Ring-like Profile Research Articles

Topological solitons in the sigma-cuscuton model

Building a multi-field theory with canonical and non-canonical contributions, one studies the topological solitons of the O(3)-sigma model. We propose a model constituted by the O(3)-sigma field, the cuscuton-like neutral scalar field, and Maxwell’s field. We investigate BPS properties considering a theory without interaction. One performs this study by adopting the first-order formalism in a model with contribution non-canonical. Thus, these contributions will preserve the spontaneous symmetry breaking of the system. Concurrently, a non-minimal coupling between the sigma and the Maxwell field is assumed. In this scenario, interesting results arise, i.e., one notes that the solitons have an internal structure and ring-like profile. Furthermore, one observes that the ring-like configurations that emerge are directly related to the contribution of the cuscuton-like term.

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.

Mapping non-laminar proton acceleration in laser-driven target normal sheath field

Abstract We report on experimental observation of non-laminar proton acceleration modulated by a strong magnetic field in laser irradiating micrometer aluminum targets. The results illustrate the coexistence of ring-like and filamentation structures. We implement the knife edge method into the radiochromic film detector to map the accelerated beams, measuring a source size of 30–110 μm for protons of more than 5 MeV. The diagnosis reveals that the ring-like profile originates from low-energy protons far off the axis whereas the filamentation is from the near-axis high-energy protons, exhibiting non-laminar features. Particle-in-cell simulations reproduced the experimental results, showing that the short-term magnetic turbulence via Weibel instability and the long-term quasi-static annular magnetic field by the streaming electric current account for the measured beam profile. Our work provides direct mapping of laser-driven proton sources in the space-energy domain and reveals the non-laminar beam evolution at featured time scales.

Phase transitions in the logarithmic Maxwell O(3)-sigma model

We investigate the presence of topological structures and multiple phase transitions in the O(3)-sigma model with the gauge field governed by Maxwell’s term and subject to a so-called Gausson’s self-dual potential. To carry out this study, it is numerically shown that this model supports topological solutions in 3-dimensional spacetime. In fact, to obtain the topological solutions, we assume a spherically symmetrical ansatz to find the solutions, as well as some physical behaviors of the vortex, as energy and magnetic field. It is presented a planar view of the magnetic field as an interesting configuration of a ring-like profile. To calculate the differential configurational complexity (DCC) of structures, the spatial energy density of the vortex is used. In fact, the DCC is important because it provides us with information about the possible phase transitions associated with the structures located in the Maxwell–Gausson model in 3D. Finally, we note from the DCC profile an infinite set of kink-like solutions associated with the parameter that controls the vacuum expectation value.

Planar ringlike vortices

We investigate the presence of vortex structures in generalized Maxwell–Higgs and Chern–Simons–Higgs models in the three-dimensional spacetime. Despite the important difference between the Maxwell and Chern–Simons dynamics, we have been able to introduce first order differential equations that solve the equations of motion for static and rotationally symmetric field configurations. In both cases, solutions of the first order equations engender minimum energy, and we have found vortex configurations whose internal structure unveils interesting and unusual ringlike profile.

Repeatability of the macular pigment spatial profile: A comparison of objective versus subjective classification.

PurposeClassification of macular pigment (MP) spatial profile phenotypes varies and is often based on subjective visualisation. We investigated repeatability of MP optical density (MPOD) comparing an objective versus subjective profiling system.MethodsThe coefficient of repeatability (CoR) was calculated for point MPOD values (0–3.8°) obtained by dual‐wavelength fundus autofluorescence (FAF) from two scans obtained in a single visit of 40 healthy individuals (39 ± 9 years). For each individual's dataset, the MP profile was classified as exponential, ring‐like or central dip using an objective method (based on deviations away from an exponential fit), as well as by subjective visual profiling. Existing FAF images of 88 monozygotic (MZ) and 69 dizygotic (DZ) twin pairs were reanalysed using the objective profiling method and concordance and heritability of ring‐like profiles determined.ResultsThe CoR was 0.23 at 0° and 0.06 at 0.8°. Agreement of objective profiling between scans was excellent (κ = 0.85, 95% CI 0.69 to 1.00; p < 0.0005). Subjective profiling showed moderate agreement between scans (κ = 0.48, 95% CI 0.23 to 0.73; p < 0.0005). Agreement between objective and subjective classification was low (κ = 0.23, 95% CI 0.04 to 0.42; p = 0.02). Concordance for the ring‐like profile using objective profiling was 0.74 for MZ compared to 0.36 for DZ twins. Heritability was calculated as 81.5% (95% confidence interval 61.1–93.1%).ConclusionCompared to visual assessment, objective MP profiling is a more reliable method and should be considered in future observational and interventional studies. In addition, MP profile phenotypes showed high heritability.

