Ring-like Structure Research Articles

Ringlike vortex structures in models with anomalous magnetic moment

This paper deals with vortices in Maxwell-Chern-Simons models with nonminimal coupling. We introduce constraints between the functions that govern the model and find the conditions to minimize the energy. In this direction, a set of first-order equations with novel features are obtained, allowing us to smoothly modify the slope of the function that drives the scalar field in the rotationally symmetric configurations. The results show that, under specific conditions, the solutions may attain an inflection point outside the origin, while the energy density and the electric and magnetic fields get a ringlike profile. We also introduce a procedure to get multiring vortex configurations whose associated solutions engender several inflection points.

Topological order detection and qubit encoding in Su–Schrieffer–Heeger type quantum dot arrays

In this study, building on the 1D topological Su–Schrieffer–Heeger (SSH) model, we propose a model of quantum dot arrays with odd and even parity and variable on-site local potentials to examine topological edge states and a possible quantum information encoding, using these states. We first investigate the SSH model with alternating tunneling amplitudes t1 and t2. We study the model in a ring-like structure and then proceed to minimal open-end chains with even (N=4) and odd (N=5) number of dots. Furthermore, we depart from the basic SSH model by introducing local potentials μi, which offer additional control at the cost of breaking the chiral symmetry of the Hamiltonian and study the implications. Then, we propose an idealized “static” charge qubit design, based on encoding the topological invariant ν as qubit states, that exploits the topological nature of the edge states and their collective character. We introduce perturbing noise δtij(t) into the system and demonstrate the robustness of the states for some range of the ratio ξ=t1/t2. Moreover, we show a possible way to detect the presence of topological order in the system using equilibrium dynamics for both even and odd chains. We utilize the quantum informatic measure of bipartite mutual information I{b:e}(2)(t) as a measure of bulk-edge quantum correlations and a quantitative indicator for the manifestation of bulk-edge correspondence; here, we also propose a dynamical qubit encoding with ν for specific quantum chain parity. Finally, we offer a few remarks on potential future explorations.

Tendinous annulus of Zinn for a common origin of the extraocular rectus muscles: a histological study of the orbital apex from donated elderly cadavers.

The medial, inferior, lateral, and superior rectus muscles (MR, IR, LR, SR), levator palpebrae superioris (LPS), and superior oblique muscle (SO) seem to originate from the tendinous annulus of Zinn, ring-like fibrous tissue crossing the bony orbital fissure. We observed the histological annulus structure using semi-serial histological sections of the orbital apex from 30 elderly donated cadavers. Nearly frontal sections demonstrated a ring-like fibrous structure (a candidate annulus) connecting or embedding four rectus muscles. The candidate annulus did not contain the LPS and SO, and, in the anterior side, the latter muscles originated from the optic canal opening. Far posterior to the annulus, there was a common tendon of the MR, IR, and LR attached to the infero-medial wall of the bony orbital fissure. At the superior part, the annulus is tightly attached to the optic nerve sheath and the periosteum. Sagittal (or Horizontal) sections clearly exhibited parts of the annulus at the MR (SR) origin. Both sagittal and horizontal sections displayed (1) the common origin of the three rectus muscles near the oculomotor nerve in the bony fissure and (2) an accessory, independent muscle bundle of the MR originating from the superomedial margin of the optic canal near the origins of the LPS or SO. Consequently, the so-called tendinous annulus appeared not to provide origins of all six muscles.

Phase-field modeling of the morphological evolution of ringlike structures during growth: Thermodynamics, kinetics, and template effects

Understanding and controlling the morphology of crystals growing from prepatterned shapes, as in selective-area epitaxy, is fundamental for the development of novel device architectures. Here, an in-depth analysis of the faceted growth of ring-shaped crystal structures is presented. This is a prototypical case for assessing the role of thermodynamic and kinetic driving forces, as they induce different faceting between the outer convex region and the inner concave one. The well-established concepts of equilibrium crystal shape, set by surface energy minimization, and its kinetic counterpart, determined by orientation-dependent growth rates, provide a qualitative indication of the outcome of growth experiments. However, they are insufficient to capture the whole evolution pathway. A phase-field growth model including deposition, incorporation, and surface diffusion dynamics is considered, and extensive two- and three-dimensional simulations are performed. A continuum transition in the crystal morphology is recognized by varying the magnitude of the anisotropic surface energy vs the incorporation times. The in-depth analysis of a realistic case, mimicking experiments in the literature, highlights the prominent role of kinetics and of material redistribution from the outer to the inner perimeter of the ring. Finally, the templating effect of the initial pattern is investigated by considering polygonal profiles with different orientations, showing their effect on the facet formation and evolution.

