141 research outputs found

    Search for ZZ and ZW Production in ppbar Collisions at sqrt(s) = 1.96 TeV

    Get PDF
    We present a search for ZZ and ZW vector boson pair production in ppbar collisions at sqrt(s) = 1.96 TeV using the leptonic decay channels ZZ --> ll nu nu, ZZ --> l l l' l' and ZW --> l l l' nu. In a data sample corresponding to an integrated luminosity of 194 pb-1 collected with the Collider Detector at Fermilab, 3 candidate events are found with an expected background of 1.0 +/- 0.2 events. We set a 95% confidence level upper limit of 15.2 pb on the cross section for ZZ plus ZW production, compared to the standard model prediction of 5.0 +/- 0.4 pb.Comment: 7 pages, 2 figures. This version is accepted for publication by Phys. Rev. D Rapid Communication

    Measurement of the ttbar Production Cross Section in ppbar Collisions at sqrt{s}=1.96 TeV using Lepton + Jets Events with Secondary Vertex b-tagging

    Full text link
    We present a measurement of the ttbar production cross section using events with one charged lepton and jets from ppbar collisions at a center-of-mass energy of 1.96 TeV. In these events, heavy flavor quarks from top quark decay are identified with a secondary vertex tagging algorithm. From 162 pb-1 of data collected by the Collider Detector at Fermilab, a total of 48 candidate events are selected, where 13.5 +- 1.8 events are expected from background contributions. We measure a ttbar production cross section of 5.6^{+1.2}_{-1.1} (stat.) ^{+0.9}_{0.6} (syst.) pb.Comment: 28 pages, 20 figures. Published in Physical Review

    A rare Von Hippel–Lindau disease that mimics acute myelitis: case report and review of the literature

    Get PDF
    Von Hippel–Lindau disease (VHL) comprises a series of complicated clinical manifestations. We hereby report one unique case of VHL with a natural history that mimics acute myelitis. MRI and biopsy in this patient showed multiple solid hemangioblastomas of the central nervous system and kidney. This study further confirmed that VHL is of highly clinical, imaging, and pathological heterogeneity. Diagnosis for VHL should be based on combination of clinical, radiological, pathological, and genetic data

    Measurement of the W+W- Production Cross Section in ppbar Collisions at sqrt(s)=1.96 TeV using Dilepton Events

    Get PDF
    We present a measurement of the W+W- production cross section using 184/pb of ppbar collisions at a center-of-mass energy of 1.96 TeV collected with the Collider Detector at Fermilab. Using the dilepton decay channel W+W- -> l+l-vvbar, where the charged leptons can be either electrons or muons, we find 17 candidate events compared to an expected background of 5.0+2.2-0.8 events. The resulting W+W- production cross section measurement of sigma(ppbar -> W+W-) = 14.6 +5.8 -5.1 (stat) +1.8 -3.0 (syst) +-0.9 (lum) pb agrees well with the Standard Model expectation.Comment: 8 pages, 2 figures, 2 tables. To be submitted to Physical Review Letter

    Measurement of prompt charm meson production cross sections in p(p)over-bar collisions at root s=1.96 TeV

    Get PDF
    We report on measurements of differential cross sections dsigma/dp(T) for prompt charm meson production in p (p) over bar collisions at roots=1.96 TeV using 5.8+/-0.3 pb(-1) of data from the CDF II detector at the Fermilab Tevatron. The data are collected with a new trigger that is sensitive to the long lifetime of hadrons containing heavy flavor. The charm meson cross sections are measured in the central rapidity region \y\less than or equal to1 in four fully reconstructed decay modes: D-0--\u3eK(-)pi(+), D*+--\u3eD(0)pi(+), D+--\u3eK(-)pi(+)pi(+), D-s(+)--\u3ephipi(+), and their charge conjugates. The measured cross sections are compared to theoretical calculations

    Observation of the narrow state X(3872)-\u3e J/psi pi(+)pi(-) in (p)over-barp collisions at root s=1.96 TeV

