Identification of unique DNA sequences present in highly virulent 2009 Alabama isolates of Aeromonas hydrophila     

Pridgeon JW  Klesius PH  Mu X  Carter D  Fleming K  Xu D  Srivastava K  Reddy G 《Veterinary microbiology》2011,152(1-2):117-125

In 2009, a disease outbreak caused by Aeromonas hydrophila occurred in 48 catfish farms in West Alabama, causing an estimated loss of more than 3 million pounds of food size channel catfish. Virulence studies have revealed that the 2009 isolates of A. hydrophila are at least 200-fold more virulent than a 1998 Alabama isolate AL98-C1B. However, up to now, no molecular markers have been identified to differentiate the highly virulent 2009 isolates from other isolates of A. hydrophila. To understand the genetic differences between the highly virulent 2009 isolates and the less virulent AL98-C1B at molecular level, PCR-select bacterial genome subtractive hybridization was used in this study. A total of 96 clones were selected from the subtractive genomic DNA library. Sequencing results revealed that the 96 clones represented 64 unique A. hydrophila sequences. Of the 64 sequences, three (hypothetical protein XAUC_13870, structural toxin protein RtxA, and putative methyltransferase) were confirmed to be present in the three virulent 2009 Alabama isolates but absent in the less virulent AL98-C1B. Using genomic DNAs from nine field isolates of A. hydrophila with different virulence as templates, two sequences (hypothetical protein XAUC_13870 and putative methyltransferase) were found to be only present in highly virulent A. hydrophila isolates, but absent in avirulent isolates.  相似文献   

Nitrogen and phosphorus availability from liquid dairy manure to potatoes     

Meghan A. Curless  Keith A. Kelling  Phillip E. Speth 《American Journal of Potato Research》2005,82(4):287-297

The effective use of manure nutrients requires an accurate assessment of their availability to the specific crops being grown. A fertilizer equivalence approach was used to evaluate the availability of nitrogen (N) and phosphorus (P) from liquid dairy manure to potatoes in field experiments conducted in northeast Wisconsin in 2000, 2001, and 2002. Crop responses to moderate and high rates of liquid dairy manure (93,500 and 187,000 L ha^?1) were compared to results obtained from N or P fertilizer applied at five rates (0 to 269 kg ha^?1). Availability estimates were made using the fertilizer equivalence method based on tuber yield, harvested tuber N or P concentration and uptake, petiole nitrate or total P concentration, and soil nitrate or extractable P phosphate levels. Results showed an apparent availability of manurial N from 10% to 40%, with an overall average across all 3 years and all parameters of 28.6% for the lower rate and 24.6% for the high rate. These values are slightly less than average availability measured where corn has been used as the test crop. Although all parameters did not show responses to P fertilizer additions in these trials, where estimates were possible, P availability ranged from 20% to 90% with an overall average across all 3 years of 55.4% for the low and 50.5% for the high manure rates. Despite potato being more shallow-rooted and somewhat less efficient in N and P use compared to corn, it appears that only minor adjustments to manurial nutrient availability estimates are warranted when potatoes are grown.  相似文献   

On inorganic N uptake by vascular plants: Can 15N tracer techniques resolve the NH4+ versus NO3− “preference” conundrum?     

Phillip Chalk  Christopher Smith 《European Journal of Soil Science》2021,72(4):1762-1779

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Crototropone, a new tropone derivative from Croton zehntneri     

Bracher F  Randau KP  Lerche H 《Fitoterapia》2008,79(3):236-237

Crototropone (3-hydroxy-5,6-dimethoxy-2-methylcyclohepta-2,4,6-trien-1-one) was isolated from roots of Croton zehntneri. The structure was established by spectroscopic methods.  相似文献   

Calcium oxalate accumulation and soil weathering in mats of the hypogeous fungus Hysterangium crassum     

Kermit Cromack  Phillip Sollins  William C. Graustein  Karen Speidel  Allen W. Todd  Gody Spycher  Ching Y. Li  Robert L. Todd 《Soil biology & biochemistry》1979,11(5):463-468

Fungal mats of Hysterangium crassum (Tul. and Tul.) Fischer occupied a mean of 9.6% of the upper 10 cm of soil developed under a 40–65 yr old stand of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) in Oregon. This hypogeous basidiomycete exudes large amounts of oxalic acid, some of which precipitates with Ca in microscopic crystals of calcium oxalate, resulting in a mean CaC₂O₄ content of 82g m^?2 for the entire soil. Soil oxalate concentration was significantly greater within fungal mats (P < 0.01) and soil pH was significantly lower (P < 0.01) than in soil adjacent to mats. The quantity of Ca present as CaC₂O₄ is 0.5 the amount of exchangeable Ca in the soil and exceeds the mass of Ca lost annually in runoff. Scanning electron micrographs show intense chemical weathering, attributable to oxalate attack, in the immediate vicinity of hyphae. X-ray diffraction patterns of clay indicate bulk weathering is more intense within the fungal mats than in adjacent uncolonized soil.  相似文献   

Sectional notes     

H. G. Zuckerman  C. H. Metzger  W. B. Ward  C. L. Fitch  Julian C. Miller  Ralph W. Donaldson  A. G. Tolaas  Phillip A. Hoff  Dan O'Brien  E. V. Hardenburg  E. B. Tussing  S. P. Swenson 《American Journal of Potato Research》1936,13(10):291-296

