Size at maturity of the smallnose fanskate Sympterygia bonapartii (Muller & Henle, 1841) (Pisces, Elasmobranchii, Rajidae) in the SW Atlantic     

Oddone  Maria Cristina; Velasco  Gonzalo 《ICES Journal of Marine Science》2004,61(2):293-296

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An in vitro procedure for evaluation of early stage oxidative stress in an established fish cell line applied to investigation of PHAH and pesticide toxicity   总被引：1，自引：0，他引：1  

Ruiz-Leal M  George S 《Marine environmental research》2004,58(2-5):631-635

Oxidative stress by increased production of reactive oxygen species such as superoxide has been implicated in the toxicity of PCB's and non-target toxicity of many pesticides. We report the development of a microplate-based method for determination of early stage oxidative stress using an established cell line (EPC) from a skin tumour of carp Cyprinus carpio L. and 2',7'-dichlorodihydrofluorescein diacetate (H(2)-DCFDA) as a fluorescent probe for detection of reactive oxygen species (ROS) formation. Sublethal concentrations of the herbicide Paraquat, an established redox cycling agent and a crude PCB mixture, Arochlor 1254 elicited a linear increase in ROS formation over 2 h exposure which was some 45- and 10-fold higher, respectively, than attributable to basal respiration, confirming the suitability and response of the test system. Whilst in vivo studies in mammals have implicated early stage oxidative stress in the toxicity of pesticides, we did not observe an increase in ROS production after exposure of EPC cells to sublethal concentrations of Carbaryl, 2,4-DDT, Lindane or Malathion implying that this is not the causative mechanism of acute toxicity in this fish cell line. The apparent involvement of oxidative stress in their mammalian toxicity may therefore be an indirect effect or dependent upon compound metabolism.  相似文献   

A tribute to Lucia Mazzella (1947–1999)     

Maria Cristina Buia  Gabriele Procaccini  & Maria Cristina Gambi 《Marine Ecology》2006,27(4):273-276

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A new methodology to compute the gravitational contribution of a spherical tesseroid based on the analytical solution of a sector of a spherical zonal band     

Anna Maria Marotta  Riccardo Barzaghi 《Journal of Geodesy》2017,91(10):1207-1224

A new methodology for computing the gravitational effect of a spherical tesseroid has been devised and implemented. The methodology is based on the rotation from the global Earth-Centred Rotational reference frame to the local Earth-Centred P-Rotational reference frame, referred to the computation point P, and it requires knowledge of the height and the angular extension of each topographic column. After rotation, the gravitational effect of the tesseroid is computed via the effect of a sector of the spherical zonal band. In this respect, two possible procedures for handling the rotated tesseroids have been proposed and tested. The results obtained with the devised methodology are in good agreement with those derived by applying other existing methodologies.  相似文献   

The impacts of source structure on geodetic parameters demonstrated by the radio source 3C371     

Ming H. Xu  Robert Heinkelmann  James M. Anderson  Julian Mora-Diaz  Maria Karbon  Harald Schuh  Guang L. Wang 《Journal of Geodesy》2017,91(7):767-781

Closure quantities measured by very-long-baseline interferometry (VLBI) observations are independent of instrumental and propagation instabilities and antenna gain factors, but are sensitive to source structure. A new method is proposed to calculate a structure index based on the median values of closure quantities rather than the brightness distribution of a source. The results are comparable to structure indices based on imaging observations at other epochs and demonstrate the flexibility of deriving structure indices from exactly the same observations as used for geodetic analysis and without imaging analysis. A three-component model for the structure of source 3C371 is developed by model-fitting closure phases. It provides a real case of tracing how the structure effect identified by closure phases in the same observations as the delay observables affects the geodetic analysis, and investigating which geodetic parameters are corrupted to what extent by the structure effect. Using the resulting structure correction based on the three-component model of source 3C371, two solutions, with and without correcting the structure effect, are made. With corrections, the overall rms of this source is reduced by 1 ps, and the impacts of the structure effect introduced by this single source are up to 1.4 mm on station positions and up to 4.4 microarcseconds on Earth orientation parameters. This study is considered as a starting point for handling the source structure effect on geodetic VLBI from geodetic sessions themselves.  相似文献   

Finding meaningful participation in volunteer geographic information and citizen science: a case comparison in environmental application     

Mu-Ning W. Brandeis  Maria Isabel Carrera Zamanillo 《制图学和地理信息科学》2017,44(6):539-550

