803 research outputs found
Access to consciousness of briefly presented visual events is modulated by transcranial direct current stimulation of left dorsolateral prefrontal cortex
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 â 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
We report on the -Newton observation of DW Cnc, a candidate intermediate
polar candidate whose historical optical light curve shows the existence of
periods at , and minutes which were
interpreted as the white dwarf spin, the orbital and the spin-orbit beat
periodicities. By studying the keV light curves, we confirm the
existence of a period at minutes and find in the OM light curve a
signature for a period at 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 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
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
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 (ââBiodiversity andEcosystem Functioning in Contrasting Southern European Deep-sea Environments: from viruses to megafaunaââ), 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
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 m and 857 GHz / 350 m. 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 ( 0.0069) and 1.003 ( 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
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 1.3â2 in thespectrometer long wavelength band (447â1018 GHz; 671â294 ÎŒm) and 1.4â1.5 in the spectrometer short wavelength band (944â1568 GHz; 318â191 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 2â4âperâcent â 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
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
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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