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Squamish, Canada

Prud'homme-Genereux A.,Quest University Canada
American Biology Teacher | Year: 2013

"What is life?" This deceptively simple question lies at the heart of biology. In this activity, students work in groups to come up with their own definition using a set of prompting cards that differs for each team. In doing so, students gain an appreciation of the complexities of addressing this question. The activity takes approximately 60-90 minutes to complete, but students often discuss its implications for weeks afterward. This activity successfully engaged freshman undergraduate students and could easily be adapted to high school and even elementary school students. © 2013 by National Association of Biology Teachers. Source

Shields G.A.,University of Texas at Austin | Bonning E.W.,Quest University Canada
Astrophysical Journal Letters | Year: 2013

Recent results indicate that the compact lenticular galaxy NGC 1277 in the Perseus Cluster contains a black hole of mass ∼1010 M ⊙. This far exceeds the expected mass of the central black hole in a galaxy of the modest dimensions of NGC 1277. We suggest that this giant black hole was ejected from the nearby giant galaxy NGC 1275 and subsequently captured by NGC 1277. The ejection was the result of gravitational radiation recoil when two large black holes merged following the merger of two giant ellipticals that helped to form NGC 1275. The black hole wandered in the cluster core until it was captured in a close encounter with NGC 1277. The migration of black holes in clusters may be a common occurrence. © 2013. The American Astronomical Society. All rights reserved. Source

Helfand D.J.,Columbia University | Helfand D.J.,Quest University Canada | White R.L.,US Space Telescope Science Institute | Becker R.H.,University of California at Davis | Becker R.H.,Lawrence Livermore National Laboratory
Astrophysical Journal | Year: 2015

The FIRST survey, begun over 20 years ago, provides the definitive high-resolution map of the radio sky. This Very Large Telescope (VLA) survey reaches a detection sensitivity of 1 mJy at 20 cm over a final footprint of 10,575 deg2 that is largely coincident with the Sloan Digital Sky Survey (SDSS) area. Both the images and a catalog containing 946,432 sources are available through the FIRST Web site (http://sundog.stsci.edu). We record here the authoritative survey history, including hardware and software changes that affect the catalog's reliability and completeness. In particular, we use recent observations taken with the JVLA to test various aspects of the survey data (astrometry, CLEAN bias, and the flux density scale). We describe a new, sophisticated algorithm for flagging potential sidelobes in this snapshot survey, and show that fewer than 10% of the cataloged objects are likely sidelobes, and that these are heavily concentrated at low flux densities and in the vicinity of bright sources, as expected. We also report a comparison of the survey with the NRAO VLA Sky Survey (NVSS), as well as a match of the FIRST catalog to the SDSS and Two Micron Sky Survey (2MASS) sky surveys. The NVSS match shows very good consistency in flux density scale and astrometry between the two surveys. The matches with 2MASS and SDSS indicate a systematic 10-20 mas astrometric error with respect to the optical reference frame in all VLA data that has disappeared with the advent of the JVLA. We demonstrate strikingly different behavior between the radio matches to stellar objects and to galaxies in the optical and IR surveys reflecting the different radio populations present over the flux density range 1-1000 mJy. As the radio flux density declines, stellar counterparts (quasars) get redder and fainter, while galaxies get brighter and have colors that initially redden but then turn bluer near the FIRST detection limit. Implications for future radio sky surveys are also briefly discussed. In particular, we show that for radio source identification at faint optical magnitudes, high angular resolution observations are essential, and cannot be sacrificed in exchange for high signal-to-noise data. The value of a JVLA survey as a complement to Square Kilometer Array precursor surveys is briefly discussed. © 2015. The American Astronomical Society. All rights reserved.. Source

Porritt L.A.,University of British Columbia | Russell J.K.,University of British Columbia | Quane S.L.,Quest University Canada
Earth and Planetary Science Letters | Year: 2012

Pele's tears are a well known curiosity commonly associated with low viscosity basaltic explosive eruptions. However, detailed studies of these pyroclasts are rare and, thus, there is no full explanation for their formation. These intriguing pyroclasts have smooth glassy surfaces, vesiculated interiors (~30%), and fluidal morphologies trending towards teardrops and then spheres as they decrease in size to <2. mm. Detailed characterisation of Pele's tears from the 1959 fire-fountaining eruption of Kilauea Iki has led to a reassessment of the mechanisms of magma disruption and fragmentation, timescales of relaxation, and cooling rates that are responsible for their formation. We conclude that the particle size distributions and vesicularities of Pele's tears are representative of the magma properties at the moment of explosive disruption. However, the morphology of these unique pyroclasts results from reshaping through viscous relaxation, driven by surface tension forces, on a time scale fast enough to compete with cooling times. © 2012 Elsevier B.V. Source

Yasue M.,Quest University Canada | Yasue M.,University of British Columbia | Nellas A.,Project Seahorse Foundation for Marine Conservation | Vincent A.C.J.,University of British Columbia
Environmental Conservation | Year: 2012

In marine environments, charismatic or economically valued taxa have been used as flagships to garner local support or international funds for the establishment and management of marine protected areas (MPAs). Seahorses (Hippocampus spp.) are frequently used as flagship species to help engender support for the creation of small community-managed no-take MPAs in the central Philippines. It is thus vital to determine whether such MPAs actually have an effect on seahorse abundance, reproductive status and size. A survey of seahorses inside and immediately adjacent to eight MPAs, and in four distant unprotected fishing areas, showed these MPAs had no significant effect on seahorse densities; although densities in and near MPAs were higher than in the distant fished sites, seahorse densities did not change over time. Seahorse size did show a marginal reserve effect, with slightly larger seahorses being found inside MPAs as compared to the distant unprotected fishing areas, but, in general, MPAs had little impact on seahorse size. Although MPAs may eliminate local fishing pressure, they may not reduce other threats such as pollution or destructive fishing outside the reserves. Other recovery tools, such as ecosystem-based management, habitat restoration and limits on destructive fishing outside of MPAs, may be necessary to rebuild seahorse populations. The effects of MPAs depend on species, as well as conditions outside the reserve boundaries. MPA management objectives must thus be clearly and realistically articulated to the communities, especially if support for an MPA was derived at least partly to conserve a particular flagship species. © Foundation for Environmental Conservation 2012. Source

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