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Increased blood lipid levels are heritable risk factors of cardiovascular disease with varied prevalence worldwide owing to different dietary patterns and medication use 1 . Despite advances in prevention and treatment, in particular through reducing low-density lipoprotein cholesterol levels 2 , heart disease remains the leading cause of death worldwide 3 . Genome-wideassociation studies (GWAS) of blood lipid levels have led to important biological and clinical insights, as well as new drug targets, for cardiovascular disease. However, most previous GWAS 4 – 23 have been conducted in European ancestry populations and may have missed genetic variants that contribute to lipid-level variation in other ancestry groups. These include differences in allele frequencies, effect sizes and linkage-disequilibrium patterns 24 . Here we conduct a multi-ancestry, genome-wide genetic discovery meta-analysis of lipid levels in approximately 1.65 million individuals, including 350,000 of non-European ancestries. We quantify the gain in studying non-European ancestries and provide evidence to support the expansion of recruitment of additional ancestries, even with relatively small sample sizes. We find that increasing diversity rather than studying additional individuals of European ancestry results in substantial improvements in fine-mapping functional variants and portability of polygenic prediction (evaluated in approximately 295,000 individuals from 7 ancestry groupings). Modest gains in the number of discovered loci and ancestry-specific variants were also achieved. As GWAS expand emphasis beyond the identification of genes and fundamental biology towards the use of genetic variants for preventive and precision medicine 25 , we anticipate that increased diversity of participants will lead to more accurate and equitable 26 application of polygenic scores in clinical practice. A genome-wide association meta-analysis study of blood lipid levels in roughly 1.6 million individuals demonstrates the gain of power attained when diverse ancestries are included to improve fine-mapping and polygenic score generation, with gains in locus discovery related to sample size.

The morphology and motion of auroras have been widely studied due to their indications on magnetospheric processes. Here, we report a new kind of “auroral curls,” which have wavelengths in the mesoscale (∼100 km) and propagate azimuthally. Utilizing data from the Chinese Antarctic Zhongshan Station (the all‐sky imager and the high‐frequency radar), the Active Magnetosphere and Planetary Electrodynamics Response Experiment and the Defense Meteorological Satellite Program, we analyze an event occurred on 23 April 2019. We find these curls are fine structures in the poleward boundary of multiple arcs. Corresponding field‐aligned currents manifest as a series of longitudinally arranged pairs, while ionospheric flow velocities nearby oscillate with periods in the Pc 5 band. Observational evidence suggests these curls are connected with ultra‐low frequency (ULF) waves, which opens the possibility of using auroras to globally image ULF waves. Plain Language Summary Auroras caused by precipitation of magnetospheric particles contain information about physical processes happened in the magnetosphere. In this letter, we report a new kind of auroral dynamic forms observed in Antarctica. These structures present both spatial and temporal periodic characteristics, which have similar scales with those of magnetospheric ultra‐low frequency (ULF) waves. We propose these auroral forms are connected with ULF waves, which provides a potential method to globally image ULF waves by analyzing properties of these auroras. Key Points Azimuthally propagating “auroral curls” with mesoscale wavelengths were observed in Antarctica These curls are fine structures in the poleward boundary of multiple arcs formed by longitudinal‐arranged field‐aligned current pairs Ionospheric flow velocities nearby oscillate with periods in the Pc 5 band, indicating connections with ultra‐low frequency waves

Wave‐particle interactions are essential for energy transport in the magnetosphere. In this study, we investigated an event during which electrons interact simultaneously with waves in different scales, using data from the Magnetospheric Multiscale mission. At the macroscale (∼105${\\sim} 1{0}^{5}$km), drift resonance between ultra‐low frequency (ULF) waves and 70–300 keV electrons is observed. At the microscale (∼100−101${\\sim} 1{0}^{0}-1{0}^{1}$km), lower‐band chorus waves and electron cyclotron harmonic (ECH) waves are alternately generated, showing signatures of modulation by ULF waves. We found that compressional ULF waves affect the temperature anisotropy of 1–10 keV electrons, thereby periodically exciting chorus waves. Through linear instability analysis, we propose that ULF waves modulate ECH wave emissions by regulating the gradient of electron phase space density at the edge of the loss cone. Our results enhance the understanding of cross‐scale wave‐particle interactions, highlighting their importance in magnetospheric dynamics.