Photoelectron interference of He atoms in the attosecond ionization gating.

We theoretically investigate the photoelectron momentum distribution of He atoms by numerically solving the time-dependent Schro¨dinger equation (TDSE) in few-cycle ionization gating, which is synthesized by two linearly polarized laser pulses. When applying the TDSE, we can clearly see the spider-like structures in the photoelectron momentum spectra. We also find that the spider-like structures can be isolated by changing the relative phase. The directionality of the spider-like structure is changed from right-side to left-side and the ring-like interference structure gradually appears in the photoelectron momentum spectra when increasing the relative phase. The interference patterns observed in TDSE are recaptured well by the quantum-trajectory Monte Carlo (QTMC) model. We separate the ionization time window of the tunneling electron by analyzing the ionization rate. With the help of QTMC simulation, we illustrate the change of the interference structure and its directionality in the photoelectron momentum spectra. By changing the relative phase, the forward-backward asymmetry of the momentum distribution of the emitted electrons can also be controlled. Moreover, we find that the relative contribution of the nonrescattering and the rescattering trajectories can be controlled. These properties are beneficial for the application of photoelecron holography in probing atomic and molecular structures and dynamics.

Formation mechanism of ring-like segregation and structure during directional solidification under axial static magnetic field

• The ring-like structure forms under a moderate axial magnetic field. • The ring-like convection and segregation form under a moderate axial magnetic field. • The formation of the ring-like structure is attributed to solute redistribution under magnetic field. The effect of the axial static magnetic field on the macro-segregation and structure in the Al-Cu and Ni-Mn-Ga alloys during directional solidification is investigated experimentally and numerically. It is found that the ring-like segregation and structure in the above-mentioned two alloys form during directional solidification at a certain growth speed under a moderate magnetic field. For the Al-Cu and Ni-Mn-Ga alloys, the moderate values of the magnetic field under which the ring-like structure forms are about 0.5 T and 1.0 T at respective growth speed of 10 μm/s and 5 μm/s. Further, the distributions of the flow and solute in the Al-Cu alloy during directional solidification under the axial static magnetic field is numerically simulated. Numerical results reveal that the rotary thermoelectric (TE) magnetic convection forms in the mushy zone during directional solidification under an axial magnetic field. This flow will induce the formation of the ring-like macro-segregation and structure. Changes in structures under the magnetic field in the experimental results are in good agreement with the distributions of the TE magnetic convection and solute in the numerical results. Therefore, the formation of the ring-like structure and segregation under the magnetic field should be attributed to the solute redistribution induced by the TE magnetic convection.

Spire1 and Myosin Vc promote Ca2+-evoked externalization of von Willebrand factor in endothelial cells

Weibel–Palade bodies (WPB) are endothelial cell-specific storage granules that regulate vascular hemostasis by releasing the platelet adhesion receptor von Willebrand factor (VWF) following stimulation. Fusion of WPB with the plasma membrane is accompanied by the formation of actin rings or coats that support the expulsion of large multimeric VWF fibers. However, factor(s) organizing these actin ring structures have remained elusive. We now identify the actin-binding proteins Spire1 and Myosin Vc (MyoVc) as cytosolic factors that associate with WPB and are involved in actin ring formation at WPB-plasma membrane fusion sites. We show that both, Spire1 and MyoVc localize only to mature WPB and that upon Ca2+ evoked exocytosis of WPB, Spire1 and MyoVc together with F-actin concentrate in ring-like structures at the fusion sites. Depletion of Spire1 or MyoVc reduces the number of these actin rings and decreases the amount of VWF externalized to the cell surface after histamine stimulation.

