Snake Cathelicidin from Bungarus fasciatus Is a Potent Peptide Antibiotics

Background: Cathelicidins are a family of antimicrobial peptides acting as multifunctional effector molecules of innate immunity, which are firstly found in mammalians. Recently, several cathelicidins have also been found from chickens and fishes. No cathelicidins from other non-mammalian vertebrates have been reported. Principal Findings: In this work, a cathelicidin-like antimicrobial peptide named cathelicidin-BF has been purified from the snake venoms of Bungarus fasciatus and its cDNA sequence was cloned from the cDNA library, which confirm the presence of cathelicidin in reptiles. As other cathelicidins, the precursor of cathelicidin-BF has cathelin-like domain at the N terminus and carry the mature cathelicidin-BF at the C terminus, but it has an atypical acidic fragment insertion between the cathelin-like domain and the C-terminus. The acidic fragment is similar to acidic domains of amphibian antimicrobial precursors. Phylogenetic analysis revealed that the snake cathelicidin had the nearest evolution relationship with platypus cathelicidin. The secondary structure of cathelicidin-BF investigated by CD and NMR spectroscopy in the presence of the helicogenic solvent TFE is an amphipathic α-helical conformation as many other cathelicidins. The antimicrobial activities of cathelicidin BF against forty strains of microorganisms were tested. Cathelicidin-BF efficiently killed bacteria and some fungal species including clinically isolated drug-resistance microorganisms. It was especially active against Gram-negative bacteria. Furthermore, it could exert antimicrobial activity against some saprophytic fungus. No hemolytic and cytotoxic activity was observed at the dose of up to 400 µg/ml. Cathelicidin-BF could exist stably in the mice plasma for at least 2.5 hours. Conclusion: Discovery of snake cathelicidin with atypical structural and functional characterization offers new insights on the evolution of cathelicidins. Potent, broad spectrum, salt-independent antimicrobial activities make cathelicidin-BF an excellent candidate for clinical or agricultural antibiotics

Measurement of the Dipion Mass Spectrum in X(3872) -> J/Psi Pi+ Pi- Decays

We measure the dipion mass spectrum in X(3872)--> J/Psi Pi+ Pi- decays using 360 pb-1 of pbar-p collisions at 1.96 TeV collected with the CDF II detector. The spectrum is fit with predictions for odd C-parity (3S1, 1P1, and 3DJ) charmonia decaying to J/Psi Pi+ Pi-, as well as even C-parity states in which the pions are from Rho0 decay. The latter case also encompasses exotic interpretations, such as a D0-D*0Bar molecule. Only the 3S1 and J/Psi Rho hypotheses are compatible with our data. Since 3S1 is untenable on other grounds, decay via J/Psi Rho is favored, which implies C=+1 for the X(3872). Models for different J/Psi-Rho angular momenta L are considered. Flexibility in the models, especially the introduction of Rho-Omega interference, enable good descriptions of our data for both L=0 and 1.Comment: 7 pages, 4 figures -- Submitted to Phys. Rev. Let

Forward-Backward Asymmetry in Top Quark Production in ppbar Collisions at sqrt{s}=1.96 TeV

Reconstructable final state kinematics and charge assignment in the reaction ppbar->ttbar allows tests of discrete strong interaction symmetries at high energy. We define frame dependent forward-backward asymmetries for the outgoing top quark in both the ppbar and ttbar rest frames, correct for experimental distortions, and derive values at the parton-level. Using 1.9/fb of ppbar collisions at sqrt{s}=1.96 TeV recorded with the CDF II detector at the Fermilab Tevatron, we measure forward-backward top quark production asymmetries in the ppbar and ttbar rest frames of A_{FB,pp} = 0.17 +- 0.08 and A_{FB,tt} = 0.24 +- 0.14.Comment: 7 pages, 2 figures, submitted to Phys.Rev.Lett, corrected references and change of tex

Study of CP violation in Dalitz-plot analyses of B0 --> K+K-KS, B+ --> K+K-K+, and B+ --> KSKSK+

We perform amplitude analyses of the decays $B^0 \to K^+K^-K^0_S$, $B^+ \rightarrow K^+K^-K^+$, and $B^+ \to K^0_S K^0_S K^+$, and measure CP-violating parameters and partial branching fractions. The results are based on a data sample of approximately $470\times 10^6$ $B\bar{B}$ decays, collected with the BABAR detector at the PEP-II asymmetric-energy $B$ factory at the SLAC National Accelerator Laboratory. For $B^+ \to K^+K^-K^+$, we find a direct CP asymmetry in $B^+ \to \phi(1020)K^+$ of $A_{CP}= (12.8\pm 4.4 \pm 1.3)$, which differs from zero by $2.8 \sigma$. For $B^0 \to K^+K^-K^0_S$, we measure the CP-violating phase $\beta_{\rm eff} (\phi(1020)K^0_S) = (21\pm 6 \pm 2)^\circ$. For $B^+ \to K^0_S K^0_S K^+$, we measure an overall direct CP asymmetry of $A_{CP} = (4 ^{+4}_{-5} \pm 2)$. We also perform an angular-moment analysis of the three channels, and determine that the $f_X(1500)$ state can be described well by the sum of the resonances $f_0(1500)$, $f_2^{\prime}(1525)$, and $f_0(1710)$.Comment: 35 pages, 68 postscript figures. v3 - minor modifications to agree with published versio

Search for Higgs Boson Decaying to b-bbar and Produced in Association with W Bosons in p-pbar Collisions at sqrt{s}=1.96 TeV

