131,680 research outputs found
De plantarum polline
No full textCarl Julius von Fritzsche (1808-1871), Pharmazeut und Chemiker. Geb. Neustadt (Sachsen, D.) 29.10.1808, gest. Dresden 20.06.1871 (nach dem im Russischen Reich bis Februar 1918 verwendeten Julianischen Kalender eine Differenz von 12 Tagen: 17.10.1808 – 08.06.1871).- Fritzsche, Sohn des Arztes Christian Ferdinand Fritzsche, erhielt bis zu seinem 14. Lebensjahr Privatunterricht in Dresden, danach eine pharmazeutische Ausbildung bei seinem Onkel Friedrich Adolph Struve (1781-1840). 1830 wurde Fritzsche Assistent im Laboratorium des Chemikers Eilhard Mitscherlich (1794-1863) und immatrikulierte 1831 an der Philosophischen Fakultät der Universität Berlin. Hier promovierte er am 10. August 1833 mit seiner Schrift „De plantarum polline“ (Über den Pflanzenpollen; hier präsientiert) zum Dr. phil. Noch 1833 nahm Fritzsche das Angebot seines Onkels Struve an, in St. Petersburg die Leitung einer neu gegründeten Anstalt zur Herstellung künstlicher Mineralwässer zu übernehmen, und übersiedelte nach Russland. Am 24. August 1838 wählte ihn die Akademie der Wissenschaften in St. Petersburg zum Adjunkten für Chemie, was eine zusätzliche fixe Bezahlung und deutliche Reputation bedeutete. Am 06.04.1844 wurde Fritzsche überdies zum außerordentlichen, am 10.04.1852 dann sogar zum ordentlichen Akademiemitglied gewählt; 1870 verlieh man ihm den russischen erblichen Adel. 1869 erlitt Fritzsche einen Schlaganfall, von dem er sich nie wieder ganz erholte; 1870 reiste er nach Deutschland und starb 1871 im Kreis seiner Familie in Dresden. Von seinen 81 wissenschaftlichen Publikationen sind nur fünf botanischen Inhalts, die anderen behandeln rein chemische Themen. Die botanischen Publikationen sind: Beiträge zur Kenntniss des Pollens. Erstes Heft (Berlin 1832); Dissertatio de plantarum polline (Berlin 1833); Ueber den Pollen der Pflanzen und das Pollenin. In: Annalen der Physik und Chemie 108 (= 2. F., 32), 1834, S. 481-492; Ueber die Entwicklung des Pflanzeneies in seinen frühesten Zuständen und über die Bildung der Häute desselben. In: Archiv für Naturgeschichte 2, 1835, 229-232; Ueber den Pollen. In: Mémoirs de savants étrangers 3, 1837, S. 649-670.
Biographische Daten: J. H. Barnhart, Biographical notes upon botanists Vol. 2, S. 13 / ADB 8, 1878, S. 122-123 / A. B. Butlerov, Julij Fedorovič Fricše. In: Zapiski Imperatorskoj Akademii nauk 20, 1872, 190-204 / Leopoldina 7, 1871/72, S. 50 / I. Grosse, Dem Chemiker und Akademiker Carl Julius Fritzsche zum 200. Geburtstag. In: Sächsische Heimatblätter 2008 (2), S. 126-138 / R. Pfrepper, Carl Julius Fritzsche (1808-1871) – Pharmazeut und Chemiker in Dresden, Berlin und St. Petersburg. In: H. Kaden & O. Riha (Hrsg.), Studien zu Carl Julius Fritzsche (1808-1871) und Il’ja Il’ic Mecnikov (1845-1916). Quellenarbeiten in der Wissenschaftsgeschichte (= Relationes 1), Aachen 2008.
Bibliographische Daten: G. A. Pritzel, Thesaurus literaturae botanicae, No. 312
Book Reviews
No full textHuch, M., Von Leszczynski, H., Krause, R.A., Rack, U., Fritzsche, D. (2013): Book Reviews. Zoological Journal of the Linnean Society 168: 669-670, DOI: 10.2312/polarforschung.83.2.83, URL: http://dx.doi.org/10.2312/polarforschung.83.2.8
Buchbesprechungen / Book Reviews
No full textLüdecke, C., Fritzsche, D., Dullo, C., Thiede, J., Salewski, C. (2016): Book Reviews. Zoological Journal of the Linnean Society 176: 224-225, DOI: 10.2312/polarforschung.86.1.72, URL: http://dx.doi.org/10.2312/polarforschung.86.1.7
MeSH term explosion and author rank improve expert recommendations
No full textInformation overload is an often-cited phenomenon that reduces the productivity, efficiency and efficacy of scientists. One challenge for scientists is to find appropriate collaborators in their research. The literature describes various solutions to the problem of expertise location, but most current approaches do not appear to be very suitable for expert recommendations in biomedical research. In this study, we present the development and initial evaluation of a vector space model-based algorithm to calculate researcher similarity using four inputs: 1) MeSH terms of publications; 2) MeSH terms and author rank; 3) exploded MeSH terms; and 4) exploded MeSH terms and author rank. We developed and evaluated the algorithm using a data set of 17,525 authors and their 22,542 papers. On average, our algorithms correctly predicted 2.5 of the top 5/10 coauthors of individual scientists. Exploded MeSH and author rank outperformed all other algorithms in accuracy, followed closely by MeSH and author rank. Our results show that the accuracy of MeSH term-based matching can be enhanced with other metadata such as author rank
Going Beyond Counting First Authors in Author Co-citation Analysis
No full textThe 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
Preempting Pandemics. Rez.: The Viral Storm. The Dawn of a New Pandemic Age by Nathan Wolfe Times Books (Holt), New York, 2011
No full textHan BA, Rushmore J, Fritzsche A, Satterfield D, Winternitz J. Preempting Pandemics. Rez.: The Viral Storm. The Dawn of a New Pandemic Age by Nathan Wolfe Times Books (Holt), New York, 2011. Science. 2012;337(6095):647-648
"Closing the R&D Gap, Evaluating the Sources of R&D Spending"
No full textBoth spending and tax policies have been implemented in the United States with the goal of stimulating private sector research and development (R&D). Karier questions whether current R&D policy, especially the research and experimentation tax credit, can contribute to closing the gap between nondefense expenditures on R&D in the United States and such expenditures in other countries, such as Japan and Germany. He also explores possible changes to our current R&D policy to make it more effective.
Reconciliation, business achievement, the missing link
No full textThe content of this book will explain A For various reasons Europeans and Germans left their Homeland. B How they travelled in groups and individually. C How they landed in South Australia. D The Newcomers reception in a British colony. E The treatment they received in Australia. F What the Germans and Europeans achieved in Australia
Dispelling the Myths Behind First-author Citation Counts
No full textWe 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
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