Neural representations of location composed of spatially periodic bands     

J Krupic  N Burgess  J O'Keefe 《Science (New York, N.Y.)》2012,337(6096):853-857

The mammalian hippocampal formation provides neuronal representations of environmental location, but the underlying mechanisms are poorly understood. Here, we report a class of cells whose spatially periodic firing patterns are composed of plane waves (or bands) drawn from a discrete set of orientations and wavelengths. The majority of cells recorded in parasubicular and medial entorhinal cortices of freely moving rats belonged to this class and included grid cells, an important subset that corresponds to three bands at 60° orientations and has the most stable firing pattern. Occasional changes between hexagonal and nonhexagonal patterns imply a common underlying mechanism. Our results indicate a Fourier-like spatial analysis underlying neuronal representations of location, and suggest that path integration is performed by integrating displacement along a restricted set of directions.  相似文献   

Causes of morbidity and mortality of wild aquatic birds at Billabong Sanctuary, Townsville, North Queensland, Australia     

Hoque MA  Burgess GW  Greenhil AR  Hedlefs R  Skerratt LF 《Avian diseases》2012,56(1):249-256

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Treatment of immune-mediated hemolytic anemia in dogs with cyclophosphamide     

Burgess K  Moore A  Rand W  Cotter SM 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2000,14(4):456-462

A review of 60 cases of immune-mediated hemolytic anemia (IMHA) in the dog was performed in order to characterize the disease and to identify potential prognostic indicators. Dogs ranged in age from 1 to 13 years, with a mean age of 6.5 years. The 2 most commonly affected breeds were Cocker Spaniels and Labrador Retrievers. Fifty-two of the 60 dogs tested (87%) were autoagglutination positive and spherocytes were present in 45 (75%). Forty-one (89%) of 46 patients tested positive for the presence of immunoglobulin on the red blood cell surface (Coombs assay). The most common clinical signs at presentation were lethargy, weakness, pale mucous membranes, icterus, hemoglobinuria, and anorexia. PCV less than 25% was present in 59 (98%) dogs. At the time of presentation, 35 dogs (58%) had a nonregenerative anemia, whereas 25 patients (42%) had a regenerative response. Thrombocytopenia was seen in 41 (68%) dogs. Nine of 34 dogs (26%) had a prolonged prothrombin time, 19 of 34 (56%) had a prolonged activated partial thromboplastin clotting time, and 12 of 34 (35%) had abnormal fibrinogen concentrations. All dogs received prednisone at immunosuppressive doses (2.2-4.4 mg/kg PO as a single or divided dose every 24 hours) and cyclophosphamide as primary therapy. Forty-one dogs (63%) received cyclophosphamide at 50 mg/m2 q24h for 4 days, whereas 9 dogs (15%) received an initial high dose (200 mg/m2) followed by 3 days of a lower dose (50 mg/m2 q24h). No statistical difference in survival times was found for either protocol. Thirteen dogs were treated with azathioprine in addition to cyclophosphamide and prednisone. The median survival time of dogs that received all 3 drugs was 370 days as compared to 9 days for those dogs that were treated with cyclophosphamide and prednisone alone. Thirty-one (52%) dogs died from the disease, 13 (22%) dogs were alive, and 15 (25%) dogs were lost to follow-up. The median length of survival for all dogs was 21 days. Eight dogs that were discharged from the hospital suffered a relapse (PCV < 25%).  相似文献   

Epithelial surface changes and spermatozoa storage in the reproductive tract of the bitch     

G.C.W. England  C.M. Burgess  A.L. Clutterbuck  S.L. Freeman 《Veterinary journal (London, England : 1997)》2013,195(2):185-191

