2,980 research outputs found
Transportability of non-target arthropod field data for the use in environmental risk assessment of genetically modified maize in Northern Mexico
In country, non-target arthropod (NTA) field evaluations are required to comply with the regulatory process for cultivation of genetically modified (GM) maize in Mexico. Two sets of field trials, Experimental Phase and Pilot Phase, were conducted to identify any potential harm of insect-protected and glyphosate-tolerant maize (MON89Ă34-3 Ă MON-88Ă17-3 and MON-89Ă34-3 Ă MON-ĂĂ6Ă3-6) and glyphosatetolerant maize (MON-ĂĂ6Ă3-6) to local NTAs compared to conventional maize. NTA abundance data were collected at 32 sites, providing high geographic and environmental diversity within maize production areas from four ecological regions (ecoregions) in northern Mexico. The most abundant herbivorous taxa collected included field crickets, corn flea beetles, rootworm beetles, cornsilk flies, aphids, leafhoppers, plant bugs and thrips while the most abundant beneficial taxa captured were soil mites, spiders, predatory ground beetles, rove beetles, springtails (Collembola), predatory earwigs, ladybird beetles, syrphid flies, tachinid flies, minute pirate bugs, parasitic wasps and lacewings. Across the taxa analysed, no statistically significant differences in abundance were detected between GM maize and the conventional maize control for 69 of the 74 comparisons (93.2%) indicating thatthe single or stacked insect-protected and herbicide-tolerant
GM traits generally exert no marked adverse effects on the arthropod populations compared with conventional maize. The distribution of taxa observed in this study provides evidence that irrespective of variations in overall biodiversity of a given ecoregion, important herbivore, predatory and parasitic arthropod taxa within the commercial maize agroecosystem are highly similar indicating that relevant data generated in one ecoregion can be transportable for the risk assessment of the same or similar GM crop in another ecoregion
Role of the 4Kscore test as a predictor of reclassification in prostate cancer active surveillance
Background: Management of active surveillance (AS) in low-risk prostate cancer (PCa) patients could be improved with new biomarkers, such as the 4Kscore test. We analyze its ability to predict tumor reclassification by upgrading at the confirmatory biopsy at 6 months. Methods: Observational, prospective, blinded, and non-randomized study, within the Spanish National Registry on AS (AEU/PIEM/2014/0001; NCT02865330) with 181 patients included after initial Bx and inclusion criteria: PSA =10 ng/mL, cT1c-T2a, Grade group 1, =2 cores, and =5 mm/50% length core involved. Central pathological review of initial and confirmatory Bx was performed on all biopsy specimens. Plasma was collected 6 months after initial Bx and just before confirmatory Bx to determine 4Kscore result. In order to predict reclassification defined as Grade group =2, we analyzed 4Kscore, percent free to total (%f/t) PSA ratio, prostate volume, PSA density, family history, body mass index, initial Bx, total cores, initial Bx positive cores, initial Bx % of positive cores, initial Bx maximum cancer core length and initial Bx cancer % involvement. Wilcoxon rank-sum test, non-parametric trend test or Fisherâs exact test, as appropriate established differences between groups of reclassification. Results: A total of 137 patients met inclusion criteria. Eighteen patients (13.1%) were reclassified at confirmatory Bx. The %f/t PSA ratio and 4Kscore showed differences between the groups of reclassification (Yes/No). Using 7.5% as cutoff for the 4Kscore, we found a sensitivity of 89% and a specificity of 29%, with no reclassifications to Grade group 3 for patients with 4Kscore below 7.5% and 2 (6%) missed Grade group 2 reclassified patients. Using this threshold value there is a biopsy reduction of 27%. Additionally, 4Kscore was also associated with changes in tumor volume. Conclusions: Our preliminary findings suggest that the 4Kscore may be a useful tool in the decision-making process to perform a confirmatory Bx in active surveillance management
Evidence for t\bar{t}\gamma Production and Measurement of \sigma_t\bar{t}\gamma / \sigma_t\bar{t}
Using data corresponding to 6.0/fb of ppbar collisions at sqrt(s) = 1.96 TeV
collected by the CDF II detector, we present a cross section measurement of
top-quark pair production with an additional radiated photon. The events are
selected by looking for a lepton, a photon, significant transverse momentum
imbalance, large total transverse energy, and three or more jets, with at least
one identified as containing a b quark. The ttbar+photon sample requires the
photon to have 10 GeV or more of transverse energy, and to be in the central
region. Using an event selection optimized for the ttbar+photon candidate
sample we measure the production cross section of, and the ratio of cross
sections of the two samples. Control samples in the dilepton+photon and
lepton+photon+\met, channels are constructed to aid in decay product
identification and background measurements. We observe 30 ttbar+photon
candidate events compared to the standard model expectation of 26.9 +/- 3.4
events. We measure the ttbar+photon cross section to be 0.18+0.08 pb, and the
ratio of the cross section of ttbar+photon to ttbar to be 0.024 +/- 0.009.
