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Sample records for fold vibratory patterns

  1. Electroglottographic parameterization of the effects of gender, vowel and phonatory registers on vocal fold vibratory patterns: an Indian perspective.

    Science.gov (United States)

    Paul, Nilanjan; Kumar, Suman; Chatterjee, Indranil; Mukherjee, Biswarup

    2011-01-01

    In-depth study on laryngeal biomechanics and vocal fold vibratory patterns reveal that a single vibratory cycle can be divided into two major phases, the closed and open phase, which is subdivided into opening and closing phases. Studies reveal that the relative time course of abduction and adduction, which in turn is dependent on the relative relaxing and tensing of the vocal fold cover and body, to be the determining factor in production of a particular vocal register like the modal (or chest), falsetto, glottal fry registers. Studies further point out Electroglottography to be particularly suitable for the study of vocal vibratory patterns during register changes. However, to date, there has been limited study on quantitative parameterization of EGG wave form in vocal fry register. Moreover, contradictory findings abound in literature regarding effects of gender and vowel types on vocal vibratory patterns, especially during phonation at different registers. The present study endeavors to find out the effects of vowel and gender differences on the vocal fold vibratory patterns in different registers and how these would be reflected in standard EGG parameters of Contact Quotient (CQ) and Contact Index (CI), taking into consideration the Indian sociolinguistic context. Electroglottographic recordings of 10 young adults (5 males and 5 females) were taken while the subjects phonated the three vowels /a/,/i/,/u/ each in two vocal registers, modal and vocal fry. Obtained raw EGG were further normalized using the Derived EGG algorithm and theCQ and CI values were derived. Obtained data were subject to statistical analysis using the 3-way ANOVA with gender, vowel and vocal register as the three variables. Post-hoc Dunnett C multiple comparison analysis were also performed. Results reveal that CQ values are significantly higher in vocal fry than modal phonation for both males and females, indicating a relatively hyperconstricted vocal system during vocal fry. The males

  2. Repairing the vibratory vocal fold.

    Science.gov (United States)

    Long, Jennifer L

    2018-01-01

    A vibratory vocal fold replacement would introduce a new treatment paradigm for structural vocal fold diseases such as scarring and lamina propria loss. This work implants a tissue-engineered replacement for vocal fold lamina propria and epithelium in rabbits and compares histology and function to injured controls and orthotopic transplants. Hypotheses were that the cell-based implant would engraft and control the wound response, reducing fibrosis and restoring vibration. Translational research. Rabbit adipose-derived mesenchymal stem cells (ASC) were embedded within a three-dimensional fibrin gel, forming the cell-based outer vocal fold replacement (COVR). Sixteen rabbits underwent unilateral resection of vocal fold epithelium and lamina propria, as well as reconstruction with one of three treatments: fibrin glue alone with healing by secondary intention, replantation of autologous resected vocal fold cover, or COVR implantation. After 4 weeks, larynges were examined histologically and with phonation. Fifteen rabbits survived. All tissues incorporated well after implantation. After 1 month, both graft types improved histology and vibration relative to injured controls. Extracellular matrix (ECM) of the replanted mucosa was disrupted, and ECM of the COVR implants remained immature. Immune reaction was evident when male cells were implanted into female rabbits. Best histologic and short-term vibratory outcomes were achieved with COVR implants containing male cells implanted into male rabbits. Vocal fold cover replacement with a stem cell-based tissue-engineered construct is feasible and beneficial in acute rabbit implantation. Wound-modifying behavior of the COVR implant is judged to be an important factor in preventing fibrosis. NA. Laryngoscope, 128:153-159, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  3. Vocal Fold Vibratory Changes Following Surgical Intervention.

    Science.gov (United States)

    Chen, Wenli; Woo, Peak; Murry, Thomas

    2016-03-01

    High-speed videoendoscopy (HSV) captures direct cycle-to-cycle visualization of vocal fold movement in real time. This ultrafast recording rate is capable of visualizing the vibratory motion of the vocal folds in severely disordered phonation and provides a direct method for examining vibratory changes after vocal fold surgery. The purpose of this study was to examine the vibratory motion before and after surgical intervention. HSV was captured from two subjects with identifiable midvocal fold benign lesions and six subjects with highly aperiodic vocal fold vibration before and after phonosurgery. Digital kymography (DKG) was used to extract high-speed kymographic vocal fold images sampled at the midmembranous, anterior 1/3, and posterior 1/3 region. Spectral analysis was subsequently applied to the DKG to quantify the cycle-to-cycle movements of the left and the right vocal fold, expressed as a spectrum. Before intervention, the vibratory spectrum consisted of decreased and flat-like spectral peaks with robust power asymmetry. After intervention, increases in spectral power and decreases in power symmetry were noted. Spectral power increases were most remarkable in the midmembranous region of the vocal fold. Surgical modification resulted in improved lateral excursion of the vocal folds, vibratory function, and perceptual measures of Voice Handicap Index-10. These changes in vibratory behavior trended toward normal vocal fold vibration. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  4. A method for assessing the regional vibratory pattern of vocal folds by analysing the video recording of stroboscopy.

    Science.gov (United States)

    Lee, J S; Kim, E; Sung, M W; Kim, K H; Sung, M Y; Park, K S

    2001-05-01

    Stroboscopy and kymography have been used to examine the motional abnormality of vocal folds and to visualise their regional vibratory pattern. In a previous study (Laryngoscope, 1999), we introduced the conceptual idea of videostrobokymography, in which we applied the concept of kymography on the pre-recorded video images using stroboscopy, and showed its possible clinical application to various disorders in vocal folds. However, a more detailed description about the software and the mathematical formulation used in this system is needed for the reproduction of similar systems. The composition of hardwares, user-interface and detail procedures including mathematical equations in videostrobokymography software is presented in this study. As an initial clinical trial, videostrobokymography was applied to the preoperative and postoperative videostroboscopic images of 15 patients with Reinke's edema. On preoperative examination, videostrobokymograms showed irregular pattern of mucosal wave and, in some patients, a relatively constant glottic gap during phonation. After the operation, the voice quality of all patients was improved in acoustic and aerodynamic assessments, and videostrobokymography showed clearly improved mucosal waves (change in open quotient: mean +/- SD= 0.11 +/- 0.05).

  5. Complex vibratory patterns in an elephant larynx.

    Science.gov (United States)

    Herbst, Christian T; Svec, Jan G; Lohscheller, Jörg; Frey, Roland; Gumpenberger, Michaela; Stoeger, Angela S; Fitch, W Tecumseh

    2013-11-01

    Elephants' low-frequency vocalizations are produced by flow-induced self-sustaining oscillations of laryngeal tissue. To date, little is known in detail about the vibratory phenomena in the elephant larynx. Here, we provide a first descriptive report of the complex oscillatory features found in the excised larynx of a 25 year old female African elephant (Loxodonta africana), the largest animal sound generator ever studied experimentally. Sound production was documented with high-speed video, acoustic measurements, air flow and sound pressure level recordings. The anatomy of the larynx was studied with computed tomography (CT) and dissections. Elephant CT vocal anatomy data were further compared with the anatomy of an adult human male. We observed numerous unusual phenomena, not typically reported in human vocal fold vibrations. Phase delays along both the inferior-superior and anterior-posterior (A-P) dimension were commonly observed, as well as transverse travelling wave patterns along the A-P dimension, previously not documented in the literature. Acoustic energy was mainly created during the instant of glottal opening. The vestibular folds, when adducted, participated in tissue vibration, effectively increasing the generated sound pressure level by 12 dB. The complexity of the observed phenomena is partly attributed to the distinct laryngeal anatomy of the elephant larynx, which is not simply a large-scale version of its human counterpart. Travelling waves may be facilitated by low fundamental frequencies and increased vocal fold tension. A travelling wave model is proposed, to account for three types of phenomena: A-P travelling waves, 'conventional' standing wave patterns, and irregular vocal fold vibration.

  6. Automated Measurement of Vocal Fold Vibratory Asymmetry from High-Speed Videoendoscopy Recordings

    Science.gov (United States)

    Mehta, Daryush D.; Deliyski, Dimitar D.; Quatieri, Thomas F.; Hillman, Robert E.

