Detection of koi herpes virus (CyHV-3) in goldfish, Carassius auratus (L.), exposed to infected koi     

Sadler J  Marecaux E  Goodwin AE 《Journal of fish diseases》2008,31(1):71-72

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Separating spatial and temporal sources of variation for model testing in precision agriculture     

E. John Sadler  Kenneth A. Sudduth  James W. Jones 《Precision Agriculture》2007,8(6):297-310

The application of crop simulation models in precision agriculture research appears to require only the specification of some input parameters and then running the model for each desired location in a field. Reports in the extensive literature on modeling have described independent tests for different cultivars, soil types and weather, and these have been presumed to validate the model performance in general. However, most of these tests have evaluated model performance for simulating mean yields for multiple plots in yield trials or in other large-area studies. Precision agriculture requires models to simulate not only the mean, but also the spatial variation in yield. No consensus has emerged about how to test model performance rigorously, or what level of performance is sufficient. In addition, many measures of goodness of fit between the observed and simulated data (i.e., model performance) depend on the range of variation in the observed data. If, for example, inter-annual and spatial sources of variation are combined in a test, poor performance in one might be masked by good performance in the other. Our objectives are to: (1) examine research aims that are common in precision agriculture, (2) discuss expectations of model performance, and (3) compare several traditional and some alternative measures of model performance. These measures of performance are explained with examples that illustrate their limitations and strengths. The risk of relying on a test that combines spatial and temporal data was shown with data where the overall fit was good (r ²  > 0.8), but the fit within any year was zero. Information gained using these methods can both guide and help to build confidence in future modeling efforts in precision agriculture.

E. John SadlerEmail:

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The effect of experimental Mycoplasma synoviae infection on the wholesomeness of young adult turkeys     

W W Sadler  R E Corstvet 《American journal of veterinary research》1965,26(115):1421-1428

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The effect of Erysipelothrix insidiosa infection on wholesomeness of market turkeys     

W W Sadler  R E Corstvet 《American journal of veterinary research》1965,26(115):1429-1436

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Cadmium-Resistant Pseudomonas putida Synthesizes Novel Cadmium Proteins     

Higham DP  Sadler PJ  Scawen MD 《Science (New York, N.Y.)》1984,225(4666):1043-1046

Three cysteine-rich proteins of molecular weight 4000 to 7000, containing 4 to 7 gram atoms of cadmium, zinc, and copper per mole were isolated from Pseudomonas putida growing in 3 mM cadmium. The three proteins were induced during different phases of growth, and the smallest (molecular weight 3600; 3 gram atoms of cadmium) was released into the medium when the cells lysed. The results of amino acid analyses and of ultraviolet, circular dichroism, electron paramagnetic resonance, and cadmium-113 nuclear magnetic resonance spectroscopy suggest a novel cadmium(II)-zinc(II)-copper(I) cluster structure for the major protein.  相似文献   

Serum lipid concentrations in six canid and four ursid species in four zoos.     

Susan D Crissey  Kimberly D Ange  Kerri A Slifka  William Sadler  Stephen Kahn  Ann M Ward 《Journal of zoo and wildlife medicine》2004,35(1):34-39

Serum lipid levels were measured in healthy captive wild canids and ursids, and the values were compared with previously published data. Serum lipid levels were evaluated in blood samples collected from eight African wild dogs (Lycaon pictus), three arctic foxes (Alopex lagopus), nine gray wolves (Canis lupus), four maned wolves (Chrysocyon brachyurus), two Mexican wolves (Canis lupus baleiyi), nine red wolves (Canis rufus), two brown bears (Ursus arctos), six polar bears (Ursus maritimus), six spectacled bears (Tremarctos ornatus), and five sun bears (Ursus malayanus). Samples were analyzed for total cholesterol, triacylglycerides, high-density lipoprotein-cholesterol, and low-density lipoprotein-cholesterol. Although the results showed a great variation among species, circulating lipids appeared especially high, sometimes extremely so, in the spectacled bears, polar bears, sun bears, and maned wolves compared with all other species sampled. The study provides a substantial basis for comparing lipid levels in presumed healthy animals and indicates a need for controlled study of the effects of diet on circulating lipid levels.  相似文献   

Exposed riverine sediments (ERS) in England and Wales: distribution,controls and management     

Matthew J. O'Callaghan  David M. Hannah  Mike Williams  Jon P. Sadler 《水产资源保护:海洋与淡水生态系统》2013,23(6):924-938