Spermatozoa are known to bind to the epithelial cells lining the uterine tube in various species, but information in canids is conflicting and sparse. The first aim of this study was to measure the epithelial surface outline (ESO) of different regions of the canine uterine tube in the four stages of the oestrous cycle as an indicator of a changing potential reservoir for spermatozoa. The second aim was to identify the site of sperm storage in the bitch after natural mating. Reproductive tracts were collected from bitches undergoing routine ovariohysterectomy.Histological analysis showed that, when corrected for uterine tube size, the ESO of pro-oestrus (P < 0.005) and oestrus (P < 0.05) tubes were larger than anoestrus, but not metoestrus, tubes. The second study examined reproductive tracts from 12 Beagle bitches at 6, 12, 24 and 48 h after mating. Light and electron microscopy revealed large numbers of spermatozoa in the proximal regions of the uterus and particularly the distal utero-tubal junction (UTJ), with few present in the proximal UTJ or uterine tubes. Spermatozoa were bound by their heads to microvilli on the epithelial surface of the uterine lumen and to ciliated cells in the distal UTJ. This is the first report to measure and document differences in potential epithelial attachment sites of the uterine tubes at different stages of the oestrous cycle and to provide compelling evidence that the main spermatozoal storage site in the reproductive tract of the bitch is the distal UTJ.  相似文献   

A limited serological survey of North Island cattle for antibody to a number of endemic viruses     

P.J.K. Durham  G.W. Burgess 《New Zealand veterinary journal》2013,61(5):132-133

Abstract

Extract

Little published data is available on the distribution and prevalence of viral diseases in the New Zealand cattle population. Infectious bovine rhinotracheitis (IBR) virus(4) Abinanti, F. R., Hoelein, A. B., Watson, R.L and Heuber, R. J. 1961. Serological studies of myxovirus para-influenza 3 in cattle and the prevalence of antibodies in bovines. J. Immunol., 86: 505–511.  [Google Scholar] (5) Bakos, K and Dinier, Z. 1960. Identification of a bovine mucosal disease virus isolated in Sweden as myxovirus parainfluenza 3. Nature, 185: 549–550.  [Google Scholar] (7) Dawson, P. S. 1963. The nature of substances present in normal bovine sera inhibiting the activity of parainfluenza 3 virus. J. Comp. Path., 73: 428–436.  [Google Scholar] and bovine virus diarrhoea (BVD) virus (5) Bakos, K and Dinier, Z. 1960. Identification of a bovine mucosal disease virus isolated in Sweden as myxovirus parainfluenza 3. Nature, 185: 549–550.  [Google Scholar] (7) Dawson, P. S. 1963. The nature of substances present in normal bovine sera inhibiting the activity of parainfluenza 3 virus. J. Comp. Path., 73: 428–436.  [Google Scholar] (l0) Dean, R. A. and Burgess, G. W. 1976. A survey of New Zealand cattle sera for antibodies to infectious bovine rhinotracheitis virus. N.Z. vet. J., 24: 198–200. [Taylor &; Francis Online] , [Google Scholar] appear on serological grounds to be widespread. A serological survey by Fastier and Hansen (7) Dawson, P. S. 1963. The nature of substances present in normal bovine sera inhibiting the activity of parainfluenza 3 virus. J. Comp. Path., 73: 428–436.  [Google Scholar] also suggests that parainfluenza type 3 (PI₃) virus is common in the North Island.  相似文献   

Isolation and preliminary characterisation of some bovine enteric viruses     

P.J.K. Durham  G.W. Burgess 《New Zealand veterinary journal》2013,61(9):233-235

Fifty-eight faeces samples from calves and yearling cattle with diarrhoea were subject to a virus cultural study in monkey kidney cells and bovine embryonic kidney and lung cells. The properties of the 6 viruses isolated indicated that 5 were bovine enteroviruses belonging to 2 biologically different groups, and the remaining virus was probably a rotavirus (reo-like virus).  相似文献   

Susceptibility of Eucalyptus grandis and Acacia mearnsii seedlings to five Phytophthora species common in South African plantations     

Tanay Bose  Jolanda Roux  Treena I. Burgess  Christopher Shaw  Michael J. Wingfield 《Forest Pathology》2019,49(6)

