Prominence Parameters Research Articles

The Immediate Effect of Straw Phonation in Children With Repaired Cleft Palate

ObjectiveThis study aims to investigate the immediate effect of straw phonation on the phonation of Persian-speaking children with repaired cleft palate. Study DesignQuasi-experimental intervention pre and post intervention. MethodsSeventeen children with repaired cleft palate and velopharyngeal dysfunction (VPD) were investigated. A control group was established comprising children without a cleft palate (control group), carefully matched in terms of age and gender. All participants underwent straw phonation and assessment. The assessments were made two times: at baseline and immediately after straw phonation. Each participant performs straw phonation (a short straw measuring 3mm in inner diameter and 20 cm in length) once for 3 minutes. The acoustic analysis including parameters such as jitter, shimmer, harmonics-to-noise ratio (HNR), cepstral peak prominence (CPP) parameters, as well as the electroglottography (CQ) analysis were performed at pretreatment and immediately after treatment. ResultsCompared with the pretreatment values, after treatment observation demonstrated a significant reduction in Jitt % and Shimm %, and a significant enhancement in HNR and CPP among children with repaired cleft palate. No significant difference intragroup data just in the CPP and CQ in pretreatment. ConclusionsThe proposed straw phonation technique results in an immediate positive change on the quality of voice in both groups. Moreover, assessments in clinical group showed a significantly decrease shimmer and jitter perturbation, alongside elevated levels of HNR and CPP subsequent to straw phonation, irrespective of the phonatory task.

Sex Determination through Pelvic Bone Using Anteroposterior Radiographs

Background: Forensic anthropology uses digital radiography to identify victims' gender, despite the population-specific nature of determining gender from bones, offering a cost-effective and straightforward method. The objective of the study was to evaluate the accuracy of the digital radiography technology for sex recognition of the selected participant group in Hyderabad, Sindh Time and location: Cross-sectional study conducted by department of Forensic medicine Liaquat University of medical and Health Sciences Jamshoro and Isra University Hyderabad at the outpatient of Liaquat University hospital, Hyderabad from February to May 2023. Methods: The study included male and female patients aged 18-50 years and was authorized by the Research and Ethics Committee LUMHS. Study participants were divided into two groups; male and female. Differences in pelvis bone fragments parameters like iliac height, inter-acetabular distance, pelvic inlet (breadth), acetabulum diameter, pubic length, Ischial length and ischio-pubic index on digital x-ray radiographs of both groups were examined and compared. Results: A statistically significant difference (p<0.05) in bony prominence parameters including inter-acetabular distance, acetabular diameter, breadth of the pelvic inlet, pubic length, ischial length and ischio-pubic index was observed between group A and group B. The study revealed that the accuracy in recognizing male individuals through ileum height (68.8%), inter-acetabular distance (64.7%), and the pelvic inlet breadth (61.0 %) Conclusion: The iliac height, inter-acetabular distance, pelvic inlet (breadth), inter-acetabular diameter, pubic length, Ischial length and ischio-pubic index on radiographs (x-rays) of pelvic bones are a reliable bone fragments parameters in sex determination with high precision.

A Cognitive Semantic Analysis of Selected American Political Caricatures on Covid 19

Political caricatures are reflections of real situations or affairs that are summarized through drawings. Recently, they have become key elements in political communication since they manipulate different verbal and visual elements in shaping the political messages and attracting the recipient's attention. These different modes include verbal and visual elements. Accordingly, they provide a new framework to understand political discourse. This paper is an attempt to examine the efficiency of Langacker’s (2008-2017) construal dimension of prominence to the analysis of visual and verbal elements of political caricatures. It aims to prove that the prominence parameters of profiling and trajectory/ landmark alignment can account for the phenomenon of multiple construal triggered by visual and verbal modes, and the process of meaning construction in political caricatures. To achieve these aims, a sample of American political caricatures published on Covid 19 has been selected to be analyzed. Analysis of the selected data shows that the semantic content of the political cartoons resides on the visual and verbal elements employed in these caricatures. Both types of elements highly depend on Langacker’s two construal parameters of prominence, profiling and trajector/landmark, in constructing and conveying their intended messages. In addition, the way the conceptualizers construe the scenes participates greatly to decoding these messages.

