated through measurement of corticosteroids (Cort). Corticosteroid-binding globulin (CBG) plays a key role in regulating the bioavailability of Cort, with only free unbound Cort being biologically active. We investigated the effects of prenatal predator odour exposure (POE) in...

Data from: Shade tree traits and microclimate modifications: Implications for pathogen management in biodiverse coffee agroforests

Stephanie Gagliardi, Jacques Avelino, Elias De Melo Virginio Filho & Marney Isaac
Diversified coffee agroforests modify microclimate conditions in comparison to monocultures, impacting the success of significant plant pathogens, such as Hemileia vastatrix, which causes coffee leaf rust (CLR). However, research is often limited to the dichotomous analysis of shaded agroforestry systems or unshaded monocultures, often overlooking the nuanced effect of shade tree trait diversity. Our study aims to determine the cumulative effects of shade tree canopy architectural characteristics and leaf functional traits in biodiverse agroforests on...

A new model of forelimb ecomorphology for predicting the ancient habitats of fossil turtles

Thomas Dudgeon, Marissa Livius, Noel Alfonso, Stéphanie Tessier & Jordan Mallon
Various morphological proxies have been used to infer habitat preferences among fossil turtles and their early ancestors, but most are tightly linked to phylogeny, thereby minimizing their predictive power. One particularly widely used model incorporates linear measurements of the forelimb (humerus + ulna + manus) but, in addition to the issue of phylogenetic correlation, it does not estimate the likelihood of habitat assignment. Here, we introduce a new model that uses intramanual measurements (digit III...

Do annual and perennial populations of an insect-pollinated plant species differ in mating system?

Wei-Ning Bai, Yue Ma, Spencer Barrett, Fang-Yuan Wang & Jun-Chen Deng
Background and Aims Theory predicts that outcrossing should be more prevalent among perennials than annuals, a pattern confirmed by comparative evidence from diverse angiosperm families. However, intraspecific comparisons between annual and perennial populations are few because such variation is uncommon among flowering plants. Here, we test the hypothesis that perennial populations outcross more than annual populations by investigating Incarvillea sinensis, a wide-ranging insect-pollinated herb native to China. The occurrence of both allopatric and sympatric populations...

Is Niagara Falls a barrier to gene flow in riverine fishes? A test using genome-wide SNP data from seven native species

Nathan Lujan, Jason Weir, Brice Noonan, Nathan Lovejoy & Nicholas Mandrak
Since the early Holocene, fish population genetics in the Laurentian Great Lakes have been shaped by the dual influences of habitat structure and post-glacial dispersal. Riverscape genetics theory predicts that longitudinal habitat corridors and unidirectional downstream water-flow drive the downstream accumulation of genetic diversity, whereas post-glacial dispersal theory predicts that fish genetic diversity should decrease with increasing distance from glacial refugia. This study examines populations of seven native fish species codistributed above and below the...

Data from: A Burgess Shale mandibulate arthropod with a pygidium – a case of convergent evolution

Alejandro Izquierdo-López & Jean-Bernard Caron
Cambrian ‘bivalved’ arthropods are a polyphyletic group of carapace-bearing arthropods which include stem euarthropods, stem mandibulates and crustaceans. Here, we describe Pakucaris apatis gen et. sp. nov. a new ‘bivalved’ mandibulate from the middle Cambrian (Wuliuan Stage) Burgess Shale (Marble Canyon, Kootenay National Park, British Columbia, Canada). Two morphotypes of this small arthropod (11.6–26.6 mm long) are recognized, differing mainly in their sizes and number of segments, possibly reflecting sexual dimorphism or different anamorphic stages....

Genotype-environment interactions shape leaf functional traits of cacao in agroforests

Marie Sauvadet, Adam Dickinson, Eduardo Somarriba, Wilbert Phillips-Mora, Rolando Cerda, Adam Martin & Marney Isaac
The outbreak of frosty (Moniliophthora roreri) and black pod (Phytophthora palmivora) in Central American cacao agroforests throughout the 1980s, led to the breeding of Theobroma cacao clones resistant to these diseases. However, while clonal disease resistance has been well documented, clonal adaptability to contrasting pedoclimates remains less understood. Plant functional responses to environmental constraints can be assessed by evaluating intraspecific trait variation (ITV), but trait-based approaches have rarely been implemented in genotype assessments. The objective...

The relationship between sternum variation and mode of locomotion in birds

Talia M. Lowi-Merri, Roger B. J. Benson, Santiago Claramunt & David C. Evans
Background: The origin of powered avian flight was a locomotor innovation that expanded the ecological potential of maniraptoran dinosaurs, leading to remarkable variation in modern birds (Neornithes). The avian sternum is the anchor for the major flight muscles and, despite varying widely in morphology, has not been extensively studied from evolutionary or functional perspectives. We quantify sternal variation across a broad phylogenetic scope of birds using 3D geometric morphometrics methods. Using this comprehensive dataset, we...

Data from: Bioregions are predominantly climatic for fishes of northern lakes

Charlie Loewen, Donald Jackson, Cindy Chu, Karen Alofs, Gretchen Hansen, Andrew Honsey, Charles Minns & Kevin Wehrly
Aim: Recurrent species assemblages integrate important biotic interactions and joint responses to environmental and spatial filters that enable local coexistence. Here, we applied a bipartite (site-species) network approach to develop a natural typology of lakes sharing distinct fish faunas and provide a detailed, hierarchical view of their bioregions. We then compared the roles of key biogeographic factors to evaluate alternative hypotheses about how fish communities are assembled from the regional species pool. Location: Ontario, Canada...

