McGill University

About: McGill University is a education organization based out in Montreal, Quebec, Canada. It is known for research contribution in the topics: Population & Context (language use). The organization has 72688 authors who have published 162565 publications receiving 6966523 citations. The organization is also known as: Royal institution of advanced learning & University of McGill College.

Nanocellulose, a Versatile Green Platform: From Biosources to Materials and Their Applications

Abstract: With increasing environmental and ecological concerns due to the use of petroleum-based chemicals and products, the synthesis of fine chemicals and functional materials from natural resources is of great public value. Nanocellulose may prove to be one of the most promising green materials of modern times due to its intrinsic properties, renewability, and abundance. In this review, we present nanocellulose-based materials from sourcing, synthesis, and surface modification of nanocellulose, to materials formation and applications. Nanocellulose can be sourced from biomass, plants, or bacteria, relying on fairly simple, scalable, and efficient isolation techniques. Mechanical, chemical, and enzymatic treatments, or a combination of these, can be used to extract nanocellulose from natural sources. The properties of nanocellulose are dependent on the source, the isolation technique, and potential subsequent surface transformations. Nanocellulose surface modification techniques are typically used to introduce e...

Peatlands and the carbon cycle: from local processes to global implications - a synthesis

Abstract: Although peatlands cover only 3% of the Earth's land surface, boreal and subarctic peatlands store about 15?30% of the world's soil carbon as peat. Despite their potential for large positive feedbacks to the climate system through sequestration and emission of greenhouse gases, peatlands are not explicitly included in global climate models and therefore in predictions of future climate change. In April 2007 a symposium was held in Wageningen, the Netherlands, to advance our understanding of peatland C cycling through integration across disciplines and research approaches and to develop a more synthetic picture of the present and future role of peatlands in the global C cycle and their interactions with the climate system. This paper aims to synthesize the main findings of the symposium, focusing on (i) small-scale processes, (ii) C fluxes at the landscape scale, and (iii) peatlands and climate. The paper concludes with a summary of the main drivers of the C balance of peatlands, and proposes directions for new research to reduce key uncertainties in our knowledge of C cycling in peatlands in order to facilitate the explicit inclusion of these ecosystems in a new generation of earth system models.

Modelling food chain structure and contaminant bioaccumulation using stable nitrogen isotopes

Abstract: THE nitrogen pools of animals are enriched in 15N relative to their food1, with the top predators having the highest concentrations of this stable isotope2. The use of δ15N to indicate trophic position depends on the degree to which it reflects variation in the underly-ing food-web structure, rather than variable fractionation along the food chain. Here we compare adult lake trout, a top pelagic predator, from a series of lakes, and find that δ15N values vary from 7.5 to 17.5%o, a surprisingly wide range for one species. The length of the food chain can explain this variation, supporting the idea that δ15N is a food-web descriptor. Food-chain length was measured by the presence or absence of two intermediate trophic levels, pelagic forage fish and the macrozooplankter, Mysis relicta, each of which when present contributes about three δ15N units to the trout signature. We find that δ15N can be used as a continuous, integrative measure of trophic position, which is supported by its correlation to mercury levels in lake trout.