1,721,133 research outputs found
FIGURES 55–61 in New Amphicocconeis (Bacillariophyta) from Raivavae and Tahiti Islands (South Pacific) and Porto Belo (Brazil), with re-examination of Psammococconeis
No full textFIGURES 55–61. Amphicocconeis ruatara sp. nov. (material RAI 20 from Raivavae, Austral Islands, South Pacific). RVs in external view (Figs 55–56), RV in internal view (Fig. 57), detail of the RV apex with terminal raphe fissure (Fig. 58), central area in external view (Fig. 59), head pole of the RVVC in advalvar view (Fig. 61), entire RVVC in advalvar view (Fig. 60). Scale bars: 3 µm (Figs 55–56, 60), 2 µm (Fig. 57), 1 µm (Figs 58–59, 61).Published as part of Riaux-Gobin, Catherine, Garcia, Marinês, Witkowski, Andrzej, Saenz-Agudelo, Pablo, Coste, Michel & Daniszewska-Kowalczyk, Genowefa, 2021, New Amphicocconeis (Bacillariophyta) from Raivavae and Tahiti Islands (South Pacific) and Porto Belo (Brazil), with re-examination of Psammococconeis, pp. 30-54 in Phytotaxa 513 (1) on page 42, DOI: 10.11646/phytotaxa.513.1.2, http://zenodo.org/record/530693
Amphicocconeis mascarenica Riaux-Gobin & Compere 2011
No full textAmphicocconeis cf. mascarenica Riaux-Gobin & Compère, 2011 (Figs 62–67). Table 1 Remarks:—The measurements and features of the specimens from the Pacific islands (Raivavae, Tahiti and Moorea Isls, Table 1) are close to those from the Mascarenes (Riaux-Gobin et al. 2011: tabl. 2), i.e., with valvocopulae with regularly biseriate rows of simple pores. This taxon is dominant on the Society Archipelago (Tahiti and Moorea Isls) as well as in the Austral Archipelago (Raivavae Isl.). In Tuamotu and Marquesas Archipelagos, Amphicocconeis are less abundant, but with, here again, A. cf. mascarenica as dominant taxon (pers. obs.).Published as part of Riaux-Gobin, Catherine, Garcia, Marinês, Witkowski, Andrzej, Saenz-Agudelo, Pablo, Coste, Michel & Daniszewska-Kowalczyk, Genowefa, 2021, New Amphicocconeis (Bacillariophyta) from Raivavae and Tahiti Islands (South Pacific) and Porto Belo (Brazil), with re-examination of Psammococconeis, pp. 30-54 in Phytotaxa 513 (1) on page 52, DOI: 10.11646/phytotaxa.513.1.2, http://zenodo.org/record/530693
Amphicocconeis catharinensis Riaux-Gobin & Garcia. SEM
No full textAmphicocconeis catharinensis Riaux-Gobin & Garcia. SEM, Figs 7–17. Table 1 Description:— SEM.Valves robust, oval-elliptic, with round apices. Valve length 18 ± 3 µm, 14–22 µm. Valve width 11 ± 2 µm, 9–13 µm; n = 10 (SEM) (Table 1). SV: surface convex, striae radiate and regularly spaced, uniseriate, composed of large rectangular areolae. On the valve face, each areola is positioned on the bottom of a depression with opening bordered by digit flaps (Figs 8–9). Areolae are internally closed by hymenes (Figs 10–12). On the mantle, each oblong areola is separated from the next by a granular and concave plain structure of triangular to rectangular shape (Figs 8–9, arrows). Short marginal striae not observed. 11 ± 1 SV stria in 10 µm. SVVC relatively narrow with big pores corresponding to each areola. RV: surface flat, striae radiate, composed of macro-areolae (large along the margin, short along the raphe, with short areolae dispersed in between, Fig. 13). Terminal-distal raphe endings strongly curved on same side (Figs 13, 15). Proximal raphe endings slightly enlarged and curved on same side (opposite to the terminal raphe endings, Fig. 16). 26 ± 2.5 RV stria in 10 µm. RVVC 1/4 of the valve width, with marginal transapical oblong pores corresponding to each macro-alreola (Fig. 17, twin arrowheads). Remarks:—The SV of Amphicocconeis catharinensis was illustrated as being the SV of Psammococconeis disculoides in Garcia (2001: figs 21, 23). The specific ornamentation of the SV mantle, with a concave structure in between each oblong areola (Figs 8–9) seems unique. The RV of A. catharinensis has some similarities with that of A. disculoides and A. debesi (large area with short radiate macro-areolae), but these short areolae in median-area are in very low density in A. catharinensis (Fig. 13), furthermore the SV of A. catharinensis is highly dissimilar to that of Amphicocconeis disculoides (Hustedt) De Stefano & Marino (figs 2–3, 6– 7 in De Stefano & Marino 2003; Figs 1). Type locality:—Zimbros, Peninsula do Porto Belo, Santa Catarina State, Brazil. Holotype:—Stub 4 19/06/2020, BM001222889. Holotype specimen illustrated in Fig. 7. Etymology:—The epithet refers to the location of the type habitat of this taxon in Brazil (locality Santa Catarina State).Published as part of Riaux-Gobin, Catherine, Garcia, Marinês, Witkowski, Andrzej, Saenz-Agudelo, Pablo, Coste, Michel & Daniszewska-Kowalczyk, Genowefa, 2021, New Amphicocconeis (Bacillariophyta) from Raivavae and Tahiti Islands (South Pacific) and Porto Belo (Brazil), with re-examination of Psammococconeis, pp. 30-54 in Phytotaxa 513 (1) on page 44, DOI: 10.11646/phytotaxa.513.1.2, http://zenodo.org/record/530693
