Open Access. Powered by Scholars. Published by Universities.®
- Discipline
- Keyword
Articles 1 - 12 of 12
Full-Text Articles in Life Sciences
Sex-Specific Development Of Avian Flight Performance Under Experimentally Altered Rearing Conditions, Jan J. Verspoor, Oliver P. Love, Eloise Rowland, Eunice H. Chin, Tony D. Williams
Sex-Specific Development Of Avian Flight Performance Under Experimentally Altered Rearing Conditions, Jan J. Verspoor, Oliver P. Love, Eloise Rowland, Eunice H. Chin, Tony D. Williams
Integrative Biology Publications
Numerous studies have examined predation risk resulting from the costs of impaired flight performance associated with many key life-history stages such as reproduction and migration. Interestingly, although avian nestlings experience multiple resource-based physiological trade-offs and undergo considerable morphological and physiological changes during postnatal development, there is no data available on how nestlings manage the competing demands of growth and the development of flight ability at this critical life-history stage. We examined numerous morphological traits to determine which are responsible for variation in flight performance in juvenile European starlings (Sturnus vulgaris), a sexually size-dimorphic passerine. We then manipulated maternal quality during …
Adhesion Is Prerequisite, But Alone Insufficient, To Elicit Stem Cell Pluripotency, Phillip Karpowicz, Tomoyuki Inoue, Sue Runciman, Brian Deveale, Raewyn Seaberg, Marina Gertsenstein, Lois Byers, Yojiro Yamanaka, Sandra Tondat, John Slevin, Seiji Hitoshi, Janet Rossant, Derek Van Der Kooy
Adhesion Is Prerequisite, But Alone Insufficient, To Elicit Stem Cell Pluripotency, Phillip Karpowicz, Tomoyuki Inoue, Sue Runciman, Brian Deveale, Raewyn Seaberg, Marina Gertsenstein, Lois Byers, Yojiro Yamanaka, Sandra Tondat, John Slevin, Seiji Hitoshi, Janet Rossant, Derek Van Der Kooy
Biological Sciences Publications
Primitive mammalian neural stem cells (NSCs), arising during the earliest stages of embryogenesis, possess pluripotency in embryo chimera assays in contrast to definitive NSCs found in the adult. We hypothesized that adhesive differences determine the association of stem cells with embryonic cells in chimera assays and hence their ability to contribute to later tissues. We show that primitive NSCs and definitive NSCs possess adhesive differences, resulting from differential cadherin expression, that lead to a double dissociation in outcomes after introduction into the early- versus midgestation embryo. Primitive NSCs are able to sort with the cells of the inner cell mass …
Alternative Methods In Tracking Sources Of Microbial Contamination In Waters, N. Biswas, J. K. Bewtra, Andrew V. Hubberstey, M. Cimenti
Alternative Methods In Tracking Sources Of Microbial Contamination In Waters, N. Biswas, J. K. Bewtra, Andrew V. Hubberstey, M. Cimenti
Biological Sciences Publications
A key factor in the management and remediation of impaired ground- and surface water is the ability to distinguish the sources of faecal contamination. Several approaches have been adopted as microbial source tracking methods (MST), which are generally classified as culturing, phenotypic, genetic, and chemical MST. None of the techniques used thus far can be considered a standard; important factors, such as the statistical correlation between the source and the faecal indicator and the understanding of the environmental fate of the faecal pollutants, still need attention. The most promising MST methods available today are based on the genetic fingerprinting of …
Detection And Discrimination Of Simple And Complex Sounds By Hearing-Impaired Belgian Waterslager Canaries, A. M. Lauer, R. J. Dooling, Leek, M.R. Leek, M.R., K. Poling
Detection And Discrimination Of Simple And Complex Sounds By Hearing-Impaired Belgian Waterslager Canaries, A. M. Lauer, R. J. Dooling, Leek, M.R. Leek, M.R., K. Poling
Biological Sciences Publications
No abstract provided.
