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431.
A curve is constructed showing changes in sea level at the Santa Monica shelf over the past 18,000 years. The curve is based on radiocarbon dates, sedimentologic data, and high-resolution seismic stratigraphic analysis of late Quaternary terrace deposits. Sea level was 117 meters below its present position about 18,000 years ago. During the first 8000 years of the Flandrian transgression, sea level rose to at least 24 meters, fell to about 46 meters, and then rose to 20 meters, all below present sea level. Subsequently, sea level rose more slowly and without discernible interruption to its present position. 相似文献
432.
Internal solitons in the andaman sea 总被引:6,自引:0,他引:6
The solitary wave is a localized hydrodynamic phenomenon that can occur because of a balance between nonlinear cohesive and linear dispersive forces in a fluid. It has been shown theoretically, and observed experimentally, that some solitary waves have properties analogous to those of elementary particles, and the waves have therefore been named solitons. During a measurement program in the Andaman Sea near northern Sumatra, large-amplitude, long internal waves were observed with associated surface waves called tide rips. Using theoretical results from the physics of nonlinear waves, it is shown that the internal waves are solitons and their interactions with surface waves are described. 相似文献
433.
The single-kernel characterisation system (SKCS) 4100 instrument has previously been shown to provide in situ measurements of the rheological properties of the bran and endosperm layers of wheat, otherwise only possible following their isolation by dissection or machining. The current study has confirmed that endosperm maximum stress (endosperm strength (ES) as measured using the SKCS 4100 correlates highly (r=0.898) with compressive strength (maximum stress, σmax) measurements performed on specimens of endosperm tissues of known dimensions, isolated from different subsamples of the same bulk wheat samples. This provides a means of scaling the stress axis of the crush–response profile plots to the Instron scale (MPa) so that the SKCS endosperm stress/strain curves for hard wheat, soft wheat and durum can be compared with Instron results presented in the literature. In addition, a simple method for the measurement of ES and stiffness, using the SKCS 4100, has been developed. The method has been shown to rank wheat samples according to their performance when processed on a 650 kg/h pilot mill. The criterion against which the SKCS-derived rankings were compared was the Milling Quality Index, which uses both the percentage flour extraction and Branscan speck count measurements. 相似文献
434.
Compositional,functional and storage properties of flours from raw and heat processed African breadfruit (Treculia africana Decne) seeds 总被引:1,自引:0,他引:1
Giami SY Adindu MN Akusu MO Emelike JN 《Plant foods for human nutrition (Dordrecht, Netherlands)》2000,55(4):357-368
African breadfruit (Treculia africana Decne) seeds were either boiled or roasted and then milled into flour. Chemical composition, functional properties and storage characteristics of raw and treated flours and the effect of partial proteolysis on selected functional properties of the raw flour were determined. Raw flour contained 20.1% crude protein, 2.5% total ash and 13.7% fat. Heat processing significantly (p<0.05) improved in vitro protein digestibility, and water and fat absorption capacities but decreased bulk density, nitrogen solubility, emulsion and foaming properties, trypsin inhibitor, and phytic acid and polyphenol contents of the samples. Boiling proved more effective than roasting for improving protein digestibility, emulsion capacity and foam stability and reducing antinutritional factor levels. Partial proteolysis increased nitrogen solubility, bulk density and water and fat absorption capacities but decreased foam capacity at hydrolysis levels greater than 35%. Fatty acid and peroxide values of the samples increased during storage. Compared to raw samples, heat processed samples had significantly (p<0.05) lower and more acceptable peroxide values and free fatty acid contents and higher and more stable water (3.0 g/g sample) and fat (2.4 g/g sample) absorption capacities. 相似文献
435.
Burrows DN Romano P Falcone A Kobayashi S Zhang B Moretti A O'brien PT Goad MR Campana S Page KL Angelini L Barthelmy S Beardmore AP Capalbi M Chincarini G Cummings J Cusumano G Fox D Giommi P Hill JE Kennea JA Krimm H Mangano V Marshall F Mészáros P Morris DC Nousek JA Osborne JP Pagani C Perri M Tagliaferri G Wells AA Woosley S Gehrels N 《Science (New York, N.Y.)》2005,309(5742):1833-1835
Gamma-ray burst (GRB) afterglows have provided important clues to the nature of these massive explosive events, providing direct information on the nearby environment and indirect information on the central engine that powers the burst. We report the discovery of two bright x-ray flares in GRB afterglows, including a giant flare comparable in total energy to the burst itself, each peaking minutes after the burst. These strong, rapid x-ray flares imply that the central engines of the bursts have long periods of activity, with strong internal shocks continuing for hundreds of seconds after the gamma-ray emission has ended. 相似文献
436.
Osborne TB 《Science (New York, N.Y.)》1913,37(944):185-191
437.