Data from: Vertebrate scavenging dynamics differ between carnivore and herbivore carcasses in the northern boreal forest

Michael Peers, Sean Konkolics, Yasmine Majchrzak, Allyson Menzies, Emily Studd, Rudy Boonstra, Stan Boutin & Clayton Lamb
Vertebrate scavenging can impact food web dynamics, but our understanding of this process stems predominantly from monitoring herbivore carrion and extrapolating results across carcass types. Recent evidence suggests carnivores may avoid intraguild scavenging to reduce parasite transmission. If this behavior is widespread across diverse ecosystems, estimation of nutrient cycling and community scavenging rates are likely biased to a currently unknown degree. We examined whether the time to initiate scavenging, carcass persistence, or the richness of...

The potential for genotype-by-environment interactions to maintain genetic variation in a model legume–rhizobia mutualism

Priya Vaidya & John R. Stinchcombe
The maintenance of genetic variation in mutualism-related traits is key for understanding mutualism evolution, yet the mechanisms maintaining variation remain unclear. We asked whether genotype-by-environment (G×E) interaction is a potential mechanism maintaining variation in the model legume–rhizobia system, Medicago truncatula–Ensifer meliloti. We planted 50 legume genotypes in a greenhouse under ambient light and shade to reflect reduced carbon availability for plants. We found an expected reduction under shaded conditions for plant performance traits, such as...

Using Delaunay triangulation to sample whole-specimen color from digital images

Jennifer Valvo, J. Aponte, Mitch Daniel, Kenna Dwinell, Helen Rodd, David Houle & Kimberly Hughes
1. Color variation is one of the most obvious examples of variation in nature, but biologically meaningful quantification and interpretation of variation in color and complex patterns is challenging. Many current methods for assessing variation in color patterns classify color patterns using categorical measures, provide aggregate measures that ignore spatial pattern, or both, losing potentially important aspects of color pattern. 2. Here, we present Colormesh, a novel method for analyzing complex color patterns that offers...

Urbanization alters interactions between Darwin’s finches and Tribulus cistoides on the Galápagos Islands

Ruth Rivkin, Reagan Johnson, Jaime Chaves & Marc Johnson
Emerging evidence suggests that humans shape the ecology and evolution of species interactions. Islands are particularly susceptible to anthropogenic disturbance due to the fragility of their ecosystems; however, we know little about the susceptibility of species interactions to urbanization on islands. To address this gap, we studied how the earliest stages of urban development affect interactions between Darwin’s finches and its key food resource, Tribulus cistoides, in three towns on the Galápagos Islands. We measured...

Fine-scale spatial segregation in a pelagic seabird driven by differential use of tidewater glacier fronts

Philip Bertrand, Joël Bêty, Nigel Gilles Yoccoz, Marie-Josée Fortin, Hallvard Strøm, Harald Steen, Jack Kohler, Stephanie M. Harris, Samantha C. Patrick, Olivier Chastel, Pierre Blévin, Haakon Hop, Geir Moholdt, Joséphine Maton & Sébastien Descamps
In colonially breeding marine predators, individual movements and colonial segregation are influenced by seascape characteristics. Tidewater glacier fronts are important features of the Arctic seascape and are often described as foraging hotspots. Albeit their documented importance for wildlife, little is known about their structuring effect on arctic predator movements and space use. In this study, we tested the hypothesis that tidewater glacier fronts can influence marine bird foraging patterns and drive spatial segregation among adjacent...

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...

Data from: Drivers of native and non-native freshwater fish richness across North America: Disentangling the roles of environmental, historical and anthropogenic factors

M. U. Mohamed Anas & Nicholas Mandrak
Aim: A better understanding of native and non-native species response to environmental conditions, historical processes, and human pressures is crucial in the face of global environmental changes affecting biodiversity. Here, we evaluate the relative roles of environmental, historical, and anthropogenic factors in influencing species richness of native and non-native freshwater fishes in watersheds across North America. Location: North America (exclusive of Mexico) Time period: Recent Major taxa studied: Freshwater fishes Methods: We compiled an extensive...

Decentralizing PrEP delivery: implementation and dissemination strategies to increase PrEP uptake among MSM in Toronto, Canada

Maxime Charest & Darrell H. S. Tan
Pre-exposure prophylaxis (PrEP) is traditionally prescribed by HIV specialist physicians. Given finite specialist resources, there is a need to scale up PrEP delivery by decentralizing services via other healthcare professionals. We aimed to assess the feasibility of delivering PrEP to men who have sex with men (MSM) through primary care physicians and sexual health clinic nurses. We piloted a multi-component, implementation and dissemination research program to increase provision of PrEP through primary care physicians and...

Data from: Prolonged impacts of past agriculture and ungulate overabundance on soil fungal communities in restored forests

Shinichi Tatsumi, Shunsuke Matsuoka, Saori Fujii, Kobayashi Makoto, Takashi Osono, Forest Isbell & Akira Mori
Soil fungi can help improve ecosystem restoration, yet our understanding of how they reassemble in degraded land is limited. Here, using DNA metabarcoding, we studied the fungal community structure in reforested sites following agricultural abandonment and ungulate overabundance. Two treatments, namely ‘reforestation using different numbers of tree species’ and ‘deer exclusion,’ have been applied for multiple decades in the study sites. We found that local fungal richness (alpha diversity) and total fungal richness (gamma diversity)...

Registration Year

  • 2021
    51

Resource Types

  • Dataset
    51

Affiliations

  • University of Toronto
    51
  • University of Minnesota
    5
  • University of British Columbia
    5
  • McGill University
    3
  • University of Calgary
    3
  • Royal Ontario Museum
    2
  • University of Alberta
    2
  • Monash University
    2
  • East China Normal University
    2
  • Queen's University
    2