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1.
S.K. Weldon D.A. Mosier K.R. Simons R.C. Craven A.W. Confer 《Veterinary microbiology》1994,40(3-4):283-291
To identify antigens which may be important for stimulating immunity to pneumonic pasteurellosis, a bovine antiserum to whole P. haemolytica was used to screen a recombinant lambda gt11/P. haemolytica expression library. One of the recombinant bacteriophage clones identified with the bovine antiserum, SW20C, expressed a fusion protein which was also recognized by rabbit antiserum to partially purified P. haemolytica culture supernatant and was found to be immunogenic in guinea pigs. The guinea pig antibody recognized a 100 kDa protein in P. haemolytica cell lysates. Sequence analysis of the cloned DNA from SW20C identified a fragment of 1443 bp with a small open reading frame that was contiguous with the lacZ sequence. The 153 bp P. haemolytica-specific open reading frame encoded a polypeptide of approximately 6kDa. Homology searches of Genbank and the EMBL data bases revealed no homology of this open reading frame with any other bacterial sequences including P. haemolytica leukotoxin and Ssa1. Evaluation of sera from calves that were scored either susceptible or resistant to experimental pneumonic pasteurellosis demonstrated a significant (P < 0.001) correlation between the intensity of the antibody response to the SW20C antigen and resistance to disease. 相似文献
2.
The earliest fossil record of African anthropoid primates (monkeys and apes) comes from the Jebel Qatrani Formation in the Fayum depression of Egypt. Reevaluation of both geologic and faunal evidence indicates that this formation was deposited in the early part of the Oligocene Epoch, more than 31 million years ago, earlier than previous estimates. The great antiquity of the fossil higher primates from Egypt accords well with their primitive morphology compared with later Old World higher primates. Thus, the anthropoid primates and hystricomorph rodents from Fayum are also considerably older than the earliest higher primates and rodents from South America. 相似文献
3.
Sorghum ergot produces dihydroergosine (DHES) and related alkaloids, which cause hyperthermia in cattle. Proportions of infected panicles (grain heads), leaves and stems were determined in two forage sorghum crops extensively infected 2 to 4 weeks prior to sampling and the panicles were assayed for DHES. Composite samples from each crop, plus a third grain variety crop, were coarsely chopped and half of each sealed in plastic buckets for 6 weeks to simulate ensilation. The worst-infected panicles contained up to 55 mg DHES/kg, but dilution reduced average concentrations of DHES in crops to approximately 1 mg/kg, a relatively safe level for cattle. Ensilation significantly (P = 0.043) reduced mean DHES concentrations from 0.85 to 0.46 mg/kg. 相似文献
4.
Agroforestry Systems - We execute tree ‘domestication’ as a farmer-driven and market-led process, which matches the intraspecific diversity of locally important trees to the needs of... 相似文献
5.
6.
Simons AL Renouf M Hendrich S Murphy PA 《Journal of agricultural and food chemistry》2005,53(10):4258-4263
The relationship between chemical structure and gut microbial degradation rates of 14 flavonoids, flavone, apigenin, chrysin, naringenin, kaempferol, genistein, daidzein, daidzin, puerarin, 7,4'-dihydroxyflavone, 6,4'-dihydroxyflavone, 5,4'-dihydroxyflavone, 5,3'-dihydroxyflavone, and 4'-hydroxyflavone, was investigated by anaerobically fermenting the flavonoids with human gut microflora (n = 11 subjects). Degradation rates for the 5,7,4'-trihydroxyl flavonoids, apigenin, genistein, naringenin, and kaempferol, were significantly faster than the other structural motifs. Puerarin was resistant to degradation by the gut microflora. Extensive degradation of flavonoids by gut microflora may result in lower overall bioavailability than those flavonoids that are slowly degraded because rapidly degrading flavonoids are less likely to be absorbed intact. 相似文献
7.
