Adenovirus pathogenicity in immature ostriches.     

J El-Attrache  P Villegas  B O'Connor  J R Buhr  G N Rowland 《Avian diseases》2001,45(2):442-446

Two group I avian adenoviruses implicated as the possible cause of "fading chick syndrome" in ostriches less than 8 wk of age were isolated in primary chicken embryo liver cells. These viruses were identified by virus neutralization and further characterized by a pathogenicity trial in immature ostriches. The results showed that these isolates were noninfectious in ostrich chicks.  相似文献   

Molecular confinement accelerates deformation of entangled polymers during squeeze flow     

Rowland HD  King WP  Pethica JB  Cross GL 《Science (New York, N.Y.)》2008,322(5902):720-724

The squeezing of polymers in narrow gaps is important for the dynamics of nanostructure fabrication by nanoimprint embossing and the operation of polymer boundary lubricants. We measured stress versus strain behavior while squeezing entangled polystyrene films to large strains. In confined conditions where films were prepared to a thickness less than the size of the bulk macromolecule, resistance to deformation was markedly reduced for both solid-glass forging and liquid-melt molding. For melt flow, we further observed a complete inversion of conventional polymer viscosity scaling with molecular weight. Our results show that squeeze flow is accelerated at small scales by an unexpected influence of film thickness in polymer materials.  相似文献   

Continuing worldwide increase in tropospheric methane, 1978 to 1987   总被引：1，自引：0，他引：1  

Blake DR  Rowland FS 《Science (New York, N.Y.)》1988,239(4844):1129-1131

The average worldwide tropospheric mixing ratio of methane has increased by 11% from 1.52 parts per million by volume (ppmv) in January 1978 to 1.684 ppmv in September 1987, for an increment of 0.016 +/- 0.001 ppmv per year. Within the limits of our measurements, the global tropospheric mixing ratio for methane over the past decade is consistent either with a linear growth rate of 0.016 +/- 0.001 ppmv per year or with a slight lessening of the rate of growth over the past 5 years. No indications were found of an effect of the El Ni?o-Southern Oscillation-El Chichon events of 1982-83 on total global methane, although severe reductions were reported in the Pacific Northwest during that time period. The growth in tropospheric methane may have increased the water concentration in the stratosphere by as much as 28% since the 1940s and 45% over the past two centuries and thus could have increased the mass of precipitable water available for formation of polar stratospheric clouds.  相似文献   

Mercury concentrations in museum specimens of tuna and swordfish   总被引：1，自引：0，他引：1  

G E Miller  P M Grant  R Kishore  F J Steinkruger  F S Rowland  V P Guinn 《Science (New York, N.Y.)》1972,175(26):1121-1122

The mercury levels of museum specimens of seven tuna caught 62 to 93 years ago and a swordfish caught 25 years ago have been determined by instrumental neutron activation analysis. These levels are in the same range as those found in specimens caught recently.  相似文献   

A comparison of genetic relationship measures in strawberry (Fragaria × ananassa Duch.) based on AFLPs, RAPDs, and pedigree data     

Chemda Degani  Lisa J. Rowland  James A. Saunders  Stan C. Hokanson  Elizabeth L. Ogden  Avi Golan-Goldhirsh  Gene J. Galletta 《Euphytica》2001,117(1):1-12

Nineteen of the major strawberry (Fragaria × ananassa Duch.) cultivars grown in the UnitedStates and Canada were examined for AFLP markerpolymorphisms. For the AFLP reactions, the EcoRI-ACC primer was used in combination with fourMseI primers (MseI-CAC, MseI-CAG,MseI-CAT, or MseI-CTT). Each set ofprimers produced 46–66 scorable fragments ranging insize between 50 and 500 bp. The polymorphic fragmentsproduced from each set of primers were more thansufficient to distinguish among all the cultivars,demonstrating the usefulness of AFLP markers forcultivar identification. Similarity coefficients werecalculated based on data from 228 AFLP markers anddata from 15 previously characterized RAPD markers. The RAPD markers had been specifically selected forfingerprinting purposes because they succesfullydistinguish 41 strawberry cultivars, including the 19cultivars analyzed in this study. Separatedendrograms were constructed based on analysis of theAFLP and RAPD marker data using a neighbor-joiningalgorithm. The dendrograms were compared and found tobe very different. Correlations between similaritycoefficients calculated from AFLP marker data,similarity coefficients calculated from RAPD markerdata, and coefficients of coancestry calculated frompedigree information were evaluated. Interestingly,a better correlation with the coefficients ofcoancestry was observed with the RAPD marker data thanwith the AFLP marker data.  相似文献   

The application of chemical mutagenesis and biotechnology to the modification of linseed (Linum usitatissimum L.)     

