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191.
Francisco Llorente Elisa Pérez-Ramírez Jovita Fernández-Pinero Maia Elizalde Jordi Figuerola Ramón C. Soriguer Miguel ángel Jiménez-Clavero 《Veterinary research》2015,46(1)
Bagaza virus (BAGV) is a mosquito-borne flavivirus belonging to the Ntaya serocomplex. In 2010, a disease outbreak was reported in Cádiz (Southern Spain) affecting game birds (red-legged partridges and common pheasants). In this work, red-legged partridges were inoculated experimentally with infectious BAGV isolated from this outbreak in order to make a complete clinical and analytical assessment of the disease caused by the pathogen in this species. Viral load (by real-time RT-PCR) in blood, oral and cloacal swabs, and feathers, and neutralizing antibody titres (by VNT) were measured. In order to determine direct contact transmission, non-inoculated partridges were caged together with the inoculated ones. To assess infectiousness in other species, house sparrows and mice were also inoculated with the virus. All the inoculated partridges were clinically affected, and 30% of them died. All the infected individuals lost weight, with larger losses being recorded in females. Conversely, no mortality or disease symptoms were observed in the sparrows or mice. Remarkably, all the contact partridges acquired the infection by direct (non-vectored) transmission. This study confirms that the red-legged partridge is a susceptible host for BAGV infection, and that this pathogen is transmitted by direct contact. Long-lasting viral loads detected in calami of immature feathers demonstrate that feather sampling could be a useful strategy in active surveillance programs for early detection of BAGV.
Electronic supplementary material
The online version of this article (doi:10.1186/s13567-015-0233-9) contains supplementary material, which is available to authorized users. 相似文献192.
Elisa N. Salas Debra Royal Lance Kurz J. Dustin Loy 《The Canadian veterinary journal. La revue veterinaire canadienne》2015,56(5):466-470
We report the first detection of Nocardiopsis composta in association with osteomyelitis in a young male miniature Australian shepherd dog. Findings included suppurative osteomyelitis containing intralesional Fite’s acid fast bacilli, aerobic culture of branching Gram-positive rods, and positive identification via phenotypic analysis and 16S rDNA sequencing. 相似文献
193.
194.
Angeles Adn Pedro Del Estal Flor Budia Manuel Gonzlez Elisa Viuela 《Pest management science》1996,48(3):261-268
Laboratory studies were conducted to determine the effect of the naturally derived compound spinosad on Ceratitis capitata Wied. (Diptera, Tephritidae). The organophosphate fenthion was used as a standard. Direct dose-dependent mortality and reduced fecundity were observed in oral treatment of adults with spinosad. The LC90 values 14 h and seven days after treatment were 19·50 and 0·49 mg litre−1 respectively. Fenthion was less active (the LC50 eight days after treatment was 1·17 mg litre−1) and did not affect the fecundity of the fly. Adults were also very susceptible to spinosad and fenthion via residual contact. For spinosad, 100% mortality was recorded 48 h after treatment for a dose of 10 mg litre−1. Spinosad was more effective than fenthion in suppressing larval development when neonate larvae were reared on treated diet supplemented with a range of concentrations from 0·02 to 0·83 mg kg−1 diet. Last-instar larvae were much less susceptible to spinosad or fenthion when exposed via dipping or when they pupated in treated medium and both products had similar performance. A lack of ovicidal activity was observed in direct egg-treatments with spinosad but significant reductions from 1 mg litre−1 onwards were recorded for fenthion. 相似文献
195.