Macular Pigment Spatial Profiles in South Asian and White Subjects

Variability in central macular pigment optical density (MPOD) has been reported among healthy individuals. These variations seem to be related to risk factors of AMD, such as female sex, smoking, and ethnicity. This study investigates variations in the spatial profiles of MPOD among ethnicities. Using heterochromatic flicker photometry (HFP), MPOD was measured at seven retinal locations in 54 healthy, young South Asian and 19 white subjects of similar age. Macular pigment spatial profiles were classified as either typical exponential, atypical ring-like, or atypical central dip. Central MPOD was significantly greater in South Asian (0.56 ± 0.17) compared with white subjects (0.45 ± 0.18; P = 0.015). Integrated MPOD up to 1.8° (i.e., average MPOD [MPODav(0-1.8)]) was also significantly increased in South Asian (0.34 ± 0.09) compared to white subjects (0.27 ± 0.10; P = 0.003). Average MPOD(0-1.8) was significantly increased in all subjects presenting a ring-like profile (0.35 ± 0.08) or central dip profile (0.39 ± 0.09), compared with typical exponential profiles (0.28 ± 0.09; P < 0.0005). We found a statistically significant association between ethnicity and spatial profile type (P = 0.008), whereby an exponential profile was present in 79% of white compared with 41% of the South Asian subjects. Central MPOD, MPODav(0-1.8), and the prevalence of atypical spatial profiles were significantly increased in South Asian compared with white subjects. Atypical profiles resulted in increased integrated MPOD up to 1.8°, and may therefore offer enhanced macular protection from harmful blue light.

Controlling the Drying and Film Formation Processes of Polymer Solution Droplets with Addition of Small Amount of Surfactants

We studied how the addition of surfactants alters the drying and film formation processes of polymer solution droplets with contact lines strongly fixed by bank structures. We found that even if the amount of surfactant is quite small, it drastically changes the final profile of the polymer film from a ringlike profile to a flat profile. This property is observed commonly, irrespective of the polymer concentration, droplet volume, and type of solvent. We conjecture that the inhomogeneous distribution of the surfactant caused by the outward capillary flow induces the Marangoni flow directed toward the center of the droplet, which suppresses the outward flow. The present phenomenon implies an effective method for controlling the profile of the polymer film in inkjet printing technologies.

Ring formation of focused half-cycle terahertz pulses

Studies using a terahertz (THz) imaging system have shown that focused THz electromagnetic pulses exhibit a ring-like spatial intensity distribution. In the study, almost half-cycle THz pulses were generated from a large-aperture photoconductive antenna and focused by an off-axis parabolic mirror. Time-resolved spatial distribution of the THz electric field on the focal plane was found to form a ring before and after the time region where a single peak is formed around the time origin. On the other hand, with the delay time fixed at the origin, the field distribution was also found to exhibit a ring-like profile at positions away from the focal plane. Existence of relatively low-frequency components in the power spectrum of the THz field gives these observable phenomena. Numerical simulations using diffraction integral calculations reproduced the observed features. A simpler numerical analysis based on the Gaussian beam approximation was shown to yield the observed features and also predicted the dependence on the beam parameters.

Isolation and analysis of nuclear bodies from estrogen-stimulated chick liver

The target cells of most steroid hormones contain prominent structures termed nuclear bodies (NB). Estrogen (ES) responsive tissues have very distinctive NB, whose development has been associated with both the level of ES receptors and their retention times in nuclei. It has been suggested that these NB may be large-scale ES binding centers at transcriptionally hyperstimulated sites. We examined the formation of NB in ES-stimulated rooster liver, after primary induction of vitellogenesis and during subsequent decay of this response. Distinct NB appear 6 h postinduction, initially as compact spheroids with ring-like profiles and later on as more complex morphotypes. Nuclei average 15–17 NB each at peak induction (24–48 h), but this declines again gradually as the hormonal response abates. This transient pattern is paralleled closely by the [ 3H]ES binding capacity of nuclei in vitro and the calculated number of specific hormone receptors present. There is no direct numerical correspondence, however, between the NB and the ES receptors, either on a one-to-one basis or as some simple ratio. Hence any links between ES binding activity in nuclei and the NB must be both complex and indirect. Nuclear bodies were isolated following lysis of nuclei by sonication and separation of subfractions on discontinuous sucrose gradients. The resultant NB-enriched fraction consisted primarily of protein, with traces of DNA and RNA. Analysis of proteins by sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed a complex pattern of polypeptides, some apparently unique and probably NB-derived.

