Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 25
Filter
1.
Talanta ; 281: 126816, 2024 Sep 05.
Article in English | MEDLINE | ID: mdl-39250869

ABSTRACT

An effective and rapid Raman measurement scheme to determine Fe3O4 concentration in sintered ores was explored. Because sintered ores are brownish-black materials that easily absorb laser photons, accurate quantitative analysis requires obtaining an Fe3O4 peak with a high signal-to-ratio by reducing the possibility of local sample heating and degradation. For this purpose, a wide area coverage (WAC) Raman scheme with a laser-illumination diameter of 1 mm was adopted to decrease the laser power per area (LP/A) on each sample. The sintered ore sample was also wetted with water to reduce the chance of further heating by the laser. The combination of the WAC scheme and water-wetting allowed to increase the laser power during sample measurement, and the subsequent intensity (as well as the signal-to-noise ratio) of the Fe3O4 peak was elevated compared with both that measured by a Raman microscope yielding a higher LP/A and without water-wetting of the sample. In the Raman spectra of 93 real sintered ore samples measured using the proposed scheme, the ratio of Fe3O4 and Fe2O3 peak areas correlated closely (R2 = 0.94) with Fe3O4 concentration determined by titration. The demonstrated scheme is practical when Raman spectroscopy is employed for compositional analysis of dark and highly photon-absorbing samples.

2.
Laryngoscope ; 134(3): 1327-1332, 2024 Mar.
Article in English | MEDLINE | ID: mdl-37676064

ABSTRACT

INTRODUCTION: Asymmetry of vocal fold (VF) vibration is common in patients with voice complaints and also observed in 10% of normophonic individuals. Although thyroarytenoid (TA) muscle activation plays a crucial role in regulating VF vibration, how TA activation asymmetry relates to voice acoustics and perception is unclear. We evaluated the relationship between TA activation asymmetry and the resulting acoustics and perception. METHODS: An in vivo canine model of phonation was used to create symmetric and increasingly asymmetric VF vibratory conditions via graded stimulation of bilateral TA muscles. Naïve listeners (n = 89) rated the perceptual quality of 100 unique voice samples using a visual sort-and-rate task. For each phonatory condition, cepstral peak prominence (CPP), harmonic amplitude (H1-H2), and root-mean-square (RMS) energy of the voice were measured. The relationships between these metrics, vibratory asymmetry, and perceptual ratings were evaluated. RESULTS: Increasing levels of TA asymmetry resulted in declining listener preference. Furthermore, only severely asymmetric audio samples were perceptually distinguishable from symmetric and mildly asymmetric conditions. CPP was negatively correlated with TA asymmetry: voices produced with larger degrees of asymmetry were associated with lower CPP values. Listeners preferred audio samples with higher values of CPP, high RMS energy, and lower H1-H2 (less breathy). CONCLUSION: Listeners are sensitive to changes in voice acoustics related to vibratory asymmetry. Although increasing vibratory asymmetry is correlated with decreased perceptual ratings, mild asymmetries are perceptually tolerated. This study contributes to our understanding of voice production and quality by identifying perceptually salient and clinically meaningful asymmetry. LEVEL OF EVIDENCE: N/A (Basic Science Study) Laryngoscope, 134:1327-1332, 2024.


Subject(s)
Dysphonia , Voice , Humans , Animals , Dogs , Vibration , Speech Acoustics , Voice/physiology , Phonation/physiology , Acoustics , Perception
3.
Nurs Open ; 10(8): 5446-5452, 2023 08.
Article in English | MEDLINE | ID: mdl-37114859

