4 research outputs found

    Application of Airborne, Laboratory, and Field Hyperspectral Methods to Mineral Exploration in the Canadian Arctic: Recognition and Characterization of Volcanogenic Massive Sulfide-Associated Hydrothermal Alteration in the Izok Lake Deposit Area, Nunavut, Canada

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    We have investigated the application of ground, laboratory, and airborne optical remote sensing methods for the detection of hydrothermal alteration zones associated with the Izok Lake volcanogenic massive sulfide (VMS) deposit in Nunavut, Canada. This bimodal-felsic Zn-Cu-Pb-Ag deposit is located above the tree line in a subarctic environment where lichens are the dominant cryptogamic species coating the rocks. The immediate host rhyolitic rocks have been hydrothermally altered and contain biotite, chlorite, and white micas as dominant alteration minerals. These minerals have spectral Al-OH and Fe-OH absorption features in the shortwave infrared wavelength region that display wavelength shifts, which are documented to be due to chemical compositional changes. Our ground spectrometer measurements indicate that there is a systematic trend in the Fe-OH absorption feature wavelength position of biotite/chlorite with increasing distance from the VMS deposit: the average Fe-OH absorption feature wavelength position of the proximal areas (398–3,146 m from mineralization) is observed at 2,254 nm, and that of the distal areas (5,782–6,812 m) at 2,251 nm. Moreover, the proximal areas have an average Al-OH absorption feature wavelength position at 2,203 nm, in contrast with the average wavelength position at 2,201 nm in the distal areas, implying a spectral shift of 2 nm. These findings indicate that hydrothermal alteration zones can be detected by hyperspectral remote sensing, despite the presence of abundant lichen cover. However, the airborne results discussed in this study required the screening out of more than 99% of the pixels in the area

    The International Olympic Committee (IOC) consensus statement on periodic health evaluation of elite athletes, March 2009.

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    The Olympic Games is the largest sport event in the world. In Beijing, 10 500 athletes competed, selected from a large group of elite athletes in 204 countries. Sports participation on the elite level, aside from winning medals, fame and other rewards, is also important from a health perspective. There is no longer any doubt that regular physical activity reduces the risk of premature mortality in general, and of coronary heart disease, hypertension, colon cancer, obesity and diabetes mellitus in particular. The question is whether the health benefits of sports participation outweigh the risk of injury and long-term disability, especially in high-level athletes. Sarna et al1 have studied the incidence of chronic disease and life expectancy of former male world-class athletes from Finland in endurance sports, power sports and team sports. The overall life expectancy was longer in the high-level athlete compared with a reference group (75.6 vs 69.9 years). The same group also showed that the rate of hospitalisation later in life was lower for endurance sports and power sports compared with the reference group.2 This resulted from a lower rate of hospital care for heart disease, respiratory disease and cancer. However, the athletes were more likely to have been hospitalised for musculoskeletal disorders. Thus, the evidence suggests that although there is a general health benefit from sports participation, injuries represent a significant side effect
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