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EFFECTS OF EXPERIMENTAL NERVE ROOT COMPRESSION ON ARTERIAL BLOOD FLOW VELOCITY IN THE SEVENTH LUMBAR SPINAL GANGLION OF THE DOG: MEASUREMENT USING INTRAOPERATIVE DOPPLER ULTRASONOGRAPHY     

Jeryl C.  Jones  DVM  PHD  Judith A.  Hudson  DVM  PhD  Donald C.  Sorjonen  DVM  MS  Charles E.  Hoffman  CVT  BS  LATG  Kyle G.  Braund  BVS  MVS  PhD  James C.  Wright  DVM  MS  PhD  Phillip D.  Garrett  DVM  MS  Jan E.  Bartels  DVM  MS 《Veterinary radiology & ultrasound》1996,37(2):133-140

Intraoperative Doppler ultrasonography was used to measure the effects of four experimental nerve root compression treatments (central compression, central-plus-lateral compression, lateral compression, and compression release) on arterial blood flow velocities in the seventh lumbar spinal ganglion of three dogs. Graphed blood flow velocity changes (change = treatment value − pretreatment value) were below baseline during the first three compression treatments and above baseline following compression release. Mean blood flow velocity changes for both central-plus-lateral compression and lateral compression differed (p ≤ 0.05) from changes for central compression. Changes for central-plus-lateral compression did not differ (p > 0.05) from changes for lateral compression. Changes among the first three compression treatments differed (p ≤ 0.05) from changes for compression release. No histologic abnormalities were identified in compressed nerve tissues, compared to contralateral controls. These findings indicate that stenosis within the L7-S1 intervertebral foramen may cause ischemia of the L7 spinal ganglion in dogs.  相似文献   

A rapid high-pressure liquid chromatographic method for the determination of carbaryl residues in wheat grain     

Phillip A. Hargreaves  Kevin J. Melksham 《Pest management science》1983,14(4):347-353

Carbaryl residues in wheat grain have been determined in methanol extracts using normal-phase high-pressure liquid chromatography (h. p. l. c.) with ultraviolet detection. A single-injection, clean-up and analysis technique was used to allow more rapid analysis of samples after extraction. A detection limit of 0.1 mg kg^?1 in a 50 g sample of wheat was achieved. Recoveries of 86% at the 1 mg kg^?1 level and 90-99% at the 5 mg kg^?1 level were obtained for fortified grain samples. Methanol was found to be a superior extractant for carbaryl from wheat when compared with hexane, acetone and dichloromethane. Twelve samples containing aged carbaryl residues were analysed by the h. p. l. c. technique and by a colorimetric procedure which allowed statistical analysis of errors. For the h. p. l. c. method (excluding sampling error), a relative standard deviation of 4.4% was obtained.  相似文献   

Seroprevalence of bovine brucellosis and associated risk factors in Nakasongola district,Uganda     

Bugeza  James  Muwonge  Adrian  Munyeme  Musso  Lasuba  Phillip  Godfroid  Jacques  Kankya  Clovice 《Tropical animal health and production》2019,51(7):2073-2076

A cross-sectional study was carried out between November 2015 and January 2016 to determine the seroprevalence of Brucella antibodies in cattle raised under communal, fenced farms and tethering systems and the associated factors. Seven hundred twenty-eight bovine sera were collected and tested with rose Bengal test as a screening test and the indirect enzyme-linked immunosorbent assay as a confirmatory test. Animal- and herd-level data were collected and binary logistic regression was used to assess the potential risk factors. True animal- and herd-level prevalence was highest in the fenced farms (4.5% (95%CI, 2.3–6.9) and 19.5% (95%CI, 8.2–32.7) respectively). The risks for natural brucellosis infection were sharing water with wild animals (OR = 0.21, 95%CI, 0.104–0.83), herd size (medium: OR = 0.089, 95%CI 0.017–0.449; large: OR = 0.024, 95%CI 0.003–0.203), fenced farms (OR = 3.7, 95% CI, 1.7–7.9), sex (OR = 0.03, 95%CI, 0.01–0.079), and lactation (OR = 0.013, 95%CI, 0.004–0.049). Changes in rangeland tenure and the shift towards intensive cattle production have influenced brucellosis epidemiology. Future studies should aim at identifying the infecting Brucellae and examining the role of wildlife in brucellosis epidemiology.

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Pet Ownership,Attitude Toward Pets,and Support for Wildlife Management Strategies     

Cameron Z. Shuttlewood  Phillip J. Greenwell 《Human Dimensions of Wildlife》2016,21(2):180-188

Pet ownership affects engagement with animal-related activities and may be related to support of wildlife management. British participants (N = 220) completed an online survey providing information on pet ownership, attitudes toward pets, and support for wildlife management strategies. Within this sample, pet owners and individuals with positive attitudes toward pets were less supportive of strategies that put human needs before the needs of wildlife, more supportive of strategies attempting to avoid species extinctions, and opposed to strategies requiring compromises of individual species. Pet owners’ affectionate attitudes toward animals and opposition to their exploitation may be important in dictating attitudes toward wildlife. Conservation planners could apply these findings when seeking support for management strategies that constrain freedoms of pets and wildlife. Utilizing the sympathetic attitudes of pet owners toward animals by focusing on welfare and survival benefits for wildlife species may help foster support for management strategies.  相似文献