Comparative histopathological and immunological study of two field strains of chicken anemia virus     

Agustina Rimondi  Silvina Pinto  Valeria Olivera  Marina Dibárbora  Mariano Pérez-Filgueira  María Isabel Craig  Ariel Pereda 《Veterinary research》2014,45(1)

Infection of poultry with chicken anemia virus (CAV) is implicated in several field problems in broiler flocks due to the immunosuppression generated and, consequently, the increased susceptibility to secondary infections. Recently, we have reported an increased occurrence of clinical cases caused by CAV strains distantly related to those commonly used for vaccination. In order to understand the behavior of two Argentinean CAV strains (CAV-10 and CAV-18) in two-week-old chickens, an immune and histopathological study was performed. Neither mortality nor clinical signs were observed in the infected or control groups. Thymus lobes from chickens infected with both CAV viruses were smaller compared to the negative control group. At 14 days post-infection (dpi), only chickens inoculated with CAV-10 show a severe depletion of lymphocytes in the thymus cortex and in follicles from the bursa of Fabricius. Also thymopoiesis disorders, such as reduction in the percentage of total DP (CD4 + CD8α+) thymocytes and alteration in the percentages of DP subpopulations, were more important in animals inoculated with the CAV-10 than the CAV-18 strain. In addition, only animals infected with CAV-10 show a decrease in CD8αβ splenocytes. Altogether our results show that, although both Argentinean CAV strains produce subclinical infections in chickens causing immunosuppression at 14 dpi, they might differ in their in vivo pathogenicity.  相似文献   

Natural and experimental hepatitis E virus genotype 3 - infection in European wild boar is transmissible to domestic pigs     

Josephine Schlosser  Martin Eiden  Ariel Vina-Rodriguez  Christine Fast  Paul Dremsek  Elke Lange  Rainer G Ulrich  Martin H Groschup 《Veterinary research》2014,45(1)

Hepatitis E virus (HEV) is the causative agent of acute hepatitis E in humans in developing countries, but sporadic and autochthonous cases do also occur in industrialised countries. In Europe, food-borne zoonotic transmission of genotype 3 (gt3) has been associated with domestic pig and wild boar. However, little is known about the course of HEV infection in European wild boar and their role in HEV transmission to domestic pigs. To investigate the transmissibility and pathogenesis of wild boar-derived HEVgt3, we inoculated four wild boar and four miniature pigs intravenously. Using quantitative real-time RT-PCR viral RNA was detected in serum, faeces and in liver, spleen and lymph nodes. The antibody response evolved after fourteen days post inoculation. Histopathological findings included mild to moderate lymphoplasmacytic hepatitis which was more prominent in wild boar than in miniature pigs. By immunohistochemical methods, viral antigens were detected mainly in Kupffer cells and liver sinusoidal endothelial cells, partially associated with hepatic lesions, but also in spleen and lymph nodes. While clinical symptoms were subtle and gross pathology was inconspicuous, increased liver enzyme levels in serum indicated hepatocellular injury. As the faecal-oral route is supposed to be the most likely transmission route, we included four contact animals to prove horizontal transmission. Interestingly, HEVgt3-infection was also detected in wild boar and miniature pigs kept in contact to intravenously inoculated wild boar. Given the high virus loads and long duration of viral shedding, wild boar has to be considered as an important HEV reservoir and transmission host in Europe.

Electronic supplementary material

The online version of this article (doi:10.1186/s13567-014-0121-8) contains supplementary material, which is available to authorized users.  相似文献   

Investigation of ornamental fish entering the EU for the presence of ranaviruses     

Vesely T  Cinkova K  Reschova S  Gobbo F  Ariel E  Vicenova M  Pokorova D  Kulich P  Bovo G 《Journal of fish diseases》2011,34(2):159-166

A survey was performed on ornamental fish imported into the EU to detect viral agents belonging to the genus Ranavirus. The objective was to gain knowledge of the potential for these systemic iridoviruses to gain entry into the EU via international trade in ornamental fish. A total of 208 pooled samples, representing 753 individual fish, were tested. The samples included 13 orders and 37 families, originating from different countries and continents. Tissues from fish that died during or just after transport were collected and examined by standard virological techniques in epithelioma papulosum cyprini cells, by transmission electron microscopy and by PCR for the detection of the major capsid protein and DNA polymerase gene sequences of ranaviruses. Virus was isolated from nine fish species but ranavirus was not identified in those samples. The results suggest that ranaviruses are not highly prevalent in ornamental fish imported into the EU.  相似文献   

Center of rotation of angulation-based leveling osteotomy combined with a coplanar cranial closing wedge ostectomy to manage cranial cruciate ligament insufficiency in dogs with excessive tibial plateau angle     

Ariel N. Schlag DVM  Laura E. Peycke DVM  MS  DACVS  DACVSMR  Don A. Hulse DVM  DACVS  DECVS 《Veterinary surgery : VS》2020,49(6):1125-1131

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Foreword     

Ariel E. Lugo 《Water, air, and soil pollution》1993,70(1-4):ix-x

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Economic evaluation of salinity,drainage and non-uniformity of infiltrated irrigation water     

Ariel Dinar  J. Letey  Keith C. Knapp 《Agricultural Water Management》1985,10(3):221-233

