Carleton University

About: Carleton University is a education organization based out in Ottawa, Ontario, Canada. It is known for research contribution in the topics: Population & Large Hadron Collider. The organization has 15852 authors who have published 39650 publications receiving 1106610 citations.

Geologic transect across the Grenville orogen of Ontario and New York

Abstract: Revised cross sections of the western Grenville Province incorporate new geologic results and reprocessed seismic reflection data. The geology is presented in terms of three tectonic elements: (1) ...

Comparison of Laminar Separation Bubble Measurements on a Low Reynolds Number Airfoil in Three Facilities

Abstract: This paper describes a series of experiments on the SD7003 airfoil, conducted in three different facilities: a low-turbulence wind tunnel, a water tunnel, and a tow tank. An attempt was made to achieve commonality of model geometry, Reynolds number and test conditions, in order to directly compare the experimental results. The SD7003 airfoil was chosen because of its robust, thin laminar separation bubble, which challenges the capability of current Particle Image Velocimetry (PIV) methods to accurately resolve the near-wall flowfield. Chordwise locations of separation, reattachment, and transition were compared. Since the time-averaged bubble geometry is a strong function of the flowfield ambient turbulence level, comparison of bubble geometry gives some assessment of facility flow quality, and hence of facility suitability for low Reynolds number testing in general.

Phylogenomics Reveals the Evolutionary Timing and Pattern of Butterflies and Moths

Abstract: Butterflies and moths (Lepidoptera) are one of the major superradiations of insects, comprising nearly 160,000 described extant species. As herbivores, pollinators, and prey, Lepidoptera play a fundamental role in almost every terrestrial ecosystem. Lepidoptera are also indicators of environmental change and serve as models for research on mimicry and genetics. They have been central to the development of coevolutionary hypotheses, such as butterflies with flowering plants and moths' evolutionary arms race with echolocating bats. However, these hypotheses have not been rigorously tested, because a robust lepidopteran phylogeny and timing of evolutionary novelties are lacking. To address these issues, we inferred a comprehensive phylogeny of Lepidoptera, using the largest dataset assembled for the order (2,098 orthologous protein-coding genes from transcriptomes of 186 species, representing nearly all superfamilies), and dated it with carefully evaluated synapomorphy-based fossils. The oldest members of the Lepidoptera crown group appeared in the Late Carboniferous (∼300 Ma) and fed on nonvascular land plants. Lepidoptera evolved the tube-like proboscis in the Middle Triassic (∼241 Ma), which allowed them to acquire nectar from flowering plants. This morphological innovation, along with other traits, likely promoted the extraordinary diversification of superfamily-level lepidopteran crown groups. The ancestor of butterflies was likely nocturnal, and our results indicate that butterflies became day-flying in the Late Cretaceous (∼98 Ma). Moth hearing organs arose multiple times before the evolutionary arms race between moths and bats, perhaps initially detecting a wide range of sound frequencies before being co-opted to specifically detect bat sonar. Our study provides an essential framework for future comparative studies on butterfly and moth evolution.