165 research outputs found

    Joint genetic analysis for dairy cattle performance across countries in sub-Saharan Africa

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    This study assessed the feasibility of across-country genetic evaluation of dairy cattle in sub-Saharan Africa where data on livestock production are scarce. Genetic parameters were estimated for the 305-day milk yield in the first lactation and across five lactations, for age at first calving and for interval between first and second calving. Estimated breeding values of individual animals for these traits were calculated. There were records from 2 333, 25 208, and 5 929 Holstein cows in Kenya, South Africa, and Zimbabwe, and 898 and 65134 Jersey cows from Kenya and South Africa. Genetic gain from sire selection within and across countries. was predicted Genetic links between countries were determined from sires with daughters that had records in two or more countries, and from common ancestral sires across seven generations on both the maternal and paternal sides of the pedigree. Each country was treated as a trait in the across-country evaluation. The results showed that genetic variance and heritability were not always estimable within country, but were significantly different from zero in the across-country evaluation. In all three countries, there was greater genetic gain in all traits from an across-country genetic evaluation owing to greater accuracy of selection compared with within country. Kenya stood to benefit most from an across-country evaluation, followed by Zimbabwe, then South Africa. An across-country breeding programme using joint genetic evaluation would be feasible, provided that there were genetic links across countries, and would provide a platform for accelerated genetic progress through selection and germplasm exchange between sub-Saharan African countries.Keywords: across-country genetic evaluation, genetic connectedness, genetic progres

    Symplectically-invariant soliton equations from non-stretching geometric curve flows

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    A moving frame formulation of geometric non-stretching flows of curves in the Riemannian symmetric spaces Sp(n+1)/Sp(1)×Sp(n)Sp(n+1)/Sp(1)\times Sp(n) and SU(2n)/Sp(n)SU(2n)/Sp(n) is used to derive two bi-Hamiltonian hierarchies of symplectically-invariant soliton equations. As main results, multi-component versions of the sine-Gordon (SG) equation and the modified Korteweg-de Vries (mKdV) equation exhibiting Sp(1)×Sp(n1)Sp(1)\times Sp(n-1) invariance are obtained along with their bi-Hamiltonian integrability structure consisting of a shared hierarchy of symmetries and conservation laws generated by a hereditary recursion operator. The corresponding geometric curve flows in Sp(n+1)/Sp(1)×Sp(n)Sp(n+1)/Sp(1)\times Sp(n) and SU(2n)/Sp(n)SU(2n)/Sp(n) are shown to be described by a non-stretching wave map and a mKdV analog of a non-stretching Schr\"odinger map.Comment: 39 pages; remarks added on algebraic aspects of the moving frame used in the constructio

    Distância genética em caprinos naturalizados por meio de microssatélites de DNA.

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    Há uma necessidade de adotar estratégias de conservação para as populações naturalizadas de animais domésticos para assegurar a manutenção destas para o futuro. Este estudo visa contribuir para o conhecimento da variabilidade genética por meio de marcadores de microssatélites em caprinos naturalizados Moxotó, Canindé e Marota. Foram amostrados 124 animais adultos dos grupos Moxotó, Canindé e Marota dos núcleos de conservação da Embrapa. O DNA extraído foi amplificado mediante a reação em cadeia polimerase (PCR) e genotipado através do programa Fragment Profile (Amersham Bioscience). O método UPGMA (Unweighted Pair Group Method With Arithmetic Mean) foi utilizado para construção do dendograma com bootstrap (1000 repetições) pelo programa TFPGA (Miller, 1997). O dendograma agrupou no primeiro nódulo as populações Moxotó e Canindé e o bootstrap apresentou 75% de similaridade neste nódulo. No segundo nódulo houve a inclusão das três populações e obteve bootstrap de 100%. O número de loci suportando cada nódulo foram quatro e cinco, respectivamente. O método UPGMA, utilizando as distâncias de Nei (1978), permitiu o discernimento das populações caprinas com base em dados moleculares

    The biomarker HE4 (WFDC2) promotes a pro-angiogenic and immunosuppressive tumor microenvironment via regulation of STAT3 target genes

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    © 2020, The Author(s). Epithelial ovarian cancer (EOC) is a highly lethal gynecologic malignancy arising from the fallopian tubes that has a high rate of chemoresistant recurrence and low five-year survival rate. The ovarian cancer biomarker HE4 is known to promote proliferation, metastasis, chemoresistance, and suppression of cytotoxic lymphocytes. In this study, we sought to examine the effects of HE4 on signaling within diverse cell types that compose the tumor microenvironment. HE4 was found to activate STAT3 signaling and promote upregulation of the pro-angiogenic STAT3 target genes IL8 and HIF1A in immune cells, ovarian cancer cells, and endothelial cells. Moreover, HE4 promoted increases in tube formation in an in vitro model of angiogenesis, which was also dependent upon STAT3 signaling. Clinically, HE4 and IL8 levels positively correlated in ovarian cancer patient tissue. Furthermore, HE4 serum levels correlated with microvascular density in EOC tissue and inversely correlated with cytotoxic T cell infiltration, suggesting that HE4 may cause deregulated blood vessel formation and suppress proper T cell trafficking in tumors. Collectively, this study shows for the first time that HE4 has the ability to affect signaling events and gene expression in multiple cell types of the tumor microenvironment, which could contribute to angiogenesis and altered immunogenic responses in ovarian cancer

    Negative Effect of Smoking on the Performance of the QuantiFERON TB Gold in Tube Test.

