Ages, irradiation history, and chemical composition of lunar rocks from the sea of tranquillity     

Albee AL  Burnett DS  Chodos AA  Eugster OJ  Huneke JC  Papanastassiou DA  Podosek FA  Russ GP  Sanz HG  Tera F  Wasserburg GJ 《Science (New York, N.Y.)》1970,167(3918):463-466

The (87)Rb-(87)Sr internal isochrons for five rocks yield an age of 3.65 +/-0.05 x 10(9) years which presumably dates the formation of the Sea of Tranquillity. Potassium-argon ages are consistent with this result. The soil has a model age of 4.5 x10(9) years, which is best regarded as the time of initial differentiation of the lunar crust. A peculiar rock fragment from the soil gave a model age of 4.44 x 10(9) years. Relative abundances of alkalis do not suggest differential volatilization. The irradiation history of lunar rocks is inferred from isotopic measurements of gadolinium, vanadium, and cosmogenic rare gases. Spallation xenon spectra exhibit a high and variable (131)Xe/(126)Xe ratio. No evidence for (129)I was found. The isotopic composition of solar-wind xenon is distinct from that of the atmosphere and of the average for carbonaceous chondrites, but the krypton composition appears similar to average carbonaceous chondrite krypton.  相似文献   

Three-dimensional structure of the adenovirus major coat protein hexon   总被引：19，自引：0，他引：19  

M M Roberts  J L White  M G Grütter  R M Burnett 《Science (New York, N.Y.)》1986,232(4754):1148-1151

The three-dimensional crystal structure of the adenovirus major coat protein is presented. Adenovirus type 2 hexon, at 967 residues, is now the longest polypeptide whose structure has been determined crystallographically. Taken with our model for hexon packing, which positions the 240 trimeric hexons in the capsid, the structure defines 60% of the protein within the 150 X 10(6) dalton virion. The assembly provides the first details of a DNA-containing animal virus that is 20 times larger than the spherical RNA viruses previously described. Unexpectedly, the hexon subunit contains two similar beta-barrels whose topology is identical to those of the spherical RNA viruses, but whose architectural role in adenovirus is very different. The hexon structure reveals several distinctive features related to its function as a stable protective coat, and shows that the type-specific immunological determinants are restricted to the virion surface.  相似文献   

The genetic basis of scald resistance in western Canadian barley cultivars     

G. A. Penner  A. Tekauz  E. Reimer  G. J. Scoles  B. G. Rossnagel  P. E. Eckstein  W. G. Legge  P. A. Burnett  T. Ferguson  J. F. Helm 《Euphytica》1995,92(3):367-374

Summary The genetic basis of resistance to scald (Rhynchosporium secalis) within barley breeding populations is poorly understood. The design of effective genetically based resistance strategies is predicated on knowledge of the identity of the resistance genes carried by potential parents. The resistance exhibited by a broad selection of western Canadian barley lines was investigated by evaluating their reactions to five R. secalis isolates. Results were compared to the resistance exhibited by previously characterized lines. This comparison, combined with pedigree analysis indicated that there are two different resistance genes present inwwestern Canadian cultivars. These genes were shown to be independent through analysis of a segregating population derived from a cross between Falcon and CDC Silky. This evidence, along with observed linkage of the gene in CDC Silky with an allele specific amplicon developed for a Rhynchosporium secalis resistance locus on chromosome 3, provides evidence that the gene in Falcon is the Rh2 gene derived from Atlas, and the gene (s) in CDC Silky is located within the Rh/Rh3/Rh4 cluster and is similar to the Rh gene in Hudson.  相似文献   

ON THE ENCOURAGEMENT OF MR. CHARLES D. SNYDER     

Loeb J  Robertson TB  Maxwell SS  Burnett TC 《Science (New York, N.Y.)》1908,28(723):645-648

  相似文献   

Isolation of bovine herpesvirus type 5 from the semen of a healthy bull in Australia     

IS Diallo  GR Hewitson  J Hoad  S Turner  BG Corney  BJ Rodwell 《Australian veterinary journal》2010,88(3):93-95

Artificial insemination is widely used in the cattle industry and a major challenge is to ensure that semen is free of infectious agents. A healthy donor bull was tested for freedom from infectious agents. A bovine herpesvirus was isolated in testis cells and identified as bovine herpesvirus type 5 (BoHV-5) by polymerase chain reaction and by direct amplicon sequencing. The amplicon sequence shared 100% similarity with the published sequence of BoHV-5. This is the first report in Australia of BoHV-5 in semen. The implications of this finding are discussed.  相似文献   

