6 resultados para Earth’s early history

em Brock University, Canada


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John N. Jackson was born and raised in London England. He served in the Royal Navy, acquired a B.A. and a Ph.D, conducted research for a city planning office and lectured at the University of Manchester. He joined Brock University’s faculty in 1965 as a Professor of Applied Geography. Since his retirement in 1991 he has been Professor Emeritus to Brock. Throughout his time in academia Jackson has focused his research on the history of the modern city, both throughout Europe and Canada. Jackson has also completed specific research on the Niagara Peninsula; including industrial geography, recreation along the Lake Erie shore, St. Catharines early history, the Welland Canals, railway development, comparisons across the Niagara River. While living in the Niagara region Jackson has become involved in many community events. He has been the Director for the Bruce Trail Association, President of the Welland Canals Foundation, and been involved in local historical groups throughout the Niagara region.

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Colin Duquemin was born in 1932 in Guernsey, British Channel Islands, and came to Canada as a young adult. He attended McMaster University (B.A.), the University of Toronto (B.Ed.), the State University of New York at Buffalo (M.A.) and the University of London, London, England (M.Sc.). He began his career as a tea taster and tea buyer in Colombo, Ceylon (Sri Lanka), but later became a teacher. He spent most of his teaching career as a manager of the St. Johns Outdoor Studies Centre, north of Fonthill, Ontario, developing environmentally related programmes for elementary and secondary school students. He was also active in many local organizations, serving as Associate Director of the St. Catharines Grape and Wine Festival Board, Chairman of the St. Catharines Historical Museum Board, President of the Niagara Military Institute and President of the Canadian Canal Society. In addition to the numerous curriculum materials he authored, Colin wrote the Driver’s Guide Series, highlighting the many points of interest in the Niagara region, including the Welland Canal, battlefields of the War of 1812, and the Niagara Parkway. He also wrote A Guide to the Grand River Canal (1980) with Daniel Glenney, The Fur Trade in Rupert’s Land: Opening up the Canadian Northwest (1992), Stick to the Guns! A short history of the 10th field battery, Royal Regiment of Canadian Artillery (1996), Niagara Rebels: the Niagara Frontier Incidents in the Upper Canada Rebellion, 1837-1838 ( 2001), and edited and contributed to A Lodge of Friendship: the History of Niagara Lodge, No. 2, A.F. & A.M, Niagara-on-the-Lake, Ontario, Canada, 1792-1992 (1991). He died in December 2012.

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Obesity is a condition associated with a wide variety of health problems including hypertension, dyslipidemia, diabetes mellitus, certain forms of cancer, cardiovascular disease, and gallstones (157). TTiere is growing evidence that obesity may also be related to compromised immune function due to altered metabolic, psychological, and physical attributes (93). The aim of this study was to compare: a) immunity-related variables such as frequency of upper respiratory tract infections (URTI) and salivary secretory immunoglobulin A (sIgA) levels between overweight/obese (OB) and normal weight (NW) early-pubertal and late-pubertal girls, and b) stress-related variables such as Cortisol, melatonin, the melatonin/cortisol ratio, testosterone and the testosterone/cortisol ratio. Physical activity levels, stress indicators, and fatigue were used to explain potential differences in the dependent variables. It was hypothesized that the OB females would have lower melatonin (M) and higher Cortisol (C) and testosterone (T) levels compared with NW girls, regardless of maturity status. The altered levels of melatonin, Cortisol, and testosterone, would result in decreased M/C and T/C ratios, despite the increase in testosterone in OB females. It was hypothesized that this altered hormonal status results in a compromised immunity marked by higher frequency of upper respiratory tract infections (URTI) and decreased levels of secretory immunoglobulin A (sIgA). It was also hypothesized that OB girls would participate in less hours of physical activity than their NW counterparts and that this would relate to their stress and immunity levels. Forty (16 early- and 24 late-pubertal) overweight and obese females were compared to fifty-three (27 eariy- and 26 late-pubertal) age-matched normal-weight control subjects. Participants were categorized as early-pubertal (EP) or late-pubertal (LP) using Tanner self-staging of secondary sex characteristics. Subjects were classified into the two adiposity groups according to relative body fat (%BF), where normal weight (NW) subjects had a %BF less than 25%, and overweight and obese (OB) subjects had a %BF greater than 27.5%. Participants completed a number of questionnaires and information was collected on menstrual history, smoking history, alcohol and caffeine consumption, and medical history. Following the determination of maturity status, a complete anthropometric assessment was made including height, body mass, and body composition. All questionnaires and measurements were completed during a one-hour visit between 1 500 and 1900 hours Relative body fat was assessed using bioelectrical impedance analysis. Resting saliva samples were obtained and assayed (ELISA) for testosterone, Cortisol, melatonin and secretory immunoglobulin A. Physical activity was self-reported using the Godin- Shephard Leisure time questionnaire, and quantified using Actigraph GTIM accelerometers, which participants wore for seven consecutive days from the time they woke up in the morning, until the time they went to bed. Late-pubertal girls also completed questionnaires on their perceived stress and fatigue. Finally, all participants also filled out a one-month health log to record frequency of symptoms of upper respiratory tract infections (URTI). Significant age effects were found for testosterone, Cortisol, incidence of sickness, and sIgA when controlling for physical activity, however there were no significant effects of adiposity on any of the variables. There was a trend which neared-significance for an effect of adiposity on sIgA (p=0.01). There were no significant differences between the groups on the total selfreported leisure-time physical activity in METs per week, however EP girls recorded significantly greater levels of moderate, hard, and very hard physical activity from accelerometers. Results of the perceived stress and fatigue questionnaires in late-pubertal girls demonstrated that contrary to what was hypothesized, NW girls reported more stress and more fatigue than OB girls. Results of the present study suggest that excess adiposity in early- and latepubescent girls may not have a negative impact on immunity as hypothesized.

