732 research outputs found

    Search for X(3872) in gamma gamma Fusion and ISR at CLEO

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    We report on a search for the X(3872) state using 15.1 fb^{-1} of e+ e- annihilation data taken with the CLEO III detector in the sqrt{s} = 9.46-11.30 GeV region. Separate searches for the production of X(3872) in untagged gamma gamma fusion and e+ e- annihilation following initial state radiation are made by taking advantage of the unique correlation of J/psi -> l+ l- in X(3872) decay into J/psi pi+ pi-. No signals are observed in either case, and 90% confidence upper limits are established as (2J+1)Gamma_{gammagamma}(X(3872))B(X -> J/psi pi+ pi-) J/psi pi+ pi-) < 8.3 eV.Comment: 4 pages, 2 figures, to appear in the proceedings of the 1st Meeting of the APS Topical Group on Hadronic Physics, Fermilab, Oct. 24-26, 200

    Diversidad genética molecular y relación entre ovejas de razas autóctonas de Pakistan basada en locus microsatelitales nucleares

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    Sheep genetic resources are high in Pakistan with a number of different breeds spread throughout the country. However, the molecular diversity of sheep breeds is poorly understood in Pakistan. Therefore, in the present study 16 microsatellite markers were used in microsatellite on Buchi and Hashtnagri indigenous breeds of Punjab and Balochistan provinces, respectively. Blood samples from 25 unrelated individuals were collected for genetic diversity and relationship investigation. The mean number of alleles on Buchi and Hashtnagri were 3.375±1.455 and 3.50±1.591, respectively. The mean observed heterozygosity for Buchi was 0.878±0.204 while for Hashtnagri it was 0.885±0.218. The mean Shannon Index showed 1.032±0.371 and 1.070±0.412 for Buchi and Hashtnagri respectively. Inbreeding estimates (FIS and FIT) showed negative values while mean gene flow showed 10.09 and mean population difference (FST) showed 2.4%. According to these results, Buchi and Hashtnagri indigenous breeds showed considerable amount of genetic diversity. There is a decent scope for conservation, effective improvement, and designing suitable breeding strategies for sheep breeds in near future.En Pakistán los recursos genéticos ovinos son abundantes, disponiéndose de varias diferentes castas extendidas en todo el país. No obstante, la diversidad molecular de las razas de ovejas es poco conocida en la región. Por ello, en el presente estudio se investigaron 16 marcadores microsatelitales de las razas indígenas Buchi y Hashtnagri, en las provincias de Pendjab y Balochistan respectivamente. Para indagar la diversidad genética se obtuvieron muestras de sangre de 25 animales de cada raza. El promedio del número de alelos en Buchi y Hashtnagri fue de 3,375±1,455 y 3,50±1,591 respectivamente. Los promedios de heterocigosis registradas fueron de 0,878±0,204 para la raza Buchi y 0,885±0,218 para Hashtnagri. Los índices de Shannon fueron 1,032±0,371 para Buchi y 1,070±0,412 para Hashtnagri, respectivamente. La estimación de los coeficientes de endogamia (FIS y FIT) mostró valores negativos, en tanto que el flujo genético (migración) fue de 10,09 y el promedio de la diferencia poblacional (FST) resultó de 2,4%. En ambas razas, el índice de información polimórfica fue 0,56, indicando el valor del marcador del tablero. Entre las ovejas Buchi y Hashtnagri, la distancia genética estándar de Nei (Ds) fue 0,0218. Según estos resultados, ambas razas mostraron considerable diversidad genética. Los datos obtenidos permiten vislumbrar una promisoria mejoría en el área de la conservación y en el diseño de las estrategias para la cría de ovejas en el futuro cercano

    APC-β-catenin-TCF signaling silences the intestinal guanylin-GUCY2C tumor suppressor axis.

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    Sporadic colorectal cancer initiates with mutations in APC or its degradation target β-catenin, producing TCF-dependent nuclear transcription driving tumorigenesis. The intestinal epithelial receptor, GUCY2C, with its canonical paracrine hormone guanylin, regulates homeostatic signaling along the crypt-surface axis opposing tumorigenesis. Here, we reveal that expression of the guanylin hormone, but not the GUCY2C receptor, is lost at the earliest stages of transformation in APC-dependent tumors in humans and mice. Hormone loss, which silences GUCY2C signaling, reflects transcriptional repression mediated by mutant APC-β-catenin-TCF programs in the nucleus. These studies support a pathophysiological model of intestinal tumorigenesis in which mutant APC-β-catenin-TCF transcriptional regulation eliminates guanylin expression at tumor initiation, silencing GUCY2C signaling which, in turn, dysregulates intestinal homeostatic mechanisms contributing to tumor progression. They expand the mechanistic paradigm for colorectal cancer from a disease of irreversible mutations in APC and β-catenin to one of guanylin hormone loss whose replacement, and reconstitution of GUCY2C signaling, could prevent tumorigenesis