Effect of continuous darkness on circadian morphological rhythms in pinealocytes of the Chinese hamster, Cricetulus griseus.

Effects of a short-term exposure to continuous darkness on 24-h morphological variations in pinealocytes in the superficial pineal of the Chinese hamster (Cricetulus griseus) were examined. Pinealocytes contained type-1, -2 and -3 synaptic ribbons (SR), which had a central dense structure showing rod-like, various and ring-like profiles, respectively, and the quantity of each type of SR was expressed by SR index. 24-h changes in the type-1 and type-3 SR indices persisted in darkness and thus may be endogenous in nature. As under alternating light and dark (LD) conditions, the type-2 SR indices were almost constant over a 24-h period under continuous darkness, but the indices were larger in animals under darkness than in those under LD conditions. The 24-h variations in the nuclear and cytoplasmic volumes were abolished after exposing animals to darkness for 7 days, suggesting that these rhythms may be regulated exogenously. The amount of condensed chromatin exhibited a circadian change; this rhythm persisted under darkness. The results suggest that 24-h variations in the nuclear and cytoplasmic volumes in pinealocytes of the Chinese hamster are regulated by mechanisms different from those controlling the rhythms in SR and chromatin, and that the changes in the nuclear and cytoplasmic volumes and chromatin are related to the change in synthetic activity of pinealocytes.

Strawberry Vein-Banding Virus, a Member of the Cauliflower Mosaic Virus Group

SUMMARY Cytoplasmic inclusions, made up of a dense, finely granular matrix up to 3 to 4 µm in diam. were consistently found in ultrathin sections of leaf tissues from Fragaria vesca infected with strawberry vein-banding virus (SVBV). Isometric particles, usually with ring-like profiles, 40 to 45 nm in diam. were seen either embedded in the dense matrix or scattered in some electron-lucent areas of the inclusion. The particle morphology and the type of the inclusion found associated with SVBV places it in the cauliflower mosaic virus group.

Structure of a murine leukemia virus after disruption with tween-ether and comparison with two myxoviruses

The effects of treatment with Tween-ether (TE) on physical and morphological properties of Rauscher leukemia virus (RLV) were studied and compared with those obtained on two myxoviruses (NDV and PR8 influenza virus). TE treatment readily produced viral disruption. The buoyant density of the released internal components was similar in all three cases, and greater than that of the intact virus. Electron microscopic study of intact and TE-treated virus was performed. (1) NDV easily released its characteristic nucleocapsid. PR8 influenza virus was more resistant to disruption and the internal component appeared as a coiled cylinder 70 A in diameter. (2) Preparations of intact Rauscher virus showed two types of virions: the “immature” type where two concentric shells were enclosed in the viral envelope, and the “mature” virion where a dense nucleoid was enclosed in the envelope. (3) Treatment with Tween-ether readily removed the envelope of RLV, as seen in thin sections of TE-treated preparations. (4) Ringlike profiles appeared in negatively stained preparations of the aqueous phase of RLV. These ring profiles were 750–850 A in diameter, 75 A thick, with two threads and a central circular core, 15–25 A in diameter. Morphological units and possible helical structure appeared in these structures which corresponded in size to the outer shell of the immature virions. (5) Dense, spherical bodies, 700–750 A in diameter, were also present in the aqueous phase. They represented the naked dense nucleoids of the mature virions. (6) Ribonuclease treatment performed on TE-treated RLV resulted in a significant decrease of the stainability of the naked nucleoids, the same treatment was ineffective on virus not treated by TE. (7) The structure of RLV has been envisioned and compared with that of other types of virus. The outer shell of the immature virion may represent the capsid of the virus, made up of a coiled cylinder. The genetic material appears to lie more internally in the inner shell. The structure of the mature virion results from the collapse of the two shells inside the envelope.