168 research outputs found

    Behavioral, morphological, and ecological trait evolution in two clades of New World Sparrows (Aimophila and Peucaea, Passerellidae)

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    Copyright 2020 Cicero et al. The New World sparrows (Passerellidae) are a large, diverse group of songbirds that vary in morphology, behavior, and ecology. Thus, they are excellent for studying trait evolution in a phylogenetic framework. We examined lability versus conservatism in morphological and behavioral traits in two related clades of sparrows (Aimophila, Peucaea), and assessed whether habitat has played an important role in trait evolution. We first inferred a multi-locus phylogeny which we used to reconstruct ancestral states, and then quantified phylogenetic signal among morphological and behavioral traits in these clades and in New World sparrows more broadly. Behavioral traits have a stronger phylogenetic signal than morphological traits. Specifically, vocal duets and song structure are the most highly conserved traits, and nesting behavior appears to be maintained within clades. Furthermore, we found a strong correlation between open habitat and unpatterned plumage, complex song, and ground nesting. However, even within lineages that share the same habitat type, species vary in nesting, plumage pattern, song complexity, and duetting. Our findings highlight trade-offs between behavior, morphology, and ecology in sparrow diversification

    Endometrial carcinoma in a single horn of a bicornuate uterus: A case report

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    We discuss the diagnosis and the management of endometrial carcinoma in a single horn of bicornuate uterus in a 64-year-old woman as a case report. The case underwent laparoscopic radical hysterectomy and bilateral iliac lymphadenectomy.The gross examination of the uterus revealed a bicornuate uterus with a greater horn of 12 × 9 × 8 cm and a smaller horn of 10 × 3 cm. The cavity of the greater horn showed a neoplastic growth of 10 cm with infiltration of about 1,8 cm of the myometrium from whole thickness of 1.9 cm. while the other horn was free of tumor tissue.The microscopic examination of the uterus revealed G2 endometrioid adenocarcinoma of the endometrium of the greater horn with infiltration of more than 50% of the myometrium.In the presence of bicornuate uterus, a bilateral endometrial biopsy should be performed in order to reduce the risk of delayed or missed diagnosis.The management of a case of bicornuate unicollis uterus with endometrial carcinoma in only one horn is the same as patients with endometrial cancer in single uterus and depends mainly on stage and histological grade of the tumor.The possibility of existence of a separate uterine cavity should always be considered when endometrial cancer is clinically suspected but pathology fails to confirm the diagnosis. This points out the importance of a careful physical examination and radiographic evaluation in such cases. Keywords: Bicornuate uterus, Endometrial cance

    Genetic variation among western populations of the Horned Lark (Eremophila alpestris) indicates recent colonization of the Channel Islands off southern California, mainland-bound dispersal, and postglacial range shifts

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    © 2014 American Ornithologists\u27 Union. The Channel Islands off the coast of southern California host \u3e50 species of terrestrial vertebrates with varying degrees of phenotypic differentiation. However, most organisms that breed on the Channel Islands remain unstudied with respect to genetic differentiation from mainland populations. By comparing patterns of genetic variation between the Channel Islands and the mainland, we aimed to further our understanding of the role that the Channel Islands have played in diversification of the North American biota. We evaluated long-standing, untested hypotheses regarding colonization patterns and evolutionary relationships among western populations of the Horned Lark (Eremophila alpestris), including the endemic Channel Island subspecies E. a. insularis. We also examined how many times Horned Larks have colonized the Channel Islands, whether the species exhibits asymmetrical patterns of gene flow between mainland and island populations, and whether E. a. strigata of the Pacific Northwest is closely related to the phenotypically similar, but geographically separated, island subspecies. We found that E. a. insularis is polyphyletic, which suggests either multiple colonization events from the mainland or incomplete lineage sorting of a large ancestral population. We also inferred higher rates of migration from the Channel Islands to the mainland, with E. a. strigata being closely related to individuals from the Channel Islands and coastal southern California. Moreover, ecological niche models for E. a. strigata identified suitable abiotic conditions in southern California and the Pacific Northwest during the Last Glacial Maximum, which suggests that E. a. strigata experienced a postglacial range shift in addition to a population bottleneck. Our results provide novel insight regarding the origins of the Channel Island avifauna and the evolutionary history of the Horned Lark in the western United States. Moreover, our findings suggest that Channel Island birds may be weakly differentiated from mainland populations despite phenotypic differences between recognized subspecies

    Speciation in Western Scrub-Jays, Haldane’s rule, and genetic clines in secondary contact

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    Background Haldane’s Rule, the tendency for the heterogametic sex to show reduced fertility in hybrid crosses, can obscure the signal of gene flow in mtDNA between species where females are heterogametic. Therefore, it is important when studying speciation and species limits in female-heterogametic species like birds to assess the signature of gene flow in the nuclear genome as well. We studied introgression of microsatellites and mtDNA across a secondary contact zone between coastal and interior lineages of Western Scrub-Jays (Aphelocoma californica) to test for a signature of Haldane’s Rule: a narrower cline of introgression in mtDNA compared to nuclear markers. Results Our initial phylogeographic analysis revealed that there is only one major area of contact between coastal and interior lineages and identified five genetic clusters with strong spatial structuring: Pacific Slope, Interior US, Edwards Plateau (Texas), Northern Mexico, and Southern Mexico. Consistent with predictions from Haldane’s Rule, mtDNA showed a narrower cline than nuclear markers across a transect through the hybrid zone. This result is not being driven by female-biased dispersal because neutral diffusion analysis, which included estimates of sex-specific dispersal rates, also showed less diffusion of mtDNA. Lineage-specific plumage traits were associated with nuclear genetic profiles for individuals in the hybrid zone, indicating that these differences are under genetic control. Conclusions This study adds to a growing list of studies that support predictions of Haldane’s Rule using cline analysis of multiple loci of differing inheritance modes, although alternate hypotheses like selection on different mtDNA types cannot be ruled out. That Haldane’s Rule appears to be operating in this system suggests a measure of reproductive isolation between the Pacific Slope and interior lineages. Based on a variety of evidence from the phenotype, ecology, and genetics, we recommend elevating three lineages to species level: A. californica (Pacific Slope); A. woodhouseii (Interior US plus Edwards Plateau plus Northern Mexico); A. sumichrasti (Southern Mexico). The distinctive Edwards Plateau population in Texas, which was monophyletic in mtDNA except for one individual, should be studied in greater detail given habitat threat

    Magnetic Field Measurements Based on Terfenol Coated Photonic Crystal Fibers

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    A magnetic field sensor based on the integration of a high birefringence photonic crystal fiber and a composite material made of Terfenol particles and an epoxy resin is proposed. An in-fiber modal interferometer is assembled by evenly exciting both eigenemodes of the HiBi fiber. Changes in the cavity length as well as the effective refractive index are induced by exposing the sensor head to magnetic fields. The magnetic field sensor has a sensitivity of 0.006 (nm/mT) over a range from 0 to 300 mT with a resolution about ±1 mT. A fiber Bragg grating magnetic field sensor is also fabricated and employed to characterize the response of Terfenol composite to the magnetic field
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