    2011-01-01

    Purpose: In prior work, a manually derived measure of vocal fold vibratory phase asymmetry correlated to varying degrees with visual judgments made from laryngeal high-speed videoendoscopy (HSV) recordings. This investigation extended this work by establishing an automated HSV-based framework to quantify 3 categories of vocal fold vibratory…

  7. Vibratory function and healing outcomes after small intestinal submucosa biomaterial implantation for chronic vocal fold scar.

    Science.gov (United States)

    Pitman, Michael J; Kurita, Takashi; Powell, Maria E; Kimball, Emily E; Mizuta, Masanobu; Chang, Siyuan; Garrett, C Gaelyn; Rousseau, Bernard

    2018-04-01

    Vocal fold scar is a major cause of dysphonia, and optimal treatments do not currently exist. Small intestinal submucosa (SIS) is a biomaterial developed for the treatment of a variety of pathologies. The purpose of this study was to investigate the effects of SIS implantation on tissue remodeling in scarred vocal folds using routine staining, immunohistochemistry, and high-speed videoendoscopy (HSV). Prospective, blinded group analysis. Thirteen New Zealand White rabbits underwent a vocal fold scarring procedure followed by microflap elevation with or without SIS implantation. Seven months later, they underwent a phonation procedure with HSV and laryngeal harvest. Alcian blue and elastica van Gieson staining and immunohistochemistry for collagen types I and III were used to evaluate histological healing outcomes. Dynamic functional remodeling of the scarred vocal fold in the presence of SIS implants was evaluated using HSV imaging to capture restoration of vibratory amplitude, amplitude ratio, and left-right phase symmetry. Density of collagen I was significantly decreased in SIS versus microflap-treated vocal folds. No differences were found between groups for hyaluronic acid, elastin, or collagen type III. Organization of elastin in the subepithelial region appeared to affect amplitude of vibration and the shape of the vocal fold edge. SIS implantation into chronic scar reduced the density of collagen I deposits. There was no evidence of a negative impact or complication from SIS implantation. Regardless of treatment type, organization of elastin in the subepithelial region may be important to vibratory outcomes. NA. Laryngoscope, 128:901-908, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  8. The diagnostic role of high-speed vocal fold vibratory imaging.

    Science.gov (United States)

    Mendelsohn, Abie H; Remacle, Marc; Courey, Mark S; Gerhard, Friedrich; Postma, Gregory N

    2013-09-01

    Although high-speed imaging (HSI) has been identified as a valuable tool in phonatory biomechanics research, to date, there have only been a selected number of reports investigating the clinical utility of HSI. We aim to elucidate the role of HSI in the diagnosis of the dysphonic patient. The video files from 28 consecutive dysphonic patients with concurrently acquired videostroboscopy and HSI were retrospectively collected. Stroboscopy video files were edited to include vibratory motion only. Videos were then anonymously and randomly presented to four academic laryngologists. Experts were asked to assign a single best diagnosis for each video file. Assigned diagnoses were then compared with treatment diagnoses conferred based on medical history, phonatory evaluation, laryngeal examination, and response to treatment. Interrater analysis for the four laryngologists demonstrated significant and meaningful correlations for the diagnoses of polyps, cysts, nodules, and normal examination using stroboscopy (kappa > 0.40, P 0.40, P diagnostic accuracy above stroboscopy alone. Although specific laryngeal states such as presbyphonia may be better diagnosed with HSI, further studies are required to define HSI's precise role in the clinical setting. Copyright © 2013 The Voice Foundation. All rights reserved.

  9. Segmentation of turbo generator and reactor coolant pump vibratory patterns: a syntactic pattern recognition approach

    International Nuclear Information System (INIS)

    Tira, Z.

    1993-02-01

    This study was undertaken in the context of turbogenerator and reactor coolant pump vibration surveillance. Vibration meters are used to monitor equipment condition. An anomaly will modify the signal mean. At the present time, the expert system DIVA, developed to automate diagnosis, requests the operator to identify the nature of the pattern change thus indicated. In order to minimize operator intervention, we have to automate on the one hand classification and on the other hand, detection and segmentation of the patterns. The purpose of this study is to develop a new automatic system for the segmentation and classification of signals. The segmentation is based on syntactic pattern recognition. For the classification, a decision tree is used. The signals to process are the rms values of the vibrations measured on rotating machines. These signals are randomly sampled. All processing is automatic and no a priori statistical knowledge on the signals is required. The segmentation performances are assessed by tests on vibratory signals. (author). 31 figs

  10. Vocal fold contact patterns based on normal modes of vibration.

    Science.gov (United States)

    Smith, Simeon L; Titze, Ingo R

    2018-05-17

    The fluid-structure interaction and energy transfer from respiratory airflow to self-sustained vocal fold oscillation continues to be a topic of interest in vocal fold research. Vocal fold vibration is driven by pressures on the vocal fold surface, which are determined by the shape of the glottis and the contact between vocal folds. Characterization of three-dimensional glottal shapes and contact patterns can lead to increased understanding of normal and abnormal physiology of the voice, as well as to development of improved vocal fold models, but a large inventory of shapes has not been directly studied previously. This study aimed to take an initial step toward characterizing vocal fold contact patterns systematically. Vocal fold motion and contact was modeled based on normal mode vibration, as it has been shown that vocal fold vibration can be almost entirely described by only the few lowest order vibrational modes. Symmetric and asymmetric combinations of the four lowest normal modes of vibration were superimposed on left and right vocal fold medial surfaces, for each of three prephonatory glottal configurations, according to a surface wave approach. Contact patterns were generated from the interaction of modal shapes at 16 normalized phases during the vibratory cycle. Eight major contact patterns were identified and characterized by the shape of the flow channel, with the following descriptors assigned: convergent, divergent, convergent-divergent, uniform, split, merged, island, and multichannel. Each of the contact patterns and its variation are described, and future work and applications are discussed. Copyright © 2018 Elsevier Ltd. All rights reserved.

  11. High-speed image analysis reveals chaotic vibratory behaviors of pathological vocal folds

    Energy Technology Data Exchange (ETDEWEB)

    Zhang Yu, E-mail: yuzhang@xmu.edu.c [Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen Fujian 361005 (China); Shao Jun [Shanghai EENT Hospital of Fudan University, Shanghai (China); Krausert, Christopher R. [Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375 (United States); Zhang Sai [Key Laboratory of Underwater Acoustic Communication and Marine Information Technology of the Ministry of Education, Xiamen University, Xiamen Fujian 361005 (China); Jiang, Jack J. [Shanghai EENT Hospital of Fudan University, Shanghai (China); Department of Surgery, Division of Otolaryngology - Head and Neck Surgery, University of Wisconsin School of Medicine and Public Health, Madison, WI 53792-7375 (United States)

    2011-01-15

    Research highlights: Low-dimensional human glottal area data. Evidence of chaos in human laryngeal activity from high-speed digital imaging. Traditional perturbation analysis should be cautiously applied to aperiodic high speed image signals. Nonlinear dynamic analysis may be helpful for understanding disordered behaviors in pathological laryngeal systems. - Abstract: Laryngeal pathology is usually associated with irregular dynamics of laryngeal activity. High-speed imaging facilitates direct observation and measurement of vocal fold vibrations. However, chaotic dynamic characteristics of aperiodic high-speed image data have not yet been investigated in previous studies. In this paper, we will apply nonlinear dynamic analysis and traditional perturbation methods to quantify high-speed image data from normal subjects and patients with various laryngeal pathologies including vocal fold nodules, polyps, bleeding, and polypoid degeneration. The results reveal the low-dimensional dynamic characteristics of human glottal area data. In comparison to periodic glottal area series from a normal subject, aperiodic glottal area series from pathological subjects show complex reconstructed phase space, fractal dimension, and positive Lyapunov exponents. The estimated positive Lyapunov exponents provide the direct evidence of chaos in pathological human vocal folds from high-speed digital imaging. Furthermore, significant differences between the normal and pathological groups are investigated for nonlinear dynamic and perturbation analyses. Jitter in the pathological group is significantly higher than in the normal group, but shimmer does not show such a difference. This finding suggests that the traditional perturbation analysis should be cautiously applied to high speed image signals. However, the correlation dimension and the maximal Lyapunov exponent reveal a statistically significant difference between normal and pathological groups. Nonlinear dynamic analysis is capable of

  12. High-speed image analysis reveals chaotic vibratory behaviors of pathological vocal folds

    International Nuclear Information System (INIS)

    Zhang Yu; Shao Jun; Krausert, Christopher R.; Zhang Sai; Jiang, Jack J.

