Crescent Shape Research Articles

Relationships between Abelson tyrosine kinase (c-abl) and spindle during meiotic division in mouse oocyte in vitro

The c-Abl gene is a nonreceptor tyrosine kinase that has roles in cell growth, control of the cell cycle, initiation of pronuclear movement and actin cytoskeleton dynamics. The present study has examined the localization of c-Abl protein during oocyte activation in mouse in vitro . Confocal immunofluorescence analysis showed that c-Abl originates at the cortex with a crescent shape before the activation and continues up along both sides of the cortex after activation during meiotic division until pronuclear stage. These results demonstrate that c-Abl may play role in asymmetric division of the egg to produce polar body, positioning of the spindle, and may regulate the microtubule cytoskeleton or have some roles in this process.

OUP accepted manuscript

Based on the catastrophe model of the solar eruption, we explore the disturbances caused by solar eruptions via numerical experiments, with special attention given to large-scale waves. In addition to the phenomena shown by previous works, a new structure known as the plasma pile-up is also seen. As the disrupting magnetic structure moves outwards, a fast-mode shock is driven ahead of it. The fast-mode shock expands sideways when propagating forward and evolves to a crescent shape. Eventually the two ends of the crescent touch the bottom boundary and cause various types of disturbance behind the shock, including a shock echo. A plasma pile-up region produced by plasma accumulation behind the echo is associated with this. This is a brand new phenomenon that was not reported previously. Two features of the pile-up region draw our attention: first, its height from the bottom boundary is similar to that of some extreme ultraviolet (EUV) waves and second, its velocity is about one-third of the velocity of the fast-mode shock along the low layer of the atmosphere, which is believed to be the location of the Moreton wavefront. This suggests that the pile-up may be a source of EUV waves as well. According to our numerical results, we also synthesize the 'observed' Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) images in different wavebands. The results demonstrate that the characteristics of the EUV waves 'observed' in different bands are indeed different, which is consistent with the true observational results regarding EUV waves in a certain sense.

Numerical simulation of EWOD on a printed circuit board for cleanroom-less digital fluidic manufacturing applications

PurposeDigital microfluidic devices have been demonstrated to have great potential for a wide range of applications. These devices need expensive photolithography process and clean room facilities, while printed circuit board (PCB) technology provides high configurability and at low cost. This study aims to investigate the mechanism of electrowetting-on-a-dielectric (EWOD) on PCB by solving the multiphysics interaction between fluid droplet and electric field. The performance of system will be improved by inducing an efficient electric field inside the droplet.Design/methodology/approachTo induce an electric field inside the droplet on a PCB and change the initial contact angle, the mechanism of EWOD is studied based on energy minimization method and a set of simulations are carried out by considering multiphysics interaction between the fluid droplet and external electric field. The performance of EWOD on a PCB system is investigated using different electrode structures.FindingsSurface tension plays an efficient role in smaller sizes and can be used to move and control a fluid droplet on a surface by changing the interfacial surface tension. EWOD on a PCB system is studied. and it revealed that any change in electric field affects the droplet contact angle and as a result droplet deformation and movement. The electrode pattern is an important parameter which could change the electric potential distribution inside the droplet. Array of electrodes with square, zigzag interdigitated and crescent shapes are studied to enhance the EWOD force on a PCB substrate. Based on the results, the radial shape of the crescent electrodes keeps almost the same actuated contact line, applies uniform force on the droplet periphery and prevents the droplet from large deformation. A droplet velocity of 0.6 mm/s is achieved by exciting the crescent electrodes at 315 V. Furthermore, the behavior of system is characterized for process parameters such as actuation voltage, dielectric constant of insulator layer, fluidic material properties and the resultant velocity and contact angle. The study of contact angle distribution and droplet motion revealed that it is helpful to generate EWOD mechanism on a PCB which does not need more complicated fabrication processes.Originality/valueThe ability to handle and manipulate the droplets is very important for chemistry on-chip analysis such as immunoassay chips. Furthermore, a PCB-based electrowetting-on-dielectric device is of high interest because it does not need cleanroom facilities and avoids additional high-cost fabrication processes. In the present research, the EWOD mechanism is studied on a PCB by using different electrode patterns.

