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.

Montreal Cognitive Assessment (MoCA): Concept and Clinical Review

Abstract: The Montreal Cognitive Assessment (MoCA) is a cognitive screening instrument developed to detect mild cognitive impairment (MCI). It is a simple 10 min paper and pencil test that assesses multiple cognitive domains including memory, language, executive functions, visuospatial skills, calculation, abstraction, attention, concentration, and orientation. Its validity has been established to detect mild cognitive impairment in patients with Alzheimer’s disease and other pathologies in cognitively impaired subjects who scored in the normal range on the MMSE. MoCA’s sensitivity and specificity to detect subjects with MCI due to Alzheimer’s disease and distinguish them from healthy controls are excellent. MoCA is also sensitive to detect cognitive impairment in cerebrovascular disease and Parkinson’s disease, Huntington’s disease, brain tumors, systemic lupus erythematosus, substance use disorders, idiopathic rapid eye movement sleep behavior disorder, obstructive sleep apnea, risk of falling, rehabilitation outcome, epilepsy, chronic obstructive pulmonary disease and human immunodeficiency virus infection. There are several features in MoCA’s design that likely explain its superior sensitivity for detecting MCI. MoCA’s memory testing involves more words, fewer learning trials, and a longer delay before recall than the MMSE. Executive functions, higher-level language abilities, and complex visuospatial processing can also be mildly impaired in MCI participants of various etiologies and are assessed by the MoCA with more numerous and demanding tasks than the MMSE. MoCA was developed in a memory clinic setting and normed in a highly educated population. A new version of the MoCA called MoCA-Basic (MoCA-B) was developed to fulfill the limitation of the MoCA among the low educated and illiterate population. MoCA Memory Index Score is a newly devised score that can help clinicians better predict which patients with MCI are most likely to convert to dementia. The MoCA is freely accessible for clinical and educational purposes (www.mocatest.org), and is available in 56 languages and dialects.

Greater temperature sensitivity of plant phenology at colder sites: implications for convergence across northern latitudes

Abstract: Warmer temperatures are accelerating the phenology of organisms around the world. Temperature sensitivity of phenology might be greater in colder, higher latitude sites than in warmer regions, in part because small changes in temperature constitute greater relative changes in thermal balance at colder sites. To test this hypothesis, we examined up to 20 years of phenology data for 47 tundra plant species at 18 high-latitude sites along a climatic gradient. Across all species, the timing of leaf emergence and flowering was more sensitive to a given increase in summer temperature at colder than warmer high-latitude locations. A similar pattern was seen over time for the flowering phenology of a widespread species, Cassiope tetragona. These are among the first results highlighting differential phenological responses of plants across a climatic gradient and suggest the possibility of convergence in flowering times and therefore an increase in gene flow across latitudes as the climate warms.

A structural equation model to integrate changes in functional strategies during old‐field succession

Abstract: From a functional perspective, changes in abundance, and ultimately species replacement, during succession are a consequence of integrated suites of traits conferring different relative ecological advantages as the environment changes over time. Here we use structural equations to model the interspecific relationships between these integrated functional traits using 34 herbaceous species from a Mediterranean old-field succession and thus quantify the notion of a plant strategy. We measured plant traits related to plant vegetative and reproductive size, leaf functioning, reproductive phenology, seed mass, and production on 15 individuals per species monitored during one growing season. The resulting structural equation model successfully accounts for the pattern of trait covariation during the first 45 years post-abandonment using just two forcing variables: time since site abandonment and seed mass; no association between time since field abandonment and seed mass was observed over these herbaceous stages of secondary succession. All other predicted traits values are determined by these two variables and the cause-effect linkage between them. Adding pre-reproductive vegetative mass as a third forcing variable noticeably increased the predictive power of the model. Increasing the time after abandonment favors species with increasing life span and pre-reproductive biomass and decreasing specific leaf area. Allometric coefficients relating vegetative and reproductive components of plant size were in accordance with allometry theory. The model confirmed the trade-off between seed mass and seed number. Maximum plant height and seed mass were major determinants of reproductive phenology. Our results show that beyond verbal conceptualization, plant ecological strategies can be quantified and modeled.

Fabrication of silicon nitride waveguides for visible-light using PECVD: a study of the effect of plasma frequency on optical properties.

Abstract: This paper presents work aimed at optimizing the fabrication of silicon nitride Si(x)N(y) thin-film visible-light planar waveguides using plasma-enhanced chemical vapour deposition (PECVD). The effects of plasma frequency, precursor gas ratio, and thermal annealing in relation to waveguide optical properties (refractive index, propagation losses) are studied. Experimental results over a wide range of precursor gas ratios show convincingly that waveguides fabricated using low-frequency PECVD have lower propagation losses in the visible range compared to waveguides of equal refractive index fabricated with high-frequency PECVD.