Degree Of Constriction Research Articles

Snoopy Breast and Double Bubble Have Much in Common.

Sir: We were surprised by the statement of Ricci and Driscoll1: “the snoopy nose deformity is a completely different entity that stems from a completely different mechanism and is solved by different surgical techniques compared with the classic double bubble.” To our knowledge, these 2 major aesthetic complications of the breast augmentation are of the same origin and can be explained by the same predisposing morphological features,2 pertaining to the inframammary fold (IMF). In a number of studies, dissections were performed to find out the internal structures responsible for the surface landmarks of the breast. No matter if these studies claimed the distinct IMF ligament,3 splitting of Scarpa’s fascia into the anterior and posterior lamellae of the breast capsule along the IMF,4 or just condensation of criss-crossing ligaments5, all these data prove the reality of the superficial fascial system framework, which shapes the lower pole and the IMF. “The amount and density of the criss-crossing insertions here create the degree of constriction of the lower pole, and also the degree of fold definition.”5 It seems proper to add to the quotation, the degree of IMF tightness, which is generally graded as tight, moderate, or loose IMF.6 The tight IMF is “morphologically predisposed”2 for double bubble formation because of the density and rigidity of its fascial framework, which is able to resist stretching over the implant’s lower ventral curvature or even may be able to resume its initial shape after surgical release. This memory of shape restores the original IMF after its seemingly successful effacement and lowering at augmentation mammoplasty in 2 ways: first, by restoration of the original inframammary groove above the new one formed by the implant’s lower edge—double bubble; second, by restoration of whole IMF and lower pole fascial framework at the original position, causing the upward shift of the implant—snoopy nose. Both variants have the same morphological scene (fascial framework rigidity) and the same solution—respect or efface the IMF memory of shape. Comparing Figures 1 and 2 from the study by Ricci and Driscoll1 reveals that the original IMF is pretty high (morphologically prone2) in both pictures. In Figure 1, the necessity to remove the IMF shape memory by radical scoring or even resection of the lower pole parenchyma is obvious. In Figure 2, we see the “high riding implant,” meaning either misjudgment in pocket dissection or, most probably, recurrence of preoperative IMF location with forced implant cranial shifting. In Figure 2, the indentation of the initial IMF is actually clearly seen, no matter that the general breast contour differs drastically from that shown in Figure 1. Cause and cure are the same. Higher position and smaller implant in case 1 will most probably produce the contour as shown in Figure 2. Vice versa, placing the implant lower than shown in patient in Figure 2 will surely cause double bubble, as shown in Figure 1. Pertinent solutions include nipple elevation, implant size decrease, and IMF fascial framework release. We are motivated with the same urge as the authors to clarify the anatomical underpinning of these complications to better avoid or treat them. For that very reason, we cannot help but draw attention to the mistakes, like the following: “snoopy nose deformity is not caused by issues with the inframammary fold, but rather by ptosis of the breast gland relative to the implant causing a superior implant-to-nipple malposition.”1 Imagine now a high-breasted patient in whom the nipple will always look “ptotic” relative to the implant positioned at the IMF level. Imagine the catastrophe that may follow after “mastopexy” with the nipple elevation even closer to the clavicle, instead of prudently considering lowering the IMF. Both double bubble and snoopy deformities stem from the same morphological reason—tight IMF, with memory of shape and propensity to resume shape after release. Understanding and accepting that the shape memory is key, to our mind, is a sine qua non to standardize the terminology.

Articulatory reflexes of the three-way contrast in labial stops and kinematic evidence for domain-initial strengthening in Korean

