The influence of geographic heterogeneity in predation pressure on sexual signal divergence in an Amazonian frog species complex.

Sexual selection plays an important role in mating signal divergence, but geographic variation in ecological factors can also contribute to divergent signal evolution. We tested the hypothesis that geographic heterogeneity in predation causes divergent selection on advertisement call complexity within the Engystomops petersi (previously Physalaemus petersi) frog species complex. We conducted predator phonotaxis experiments at two sites where female choice is consistent with call trait divergence. Engystomops at one site produces complex calls, whereas the closely related species at the other site produces simple calls. Bats approached complex calls more than simple calls at both sites, suggesting selection against complex calls. Moreover, bat predation pressure was greater at the site with simple calls, suggesting stronger selection against complex calls and potentially precluding evolution of complex calls at this site. Our results show that geographic variation in predation may play an important role in the evolution and maintenance of mating signal divergence.

Torsión aislada de trompa de Falopio / Isolated torsion of the Fallopian tube

La torsión aislada de trompa de Falopio es una rara entidad clínica, descrita por primera vez en 1890 por Sutton1. Esta entidad va a debutar con un cuadro de dolor abdominal inespecífico, por lo que es necesario pensar en esta patología cara al diagnóstico diferencial y al tratamiento quirúrgico precoz con el objetivo de preservar dicho órgano. Presentamos el caso clínico de una paciente cuyo diagnóstico se realizó intraoperatoriamente, dado que se intervino con la sospecha de apendicitis aguda (AU)

Occasional torsion of the Fallopian tube is a rare clinical entity, first described in 1980 by Sutton. This entity produces symptoms of nonspecific abdominal pain and consequently should be included in the differential diagnosis of early surgical treatment, with the goal of preserving the organ. We present the case of a patient whose diagnosis was made during surgery, since the intervention was performed for suspected acute appendicitis (AU)

Song types and their structural features are associated with specific contexts in the banded wren.

We studied the use of song types and their acoustic features in different social contexts in the banded wren (Thryothorus pleurostictus), a resident tropical songbird in which males possess about 20 distinctive song types varying in duration, bandwidth, note composition, and trill structure. We recorded six focal males intensively for four days each while we observed context information such as during versus after dawn chorus, presence of the female, counter-versus solo-singing, location at the edge versus centre of the territory, and proximity to the nest. All males used at least some song types differentially during each of these pairs of alternative contexts. Males also preferentially used the song types they shared with a given neighbour when interacting with that bird. Songs delivered during dawn chorus were significantly longer, wider in bandwidth, often compound (double songs), and more likely to contain a rattle or buzz and an up-sweeping trill, compared to songs delivered after dawn chorus. Similar features were also more commonly observed when birds were engaged in intense male-male interactions and boundary disputes after dawn chorus, especially when countersinging at the edge of the territory. The presence of the female caused the male to deliver song types with narrower whole-song and trill bandwidth and fewer rattles and buzzes, and song-type diversity and fraction of compound songs were higher when the female was present. Thus, in addition to using type matching and variations in song-type switching and diversity to signal different levels of aggressive intention, male banded wrens also select song types based on their acoustic structure in different social contexts.

Calcificaciones endometriales / Endometrial calcification

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[Changes in plasma levels of intestinal regulatory peptides following colonic resection in the rat]. / Evolución de los niveles plasmáticos de péptidos reguladores intestinales tras resección de colon en la rata.

The colon is considered as an endocrine organ producing regulatory peptides. Colon resection exerts an influence on remnant bowel including proliferative adaptive phenomena. The aim of this work was to determine the modifications of several regulatory peptides after colectomy and its relation with the gastrointestinal proliferative changes. 75% proximal colectomy was performed in Wistar rats. Seven groups were used according to sacrifice times: 24 h, 48 h, 72 h, 7 days, 14 days, 21 days and control group without resection. Results show significant decreases in somatostatin, neurotensin and cholecystokinin plasma levels maintained up to 21 days postsurgery. Gastrin is elevated with a highest peak at 72 h achieving basal levels at 21 day. Peptide YY show significant high levels between 72 h and 7 days. Secretin plasma levels are increased 24 h post-surgery, decreasing significantly at day 14. It is suggested that maintained low plasmatic levels of somatostatin, a known mucosal growth inhibitor, after colectomy may help the proliferative adaptation.