    2011-01-01

    Research highlights: → Low-dimensional human glottal area data. → Evidence of chaos in human laryngeal activity from high-speed digital imaging. → Traditional perturbation analysis should be cautiously applied to aperiodic high speed image signals. → Nonlinear dynamic analysis may be helpful for understanding disordered behaviors in pathological laryngeal systems. - Abstract: Laryngeal pathology is usually associated with irregular dynamics of laryngeal activity. High-speed imaging facilitates direct observation and measurement of vocal fold vibrations. However, chaotic dynamic characteristics of aperiodic high-speed image data have not yet been investigated in previous studies. In this paper, we will apply nonlinear dynamic analysis and traditional perturbation methods to quantify high-speed image data from normal subjects and patients with various laryngeal pathologies including vocal fold nodules, polyps, bleeding, and polypoid degeneration. The results reveal the low-dimensional dynamic characteristics of human glottal area data. In comparison to periodic glottal area series from a normal subject, aperiodic glottal area series from pathological subjects show complex reconstructed phase space, fractal dimension, and positive Lyapunov exponents. The estimated positive Lyapunov exponents provide the direct evidence of chaos in pathological human vocal folds from high-speed digital imaging. Furthermore, significant differences between the normal and pathological groups are investigated for nonlinear dynamic and perturbation analyses. Jitter in the pathological group is significantly higher than in the normal group, but shimmer does not show such a difference. This finding suggests that the traditional perturbation analysis should be cautiously applied to high speed image signals. However, the correlation dimension and the maximal Lyapunov exponent reveal a statistically significant difference between normal and pathological groups. Nonlinear dynamic

  13. Bifurcation Analysis and Spatiotemporal Patterns in Unidirectionally Delay-Coupled Vibratory Gyroscopes

    Science.gov (United States)

    Li, Li; Xu, Jian

    Time delay is inevitable in unidirectionally coupled drive-free vibratory gyroscope system. The effect of time delay on the gyroscope system is studied in this paper. To this end, amplitude death and Hopf bifurcation induced by small time delay are first investigated by analyzing the related characteristic equation. Then, the direction of Hopf bifurcations and stability of Hopf-bifurcating periodic oscillations are determined by calculating the normal form on the center manifold. Next, spatiotemporal patterns of these Hopf-bifurcating periodic oscillations are analyzed by using the symmetric bifurcation theory of delay differential equations. Finally, it is found that numerical simulations agree with the associated analytic results. These phenomena could be induced although time delay is very small. Therefore, it is shown that time delay is an important factor which influences the sensitivity and accuracy of the gyroscope system and cannot be neglected during the design and manufacture.

  14. Relation of Structural and Vibratory Kinematics of the Vocal Folds to Two Acoustic Measures of Breathy Voice Based on Computational Modeling

    Science.gov (United States)

    Samlan, Robin A.; Story, Brad H.

    2011-01-01

    Purpose: To relate vocal fold structure and kinematics to 2 acoustic measures: cepstral peak prominence (CPP) and the amplitude of the first harmonic relative to the second (H1-H2). Method: The authors used a computational, kinematic model of the medial surfaces of the vocal folds to specify features of vocal fold structure and vibration in a…

  15. A Universal Crease Pattern for Folding Orthogonal Shapes

    Science.gov (United States)

    2009-09-29

    Demaine∗† Martin L. Demaine∗ Aviv Ovadya∗ Abstract We present a universal crease pattern—known in geometry as the tetrakis tiling and in origami as box...13. SUPPLEMENTARY NOTES 14. ABSTRACT We present a universal crease pattern?known in geometry as the tetrakis tiling and in origami as box pleating... origami . Computational Geometry : The- ory and Applications, 16(1):3–21, 2000. [DO07] Erik D. Demaine and Joseph O’Rourke. Geometric Folding Al- gorithms

  16. Vocal Fold Vibration Following Surgical Intervention in Three Vocal Pathologies: A Preliminary Study.

    Science.gov (United States)

    Chen, Wenli; Woo, Peak; Murry, Thomas

    2017-09-01

    High-speed videoendoscopy captures the cycle-to-cycle vibratory motion of each individual vocal fold in normal and severely disordered phonation. Therefore, it provides a direct method to examine the specific vibratory changes following vocal fold surgery. The purpose of this study was to examine the vocal fold vibratory pattern changes in the surgically treated pathologic vocal fold and the contralateral vocal fold in three vocal pathologies: vocal polyp (n = 3), paresis or paralysis (n = 3), and scar (n = 3). Digital kymography was used to extract high-speed kymographic vocal fold images at the mid-membranous region of the vocal fold. Spectral analysis was subsequently applied to the digital kymography to quantify the cycle-to-cycle movements of each vocal fold, expressed as a spectrum. Surgical modification resulted in significantly improved spectral power of the treated pathologic vocal fold. Furthermore, the contralateral vocal fold also presented with improved spectral power irrespective of vocal pathology. In comparison with normal vocal fold spectrum, postsurgical vocal fold vibrations continued to demonstrate decreased vibratory amplitude in both vocal folds. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  17. Microvascular lesions of the true vocal fold.

    Science.gov (United States)

    Postma, G N; Courey, M S; Ossoff, R H

    1998-06-01

    Microvascular lesions, also called varices or capillary ectasias, in contrast to vocal fold polyps with telangiectatic vessels, are relatively small lesions arising from the microcirculation of the vocal fold. Varices are most commonly seen in female professional vocalists and may be secondary to repetitive trauma, hormonal variations, or repeated inflammation. Microvascular lesions may either be asymptomatic or cause frank dysphonia by interrupting the normal vibratory pattern, mass, or closure of the vocal folds. They may also lead to vocal fold hemorrhage, scarring, or polyp formation. Laryngovideostroboscopy is the key in determining the functional significance of vocal fold varices. Management of patients with a varix includes medical therapy, speech therapy, and occasionally surgical vaporization. Indications for surgery are recurrent hemorrhage, enlargement of the varix, development of a mass in conjunction with the varix or hemorrhage, and unacceptable dysphonia after maximal medical and speech therapy due to a functionally significant varix.

  18. Settlement during vibratory sheet piling

    NARCIS (Netherlands)

    Meijers, P.

    2007-01-01

    During vibratory sheet piling quite often the soil near the sheet pile wall will settle. In many cases this is not a problem. For situations with houses, pipelines, roads or railroads at relative short distance these settlements may not be acceptable. The purpose of the research described in this

  19. Vocal fold scars : current concepts and future directions. Consensus report of the phonosurgery committee of the European laryngological society

    NARCIS (Netherlands)

    Friedrich, G.; Dikkers, F. G.; Arens, C.; Remacle, M.; Hess, M.; Giovanni, A.; Duflo, S.; Hantzakos, A.; Bachy, V.; Gugatschka, M.

    Scarring of the vocal folds leads to a deterioration of the highly complex micro-structure with consecutively impaired vibratory pattern and glottic insufficiency. The resulting dysphonia is predominantly characterized by a reduced vocal capacity. Despite the considerable progress in understanding

  20. Computed tomography of the small bowel in adult celiac disease: the jejunoileal fold pattern reversal

    International Nuclear Information System (INIS)

    Tomei, E.; Di Giovambattista, F.; Greco, M.; Marini, M.; Messineo, D.; Passariello, R.; Picarelli, A.

    2000-01-01

    The aim of this retrospective study was to establish whether the distinctive intestinal fold pattern of celiac disease (CD), known by barium studies as jejunoileal fold pattern reversal (JFPR) may be recognized at CT. The number of intestinal folds per 2.5 cm, seen at CT, were counted in the jejunum and in the ileum of 22 adult patients with CD and compared with the folds of 30 consecutive subjects in whom an intestinal disease had been excluded. The results were submitted to statistical analysis by Student's t-test. In the control group the number of folds per 2.5 cm were 4.88 (SD ± 0.78) in the jejunum and 2.84 (± 0.62) in the ileum; in the CD group the number of folds were 2.42 (± 1.61) in the jejunum and 5.11 (± 1.24) in the ileum. There was a statistically significant difference in the number of jejunal and ileal folds between the CD patients and the control group (in both cases p < 0.001). The JFPR was seen in 15 patients with CD (68.2 %) but in none of the controls. Our study shows that JFPR is not a normal finding and can be demonstrated by CT in the majority of patients with CD. (orig.)

