Compressibility of molten Apollo 17 orange glass and implications for density crossovers in the lunar mantle

We performed density measurements on a synthetic equivalent of lunar Apollo 17 74,220 "orange glass", containing 9.1wt% Ti

Identification of common genetic risk variants for autism spectrum disorder

Autism spectrum disorder (ASD) is a highly heritable and heterogeneous group of neurodevelopmental phenotypes diagnosed in more than 1% of children. Common genetic variants contribute substantially to ASD susceptibility, but to date no individual variants have been robustly associated with ASD. With a marked sample-size increase from a unique Danish population resource, we report a genome-wide association meta-analysis of 18,381 individuals with ASD and 27,969 controls that identified five genome-wide-significant loci. Leveraging GWAS results from three phenotypes with significantly overlapping genetic architectures (schizophrenia, major depression, and educational attainment), we identified seven additional loci shared with other traits at equally strict significance levels. Dissecting the polygenic architecture, we found both quantitative and qualitative polygenic heterogeneity across ASD subtypes. These results highlight biological insights, particularly relating to neuronal function and corticogenesis, and establish that GWAS performed at scale will be much more productive in the near term in ASD.Peer reviewe

A complex history of silicate differentiation of Mars from Nd and Hf isotopes in crustal breccia NWA 7034

Resolving the possible mantle and crustal sources for shergottite meteorites is crucial for understanding the formation and early differentiation of Mars. Orbiter and rover characterization of the martian surface reveal that the major element composition of most of its surface does not match the shergottites (McSween et al. 2009) leaving the relationship between them poorly understood. The identification of the meteorite NWA 7034 and its pairs as a Mars surface rock (Cartwright et al. 2014) provides access to a representative sample of Mars' crust (Agee et al. 2013; Humayun et al. 2013). Utilizing the short-lived 146Sm–142Nd, and long-lived 147Sm–143Nd and 176Lu–176Hf chronometers, which are sensitive to silicate differentiation, we analyzed three fragments of NWA 7034. The very negative mean isotopic compositions for this breccia, μ142NdJNdi-1=−45±5 (2SD), ε143NdCHUR=−16.7±0.4 (2SD) and ε176HfCHUR=−61±9 (2SD) point to an ancient origin for this martian crust. However, modeling of the data shows that the crust sampled by NWA 7034 possesses a Hf/Nd ratio and coupled ε143Nd–μ142Nd model age that are incompatible with this crustal reservoir being an end-member that generated the shergottite source mixing array. In addition, this crust is not juvenile, despite its rare earth element profile, but has had a multistage formation history. Therefore, early crustal extraction alone was not responsible for the creation of the reservoirs that produced the shergottites. Instead mantle reservoirs formed via other early differentiation processes such as in a Mars magma ocean must be responsible for the trace element and isotopic signatures present in shergottites.SCOPUS: ar.jinfo:eu-repo/semantics/publishe

Gamma-ray transitions induced in nuclear spin isomers by X-rays

Because of the high density of energy storage and the large cross section for its release there is considerable significance of the triggering of induced gamma emission from nuclear spin isomers to efforts to develop intense sources of short-wavelength radiation. The work reported here describes the current experimental focus and results recently obtained