ABSTRACT

AIM: To investigate the mediating effect of sleep-related problems on the relationship between depression and work-family conflicts (WFCs) among middle-aged female workers. DESIGN: Secondary analysis of cross-sectional study. METHODS: Overall, 15,718 female workers aged 40-65 years from the Sixth Korean Working Conditions Survey (KWCS) were included. Depression was assessed using the WHO-5 wellbeing index; sleep-related problems and WFCs were measured with five items on a Likert scale. The mediating effect of sleep-related problems between depression and WFCs was analysed using model 4 of Hayes PROCESS macro for SPSS. RESULTS: There was a significant positive correlation between depression and both sleep-related problems (r = 0.225, p < 0.001) and WFCs (r = 0.124, p < 0.001). Depression also had a significant effect on sleep-related problems (ß = 0.221, p < 0.001) and WFCs (ß=0.061, p < 0.001). Sleep-related problems had a significant effect on WFCs (ß = 0.282, p < 0.001). The indirect effect of depression on WFCs by mediating sleep-related problems was ß = 0.062 (95% bootstrap confidence interval = 0.057-0.068). The study also confirmed the significance of the mediating effect of sleep-related problems in the relationship between depression and WFCs.


Subject(s)
Dyssomnias , Family Conflict , Middle Aged , Humans , Female , Depression/epidemiology , Cross-Sectional Studies , Surveys and Questionnaires
4.
Laryngoscope ; 133(2): 357-365, 2023 02.
Article in English | MEDLINE | ID: mdl-35633189

ABSTRACT

INTRODUCTION: Although phonatory glottal posture and airflow pulse shape affect voice quality, studies to date have been limited by visualization of vocal fold (VF) vibration from a superior view. We performed a 3D reconstruction of VF vibratory motion during phonation from a medial view and assessed the glottal volume waveform and resulting acoustics as a function of neuromuscular stimulation. STUDY DESIGN: In vivo canine hemilarynx phonation. METHODS: Across 121 unique combinations of the superior laryngeal nerve (SLN) and recurrent laryngeal nerve (RLN) stimulation, the hemilarynx was excited to the oscillation with airflow. VF medial surface reference points were tracked on high-speed video, mapped into 3D space, and surface shape was restored using cubic spline interpolation. Glottal surface shape, reconstruction-based parameters, and glottal volume waveform were calculated. Fundamental frequency (F0), cepstral peak prominence (CPP), and harmonic amplitude (H1-H2) were measured from high-quality audio samples. RESULTS: The glottis was convergent during opening and divergent during closing. Neuromuscular activation changed phonatory glottal shape and reduced glottal volume. Significant reduction in glottal volume and closing quotient were present with SLN stimulation. RLN stimulation significantly increased F0 and CPP and decreased H1-H2 (constricted glottis), while SLN effects were similar and synergistic with concurrent RLN stimulation. CONCLUSION: 3D reconstruction of in vivo medial surface vibration revealed effects of laryngeal nerve stimulation on glottal vibratory pattern and acoustic correlates of voice quality. SLN activation resulted in significantly quicker glottal closure per cycle, decreased glottal volume, and higher-pitched, less breathy, and less noisy voice. RLN had a similar effect on acoustic measures. LEVEL OF EVIDENCE: NA, Basic Science Laryngoscope, 133:357-365, 2023.


Subject(s)
Glottis , Imaging, Three-Dimensional , Animals , Dogs , Glottis/physiology , Vocal Cords/physiology , Phonation/physiology , Voice Quality , Vibration
5.
J Acoust Soc Am ; 151(5): 3462, 2022 05.
Article in English | MEDLINE | ID: mdl-35649890

ABSTRACT

This study replicates and extends the recent findings of Lee, Keating, and Kreiman [J. Acoust. Soc. Am. 146(3), 1568-1579 (2019)] on acoustic voice variation in read speech, which showed remarkably similar acoustic voice spaces for groups of female and male talkers and the individual talkers within these groups. Principal component analysis was applied to acoustic indices of voice quality measured from phone conversations for 99/100 of the same talkers studied previously. The acoustic voice spaces derived from spontaneous speech are highly similar to those based on read speech, except that unlike read speech, variability in fundamental frequency accounted for significant acoustic variability. Implications of these findings for prototype models of speaker recognition and discrimination are considered.


