225 research outputs found
Organophosphate pesticides exposure in pregnant women and maternal and cord blood thyroid hormone concentrations
Background: Animal studies suggest that organophosphate (OP) pesticides exposure affects thyroid function, but
evidence in humans remains sparse and inconclusive. Gestational exposure is of particular interest, since thyroid
hormone is essential for fetal brain development. OP pesticides are able to cross the placental and blood-brain
barrier and may interfere with fetal development processes regulated by thyroid hormone.
Objective: To investigate the association of gestational OP pesticides exposure during pregnancy with maternal
and cord blood thyroid hormone concentrations.
Methods: This study was embedded within Generation R (Rotterdam, the Netherlands), a prospective population-based birth cohort. Mother-child pairs with OP pesticides assessment and maternal (N = 715) or cord blood
(N = 482) thyroid hormone measurements were included. OP pesticides exposure was assessed at < 18, 18–25,
and > 25 weeks gestation by measuring six urinary dialkylphosphate (DAP) metabolites. Thyroid stimulating
hormone (TSH) and free thyroxine (FT4) were measured in maternal and cord blood. Maternal measures also
included total thyroxine (TT4) and TPO antibodies (TPOAbs). To study the association of creatinine-adjusted
DAP metabolite concentrations with thyroid function and TPO antibodies, multivariable linear regression
models including relevant confounders were used.
Results: There was no association of DAP metabolites with maternal TSH, FT4, TT4 or TPOAb concentrations
during pregnancy. Similarly, there was no association of DAP metabolites with cord blood TSH or FT4. Results
did not change when DAP concentrations were analyzed at individual time points or as mean gestational exposure.
Conclusion: Gestational OP pesticides exposure, as assessed by repeatedly measured urinary DAP metabolite
concentrations in an urban population, was not associated with maternal or cord blood t
Observation of a Narrow Resonance of Mass 2.46 GeV/c^2 Decaying to D_s^*+ pi^0 and Confirmation of the D_sJ^* (2317) State
Using 13.5 inverse fb of e+e- annihilation data collected with the CLEO II
detector we have observed a narrow resonance in the Ds*+pi0 final state, with a
mass near 2.46 GeV. The search for such a state was motivated by the recent
discovery by the BaBar Collaboration of a narrow state at 2.32 GeV, the
DsJ*(2317)+ that decays to Ds+pi0. Reconstructing the Ds+pi0 and Ds*+pi0 final
states in CLEO data, we observe peaks in both of the corresponding
reconstructed mass difference distributions, dM(Dspi0)=M(Dspi0)-M(Ds) and
dM(Ds*pi0)=M(Ds*pi0)-M(Ds*), both of them at values near 350 MeV. We interpret
these peaks as signatures of two distinct states, the DsJ*(2317)+ plus a new
state, designated as the DsJ(2463)+. Because of the similar dM values, each of
these states represents a source of background for the other if photons are
lost, ignored or added. A quantitative accounting of these reflections confirms
that both states exist. We have measured the mean mass differences
= 350.0 +/- 1.2 [stat] +/- 1.0 [syst] MeV for the DsJ*(2317) state, and
= 351.2 +/- 1.7 [stat] +/- 1.0 [syst] MeV for the new DsJ(2463)+
state. We have also searched, but find no evidence, for decays of the two
states via the channels Ds*+gamma, Ds+gamma, and Ds+pi+pi-. The observations of
the two states at 2.32 and 2.46 GeV, in the Ds+pi0 and Ds*+pi0 decay channels
respectively, are consistent with their interpretations as (c anti-strange)
mesons with orbital angular momentum L=1, and spin-parities of 0+ and 1+.Comment: 16 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, version to be published in Physical
Review D; minor modifications and fixes to typographical errors, plus an
added section on production properties. The main results are unchanged; they
supersede those reported in hep-ex/030501
SARS-CoV Antibody Prevalence in All Hong Kong Patient Contacts
