Coronal Height Research Articles

The convergent cavopulmonary connection: A novel and efficient configuration of Fontan to accommodate mechanical support

ObjectiveThe current total cavopulmonary connection Fontan has competing inflows and outflows, creating hemodynamic inefficiencies that contribute to Fontan failure and complicate placement and efficiency of mechanical circulatory support. We propose a novel convergent cavopulmonary connection (CCPC) Fontan design to create a single, converged venous outflow to the pulmonary arteries, thus increasing efficiency and mechanical circulatory support access. We then evaluate the feasibility and hemodynamic performance of the CCPC in various patient sizes using computational fluid dynamic assessments of computer-aided designs. MethodsCardiac magnetic resonance imaging data from 12 patients with single ventricle (10 total cavopulmonary connection, 2 Glenn) physiology (body surface area, 0.5-2.0 m2) were segmented to create 3-dimensional replicas of all thoracic structures. Surgically feasible CCPC shapes within constraints of anatomy were created using iterative computational fluid dynamic and clinician input. Designs varied based on superior and inferior vena cava conduit sizes, coronal attachment height, coronal entry angle, and axial entry angle of the superior vena cava to the inferior vena cava. CCPC designs were optimized based on efficiency (indexed power loss), risk of arteriovenous malformations (hepatic flow distribution), and risk of flow stasis (% nonphysiologic wall shear stress). ResultsAll CCPC designs met hemodynamic performance thresholds for indexed power loss and hepatic flow distribution. CCPC designs showed improvements in reducing % nonphysiologic wall shear stress and balancing HFD. ConclusionsCCPC is physiologically and surgically feasible in various patient sizes using validated computational fluid dynamic models. CCPC configuration has analogous indexed power loss, hepatic flow distribution, and % nonphysiologic wall shear stress compared with total cavopulmonary connection, and the single inflow and outflow may ease mechanical circulatory support therapies. Further studies are required for design optimization and mechanical circulatory support institution.

Outcomes and Safety of Traditional Growing Rod Technique in the Treatment of Early-onset Dystrophic Scoliosis Secondary to Type 1 Neurofibromatosis With Intraspinal Rib Head Dislocation in Children.

The purpose of this study was to investigate the outcomes and safety of traditional growing rod (TGR) in the treatment of early-onset dystrophic scoliosis secondary to type 1 neurofibromatosis (NF1-EOS) with intraspinal rib head dislocation (IRH) in children. From September 2006 to June 2020, 21 patients with NF1-EOS were treated with TGR. The patients comprised 13 boys and 8 girls with a mean age of 7.1±1.5 years. Two patients had IRH-induced nerve injury [American Spinal Injury Association (ASIA) grade D]. No neurological symptoms were found in the other patients. The intraspinal rib proportion, apical vertebral rotation, apical vertebral translation, coronal main thoracic curve, trunk shift, thoracic kyphosis, lumbar lordosis, sagittal balance, and T1-S1 height were measured before and after TGR implantation and at the last follow-up. Complications were also evaluated. The mean follow-up time was 3.4±2.0 years. An average of 3.1 times (range: 1 to 8 times) lengthening procedures were performed in each patient. The intraspinal rib proportion was significantly lower postoperatively than preoperatively (22±11% vs. 33±18%, respectively; P <0.001), and no significant correction loss was found at the last follow-up (24±12%, P= 0.364). Compared with the measurements before TGR implantation, the major coronal curve and T1-S1 height after TGR implantation and at the last follow-up were significantly different ( P <0.05). Significant correction of apical vertebral translation, thoracic kyphosis, lumbar lordosis, and sagittal balance were noted after TGR implantation, and no significant correction loss was found at the last follow-up ( P >0.05). Ten complications occurred in 7 patients. Two patients with nerve injury recovered after the operation. No neurological complications were found during the follow-up. TGR is a safe and effective therapy for NF1-EOS with IRH where there was no direct compression of the spinal cord, which was confirmed by preoperative magnetic resonance imaging. Through this procedure, IRH could be partly removed from the spinal canal. Level III.

Application of odontometric dimensions of molars in sex assessment in Bulgarians.

