307 research outputs found

    Storing the wisdom: chemical concepts and chemoinformatics

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    The purpose of the paper is to examine the nature of chemical concepts, and the ways in which they are applied in chemoinformatics systems. An account of concepts in philosophy and in the information sciences leads to an analysis of chemical concepts, and their representation. The way in which concepts are applied in systems for information retrieval and for structure–property correlation are reviewed, and some issues noted. Attention is focused on the basic concepts or substance, reaction and property, on the organising concepts of chemical structure, structural similarity, periodicity, and on more specific concepts, including two- and three-dimensional structural patterns, reaction types, and property concepts. It is concluded that chemical concepts, despite (or perhaps because of) their vague and mutable nature, have considerable and continuing value in chemoinformatics, and that an increased formal treatment of concepts may have value in the future

    Cognitive Information Processing

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    Contains reports on three research projects.National Science Foundation (Grant GP-2495)National Institutes of Health (Grant MH-04737-04)National Aeronautics and Space Administration (Grant NsG-496

    Heat Flux-Based Emissivity Measurement

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    A method for measuring the emissivity of a surface using heat flux sensors is described. The emissivity is calculated by directly measuring the heat flux passing through the surface using a heat flux sensor. Unlike calorimetric techniques, it does not require accounting for parasitic heat losses or knowing the temperature history of the sample. This technique allows emissivity measurements of newly developed variable emissivity surfaces, including electrostatic devices which cannot be directly measured using optical techniques. It can measure both passive and active thermal control coatings, and can evaluate many surfaces on the same substrate simultaneously. An experimental setup is detailed and results are presented for emissivity measurements of both active and passive surfaces using commercially available heat flux sensors. Errors are estimated for these measurements. A space-based experiment is also described and results of pre-flight testing are presented

    Findability, Keywords, and the Content in the Journal of Chemical Education

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    The role of keywords in improving findability of articles published in the Journal of Chemical Education has been developing and progressing for decades. Presently, as computational power and convenience have increased, the ability to consider new paradigms for keyword usage has emerged. Enhanced computing capacity and improved electronic information retrieval create an environment in which authors can choose their own descriptive keywords, rather than rely on the long used but somewhat dated taxonomy of keyword terms supplied by the Journal. The new keyword guidelines and strategies presented to best use them for effective classification of articles represent an important development for authors and readers of the Journal.This is a manuscript of the article Published as Currano, Judith N., and Thomas A. Holme. "Findability, Keywords, and the Content in the Journal of Chemical Education." Journal of Chemical Education 99, no. 3 (2022): 1147-1148. doi: https://doi.org/10.1021/acs.jchemed.2c00139. Copyright © Published 2022 by American Chemical Society and Division of Chemical Education, Inc. Posted with Permission

    Information retrieval and text mining technologies for chemistry

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    Efficient access to chemical information contained in scientific literature, patents, technical reports, or the web is a pressing need shared by researchers and patent attorneys from different chemical disciplines. Retrieval of important chemical information in most cases starts with finding relevant documents for a particular chemical compound or family. Targeted retrieval of chemical documents is closely connected to the automatic recognition of chemical entities in the text, which commonly involves the extraction of the entire list of chemicals mentioned in a document, including any associated information. In this Review, we provide a comprehensive and in-depth description of fundamental concepts, technical implementations, and current technologies for meeting these information demands. A strong focus is placed on community challenges addressing systems performance, more particularly CHEMDNER and CHEMDNER patents tasks of BioCreative IV and V, respectively. Considering the growing interest in the construction of automatically annotated chemical knowledge bases that integrate chemical information and biological data, cheminformatics approaches for mapping the extracted chemical names into chemical structures and their subsequent annotation together with text mining applications for linking chemistry with biological information are also presented. Finally, future trends and current challenges are highlighted as a roadmap proposal for research in this emerging field.A.V. and M.K. acknowledge funding from the European Community’s Horizon 2020 Program (project reference: 654021 - OpenMinted). M.K. additionally acknowledges the Encomienda MINETAD-CNIO as part of the Plan for the Advancement of Language Technology. O.R. and J.O. thank the Foundation for Applied Medical Research (FIMA), University of Navarra (Pamplona, Spain). This work was partially funded by Consellería de Cultura, Educación e Ordenación Universitaria (Xunta de Galicia), and FEDER (European Union), and the Portuguese Foundation for Science and Technology (FCT) under the scope of the strategic funding of UID/BIO/04469/2013 unit and COMPETE 2020 (POCI-01-0145-FEDER-006684). We thank Iñigo Garciá -Yoldi for useful feedback and discussions during the preparation of the manuscript.info:eu-repo/semantics/publishedVersio

    Origin and Early Evolution of Hydrocharitaceae and the Ancestral Role of Stratiotes

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    Funding Information: This study was funded by the Austrian Science Fund (FWF) with a grant to F.G., project number P34303; Open Access Funding by the University of Vienna. For the purpose of open access, the author has applied a CC BY public copyright license to any author accepted manuscript version arising from this submission. Publisher Copyright: © 2024 by the authors.The combined morphological features of Stratiotes (Hydrocharitaceae) pollen, observed with light and electron microscopy, make it unique among all angiosperm pollen types and easy to identify. Unfortunately, the plant is (and most likely was) insect-pollinated and produces relatively few pollen grains per flower, contributing to its apparent absence in the paleopalynological record. Here, we present fossil Stratiotes pollen from the Eocene of Germany (Europe) and Kenya (Africa), representing the first reliable pre-Pleistocene pollen records of this genus worldwide and the only fossils of this family discovered so far in Africa. The fossil Stratiotes pollen grains are described and compared to pollen from a single modern species, Stratiotes aloides L. The paleophytogeographic significance and paleoecological aspects of these findings are discussed in relation to the Hydrocharitaceae fossil records and molecular phylogeny, as well as the present-day distribution patterns of its modern genera.publishersversionpublishe

    Integration of EndNote Online in information literacy instruction designed for small and large chemistry courses

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    The blended model for information literacy instruction described in this article introduces students not only to efficient techniques for finding scientific literature and properties of chemical compounds, but also to managing this information with a bibliographic management program (EndNote Online). The model blends face-to-face instruction with online tutorials posted on a LibGuide page prepared for each course. A graded online assignment designed in SurveyMonkey was used to assess student learning. During the instruction, students learned to find literature in Google Scholar, PubMed, Scopus, SciFinder, and Web of Science. They also searched for properties of chemical compounds in ChemSpider, PubChem, Reaxys, and SciFinder using a chemical name, molecular formula, CAS Registry Number, or by drawing a molecular structure. The results from the assignments showed that students learned how to find literature and chemical property information efficiently and use a bibliographic management program to store, organize, share, and cite references. This article presents the implementation of the model in two small (40–60 students) and one large (380–460 students) undergraduate chemistry courses. The information literacy instruction described in this article was carried out in more than 20 undergraduate and graduate courses at the University of Maryland College Park. It provided more than 5000 students with versatile skills that they can use throughout their college education and even later in their professional life. The design of the model and its implementation was a result of a close collaboration between the chemistry librarian and the course instructors
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