64 research outputs found
Crime et châtiment : le Parti progressiste-conservateur du Canada entre 1984 et 1993
La volatilité de l’électorat canadien est considéré comme un élément marquant du comportement électoral au pays. Ce phénomène a été le plus souvent expliqué soit par les caractéristiques des votants, soit par celles des partis politiques. Dans cet article, nous soutenons plutôt que, dans l’ensemble, l’électorat canadien s’est comporté de façon rationnelle et constante. L’instabilité qui a caractérisé le choix des votants en 1993 et qui a fait éclater le système partisan est due aux partis eux-mêmes; ce sont les manoeuvres partisanes dans la quête de l’électeur médian et la stratégie du « quitte ou double » de la politique de médiation qui ont ébranlé le sentiment d’appartenance aux partis et qui ont modifié le comportement de l’électorat. C’était particulièrement le cas pour le Parti progressiste-conservateur qui, entre 1984 et 1993, a poursuivi une politique trop ambitieuse visant à s’assurer l’appui du Québec en lui proposant continuellement de nouveaux accommodements. Cette politique a eu pour conséquence d’empêcher le parti de faire les ajustements nécessaires au cours de la campagne de 1993 pendant que de nouveaux partis de protestation grugeaient sa base de supporters.The volatility of the Canadian electorate has been a notable feature of Canadian electoral politics. Usually this has been explained either by referring to the characteristics of the voter, or the parties, or both. This paper will argue that the Canadian electorate, on the whole, has been rational and consistent in its electoral behavior. The instability in voter choice in 1993 that shattered the party system was party-induced; it was party maneuvering in search of the median voter and "roll-of-the-dice" brokerage politics that eroded the stability of partisanship and voter behavior. This was particularly the case for the Progressive Conservative Party, who between 1984 and 1993 engaged in a form of "imperial overstretch" in order to win and continuously accommodate Quebec. This prevented the Conservatives from making the necessary adjustments during the 1993 campaign once it was clear that the new protest parties were stealing away the party's support base
Scintillation noise in exoplanet transit photometry.
Transit photometry is a powerful technique for studying exoplanets. Transit observations from the ground of targets of magnitude V= 10 or brighter, however, are limited by scintillation noise due to Earth's atmosphere. Through turbulence profiling using instruments such as the stereo-SCIDAR, we have shown to able to accurately model scintillation noise, which is essential in order to fully account for the error budget of the observation. Through numerical modelling we find that employing scintillation reducing techniques enables an improvement of a factor between 1.36 — 1.6 on the astrophysical parameters
A Divergent Synthetic Approach to Diverse Molecular Scaffolds: Assessment of Lead-Likeness using LLAMA, an Open-Access Computational Tool
Complementary cyclisation reactions of hex-2-ene-1,6-diamine derivatives were exploited in the synthesis of alternative molecular scaffolds. The value of the synthetic approach was analysed using LLAMA, an open-access computational tool for assessing the lead-likeness and novelty of molecular scaffolds
Prime Focus Spectrograph - Subaru's future -
The Prime Focus Spectrograph (PFS) of the Subaru Measurement of Images and
Redshifts (SuMIRe) project has been endorsed by Japanese community as one of
the main future instruments of the Subaru 8.2-meter telescope at Mauna Kea,
Hawaii. This optical/near-infrared multi-fiber spectrograph targets cosmology
with galaxy surveys, Galactic archaeology, and studies of galaxy/AGN evolution.
Taking advantage of Subaru's wide field of view, which is further extended with
the recently completed Wide Field Corrector, PFS will enable us to carry out
multi-fiber spectroscopy of 2400 targets within 1.3 degree diameter. A
microlens is attached at each fiber entrance for F-ratio transformation into a
larger one so that difficulties of spectrograph design are eased. Fibers are
accurately placed onto target positions by positioners, each of which consists
of two stages of piezo-electric rotary motors, through iterations by using
back-illuminated fiber position measurements with a wide-field metrology
camera. Fibers then carry light to a set of four identical fast-Schmidt
spectrographs with three color arms each: the wavelength ranges from 0.38
{\mu}m to 1.3 {\mu}m will be simultaneously observed with an average resolving
power of 3000. Before and during the era of extremely large telescopes, PFS
will provide the unique capability of obtaining spectra of 2400
cosmological/astrophysical targets simultaneously with an 8-10 meter class
telescope. The PFS collaboration, led by IPMU, consists of USP/LNA in Brazil,
Caltech/JPL, Princeton, & JHU in USA, LAM in France, ASIAA in Taiwan, and
NAOJ/Subaru.Comment: 13 pages, 11 figures, submitted to "Ground-based and Airborne
Instrumentation for Astronomy IV, Ian S. McLean, Suzanne K. Ramsay, Hideki
Takami, Editors, Proc. SPIE 8446 (2012)
The Seventh Data Release of the Sloan Digital Sky Survey
This paper describes the Seventh Data Release of the Sloan Digital Sky Survey
(SDSS), marking the completion of the original goals of the SDSS and the end of
the phase known as SDSS-II. It includes 11663 deg^2 of imaging data, with most
of the roughly 2000 deg^2 increment over the previous data release lying in
regions of low Galactic latitude. The catalog contains five-band photometry for
