1,720,994 research outputs found
Figs 1–6 in Stick insects of the genus Interphasma Chen et He, 2008 (Phasmida: Phasmatidae) from China
No full textFigs 1–6. Interphasma huayingshanense sp. n.: 1, 3 – female (holotype); 2, 5 – malePublished as part of Li, B.L., Shi, F.M. & Wang, H.J., 2021, Stick insects of the genus Interphasma Chen et He, 2008 (Phasmida: Phasmatidae) from China, pp. 24-32 in Far Eastern Entomologist 422 on page 27, DOI: 10.25221/fee.422.3, http://zenodo.org/record/716634
Effect of zooplankton growth rate on the spatiotemporal dynamics of plankton communities in heterogeneous environments
No full textA conceptual mathematical model of the reaction-diffusion type was used to study the basic mechanisms underlying the patchy spatial distribution and intricate temporal behavior of plankton in an inhomogeneous medium. The model describes trophic interactions of the prey-predator type between phytoplankton, zooplankton, and fish in surface waters, assuming that plankton is passively driven by turbulent diffusion. Simulations suggest the different growth rates of phytoplankton in neighboring biotopes to be the cause of patch formation in the spatial distribution of plankton. Analysis of the model shows that the biomass of phytoplankton and zooplankton may exhibit regular temporal dynamics or vary chaotically with time. If the habitat conditions are heterogeneous, the spatiotemporal dynamics of plankton depends significantly on the rate of fish predation upon zooplankton.</p
Interrelation between spatial and temporal variations in plankton biomass: a study by mathematical modeling
No full textDynamics of aquatic biological communities in patchy environments is a topic of substantial interest in the study of interrelationships between phenomena of very different space and time scales. A simple reaction-diffusion model of trophic interactions between phytoplankton, zooplankton, and fish was used to examine how the intricate dynamics of plankton changes on varying the rate of fish predation upon zooplankton. In this study, plankton was assumed to be distributed between two biotopes, of which one contained no fish because of the hydrological conditions in that biotope. Varying the fish predation rate did not bias the correspondence between the scales of spatial patterning and temporal changes in its biomass. Specifically, plankton distributed in large patches exhibited regular temporal oscillations of its abundance. The formation of small patches was associated with chaotic oscillations. As in the case when the fish predation rate was fixed, the dynamic behavior of plankton was determined by the coexistence of a chaotic attractor with a limit cycle.</p
Vzaimozavisimost' raspredeleniia planktona v prostranstve i izmenenii biomassy planktona vo vremeni: matematicheskoe modelirovanie
No full textThe dynamics of aquatic biological communities in a patchy environment is of great interest in respect to interrelations between phenomena at various spatial and time scales. To study the complex plankton dynamics in relation to variations of such a biologically essential parameter as the fish predation rate, we use a simple reaction-diffusion model of trophic interactions between phytoplankton, zooplankton, and fish. We suggest that plankton is distributed between two habitats one of which is fish-free due to hydrological inhomogeneity, while the other is fish-populated. We show that temporal variations in the fish predation rate do not violate the strong correspondence between the character of spatial distribution of plankton and changes of plankton biomass in time: regular temporal oscillations of plankton biomass correspond to large-scale plankton patches, while chaotic oscillations correspond to small-scale plankton patterns. As in the case of the constant fish predation rate, the chaotic plankton dynamics is characterized by coexistence of the chaotic attractor and limit cycle.</p
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
- …
