1,720,956 research outputs found
Ecological and environmental factors influencing exclusion patterns of phytoplankton size classes in lake systems
No full text<p>There are three netCDF data files comprise of a multidimensional dataset with different attributes. The files store solution for, respectively, the standard allometric relationships ('standard_PZ_365.nc'), the variations to phytoplankton maximum growth rate, μmax ('alpha_mu_PZ_365.nc'), and the variations to zooplankton maximum ingestion rates, Imax ('alpha_im_PZ_365.nc'). </p>
<p>#############################<br>
##### 'standard_PZ_365.nc' #####<br>
#############################</p>
<p>This netCDF datafile, 'standard_PZ_365.nc', stores the simulation data for a standard set of allometric relationships listed in the main text. The dataset contains phytoplankton biomass ('Phy'; Pi, i=1,2,..,150) and zooplankton biomass ('Zoo'; Zj, j=1,2) data of each size class from day 0 to day 365. It also contains simulation results from different environmental conditions, nutrient levels, mixing frequencies, and grazing strategies.</p>
<p><br>
# To extract the data, one could use the netCDF4 library in python (https://unidata.github.io/netcdf4-python/)</p>
<p>import netCDF4 <br>
out = netCDF4.Dataset('workingdirectory/filename.nc') # output file<br>
sol_phy = out.variables['Phy'][:]<br>
sol_zoo = out.variables['Zoo'][:]<br>
sol_nut = out.variables['Nut'][:]</p>
<p># The shape of sol_phy, sol_zoo, and sol_nut correspond to the below descriptions.</p>
<p><br>
The coordinates (dimensions) of the 'Phy' dataset are as below:</p>
<p>'time': '365 days',<br>
'Ps': '150 phytoplankton size classes ranged from 1 to 100µmESD',<br>
'nut': '3 different nutrient levels are considered: Oligotrophic (1µmolN/L); Eutrophic (15µmolN/L); Hypertrophic (50µmolN/L)',<br>
'mix': '3 different mixing regimes are considered: Constant (No mixing during the year); Medium (4 mixing/year); High (12 mixing/year)',<br>
'GrazStrtgy': '3 different combinations of grazing strategies are considered: SS (two specialists); SG (one specialist and one generalist); GG (two generalists)',<br>
<br>
The coordinates (dimensions) of the 'Zoo' dataset are as below:</p>
<p>'time': '365 days',<br>
'Zs': '2 zooplankton size classes at 5 and 200µmESD',<br>
'nut': '3 different nutrient levels are considered: Oligotrophic (1µmolN/L); Eutrophic (15µmolN/L); Hypertrophic (50µmolN/L)',<br>
'mix': '3 different mixing regimes are considered: Constant (No mixing during the year); Medium (4 mixing/year); High (12 mixing/year)',<br>
'GrazStrtgy': '3 different combinations of grazing strategies are considered: SS (two specialists); SG (one specialist and one generalist); GG (two generalists)',<br>
</p>
<p>The coordinates (dimensions) of the 'Nut' dataset are as below:</p>
<p>'time': '365 days',<br>
'nut': '3 different nutrient levels are considered: Oligotrophic (1µmolN/L); Eutrophic (15µmolN/L); Hypertrophic (50µmolN/L)',<br>
'mix': '3 different mixing regimes are considered: Constant (No mixing during the year); Medium (4 mixing/year); High (12 mixing/year)',<br>
'GrazStrtgy': '3 different combinations of grazing strategies are considered: SS (two specialists); SG (one specialist and one generalist); GG (two generalists)',</p>
<p>#############################<br>
##### 'alpha_mu_PZ_365.nc' #####<br>
##### 'alpha_im_PZ_365.nc' #####<br>
#############################<br>
These netCDF datafile support the experimental simulation data on variations (+/-50%) on the slope of allometric relationships for phytoplankton maxmimum growth rate (μmax) and zooplankton maximum ingestion rate (Imax). The dimensions in the file are similar to the standard file, with an additional dimension storing the variations in the allometric parameters.</p>
<p> </p>
<p>The coordinates (dimensions) of the 'Phy' dataset are as below:</p>
<p>Dimensions of data:<br>
'time': '365 days',<br>
'Ps': '150 phytoplankton size classes ranged from 1 to 100µmESD',<br>
'nut': '3 different nutrient levels are considered: Oligotrophic (1µmolN/L); Eutrophic (15µmolN/L); Hypertrophic (50µmolN/L)',<br>
'mix': '3 different mixing regimes are considered: Constant (No mixing during the year); Medium (4 mixing/year); High (12 mixing/year)',<br>
'GrazStrtgy': '3 different combinations of grazing strategies are considered: SS (two specialists); SG (one specialist and one generalist); GG (two generalists)',<br>
'mu_slope': '3 different allometric relationships (including the standard one) on phytoplankton maximum growth rate are tested by systematically manipulating the slope of the relationship, causing a trade-off that favours larger cells as the value increases'</p>
<p>OR</p>
<p>'im_slope': '3 different allometric relationships (including the standard one) on zooplankton maximum ingestion rate are tested by systematically manipulating the slope of the relationship, causing a trade-off that favours smaller cells as the value increases'</p>
<p> </p>
Modelling plankton dynamics and community compositions in temperate lakes
No full textIn recent years, lakes have faced rising pressure from anthropogenic activities and climate warming, and the aquatic communities of some lake ecosystems are reshaping in ways that can form harmful algal blooms. It is crucial to understand how lake phytoplankton communities respond to environmental stressors under varying environmental conditions. The cell size of phytoplankton has multiple important implications for the dynamics, diversity, and productivity of a phytoplankton community. Empirical investigations in lakes showed that the size composition of phytoplankton communities differs with inorganic nutrient conditions, grazing pressure (usually quantified by zooplankton abundance), and water temperature. However, it is not clear how these three factors interact to shape the size composition of lake phytoplankton. In this thesis, I use size-based plankton modelling to elucidate how a trade-off mechanism, dependent on inorganic nutrient availabilities and zooplankton size-specific grazing strategies, shapes the dynamics, the size composition, and the exclusion pattern of phytoplankton in a generic temperate lake. Lastly, I recast the model to a specific Swiss lake, Greifensee, by using high-frequency data comprising phytoplankton cell size (biovolume) and plankton abundances. In summary, this thesis investigates the interactive effects of inorganic nutrient regimes and zooplankton grazing strategies on the community dynamics and compositions of lake phytoplankton and offers a glimpse into the future size compositions of phytoplankton and nutrient and plankton dynamics of Greifensee. The results not only advance our understanding of plankton communities in temperate lakes, but they also identify hypotheses related to zooplankton grazing strategies that can be further tested experimentally. The data-driven modelling approach presented here can contribute to strategic conservation and management plans for mitigating the effects of ongoing environmental change
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
koamabayili/VECTRON-author-checklist: VECTRON author checklist
No full textWe have done our best to complete the author checklist relating to the use of animals in the hut study. Note that the objective for the hut study was to evaluate the IRS treatment applications for residual efficacy against Anopheles mosquitoes, including the local An. coluzzii mosquito population. Cows were only used to attract mosquitoes into the huts and no tests were carried out directly on the cows. The author checklist is intended for use with studies where experiments are carried out on animals, which is why we have had such difficulty in completing this for the hut study, as many of the questions do not relate to how the cows were used
Author-wise bibliometric analysis based on entropy.
No full textAuthor-wise bibliometric analysis based on entropy.</p
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