Population genetic structure and landscape connectivity of the Eastern Yellowbelly Racer (<Emphasis Type="Italic">Coluber constrictor flaviventris</Emphasis>) in the contiguous tallgrass prairie of northeastern Kansas,USA     

Page E. Klug  Samantha M. Wisely  Kimberly A. With 《Landscape Ecology》2011,26(2):281-294

The tallgrass prairie of North America has undergone widespread habitat loss and fragmentation (<4% remains). The Flint Hills region of Kansas and Oklahoma is the largest tallgrass prairie remaining and therefore provides an opportunity to study the population genetic structure of grassland species in a relatively contiguous landscape and set a baseline for evaluating changes when the habitat is fragmented. We adopted a landscape genetics approach to identify how landscape structure affected dispersal, population genetic structure, and landscape connectivity of the Eastern Yellowbelly Racer (Coluber constrictor flaviventris) across a 13,500-km² landscape in northeastern Kansas, USA. The racer population had high allelic diversity, high heterozygosity, and was maintaining migration-drift equilibrium. Autocorrelation between genetic and geographic distance revealed that racers exhibited restricted dispersal within 3 km, and isolation-by-distance. Significant isolation-by-distance occurred at broad regional scales (>100 km), but because of sufficient gene flow between locations, we were unable to define discrete subpopulations using Bayesian clustering analyses. Resistance distance, which considers the permeability of habitats, did not explain significant variation in genetic distance beyond Euclidean distance alone, suggesting that racers are not currently influenced by landscape composition. In northeastern Kansas, racers appear to be an abundant and continuously distributed snake that perceives the landscape as well connected with no cover type currently impeding snake dispersal or gene flow.  相似文献   

Liquid chromatographic determination of seven antioxidants in dry food   总被引：2，自引：0，他引：2  

B D Page  C F Charbonneau 《Journal of the Association of Official Analytical Chemists》1989,72(2):259-265

The liquid chromatographic determinative step of the official method for propyl gallate, trihydroxybutyrophenone, tert-butylhydroquinone, nordihydroguaiaretic acid, butylated hydroxyanisole (BHA), 3,5-di-tert-butyl-4-hydroxymethylphenol, and butylated hydroxytoluene (BHT) in fats and oils has been applied to their determination in a number of dry foods. A representative sample (10 g) is homogenized first with hexane (25 mL), then with 5 mL added water, and finally with 75 mL added acetonitrile. The hexane and acetonitrile are decanted, filtered, and separated; the hexane and rehydrated food are reextracted with 2 additional portions of acetonitrile, and the combined acetonitrile extracts are concentrated and diluted to 10 mL. An aliquot is analyzed as described in the official method, using a 150 x 4.6 mm 5 microns C-18 column. The need for rehydration to maximize the recovery of BHA and other antioxidants from marketplace dry food samples such as potato flakes, dry coffee whiteners, and dessert topping mixes was demonstrated. Rehydration was not required for cheese snacks, breakfast cereals, cake mixes, and some other foods. The need for rehydration should be determined by analyzing other foods with and without the addition of water. Potato and corn chips, popcorn and cheese snacks, breakfast cereals, dry beverage mixes, rice, potato flakes, french fried potatoes, and cake mixes were spiked with the above antioxidants at 10-50 ppm. Overall recoveries ranged from 64.3 to 105.6% and repeatabilities ranged from 0.7 to 10.8%. A total of 109 samples of the above foods were analyzed, and 64% contained detectable (greater than 1-2 ppm) antioxidants, mainly BHA and BHT.  相似文献   

Enzyme-linked immunosorbent assay for screening aflatoxin B1 in cottonseed products and mixed feed: collaborative study     

D L Park  B M Miller  L P Hart  G Yang  J McVey  S W Page  J Pestka  L H Brown 《Journal of the Association of Official Analytical Chemists》1989,72(2):326-332

A joint AOAC/IUPAC (International Union of Pure and Applied Chemistry) interlaboratory study of an enzyme-linked immunosorbent screening assay (ELISA) for aflatoxins was conducted in laboratories in Canada, France, Japan, South Africa, Switzerland, The Netherlands, Tunisia, and the United States. Twenty-eight samples of raw and roasted peanuts, corn, whole cottonseed, cottonseed meal, ammoniated cottonseed meal, and poultry feed containing various quantities of natural aflatoxins and supplemented when appropriate with aflatoxin B1 were distributed to participating laboratories for testing. The assay is based on conjugation of pure aflatoxin B1 to an enzyme and the competition between this conjugate and (free) aflatoxins in the product for aflatoxin-specific antibodies coated onto microtiter well walls. After a wash step to remove all unbound aflatoxins, a substrate, added to each well, is catalyzed from a colorless to a green solution by any bound enzyme-conjugated aflatoxin B1 present. The intensity of the color decreases as the amount of free aflatoxin B1 in the product increases. Overall correlation was good between ELISA and thin-layer chromatographic (TLC) results for cottonseed products and mixed feed. Variable results were reported for corn and peanut product samples. Although some positive samples (greater than 15 ng/g) of cottonseed products and mixed feed were reported to contain less than 15 ng/g by visual determination, a review of data for absorbance measurements showed that the contamination level was close to the greater than or equal to 15 ng/g standard and would not have been reported as negative under routine screening.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

Predictive Capability in Estimating Changes in Water Quality: Long-Term Responses to Atmospheric Deposition     

Page  T.  Beven  K. J.  Whyatt  D. 《Water, air, and soil pollution》2004,151(1-4):215-244