Impact of the four-wave quasi-resonance on freak wave shapes in the ocean

Two freak waves were observed a day apart in October 2009 at a 5000-m deep moored station in the northwest Pacific Ocean. As the typhoon passed by, the wave system transitioned within a day from a narrow and unimodal spectrum to the broad and bi-modal spectrum. The occurrence probability of a freak wave is known to increase due to a modulational instability; however, whether the modulational instability survives under a realistic directional sea state has not been conclusively determined yet. In this study, a phase-resolving wave model was used to obtain ensembles of realizations based on observed and simulated directional spectra. Unlike previous studies that focused only on the probability of freak wave occurrence, this study focuses on wave shape. It reveals that the front-to-rear asymmetry and crescent shape deformation of the crest are more pronounced for narrower spectrum and longer-lifetime freak waves; this distortion of wave shape and extended lifetime are both characteristics of nonlinear wave groups. This study also shows that the distribution of the lifetime of a freak wave depends on the sea state and that the number of nonlinear wave groups increases for a narrower spectrum. We therefore conjecture that both the four-wave quasi-resonance and dispersive focusing are responsible for freak wave generation, but their relative significance depends on the spectral broadness. Investigating the total kurtosis or occurrence probability alone is insufficient to unravel the underlying mechanisms of individual freak-wave generation.

Self-Assembly of the RZZ Complex into Filaments Drives Kinetochore Expansion in the Absence of Microtubule Attachment

SummaryThe kinetochore is a dynamic multi-protein assembly that forms on each sister chromatid and interacts with microtubules of the mitotic spindle to drive chromosome segregation. In animals, kinetochores without attached microtubules expand their outermost layer into crescent and ring shapes to promote microtubule capture and spindle assembly checkpoint (SAC) signaling. Kinetochore expansion is an example of protein co-polymerization, but the mechanism is not understood. Here, we present evidence that kinetochore expansion is driven by oligomerization of the Rod-Zw10-Zwilch (RZZ) complex, an outer kinetochore component that recruits the motor dynein and the SAC proteins Mad1-Mad2. Depletion of ROD in human cells suppresses kinetochore expansion, as does depletion of Spindly, the adaptor that connects RZZ to dynein, although dynein itself is dispensable. Expansion is also suppressed by mutating ZWILCH residues implicated in Spindly binding. Conversely, supplying cells with excess ROD facilitates kinetochore expansion under otherwise prohibitive conditions. Using the C. elegans early embryo, we demonstrate that ROD-1 has a concentration-dependent propensity for oligomerizing into micrometer-scale filaments, and we identify the ROD-1 β-propeller as a key regulator of self-assembly. Finally, we show that a minimal ROD-1-Zw10 complex efficiently oligomerizes into filaments in vitro. Our results suggest that RZZ’s capacity for oligomerization is harnessed by kinetochores to assemble the expanded outermost domain, in which RZZ filaments serve as recruitment platforms for SAC components and microtubule-binding proteins. Thus, we propose that reversible RZZ self-assembly into filaments underlies the adaptive change in kinetochore size that contributes to chromosome segregation fidelity.

Role of Transverse Displacements in the Formation of Subaqueous Barchan Dunes.

Crescentic shape dunes, known as barchan dunes, are formed by the action of a fluid flow on a granular bed. These bedforms are common in many environments, existing under water or in air, and being formed from grains organized in different initial arrangements. Although they are frequently found in nature and industry, details about their development are still to be understood. In a recent paper [C. A. Alvarez and E. M. Franklin, Phys. Rev. E 96, 062906 (2017)PRESCM2470-004510.1103/PhysRevE.96.062906], we proposed a timescale for the development and equilibrium of single barchans based on the growth of their horns. In the present Letter, we report measurements of the growth of horns at the grain scale. In our experiments, conical heaps were placed in a closed conduit and individual grains were tracked as each heap, under the action of a water flow, evolved into a barchan dune. We identified the trajectories of the grains that migrated to the growing horns, and found that most of them came from upstream regions on the periphery of the initial heap, with an average displacement of the order of the heap size. In addition, we show that individual grains had transverse displacements by rolling and sliding that are not negligible, with many of them going around the heap. The mechanism of horns formation revealed by our experiments contrasts with the general picture that barchan horns form from the advance of the lateral dune flanks due to the scaling of migration velocity with the inverse of dune size. Our results change the way in which the growth of subaqueous barchan dunes is explained.

