2 research outputs found

    Genetic polymorphism of the \u3b1s1-casein locus in five populations of goats from Mexico

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    With the objective of estimating allele frequencies, and testing for population divergence for the CSN1S1 locus, genotypes of animals from five goat populations; Saanen (n = 97), Alpine (n = 81) Toggenburg (n = 92), local goats with external appearance similar to the Murciana-Granadina breed from Central Mexico (n = 26) and heterogeneous local animals denominated Mosaico Lagunero (n = 30), from Northern Mexico, were identified using PCR and Xmn1 PCR-RFLP methodology. For Saanen, Alpine and Toggenburg, the sum of E and F alleles had the largest frequencies (from 0.468 to 0.789), while for the groups local Murciana-Granadina and Mosaico Lagunero the sum of the most frequent allelic groups (A* and B*), were 0.385 and 0.533 respectively. Both local Murciana-Granadina and Mosaico Lagunero populations showed heterozygote excess (P < 0.08). The percentage of the total genetic variation (FST) explained by population differences was 5.16. There was genetic differentiation for most pair comparisons between populations (P < 0.05), excepting for Alpine versus Toggenburg, and Toggenburg versus Mosaico Lagunero (P > 0.05). For Saanen and Alpine the frequencies of alleles E and F were similar to the same breeds previously analyzed in Europe. Therefore there are opportunities of increasing the frequency of the strong alleles for protein content Gene Assisted Selection (GAS) in these two breeds. For Toggenburg the most frequent allelic groups were F (0.32) and B* (0.21). Results indicate differentiation between most populations for this locus. Moreover, heterozygote excess in local populations indicated breed admixture

    Search for ultrarelativistic magnetic monopoles with the Pierre Auger Observatory

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    We present a search for ultrarelativistic magnetic monopoles with the Pierre Auger observatory. Such particles, possibly a relic of phase transitions in the early Universe, would deposit a large amount of energy along their path through the atmosphere, comparable to that of ultrahigh-energy cosmic rays (UHECRs). The air-shower profile of a magnetic monopole can be effectively distinguished by the fluorescence detector from that of standard UHECRs. No candidate was found in the data collected between 2004 and 2012, with an expected background of less than 0.1 event from UHECRs. The corresponding 90% confidence level (C.L.) upper limits on the flux of ultrarelativistic magnetic monopoles range from 10^ 1219(cm2 sr s)^ 121 for a Lorentz factor \u3b3 = 10^9 to 2.5 7 10 1221(cm2 sr s)^ 121 for \u3b3 = 10^12. These results\u2014the first obtained with a UHECR detector\u2014improve previously published limits by up to an order of magnitude
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