    Detection of Four Novel Polymorphisms in PrP gene of Pakistani sheep (Damani and Hashtnagri) and goats (Kamori and Local Hairy) breeds

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    Scrapie is a fatal neurodegenerative disorder of sheep and goats caused by post-translational conformational change in the host-encoded prion protein (PrPC). Susceptibility or resistance to scrapie has been associated with the presence of polymorphisms in the prion protein (PrP) gene. In the present study, we analyzed the PrP gene sequence to determine the frequency of polymorphisms in 56 sheep (28 each from Damani and Hashtnagri breeds) and 56 goats (28 each from Kamori and Local Hairy breeds). A total of 7 amino acid polymorphisms were detected in the PrP gene for sheep and 4 for goats. These amino acid polymorphisms were combined in 13 alleles and 15 genotypes in sheep and 5 alleles and 6 genotypes in goats. The overall frequency of the most sheep scrapie-resistant polymorphism (Q171R) was calculated to be 0.107. The most scrapie-susceptible polymorphism (A136V) was not detected in any of the studied sheep. The overall frequency of scrapie-associated polymorphism (H143R) in goats was found to be 0.152. Along with already known amino acid polymorphisms, two novel polymorphisms were also detected for each of sheep (Q171N and T191I) and goats (G22C and P63L). However, the overall frequency of these polymorphisms was extremely low

    Characterizing the Youngest Herschel-detected Protostars I. Envelope Structure Revealed by CARMA Dust Continuum Observations

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    We present CARMA 2.9 mm dust continuum emission observations of a sample of 14 Herschel-detected Class 0 protostars in the Orion A and B molecular clouds, drawn from the PACS Bright Red Sources (PBRS) sample (Stutz et al.). These objects are characterized by very red 24 \micron\ to 70 \micron\ colors and prominent submillimeter emission, suggesting that they are very young Class 0 protostars embedded in dense envelopes. We detect all of the PBRS in 2.9 mm continuum emission and emission from 4 protostars and 1 starless core in the fields toward the PBRS; we also report 1 new PBRS source. The ratio of 2.9 mm luminosity to bolometric luminosity is higher by a factor of \sim5 on average, compared to other well-studied protostars in the Perseus and Ophiuchus clouds. The 2.9 mm visibility amplitudes for 6 of the 14 PBRS are very flat as a function of uv-distance, with more than 50\% of the source emission arising from radii << 1500 AU. These flat visibility amplitudes are most consistent with spherically symmetric envelope density profiles with ρ\rho~\propto~R2.5^{-2.5}. Alternatively, there could be a massive unresolved structure like a disk or a high-density inner envelope departing from a smooth power-law. The large amount of mass on scales << 1500 AU (implying high average central densities) leads us to suggest that that the PBRS with flat visibility amplitude profiles are the youngest PBRS and may be undergoing a brief phase of high mass infall/accretion and are possibly among the youngest Class 0 protostars. The PBRS with more rapidly declining visibility amplitudes still have large envelope masses, but could be slightly more evolved.Comment: Accepted to ApJ, 40 pages, 9 Figures, 4 Table

    Neural network parametrization of the lepton energy spectrum in semileptonic B meson decays

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    We construct a parametrization of the lepton energy spectrum in inclusive semileptonic decays of B mesons, based on the available experimental information: moments of the spectrum with cuts, their errors and their correlations, together with kinematical constraints. The result is obtained in the form of a Monte Carlo sample of neural networks trained on replicas of the experimental data, which represents the probability density in the space of lepton energy spectra. This parametrization is then used to extract the b quark mass m_b^{1S} in a way that theoretical uncertainties are minimized, for which the value m_b^{1S}=4.84 \pm 0.14^{exp}\pm 0.05^{th} GeV is obtained.Comment: 32 pages, 22 figures, JHEP3 class. v4 version accepted for publication in JHE