A production season of turbot larvae Scophthalmus maximus (Linnaeus, 1758) reared on copepods in a Danish (56°N) semi‐intensive outdoor system 下载免费PDF全文
Per M Jepsen Hans H Jakobsen Thomas A Rayner Elisa Blanda Aliona Novac Kirsten Engell‐Sørensen Benni W Hansen 《Aquaculture Research》2017,48(9):4958-4974
Turbot were reared from yolk sack larvae to juvenile in an outdoor semi‐intensive system. Three production cycles were monitored from May to September. A pelagic food chain was established with phytoplankton, copepods and turbot larvae. Abiotic and biotic parameters of lower trophic levels together with turbot larval survival, development, prey electivity and growth were monitored. A decreasing larval survival from 18.4% in May to 13.6% in July and just 7.0% in September was observed. The overall phytoplankton and copepod abundance decreased during the productive season. The turbot larval growth showed significant differences between larvae below (isometric) and above (allometric) 7 mm. Larval fish gut content showed no differences with available prey between production cycles. Therefore, it appears that the available prey concentration is governing their growth in this outdoor system. First‐feeding turbot larvae exhibited active selection for nauplii whereas developed larvae switched to copepodites and adult copepods. Although developing turbot larva exhibited active selection towards copepod size classes, there was no evidence of selective feeding on either of the two dominant copepod species. The turbot larvae's prey ingestion was modelled together with the standing stock of copepod biomass. The model results indicated that the estimated need for daily ingestion exceeded the standing stock of copepods. Hence, the initially established food web was unable to sustain the added turbot larvae with starvation as a consequence. We therefore suggest several solutions to circumvent starvation in the semi‐intensive system. 相似文献
196.
Villalba-Villalba Ana Gloria Pacheco-Aguilar Ramón Ramirez-Suarez Juan Carlos Valenzuela-Soto Elisa Miriam Castillo-Yáñez Francisco Javier Márquez-Ríos Enrique 《Fisheries Science》2011,77(4):697-705
Vermiculated sailfin catfish (Pterygoplichthys disjunctivus, Weber, 1991), a member of the Loricariidae family and an invasive species of several inland waters around the world, possess
an enormous digestive tract representing about 10% of fish weight. Thus, the aim of this study was to partially characterize
proteases from their digestive tracts. Azocasein digestion of the crude extract of intestine at different pH values and temperatures
revealed the presence of alkaline proteases with optimum activities at pH 9.0 and 50°C. Incubation assays of the crude extract
with inhibitors such as phenyl methyl sulfonyl fluoride, N-α-p-tosyl-l-lysine chloromethyl ketone, N-tosyl-phenyalanine chloromethyl ketone, benzamidine, pepstatin A and ethylenediamine tetra-acetic acid showed that trypsin
and chymotrypsin are the main alkaline proteinases present. Zymography showed that the crude extract of Pterygoplichthys
disjunctivus viscera contained proteases with molecular masses ranging from 21.5 to 116 kDa. Trypsin and chymotrypsin were inhibited by
the following ions in decreasing order: Hg2+, Fe2+, Cu2+, Li+, Mg2+, K+, while Mn2+, and Ca2+ had no effect. Activities decreased continuously as the NaCl concentration increased from 0 to 30%. These results constitute
important background information for future studies and for the potential biotechnological use of the crude digestive extract
from this invasive species. 相似文献
197.
Juan Estrella‐Martínez Bernd R. Schne Ruth H. Thurstan Elisa Capuzzo James D. Scourse Paul G. Butler 《Fish and Fisheries》2019,20(3):537-551
Understanding the recruitment variability of the Atlantic herring North Sea stock remains a key objective of stock assessment and management. Although many efforts have been undertaken linking climatic and stock dynamic factors to herring recruitment, no major attempt has been made to estimate recruitment levels before the 20th century. Here, we present a novel annually resolved, absolutely dated herring recruitment reconstruction, derived from stable carbon isotope geochemistry (δ13C), from ocean quahog shells from the Fladen Ground (northern North Sea). Our age model is based on a growth increment chronology obtained from fourteen shells. Ten of these were micromilled at annual resolution for δ13C analysis. Our results indicate that the anthropogenically driven relative depletion of 13C, the oceanic Suess effect (oSE), became evident in the northern North Sea in the 1850s. We calculated a regression line between the oSE‐detrended δ13C results (δ13C?) and diatom abundance in the North Sea, the regression being mediated by the effect of phytoplankton on the δ13C of the ambient dissolved inorganic carbon. We used this regression to build an equation mediated by a nutritional link to reconstruct herring recruitment using δ13C?. The reconstruction suggests that there were five extended episodes of low‐recruitment levels before the 20th century. These results are supported by measured recruitment estimates and historical fish catch and export documentation. This work demonstrates that molluscan sclerochronological records can contribute to the investigation of ecological baselines and ecosystem functioning impacted by anthropogenic activity with implications for conservation and stock management. 相似文献
198.