Subject(s)
Speech , Voice , Acoustics , Female , Humans , Male , Speech Acoustics , Voice Quality
6.
Mol Cells ; 45(7): 454-464, 2022 Jul 31.
Article in English | MEDLINE | ID: mdl-35444068

ABSTRACT

DJ-1 is one of the causative genes of early-onset familial Parkinson's disease (PD). As a result, DJ-1 influences the pathogenesis of sporadic PD. DJ-1 has various physiological functions that converge to control the levels of intracellular reactive oxygen species (ROS). Based on genetic analyses that sought to investigate novel antioxidant DJ-1 downstream genes, pyruvate dehydrogenase (PDH) kinase (PDK) was demonstrated to increase survival rates and decrease dopaminergic (DA) neuron loss in DJ-1 mutant flies under oxidative stress. PDK phosphorylates and inhibits the PDH complex (PDC), subsequently downregulating glucose metabolism in the mitochondria, which is a major source of intracellular ROS. A loss-of-function mutation in PDK was not found to have a significant effect on fly development and reproduction, but severely ameliorated oxidative stress resistance. Thus, PDK plays a critical role in the protection against oxidative stress. Loss of PDH phosphatase (PDP), which dephosphorylates and activates PDH, was also shown to protect DJ-1 mutants from oxidative stress, ultimately supporting our findings. Further genetic analyses suggested that DJ-1 controls PDK expression through hypoxia-inducible factor 1 (HIF-1), a transcriptional regulator of the adaptive response to hypoxia and oxidative stress. Furthermore, CPI-613, an inhibitor of PDH, protected DJ-1 null flies from oxidative stress, suggesting that the genetic and pharmacological inhibition of PDH may be a novel treatment strategy for PD associated with DJ-1 dysfunction.


Subject(s)
Drosophila , Parkinson Disease , Animals , Dopaminergic Neurons/metabolism , Drosophila/genetics , Oxidative Stress/genetics , Parkinson Disease/pathology , Pyruvate Dehydrogenase Acetyl-Transferring Kinase , Reactive Oxygen Species/metabolism
7.
Int J Mol Sci ; 24(1)2022 Dec 22.
Article in English | MEDLINE | ID: mdl-36613636

ABSTRACT

Prion diseases are neurodegenerative disorders in humans and animals for which no therapies are currently available. Here, we report that Curcuma phaeocaulis Valeton (Zingiberaceae) (CpV) extract was partly effective in decreasing prion aggregation and propagation in both in vitro and in vivo models. CpV extract inhibited self-aggregation of recombinant prion protein (PrP) in a test tube assay and decreased the accumulation of scrapie PrP (PrPSc) in ScN2a cells, a cultured neuroblastoma cell line with chronic prion infection, in a concentration-dependent manner. CpV extract also modified the course of the disease in mice inoculated with mouse-adapted scrapie prions, completely preventing the onset of prion disease in three of eight mice. Biochemical and neuropathological analyses revealed a statistically significant reduction in PrPSc accumulation, spongiosis, astrogliosis, and microglia activation in the brains of mice that avoided disease onset. Furthermore, PrPSc accumulation in the spleen of mice was also reduced. CpV extract precluded prion infection in cultured cells as demonstrated by the modified standard scrapie cell assay. This study suggests that CpV extract could contribute to investigating the modulation of prion propagation.


