Molecular epidemiology of two fowl cholera outbreaks on a free-range chicken layer farm.     

P Zhang  N Fegan  I Fraser  P Duffy  R E Bowles  A Gordon  P J Ketterer  W Shinwari  P J Blackall 《Journal of veterinary diagnostic investigation》2004,16(5):458-460

Two outbreaks of fowl cholera on a multiage free-range egg farm were investigated. The outbreaks occurred in 1994 and 2002. A total of 22 strains of Pasteurella multocida were available for study, 11 from the 1994 outbreak and 11 from the 2002 outbreak. Lesions typical of acute fowl cholera were seen in the 1994 outbreak, whereas both acute and chronic fowl cholera occurred in the 2002 outbreak. The isolates were examined in an extended phenotypic typing methodology, by a P. multocida-specific polymerase chain reaction (PCR), by the Heddleston somatic serotyping scheme, and by restriction endonuclease analysis (REA) typing using the enzyme HpaII. All 22 strains had the same phenotypic properties, all were confirmed as P. multocida by PCR, all were Heddleston serovar 4, and all had the same REA pattern. The results indicate that these 2 outbreaks were caused by the same clone of P. multocida--despite the 8-year time period between the outbreaks.  相似文献   

Systemic accumulation of novel proteins in the apoplast of the leaves of potato plants following root invasion by the cyst-nematode Globodera rostochiensis     

Kim E. Hammond-Kosack  Howard J. Atkinson  Dianna J. Bowles   《Physiological and Molecular Plant Pathology》1989,35(6)

Systemic changes in gene expression have been analysed in potato plants following root infection with the cyst nematode Globodera rostochiensis. Root invasion by the pathogen induced major changes to occur in the composition of proteins extracted in intercellular fluid from the leaf apoplastic space. The changes involved the disappearance of innate leaf proteins and the accumulation of novel gene products. Analysis by SDS-PAGE indicated that the leaf polypeptides induced on nematode invasion are not cultivar or nematode pathotype-specific. Aspirin treatment of leaves induced a similar pattern to that induced systemically by nematodes, but several gene products were specific for the latter method of induction. In particular, two abundant [¹²⁵I]-Con A binding polypeptides of high M_r accumulated in intercellular fluid only on aspirin treatment. The results are discussed in the context of the role of the extracellular leaf proteins and their modulation by systemic signals.  相似文献   

Measuring Plasma Density of the Magnetosphere: Electron-density and temperature profiles are measured by the incoherent-scatter technique of radar     

Bowles KL 《Science (New York, N.Y.)》1963,139(3553):389-391

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The comparative serum disposition kinetics of subcutaneous administration of doramectin, ivermectin and moxidectin in the Australian Merino sheep     

Barber S  Bowles V  Lespine A  Alvinerie M 《Journal of veterinary pharmacology and therapeutics》2003,26(5):343-348

This study evaluates the comparative serum disposition kinetics of injectable formulations of doramectin (DRM), ivermectin (IVM) and moxidectin (MXD) in Australian Merino sheep. Thirty-six, 2-year-old sheep were allocated by weight into six groups of six animals. Animals in each group received 200 microg/kg of DRM, MXD, IVM or a combination of two of these drugs by subcutaneous (s.c.) injection. Blood was collected at designated intervals (between 1 h and 40 days after treatment) and the serum analysed by high performance liquid chromatography (HPLC) using fluorescence detection. The results indicated that MXD administration produced a significantly higher maximum serum concentration and a more rapid absorption as compared with DRM and IVM. MXD and DRM had a significantly larger area under the concentration vs. time curve (AUC) than IVM, suggesting a more persistent effect for the former two products in sheep. The AUC for DRM was significantly higher when administered alone as compared with that observed when given in combination with MXD or IVM, suggesting preferential elimination of DRM compared with IVM and MXD from concurrent s.c. administration.  相似文献   

COLORATION OF THE RUFFED GROUSE     

Bowles JH 《Science (New York, N.Y.)》1894,23(571):16

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Syndrome of Inappropriate Antidiuretic Hormone in a Bulldog with Aspiration Pneumonia          下载免费PDF全文

K.D. Bowles  B.M. Brainard  K.D. Coleman 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2015,29(3):972-976

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Impact of Endocrine‐Disrupting Chemicals on Reproductive Function in Zebrafish (Danio rerio)          下载免费PDF全文

Y Huang  XL Wang  JW Zhang  KS Wu 《Reproduction in domestic animals》2015,50(1):1-6

The prevalence of endocrine‐disrupting chemicals (EDCs) in the aquatic environment has been associated with the wide detection of alterations in the development and physiology of vertebrates. Zebrafish, as a model species, has been extensively used in toxicological research. In this review, we focus on recent published evidence of the harmful effects of EDCs on reproductive function in zebrafish, including skewed sex ratio, immature gonads, diminished sexual behaviour, decreased sperm count, reduced spawning and fertilization. These impairments mostly result from disruption to sex‐steroid hormones induced by endocrine disruptors. We also discuss other effects of exposure to EDCs. In EDC exposure research, despite incomplete assessments of altered gonad histopathology and sexual behaviour, these present potential effective biomarkers or pathways for evaluating the reproductive function in zebrafish on EDC exposure. To date, the pernicious effects of some EDCs on the reproductive performance in laboratory zebrafish are well understood; however, similar alterations remain for further determination in wild‐type fish and more kinds of EDCs. More studies should be performed under established scientific regulatory criteria to investigate the impact of EDCs on reproduction in zebrafish. Moreover, further research is required to explain the definite mechanism of sexual differentiation, which helps in understanding the shift of sexual phenotype with EDC exposure.  相似文献   

