Akodon polopi Jayat et al., 2010 is a senior subjective synomym of Akodon viridescens Braun et al., 2010

Two new taxa of species level were recently named for grass mice of the genus Akodon (Cricetidae, Sigmodontinae) from central Argentina: Akodon polopi Jayat, Ortiz, Salazar-Bravo, Pardiñas et D’Elía, 2010 and Akodon viridescens Braun, Mares, Coyner et Van Den Bussche, 2010. Several lines of evidence show that both taxa refer to the same biological species. Various morphologic characters enumerated by the two research teams for A. polopi and A. viridescens are coincident. The brownish coloration of the dorsal pelage, the chin with a small but distinguishable white patch, the tail of approximately 70% of head and body length, and the broad rostrum are among the diagnostic characters cited for both forms. Other additional characters mentioned in the diagnosis of only one of the nominal forms are also enumerated in the general description of the other. These include the size intermediate for the genus, the hour-glass shaped interorbital region with sharply squared posterior margins in older individuals, the anterior border of mesopterygoid fossa rounded with sides parallel or slightly diverging backward, and the parapterygoid fossae with straight and gradually divergent sides. Many additional features are mentioned for both nominal forms in their general descriptions.Fil: D' Elía, Guillermo. Universidad Austral de Chile. Instituto de Ecología y Evolución; ChileFil: Jayat, Jorge Pablo. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Laboratorio de Investigaciones Ecológicas de Las Yungas; ArgentinaFil: Ortiz, Pablo Edmundo. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo. Cátedra de Paleontología; ArgentinaFil: Salazar-bravo, Jorge. Texas Tech University. Department of Biological Sciences; Estados UnidosFil: Pardiñas, Ulises Francisco J.. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Nacional Patagónico; Argentin

Taxonomy based on science is necessary for global conservation

Peer reviewe

Analyse des remaniements du protéome associés à la levée de dormance d’une graine imbibée

National audienc

Revision and analysis of the chromosome variability in the speciose genus Akodon (Rodentia, Sigmodontinae), including new data from Argentina

Abstract Rodentia has a high species number and chromosomal variability. The South American genus Akodon is one of the most speciose muroids, with more than 40 species included in several species groups. Here, we characterize cytogenetically specimens of Akodon from central-western Argentina. Subsequently, we reviewed and analyzed the cytogenetic data for this genus, build a phylogeny and mapped chromosome changes to interpret its evolution. Specimens of A. dolores from central-western Argentina have 2n=42-44/FNa=44 (46, 48) due to a Robertsonian rearrangement. Our data expand the distribution range known for this polymorphism and confirm its geographic structure. Other specimens had 2n=40/FNa=40, representing populations of A. oenos, A. polopi, and A. spegazzinii. All karyotypes have a low amount of heterochromatin, concentrated in centromeres and sex chromosomes, as in other rodents. The complement with 2n=40/FNa=40 is the most frequent in Akodon and is shared by most species in some groups. Chromosome numbers are very diverse. The FNa shows less variability; FNa=42 was recovered as ancestral, excluding A. mimus, which was connected at the base of the Akodon tree and has FNa=44. This indicates a complex chromosome evolution in Akodon, and suggests that reductions and increases in the 2n and FNa evolved independently in some lineages

Toward an Estimation of the Optical Feedback Factor C on the Fly for Displacement Sensing

In this paper, a method based on the inherent event-based sampling capability of laser optical feedback interferometry (OFI) is proposed to assess the optical feedback factor C when the laser operates in the moderate and strong feedback regimes. Most of the phase unwrapping open-loop OFI algorithms rely on the estimation of C to retrieve the displacement with nanometric precision. Here, the proposed method operates in open-loop configuration and relies only on OFI’s fringe detection, thereby improving its robustness and ease of use. The proposed method is able to estimate C with a precision of &lt;5%. The obtained performances are compared to three different approaches previously published and the impacts of phase noise and sampling frequency are reported. We also show that this method can assess C on the fly even when C is varying due to speckle. To the best of the authors’ knowledge, these are the first reported results of time-varying C estimation. In addition, through C estimation over time, it could pave the way not only to higher performance phase unwrapping algorithms but also to a better control of the optical feedback level via the use of an adaptive lens and thus to better displacement retrieval performances.</jats:p