Sensitivity of landscape resistance estimates based on point selection functions to scale and behavioral state: pumas as a case study   总被引：1，自引：1，他引：0  

Katherine A. Zeller  Kevin McGarigal  Paul Beier  Samuel A. Cushman  T. Winston Vickers  Walter M. Boyce 《Landscape Ecology》2014,29(3):541-557

Estimating landscape resistance to animal movement is the foundation for connectivity modeling, and resource selection functions based on point data are commonly used to empirically estimate resistance. In this study, we used GPS data points acquired at 5-min intervals from radiocollared pumas in southern California to model context-dependent point selection functions. We used mixed-effects conditional logistic regression models that incorporate a paired used/available design to examine the sensitivity of point selection functions to the scale of available habitat and to the behavioral state of individual animals. We compared parameter estimates, model performance, and resistance estimates across 37 scales of available habitat, from 250 to 10,000 m, and two behavioral states, resource use and movement. Point selection functions and resistance estimates were sensitive to the chosen scale of the analysis. Multiple characteristic scales were found across our predictor variables, indicating that pumas in the study area are responding at different scales to different landscape features and that multi-scale models may be more appropriate. Additionally, point selection functions and resistance estimates were sensitive to behavioral state; specifically, pumas engaged in resource use behavior had an opposite selection response to some land cover types than pumas engaged in movement behavior. We recommend examining a continuum of scales and behavioral states when using point selection functions to estimate resistance.  相似文献   

Airline deregulation and public policy     

Morrison SA  Winston C 《Science (New York, N.Y.)》1989,245(4919):707-711

An assessment of the effects of airline deregulation on travelers and carriers indicates that deregulation has provided travelers and carriers with $14.9 billion of annual benefits (1988 dollars). Airport congestion, airline safety, airline bankruptcy, and mergers are also analyzed and found in most cases to have reduced benefits. But, these costs should not be attributed to deregulation per se, but to failures by the government to pursue appropriate policies in these areas. Pursuit of policies that promote airline competition and efficient use of airport capacity would significantly increase the benefits from deregulation and would provide valuable guidance for other industries undergoing the transition to deregulation.  相似文献   

Landscape configuration and urban heat island effects: assessing the relationship between landscape characteristics and land surface temperature in Phoenix,Arizona   总被引：1，自引：0，他引：1  

Connors  John Patrick  Galletti  Christopher S.  Chow  Winston T. L. 《Landscape Ecology》2013,28(2):271-283

Landscape Ecology - The structure of urban environments is known to alter local climate, in part due to changes in land cover. A growing subset of research focuses specifically on the UHI in terms...  相似文献   

Mycorrhizal inoculation increases genes associated with nitrification and improved nutrient retention in soil     

E.?Morrison  L.?Lagos  A.?Al-Agely  H.?Glaab  Winston?Johnson  Milko?A.?Jorquera  A.?OgramEmail author 《Biology and Fertility of Soils》2017,53(3):275-279

The effects of arbuscular mycorrhizal (AM) inoculation on prokaryote abundance within the maize rhizosphere and hyphosphere, and retention of nutrients were investigated. Maize plants were grown in pots with a membrane located at a soil depth of approximately 16 cm that allowed growth of fungal hyphae above and below the membrane, but did not allow growth of roots below the membrane. As expected, mycorrhizal inoculation significantly increased the contents of soil organic matter, Total Kjeldahl Nitrogen (primarily organic N), and Mehlich 1 phosphorus relative to the non-inoculated control. Copy numbers of 16S rRNA genes were significantly higher in the mycorrhizal compartments relative to non-mycorrhizal controls. Bacterial ammonia monooxygenase (AOB) genes, but not archaeal monooxygease genes (AOA), were significantly higher in planted treatments with and without addition of mycorrhizae, indicating that mycorrhizae stimulate prokaryotic growth and bacterial nitrification. The ecological relevance of increased NOx-N resulting from the growth of AOB in inoculated soils is not clear; however, increased mobility of NOx-N over NH₄ ⁺ could result in a competition between leaching loss and increased uptake by mycorrhizae.  相似文献   

Validity of carbohydrate, glycaemic index and glycaemic load data obtained using a semi-quantitative food-frequency questionnaire     

Barclay AW  Flood VM  Brand-Miller JC  Mitchell P 《Public health nutrition》2008,11(6):573-580

OBJECTIVE: To assess the ability of a food-frequency questionnaire (FFQ) to rank Australians according to their intake of total carbohydrate, sugar, starch, fibre, glycaemic index (GI) and glycaemic load (GL). DESIGN: Cross-sectional sample from a population cohort. SETTING: Two postcode areas west of Sydney, Australia. SUBJECTS: From 1992 to 1994, a total of 2868 older Australians provided dietary data using a 145-item Willett-derived FFQ. A representative sub-sample of 78 subjects completed three 4-day weighed food records (WFRs). Pearson and Spearman correlations, Bland-Altman plots and weighted kappa values were calculated. RESULTS: Compared with the WFR, the FFQ provided higher mean estimates of all nutrients except starch and GI. All Pearson and/or Spearman correlations were greater than 0.5, except for GL. For GI, sugar, starch and fibre, the regression lines from the Bland-Altman analysis indicated a non-significant linear trend (P = 0.07, P = 0.36, P = 0.28 and P = 0.10, respectively). For GL and total carbohydrate, however, there was a significant linear trend (P = 0.006 and P < 0.0001, respectively), indicating that as the GL and carbohydrate intake of individuals increased, so did the magnitude of the error between the FFQ and WFR. Weighted kappa values all indicated moderate to good agreement, with the exception of GL which was only fair. The proportions of subjects correctly classified within one quintile for all of the nutrients were over 50% and gross misclassification was low (<10%). CONCLUSION: This FFQ was able to rank individuals according to their intakes of total carbohydrate, sugar, starch, fibre and GI, but not as well for GL.  相似文献   