Quantifying osteosynthesis plate prominence – mathematical definitions and case study on a clavicle plate

Hardware prominence remains a clinical challenge in focus for implant design in subcutaneous plate applications. Existing evaluation of hardware prominence relies on plate-to-bone distance at a single point or on average. A reproducible measure for plate prominence remains undefined. This study mathematically defines the plate prominence linked to the cross-sectional area change due to the plate presence on the bone. Two anatomical plate designs were fitted to 100 clavicles, and afterwards plate prominence parameters were evaluated and compared. This methodology enables the quantification of hardware prominence for different plate designs to inform the development of implants targeting low prominence.

Modeling Balmer line signatures of stellar CMEs

Abstract From the Sun we know that coronal mass ejections (CMEs) are a transient phenomenon, often correlated with flares. They have an impact on solar mass- and angular momentum loss, and therefore solar evolution, and make a significant part of space weather. The same is true for stars, but stellar CMEs are still not well constrained, although new methodologies have been established, and new detections presented in the recent past. So far, probable detections of stellar CMEs have been presented, but their physical parameters which are not directly accessible from observations, such as electron density, optical thickness, temperature, etc., have been so far not determined for the majority of known events. We apply cloud modeling, as commonly used on the Sun, to a known event from the literature, detected on the young dMe star V374 Peg. This event manifests itself in extra emission on the blue side of the Balmer lines. By determining the line source function from 1D NLTE modeling together with the cloud model formulation we present distributions of physical parameters of this event. We find that except for temperature and area all parameters are at the upper range of typical solar prominence parameters. The temperature and the area of the event were found to be higher than for typical solar prominences observed in Balmer lines. We find more solutions for the filament than for the prominence geometry. Moreover we show that filaments can appear in emission on dMe stars contrary to the solar case.

ALMA as a Prominence Thermometer: First Observations

Abstract We present first prominence observations obtained with Atacama Large Millimeter Array (ALMA) in Band 3 at the wavelength of 3 mm. High-resolution observations have been coaligned with the MSDP Hα data from Wrocław–Białków large coronagraph at similar spatial resolution. We analyze one particular cotemporal snapshot, first calibrating both ALMA and MSDP data and then demonstrating a reasonable correlation between both. In particular, we can see quite similar fine-structure patterns in both ALMA brightness-temperature maps and MSDP maps of Hα intensities. Using ALMA, we intend to derive the prominence kinetic temperatures. However, having current observations only in one band, we use an independent diagnostic constraint, which is the Hα line integrated intensity. We develop an inversion code and show that it can provide realistic temperatures for brighter parts of the prominence where one gets a unique solution, while within faint structures, such inversion is ill conditioned. In brighter parts, ALMA serves as a prominence thermometer, provided that the optical thickness in Band 3 is large enough. In order to find a relation between brightness and kinetic temperatures for a given observed Hα intensity, we constructed an extended grid of non-LTE prominence models covering a broad range of prominence parameters. We also show the effect of the plane-of-sky filling factor on our results.

Variational mode decomposition-based seizure classification using Bayesian regularized shallow neural network

This work presents a new epileptic seizures epoch classification scheme. Variational mode decomposition (VMD), has been explored for non-recursively decomposing the electroencephalogram (EEG) signals into fourteen band limited intrinsic mode functions (IMFs). Data augmentation (DA), has been used for handling unbalanced classification problem. Normalized energy, fractal dimension, number of peaks, and prominence parameters were computed from the band-limited IMFs for the discrimination of seizure and non-seizure epochs. Bayesian regularized shallow neural network (BR-SNNs) and six other well-known classifiers were tested. Sensitivity, specificity, and accuracy have been used as performance metrics. This study includes two different epoch lengths of 1-second and 2-seconds. A total of 32 test cases for both, class balanced and unbalanced classification problems have been taken for the performance evaluation. The best performance obtained is 100% for all the three metrics from the test cases of database-2 and 3. For database-1, average sensitivity, specificity, and accuracy of 99.71, 99.75, and 99.73% have been achieved, respectively for the 1-second epoch. The presented work shows better performance results compared to many previously reported works.

Modelling of Mg II lines in solar prominences

Context. Observations of the Mg II h and k lines in solar prominences with IRIS reveal a wide range of line shapes from simple non-reversed profiles to typical double-peaked reversed profiles, and with many other possible complex line shapes. The physical conditions responsible for this variety are not well understood. Aims. Our aim is to understand how physical conditions inside a prominence slab influence shapes and properties of emergent Mg II line profiles. Methods. We compute the spectrum of Mg II lines using a one-dimensional non-LTE radiative transfer code for two large grids of model atmospheres (isothermal isobaric, and with a transition region). Results. The influence of the plasma parameters on the emergent spectrum is discussed in detail. Our results agree with previous studies. We present several dependencies between observables and prominence parameters which will help with the interpretation of observations. A comparison with known limits of observed line parameters suggests that most observed prominences emitting in Mg II h and k lines are cold, low-pressure, and optically thick structures. Our results indicate that there are good correlations between the Mg II k line intensities and the intensities of hydrogen lines, and the emission measure. Conclusions. One-dimensional non-LTE radiative transfer codes allow us to understand the main characteristics of the Mg II h and k line profiles in solar prominences, but more advanced codes will be necessary for detailed comparisons.