    Get PDF
    We report the observation of a narrow state decaying into J/psipi(+)pi(-) and produced in 220 pb(-1) of (p) over barp collisions at roots=1.96 TeV in the CDF II experiment. We observe 730+/-90 decays. The mass is measured to be 3871.3+/-0.7(stat)+/-0.4(syst) MeV/c(2), with an observed width consistent with the detector resolution. This is in agreement with the recent observation by the Belle Collaboration of the X(3872) meson

    Measurement of the t(t)over-bar production cross section in p(p)over-bar collisions at root s=1.96 TeV using dilepton events

    Get PDF
    We report a measurement of the t (t) over bar production cross section using dilepton events with jets and missing transverse energy in p (p) over bar collisions at a center-of-mass energy of 1.96 TeV. Using a 197+/-12 pb(-1) data sample recorded by the upgraded Collider Detector at Fermilab, we use two complementary techniques to select candidate events. We compare the number of observed events and selected kinematical distributions with the predictions of the standard model and find good agreement. The combined result of the two techniques yields a t (t) over bar production cross section of 7.0(-2.1)(+2.4)(stat)(-1.1)(+1.6)(syst)+/-0.4(lum) pb

    Nutritionally Enhanced Staple Food Crops

    Get PDF
    Crop biofortification is a sustainable and cost-effective strategy to address malnutrition in developing countries. This review synthesizes the progress toward developing seed micronutrient-dense cereals and legumes cultivars by exploiting natural genetic variation using conventional breeding and/or transgenic technology, and discusses the associated issues to strengthen crop biofortification research and development. Some major QTL for seed iron and zinc, seed phosphorus, and seed phytate in common bean, rice,J;md wheat have been mapped. An iron reductase QTL associated with seed-iron ~QTL is found in common bean where the genes coding for candidate enzymes involved in phytic acid synthesis have also been mapped. Candidate genes for Ipa co segregate with mutant phenotypes identified in rice and soybean. The Gpe-B1 locus in wild emmer wheat accelerates senescence and increases nutrient remobilization from leaves to developing seeds, and another gene named TtNAM-B1 affecting these traits has been cloned. Seed iron-dense common bean and rice in Latin America; seed iron-dense common bean in eastern and southern Africa;....

    Interspecies somatic cell nuclear transfer is dependent on compatible mitochondrial DNA and reprogramming factors

    Get PDF
    Interspecies somatic cell nuclear transfer (iSCNT) involves the transfer of a nucleus or cell from one species into the cytoplasm of an enucleated oocyte from another. Once activated, reconstructed oocytes can be cultured in vitro to blastocyst, the final stage of preimplantation development. However, they often arrest during the early stages of preimplantation development; fail to reprogramme the somatic nucleus; and eliminate the accompanying donor cell’s mitochondrial DNA (mtDNA) in favour of the recipient oocyte’s genetically more divergent population. This last point has consequences for the production of ATP by the electron transfer chain, which is encoded by nuclear and mtDNA. Using a murine-porcine interspecies model, we investigated the importance of nuclear-cytoplasmic compatibility on successful development. Initially, we transferred murine fetal fibroblasts into enucleated porcine oocytes, which resulted in extremely low blastocyst rates (0.48%); and failure to replicate nuclear DNA and express Oct-4, the key marker of reprogramming. Using allele specific-PCR, we detected peak levels of murine mtDNA at 0.1460.055% of total mtDNA at the 2-cell embryo stage and then at ever-decreasing levels to the blastocyst stage (,0.001%). Furthermore, these embryos had an overall mtDNA profile similar to porcine embryos. We then depleted porcine oocytes of their mtDNA using 10 mM 29,39- dideoxycytidine and transferred murine somatic cells along with murine embryonic stem cell extract, which expressed key pluripotent genes associated with reprogramming and contained mitochondria, into these oocytes. Blastocyst rates increased significantly (3.38%) compared to embryos generated from non-supplemented oocytes (P,0.01). They also had significantly more murine mtDNA at the 2-cell stage than the non-supplemented embryos, which was maintained throughout early preimplantation development. At later stages, these embryos possessed 49.9962.97% murine mtDNA. They also exhibited an mtDNA profile similar to murine preimplantation embryos. Overall, these data demonstrate that the addition of species compatible mtDNA and reprogramming factors improves developmental outcomes for iSCNT embryos
    corecore