Receiver operating characteristic-based assessment of a serological test used to detect Johne’s disease in Israeli dairy herds          下载免费PDF全文

Marcelo Chaffer  Ariel L. Rivas  Daniel Elad  Ori Koren  Shlomo Garazi  Gerardo Chowell    Steven J. Schwager 《Canadian journal of veterinary research》2008,72(1):18-26

The overall accuracy of an enzyme-linked immunosorbent assay (ELISA) used to detect Johne's disease at herd level was explored in relation to an imperfect test (fecal culture) in 57 Israeli dairy herds. Receiver-operating characteristic (ROC) analysis indicated an area under the curve (AUC) that corresponded to a test accuracy of 82.0% (69.5% to 90.9%; 95% confidence), with optimized herd sensitivity and herd specificity of 70.4% and 83.3%, respectively; and predictive values of 79.2 (+) and 75.8% (-). The optimal ELISA cutoff was 3.16% (> 3.16% seropositive cows in a herd), which was associated with likelihood ratios (LR) of 4.22 (+LR) and 0.36 (-LR), and post-test probabilities of 0.79 (+) and 0.17 (-). For herds with < or = 200 cows (n = 19 herds), the 95% confidence interval (CI) for the AUC was 0.62-0.97 and the optimal cutoff was 3.33% (HSe = 87.5, HSp = 81.8); for herds with > 200 but < or = 270 cows (n = 19 herds), the 95% AUC CI was 0.62-0.97 and the optimal cutoff was 1.13% (HSe = 90.0, HSp = 77.78); and for herds with > 270 cows (n = 19 herds), the 95% AUC CI was 0.69-0.99 and the optimal cutoff was 0.7% (HSe = 100.0, HSp = 70.0). The AUC was not influenced by across-herd prevalence [R2 (adjusted) = 0.0, P > 0.05]. Findings may be applied to facilitate targeted sampling of herds similar to those evaluated. For instance, a test cutoff of 0.76% could be considered for "ruling disease in," while a cutoff of 3.7% could be used for "ruling disease out." Caveats that may influence this analysis are discussed.  相似文献   

1-Methylcyclopropene (1-MCP) delays senescence,maintains quality and reduces browning of non-climacteric eggplant (Solanum melongena L.) fruit     

Juan F. Massolo  Analía Concellón  Alicia R. Chaves  Ariel R. Vicente 《Postharvest Biology and Technology》2011,59(1):10-15

Ethylene action can be counteracted by 1-methylcyclopropene (1-MCP), which has been used during postharvest storage to maintain quality. In this work, we evaluated the effect of 1-MCP treatments on eggplant quality and phenolic metabolism during refrigerated storage. Eggplants (cv. Lucía) were harvested at commercial maturity, treated with 1-MCP (1 μL/L, 12 h at 20 °C), stored at 10 °C for 21 d and subsequently held at 20 °C for 2 d. Corresponding controls were stored at 10 °C and then transferred to 20 °C for 2 d. During storage calyx color, damage and chlorophyll content, fruit weight loss and firmness, pulp sugar content, acidity, browning and total phenolics were measured. In addition, polyphenol oxidase (PPO), pyrogallol peroxidase (POD), and phenylalanine ammonia-lyase (PAL) activities were evaluated. Fruit calyxes showed reduced damage and remained greener in 1-MCP treated than in control fruit. 1-MCP treated eggplants showed lower weight loss. Pulp browning was clearly prevented as a consequence of 1-MCP exposure, and this was associated with delayed senescence, lower accumulation of total phenolics and reduced activity of PAL. The activity of the enzymes PPO and POD involved in the oxidation of phenolics compounds was also decreased in 1-MCP treated fruit. Results suggest that 1-MCP treatments delay senescence, prevent browning and are beneficial to complement low temperature storage and maintain quality of non-climacteric eggplant fruit.  相似文献   

Vertical distribution of phosphorus in a sandy soil fertilized with recovered manure phosphates   总被引：2，自引：2，他引：0  

Ariel A. Szogi  Philip J. Bauer  Matias B. Vanotti 《Journal of Soils and Sediments》2012,12(3):334-340

Purpose  

The aim of the study was to evaluate the environmental fate of recovered manure phosphates for their effective use as crop fertilizers.  相似文献   

Pharmacokinetics of clarithromycin and concentrations in body fluids and bronchoalveolar cells of foals     

