742 research outputs found
Final results of space exposed experiment developed for students
SEEDS was a cooperative endeavor of NASA Headquarters, the NASA Langley Research Center, and the George W. Park Seed Company. Approximately 132,000 SEEDS kits containing Rutger's tomato seeds that had flown on LDEF, as well as similar seeds that had been stored in a climate-controlled warehouse for the same time period, were sent to schools in every state and 30 foreign countries. Student researchers from kindergarten through university compared germination and growth characteristics of the space-exposed and Earth-based seeds and returned data to NASA for analysis. Important scientific information was gained as students reported very little difference between the two seed groups
Cisplatin chemotherapy (without erythropoietin) and risk of life-threatening thromboembolic events in carcinoma of the uterine cervix: the tip of the iceberg? A review of the literature
BACKGROUND: The risk of severe cardiovascular toxicity, specifically thromboembolic events (TE), in patients with cervical cancer receiving concurrent irradiation and cisplatin chemotherapy is reported to be less than 1% in several large prospective trials. However, the anecdotal risk appears to be far higher. RESULTS AND DISCUSSION: A review of several prospective trials demonstrates no treatment related grade 4 cardiovascular toxicities and only two grade 5 toxicities in 1424 (0.1%) collective patients. A recent publication and our own unpublished experience finds 6 of 128 (4.7%) patients developed grade 4 to 5 cardiovascular (thrombosis/embolism) toxicity. The differenc in incidence of severe or life threatening cardiovascular toxicity of 0.1 versus 4.7% is highly statistically significant (p < 0.00001.) CONCLUSION: This dramatic difference in incidence of cardiovascular toxicity raises the possibility that cardiovascular toxicities were inadequately reported on the listed prospective trials. For those patients enrolled in prospective trials, we suggest that thromboses should be diligently documented and reported. Only after the true incidence of thromboses is established can we implement appropriate levels of early screening and intervention that may prevent life threatening complications
Effect of Supplementation on Performance and Faecal Particle Size Distribution for Yearling Horses and Weaned Calves Grazing Coastal Bermudagrass
Supplements are often fed, especially to horses, without realistic expectations of the magnitude of performance response nor knowledge of biological or economic efficiencies of supplementation. The objectives of this experiment were to compare performance of weaned calves vs yearling horses grazing \u27Coastal\u27 bermudagrass [Cynodon dactylon (L.) Pers] (COS) pastures with and without a protein-energy supplement, and to assess faecal particle size distribution for both calves and horses to document digesta dynamics
Knot Floer homology detects fibred knots
Ozsv\'ath and Szab\'o conjectured that knot Floer homology detects fibred
knots in . We will prove this conjecture for null-homologous knots in
arbitrary closed 3--manifolds. Namely, if is a knot in a closed 3--manifold
, is irreducible, and is monic, then is fibred.
The proof relies on previous works due to Gabai, Ozsv\'ath--Szab\'o, Ghiggini
and the author. A corollary is that if a knot in admits a lens space
surgery, then the knot is fibred.Comment: version 4: incorporates referee's suggestions, to appear in
Inventiones Mathematica
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Secondary Natural Gas Recovery: Reservoir Heterogeneity and Potential for Reserve Growth through Infield Drilling: An Example from McAllen Ranch Field, Hidalgo County, Texas
Integrated engineering, geological, geophysical, and petrophysical analyses of McAllen Ranch field have delineated several controls on secondary recovery of natural gas. Barriers to the flow of natural gas within laterally continuous lower Vicksburg sandstone reservoirs can be demonstrated through finite-element modeling. These barriers are probably diagenetic in origin. In the B area of McAllen Ranch field, faults are unlikely to be the primary barriers to gas flow because faults were not inferred from analysis of high-quality three-dimensional seismic images between the key wells used in this study (Hill and others, 1991). Barriers result in incremental reserve additions when some reservoir domains contain no well completions. Areas containing potential incremental gas resources, identified through this analysis, were confirmed by subsequent recompletions in 1991. Three recompletions proposed by this project have proved successful. Our analysis of public domain production data indicates that new infield wells in the Vicksburg S reservoir have increased reserves 69 percent above an estimate made from analysis of 1980 public domain data. Additionally, more than 100 barrels per day of reserves has been added through new wells drilled between 1988 and 1991. Most of the McAllen Ranch Vicksburg S reserve increases are due to a geological reinterpretation that has stimulated infield step-out development of the Vicksburg S reservoir. Distributary-channel-fill sandstones are the most likely candidates to contain incremental reserves because they are laterally discontinuous and are predominant in areas where numerous reservoir sandstones are stacked.Bureau of Economic Geolog
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