This study examines articulatory characteristics of the three-way contrast in labial stops /p php*/ (lenis, aspirated, fortis, respectively) in Korean in phrase-initial and phrase-medial prosodic positions with a two-fold goal. First, it investigates supralaryngeal articulatory reflexes of the stops and explores articulatory invariance of these stops across prosodic positions. Second, it investigates Korean stops in kinematic terms from the perspective of domain-initial strengthening, and explores the nature of prosodically-conditioned speech production from a dynamical perspective. Results showed that the articulatory reflex of the three-way contrast was invariantly observed across prosodic positions with lip constriction degree (/p/</ph/</p*/), while lip constriction duration showed a binary distinction (/p/</php*/). Kinematically, there was only very weak articulatory evidence for the contrast across prosodic positions: The V-to-C lip closing movement tended to be faster for /ph/ than for /p/, and the C-to-V lip opening movement tended to be larger for /php*/ than for /p/. As for domain-initial strengthening, the consonantal lip closing gesture was characterized by a larger, longer and slower articulation, whereas the vocalic lip opening gesture (after the release) was larger and faster, but not longer. Kinematic relations indicated that the lip closing movement is most likely controlled by a rate of the clock (possibly modulated by a temporal modulation gesture, or π-gesture) comparable to boundary effects in English, but the boundary-induced lip opening movement was better accounted for by a change in target (possibly modulated by a spatial modulation gesture, or μ-gesture) which was comparable to prominence rather than boundary effects in English. The cross-linguistic difference was interpreted as coming from different prosodic systems between Korean and English, presumably instantiated in dynamical terms of how the temporal and the spatial modulation gestures are phased with constriction gestures in relation to boundary marking versus prominence marking.

Exploration quantitative de la phonation par aérophonoscopie : étude de reproductibilité sur sujets sains

The aerophonoscope allows for recording buccal and nasal airflow during breathing and speech and the sounds emitted by the patient. It is known to be useful in the postoperative follow-up of cleft lip and palate children, but there are currently no studies that quantitatively validate its reliability in pathological or non-pathological situations. The aim of our study was to measure the reliability of aerophonoscopic measures in adult healthy volunteers. A quantitative evaluation of the reliability of aerophonoscopy has been carried out in 30 healthy adult volunteers by measuring its inter- and intra-individual reproducibility and its sensibility in relation with the degree of the velopharyngeal sphincter constriction using a test-retest protocol. The aerophonoscope allows for inter- and intra-individual reproducible measures in healthy adult volunteers. Its sensibility to velopharyngeal sphincter constriction is good in healthy adult volunteers. The interest of aerophonoscopy in the treatment strategy of cleft lip and palate patients remains unclear. More reliable quantitative data would be of major interest to determine whether this device is suitable for the follow-up of cleft lips and palate patients or not. This would also allow for planning a second soft-palate operation and for assessing the efficacy of revision surgery such as superior or inferior pedicled pharyngoplasty.

Allophony of /ʝ/ in Peninsular Spanish

The p honeme /ʝ/ in Spanish is known to have a wide range of phonetic realizations, even within a single dialect. Whereas the influence of different contextual factors in conditioning the allophony of /b d ɡ/ has been the object of much recent acoustic investigation, somewhat surprisingly there are no comparable studies of the voiced palatal obstruent. We report on an acoustic investigation of this consonant in Peninsular Spanish. Both preceding context and stress appear to be relevant factors. We also find an effect of style, with more constriction in more formal styles. The presence of a word boundary also affects the degree of constriction, although to a lesser extent. Although we have identified several conditioning factors in the degree of constriction of this consonant, compared to /b d ɡ/, there appears to be greater variability in a given context, including very constricted, stop-like realizations of /ʝ/ in conversational styles even within the intervocalic context. Whereas our results largely confirm previous nonquantified description, they offer a more nuanced view of the continuum of the degree of constriction in the realization of this consonant and the factors that affect it, going beyond earlier views that postulated distinct allophones.

Catalan voiced prepalatals: Effects of nonphonetic factors on phonetic variation?

Central Catalan ‘prepalatal’ (postalveolar) consonants show a complex phonological distribution. Whereas in word-internal intervocalic position a four-way opposition obtains, involving a contrast in voice and a fricative/affricate distinction, elsewhere at least one of the two oppositions is neutralized. Position in word determines whether affrication and/or voicing is contrastive. We study the effect of this factor as well as other phonetic factors and style on the allophony of the voiced prepalatals in a large corpus of Central Catalan. The most significant conditioning factor turns out to be the preceding context, whereas position in word per se is not significant either for degree of constriction or for voicing. Thus, we do not find a direct effect of phonological contrastiveness on phonetic variation.

