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761.
Moreno José L. Pérez Aurelia Aliaga Asunción Hernández Teresa 《Water, air, and soil pollution》2003,143(1-4):289-300
Nickel pollution may affect microbial communitydevelopment and its activity in soil and, therefore, itsfertility, while organic amendment may affect Ni mobilityand bioavailability. The aim of this research was toascertain the extent to which the addition of sewage sludgeto soil may affect Ni toxicity and to establish theecological dose of this heavy metal. Unamended and amendedsoils with sewage sludge were spiked with differentconcentrations of Ni (0–8000 mg kg-1) and then incubatedfor 3 hours, 12 days and 40 days. Soil dehydrogenaseactivity, ATP content, microbial respiration and microbialbiomass C were measured in the samples containing differentNi concentrations. A mathematical model which describe theinhibition of these soil parameters were used to calculatethe ecological dose of Ni: ED50. Soil microbialbiomass C measurements of all treatments better fitted themodel (r2 = 0.95–0.69 with p < 0.05) than the otherparameters studied; but the ED50 values predicted by the modelhad a high coefficient of variation. For both ATP contentand microbial biomass C, the ED50 values calculatedfor the amended soil were higher than for the unamendedsoil and so that the effect of Ni toxicity on theseparameters of microbial activity may be considered lower inthe former. In this study, an increase in ED50 valueswith the time elapsed was also observed. 相似文献
762.
Carla S. Pimentel Jessica McKenney Paulo N. Firmino Teresa Calvão Mathew P. Ayres 《Plant pathology》2020,69(8):1565-1573
Bursaphelenchus xylophilus, the pinewood nematode and causal agent of pine wilt disease (PWD), is a globally destructive pine pest. PWD is favoured by high temperatures and drought, but B. xylophilus can also persist in symptomless hosts in areas not prone to PWD. We compared seedlings of different Pinus species that were inoculated with B. xylophilus when well-watered and under moderate temperatures, conditions that favour sublethal infections. We compared isolates of B. xylophilus in south-west Europe (Portugal) and south-east USA (Louisiana). P. pinea, P. pinaster, and P. radiata were challenged in both areas with inoculations of local B. xylophilus. P. sylvestris in Portugal and P. palustris in Louisiana were also tested. Seedling mortality was low, as expected, but nematode establishment was common. There were higher nematode densities and more damage in seedlings of P. sylvestris and P. radiata, followed by P. pinaster, with P. pinea and P. palustris proving to be more tolerant. Life history of hosts was a better predictor of resistance to B. xylophilus than geographical origin, even under sublethal conditions. Fast-growing species (P. radiata and P. pinaster) appeared most likely to be symptomless carriers in areas not prone to the development of PWD. Cold-adapted species (P. sylvestris) may still be suitable hosts for the pathogen, even at the sublethal conditions of their distribution areas. There were more nematodes per gram of host using nematode isolates from Portugal. Nonetheless, our results opposed the hypothesis that North American pinewood nematodes have such low virulence that they are obligatorily saprophytic. 相似文献
763.
Under the name of lipophilic marine toxins, there are included more than 1000 toxic secondary metabolites, produced by phytoplankton, with the common chemical property of lipophilicity. Due to toxicological effects and geographical distribution, in European legislation relevant compounds are regulated, and their determination is accomplished with the reference liquid chromatography-tandem mass spectrometry method. In this study a modified ultra-high performance liquid chromatography-tandem mass spectrometry (UHPLC-MS/MS) method has been developed for the identification and quantification of EU-regulated lipophilic toxins. The method optimization included a refinement of SPE-C18 clean-up, in order to reduce matrix interferences. Improved LC conditions and upgraded chromatographic ammonia-based gradient ensured the best separation of all analytes and, in particular, of the two structural isomers (OA and DTX2). Also, different MS parameters were tested, and confirmation criteria finally established. The validation studies confirmed that all parameters were satisfactory. The requirements for precision (RSD% < 11.8% for each compound), trueness (recoveries from 73 to 101%) and sensitivity (limits of quantification in the range 3–8 µg kg−1) were fulfilled. The matrix effect, ranging from −9 to 19%, allowed the use of a calibration curve in solvent (3–320 µg kg−1 in matrix) for quantification of real samples. Method relative uncertainty ranged from 12 to 20.3%. Additionally, a total of 1000 shellfish samples was analysed, providing a first preliminary surveillance study that may contribute to the knowledge of lipophilic marine toxins contamination. Increase in algae proliferation events and intoxication cases, EFSA suggestions for modification of maximum permitted levels and toxicity equivalency factors, and new studies of important toxic effects underline that implementation of reference methods still represents an important task for health and food safety laboratories. 相似文献
764.
