Measurement of the difference in CP-violating asymmetries in D(0)→K(+)K(-) and D(0)→π(+)π(-) decays at CDF

We report a measurement of the difference (ΔA(CP)) between time-integrated CP-violating asymmetries in D(0)→K(+)K(-) and D(0)→π(+)π(-) decays reconstructed in the full data set of proton-antiproton collisions collected by the Collider Detector at Fermilab, corresponding to 9.7  fb(-1) of integrated luminosity. The strong decay D(*+)→D(0)π(+) is used to identify the charm meson at production as D(0) or D[over ¯](0). We measure ΔA(CP)=[-0.62±0.21(stat)±0.10(syst)]%, which differs from zero by 2.7 Gaussian standard deviations. This result supports similar evidence for CP violation in charm-quark decays obtained in proton-proton collisions.

Combined search for the standard model Higgs boson decaying to a bb pair using the full CDF data set

We combine the results of searches for the standard model (SM) Higgs boson based on the full CDF Run II data set obtained from sqrt[s]=1.96  TeV pp collisions at the Fermilab Tevatron corresponding to an integrated luminosity of 9.45  fb(-1). The searches are conducted for Higgs bosons that are produced in association with a W or Z boson, have masses in the range 90-150  GeV/c(2), and decay into bb pairs. An excess of data is present that is inconsistent with the background prediction at the level of 2.5 standard deviations (the most significant local excess is 2.7 standard deviations).

Search for the standard model Higgs boson decaying to a bb pair in events with no charged leptons and large missing transverse energy using the full CDF data set

We report on a search for the standard model Higgs boson produced in association with a vector boson in the full data set of proton-antiproton collisions at sqrt[s]=1.96  TeV recorded by the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45  fb(-1). We consider events having no identified charged lepton, a transverse energy imbalance, and two or three jets, of which at least one is consistent with originating from the decay of a b quark. We place 95% credibility level upper limits on the production cross section times standard model branching fraction for several mass hypotheses between 90 and 150  GeV/c(2). For a Higgs boson mass of 125  GeV/c(2), the observed (expected) limit is 6.7 (3.6) times the standard model prediction.

Search for the standard model Higgs boson decaying to a bb pair in events with two oppositely charged leptons using the full CDF data set

We present a search for the standard model Higgs boson produced in association with a Z boson in data collected with the CDF II detector at the Tevatron, corresponding to an integrated luminosity of 9.45  fb(-1). In events consistent with the decay of the Higgs boson to a bottom-quark pair and the Z boson to electron or muon pairs, we set 95% credibility level upper limits on the ZH production cross section times the H→bb branching ratio as a function of Higgs boson mass. At a Higgs boson mass of 125  GeV/c(2), we observe (expect) a limit of 7.1 (3.9) times the standard model value.

Evidence for a particle produced in association with weak bosons and decaying to a bottom-antibottom quark pair in higgs boson searches at the tevatron

We combine searches by the CDF and D0 Collaborations for the associated production of a Higgs boson with a W or Z boson and subsequent decay of the Higgs boson to a bottom-antibottom quark pair. The data, originating from Fermilab Tevatron pp collisions at √s = 1.96 TeV, correspond to integrated luminosities of up to 9.7 fb(-1). The searches are conducted for a Higgs boson with mass in the range 100-150 GeV/c(2). We observe an excess of events in the data compared with the background predictions, which is most significant in the mass range between 120 and 135 GeV/c(2). The largest local significance is 3.3 standard deviations, corresponding to a global significance of 3.1 standard deviations. We interpret this as evidence for the presence of a new particle consistent with the standard model Higgs boson, which is produced in association with a weak vector boson and decays to a bottom-antibottom quark pair.

Search for dark matter in events with one jet and missing transverse energy in pp¯ collisions at √s=1.96 TeV

We present the results of a search for dark matter production in the monojet signature. We analyze a sample of Tevatron pp[over ¯] collisions at √s=1.96 TeV corresponding to an integrated luminosity of 6.7 fb(-1) recorded by the CDF II detector. In events with large missing transverse energy and one energetic jet, we find good agreement between the standard model prediction and the observed data. We set 90% confidence level upper limits on the dark matter production rate. The limits are translated into bounds on nucleon-dark matter scattering rates which are competitive with current direct detection bounds on spin-independent interaction below a dark matter candidate mass of 5 GeV/c(2), and on spin-dependent interactions up to masses of 200 GeV/c(2).