Abstract 19562: PKG-I[[Unable to Display Character: ɑ]] Oxidative Activation Regulates Small Artery Myogenic Tone Through Calcium Sparks and the BK Channel

Small resistance arteries function in a state of partial constriction generated by vascular smooth muscle cells (VSMC) in response to intraluminal pressure (‘myogenic constriction’). Collectively, the degree of myogenic constriction determines peripheral resistance and so influences systemic blood pressure. cGMP-dependent protein kinase (PKG) is widely implicated in vascular physiology, but until now has been assumed to play no role in modulation of this important vascular function on the basis that inhibitors of cGMP have no influence on pressure-induced tone. Recent identification of a novel redox mechanism by which PKG can be activated independently of the ‘classical’ NO-sGC-cGMP pathway made it important to revisit PKG’s role in these processes. To examine the relative contribution of these pathways, a transgenic mouse model was utilized, in which a single point mutation precludes activation via oxidative dimerization of PKG, whist preserving classical activation by cGMP. Diameter studies of small arteries from this ‘knock-in’ model were investigated in a pressure-myograph system, and demonstrated reduced constitutively functioning BKCa channel activity in these animals, and in consequence markedly enhanced myogenic constriction. Through imaging of calcium sparks with a spinning disc confocal microscope, the loss of BKCa channel function was shown to be due to diminished VSMC calcium sparks. Patch clamp electrophysiological studies showed that the amplitude and frequency of spontaneous transient outward currents were also reduced, consistent with these findings. Pharmacological studies using both pressure and wire myography with the application of the oxidant hydrogen peroxide provided a signal that myogenic tone initiates oxidant-induced activation of PKG. Western blot analysis of vessels fixed during relevant functional responses confirmed that generation of pressure-induced tone triggers oxidant activation of PKG. Finally, optical monitoring confirmed elevated ROS production with the induction of tone. Our results provide a conceptual framework by which vascular tone is modulated through release of ROS and oxidant-activation of PKG through calcium signalling. This may have important implications for blood pressure.

Stenosis map for volume visualization of constricted tubular structures: Application to coronary artery stenosis

Although direct volume rendering (DVR) has become a commodity, effective rendering of interesting features is still a challenge. In one of active DVR application fields, the medicine, radiologists have used DVR for the diagnosis of lesions or diseases that should be visualized distinguishably from other surrounding anatomical structures. One of most frequent and important radiologic tasks is the detection of lesions, usually constrictions, in complex tubular structures. In this paper, we propose a 3D spatial field for the effective visualization of constricted tubular structures, called as a stenosis map which stores the degree of constriction at each voxel. Constrictions within tubular structures are quantified by using newly proposed measures (i.e. line similarity measure and constriction measure) based on the localized structure analysis, and classified with a proposed transfer function mapping the degree of constriction to color and opacity. We show the application results of our method to the visualization of coronary artery stenoses. We present performance evaluations using twenty eight clinical datasets, demonstrating high accuracy and efficacy of our proposed method. The ability of our method to saliently visualize the constrictions within tubular structures and interactively adjust the visual appearance of the constrictions proves to deliver a substantial aid in radiologic practice.

Modeling and validation of auto-oscillation onset in a constricted tube with application to phonation

An experimental study of the auto-oscillation onset is performed for airflow in a rigid tube containing a constriction downstream from a deformable portion as a function of the constriction degree. A quasi-one dimensional laminar flow model in combination with a reduced order mechanical model (symmetric two mass model) provides a physical fluid–structure interaction model of the deformable portion. Mechanical, geometrical and flow model parameters are chosen to match the experimental setup. Modeled as well as experimental results show that a severe constriction (>80%) at first hinders (≥89%) and eventually inhibits (≥95%) auto-oscillation. Constrictions of different severity occur naturally in voiced speech sound production (phonation) due to articulation. The current study provides quantitative evidence of the role of the vocal tract constriction degree as a control parameter for phonation (voiced speech sound production) since increasing the constriction degree decreases the vocal folds oscillation frequency (decrease by 25%) and increases the minimum pressure needed to initiate oscillation (increase by 80%).

