45 Works

Three-phase parabolic inhomogeneities with internal uniform stresses in plane and anti-plane elasticity

X. Wang & P. Schiavone
We examine the in-plane and anti-plane stress states inside a parabolic inhomogeneity which is bonded to an infinite matrix through an intermediate coating. The interfaces of the three-phase parabolic inhomogeneity are two confocal parabolas. The corresponding boundary value problems are studied in the physical plane rather than in the image plane. A simple condition is found that ensures that the internal stress state inside the parabolic inhomogeneity is uniform and hydrostatic. Furthermore, this condition is...

Dataset of mountain pine beetle outbreak dynamics and direct control in Cypress Hills, SK

Mélodie Kunegel-Lion, Rory L. McIntosh & Mark A. Lewis
The data presented in this article are related to the research article entitled “Mountain pine beetle outbreak duration and pine mortality depend on direct control effort” [1]. This article provides presence of mountain pine beetle infested trees detected by the Saskatchewan Forest Service on a grid covering the spatial extent of the Saskatchewan portion of the Cypress Hills interprovincial park between 2006 and 2018. For each grid cell, associated ecological and environmental covariates, such as...

Data from: A prospective harmonized multicentre DTI study of cerebral white matter degeneration in ALS

Sanjay Kalra, Hans-Peter Müller, Abdullah Ishaque, Lorne Zinman, Lawrence Korngut, Angela Genge, Christian Beaulieu, Richard Frayne, Simon J. Graham & Jan Kassubek
Objective: To evaluate progressive white matter (WM) degeneration in ALS. Methods: Sixty-six patients with ALS and 43 healthy controls were enrolled in a prospective, longitudinal, multicentre study in the Canadian ALS Neuroimaging Consortium (CALSNIC). Participants underwent a harmonized neuroimaging protocol across 4 centres including diffusion tensor imaging (DTI) for assessment of WM integrity. Three visits were accompanied by clinical assessments of disability (ALSFRS-R) and upper motor neuron (UMN) function. Voxel-wise whole brain and quantitative tractwise...

Interactive effects of global change factors on terrestrial net primary productivity are treatment length- and intensity-dependent

Zilong Ma, Scott Chang, Han Chen & Yongchun Li
1. Individual effects of co‐occurring global change factors on net primary productivity (NPP) have been widely studied; however, their interactive effects remain highly debated. 2. Here, we conducted a global meta‐analysis based on 919 multifactor observations from 120 published studies to examine the interactive effects on NPP of global change factors including elevated [CO2], warming, nitrogen addition, irrigation, drought, and changes in species diversity. 3. On average, of the factors studied, six pairs of factors...

Gene flow and climate-associated genetic variation in a vagile habitat specialist

Zachary MacDonald, Julian Dupuis, Corey Davis, John Acorn, Scott Nielsen & Felix Sperling
Previous work in landscape genetics suggests that geographic isolation is of greater importance to genetic divergence than variation in environmental conditions. This is intuitive when configurations of suitable habitat are the dominant factor limiting dispersal and gene flow, but has not been thoroughly examined for habitat specialists with strong dispersal capability. Here, we evaluate the effects of geographic and environmental isolation on genetic divergence in a vagile invertebrate with high habitat specificity and a discrete...

Data from: Age and sex as compounding factors in the relationship between cardiac mitochondrial function and type 2 diabetes in the Nile Grass rat

Jillian Schneider, Woo Hyun Han, Rebecca Matthew, Yves Sauvé & Hélène Lemieux
Our study revisits the role of cardiac mitochondrial adjustments during the progression of type 2 diabetes mellitus (T2DM), while considering age and sex as potential confounding factors. We used the Nile Grass rats (NRs) as the animal model. After weaning, animals were fed either a Standard Rodent Chow Diet (SRCD group) or a Mazuri Chinchilla Diet (MCD group) consisting of high-fiber and low-fat content. Both males and females in the SRCD group, exhibited increased body...

Data from: Functional diversity of decomposers modulates litter decomposition affected by plant invasion along a climate gradient

Junwei Luan, Shirong Liu, Siyu Li, Joann Whalen, Yi Wang, Jingxi Wang, Yanchun Liu, Wei Dong & Scott Chang
1. Litter decomposition is fundamental to carbon (C) and nutrient cycling in ecosystems, which could be altered by plant invasion. The impacts of plant invasion on litter decomposition are generally predicted by traits difference between leaf litters of invasive and non-invasive species. However, plant invasion not only changes litter composition, but might also increase the activity or change the functional diversity of decomposers to alter litter decomposition, which is barely studied, and the effect could...

