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排序方式: 共有223条查询结果,搜索用时 15 毫秒
1.
Mariano Carossino Rudy Bauer Mark A. Mitchell Charles O. Cummings Anke C. Sthr Nobuko Wakamatsu Kimberly Harper Ingeborg M. Langohr Kendra Schultz Maria S. Mitchell Daniel K. Howe Udeni B. R. Balasuriya 《Journal of veterinary diagnostic investigation》2021,33(3):554
Toxoplasma gondii is a zoonotic protozoan pathogen that infects many endothermic vertebrates, including humans; the domestic cat and other felids serve as the definitive host. Macropodids are considered highly susceptible to toxoplasmosis. Here, we describe the clinical, pathologic, and immunohistochemical findings of an outbreak of systemic toxoplasmosis in a mob of 11 red kangaroos (Macropus rufus), with high morbidity (73%) and mortality (100%) rates. Affected animals had either severe and rapidly deteriorating clinical conditions or sudden death, which was correlated with widespread necrotizing lesions in multiple organs and intralesional T. gondii organisms identified via MIC3-specific immunohistochemistry and confirmed by REP529-specific rtPCR. Quantification of parasites demonstrated the highest parasite density in pulmonary parenchyma compared with other tissues. Our study highlights the continued importance of this severe condition in Australian marsupials. 相似文献
2.
From small-scale habitat loopholes to decadal cycles: a habitat-based hypothesis explaining fluctuation in pelagic fish populations off Peru 总被引:22,自引:0,他引:22
Arnaud Bertrand Marceliano Segura Mariano Gutiérrez & Luis Vásquez 《Fish and Fisheries》2004,5(4):296-316
The Peru‐Humboldt Current system (HCS) supports the world's largest pelagic fisheries. Among the world's eastern boundary current systems, it is the most exposed to high climatic stress and is directly affected by El Niño and La Niña events. In this volatile ecosystem, fish have been led to develop adaptive strategies in space and time. In this paper, we attempt to understand the mechanisms underlying such strategies, focusing on the El Niño 1997–98 in Peru from which an extensive set of hydrographic, capture and acoustic survey data are available. An integrated analysis of the data is crucial, as each has substantial shortcomings individually; for example, both catch data and acoustic surveys may easily lead to wrong conclusions. Existing hypotheses on anchovy and sardine alternations lead us to a ‘habitat‐based’ synthetic hypothesis. Using our data, an integrated approach evaluated how fish responded to habitat variation, and determined the consequences in terms of fish‐population variability. Various factors occurring at a range of different spatio‐temporal scales were considered: interdecadal regime (warm ‘El Viejo’/cool ‘La Vieja’ decadal scale); strength and the duration of the El Niño Southern Oscillation event (interannual scale); population condition before the event (interannual scale); fishing pressure and other predation (annual scale); changes in reproductive behaviour (intra‐annual scale); presence of local upwelling (local scale). During El Niño 1997–98, anchovy was able to exploit a small‐scale temporal and spatial ‘loophole’ inside the general unfavourable conditions. Moreover, sardine did not do better than anchovy during this El Niño and was not able to take advantage of the ‘loophole’ opened by this short‐term event. Our results question the traditional view that El Niño is bad for anchovy and good for sardine. 相似文献
3.
Supercritical fluid extraction of pesticides from a table-ready food composite of plant origin (gazpacho) 总被引:1,自引:0,他引:1
Aguilera A Brotons M Rodríguez M Valverde A 《Journal of agricultural and food chemistry》2003,51(19):5616-5621
Supercritical fluid carbon dioxide extraction (SFE) has been evaluated for the extraction of 17 organohalogen and organophosphate pesticides in gazpacho (a table-ready food composite containing crude vegetables, white bread, vegetable oil, water, and other minor components) using anhydrous magnesium sulfate as drying agent. The effects of different parameters, such as fat content in gazpacho composites, magnesium sulfate/gazpacho ratio, supercritical fluid volume, pressure, temperature, and static modifier additions, on SFE recoveries from spiked gazpacho samples have been studied. Analyses were performed by gas chromatography (GC) with flame photometric (FPD), electron capture (ECD), and mass spectrometry (MSD) detectors. In most experiments, recoveries obtained for the nonpolar organohalogen pesticides were lower than those obtained for the most polar organophosphate pesticides, but overall pesticide recoveries determined by using the optimal SFE conditions indicate that SFE could be used to determine pesticide residue levels in gazpacho. 相似文献
4.
Dynamics of porcine circovirus type 2 infection in a herd of pigs with postweaning multisystemic wasting syndrome 总被引:6,自引:0,他引:6
Rodríguez-Arrioja GM Segalés J Calsamiglia M Resendes AR Balasch M Plana-Duran J Casal J Domingo M 《American journal of veterinary research》2002,63(3):354-357
OBJECTIVE: To determine the pattern of infection for porcine circovirus type 2 (PCV2) in a herd of pigs with postweaning multisystemic wasting syndrome (PMWS). ANIMALS: 29 sows and 250 pigs. PROCEDURE: Blood samples were collected from all 3-, 7-, and 12-week old pigs and 59 pigs at 28 weeks of age. Pigs that died during the study were necropsied. Porcine parvovirus and PCV2 antibodies were assayed. A polymerase chain reaction (PCR) was used to detect PCV2 genome in serum of selected pigs. RESULTS: The PMWS started when pigs were 8 weeks old, with a prevalence of 30% in 8- to 10-week-old pigs. Eighty-three pigs died during the period between 3 and 12 weeks of age. Microscopic lesions consistent with PMWS were observed, and PCV2 nucleic acid was detected (50 of 68 pigs). Antibodies to PCV2 decreased from 3 to 7 weeks of age, increased at 12 weeks of age, and were maintained until 28 weeks of age. One sow had a positive result for PCR of serum. Nine, 37 and 8 pigs had PCV2 genome in serum obtained at 7, 12, and 28 weeks of age, respectively. CONCLUSIONS AND CLINICAL RELEVANCE: Infection with PCV2 coincided with severe clinical signs; however, infected 28-week-old pigs did not have evidence of disease. Immunity declined over time in young pigs. A long duration of PCV2 viremia was apparent in a high percentage of infected pigs, which may affect transmission and persistence of the virus in a herd. 相似文献
5.