Sex estimation is an important step in developing a biological profile. Teeth are one of the most durable physical elements in the human body and thus can be used very successfully for this purpose. The aim of the present study was to determine sex differences in odontometric dimensions of maxillary and mandibular molars in Bulgarians.

Swift and XMM–Newton observations of an RS CVn-type eclipsing binary SZ Psc: superflare and coronal properties

ABSTRACT We present an in-depth study of a large and long duration (&amp;gt;1.3 d) X-ray flare observed on an RS CVn-type eclipsing binary system SZ Psc using observations from Swift observatory. In the 0.35–10 keV energy band, the peak luminosity is estimated to be 4.2 × 1033 $\rm {erg}~\rm {s}^{-1}$. The quiescent corona of SZ Psc was observed ∼5.67 d after the flare using Swift observatory, and also ∼1.4 yr after the flare using the XMM–Newton satellite. The quiescent corona is found to consist of three temperature plasma: 4, 13, and 48 MK. High-resolution X-ray spectral analysis of the quiescent corona of SZ Psc suggests that the high first ionization potential (FIP) elements are more abundant than the low-FIP elements. The time-resolved X-ray spectroscopy of the flare shows a significant variation in the flare temperature, emission measure, and abundance. The peak values of temperature, emission measure, and abundances during the flare are estimated to be 199 ± 11 MK, 2.13 ± 0.05 × 1056 cm−3, 0.66 ± 0.09 $\rm {Z}_{\odot }$, respectively. Using the hydrodynamic loop modelling, we derive the loop length of the flare as 6.3 ± 0.5 × 1011 cm, whereas the loop pressure and density at the flare peak are derived to be 3.5 ± 0.7 × 103 dyn cm−2 and 8 ± 2 × 1010 cm−3, respectively. The total magnetic field to produce the flare is estimated to be 490 ± 60 G. The large magnetic field at the coronal height is supposed to be due to the presence of an extended convection zone of the subgiant and the high orbital velocity.

X-ray illuminated accretion discs and quasar microlensing disc sizes

Aims. We study the half-light radius versus black hole mass as well as the luminosity versus black hole mass relations in active galactic nuclei (AGN) when the disc is illuminated by the X-ray corona. Methods. We used KYNSED, a recently developed spectral model for studying broadband spectral energy distribution in AGN. We considered non-illuminated Novikov-Thorne discs and X-ray illuminated discs based on a Novikov-Thorne temperature radial profile. We also considered the case where the temperature profile is modified by a colour-correction factor. In the case of X-ray illumination, we assumed that the X-ray luminosity is equal to the accretion power that is dissipated to the disc below a transition radius and we computed the half-light radius and the disc luminosity for many black hole masses, as well as a wide range of accretion rates, black hole spins, X-ray luminosities and heights of the corona. Results. The half-light radius of X-ray illuminated radii can be up to ∼3.5 times greater than the radius of a standard disc, even for a non-spinning black hole, based on a wide range of model parameters – as long as the transition radius is larger than three times the radius of the innermost stable circular orbit and the coronal height is greater than ∼40 Rg. This result is due to the fact that the absorbed X-rays act as a secondary source of energy, increasing the disc temperature, and mainly at large radii. Non-illuminated discs are consistent with observations, but only at the 2.5σ level. On the other hand, X-ray illuminated discs can explain both the half-light radius-black hole mass as well as the luminosity-black hole mass relation in AGN, for a wide range of physical parameters. The range of the parameter space is broader in the case where we consider the colour-correction factor. X-ray illuminated discs can explain the data when we observe gravitationally lensed quasars mainly face-on, but also if the mean inclination angle is 60°. In addition, we show that the observed X-ray luminosity of the gravitationally lensed quasars is fully consistent with the X-ray luminosity that is necessary for heating the disc. Conclusions. X-ray disc illumination was proposed many years ago to explain various features that are commonly observed in the X-ray spectra of AGN. Recently, we showed that X-ray illumination of the accretion disc can also explain the observed UV/optical time-lags in AGN, while in this work, we show that the same model can also account for the quasar micro-lensing disc size problem. These results support the hypothesis of the disc X-ray illumination in AGN.