Although elastic metamaterials in a subwavelength scale can control macroscopic waves, it is still a big challenge to attenuate elastic waves at very low frequency (a few tens Hz). The main contribution of this paper is to develop a high-static-low-dynamic-stiffness (HSLDS) resonator with an inertial amplification mechanism (IAM), which is able to create a much lower band gap than a pure HSLDS resonator. The nonlinear characteristics of a locally resonant (LR) beam attached with such new resonators are also explored. The band gap of this LR-IAM beam is revealed by employing transfer matrix method and validated by numerical simulations using Galerkin discretization. It is shown that a very low-frequency band gap can be formed by tuning the net stiffness of the resonator towards an ultra-low value. In addition, the nonlinearity, arising from the restoring force of the resonator, the damping force and effective inertia of the IAM, gives rise to an intriguing feature of amplitude-dependent wave attenuation, which could potentially act as a switch or filter to manipulate flexural waves.

In this study employing data from the Swarm satellites at an altitude of ≈500 km, we present evidence of field‐line resonances (FLRs) in the Pc2‐3 (0.02–0.2 Hz) frequency band in the undisturbed post‐sunset region of the equatorial ionosphere. We identify 26 events extending to magnetic latitudes as low as 2°, which was previously thought to be too low for FLRs to exist due to ionospheric damping. Identification of FLRs is supported by a narrow‐band fundamental and first harmonics, an oscillating field‐aligned Poynting vector, a relative phase shift between E and δB of ≈90°, and in one case observation of one wave in conjugate hemispheres by two satellites separated by 4 min. We show that, contrary to the non‐uniform trend of ground‐based observations, the fundamental frequencies of these occurrences decline monotonically with increasing field‐line length. Their frequencies differ from those of ground‐based magnetometer observations reported in the literature. Plain Language Summary Ultra‐low‐frequency (ULF) waves play a crucial role in the coupling of the magnetosphere‐ionosphere system. These waves have been reported abundantly in the high latitude ionosphere, where they are driven directly by processes in the magnetosphere and solar wind. ULF waves have also been reported at the equatorial ionosphere, but less frequently. In some cases, low‐latitude waves are thought to be driven by high‐latitude waves ducting through the ionosphere or by compressional waves, which can propagate across geomagnetic field lines from high altitudes in the equatorial region. These waves can then excite interhemispheric field‐line resonances (FLRs), in which Earth's magnetic field lines vibrate like a guitar string, with longer field lines oscillating at lower frequencies. In this work, we use the Swarm satellites to study low‐latitude FLRs at an altitude of ≈500 km in the quiet ionosphere at geomagnetic latitudes below 3°. We demonstrate the existence of FLRs with periods between 5 and 50 s which increase with magnetic latitude, as expected when field line lengths increase. Key Points Field line resonances (FLRs) are identified at the lowest magnetic latitude ever reported The fundamental frequency of our events decreases with increasing magnetic latitude in a uniform trend FLRs detected at conjugate latitudes by two spacecraft at the equatorial ionosphere

