Sampling strategies for the detection of grapevine fanleaf virus and the grapevine strain of tomato ringspot virus

This study was conducted to determine the influence of season, host genotype virus isolate and sample tissue on ELISA detection of the two nepoviruses. Enzyme-linked immunosorbent assay (ELISA) readily detects grapevine fanleaf virus (GFLV) and the causal agent of grapevine yellow vein, tomato ringspot virus (TomRSV) in infected grapevines. Three serologically identical isolates of GFLV (fanleaf deformation, vein-banding and yellow mosaic) were examined in one cultivar of Vitis rupestris SCHEELE and in three cultivars of V.. vinifera L. TomRSV was examined in V. vinifera cv. Carignane. The tissues tested included: shoot tips, mature leaves and cambial scrapings. The following tissues taken from GFLV-infected dormant canes were also tested: sawdust, cambial scrapings, dormant buds, and induced shoots, roots and callus. There were no differences in GFLV ELISA results when different cultivars and virus isolates were compared. However, seasonal differences in ELISA detection of GFLV were observed. Shoot tip values went from a high of > 4.00 OD450nm in May to a low of 0.05 OD450nm in September. 'Mature leaves also gave the highest values in May and rapidly decreased to relatively low and constant levels throughout the rest of the season. ELISA values from cambial scrapings were moderately high and relatively constant throughout the season. When GFLV-infected dormant canes were tested, induced actively growing tissues gave the highest ELISA values. TomRSV ELISA values were relatively constant over the season and shoot tips, mature leaves and cambial scrapings produced similar ELISA values.Strategien der Probenahme zur Feststellung des Grapevine fanleaf-Virus und des Tomato ringspot-Virus der RebeDas Ziel der vorliegenden Untersuchung war es, den Einfluß der Jahreszeit, des Wirtsgenotyps, des Virusisolates und des Pflanzengewebes auf den Nachweis zweier Nepoviren durch ELISA zu bestimmen. Das Virus der Reisigkrankheit (GFLV} und der Erreger der Adernvergilbung bei Reben, das Tomatenringfleckenvirus (TomRSV}, können durch Enzyme-linked immunosorbent assay (ELISA) leicht nachgewiesen werden. Drei serologisch identische Isolate von GFLV (verantwortlich für Fächerblättrigkeit, Adernaufhellung und Panaschüre) wurden an einer Sorte von Vitis rupestris SCHEELE und drei Sorten von V. vinifera L., TomRSV wurde an V. vinifera cv. Carignane getestet. Hierbei wurden Triebspitzen, ausgewachsene Blätter und Kambiumschabsel geprüft. Von dormantem GFLV-infiziertem Rebholz wurden untersucht: Sägemehl, Kambiumschabsel, Ruheknospen, sowie aus dem Holz entstandene Triebe, Wurzeln und Kallusgewebe. Die Ergebnisse des ELISA-Tests wurden weder durch die Testrebensorte noch durch das Virusisolat beeinflußt. Mittels ELISA konnten jedoch jahreszeitlich bedingte Unterschiede im GFLV-Titer nachgewiesen werden. Bei den Triebspitzen sanken die Werte von einem Maximum > 4.00 OD450nm im Mai auf ein Minimum von 0.05 OD450nm im September. Auch ausgewachsene Blätter zeigten im Mai die höchsten Werte, die dann rasch auf ein relativ niedriges und gleichbleibendes Niveau zurückgingen. Die ELISA-Werte des Kambiumschabsels blieben während der ganzen Vegetationsperiode relativ hoch und stabil. Beim Test von GFLV-infiziertem dormantem Schnittholz zeigten die induzierten, wachsenden Gewebe die höchsten ELISA-Werte. Die ELISA-Werte für TomRSV blieben während der Vegetationsperiode relativ konstant, und es gab kaum Unterschiede zwischen Triebspitzen, ausgewachsenen Blättern und Kambiumschabsel

Evaluation of the Stability of Coated Plates with Antigen at Different Temperatures and Times by ELISA Test to Diagnose Fasciolosis