Splenic Size and Volume Measurements in Patients with Chronic Lymphocytic Leukemia

To determine which methods of assessment of splenic size most accurately represent the actual spleen volume in patients with Chronic Lymphocytic Leukemia (CLL). The Abdominal Computed Tomography images of 48 patients with CLL enrolled on a phase 2 clinical trial at two time-points before and after 2-months of continuous acalabrutinib treatment were analyzed. Linear one-dimensional measurements of the spleen were taken in different planes. Two-dimensional and three-dimensional measurements were calculated from the linear measurements using mathematical formulae. The spleen volume was determined by manual segmentation as the ground truth. Data derived were analyzed using Pearson correlation and statistical significance was set at p < 0.05. Among the single-dimensional measurements, the strongest correlation with the segmented splenic volume was the sagittal long axis diameter (LAD) (r=0.89, p < 0.05), followed closely by Coronal LAD (r=0.87, p < 0.05) and cephalocaudal length (iwCLL) (r=0.84, p < 0.05). For the two-dimensional indices, the sum of LAD and short axis diameter (SAD) of the spleen in axial plane showed good correlation with the splenic volume (r=0.77, p < 0.05). Among the three-dimensional indices, the splenic index (0.523 x axial LAD x axial SAD x coronal height) and a formula for volume (30+0.58 x axial LAD x axial SAD x coronal height) had the strongest correlation (both r=0.92, p < 0.05) with the spleen volume. The three-dimensional formulae showed the strongest correlation with volumetric reference spleen measurement. Among unidimensional measurements, the sagittal LAD had the best correlation with the actual splenic volume. The two-dimensional calculation methods were less reliable.

A truncated inner disc in the Seyfert 1 galaxy WKK 4438

ABSTRACT Understanding whether and when the accretion disc extends down to the innermost stable circular orbit is important since it is the fundamental assumption behind measuring black hole spin. Here, we examine the 2013 and 2018 NuSTAR and Swift data ($0.5\!-\!50{\rm \, keV}$) of the narrow-line Seyfert 1 galaxy, WKK 4438. The X-ray emission can be fitted well with models depicting a corona and blurred reflection originating from a disc around a low-spin (a* ≈ 0) black hole. However, such models result in unconventional values for some of the parameters (e.g. inverted emissivity profile and high coronal height). Alternatively, equally good fits can be achieved if the disc is truncated at $\sim 10{\, r_{\rm g}}$ and the black hole is spinning at the Thorne limit (a* = 0.998). In these cases, the model parameters are consistent with the interpretation that the corona is centrally located close to the black hole and illuminating the disc at a larger distance.

A phenomenological study and comparison of the characteristics of droplet impact liquid film dynamics on randomly rough surfaces

The fouling of aero-engine blades is the main cause of degradation of engine performance and online washing is one of the most effective methods for restoring engine performance. The flow characteristics of the washing fluid after it impinges on the blade surface are critical to the process. The liquid film flow becomes complicated after being impacted by a droplet, because the fouling blade is a random rough surface. The purpose of this study is to evaluate the dynamical characteristics of droplets after they impact the liquid film, focusing on the diameter, the height of the coronal water bloom, and the near-wall flow. We establish a random rough surface to simulate the droplet impacting the liquid film on the fouling surface and analyze the morphological evolution of the corona during the droplet impact process. The results show that an increase in the particle size has a greater impact on the coronal diameter than the coronal height. In addition, a higher droplet impact velocity and thicker liquid film are conducive to the secondary atomization of droplets and improve the transport rate of the cleaning solution. However, the flowability of the liquid film at the impact point is best when the droplet impacts the thin liquid film. Increasing the thickness of the liquid film gradually helps to improve its overall fluidity and results in a better cleaning effect.

Relationship between Physiological Resorption of Primary Molars with Its Permanent Successors, Dental Age and Chronological Age.