The effect of the degree of left renal vein constriction on the development of adolescent varicocele in Sprague-Dawley rats.

Experimental models have allowed inquiry into the pathophysiology of varicocele (VC) beyond that possible with human patients. A randomized controlled study in rats was designed to clarify the influence of the degree of left renal vein constriction on the development of adolescent VC. Fifty adolescent male Sprague–Dawley rats (Rattus norvegicus) were randomly assigned to five groups of 10: the experimental groups (I–IV) underwent partial ligation of left renal veins with 0.5-, 0.6-, 0.7-, and 0.8-mm diameter needles, respectively. The control group (V) underwent a sham operation. The diameter of the left spermatic vein (LSV) was measured at baseline and 30 days postoperatively. In addition, the lesion of the left kidney was examined with the naked eye and assessed by Masson's trichrome staining. VC was successfully induced in 2 (20%), 4 (40%), 7 (70%), and 10 (100%) rats in groups I–IV, respectively. The other rats failed to develop VCs primarily due to left renal atrophy. No VC was observed in group V. The postsurgical LSV diameters in VC rats in groups III and IV were 1.54 ± 0.16 and 1.49 ± 0.13 mm, respectively (P > 0.05), and their increments were 1.36 ± 0.10 and 1.31 ± 0.10 mm, respectively (P > 0.05). These results suggest that suitable constriction of the left renal vein is critical for adolescent VC development. In addition, the 0.8-mm diameter needle may be more suitable for inducing left renal vein constriction in adolescent rat models.

The Effect of Contextual Consonants on Voiced Stop Lenition: Evidence from Catalan.

Abstract This study uses acoustic energy measures for /b, d, g/ after /f, s, ∫, l, r/ in Catalan in order to test whether postconsonantal voiced stop lenition is ruled by minimization of articulatory effort, acoustico-perceptual continuity of an ongoing prosodic constituent or some other principle of articulatory organization. Data for eight speakers reveal that lenition is more prone to operate on /g/ than on /b, d/, after a sonorant than after a fricative, and when the two cluster consonants are heterorganic than when they are (quasi)-homorganic. Moreover, a positive correlation was found to hold between the degrees of stop lenition and stop voicing. The /fC/ sequences had an exceptional behaviour since, in comparison to other consonants appearing in CI position, /f/ was at the same time less intense and triggered more stop-like realizations of /b, d, g/. These results indicate that, while regularly treated as a phonological process, postconsonantal voiced stop lenition in Catalan is subject to much contextual variability, and should be dealt with by a production-based model which takes into consideration several articulatory and aerodynamic factors such as constriction degree and intraoral pressure level for C1 and C2, as well as homorganicity degree between the two consecutive consonants.

Articulation of vowel height in Taiwanese Vowels: An EMA study

Whalen et al.’s (2010) ultrasound study has suggested that constriction degree “may be the best descriptor for height” in American English front vowels {i, ɪ, e, ɛ}. The present study took a further step, investigating the case of height and backness distinction in Taiwanese front and back vowels. Stimuli consisted in /CV/ sequences with V corresponding to one of the six vowels {i, e, a, ɔ, ɣ, u} (Southern variety). Five adult speakers were asked to repeat each sequence six times in random order. The articulatory data were collected using the Carstens AG500 EMA system. Our results show that vowel height and backness in Taiwanese vowels can be reliably differentiated as follows: (1) for front and central vowels, height is primarily distinguished by Tongue Body Constriction Degree (TBCD) (i>e>a) (less robustly by Tongue Tip Constriction Degree), whereas height distinction of back vowels is made in Tongue Dorsum Constriction Degree (TDCD) (u>ɣ>ɔ), (2) backness can be distinguished by Tongue Tip and Tongue Body Constriction Location. Therefore, Whalen et al.’s (2010) claim can be extended to back vowels as well (at least in Taiwanese). Furthermore, our results are compatible with Ladefoged’s (2001) “holistic” view of vowel height as long as his “highest point of the tongue” can be “locally” interpreted: TBCD for height of front and central vowels and TDCD for back vowels. In sum, the present study suggests that distinction in vowel height be relativized to different gestural constriction degree.