This study reassesses the application of the geochemical model MAGIC in the prediction of long-term changes of water quality in response to changes in atmospheric deposition. It does so within the Monte Carlo based GLUE methodology in which it is possible to evaluate the performance of sets of model parameters in predicting the available observations as a means of constraining the uncertainty in current and future predictions. This work was prompted by previous work which showed that, for a typical upland site in Wales, MAGIC predictions were dominated by the depositional scenario used. Uncertainties in the depositional scenario are taken into account by using estimates of uncertainty for the different depositional sources including European anthropogenic sources as produced by the HARM model. The results show almost no change in predictive uncertainty bounds, in the form of 5th and 95th percentiles of the likelihood-weighted distributions, owing to tight observational data constraints. The implications of this lack of change with respect to predictive capability and possible over-constraint by observed data are discussed.  相似文献   

Difference between influences of homologous and heterologous maternal antibodies on response to serotype-2 and serotype-3 Marek's disease vaccines     

D King  D Page  K A Schat  B W Calnek 《Avian diseases》1981,25(1):74-81

Marek's disease (MD) vaccines representing serotypes 2 (SB-1 strain of MD virus) and 3 (FC-126 strain of turkey herpesvirus) were administered to 1-day-old MD-susceptible chicks that either were free of antibodies or carried maternally derived antibodies against SB-1, FC-126, or a serotype-1 MD virus, CU-2 strain. Homologous antibodies delayed the development of vaccine virus viremias and inhibited vaccinal immunity, as judged by protection against challenge with the virulent JM-10 strain of MD virus 7 days postvaccination. Heterologous antibodies had little effect on vaccine responses. Antibodies were shown to interfere with both cell-associated and cell-free vaccine virus.  相似文献   

Acute tumor lysis syndrome     

R L Page 《Seminars in veterinary medicine and surgery (small animal)》1986,1(1):58-60

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Hepatic encephalopathy associated with hemochromatosis in a toco toucan     

M G Spalding  G V Kollias  M B Mays  C D Page  M G Brown 《Journal of the American Veterinary Medical Association》1986,189(9):1122-1123

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Proliferative glomerulonephritis and chronic active hepatitis with cirrhosis associated with Corynebacterium parvum immunotherapy in a dog   总被引：1，自引：0，他引：1  

C E Leifer  R L Page  R E Matus  A K Patnaik  E G MacEwen 《Journal of the American Veterinary Medical Association》1987,190(1):78-80

Ivermectin, a broad-spectrum antiparasitic agent, was believed responsible for signs of CNS dysfunction in a dog. Within 2 hours of oral administration of ivermectin, the dog had hind limb ataxia. Neurologic signs progressed rapidly until the dog was in a semicomatose state at admission 20 hours later. The dog improved gradually under supportive care. The ivermectin had been given for suspected endoparasitism. Clinical signs were similar to those reported in dogs with clinical and experimental exposure to ivermectin.  相似文献   

Interaction of aflatoxin with Eimeria tenella infection and monensin in young broiler chickens.     

R D Wyatt  M D Ruff  R K Page 《Avian diseases》1975,19(4):730-740

Young broiler chicks inoculated with Eimeria tenella and given a diet containing 2.5 mug aflatoxin/g had significantly higher mortality than birds with aflatoxicosis or coccidiosis alone or uninoculated controls. This effect was seen even when a light coccidial infection alone did not increase mortality or cause weight depression. In addition this higher mortality with the combination began earleir and occurred at a higher rate than did mortality from aflatoxin or cecal coccidiosis alone. Dietary monensin sodium (99 umg/g) did not completely prevent mortality and weight depression when aflatoxin and E. tenella were in combination. Aflatoxin and E. tenella singly significantly depressed three-week body weights; however, the depression was most severe when the two were in combination. Both dietary aflatoxin and E. tenella significantly reduced hemoglobin, packed cell volume, and plasma pigmentation, and in combination resulted in more severely reduced hemoglobin, packed cell volume, and plasma pigmentation. Coccidial lesion scores were significantly less for the combination of E. tenella and aflatoxicosis than for coccidiosis alone. This atypical response of the ceca to E. tenella in the presence of dietary aflatoxin was characterized by less distended ceca, very little coagulated blood in the ceca, and apparently more profuse cecal hemorrhage.  相似文献   

Efficacy and Toxicity of Doxorubicin/Cyclophosphamide Maintenance Therapy in Dogs with Multicentric Lymphosarcoma   总被引：1，自引：1，他引：0  

G. Sylvester Price DVM    Rodney L. Page MS  DVM    Bernard M. Fischer DVM    Jay F. Levine DVM  MPH  Thomas M. Gerig PhD 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》1991,5(5):259-262

Doxorubicin/cyclophosphamide were evaluated as maintenance drugs for dogs with multicentric lymphosarcoma (n = 28). Median remission time of all dogs was 173 days. Remission duration was shorter, however, in dogs with stage IV/V disease, in dogs with pretreatment hypoalbuminemia, and in dogs that had received glucocorticoids before initiation of chemotherapy (P less than 0.04). Nineteen dogs were evaluable for toxicity. Dose-limiting gastrointestinal toxicosis was observed in three dogs, neutropenia was observed in three dogs, and cardiomyopathy was observed in three dogs. The doxorubicin/cyclophosphamide protocol described in this report is safe and effective in treating canine multicentric lymphosarcoma. Clinical stage, pretreatment steroid therapy, and hypoalbuminemia are prognostic factors for response to this protocol.  相似文献