The aim of the present study was to analyse root resorption of the primary mandibular molars and their relationship with their permanent successors and the age of the patient. Methods: The sample consisted of 408 digital panoramic radiographs. The mesial and distal crown-to-root ratios (CRR) of #74 and #75 were calculated by dividing the measures of the length of each root by its coronal height. The Demirjian formation stage of the premolar was established, and dental age was determined. A descriptive and statistical analysis was performed using SPSS to determine the correlation between the variables (Pearson’s correlation coefficient) and to identify the differences between them (Student’s t-test), with a confidence level of 95%. Results: 723 molars were measured, and tables of CRR depending on dental and chronological age were obtained. The CRR decreased with increasing dental and chronological age, but not uniformly. The CRR of #74 and #75 decreased slightly when the successor premolar was in the initial stages of formation. Gender differences were obtained with respect to chronological age, mainly in girls, because the root resorption of #74 was always more advanced, and the formation of the #34 more advanced. Conclusions: Root resorption of the molar is slight and progressive when the successor premolar begins formation until stage D, and becomes higher starting at stage E. It is possible to determine the state of the child’s maturation and the CRR according to dental and chronological age.

On the Relation Between Coronal Green Line Brightness and Magnetic Fields Intensity

Two-dimensional (2D) solar coronal magnetogram is difficult to be measured directly until now. From the previous knowledge, a general relation has been noticed that the brighter green-line brightness for corona, the higher coronal magnetic field intensity may correspond to. To try to further reveal the relationship between coronal green line brightness and magnetic field intensity, we use the 2D coronal images observed by Yunnan Observatories Green-line Imaging System (YOGIS) of the 10 cm Lijiang coronagraph and the coronal magnetic field maps calculated from the current-free extrapolations with the photospheric magnetograms taken by Helioseismic and Magnetic Imager (HMI) on board the Solar Dynamics Observatory (SDO) spacecraft. In our analysis, we identified the coronal loop structures and construct two-dimensional maps of the corresponding magnetic field intensity in the plane of the sky (POS) above the limb. We derive the correlation coefficients between the coronal brightness and the magnetic field intensity for different heights of coronal layers. We further use a linear combination of a Gaussian and a quadratic profile to fit the correlation coefficients distribution, finding a largest correlation coefficient of 0.82 near 1.1 R ⊙ (solar radii) where is almost the top of the closed loop system. For the small closed loop system identified, the correlation coefficient distributions crossing and covering the loop are calculated. We also investigate the correlation with extended heliocentric latitude zones and long period of one whole Carrington Rotation, finding again that the maximum correlation coefficient occurs at the same height. It is the first time for us to find that the correlation coefficients are high (all are larger than 0.8) at the loop-tops and showing poor correlation coefficients with some fluctuations near the feet of the coronal loops. Our findings indicate that, for the heating of the low-latitude closed loops, both DC (dissipation of currents) and AC (dissipation of Alfvén and magnetosonic waves) mechanisms should act simultaneously on the whole closed loop system while the DC mechanisms dominate in the loop-top regions. Therefore, in the distributions of the correlation coefficients with different heights of coronal layers, for both large- and small-scale latitude ranges, the coefficients can reach their maximum values at the same coronal height of 1.1 R ⊙, which may indicate the particular importance of the height of closed loops for studying the coupling of the local emission mechanism and the coronal magnetic fields, which maybe helpful for studying the origin of the low-speed solar wind.

Increased proximal vertebral rotation is associated with shoulder imbalance after posterior spinal fusion for severe adolescent idiopathic scoliosis.

Residual shoulder imbalance is associated with suboptimal outcomes following the surgical correction of adolescent idiopathic scoliosis (AIS) including poor patient satisfaction. In this retrospective study, we evaluate the radiographic parameters and the relationship between the global and local indices of spinal alignment with shoulder balance pre- and postoperatively utilizing EOS imaging and 3D reconstruction. A retrospective radiographic analysis was performed on patients with AIS, treated with posterior spinal fusion. Postoperative radiographs were obtained immediately following surgery, at 6months and final follow-up over 2years postoperatively. 3D Radiographic measurements included in the coronal plane radiographic shoulder height difference (RSHD), proximal thoracic Cobb angle (PT) and main thoracic Cobb (MT), in the sagittal plane T4-T12 kyphosis, T12-L5 lordosis, in the axial plane proximal thoracic (PT AVR) and main thoracic apical vertebral rotation (MT AVR). Sixty-six patients were included (63 females) with an average main thoracic curvature of 76 degrees. RSHD averaged 14mm ± 14 preoperatively, -15mm ± 12 postoperatively, -8.5mm ± 11 at 6months, and -8.3mm ± 8.7 at final follow-up, respectively. Statistical analysis revealed a significant correlation between RSHD and proximal thoracic Cobb angle, between RSHD and proximal thoracic apical vertebral rotation (PTAVR) (r > 0.20, p < 0.05). The significant correlation presented in this study suggests that PT Cobb angle and PT AVR are involved in postoperative shoulder imbalance. Level 4.

