Physical Sciences and Mathematics Commons^™

Evidence Of Intermittent Residency In The Northern Fur Seal (Callorhinus Ursinus)., Megan Foley

HCNSO Student Theses and Dissertations

This study found evidence of intermittent, multi-year residency periods in northern fur seals (Callorhinus ursinus) using stable isotope ratios in vibrissae and canine teeth. Northern fur seals migrate from the Bering Sea during summer months to lower latitudes and slightly warmer waters of the northeastern Pacific Ocean and California Current in the winter. To determine the length of time spent away from the Bering Sea, growth rate was estimated using the covarying oscillations δ¹³C and δ¹⁵N, estimated to be 0.09 mm/day. The δ¹³C and δ¹⁵N in vibrissae from 30 male …

Biogeophysical And Physiological Processes Drive Movement Patterns In A Marine Predator, Lucy A. Howey, Bradley M. Wetherbee, Emily R. Tolentino, Mahmood S. Shivji

Marine & Environmental Sciences Faculty Articles

Background

Blue sharks (Prionace glauca) are among the most abundant and widely distributed of oceanic elasmobranchs. Millions are taken annually in pelagic longline fisheries and comprise the highest component of auctioned fin weight in the international shark fin trade. Though studies of blue sharks outnumber those of other large pelagic sharks, the species’ complicated and sexually segregated life history still confound current understanding of Atlantic movement patterns. Lack of detailed information regarding movement and vertical behavior continues to limit management efforts that require such data for stock assessment and sustainable catch modeling. Therefore, this study aims to describe …

Climate Change, Managed Relocation, And The Risk Of Intra-Continental Plant Invasions: A Theoretical And Empirical Exploration Relative To The Flora Of New England, Jesse Bellemare, Bryan Connolly, Dov F. Sax

Biological Sciences: Faculty Publications

The high rate of anthropogenic climate change projected for coming decades and evidence of low migration ability for many species have led researchers to warn of a looming extinction crisis. This threat is expected to be most acute for small-ranged endemic species, which could see novel climatic conditions develop rapidly across the entirety of their limited geographic ranges. To avoid extinctions, some conservationists have proposed that climateimperiled species might be candidates for "assisted colonization" or "managed relocation" to new regions, outside their historical ranges. One major concern related to managed relocation is the possibility that some relocated species could later …

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 …

Shorebird Stopover Habitat Decisions In A Changing Landscape, Caitlyn Gillespie, Joseph J. Fontaine

Nebraska Cooperative Fish and Wildlife Research Unit: Staff Publications

To examine how habitat use by sandpipers (Calidris spp.; Baird’s sandpipers, dunlin, least sandpipers, pectoral sandpipers, semipalmated sandpipers, stilt sandpipers, and white-rumped sandpipers) varies across a broad suite of environmental conditions, we conducted surveys at wetlands throughout the spring migratory period in 2013 and 2014 in 2 important stopover regions: the Rainwater Basin (RWB) in Nebraska, USA, and the Prairie Pothole Region (PPR) in South Dakota, USA. Because providing adequate energetic resources for migratory birds is a high priority for wetland management, we also measured invertebrate abundance at managed wetlands in the RWB to determine how food abundance influences …

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 …

Minimizing Scheduling Overhead In Lre-Tl Real-Time Multiprocessor Scheduling Algorithm, Hitham Seddig Alhassan Alhussian, Mohamed Nordin Bin Zakaria, Fawnizu Azmadi Bin Hussin

Turkish Journal of Electrical Engineering and Computer Sciences

In this paper, we present a modification of the local remaining execution-time and local time domain (LRE-TL) real-time multiprocessor scheduling algorithm, aimed at reducing the scheduling overhead in terms of task migrations. LRE-TL achieves optimality by employing the fairness rule at the end of each time slice in a fluid schedule model. LRE-TL makes scheduling decisions using two scheduling events. The bottom (B) event, which occurs when a task consumes its local utilization, has to be preempted in order to resume the execution of another task, if any, or to idle the processor if none exist. The critical (C) event …