Kinematics, structure and abundances of supernova remnant 0540-69.3

Aims. Our goal is to investigate the structure, elemental abundances, physical conditions, and the immediate surroundings of supernova remnant 0540-69.3 in the Large Magellanic Cloud. Methods. Imaging in [O III] and spectroscopic studies through various slits were carried out using European Souther Observatory’s Very Large and New Technology Telescopes. Densities, temperatures, and abundances were estimated applying nebular analysis for various parts of the remnant. Results. Several new spectral lines are identified, both from ejecta embedded in the pulsar-wind nebula, and in interstellar clouds shocked by the supernova blast wave. For the filaments in the pulsar-wind nebula, all lines are redshifted by 440 ± 80 km s−1 with respect to the rest frame of the host galaxy, and a 3D representation of the [O III] emission displays a symmetry axis of ring-like structures which could indicate that the pulsar shares the same general redshift as the central supernova ejecta. We note that [O II], [S II], [Ar III], and Hβ share a common more compact structure than [O III], and possibly [Ne III]. The average [O III] temperature for the filaments in the pulsar-wind nebula is 23 500 ± 1800 K, and the electron density derived from [S II] is typically ∼ 103 cm−3. By mass, the relative elemental abundances of the shocked ejecta in the pulsar-wind nebula are O : Ne : S : Ar ≈ 1 : 0.07 : 0.10 : 0.02, consistent with explosion models of 13 − 20 M⊙ progenitors, and similar to that of SN 1987A, as is also the explosive mixing of hydrogen and helium into the center. From Hβ and He Iλ5876, the mass ratio of He/H in the center is estimated to be in excess of ∼0.8. The rapid cooling of the shocked ejecta could potentially cause variations in the relative abundances if the ejecta are not fully microscopically mixed, and this is highlighted for S/O for the period 1989–2006. Also, [O III] is seen in presumably freely coasting photoionized ejecta outside the pulsar-wind nebula at inferred velocities out to well above 2000 km s−1, and in projection, [O III] is seen out to ∼10″ from the pulsar. This was used to estimate that the pulsar age is ≈1200 years. The freely coasting [O III]-emitting ejecta have a strictly nonspherical distribution, and their mass is estimated to be ∼0.12 M⊙. A possible outer boundary of oxygen-rich ejecta is seen in [O II] λλ3726,3729 at ∼2000 − 2100 km s−1. Four filaments of a shocked interstellar medium are identified, and there is a wide range in the degree of ionization of iron, from Fe+ to Fe13+. One filament belongs to a region also observed in X-rays, and another one has a redshift of 85 ± 30 km s−1 relative to the host. From this we estimate that the electron density of the [O III]-emitting gas is ∼ 103 cm−3, and that the line of the most highly ionized ion, [Fe XIV] λ5303, comes from an evaporation zone in connection with the radiatively cooled gas emitting, for example, [O III], and not from immediately behind the blast wave. We do not find evidence for nitrogen-enriched ejecta in the southwestern part of the remnant, as was previously suggested. Emission in this region is instead from a severely reddened H II-region.

Different micro/nano-scale patterns of surface materials influence osteoclastogenesis and actin structure

The surface topography of a material can influence osteoclast activity. However, the surface structural factors that promote osteoclast activity have not yet been investigated in detail. Therefore, we investigated osteoclastogenesis by testing various defined patterns with different dimensions and shapes. The systematic patterns, made of a cyclo-olefin polymer, were prepared at a micron-, submicron-, and nano-scale with a groove, hole, or pillar shape with a 1:1 pitch ratio. RAW264.7 cells were cultured on these patterns in the presence of the receptor activator of NF-κB ligand (RANKL). Osteoclast formation was induced in the order: pillar > groove ≥ hole. The two-dimensional factors also indicated that submicron-sized patterns strongly induced osteoclast formation. The optimal pillar dimension for osteoclast formation was 500 nm in diameter and 2 µm in height. Furthermore, we observed two types of characteristic actin structure, i.e., belt-like structures with small hollow circles and isolated ring-like structures, which formed on or around the pillars depending on size and height. Furthermore, resorption pits were observed mainly on the top of calcium phosphate-coated pillars. Thus, osteoclasts prefer convex shapes, such as pillars for differentiation and resorption. Our results indicate that osteoclastogenesis can be controlled by designing surfaces with specific morphologies.