Development of the coelomic cavities in larvae of the living isocrinid sea lily Metacrinus rotundus

AbstractCoelomogenesis in the isocrinid sea lily, Metacrinus rotundus, is described through the swimming larval stages. After the late gastrula stage, the archenteron separates from the ectoderm to form an archenteral sac, which develops into a dumbbell shape consisting of anterior and posterior lobes, and a middle part connecting both lobes. The anterior and posterior lobes, and the middle part, become separated into an axo‐hydrocoel, the left and right somatocoels and an enteric sac, respectively. The hydrocoel forms from the left lower edge of the axo‐hydrocoel and becomes separated from the axocoel by the late dipleurula stage, when chambered organs and coelom X bud off from the anterior tip of the right and left somatocoels, respectively. Coelom X does not occur in comatulid crinoids (feather stars), and its fate is unclear. The pore canal extends from the axocoel. The hydrocoel differentiates into a crescent shape at the overtime semidoliolaria stage, a few days after the semidoliolaria becomes competent to settle. Coelomogenesis in M. rotundus is much simpler than in the comatulids and probably represents the ancestral mode of the crinoids. As each portion of the dumbbell sac differentiates almost in situ into each coelom, presumptive fates in the sac are easily followed in M. rotundus.

Numerical simulation of super upper branch of a cylindrical structure with a low mass ratio

SST (shear stress transport) k-ω and Newmark-β methods are used to comprehensively understand vortex-induced vibration (VIV) characteristics of a cylindrical structure with a mass ratio of 2.6 in a range of reduced velocity from 2.0 to 14.0. The details of drag and lift forces, cross-flow and streamwise displacements, vortex pattern, trajectory, and frequency of VIV are presented and compared systematically with the experimental work of Jauvtis and Williamson that first captured the super upper branch in VIV with the maximum value of 1.5 D (diameter). In this study, the numerical simulation results successfully captured the initial branch, the lower branch, and the super upper branch. Very few research studies have successfully simulated the super upper branch by numerical methods. The vibration amplitude corresponding to the super upper branch is stable and the maximum value of the super upper branch is 1.46 D, which is fairly consistent with the results of the Jauvtis and Williamson experiment. This research also successfully captured the law of trajectory under different reduced velocities. With the reduced velocity increasing, the trajectories switch from an irregular shape to a regular "Figure 8″ shape and then enter into an irregular movement, finally again into a regular movement of a Figure 8 shape or crescent. In the range of the super upper branch, the vibration trajectories gradually change from a Figure 8 shape to a crescent shape with the increase of the transverse vibration amplitude. This work has successfully captured the different vortex patterns corresponding to each branch under different reduced velocities, and found the transitional forms of 2S to 2T, 2T to 2P, and 2P to 2S, respectively.

Chiral comma-shaped gold nanoparticles: fabrication and refractive index sensitivity

Chiral gold nanoparticles with asymmetric crescent shape have been fabricated using the In-situ resist colloidal lithography approach. Optical properties of these plasmonic particles have been studied experimentally and using the finite-difference time-domain simulations. Nanocommas exhibit a considerable circular dichroism with high anisotropic g-factor of about 0.2. Numerically studied refractive index sensitivity of the material has been demonstrated.

Numerical Study for Performance Evaluation of Plastic Solar Air Heater with Different Cross-Sectional Configuration

In this research, a numerical investigation was performed on five solar air heaters with different cross-sectional shape to find the best configuration relevant to thermal performance. The selected tested shapes in this study were (circular, semi-circular, half-circle plus isosceles triangle, half circle-negative isosceles triangle shape and crescent shape) and all tested shapes hade the same absorber surface area. The effect of two parameter (velocity and solar radiation intensity) on thermal performance of solar air heater were studied numerically by ANSYS 14.0. The velocity of air was changed from 0.25 to 2.0 (m.s -1 ). Results indicated that the highest efficiencies were accomplished for the circular configuration and reached to about 51.79% at solar radiation intensity 850 (W.m-2 ). The solar radiation intensity was changed from 400 to 1200 (W.m-2 ). Results indicated that the highest efficiencies were accomplished for the circular configuration and reached to about 35.51% at air velocity 1.0 (m.s-1 ).

