RESUMEN

Over a four-year period, serum haptoglobin was measured in 152 patients with adnexal masses in an attempt to discriminate between benign and malignant disease. When serum haptoglobin exceeded 150 mg/dl, malignancy could be identified with a sensitivity of 83% and a specificity of 84%. While the predictive value of a positive test is only 66%, the predictive value of a negative test is 93%, and this inexpensive test may be clinically useful. Stage, grade, and size of tumor did not correlate with serum haptoglobin levels.

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RESUMEN

Research in Antarctica is becoming increasingly important in the large interdisciplinary studies of connections within the earth's geosphere-biosphere system. Four examples of broad research areas are discussed. Upper atmosphere research explores the sun-earth interactions, which are most intense in the polar regions. The mass balance and dynamics of the large Antarctic ice sheet, and its paleoclimatic records recovered from deep ice cores, are important indicators of past and present global changes. Antarctica and sediment cores from the Southern Ocean contain the history of inception and growth of the ice masses and their subsequent fluctuations, and the long-term history of paleoclimate. The remarkable adaptations of Antarctic biota to extreme cold and drought may allow, through biotic monitoring, the detection of changes in the ocean and climate of Antarctica.

RESUMEN

Proposed further developments on Alaska's Arctic Coastal Plain raise questions about cumulative effects on arctic tundra ecosystems of development of multiple large oil fields. Maps of historical changes to the Prudhoe Bay Oil Field show indirect impacts can lag behind planned developments by many years and the total area eventually disturbed can greatly exceed the planned area of construction. For example, in the wettest parts of the oil field (flat thaw-lake plains), flooding and thermokarst covered more than twice the area directly affected by roads and other construction activities. Protecting critical wildlife habitat is the central issue for cumulative impact analysis in northern Alaska. Comprehensive landscape planning with the use of geographic information system technology and detailed geobotanical maps can help identify and protect areas of high wildlife use.

RESUMEN

Measured data are presented on glass transition temperature, thermal expansion coefficient, and refractive index for glasses in the Ge-As-Se system. The range of reciprocal dispersive power between 8 microm and 12 microm of 110-159 for these glasses is discussed in relation to their basic physical properties, and it is shown that useful compositions for bulk synthesis can be identified. A brief account is given of the preparation techniques, which enable glass to be made with an oxide content of the order of 1 ppm wt as measured by gamma photon activation analysis. The influence of oxide impurity on the transmission is shown for the three glasses Ge2O-Se80, As40-Se60, and Ge30-Asl5-Se55.