Estimation of sensitivity and specificity of two diagnostics tests for bovine immunodeficiency virus using Bayesian techniques     

Orr KA  O'Reilly KL  Scholl DT 《Preventive veterinary medicine》2003,61(2):79-89

The validation of assays for bovine immunodeficiency virus (BIV) in cattle is hampered by the absence of a gold standard. Two tests that often are used to detect BIV are the indirect fluorescent-antibody assay (IFA) and the nested-set polymerase chain-reaction assay (PCR). IFA detects an antibody response whereas PCR detects the provirus in white blood cells.Using Bayesian techniques performed simultaneously on animals from two different dairy herds, we estimated the performance of the IFA and PCR assays and infection prevalence. Bayesian techniques also were used to derive posterior distributions of sensitivities, specificities, and prevalences. The Bayesian estimates were IFA sensitivity=60%, IFA specificity=88%, PCR sensitivity=80%, PCR specificity=86%, Herd A prevalence=20%, and Herd B prevalence=71%. Although PCR was the more sensitive assay, substantial misclassification of infection would be expected in epidemiological studies of BIV regardless of which assay was used.  相似文献   

Sustainable management, earthquake disturbances, and transient dynamics: modelling timber harvesting impacts in mixed-species forests     

Georges Kunstler  Robert B. Allen  David A. Coomes  Charles D. Canham  Elaine F. Wright 《Annals of Forest Science》2013,70(3):287-298

Context

There is strong interest in sustainable forest management systems that preserve characteristics of forests close to naturalness. Assessing the effectiveness of these systems is difficult because defining “natural” baselines from which impacts are estimated is challenging and because the influence of harvesting can have complex interactions with major natural disturbances.

Aims

We used SORTIE/NZ, an individual tree-based forest dynamics model, to understand how harvesting and earthquake disturbance affect the dynamics of a New Zealand podocarp–angiosperm forest.

Methods

Having parameterized SORTIE/NZ with extensive field data, we ran simulations for three natural dynamics scenarios (no disturbance and two earthquake scenarios) and then added podocarp harvesting scenario to each of these.

Results

Simulations suggest that this forest is experiencing transient dynamics, with a natural rise in the dominance of one species of slow-growing podocarp with and without earthquake. Harvesting podocarps strongly affected its increase in basal area.

Conclusion

Our results indicate that transient dynamics may occur in mixed podocarp forests and major disturbances may have complex interactions with management. Evaluating management impacts without accounting for these complex dynamics may be misleading. Models make predictions about transient trajectories that may help to evaluate these impacts.  相似文献   

Fatty acid and tocopherol patterns of variation within the natural range of the shea tree (Vitellaria paradoxa)     

François Allal  Georges Piombo  Bokary A. Kelly  John B. L. Okullo  Massamba Thiam  Ousmane B. Diallo  George Nyarko  Fabrice Davrieux  Peter N. Lovett  Jean-Marc Bouvet 《Agroforestry Systems》2013,87(5):1065-1082

The shea tree, Vitellaria paradoxa, is one of the most economically and culturally important indigenous tree species in the Sudano-Sahelian region. Its seeds contain a vegetable fat, internationally known as shea butter, which is widely used in edible, cosmetic and pharmaceutical sectors. Based on samples from 456 trees distributed in 17 locations across the species natural range from Senegal to Uganda, the fatty acid and tocopherol variation, and its relationship with geographic and climatic variables, was assessed in order to address the pattern and the origin of this variation across the natural range. Significant differences between Western and Eastern regions for oleic, stearic acid, saturated–unsaturated acid ratio and γ-tocopherol were identified that it is postulated maybe a result of genetic drift due to the evolutionary history of shea tree populations. Within regions the difference among stands was significant for most constituents; however the major part of the variation was observed among trees within stand (53–90 %). Relationships with climatic variables were not verified, weakening evidence for clinal variation hypotheses suggested by previous studies.  相似文献   

Sucrose (JrSUT1) and hexose (JrHT1 and JrHT2) transporters in walnut xylem parenchyma cells: their potential role in early events of growth resumption     

Decourteix M  Alves G  Bonhomme M  Peuch M  Ben Baaziz K  Brunel N  Guilliot A  Rageau R  Améglio T  Pétel G  Sakr S 《Tree physiology》2008,28(2):215-224

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Progressive Juvenile Glomerulonephropathy in 16 Related French Mastiff (Bordeaux) Dogs     

R. Lavoué  J.J. Van Der Lugt  M.J. Day  M. Georges  V. Busoni  A.C. Merveille  A. Poujade  D. Peeters 《Journal of veterinary internal medicine / American College of Veterinary Internal Medicine》2010,24(2):314-322

Background: Familial juvenile glomerulonephropathy (JGN) is reported in several breeds of dogs. The mode of inheritance and spectrum of pathological lesions vary among breeds. A progressive JGN was detected in a pedigree of French Mastiff (FM) dogs. Objectives: To describe clinical, laboratory, and histopathologic findings in related FM dogs suffering from progressive JGN and to determine the mode of inheritance of this condition. Animals: Sixteen affected and 35 healthy related FM dogs Methods: FM dogs <24 months of age and diagnosed with chronic kidney disease with evidence of proteinuria entered the study. Clinical, laboratory, histopathologic findings, and pedigree data were recorded. Results: Clinical signs were typical of progressive glomerulopathy with resultant renal failure. Increased blood urea nitrogen, creatinine and total cholesterol concentrations, and proteinuria were found in all patients. Affected dogs had abnormal kidney structure on abdominal ultrasound examination. Histopathologic examination revealed extensive cystic glomerular atrophy, glomerular hypercellularity, and capillary wall thickening without immune complex deposition when tested with immunohistochemistry or immunofluorescence. Electron microscopy did not disclose specific primary glomerular lesions. Mean age at death was 20 months and mean length of survival after diagnosis was 6 months. Both males and females from healthy parents were affected. An autosomal recessive mode of transmission is suspected, but a more complex mode of inheritance cannot be excluded. Conclusions and Clinical Importance: Progressive familial JGN occurs in FM dogs. Characterization of the pathogenesis and mode of inheritance of this disease warrants additional study.  相似文献   