Plant Biomass data from: Bottom-up Herbivore-Plant Feedbacks Trump Trophic Cascades in a Wolf-Elk-Grassland System

Trevor Weeks, Evelyn Merril & Mark Hebblewhite
Top-down predator-prey effects that alter the abundance, biomass, or productivity of a population community across more than one link in a food web are referred to as trophic cascades. While these effects have been extensively studied in aquatic environments, fewer studies have examined trophic cascades in terrestrial ecosystems. And fewer still terrestrial studies have tested for trophic cascades between vertebrates and grassland vegetation. Across the globe, grassland plant biomass is driven by both precipitation and...

Data from: Body temperature, heart rate, and activity patterns of two boreal homeotherms in winter: homeostasis, allostasis, and ecological coexistence

Allyson Menzies, Emily Studd, Yasmine Majchrzak, Michael Peers, Stan Boutin, Ben Dantzer, Jeffrey Lane, Andrew McAdam & Murray Humphries
Organisms survive environmental variation by combining homeostatic regulation of critical states with allostatic variation of other traits, and species differences in these responses can contribute to coexistence in temporally-variable environments. In this paper, we simultaneously record variation in three functional traits – body temperature (Tb), heart rate, and activity - in relation to three forms of environmental variation – air temperature (Ta), photoperiod, and experimentally-manipulated resource levels – in free-ranging snowshoe hares and North American...

Data from: Prey availability and ambient temperature influence carrion persistence in the boreal forest

Michael Peers, Sean Konkolics, Clayton Lamb, Yasmine Majchrzak, Allyson Menzies, Emily Studd, Rudy Boonstra, Alice Kenney, Charles Krebs, April Robin Martinig, Baily McCulloch, Joseph Silva, Laura Garland & Stan Boutin
1. Scavenging by vertebrates can have important impacts on food web stability and persistence, and can alter the distribution of nutrients throughout the landscape. However, scavenging communities have been understudied in most regions around the globe, and we lack understanding of the biotic drivers of vertebrate scavenging dynamics. 2. In this paper, we examined how changes in prey density and carrion biomass caused by population cycles of a primary prey species, the snowshoe hare (Lepus...

Data from: Recovery of a boreal ground-beetle (Coleoptera: Carabidae) fauna 15 years after variable retention harvest

Linhao Wu, Fangliang He & John Spence
1. Retention harvests are preferred over traditional clear-cuts for sustainable forest management because maintenance and re-establishment of native forest biodiversity is a priority. However, few studies have examined long-term responses of biotic assemblages to retention harvest at particular sites. 2. We studied the effects of decreasing initial harvest intensities (clear-cut, 10, 20, 50, and 75% dispersed green tree retention) on carabid beetle assemblages relative to assemblage changes in un-harvested control stands in four successionally ordered...

Isotopic evidence for long-distance connections of the AD thirteenth century Promontory caves occupants

Jessica Metcalfe, John Ives, Sabrina Shirazi, Kevin Gilmore, Jennifer Hallson, Fiona Brock, Bonnie Clark & Beth Shapiro
The Promontory caves (Utah) and Franktown Cave (Colorado) contain high-fidelity records of short-term occupations by groups with material culture connections to the Subarctic/Northern Plains. This research uses Promontory and Franktown bison dung, hair, hide, and bone collagen to establish local baseline carbon isotopic variability and identify leather from a distant source. The ankle wrap of one Promontory Cave 1 moccasin had a δ13C value that indicates a substantial C4 component to the animal’s diet, unlike...

