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1.
Bravo Carlo Millo Christian Covelli Stefano Contin Marco De Nobili Maria 《Journal of Soils and Sediments》2020,20(2):1074-1086
Journal of Soils and Sediments - Humic acids (HA) have several environmental roles, but are particularly important in aquatic environments, being recognized as redox active natural organic matter... 相似文献
2.
Mark E. Hines Stefano Covelli Jadran Faganeli Milena Horvat 《Journal of Soils and Sediments》2017,17(7):1961-1971
Purpose
Concentrations and transformations of mercury were measured in river, estuarine, and marine sediments to determine factors affecting the fate of mercury entering the northern Adriatic Sea.Materials and methods
Radiotracer methodology was used to compare rates of mercury methylation (203Hg), MeHg demethylation (14C), and sulfate reduction (35S) in sediment depth profiles to concentrations of total and dissolved mercury species in the lower freshwater region of the Isonzo River, the coastal lagoons, and in the Gulf of Trieste, northern Adriatic Sea.Results and discussion
Mercury was readily methylated and demethylated in all sediments, but the relative activity of these processes varied greatly with location. Methylation activity increased greatly from freshwater to the marine regions; however, demethylation was extremely high in the estuarine and lagoon sites. Ratios of methylation to demethylation were low in these coastal sites but increased further offshore in the gulf, which agreed with increased ratios of MeHg to total Hg (%MeHg) in gulf sediments. Comparisons of microbial activities indicated that sulfate reduction strongly controlled both methylation and demethylation. However, Hg methylation in coastal lagoon sediments was controlled by rapid demethylation and the bioavailability of Hg that was affected by Hg adsorption and precipitation. Methylation in offshore marine sites correlated with sulfate reduction but not the partitioning of Hg between pore water and solid phases. The decrease in sulfide production offshore exacerbated Hg methylation.Conclusions
The freshwater to marine gradient in the Idrija/So?a/Isonzo/Adriatic region is dynamic, exhibiting horizontally variable rates of microbial activities and Hg transformations that create “hot spots” of MeHg accumulation that are controlled differently in each region.3.
State fish and wildlife agencies are particularly interested in attracting female participation because of the potential to offset declining participation in hunting. Understanding female hunters’ motivations will be critical for designing effective recruitment and retention programs for women hunters. Although female participation in hunting is increasing, males still outnumber females by about tenfold. Gender differences in deer hunters were explored by comparing ratings of eight motivations (social, nature, excitement, meat, challenge, trophy, extra hunting opportunity, and solitude). Hunter types were defined by hunters’ selection of the most important motivation for why they like Black Hills deer hunting. Overall, females and males were relatively similar in their ratings of the eight motivations, and we found 85% gender similarity in the selection of the most important motivation. Women were slightly more motivated by the food aspect of the hunt while men placed slightly more value on the hunt as a sporting activity. 相似文献
4.
Elías J. Mongiardini Julieta Prez-Gimnez M. Julia Althabegoiti Julieta Covelli J. Ignacio Quelas Silvina L. Lpez-García Aníbal R. Lodeiro 《Soil biology & biochemistry》2009,41(9):2017-2020
Competition for nodulation is a complex problem where bacterial adhesins, which are required for root colonization, may play a role. However, the possible influence of adhesins on competitiveness was scarcely studied. In this work, the Rhizobium leguminosarum bv trifolii adhesion protein RapA1 was overproduced from a pHC60-derived plasmid and expressed in R200 strain. When an overproducing strain and a control-carrying empty vector were co-inoculated on clover plants, a positive effect of RapA1 on competition for nodule occupation was observed. Therefore, optimization of RapA1 expression may be considered for improvement of rhizobial competitiveness. 相似文献
5.