Katja Kehlenbeck Roeland Kindt Fergus L. Sinclair Anthony J. Simons Ramni Jamnadass 《Agroforestry Systems》2011,83(2):133-147
Agroforestry systems are potentially suitable for conservation of tree genetic resources. Farmers around Mt. Kenya usually
integrate trees into their farm. Large parts of these trees seem to be of exotic origin, whereas indigenous species have priority
for conservation. This study aimed at determining on-farm richness, composition and frequency of indigenous and exotic woody
species around Mount Kenya to assess the suitability of farms for the conservation of indigenous tree species. 265 on-farm
plots of 0.5 ha size each were selected in 18 different agro-ecological zones by using a stratified sampling scheme. All woody
species within the plot were recorded with their local and scientific names. Total species richness was 424 (including 306
indigenous ones), mean richness per plot 16.5 species (including 8.8 indigenous ones). Eight out of the 10 most frequent species
were exotic ones with Grevillea robusta from Australia ranking first (found on almost 76% of the surveyed farms). The proportion of indigenous species increased
with increasing aridity and temperature. Dominance of exotic species was found at farms of humid mid- and highlands. Ordination
analysis revealed that mostly exotic species contributed to separation of farms in the highlands and upper midlands, whereas
indigenous species in the lower midlands and lowlands. As the frequencies of most indigenous trees were low, only parts of
the surveyed farms can contribute to conservation of tree genetic resources, particularly the less intensively managed farms
of the more arid lands. Farmers’ access to knowledge on valuable indigenous tree species and to quality seedlings of these
trees need to be improved to increase indigenous species’ frequencies on farms and possibly to replace some of the exotic
species in the future. 相似文献
8.
Trajkovic K Hsu C Chiantia S Rajendran L Wenzel D Wieland F Schwille P Brügger B Simons M 《Science (New York, N.Y.)》2008,319(5867):1244-1247
Intraluminal vesicles of multivesicular endosomes are either sorted for cargo degradation into lysosomes or secreted as exosomes into the extracellular milieu. The mechanisms underlying the sorting of membrane into the different populations of intraluminal vesicles are unknown. Here, we find that cargo is segregated into distinct subdomains on the endosomal membrane and that the transfer of exosome-associated domains into the lumen of the endosome did not depend on the function of the ESCRT (endosomal sorting complex required for transport) machinery, but required the sphingolipid ceramide. Purified exosomes were enriched in ceramide, and the release of exosomes was reduced after the inhibition of neutral sphingomyelinases. These results establish a pathway in intraendosomal membrane transport and exosome formation. 相似文献
9.
Gilbert SJ Dumontheil I Simons JS Frith CD Burgess PW 《Science (New York, N.Y.)》2007,317(5834):43; author reply 43
Mason et al. (Reports, 19 January 2007, p. 393) attributed activity in certain regions of the "resting" brain to the occurrence of mind-wandering. However, previous research has demonstrated the difficulty of distinguishing this type of stimulus-independent thought from stimulus-oriented thought (e.g., watchfulness). Consideration of both possibilities is required to resolve this ambiguity. 相似文献
10.
Fialko Y Sandwell D Agnew D Simons M Shearer P Minster B 《Science (New York, N.Y.)》2002,297(5588):1858-1862
Interferometric Synthetic Aperture Radar observations of surface deformation due to the 1999 Hector Mine earthquake reveal motion on several nearby faults of the eastern California shear zone. We document both vertical and horizontal displacements of several millimeters to several centimeters across kilometer-wide zones centered on pre-existing faults. Portions of some faults experienced retrograde (that is, opposite to their long-term geologic slip) motion during or shortly after the earthquake. The observed deformation likely represents elastic response of compliant fault zones to the permanent co-seismic stress changes. The induced fault displacements imply decreases in the effective shear modulus within the kilometer-wide fault zones, indicating that the latter are mechanically distinct from the ambient crustal rocks. 相似文献