Age estimation by Antegonial Angle, depth measurement and tooth coronal index by digital panoramic radiography

Background: Estimating age in alive humans is a recent area undergoing exploration in forensic sciences. The relationship of pulp size and age as seen in radiographs is utilized by TCI (tooth coronal Index) for age estimation. Aim: The present study was carried out to use a cost-effective and simple method of estimating age using morphometric analysis of dental pulp. Methods: The study was completed on 160 subjects classified into 4 groups based on age including 21-30, 31-40, 41-50, and 51-60 years, followed by capturing digital radiographs (either OPG/ RVG). Morphometric analysis was then done using antegonial angle, depth, and TCI for age estimation, and the results were made. Results: Coronal height of pulp, coronal height in the millimeters, and TCI on OPG were seen as 8.24±1.02, 2.55±0.66, and 30.48±6.59 respectively for 2nd premolar. For 1st molars, respective values of TCI, the coronal height of pulp, and coronal height were seen as 29.16±6.43, 2.65±0.68, and 9.01±1.05 respectively. Antegonial depth for the right side was 2.39±1.17, whereas, for the left side, it was 2.28±1.09. The result was statistically significant with p=0.015.

Eruption of the EUV Hot Channel from the Solar Limb and Associated Moving Type IV Radio Burst

Abstract Using the observations from the Solar Dynamics Observatory, we study an eruption of a hot-channel flux rope (FR) near the solar limb on 2015 February 9. The pre-eruptive structure is visible mainly in EUV 131 Å images, with two highly sheared loop structures. They undergo a slow rising motion and then reconnect to form an eruptive hot channel, as in the tether-cutting reconnection model. The J-shaped flare ribbons trace the footpoint of the FR that is identified as the hot channel. Initially, the hot channel is observed to rise slowly at 40 km s−1, followed by an exponential rise from 22:55 UT at a coronal height of 87 ± 2 Mm. Following the onset of the eruption at 23:00 UT, the flare reconnection then adds to the acceleration process of the coronal mass ejection (CME) within 3 R ⊙. Later on, the CME continues to accelerate at 8 m s−2 during its propagation period. Further, the eruption also launched type II radio bursts, which were followed by type III and type IVm radio bursts. The start and end times of the type IVm burst correspond to the CME’s core height of 1.5 and 6.1 R ⊙, respectively. Also, the spectral index is negative, suggesting that nonthermal electrons are trapped in the closed loop structure. Accompanied by this type IVm burst, this event is unique in the sense that the flare ribbons are very clearly observed together with the erupting hot channel, which strongly suggests that the hooked parts of the J-shaped flare ribbons outline the boundary of the erupting FR.

Origins of the UV/X-ray relation in Arakelian 120

ABSTRACTWe explore the accretion geometry in Arakelian 120 using intensive UV and X-ray monitoring from Swift. The hard X-rays (1–10 keV) show large amplitude, fast (few-day) variability, so we expect reverberation from the disc to produce UV variability from the varying hard X-ray illumination. We model the spectral energy distribution (SED) including an outer standard disc (optical), an intermediate warm-Comptonization region (UV and soft X-ray), and a hot corona (hard X-rays). Unlike the lower Eddington fraction AGN (NGC 4151 and NGC 5548 at L/LEdd ∼ 0.02 and 0.03, respectively), the SED of Akn 120 (L ∼ 0.05LEdd) is dominated by the UV, restricting the impact of reverberating hard X-rays by energetics alone. Illumination from a hard X-ray corona with height ∼10 Rg produces minimal UV variability. Increasing the coronal scale height to ∼100 Rg improves the match to the observed amplitude of UV variability as the disc subtends a larger solid angle, but results in too much fast variability to match the UV data. The soft X-rays (connected to the UV in the warm-Comptonization model) are more variable than the hard, but again contain too much fast variability to match the observed smoother variability seen in the UV. Results on lower Eddington fraction AGN have emphasized the contribution from reverberation from larger scales (the broad-line region), but reverberation induces lags on similar time-scales to the smoothing, producing a larger delay than is compatible with the data. We conclude that the majority of the UV variability is therefore intrinsic, connected to mass-accretion rate fluctuations in the warm-Comptonization region.