Multimodal assessment of choroideremia patients defines pre-treatment characteristics.

Choroideremia (CHM) is a X-chromosomal disorder leading to blindness by progressive degeneration of choroid, retinal pigment epithelium (RPE), and retinal neurons. A current clinical gene therapy trial (NCT01461213) showed promising safety and efficacy data in a carefully selected patient population. The present study was performed to shed light on pre-treatment characteristics of a larger cohort of CHM patients using a high resolutionmulti-modal approach. In a retrospective cross-sectional study, data from 58 eyes of 29 patients with clinically confirmed CHM were analysed including best-corrected visual acuity (BCVA), refractive error, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF), perimetry, and tonometry. Residual retinal volume, area of residual RPE, and foveal thickness were quantified to further define natural disease progression and assess symmetry. We evaluated 98 data points of BCVA [0.34 ± 0.06 (logMAR); mean ± 95% confidence interval], 80 of IOP (14.6 ± 0.6mmHg), and 98 of refraction (-2.16 ± 1.08 spherical equivalent). Visual fields (n = 76) demonstrated variable degrees of concentric constriction (54% <10°, 25% 10-30°, 21% >30°). Mean residual RPE area on FAF (n = 64) measured 8.47 ± 1.91mm(2) (range 0.30-38.5mm(2)), while mean neuroretinal volume (n = 42) was found to be 1.76 ± 0.12mm(3). Age at examination was exponentially associated with BCVA, while logarithmic functions best described progressive loss of retinal area and volume. A high degree of left to right symmetry was found in all modalities with structural markers showing the best correlation (r (2) area = 0.83; r (2) volume = 0.75). Analysis of these widely available clinical data defines the natural disease characteristics of a relevant patient population eligible for gene therapeutic intervention. In the wake of preliminary reports on safety and efficacy of CHM gene therapy (NCT01461213), this multi-modal assessment of a cohort of CHM patients provides important evidence of the natural rate of disease progression and degree of symmetry between eyes.

Radiation dose to the tongue and velopharynx predicts acoustic-articulatory changes after chemo-IMRT treatment for advanced head and neck cancer

The aim of this study was to investigate to what extent changes in speech after C-IMRT treatment are related to mean doses to the tongue and velopharynx (VP). In 34 patients with advanced hypopharyngeal, nasopharyngeal, or oropharyngeal cancer, changes in speech from pretreatment to 10 weeks and 1 year posttreatment were correlated with mean doses to the base of tongue (BOT), oral cavity (OC) and tonsillar fossa/soft palate (VP). Differences in anteroposterior tongue position, dorsoventral degree of tongue to palate or pharynx constriction, grooving, strength, nasality, and laryngeal rise, were assessed by acoustic changes in three speech sounds that depend on a (post-) alveolar closure or narrowing (/t/, /s/, /z/), three with a tongue to palate/pharyngeal narrowing (/l/, /r/, /u/), and in vowel /a/ at comfortable and highest pitch. Acoustically assessed changes in tongue positioning, shape, velopharyngeal constriction, and laryngeal elevation were significantly related to mean doses to the tongue and velopharynx. The mean dose to BOT predicted changes in anteroposterior tongue positioning from pre- to 10-weeks posttreatment. From pretreatment to 1-year, mean doses to BOT, OC, and VP were related to changes in grooving, strength, laryngeal height, nasality, palatalization, and degree of pharyngeal constriction. Changes in speech are related to mean doses to the base of tongue and velopharynx. The outcome indicates that strength, motility, and the balance between agonist and antagonist muscle forces change significantly after radiotherapy.