Data from - Ecological insights from three decades of animal movement tracking across a changing Arctic

Gil Bohrer, Sarah Davidson, Eliezer Gurarie, Scott LaPoint, Peter Mahoney, Emma Grier, Ophélie Couriot, Allicia Kelly, Bryan Bedrosian, Jerrold Belant, Travis Booms, Bridget Borg, Stan Boutin, Erica Craig, Tracy Davison, Robert Domenech, James Hodson, Kyle Joly, Nicholas Larter, A. David M. Latham, Stephen Lewis, Carol McIntyre, Tricia Miller, Kelsey Russell, Dale Seip … & Judy Williams
We provide here the data used in analysis of 3 test cases, presented in the manuscript "Ecological insights from three decades of animal movement tracking across a changing Arctic". We utilized the new Arctic Animal Movement Archive (AAMA), a growing collection of 201 standardized terrestrial and marine animal tracking studies from 1991–present. The AAMA supports public data discovery, preserves fundamental baseline data for the future, and facilitates efficient, collaborative data analysis. With three AAMA-based case...

Data associated with 'Aggregation Behaviour of E-SARA Asphaltene Fractions Studied by Small-angle Neutron Scattering'

Dewi Ballard, Peiqi Qiao, Beatrice Cattoz, Peter Dowding, Sylvain Prevost, Mohammed Alshamsi, Thibaut V J Charpentier, Kevin Roberts, Zhenghe Xu & David Harbottle
Using the Extended-SARA method to fractionate asphaltenes based on their interfacial activity, the current study reports the first results on the estimated size and shape of interfacially active (IAA) and remaining (RA) asphaltene nanoaggregates. These fractions have been reported to exhibit distinctly different chemical architectures that influence the size of asphaltene clusters in good and poor solvents. However, little is known about the building blocks, commonly referred to as nanoaggregates, which form these clusters and...

What Peer-review Experiences Can Offer To Early Career Scientists And To The Scientific Community

Gwenaëlle Gremion, Mathieu Casado, Kelsey Aho, Jilda Alicia Caccavo, Nicolas Champollion, Emily Choy, Sarah L. Connors, Rahul Dey, Alfonso Fernandez, Gerlis Fugmann, Juan Höfer, Shridhar Jawak, Martine Lizotte, Sarah Maes, Kyle Mayers, Katja Mintenbeck, Jhon Fredy Mojica Moncada, Prashant H. Pandit, Elvira Poloczanska, Paul Rosenbaum, Elisa Seyboth, Sarah Shakil & Maud van Soest

Multiscale drivers of phytoplankton communities in north-temperate lakes

Ron Zurawell, Charlie Loewen, Faye Wyatt, Colleen Mortimer & Rolf Vinebrooke
Multiple factors operating across different spatial and temporal scales affect beta-diversity—the variation in community composition among sites. Disentangling the relative influence of co-occurring ecological drivers over broad biogeographic gradients and time is critical to developing mechanistic understandings of community responses to natural environmental heterogeneity as well as predicting the effects of anthropogenic change. We partitioned taxonomic beta-diversity in phytoplankton communities across 75 north-temperate lakes and reservoirs in Alberta, Canada, using data-driven, spatially-constrained null models to...

Climate change and defoliation interact to affect root length across northern temperate grasslands

Zilong Ma, Scott X. Chang, Edward Bork, Diego Steinaker, Scott Wilson, Shannon White & James F Cahill
1. Grassland plants, especially their root systems, are dynamic and can buffer changes resulting from exposure to multiple stressors; however, the interactive stressor effects on root dynamics and associated aboveground growth are poorly understood. 2. Here, we examine the effects of changed precipitation and air temperature, and defoliation intensity on root length dynamics and aboveground biomass using the third year data from a multifactor experiment conducted across three northern temperate grasslands. 3. We found that...

Extending the ecology of fear: Parasite-mediated sexual selection drives host response to parasites

Collin Horn, Monika Mierzejewski & Lien Luong
The ‘ecology of fear’ describes the negative effects natural enemies have on potential victims even when those victims are not consumed or infected. Although recent work has demonstrated parasites have non-consumptive effects (NCE) on potential hosts, how these effects vary within host populations is not well understood. We investigated how NCE vary based on host risk of infection and relative cost of infection by measuring the metabolic rate (MR) of naive Drosophila nigrospiracula exposed to...

The influence of a priori grouping on inference of genetic clusters: simulation study and literature review of the DAPC method

Joshua Miller, Catherine Cullingham & Rhiannon Peery
Inference of genetic clusters is a key aim of population genetics, sparking development of numerous analytical methods. Within these, there is a conceptual divide between finding de novo structure versus assessment of a priori groups. Recently developed, Discriminant Analysis of Principal Components (DAPC), combines discriminant analysis (DA) with principal component (PC) analysis. When applying DAPC, the groups used in the DA (specified a priori or described de novo) need to be carefully assessed. While DAPC...

