Coherent x-ray magnetic imaging with 5 nm resolution

Soft x-ray microscopy plays an important role in modern spintronics. However, the achievable resolution of most x-ray magnetic imaging experiments limits access to fundamental and technologically relevant length scales in the sub-10 nm regime. Here, we demonstrate x-ray magnetic microscopy with 5 nm resolution by combining holography-assisted coherent diffractive imaging with heterodyne amplification of the weak magnetic signal. The gain in resolution and contrast makes magnetic pinning sites visible and allows to measure the local width of domain walls. The ability to detect and map such properties with photons opens new horizons for elementspecific, time-resolved, and operando research on magnetic materials and beyond

Neurobeachin, a Regulator of Synaptic Protein Targeting, Is Associated with Body Fat Mass and Feeding Behavior in Mice and Body-Mass Index in Humans

Neurobeachin (Nbea) regulates neuronal membrane protein trafficking and is required for the development and functioning of central and neuromuscular synapses. In homozygous knockout (KO) mice, Nbea deficiency causes perinatal death. Here, we report that heterozygous KO mice haploinsufficient for Nbea have higher body weight due to increased adipose tissue mass. In several feeding paradigms, heterozygous KO mice consumed more food than wild-type (WT) controls, and this consumption was primarily driven by calories rather than palatability. Expression analysis of feeding-related genes in the hypothalamus and brainstem with real-time PCR showed differential expression of a subset of neuropeptide or neuropeptide receptor mRNAs between WT and Nbea+/− mice in the sated state and in response to food deprivation, but not to feeding reward. In humans, we identified two intronic NBEA single-nucleotide polymorphisms (SNPs) that are significantly associated with body-mass index (BMI) in adult and juvenile cohorts. Overall, data obtained in mice and humans suggest that variation of Nbea abundance or activity critically affects body weight, presumably by influencing the activity of feeding-related neural circuits. Our study emphasizes the importance of neural mechanisms in body weight control and points out NBEA as a potential risk gene in human obesity

Application concepts for ultrafast laser-induced skyrmion creation and annihilation

Magnetic skyrmions can be created and annihilated in ferromagnetic multilayers using single femtosecond infrared laser pulses above a material-dependent fluence threshold. From the perspective of applications, optical control of skyrmions offers a route to a faster and, potentially, more energy-efficient new class of information-technology devices. Here, we investigate laser-induced skyrmion generation in two different materials, mapping out the dependence of the process on the applied field and the laser fluence. We observe that sample properties like strength of the Dzyaloshinskii–Moriya interaction and pinning do not considerably influence the initial step of optical creation. In contrast, the number of skyrmions created can be directly and robustly controlled via the applied field and the laser fluence. Based on our findings, we propose concepts for applications, such as all-optical writing and deletion, an ultrafast skyrmion reshuffling device for probabilistic computing, and a combined optical and spin–orbit torque-controlled racetrack

Coherent x-ray magnetic imaging with 5 nm resolution

Soft x-ray microscopy plays an important role in modern spintronics. However, the achievable resolution of most x-ray magnetic imaging experiments limits access to fundamental and technologically relevant length scales in the sub-10 nm regime. Here, we demonstrate x-ray magnetic microscopy with 5 nm resolution by combining holography-assisted coherent diffractive imaging with heterodyne amplification of the weak magnetic signal. The gain in resolution and contrast makes magnetic pinning sites visible and allows to measure the local width of domain walls. The ability to detect and map such properties with photons opens new horizons for element-specific, time-resolved, and operando research on magnetic materials and beyond.Helmholtz Young Investigator Group ProgramLeibniz-Gemeinschaft http://dx.doi.org/10.13039/50110000166

Supplementary document for Coherent x-ray magnetic imaging with 5 nm resolution - 6734477.pdf

Document with expanded descriptions or methods and analysi

Dataset for 'Coherent x-ray magnetic imaging with 5 nm resolution'

Dataset for the paper "Coherent x-ray magnetic imaging with 5 nm resolution", undergoing peer review on Optica. This dataset contains raw data and code useful to produce the results found in the paper

Dataset for 'Coherent x-ray magnetic imaging with 5 nm resolution'

Dataset for the paper "Coherent x-ray magnetic imaging with 5 nm resolution", published on Optica. This dataset contains raw data and code useful to produce the results found in the paper

Dense sampling of bird diversity increases power of comparative genomics

Whole-genome sequencing projects are increasingly populating the tree of life and characterizing biodiversity(1-4). Sparse taxon sampling has previously been proposed to confound phylogenetic inference(5), and captures only a fraction of the genomic diversity. Here we report a substantial step towards the dense representation of avian phylogenetic and molecular diversity, by analysing 363 genomes from 92.4% of bird families-including 267 newly sequenced genomes produced for phase II of the Bird 10,000 Genomes (B10K) Project. We use this comparative genome dataset in combination with a pipeline that leverages a reference-free whole-genome alignment to identify orthologous regions in greater numbers than has previously been possible and to recognize genomic novelties in particular bird lineages. The densely sampled alignment provides a single-base-pair map of selection, has more than doubled the fraction of bases that are confidently predicted to be under conservation and reveals extensive patterns of weak selection in predominantly non-coding DNA. Our results demonstrate that increasing the diversity of genomes used in comparative studies can reveal more shared and lineage-specific variation, and improve the investigation of genomic characteristics. We anticipate that this genomic resource will offer new perspectives on evolutionary processes in cross-species comparative analyses and assist in efforts to conserve species. A dataset of the genomes of 363 species from the Bird 10,000 Genomes Project shows increased power to detect shared and lineage-specific variation, demonstrating the importance of phylogenetically diverse taxon sampling in whole-genome sequencing.Peer reviewe

Differential expression of feeding-related genes in <i>Nbea+/−</i> and WT mice under different feeding paradigms.

<p><i>Ad libitum</i>-fed, sated <i>Nbea</i>+/− and WT mice showed a differential expression of the dynorphin (DYN) mRNA in the hypothalamus <i>(A)</i> and of the melanocortin (MC) receptor-3 mRNA in the brainstem <i>(B)</i>. 16-h food deprivation differently affected expression of mRNAs encoding DYN, proopiomelanocortin (POMC), opioid-like receptor-1 (ORL1) and corticotropin releasing hormone (CRH) in the hypothalamus <i>(A)</i>, whereas no differences between the genotypes were triggered by food deprivation in the brainstem <i>(B)</i>. Exposure to the palatable HFHS diet did not affect gene expression differently in the <i>Nbea</i>+/− and WT animals. Only DYN mRNA was increased in the standard chow-fed controls <i>(C)</i>. * P<0.05; error bars, ± SEM. The following other genes were also analyzed, but their expression levels did not differ between the genotypes: AGRP, Agouti-related protein; AVP, vasopressin; CCK, cholecystokinin; CRHR, CRH receptor; DOR, delta opioid receptor; ENK, enkephalin; GHSR, growth hormone secretagogue receptor; GLP1R1, glucagon-like peptide 1 receptor 1; KOR, kappa opioid receptor; MCH, melanin concentrating hormone; MOR, mu opioid receptor; NPY, neuropeptide Y; ORX, orexin.</p

Association with BMI and body weight as continuous traits in adults and children for <i>NBEA</i> rs17775456 and rs7990537.

<p>Beta indicates transformed beta-values. P indicates p-values adjusted for significant covariates.</p