A total of 1,068 asymptomatic close contacts of patients with severe acute respiratory (SARS) from the 2003 epidemic in Hong Kong were serologically tested, and 2 (0.19%) were positive for SARS coronavirus immunoglobulin G antibody. SARS rarely manifests as a subclinical infection, and at present, wild animal species are the only important natural reservoirs of the virus
Study of the q^2-Dependence of B --> pi ell nu and B --> rho(omega)ell nu Decay and Extraction of |V_ub|
We report on determinations of |Vub| resulting from studies of the branching
fraction and q^2 distributions in exclusive semileptonic B decays that proceed
via the b->u transition. Our data set consists of the 9.7x10^6 BBbar meson
pairs collected at the Y(4S) resonance with the CLEO II detector. We measure
B(B0 -> pi- l+ nu) = (1.33 +- 0.18 +- 0.11 +- 0.01 +- 0.07)x10^{-4} and B(B0 ->
rho- l+ nu) = (2.17 +- 0.34 +0.47/-0.54 +- 0.41 +- 0.01)x10^{-4}, where the
errors are statistical, experimental systematic, systematic due to residual
form-factor uncertainties in the signal, and systematic due to residual
form-factor uncertainties in the cross-feed modes, respectively. We also find
B(B+ -> eta l+ nu) = (0.84 +- 0.31 +- 0.16 +- 0.09)x10^{-4}, consistent with
what is expected from the B -> pi l nu mode and quark model symmetries. We
extract |Vub| using Light-Cone Sum Rules (LCSR) for 0<= q^2<16 GeV^2 and
Lattice QCD (LQCD) for 16 GeV^2 <= q^2 < q^2_max. Combining both intervals
yields |Vub| = (3.24 +- 0.22 +- 0.13 +0.55/-0.39 +- 0.09)x10^{-3}$ for pi l nu,
and |Vub| = (3.00 +- 0.21 +0.29/-0.35 +0.49/-0.38 +-0.28)x10^{-3} for rho l nu,
where the errors are statistical, experimental systematic, theoretical, and
signal form-factor shape, respectively. Our combined value from both decay
modes is |Vub| = (3.17 +- 0.17 +0.16/-0.17 +0.53/-0.39 +-0.03)x10^{-3}.Comment: 45 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Measurement of the Charge Asymmetry in
We report on a search for a CP-violating asymmetry in the charmless hadronic
decay B -> K*(892)+- pi-+, using 9.12 fb^-1 of integrated luminosity produced
at \sqrt{s}=10.58 GeV and collected with the CLEO detector. We find A_{CP}(B ->
K*(892)+- pi-+) = 0.26+0.33-0.34(stat.)+0.10-0.08(syst.), giving an allowed
interval of [-0.31,0.78] at the 90% confidence level.Comment: 7 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Search for CP Violation in D^0--> K_S^0 pi^+pi^-
We report on a search for CP violation in the decay of D0 and D0B to Kshort
pi+pi-. The data come from an integrated luminosity of 9.0 1/fb of e+e-
collisions at sqrt(s) ~ 10 GeV recorded with the CLEO II.V detector. The
resonance substructure of this decay is well described by ten quasi-two-body
decay channels (K*-pi+, K*0(1430)-pi+, K*2(1430)-pi+, K*(1680)-pi+, Kshort rho,
Kshort omega, Kshort f0(980), Kshort f2(1270), Kshort f0(1370), and the ``wrong
sign'' K*+ pi-) plus a small non-resonant component. We observe no evidence for
CP violation in the amplitudes and phases that describe the decay D0 to K_S^0
pi+pi-.Comment: 10 pages, 3 figures, also available at
http://w4.lns.cornell.edu/public/CLNS/, submitted to PR
Measurement of Lepton Momentum Moments in the Decay bar{B} \to X \ell \bar{\nu} and Determination of Heavy Quark Expansion Parameters and |V_cb|
We measure the primary lepton momentum spectrum in B-bar to X l nu decays,
for p_l > 1.5 GeV/c in the B rest frame. From this, we calculate various
moments of the spectrum. In particular, we find R_0 = [int(E_l>1.7)
(dGam/dE_sl)*dE_l] / [int(E_l>1.5) (dGam/dE_sl)*dE_l] = 0.6187 +/- 0.0014_stat
+/- 0.0016_sys and R_1 = [int(E_l>1.5) E_l(dGam/dE_sl)*dE_l] / [int(E_l>1.5)
(dGam/dE_sl)*dE_l] = (1.7810 +/- 0.0007_stat +/- 0.0009_sys) GeV. We use these
moments to determine non-perturbative parameters governing the semileptonic
width. In particular, we extract the Heavy Quark Expansion parameters
Lambda-bar = (0.39 +/- 0.03_stat +/- 0.06_sys +/- 0.12_th) GeV and lambda_1 =
(-0.25 +/- 0.02_stat +/- 0.05_sys +/- 0.14_th) GeV^2. The theoretical
constraints used are evaluated through order 1/M_B^3 in the non-perturbative
expansion and beta_0*alpha__s^2 in the perturbative expansion. We use these
