Université de Sherbrooke

About: Université de Sherbrooke is a education organization based out in Sherbrooke, Quebec, Canada. It is known for research contribution in the topics: Population & Receptor. The organization has 14922 authors who have published 28783 publications receiving 792511 citations. The organization is also known as: Universite de Sherbrooke & Sherbrooke University.

Efficient molecular dissociation by a chirped ultrashort infrared laser pulse.

Abstract: Dissociation probabilities and populations of excited vibrational states are calculated numerically for interaction of a Morse oscillator with a chirped, ultrashort (${\mathit{t}}_{\mathit{p}}$${10}^{\mathrm{\ensuremath{-}}11}$ sec), intense laser pulse. It is shown that if the pulse frequency \ensuremath{\omega}(t) decreases at a specific rate adapted to the molecular anharmonicity, the dissociation probability is many orders of magnitude higher than for a monochromatic pulse of the same intensity. Such pulses should be useful for more efficient multiphoton dissociation of molecular bonds.

Impact of a Reduction in the Use of High-Risk Antibiotics on the Course of an Epidemic of Clostridium difficile-Associated Disease Caused by the Hypervirulent NAP1/027 Strain

Abstract: A series of measures were implemented, in a secondary/tertiary-care hospital in Quebec, to control an epidemic of nosocomial Clostridium difficile-associated disease (n-CDAD) caused by a virulent strain; these measures included the development of a nonrestrictive antimicrobial stewardship program. Interrupted time-series analysis was used to evaluate the impact of these measures on n-CDAD incidence. From 2003-2004 to 2005-2006, total and targeted antibiotic consumption, respectively, decreased by 23% and 54%, and the incidence of n-CDAD decreased by 60%. No change in n-CDAD incidence was noted after strengthening of infection control procedures (P=.63), but implementation of the antimicrobial stewardship program was followed by a marked reduction in incidence (P=.007). This suggests that nonrestrictive measures to optimize antibiotic usage can yield exceptional results when physicians are motivated and that such measures should be a mandatory component of n-CDAD control. The inefficacy of infection control measures targeting transmission through hospital personnel might be a result of their implementation late in the epidemic, when the environment was heavily contaminated with spores.

Diffusion MRI fiber tractography of the brain

Abstract: The ability of fiber tractography to delineate non-invasively the white matter fiber pathways of the brain raises possibilities for clinical applications and offers enormous potential for neuroscience In the last decade, fiber tracking has become the method of choice to investigate quantitative MRI parameters in specific bundles of white matter For neurosurgeons, it is quickly becoming an invaluable tool for the planning of surgery, allowing for visualization and localization of important white matter pathways before and even during surgery Fiber tracking has also claimed a central role in the field of “connectomics,” a technique that builds and studies comprehensive maps of the complex network of connections within the brain, and to which significant resources have been allocated worldwide Despite its unique abilities and exciting applications, fiber tracking is not without controversy, in particular when it comes to its interpretation As neuroscientists are eager to study the brain's connectivity, the quantification of tractography-derived “connection strengths” between distant brain regions is becoming increasingly popular However, this practice is often frowned upon by fiber-tracking experts In light of this controversy, this paper provides an overview of the key concepts of tractography, the technical considerations at play, and the different types of tractography algorithm, as well as the common misconceptions and mistakes that surround them We also highlight the ongoing challenges related to fiber tracking While recent methodological developments have vastly increased the biological accuracy of fiber tractograms, one should be aware that, even with state-of-the-art techniques, many issues that severely bias the resulting structural “connectomes” remain unresolved

Mutations in ARFGEF2 implicate vesicle trafficking in neural progenitor proliferation and migration in the human cerebral cortex

Abstract: Mutations in ARFGEF2 implicate vesicle trafficking in neural progenitor proliferation and migration in the human cerebral cortex