Diagnosis of highly pathogenic avian influenza in chickens: Bendigo 1992     

WM FORSYTH  DC GRIX  CA GIBSON 《Australian veterinary journal》1993,70(3):118-119

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Rapid enzyme-linked immunosorbent assay for detecting antibodies to canine parvovirus     

S A Fiscus  M M Mildbrand  J C Gordon  Y A Teramoto  S Winston 《American journal of veterinary research》1985,46(4):859-863

A rapid screening assay for determining antibodies to canine parvovirus in dog serum using monoclonal antibodies and enzyme-linked immunosorbent assay (ELISA) technology was developed. The ELISA could be read visually, and the results correlated well with serum neutralization (SN) and hemagglutination inhibition (HI) titers. Sera with SN less than or equal to 1:4 or HI less than or equal to 1:10 had an 87.9% correlation with ELISA and sera with SN greater than or equal to 1:64 or HI greater than or equal to 1:80 had a 94.4% correlation. The assay took only 10 to 15 minutes to perform and did not require specialized equipment. The ELISA should be useful in monitoring dogs for the presence of maternal antibodies against parvovirus and for determining seroconversion after vaccination.  相似文献   

An Attempt to Passively Immunize Chicks against The Virus Of Newcastle Disease by the use of an Antiserum of Equine origin          下载免费PDF全文

Irvin WM. Moynihan  R. V. L. Walker  E. P. B. Powell    D. M. Cooper 《Canadian journal of veterinary research》1954,18(2):62-64

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Repeat Ovum Pick-up and In Vitro Embryo Production from Adult Ewes with and without FSH Treatment     

KM Morton  SP de  Graaf  A Campbell  LM Tomkins  WM Chis Maxwell  G Evans 《Reproduction in domestic animals》2005,40(5):422-428

Ovum pick-up (OPU) was performed three times on adult ewes after synchronization with (n = 4) or without (n = 4) FSH treatment to investigate the effects of FSH treatment on the number of ovarian follicles, oocytes recovered, oocyte quality and development in vitro. FSH treatment increased the number of ovarian follicles (85 vs 162) and oocytes recovered (33 vs 91), although recovery rate was similar for ewes with and without FSH (91/162, 56.2% and 33/85, 38.8% respectively). Of the oocytes recovered, those classified as grades I and II were similar between ewes with (78/91, 85.7%) and without FSH treatment (27/33, 81.8%). The number of ovarian follicles was similar after repeated OPU for ewes treated with FSH, but for ewes not treated with FSH the number of ovarian follicles decreased with repeated OPU. The number of oocytes recovered decreased for FSH-treated ewes only, while the oocyte recovery rate and proportion of oocytes classified as grades I and II were not affected by repeated OPU. Oocyte cleavage (46/78, 58.9% and 19/24, 79.2%) and blastocyst formation (35/46, 76.1% and 12/19, 63.2% respectively) were similar for ewes with and without FSH treatment. The number of ovarian follicles varied between ewes (p < 0.05) although the number of oocytes recovered and oocyte development in vitro were similar between ewes.  相似文献   

RADIOGRAPHIC AND COMPUTED TOMOGRAPHIC DETERMINATION OF FEMORAL VARUS AND TORSION IN THE DOG   总被引：1，自引：0，他引：1  

ROBERT M. DUDLEY  MICHAEL P. KOWALESKI  WM TOD DROST  JONATHAN DYCE 《Veterinary radiology & ultrasound》2006,47(6):546-552

Diagnosis and quantification of femoral varus and femoral torsion using radiographs is technically challenging due to the difficulty in determining proper positioning. The purpose of this study is to describe a computed tomographic technique for determination of femoral varus and femoral torsion and to compare this technique, and standard radiography, to anatomic preparation, for the measurement of femoral varus and femoral torsion in normal dogs. Nine canine cadavers, visually and radiographically free of orthopedic disease of the hip and stifle joints, were utilized for analysis. Femoral varus was determined using a craniocaudal radiograph, a craniocaudal radiograph obtained after confirming accurate positioning using horizontal beam fluoroscopy, and computed tomography (CT). Femoral torsion (expressed as angle of version) was determined using an axial radiographic projection obtained from distal to proximal and CT. Each femur was dissected free of soft tissues, and direct determination of femoral varus and femoral torsion was performed using digital photographic images. All radiologic and photographic images were digitally measured to quantify the magnitude of femoral varus and femoral torsion. For femoral varus, no difference ( P =0.149) between the three different imaging techniques and the anatomic preparation was identified. For femoral torsion, no difference ( P =0.059) between the two imaging techniques and the anatomic preparation was identified. Well positioned radiographs and the described computed tomographic method are both as accurate as anatomic preparation for the measurement of both femoral varus and femoral torsion in normal dogs.  相似文献