parameters to extract |V_cb| from the world average of the semileptonic width
and find |V_cb| = (40.8 +/- 0.5_Gam-sl +/- 0.4_(lambda_1,Lambda-bar)-exp +/-
0.9_th) x 10^-3. In addition, we extract the short range b-quark mass m_b^1S =
(4.82 +/- 0.07_exp +/- 0.11_th) GeV/c^2. Finally, we discuss the implications
of our measurements for the theoretical understanding of inclusive semileptonic
processes.Comment: 21 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, submitted to PR
Anti-Search for the Glueball Candidate f_J(2220) in Two-Photon Interactions
Using 13.3 fb^{-1} of e^+e^- data recorded with the CLEO II and CLEO II.V
detector configurations at CESR, we have searched for f_J(2220) decays to
K^0_{S} K^0_{S} in untagged two-photon interactions. We report an upper limit
on the product of the two-photon partial width and the branching fraction,
Gamma_gamma gamma cdot B (f_J(2220) to K^0_{S} K^0_{S}) of less than 1.1 eV at
the 95% C.L: systematic uncertainties are included. This dataset is four times
larger than that used in the previous CLEO publication.Comment: 10 pages postscript, also available through
http://w4.lns.cornell.edu/public/CLNS, Submitted to PRD (R
A Reverse Logistics Network Model for Handling Returned Products
58827Due to the emergence of e-commerce and the proliferation of liberal return policies, product returns have become daily routines for many companies. Considering the significant impact of product returns on the company’s bottom line, a growing number of
companies have attempted to streamline the reverse logistics process. Products are usually returned to initial collection points (ICPs) in small quantities and thus increase the unit shipping cost due to lack of freight discount opportunities. One way to address this issue is to aggregate the returned products into a larger shipment. However, such aggregation increases the
holding time at the ICP, which in turn increases the inventory carrying costs. Considering this logistics dilemma, the main objectives of this research are to minimize the total cost by determining the optimal location and collection period of holding time of ICPs; determining the optimal location of a centralized return centre; transforming the nonlinear objective function of the proposed model formulation by Min et al. (2006a) into a linear form; and conducting a sensitivity analysis to the model solutions according to varying parameters such as shipping volume. Existing models and solution procedures are too complicated to solve real-world problems. Through a series of computational experiments, we discovered that the linearization model obtained the optimal solution at a fraction of the time used by the traditional nonlinear model and solution procedure, as well as the ability to handle up to 150 customers as compared to 30 in the conventional nonlinear model. As such, the proposed linear model is
more suitable for actual industry applications than the existing models.S
First Observation of a Upsilon(1D) State
We present the first evidence for the production of Upsilon(1D) states in the
four-photon cascade, Upsilon(3S)-->gamma chib(2P), chib(2P)-->gamma
Upsilon(1D), Upsilon(1D)-->gamma chib(1P), chib(1P)-->gamma Upsilon(1S),
followed by the Upsilon(1S) annihilation into e+e- or mu+mu-. The signal has a
significance of 10.2 standard deviations. The measured product branching ratio
for these five decays, (2.5+-0.5+-0.5)x10^(-5), is consistent with the
theoretical estimates. The data are dominated by the production of one
Upsilon(1D) state consistent with the J=2 assignment. Its mass is determined to
be (10161.1+-0.6+-1.6) MeV, which is consistent with the predictions from
potential models and lattice QCD calculations.
We also searched for Upsilon(3S)-->gammachib(2P),
chib(2P)-->gammaUpsilon(1D), followed by either Upsilon(1D)-->eta Upsilon(1S)
or Upsilon(1D)-->pi+pi- Upsilon(1S). We find no evidence for such decays and
set upper limits on the product branching ratios.Comment: 12 pages postscript,also available through this
http://w4.lns.cornell.edu/public/CLNS/, submitted to PR
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