Womble AY  Giguère S  Lee EA  Vickroy TW 《American journal of veterinary research》2006,67(10):1681-1686

OBJECTIVE: To determine pharmacokinetics of clarithromycin and concentrations in body fluids and bronchoalveolar (BAL) cells of foals. ANIMALS: 6 healthy 2-to 3-week-old foals. PROCEDURES: In a crossover design, clarithromycin (7.5 mg/kg) was administered to each foal via IV and intragastric (IG) routes. After the initial IG administration, 5 additional doses were administered IG at 12-hour intervals. Concentrations of clarithromycin and its 14-hydroxy metabolite were measured in serum by use of high-performance liquid chromatography. A microbiologic assay was used to measure clarithromycin activity in serum, urine, peritoneal fluid, synovial fluid, CSF, pulmonary epithelial lining fluid (PELF), and BAL cells. RESULTS: After IV administration, elimination half-life (5.4 hours) and mean +/- SD body clearance (1.27 +/- 0.25 L/h/kg) and apparent volume of distribution at steady state (10.4 +/- 2.1 L/kg) were determined for clarithromycin. The metabolite was detected in all 6 foals by 1 hour after clarithromycin administration. Oral bioavailability of clarithromycin was 57.3 +/- 12.0%. Maximum serum concentration of clarithromycin after multiple IG administrations was 0.88 +/- 0.19 microg/mL. After IG administration of multiple doses, clarithromycin concentrations in peritoneal fluid, CSF, and synovial fluid were similar to or lower than concentrations in serum, whereas concentrations in urine, PELF, and BAL cells were significantly higher than concentrations in serum. CONCLUSIONS AND CLINICAL RELEVANCE: Oral administration of clarithromycin at 7.5 mg/kg every 12 hours maintains concentrations in serum, PELF, and BAL cells that are higher than the minimum inhibitory concentration (0.12 microg/mL) for Rhodococcus equiisolates for the entire 12-hour dosing interval.  相似文献   

Phylogeny of Coccomyxa (Myxosporea: Myxidiidae) spp. with the description of a new species from Bathygobius cyclopterus (Gobiidae) in the northern Red Sea     

Diamant A  Lipshitz A  Ucko M 《Folia parasitologica》2007,54(2):109-116

Two species of Coccomyxa Léger et Hesse, 1907, one of the least studied myxosporean genera, are reported from shallow coastal waters in the Gulf of Eilat, Red Sea, Israel. A new species, Coccomyxajirilomi sp. n. is described from the spotted frillgoby Bathygobius cyclopterus (Valenciennes) (Gobiidae). It forms polysporous plasmodia that invade the liver and form packed clusters inside the bile ductules. Plasmodia also occur in the bile ducts and gall bladder of the host, attached to the epithelial lining or free floating in the bile. Infected hepatic bile ductules packed with plasmodia were partially occluded, with evidence of cholestasis, periductular fibrosis and pericholangitis. The mature spore is ellipsoid, has smooth valves and contains a single polar capsule with the polar filament arranged in 4-5 oblique coils. Spore dimensions are 9.0-11.3 x 5.0-7.0 microm. A second species, Coccomyxa sp., with smaller 7.6-9.6 x 4.2-5.2 microm and more delicate spores, was found in the gall bladder of the rippled rockskipper, Istiblennius edentulus (Forster et Schneider) (Blenniidae). The small subunit (SSU) rDNA sequence analysis of both Coccomyxa species suggests that they are closely related to members of the genera Myxidium, Zschokkella and Auerbachia, whose members infect the gall bladder of marine fish.  相似文献   

Diagnosis and management of a wooden foreign body in the orbit of a cat     

Pascale Lybaert  Isabelle Delbecke  Ariel Cohen-Solal 《Journal of Feline Medicine and Surgery》2009,11(3):219-221

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Improving xanthophyll extraction from marigold flower using cellulolytic enzymes   总被引：1，自引：0，他引：1  

Navarrete-Bolaños JL  Jiménez-Islas H  Botello-Alvarez E  Rico-Martínez R  Paredes-López O 《Journal of agricultural and food chemistry》2004,52(11):3394-3398