438.
Ralph C. Weichselbaum DVM Daniel A. Feeney DVM MS Carl R. Jessen DVM PhD Carl A. Osborne DVM PhD J. Holte PHD 《Veterinary radiology & ultrasound》2001,42(4):311-319
Research involved 2 databases. One database (occurrence frequency) comprised the age, breed, gender and urocystolith mineral type (pure chemical types only) from 2041 canine patients submitted to the Minnesota Urolith Center. The other database (imaging) comprised the maximum size, surface (rough, smooth, and smooth with blunt tips), shape (faceted, irregular, jackstone, ovoid, and round) and internal architecture (lucent center, random-nonuniform, and uniform) from 434 canine patients imaged in a urinary bladder phantom. The imaging database was a partial subset of the occurrence frequency database. Imaging techniques simulated were survey radiography and double contrast cystography. The databases were compared using multivariate analysis techniques. Equations were developed to use clinically-relevant characteristics (age, breed, gender, maximum size, surface, shape, and internal architecture) to predict urocystolith mineral types. The goal was to assess the accuracy of the various techniques in predicting the urocystolith mineral types. The combination of signalment (age, breed, gender) and simulated survey radiographic findings does not improve mineral type prediction accuracy (average across all mineral types is 69.9%) beyond that achievable with signalment alone (average across all mineral types is 69.8%). However, the combination of signalment and double contrast cystography does improve mineral type prediction accuracy (average across all mineral types is 75.3%). For comparison, mineral type prediction accuracy without signalment from survey radiographs only was 65.7% across all mineral types. The clinical utility of the algorithm is the option to distinguish urocystolith mineral types requiring surgical vs. medical treatment. 相似文献
439.
Rapid predictions of cold tolerance in Douglas-fir seedlings using chlorophyll fluorescence after freezing 总被引:3,自引:0,他引:3
Chlorophyll fluorescence measurements were performed on the foliage of 3-year-old (11/2+11/2) nursery-grown Douglas-fir [Pseudotsuga menziesii (Mirb.) Franco] seedlings after exposure to controlled freezing temperatures, in the laboratory, to assess low temperature tolerance. The seedlings were propagated in an Irish nursery and lifted at monthly intervals overwinter 1999 and 1999–2000. Excised shoots from first-order laterals were frozen, in the dark. After freezing, needles were immediately assessed using chlorophyll fluorescence. The excised shoots were then maintained under controlled conditions for 14 days and visually assessed for needle damage. The chlorophyll fluorescence parameter, F
v/F
m, accurately predicted cold hardiness and was linearly related to visual needle damage and short-term survival. An equation was constructed using F
v/F
m data for determining the LT50, that is, the freeze temperature causing 50% seedling damage. The predictions of F.LT50 (fluorescence-based empirical determination of LT50) have been tested over two seasons (i.e., against a second independent data set) with variability between 0 and 1.8°C of visual estimates, though predictions were often 1.1°C of the visual assessment. This approach provided a simple, rapid and accurate prediction of cold tolerance, under climatic conditions where in situ measurements are unreliable. The method can be used to predict if Douglas-fir seedlings have developed sufficient tolerance for lifting to the cold-store, or for planting. 相似文献
440.
Wells RJ Gionfriddo JR Hackett TB Radecki SV 《Journal of the American Veterinary Medical Association》2007,231(2):251-253
OBJECTIVE: To determine the frequency of canine and feline emergency visits with respect to the lunar cycle. DESIGN: Retrospective case series. ANIMALS: 11,940 dogs and cats evaluated on an emergency basis during an 11-year period. PROCEDURES: Date of emergency visit, signalment, and chief complaint were retrieved from a medical records database. Emergency type was categorized as animal bite, cardiac arrest, epilepsy, ophthalmic, gastric dilatation-volvulus, trauma, multiple diseases, neoplasia, or toxicosis. The corresponding lunar phase was calculated and recorded as new moon, waxing crescent, first quarter, waxing gibbous, full moon, waning gibbous, last quarter, or waning crescent. The effect of lunar phase on the frequency of emergency visits was evaluated by calculating relative risk. RESULTS: Of 11,940 cases, 9,407 were canine and 2,533 were feline. Relative risk calculations identified a significant increase in emergencies for dogs and cats on fuller moon days (waxing gibbous to waning gibbous), compared with all other days. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggested that more emergency room visits occurred on fuller moon days for dogs and cats. It is unlikely that an attending clinician would notice the fractional increase in visits (0.59 and 0.13 more canine and feline visits, respectively) observed in this study at a facility with a low caseload. If the study is repeated at a facility with a robust emergency caseload, these results may lead to reorganization of staffing on fuller moon dates. A prospective study evaluating these findings under conditions of high caseload is necessary to determine the clinical relevance. 相似文献