Nanoparticle deposition pattern during colloidal droplet evaporation as in-situ investigated by Low-Field NMR: The critical role of bound water

The evaporation of a colloidal droplet on a solid surface produces a ring-like structure at the pinned contact line due to induced capillary flow, also known as the coffee-ring effect (CRE). However, the addition of certain additives can significantly reduce CRE, whose physical origin remains in debate. In this study, the time-resolved low field (LF)-NMR technique highlights the effect of different water fractions in colloidal droplets on the ultimate distribution of silica nanoparticles during evaporation. With the assistance of 1H T2 relaxometry, the impact of decreasing evaporation rate (J) and additives on the fractions of bound, trapped, and free water can be obtained. Utilizing the T2 Carr-Purcell-Meiboom-Gill (CPMG) sequence approach, in-situ tracking during droplets evaporation, with varying J, was obtained to conclude the minimum existence time of bound water required during evaporation for CRE suppression. As the droplet J decreases, the competition between the time scale of totally droplet evaporation tF and the time spent of bound water during evaporation tB may influence the ring formation. Experimentally a shorter duration of tB/tF ≤ 0.5 is required for formating the coffee ring structure and successfully suppressed when its existence time surpasses a particular threshold ≥ 0.5.

ECCsplorer: a pipeline to detect extrachromosomal circular DNA (eccDNA) from next-generation sequencing data

BackgroundExtrachromosomal circular DNAs (eccDNAs) are ring-like DNA structures physically separated from the chromosomes with 100 bp to several megabasepairs in size. Apart from carrying tandemly repeated DNA, eccDNAs may also harbor extra copies of genes or recently activated transposable elements. As eccDNAs occur in all eukaryotes investigated so far and likely play roles in stress, cancer, and aging, they have been prime targets in recent research—with their investigation limited by the scarcity of computational tools.ResultsHere, we present the ECCsplorer, a bioinformatics pipeline to detect eccDNAs in any kind of organism or tissue using next-generation sequencing techniques. Following Illumina-sequencing of amplified circular DNA (circSeq), the ECCsplorer enables an easy and automated discovery of eccDNA candidates. The data analysis encompasses two major procedures: first, read mapping to the reference genome allows the detection of informative read distributions including high coverage, discordant mapping, and split reads. Second, reference-free comparison of read clusters from amplified eccDNA against control sample data reveals specifically enriched DNA circles. Both software parts can be run separately or jointly, depending on the individual aim or data availability. To illustrate the wide applicability of our approach, we analyzed semi-artificial and published circSeq data from the model organisms Homo sapiens and Arabidopsis thaliana, and generated circSeq reads from the non-model crop plant Beta vulgaris. We clearly identified eccDNA candidates from all datasets, with and without reference genomes. The ECCsplorer pipeline specifically detected mitochondrial mini-circles and retrotransposon activation, showcasing the ECCsplorer’s sensitivity and specificity.ConclusionThe ECCsplorer (available online at https://github.com/crimBubble/ECCsplorer) is a bioinformatics pipeline to detect eccDNAs in any kind of organism or tissue using next-generation sequencing data. The derived eccDNA targets are valuable for a wide range of downstream investigations—from analysis of cancer-related eccDNAs over organelle genomics to identification of active transposable elements.

