74 research outputs found

    Early maternal deprivation immunologically primes hippocampal synapses by redistributing interleukin-1 receptor type I in a sex dependent manner

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    Challenges experienced in early life cause an enduring phenotypical shift of immune cells towards a sensitised state that may lead to an exacerbated reaction later in life and contribute to increased vulnerability to neurological diseases. Peripheral and central inflammation may affect neuronal function through cytokines such as IL-1. The extent to which an early life challenge induces long-term alteration of immune receptors organization in neurons has not been shown. We investigated whether a single episode of maternal deprivation (MD) on post-natal day (PND) 9 affects: (i) the synapse distribution of IL-1RI together with subunits of NMDA and AMPA receptors; and (ii) the interactions between IL-1RI and the GluN2B subunit of the NMDAR in the long-term, at PND 45. MD increased IL-1RI levels and IL-1RI interactions with GluN2B at the synapse of male hippocampal neurons, without affecting the total number of IL-1RI or NMDAR subunits. Although GluN2B and GluN2A were slightly but not significantly changed at the synapse, their ratio was significantly decreased in the hippocampus of the male rats who had experienced MD; the levels of the GluA1 and GluA2 subunits of the AMPAR were also decreased. These changes were not observed immediately after the MD episode. None of the observed alterations occurred in the hippocampus of the females or in the prefrontal cortex of either sex. These data reveal a long-term, sex-dependent modification in receptor organisation at the hippocampal post-synapses following MD. We suggest that this effect might contribute to priming hippocampal synapses to the action of IL-1\u3b2

    Space Telescope and Optical Reverberation Mapping Project. VII. Understanding the Ultraviolet Anomaly in NGC 5548 with X-Ray Spectroscopy

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    During the Space Telescope and Optical Reverberation Mapping Project observations of NGC 5548, the continuum and emission-line variability became decorrelated during the second half of the six-month-long observing campaign. Here we present Swift and Chandra X-ray spectra of NGC 5548 obtained as part of the campaign. The Swift spectra show that excess flux (relative to a power-law continuum) in the soft X-ray band appears before the start of the anomalous emission-line behavior, peaks during the period of the anomaly, and then declines. This is a model-independent result suggesting that the soft excess is related to the anomaly. We divide the Swift data into on- and off-anomaly spectra to characterize the soft excess via spectral fitting. The cause of the spectral differences is likely due to a change in the intrinsic spectrum rather than to variable obscuration or partial covering. The Chandra spectra have lower signal-to-noise ratios, but are consistent with the Swift data. Our preferred model of the soft excess is emission from an optically thick, warm Comptonizing corona, the effective optical depth of which increases during the anomaly. This model simultaneously explains all three observations: the UV emission-line flux decrease, the soft-excess increase, and the emission-line anomaly

    Characterisation of <i>Herschel</i>-selected strong lens candidates through <i>HST</i> and sub-mm/mm observations

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    We have carried out HST snapshot observations at 1.1 μm of 281 candidate strongly lensed galaxies identified in the wide-area extragalactic surveys conducted with the Herschel space observatory. Our candidates comprise systems with flux densities at 500 μm S500 ≥ 80 mJy. We model and subtract the surface brightness distribution for 130 systems, where we identify a candidate for the foreground lens candidate. After combining visual inspection, archival high-resolution observations, and lens subtraction, we divide the systems into different classes according to their lensing likelihood. We confirm 65 systems to be lensed. Of these, 30 are new discoveries. We successfully perform lens modelling and source reconstruction on 23 systems, where the foreground lenses are isolated galaxies and the background sources are detected in the HST images. All the systems are successfully modelled as a singular isothermal ellipsoid. The Einstein radii of the lenses and the magnifications of the background sources are consistent with previous studies. However, the background source circularised radii (between 0.34 kpc and 1.30 kpc) are ∼3 times smaller than the ones measured in the sub-mm/mm for a similarly selected and partially overlapping sample. We compare our lenses with those in the SLACS survey, confirming that our lens-independent selection is more effective at picking up fainter and diffuse galaxies and group lenses. This sample represents the first step towards characterising the near-IR properties and stellar masses of the gravitationally lensed dusty star-forming galaxies

    The Influence of Number and Timing of Pregnancies on Breast Cancer Risk for Women With BRCA1 or BRCA2 Mutations

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    Background: Full-term pregnancy (FTP) is associated with a reduced breast cancer (BC) risk over time, but women are at increased BC risk in the immediate years following an FTP. No large prospective studies, however, have examined whether the number and timing of pregnancies are associated with BC risk for BRCA1 and BRCA2 mutation carriers. Methods: Using weighted and time-varying Cox proportional hazards models, we investigated whether reproductive events are associated with BC risk for mutation carriers using a retrospective cohort (5707 BRCA1 and 3525 BRCA2 mutation carriers) and a prospective cohort (2276 BRCA1 and 1610 BRCA2 mutation carriers), separately for each cohort and the combined prospective and retrospective cohort. Results: For BRCA1 mutation carriers, there was no overall association with parity compared with nulliparity (combined hazard ratio [HRc] ¼ 0.99, 95% confidence interval [CI] ¼ 0.83 to 1.18). Relative to being uniparous, an increased number of FTPs was associated with decreased BC risk (HRc¼ 0.79, 95% CI ¼ 0.69 to 0.91; HRc¼ 0.70, 95% CI ¼ 0.59 to 0.82; HRc¼ 0.50, 95% CI ¼ 0.40 to 0.63, for 2, 3, and 4 FTPs, respectively, Ptrend < .0001) and increasing duration of breastfeeding was associated with decreased BC risk (combined cohort Ptrend ¼ .0003). Relative to being nulliparous, uniparous BRCA1 mutation carriers were at increased BC risk in the prospective analysis (prospective hazard ration [HRp] ¼ 1.69, 95% CI ¼ 1.09 to 2.62). For BRCA2 mutation carriers, being parous was associated with a 30% increase in BC risk (HRc ¼ 1.33, 95% CI ¼ 1.05 to 1.69), and there was no apparent decrease in risk associated with multiparity except for having at least 4 FTPs vs. 1 FTP (HRc¼ 0.72, 95% CI ¼ 0.54 to 0.98). Conclusions: These findings suggest differential associations with parity between BRCA1 and BRCA2 mutation carriers with higher risk for uniparous BRCA1 carriers and parous BRCA2 carriers

    The intrinsic shape and dynamical structure of the bulges of lenticular galaxies

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    This work was supported by Padua University through grants 60A02-5052/11, 60A02-4807/12, 60A02-5857/13, and CPDA133894. J.M.A. acknowledges support from the European Research Council Starting Grant (SEDmorph; P.I. V. Wild). L.M. received financial support from Padua University grant CPS0204.Several scenarios have been proposed to account for the formation and evolution of galactic bulges and to explain the variety of their observed properties. Both the intrinsic shape and dynamical structure of bulges depend on the mechanisms and timescales of their formation. We are deriving the intrinsic axial ratios of the bulges of a sample of unbarred lenticular galaxies to look for a possible relationship with their known orbital structure. Preliminary results show that the orbits of stars of the triaxial bulge of NGC 4476 are more anisotropic than those in the axisymmetric bulge of NGC 4249 hinting at a different formation process.Publisher PDFPeer reviewe
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