357 million distinct objects. The survey also includes repeat photometry over
250 deg^2 along the Celestial Equator in the Southern Galactic Cap. A
coaddition of these data goes roughly two magnitudes fainter than the main
survey. The spectroscopy is now complete over a contiguous area of 7500 deg^2
in the Northern Galactic Cap, closing the gap that was present in previous data
releases. There are over 1.6 million spectra in total, including 930,000
galaxies, 120,000 quasars, and 460,000 stars. The data release includes
improved stellar photometry at low Galactic latitude. The astrometry has all
been recalibrated with the second version of the USNO CCD Astrograph Catalog
(UCAC-2), reducing the rms statistical errors at the bright end to 45
milli-arcseconds per coordinate. A systematic error in bright galaxy photometr
is less severe than previously reported for the majority of galaxies. Finally,
we describe a series of improvements to the spectroscopic reductions, including
better flat-fielding and improved wavelength calibration at the blue end,
better processing of objects with extremely strong narrow emission lines, and
an improved determination of stellar metallicities. (Abridged)Comment: 20 pages, 10 embedded figures. Accepted to ApJS after minor
correction
The Eighth Data Release of the Sloan Digital Sky Survey: First Data from SDSS-III
The Sloan Digital Sky Survey (SDSS) started a new phase in August 2008, with
new instrumentation and new surveys focused on Galactic structure and chemical
evolution, measurements of the baryon oscillation feature in the clustering of
galaxies and the quasar Ly alpha forest, and a radial velocity search for
planets around ~8000 stars. This paper describes the first data release of
SDSS-III (and the eighth counting from the beginning of the SDSS). The release
includes five-band imaging of roughly 5200 deg^2 in the Southern Galactic Cap,
bringing the total footprint of the SDSS imaging to 14,555 deg^2, or over a
third of the Celestial Sphere. All the imaging data have been reprocessed with
an improved sky-subtraction algorithm and a final, self-consistent photometric
recalibration and flat-field determination. This release also includes all data
from the second phase of the Sloan Extension for Galactic Understanding and
Evolution (SEGUE-2), consisting of spectroscopy of approximately 118,000 stars
at both high and low Galactic latitudes. All the more than half a million
stellar spectra obtained with the SDSS spectrograph have been reprocessed
through an improved stellar parameters pipeline, which has better determination
of metallicity for high metallicity stars.Comment: Astrophysical Journal Supplements, in press (minor updates from
submitted version
A unified lead-oriented synthesis of over fifty molecular scaffolds
Controlling the properties of lead molecules is critical in drug discovery, but sourcing large numbers of lead-like compounds for screening collections is a major challenge. A unified synthetic approach is described that enabled the synthesis of 52 diverse lead-like molecular scaffolds from a minimal set of 13 precursors. The divergent approach exploited a suite of robust, functional group-tolerant transformations. Crucially, after derivatisation, these scaffolds would target significant lead-like chemical space, and complement commercially-available compounds
Progress with the Prime Focus Spectrograph for the Subaru Telescope: a massively multiplexed optical and near-infrared fiber spectrograph
The Prime Focus Spectrograph (PFS) is an optical/near-infrared multi-fiber
spectrograph with 2394 science fibers, which are distributed in 1.3 degree
diameter field of view at Subaru 8.2-meter telescope. The simultaneous wide
wavelength coverage from 0.38 um to 1.26 um, with the resolving power of 3000,
strengthens its ability to target three main survey programs: cosmology,
Galactic archaeology, and galaxy/AGN evolution. A medium resolution mode with
resolving power of 5000 for 0.71 um to 0.89 um also will be available by simply
exchanging dispersers. PFS takes the role for the spectroscopic part of the
Subaru Measurement of Images and Redshifts project, while Hyper Suprime-Cam
works on the imaging part. To transform the telescope plus WFC focal ratio, a
3-mm thick broad-band coated glass-molded microlens is glued to each fiber tip.
A higher transmission fiber is selected for the longest part of cable system,
while one with a better FRD performance is selected for the fiber-positioner
and fiber-slit components, given the more frequent fiber movements and tightly
curved structure. Each Fiber positioner consists of two stages of
piezo-electric rotary motors. Its engineering model has been produced and
tested. Fiber positioning will be performed iteratively by taking an image of
artificially back-illuminated fibers with the Metrology camera located in the
Cassegrain container. The camera is carefully designed so that fiber position
measurements are unaffected by small amounts of high special-frequency
inaccuracies in WFC lens surface shapes. Target light carried through the fiber
system reaches one of four identical fast-Schmidt spectrograph modules, each
with three arms. Prototype VPH gratings have been optically tested. CCD
production is complete, with standard fully-depleted CCDs for red arms and
more-challenging thinner fully-depleted CCDs with blue-optimized coating for
blue arms.Comment: 14 pages, 12 figures, submitted to "Ground-based and Airborne
Instrumentation for Astronomy V, Suzanne K. Ramsay, Ian S. McLean, Hideki
Takami, Editors, Proc. SPIE 9147 (2014)
- …