1,720,991 research outputs found
Table S2, Mass-to-charge ratios (m/z) used for selective reaction monitoring of Bacteriohopanepolyols (BHPs) at Quadrupole 1 (Q1) and 3 (Q3)
No full textBacteriohopanepolyols (BHPs) were analyzed using an Agilent 1290 ultra high-performance liquid chromatograph coupled to an Agilent 6410 triple quadrupole mass spectrometer equipped with an atmospheric chemical ionization interface operated in positive mode, following Kusch et al. (2018).
This work was supported by the Gordon and Betty Moore Foundation
Table S4, Content and stable isotopic composition of total organic carbon (TOC) and total nitrogen (TN) for ODP cores at sites 964 and 967
No full textBulk organic carbon (OC) and nitrogen content and stable isotope compositions for ODP cores at sites 964 and 967, including: event name, sapropel layer, core, depth (top), depth (bottom), OC content (mean), OC content (std. dev.), OC d13C (mean), OC d13C (std. dev.), nitrogen content (mean), nitrogen content (std. dev.), d15N (mean), d15N (std. dev.), and C/N ratio. All content and isotope data were generated using a Thermo Scientific Delta V isotope ratio mass spectrometer run in continuous flow mode. Samples were acidified by fumigation prior to OC content and d13C analysis; samples were run without acidification for N content and d15N analysis.
This work was supported by the Gordon and Betty Moore Foundation
Mediterranean sapropel bulk organic matter and biomarker concentrations and carbon isotope compositions
No full textThis dataset contains bulk organic matter and biomarker data for two Mediterranean Sea sites: ODP Leg 160 site 964 (including sapropels S5, S7, and i-282) and ODP Leg 160 site 967 (including sapropels S4, S5, and S74). This dataset includes: (i) compiled age model data from the literature; (ii) diagnostic mass spectrometry selective reaction monitoring m/z ratios for bacteriohopanepolyol (BHP) and heterocyst glycol (HG) analysis; (iii) bulk sediment % organic carbon (OC), % total nitrogen (TN), OC-d13C, and TN-d15N; (iv) OC-normalized abundances of various BHPs, HGs, and crenarchaeol; (v) d13C values for BHPs and crenarchaeol; and (vi) literature compilation of Eastern Mediterranean Sea diatom frustule preservation observations. Samples were analyzed at Harvard University in 2017-2018 from samples collected in 1995 during ODP Leg 160; sample ages range from 101 to 3004 kilo years before present. Samples were collected from the Eastern Mediterranean Sea and cover the Ionian and Levantine Seas. These data were generated to study the microbial ecological and biogeochemical responses to ocean anoxia in an enclosed basin; samples were analyzed using mass spectrometric and isotope-ratio mass spectrometric methods (coupled to liquid- and gas-chromatography and elemental analysis).
This work was supported by the Gordon and Betty Moore Foundation
Table S5, Abundance of crenarchaeol, bacteriohopanetetrol I (BHT-I), bacteriohopanetetrol II (BHT-II), as well as C5 and C6 heterocyst glycolipids (HGs) in ODP cores at sites 964 and 967
No full textCarbon-normalized abundance of individual bacteriohopanetetrol (BHP) and heterocyst glycolipid (HG) compounds, as well as the relative abundance of BHT-I vs. BHT-II and HG-C5 compounds vs. HG-C6 compounds in ODP cores at sites 964 and 967. Concentration data for BHPs and HGs were generated using ultra high-performance liquid chromatography coupled to triple quadrupole mass spectrometry following Kusch et al. (2018) and Wörmer et al. (2012), respectively.
This work was supported by the Gordon and Betty Moore Foundation
Table S6, Biomarker isotopic data of crenarchaeol (δ13C Cren.), bacteriohopanetetrol I (δ13C BHT-I), and bacteriohopanetetrol II (δ13C BHT-II) for ODP cores at sites 964 and 967
No full textStable-carbon isotope compositions for crenarchaeol, bacteriohopanetetrol I (BHT-I), and bacteriohopanetetrol II (BHT-II) for ODP cores at sites 964 and 967. All biomarkers were measured using a Thermo Scientific Delta V isotope ratio mass spectrometer at least in triplicate. For BHT-I and BHT-II, compounds were isolated using high-performance preparative liquid chromatography and individually analyzed by high-temperature gas-chromatography-IRMS following Hemingway et al. (2018). Crenarchaeol was isolated using high-pressure preparative chromatography and analyzed using a spooling-wire microcombustion interface on a Thermo Scientific Delta V isotope ratio mass spectrometer at least in quintuplicate following Polik et al. (2018).
This work was supported by the Gordon and Betty Moore Foundation
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
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
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