"nBackground: Considering that ELISA method presently is the test of choice for diagnosis of fasciolo­sis, the present study was undertaken to evaluate the maximum validity of coated plates at dif­ferent temperatures and different times during one year of evaluation."nMethods: Serum samples of patients infected with fasciolosis (n=10), hydatidosis (n=5), toxocaria­sis (n=5), and negative control sera (n=5) were examined. Two series of plates were consid­ered. The first series were coated with Fasciola homogenate Ag 12 ug/ml, and after some steps were blocked with gelatin and preserved at different temperatures as -80 °C , -20 °C, -4 °C and +4°C. The 2nd series were treated under the same criteria but were not blocked with gelatin. Each series were examined by ELISA test from 1st month to 12th month. Sera with 1:125 dilution, and peroxidase-conjugated goat anti-human IgG diluted 1:10000 were considered optimum."nResults: To ease reporting the results and due to many similarities only results related to 1st, 6th and 12th months were analyzed and sensitivity, specificity plus cut-off were determined for each series separately. "nConclusion: Preserving the coated plates, while unblocked at -80°C for 6-8 months is pertinent and functional and in that case, we can be sure the best out put would be applicable

Ballistic and Diffuse Electron Transport in Nanocontacts of Magnetics

The transition from the ballistic electron transport to the diffuse one is experimentally observed in the study of the magnetic phase transition in Ni nanocontacts with different sizes. It is shown that the voltage $U_C$ needed for Joule heating of the near-contact region to the critical temperature does not depend on the contact size only in the diffuse mode. For the ballistic contact it increases with decrease in the nanocontact size. The reduction of the transport electron mean free path due to heating of NCs may result in change of the electron transport mode from ballistic to diffusive one.Comment: 7 pages, 2 figures accepted for the publication in JETPL (http://www.jetpletters.ac.ru). Will be published on 25 april 201

Establishment of Hymenolepis diminuta Life Cycle to Provide Parasite Mass Production

Background: The main object of this experimental work was to practise laboratory production both adult and the larval stage of Hymenolepis diminuta with conventional modification to make further studies easier.Materials & Method: Adults H. diminuta were collected from urban rats in Tehran, Iran. The beetles became infected using blended gravid segments with flour as bait. Cysticercoids have been saved after precise dissection of invertebrate hosts. The exposure of infected beetles to labora­tory rats was performed to establish the life cycle. Result: Out of 57 collected rats, three rats were infected with H. diminuta. Almost all exposed beetles found infected with the larval stage of parasite. About one-month later H. diminuta eggs were seen in stool examination of laboratory rats.Conclusion: Rare human occurrence of H. diminuta along with light level of clinical manifesta­tion of this parasite, underestimate the concerns toward its public health importance. Nowadays, various field of studies, such as biochemistry with special focuses on the capability of H. di­minuta tegument absorption have performed apart from parasitological views alone. In the pre­sent study, establishment of this parasite life cycle has practically provided the access of adult and cysticercoid stages of the tapeworm in further researches

Identification and differentiation of Fasciola hepatica and Fasciola gigantica using a simple PCR-restriction enzyme method

Accurate morphological differentiation between the liver fluke species Fasciola hepatica and Fasciola gigantica is difficult. We evaluated PCR-restriction enzyme profiles of internal transcribed spacer 1 (ITS1) that could aid in their identification. Fifty F. hepatica and 30 F. gigantica specimens were collected from different hosts in three provinces of Iran. For DNA extraction, we crushed fragments of the worms between two glass slides as a new method to break down the cells. DNA from the crushed materials was then extracted with a conventional phenol-chloroform method and with the newly developed technique, commercial FTA cards. A primer pair was selected to amplify a 463-bp region of the ITS1 sequence. After sequencing 14 samples and in silico analysis, cutting sites of all known enzymes were predicted and TasI was selected as the enzyme that yielded the most informative profile. Crushing produced enough DNA for PCR amplification with both the phenol-chloroform and commercial FTA card method. The DNA extracted from all samples was successfully amplified and yielded a single sharp band of the expected size. Digestion of PCR products with TasI allowed us to distinguish the two species. In all samples, molecular identification was consistent with morphological identification. Our PCR-restriction enzyme profile is a simple, rapid and reliable method for differentiating F. hepatica and F. gigantica, and can be used for diagnostic and epidemiological purposes. © 2009 Elsevier Inc. All rights reserved

Fluid properties at high pressures and temperatures: Experimental and modelling challenges

Thermophysical properties impact many aspects of the chemical process industries. Here three example areas, primarily in the energy sector, are highlighted to provide context for the experimental and modelling challenges associated with obtaining fluid property data at high pressures and temperatures (HPHT). These three areas include the recovery of petroleum reserves in ultra-deep reservoirs, the use of lubricants to reduce frictional losses in the automotive industries, and the use of high-pressure, common rail diesel fuel delivery to reduce soot emissions for greener environments. The accurate knowledge of thermodynamic and transport properties in these three focused areas minimizes associated operating uncertainties and accelerates safe, reliable, and robust process and product development