Subject(s)
Prion Diseases , Prions , Scrapie , Zingiberaceae , Animals , Mice , Curcuma/metabolism , Models, Animal , Plant Extracts/pharmacology , Prion Diseases/drug therapy , Prion Proteins , Prions/metabolism , Scrapie/metabolism , Sheep
8.
Anal Chim Acta ; 1175: 338746, 2021 Aug 29.
Article in English | MEDLINE | ID: mdl-34330445

ABSTRACT

When Raman spectroscopy is employed for a direct in situ determination of ingredient concentration for a product stored in a glass container, minimization of the interfering glass background in the collected spectrum is demanding to secure a more accurate analysis. To meet this request, an axially slanted illumination (ASI) scheme slantingly irradiating laser on the headspace side of a glass container and positioning a detector beneath the container was demonstrated in this study. This ASI scheme was basically designed to increase the distance between the laser illumination spot and detector location to minimize the number of glass photons reaching the detector. The analytical utility of the scheme was evaluated for the determination of gemcitabine concentration (42.9-58.2 wt%) in the gemcitabine injection powder housed in a glass container. Using the ASI scheme, the spectral features of the gemcitabine powder became distinct with only a weak underlying glass background signal. For comparative purpose, when an axially perpendicular offset (APO) scheme perpendicularly irradiating laser on the side wall where the sample was filled was used, the magnitude of glass background was higher, and the most intense gemcitabine peak was largely buried in the glass peak. The accuracy for determination of gemcitabine concentration using the ASI scheme was superior with an error of 0.20 wt%, while 0.33 wt% with employing the APO scheme. Overall, this study demonstrates that the ASI scheme is a potentially versatile Raman spectroscopic tool for fast non-sampling analysis of other products stored in a glass container.


Subject(s)
Lighting , Spectrum Analysis, Raman , Deoxycytidine/analogs & derivatives , Glass , Lasers , Powders , Gemcitabine
9.
Sci Data ; 8(1): 187, 2021 07 20.
Article in English | MEDLINE | ID: mdl-34285240

ABSTRACT

Real-time magnetic resonance imaging (RT-MRI) of human speech production is enabling significant advances in speech science, linguistics, bio-inspired speech technology development, and clinical applications. Easy access to RT-MRI is however limited, and comprehensive datasets with broad access are needed to catalyze research across numerous domains. The imaging of the rapidly moving articulators and dynamic airway shaping during speech demands high spatio-temporal resolution and robust reconstruction methods. Further, while reconstructed images have been published, to-date there is no open dataset providing raw multi-coil RT-MRI data from an optimized speech production experimental setup. Such datasets could enable new and improved methods for dynamic image reconstruction, artifact correction, feature extraction, and direct extraction of linguistically-relevant biomarkers. The present dataset offers a unique corpus of 2D sagittal-view RT-MRI videos along with synchronized audio for 75 participants performing linguistically motivated speech tasks, alongside the corresponding public domain raw RT-MRI data. The dataset also includes 3D volumetric vocal tract MRI during sustained speech sounds and high-resolution static anatomical T2-weighted upper airway MRI for each participant.


Subject(s)
Larynx/physiology , Magnetic Resonance Imaging/methods , Speech , Adolescent , Adult , Computer Systems , Female , Humans , Male , Middle Aged , Time Factors , Video Recording , Young Adult
10.
J Acoust Soc Am ; 149(1): 457, 2021 01.
Article in English | MEDLINE | ID: mdl-33514179

ABSTRACT

No agreed-upon method currently exists for objective measurement of perceived voice quality. This paper describes validation of a psychoacoustic model designed to fill this gap. This model includes parameters to characterize the harmonic and inharmonic voice sources, vocal tract transfer function, fundamental frequency, and amplitude of the voice, which together serve to completely quantify the integral sound of a target voice sample. In experiment 1, 200 voices with and without diagnosed vocal pathology were fit with the model using analysis-by-synthesis. The resulting synthetic voice samples were not distinguishable from the original voice tokens, suggesting that the model has all the parameters it needs to fully quantify voice quality. In experiment 2 parameters that model the harmonic voice source were removed one by one, and the voice tokens were re-synthesized with the reduced model. In every case the lower-dimensional models provided worse perceptual matches to the quality of the natural tokens than did the original set, indicating that the psychoacoustic model cannot be reduced in dimensionality without loss of fit to the data. Results confirm that this model can be validly applied to quantify voice quality in clinical and research applications.


