University of Saskatchewan

About: University of Saskatchewan is a education organization based out in Saskatoon, Saskatchewan, Canada. It is known for research contribution in the topics: Population & Health care. The organization has 25021 authors who have published 52579 publications receiving 1483049 citations. The organization is also known as: USask.

Impact Exercise Increases BMC During Growth: An 8-Year Longitudinal Study

Abstract: Our aim was to assess BMC of the hip over 8 yr in prepubertal children who participated in a 7-mo jumping intervention compared with controls who participated in a stretching program of equal duration. We hypothesized that jumpers would gain more BMC than control subjects. The data reported come from two cohorts of children who participated in separate, but identical, randomized, controlled, school-based impact exercise interventions and reflect those subjects who agreed to long-term follow-up (N = 57; jumpers = 33, controls = 24; 47% of the original participants). BMC was assessed by DXA at baseline, 7 and 19 mo after intervention, and annually thereafter for 5 yr (eight visits over 8 yr). Multilevel random effects models were constructed and used to predict change in BMC from baseline at each measurement occasion. After 7 mo, those children that completed high-impact jumping exercises had 3.6% more BMC at the hip than control subjects whom completed nonimpact stretching activities (p < 0.05) and 1.4% more BMC at the hip after nearly 8 yr (BMC adjusted for change in age, height, weight, and physical activity; p < 0.05). This provides the first evidence of a sustained effect on total hip BMC from short-term high-impact exercise undertaken in early childhood. If the benefits are sustained into young adulthood, effectively increasing peak bone mass, fracture risk in the later years could be reduced.

Re-Os Dating of Polymetallic Ni-Mo-PGE-Au Mineralization in Lower Cambrian Black Shales of South China and Its Geologic Significance

Abstract: Black shales of the basal Lower Cambrian Niutitang Formation, southeast China, host a regionally distributed concordant, several centimeter-thick, sulfide layer which displays extreme metal enrichment, i.e., Mo-NiSe-Re-Os-As-Hg-Sb >1,000 times enriched and Ag-Au-Pt-Pd >100 times enriched over bulk continental crust. Mineable portions have about 5.5 wt percent Mo, 3.5 wt percent Ni, and 1 g/t PGE + Au. A six-point 187 Os/ 188 Os versus 187 Re/ 188 Os isochron on molybdenum-nickel ore samples defines an age of 541 ± 16 Ma (2σ) with an initial 187 Os/ 188 Os ratio of 0.78 ± 0.19. This age is in agreement with the depositional age of the black shale host; the initial ratio is close to present-day seawater. The sulfide layer/average seawater metal ratio is on the order of 10 6 to 10 8 , about 10 to 100 times higher than that for the black shale host and for average metalliferous black shale. Synsedimentary metal enrichment from seawater under anoxic (sulfate-reducing) conditions appears likely but requires an unusually low sedimentation rate and/or high replenishment rate of fresh seawater to the marine basin. The paleogeographic setting of the Lower Cambrian continental margin of the Yangtze craton indicates local basins controlled by synsedimentary rifting. Stagnant water episodically replenished by upwelling oxidized seawater is thought to be responsible for the formation of the polymetallic sulfide layer and of phosphorite, barite, and sapropelic “stone coal” (combustible black shale) beds.

First Sight: A human body outline labeling system

Abstract: First Sight, a vision system in labeling the outline of a moving human body, is proposed in this paper. The emphasis of First Sight is on the analysis of motion information gathered solely from the outline of a moving human object. Two main processes are implemented in First Sight. The first process uses a novel technique to extract the outline of a moving human body from an image sequence. The second process, which employs a new human body model, interprets the outline and produces a labeled two-dimensional human body stick figure for each frame of the image sequence. Extensive knowledge of the structure, shape, and posture of the human body is used in the model. The experimental results of applying the technique on unedited image sequences with self-occlusions and missing boundary lines are encouraging. >

Understanding plant cold hardiness: an opinion

Abstract: How plants adapt to freezing temperatures and acclimate to survive the formation of ice within their tissues has been a subject of study for botanists and plant scientists since the latter part of the 19th century. In recent years, there has been an explosion of information on this topic and molecular biology has provided new and exciting opportunities to better understand the genes involved in cold adaptation, freezing response and environmental stress in general. Despite an exponential increase in our understanding of freezing tolerance, understanding cold hardiness in a manner that allows one to actually improve this trait in economically important crops has proved to be an elusive goal. This is partly because of the growing recognition of the complexity of cold adaptation. The ability of plants to adapt to and survive freezing temperatures has many facets, which are often species specific, and are the result of the response to many environmental cues, rather than just low temperature. This is perhaps underappreciated in the design of many controlled environment experiments resulting in data that reflects the response to the experimental conditions but may not reflect actual mechanisms of cold hardiness in the field. The information and opinions presented in this report are an attempt to illustrate the many facets of cold hardiness, emphasize the importance of context in conducting cold hardiness research, and pose, in our view, a few of the critical questions that still need to be addressed.