Enrichment of anhydrous milk fat in polyunsaturated fatty acid residues from linseed and rapeseed oils through enzymatic interesterification   总被引：1，自引：0，他引：1  

Aguedo M  Hanon E  Danthine S  Paquot M  Lognay G  Thomas A  Vandenbol M  Thonart P  Wathelet JP  Blecker C 《Journal of agricultural and food chemistry》2008,56(5):1757-1765

Lipozyme TL IM was used in a solvent-free batch and microaqueous system for enzymatic interesterification of anhydrous milkfat (AMF) with linseed oil (LO) in binary blends and with rapeseed oil (RO) in one ternary blend. The aim was to obtain and characterize physicochemically fats enriched with unsaturated C 18 fatty acids (oleic, linoleic, and, especially, linolenic acids) from natural vegetable oils. Binary blends of AMF/LO 100/0, 90/10, 80/20, 70/30, and 60/40 (w/w) were interesterified. The change in triacylglycerol (TAG) profiles showed that quasi-equilibrium conditions were reached after 4-6 h of reaction. Free fatty acid contents <1%. The decrease in solid fat content and in dropping point temperature obtained with increasing content of LO and interesterification resulted in good plastic properties for the products originating from the blends 70/30 and 60/40. This was confirmed by textural measurements. Melting profiles determined by differential scanning calorimetry showed complete disappearance of low-melting TAGs from LO and the formation of intermediary species with a lower melting temperature. Oxidative stability of the interesterified products was diminished with increasing LO content, resulting in low oxidation induction times. A ternary blend composed of AMF/RO/LO 70/20/10 gave satisfactory rheological and oxidative properties, fulfilling the requirements for a marketable spread and, moreover, offering increased potential health benefits due to the enriched content in polyunsaturated fatty acid residues.  相似文献   

A recirculation system for experimental aquaria     

M.B. New  J.P. Scholl  J.C. McCarty  J.P. Bennett 《Aquaculture (Amsterdam, Netherlands)》1974,3(1):95-103

This paper describes a basis design for a compact, self-contained unit for experimental aquaria. Thirty-six 10-gallon tanks are linked in a temperature-controlled water recirculation system. Water turnover rates up to 85% per hour are maintained through an upward displacement biological filter, with temperature control of ±0.1°C in the system and ±0.2°C between individual tanks. The complete unit occupies 36 ft² (3.3 m²) of floor space. All tanks are easily inspected and maintenance is minimal.  相似文献   

Use of DNA bar codes to resolve a canine paternity dispute     

M Georges  P Hilbert  A S Lequarré  V Leclerc  R Hanset  G Vassart 《Journal of the American Veterinary Medical Association》1988,193(9):1095-1098

The DNA fingerprinting method was used to resolve a canine paternity dispute. During the same estrus, a Shih Tzu bitch was inseminated by 2 dogs--a Shih Tzu and a Coton de Tulear. Because both breeds are alike phenotypically, it was difficult to decide whether the pups were purebred or of mixed breeding. The DNA bar codes indicated unambiguously that the 2 sires had fathered one pup each, thus documenting superfecundation.  相似文献   

Occurrence of Aujeszky's disease in swine in Switzerland     

F Steck  E Scholl  M Vandevelde  H H?ni  H Hartmann  G Kilchsperger  J Pohlenz 《Schweizer Archiv für Tierheilkunde》1974,116(7):315-327

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Effects of a quantitative trait locus for muscle hypertrophy from Belgian Texel sheep on carcass conformation and muscularity     

Laville E  Bouix J  Sayd T  Bibé B  Elsen JM  Larzul C  Eychenne F  Marcq F  Georges M 《Journal of animal science》2004,82(11):3128-3137

A QTL for muscle hypertrophy has been identified in the Belgian Texel breed. A population of F2 and backcross lambs created from crosses of Belgian Texel rams with Romanov ewes was studied. Effects on carcass traits and muscle development of the Belgian Texel breed polygenes and Belgian Texel single QTL were compared. In both cases, carcass conformation and muscularity were improved. The Texel polygenic environment improved conformation mainly through changes in skeletal frame shape. Segments were shorter and bone weight lower. Muscles were more compact, shorter, and thicker. The single QTL affected muscle development. Thickness and weight of muscles were increased. Composition in myosin changed toward an increase of fast contractile type. The relative contribution of hind limb joint to carcass weight was increased. Differences in skeletal frame morphology among the three genotypes of the single QTL were small. Conformation scoring was mainly influenced by leg muscularity. Back and shoulder muscle development, which largely contributed to variability of muscularity, were less involved in the conformation scoring. Lastly, the QTL explains a small part of differences between these Belgian Texel and Romanov breeds for conformation or muscle development. A large part of genetic variability remains to be explored.  相似文献