In this work is studied the effect of a noncommercial enzyme preparation on xanthophyll extraction from marigold flower (Tagetes erecta). The enzymatic extract was synthesized by endogenous microorganisms previously isolated and identified as Flavobacterium IIb, Acinetobacter anitratus, and Rhizopus nigricans. The results show that the extraction yield depends directly on the extent of the enzymatic hydrolysis of cell walls in the flower petals and that it is possible to reach yields in excess of those previously reported for treatments with commercially available enzymes (29.3 g/kg of dry weight). HPLC analysis of the product indicates that the original xanthophyll profile is not altered. The enhanced extraction system appears to be very competitive when compared to the traditional process and current alternatives.  相似文献   

Allometry, biomass, and chemical content of Novel African Tulip Tree (Spathodea campanulata) Forests in Puerto Rico     

Ariel E. Lugo  Oscar J. Abelleira  Alexander Collado  Christian A. Viera  Cynthia Santiago  Diego O. V��lez  Emilio Soto  Giovanni Amaro  Graciela Char��n  H��ctor Col��n Jr.  Jennifer Santana  Jos�� L. Morales  Katherine Rivera  Luis Ortiz  Luis Rivera  Mianel Maldonado  Natalia Rivera  Norelis J. V��zquez 《New Forests》2011,42(3):267-283

The African tulip tree, Spathodea campanulata, the most common tree in Puerto Rico, forms novel forest types with mixtures of native and other introduced tree species. Novel forests increase in area in response to human activity and there is no information about their biomass accumulation and nutrient cycling. We established allometric relationships and chemically analyzed plant parts of African tulip trees to determine the concentration and standing stock of chemical elements (C, N, P, K, Ca, Mg, S, Mn, Al, Fe, Na), and ash. Trees ranged in diameter at breast height from 8 to 85 cm and in height from 8.8 to 28 m. The concentrations of N, P, K, and Ca in leaves of the African tulip tree were similar to those of the native pioneer Cecropia schreberiana and higher than those of mature forest tree species in Puerto Rico. The over bark wood volume of African tulip trees in nine forest stands where it was dominant ranged from 163 to 849 m³/ha. Aboveground biomass ranged from 60 to 296 Mg/ha, and N and P stocks ranged from 190 to 988 and 32 to 137 kg/ha, respectively. Novel forests on abandoned agricultural lands can store more biomass and elements than native and plantation forest stands of similar age.  相似文献   

Technical Note: Coccygeal vein catheterization for sampling of reproductive tract-derived products from the uterine–ovarian drainage     

Sydney T Reese  Gessica A Franco  Ramiro V Oliveira Filho  Reinaldo F Cooke  Michael F Smith  Ky G Pohler 《Journal of animal science》2021,99(2)

Blood sample collection from the caudal vena cava at the site of uterine–ovarian drainage provides a more exact evaluation of the concentration and pattern of secretion of uterine or ovarian secreted products for studies of reproductive processes in cyclic and pregnant cattle compared with samples collected from general circulation. This paper describes a thorough and updated procedure for cannulating the coccygeal vein into the caudal vena cava for the collection of serial blood samples at or near the site of uterine–ovarian drainage. Concentrations of progesterone were quantified in cows of different reproductive tract sizes with an active corpus luteum to assess the distance for proper catheter placement compared with circulating concentrations collected from the jugular vein. This procedure has a low risk for side effects, can be used effectively in pregnant animals with no major consequence to the viability of the pregnancy, and provides means for frequent collections up to 12 d.  相似文献   

Economic factors and opportunities as determinants of water use efficiency in agriculture     

Ariel Dinar 《Irrigation Science》1993,14(2):47-52

A consequence of water scarcity is that it has enhanced research and development aimed at increasing water use efficiency in irrigated agriculture. Although biological, genetic, and technological achievements may induce potential high levels of water use efficiency, actual observed values may be much smaller. This paper distinguishes between potential and actual water use efficiency measures, and discusses factors and opportunities that may affect actual water use efficiency in irrigated agriculture. These include economic forces, environmental effects, and institutional arrangements, each of which may affect water use decisions at field, farm, regional, and national levels. The paper develops a scheme to generally address differences between private and social considerations that determine water use efficiency decisions. Using this scheme, several examples from California and Israel are provided to support the arguments. The paper concludes that the concept of water use efficiency is much broader than its definition: yield per water applied or transpired. Moreover, determination of water use efficiency levels in irrigated agriculture is a complex issue that requires interdisciplinary considerations.  相似文献