Automated classification of avian vocal activity using acoustic indices in regional and heterogeneous datasets

Daniel Yip, Lisa Mahon, Alex MacPhail & Erin Bayne
Acoustic indices combined with clustering and classification approaches have been increasingly used to automate identification of the presence of vocalizing taxa or acoustic events of interest. While most studies using this approach standardize data collection and study design parameters at the project or study level, recent trends in ecological research are to investigate patterns at regional or continental scales. Large-scale studies often require collaboration between research groups and integration of data from multiple sources to...

Demographic fluctuations lead to rapid and cyclic shifts in genetic structure among populations of an alpine butterfly, Parnassius smintheus

Maryam Jangjoo, Stephen Matter, Jens Roland & Nusha Keyghobadi
Many populations, especially in insects, fluctuate in size and periods of particularly low population size can have strong effects on genetic variation. Effects of demographic bottlenecks on genetic diversity of single populations are widely documented. Effects of bottlenecks on genetic structure among multiple inter-connected populations are less studied, as are genetic changes across multiple cycles of demographic collapse and recovery. We take advantage of a long-term dataset comprising demographic, genetic, and movement data from a...

Feeding preferences and nutritional niche of wild water buffalo (Bubalus arnee) in Koshi Tappu Wildlife Reserve, Nepal.

Lee Hecker, Tej Sherstha, Achyut Aryal & Sean Coogan
We sought to further the understanding of how an animal’s foraging ecology is influenced by their feeding preferences and nutritional composition of forage items. Our research identified these aspects of wild water buffalo’s (Bubalus arnee) foraging ecology in Nepal. First, we sought to describe the foraging preferences of wild water buffalo in terms of the relative abundance of functional forage groups (i.e., forbs, graminoids, and browse) in their diet. We observed signs of wild water...

Maps of northern peatland extent, depth, carbon storage and nitrogen storage

Gustaf Hugelius, Julie Loisel, Sarah Chadburn, Robert B. Jackson, Miriam Jones, Glen MacDonald, Maija Marushchak, David Olefeldt, Maara Packalen, Matthias B. Siewert, Claire Treat, Merritt Turestsky, Carolina Voigt & Zicheng Yu
This dataset is grids of peatland extent, peat depth, peatland organic carbon storage, peatland total nitrogen storage and approximate extent of ombrotrophic/minerotrophic peatlands. The grids are geotiff files in 10 km pixel resolution projected in the World Azimuthal Equidistant projection. Note that the peat depth grid shows potential peat depth everywhere,also where there is no peatland cover. For files on peatland organic carbon, total nitrogen extent and extent of ombrotrophic/minerotrophic peatlands, there are separate files...

Poisson models for publications, leadership and recognition awards in the American Academy of Neurology

Janis Miyasaki
We sought to study sex with respect to publications, leadership and recognition awards in the American Academy of Neurology (AAN) in light of recent research highlighting inequities in these domains. Methods: We examined medical school graduation, neurology residency (using American Medical Association and the American Council for Graduate Medical Education), membership in the AAN, first and last authorship in Neurology, membership on AAN committees, and AAN recognition awards, by sex, in 1997, 2007, 2017. Results:...

Variance in lifetime reproductive success of male polar bears

Evan Richardson, Corey Davis, Ian Stirling, Andrew Derocher, Nicholas Lunn & René Malenfant
Despite the important role that population density plays in ecological and evolutionary processes, studies of solitary species that occur at low densities remain scarce. In the context of mating systems, density is expected to influence the ability of males to find and monopolize mates, in turn influencing variance in lifetime mating/reproductive success and the opportunity for selection. Herein we investigate variance in male lifetime mating success, lifetime reproductive success, and the mating system of a...

Registration Year

  • 2020
    45

Resource Types

  • Dataset
    42
  • Text
    2
  • Data Paper
    1

Affiliations

  • University of Alberta
    45
  • McGill University
    6
  • University of British Columbia
    4
  • Lakehead University
    3
  • Environment Canada
    3
  • University of Toronto
    3
  • University of Montana
    2
  • University of Saskatchewan
    2
  • University of Cincinnati
    2
  • Uppsala University
    2