G. G. Rowland  A. McHughen  L. V. Gusta  R. S. Bhatty  S. L. MacKenzie  D. C. Taylor 《Euphytica》1955,85(1-3):317-321

Summary In the early 1980s the phenomenon of somaclonal variation induced by cell culture was exploited to produce genetic variation in linseed. The linseed variety Andro, derived from the widely grown Canadian variety McGregor, was selected in saline culture and was released for production in Canada. Andro possesses traits very different from its parent, such as increased seedling vigour and tolerance to heat stress. Additional stable somaclonal variation in characters such as yield, days to maturity, seed weight and oil content were subsequently induced in McGregor. However, despite extensive screening of the somaclonal variants, no significant variation in the fatty acid profile was found.Chemical mutagenesis using ethyl methanesulphonate was, however, succesful in modifying the fatty acid profile of McGregor. Initial screening of M₂ seed by the thiobarbituric acid colourimetric procedure was followed by gas chromatography to select half-seeds with atypical fatty acid profiles. Two independent, partially dominant genes were identified that were responsible for reducing the linolenic acid (18 : 3) from 50% to 2% while increasing linoleic acid (18 : 2) to 70%. A single, partially dominant gene, inherited independently of the linolenic acid genes, increased palmitic acid (16 : 0) from 7% to 30% and palmitoleic acid (16 : 1) from trace amounts to 4%. Agrobacterium-mediated transformation of linseed has also been successful. Herbicide tolerance genes for glyphosate, sulfonylurea and phosphinothricin have been incorporated into Canadian varieties. Commercially useful levels of tolerance to sulfonylurea herbicides have been achieved with no adverse agronomic affect. It is expected that a transgenic variety containing this resistance will be registered for commercial production in Canada in 1994.Standard breeding techniques, the application of antisense technology and the overexpression of fatty acid synthesis genes are being used to further modify the fatty acid profile of linseed, as well as for the transfer of abiotic stress-related genes identified in bromegrass.  相似文献   

Requests clarification on study of surgical removal of mast cell tumors     

Rowland P 《Journal of the American Veterinary Medical Association》2011,239(3):297; author reply 297

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Fibrosing myopathy of the temporal muscles causing lockjaw in a veiled chameleon (Chamaeleo calyptratus)     

Rowland MN 《The Veterinary record》2011,169(20):527

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Use of a deslorelin implant to control aggression in a male bearded dragon (Pogona vitticeps)     

Rowland MN 《The Veterinary record》2011,169(5):127

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Multidrug-resistant extraintestinal pathogenic Escherichia coli of sequence type ST131 in animals and foods     

Platell JL  Johnson JR  Cobbold RN  Trott DJ 《Veterinary microbiology》2011,153(1-2):99-108

Multidrug-resistant Escherichia coli sequence type 131 (ST131) has recently emerged as a globally distributed cause of extraintestinal infections in humans. Diverse factors have been investigated as explanations for ST131's rapid and successful dissemination, including transmission through animal contact and consumption of food, as suggested by the detection of ST131 in a number of nonhuman species. For example, ST131 has recently been identified as a cause of clinical infection in companion animals and poultry, and both host groups have been confirmed as faecal carriers of ST131. Moreover, a high degree of similarity has been shown among certain ST131 isolates from humans, companion animals, and poultry based on resistance characteristics and genomic background and human and companion animal ST131 isolates tend to exhibit similar virulence genotypes. However, most ST131 isolates from poultry appear to possess specific virulence genes that are typically absent from human and companion animal isolates, including genes associated with avian pathogenic E. coli. Since the number of reported animal and food-associated ST131 isolates is quite small, the role of nonhuman host species in the emergence, dissemination, and transmission of ST131 to humans remains unclear. Nevertheless, given the profound public health importance of the emergent ST131 clonal group, even the limited available evidence indicates a pressing need for further careful study of this significant question.  相似文献