Relativistic X-Ray Reverberation from Super-Eddington Accretion Flow

Abstract X-ray reverberation is a powerful technique that uses the echoes of the coronal emission reflected by a black hole (BH) accretion disk to map out the inner disk structure. While the theory of X-ray reverberation has been developed almost exclusively for standard thin disks, reverberation lags have recently been observed from likely super-Eddington accretion sources such as the jetted tidal disruption event Swift J1644+57. In this paper, we extend X-ray reverberation studies into the regime of super-Eddington accretion with a focus on investigating the lags in the fluorescent Fe Kα line region. We find that the coronal photons are mostly reflected by the fast and optically thick winds launched from the super-Eddington accretion flow, and this funnel-like reflection geometry produces lag–frequency and lag–energy spectra with unique observable characteristics. The lag–frequency spectrum exhibits a step-function-like decline near the first zero-crossing point. As a result, the magnitude of the lag scales linearly with the BH mass for a large parameter space, and the shape of the lag–energy spectrum remains almost independent of the choice of frequency bands. Not only can these features be used to distinguish super-Eddington accretion systems from sub-Eddington systems, but they are also key for constraining the reflection geometry and extracting parameters from the observed lags. When fitting the observed reverberation lag of Swift J1644+57 to our modeling, we find that the super-Eddington disk geometry is slightly preferred over the thin disk geometry, and we obtain a BH mass of 5–6 × 106 M ☉ and a coronal height around 10 Rg .

Age estimation in Western Indian population by Cameriere's and Drusini's methods.

Objectives:The aim of the present study is to determine applicability of Cameriere's and Drusini's methods in Western Indian population.Methodology:Panoramic radiographs of total 300 Gujarati individuals, equally divided into four study groups were studied by two investigators. The pulp/tooth area ratio (AR) were calculated for maxillary and mandibular canines and tooth coronal indexes (TCI) i.e., the ratio between coronal pulp cavity height and crown height were calculated for mandibular premolars and first and second molars. The acquired data were subjected to correlation and regression analysis and also inter and intraobserver reliability was obtained for both the investigators.Results:The ARs and TCIs for all the respective teeth were significantly correlated with the age of the individuals. The individual regression formulae were derived for all the teeth and were then used separately to calculate the age. There was no statistically significant difference between the mean chronological age and mean calculated age for all the teeth.(P > 0.05). The mean absolute errors for all the teeth were <10 years.Conclusion:The findings of this study prove the applicability of Cameriere's and Drusini's age estimation methods for Western Indian population. However, the weak correlation coefficients suggest the need for further studies to get more accurate results.

Connective Tissue Disease Patients Maintain Greater Distraction During Growth Friendly Surgery

Study Design: Multicenter retrospective study. Background: Recent studies have demonstrated diminishing returns in patients with early onset scoliosis (EOS) undergoing repeated lengthening of growing rods. Little is known about whether this same phenomenon occurs in patients with lax connective tissue disease (CTD). The primary purpose of this study is to investigate whether EOS patients with connective tissue laxity disorders have diminishing returns during growth friendly surgery. Methods: CTD EOS patients below 10 years old, underwent growth friendly spine surgery with distal anchors and at least 1 proximal spine anchor, and had minimum follow-up of 5 years were included in this study. Coronal T1-S1 height at preindex surgery, postindex, and every available lengthening was assessed. Mean coronal height change during early set distractions and late set distractions were calculated for the cohort. To account for varying distraction intervals, we normalized the distractions by the time interval. The outcome parameter was T1-S1 height gain, mm/year. Results: Twenty-one CTD patients were included in this study. Total coronal height (T1-S1) was 26.7MHCcm before index, 32.2 cm at D1-D3, 34.7 cm at D4-D6, and 36.7 cm at D7-L10. There were no significant differences in coronal height gains between early and late distractions (P=0.70). Moreover, when normalized for time, there was no significant difference in net gain per year at different lengthening time points for the CTD group, P=0.59. Conclusion: There is no evidence of diminishing returns in coronal T1-S1 height gain in patients with EOS in the setting of CTD. Level of Evidence: Level III.