Subject(s)
Psychoacoustics , Voice Disorders , Voice , Female , Humans , Male , Speech , Speech Acoustics , Voice Quality
11.
Analyst ; 145(16): 5539-5546, 2020 Aug 10.
Article in English | MEDLINE | ID: mdl-32608463

ABSTRACT

The axially perpendicular offset (APO) scheme was previously demonstrated as a versatile scheme able to minimize or eliminate the glass background in the direct and non-sampling Raman measurement of an ethanol sample housed in a glass bottle. Alternatively, when directly analyzing a sample housed in a plastic container, another typical container yielding strong Raman peaks itself, the Raman peaks of both the container and the housed sample are unavoidably present together in a collected spectrum. Therefore, a crucial issue to investigate under this situation is how the magnitude of the co-appearing container peaks influences the accuracy for quantitative analysis of the housed sample. For the evaluation, a non-sampling Raman spectroscopic measurement of the urea concentration in a urea gel housed in a circular polypropylene (PP) container was attempted by employing two axially perpendicular offset (APO) schemes with detection windows of different sizes (25.4 and 10.0 mm, referred to as the wide-window APO (WW-APO) and narrow-window APO (NW-APO), respectively), and transmission and back-scattering schemes incorporating a 25.4 mm detection window. The intensity ratios between the container and urea peaks in the collected spectra were different depending on the adopted measurement scheme. The intensity ratio was greatest (smallest container peak) in the NW-APO measurement due to the narrowed detection window, making the generated container Raman photons at the side-wall less detectable to the bottom-positioned detector. A spectral acquisition scheme allowing the maximal suppression of the container peaks, while still maintaining the sample features, was a key requirement to secure an accurate measurement of the sample concentration. In addition, a Monte Carlo simulation was used to visualize the distributions of the container and urea photons inside the sample-housed container.

12.
Anal Chem ; 92(1): 1016-1023, 2020 01 07.
Article in English | MEDLINE | ID: mdl-31769285

ABSTRACT

A strategy to improve accuracy of near-infrared (NIR) quantitative analysis of powder samples by alleviating the subsampling problem is demonstrated. The approach is to increase spectroscopic sampling volume for more accurate representation of its composition by filling the void space in a packed sample with liquid to reduce differences in refractive index between particle and unoccupied space. By this way, NIR radiation can propagate deeper into the packed powder due to decreased degree of reflection at the interfaces, leading to greater sampling volume. Perfluorohexane (PFH) was chosen as the space-filling liquid since it does not readily absorb NIR radiation and does not disintegrate sample particles due to its strong hydrophobicity. For evaluation, binary mixtures composed of ambroxol and lactose at different concentrations were prepared, and their diffuse reflectance spectra were collected in two ways: conventional direct powder measurement and PFH-incorporated powder measurement. The accuracy of ambroxol concentration determination improved in the PFH-incorporated measurement due to acquisition of more composition-representative spectra by the greater sampling volume. Also, the sample morphology did not change in PFH medium based on XRD analysis. In parallel, Monte Carlo simulation was executed to track NIR photons in the samples and explain the improved accuracy. Improvement in accuracy was also realized when analyzing real pharmaceutical samples containing an active pharmaceutical ingredient in granular form, demonstrating expandability of the proposed scheme.

