Polar cap observations of thermospheric winds and temperatures at Sondre Stromfjord, Greenland

An agreement of averaged temperatures with mass spectrometer incoherent scatter radar looked reasonable for several nights, but for many nights there are differences: (1) midnight period of cooling, and (2) temperature increases associated with overhead crossings of the auroral belt. The observed rise of the temperature before dawn in conjunction with the high 6300A intensities suggests a connection between the two effects: soft particle precipitation most likely candidate but frictional heating perhaps also a possibility. A comparison with the thermospheric general circulation model calculations also needed. The technique for formulating neutral wind vectors performs well in most cases. The observed patterns show evidence for abatement in the midnight sector in the meridional wind component at the separatix between the two cells with a frequency of the order of 20 to 25%, also observed in radar observations at Sondre Stromfjord. The observed patterns for magnetically quiet conditions show flow characteristic of the auroral belt, westward in evening followed by the midnight surge. The observed patterns for active conditions show dominance either by the evening cell or the morning cell, but most often the former

Ground-based observations of equatorial thermosphere dynamics with a Fabry-Perot interferometer

Fabry-Perot determinations of thermospheric temperatures from 630.0 nm nightglow line width measurements were carried out for the period April to August, 1983. The nightly variation of the thermospheric temperature measured on 53 nights is compared with MSIS model predictions and found to agree occasionally with the model but, on the average, to exceed model predictions by approximately 180 K. The largest differences, 400 to 500 K occur during strongly increasing geomagnetic activity. Significant differences occur both during high geomagnetic/low solar activity and during low geomagnetic/high solar activity

Does tamoxifen prevent breast cancer?

Tamoxifen prevents breast cancer in women older than 60 years and in younger women with equally high risk because of breast disease and reproductive and family history, but there is no current evidence for or against long-term survival or overall health benefits.(Grade of recommendation A: randomized controlled trials [RCTs]) a 49% reduction in 5-year incidence of invasive and noninvasive breast cancer but increased risk for endometrial cancer, pulmonary emboli, deep vein thrombosis, and cataracts. The long-term benefits and overall health effects of tamoxifen for primary prevention of breast cancer remain unclear; the ongoing International Breast Cancer Intervention Study trial is designed to address this question