1,721,315 research outputs found
Related data for: Mapping floodplain bathymetry in the middle-lower Amazon River using inundation frequency and field control
No full textThis dataset contains the bathymetry (at 100m) of 12 major floodplains along a 900 km reach of the middle-lower Amazon River (Manaus – Monte Alegre; total floodplain area of 5,164 km2), based on the inundation frequency (IF) derived from 36 years of Landsat data. Using a mathematical relationship between IF and surveyed depth at the Curuai floodplain in June 2004, this IF-depth model is applied across floodplains of the middle-lower Amazon to estimate bathymetry. The bathymetry is validated with field survey data across eight floodplains (covering over 200km survey distance) collected in June – July 2016
Replication Data for: Dams in the Mekong: A comprehensive database, spatiotemporal distribution, and hydropower potentials
No full textThis dataset is a comprehensive open-access database of 1,055 georeferenced dams in the Mekong basin, with detailed dam attributes such as dam status, dam height, reservoir volume, and dam capacity. The dams are compiled from 18 databases (six global, five regional, and seven national), validated using satellite imagery in Google Earth, and supplemented with information from public literature (reports, research papers, news articles, and websites). Additional attributes including dam elevation and dam catchment area are added through GIS analysis. The dataset also contains five files for spatiotemporal analysis, with each file corresponding to the dams in each decade from the 1980s to post-2020s. Post-2020s includes dams that began operation in 2020 or later, dams under construction, and planned dams with available information. All files are in comma-separated values (CSV) format
The role of surface chemistry in impedimetric aptasensing
No full textSurface chemistry is a key parameter in the choice of proper materials for electrochemical detection. It has been previously shown that the presence of oxygen containing groups (OCGs) on the surface of graphene oxide (GO) can be both effective and detrimental. This poses a question when GO materials are used as electrochemical platforms for biosensing. In this work, we study how the surface chemistry of graphene oxide nanocolloids (GONCs) affects the impedimetric biosensing of ochratoxin A (OTA), in terms of immobilization of biorecognition element and detection step. OCGs on GONCs were tuned by applying increasing reduction potentials from −0.3 V to −1.2 V, resulting in GONC platforms with decreasing amounts of oxygen functionalities. It was discovered that the sensitivity of biosensing is correlated to the residual amount of OCGs on GO surface. For a more detailed investigation, three representative materials, namely unreduced GONCs, as well as GONCs reduced at potentials of −0.8 V and −1.2 V were chosen. Results were compared in terms of calibration sensitivity, selectivity and reproducibility of the impedimetric response. GONCs reduced at −1.2 V have shown the best electroanalytical response for the impedimetric detection of OTA. These findings are anticipated to contribute to the design of novel biosensors, whereby an optimized platform is employed for the immobilization of the biorecognition element
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Unravelling the Aptamer‐Analyte Interaction Dynamics through Fluorescence Quenching in Graphene Quantum Dots (GQDs) Based Homogeneous Assays
No full textGraphene quantum dots (GQDs) are used here as a biosensing platform for the recognition of the major food contaminant ochratoxin A (OTA), with a fluorescently labelled DNA aptamer (FAM OTA aptamer) functioning as the biorecognition element. The detection principle lies in the formation of noncovalent interactions between the FAM OTA aptamer and the GQD surface, and the consequent fluorescence quenching. The further change in the fluorescence signal, induced by the formation of the FAM OTA Aptamer/OTA conjugate during the detection step, could then be correlated to the presence and concentration of the target analyte. Upon tuning the concentration of GQDs, a switch in the biorecognition mechanism occurred. Specifically, while a lower GQD concentration (0.060 mg/mL) resulted in a restoration of the fluorescence intensity upon incubation with OTA, a higher GQD concentration (0.150 mg/mL) provided a further quenching of the final fluorescence intensity. Upon further calibration study, it was discovered that the latter mechanism provided a better option in terms of linearity of response, detection limit and selectivity.Nanyang Technological UniversityA. B. acknowledges Nanyang Technological University for the financial support
Electroactive Nanocarbon Can Simultaneously Work as Platform and Signal Generator for Label‐Free Immunosensing
No full textElectroactive nanocarbon can be defined as a carbon nanomaterial that contains electrochemically reducible oxygen functionalities. We show here how an electroactive nanocarbon material can work both as a platform and as a signal generator when developing an immunosensor for the detection of mycotoxins. The suitability of the material for the immobilization of the biorecognition element by the formation of multiple noncovalent interactions, and the concurrent ability to provide a significant reduction peak are combined here in a label-free, single-step immunosensor. The variation in the current intensity, owing to the reduction of the electroactive platform, is correlated to the electrochemical availability of the oxygen functionalities involved in the interaction with the biorecognition element first, and the antibody/antigen conjugate in the detection step. We demonstrated here a direct dependence between the signal generated from the electroactive nanocarbon platform and each step of the biorecognition event, which allows the selective and precise detection of the analyte under investigation
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
Dispelling the Myths Behind First-author Citation Counts
Full text linkWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
- …
