The genetic architecture of the human cerebral cortex

The cerebral cortex underlies our complex cognitive capabilities, yet little is known about the specific genetic loci that influence human cortical structure. To identify genetic variants that affect cortical structure, we conducted a genome-wide association meta-analysis of brain magnetic resonance imaging data from 51,665 individuals. We analyzed the surface area and average thickness of the whole cortex and 34 regions with known functional specializations. We identified 199 significant loci and found significant enrichment for loci influencing total surface area within regulatory elements that are active during prenatal cortical development, supporting the radial unit hypothesis. Loci that affect regional surface area cluster near genes in Wnt signaling pathways, which influence progenitor expansion and areal identity. Variation in cortical structure is genetically correlated with cognitive function, Parkinson's disease, insomnia, depression, neuroticism, and attention deficit hyperactivity disorder

Search for gravitational-lensing signatures in the full third observing run of the LIGO-Virgo network

Gravitational lensing by massive objects along the line of sight to the source causes distortions of gravitational wave-signals; such distortions may reveal information about fundamental physics, cosmology and astrophysics. In this work, we have extended the search for lensing signatures to all binary black hole events from the third observing run of the LIGO--Virgo network. We search for repeated signals from strong lensing by 1) performing targeted searches for subthreshold signals, 2) calculating the degree of overlap amongst the intrinsic parameters and sky location of pairs of signals, 3) comparing the similarities of the spectrograms amongst pairs of signals, and 4) performing dual-signal Bayesian analysis that takes into account selection effects and astrophysical knowledge. We also search for distortions to the gravitational waveform caused by 1) frequency-independent phase shifts in strongly lensed images, and 2) frequency-dependent modulation of the amplitude and phase due to point masses. None of these searches yields significant evidence for lensing. Finally, we use the non-detection of gravitational-wave lensing to constrain the lensing rate based on the latest merger-rate estimates and the fraction of dark matter composed of compact objects

Search for eccentric black hole coalescences during the third observing run of LIGO and Virgo

Despite the growing number of confident binary black hole coalescences observed through gravitational waves so far, the astrophysical origin of these binaries remains uncertain. Orbital eccentricity is one of the clearest tracers of binary formation channels. Identifying binary eccentricity, however, remains challenging due to the limited availability of gravitational waveforms that include effects of eccentricity. Here, we present observational results for a waveform-independent search sensitive to eccentric black hole coalescences, covering the third observing run (O3) of the LIGO and Virgo detectors. We identified no new high-significance candidates beyond those that were already identified with searches focusing on quasi-circular binaries. We determine the sensitivity of our search to high-mass (total mass M>70 M⊙) binaries covering eccentricities up to 0.3 at 15 Hz orbital frequency, and use this to compare model predictions to search results. Assuming all detections are indeed quasi-circular, for our fiducial population model, we place an upper limit for the merger rate density of high-mass binaries with eccentricities 0<e≤0.3 at 0.33 Gpc−3 yr−1 at 90\% confidence level

Phonological awareness intervention and the acquisition of literacy skills in children from deprived social backgrounds

Purpose: This study examined the effect of phonological awareness intervention that focused on syllable and rhyme awareness on the acquisition of literacy and the development of phonological awareness skills 2 years post intervention. The longitudinal study compared two groups of children from deprived socioeconomic backgrounds in the United Kingdom. One group received a program of phonological awareness intervention and one did not. Method: Ninety-nine children received a 9-week program of phonological awareness intervention in the summer term of their final preschool year. These children were then assessed on measures of phonological awareness and language in the first term of their first year at school (M age = 4;7 [years;months]) and again 2 years later (M age = 6;8) on measures of phonological awareness and literacy. One year earlier, a control group of 114 children from the same schools were also assessed at these two points in their schooling on the same measures. This group did not receive any phonological awareness intervention. Results: At the second assessment, the group of children who received phonological awareness intervention performed better than those children who received no intervention (control group) on rhyme awareness and nonword spelling. Surprisingly, however, the control group performed better than the children who had received intervention on the phoneme segmentation task. Conclusion: The phonological awareness intervention that was implemented, which focused on enhancing syllable and rhyme awareness, had little effect on later literacy development and may have interfered with the acquisition of phoneme awareness. Implications for intervention with children from deprived socioeconomic backgrounds are discussed in the context of current research