Crops are negatively affected by abiotic and biotic stresses, however, plant‐microbe cooperation allows prompt buffering of these environmental changes. Microorganisms exhibit an extensive metabolic capability to assist plants in reducing these burdens. Interestingly, beneficial microbes may also trigger, at the host side, a sequence of events from signal perception to metabolic responses leading to stress tolerance or protection against biotic threats. Although plants are well known for their vast chemical diversity, plant‐microbial interactions often stimulate the production of a rich and different repertoire of metabolites in plants. The targeted microbial‐plant interactions reprogramming plant metabolism represent potential means to foster various pest managements. However, the molecular mechanisms of microbial modulation of plant metabolic plasticity are still poorly understood. Here, we review an increasing amount of reports providing evidence for alterations to plant metabolism caused by beneficial microbial colonization. In addition, we highlight the vital importance of these metabolic reprograms for plants under stress erratic conditions. © 2019 Society of Chemical Industry 相似文献
199.
Gregorio Egea Elisa Pagán Alain Baille Rafael Domingo Pedro A. Nortes Alejandro Pérez-Pastor 《Irrigation Science》2009,27(6):431-441
The suitability of trunk diameter reference baselines for irrigation scheduling of mature drip-irrigated almond trees [Prunus dulcis (Mill). D.A. Webb cv Marta] was assessed in a 3-year experiment conducted on well-watered trees in south-eastern Spain. Continuous
measurements of trunk daily growth rate (DGR) and maximum daily trunk shrinkage (MDS) were carried out throughout the growing
season (April–November). Day-to-day variations in MDS and DGR were related with meteorological variables. DGR was found to
be weakly correlated to all the meteorological variables, while MDS showed significant relationships with most of them. The
mean air vapour pressure deficit during the period 10.00–15.00 h solar time (VPDmx) was the environmental variable that best correlated with MDS. The relationships obtained were similar for all the phenological
phases, except postharvest, when MDS showed a tendency towards lower values for a given atmospheric evaporative demand. The
increase in trunk diameter over the 3 years also appeared to affect the relationships to some extent. As a practical procedure,
it is proposed determining the baseline periodically (every 1 or 2 years) during the early stages (II–III) of the almond phenological
cycle, for use as reference MDS for the subsequent growth stages, because over longer periods several factors affecting the
stability of the baseline, in particular trunk diameter growth, might introduce changes in the baseline. 相似文献
200.
The purpose of this study was to evaluate the effect of a skip-a-day feeding regime on the growth of one-year-old sturgeon, Acipenser stellatus. Sturgeons possess a spiral valve intestine, which slows down the passage of food to longer than 24 hours, providing a scientific justification for the experiment. The experiment had a duration of 12 weeks and consisted of two treatments groups with four replicates each. One group of sturgeons (n = 120) was offered feed every day, on a continuous basis, at 2% of their body weight daily; while a second group of sturgeons (n = 120) were fed every other day, also at 2% of their body weight daily. The sturgeons had an average initial body weight of 178 ± 32 g and measured 44.6 ± 2.9 cm in total length. At the end of the experimental period, all sturgeons were alive, in good health, and no statistically significant differences (P > 0.05) on growth performance indices were detected between sturgeons fed every day and every other day. The average weights and lengths of sturgeons at the end of the trial were 406 ± 96 g and 55.4 ± 4.4 cm. The results of this study suggest that yearling sturgeon may be fed every other day rather than daily. A skip-a-day feeding regime can result in feed savings for a commercial operation, help protect the natural resources such as those for making fish meal, and lessen the impact of excess nutrients in natural bodies of water. 相似文献