An acoustic study of Luganda liquid allophones

AbstractTranscription-based descriptions of Luganda (Bantu, Uganda) have stated that there is a rhotic (r) in the language that occurs only after a front vowel, in complementary distribution with a lateral (l) that occurs only elsewhere. However, these descriptions of the pattern have disagreed about the nature and distribution of the sounds involved. Such a pattern has been reported in a number of Bantu and non-Bantu languages, and it is intriguing because its phonetic basis is not obvious, since there is nothing rhotic about a front vowel or lateral about a non-front vowel. To clarify the facts and provide insight into this kind of pattern, a production study was conducted in which Luganda speakers produced the liquid in varying vocalic contexts. F1, F2, duration, mean harmonics-to-noise ratio (HNR), and intensity were measured. The results support the characterization of the liquid after a front vowel as a nonlateral tap, and elsewhere as a lateral sonorant. But the intensity data also show a continuum in the degree of tongue tip constriction, ranging from approximant to tap, depending on the frontness of both the preceding and following vowels. The pattern of distribution is thus more complex and gradient than has been evident from transcriptions alone.

Tuberous breast deformity: classification and treatment strategy for improving consistency in aesthetic correction.

Tuberous breast deformity is a common congenital anomaly with varying degrees of constriction, hypoplasia, skin deficiency, areolar herniation, and asymmetry that poses challenges to consistency in aesthetic correction. In this study, the authors classify tuberous breast deformities, and evaluate their techniques used for treatment. Twenty-six patients (51 breasts) treated from 2008 to 2012 were included. Mean patient age was 25 years (range, 18 to 39 years). Cases were classified using a three-tier system. A periareolar approach and glandular scoring maneuvers were used in all cases. Prosthetic placement (implant or tissue expander) was subpectoral (dual-plane) in all cases. The selection of one- versus two-stage correction and mastopexy techniques is presented with reference to the specific deformities in each tier. Mean follow-up was 22 months (range, 8 to 37 months). Twelve type I, 26 type II, and 13 type III deformities were treated. Periareolar incisions only were used in two (4 percent). Circumareolar mastopexy was used in 49 (96 percent), and vertical mastopexy was used in four (8 percent). One-stage correction was achieved in 47 (92 percent); four (8 percent) were treated in two stages with tissue expansion. The global complication rate for all patients in this study is 7.8 percent-two breasts (3.9 percent) had capsular contracture, and two (3.9 percent) had postoperative malposition. The authors' experience demonstrates that satisfactory results can be obtained with appropriate classification and treatment of tuberous breast deformity with periareolar access, glandular scoring, subpectoral implant placement, and mastopexy techniques tailored to the specific deformity type. Therapeutic, IV.

Myogenic Properties of Brain and Cardiac Vessels and their Relation to Disease

Intrinsic arterial myogenic function comprises the degree of constriction (myogenic tone), the arterial constriction to an increase in intraluminal pressure and vice versa (myogenic response), and forced dilation at high intraluminal pressure. Although the development of myogenic tone at 40-60 mmHg involves the influx of calcium (Ca(2+)) through voltage- dependent Ca(2+) channels and an elevation in arterial intracellular Ca(2+) (Ca(2+) i), myogenic responses between 60-140 mmHg involves predominantly Rho kinase (ROK)-mediated changes in Ca(2+) sensitivity. In the cerebral circulation an impaired myogenic response results in impaired cerebral autoregulation and susceptibility hypertension-induced cerebral haemorrhage. An impaired cerebral artery myogenic response, due to blunted ROK mediated changes in Ca(2+) sensitivity, may be a consequence of defective mechanotransduction of the intraluminal pressure stimulus; this may be a result of abnormalities in the extracellular matrix. In the coronary circulation distinctions between the mechanisms involved in the development of myogenic tone and the myogenic response have not been clearly defined. However, coronary artery myogenic tone is dependent on both Ca(2+) entry through voltage -dependent Ca(2+) channels and protein kinase C (PKC) activity. Impaired coronary myogenic tone has been observed in animal models of disease but the implications of these findings are currently uncertain.