Search for a heavy particle decaying to a top quark and a light quark in pp ¯ collisions at √s=1.96 TeV

We present a search for a new heavy particle X produced in association with a top quark, pp[over ¯]→t(X→t[over ¯]q) or pp[over ¯]→t[over ¯](X[over ¯]→tq[over ¯]), where q stands for up quarks and down quarks. Such a particle may explain the recent anomalous measurements of top-quark forward-backward asymmetry. If the light-flavor quark (q) is reconstructed as a jet (j), this gives a t[over ¯]+j or t+j resonance in tt[over ¯]+jet events, a previously unexplored experimental signature. In a sample of events with exactly one lepton, missing transverse momentum and at least five jets, corresponding to an integrated luminosity of 8.7 fb(-1) collected by the CDF II detector, we find the data to be consistent with the standard model. We set cross-section upper limits on the production (pp[over ¯]→Xt or X[over ¯]t[over ¯]) at 95% confidence level from 0.61 pb to 0.02 pb for X masses ranging from 200 GeV/c(2) to 800 GeV/c(2), respectively.

Evidence for the charmless annihilation decay mode B(s)(0)→π(+)π(-)

We search for annihilation decay modes of neutral b mesons into pairs of charmless charged hadrons with the upgraded Collider Detector at the Fermilab Tevatron. Using a data sample corresponding to 6 fb(-1) of integrated luminosity, we obtain the first evidence for the B(s)(0)→π(+)π(-) decay, with a significance of 3.7σ, and a measured branching ratio B(B(s)(0)→π(+)π(-))=(0.57±0.15(stat)±0.10(syst))×10(-6). A search for the B(0)→K(+)K(-) mode in the same sample yields a significance of 2.0σ, and a central value estimate B(B(0)→K(+)K(-))=(0.23±0.10(stat)±0.10(syst))×10(-6).

Image analysis of peripheral compression artefacts of ThinPrep(®) liquid-based cytology preparations

OBJECTIVE

ThinPrep (TP), one of the Food and Drug Administration-approved liquid-based cytology (LBC) preparations, is widely used for gynaecological and non-gynaecological cytology samples. A unique physical artefact caused by the compression at the periphery in TP slides has not been adequately evaluated to date.

METHODS

We processed four established tumour cell lines (MKN28, MKN45, KG-1 and NB4) and mononuclear cells isolated from whole blood over Ficoll-Plaque for TP preparations. For this part of the study, we included five normal cervical LBC preparations. We then auto-counted and auto-measured the area, mean grey value and Feret's diameter in both the inner disc and peripheral rim of the preparations by image morphometry. In addition, we compared the distribution of atypical cell groups in the peripheral rim and inner disc of 132 lung aspirates, 80 thyroid aspirates, 212 cerebrospinal fluids (CSFs) and 50 gynaecological samples.

RESULTS

The areas and Feret's diameters of the cytoplasm in the peripheral compressed rim area were statistically larger than those of cells in the inner disc. The mean grey values of cells (cytoplasm and nucleus) in the peripheral compression rim were also smaller than those in the inner disc cells, leading to decreases in nuclear and cytoplasmic chromatism. Except for the mean grey values, the differences were not significant in the cervical samples.

CONCLUSIONS

Cellular morphology may be markedly distorted in the peripheral rim, regardless of cell malignancy, which may lead to the misinterpretation of cells during the screening. Accordingly, cytological diagnosis based on the findings within the peripheral rim should take this phenomenon into account. Compressed cells found in the peripheral rim should be interpreted with caution when TP slides are used for cytopathological diagnosis.

Measurement of Bs0→Ds(*)+Ds(*)- branching ratios

The decays Bs0→Ds(*)+Ds(*)- are reconstructed in a data sample corresponding to an integrated luminosity of 6.8  fb-1 collected by the CDF II detector at the Tevatron pp[over ¯] collider. All decay modes are observed with a significance of more than 10σ, and we measure the Bs0 production rate times Bs0→Ds(*)+Ds(*)- branching ratios relative to the normalization mode B0→Ds+D-to be 0.183±0.021±0.017 for Bs0→Ds+Ds-, 0.424±0.046±0.035 for Bs0→Ds*±Ds^∓, 0.654±0.072±0.065 for Bs0→Ds*+Ds*-, and 1.261±0.095±0.112 for the inclusive decay Bs0→Ds(*)+Ds(*)-, where the uncertainties are statistical and systematic. These results are the most precise single measurements to date and provide important constraints for indirect searches for nonstandard model physics in Bs0 mixing.