Metal Ions, Metal Chelators and Metal Chelating Assay as Antioxidant Method

Heavy metals are essential for a wide range of biological processes, including the growth and reproduction of cells, synthesis of biomolecules, many enzymatic reactions, and the body’s immunity, but their excessive intake is harmful. Specifically, they cause oxidative stress (OS) and generate free radicals and reactive oxygen species (ROS) in metabolism. In addition, the accumulation of heavy metals in humans can cause serious damage to different organs, especially respiratory, nervous and reproductive and digestive systems. Biologically, metal chelation therapy is often used to treat metal toxicity. This process occurs through the interaction between the ligand and a central metal atom, forming a complex ring-like structure. After metals are chelated with appropriate chelating agents, their damage in metabolism can be prevented and efficiently removed from the body. On the other hand, heavy metals, including Zn, Fe and Cu, are necessary for the suitable functioning of different proteins including enzymes in metabolism. However, when the same metals accumulate at levels higher than the optimum level, they can easily become toxic and have harmful effects toward biomolecules. In this case, it induces the formation of ROS and nitrogen species (RNS) resulting in peroxidation of biological molecules such as lipids in the plasma membrane. Antioxidants have an increasing interest in many fields due to their protective effects, especially in food and pharmaceutical products. Screening of antioxidant properties of compounds needs appropriate methods including metal chelating assay. In this study, a general approach to the bonding and chelating properties of metals is described. For this purpose, the basic principles and chemical principles of metal chelation methods, both in vivo and in vitro, are outlined and discussed. Hence, in the main sections of this review, the descriptions related to metal ions, metal chelating, antioxidants, importance of metal chelating in biological system and definitions of metal chelating assays as widely used methods to determine antioxidant ability of compounds are provided. In addition, some chemical properties, technical and critical details of the used chelation methods are given.

Update in the Uses of Chalazion Clamp in Dermatological Procedure Revisited.

Chalazion clamp has a distal tip with a flat oval plate; other side has a ring-like structure and forceps-like handle. Handle has a thumbscrew, which can be tightened and released so as to achieve the required pressure. Available in various sizes. Used mainly in ophthalmological procedures primarily. Used in dermatology by modifying its technique and creating an adequate hemostasis in various diagnostic and interventional procedures. In the previous article chalazion clamp was used for preparing SSS for ear lobule, so this article revisited the uses of chalazion clamp in dermatology and extended use in the preparation of adequate blanching while preparing SSS from the peripheral tissue site.

Brightness Asymmetry of Black Hole Images as a Probe of Observer Inclination

Abstract The Event Horizon Telescope recently captured images of the supermassive black hole in the center of the M87 galaxy, which shows a ring-like emission structure with the south side only slightly brighter than the north side. This relatively weak asymmetry in the brightness profile along the ring has been interpreted as a consequence of the low inclination of the observer (around 17° for M87), which suppresses the Doppler beaming and boosting effects that might otherwise be expected due to the nearly relativistic velocities of the orbiting plasma. In this work, we use a large suite of general relativistic magnetohydrodynamic simulations to reassess the validity of this argument. By constructing explicit counterexamples, we show that low inclination is a sufficient but not necessary condition for images to have low brightness asymmetry. Accretion flow models with high accumulated magnetic flux close to the black hole horizon (the so-called magnetically arrested disks) and low black hole spins have angular velocities that are substantially smaller than the orbital velocities of test particles at the same location. As a result, such models can produce images with low brightness asymmetry even when viewed edge on.

First Images of the Molecular Gas around a Born-again Star Revealed by ALMA

Abstract Born-again stars allow probing stellar evolution in human timescales and provide the most promising path for the formation of hydrogen-deficient post-asymptotic giant branch objects, but their cold and molecular components remain poorly explored. Here we present ALMA observations of V 605 Aql that unveil for the first time the spatio-kinematic distribution of the molecular material associated with a born-again star. Both the continuum and molecular line emission exhibit a clumpy ring-like structure with a total extent of ≈1″ in diameter. The bulk of the molecular emission is interpreted as being produced in a radially expanding disk-like structure with an expansion velocity v exp ∼ 90 km s−1 and an inclination i ≈ 60° with respect to the line of sight. The observations also reveal a compact high-velocity component, v exp ∼ 280 km s−1, that is aligned perpendicularly to the expanding disk. This component is interpreted as a bipolar outflow with a kinematical age τ ≲ 20 yr, which could either be material that is currently being ejected from V 605 Aql, or is being dragged from the inner parts of the disk by a stellar wind. The dust mass of the disk is in the range M dust ∼ 0.2–8 × 10−3 M ⊙, depending on the dust absorption coefficient. The mass of the CO is M CO ≈ 1.1 × 10−5 M ⊙, which is more than three orders of magnitude larger than the mass of the other detected molecules. We estimate a 12C/13C ratio of 5.6 ± 0.6, which is consistent with the single stellar evolution scenario in which the star experienced a very late thermal pulse instead of a nova-like event as previously suggested.