Demand for lightweight and efficient electromagnetic wave (EW) absorbers continues to increase with technological advances in highly integrated electronics and military applications. Although MXene‐based EW absorbers have been extensively developed, more efficient electromagnetic coupling and thinner thickness are still essential. Recently, ordered heterogeneous materials have emerged as a novel design concept to address the bottleneck faced by current material development. Herein, an ordered heterostructured engineering to assemble Ti3CNTx MXenes/Aramid nanofibers/FeCo@SiO2 nanobundles (FS) aerogel (AMFS‐O) is proposed, where the commonly disordered magnetic composition is transformed to ordered FS arrays that provide more powerful magnetic loss capacity. Experiments and simulations reveal that the anisotropy magnetic networks enhance the response to the magnetic field vector of EW, which effectively improves the impedance matching and makes the reflection loss (RL) peaks shift to lower frequencies, leading to the thinner matching thickness. Furthermore, the temperature stability and excellent compressibility of AMFS‐O expand functionalized applications. The synthesized AMFS‐O achieves full‐wave absorption in X and Ku‐band (8.2–18.0 GHz) at 3.0 mm with a RLmin of −41 dB and a low density of 0.008 g cm−3. These results suggest that ordered heterostructured engineering is an effective strategy for designing high‐performance multifunctional EW absorbers. Benefiting from the enhanced response of the novel magnetic nanobundles and magnetic‐ordered structure to the magnetic field vector of electromagnetic waves, which balances the dielectric loss generated by the MXene network, the MXene based magnetically ordered heterogeneous structured aerogel material constructed in this work has excellent electromagnetic wave absorption performance covering X and Ku bands at low density.

Physiological pulsations have been shown to affect the global blood oxygen level dependent (BOLD) signal in human brain. While these pulsations have previously been regarded as noise, recent studies show their potential as biomarkers of brain pathology. We used the extended 5 Hz spectral range of magnetic resonance encephalography (MREG) data to investigate spatial and frequency distributions of physiological BOLD signal sources. Amplitude spectra of the global image signals revealed cardiorespiratory envelope modulation (CREM) peaks, in addition to the previously known very low frequency (VLF) and cardiorespiratory pulsations. We then proceeded to extend the amplitude of low frequency fluctuations (ALFF) method to each of these pulsations. The respiratory pulsations were spatially dominating over most brain structures. The VLF pulsations overcame the respiratory pulsations in frontal and parietal gray matter, whereas cardiac and CREM pulsations had this effect in central cerebrospinal fluid (CSF) spaces and major blood vessels. A quasi‐periodic pattern (QPP) analysis showed that the CREM pulsations propagated as waves, with a spatiotemporal pattern differing from that of respiratory pulsations, indicating them to be distinct intracranial physiological phenomenon. In conclusion, the respiration has a dominant effect on the global BOLD signal and directly modulates cardiovascular brain pulsations. Extensive 5 Hz spectral resolution of fast fMRI revealed a new form of physiological brain contrast illustrating respiratory‐induced modulation of cardiovascular brain pulsations. Very low frequency (VLF), respiratory and cardiovascular pulses, their harmonics and the detected modulations were found to form the global BOLD signal. Propagating respiratory pulsations should be removed cautiously with voxel‐wise Fourier filtering as they compete globally with every other BOLD signal source. ​

Low-frequency phenomena in an incompressible pressure-induced laminar separation bubble (LSB) on a flat plate is investigated using direct numerical simulation. The LSB configuration of Spalart and Strelets (J. Fluid Mech., vol. 403, 2000, pp. 329–349) is used. Wall pressure spectra indicate low-frequency-flapping $(St \\sim 0.08)$ and high-frequency-shedding $(St \\sim 1.52)$ regimes. Conditional velocity averages based on the fraction of reversed flow reveal the low frequency as an expansion/contraction of the LSB. While the high frequency only exhibits exponential growth within the LSB up to breakdown of the spanwise rollers, the low frequency and velocity fluctuations exhibit exponential growth upstream of separation. Instantaneous flow fields reveal large streamwise streaky structures forming within the LSB and extending past reattachment, much like high and low speed streaks in turbulent boundary layers. A predominance of sweep-like events ($Q4$) is observed during contraction and of ejection-like events ($Q2$) during expansion. These motions appear as dominant low-frequency modes in three-dimensional proper orthogonal and dynamic mode decompositions, exhibiting spatial amplification from separation to reattachment. The advection of a group of spanwise alternating streaky structures past the LSB results in an overall contraction after which the bubble expands to its ‘unforced’ state in the absence of the streaks. The low frequency then corresponds to the time it takes for streaks to form, amplify and advect past the LSB from separation to reattachment. This behaviour is linked to the mean flow deformation reported by Marxen and Rist (J. Fluid Mech., vol. 660, 2010, pp. 37–54), where the presence of streaks results in reduced mean bubble size. The formation of these streaky structures, in the absence of free stream turbulence, may be attributed to an absolute instability of the LSB due to the development of a secondary bubble within the primary.