13.
Lang Speech ; 63(3): 526-549, 2020 Sep.
Article in English | MEDLINE | ID: mdl-31385552

ABSTRACT

This study uses a response mouse-tracking paradigm to examine the role of sub-phonemic information in online lexical ambiguity resolution of continuous speech. We examine listeners' sensitivity to the sub-phonemic information that is specific to the ambiguous internal open juncture /s/-stop sequences in American English (e.g., "place kin" vs. "play skin"), that is, voice onset time (VOT) indicating different degrees of aspiration (e.g., long VOT for "kin" vs. short VOT for "skin") in connected speech contexts. A cross-splicing method was used to create two-word sequences (e.g., "place kin" or "play skin") with matching VOTs (long for "kin"; short for "skin") or mismatching VOTs (short for "kin"; long for "skin"). Participants (n = 20) heard the two-word sequences, while looking at computer displays with the second word in the left/right corner ("KIN" and "SKIN"). Then, listeners' click responses and mouse movement trajectories were recorded. Click responses show significant effects of VOT manipulation, while mouse trajectories do not. Our results show that stop-release information, whether temporal or spectral, can (mis)guide listeners' interpretation of the possible location of a word boundary between /s/ and a following stop, even when other aspects in the acoustic signal (e.g., duration of /s/) point to the alternative segmentation. Taken together, our results suggest that segmentation and lexical access are highly attuned to bottom-up phonetic information; our results have implications for a model of spoken language recognition with position-specific representations available at the prelexical level and also allude to the possibility that detailed phonetic information may be stored in the listeners' lexicons.


Subject(s)
Phonetics , Psychomotor Performance/physiology , Recognition, Psychology/physiology , Speech Perception/physiology , Acoustic Stimulation , Adult , Computer Peripherals , Female , Humans , Ice Cream , Male , Speech , Speech Acoustics , User-Computer Interface
14.
J Acoust Soc Am ; 146(3): 1568, 2019 09.
Article in English | MEDLINE | ID: mdl-31590565

ABSTRACT

Little is known about the nature or extent of everyday variability in voice quality. This paper describes a series of principal component analyses to explore within- and between-talker acoustic variation and the extent to which they conform to expectations derived from current models of voice perception. Based on studies of faces and cognitive models of speaker recognition, the authors hypothesized that a few measures would be important across speakers, but that much of within-speaker variability would be idiosyncratic. Analyses used multiple sentence productions from 50 female and 50 male speakers of English, recorded over three days. Twenty-six acoustic variables from a psychoacoustic model of voice quality were measured every 5 ms on vowels and approximants. Across speakers the balance between higher harmonic amplitudes and inharmonic energy in the voice accounted for the most variance (females = 20%, males = 22%). Formant frequencies and their variability accounted for an additional 12% of variance across speakers. Remaining variance appeared largely idiosyncratic, suggesting that the speaker-specific voice space is different for different people. Results further showed that voice spaces for individuals and for the population of talkers have very similar acoustic structures. Implications for prototype models of voice perception and recognition are discussed.


Subject(s)
Biological Variation, Individual , Biological Variation, Population , Speech Acoustics , Voice/physiology , Adult , Female , Humans , Male , Phonetics , Psychoacoustics
15.
J Korean Acad Nurs ; 49(3): 307-316, 2019 Jun.
Article in Korean | MEDLINE | ID: mdl-31266927

ABSTRACT

PURPOSE: This study was conducted to investigate the influence of emotional expressivity, emotional intelligence, affectivity, job autonomy, social support, and emotional labor on clinical nurses' individual well-being and to provide guidelines for interventions and strategies for its improvement. METHODS: The sample consisted of 207 nurses recruited from a general hospital in Korea. The participants completed a structured self-report questionnaire comprising measures of emotional expressivity, emotional intelligence, positive affectivity, negative affectivity, job autonomy, supervisor support, coworker support, deep acting, surface acting, emotional exhaustion, and job satisfaction. Data were analyzed using SPSS statistics 22.0 and AMOS 22.0. RESULTS: The final model was a good fit for the data based on the model fit indices. In the path analysis, surface acting, negative affectivity, supervisor support, and coworker support had statistically significant effects on emotional exhaustion, explaining 29.0% of the variance. Deep acting, emotional exhaustion, positive affectivity, and emotional intelligence had statistically significant effects on job satisfaction, explaining 43.0% of the variance. CONCLUSION: Effective strategies to improve clinical nurses' individual well-being should focus on surface acting, deep acting, affectivity, social support, and emotional intelligence. The results of this study can be utilized as base data to manage emotional labor and improve clinical nurses' individual well-being.