  1. Computed tomography of the small bowel in adult celiac disease: the jejunoileal fold pattern reversal

    Energy Technology Data Exchange (ETDEWEB)

    Tomei, E.; Di Giovambattista, F.; Greco, M. [Department of Clinical Sciences, University of Rome (Italy); Marini, M.; Messineo, D.; Passariello, R.; Picarelli, A. [Department of Radiology II, University of Rome (Italy)

    2000-01-01

    The aim of this retrospective study was to establish whether the distinctive intestinal fold pattern of celiac disease (CD), known by barium studies as jejunoileal fold pattern reversal (JFPR) may be recognized at CT. The number of intestinal folds per 2.5 cm, seen at CT, were counted in the jejunum and in the ileum of 22 adult patients with CD and compared with the folds of 30 consecutive subjects in whom an intestinal disease had been excluded. The results were submitted to statistical analysis by Student's t-test. In the control group the number of folds per 2.5 cm were 4.88 (SD {+-} 0.78) in the jejunum and 2.84 ({+-} 0.62) in the ileum; in the CD group the number of folds were 2.42 ({+-} 1.61) in the jejunum and 5.11 ({+-} 1.24) in the ileum. There was a statistically significant difference in the number of jejunal and ileal folds between the CD patients and the control group (in both cases p < 0.001). The JFPR was seen in 15 patients with CD (68.2 %) but in none of the controls. Our study shows that JFPR is not a normal finding and can be demonstrated by CT in the majority of patients with CD. (orig.)

  2. Combinatorial pattern discovery approach for the folding trajectory analysis of a beta-hairpin.

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    Laxmi Parida

    2005-06-01

    Full Text Available The study of protein folding mechanisms continues to be one of the most challenging problems in computational biology. Currently, the protein folding mechanism is often characterized by calculating the free energy landscape versus various reaction coordinates, such as the fraction of native contacts, the radius of gyration, RMSD from the native structure, and so on. In this paper, we present a combinatorial pattern discovery approach toward understanding the global state changes during the folding process. This is a first step toward an unsupervised (and perhaps eventually automated approach toward identification of global states. The approach is based on computing biclusters (or patterned clusters-each cluster is a combination of various reaction coordinates, and its signature pattern facilitates the computation of the Z-score for the cluster. For this discovery process, we present an algorithm of time complexity c in RO((N + nm log n, where N is the size of the output patterns and (n x m is the size of the input with n time frames and m reaction coordinates. To date, this is the best time complexity for this problem. We next apply this to a beta-hairpin folding trajectory and demonstrate that this approach extracts crucial information about protein folding intermediate states and mechanism. We make three observations about the approach: (1 The method recovers states previously obtained by visually analyzing free energy surfaces. (2 It also succeeds in extracting meaningful patterns and structures that had been overlooked in previous works, which provides a better understanding of the folding mechanism of the beta-hairpin. These new patterns also interconnect various states in existing free energy surfaces versus different reaction coordinates. (3 The approach does not require calculating the free energy values, yet it offers an analysis comparable to, and sometimes better than, the methods that use free energy landscapes, thus validating the

  3. Combinatorial Pattern Discovery Approach for the Folding Trajectory Analysis of a beta-Hairpin.

    Directory of Open Access Journals (Sweden)

    2005-06-01

    Full Text Available The study of protein folding mechanisms continues to be one of the most challenging problems in computational biology. Currently, the protein folding mechanism is often characterized by calculating the free energy landscape versus various reaction coordinates, such as the fraction of native contacts, the radius of gyration, RMSD from the native structure, and so on. In this paper, we present a combinatorial pattern discovery approach toward understanding the global state changes during the folding process. This is a first step toward an unsupervised (and perhaps eventually automated approach toward identification of global states. The approach is based on computing biclusters (or patterned clusters-each cluster is a combination of various reaction coordinates, and its signature pattern facilitates the computation of the Z-score for the cluster. For this discovery process, we present an algorithm of time complexity cinRO((N + nm log n, where N is the size of the output patterns and (n x m is the size of the input with n time frames and m reaction coordinates. To date, this is the best time complexity for this problem. We next apply this to a beta-hairpin folding trajectory and demonstrate that this approach extracts crucial information about protein folding intermediate states and mechanism. We make three observations about the approach: (1 The method recovers states previously obtained by visually analyzing free energy surfaces. (2 It also succeeds in extracting meaningful patterns and structures that had been overlooked in previous works, which provides a better understanding of the folding mechanism of the beta-hairpin. These new patterns also interconnect various states in existing free energy surfaces versus different reaction coordinates. (3 The approach does not require calculating the free energy values, yet it offers an analysis comparable to, and sometimes better than, the methods that use free energy landscapes, thus validating the

  4. Analysis of local concentration in stomach fold pattern by using abdominal X-ray CT image

    International Nuclear Information System (INIS)

    Watanabe, Shigeto; Hasegawa, Jun-ichi; Mekada, Yoshito; Mori, Kensaku; Nawano, Shigeru

    2004-01-01

    The paper presents a method for analysis of stomach folds pattern in abdominal X-ray CT images. Many stomach cancers have local concentration of folds at cancer lesions. Therefore, in stomach diagnosis, it is very important to evaluate quantitatively such fold concentration. In this paper, a method for calculation of concentration index for line figure on a curved surface is proposed first. Then, using this method a processing procedure for detection of stomach cancer from an abdominal X-ray CT image is developed. In the experiment using practical X-ray CT images, it is shown that by the proposed procedure, higher values of concentration index are obtained at cancer area. (author)

  5. Longitudinal stability of the folding pattern of the anterior cingulate cortex during development

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    A. Cachia

    2016-06-01

    Full Text Available Prenatal processes are likely critical for the differences in cognitive ability and disease risk that unfold in postnatal life. Prenatally established cortical folding patterns are increasingly studied as an adult proxy for earlier development events – under the as yet untested assumption that an individual's folding pattern is developmentally fixed. Here, we provide the first empirical test of this stability assumption using 263 longitudinally-acquired structural MRI brain scans from 75 typically developing individuals spanning ages 7 to 32 years. We focus on the anterior cingulate cortex (ACC – an intensely studied cortical region that presents two qualitatively distinct and reliably classifiable sulcal patterns with links to postnatal behavior. We show – without exception–that individual ACC sulcal patterns are fixed from childhood to adulthood, at the same time that quantitative anatomical ACC metrics are undergoing profound developmental change. Our findings buttress use of folding typology as a postnatally-stable marker for linking variations in early brain development to later neurocognitive outcomes in ex utero life.

  6. Patterns of Participation and Motivation in Folding@home: The Contribution of Hardware Enthusiasts and Overclockers

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    Vickie Curtis

    2018-04-01

    Full Text Available Folding@home is a distributed computing project in which participants run protein folding simulations on their computers. Participants complete work units and are awarded points for their contribution. An investigation into motivations to participate and patterns of participation revealed the significant contribution of a sub-community composed of individuals who custom-build computers to maximise their processing power. These individuals, known as “overclockers” or “hardware enthusiasts,” use distributed computing projects such as Folding@home to benchmark their modified computers and to compete with one another to see who can process the greatest number of project work units. Many are initially drawn to the project to learn about computer hardware from other overclockers and to compete for points. However, once they learn more about the scientific outputs of Folding@home, some participants become more motivated by the desire to contribute to scientific research. Overclockers form numerous online communities where members collaborate and help each other maximise their computing output. They invest heavily in their computers and process the majority of Folding@home’s simulations, thus providing an invaluable (and free resource.

  7. Quantitative Folding Pattern Analysis of Early Primary Sulci in Human Fetuses with Brain Abnormalities.

    Science.gov (United States)

    Im, K; Guimaraes, A; Kim, Y; Cottrill, E; Gagoski, B; Rollins, C; Ortinau, C; Yang, E; Grant, P E

    2017-07-01

    Aberrant gyral folding is a key feature in the diagnosis of many cerebral malformations. However, in fetal life, it is particularly challenging to confidently diagnose aberrant folding because of the rapid spatiotemporal changes of gyral development. Currently, there is no resource to measure how an individual fetal brain compares with normal spatiotemporal variations. In this study, we assessed the potential for automatic analysis of early sulcal patterns to detect individual fetal brains with cerebral abnormalities. Triplane MR images were aligned to create a motion-corrected volume for each individual fetal brain, and cortical plate surfaces were extracted. Sulcal basins were automatically identified on the cortical plate surface and compared with a combined set generated from 9 normal fetal brain templates. Sulcal pattern similarities to the templates were quantified by using multivariate geometric features and intersulcal relationships for 14 normal fetal brains and 5 fetal brains that were proved to be abnormal on postnatal MR imaging. Results were compared with the gyrification index. Significantly reduced sulcal pattern similarities to normal templates were found in all abnormal individual fetuses compared with normal fetuses (mean similarity [normal, abnormal], left: 0.818, 0.752; P the primary distinguishing features. The gyrification index was not significantly different between the normal and abnormal groups. Automated analysis of interrelated patterning of early primary sulci could outperform the traditional gyrification index and has the potential to quantitatively detect individual fetuses with emerging abnormal sulcal patterns. © 2017 by American Journal of Neuroradiology.