Semiparametric geographically weighted response curves with application to site-specific agriculture     

Scott Holan  Suojin Wang  Ali Arab  E. John Sadler  Kenneth Stone 《Journal of Agricultural, Biological & Environmental Statistics》2008,13(4):424-439

Lack of basic knowledge about spatial and treatment varying crop response to irrigation hinders irrigation management and economic analysis for site-specific agriculture. One model that has been postulated for relating crop-specific economic quantities to irrigation is a quadratic response curve of yield as a function of irrigation. Although this model has far reaching economic interpretations it does not account for spatial variation or possible nitrogen-irrigation interactions. To this end we propose a spatially treatment varying coefficient model that alleviates these limitations while providing measures of uncertainty for the estimated coefficient surfaces as well as other derived quantities of interest. The modeling framework we propose is of independent interest and can be used in many different applications. Finally, an example involving site-specific agricultural data from the U.S. Department of Agriculture-Agricultural Research Service demonstrates the applicability of this methodology.  相似文献   

Effect of selenium supplementation on semen characteristics of Brazil's ram          下载免费PDF全文

M Piagentini  DC Silva  CPF Dell'Aqua  CF Moya‐Araujo  VM Codognoto  AA Ramos  E Oba 《Reproduction in domestic animals》2017,52(3):355-358

The aim of this study was to investigate the effects of different concentrations of oral supplementation with selenium (Se) upon ram sperm parameters. Thirty rams managed in stall under intensive system were used and divided into five groups (six animals per group) as follows: control group (G1) mineral mixture supplementation without Se, group 2 (G2) mineral mixture supplemented with 5 mg/kg Se, group 3 (G3) supplemented with 10 mg/kg Se, group 4 (G4) supplemented with 15 mg/kg Se and group 5 (G5) supplemented with 20 mg/kg Se. For each group, there was an adjustment period of 14 days. The experimental period was 350 days. Every 56 days, the animals were weighed and semen samples were collected by electroejaculation. Semen analysis included volume, mass moviment, total motility, vigour, concentration and morphology. For plasmatic and acrosomal membrane integrity evaluation and mitochondrial membrane potential were used a combination of fluorescent probes. Differences between means values obtained by analysis of variance were verified by Tukey test with 5% probability. There was no statistical difference between treatment groups in relation to volume, mass moviment, total motility, vigour, concentration, plasma and acrosomal membrane integrity (p > .05). Sperm morphology was different between treatment groups, the G1 (0 mg of selenium) had the highest percentage of major defects (11.11 ± 1.11^a; p < .05). It was concluded that selenium decrease the percentage of sperm defects and did not directly influence on ram sperm volume, mass moviment, total motility, vigour, concentration and membrane integrity.  相似文献   

Detecting reproductive system abnormalities of broiler breeder roosters at different ages          下载免费PDF全文

MA Lagares  R Ecco  NRS Martins  LJC Lara  JSR Rocha  DAR Vilela  VM Barbosa  PF Mantovani  JFV Braga  IS Preis  VA Gheller  PC Cardeal  NC Baião 《Reproduction in domestic animals》2017,52(1):67-75

The objective of this study was to detect the reasons of rooster's fertility decrease at 50 weeks of age. Therefore, the reproductive system of broiler breeder roosters was laparoscopic, macroscopic and histopathology evaluated, and a comparison of the anatomical aspect with the sperm analysis and birds’ age was realized. Cobb roosters (n = 59) were distributed into two groups (30 and 50 weeks). Evaluations were performed with laparoscopy, macroscopy and histopathology, and seminal quality, blood serum testosterone concentration and weight were also determined. The old roosters presented smaller testicle size, higher intensity epididymal lithiasis and lower testicle sperm production, compared to the young roosters. The use of the endoscope could easily distinguish a normal‐sized testicle than an atrophic one. Four old roosters with severe testicular atrophy did not show spermatogenesis, although three still had sperm in the ejaculate. This would falsely indicate a wrong diagnosis of normal fertility before the testicular atrophy took place. In conclusion, in addition to the weight increase with age, the testicular atrophy and impairment of sperm production seemed to be the main reason to the decrease in the rooster's fertility at 50 weeks of age. Therefore, the use of the laparoscopy as a way to detect the roosters with testicular atrophy before 50 weeks of age and their removal from them flock could be useful as a diagnostic tool to prevent the birds’ fertility loss.  相似文献