Plumage Development And Molt In Long-Tailed Manakins (Chiroxiphia Linearis): Variation According To Sex And Age, Stéphanie M. Doucet, David B. Mcdonald, Mercedes S. Foster, Rob P. Clay, D. B. Lank
Plumage Development And Molt In Long-Tailed Manakins (Chiroxiphia Linearis): Variation According To Sex And Age, Stéphanie M. Doucet, David B. Mcdonald, Mercedes S. Foster, Rob P. Clay, D. B. Lank
Biological Sciences Publications
Lek-mating Long-tailed Manakins (Chiroxiphia linearis) exhibit an unusual pattern of delayed plumage maturation. Each year, males progress through a series of predefinitive plumages before attaining definitive plumage in their fifth calendar year. Females also exhibit variation in plumage coloration, with some females displaying male-like plumage characteristics. Using data from mist-net captures in northwest Costa Rica (n = 1,315) and museum specimens from throughout the range of Long-tailed Manakins (n = 585), we documented the plumage sequence progression of males, explored variation in female plumage, and described the timing of molt in this species. Males progressed through a series of age-specific …
Predicting Invasion Risk Using Measures Of Introduction Effort And Environmental Niche Models, Leif-Matthias Herborg, Christopher L. Jerde, David M. Lodge, Gregory M. Ruiz, Hugh J. Macisaac
Predicting Invasion Risk Using Measures Of Introduction Effort And Environmental Niche Models, Leif-Matthias Herborg, Christopher L. Jerde, David M. Lodge, Gregory M. Ruiz, Hugh J. Macisaac
Biological Sciences Publications
The Chinese mitten crab (Eriocheir sinensis) is native to east Asia, is established throughout Europe, and is introduced but geographically restricted in North America. We developed and compared two separate environmental niche models using genetic algorithm for rule set prediction (GARP) and mitten crab occurrences in Asia and Europe to predict the species' potential distribution in North America. Since mitten crabs must reproduce in water with ≥15‰ salinity, we limited the potential North American range to freshwater habitats within the highest documented dispersal distance (1260 km) and a more restricted dispersal limit (354 km) from the sea. Applying the higher …
Species Differences In The Songs Of The Critically Endangered Niceforo's Wren And The Related Rufous-And-White Wren, Sandra V. Valderrama, Jorge E. Parra, Daniel J. Mennill
Species Differences In The Songs Of The Critically Endangered Niceforo's Wren And The Related Rufous-And-White Wren, Sandra V. Valderrama, Jorge E. Parra, Daniel J. Mennill
Biological Sciences Publications
Niceforo's Wrens (Thryothorus nicefori) and Rufous-and-white Wrens (Thryothorus rufalbus) are closely related Neotropical birds. Niceforo's Wrens, critically endangered endemic Colombian songbirds, are generally considered a sister species to Rufous-and-white Wrens, although some have suggested that they may represent a well-marked race. A careful comparison of the two taxa has never been conducted. Here we present a thorough study of the songs of male Niceforo's and Rufous-and-white Wrens based on recordings collected throughout both species' geographic ranges. Both species sing low-pitched songs composed of varied pure tone whistles. Niceforo's Wren songs are shorter and simpler with fewer syllables and syllable types; …
The Duetting Behavior Of Pacific Coast Plain Wrens, Jessica L. Cuthbert, Daniel J. Mennill
The Duetting Behavior Of Pacific Coast Plain Wrens, Jessica L. Cuthbert, Daniel J. Mennill
Biological Sciences Publications
We provide the first detailed analysis of the vocal behavior of Pacific coast Plain Wrens (Thryothorus modestus modestus). Male Plain Wrens sing two categories of song phrase; one phrase is given as a solo song or duet introduction (I-phrases), while the other is sung primarily during duets (M-phrases). Females sing only one category of song phrase, usually during duets (F-phrases). Both sexes have repertoires of their respective song categories. Plain Wren duets show extreme temporal coordination: duets typically begin with male I-phrases, which are followed by the rapid alternation of female F-phrases and male M-phrases. These patterns are congruent with …
The Cdc20 (Fzy)/Cdh1-Related Protein, Cort, Cooperates With Fzy In Cyclin Destruction And Anaphase Progression In Meiosis I And Ii In Drosophila, Andrew Swan, Trudi Schüpbach
The Cdc20 (Fzy)/Cdh1-Related Protein, Cort, Cooperates With Fzy In Cyclin Destruction And Anaphase Progression In Meiosis I And Ii In Drosophila, Andrew Swan, Trudi Schüpbach
Biological Sciences Publications
Skip to Next Section Meiosis is a highly specialized cell division that requires significant reorganization of the canonical cell-cycle machinery and the use of meiosis-specific cell-cycle regulators. The anaphase-promoting complex (APC) and a conserved APC adaptor, Cdc20 (also known as Fzy), are required for anaphase progression in mitotic cells. The APC has also been implicated in meiosis, although it is not yet understood how it mediates these non-canonical divisions. Cortex (Cort) is a diverged Fzy homologue that is expressed in the female germline of Drosophila, where it functions with the Cdk1-interacting protein Cks30A to drive anaphase in meiosis II. Here, …
The Evolution Of Signal Design In Manakin Plumage Ornaments, Stéphanie M. Doucet, Daniel J. Mennill, Geoffrey E. Hill
The Evolution Of Signal Design In Manakin Plumage Ornaments, Stéphanie M. Doucet, Daniel J. Mennill, Geoffrey E. Hill
Biological Sciences Publications
Animal signals are characterized by two design components: efficacy (detectability) and content (message being conveyed). Selection for efficient signal perception should favor the evolution of traits that exhibit an optimal balance between these two design components. We examined the evolution of signal design in the colorful plumage ornaments of manakins (Aves: Pipridae). We used a model of avian color space to quantify how differences in plumage coloration would be perceived by a typical passerine bird and examined patterns of coloration across 50 species of manakin. Using phylogenetically independent contrasts, we show that plumage contrast against the background increases with sexual …
Feminist Sport Studies: Sharing Experiences Of Joy And Pain, Victoria Paraschak
Feminist Sport Studies: Sharing Experiences Of Joy And Pain, Victoria Paraschak
Human Kinetics Publications
No abstract provided.
Maintenance Of Skilled Performance With Age: A Descriptive Examination Of Professional Golfers, Joseph Baker, Janice Deakin, Sean Horton, G. W. Pearce
Maintenance Of Skilled Performance With Age: A Descriptive Examination Of Professional Golfers, Joseph Baker, Janice Deakin, Sean Horton, G. W. Pearce
Human Kinetics Publications
Demographic studies indicate a remarkable aging trend in North America. An accurate profile of the decline in physical and cognitive capabilities over time is essential to our understanding of the aging process. This study examined the maintenance of skilled performance across the careers of 96 professional golfers. Data were collected on scoring average, driving distance, driving accuracy, greens in regulation, putts per round, and number of competitive rounds played using online data archives. Analyses indicate that performance in this activity can be maintained to a greater extent than in activities relying on biologically constrained abilities. Although the generalizability of these …