Common Genetic Variation And Age at Onset Of Anorexia Nervosa

Background Genetics and biology may influence the age at onset of anorexia nervosa (AN). The aims of this study were to determine whether common genetic variation contributes to AN age at onset and to investigate the genetic associations between age at onset of AN and age at menarche. Methods A secondary analysis of the Psychiatric Genomics Consortium genome-wide association study (GWAS) of AN was performed which included 9,335 cases and 31,981 screened controls, all from European ancestries. We conducted GWASs of age at onset, early-onset AN (< 13 years), and typical-onset AN, and genetic correlation, genetic risk score, and Mendelian randomization analyses. Results Two loci were genome-wide significant in the typical-onset AN GWAS. Heritability estimates (SNP-h2) were 0.01-0.04 for age at onset, 0.16-0.25 for early-onset AN, and 0.17-0.25 for typical-onset AN. Early- and typical-onset AN showed distinct genetic correlation patterns with putative risk factors for AN. Specifically, early-onset AN was significantly genetically correlated with younger age at menarche, and typical-onset AN was significantly negatively genetically correlated with anthropometric traits. Genetic risk scores for age at onset and early-onset AN estimated from independent GWASs significantly predicted age at onset. Mendelian randomization analysis suggested a causal link between younger age at menarche and early-onset AN. Conclusions Our results provide evidence consistent with a common variant genetic basis for age at onset and implicate biological pathways regulating menarche and reproduction.Peer reviewe

Shared genetic risk between eating disorder- and substance-use-related phenotypes:Evidence from genome-wide association studies

First published: 16 February 202

Quadratic Zeeman spectral diffusion of thulium ion population in an yttrium gallium garnet crystal

The creation of well-understood structures using spectral hole burning is an important task in the use of technologies based on rare-earth ion-doped crystals. We apply a series of different techniques to model and improve the frequency dependent population change in the atomic level structure of thulium yttrium gallium garnet (Tm:YGG). In particular we demonstrate that, at zero applied magnetic field, numerical solutions to frequency-dependent three-level rate equations show good agreement with spectral hole-burning results. This allows us to predict spectral structures given a specific hole-burning sequence, the underpinning spectroscopic material properties, and the relevant laser parameters. This enables us to largely eliminate power-dependent hole broadening through the use of adiabatic hole-burning pulses. Although this system of rate equations shows good agreement at zero field, the addition of a magnetic field results in unexpected spectral diffusion proportional to the induced Tm ion magnetic-dipole moment and average magnetic-field strength, which, through the quadratic Zeeman effect, dominates the optical spectrum over long timescales. Our results allow optimization of the preparation process for spectral structures in a large variety of rare-earth ion-doped materials for quantum memories and other applications. QID/Tittel LabQID/Taminiau LabQuantum Communications La

Long-Lived Solid-State Optical Memory for High-Rate Quantum Repeaters

We argue that long optical storage times are required to establish entanglement at high rates over large distances using memory-based quantum repeaters. Triggered by this conclusion, we investigate the 795.325 nm3 H6↔H34 transition of Tm:Y3Ga5O12 (Tm:YGG). Most importantly, we find that the optical coherence time can reach 1.1 ms, and, using laser pulses, we demonstrate optical storage based on the atomic frequency comb protocol during up to 100 μs as well as a memory decay time Tm of 13.1 μs. Possibilities of how to narrow the gap between the measured value of Tm and its maximum of 275 μs are discussed. In addition, we demonstrate multiplexed storage, including with feed-forward selection, shifting and filtering of spectral modes, as well as quantum state storage using members of nonclassical photon pairs. Our results show the potential of Tm:YGG for creating multiplexed quantum memories with long optical storage times, and open the path to repeater-based quantum networks with high entanglement distribution rates.QID/Tittel GroupQuTechBUS/TNO STAFFBUS/SpiderQuantum Communications La

Measurement of the thulium ion spin Hamiltonian in an yttrium gallium garnet host crystal

We characterize the magnetic properties for thulium ion energy levels in the (Tm:YGG) lattice with the goal to improve decoherence and reduce linewidth broadening caused by local host spins and crystal imperfections. More precisely, we measure hyperfine tensors for the lowest level of and excited states using a combination of spectral hole burning, absorption spectroscopy, and optically detected nuclear magnetic resonance. By rotating the sample through a series of angles with an applied external magnetic field, we measure and analyze the orientation dependence of the ion's spin Hamiltonian. Using this spin Hamiltonian, we propose a set of orientations to improve material properties that are important for light-matter interaction and quantum information applications. Our results yield several important external field directions: some to extend optical coherence times, another to improve spin inhomogeneous broadening, and yet another that maximizes mixing of the spin states for specific sets of ions, which allows improving optical pumping and creation of lambda systems in this material.QID/Tittel GroupQuTechQuantum Communications La