1,720,970 research outputs found
High frequency data for estimation of whole stream metabolism, 2007-2008, Glensaugh, Scotland - stations and reaches metadata
No full textHigh frequency data for estimation of whole stream metabolism, 2007-2008, Glensaugh, Scotland - stations and reaches metadat
High frequency data for estimation of whole stream metabolism, 2007-2008, Birnie Burn, Glensaugh, Scotland
No full textHigh frequency data for estimation of whole stream metabolism, 2007-2008, Birnie Burn, Glensaugh, Scotlan
High frequency data for estimation of whole stream metabolism, 2007-2008, Glensaugh, Scotland
No full textThe datasets were acquired to estimate whole stream metabolism (photosynthesis, respiration).
Photosynthetic active radiation, atmospheric pressure, stream water discharge, water temperature and dissolved oxygen concentrations were recorded at five-minute time intervals at six stations (three stream reaches) along two parallel first order streams: Cairn Burn (May 2007-July 2008) and Birnie Burn (May 2007-October 2007).
In addition, stream reach parameters necessary to calculate mean travel time, oxygen reaeration coefficient and proportion of base flow under varying discharge are given with their uncertainties. The forms of the equations to calculate mean travel time τ [min], oxygen reaeration coefficient k2 [/min] and proportion of base flow p(Q_b) [range 0 to 1] are:
τ=a*Q^b
k2=a*Q+b
p(Q_b)=1/(1+exp(a*ln(Q)-b))
with discharge Q [l/s] taken as Q_ECN for Birnie Burn and Q_C1 for Cairn Burn.
The discharge for stations upstream of the calibrated flumes were also calculated after corrections for lateral inflows determined by tracer studies. The streams undercut the banks so two stream widths were given: wetted stream bed width (recommended to use in stream metabolism calculations) and open width (recommended to calculate amount of light available to stream bed). Stream reach length is also given
A methodology to model environmental preferences of EPT taxa in the Machangara River Basin (Ecuador)
Full text linkRivers have been frequently assessed based on the presence of the EphemeropteraPlecopteraTrichoptera (EPT) taxa in order to determine the water quality status and develop conservation programs. This research evaluates the abiotic preferences of three families of the EPT taxa Baetidae, Leptoceridae and Perlidae in the Machangara River Basin located in the southern Andes of Ecuador. With this objective, using generalized linear models (GLMs), we analyzed the relation between the probability of occurrence of these pollution-sensitive macroinvertebrates families and physicochemical water quality conditions. The explanatory variables of the constructed GLMs differed substantially among the taxa, as did the preference range of the common predictors. In total, eight variables had a substantial influence on the outcomes of the three models. For choosing the best predictors of each studied taxa and for evaluation of the accuracy of its models, the Akaike information criterion (AIC) was used. The results indicated that the GLMs can be applied to predict either the presence or the absence of the invertebrate taxa and moreover, to clarify the relation to the environmental conditions of the stream. In this manner, these modeling tools can help to determine key variables for river restoration and protection management
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
Effect of macrophyte removal on CO2 emissions in the river Otra, Norway
Full text linkThe main goal of this study is to examine how macrophyte removal affects CO2 emissions in rivers with a secondary aim of quantifying CO2 concentrations and emissions in the river over the course of 24 hours. The study was performed in river Otra in Norway which flows through the valley of Setesdalen. CO2 emissions were measured by floating chambers with infrared gas analyzers (IRGA) with logging abilities. The study uses before and after control impact (BACI) design. Large amounts of macrophytes (submerged growth of Juncus bulbosus) were removed between the 15th and 22nd of June 2020 from the impact site, but not from the control site. CO2 emissions and other measurements were done in both the control and the impact site before, during and after macrophyte removal. There were no significant differences in CO2 emissions between the Control and Impact site. Neither before, during nor after macrophyte removal. Even though there was a slight CO2 emission increase after removal it was probably due to factors like water-level, -velocity, and -temperature fluctuations. As secondary studies we also 1) measured CO2 emissions in the river every 2 hours for 24 hours, 2) measured the gas transfer velocity in the river. These studies helped us better understand the fluxes in the river.M-ECO
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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