111 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, 18â25,
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
A bright, high rotation-measure FRB that skewers the M33 halo
We report the detection of a bright fast radio burst, FRB\,191108, with
Apertif on the Westerbork Synthesis Radio Telescope (WSRT). The interferometer
allows us to localise the FRB to a narrow 5\arcsec\times7\arcmin ellipse by
employing both multibeam information within the Apertif phased-array feed (PAF)
beam pattern, and across different tied-array beams. The resulting sight line
passes close to Local Group galaxy M33, with an impact parameter of only
18\,kpc with respect to the core. It also traverses the much larger
circumgalactic medium of M31, the Andromeda Galaxy. We find that the shared
plasma of the Local Group galaxies could contribute 10\% of its
dispersion measure of 588\,pc\,cm. FRB\,191108 has a Faraday rotation
measure of +474\,\,rad\,m, which is too large to be explained by
either the Milky Way or the intergalactic medium. Based on the more moderate
RMs of other extragalactic sources that traverse the halo of M33, we conclude
that the dense magnetised plasma resides in the host galaxy. The FRB exhibits
frequency structure on two scales, one that is consistent with quenched
Galactic scintillation and broader spectral structure with
\,MHz. If the latter is due to scattering in the shared
M33/M31 CGM, our results constrain the Local Group plasma environment. We found
no accompanying persistent radio sources in the Apertif imaging survey data
Representational predicaments for employees: Their impact on perceptions of supervisors\u27 individualized consideration and on employee job satisfaction
A representational predicament for a subordinate vis-à -vis his or her immediate superior involves perceptual incongruence with the superior about the subordinate\u27s work or work context, with unfavourable implications for the employee. An instrument to measure the incidence of two types of representational predicament, being neglected and negative slanting, was developed and then validated through an initial survey of 327 employees. A subsequent substantive survey with a fresh sample of 330 employees largely supported a conceptual model linking being neglected and negative slanting to perceptions of low individualized consideration by superiors and to low overall job satisfaction. The respondents in both surveys were all Hong Kong Chinese. Two case examples drawn from qualitative interviews illustrate and support the conceptual model. Based on the research findings, we recommend some practical exercises to use in training interventions with leaders and subordinates. © 2013 Copyright Taylor and Francis Group, LLC
Measurement of CP observables in B± â D(â)K± and B± â D(â)ϱ decays
Measurements of CP observables in B ± âD (â) K ± and B ± âD (â) Ï Â± decays are presented, where D (â) indicates a neutral D or D â meson that is an admixture of D (â)0 and DÂŻ (â)0 states. Decays of the D â meson to the DÏ 0 and DÎł final states are partially reconstructed without inclusion of the neutral pion or photon, resulting in distinctive shapes in the B candidate invariant mass distribution. Decays of the D meson are fully reconstructed in the K ± Ï â , K + K â and Ï + Ï â final states. The analysis uses a sample of charged B mesons produced in pp collisions collected by the LHCb experiment, corresponding to an integrated luminosity of 2.0, 1.0 and 2.0 fb â1 taken at centre-of-mass energies of s=7, 8 and 13 TeV, respectively. The study of B ± âD â K ± and B ± âD â Ï Â± decays using a partial reconstruction method is the first of its kind, while the measurement of B ± âDK ± and B ± âDÏ Â± decays is an update of previous LHCb measurements. The B ± âDK ± results are the most precise to date
First observation of forward production in collisions at TeV
The decay ZâbbÂŻ is reconstructed in pp collision data, corresponding to 2 fb â1 of integrated luminosity, collected by the LHCb experiment at a centre-of-mass energy of s=8 TeV. The product of the Z production cross-section and the ZâbbÂŻ branching fraction is measured for candidates in the fiducial region defined by two particle-level b -quark jets with pseudorapidities in the range 2.220 GeV and dijet invariant mass in the range 452045 < m_{jj} < 1655462 \pm 763Z \rightarrow b \bar{b}332 \pm 46 \pm 59Z \rightarrow b \bar{b}pp$ collisions
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