1,721,221 research outputs found
Figure 3 in Oldest fossil loon documents a pronounced ecomorphological shift in the evolution of gaviiform birds
No full textFigure 3. Nasidytes ypresianus gen. et sp. nov. from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK), sternum, pectoral girdle bones and vertebrae of the holotype (NMS.Z.2021.40.24), in comparison to fossil and extant Gaviiformes. A‒D, N. ypresianus, sternum in ventral (A), dorsal (B), left lateral (C) and cranial (D) view. E, F, N. ypresianus, furcula in caudolateral (E) and caudal (F) view. G, H, Gavia stellata (SMF 7241), furcula in caudolateral (G) and caudal (H) view. I, J, N. ypresianus, right coracoid in dorsal (I) and ventral (J) view. K, left coracoid of Colymboides anglicus (holotype, NHMUK A 30330) from the late Eocene of England in dorsal view. L, right coracoid of G. stellata (SMF 7241) in dorsal view. M, N. ypresianus, right scapula in lateral view. N, right scapula of G. stellata (SMF 7241) in lateral view. O, P, N. ypresianus, thoracic (O) and caudal (P) vertebrae. Abbreviations: acr, acromion; apf, apophysis furculae; car, carina sterni; cvx, convexity on medial margin of extremitas sternalis; exo, extremitas omalis; exs, extremitas sternalis; fns, foramen nervi supracoracoidei; pct, processus costales; pla, processus lateralis; plc, pleurocoel; ppc, processus procoracoideus; spe, spina externa; trv, processus transversus. Scale bars: 10 mm.Published as part of Mayr, Gerald & Kitchener, Andrew C., 2022, Oldest fossil loon documents a pronounced ecomorphological shift in the evolution of gaviiform birds, pp. 1431-1450 in Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 196 (4) on page 1436, DOI: 10.1093/zoolinnean/zlac045, http://zenodo.org/record/739062
Figure 8 in Oldest fossil loon documents a pronounced ecomorphological shift in the evolution of gaviiform birds
No full textFigure 8. Summary of phylogenetic interrelationships and stratigraphic occurrences of stem group Gaviiformes and other taxa of Aequornithes; the phylogeny of the extant taxa is based on the studies by Prum et al. (2015) and Kuhl et al. (2021) and differs from the tree topology obtained in the morphology-based analysis performed in the present study. For gaviiform birds, the nodes are characterized by the following characters: (1) hypotarsus with distinct sulci for tendons of musculus flexor hallucis longus and m. flexor perforatus digiti 2; (2) humerus with elongated tuberculum supracondylare ventrale; tibiotarsus with narrow and strongly elongated cristae cnemiales; (3) distal end of ulna with enlarged tuberculum carpale; os metacarpale alulare long and without well-delimited processus extensorius and processus alularis (the carpometacarpus of Colymbiculus is unknown); femur strongly abbreviated and stout; and (4) os carpi ulnare with distinct notch for tendon of musculus ulnometacarpalis ventralis. Stratigraphic occurrences of non-gaviiform Aequornithes (red bars) are from Mayr (2022); the interrupted bars indicate uncertain fossil records for Pelecanidae and Sulidae.Published as part of Mayr, Gerald & Kitchener, Andrew C., 2022, Oldest fossil loon documents a pronounced ecomorphological shift in the evolution of gaviiform birds, pp. 1431-1450 in Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 196 (4) on page 1442, DOI: 10.1093/zoolinnean/zlac045, http://zenodo.org/record/739062
Novel mtDNA haplotypes represented in the European captive population of the Endangered François’ langur (Trachypithecus francoisi)
No full textAssessing the genetic diversity of captive populations of endangered species is key to the successful management of conservation-breeding programs. In this study, we sequenced a 393-bp fragment of the mitochondrial DNA (mtDNA) control region of 23 captive individuals of the Endangered François’ langur ( ) to assess the mtDNA diversity of the European captive population and to identify the possible geographical origins of the population founders. Combined with 42 sequences previously published from 29 wild François’ langurs, we identified a total of 40 haplotypes in , including 12 haplotypes in the 23 samples from the European captive population. Only one of the haplotypes from captive animals has previously been reported from wild populations; the remaining 11 haplotypes are newly reported here. Our results suggest that the captive population currently holds a relatively good genetic diversity compared with many other captive populations, that this diversity originates from a fairly broad range across the species’ distribution in the wild, and that the captive population could play a significant role in increasing genetic diversity of isolated wild populations. However, the European captive population is currently quite small, and genetic diversity could be lost rapidly, which has been demonstrated in other captive populations. We recommend further investigation of the genetic diversity of captive and wild populations, as well as the effective conservation of this diversity
