A Mercury orbiter mission is challenging from thermal and mass perspectives. The Mercury Surface, Space Environment, Geochemistry, and Ranging (MESSENGER) mission overcomes these challenges while ...avoiding esoteric technologies by using an innovative approach with commonly available materials, minimal moving parts, and maximum heritage. This approach yields a spacecraft with good margins in all categories and low technical risk. The key concepts are a ceramic-cloth sunshade, an integrated lightweight structure and high- performance propulsion system, and a solar array incorporating optical solar reflectors (OSRs). The sunshade maintains the spacecraft at room temperature. The integrated structure and propulsion system provides ample mass margin. The solar array with OSRs, which has already undergone significant testing, provides thermal margin even if the panels are inadvertently pointed directly at the Sun at 0.3 AU.
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Background The methotrexate analogue 10-ethyl-10-deazaaminopterin (10-EdAM, or edatrexate) has shown antitumor activity in preclinical testing and clinical studies of patients with breast, lung and ...head and neck carcinomas. A phase II study was conducted in patients with advanced pancreatic adenocarcinoma. Patients and methods Forty patients were enrolled on the clinical trial. Edatrexate was administered intravenously at a dose of 80 mg/m2 weekly for 5 weeks. The treatment course was repeated every 6 weeks. Results Two partial responses were observed. Both of these patients had partial responses which lasted 2 and 3.5 months. The median survival for all patients was 3.5 months. Serious (grade 3 or 4) toxic effects were primarily mucosal, hematologic, and dermatologic. Two patients experienced severe pulmonary toxic reactions. Conclusion At the dose and schedule used, edatrexate was poorly tolerated and did not demonstrate significant antitumor activity.
ON two previous occasions we presented the number and population ratios of board-certified physicians and surgeons in practice in the United States, comparing them over time with the total number of ...physicians in active practice beyond residency according to their declared fields of specialization. These data included information on residents in training and the age and sex of practitioners. Our purpose here is to update this information for the period from 1980 to 1986, adding a more detailed treatment of the number of women in the various specialties and age groups of medicine. Following on our reports of 1975
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A Phase I study was conducted to determine whether the addition of recombinant human granulocyte-macrophage colony-stimulating factor (rhGM-CSF) to a combined 5-fluorouracil (5-FU) and folinic acid ...(FA) regimen would allow an escalated starting dose of 5-FU. FA (500 mg/m2) was administered as a 2-hour infusion on days 1 through 5, with 5-FU administered as a bolus injection 1 hour after the initiation of FA. Fifteen patients were enrolled in the trial; six were entered at a dose level of 375 mg/m2 of 5-FU, six at 450 mg/m2, and three at 540 mg/m2. rhGM-CSF was administered subcutaneously on days 6 through 15. A course of therapy was repeated every 28 days. Serious toxicity was observed at 450 mg/m2, with two patients developing grade 3 mucositis and one, grade 4 mucositis. Dose-limiting toxicity occurred at 540 mg/m2, at which point three patients developed grade 4 mucositis. One patient with metastatic colon cancer who received 5-FU at 540 mg/m2 achieved a partial response. Because of this persistent mucositis, the addition of rhGM-CSF used in this schedule would not allow an increased starting dose of 5-FU.
The large uncertainties in estimates of cropland area in China may have significant implications for major cross-cutting themes of global environmental change—food production and trade, water ...resources, and the carbon and nitrogen cycles. Many earlier studies have indicated significant under-reporting of cropland area in China from official agricultural census statistics datasets. Space-borne remote sensing analyses provide an alternative and independent approach for estimating cropland area in China. In this study, we report estimates of cropland area from the National Land Cover Dataset (NLCD-96) at the 1:100,000 scale, which was generated by a multi-year National Land Cover Project in China through visual interpretation and digitization of Landsat TM images acquired mostly in 1995 and 1996. We compared the NLCD-96 dataset to another land cover dataset at 1-km spatial resolution (the IGBP DIScover dataset version 2.0), which was generated from monthly Advanced Very High Resolution Radiometer (AVHRR)-derived Normalized Difference Vegetation Index (NDVI) from April, 1992 to March, 1993. The data comparison highlighted the limitation and uncertainty of cropland area estimates from the DIScover dataset.
Spinning-wing decoys are strong attractants to ducks and increase kill rates over traditional decoying methods. However, it is unknown whether all duck species are attracted similarly to ...spinning-wing decoys and whether the effectiveness of these decoys changes with latitude. We examined the effectiveness of spinning-wing decoys for 9 species of dabbling ducks during 545 experimental hunts in California (1999–2000), Minnesota (2002), Manitoba (2001–2002), Nebraska (2000–2002), Missouri (2000–2001), and Arkansas (2001–2003). During each experimental hunt, we systematically alternated between 2 paired decoy treatments every 15–30 min (depending on study site): traditional decoys only and traditional decoys with a spinning-wing decoy. Overall, 70.2% (n = 1,925) of dabbling ducks were harvested (shot and retrieved) when spinning-wing decoys were turned on, ranging from 63.6% (n = 187) in Missouri to 76.4% (n = 356) in Minnesota. Effectiveness of spinning-wing decoys increased with latitude of study sites. Proportions of ducks shot when spinning-wing decoys were turned on differed among species, from a low of 50.0% (n = 8) for cinnamon teal (Anas cyanoptera) to a high of 79.0% (n = 119) for American wigeon (A. americana). The probability of being shot when spinning-wing decoys were turned on increased with annual survival rates among species; for example, spinning-wing decoys were more effective for American wigeon and mallard (A. platyrhynchos) than they were for cinnamon teal and American green-winged teal (A. crecca). Effectiveness of spinning-wing decoys did not differ consistently by age or sex of harvested ducks. Our results indicate that the effectiveness of spinning-wing decoys differs among duck species and changes with latitude; thus, consideration of these effects may be warranted when setting harvest regulations and methods of take.
This volume covers issues in the sociology of knowledge, the educational system and policy, professional autonomy, vocational education, educational research and teaching, as well as the nature of ...such disciplines as cultural studies, English, science and the arts. The chapters also directly address the nature of sociology of education itself.The realist position developed in the book challenges two major currents of thought that have for a long time been prominent and influential in sociology and education: postmodernism and progressivism/constructivism. This well-edited collection of papers is provocative and original in that it represents a sustained, collective critique that offers a genuine alternative to these current orthodoxies.
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