- 1. Recently, the snails Hinia reticulatus, Cyclope neritea and Cerithium rupestre and the hermit crabs Diogenes pugilator and Clibanarius erythropus from warm European coastal waters have started to be commercially collected and traded.
- 2. The average number (± standard deviation) of specimens captured per hour, by collectors were 475±237 for H. reticulatus, 363±112 for C. neritea, 384±173 for C. rupestre, 302±121 for D. pugilator and 210±54 for C. erythropus.
- 3. All species survived well during transportation, were popular among aquarium hobbyists and attained high retail values, ranging from €0.90 to €4.00 per specimen.
- 4. The collection and trade of these novel commercial species can either become a sole economic activity or an additional one for traditional fishermen and aquaculturists.
- 5. Although no destructive collection techniques are employed, the lack of population biology studies and legislation regulating the capture of these species is a major problem in ensuring the sustainable use of these highly valuable marine resources.
- 6. These species are currently mainly collected from natural parks areas protected by Portuguese and European Union designations.
765.
766.
Rosario Torres Carla Nunes José María García Maribel Abadias Inmaculada Viñas Teresa Manso Manuel Olmo Josep Usall 《European journal of plant pathology / European Foundation for Plant Pathology》2007,118(1):73-83
We determined the potential of using a formulated product based on Pantoea agglomerans CPA-2, either alone or in combination with heated sodium bicarbonate (SBC) solutions, to control the major postharvest diseases
affecting citrus crops in the Mediterranean region. Treatments applied either individually or in combination were tested in
semi-commercial and commercial trials carried out with oranges and mandarins from the Algarve, Andalusia and Catalonia. Firstly,
several formulations of the biocontrol agents were tested in laboratory trials; one of them, a freeze-dried formulation of
P. agglomerans strain CPA-2 called FD10-3, was chosen for combined with SBC. This formulation, applied at 2 × 108cfu ml−1 and the SBC treatment, applied at 3% 50°C for 20–40 s, demonstrated that it was possible to reduce decay development in laboratory
trials. Semi-commercial applications of FD10-3 and 3% SBC solution at 50°C for 40 s showed excellent control of decay in unwounded
mandarins and oranges artificially inoculated with both Penicillium digitatum and P. italicum. No rind injuries or residues attributable to hot water or SBC were observed on treated fruits. Combined treatment provided
better control than the two treatments applied separately. Commercial trials demonstrated an important reduction in natural
decay with the treatment of SBC 3% at 50°C for 40 s. Furthermore, bacterial-product formulation treatment significantly reduced
the percentage of infected fruit and in some cases this reduction was equal to chemical treatments. Even so, no improvement
in efficacy was observed with the combination of FD10-3 and SBC in the commercial test. We also assessed the ability of FD10-3
to grow at the wound site in oranges, whether alone or in the presence of SBC, and also its compatibility with standard citrus
packinghouse practices. 相似文献
767.
Teresa M. Rieser VMD Cynthia M. Otto DVM PhD 《Journal of Veterinary Emergency and Critical Care》1998,8(1):7-18
Over the past ten years, nitric oxide has been shown to be important in a number of biological systems. This article is a review of the literature on nitric oxide and its affects on hemodynamics in the kidney. Nitric oxide is a major contributor to basal vasodilatory tone in the renal vasculature and systemic vasculature. It also has effects on the mechanisms which comprise the tubuloglomerular feedback loop. (Vet Emerg & Crit Care, 1998; 8: 7–18) 相似文献
768.
First evidence of resistance to pyrethroid insecticides in Italian Aedes albopictus populations 26 years after invasion 下载免费PDF全文
Verena Pichler Romeo Bellini Rodolfo Veronesi Daniele Arnoldi Annapaola Rizzoli Riccardo Paolo Lia Domenico Otranto Fabrizio Montarsi Sara Carlin Marco Ballardini Elisa Antognini Marco Salvemini Emanuele Brianti Gabriella Gaglio Mattia Manica Pietro Cobre Paola Serini Enkelejda Velo John Vontas Ilias Kioulos Joao Pinto Alessandra della Torre Beniamino Caputo 《Pest management science》2018,74(6):1319-1327
769.
770.
Margarita Tejada Horst Karl Cristina de las Heras Sanja Vidacek Maria Teresa Solas Maria Luisa Garcia 《Journal Of Aquatic Food Product Technology》2013,22(3):221-236
The distribution of Anisakis larvae in fresh caught hake was studied, and the influence of three infection levels of the viscera (low, medium, high) on quality changes of deep frozen muscle was followed over 220 days. Differences in quality were attributed more to the size of the individuals than to the infection degree of the three groups. The removal of belly flaps diminished the risk of consumers’ infection and sensitization as prevalence and intensity was reduced to 75.6 and 5.9%, respectively. Allergens were detected after 220 days frozen storage, which represents a risk for consumers already allergic to Anisakis. 相似文献