Detection of Anti-Rod and AntiRing Autoantibodies in a Patient with Seronegative Rheumatoid Arthritis and Cirrhosis of Liver: A Case Report

Present case relates to results of diagnostic autoantibodies reactive against various antigens. Autoantibodies reactive against 16 nuclear antigens (Mi-2, ku, nRNP/Sm, S5-A(nativ), RO-52, SS-B, Scl-70, PM-Scl100, jo-1, CENPB, PCNA, DsDNA, nucleosomes, histones, ribosomal P-protein) and antigen Anti-Mitochondrial M2 Antibody (AMA-M2) were tested by indirect enzyme-linked immunosolvent assay, using a membrane as the solid phase; no colour reaction developed, suggesting absence of antibodies against above antigens. However, autoantibodies against rod and ring-like structures Inosine Monophosphate Dehydrogenase (IMPD) were detected. Presence of high titer autoantibodies against Double stranded (Ds) Deoxyribonucleic Acid (DNA) and Sm nuclear antigens might be diagnostic of Systemic Lupus Erythematosus (SLE). However, low titer antibodies against other nuclear antigens might increase the risk to develop SLE in an asymptomatic patient. Immune complexes might develop and get deposited in synovium. Later, chronic synovitis might develop. In addition, the test for rheumatoid factor was negative with serum of the current patient. Patient was diagnosed as a case of seronegative rheumatoid arthritis. The patient also had cirrhosis of the liver. Rarely, anti-rod and anti-ring autoantibodies might develop in a patient with Hepatitis C Virus (HCV) infection. Further, these antibodies might also be detected in sera of patients with SLE or Hashimoto’s thyroiditis or during treatment with interferon-α/ Ribavirin. However, the significance of these autoantibodies in pathogenesis of a autoimmune disease or HCV infection is unknown. High titer antibodies against double stranded (Ds) DNA and Sm antigens might be diagnostic of SLE.

Carbon Nanotubes and its Application in Nanotechnology

Carbon nanotubes often refer to single-wall carbon nanotubes (SWCNTs) with diameters in the range of a nanometer. Single-wall carbon nanotubes are one of the allotropes of carbon, intermediate between fullerene cages and flat graphene. Carbon nanotubes also often refer to multi-wall carbon nanotubes(MWCNTs), consisting of nested single-wall carbon nanotubes, weakly bound together by van der Waals interactions in a tree ring-like structure. If not identical, these tubes are very similar to long straight and parallel carbon layers, cylindrically arranged around a hollow tube. Multi-wall carbon nanotubes are also sometimes used to refer to double and triple wall carbon nanotubes. Carbon nanotubes can also refer to tubes with an undetermined carbon wall structure and diameters less than 100 nanometers. While nanotubes of other compositions exist, most research has been focused on the carbon ones. The length of a carbon nanotube produced by common production methods is typically much larger than its diameter. Thus, for many purposes, end effects are neglected and the length of carbon nanotubes is assumed infinite. Carbon nanotubes can exhibit remarkable unique properties. These include electrical conductivity, while others are semiconductors. They also have exceptional tensile strengthand thermal conductivity, because of their nanostructure and strength of the bonds between carbon atoms. In addition, they can be chemically modified. Thus, due to their variable, unique properties, carbon nanotubes have found applications in many realms such as electronics, optics, composite materials nanotechnology, and other applications of materials science. In addition, carbon nanotubes can be integrated into other molecules to form novel structures with unique properties, different from the individual reactants. These unique products have also found application in many realms of nanotechnology