Eucalyptus grandis and its hybrids, as well as Acacia mearnsii, are important non‐native trees commonly propagated for forestry purposes in South Africa. In this study, we conducted pathogenicity trials to assess the relative importance of five commonly isolated Phytophthora spp. (Phytophthora alticola, P. cinnamomi, P. frigida, P. multivora and P. nicotianae) from the plantation environment on E. grandis and A. mearnsii seedlings. Overall E. grandis was more susceptible to the tested Phytophthora spp. than A. mearnsii. Phytophthora cinnamomi was the only pathogen that had a significant negative effect on both the host tree species, leading to a reduction in root and shoot weight as well as to death in the case of E. grandis. Phytophthora alticola and P. nicotianae exclusively affected E. grandis and A. mearnsii, respectively. This study updated the current knowledge on the pathogenicity of Phytophthora spp. on two important non‐native commercially propagated tree species from South Africa.  相似文献   

Connecting the public with soil to improve human health     

Eric C. Brevik  Joshua J. Steffan  Jesús Rodrigo‐Comino  Darrell Neubert  Lynn C. Burgess  Artemi Cerd 《European Journal of Soil Science》2019,70(4):898-910

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Effects of conservation tillage drills on soil quality indicators in a wheat–oilseed rape rotation: organic carbon,earthworms and water-stable aggregates     

Michail L. Giannitsopoulos  Paul J. Burgess  R. Jane Rickson 《Soil Use and Management》2020,36(1):139-152

The effects of five conservation tillage drills with crop residue levels covering between 17% and 79% of the soil, and tillage depths ranging from 25 to 200 mm, were examined over 3 years. The tillage systems ranged from a relatively disruptive Farm System to a Low Disruption system, with three intermediate treatments labelled Sumo DTS, Claydon and Mzuri. The study involved field sites on a clay or clay loam soil, where winter wheat and oilseed rape were grown in rotation. In the clay field, the Mzuri and Low Disruption treatments, which produced the highest residue coverage, showed the greatest increase in surface total soil organic carbon (1.1 and 0.48 Mg C ha⁻¹, respectively) between years 1 and 3. The least disruptive tillage system also resulted in the highest density of earthworms (181–228 m⁻²), and the most disruptive system produced the lowest densities (75–98 m⁻²). In the third year, the least disruptive system also showed a higher proportion of water-stable aggregates (29.8%) than the other treatments (22.7%–25.3%). Linear regressions showed positive relationships of both soil organic carbon and earthworm density with surface residue cover, and of the proportion of water-stable aggregates with soil organic carbon.  相似文献   

Validation of a von Willebrand factor antigen enzyme-linked immunosorbent assay and newly developed collagen-binding assay          下载免费PDF全文

Hilary Burgess  Darren Wood 《Canadian journal of veterinary research》2008,72(5):420-427

No single test is comprehensive enough to detect all of the variants of von Willebrand Disease (VWD), making determination of both concentration and function of von Willebrand Factor (VWF) important for an accurate diagnosis. The objective of the study was to validate a newly developed VWF collagen binding assay (VWF:CB) and VWF antigen enzyme-linked immunosorbent assay (ELISA) developed at the Ontario Veterinary College (OVC VWF:Ag). Linearity, sensitivity, and coefficients of variation were determined. The Asserachrom VWF:Ag ELISA was used as the reference assay for this study. Concordance correlation and Bland-Altman plots were used to evaluate agreement between both VWF:Ag assays. The VWF:CB accuracy was assessed by degree of association with the VWF:Ag assays, and the VWF:Ag to VWF:CB ratio. All assays were assessed for their ability to distinguish between VWD negative and VWD positive patients. Linearity, intra-assay coefficients of variation, and inter-assay coefficients of variation were acceptable for both the newly developed VWF:CB (R² = 0.97, average CV = 4.4, and 15, respectively) and OVC VWF:Ag assays (R² = 0.96, average CV = 7.9, and 5.9, respectively). Agreement between the OVC VWF:Ag assay and reference assay was excellent (ρ_c = 0.89), and although differences between assay results precluded interchangeable use of the assays, both successfully distinguished VWD positive and VWD negative dogs (P < 0.0001). The VWF:CB showed a strong association with both VWF:Ag assays (R² = 0.86, 0.82) and VWF:Ag to VWF:CB ratios (≤ 1) were as expected. The excellent performance of both assays in this validation study confirm their reliability and potential for clinical application.  相似文献