Genomic diversity and demographic history of the Dromiciops genus (Marsupialia: Microbiotheriidae)
No full textThree orders represent the South American fauna of marsupials. Of these, Microbiotheria was until recently known as a monotypic genus with the only surviving species Dromiciops gliroides (monito del monte). The recent proposal of a new Dromiciops species (Dromiciops bozinovici), together with new information on the origin and diversification of living microbioterians has changed the prevailing paradigm around the evolutionary history of these emblematic marsupials. Here, we used a RADseq approach to test for evidence of admixture and past or current gene flow among both species of Dromiciops and evaluate the genetic structure within D. gliroides. We analyzed 127 samples of Dromiciops distributed across the known distribution range of both species. We also inferred the joint demographic history of these lineages, thus corroborating the status of D. bozinovici as a distinct species. Demographic history reconstruction indicated that D. bozinovici diverged from D. gliroides around 4my ago and has remained isolated and demographically stable ever since. In contrast, D. gliroides is subdivided into three subclades that experienced recent expansions and moderate gene flow among them (mostly from north to south). Furthermore, genetic distances among populations within D. gliroides were significantly correlated with geographic distances. These results suggest that some of the D. gliroides populations would have survived in glacial refuges, with posterior expansions after ice retreat. Our results have important implications for the systematics of the genus and have profound conservation consequences for the new species, especially considering the fragmentation level of the temperate rainforest.Fil: Quintero Galvis, Julian F.. Universidad Austral de Chile; Chile. Millenium Institute for Integrative Biology; ChileFil: Saenz Agudelo, Pablo. Universidad Austral de Chile; ChileFil: Amico, Guillermo Cesar. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Vazquez, Miriam Soledad. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte. Instituto de Investigaciones en Biodiversidad y Medioambiente. Universidad Nacional del Comahue. Centro Regional Universidad Bariloche. Instituto de Investigaciones en Biodiversidad y Medioambiente; ArgentinaFil: Shafer, Aaron B. A.. Trent University (trent University);Fil: Nespolo, Roberto F.. Universidad Austral de Chile; Chile. Universidad Católica de Chile; Chile. Millenium Institute for Integrative Biology; Chile. Millennium Nucleus of Patagonian Limit of Life; Chil
Estimating connectivity in coral reef fish populations: a tool for understanding stability and resilience of marine ecosystems
Full text linkThe extent of larval dispersal holds a crucial role for both the dynamics and evolution of spatially structured marine populations, determines the scale at which species interact with their environment, respond to perturbations and evolve. Designing effective conservation strategies such as marine reserve networks will depend to some extent in our comprehension of how marine populations are interconnected. However, measuring exchange among populations given the small size of larvae of most marine species and the high dispersal potential in the ocean matrix, remains challenging because of the difficulty of tracking individual larvae in the ocean. As a consequence, there is still little knowledge about the patterns of demographic connectivity in marine environments and the main factors that influence the shape of dispersal. The aim of this dissertation is to provide new leads on the scale of marine larval dispersal in a coastal environment and the role of the parental environment as driver of the variation in magnitude of local population replenishment. A metapopulation consisting of discrete adjacent subpopulations of the anemonefish Amphiprion polymnus along 30 km of coastline in Bootless Bay (Papua New Guinea) was used as a model system. Highly variable microsatellite loci as genetic markers and parentage analysis were used to trace back the parental origins of juvenile fish. This method allowed for the estimation of self recruitment and population connectivity within the metapopulation. This dissertation starts by exploring some methodological issues related to the use of parentage analysis in natural populations and estimates the minimal sampling effort required (in terms of number of genetic markers) to attain high parentage assignment accuracy (~94%) in this specific metapopulation. Second, larval retention within and exchange among the subpopulations previously mentioned were quantified over two consecutive years. The results of this chapter suggest that in this coastal metapopulation, self recruitment at small spatial scale (individual reefs) is low (~8% in average), highly variable among sites, but rather constant between years. At the metapopulation level, connectivity and