Figure 4 in Oldest fossil loon documents a pronounced ecomorphological shift in the evolution of gaviiform birds
No full textFigure 4. Nasidytes ypresianus gen. et sp. nov. from the early Eocene London Clay of Walton-on-the-Naze (Essex, UK), wing bones in comparison to fossil and extant gaviiforms and to Australornis lovei from the late early Palaeocene of New Zealand. Except for X, which is from the referred specimen NMS.2021.40.25, all bones of N. ypresianus are from the holotype (NMS.Z.2021.40.24). A, B, N. ypresianus, right (A) and left (B) humerus in caudal (A) and cranial (B) view; the arrow denotes a detail of the distal end. C, Colymbiculus udovichenkoi from the middle Eocene of Ukraine, left humerus lacking proximal end (SMF Av 545) in cranial view. D, left humerus of Gavia stellata (SMF 7241) in cranial view; the arrow denotes a detail of the distal end. E, Australornis lovei (holotype, CM 2010.108.2), right humerus in caudal view. F‒H, N. ypresianus, left ulna in ventral (F), cranial (G) and dorsal (H) view. I, Colymbiculus udovichenkoi, right ulna (SMF Av 548) in ventral view. J, right ulna of`?Colymboides metzleri' from the early Oligocene of Belgium (IRSNB Av 85) in ventral view. K, L, left ulna of G. stellata (SMF 7241) in ventral (K) and cranial (L) view. M, N, N. ypresianus, proximal (M; cranial view) and distal (N; ventral view) ends of left ulna. O, P, Colymbiculus udovichenkoi, proximal (O; cranial view) and distal (P; ventral view) ends of right ulna (SMF Av 548). Q, R, G. stellata, proximal (Q; cranial view) and distal (R; ventral view) ends of left ulna (SMF 7241). S, N. ypresianus, proximal end of left carpometacarpus in ventral view. T, N. ypresianus, os carpi ulnare. U, N. ypresianus, os carpi radiale. V, G. stellata, os carpi ulnare (SMF 7241). W, G. stellata, os carpi radiale (SMF 4435). X, N. ypresianus, left carpometacarpus of referred specimen (NMS.Z.2021.40.25) in ventral view. Y, right carpometacarpus of '?Colymboides metzleri' from the early Oligocene of Belgium (IRSNB Av 85) in ventral view. Z, left carpometacarpus of G. stellata (SMF 7241) in ventral view. Abbreviations: bcp, crista bicipitalis; cdd, condylus dorsalis; cdp, crista deltopectoralis; cdv, condylus ventralis; ctd, cotyla dorsalis; ctv, cotyla ventralis; flx, processus flexorius; fur, transverse furrow; imc, incisura metacarpalis; ntc, notch for tendon of musculus ulnometacarpalis ventralis; olc, olecranon; oma, os metacarpale alulare; pal, processus alularis; pex, processus extensorius; pis, processus pisiformis; tbc, tuberculum carpale; tbd, tuberculum dorsale; tsv, tuberculum supracondylare ventrale. Scale bars: 10 mm.Published as part of Mayr, Gerald & Kitchener, Andrew C., 2022, Oldest fossil loon documents a pronounced ecomorphological shift in the evolution of gaviiform birds, pp. 1431-1450 in Zoological Journal of the Linnean Society (Zool. J. Linn. Soc.) 196 (4) on page 1437, DOI: 10.1093/zoolinnean/zlac045, http://zenodo.org/record/739062
spp.): implications for conservation
No full textRuffed lemurs ( and ) are categorized as Critically Endangered on the IUCN Red List, and genetic studies are needed for assessing the conservation value of captive populations. Using 280 mitochondrial DNA (mtDNA) D-loop sequences, we studied the genetic diversity and structure of captive ruffed lemurs in Madagascar, Europe and North America. We found 10 new haplotypes: one from the European captive population, three from captive (one from Europe and two from Madagascar) and six from other captive in Madagascar. We found low mtDNA genetic diversity in the European and North American captive populations of . Several founder individuals shared the same mtDNA haplotype and therefore should not be assumed to be unrelated founders when making breeding recommendations. The captive population in Madagascar has high genetic diversity, including haplotypes not yet identified in wild populations. We determined the probable geographical provenance of founders of captive populations by comparison with previous studies; all reported haplotypes from captive ruffed lemurs were identical to or clustered with haplotypes from wild populations located north of the Mangoro River in Madagascar. Effective conservation strategies for wild populations, with potentially unidentified genetic diversity, should still be considered the priority for conserving ruffed lemurs. However, our results illustrate that the captive population in Madagascar has conservation value as a source of potential release stock for reintroduction or reinforcement projects and that cross-regional transfers within the global captive population could increase the genetic diversity and therefore the conservation value of each regional population
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
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