Assuming no ttbar+photon production, we observe a probability of 0.0015 of the
background events alone producing 30 events or more, corresponding to 3.0
standard deviations.Comment: 9 pages, 3 figure
Search for the Higgs boson in events with missing transverse energy and b quark jets produced in proton-antiproton collisions at s**(1/2)=1.96 TeV
We search for the standard model Higgs boson produced in association with an
electroweak vector boson in events with no identified charged leptons, large
imbalance in transverse momentum, and two jets where at least one contains a
secondary vertex consistent with the decay of b hadrons. We use ~1 fb-1
integrated luminosity of proton-antiproton collisions at s**(1/2)=1.96 TeV
recorded by the CDF II experiment at the Tevatron. We find 268 (16) single
(double) b-tagged candidate events, where 248 +/- 43 (14.4 +/- 2.7) are
expected from standard model background processes. We place 95% confidence
level upper limits on the Higgs boson production cross section for several
Higgs boson masses ranging from 110 GeV/c2 to 140 GeV/c2. For a mass of 115
GeV/c2 the observed (expected) limit is 20.4 (14.2) times the standard model
prediction.Comment: 8 pages, 2 figures, submitted to Phys. Rev. Let
Search for Third Generation Vector Leptoquarks in p anti-p Collisions at sqrt(s) = 1.96 TeV
We describe a search for a third generation vector leptoquark (VLQ3) that
decays to a b quark and tau lepton using the CDF II detector and 322 pb^(-1) of
integrated luminosity from the Fermilab Tevatron. Vector leptoquarks have been
proposed in many extensions of the standard model (SM). Observing a number of
events in agreement with SM expectations, assuming Yang-Mills (minimal)
couplings, we obtain the most stringent upper limit on the VLQ3 pair production
cross section of 344 fb (493 fb) and lower limit on the VLQ3 mass of 317
GeV/c^2 (251 GeV/c^2) at 95% C.L.Comment: 7 pages, 2 figures, submitted to PR
Measurement of Ratios of Fragmentation Fractions for Bottom Hadrons in p-pbar Collisions at sqrt{s}=1.96 TeV
This paper describes the first measurement of b-quark fragmentation fractions
into bottom hadrons in Run II of the Tevatron Collider at Fermilab. The result
is based on a 360 pb-1 sample of data collected with the CDF II detector in
p-pbar collisions at sqrt{s}=1.96 TeV. Semileptonic decays of B0, B+, and B_s
mesons, as well as Lambda_b baryons, are reconstructed. For an effective bottom
hadron p_T threshold of 7 GeV/c, the fragmentation fractions are measured to be
f_u/f_d=1.054 +/- 0.018 (stat) +0.025-0.045(sys) +/- 0.058 (Br),
f_s/(f_u+f_d)=0.160 +/- 0.005 (stat) +0.011-0.010 (sys) +0.057-0.034 (Br), and
f_{Lambda_b}/(f_u+f_d)=0.281\pm0.012 (stat) +0.058-0.056 (sys) +0.128-0.086
(Br), where the uncertainty (Br) is due to uncertainties on measured branching
ratios. The value of f_s/(f_u+f_d) agrees within one standard deviation with
previous CDF measurements and the world average of this quantity, which is
dominated by LEP measurements. However, the ratio f_{Lambda_b}/(f_u+f_d) is
approximately twice the value previously measured at LEP. The approximately 2
sigma discrepancy is examined in terms of kinematic differences between the two
production environments.Comment: Submitted to PRD, 54 pages, 53 plot
Two-Particle Momentum Correlations in Jets Produced in ppbar Collisions at s**(1/2) = 1.96-TeV
We present the first measurement of two-particle momentum correlations in
jets produced in collisions at TeV. Results are
