36 research outputs found

    Evaluation of Xpert® MTB/RIF and ustar easyNAT™ TB IAD for diagnosis of tuberculous lymphadenitis of children in Tanzania : a prospective descriptive study

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    Fine needle aspiration biopsy has become a standard approach for diagnosis of peripheral tuberculous lymphadenitis. The aim of this study was to compare the performance of Xpert MTB/RIF and Ustar EasyNAT TB IAD nucleic acid amplification assays, against acid-fast bacilli microscopy, cytology and mycobacterial culture for the diagnosis of TB lymphadenitis in children from a TB-endemic setting in Tanzania.; Children of 8 weeks to 16 years of age, suspected of having TB lymphadenitis, were recruited at a district hospital in Tanzania. Fine needle aspirates of lymph nodes were analysed using acid-fast bacilli microscopy, liquid TB culture, cytology, Xpert MTB/RIF and EasyNAT. Latent class analysis and comparison against a composite reference standard comprising "culture and/or cytology" was done, to assess the performance of Xpert MTB/RIF and EasyNAT for the diagnosis of TB lymphadenitis.; Seventy-nine children were recruited; 4 were excluded from analysis. Against a composite reference standard of culture and/or cytology, Xpert MTB/RIF and EasyNAT had a sensitivity and specificity of 58 % and 93 %; and 19 % and 100 % respectively. Relative to latent class definitions, cytology had a sensitivity of 100 % and specificity of 94.7 %.; Combining clinical assessment, cytology and Xpert MTB/RIF may allow for a rapid and accurate diagnosis of childhood TB lymphadenitis. Larger diagnostic evaluation studies are recommended to validate these findings and on Xpert MTB/RIF to assess its use as a solitary initial test for TB lymphadenitis in children

    The Evolution of a Female Genital Trait Widely Distributed in the Lepidoptera: Comparative Evidence for an Effect of Sexual Coevolution

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    Sexual coevolution is considered responsible for the evolution of many male genital traits, but its effect on female genital morphology is poorly understood. In many lepidopterans, females become temporarily unreceptive after mating and the length of this refractory period is inversely related to the amount of spermatophore remaining in their genital tracts. Sperm competition can select for males that delay female remating by transferring spermatophores with thick spermatophore envelopes that take more time to be broken. These envelopes could select for signa, sclerotized sharp structures located within the female genital tract, that are used for breaking spermatophores. Thus, this hypothesis predicts that thick spermatophore envelopes and signa evolve in polyandrous species, and that these adaptations are lost when monandry evolves subsequently. Here we test the expected associations between female mating pattern and presence/absence of signa, and review the scant information available on the thickness of spermatophore envelopes.We made a literature review and found information on female mating pattern (monandry/polyandry), presence/absence of signa and phylogenetic position for 37 taxa. We built a phylogenetic supertree for these taxa, mapped both traits on it, and tested for the predicted association by using Pagel's test for correlated evolution. We found that, as predicted by our hypothesis, monandry evolved eight times and in five of them signa were lost; preliminary evidence suggests that at least in two of the three exceptions males imposed monandry on females by means of specially thick spermatophore envelopes. Previously published data on six genera of Papilionidae is in agreement with the predicted associations between mating pattern and the characteristics of spermatophore envelopes and signa.Our results support the hypothesis that signa are a product of sexually antagonistic coevolution with spermatophore envelopes

    Adult and early-stage characters of Brassolini contain conflicting phylogenetic signal (Lepidoptera, Nymphalidae)

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    Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)This study examines the contribution of early-stages and adult characters to the reconstruction of the phylogeny of Brassolini butterflies. Parsimony analyses used both equal weights and implied weights, and a series of analyses were performed. First, we analysed adult and early-stages partitions independently and in combination for a subset of 27 species; in these cases the matrices were mostly complete. Whereas the adult partition alone produced a topology that was well resolved and congruent with previous studies, the early-stages partition produced a poorly resolved tree under equal weights. Furthermore, implied weights produced a well-resolved early-stages topology that differed significantly from the adult topology. When both partitions were combined for 27 species, implied weights yielded a topology that resembled the adult tree except for the positions of Bia and Penetes, but statistical node support was generally lower. This suggests that stochastic noise increased when early-stage characters were added to the adult partition, but the combined partitions topology was not statistically different from that based on adult characters alone. Second, given that preserved early stages are not as readily available as adults, we analysed a matrix including 45 species in which early-stage data were missing for 18 species, and compared the topology to that produced by the adult partition alone. Results were similar to the analyses including fewer species; the combined partitions tree was similar to that from the adult partition except for the position of Bia and Penetes. We compare our findings to other genus-level phylogenetic studies within Lepidoptera that have also used early-stages and adult characters.382316333National Science Foundation [DEB 0527441]Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)National Science Foundation [DEB 0527441]FAPESP [04/05269-9, 10/51340-8]FAPESP [2011/50225-3]CNPq [302585/2011-7]CNPq [563332/2010-7]CNPq [140183/2006-0

    Diets formulated on total or digestible amino acid basis with different energy levels and physical form on broiler performance

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    We studied the effects of two different systems of expressing amino acid requirements (total - TAA or digestible - DAA), two energy levels (2,900 or 3,200 kcal of ME/kg) and two physical forms (mash or pellet) on the performance of male broilers from 21 to 42 d of age. Diets formulated on DAA basis improved feed conversion (p<0.001) and the conversion of consumed ME into body weight gain (p<0.001). Birds fed 3,200 kcal ME/kg presented better feed conversion (p<0.001), higher abdominal fat deposition (p<0.001) and worse conversion of consumed ME into body weight gain (p<0.001) as compared to birds fed 2,900 kcal ME/kg. Birds fed pelleted feed had higher feed intake (p<0.001), higher weight gain (p<0.001), better feed conversion (p<0.001), better conversion of consumed ME into body weight gain (p<0.001) and higher abdominal fat deposition (p<0.001). The results obtained in the present study suggest that feed formulation based on DAA is required when diets contain protein sources which amino acid digestibility is unreliable. Besides, pelleted feed improves performance parameters of broilers
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