1,721,010 research outputs found
Archaeal nitrification in Lake Constance, Germany
No full textThe aim of this work was to study freshwater Nitrososphaeria and their impact on the nitrogen cycling in lakes. We followed their absolute abundance in oligotrophic Lake Constance (Germany) with quantitative polymerase chain reaction (qPCR) over a time frame of two consecutive years from November 2017 until November 2019. During this time we took water samples monthly (2017/2018) or as required (2019) at a depth of 85 m. We combined this data with measurements of nitrate and ammonia concentrations in the whole water column. In addition, we performed stable isotope experiments with addition of 15N-ammonium in 2019 to analyze nitrification rate in the hypolimnion of Lake Constance. The bundled publication also includes measurements of chlorophyll a concentrations in the upper water column and measurements of temperature and oxygen in the whole water column
Temperature and oxygen measurements in Lake Constance, Germany
No full textThis dataset is part of a study investigating the freshwater Nitrososphaeria and their impact on the nitrogen cycling in lakes. It includes monthly measurements of temperature and oxygen in the whole water column (0-132 m) in Lake Constance (Germany) from November 2017 to November 2019. The probes, which were used, derived from Sea & Sun Technology GmbH, Trappenkamp, Germany or bbe Moldaenke GmbH or RBR Ltd.; Ottawa, Canada
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe 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
Get PDF“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
Get PDFWe 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
Abundance of freshwater Nitrososphaeria in Lake Constance, Germany
No full textThe aim of this work was to study freshwater Nitrososphaeria and their impact on the nitrogen cycling in lakes. We followed their absolute abundance in oligotrophic Lake Constance (Germany) with quantitative polymerase chain reaction (qPCR) over a time frame of two consecutive years from November 2017 until November 2019. During this time we took water samples monthly (2017/2018) or as required (2019) at a depth of 85 m. Water was taken with a Niskin bottle and filtered on board directly using 5 μm and 0.2 μm polycarbonate filters. The indicated time represents the sampling time.
We extracted DNA with a phenol-chloroform protocol (Klotz et al., 2021). We used the primer pair CamoA420F (50-CGT ACT GGT AGG AAT GTC-30; Herber et al., 2020) and CamoA616R (50-GCC ATC CAB CKR TAN GTC CA-30; Tourna et al., 2008), which are specific for the archaeal ammonia monooxygenase (amoA). The universal primer pair 1389F (50-TGY ACA CAC CGC CCG T-30) and 1492R (50-GGY TAC CTT GTT ACG ACT T-30; Hausmann et al., 2016) was applied to target the 16S rRNA gene of total Archaea and Bacteria. With this, we were able to gain absolute abundances of ammonia oxidizing archaea based on their functional marker gene amoA and relative abundances by comparing it to total Archaea and Bacteria abundances over a cycle of two years
Chlorophyll a concentrations in Lake Constance, Germany
No full textThis dataset is part of a study investigating the freshwater Nitrososphaeria and their impact on the nitrogen cycling in lakes. It includes biweekly-monthly measurements of chlorophyll a concentrations in the upper water column (0-60 m) in Lake Constance (Germany) from November 2017 to November 2019. Water was taken with a Niskin bottle and filtered on board directly using Glasfiber filters
Dispelling the Myths Behind First-author Citation Counts
Get PDFWe 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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