  8. GEC Ferranti piezo vibratory gyroscope

    Science.gov (United States)

    Nuttall, J. D.

    1993-01-01

    Prototypes of a piezo-electric vibratory angular rate transducer (gyroscope) (PVG) have been constructed and evaluated. The construction is on the lines suggested by Burdess. The sensitive element is a cylinder of radially poled piezo-electric ceramic. The cylinder is metallized inside and out, and the outer metallization is divided into eight electrodes. The metallization on the inside is earthed. A phase locked loop, using pairs of the electrodes, causes the cylinder to vibrate in one of its two fundamental, degenerate modes. In the presence of rotation, some of the vibration is coupled into the outer mode. This can be detected, or suppressed with a closed-up technique and provides a measure of rotation rate. The gyroscope provides a number of advantages over rotating mass and optical instruments: low size and mass, lower power consumption, potentially high reliability, potentially good dormancy, low cost and high maximum rate.

  9. A Rat Excised Larynx Model of Vocal Fold Scar

    Science.gov (United States)

    Welham, Nathan V.; Montequin, Douglas W.; Tateya, Ichiro; Tateya, Tomoko; Choi, Seong Hee; Bless, Diane M.

    2009-01-01

    Purpose: To develop and evaluate a rat excised larynx model for the measurement of acoustic, aerodynamic, and vocal fold vibratory changes resulting from vocal fold scar. Method: Twenty-four 4-month-old male Sprague-Dawley rats were assigned to 1 of 4 experimental groups: chronic vocal fold scar, chronic vocal fold scar treated with 100-ng basic…

  10. Computer Simulations of Contact Forces for Airbags with Different Folding Patterns During Deployment Phase

    Directory of Open Access Journals (Sweden)

    King H. Yang

    1995-01-01

    Full Text Available An explicit finite element method was used to study the neck load and the contact force between an occupant and an airbag during an out-of-position frontal automobile crash. Two different folding patterns and two different mounting angles of the airbag were simulated. For the four cases simulated, the occupant’s neck axial force ranged from 156 to 376% of the data obtained from in-position sled tests using the Hybrid III dummy. The neck shear force ranged from 87 to 229% and the neck flexion moment ranged from 68 to 127% of in-position experimental results. In both 300 mounting angle simulations, the neck axial forces were higher than that of the two simulations with 00 mounting angles, but the trend for the neck shear force was the opposite. Although the kinematics of the model appear reasonable, the numbers generated by the model must be reviewed with great caution because the model has not been fully validated.

  11. Fracture patterns in the Zagros fold-and-thrust belt, Kurdistan Region of Iraq

    Science.gov (United States)

    Reif, Daniel; Decker, Kurt; Grasemann, Bernhard; Peresson, Herwig

    2012-11-01

    Fracture data have been collected in the Kurdistan Region of Iraq, which is a poorly accessible and unexplored area of the Zagros. Pre to early folding NE-SW striking extensional fractures and NW-SE striking contractive elements represent the older set affecting the exposed multilayer of the area. These latter structures are early syn-folding and followed by folding-related mesostructural assemblages, which include elements striking parallel to the axial trend of major folds (longitudinal fractures). Bedding perpendicular joints and veins, and extensional faults belonging to this second fracture set are located in the outer arc of exposed anticlines, whilst longitudinal reverse faults locate in the inner arcs. Consistently, these elements are associated with syn-folding tangential longitudinal strain. The younger two sets are related to E-W extension and NNE-SSW to N-S shortening, frequently displaying reactivation of the older sets. The last shortening event, which is described along the entire Zagros Belt, probably relates with the onset of N-S compression induced by the northward movement of the Arabian plate relative to the Eurasian Plate. In comparison between the inferred palaeostrain directions and the kinematics of recent GPS measurements, we conclude that the N-S compression and the partitioning into NW-SE trending folds and NW to N trending strike-slip faults likely remained unchanged throughout the Neogene tectonic history of the investigated area.

  12. Coordination of respiration and swallowing: functional pattern and relevance of vocal folds closure

    Directory of Open Access Journals (Sweden)

    Milton Melciades Barbosa Costa

    2010-03-01

    Full Text Available CONTEXT: Breathing and swallowing coordination, despite the expressive number of study, remain as theme deserving further research. OBJECTIVE: To identify a coordination pattern between swallowing and the natural breathing pause that occur in association with it (swallowing apnea and also the relevance of the vocal folds closure in this process. METHODS: Sixty-six adults, male and female, including normal health people, post-laryngectomy individuals and patients with digestive complaints without dysphagia were analyzed. The respiratory air flux interruptions produced by wet requested swallows and dry, requested and spontaneous swallows, were registered using thermo and piezoelectric receptors coupled to synectics medical manometry equipment, using Polygram upper 4.21 software. The results were analyzed with the Chi-square (3×2 and (2×2 nonparametric independency test with P = 0.05. RESULTS: Swallowing apnea is a preventive breathing stop that start just before and stay present during all deglutition pharyngeal phase. It is a well coordinated phenomena that occur as pattern in association with low elastic resistance of the lung, on the expiratory final phase until inspiration initial phase. This breathing stoppage it is usually followed by a short expiraton preceding a new breathing cycle. The swallow apnea and vocal folds closure are both independents mechanisms. CONCLUSION: It is possible to suppose that in the subconscious condition, swallowing apnea is integrated under coordination of the same control mechanism that also involves the elastic resistance of the lung.CONTEXTO: Apesar do expressivo número de estudos sobre a coordenação da respiração com a deglutição, o tema permanece aberto à pesquisa. OBJETIVO: Identificar um padrão de coordenação entre a pausa respiratória e a deglutição que ocorre em associação a esta usual apneia (apneia de deglutição e estabelecer a importância do fechamento das pregas vocais que ocorre

  13. Laryngeal ultrasound and pediatric vocal fold nodules.

    Science.gov (United States)

    Ongkasuwan, Julina; Devore, Danielle; Hollas, Sarah; Jones, Jeremy; Tran, Brandon

    2017-03-01

    The term vocal fold nodules refers to bilateral thickening of the membranous folds with minimal impairment of the vibratory properties of the mucosa. Nodules are thought to be related to repetitive mechanical stress, associated with voice use patterns. Diagnosis is typically made in the office via either rigid or flexible laryngeal stroboscopy. Depending on the individual child, obtaining an optimal view of the larynx can be difficult if not impossible. Recent advances in high-frequency ultrasonography allows for transcervical examination of laryngeal structures. The goal of this project was to determine if laryngeal ultrasound (LUS) can be used to identify vocal fold nodules in dysphonic children. Prospective case-control study in which the patient acted as his or her own control. Forty-six pediatric patients were recruited for participation in this study; the mean age was 4.8 years. Twenty-three did not have any vocal fold lesions and 23 had a diagnosis of vocal fold nodules on laryngeal stroboscopy. Recorded LUSs were reviewed by two pediatric radiologists who were blinded to the nodule status. There was substantial inter-rater agreement (κ = 0.70, 95% confidence interval [CI]: 0.50-0.89) between the two radiologists regarding the presence of nodules. There was also substantial agreement (κ = 0.87, 95% CI: 0.72-1) between LUS and laryngeal stroboscopy. Sensitivity of LUS was 100% (95% CI: 85%-100%) and specificity was 87% (95% CI: 66%-97%). LUS can be used to identify vocal fold nodules in children with substantial agreement with laryngeal stroboscopy. 3b Laryngoscope, 127:676-678, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Benign Lesions of The Vocal Fold

    Directory of Open Access Journals (Sweden)

    Ozgur Surmelioglu

    2013-02-01

    Full Text Available Benign lesions of vocal folds are common disorders. Fifty percent of patients who have sound complaints are found to have these lesions after endoscopic and stroboscopic examinations. Benign vocal fold diseases are primarily caused by vibratory trauma. However they may also occur as a result of viral infections and congenital causes. These lesions are often presented with the complaints of dysphonia. [Archives Medical Review Journal 2013; 22(1.000: 86-95

  15. Coriolis vibratory gyroscopes theory and design

    CERN Document Server

    Apostolyuk, Vladislav

    2016-01-01

    This book provides the latest theoretical analysis and design methodologies of different types of Coriolis vibratory gyroscopes (CVG). Together, the chapters analyze different types of sensitive element designs and their kinematics, derivation of motion equations, analysis of sensitive elements dynamics in modulated and demodulated signals, calculation and optimization of main performance characteristics, and signal processing and control. Essential aspects of numerical simulation of CVG using Simulink® are also covered. This is an ideal book for graduate students, researchers, and engineers working in fields that require gyroscope application, including but not limited to: inertial sensors and systems, automotive and consumer electronics, small unmanned aircraft control systems, personal mobile navigation systems and related software development, and augmented and virtual reality systems.