Maximising lucerne (Medicago sativa L.) production with fixed‐length recovery intervals after defoliation in mild winter environments     

Stephen Gary Clark  Meredith L. Mitchell  Zhongnan Nie  Vivienne F. Burnett  Kym L. Butler  Reto P. Zollinger  Greg R. Seymour 《Journal of Agronomy and Crop Science》2019,205(1):88-98

Lucerne (Medicago sativa L.) is an important temperate legume for livestock production systems. Lucerne requires a recovery period after a defoliation event so that taproot energy and nutrient stores can be replenished. A field experiment examined the effects of recovery period management following defoliation, on lucerne herbage production and nutritive value at two contrasting sites in Victoria, Australia. Sites were established at Rutherglen and Hamilton, using established SARDI Seven lucerne stands. Treatments were short recovery (SR; plots cut at 21‐day intervals), long recovery (LR; plots cut at 42‐day intervals), new shoots (NS; plots cut when new shoots from the crown were at least 2 cm long) and new shoots + flowering (NSF; as for NS but plots were left to grow to reach late flowering from late summer to mid‐autumn). At each defoliation, measurements were made of phenology, dry matter production and herbage nutrient concentrations (neutral detergent fibre, crude protein, metabolisable energy and water‐soluble carbohydrate %). Persistence was measured at approximately 6‐month intervals. At both sites, lucerne persisted equally well in all treatments although SR showed some decline at Hamilton at the final measurement. LR led to a more productive pasture (in terms of cumulative dry matter, neutral detergent fibre, crude protein, metabolisable energy and water‐soluble carbohydrate %) than the three other treatments. The results indicate that phenological management systems that allow lucerne to replenish reserves through late summer and autumn are unnecessary in mild winter environments.  相似文献   

Effects of the 1B/1R translocation in wheat on composition and properties of grain and flour   总被引：5，自引：0，他引：5  

C. J. Burnett  K. J. Lorenz  B. F. Carver 《Euphytica》1995,86(3):159-166

Summary Near-isoline pairs of 1B-1R translocation lines and their parents were compared for protein, hardness, SDS sedimentation, Falling number, pentosan content and flour yield. Comparisons in mixograph characteristics and dough stickiness were made on the flour. The 1B/1R lines were higher in protein than their 1B near isolines. There were no significant differences in hardness, Falling number and pentosan content. 1B/1R wheats produced statistically significant lower SDS sedimentation values. There were no significant differences in milling performance, mixograph characteristics and dough stickiness.  相似文献   

Determination of morantel-related residues in bovine milk by electron capture gas chromatography     

M J Lynch  D M Burnett  F R Mosher  M E Dimmock  S R Bartolucci 《Journal of the Association of Official Analytical Chemists》1986,69(4):646-651

A gas chromatographic assay was developed to determine major residues of morantel in bovine milk over a range that is suitable for monitoring residues of the drug. The method is based on hydrolysis of the N-methyl-tetrahydropyrimidine portion of morantel and its metabolites to N-methyl-1,3-propanediamine, and converting the diamine to an N,N-bis-(2-nitro-4-trifluoromethylphenyl) derivative. The addition of an internal standard, the N-desmethyl-N-ethyl homolog of pyrantel, to the milk sample circumvents any potential problem that could arise from variable reaction yields, and eliminates the true recovery as a factor affecting the accuracy and precision of the procedure. The concentrations of the derivatives are determined by pulsed electron capture gas chromatography over a linear dynamic range that is equivalent to 12.5-50 ppb morantel. The method was evaluated at the 0, 12.5, 25, and 50 ppb levels in fortified bovine milk, and in a withdrawal sample containing physiologically incurred morantel residues. Mean values of 14 +/- 1.7, 24 +/- 3.7, and 47 +/- 6.9 were found for the fortified samples, approximately 3 ppb for control milk, and 16 +/- 1.7 ppb for the withdrawal sample.  相似文献   

Congenital deafness in animals     

Burnett SM 《Science (New York, N.Y.)》1884,3(57):275-276

  相似文献   

Effects of two pasture systems on faecal nematode egg counts in breeding ewes     

GR SAUL 《Australian veterinary journal》1996,74(2):154-155

  相似文献