obtained for charged particles within a restricted cone with an opening angle
of 0.5 radians around the jet axis and for events with dijet masses between 66
and 563 GeV/c. A comparison of the experimental data to theoretical
predictions obtained for partons within the framework of resummed perturbative
QCD in the next-to-leading log approximation (NLLA) shows that the parton
momentum correlations survive the hadronization stage of jet fragmentation,
giving further support to the hypothesis of local parton-hadron duality. The
extracted value of the NLLA parton shower cutoff scale set
equal to is found to be
MeV.Comment: Submitted to Phys.Rev.
Transverse sphericity of primary charged particles in minimum bias proton-proton collisions at , 2.76 and 7 TeV
Measurements of the sphericity of primary charged particles in minimum bias
proton--proton collisions at , 2.76 and 7 TeV with the ALICE
detector at the LHC are presented. The observable is linearized to be collinear
safe and is measured in the plane perpendicular to the beam direction using
primary charged tracks with GeV/c in . The
mean sphericity as a function of the charged particle multiplicity at
mid-rapidity () is reported for events with different
scales ("soft" and "hard") defined by the transverse momentum of the leading
particle. In addition, the mean charged particle transverse momentum versus
multiplicity is presented for the different event classes, and the sphericity
distributions in bins of multiplicity are presented. The data are compared with
calculations of standard Monte Carlo event generators. The transverse
sphericity is found to grow with multiplicity at all collision energies, with a
steeper rise at low , whereas the event generators show the
opposite tendency. The combined study of the sphericity and the mean with multiplicity indicates that most of the tested event generators
produce events with higher multiplicity by generating more back-to-back jets
resulting in decreased sphericity (and isotropy). The PYTHIA6 generator with
tune PERUGIA-2011 exhibits a noticeable improvement in describing the data,
compared to the other tested generators.Comment: 21 pages, 9 captioned figures, 3 tables, authors from page 16,
published version, figures from
http://aliceinfo.cern.ch/ArtSubmission/node/308
Measurement of in Collisions at TeV
We present the first observation of the baryon decay
followed by in 106 pb-1
of collisions at TeV in the CDF experiment. In
order to reduce systematic error, the measured rate for decay is
normalized to the kinematically similar meson decay followed
by . We report the ratio of production cross sections
() times the ratio of branching fractions (BR) for the momentum region
integrated above GeV/c and pseudorapidity range :
.Comment: Submitted to Phys.Rev.Let
Search for the standard model Higgs boson in the H to ZZ to 2l 2nu channel in pp collisions at sqrt(s) = 7 TeV
A search for the standard model Higgs boson in the H to ZZ to 2l 2nu decay
channel, where l = e or mu, in pp collisions at a center-of-mass energy of 7
TeV is presented. The data were collected at the LHC, with the CMS detector,
and correspond to an integrated luminosity of 4.6 inverse femtobarns. No
significant excess is observed above the background expectation, and upper
limits are set on the Higgs boson production cross section. The presence of the
standard model Higgs boson with a mass in the 270-440 GeV range is excluded at
95% confidence level.Comment: Submitted to JHE
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