  16. [The impact of vibratory stimulation therapy on voice quality in hyperfunctional occupational dysphonia].

    Science.gov (United States)

    Kosztyła-Hojna, Bożena; Kuryliszyn-Moskal, Anna; Rogowski, Marek; Moskal, Diana; Dakowicz, Agnieszka; Falkowski, Dawid; Kasperuk, Joanna

    2012-01-01

    Hyperfunctional dysphonia is the most frequent type of occupational functional dysphonia. Pharmacotherapy, physiotherapy and psychotherapy are used in the treatment of occupational dysphonia. Vibratory massages of the regions of the larynx relax the external muscles of neck, which have an indirect impact on the tension of the vocal folds. The aim of the study is to assess the impact of vibratory stimulation therapy on voice quality in patients with hyperfunctional occupational dysphonia treated pharmacologically. Forty patients with hyperfunctional occupational dysphonia treated phoniatrically in the Phoniatric Outpatient Clinic were included in the study. Patients were divided into two groups. Group I consisted of 20 patients treated pharmacologically. In group II, including 20 patients, apart from pharmacotherapy the vibratory stimulation therapy by the device of VR type (CyberBioMed LLC) was used. In the analysis of voice quality the evaluation of the vocal folds vibration using videolaryngostroboscopy and acoustic assessment of voice were conducted. The perceptual assessment of voice, the visualization of the vocal folds vibration in stroboscopic examination of the larynx and the acoustic assessment of voice enable the appropriate diagnostics of the clinical type and voice quality in hyperfunctional dysphonia. The tension of superficial and deep muscles of neck has the impact on the phonatory function of the larynx. Pharmacological treatment improves the voice quality in hyperfunctional occupational dysphonia. Pharmacological treatment combines with the relaxation of muscles of neck using the device of VR type significantly improve voice quality in hyperfunctional occupational dysphonia. Copyright © 2012 Polish Otolaryngology Society. Published by Elsevier Urban & Partner Sp. z.o.o. All rights reserved.

  17. Vibratory gyroscopes : identification of mathematical model from test data

    CSIR Research Space (South Africa)

    Shatalov, MY

    2007-05-01

    Full Text Available Simple mathematical model of vibratory gyroscopes imperfections is formulated, which includes anisotropic damping and variation of mass-stiffness parameters and their harmonics. The method of identification of parameters of the mathematical model...

  18. Optimization of vibratory welding process parameters using response surface methodology

    Energy Technology Data Exchange (ETDEWEB)

    Singh, Pravin Kumar; Kumar, S. Deepak; Patel, D.; Prasad, S. B. [National Institute of Technology Jamshedpur, Jharkhand (India)

    2017-05-15

    The current investigation was carried out to study the effect of vibratory welding technique on mechanical properties of 6 mm thick butt welded mild steel plates. A new concept of vibratory welding technique has been designed and developed which is capable to transfer vibrations, having resonance frequency of 300 Hz, into the molten weld pool before it solidifies during the Shielded metal arc welding (SMAW) process. The important process parameters of vibratory welding technique namely welding current, welding speed and frequency of the vibrations induced in molten weld pool were optimized using Taguchi’s analysis and Response surface methodology (RSM). The effect of process parameters on tensile strength and hardness were evaluated using optimization techniques. Applying RSM, the effect of vibratory welding parameters on tensile strength and hardness were obtained through two separate regression equations. Results showed that, the most influencing factor for the desired tensile strength and hardness is frequency at its resonance value, i.e. 300 Hz. The micro-hardness and microstructures of the vibratory welded joints were studied in detail and compared with those of conventional SMAW joints. Comparatively, uniform and fine grain structure has been found in vibratory welded joints.

  19. Gearbox fault diagnosis based on deep random forest fusion of acoustic and vibratory signals

    Science.gov (United States)

    Li, Chuan; Sanchez, René-Vinicio; Zurita, Grover; Cerrada, Mariela; Cabrera, Diego; Vásquez, Rafael E.

    2016-08-01

    Fault diagnosis is an effective tool to guarantee safe operations in gearboxes. Acoustic and vibratory measurements in such mechanical devices are all sensitive to the existence of faults. This work addresses the use of a deep random forest fusion (DRFF) technique to improve fault diagnosis performance for gearboxes by using measurements of an acoustic emission (AE) sensor and an accelerometer that are used for monitoring the gearbox condition simultaneously. The statistical parameters of the wavelet packet transform (WPT) are first produced from the AE signal and the vibratory signal, respectively. Two deep Boltzmann machines (DBMs) are then developed for deep representations of the WPT statistical parameters. A random forest is finally suggested to fuse the outputs of the two DBMs as the integrated DRFF model. The proposed DRFF technique is evaluated using gearbox fault diagnosis experiments under different operational conditions, and achieves 97.68% of the classification rate for 11 different condition patterns. Compared to other peer algorithms, the addressed method exhibits the best performance. The results indicate that the deep learning fusion of acoustic and vibratory signals may improve fault diagnosis capabilities for gearboxes.

  20. Quantitative Study of Vibrational Symmetry of Injured Vocal Folds via Digital Kymography in Excised Canine Larynges

    Science.gov (United States)

    Krausert, Christopher R.; Ying, Di; Zhang, Yu; Jiang, Jack J.

    2011-01-01

    Purpose: Digital kymography and vocal fold curve fitting are blended with detailed symmetry analysis of kymograms to provide a comprehensive characterization of the vibratory properties of injured vocal folds. Method: Vocal fold vibration of 12 excised canine larynges was recorded under uninjured, unilaterally injured, and bilaterally injured…

  1. Influence of Embedded Fibers and an Epithelium Layer on the Glottal Closure Pattern in a Physical Vocal Fold Model

    Science.gov (United States)

    Xuan, Yue; Zhang, Zhaoyan

    2014-01-01

    Purpose: The purpose of this study was to explore the possible structural and material property features that may facilitate complete glottal closure in an otherwise isotropic physical vocal fold model. Method: Seven vocal fold models with different structural features were used in this study. An isotropic model was used as the baseline model, and…

  2. Configuration System for Simulation Based Design of Vibratory Bowl Feeders

    DEFF Research Database (Denmark)

    Hansson, Michael Natapon; Mathiesen, Simon; Ellekilde, Lars-Peter

    2017-01-01

    Vibratory bowl feeders are still among the most commonly used production equipment for automated part feeding, where parts are correctly oriented for further manipulation by being conveyed through a set of orienting devices. Designing vibratory bowl feeders involves selecting and sequencing...... a number of these devices that either reorients or rejects the part until a desirable orientation is achieved. To aid the designer in this task, this work presents a configuration system where knowledge of the behaviour for each device is acquired through dynamic simulation, and used to solve...