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    False negative and indeterminate Interferon Gamma Release Assay (IGRA) results are a well documented problem. Cigarette smoking is known to increase the risk of tuberculosis (TB) and to impair Interferon-gamma (IFN-γ) responses to antigenic challenge, but the impact of smoking on IGRA performance is not known. The aim of this study was to evaluate the effect of smoking on IGRA performance in TB patients in a low and high TB prevalence setting respectively. Patients with confirmed TB from Denmark (DK, n = 34; 20 smokers) and Tanzania (TZ, n = 172; 23 smokers) were tested with the QuantiFERON-TB Gold In tube (QFT). Median IFN-γ level in smokers and non smokers were compared and smoking was analysed as a risk factor for false negative and indeterminate QFT results. Smokers from both DK and TZ had lower IFN-γ antigen responses (median 0.9 vs. 4.2 IU/ml, p = 0.04 and 0.4 vs. 1.6, p < 0.01), less positive (50 vs. 86%, p = 0.03 and 48 vs. 75%, p < 0.01) and more false negative (45 vs. 0%, p < 0.01 and 26 vs. 11%, p = 0.04) QFT results. In Tanzanian patients, logistic regression analysis adjusted for sex, age, HIV and alcohol consumption showed an association of smoking with false negative (OR 17.1, CI: 3.0-99.1, p < 0.01) and indeterminate QFT results (OR 5.1, CI: 1.2-21.3, p = 0.02). Cigarette smoking was associated with false negative and indeterminate IGRA results in both a high and a low TB endemic setting independent of HIV status

    Application of COMPOCHIP Microarray to Investigate the Bacterial Communities of Different Composts

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    A microarray spotted with 369 different 16S rRNA gene probes specific to microorganisms involved in the degradation process of organic waste during composting was developed. The microarray was tested with pure cultures, and of the 30,258 individual probe-target hybridization reactions performed, there were only 188 false positive (0.62%) and 22 false negative signals (0.07%). Labeled target DNA was prepared by polymerase chain reaction amplification of 16S rRNA genes using a Cy5-labeled universal bacterial forward primer and a universal reverse primer. The COMPOCHIP microarray was applied to three different compost types (green compost, manure mix compost, and anaerobic digestate compost) of different maturity (2, 8, and 16 weeks), and differences in the microorganisms in the three compost types and maturity stages were observed. Multivariate analysis showed that the bacterial composition of the three composts was different at the beginning of the composting process and became more similar upon maturation. Certain probes (targeting Sphingobacterium, Actinomyces, Xylella/Xanthomonas/ Stenotrophomonas, Microbacterium, Verrucomicrobia, Planctomycetes, Low G + C and Alphaproteobacteria) were more influential in discriminating between different composts. Results from denaturing gradient gel electrophoresis supported those of microarray analysis. This study showed that the COMPOCHIP array is a suitable tool to study bacterial communities in composts

    Crescimento e mortalidade em um rebanho de conservação de caprinos Marota no Brasil.

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    O caprino Marota consiste em um importante recurso genético adaptado ao Semiárido brasileiro e encontra-se em risco de extinção. A Embrapa Meio-Norte mantém um núcleo de conservação destes caprinos no município de Castelo do Piauí, região de transição caatinga-cerrado. O manejo deste rebanho é semi-extensivo para sobrepujar as características de rusticidade do ecotipo Marota. Esta pesquisa foi realizada com o objetivo de monitorar o desempenho fenotípico do núcleo com relação ao peso ao nascimento, prolificidade e mortalidade nos anos de 2004 a 2008, e relacioná-los a outros dados observados no Semiárido e obtidos na literatura especializada. As médias obtidas corrigidas foram 1,89±0,09 e 22,8±5,9 kg, respectivamente para peso ao nascer e peso ao parto. Os resultados obtidos demonstram peso ao nascer abaixo das raças exóticas no Semiárido e de ecotipos brasileiros em menor risco de extinção (p.ex. Moxotó). As taxas de mortalidade e a prolificidade obtidas são vantajosas em relação às apresentadas por raças exóticas presentes no Semiárido, mas não superiores aos demais tipos naturalizados. Estudos econômicos devem estabelecer se a relação entre tais caracteristicas implicam em eficiência para o sistema produtivo

    Genome analysis of the necrotrophic fungal pathogens Sclerotinia sclerotiorum and Botrytis cinerea

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    Sclerotinia sclerotiorum and Botrytis cinerea are closely related necrotrophic plant pathogenic fungi notable for their wide host ranges and environmental persistence. These attributes have made these species models for understanding the complexity of necrotrophic, broad host-range pathogenicity. Despite their similarities, the two species differ in mating behaviour and the ability to produce asexual spores. We have sequenced the genomes of one strain of S. sclerotiorum and two strains of B. cinerea. The comparative analysis of these genomes relative to one another and to other sequenced fungal genomes is provided here. Their 38–39 Mb genomes include 11,860–14,270 predicted genes, which share 83% amino acid identity on average between the two species. We have mapped the S. sclerotiorum assembly to 16 chromosomes and found large-scale co-linearity with the B. cinerea genomes. Seven percent of the S. sclerotiorum genome comprises transposable elements compared t

    Lagrangian Curves in a 4-dimensional affine symplectic space

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    Lagrangian curves in R4 entertain intriguing relationships with second order deformation of plane curves under the special affine group and null curves in a 3-dimensional Lorentzian space form. We provide a natural affine symplectic frame for Lagrangian curves. It allows us to classify La- grangrian curves with constant symplectic curvatures, to construct a class of Lagrangian tori in R4 and determine Lagrangian geodesic
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