The Earth’s surface comprises minerals diagnostic of weathering, deposition and erosion. The first continental-scale mineral maps generated from an imaging satellite with spectral bands designed to measure clays, quartz and other minerals were released in 2012 for Australia. Here we show how these satellite mineral maps improve our understanding of weathering, erosional and depositional processes in the context of changing weather, climate and tectonics. The clay composition map shows how kaolinite has developed over tectonically stable continental crust in response to deep weathering during northwardly migrating tropical conditions from 45 to 10 Ma. The same clay composition map, in combination with one sensitive to water content, enables the discrimination of illite from montmorillonite clays that typically develop in large depositional environments over thin (sinking) continental crust such as the Lake Eyre Basin. Cutting across these clay patterns are sandy deserts that developed <10 Ma and are well mapped using another satellite product sensitive to the particle size of silicate minerals. This product can also be used to measure temporal gains/losses of surface clay caused by periodic wind erosion (dust) and rainfall inundation (flood) events. The accuracy and information content of these satellite mineral maps are validated using published data.

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We examined the role of nitric oxide (NO) in muscle repair and regeneration following repetitive eccentric contractions (ECC). A standardized exercise protocol was used to create eccentric contraction-induced injury to the left tibialis anterior muscle of 48 male Wistar rats (body wt 250-350 g), using a customized isokinetic test device and a bout of 40 ECCs under electrical stimulation. A nitric oxide synthase inhibitor, N(G)-nitro-L-arginine-methyl ester (L-NAME; 35 mg kg(-1) day(-1)), was included in the diet for half the animals (n = 24) beginning 3 days prior to the ECC and continuing throughout the experiment, whereas the other half (n = 24) received a control diet. ECC/+L-NAME and ECC/-L-NAME were killed after the ECC protocol at 0, 1, 3 and 7 days (n = 6 on each day). An unexercised contralateral limb with and without L-NAME infusion served as a respective control muscle at each time point. Muscle NO content, skeletal muscle damage, leukocyte infiltration, calpain activity, and MyoD and myogenin expression were assessed. NO has both pro-inflammatory and anti-inflammatory properties, and several possible roles for NO in skeletal muscle damage have been postulated. NO content was greater in the ECC/-L-NAME group at all time points (p < 0.05) compared to ECC/+L-NAME. Additionally, significant differences in NO content were observed on day 0 (p < 0.05), and day 3 (p < 0.05), ECC/+L-NAME versus ECC/-L-NAME. One day following the bout of ECC, and NO levels were increased in the ECC/-L-NAME group. Three days following ECC, there was greater myofiber damage (measured by β-glucuronidase activity) and leukocyte invasion in the ECC/-L-NAME group as compared to the ECC/+L-NAME group. One day after ECC, calpain activity was significantly increased in ECC/-L-NAME compared with control muscles (p < 0.05). On days 3 and 7, Myo-D and myogenin gene expression was increased in both groups; however, the degree of regeneration was less in the ECC/+L-NAME-treated animals. These data suggest that NO dynamics have important implications in the regulation of various factors during skeletal muscle regeneration following damaging eccentric muscle contractions.

The influences of both hypobaric hypoxia and cold on peripheral circulation were studied using the finger cooling test (measurement of the decrease in finger temperature, measured at the dorsal surface of the finger, during immersion of the hand in 0 degrees C water for 20 min) at Qinghai Plateau. The same test was carried out at simulated altitudes in a 25 degrees C climatic chamber to separate the hypobaric hypoxia influence from that of cold. In Japanese subjects at Qinghai Plateau there was a significant difference between finger skin temperatures (FSTs) during 20 min of 0 degrees C water immersion at altitudes of 2260 m and 4860 m by ANOVA. Mean finger skin temperature during the 20-min immersion (5-20 min, MST) measured at 4860 m was significantly lower than that at 2260 m. In Tibetan subjects, there was also a significant difference between FSTs at 2260 m and at 4860 m by ANOVA. MST at 4860 m tended to be lower than that at 2260 m. In the 25 degrees C climatic chamber, there was a significant difference between FSTs of Japanese expedition members at 2000 m and at 4000 m by ANOVA. MST was higher at 4000 m than at 2000 m, contrary to the data obtained in Qinghai. In conclusion, the higher skin temperature in response to local cold immersion, which would have been caused by stronger hypobaric hypoxia, must have been masked by the lower ambient temperature.

The present study was undertaken to determine whether exercise-training for 6 weeks would inhibit pulmonary vasoconstriction induced by hypoxia in isolated, blood-perfused rat lungs. Hypoxic pulmonary vasoconstriction (HPV) and angiotensin II (AII)-induced pulmonary vasoconstriction were significantly less in the exercise-trained (ET) group than in the control (cont) group with all challenges. Normoxic pulmonary arterial and capillary pressures in the ET group were significantly lower than those in the cont group and capillary pressor response to hypoxia was less in the ET group than in the cont group. In conclusion, it appears that HPV and AII-induced vasoconstrictions can be reduced by exercise-training, because it would seem that exercise-training repeated responses to increased shear-stress resulting from elevated blood flow in pulmonary vessels.