not self recruitment seems to be the dominant pattern. Third, by using individual multi-locus profiles as natural tags, parentage analysis and field observations, it is shown for the first time in a natural marine population, that larger females in the local population contribute more than twice to local replenishment than smaller females. In addition, results from this chapter revealed that habitat degradation can have negative consequences on the reproductive output for this species. Finally, I used empirical data from previous chapters to estimate population's demographic rates (survival, fecundity and size-category transition frequency) and integrated this in a simple matrix model. In this way I was able to show that metapopulation self persistence is only achieved in this system when considering at least 50 km of coastline. In general, the results of this work reinforce the notion that in scenarios where spacing between suitable habitat patches is small, populations operate as open systems even at relatively large spatial scales. Comparison with previous studies suggests that dispersal of coral reef larvae might be more influenced by geographic settings than species specific life history traits. Finally, in a conservation perspective, these results indicate that protecting large healthy females will be crucial to population replenishment, argue for the implementation of management strategies that will restore and protect size/age structure of marine populations and highlight that, in relatively continuous habitats, a small Marine Protected Area (MPA) could not be considered as self-sustaining if populations outside the MPA are depleted
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
Single nucleotide polymorphism (SNPs) data for Scurria scurra, Scurria variabilis, Scurria ceciliana and Scurria araucana
No full text<p>The distribution of genetic diversity is often heterogeneous in space, and it usually correlates with environmental transitions or historical processes that affect demography. The coast of Chile encompasses two biogeographic provinces and spans a broad environmental gradient together with oceanographic processes linked to coastal topography that can affect species' genetic diversity. Here, we evaluated the genetic connectivity and historical demography of four <em>Scurria</em> limpets, <em>S. scurra, S. variabilis, S. ceciliana</em> and <em>S. araucana</em>, between ca. 19° S and 53° S in the Chilean coast using genome-wide SNPs markers. Genetic structure varied among species which was evidenced by species-specific breaks together with two shared breaks. One of the shared breaks was located at 22–25° S and was observed in <em>S. araucana</em> and <em>S. variabilis</em>, while the second break around 31–34° S was shared by three <em>Scurria</em> species. Interestingly, the identified genetic breaks are also shared with other low-disperser invertebrates. Demographic histories show bottlenecks in <em>S. scurra</em> and <em>S. araucana</em> populations and recent population expansion in all species. The shared genetic breaks can be linked to oceanographic features acting as soft barriers to dispersal and also to historical climate, evidencing the utility of comparing multiple and sympatric species to understand the influence of a particular seascape on genetic diversity.</p><p>To open VCF files, any program that read such files can be used, such as VCFtools, snpR package in R, etc.</p><p>Funding provided by: Agencia Nacional de Investigación y Desarrollo<br>Crossref Funder Registry ID: https://ror.org/02ap3w078<br>Award Number: 1190710</p><p>These data were retrieved by restriction-site associate DNA sequencing of muscle (foot) tissue using the enzyme pstI. </p>
<p>Raw reads were demultiplexed using Stacks. <em>Scurria scurra</em>, <em>Scurria ceciliana</em> and <em>Scurria araucana</em> RAD loci were mapped to the reference genome of <em>Scurria scurria</em> (Saenz-Agudelo P., unpublished) using the ref_map.pl pipeline of Stacks, while for <em>Scurria variabilis</em> loci were called de novo using the denovo_map.pl pipline of Stacks.</p>
<p>VCF files were generated in populations from Stacks, keeping only 80% as the minimum percentage of all individuals to process a locus. Further filtering steps were made in VCFtools, namely mean minimum read depth per locus (15), maximum mean depth per site (62-73, depending on the species) and a final genotype call rate of 90%. No individuals with more than 20% missing data were kept. The final filter consisted of removing loci with evidence of linkage disequilibrium, which was estimated using the function snpgdsLDpruning from the R package SNPRelate.</p>
<p>For detecting putatively outlier loci, BayeScan and pcadapt were used and the common loci detected by both analyses were removed from the "NoOuts" datasets and only these outlier loci were kept in the "Outs" datasets.</p>
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