Subject(s)
Emotions , Nursing Staff, Hospital/psychology , Adult , Emotional Intelligence , Female , Hospitals, General , Humans , Job Satisfaction , Middle Aged , Self Report , Social Support , Surveys and Questionnaires , Young Adult
16.
Analyst ; 144(7): 2403-2410, 2019 Mar 25.
Article in English | MEDLINE | ID: mdl-30809627

ABSTRACT

As a training set for multivariate quantitative analysis, lab-blended powder samples are frequently used due to the facile concentration variation of the individual components. Real pharmaceutical process samples, however, are often granular in form. The different morphologies between training and process samples result in dissimilar Raman spectral features, thereby seriously deteriorating the accuracy of the analysis. To overcome this hurdle, an effective and simple strategy to make physical presentations of both training and process samples similar, called water wetting, was demonstrated in this study. Wetting potentially dismantles process granule samples into smaller aggregates, whereas lab powder samples could be somewhat aggregated by water-bridging. Thus, water wetting would produce similar morphologies of both samples. To evaluate the strategy, samples containing esomeprazole magnesium dihydrate (EMD) as an active pharmaceutical ingredient (API) and five additional components were employed. Initially, training samples were mixed with the individual components at the intended concentration ranges. A partial least squares (PLS) model developed using the Raman spectra of the training samples was inaccurate in determining EMD concentrations in the real process samples. When both training and process samples were wetted prior to analysis, accurate concentration determination was realized due to no significant difference in Raman spectral features between samples. The similar morphologies and crystallinities of the two types of wetted samples were confirmed by analyzing the corresponding SEM images and XRD patterns. The proposed strategy is versatile and expandable for further vibrational spectroscopic analysis of various other samples with different morphologies.


Subject(s)
Drug Discovery , Laboratories , Spectrum Analysis, Raman/methods , Wettability , Calibration , Least-Squares Analysis
17.
J Acoust Soc Am ; 144(4): EL290, 2018 10.
Article in English | MEDLINE | ID: mdl-30404513

ABSTRACT

Real-time magnetic resonance imaging (MRI) speech production data have expanded the understanding of vocal tract actions. This letter presents an Automatic Centroid Tracking tool, ACT, which obtains both spatial and temporal information characterizing multi-directional articulatory movement. ACT auto-segments an articulatory object composed of connected pixels in a real-time MRI video, by finding its intensity centroids over time and returns kinematic profiles including direction and magnitude information of the object. This letter discusses the utility of ACT, which outperforms other similar object tracking techniques, by demonstrating its successful online tracking of vertical larynx movement. ACT can be deployed generally for dynamic image processing and analysis.


Subject(s)
Larynx/diagnostic imaging , Magnetic Resonance Imaging/methods , Software , Speech , Voice , Humans
18.
PLoS One ; 13(8): e0201444, 2018.
Article in English | MEDLINE | ID: mdl-30086554

ABSTRACT

This study uses a maze navigation task in conjunction with a quasi-scripted, prosodically controlled speech task to examine acoustic and articulatory accommodation in pairs of interacting speakers. The experiment uses a dual electromagnetic articulography set-up to collect synchronized acoustic and articulatory kinematic data from two facing speakers simultaneously. We measure the members of a dyad individually before they interact, while they are interacting in a cooperative task, and again individually after they interact. The design is ideally suited to measure speech convergence, divergence, and persistence effects during and after speaker interaction. This study specifically examines how convergence and divergence effects during a dyadic interaction may be related to prosodically salient positions, such as preceding a phrase boundary. The findings of accommodation in fine-grained prosodic measures illuminate our understanding of how the realization of linguistic phrasal structure is coordinated across interacting speakers. Our findings on individual speaker variability and the time course of accommodation provide novel evidence for accommodation at the level of cognitively specified motor control of individual articulatory gestures. Taken together, these results have implications for understanding the cognitive control of interactional behavior in spoken language communication.