Valeria Gualandri Elisa Asquini Pierluigi Bianchedi Laura Covelli Matteo Brilli Umberto Malossini Paola Bragagna Pasquale Saldarelli Azeddine Si-Ammour 《European journal of plant pathology / European Foundation for Plant Pathology》2017,147(1):21-25
Grapevine Pinot gris Virus (GPGV) is a single stranded RNA of the genus Trichovirus infecting grapevine (Vitis vinifera) and associated with stunting, chlorotic mottling and leaf deformation symptoms. During a monitoring of GPGV infection in vineyards of the Trentino region in Italy, we have detected the virus in the herbaceous plants Silene latifolia subsp. Alba (Mill.) (bladder campion) and Chenopodium album L. (white goosefoot), which showed symptoms of viral infection. The full-length GPGV RNA genome, amplified from these infected hosts, was sequenced and a phylogenetic analysis revealed that its closest relative is the strain SK13, recently isolated in Slovakia. Our results indicate that herbaceous plants can be considered as a reservoir for the GPGV virus. This finding is important for studying the epidemiological aspects of GPGV disease and to formulate appropriate control measures. 相似文献
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7.
Targeting your audience: wildlife value orientations and the relevance of messages about bear safety
Zachary D Miller Wayne Freimund Elizabeth Covelli Metcalf Norma Nickerson 《Human Dimensions of Wildlife》2018,23(3):213-226
While there is an assumption that wildlife value orientations can be useful in strategic communication, few studies have empirically explored this topic. This article used the concept of wildlife value orientations to understand how to increase the motivation of people to process information about wildlife in the context of persuasive communication. A confirmatory factor analysis was used to identify mutualism and domination wildlife value orientations. From the wildlife value orientations, crosstabs were used to create a typology with four discreet segments: mutualists, pluralists, traditionalists, and distanced. A series of ANOVAs examined how important different messages about bear safety were to the typology segments. Results indicated that message relevancy differs among wildlife value orientations. Managers can use this information to help frame their communications about wildlife-related issues. Future research should continue to explore the impact of this value-framing approach to other persuasive communication concepts, like attitudes and behaviors. 相似文献
8.
Marco Russo DVM PHD Eucenio M. Covelli MD Leonardo Meomartino DVM PHD Christopher R. Lamb MA Vetmb Arturo Brunetti MD 《Veterinary radiology & ultrasound》2002,43(1):22-26
A series of high-resolution computed x-ray tomography (CT) images of the normal canine middle and inner ear are presented to serve as a reference for optimal interpretation of clinical CT images of animals with diseases affecting this region. 相似文献
9.
Efrén Garcia-Ordiales Jorge Loredo Stefano Covelli José M. Esbrí Rocio Millán Pablo Higueras 《Journal of Soils and Sediments》2017,17(7):1893-1904
Purpose
The Almadén mining district has suffered long-term extraction activity, and this has left significant areas of decommissioned mining liabilities. Nowadays, the uncontrolled runoff and related erosion and transport of trace metal-enriched soils and sediments affect the whole freshwater ecosystem. The goal of this study was to distinguish geogenic from mining-related sources of trace metals in freshwater sediments, to understand their dispersion in the watershed, and, finally, to evaluate the potential environmental implications for future corrective plans.Materials and methods
Freshwater surface sediment samples were collected from ten points along the main streams of the watershed (nine inside the mining district and one control point outside the district). Sediments were air dried and analyzed by different standard methods for pH, total major and trace element concentrations, total organic carbon, and grain size. In addition to the determination of the enrichment factor, a multi-statistical approach was applied involving discriminant analysis, Student’s t test, and Mann-Whitney U analysis.Results and discussion
Sediments inside the district contained high levels of major and trace elements with respect to the control point. The predominance of fine fractions in these sediment samples appears to be one of the most important factors that affects trace metal concentrations. Among the trace elements, not only Hg but also As, Pb, and Zn are discriminative geochemical markers, thus allowing the identification of the different mining sources and their individual or combined impact throughout the district. Furthermore, the high enrichment factors obtained for As, Hg, Pb, and Zn with respect to the local background values highlight the persistent and severe impact from the decommissioned mines on the freshwater surficial sediments and their potential geoavailable risk for aquatic organisms.Conclusions
The geochemistry of freshwater sediments alone demonstrates that different contamination sources are recognizable within the mining district and these can be related to the specific decommissioned mines. In addition, the discrete sources can be clearly distinguished on the basis of the statistical analysis of the geochemical data. Despite the closure of the mines, stream sediments are still the main repository of trace metals within the district, and they are therefore a potential threat to the freshwater ecosystem.10.
Elisa Petranich Alessandro Acquavita Stefano Covelli Andrea Emili 《Journal of Soils and Sediments》2017,17(7):1986-1998