Genetic diversity and structure of the portuguese pear (Pyrus communis L.) germplasm

A rich heritage of traditional pear varieties is kept in national Portuguese collections. Out of these varieties, “Rocha” dominates national pear production. Although a noticeable phenotypic variation among clones of this variety has been reported, little is known about its genetic variability, as to date molecular studies have been performed on a single “Rocha” clone. Eleven Simple Sequence Repeats (SSR) markers were used to assess the genetic diversity of 130 local cultivars, 80 of them being “Rocha” clones. The results allowed the di erentiation of 75 genotypes of which 29 are “Rocha”. Three synonyms groups and four homonymous groups of other local varieties were confirmed. A Bayesian model-based clustering approach identified two distinct clusters. Using flow cytometry, six cultivars were found to be triploids. These results show high genetic variability among “Rocha” clones. In conclusion, there is a need for di erent “Rocha” clones to be preserved to enable the correct selection of the multiplication materialinfo:eu-repo/semantics/publishedVersio

Book Review: Crossing the Borders: Essays in Honour of Francis X. D\u27Sa on the Occasion of his 65th Birthday

A review of Crossing the Borders: Essays in Honour of Francis X. D\u27Sa on the Occasion of his 65th Birthday edited by Anand Amaladass and Rosario Rocha

Drive Thru—An Interview with Artist Matheus Rocha-Pitta

Latin American Studie

Record of a bypass on the oral siphon of Ascidia sydneiensis (Tunicata: Ascidiacea) in a tropical bay from south-eastern Brazil

Ascidia sydneiensis Stimpson, 1855 is a solitary ascidian (Order Phlebobranchia) first described in the China Sea and Japan. Recently, it has been recorded in subtropical and tropical regions and is abundant in the Caribbean (Rocha et al., 2005; Worms, 2020). In Brazil, it was first recorded in the São Paulo State (Bjornberg, 1956) and ranges from Ceará to Santa Catarina (Rodrigues, 1962; Rocha and Nasser, 1998; Rocha and Costa, 2005; Rocha and Kremmer, 2005; Rocha et al., 2012). On the coast of Rio de Janeiro State, it was recorded at Ilha Grande Bay, Sepetiba Bay, Arraial do Cabo, and Búzios (Marins et al., 2010; Granthon-Costa et al., 2016)

An electric charge has no screw sense--a comment on the twistfree formulation of electrodynamics by da Rocha & Rodrigues

Da Rocha and Rodigues (RR) claim (i) that in classical electrodynamics in vector calculus the distinction between polar and axial vectors and in exterior calculus between twisted and untwisted forms is inappropriate and superfluous, and (ii) that they can derive the Lorentz force equation from Maxwell's equations. As to (i), we point out that the distinction of polar/axial and twisted/untwisted derives from the property of the electric charge of being a pure scalar, that is, not carrying any screw sense. Therefore, the mentioned distinctions are necessary ingredients in any fundamental theory of electrodynamics. If one restricted the allowed coordinate transformations to those with positive Jacobian determinants (or prescribed an equivalent constraint), then the RR scheme could be accommodated; however, such a restriction is illegal since electrodynamics is, in fact, also covariant under transformations with negative Jacobians. As to (ii), the "derivation" of the Lorentz force from Maxwell's equations, we point out that RR forgot to give the symbol F (the field strength) in Maxwell's equations an operational meaning in the first place. Thus, their proof is empty. Summing up: the approach of RR does not bring in any new insight into the structure of electrodynamics.Comment: Added answer to da Rocha & Rodrigues arXiv:0912.212