University of Guelph

About: University of Guelph is a education organization based out in Guelph, Ontario, Canada. It is known for research contribution in the topics: Population & Poison control. The organization has 26542 authors who have published 50553 publications receiving 1715255 citations. The organization is also known as: U of G & Guelph University.

Gastrointestinal melatonin: localization, function, and clinical relevance.

Abstract: The gastrointestinal tract of vertebrate species is a rich source of extrapineal melatonin. The concentration of melatonin in the gastrointestinal tissues surpasses blood levels by 10-100 times and there is at least 400x more melatonin in the gastrointestinal tract than in the pineal gland. The gastrointestinal tract contributes significantly to circulating concentrations of melatonin, especially during the daytime and melatonin may serve as an endocrine, paracrine, or autocrine hormone influencing the regeneration and function of epithelium, enhancing the immune system of the gut, and reducing the tone of gastrointestinal muscles. As binding sites for melatonin exhibit circadian variation in various species, it has been hypothesized that some melatonin found in the gastrointestinal tract might be of pineal origin. Unlike the photoperiodically regulated production of melatonin in the pineal, the release of gastrointestinal melatonin seems to be related to the periodicity of food intake. Phylogenetically, melatonin and its binding sites were detected in the gastrointestinal tract of lower vertebrates, birds, and mammals. Melatonin was found also in large quantities in the embryonic tissue of the mammalian and avian gastrointestinal tract. Food intake and, paradoxically, also longterm food deprivation resulted in an increase of tissue and plasma concentrations of melatonin. Melatonin release may have a direct effect on many gastrointestinal tissues but may also well influence the digestive tract indirectly, via the central nervous system and the sympathetic and parasympathetic nerves. Melatonin prevents ulcerations of gastrointestinal mucosa by an antioxidant action, reduction of secretion of hydrochloric acid, stimulation of the immune system, fostering epithelial regeneration, and increasing microcirculation. Because of its unique properties, melatonin could be considered for prevention or treatment of colorectal cancer, ulcerative colitis, gastric ulcers, irritable bowel syndrome, and childhood colic.

Perspective on Polylactic Acid (PLA) based Sustainable Materials for Durable Applications: Focus on Toughness and Heat Resistance

Abstract: Evolution of the bioplastics industry has changed directions dramatically since the early 1990s. The latest generation is moving toward durable bioplastics having high biobased content. The main objective is to replace “fossil carbon” with “renewable carbon”, a holistic strategy to mitigate climate change by minimizing the environmental impact of a product throughout its life cycle. Durable bioplastics is desired for multiuse long-term application in automotive, electronics and other industries. One necessary requirement for them is to be both tough and strong, yet the two attributes are often mutually exclusive. Does this mean a biobased and biodegradable polymer as polylactic acid (PLA) with its high strength but low toughness cannot be adopted for durable applications? Well, not exactly; this is where the concept of tailoring the properties of PLA to achieve stiffness–toughness balance along with acceptable heat resistance comes into play. In this perspective, we summarize the recent research progress ...

Investigating web services on the world wide web

Abstract: Searching for Web service access points is no longer attached to service registries as Web search engines have become a new major source for discovering Web services. In this work, we conduct a thorough analytical investigation on the plurality of Web service interfaces that exist on the Web today. Using our Web Service Crawler Engine (WSCE), we collect metadata service information on retrieved interfaces through accessible UBRs, service portals and search engines. We use this data to determine Web service statistics and distribution based on object sizes, types of technologies employed, and the number of functioning services. This statistical data can be used to help determine the current status of Web services. We determine an intriguing result that 63% of the available Web services on the Web are considered to be active. We further use our findings to provide insights on improving the service retrieval process.