Search for a dark matter candidate produced in association with a single top quark in pp collisions at √[s]=1.96 TeV

We report a new search for dark matter in a data sample of an integrated luminosity of 7.7  fb-1 of Tevatron pp[over ¯] collisions at √[s]=1.96  TeV, collected by the CDF II detector. We search for production of a dark-matter candidate, D, in association with a single top quark. We consider the hadronic decay mode of the top quark exclusively, yielding a final state of three jets with missing transverse energy. The data are consistent with the standard model; we thus set 95% confidence level upper limits on the cross section of the process pp[over ¯]→t+D as a function of the mass of the dark-matter candidate. The limits are approximately 0.5 pb for a dark-matter particle with mass in the range of 0-150  GeV/c2.

Search for a low-mass standard model Higgs boson in the ττ decay channel in pp collisions at sqrt[s]=1.96 TeV

We report on a search for the standard model Higgs boson decaying into pairs of τ leptons in pp collisions produced by the Tevatron at sqrt[s]=1.96  TeV. The analyzed data sample was recorded by the CDFII detector and corresponds to an integrated luminosity of 6.0  fb(-1). The search is performed in the final state with one τ decaying leptonically and the second one identified through its semihadronic decay. Since no significant excess is observed, a 95% credibility level upper limit on the production cross section times branching ratio to the ττ final state is set for hypothetical Higgs boson masses between 100 and 150  GeV/c2. For a Higgs boson of 120  GeV/c2 the observed (expected) limit is 14.6 (15.3) the predicted value.

Contrast-enhanced MR cholangiography: comparison of Gd-EOB-DTPA and Mn-DPDP in healthy volunteers

OBJECTIVE

The purpose of this study was to compare the biliary enhancement dynamics of gadolinium-ethoxybenzyl-diethylenetriamine-pentaacetic-acid (Gd-EOB-DTPA) and mangafodipir trisodium (Mn-DPDP) for contrast-enhanced MR cholangiography (MRC) in healthy subjects.

METHODS

15 healthy volunteers underwent MRI at 1.5 T with volumetric interpolated breath-hold examination sequence. Each volunteer was scanned once for each contrast agent. The signal-to-noise ratio (SNR) of the liver parenchyma and common hepatic duct (CHD) and the contrast-to-noise ratio (CNR) of CHD to liver parenchyma were evaluated and compared before and at several time points (5, 15, 30, 45, 60, 90, and 120 min) after injection of each agent.

RESULTS

SNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP in liver parenchyma after 5 min and in CHD after 15 min (p<0.05). CNR of CHD to liver parenchyma using Gd-EOB-DTPA showed an initial decrease at 5 min post-injection followed by a steep increase to a peak at 15 min post-injection. CNR using Mn-DPDP showed a steady increase to a peak at 15 min post-injection without an initial decrease. At 15 min, the value of CNR was significantly higher for Gd-EOB-DTPA than for Mn-DPDP (p<0.05).

CONCLUSION

For both contrast agents, CNR reached a peak at 15 min after contrast injection. At this time point, CNR of Gd-EOB-DTPA was significantly higher than that of Mn-DPDP. Therefore, Gd-EOB-DTPA may provide better contrast-enhanced MRC than Mn-DPDP at 15 min after contrast administration.