Interpretation of runaway electron synchrotron and bremsstrahlung images

The crescent spot shape observed in DIII-D runaway electron synchrotron radiation images is shown to result from the high degree of anisotropy in the emitted radiation, the finite spectral range of the camera and the distribution of runaways. The finite spectral camera range is found to be particularly important, as the radiation from the high-field side can be stronger by a factor 106 than the radiation from the low-field side in DIII-D. By combining a kinetic model of the runaway dynamics with a synthetic synchrotron diagnostic we see that physical processes not described by the kinetic model (such as radial transport) are likely to be limiting the energy of the runaways. We show that a population of runaways with lower dominant energies and larger pitch-angles than those predicted by the kinetic model provide a better match to the synchrotron measurements. Using a new synthetic bremsstrahlung diagnostic we also simulate the view of the gamma ray imager diagnostic used at DIII-D to resolve the spatial distribution of runaway-generated bremsstrahlung.

Clinical outcomes and structural integrity of C-shaped rotator cuff tears after arthroscopic repair: comparison with crescent-shaped tears

BackgroundWe aimed to describe a new C-shaped tear configuration, and to compare clinical outcomes and structural integrity between the C-shaped and the established crescent-shaped small to medium-sized rotator cuff tears after arthroscopic repair.MethodsThis retrospective study included 102 patients who underwent arthroscopic repair in a single-row fashion for small- to medium-sized rotator cuff tears of either C or crescent shape from March 2009 to June 2014. Visual analogue scale (VAS) pain score, subjective shoulder value (SSV), American Shoulder and Elbow Surgeon (ASES) score, and active range of motion (ROM) were evaluated for functional outcomes. Postoperative magnetic resonance arthrography (MRA) or computed tomographic arthrography (CTA) was performed 6 months postoperatively to assess structural integrity.ResultsAfter 2 years of follow-up, both groups showed no significant difference in VAS pain score, functional scores, or ROM, although the C-shaped tear group exhibited significantly inferior outcomes 3 months after surgery. There was no significant difference in the re-tear rate on follow-up MRA and CTA between groups A and B (24.4 vs. 19.7%, respectively; p = 0.570). The postoperative stiffness rate was significantly higher in the C-shaped tear group than that in crescent-shaped tear group only at 3-month follow-up point after surgery (26.8 vs. 9.8%, respectively; p = 0.024).ConclusionsContrary to our hypothesis, there were no significant differences in functional outcomes and structural integrity between C-shaped and crescent-shaped small- to medium-sized tears 2 years after arthroscopic repair. However, C-shaped tears exhibited significantly worse clinical outcomes, including a higher postoperative stiffness rate than crescent-shaped tears in the early postoperative period at the 3-month follow-up point.

Influence of the pore diameter in Cu/Co/Cu antidots: A XANES study

Antidot materials, i.e., two-dimensional nanostructures with a periodic array of nanopores, are of great scientific interest due to their unique nanomagnetic properties and their potential application in storage devices. It is well known that physical properties of antidots are directly linked to the diameter of nanopores and their spacing, as well as to the morphology and the localizations of chemical species. However, due to their nanoscale size, their characterization remains challenging. Here, we present a detailed investigation of the morphology and presence of oxide species in antidots as a function of the pore diameter using polarized x-ray absorption spectroscopy. For this study we synthesized and characterized Cu(10 nm)/Co(12 nm)/Cu(10 nm) sputtered antidots, fabricated by the double-anodization technique assisted by atomic layer deposition. The pore size ranged from 20 to 80 nm, with a fixed interpore distance (105 nm). An unholed multilayer deposited on Si/${\mathrm{SiO}}_{2}$ was also investigated for comparison. We observed a clear correlation between the increase of pore diameter and the enhancement of oxide content from three different x-ray absorption near edge structure analysis methods. Polarized XAS allowed us to localize the CoO nanorings inside the pores. We propose that the CoO formation is directly related to the crescent shape of the multilayer deposit inside the pores. The coercivity of antidots is enhanced by increasing the magnetic atomic proportion in the periphery of nanopores. The structural observations were also used to develop a simple model in order to estimate the proportion of atoms inside the pores and on the top of the antidots as a function of the interpore distance, the hole diameter, and the penetration length of deposition inside the pores. This model can be easily used in the literature for estimating the atomic species deposited on antidots.

