Divergence of acoustic signals in a geographic scale results from diverse evolutionary forces acting in parallel and affecting directly inter-male vocal interactions among disjunct populations. Pleurodema thaul is a frog having an extensive latitudinal distribution in Chile along which males' advertisement calls exhibit an important variation. Using the playback paradigm we studied the evoked vocal responses of males of three populations of P. thaul in Chile, from northern, central and southern distribution. In each population, males were stimulated with standard synthetic calls having the acoustic structure of local and foreign populations. Males of both northern and central populations displayed strong vocal responses when were confronted with the synthetic call of their own populations, giving weaker responses to the call of the southern population. The southern population gave stronger responses to calls of the northern population than to the local call. Furthermore, males in all populations were stimulated with synthetic calls for which the dominant frequency, pulse rate and modulation depth were varied parametrically. Individuals from the northern and central populations gave lower responses to a synthetic call devoid of amplitude modulation relative to stimuli containing modulation depths between 30–100%, whereas the southern population responded similarly to all stimuli in this series. Geographic variation in the evoked vocal responses of males of P. thaul underlines the importance of inter-male interactions in driving the divergence of the acoustic traits and contributes evidence for a role of intra-sexual selection in the evolution of the sound communication system of this anuran.

Background/Objective: Data on IgG4-related disease (IgG4-RD) come almost exclusively from cohorts from Asia, Europe, and North America. We conducted this study to describe the clinical presentation, phenotype distribution, and association with sex, ethnicity, and serological markers in a large cohort of Latin American patients with IgG4-RD. Methods:We performed a multicenter medical records review study including 184 Latin American IgG4-RD patients. We assigned patients to clinical phenotypes: group 1 (pancreato-hepato-biliary), group 2 (retroperitoneal/ aortic), group 3 (head and neck-limited), group 4 (Mikulicz/systemic), and group 5 (undefined). We focused the analysis on how sex, ethnicity, and clinical phenotype may influence the clinical and serological presentation. Results:The mean age was 50.8 ± 15 years. Men and women were equally affected (52.2% vs 48.8%). Fifty-four patients (29.3%) were assigned to group 1, 21 (11.4%) to group 2, 57 (30.9%) to group 3, 32 (17.4%) to group 4, and 20 (10.8%) to group 5. Male sex was associated with biliary tract (odds ratio [OR], 3.4; 95% confidence interval [CI], 1.36-8.26), kidney (OR, 3.4; 95% CI, 1.28-9.25), and retroperitoneal involvement (OR, 5.3; 95% CI,. Amerindian patients presented more frequently with atopy history and gallbladder involvement. Group 3 had a female predominance.Conclusions: Latin American patients with IgG4-RD were younger, and men and women were equally affected compared with White and Asian cohorts. They belonged more commonly to group 1 and group 3. Retroperitoneal and aortic involvement was infrequent. Clinical and serological features differed according to sex, ethnicity, and clinical phenotype.

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