Spectral Characteristics of the He i D3 Line in a Quiescent Prominence Observed by THEMIS

We analyze the observations of a quiescent prominence acquired by the Telescope Heliographique pour l'Etude du Magnetisme et des Instabilites Solaires (THEMIS) in the He I 5876 A (He I D3) multiplet aiming to measure the spectral characteristics of the He I D3 profiles and to find for them an adequate fitting model. The component characteristics of the He I D3 Stokes I profiles are measured by the fitting system approximating them with a double Gaussian. This model yields an He I D3 component peak intensity ratio of $5.5\pm0.4$, which differs from the value of 8 expected in the optically thin limit. Most of the measured Doppler velocities lie in the interval $\pm5$ km/s, with a standard deviation of $\pm1.7$ km/s around the peak value of 0.4 km/s. The wide distribution of the full-width at half maximum has two maxima at 0.25 A and 0.30 A for the He I D3 blue component and two maxima at 0.22 A and 0.31 A for the red component. The width ratio of the components is $1.04\pm0.18$. We show that the double-Gaussian model systematically underestimates the blue wing intensities. To solve this problem, we invoke a two-temperature multi-Gaussian model, consisting of two double-Gaussians, which provides a better representation of He I D3 that is free of the wing intensity deficit. This model suggests temperatures of 11.5 kK and 91 kK, respectively, for the cool and the hot component of the target prominence. The cool and hot components of a typical He I D3 profile have component peak intensity ratios of 6.6 and 8, implying a prominence geometrical width of 17 Mm and an optical thickness of 0.3 for the cool component, while the optical thickness of the hot component is negligible. These prominence parameters seem to be realistic, suggesting the physical adequacy of the multi-Gaussian model with important implications for interpreting He I D3 spectropolarimetry by current inversion codes.

Multi-Wavelength Eclipse Observations of a Quiescent Prominence

We construct the maps of temperatures, geometrical thicknesses, electron densities and gas pressures in a quiescent prominence. For this we use the RGB signal of the prominence visible-light emission detected during the total solar eclipse of 1 August 2008 in Mongolia and quasi-simultaneous Hα spectra taken at Ondřejov Observatory. The method of disentangling the electron density and geometrical (effective) thickness was described by Jejcic and Heinzel (Solar Phys. 254, 89 – 100, 2009) and is used here for the first time to analyse the spatial variations of prominence parameters. For the studied prominence we obtained the following range of parameters: temperature 6000 – 15 000 K, effective thickness 200 – 15000 km, electron density 5×109 – 1011 cm−3 and gas pressure 0.02 – 0.2 dyn cm−2 (assuming a fixed ionisation degree n p/n H=0.5). The electron density increases towards the bottom of the prominence, which we explain by an enhanced photoionisation due to the incident solar radiation. To confirm this, we construct a two-dimensional radiative-transfer model with realistic prominence illumination.

Global magnetic field cycle evolution and prominence eruptions

AbstractA comparison of changes in the structure of the global solar magnetic field and that in the prominence parameters, in solar cycles 21–23, are presented. It is proposed that the observed global magnetic field structure changes and periodicities in the mean solar magnetic field are the result of the excitation of large-scale Rossby waves. The changes in the prominence parameters are assumed to be the result of the global magnetic field structure changes, which may be triggered or modulated quasi-periodically by large-scale Rossby waves.

Mapping prominence plasma parameters from eclipse observations

AbstractUsing the eclipse observations, we construct the maps of quiescent prominence temperatures, electron densities, pressures and geometrical thicknesses. For this we use the RGB signal of prominence visible-light emission detected during the total solar eclipse on August 1, 2008 in Mongolia, and quasi-simultaneous Hα spectra taken at Ondřejov observatory. The method of disentangling the electron density and effective geometrical thickness was described by Jejčič & Heinzel (2009) and is used here for the first time to analyse the spatial variations of various prominence parameters.

