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Impact of past and present climate changes on dipper (Cinclus cinclus) genetic and demography
Get PDFClimate change is emerging as the greatest threat to natural communities in many, if not most, of the world’s ecosystems in coming decades. Numerous studies have revealed present and probable future consequences that climate change will have on many animal and vegetal species. According to these studies, birds could be affected, mostly negatively, in various ways : distribution, abundance, phenology, ethology ...
The purpose of this work is to determine how the White-throated Dipper (Cinclus cinclus), a Palearctic, temperate, passerine bird that is exclusively associated with flowing water, reacted to the climate changes that occurred during the Pleistocene, and how climate change currently affects this species :
- For this purpose, we conducted a phylogeographic study : we analysed three fragments of mtDNA (i.e. fragments coding for cytochrome b, ND2 and domains II and III of the controle region) from 106 tissue samples originating from 24 dipper populations, mostly located in the Western Palearctic.
- The second part of this work consisted in analysing ringing recoveries and nest-boxes frequentation from a dippers population settled on the river Syre and its tributaries (Luxemburg) and followed from 1979 to 2001. Populations census were also conducted on different water courses in Luxemburg, in order to determine dipper habitat preferences.
1. Phylogeography of the dipper in the Western Palearctic region
In spite of a low genetic variability, the results of our phylogeographic study reveal a complex phylogeographic structure for this species with at least five distinct lineages for the Western Palearctic region. As for many species of the Western Palearctic fauna and flora, this genetic structure is probably linked to the isolation of populations in different southern refuges during glacial periods. Furthermore, the isolation of populations in Scandinavia and/or Eastern regions, but also in Morocco and probably in Corsica, was accentuated by ecological and biogeographic barriers during Quaternary interglacial periods. During glacial periods, Italy, Sicily and the Balkano-Carpathian region acted as major refuge zones for the dipper. At the end of the last ice age, Western Europe was repopulated by dippers from a refuge located in Italy and, probably, South-East France, while Eastern Europe was recolonised by Balkano-Carpathian birds. A large contact zone between these two lineages was evidenced and extends from Luxembourg to Hungary. Finally, our results indicate the need to clarify the taxonomic status of the dipper, especially concerning the European subspecies whose validity appears uncertain.
2. Dipper demography – Influence of climate change and other anthropic pertubations
Results obtained from the analysis of demographic and morphologic variables of the Luxemburger population are in agreement with results obtained from other European populations. Differences observed between these populations are mostly due to climate and habitat quality differences. However, other factors could also partly explain these differences. As for other places in Europe, nest boxes installation dramatically increased dippers population size on the river Syre. Our results also suggest that the installation of nest boxes could influence some demographic and morphologic variables, probably as a result of population increase. But, above all, our results show how temperatures and precipitations affect these variables, and particularly laying dates. Climatic changes that occurred during the last decades provoked earlier laying dates. Whereas clutch size and nest size remained unchanged, the Luxemburger population size decreased during the same period, as observed for other European populations. The main cause to this decrease should be an increase of environmental instability inducing notably a decrease of food ressources for dippers. As a result, we observed a significant decrease of females body weight during this period.
Climate change will also probably have a serious impact on dipper genetic diversity, leading to the disappearance of the most southern populations and eventually of certain genetic clades. The results obtained concerning the taxonomic status of the dipper and its demography could be useful in the framework of a conservation program, if necessary. In this perspective, the development of habitat suitability prediction tools, as the one we developed, could also be very helpful
Impact of past and present climate changes on dipper (Cinclus cinclus) genetic and demography - Impacts des changements climatiques pass\ue9s et pr\ue9sents sur la g\ue9n\ue9tique et la d\ue9mographie du Cincle plongeur (Cinclus cinclus)
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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
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
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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