1,721,079 research outputs found
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
Reconstruction of a pool-and-weir fishway to a vertical slot hybrid fishway in the inland river Glomma : effects on upstream migration of European grayling (Thymallus thymallus) and brown trout (Salmo trutta)
Full text linkDet er godt dokumentert at installasjoner i vassdrag kan ha store negative konsekvenser på ulike fiskearter og deres habitater. Demninger kan blokkere og forsinke migrasjon, samt endre den romlige fordeling av individer. Fisketrapper blir ofte implementert for å opprettholde biologisk kontinuitet og forhindre fragmentering av habitater, men problemet er at mange fisketrapper ikke fungerer tilfredsstillende. Dette kan føre til reduserte bestander og lokal utryddelse av enkeltarter. Målet med denne studien var å undersøke hvilke effekter ombyggingen av fisketrappen ved Høyeggadammen i Glomma hadde for oppvandrende harr (Thymallus thymallus) og ørret (Salmo trutta). Fisketrappen ble ombygget i 2016, fra en kulpetrapp til en hybrid spaltetrapp med naturlig substrat i hvert kammer. Spaltetrapper har ofte lavere vannhastighet og turbulens, samt kan takle større vannstandsendringer bedre enn kulpetrapp-utformingen. Spalten går helt ned til bunnen av hvert kammer og gir fisken mulighet til å svømme opp eller ned uten å hoppe mellom kammerene. Viktigheten av disse faktorene har blitt belyst i tidligere studier på lokaliteter med høy diversitet i artssammensetning.
Datasettet som ble brukt i denne studien er basert på registreringer av oppvandrende fisk i fisketrappen. En VAKI fisketeller har registrert fisk i trappen, og inneholder registreringer to år før (2014 & 2015) og to år etter (2016 & 2017) ombyggingen. Antall registrerte oppvandrende fisk økte med totalt 76.5% etter ombyggingen. Det var også signifikant endring i artssammensetning blant de registrerte individene. En zero-inflated Poisson modell ble tilpasset vandringsdataene og brukt for å kvantifisere hvilke effekter miljøfaktorer og ombyggingen hadde på oppvandrende harr og ørret. Estimatene fra modellen predikterte at oppvandring hos harr var favorisert av lavere vannføringer sammenlignet med ørret. Ørretens oppvandring viste seg å være mer avhengig av temperatur. Det er imidlertid for tidlig å konkludere med at ombyggingen av fisketrappen ved Høyeggadammen er grunnen til økt antall oppvandrende fisk. Modellene peker allikevel på en klart økende tendens for oppvandring hos harr for en gitt temperatur og vannføring etter ombygging. Økningen i antall registrerte arter indikerer også at ombyggingen har ført til positive endringer. Denne studien illustrerer at ombygging kan være et mulig tiltak for å forbedre mange av dagens eksisterende fisketrapper. Lignende ombygginger burde bli gjennomført og overvåket andre steder for å øke kunnskapsgrunnlaget. Et slikt tiltak vil sannsynligvis også øke funksjonaliteten og være en kostnadseffektiv endring sammenlignet med konstruering og installasjon av en helt ny fisketrapp.It is well documented that man-made barriers in rivers can have severe negative effects on numerous fish species and their ecology. Obstructions can block and delay fish migrations, which may be critical for the life cycle and spatial distribution of many fish species. Fishways are one of the most used measures to maintain biological connectivity at artificial barriers in rivers. However, fishways often show poor functionality, which can result in fragmented and declining populations or even local extinctions. The aim of this study was to investigate the effects of a reconstruction of the fishway at the Høyegga dam in the inland river Glomma, Norway, on upstream migration of grayling (Thymallus thymallus) and brown trout (Salmo trutta). The fishway was reconstructed in 2016 from a pool-and-weir type to a vertical slot hybrid design. The vertical slot design often has lower velocity and turbulence levels, and are generally more suited to handle a broader range of discharges, compared to the pool-and-weir fishway design. The vertical slot type also allows the fish to pass the fishway by swimming close to the bottom to ascend the fishway. Previous studies have shown that these factors can be of great importance at locations with complex species composition.
The dataset in this study is based on automatically registrations of upstream migratory fish individuals collected by a VAKI Riverwatcher fish counter placed in the fishway. The two years prior to reconstruction (2014 & 2015) and the two years after reconstruction (2016 & 2017) are included in the data analysis. After the reconstruction, the number of upstream migratory individuals increased with 76.5% in total. It was also found a significant change in the species composition among registered individuals. To predict impact of external factors and the fishway reconstruction on upstream migration of grayling and brown trout, a zero-inflated Poisson model was used. Grayling and brown trout migration intensity were predicted to increase with higher temperature, and grayling was more dependent on low river discharges compared to brown trout. It is too early to state that the reconstruction of the fishway at Høyegga led to increased numbers of upstream migration of grayling and brown trout. It was, however, a clear tendency that larger numbers of grayling ascended the fishway after reconstruction for any given temperature and water discharge. The increased number of species registered, also indicates that the reconstruction led to some positive changes. This study illustrates that redesigns can have great potential for improving many of today’s pool-and-weir fishways. Similar measures should be undertaken elsewhere to increase the knowledge about this method, as this is a cost-efficient measure compared to construction of a brand new fishway.publishedVersionM-N
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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