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Il tondo Riccardi del Vernaccia: un’opera riscoperta di Mariotto Albertinelli e il suo rapporto con Raffaello
No full textIn the commentary to the life of Mariotto Albertinelli in the 1851 edition of Vasari’s Vite, among the works not mentioned by the biographer is a tondo the curators accurately describe then in the palace of Francesco del Vernaccia in Borgo Pinti, Florence. This painting, representing a Holy Family with the Infant Saint John the Baptist, has never been considered or traced by scholars and can now be recognized in a panel preserved in excellent condition in a private collection. Comprehensive documentation found in various archives has made it possible to reconstruct its entire collection history. The Tondo Riccardi del Vernaccia is not only a very
high-quality addition to the artist’s catalogue, but also a fundamental piece of evidence for understanding Albertinelli’s
development during the last years of the first decade of the sixteenth century. In particular, the fact that it is based on a design by Raphael sheds new light on the relationship between the two artists
On groups whose subgroups are either modular or contranormal
No full texthttp://dx.doi.org/10.1017/S000497271200033
Groups with the weak minimal condition on non-normal non-abelian subgroups
No full textA group is called metahamiltonian if all its non-abelian subgroups are normal. It is proved here that a (generalized) soluble group satisfying the weak minimal condition on non-normal non-abelian subgroups is either minimax or metahamiltonian
Groups with many modular or self-normalizing subgroups
No full textIn this paper, locally graded group satisfying the minimal condition on subgroups which are neither modular nor self-normalizing are described; locally (soluble-by-finite) groups of infinite rank in which every subgroup is either modular or self-normalizing are also characterized in terms of their subgroups of infinite rank. Moreover, the results obtained are used to study groups satisfying similar restrictions on subgroups which are neither permutable nor self-normalizing
Groups with all subgroups either modular or soluble of finite rank
No full textWe study locally graded groups whose non-modular subgroups are soluble and satisfy some rank condition. In particular, in order to characterize locally graded groups whose subgroups are either modular or polycyclic, we describe (generalized) soluble groups whose non-modular subgroups are finitely generated
Groups with restricted non-permutable subgroups
No full textA subgroup H of a group G is said to be permutable if HK = KH for every subgroup K of G and the group G is called metaquasihamiltonian if all subgroups of G are either permutable or abelian. It is known that a locally graded metaquasihamiltonian group G is soluble with derived length at most 4 and contains a finite normal subgroup N such that all subgroups of the factor G/N are permutable. In this paper, we describe locally graded groups in which the set of all nonmetaquasihamiltonian subgroups satisfies the minimal condition and locally graded groups with the minimal condition on subgroups which are neither abelian nor permutable. Moreover, it is proved here that a finitely generated hyper-(abelian or finite) group whose finite homomorphic images are metaquasihamiltonian is itself metaquasihamiltonian
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
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