  3. Feasibility of Clinical Endoscopy and Stroboscopy in Children With Bilateral Vocal Fold Lesions.

    Science.gov (United States)

    Zacharias, Stephanie R C; Brehm, Susan Baker; Weinrich, Barbara; Kelchner, Lisa; Tabangin, Meredith; de Alarcon, Alessandro

    2016-11-01

    The purpose of this study was to examine the utility of flexible and rigid endoscopy and stroboscopy for the identification of anatomical and physiological features in children with bilateral vocal fold lesions. The secondary purpose was to describe the age distribution of patients who could tolerate use of the different types of endoscopes. This cross-sectional clinic-based study included 38 children (ages 5 to 12 years) diagnosed with bilateral vocal fold lesions via videoendoscopy. Vocal fold vibratory characteristics (e.g., mucosal wave) were rated by 4 clinicians by consensus. Bilateral vocal fold lesions could be well described anatomically after visualization with both flexible and rigid endoscopes and were most commonly described as symmetrical and broad based. However, the clinicians' confidence in the accuracy of stroboscopy for rating vocal fold vibratory characteristics was limited for both flexible and rigid stroboscopes. Videoendoscopy was adequate for viewing and characterizing anatomical structures of bilateral vocal fold lesions in pediatric patients; however, vibratory characteristics were often not fully visualized with videostroboscopy. In view of the importance of visualizing vocal fold vibration in the differential diagnosis and treatment of vocal fold lesions, other imaging modalities, such as high-speed videoendoscopy, may provide more accurate descriptions of vocal fold vibratory characteristics in this population.

  4. General problems of dynamics and control of vibratory gyroscopes

    CSIR Research Space (South Africa)

    Shatalov, MY

    2008-05-01

    Full Text Available A general model of operation of vibratory gyroscopes, which is applicable to a broad class of instruments, including cylindrical, disc and micro-machined gyros, is formulated on the basis of analysis of dynamics and control of a hemispherical...

  5. Dynamics and control of vibratory gyroscopes with special spherical symmetry

    CSIR Research Space (South Africa)

    Shatalov, M

    2006-01-01

    Full Text Available It was shown in 1985 by Acad. V. Zhuravlev that the angular rate of a pure vibrating mode excited in a vibratory gyroscope with spherical symmetry is proportional to an inertial angular rate of the gyroscope. The effect is three dimensional...

  6. Optimisation of Trap Design for Vibratory Bowl Feeders

    DEFF Research Database (Denmark)

    Mathiesen, Simon; Sørensen, Lars Carøe; Kraft, Dirk

    2018-01-01

    Vibratory bowl feeders (VBFs) are a widely used option for industrial part feeding, but their design is still largely manual. A subtask of VBF design is determining an optimal parameter set for the passive devices, called traps, which the VBF uses to ensure correct part orientation. This paper...

  7. Evaluation of vibratory ground motion at nuclear power plant sites

    International Nuclear Information System (INIS)

    Hofmann, R.B.; Greeves, J.T.

    1978-01-01

    The evaluation of vibratory ground motion at nuclear power plant sites requires the cooperative effort of scientists and engineers in several disciplines. These include seismology, geology, geotechnical engineering and structural engineering. The Geosciences Branch of the NRC Division of Site Safety and Environmental Analysis includes two sections, the Geology/Seismology Section and the Geotechnical Engineering Section

  8. Sampling of Stochastic Input Parameters for Rockfall Calculations and for Structural Response Calculations Under Vibratory Ground Motion

    International Nuclear Information System (INIS)

    M. Gross

    2004-01-01

    The purpose of this scientific analysis is to define the sampled values of stochastic (random) input parameters for (1) rockfall calculations in the lithophysal and nonlithophysal zones under vibratory ground motions, and (2) structural response calculations for the drip shield and waste package under vibratory ground motions. This analysis supplies: (1) Sampled values of ground motion time history and synthetic fracture pattern for analysis of rockfall in emplacement drifts in nonlithophysal rock (Section 6.3 of ''Drift Degradation Analysis'', BSC 2004 [DIRS 166107]); (2) Sampled values of ground motion time history and rock mechanical properties category for analysis of rockfall in emplacement drifts in lithophysal rock (Section 6.4 of ''Drift Degradation Analysis'', BSC 2004 [DIRS 166107]); (3) Sampled values of ground motion time history and metal to metal and metal to rock friction coefficient for analysis of waste package and drip shield damage to vibratory motion in ''Structural Calculations of Waste Package Exposed to Vibratory Ground Motion'' (BSC 2004 [DIRS 167083]) and in ''Structural Calculations of Drip Shield Exposed to Vibratory Ground Motion'' (BSC 2003 [DIRS 163425]). The sampled values are indices representing the number of ground motion time histories, number of fracture patterns and rock mass properties categories. These indices are translated into actual values within the respective analysis and model reports or calculations. This report identifies the uncertain parameters and documents the sampled values for these parameters. The sampled values are determined by GoldSim V6.04.007 [DIRS 151202] calculations using appropriate distribution types and parameter ranges. No software development or model development was required for these calculations. The calculation of the sampled values allows parameter uncertainty to be incorporated into the rockfall and structural response calculations that support development of the seismic scenario for the

  9. Influence of Left-Right Asymmetries on Voice Quality in Simulated Paramedian Vocal Fold Paralysis

    Science.gov (United States)

    Samlan, Robin A.; Story, Brad H.

    2017-01-01

    Purpose: The purpose of this study was to determine the vocal fold structural and vibratory symmetries that are important to vocal function and voice quality in a simulated paramedian vocal fold paralysis. Method: A computational kinematic speech production model was used to simulate an exemplar "voice" on the basis of asymmetric…

  10. Mechanical Assessment of the Waste Package Subject to Vibratory Motion

    Energy Technology Data Exchange (ETDEWEB)

    M. Gross

    2004-10-14

    The purpose of this document is to provide an integrated overview of the calculation reports that define the response of the waste package and its internals to vibratory ground motion. The calculation reports for waste package response to vibratory ground motion are identified in Table 1-1. Three key calculation reports describe the potential for mechanical damage to the waste package, fuel assemblies, and cladding from a seismic event. Three supporting documents have also been published to investigate sensitivity of damage to various assumptions for the calculations. While these individual reports present information on a specific aspect of waste package and cladding response, they do not describe the interrelationship between the various calculations and the relationship of this information to the seismic scenario class for Total System Performance Assessment-License Application (TSPA-LA). This report is designed to fill this gap by providing an overview of the waste package structural response calculations.

  11. Mechanical Assessment of the Waste Package Subject to Vibratory Motion

    International Nuclear Information System (INIS)

    M. Gross

    2004-01-01

    The purpose of this document is to provide an integrated overview of the calculation reports that define the response of the waste package and its internals to vibratory ground motion. The calculation reports for waste package response to vibratory ground motion are identified in Table 1-1. Three key calculation reports describe the potential for mechanical damage to the waste package, fuel assemblies, and cladding from a seismic event. Three supporting documents have also been published to investigate sensitivity of damage to various assumptions for the calculations. While these individual reports present information on a specific aspect of waste package and cladding response, they do not describe the interrelationship between the various calculations and the relationship of this information to the seismic scenario class for Total System Performance Assessment-License Application (TSPA-LA). This report is designed to fill this gap by providing an overview of the waste package structural response calculations

  12. Vibratory Urticaria Associated with a Missense Variant in ADGRE2.

    Science.gov (United States)

    Boyden, Steven E; Desai, Avanti; Cruse, Glenn; Young, Michael L; Bolan, Hyejeong C; Scott, Linda M; Eisch, A Robin; Long, R Daniel; Lee, Chyi-Chia R; Satorius, Colleen L; Pakstis, Andrew J; Olivera, Ana; Mullikin, James C; Chouery, Eliane; Mégarbané, André; Medlej-Hashim, Myrna; Kidd, Kenneth K; Kastner, Daniel L; Metcalfe, Dean D; Komarow, Hirsh D

    2016-02-18

    Patients with autosomal dominant vibratory urticaria have localized hives and systemic manifestations in response to dermal vibration, with coincident degranulation of mast cells and increased histamine levels in serum. We identified a previously unknown missense substitution in ADGRE2 (also known as EMR2), which was predicted to result in the replacement of cysteine with tyrosine at amino acid position 492 (p.C492Y), as the only nonsynonymous variant cosegregating with vibratory urticaria in two large kindreds. The ADGRE2 receptor undergoes autocatalytic cleavage, producing an extracellular subunit that noncovalently binds a transmembrane subunit. We showed that the variant probably destabilizes an autoinhibitory subunit interaction, sensitizing mast cells to IgE-independent vibration-induced degranulation. (Funded by the National Institutes of Health.).