THE THERMAL INSTABILITY OF SOLAR PROMINENCE THREADS

The fine structure of solar prominences and filaments appears as thin and long threads in high-resolution images. In H-alpha observations of filaments, some threads can be observed for only 5 - 20 minutes before they seem to fade and eventually disappear, suggesting that these threads may have very short lifetimes. The presence of an instability might be the cause of this quick disappearance. Here, we study the thermal instability of prominence threads as an explanation of their sudden disappearance from H-alpha observations. We model a prominence thread as a magnetic tube with prominence conditions embedded in a coronal environment. We assume a variation of the physical properties in the transverse direction, so that the temperature and density continuously change from internal to external values in an inhomogeneous transitional layer representing the particular prominence-corona transition region (PCTR) of the thread. We use the nonadiabatic and resistive magnetohydrodynamic equations, which include terms due to thermal conduction parallel and perpendicular to the magnetic field, radiative losses, heating, and magnetic diffusion. We combine both analytical and numerical methods to study linear perturbations from the equilibrium state, focusing on unstable thermal solutions. We find that thermal modes are unstable in the PCTR for temperatures higher than 80,000 K, approximately. These modes are related to temperature disturbances that can lead to changes in the equilibrium due to rapid plasma heating or cooling. For typical prominence parameters, the instability time scale is of the order of a few minutes and is independent of the form of the temperature profile within the PCTR of the thread. This result indicates that thermal instability may play an important role for the short lifetimes of threads in the observations.

Prominence and quiet-Sun plasma parameters derived from FUV spectral emission

Context. A solar prominence and the quiet-Sun (QS) were observed with SOHO/SUMER in October 1999. With this dataset we built the first comprehensive UV spectral atlas in the range 800–1250 A for a prominence, thus complementing the existing reference atlases for the QS. Aims. This is a detailed study based on the information in this atlas, with the aim of deriving the plasma parameters in two distinct regions. The large amount of information available allows us to establish these parameters with lower uncertainty than in previous studies, leading to reference values for theoretical investigations. Methods. The measured lines’ FWHM were used to derive the distribution of the non-thermal velocities at various temperatures. The lines intensities were used to derive the electron densities at temperatures of 7 × 10 4 Ka nd the differential emission measure. Results. The comparison with the QS shows lower velocities in the prominence for temperature T with log T < 5.4. The velocities derived in the highest part of the prominence show a lower gradient with the temperature. The value obtained for the electron density indicates a low pressure prominence. We conclude with a discussion of the energy budget in the prominence.

Neutral Atom Diffusion in a Partially Ionized Prominence Plasma

The support of solar prominences is normally described in terms of a magnetic force on the prominence plasma that balances the solar gravitational force. Because the prominence plasma is only partially ionized, this support needs to be understood in terms of the frictional coupling between the neutral and ionized components of the prominence plasma, the efficacy of which depends directly on the ion density. More specifically, the frictional force is proportional to the relative flow of neutral and ion species, and for a plasma with a sufficiently small vertical ion column density, this flow must be relatively large to produce a frictional force that balances gravity. A large relative flow, of course, implies significant draining of neutral particles from the prominence. We evaluate the importance of this draining effect for a hydrogen-helium plasma and consider the variation of the draining with a variety of prominence parameters. Our calculations show that the loss timescale for hydrogen is much longer than that for helium, which for typical prominence parameters is about one day.

The MHD stability of a twisted flux tube prominence model

The ideal MHD stability of the 2D twisted magnetic flux tube prominence model of Cartledge and Hood (1993) is investigated. The model includes a temperature profile that varies from realistic prominence values up to typical coronal values. The prominence is considered to be of finite-width and finite height. The stability properties of the prominence models are studied by using a method that generates a separate necessary condition and a sufficient condition. These conditions give bounds on the parameters that define marginal stability. In many cases these bounds are quite close so that further, more detailed, stability calculations are not necessary. A number of parameter regimes are examined, corresponding to different profiles of the prominence temperatures, densities, and magnetic field shear. It is found that the model admits realistic stable and unstable loop lengths for observed prominence parameters when the axial magnetic field component does not vanish.

Gravitational ballooning instability of prominences

Prominences can be unstable to a gravitational ballooning instability of the Rayleigh-Taylor type. A two-dimensional generalized Kippenhahn-Schluter prominence equilibrium is constructed. Its stability to ideal, three-dimensional, short-wavelength line-tied perturbations is analyzed. The instability requires a critical vertical density gradient. For a given magnetic field strength, the instability is sensitive to the angle at which the magnetic field lines cross the prominence. An approximate, sufficient, threshold condition is consistent with typical prominence parameters.