Formation and evolution of quasi-interchange convection cell on the HL-2A tokamak

Formation and evolution of quasi-interchange convection cell have been observed for the first time by an electron cyclotron emission imaging (ECEI) system on the HL-2A tokamak. The instability with mode numbers of m/n = –1/–1 and a frequency of 2–4 kHz propagates in the electron diamagnetic drift direction. The mode downgrades the inner stored energy WE and enhances the divertor Hα signal, which indicates a degradation of plasma confinement. The ECEI reveals that the colder core temperature fluctuation distorts to a crescent shape, while a bubble originates from hot fluctuation gradually and draws into the concave side of the crescent. A finger-like structure can be observed during the convection process, and it presents a typical feature of the quasi-interchange model. The radial structure of the interchange mode obtained from electron cyclotron emission is quite narrow at the high field side but relatively wider at the low field side. Further analysis suggests that the discharge parameters are favorable for the excitation of interchange mode, and the stability criterion is violated in the core region. Moreover, the experimental frequency agrees with that given by the linear dispersion relation of interchange instability. The large grow rate suggests that the mode grows on a very short time scale.

Numerical investigation of the interaction between a planar shock wave with square and triangular bubbles containing different gases

The interaction between a planar shock wave and square and triangular bubbles containing either SF6, He, Ar, or CO2 is studied numerically. It is shown that, due to the existing large differences in the molecular weight, the specific heat ratio, and the acoustic impedance between these gases, different wave patterns and pressure distribution inside the bubbles are developed during the interaction process. In the case of heavy gases, the velocity of the shock wave propagating along the bubble inner surface is always less than that of the incident shock wave and higher than that of the transmitted shock wave. However, in the case of the light gas (He), the fastest one is the transmitted shock wave and the slowest one is the incident shock wave. The largest pressure jump is witnessed in the SF6 case, while the smallest pressure jump is seen in the helium case. There are also pronounced differences in the deformation of the investigated bubbles; while triangular bubbles filled with either Ar, CO2, or SF6 were deformed to a crescent shape, the helium bubble is deformed to a trapezoidal shape with three pairs of vortices emanating from its surface.

Structures and Their Tectonic Implications of the Southern Part of Cuddapah Basin, Andhra Pradesh, India

Systematic structural observations in field outcrops can give clues to interpret orogenic events. Deformational structures studied in basement complexes as well as Cuddapah basinal sedimentary rocks indicate at least three events. The formation of N–S trending greenstone belts on gneissic basement complex is related to the oldest Kenoran orogeny. The later developed Hudsonian orogeny is related to opening of basin and numerous younger pluton as well as mafic dike emplacements. The Greenville or Eastern Ghats Orogeny is most intensively imprinted in the Cuddapah basin sedimentary rocks. The crescent shape of the Nallamalai fold belt in the east is due to the E–W compression related to thrusting followed by NNE–SSW compression. The E–W maximum compression (σ1) is related to the Eastern Ghats Orogeny, which is responsible for the development of several sympathetic E–W faults due to N–S extension (σ3). The formation of the Palaeo–Mesoproterozoic supercontinent Columbia is related to the E–W compression and the Napier Complex of east Antarctica connected with India occupying the indentation of the E part of the Cuddapah basin. Palaeostress study from the southern part of Cuddapah basin reveals that the initial E–W compression and associated fracturing produced E–W extensional regime, and subsequent NNE–SSW shear developed conjugate fracture set. However, the initial E–W compression was associated with the N–S extension component to develop broadly E–W parallel normal faults such as Vempalle fault and later strike-slip faults related to changes in the stress field. The proposed model explains the development and evolution of the Cuddapah basin as a new insight into the regional geodynamics.

Does the Rotator Cuff Tear Pattern Influence Clinical Outcomes After Surgical Repair?