The excellent dielectric properties and tunable structural design of metal sulfides have attracted considerable interest in realizing electromagnetic wave (EMW) absorption. However, compared with traditional monometallic and bimetallic sulfides that are extensively studied, the unique physical characteristics of solid‐solution‐type sulfides in response to EMW have not been revealed yet. Herein, a unique method for preparing high‐purity solid‐solution‐type sulfides is proposed based on solid‐phase in situ exsolution of different metal ions from hybrid precursors. Utilizing CoAl‐LDH/MIL‐88A composite as a precursor, Fe0.8Co0.2S single‐phase nanoparticles are uniformly in situ formed on an amorphous substrate (denoted as CoAl), forming CoAl/Fe0.8Co0.2S heterostructure. Combing with density functional theory (DFT) calculations and wave absorption simulations, it is revealed that Fe0.8Co0.2S solid solution has stronger intracrystal polarization and electronic conductivity than traditional monometallic and bimetallic sulfides, which lead to higher dielectric properties in EM field. Therefore, CoAl/Fe0.8Co0.2S heterostructure exhibits significantly enhanced EMW absorption ability in the low‐frequency region (2–6 GHz) and can achieve frequency screening by selectively absorbing EMW of specific frequency. This work not only provides a unique method for preparing high‐purity solid‐solution‐type sulfides but also fundamentally reveals the physical essence of their excellent EMW absorption performance. In situ exsolution strategy is developed to construct CoAl/Fe0.8Co0.2S heterostructures, in which solid‐solution‐type sulfides inherit internal crystal polarization and outstanding dielectric loss ability.

The low-frequency modal and non-modal linear dynamics of an incompressible, pressure-gradient-induced turbulent separation bubble (TSB) are investigated, with the objective of studying the mechanism responsible for the low-frequency contraction and expansion (breathing) commonly observed in experimental studies. The configuration of interest is a TSB generated on a flat test surface by a succession of adverse and favourable pressure gradients. The base flow selected for the analysis is the average TSB from the direct numerical simulation of Coleman et al. (J. Fluid Mech., vol. 847, 2018, pp. 28–70). Global mode analysis reveals that the eigenmodes of the linear operator are damped for all frequencies and wavenumbers. Furthermore, the least damped eigenmode appears to occur at zero frequency and low, non-zero spanwise wavenumber when scaled with the separation length. Resolvent analysis is then employed to examine the forced dynamics of the flow. At low frequency, a region of low, non-zero spanwise wavenumber is also discernible, where the receptivity appears to be driven by the identified weakly damped global mode. The corresponding optimal energy gain is shown to have the shape of a first-order, low-pass filter with a cut-off frequency consistent with the low-frequency unsteadiness in TSBs. The results from resolvent analysis are compared to the unsteady experimental database of Le Floc'h et al. (J. Fluid Mech., vol. 902, 2020, A13) in a similar TSB flow. The alignment between the optimal response and the first spectral proper orthogonal decomposition mode computed from the experiments is shown to be close to $95\\,\\%$, while the spanwise wavenumber of the optimal response is consistent with that of the low-frequency breathing motion captured experimentally. This indicates that the fluctuations observed experimentally at low frequency closely match the response computed from resolvent analysis. Based on these results, we propose that the forced dynamics of the flow, driven by the weakly damped global mode, serve as a plausible mechanism for the origin of the low-frequency breathing motion commonly observed in experimental studies of TSBs.