Canopy cover and groundlayer vegetation dynamics in a fire managed eastern sand savanna     

Marlin Bowles  Steven ApfelbaumAlan Haney  Susan LehnhardtTom Post 《Forest Ecology and Management》2011,262(11):1972-1982

Savanna vegetation is characterized by high and variable ground layer species richness regulated by functional group interactions with fire regimes and canopy cover. Frequent fire selects for C4 grasses and prairie forbs in canopy openings and C3 graminoid species and shade-adapted forbs and shrubs in canopy shade. Frequent fire also maximizes heterogeneity in partial canopy cover and species richness across the full canopy gradient. However, few studies have linked fire induced change in tree canopy cover with groundlayer vegetation dynamics in relation to this model. In 1986 and in 2007, we measured canopy cover and sampled groundlayer vegetation in 1 m² plots along 53 transects at the Tefft Savanna, a fire managed 197 ha eastern sand savanna with strong canopy cover and elevation gradients. We analyzed temporal change in canopy cover and groundlayer vegetation, correlating percent change in canopy cover with change in ground layer functional groups. After 20 years of burning at 3 fires/decade, elevation accounted for 62% of the variation in an NMS ordination of groundlayer vegetation. However, canopy cover, which averaged 24-86% in 2007, had a significant secondary effect on the ordination. Five vegetation types classified by TWINSPAN varied significantly in elevation and canopy cover. Woody vegetation comprised 8 of the 12 species with greatest niche breadths, and tended to predominant in woodland or forest, where tree cover averaged 50% or more. Forbs had greater richness in savanna, which averaged less than 30% canopy cover. The C3 sedge Carex pensylvanica was the dominant graminoid species under woodland canopy cover, and was co-dominant with the C4 grasses Andropogon scoparius and Sorghastrum nutans under savanna canopy cover. As in other savannas, N-fixing species sorted across shade and canopy openings, and heterogeneity among transects was maximized at mid-canopy cover. Over time, canopy cover decreased up to 50%, creating more open savanna conditions at mid to high elevations. This decrease was associated with a 20-100 % increase in species richness and was significantly correlated with increasing richness and cover of C4 grasses and summer flowering prairie and woodland forbs. These results support a canopy cover model of fire-maintained savanna vegetation, with greater abundance of C4 grasses and prairie forb species associated with lower canopy cover, greater heterogeneity at mid-canopy cover, and species richness maximized across the light gradient. They also indicate that decreasing canopy cover caused by repeated burning increases species richness and abundance of C4 and prairie forb species.  相似文献   

Temperatures, winds, and composition in the saturnian system     

Flasar FM  Achterberg RK  Conrath BJ  Pearl JC  Bjoraker GL  Jennings DE  Romani PN  Simon-Miller AA  Kunde VG  Nixon CA  Bézard B  Orton GS  Spilker LJ  Spencer JR  Irwin PG  Teanby NA  Owen TC  Brasunas J  Segura ME  Carlson RC  Mamoutkine A  Gierasch PJ  Schinder PJ  Showalter MR  Ferrari C  Barucci A  Courtin R  Coustenis A  Fouchet T  Gautier D  Lellouch E  Marten A  Prangé R  Strobel DF  Calcutt SB  Read PL  Taylor FW  Bowles N  Samuelson RE  Abbas MM  Raulin F  Ade P  Edgington S  Pilorz S  Wallis B  Wishnow EH 《Science (New York, N.Y.)》2005,307(5713):1247-1251

Stratospheric temperatures on Saturn imply a strong decay of the equatorial winds with altitude. If the decrease in winds reported from recent Hubble Space Telescope images is not a temporal change, then the features tracked must have been at least 130 kilometers higher than in earlier studies. Saturn's south polar stratosphere is warmer than predicted from simple radiative models. The C/H ratio on Saturn is seven times solar, twice Jupiter's. Saturn's ring temperatures have radial variations down to the smallest scale resolved (100 kilometers). Diurnal surface temperature variations on Phoebe suggest a more porous regolith than on the jovian satellites.  相似文献   

The coevolution of parochial altruism and war   总被引：1，自引：0，他引：1  

Choi JK  Bowles S 《Science (New York, N.Y.)》2007,318(5850):636-640

Altruism-benefiting fellow group members at a cost to oneself-and parochialism-hostility toward individuals not of one's own ethnic, racial, or other group-are common human behaviors. The intersection of the two-which we term "parochial altruism"-is puzzling from an evolutionary perspective because altruistic or parochial behavior reduces one's payoffs by comparison to what one would gain by eschewing these behaviors. But parochial altruism could have evolved if parochialism promoted intergroup hostilities and the combination of altruism and parochialism contributed to success in these conflicts. Our game-theoretic analysis and agent-based simulations show that under conditions likely to have been experienced by late Pleistocene and early Holocene humans, neither parochialism nor altruism would have been viable singly, but by promoting group conflict, they could have evolved jointly.  相似文献