Salinity, drainage and non-uniformity of irrigation water are important components in determining optimal water application and related profitability. A crop-water production function assuming steady state conditions is incorporated in a long-run economic model to investigate the combined effects of salinity, irrigation uniformity and different drainage requirements at the field scale for the specific crop.The analysis was conducted for corn and cotton as sensitive and tolerant crops to salinity, respectively. Optimum applied water and associated profits, yield and drainage volumes were computed for each crop. The computations were done for the condition that no drainage system was required and also where a drainage system was required and the drainage water was disposed of to either a free off-farm facility or to an on-farm evaporation pond constructed on productive or non-productive land.The main findings are that type of drainage disposal system affects the optimal values of applied water, profits, yield and drainage volumes, except for uniform water applications and non-saline irrigation water. Another finding is that in the long run, under saline conditions and/or different drainage disposal systems, a sensitive crop such as corn is not profitable and goes out of production. In general the profit levels associated with the various drainage options are in the order of no drainage requirement ? free off-farm facility > on-farm evaporation pond on non-productive land > on-farm evaporation pond on productive land. Uniformity of irrigation water affects values of the analyzed variables and the effects are greatest for the cases of on-farm evaporation ponds. Pumping cost effects are quite small, but water price effects are more significant. Breeding the crops for increased salinity tolerance has little effect when irrigating with water of low salinity and/or low irrigation uniformity.  相似文献   

Identification of case clusters and counties with high infective connectivity in the 2001 epidemic of foot-and-mouth disease in Uruguay     

Chowell G  Rivas AL  Smith SD  Hyman JM 《American journal of veterinary research》2006,67(1):102-113

OBJECTIVE: To evaluate the influence of individual spatial units (ie, counties) on the epidemic spread of foot-and-mouth disease (FMD) virus. SAMPLE POPULATION: 163 counties in Uruguay where there was an outbreak of FMD between April 23 and July 11, 2001. PROCEDURE: A geographically referenced database was created, and the distance between counties (13,203 county pairs), road density of counties (163 counties), and time when cases were reported in those counties (11 weeks of the epidemic) were considered to assess global spatial and spatial-temporal autocorrelation, determine the contribution of links connecting pairs of counties with infected animals, and allow us to hypothesize the influence for spread during the epidemic for counties with greater than the mean infective link contributions. RESULTS: Case clusters were indicated by the Moran Iand Mantel tests during the first 6 weeks of the epidemic. Spatial lags between pairs of counties with infected animals revealed case clustering before and after vaccination was implemented. Temporal lags predicted autocorrelation for up to 3 weeks. Link indices identified counties expected to facilitate epidemic spread. If control measures had been implemented in counties with a high index link (identifiable as early as week 1 of the epidemic), they could have prevented (by week 11 of the epidemic) at least 2.5 times as many cases per square kilometer than the same measures implemented in counties with average link indices. CONCLUSIONS AND CLINICAL RELEVANCE: Analysis of spatial autocorrelation and infective link indices may identify network conditions that facilitate (or prevent) disease spread.  相似文献   

Transcrystalline melt migration and Earth's mantle     

Schiano P  Provost A  Clocchiatti R  Faure F 《Science (New York, N.Y.)》2006,314(5801):970-974

Plate tectonics and volcanism involve the formation, migration, and interaction of magma and gas. Experiments show that melt inclusions subjected to a thermal gradient migrate through olivine crystals, under the kinetic control of crystal-melt interface mechanisms. Exsolved gas bubbles remain fixed and eventually separate from the melt. Scaled to thermal gradients in Earth's mantle and geological times, our results account for the grain-scale segregation of primitive melts, reinterpret CO2-rich fluid inclusions as escaped from melt, and question the existence of a free, deeply percolating fluid phase. Melt migration experiments also allow us to quantify crystal growth kinetics at very low undercoolings in conditions appropriate to many natural systems.  相似文献   

Temporal sequence of cell wall disassembly events in developing fruits. 1. Analysis of raspberry (Rubus idaeus)     

Vicente AR  Ortugno C  Powell AL  Greve LC  Labavitch JM 《Journal of agricultural and food chemistry》2007,55(10):4119-4124

Raspberry fruits were harvested at five developmental stages, from green to red ripe, and the changes in cell wall composition, pectin and hemicellulose solubilization, and depolymerization were analyzed. Fruit softening at intermediate stages of ripening was associated with increased pectin solubilization, which occurred without depolymerization. Arabinose was found to be the most abundant noncellulosic neutral sugar in the cell wall and showed dramatic solubilization late in ripening. No changes in pectin molecular size were observed even at the 100% red stage. Subsequently, as fruit became fully ripe a dramatic depolymerization occurred. In contrast, the hemicellulosic fractions showed no significant changes in content or polymer size during ripening. The paper discusses the sequence of events leading to cell wall disassembly in raspberry fruit.  相似文献   

Harnessing genetic resources and progress in plant genomics for fonio (<Emphasis Type="Italic">Digitaria</Emphasis> spp.) improvement     

Mathieu Anatole Tele Ayenan  Kpedetin Ariel Frejus Sodedji  Charles Ikenna Nwankwo  Katina Floride Olodo 《Genetic Resources and Crop Evolution》2018,65(2):373-386

Fonio plays an important role in food security and in income generation, in drought prone areas of West Africa. This review aimed at highlighting fonio production constraints, breeding objectives and available genetic resources for fonio improvement. Lack of institutional support to research, lack of improved seeds, parasitic weed infestation, grain shattering, lodging and toilsome of the post-harvest handling are the major constraints limiting fonio production. These factors lead to negligence of the crop notwithstanding its high nutritional and market values. Breeding programs on fonio should first focus on solving these problems to improve overall yield. We explored the potential of mutation breeding, somaclonal variation, somatic hybridization, molecular markers, comparative genomics, individualized targeting induced local lesions in genomes (iTILLING), genotype by sequencing and genomic selection to develop improved fonio varieties. Determination of ploidy level, wide collection and characterization of fonio genetic resources, definition of core reference set collection, and exploitation of heterosis are some key research areas that would be of great interest in fonio improvement. However, this can only be achieved with adequate funding and institutional support.  相似文献