Descrição dos gestos articulatórios envolvidos na produção dos sons /r/ e /l/

Objetivo Investigar os dados de natureza articulatória de consoantes líquidas e a coarticulação dessas consoantes diante da produção de diferentes contextos vocálicos, em adultos falantes típicos do Português Brasileiro (PB). Métodos Participaram da pesquisa cinco adultos com idades entre 25 e 37 anos. Os gestos articulatórios foram capturados pelo ultrassom Modelo DP-6600 e analisados por meio do software AAA (Articulate Assistant Advanced). Foram selecionados três pares de palavras com os sons /r/ e /l/, em Onset Medial, em diferentes contextos vocálicos: /a/, /i/, /u/. Todas as palavras foram representadas por figuras, incluídas em uma mesma frase veículo. As imagens dos gestos articulatórios visualizadas no ultrassom corresponderam aos frames relativos à elevação máxima da ponta da língua nas produções de /r/ e /l/. Resultados /r/ e /l/ apresentaram dois gestos simultâneos: ponta e corpo da língua. A vogal /i/, em contexto seguinte ao /r/, e a vogal /u/, em contexto seguinte ao /l/, proporcionaram maior grau de constrição da ponta e do corpo da língua, respectivamente. Conclusão Os segmentos pesquisados apresentaram duplos gestos de língua. A coordenação dos gestos de /r/ e /l/, associados aos diferentes contextos vocálicos, revelou diferentes configurações.

Intrinsic anomalous ferroelectricity in vertically aligned LiNbO3-type ZnSnO3 hybrid nanoparticle-nanowire arrays

An intrinsically constricted ferroelectric (FE) hysteresis behavior with a high remanent polarization of ≈26 μC/cm2 is reported from LiNbO3-type (LN-type) ZnSnO3 hybrid nanoparticle-nanowire (NP-NW) arrayed film. Vertically aligned and densely packed LN-type ZnSnO3 hybrid NP-NW arrays are synthesized using ZnO:Al seed-layer assisted process by a physical/chemical combined methodology. Post-annealing treatments and repeated poling measurements reinstate that the constricted FE loop in LN-type ZnSnO3 is an inherent feature of the hybrid NP-NW structure. This is also exemplified by the noticeable increase in the degree of constriction with higher NP concentration in the sample. A close fit to the experimental data was obtained with the Preisach model of FE hysteresis confirming a unique charge-ordering mechanism which was ascribed to the interaction of the NPs with each other and the surrounding FE ZnSnO3 NWs. The work provides a comprehensible understanding of the microstructure-property relationships in emerging Pb-free, LN-type ZnSnO3 FE material.

Chain shifts, strident vowels, and expanded vowel spaces

&lt;p&gt;&lt;span&gt;Chain shifts among vowels proceed along tightly prescribed articulatory paths: peripheral vowels raise, and high vowels, butting up against the top of the vowel space, must instead diphthongize or centralize (Labov 2004). I argue that high vowels may &lt;/span&gt;&lt;span&gt;also &lt;/span&gt;&lt;span&gt;further increase their constriction degree, resulting in spirantized vowels with phonetic characteristics of voiced fricatives (Connell 2007). I account for the rare emergence of these vowels with basic principles of dispersion (Liljencrants and Lindblom 1972): tongue height sufficient to produce frication may be integrated into the articulatory vowel space as the end result of raising in push chains. &lt;/span&gt;&lt;/p&gt;

Examining suprasegmental and morphological effects on constriction degree with ultrasound imaging

Two case studies of ultrasound imaging use tongue shape differences to investigate whether suprasegmental influences affect the articulatory implementation of otherwise equivalent phonemic sequences. First, we examine whether word-medial and word-final stop codas have the same degree of constriction (e.g., "blacktop" vs. "black top"). Previous research on syllable position effects on articulatory implementation have conflated syllable position with word position, and this study investigates whether each prosodic factor has an independent contribution. Results indicate that where consistent differences are found, they are due not to the prosodic position but to speaker-specific implementation. Second, we examine whether morphological status influences the darkness of American English /l/ in comparing words like "tallest" and "flawless." While the intervocalic /l/s in "tall-est" and "flaw-less" are putatively assigned the same syllabic status, the /l/ in "tallest" corresponds to the coda /l/ of the stem "tall" whereas that of "flawless" is the onset of the affix "-less." Results indicate that /l/ is darker—the tongue is lower and more retracted—when corresponding to the coda of the stem word. Data in both studies were analyzed with smoothing spline ANOVA, an effective statistical technique for examining differences between whole tongue curves.