Alessandra Torina Victoria Naranjo Maria Grazia Pennisi Tatiana Patania Fabrizio Vitale Pietro Laricchiuta Angelina Alongi Salvatore Scimeca Katherine M Kocan José de la Fuente 《Journal of zoo and wildlife medicine》2007,38(4):591-593
Lions (Panthera leo) are an endangered species threatened by illegal hunting, habitat loss, and infectious diseases. Little is known about the tick-borne pathogens that infect lions and could contribute to population declines. The objective of this study was to characterize Rickettsia spp., Anaplasma phagocytophilum, and Coxiella burnetii infections in 10 lions from the Fasano Safari Park in Italy by serology, polymerase chain reaction, and sequence analysis. Although animals did not show clinical signs of tick-borne diseases, evidence of infection with C. burnetii, spotted fever group Rickettsia sp., and A. phagocytophilum were found in 50%, 20%, and 10% of the lions, respectively. One of the lions tested positive for all three pathogens. This study is the first report of molecular evidence of infection with C. burnetii, Rickettsia sp., and A. phagocytophilum in lions and provides evidence that these felids become infected and serve as hosts for tick-transmitted bacteria. 相似文献
6.
Pérez-Brígido Carlos D. Romero-Salas Dora Pardío-Sedas Violeta T. Cruz-Romero Anabel González-Hernández Milagros Delprá-Cachulo Joyce Mara Ascencio Mariano Florin-Christensen Mónica Schnittger Leonhard Rodríguez Anabel E. 《Veterinary research communications》2022,46(1):295-302
Veterinary Research Communications - The black-handed spider monkey (Ateles geoffroyi) is a platyrrhine primate distributed in southern Mexico, Central America, and part of South America. Two... 相似文献
7.
A sensitive and specific method is described for the simultaneous determination of oxytetracycline, tetracycline (TC), and chlortetracycline residues in edible swine tissues, by combining liquid chromatography with spectrofluorometric and mass spectrometry detection. The procedure involved a preliminary extraction with EDTA-McIlvaine buffer acidified at pH 4.0, followed by solid-phase extraction cleanup using a polymeric sorbent. The liquid chromatography analysis was performed with spectrofluorometric detection after postcolumn derivatization with magnesium ions. The limits of quantification were 50 microg/kg for muscle and 100 microg/kg for kidney tissues. The recovery values were greater than 77.8% for muscle and 65.1% for kidney. The method has been successfully used for the quantification of tetracyclines in swine tissues samples. The selective liquid chromatography mass spectrometric analysis for confirmation of oxytetracycline in one positive swine muscle sample was made by atmospheric pressure chemical ionization (APCI). The APCI mass spectra of the TCs gave the protonated molecular ion and two typical fragment ions, required for their confirmation in single ion monitoring scan mode in animal tissues. 相似文献
8.
da Costa Eline Nayara Dantas de Souza Jéssica Carneiro Pereira Marilane Andrade de Souza Marcelo F. Landim de Souza Weber F. Landim da Silva Daniela Mariano Lopes 《Agroforestry Systems》2021,95(8):1647-1659
Agroforestry Systems - Inland waters such as streams that receive carbon from terrestrial landscapes usually have a net heterotrophic metabolism and emit significant amounts of CO2 to the... 相似文献
9.
Doychin Terziyski George Grozev Roumen Kalchev Angelina Stoeva 《Aquaculture International》2007,15(3-4):181-190
The effect of cattle organic fertilizer on plankton primary production and related variables was tested in six Bulgarian fish
ponds situated close to the town of Plovdiv in Bulgaria. At the beginning of the experiment (16th of May 2004, about 10 days
after filling with water) a suppression of plankton metabolism was observed and after that the ponds treated with manure demonstrated
significantly higher productivity than the controls, especially during the transition to the autumn season when the water
column was more regularly mixed. The other measured variables (Secchi disk readings, plankton chlorophyll-a and respiration, assimilation number per unit chlorophyll-a) did not show significant differences between the treated and control ponds. 相似文献
10.
We report the first use of 14C isotope analysis to investigate the ecological grouping of earthworms. Mature endogeic (Allolobophora caliginosa), mature epigeic (Lumbricus rubellus), and semimature anecic worms (A. longa) were collected in September 2002 from a woodland site at Lancaster, UK. Because anecic worms are known to have a variable feeding behaviour and can show dietary changes during ontogeny, additional immature and mature specimens of A. longa were also collected from the same site in January 2004. Epigeic earthworms showed the lowest radiocarbon concentration (0-3-years old), implying that they assimilated more recently fixed carbon than the anecic or endogeic earthworms. The age of carbon assimilated in mature anecic species (5-7-years old) was closer to that of endogeic species (5-8-years old) than to epigeics, suggesting that a greater proportion of older, more mineralised organic matter may form part of the diet of the anecic earthworms than previously thought. These results suggest that 14C approaches are useful in the study of the feeding behaviour of detritivorous animals by providing in situ information on the age of the carbon assimilated by the worms. This can then be related to their role in ecosystem functioning, particularly in carbon cycling. 相似文献