Low-latitude glaciation and rapid changes in the Earth's obliquity explained by obliquity-oblateness feedback.

Palaeomagnetic data suggest that the Earth was glaciated at low latitudes during the Palaeoproterozoic (about 2.4-2.2 Gyr ago) and Neoproterozoic (about 820-550 Myr ago) eras, although some of the Neoproterozoic data are disputed. If the Earth's magnetic field was aligned more or less with its spin axis, as it is today, then either the polar ice caps must have extended well down into the tropics-the 'snowball Earth' hypothesis-or the present zonation of climate with respect to latitude must have been reversed. Williams has suggested that the Earth's obliquity may have been greater than 54 degrees during most of its history, which would have made the Equator the coldest part of the planet. But this would require a mechanism to bring the obliquity down to its present value of 23.5 degrees. Here we propose that obliquity-oblateness feedback could have reduced the Earth's obliquity by tens of degrees in less than 100 Myr if the continents were situated so as to promote the formation of large polar ice sheets. A high obliquity for the early Earth may also provide a natural explanation for the present inclination of the lunar orbit with respect to the ecliptic (5 degrees), which is otherwise difficult to explain.

An all oral antiemetic regimen for patients undergoing high-dose chemotherapy with peripheral blood stem cell transplant.

The purpose of the study was to assess the toxicity and efficacy of an oral, combination antiemetic regimen including granisetron (Kytril; SmithKline Beecham Pharmaceuticals, Philadelphia, PA, USA) in the setting of highly emetogenic conditioning chemotherapy for stem cell transplantation. Antiemetic prophylaxis consisted of oral granisetron 2 mg once daily, oral prochlorperazine 10 mg q 6 h and oral dexamethasone 4 mg q 6 h, beginning 1 h prior to chemotherapy on each of the 4 days of chemotherapy and continuing until 24 h after the completion of high-dose chemotherapy (HDC). Patients received either CVP (cyclophosphamide 6 g/m2, VP-16 1800 mg/m2 and carboplatin 1200 mg/m2) or CTP (thiotepa 500 mg/m2 in place of VP-16) in four daily doses given over 4 h from days -4 to -1. Previously mobilized and cryopreserved peripheral blood stem cells (PBSC) were reinfused on day +1. Evaluation of nausea, emetic episodes (EE), adverse events, and rescue medications were recorded on a daily patient diary. Thirty-six patients were entered. Fifty-three percent (95% CI = 37-75%) of patients achieved complete response for emesis (CR = 0 EE/24 h) and 75% (95% CI = 58-90%) had combined complete and major response (CR+MR = 0-3 EE/24 h) during all 5 of the treatment days. During the 5 study days, the average number of patient-days with no emesis was 3.7 (74%) and with 1-3 EE was 4.3 (86%). On days -4, -3, -2, -1 and 0, the combined CR+MR rate for emesis was 97, 92, 86, 78 and 75%, respectively. Nausea was absent or mild on all 5 study days in 57% (95% CI = 37-75%). Eight patients had severe late-onset emesis occurring on days +1 to +3 after reinfusion of stem cells. No clinically significant toxicities attributable to the antiemetic regimen were observed. An all oral antiemetic regimen of granisetron, prochlorperazine and dexamethasone appears to be safe and highly effective in patients receiving multiple, daily, high-dose chemotherapy regimens. This regimen offers the advantage of cost-savings, a low side-effect profile and ease of administration in the predominately outpatient setting of HDC with peripheral blood stem cell transplant (PBSCT).

A controlled comparative evaluation of acetaminophen and aspirin in the treatment of postoperative pain.

The analgesic effects of acetaminophen (1 gm), aspirin (650 mg), and placebo were evaluated in a double-blind, randomized parallel study. The subjects were 162 outpatients who had experienced moderate or severe pain as a result of dental surgery involving bone removal. Patients evaluated the intensity of their pain and the extent of their relief from pain at 30 minutes, at one hour, and at each subsequent hour for six hours after the administration of the study medication. During the six-hour period, 135 of the 162 patients were remedicated. At the end of the six-hour period each patient assessed overall treatment. Two measures of analgesia were derived from patients' evaluations of the intensity of pain, and three other measures were derived from evaluations of relief from pain. On all six measures used, the groups receiving acetaminophen and aspirin reported analgesic effects significantly superior (P less than 0.05) to those of placebo. Acetaminophen was significantly better than aspirin with respect to the maximum difference in the intensity of pain (P less than 0.05) and the maximum pain relief achieved (P less than 0.03) and according to the global evaluation (P less than 0.02). These differences were most striking in patients with severe initial pain.

Movement directions in late paleozoic glacial rocks of the horlick and pensacola mountains, antarctica.

Striae and associated structures beneath and within the Buckeye Tillite in the Ohio Range of the Horlick Mountains show that Permian(?) glaciers moved toward the west-southwest. Striae in the Wisconsin Range of the Horlicks display similar orientation, but the sense of movement could not be determined. Paleoglaciers in the Neptune Range and the Cordiner Peaks of the Pensacola Mountains moved toward the south-southwest with some dispersion. Paleocurrents flowed parallel to ice motion in the Ohio Range and in the Pensacolas, but they also flowed toward the north-northeast in the Pensacolas.