    HOPS 383: An Outbursting Class 0 Protostar in Orion

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    We report the dramatic mid-infrared brightening between 2004 and 2006 of HOPS 383, a deeply embedded protostar adjacent to NGC 1977 in Orion. By 2008, the source became a factor of 35 brighter at 24 microns with a brightness increase also apparent at 4.5 microns. The outburst is also detected in the submillimeter by comparing APEX/SABOCA to SCUBA data, and a scattered-light nebula appeared in NEWFIRM K_s imaging. The post-outburst spectral energy distribution indicates a Class 0 source with a dense envelope and a luminosity between 6 and 14 L_sun. Post-outburst time-series mid- and far-infrared photometry shows no long-term fading and variability at the 18% level between 2009 and 2012. HOPS 383 is the first outbursting Class 0 object discovered, pointing to the importance of episodic accretion at early stages in the star formation process. Its dramatic rise and lack of fading over a six-year period hint that it may be similar to FU Ori outbursts, although the luminosity appears to be significantly smaller than the canonical luminosities of such objects.Comment: Accepted by ApJ Letters, 6 pages, 4 figures; v2 has an updated email address for the lead autho

    Molekularna istraživanja na rajanpuri soju pasmine beetal koza iz Pakistana potpunim područjem pomaka mtDNK i mikrosatelitnim markerima

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    The mitochondrial DNA sequences of DNA-D loops (mtDNA) from 105 individuals (11 Beetal goat Rajanpuri strains and 94 sequences extracted from GenBank) from 19 geographically and phenotypically defined domestic goat breeds in Pakistan were analysed in this experiment. In this study, we examined variability and molecular phylogeny of breeds. A total of 81 haplotypes were observed in 105 individuals, with a haplotype diversity of 0.984±0.006 and nucleotide diversity of 0.03953±0.00843. Phylogenetic analysis based on the mtDNA hyper variable segment (HVI) of the control region (481 bp), showed four mtDNA haplogroups (A, B1, C, and D) identified in Pakistani domestic goats, in which haplogroup A (84.11%) was dominant and widely distributed among all investigated breeds. The study revealed that all Rajanpuri strain haplotypes belonged to haplogroup A. The Rajanpuri is a rare local strain of Beetal goat breed located in western Punjab province of Pakistan. The results of genetic diversity based on 11 microsatellite loci revealed allelic diversity (3.6363) and high genetic diversity (0.8342) in the examined Rajanpuri goat breeds. The analysis for signature bottleneck events, using three models, revealed significant deviation of Rajanpuri goats from mutation drift equilibrium. The qualitative test of mode shift analysis also supported the results obtained under three models, indicating the presence of a recent genetic bottleneck in the Rajanpuri strain. This study provides the first information on the mtDNA architecture, genetic diversity and bottleneck analysis, which will be useful in the conservation and management of the highly valued Rajanpuri goat.Mitohondrijske DNK sekvence DNK-D petlji (mtDNK) 105 jedinki (11 ratalpuri sojeva beetal koze i 94 sekvence iz GenBank) od 19 geografskih i fenotipičnih domaćih pasmina koza u Pakistanu rabljeno je u ovom eksperimentu. U ovoj smo studiji istražili varijabilnost i njezinu molekularnu filogeniju. Zamijećen je ukupno 81 različit haplotip u 105 jedinki s raznolikošću haplotipova 0,984±0,006 i nukleotidnom raznolikošću 0,03953±0,00843. Filogenetskom analizom ustvrđen iz mtDNK hipervarijabilni segment (HVI) kontrolnog područja (481 bp) i pokazala je četiri haploskupine mtDNK (A, B1, C i D) identificirane u pakistanskih domaćih koza, u kojima se haploskupina A (84,11 %) pokazala dominantnom i široko rasprostranjenom među svim istraživanim pasminama. Studija je otkrila da svi haplotipovi rajanpuri soja pripadaju haploskupini A. Rajanpuri je rijedak lokalni soj beetal pasmine koza smješten u zapadnoj regiji provincije Punjab u Pakistanu. Rezultati genetske raznolikosti na temelju 11 mikrosatelitnih lokusa otkrili su alelnu raznolikost (3,6363) i visoku genetsku raznolikost (0,8342) istraživane rajanpuri pasmine koza. Rezultati analize za potpis za događaje uskog grla uporabom tri modela otkrili su značajno odstupanje rajanpuri koza od ravnoteže mutacija i pomaka. Kvalitativni test analize modalnog pomaka podržao je i rezultate dobivene trima modelima, ukazujući na prisutnost genetskog uskog grla u rajanpuri soja u nedavnoj prošlosti. Ova studija po prvi put pruža informacije o arhitekturi mtDNK, genetskoj raznolikosti, analizi uskog grla koje će biti korisne u donošenju odluke o očuvanju i upravljanju cijenjenom i skupocjenom rajanpuri kozom
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