Finitary ideals of direct products in quantales

The notion of quantale, which designates a complete lattice equipped with an associative binary multiplication distributing over arbitrary joins, appears in various areasof mathematics-in quantaloid theory, in non classical logic as completion of the Lindebaum algebra, and in different representations of the spectrum of a C∗ algebra asmany-valued and non commutative topologies. To put it briefly, its importance is nolonger to be demonstrated. Quantales are ring-like structures in that they share withrings the common fact that while as rings are semi groups in the tensor category ofabelian groups, so quantales are semi groups in the tensor category of sup-lattices.In 2008 Anderson and Kintzinger [1] investigated the ideals, prime ideals, radical ideals, primary ideals, and maximal of a product ring R × S of two commutativenon non necceray unital rings R and S: Something resembling rings are quantales byanalogy with what is studied in ring, we begin an investigation on ideals of a productof two quantales. In this paper, given two quantales Q1 and Q2; not necessarily withidentity, we investigate the ideals, prime ideals, primary ideals, and maximal ideals ofthe quantale Q1 × Q2

Clumps and Rings of Ejecta in SNR 0540–69.3 as Seen in 3D

Abstract The distribution of ejecta in young supernova remnants offers a powerful observational probe of their explosions and progenitors. Here we present a 3D reconstruction of the ejecta in SNR 0540-69.3, which is an O-rich remnant with a pulsar wind nebula located in the LMC. We use observations from the Very Large Telescope (VLT)/MUSE to study Hβ, [O iii] λ λ4959, 5007, Hα, [S ii] λ λ6717, 6731, [Ar iii] λ7136, and [S iii] λ9069. This is complemented by 2D spectra from VLT/X-shooter, which also cover [O ii] λ λ3726, 3729, and [Fe ii] λ12567. We identify three main emission components: (i) clumpy rings in the inner nebula (≲1000 km s−1) with similar morphologies in all lines; (ii) faint extended [O iii] emission dominated by an irregular ring-like structure with radius ∼1600 km s−1 and inclination ∼40°, but with maximal velocities reaching ∼3000 km s−1; and (iii) a blob of Hα and Hβ located southeast of the pulsar at velocities ∼1500–3500 km s−1. We analyze the geometry using a clump-finding algorithm and use the clumps in the [O iii] ring to estimate an age of 1146 ± 116 yr. The observations favor an interpretation of the [O iii] ring as ejecta, while the origin of the H-blob is more uncertain. An alternative explanation is that it is the blown-off envelope of a binary companion. From the detection of Balmer lines in the innermost ejecta we confirm that SNR 0540 was a Type II supernova and that hydrogen was mixed down to low velocities in the explosion.

Variants in ADD1 cause intellectual disability, corpus callosum dysgenesis, and ventriculomegaly in humans

PurposeAdducins interconnect spectrin and actin filaments to form polygonal scaffolds beneath the cell membranes and form ring-like structures in neuronal axons. Adducins regulate mouse neural development, but their function in the human brain is unknown. MethodsWe used exome sequencing to uncover ADD1 variants associated with intellectual disability (ID) and brain malformations. We studied ADD1 splice isoforms in mouse and human neocortex development with RNA sequencing, super resolution imaging, and immunoblotting. We investigated 4 variant ADD1 proteins and heterozygous ADD1 cells for protein expression and ADD1–ADD2 dimerization. We studied Add1 functions in vivo using Add1 knockout mice. ResultsWe uncovered loss-of-function ADD1 variants in 4 unrelated individuals affected by ID and/or structural brain defects. Three additional de novo copy number variations covering the ADD1 locus were associated with ID and brain malformations. ADD1 is highly expressed in the neocortex and the corpus callosum, whereas ADD1 splice isoforms are dynamically expressed between cortical progenitors and postmitotic neurons. Human variants impair ADD1 protein expression and/or dimerization with ADD2. Add1 knockout mice recapitulate corpus callosum dysgenesis and ventriculomegaly phenotypes. ConclusionOur human and mouse genetics results indicate that pathogenic ADD1 variants cause corpus callosum dysgenesis, ventriculomegaly, and/or ID.