Ultrasonic Imaging Investigation of Tongue Movement Patterns of Cleft-Related Lateralized and Palatalized Misarticulation.

To explore the tongue movement patterns on Mandarin speaking children with repaired cleft palate with lateralized and palatalized misarticulation (LPM) using ultrasound imaging technique. A group of 20 subjects who were diagnosed with speech sound disorder after cleft palate repairment, and another group of 18 children with LPM were recruited. A group of 20 typical children were recruited as the control group. The ultrasonography was used to collect the articulation pattern of the 8 single vowels that are /a/, /o/, / ɘ/, /i/, /u/, /y/, /ɨ/, /ʉ/ in Mandarin Chinese. Various ultrasonic tongue parameters were analyzed from both sagittal and coronal planes. Compared with the control group, coronal height of peak point, coronal tongue dorsum constraint index, sagittal peak point offset distance, sagittal distance between tongue tip and peak point, and sagittal tongue dorsum constraint index of /ɘ/,/i/, /y/ and /ɨ/ were significantly smaller in the cleft-related lateralized and palatalized group (CLP) and noncleft-related lateralized and palatalized group (NLP) ( P < 0.05). Compared with the noncleft-related later- alized and palatalized group and control group, sagittal peak point offset distance of the vowels /ɘ/ and /i/ was significant smaller in the cleft-related lateralized and palatalized group group ( P < 0.05). The ultrasound images on the children with cleft palate showed a midline elevation of the tongue and a significant apical constriction. The children with LPM showed a midline elevation at the coronal plane and anterior movement of the tongue high point at the sagittal plane. The apical vowels were more informative and accurate in indicating the features of LPM than other vowels.

Investigating the coronal structure by studying time lags in the Atoll source 4U 1705-44 using AstroSat

We performed a detailed timing study of the Atoll source 4U 1705-44 in order to understand the accretion disk geometry. Cross correlation function (CCF) studies were performed between soft (3-5 keV) and hard energy (15-30 keV) bands using the AstroSat LAXPC data. We detected hard as well as soft lags of the order of few ten to hundred seconds. A dynamical CCF study was performed in the same energy bands for one of the light curves and we found smaller lags of few tens of seconds ($<$ 50 s) suggesting that the variation is probably originating from the corona. We found a broad noise component around $\sim$ 13 Hz in the 3-10 keV band which is absent in 10-20 keV band. We interpret the observed lags as the readjustment timescales of the corona or a boundary layer around the neutron star and constrain the height of this structure to few tens of km. We independently estimated the coronal height to be around 15 km assuming that the 13 Hz feature in the PDS is originating from the oscillation of the viscous shell around the neutron star.

Exploring the inner-disc region of the atoll source 4U 1705-44 using AstroSat’s SXT and LAXPC observations

ABSTRACT For the first time, simultaneous broad-band spectral and timing study of the atoll source 4U 1705-44 was performed using AstroSat Soft X-ray Telescope (SXT) and Large Area X-ray Proportional Counter (LAXPC) data (0.8–70 keV). Based on the HID, the source was in the soft banana state during these observations. Spectral modelling was performed using the full reflection framework and an inner disc radii of 14 Rg was obtained. A hard power-law tail was noticed in the soft state and hot component fluxes and varying power-law indices point towards a varying corona/sub-Keplerian flow. Based on the spectral fits, the boundary layer radius and magnetospheric radius were constrained to be ∼14–18 and ∼9–19 km, respectively. Cross-correlation function studies were performed between the 0.8–3 keV soft SXT light curve and 10–20 keV hard LAXPC light curve and correlated and anticorrelated lags were found, which was used to constrain the coronal height to 0.6–20 km (β = 0.1). Since the inner disc radius is not varying during the observations, we conclude that the detected lags are possibly caused by a varying structure of corona/boundary layer in the inner region of the accretion disc. Based on the observations, a geometrical model is proposed for explaining the detected lags in the atoll source 4U 1705-44.