Life Sciences Commons^™

Energetics Of Migratory Bats During Stopover: A Test Of The Torpor-Assisted Migration Hypothesis, Dylan E. Baloun

Electronic Thesis and Dissertation Repository

The torpor-assisted migration hypothesis posits that during stopover bats regulate time in torpor facultatively so that daily energy expenditure is independent of ambient roosting temperature. However, direct measurements of total roosting energy expenditure in relation to ambient and body temperature are lacking. I captured migratory silver-haired bats (Lasionycteris noctivagans) at Long Point, Ontario in spring and fall 2016. I used quantitative magnetic resonance analysis to measure full-day energy expenditure of bats roosting at 10, 17 and 25°C and assessed the effects of migration season, body mass, sex and age on energy use. I found that daily energy expenditure …

Migration Frustrations Of Mir-146a Regulation, Emma Baccus, Victoria Gahman, Hannah Phillips, Shannon Rappaport, Alyssa Reiter, Kaleb M. Pauley

The Research and Scholarship Symposium (2013-2019)

The autoimmune disease, Sjögren’s Syndrome (SS), causes the degradation of salivary and lacrimal glands due to an influx of immune cells. In previous studies, a significant increase in miR-146a was observed in the peripheral blood mononuclear cells of SS patients. Since immune cell infiltration is critical in SS pathogenesis, the following research examines the effect of miR-146a on cell migration. We hypothesize that transfecting THP-1 human monocytes with synthetic miR-146a will downregulate migration of the monocytes based on other studies stating that miR-146a downregulates migration in vivo. In order to execute our experiment, we transfected THP-1 cells with synthetic miR-146a …

Costs Of Reproduction And Carry-Over Effects In Breeding Albatrosses, Glenn T. Crossin, Richard A. Phillips, Christine R. Lattin, L. Michael Romero, Xavier Bordeleau, Christopher M. Harris, Oliver P. Love, Tony D. Williams

Integrative Biology Publications

We investigated the physiology of two closely related albatross species relative to their breeding strategy: black-browed albatrosses (Thalassarche melanophris) breed annually, while grey-headed albatrosses (T. chrysostoma) breed biennially. From observations of breeding fate and blood samples collected at the end of breeding in one season and feather corticosterone levels (fCort) sampled at the beginning of the next breeding season, we found that in both species some post-breeding physiological parameters differed according to breeding outcome (successful, failed, deferred). Correlations between post-breeding physiology and fCort, and links to future breeding decisions, were examined. In black-browed albatrosses, post-breeding physiology and fCort were not …

Transient Movements Of A Deep-Water Flatfish In Coastal Waters: Implications Of Inshore-Offshore Connectivity For Fisheries Management, Amanda N. Barkley, Aaron T. Fisk, Kevin J. Hedges, Margaret A. Treble, Nigel E. Hussey

Biological Sciences Publications

1. Globally, small-scale inshore fisheries are being recognized as highly beneficial for underdeveloped coastal communities since they directly contribute to local economies. Community coastal fisheries, however, may target species that are simultaneously harvested by large commercial vessels in adjacent offshore waters, creating uncertainty over stock units and connectivity that complicate management. 2. Greenland halibut Reinhardtius hippoglossoides, a commercially important flatfish species in the Arctic, were tagged in Scott Inlet, coastal Baffin Island, Canada, with acoustic transmitters and tracked for a 1-year period. Our aim was to measure fish movement and connectivity between inshore habitats, where Inuit fisheries are developing, and …

Within-Wing Isotopic (Δ2h, Δ13c, Δ15n) Variation Of Monarch Butterflies: Implications For Studies Of Migratory Origins And Diet, Keith A. Hobson, Tessa Plint, Eligio García Serrano, Xiomara Mora Alvarez, Isabel Ramirez, Fred J. Longstaffe

Earth Sciences Publications

Increasingly, stable isotope measurements are being used to assign individuals to broad geographic origins based on established relationships between animal tissues and tissue-specific isoscapes. In particular, the eastern North American population of the monarch butterfly (Danaus plexippus) has been the subject of several studies using established δ²H and δ¹³C wing-tissue isoscapes to infer natal origins of migrating and overwintering individuals. However, there has been no study investigating potential variance that can derive from sub-sampling different regions of the wings, especially those regions differing in pigmentation (orange versus black). Within-wing isotopic (δ²H, …

Stable Isotope Investigation Of The Migratory Behavior Of Silverhaired Bats (Lasionycteris Noctivagans) In Eastern North America, Erin E. Fraser, Darin Brooks, Fred J. Longstaffe

Earth Sciences Publications

We investigated the migratory movements of silver-haired bats (Lasionycteris noctivagans) across the eastern extent of the species’ range. We conducted stable hydrogen isotope analysis of fur samples (δ²H_fur) from museum specimens collected across latitudes and at all times of the year. We first used these data to estimate the timing of fur replacement and to develop a model associating δ²H_fur with that of local precipitation (δ²H_precip) at the location where fur replacement occurred. We then used this model to 1) identify individuals that had migrated …

Neuropeptide Y Reduces Migration Capacity Of Human Choriocarcinomacell Line By Altering Oxidative/Antioxidative Status, Milos Matic, Milica Paunovic, Branka Ognjanovic, Andras Stajn, Zorica Saicic

Turkish Journal of Biology

Reduced migration capacity of trophoblast cells leads to poor placentation and correlates with severe pregnancy disorders such as intrauterine growth restriction and preeclampsia. Neuropeptide Y (NPY) is sympathetic cotransmitter involved in various physiological processes and its levels are significantly increased in preeclamptic pregnancy compared to healthy pregnancy. In this study the prooxidative role of NPY and its effects on migration capacity of human trophoblast cell line JEG-3 were investigated together with the effects of nitric oxide (NO) depletion, a molecule that was shown to play an important role in promoting cell migration. The cells were treated for 24 h (short-term …

Deformation But Not Migration And Rotation – A Model Study On Vesicle Biomechanics In A Uniform Dc Electric Field, Hui Ye, Austen Curcuru

Biology: Faculty Publications and Other Works

Background: Biological cells migrate, deform and rotate in various types of electric fields, which have significant impact on the normal cellular physiology. To investigate electrically-induced deformation, researchers have used artificial giant vesicles that mimic the phospholipid bilayer cell membrane. Containing primarily the neutral molecule phosphatidylcholine, these vesicles deformed under evenly distributed, strong direct current (DC) electric fields. Interestingly, they did not migrate or rotate. A biophysical mechanism underlying the kinematic differences between the biological cells and the vesicles under electric stimulation has not been worked out.

Methods: We modeled the vesicle as a leaky, dielectric sphere and computed …

Immune Profiles Vary Seasonally, But Are Not Significantly Related To Migration Distance Or Natal Dispersal, In A Migratory Songbird, Tosha R. Kelly, Heather L. Macgillivray, Keith A. Hobson, Scott A. Macdougall-Shackleton, Elizabeth A. Macdougall-Shackleton

Biology Publications

A central tenet of ecoimmunology is that an organism’s environment shapes its optimal investment in immunity. For example, the benefits of acquired (relatively pathogen-specific) versus innate (non-specific) immune defences are thought to vary with the risk of encountering familiar versus unfamiliar pathogens. Because pathogen communities vary geographically, individuals that travel farther during seasonal migration or natal dispersal are predicted to have higher exposure to novel pathogens, and lower exposure to familiar pathogens, potentially favoring investment in innate immunity. During the breeding season, migratory animals’ exposure to familiar pathogens should increase, potentially favoring investment in acquired immunity. We hypothesized that song …