FgVelB globally regulates sexual reproduction, mycotoxin production and pathogenicity in the cereal pathogen Fusarium graminearum

The velvet genes are conserved in ascomycetous fungi and function as global regulators of differentiation and secondary metabolism. Here, we characterized one of the velvet genes, designated FgVelB, in the plant-pathogenic fungus Fusarium graminearum, which causes fusarium head blight in cereals and produces mycotoxins within plants. FgVelB-deleted (ΔFgVelB) strains produced fewer aerial mycelia with less pigmentation than those of the wild-type (WT) during vegetative growth. Under sexual development conditions, the ΔFgVelB strains produced no fruiting bodies but retained male fertility, and conidiation was threefold higher compared with the WT strain. Production of trichothecene and zearalenone was dramatically reduced compared with the WT strain. In addition, the ΔFgVelB strains were incapable of colonizing host plant tissues. Transcript analyses revealed that FgVelB was highly expressed during the sexual development stage, and may be regulated by a mitogen-activated protein kinase cascade. Microarray analysis showed that FgVelB affects regulatory pathways mediated by the mating-type loci and a G-protein alpha subunit, as well as primary and secondary metabolism. These results suggest that FgVelB has diverse biological functions, probably by acting as a member of a possible velvet protein complex, although identification of the FgVelB-FgVeA complex and the determination of its roles require further investigation.

Moderate hypothermia attenuates α(1)-adrenoceptor-mediated contraction in isolated rat aorta: the role of the endothelium

Moderate hypothermia (25-31 °C) may have a significant influence on vascular tone. We investigated the cellular mechanisms by which moderate hypothermia alters α-adrenoceptor-mediated contraction in rat thoracic aortae. Cyclooxygenase inhibition by indomethacin; nitric oxide (NO) synthase inhibition by L-NAME; potassium channel and endothelium-derived hyperpolarizing factor (EDHF) inhibition by glibenclamide and TEA; G protein inhibition by pertussis toxin; α₂-adrenergic inhibition by yohimbine; and β-adrenergic inhibition by propranolol were assessed for their effect on the contractile response to the α1-adrenoceptor agonist phenylephrine (Phe) in combination with moderate hypothermia (25 °C). Moderate hypothermia produced a shift to the right for the Phe concentration-response curves in endothelium-intact (E+) and endothelium-denuded (E-) aortic rings. The maximal response to Phe in E+ rings was significantly decreased (P<0.05) at 25 °C compared to 38 °C, whereas there was no significant difference in E- rings. Hypothermia-induced vasorelaxation in E+ rings was attenuated (P<0.05) following combined pretreatment with L-NAME (10⁻⁴ M) and indomethacin (10⁻⁵ M), whereas other inhibitors had no significant effect. Importantly, the addition of TEA to rings that were pretreated with L-NAME and indomethacin exhibited no further attenuation (P>0.05) of hypothermia-induced vasorelaxation. The concentrations of cGMP and cAMP, as measured by radioimmunoassay, were significantly increased (P<0.05) in E+ rings at 25 °C compared to those at 38 °C, whereas there were no significant differences (P>0.05) in E- rings. The present study demonstrated that rat aortic endothelium is stimulated during moderate hypothermia and that the NO-cGMP and prostacyclin (PGI₂)-cAMP pathways represent endothelium-dependent mechanisms of hypothermia-induced vasorelaxation. In contrast, EDHF may not be associated with hypothermia-induced vasorelaxation.

Measurements of the angular distributions of muons from Υ decays in pp collisions at sqrt[s] = 1.96 TeV

The angular distributions of muons from Υ(1S,2S,3S) → μ+ μ- decays are measured using data from pp collisions at sqrt[s] = 1.96  TeV corresponding to an integrated luminosity of 6.7  fb(-1) and collected with the CDF II detector at the Fermilab Tevatron. This analysis is the first to report the full angular distributions as functions of transverse momentum p(T) for Υ mesons in both the Collins-Soper and s-channel helicity frames. This is also the first measurement of the spin alignment of Υ(3S) mesons. Within the kinematic range of Υ rapidity |y|<0.6 and p(T) up to 40  GeV/c, the angular distributions are found to be nearly isotropic.

Precise measurement of the W-boson mass with the CDF II detector

We have measured the W-boson mass M(W) using data corresponding to 2.2  fb(-1) of integrated luminosity collected in pp collisions at sqrt[s] = 1.96  TeV with the CDF II detector at the Fermilab Tevatron collider. Samples consisting of 470,126 W → eν candidates and 624,708 W → μν candidates yield the measurement M(W) = 80,387 ± 12(stat.) ± 15(syst.) = 80,387 ± 19  MeV/c2. This is the most precise measurement of the W-boson mass to date and significantly exceeds the precision of all previous measurements combined.