Background:Limited literature exists regarding the influence of rotator cuff tear morphology on patient outcomes.Purpose:To determine the effect of rotator cuff tear pattern (crescent, U-shape, L-shape) on patient-reported outcomes after rotator cuff repair.Study Design:Cohort study; Level of evidence, 3.Methods:Patients undergoing arthroscopic repair of known full-thickness rotator cuff tears were observed prospectively at regular intervals from baseline to 1 year. The tear pattern was classified at the time of surgery as crescent, U-shaped, or L-shaped. Primary outcome measures were the Western Ontario Rotator Cuff Index (WORC), the American Shoulder and Elbow Surgeons (ASES), and a visual analog scale (VAS) for pain. The tear pattern was evaluated as the primary predictor while controlling for variables known to affect rotator cuff outcomes. Mixed-methods regression and analysis of variance (ANOVA) were used to examine the effects of tear morphology on patient-reported outcomes after surgical repair from baseline to 1 year.Results:A total of 82 patients were included in the study (53 male, 29 female; mean age, 58 years [range, 41-75 years]). A crescent shape was the most common tear pattern (54%), followed by U-shaped (25%) and L-shaped tears (21%). There were no significant differences in outcome scores between the 3 groups at baseline. All 3 groups showed statistically significant improvement from baseline to 1 year, but analysis failed to show any predictive effect in the change in outcome scores from baseline to 1 year for the WORC, ASES, or VAS when tear pattern was the primary predictor. Further ANOVA also failed to show any significant difference in the change in outcome scores from baseline to 1 year for the WORC (P = .96), ASES (P = .71), or VAS (P = .86).Conclusion:Rotator cuff tear pattern is not a predictor of functional outcomes after arthroscopic rotator cuff repair.

Dynamics of laser-induced cavitation bubbles near two perpendicular rigid walls

The behaviour of a laser-induced cavitation bubble near two perpendicular rigid walls and its dependence on the distance between bubble and walls is investigated experimentally. It was shown by means of high-speed photography with $100\,000~\text{frames}~\text{s}^{-1}$ that an inclined jet is formed during bubble collapse and the bubble migrates in the direction of the jet. At a given position of the bubble with respect to the horizontal wall, the inclination of the jet increases with decreasing distance between the bubble and the second, vertical wall. A bubble generated at equal distances from the walls develops a jet that is directed in their bisection. The penetration of the jet into the opposite bubble surface leads to the formation of an asymmetric toroidal bubble that is perpendicular to the jet direction. At a large distance from the rigid walls, the toroidal bubble collapses in the radial direction, eventually disintegrating into tiny microbubbles. When the bubble is in contact with the horizontal wall at its maximum expansion, the toroidal ring collapses in both radial and toroidal directions, starting from the bubble part opposite to the vertical wall, and the bubble achieves a crescent shape at the moment of second collapse. The bubble oscillation is accompanied by a strong migration along the horizontal wall.

Development of a microstrip based sensor aimed at salinity and sugar detection in water considering dielectric properties

AbstractA microstrip based sensor aimed at detection of salinity and sugar content in water is presented in this study. The microstrip technology is based on the microstrip patch antenna fed by a microstrip feedline. The patch antenna is a low cost and low profile antenna, which is modeled to transmit and receive an electromagnetic signal. The presented antenna comprises of a crescent shape patch and slotted partial ground. The antenna is imprinted on an FR4 substrate and the substrate has a thickness of 1.60 mm with 4.6 relative permittivity. The antenna has a compact size of 32 × 22 mm2. To simulate the performances of the presented antenna, the High‐Frequency Structural Simulator is used. The result shows that the presented antenna achieves 10 dB return loss from 2.50 to 18 GHz. The antenna achieves consistent radiation pattern throughout the operating band with 6.10 dBi of maximum gain and considerable efficiency. The presented antenna is used as a sensor to detect the salinity and sugar in water in terms of the reflection coefficient based on the dielectric properties of the solution. The percentage of salt and sugar in water changes the dielectric properties of the solution and consequently the reflection coefficients also change. The results during the practical observations show that the reflection coefficient decreases with the increment of the salt and sugar content in the solution.

030 Comparison of Surgical Outcomes in Men with Peyronie's Disease Who Have Severe Crescent Shaped Curvature Vs. Acute Severe Angulation: A Single Institutional Analysis of 240 Patients.

030 Comparison of Surgical Outcomes in Men with Peyronie's Disease Who Have Severe Crescent Shaped Curvature Vs. Acute Severe Angulation: A Single Institutional Analysis of 240 Patients.