23 research outputs found

    Cytogenetic analysis of Astylus antis (Perty, 1830) (Coleoptera, Melyridae): Karyotype, heterochromatin and location of ribosomal genes

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    Cytogenetic analysis of Astylus antis using mitotic and meiotic cells was performed to characterize the haploid and diploid numbers, sex determination system, chromosome morphology, constitutive heterochromatin distribution pattern and chromosomes carrying nucleolus organizer regions (NORs). Analysis of spermatogonial metaphase cells revealed the diploid number 2n = 18, with mostly metacentric chromosomes. Metaphase I cells exhibited 2n = 8II+Xyp and a parachute configuration of the sex chromosomes. Spermatogonial metaphase cells submitted to C-banding showed the presence of small dots of constitutive heterochromatin in the centromeric regions of nearly all the autosomes and on the short arm of the X chromosome (Xp), as well as an additional band on one of the arms of pair 1. Mitotic cells submitted to double staining with base-specific fluorochromes (DAPI-CMA3 ) revealed no regions rich in A+T or G+C sequences. Analysis of spermatogonial mitotic cells after sequential Giemsa/AgNO 3 staining did not reveal any specific mark on the chromosomes. Meiotic metaphase I cells stained with silver nitrate revealed a strong impregnation associated to the sex chromosomes, and in situ hybridization with an 18S rDNA probe showed ribosomal cistrons in an autosomal bivalent

    Sensitivity of the Cherenkov Telescope Array to a dark matter signal from the Galactic centre

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    We provide an updated assessment of the power of the Cherenkov Telescope Array (CTA) to search for thermally produced dark matter at the TeV scale, via the associated gamma-ray signal from pair-annihilating dark matter particles in the region around the Galactic centre. We find that CTA will open a new window of discovery potential, significantly extending the range of robustly testable models given a standard cuspy profile of the dark matter density distribution. Importantly, even for a cored profile, the projected sensitivity of CTA will be sufficient to probe various well-motivated models of thermally produced dark matter at the TeV scale. This is due to CTA's unprecedented sensitivity, angular and energy resolutions, and the planned observational strategy. The survey of the inner Galaxy will cover a much larger region than corresponding previous observational campaigns with imaging atmospheric Cherenkov telescopes. CTA will map with unprecedented precision the large-scale diffuse emission in high-energy gamma rays, constituting a background for dark matter searches for which we adopt state-of-the-art models based on current data. Throughout our analysis, we use up-to-date event reconstruction Monte Carlo tools developed by the CTA consortium, and pay special attention to quantifying the level of instrumental systematic uncertainties, as well as background template systematic errors, required to probe thermally produced dark matter at these energies

    Cytogenetic characterization of Melipona rufiventris Lepeletier 1836 and Melipona mondury Smith 1863 (Hymenoptera, Apidae) by C banding and fluorochromes staining

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    The stingless bees Melipona rufiventris and M. mondury were analyzed cytogenetically by conventional staining with Giemsa, C-banding and sequential staining with the fluorochromes CMA3/DA/DAPI. Both species presented 2n = 18 and n = 9, except for one colony of M. rufiventris, in which some individuals had 2n = 19 due to the presence of a B chromosome. After Giemsa staining and C-banding the chromosomes appeared very condensed and presented a high heterochromatic content, making it difficult to localize the centromere and therefore to visualize the chromosomes morphology. The constitutive heterochromatin was located in interstitial chromosome regions covering most of the chromosomes extension and consisted mainly of AT, as shown by DAPI staining. The euchromatin was restricted to the chromosome extremities and was GC-rich, as evidenced by CMA3 staining. The B chromosome was CMA3-negative and DAPI-positive, a heterochromatic constitution similar to that of the A genome chromosomes

    Adaptação transcultural da Escala de Independência em Atividades da Vida Diária (Escala de Katz) Cross-cultural adaptation of the Independence in Activities of Daily Living Index (Katz Index)

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    Desenvolvimento e análise do desempenho de uma adaptação transcultural para o português da Escala de Katz de independência em atividades da vida diária. Duas traduções e duas retrotraduções analisaram as equivalências conceitual, de itens e semântica para a escolha da versão final. A equivalência operacional foi avaliada em um estudo piloto, testando-se a confiabilidade e a consistência interna da versão adaptada por meio de reteste no mesmo dia em 156 pacientes ou após sete dias da primeira entrevista. A resolução de diferenças sutis em alguns itens levou à equivalência cultural. A versão final foi considerada fácil de se entender e de aplicar. A concordância corrigida para o acaso (kappa ponderado) foi de 0,91. O alfa de Chronbach variou de 0,80 a 0,92. A versão em português da Escala de Katz de independência em atividades da vida diária, completamente desenvolvida e testada, provou ser equivalente à original em inglês. Os itens apresentaram consistência interna e as taxa foram confiáveis.<br>This study involved the development and performance assessment of a cultural adaptation of the Katz scale of independence in activities of daily living, translated into Portuguese in Brazil. Two translations and two back-translations of the items were analyzed by experts in order to decide on the final version. Operational equivalence was assessed in a pilot study. The reliability and internal consistency of the adapted version were assessed by retesting 156 patients on the same day or 7 days after the first interview. Cultural equivalence was achieved after resolving subtle differences in some items. The final version was considered easy to understand and use. Chance-corrected agreement (weighted kappa) was 0.91. Cronbach's alpha ranged from 0.80 to 0.92. CONCLUSIONS: a Portuguese version of the Katz scale of independence in activities of daily living, thoroughly developed and tested, proved equivalent to the original version in English. The items were internally consistent and the rates were reliable
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