ABSTRACT

Volunteer geographic information (VGI) and citizen science (CS) have been used as a way to promote a form of democratization of knowledge. Crowdsourcing facilitates the massive collection of data through nonexpert volunteers. This study compares 57 VGI and CS projects through a cross-case comparison method to explore the level of involvement of participants, based on three main analytic dimensions (project rationale, actor interaction, and data flow) and 12 sub-variables. The primary goal of this research is to analyze the purpose and the role of technology in VGI and CS projects, using three matrices to explore emerging trade-offs. Finally, we synthesized the workflow of VGI and CS project and compared based on project purposes. At the end of this study, five main purposes were found among the selected projects, uncovering that data collection is the most common purpose. A general workflow can be conceptualized, but detail implementation will involve various trade-offs, especially between local involvement and large-area expert-oriented protocol implementations. By exploring diverse relationships among selected variables of analysis in VGI and CS projects, this study pretends to build a foundation for larger, global meta-analysis that can bring some transparency in the epistemic interactions between experts and nonexperts.  相似文献   

Towards an Automated Comparison of OpenStreetMap with Authoritative Road Datasets   总被引：1，自引：0，他引：1       下载免费PDF全文

Maria Antonia Brovelli  Marco Minghini  Monia Molinari  Peter Mooney 《Transactions in GIS》2017,21(2):191-206

OpenStreetMap (OSM) is an extraordinarily large and diverse spatial database of the world. Road networks are amongst the most frequently occurring spatial content within the OSM database. These road network representations are usable in many applications. However the quality of these representations can vary between locations. Comparing OSM road networks with authoritative road datasets for a given area or region is an important task in assessing OSM's fitness for use for applications like routing and navigation. Such comparisons can be technically challenging and no software implementation exists which facilitates them easily and automatically. In this article we develop and propose a flexible methodology for comparing the geometry of OSM road network data with other road datasets. Quantitative measures for the completeness and spatial accuracy of OSM are computed, including the compatibility of OSM road data with other map databases. Our methodology provides users with significant flexibility in how they can adjust the parameterization to suit their needs. This software implementation is exclusively built on open source software and a significant degree of automation is provided for these comparisons. This software can subsequently be extended and adapted for comparison between OSM and other external road datasets.  相似文献   

A simplified stress analysis of rising salt domes          下载免费PDF全文

Mahdi Heidari  Maria A. Nikolinakou  Peter B. Flemings  Michael R. Hudec 《Basin Research》2017,29(3):363-376

We use a simple analytical model to estimate the stress field in density‐driven, rising salt domes and adjacent sediments, and to describe the evolution of these domes. We show that the pressure exerted by the salt pushing out against its wall rocks (the salt pressure) decreases linearly up the flank of the dome, but is always greater than the overburden stress. In fact, the salt pressure normal to the dome boundary is everywhere the maximum principal stress, whereas the hoop stress parallel to the circumference of the dome is the minimum stress. In addition, we quantitatively describe the critical stages of salt dome evolution (initiation, upbuilding, and downbuilding), relating these stages to sedimentation rate and basin thickness. This analysis also shows that even the highest sedimentation rates are unlikely to accumulate enough sediments to bury downbuilding domes as long as the salt supply is unrestricted. Despite the simplicity of the model, its predictions are in good agreement with field observations near salt domes. Overall, our analytical model can provide critical insight into the stress field perturbation in and near rising salt domes and can be used to assess the accuracy of numerical models and field measurements near these domes.  相似文献   

An Evaluation of Information Meetings as a Tool for Addressing Fear of Large Carnivores     

Maria Johansson  Jens Frank  Ole-Gunnar Støen  Anders Flykt 《社会与自然资源》2017,30(3):281-298

Managing authorities in Scandinavia arrange public information meetings when members of the public express fear because wolves or brown bears approach human settlements. This study aimed to increase the understanding of the potential effect of information meetings on self-reported fear of wolves and brown bears. In total, 198 participants completed questionnaires before and after the information meetings. Nine follow-up interviews were held 1 year later. The quantitative analyses revealed that participants who found the information credible reported a significant increase in social trust and a decrease in vulnerability and fear. The qualitative analyses pointed to the importance of information content and meta-communication, for example, nonverbal cues. It is proposed that, among participants who find the information credible, information meetings may change the appraisal of wolves and brown bears, and therefore they might prove useful as an intervention to address fear of these animals.  相似文献   

Knowledge rationales in human geography: Economic,policy, empowerment,and methodological     

Johanna Hautala  Maria Höyssä 《Norsk geografisk tidsskrift. Norwegian journal of geography》2017,71(5):269-287

The article presents a systematic review of 152 articles in which the concept of knowledge is applied and that are published in international human geography journals. As the importance of knowledge in society is increasing, especially economic geography has taken up the task of reviewing the concept or role of knowledge in geography. However, there is a need for a more nuanced understanding of knowledge in economic geography, drawing more broadly on human geographical research. The authors analyse how the concept of knowledge is understood and applied in contemporary human geography. Their results demonstrate four knowledge rationales: economic, policy, empowerment, and methodological. Each rationale and their combinations display a particular role and purpose for knowledge, as well as a distinct approach to space. Separately, each rationale provides several insights into a more nuanced understanding of specific aspects of knowledge. When combined, the four rationales offer a holistic overview of the field. The authors conclude that the empowerment rationale offers novel methodological choices towards a more nuanced understanding of knowledge in economic geography.  相似文献