  13. Characterization of the Bell-Shaped Vibratory Angular Rate Gyro

    Directory of Open Access Journals (Sweden)

    Junfang Fan

    2013-08-01

    Full Text Available The bell-shaped vibratory angular rate gyro (abbreviated as BVG is a novel shell vibratory gyroscope, which is inspired by the Chinese traditional bell. It sensitizes angular velocity through the standing wave precession effect. The bell-shaped resonator is a core component of the BVG and looks like the millimeter-grade Chinese traditional bell, such as QianLong Bell and Yongle Bell. It is made of Ni43CrTi, which is a constant modulus alloy. The exciting element, control element and detection element are uniformly distributed and attached to the resonator, respectively. This work presents the design, analysis and experimentation on the BVG. It is most important to analyze the vibratory character of the bell-shaped resonator. The strain equation, internal force and the resonator's equilibrium differential equation are derived in the orthogonal curvilinear coordinate system. When the input angular velocity is existent on the sensitive axis, an analysis of the vibratory character is performed using the theory of thin shells. On this basis, the mode shape function and the simplified second order normal vibration mode dynamical equation are obtained. The coriolis coupling relationship about the primary mode and secondary mode is established. The methods of the signal processing and control loop are presented. Analyzing the impact resistance property of the bell-shaped resonator, which is compared with other shell resonators using the Finite Element Method, demonstrates that BVG has the advantage of a better impact resistance property. A reasonable means of installation and a prototypal gyro are designed. The gyroscopic effect of the BVG is characterized through experiments. Experimental results show that the BVG has not only the advantages of low cost, low power, long work life, high sensitivity, and so on, but, also, of a simple structure and a better impact resistance property for low and medium angular velocity measurements.

  14. Innovative decontamination technology by abrasion in vibratory vessels

    International Nuclear Information System (INIS)

    Fabbri, Silvio; Ilarri, Sergio

    2007-01-01

    Available in abstract form only. Full text of publication follows: The possibility of using conventional vibratory vessel technology as a decontamination technique is the motivation for the development of this project. The objective is to explore the feasibility of applying the vibratory vessel technology for decontamination of radioactively-contaminated materials such as pipes and metal structures. The research and development of this technology was granted by the U.S. Department of Energy (DOE). Abrasion processes in vibratory vessels are widely used in the manufacture of metals, ceramics, and plastics. Samples to be treated, solid abrasive media and liquid media are set up into a vessel. Erosion results from the repeated impact of the abrasive particles on the surface of the body being treated. A liquid media, generally detergents or surfactants aid the abrasive action. The amount of material removed increases with the time of treatment. The design and construction of the machine were provided by Vibro, Argentina private company. Tests with radioactively-contaminated aluminum tubes and a stainless steel bar, were performed at laboratory level. Tests showed that it is possible to clean both the external and the internal surface of contaminated tubes. Results show a decontamination factor around 10 after the first 30 minutes of the cleaning time. (authors)

  15. The role of the mesenchyme in mouse neural fold elevation. II. Patterns of hyaluronate synthesis and distribution in embryos developing in vitro

    International Nuclear Information System (INIS)

    Morris-Wiman, J.; Brinkley, L.L.

    1990-01-01

    Hyaluronate (HA) distribution patterns were examined in the cranial mesenchyme underlying the mesencephalic neural folds of mouse embryos maintained in roller tube culture. Using standard image-processing techniques, the digitized images of Alcian blue-stained or 3H-glucosamine-labeled sections digested with an enzyme specific for HA, were subtracted from adjacent, undigested sections. The resultant difference picture images (DPI) accurately depicted the distribution of stained or labeled HA within the cranial mesenchyme. 3H-glucosamine-labeled HA was distributed uniformly throughout the cranial mesenchyme as 12, 18, and 24 hr of culture. By contrast, the mesenchyme was uniformly stained with Alcian blue at 12 hr, but stain intensity decreased in the central regions of the mesenchyme at 18 and 24 hr. HA distribution patterns were also examined in the cranial mesenchyme of embryos cultured in the presence of diazo-oxo-norleucine (DON), a glutamine analogue that inhibits glycosaminoglycan and glycoprotein synthesis. In DON-treated mesenchyme, Alcian blue staining of HA was decreased from that in controls at 12, 18, and 24 hr. However, incorporation of 3H-glucosamine into HA was increased. The distribution of labeled HA within treated mesenchyme as 12, 18, and 24 hr resembled that in controls at 12 hr. These results indicate that the distribution of HA within the cranial mesenchyme of normal mouse embryos during neural fold elevation and convergence is not determined solely by regional differences in HA synthesis. We propose that HA distribution patterns result from the expansion of the HA-rich extracellular matrix of the central mesenchyme regions. This expansion may play a major role in fold elevation. These results also suggest that DON treatment reversibly inhibits HA synthesis

  16. Used Furan Sand Reclamation in REGMAS Vibratory Unit

    Directory of Open Access Journals (Sweden)

    Dańko J.

    2015-09-01

    Full Text Available The paper, especially dealt with problems of reclamation of used furan sand, carried out in new, vibratory sand reclamation unit REGMAS developed by researches from AGH-University of Science and Technology, Faculty of Foundry Engineering in Cracow (Poland. Functional characteristics of reclamation unit as well as the results of reclamation of used sand with furfuryl resin are discussed in the paper. The quality of reclaim was tested by means of the LOI and pH value, dust content in the reclaim and at least by the the quality of the castings produced in moulds prepared with the use of reclaimed matrix.

  17. Automation Selection and Sequencing of Traps for Vibratory Feeders

    DEFF Research Database (Denmark)

    Mathiesen, Simon; Ellekilde, Lars-Peter

    2017-01-01

    Vibratory parts feeders with mechanical orienting devices are used extensively in the assembly automation industry. Even so, the design process is based on trial-and-error approaches and is largely manual. In this paper, a methodology is presented for automatic design of this type of feeder....... The approach uses dynamic simulation for generating the necessary data for configuring a feeder with a sequence of mechanical orienting devices called traps, with the goal of reorienting all parts from a random to fixed orientation. Then, a fast algorithm for facilitating this configuration task automatically...

  18. Field Tests to Investigate the Penetration Rate of Piles Driven by Vibratory Installation

    Directory of Open Access Journals (Sweden)

    Zhaohui Qin

    2017-01-01

    Full Text Available Factors directly affecting the penetration rate of piles installed by vibratory driving technique are summarized and classified into seven aspects which are driving force, resistance, vibratory amplitude, energy consumption, speeding up at the beginning, pile plumbness keeping, and slowing down at the end, from the mechanism and engineering practice of the vibratory pile driving. In order to find out how these factors affect the penetration rate of the pile in three major actors of vibratory pile driving: (i the pile to be driven, (ii the selected driving system, and (iii the imposed soil conditions, field tests on steel sheet piles driven by vibratory driving technique in different soil conditions are conducted. The penetration rates of three different sheet pile types having up to four different lengths installed using two different vibratory driving systems are documented. Piles with different lengths and types driven with or without clutch have different penetration rates. The working parameters of vibratory hammer, such as driving force and vibratory amplitude, have great influences on the penetration rate of the pile, especially at the later stages of the sinking process. Penetration rate of piles driven in different soil conditions is uniform because of the different penetration resistance including shaft friction and toe resistance.

  19. Vocal Fold Phase Asymmetries in Patients with Voice Disorders: A Study across Visualization Techniques

    Science.gov (United States)

    Bonilha, Heather Shaw; Deliyski, Dimitar D.; Whiteside, Joanna Piasecki; Gerlach, Terri Treman

    2012-01-01

    Purpose: To examine differences in vocal fold vibratory phase asymmetry judged from stroboscopy, high-speed videoendoscopy (HSV), and the HSV-derived playbacks of mucosal wave kymography, digital kymography, and a static medial digital kymography image of persons with hypofunctional and hyperfunctional voice disorders. Differences between the…

  20. Designing and testing a laser-based vibratory sensor

    Science.gov (United States)

    Nath, G.

    2018-04-01

    Sensor technology has proved its importance, not only in the range of few-meter applications in different fields, but in micro, nano, atomic and sub-atomic-sized objects. The present work describes the designing of a laser-based vibratory sensor using a He-Ne laser as the signal source. The received characteristics of the signal are mainly the frequency and amplitude of the vibration from which the physical parameters such as energy, power and absorption coefficients of the material are determined, which enables us to provide information of the hidden target or object. This laboratory-designed sensor finds application in different local phenomena as well as laboratory practical activity for students.

  1. Stress history and fracture pattern in fault-related folds based on limit analysis: application to the Sub-Andean thrust belt of Bolivia

    Science.gov (United States)

    Barbe, