803 research outputs found

    Access to consciousness of briefly presented visual events is modulated by transcranial direct current stimulation of left dorsolateral prefrontal cortex

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    Adaptive behaviour requires the ability to process goal-relevant events at the expense of irrelevant ones. However, perception of a relevant visual event can transiently preclude access to consciousness of subsequent events — a phenomenon called attentional blink (AB). Here we investigated involvement of the left dorsolateral prefrontal cortex (DLPFC) in conscious access, by using transcranial direct current stimulation (tDCS) to potentiate or reduce neural excitability in the context of an AB task. In a sham-controlled experimental design, we applied between groups anodal or cathodal tDCS over the left DLPFC, and examined whether this stimulation modulated the proportion of stimuli that were consciously reported during the AB period. We found that tDCS over the left DLPFC affected the proportion of consciously perceived target stimuli. Moreover, anodal and cathodal tDCS had opposing effects, and exhibited different temporal patterns. Anodal stimulation attenuated the AB, enhancing conscious report earlier in the AB period. Cathodal stimulation accentuated the AB, reducing conscious report later in the AB period. These findings support the notion that the DLPFC plays a role in facilitating information transition from the unconscious to the conscious stage of processing

    DW Cancri in x-rays

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    We report on the XMMXMM-Newton observation of DW Cnc, a candidate intermediate polar candidate whose historical optical light curve shows the existence of periods at ≃38\simeq 38, ≃86\simeq 86 and ≃69\simeq 69 minutes which were interpreted as the white dwarf spin, the orbital and the spin-orbit beat periodicities. By studying the 0.3−100.3-10 keV light curves, we confirm the existence of a period at ≃38\simeq 38 minutes and find in the OM light curve a signature for a period at 75±2175\pm 21 minutes which is consistent with both the orbital and spin-orbit beat. { These findings allow us to unveil without any doubt, the nature of DW Cnc as an accreting intermediate polar. The EPIC and RGS source spectra were analyzed and a best fit model, consisting of a multi-temperature plasma, was found. The maximum temperature found when fitting the data is kTmax≃31kT_{max}\simeq 31 keV which can be interpreted as an upper limit to the temperature of the shock.Comment: 2019. Accepted for publication on MNRAS. 5 figures, 1 table. Updated as, by mistake, an author affiliation was missing from the lis

    A systematic review of genetic polymorphisms associated with binge eating disorder

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    The genetic polymorphisms involved in the physiopathology of binge eating disorder (BED) are currently unclear. This systematic review aims to highlight and summarize the research on polymorphisms that is conducted in the BED. We looked for observational studies where there was a genetic comparison between adults with BED, in some cases also with obesity or overweight, and healthy controls or obesity/overweight without BED. Our protocol was written using PRISMA. It is registered at PROSPERO (identification: CRD42020198645). To identify potentially relevant documents, the following bibliographic databases were searched without a time limit, but until September 2020: PubMed, PsycINFO, Scopus, and Web of Science. In total, 21 articles were included in the qualitative analysis of the systematic review, as they met the eligibility criteria. Within the selected studies, 41 polymorphisms of 17 genes were assessed. Overall, this systematic review provides a list of potentially useful genetic polymorphisms involved in BED: 5-HTTLPR (5-HTT), Taq1A (ANKK1/DRD2), A118G (OPRM1), C957T (DRD2), rs2283265 (DRD2), Val158Met (COMT), rs6198 (GR), Val103Ile (MC4R), Ile251Leu (MC4R), rs6265 (BNDF), and Leu72Met (GHRL). It is important to emphasize that Taq1A is the polymorphism that showed, in two different research groups, the most significant association with BED. The remaining polymorphisms need further evidence to be confirmed

    Large Spatial Scale Variability in Bathyal Macrobenthos Abundance, Biomass, a- and b-Diversity along the Mediterranean Continental Margin

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    The large-scale deep-sea biodiversity distribution of the benthic fauna was explored in the Mediterranean Sea, which can beseen as a miniature model of the oceans of the world. Within the framework of the BIOFUN project (‘‘Biodiversity andEcosystem Functioning in Contrasting Southern European Deep-sea Environments: from viruses to megafauna’’), weinvestigated the large spatial scale variability (over .1,000 km) of the bathyal macrofauna communities that inhabit theMediterranean basin, and their relationships with the environmental variables. The macrofauna abundance, biomass,community structure and functional diversity were analysed and the a-diversity and b-diversity were estimated across sixselected slope areas at different longitudes and along three main depths. The macrobenthic standing stock and a-diversitywere lower in the deep-sea sediments of the eastern Mediterranean basin, compared to the western and central basins. Themacrofaunal standing stock and diversity decreased significantly from the upper bathyal to the lower bathyal slope stations.The major changes in the community composition of the higher taxa and in the trophic (functional) structure occurred atdifferent longitudes, rather than at increasing water depth. For the b-diversity, very high dissimilarities emerged at all levels:(i) between basins; (ii) between slopes within the same basin; and (iii) between stations at different depths; this thereforedemonstrates the high macrofaunal diversity of the Mediterranean basins at large spatial scales. Overall, the food sources(i.e., quantity and quality) that characterised the west, central and eastern Mediterranean basins, as well as sediment grainsize, appear to influence the macrobenthic standing stock and the biodiversity along the different slope areas

    Comparison of absolute gain photometric calibration between Planck/HFI and Herschel/SPIRE at 545 and 857 GHz

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    We compare the absolute gain photometric calibration of the Planck/HFI and Herschel/SPIRE instruments on diffuse emission. The absolute calibration of HFI and SPIRE each relies on planet flux measurements and comparison with theoretical far-infrared emission models of planetary atmospheres. We measure the photometric cross calibration between the instruments at two overlapping bands, 545 GHz / 500 Ό\mum and 857 GHz / 350 Ό\mum. The SPIRE maps used have been processed in the Herschel Interactive Processing Environment (Version 12) and the HFI data are from the 2015 Public Data Release 2. For our study we used 15 large fields observed with SPIRE, which cover a total of about 120 deg^2. We have selected these fields carefully to provide high signal-to-noise ratio, avoid residual systematics in the SPIRE maps, and span a wide range of surface brightness. The HFI maps are bandpass-corrected to match the emission observed by the SPIRE bandpasses. The SPIRE maps are convolved to match the HFI beam and put on a common pixel grid. We measure the cross-calibration relative gain between the instruments using two methods in each field, pixel-to-pixel correlation and angular power spectrum measurements. The SPIRE / HFI relative gains are 1.047 (±\pm 0.0069) and 1.003 (±\pm 0.0080) at 545 and 857 GHz, respectively, indicating very good agreement between the instruments. These relative gains deviate from unity by much less than the uncertainty of the absolute extended emission calibration, which is about 6.4% and 9.5% for HFI and SPIRE, respectively, but the deviations are comparable to the values 1.4% and 5.5% for HFI and SPIRE if the uncertainty from models of the common calibrator can be discounted. Of the 5.5% uncertainty for SPIRE, 4% arises from the uncertainty of the effective beam solid angle, which impacts the adopted SPIRE point source to extended source unit conversion factor (Abridged)Comment: 13 pages, 10 figures; Incorporates revisions in response to referee comments; cross calibration factors unchange

    Correcting the extended-source calibration for the <i>Herschel</i>-SPIRE Fourier-transform spectrometer

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    We describe an update to the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) Fourier-transform spectrometer (FTS) calibration for extended sources, which incorporates a correction for the frequency-dependent far-field feedhorn efficiency, ηff. This significant correction affects all FTS extended-source calibrated spectra in sparse or mapping mode, regardless of the spectral resolution. Line fluxes and continuum levels are underestimated by factors of 1.3–2 in thespectrometer long wavelength band (447–1018 GHz; 671–294 ÎŒm) and 1.4–1.5 in the spectrometer short wavelength band (944–1568 GHz; 318–191 ÎŒm). The correction was implemented in the FTS pipeline version 14.1 and has also been described in the SPIRE Handbook since 2017 February. Studies based on extended-source calibrated spectra produced prior to this pipeline version should be critically reconsidered using the current products available in the Herschel Science Archive. Once the extended-source calibrated spectra are corrected for ηff, the synthetic photometry and the broad-band intensities from SPIRE photometer maps agree within 2–4 per cent – similar levels to the comparison of point-source calibrated spectra and photometry from point-source calibrated maps. The two calibration schemes for the FTS are now self-consistent: the conversion between the corrected extended-source and point-source calibrated spectra can be achieved with the beam solid angle and a gain correction that accounts for the diffraction loss

    Low-resolution spectroscopy of the Sunyaev-Zel'dovich effect and estimates of cluster parameters

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    The Sunyaev-Zel'dovich (SZ) effect is a powerful tool for studying clusters of galaxies and cosmology. Large mm-wave telescopes are now routinely detecting and mapping the SZ effect in a number of clusters, measure their comptonisation parameter and use them as probes of the large-scale structure and evolution of the universe. We show that estimates of the physical parameters of clusters (optical depth, plasma temperature, peculiar velocity, non-thermal components etc.) obtained from ground-based multi-band SZ photometry can be significantly biased, owing to the reduced frequency coverage, to the degeneracy between the parameters and to the presence of a number of independent components larger than the number of frequencies measured. We demonstrate that low-resolution spectroscopic measurements of the SZ effect that also cover frequencies >270> 270 GHz are effective in removing the degeneracy. We used accurate simulations of observations with lines-of-sight through clusters of galaxies with different experimental configurations (4-band photometers, 6-band photometer, multi-range differential spectrometer, full coverage spectrometers) and different intracluster plasma stratifications. We find that measurements carried out with ground-based few-band photometers are biased towards high electron temperatures and low optical depths, and require coverage of high frequency and/or independent complementary observations to produce unbiased information; a differential spectrometer that covers 4 bands with a resolution of $\sim 6 \ GHz$ eliminates most if not all bias; full-range differential spectrometers are the ultimate resource that allows a full recovery of all parameters.Comment: in pres
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