Synthesis and fungicidal activity of tubulin polymerisation promoters. Part 1: pyrido[2,3‐b]pyrazines     

Patrick J Crowley  Dr Clemens Lamberth  Urs Müller  Sebastian Wendeborn  Kurt Nebel  John Williams  Olivia‐A Sageot  Neil Carter  Tanya Mathie  Hans‐Joachim Kempf  Jeremy Godwin  Peter Schneiter  Markus R Dobler 《Pest management science》2010,66(2):178-185

BACKGROUND: The excellent fungicidal activity of [1,2,4]triazolo[1,5‐a]pyrimidines suggested the search for further analogues with improved properties. RESULTS: A series of novel trisubstituted pyrido[2,3‐b]pyrazines has been designed and prepared as 6,6‐biheterocyclic analogues of related 5,6‐bicyclic [1,2,4]triazolo[1,5‐a]pyrimidines. Their fungicidal activity was evaluated against the plant pathogens Puccinia recondita Rob. ex Desm. f. sp. tritici (Eriks.) CO Johnston (wheat brown rust), Mycosphaerella graminicola (Fuckel) Schroter (Septoria tritici Rob., leaf spot of wheat) and Magnaporthe grisea (Hebert) Barr (Pyricularia oryzae Cav., rice blast). Structure–activity relationship studies revealed the advantage of a fluoro substituent in position 6 and of a secondary amine in position 8. CONCLUSION: 8‐Amino‐7‐aryl‐6‐halogen‐substituted pyrido[2,3‐b]pyrazines have been prepared as 6,6‐biheterocyclic analogues of similarly substituted triazolopyrimidine fungicides. A concise four‐step synthesis route has been worked out to prepare these novel compounds from commercially available starting materials. [(R)‐(1,2‐Dimethylpropyl)]‐[6‐fluoro‐7‐(2,4,6‐trifluorophenyl)pyrido[2,3‐b]pyrazin‐8‐yl]amine showed excellent activity against three economically important phytopathogens. Copyright © 2009 Society of Chemical Industry  相似文献   

Hoof Conformation and Palmar Process Fractures of the Distal Phalanx in Warmblood Foals     

Adrienne S. Bhatnagar  R. Scott Pleasant  John J. Dascanio  Stephanie R. Lewis  A. Grey  Olivia E. Schroeder  Kristine Doyle  Jake Hall  Rebecca K. Splan 《Journal of Equine Veterinary Science》2010

This study evaluated onset and incidence of palmar process fractures in foals and investigated corresponding changes in hoof conformation. Radiographs of 17 warmblood foals were taken at 1 week and at 2, 4, 6, 8, and 12 months of age and examined for evidence of palmar process fractures. Hoof parameters were measured from the radiographs, and comparisons were made between fractured and nonfractured feet. All foals suffered at least one fracture during the study period, with an average age of 3.68 ± 0.20 months at fracture occurrence. Hoof conformation and fracture occurrence were not significantly correlated. Foals consistently demonstrated higher lateral heights in the right foot and higher medial heights in the left foot. Hoof angle increased until 3 months of age and then gradually dropped. Hoof-pastern axis exhibited a broken forward conformation, but approached a more correct conformation by 12 months of age. There was a significant reduction in variation of variables for hoof and pastern angle in both feet, and hoof-pastern axis in the right foot. Hoof conformation does not appear to be a causative factor of palmar process fractures. It is possible that these fractures are a normal part of bone remodeling.  相似文献   

Low-field MRI findings and follow-up of central tarsal bone fractures in four non-racehorses     

Marieke Zimmerman  Michael Schramme  Olivia Eberlé  Bianca Drumond  Joe Carter  Jessica Carter-Arnold  Aurelie Thomas-Cancian  Emilie Ségard-Weisse 《Equine Veterinary Education》2023,35(2):e112-e120

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Effective mydriasis in juvenile loggerhead turtles (Caretta caretta) following topical administration of rocuronium bromide and 10% phenylephrine     

Olivia A. Petritz  Hans D. Westermeyer  Michelle C. Whitehead  Emily F. Christiansen  Kenneth J. Lohmann  Catherine M. F. Lohmann  Gregory A. Lewbart 《Veterinary ophthalmology》2020,23(1):37-43

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Running with the Red Queen: host-parasite coevolution selects for biparental sex     

Morran LT  Schmidt OG  Gelarden IA  Parrish RC  Lively CM 《Science (New York, N.Y.)》2011,333(6039):216-218

Most organisms reproduce through outcrossing, even though it comes with substantial costs. The Red Queen hypothesis proposes that selection from coevolving pathogens facilitates the persistence of outcrossing despite these costs. We used experimental coevolution to test the Red Queen hypothesis and found that coevolution with a bacterial pathogen (Serratia marcescens) resulted in significantly more outcrossing in mixed mating experimental populations of the nematode Caenorhabditis elegans. Furthermore, we found that coevolution with the pathogen rapidly drove obligately selfing populations to extinction, whereas outcrossing populations persisted through reciprocal coevolution. Thus, consistent with the Red Queen hypothesis, coevolving pathogens can select for biparental sex.  相似文献   

Adenosquamous Carcinoma of the Trachea in a Domestic Ferret (Mustela putorius furo)     

Olivia A. Petritz  Natalie Antinoff  Catherine Pfent  Wayne Corapi  Roy R. Pool  Michelle Fabiani  Sue Chen 《Journal of Exotic Pet Medicine》2013,22(3):287-292

A 4-year-old, castrated, male domestic ferret (Mustela putorius furo) was evaluated for a possible upper respiratory tract infection and wheezing for approximately 3 weeks. Supportive care for a suspected upper respiratory tract infection was initiated; however, the patient became progressively more dyspneic over the next 48 hours. A possible tracheal mass was identified upon thoracic radiographic imaging of the ferret. Tracheoscopy and a computed tomography scan of the neck and thorax confirmed the presence of a tracheal mass approximately 3 cm from the larynx obstructing 80% of the tracheal lumen. Rather than pursuing surgical resection, the owners elected humane euthanasia. An adenosquamous carcinoma of the trachea was diagnosed after histologic analysis. This tumor type has been diagnosed in the lungs of ferrets that were experimentally exposed to carcinogens found in cigarette smoke; however, there are no previous reports of this or any other tumor type associated with the ferret trachea. A tracheal mass causing a partial upper airway obstruction should be considered within the differential disease diagnosis list when a ferret is presented with dyspnea.  相似文献