Subject(s)
Cognition/physiology , Cooperative Behavior , Interpersonal Relations , Speech/physiology , Adult , Electromagnetic Phenomena , Female , Humans , Male , Speech Production Measurement/instrumentation , Speech Production Measurement/methods , Young Adult
19.
Analyst ; 143(18): 4306-4315, 2018 Sep 21.
Article in English | MEDLINE | ID: mdl-30095827

ABSTRACT

Near-infrared (NIR) spectral features of a target component can be influenced by its particle size as well as the particle sizes of the surrounding components in multi-component samples; therefore, understanding the essence of particle size-induced spectral variation is fundamental for robust quantitative analysis. For systematic investigation, two different types of binary-component samples were prepared. First, in ambroxol/lactose powders, only the particle size of lactose (surrounding filler) was varied, while the particle size of ambroxol (a target component) remained unchanged. Second, in lactose/PE pellets, the particle size of lactose (a target component) was only varied. When measuring ambroxol/lactose powders, the absorbances of both ambroxol and lactose peaks were elevated as the particle size of lactose increased. The larger lactose particle made the photon propagation broader in the sample, so a greater amount of ambroxol was able to interact with NIR photons; this led to an increase in absorbance. In the case of lactose (10 wt%)/PE pellets, the absorbance of lactose oppositely decreased as the lactose particle size increased. Since PE was the dominant component (85-95%) and had a small particle size (7 µm), the depth of photon propagation was substantially shallow. In this situation, the larger lactose particles would sometimes not be located within the small sampling volume and/or the photons would only partially interact with the particles; this led to a decrease in the absorbance. For both binary samples, the accuracies for the determination of target concentrations deteriorated as the particle size increased. This was due to the degradation of the measurement reproducibility caused by the increased uncertainty in the photon propagation. Monte Carlo simulation was effective for probing the photon propagation inside samples and supportive to explain the experimental observations.

20.
J Chromatogr A ; 1556: 97-102, 2018 Jun 29.
Article in English | MEDLINE | ID: mdl-29731290

ABSTRACT

We propose a new analytical scheme in which field-flow fractionation (FFF)-based separation of target-specific polystyrene (PS) particle probes of different sizes are incorporated with amplified surface-enhanced Raman scattering (SERS) tagging for the simultaneous and sensitive detection of multiple microRNAs (miRNAs). For multiplexed detection, PS particles of three different diameters (15, 10, 5 µm) were used for the size-coding, and a probe single stranded DNA (ssDNA) complementary to a target miRNA was conjugated on an intended PS particle. After binding of a target miRNA on PS probe, polyadenylation reaction was executed to generate a long tail composed of adenine (A) serving as a binding site to thymine (T) conjugated Au nanoparticles (T-AuNPs) to increase SERS intensity. The three size-coded PS probes bound with T-AuNPs were then separated in a FFF channel. With the observation of extinction-based fractograms, separation of three size-coded PS probes was clearly confirmed, thereby enabling of measuring three miRNAs simultaneously. Raman intensities of FFF fractions collected at the peak maximum of 15, 10 and 5 µm PS probes varied fairy quantitatively with the change of miRNA concentrations, and the reproducibility of measurement was acceptable. The proposed method is potentially useful for simultaneous detection of multiple miRNAs with high sensitivity.


Subject(s)
DNA Probes/chemistry , Fractionation, Field Flow/methods , MicroRNAs/analysis , Particle Size , Polystyrenes/chemistry , Spectrum Analysis, Raman/methods , DNA, Single-Stranded/chemistry , Feasibility Studies , Gold/chemistry , Nanoparticles/chemistry , Reproducibility of Results
SELECTION OF CITATIONS
SEARCH DETAIL