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The Phylogenetic position of Daubentonia madagascariensis (Gmelin, 1788; primates, Strepsirhini) as revealed by chromosomal analysis
Full text linkOne of the major topics in primate evolution is the phylogenetic position of the bizarre Daubentonia madagascariensis (DMA, aye-aye). The principal points that have been discussed for many decades are whether the aye-aye is: (i) the sister group of primates; (ii) the sister group of strepsirhines; or (iii) the sister group of lemurs. Very little is known about Daubentonia evolution, particularly on the chromosomal background. The present report focuses on the chromosomal history of this species. We used available chromosome painting data as the main source to identify conserved chromosomes, chromosomal segments and syntenic associations that have characterized the aye-aye karyotype. The dataset includes 47 characters that have been subjected to a concatenated analysis using maximum parsimony (MP) and Bayesian inference (BI). Both MP and BI topologies show Daubentonia as an independent monophyletic lineage, sister group of all other Strepsirhini. Further, both trees have weak statistical support as result of the high number of autapomorphies and homoplasies that have characterized the history of this group of specie
Reconstructing the Phylogeny of the Human Chromosome 4 Synteny using Comparative Karyology and Genomic Data Analysis
No full textThis work focuses on the evolution of the architecture of human chromosome 4 (HSA4) through
the analysis of chromosomal regions that have been conserved over time, and the comparison of regions that
have been involved in different rearrangements in placental lineages. As with most elements of the human
genome, HSA4 is considered to be evolutionarily stable. A more detailed analysis indicates that the syntenic association has been reshuffl ed by a series of rearrangements, yielding different chromosomes in various taxa. In
its ancestral eutherian state, HSA4 has a syntenic association with HSA8p. We investigated the complex origin
of this human chromosome using three different approaches, including: the analysis of chromosome painting features among 157 mammalian species gleaned from published data; the analysis of conserved syntenic
orthologous blocks derived from the Ensembl dataset (www.ensembl.org); and the reconstruction of the orthologues of HSA4 in various species, using a maximum parsimony (MP) analysis of evolutionary breakpoints.
The phylogenetic pattern recovered shows four discrete chromosomal regions have primarily been implicated
in chromosomal rearrangement: 4p15.3, 4p16.1, 4q12 and 4q31.1. Our results demonstrate that chromosome
painting and ancestral chromosome reconstructions can elucidate the diverse structural rearrangements that
characterize different evolutionary lineage
Special arrangements of lines: Codimension 2 ACM varieties in P 1 × P 1 × P 1
Full text linkIn this paper, we investigate special arrangements of lines in multiprojective spaces. In particular, we characterize codimension 2 arithmetically Cohen-Macaulay (ACM) varieties in P 1 × P 1 × P 1 , called varieties of lines. We also describe their ACM property from a combinatorial algebra point of view
Susceptibility to Mycobacterium tubercolosis: importance of multiple key genes in human and nonhuman primates
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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
Testing the uncertain phylogenetic position of Daubentonia madagascariensis (Strepsirhines) using chromosomes
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