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This study has three purposes: to establish a chronologically controlled vegetational history for a number of sites in south Southwestern Ontario; to utilize the resulting data to support and/or add to the current understanding of Quaternary geology and stratigraphy, and the glacial and postglacial history of the Great Lakes in south Southwestern Ontario; and to attempt to propose a possible explanation for the extinction of the mastodon in Southern Ontario. Palynological and geochronological analyses were conducted on material collected from eleven sites (east to west): Verbeke Mastodon Site, Woloshko Mastodon Site, Walker Pond II, Pond Mills I, Lake Hunger Bog, Bouckaert Site. Mabee Site, Cornell Bog. Colles Lake I, Folden Mastodon Site and Forest Pond. Individual geochronologically controlled (where possible) vegetational histories were reconstructed for each of the sites investigated. The results of the individual studies, when considered in overview. indicated the existance of an established closed boreal forest throughout south Southwestern Ontario by 10,000 years B.P. This evidence for a significant climatic change coincident throughout south Southwestern Ontario supports the proposed age of 10,000 years B.P. for the Pleistocene/Holocene Boundary (Terasmae, 1972). Remnant patches of 'open spruce parkland' persisted in small local 'wet' areas. It was in these areas that the mastodon was restricted during early Holocene time. With continued encroachment by the surrounding boreal forest, possibly speeded up by this browser's destructive feeding habits, the spruce enclaves shrank and the mastodon became extinct in south Southwestern Ontario. The results of this thesis basically support Dreimanis' (1967, 1968) proposed 'Environmental-Climatic' theory for mastodon extinction. It is suggested that increased dryness during the present interglacial compared to the climate of earlier interglacials may be the key to unravelling the problem of mastodon extinction in eastern North America.

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A black and white photograph of a very young Rick Bell with his grandmother, Mary Bell. The location is not recorded on the photo, however, it is likely to be Niagara Falls or St. Catharines, Ontario. This photograph was in the possession of Rick Bell, who retrieved family memorabilia from the attic of his mother, Iris, in the 1980s. The Bell family ancestry includes former African American slaves who settled in Canada.

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The first Europeans who wrote about the Indigenous people of the newly discovered Americas, not only used medieval, but also classical literature as a tool of reference to describe 'otherness.' As true humanists, the French Jesuits who arrived in the New World were deeply influenced by their classical education and, as claimed by Grafton, reverted to ancient ethnographic texts, like Tacitus' Germania, to support their analyse of the Indigenous people they encountered. Books talk to books. Inspired by Germania, the early French Jesuits managed to convey to their readers a subtle critique of their own civilization, enhancing, like Tacitus, the virtuous aspect of the so-called barbarians they described while illustrating the corruption of their respective civilized worlds. This thesis suggests that the essence of Tacitus' work is definitively present in Pierre Biard's letters and his Relation. His testimonies illustrate the connection the early French Jesuits had with the humanist thought of their time.