We present a search for Higgs bosons decaying into b-bbar and produced in association with W bosons in p-pbar collisions at sqrt{s}=1.96 TeV. This search uses 320 pb-1 of the dataset accumulated by the upgraded Collider Detector at Fermilab. Events are selected that have a high-transverse momentum electron or muon, missing transverse energy, and two jets, one of which is consistent with a hadronization of a b quark. Both the number of events and the dijet mass distribution are consistent with standard model background expectations, and we set 95% confidence level upper limits on the production cross section times branching ratio for the Higgs boson or any new particle with similar decay kinematics. These upper limits range from 10 pb for mH=110 GeV/c2 to 3 pb for mH=150 GeV/c2.Comment: 7 pages, 3 figures; updated title to published versio

Search for Pair Production of Scalar Top Quarks Decaying to a tau Lepton and a b Quark in ppbar Collisions at sqrt{s}=1.96 TeV

We search for pair production of supersymmetric top quarks (~t_1), followed by R-parity violating decay ~t_1 -> tau b with a branching ratio beta, using 322 pb^-1 of ppbar collisions at sqrt{s}=1.96 TeV collected by the CDF II detector at Fermilab. Two candidate events pass our final selection criteria, consistent with the standard model expectation. We set upper limits on the cross section sigma(~t_1 ~tbar_1)*beta^2 as a function of the stop mass m(~t_1). Assuming beta=1, we set a 95% confidence level limit m(~t_1)>153 GeV/c^2. The limits are also applicable to the case of a third generation scalar leptoquark (LQ_3) decaying LQ_3 -> tau b.Comment: 7 pages, 2 eps figure

Search for Second-Generation Scalar Leptoquarks in ppˉ\bm{p \bar{p}} Collisions at s\sqrt{s}=1.96 TeV

Results on a search for pair production of second generation scalar leptoquark in $p \bar{p}$ collisions at $\sqrt{s}$=1.96 TeV are reported. The data analyzed were collected by the CDF detector during the 2002-2003 Tevatron Run II and correspond to an integrated luminosity of 198 pb$^{-1}$. Leptoquarks (LQ) are sought through their decay into (charged) leptons and quarks, with final state signatures represented by two muons and jets and one muon, large transverse missing energy and jets. We observe no evidence for $LQ$ production and derive 95% C.L. upper limits on the $LQ$ production cross sections as well as lower limits on their mass as a function of $\beta$, where $\beta$ is the branching fraction for $LQ \to \mu q$.Comment: 9 pages (3 author list) 5 figure

Evidence for the h_b(1P) meson in the decay Upsilon(3S) --> pi0 h_b(1P)

Using a sample of 122 million Upsilon(3S) events recorded with the BaBar detector at the PEP-II asymmetric-energy e+e- collider at SLAC, we search for the $h_b(1P)$ spin-singlet partner of the P-wave chi_{bJ}(1P) states in the sequential decay Upsilon(3S) --> pi0 h_b(1P), h_b(1P) --> gamma eta_b(1S). We observe an excess of events above background in the distribution of the recoil mass against the pi0 at mass 9902 +/- 4(stat.) +/- 2(syst.) MeV/c^2. The width of the observed signal is consistent with experimental resolution, and its significance is 3.1sigma, including systematic uncertainties. We obtain the value (4.3 +/- 1.1(stat.) +/- 0.9(syst.)) x 10^{-4} for the product branching fraction BF(Upsilon(3S)-->pi0 h_b) x BF(h_b-->gamma eta_b).Comment: 8 pages, 4 postscript figures, submitted to Phys. Rev. D (Rapid Communications

Search for anomalous semileptonic decay of heavy flavor hadrons produced in association with a W boson at CDF II

We present a search for anomalous semileptonic decays of heavy flavor hadrons produced in association with a $W$ boson, in proton-antiproton collisions at sqrt{s}=1.96 TeV. We use 162 pb-1 of data collected with the CDF II detector at the Fermilab Tevatron Collider. We select events with one W boson and at least one jet with an identified secondary vertex. In the jets with a secondary vertex we look for a semileptonic decay to a muon. We compare the number of jets with both a secondary vertex and a semileptonic decay, and the kinematic properties of these jets, with the standard model expectation of W plus heavy flavor production and decay. No discrepancy is seen between the observation and the expectation, and we set limits on the production cross section of a B-like hadron with an anomalously high semileptonic branching ratio.Comment: 8 pages, 2 figures, submitted to PRD-RC; replaced to adjust the page forma

Measurement of the Ratios of Branching Fractions B(Bs->Ds- pi+)/B(B0->D-pi+) and B(B+->D0bar pi+)/B(B0->D-pi+)

We report an observation of the decay Bs -> Ds- pi+ in p pbar collisions at sqrt(s) = 1.96 TeV using 115 pb^(-1) of data collected by the CDF II detector at the Fermilab Tevatron. We observe 83 +/- 11 Bs -> Ds- pi+ candidates, representing a large increase in statistics over previous measurements and the first observation of this decay at a p pbar collider. We present the first measurement of the relative branching fraction B(Bs -> Ds- pi+) / B(B0 -> D- pi+) = 1.32 +/- 0.18 (stat.) +/- 0.38 (syst.). We also measure B(B+ -> D0bar pi+) / B(B0 -> D- pi+) = 1.97 +/- 0.10(stat.) +/- 0.21(syst.), which is consistent with previous measurements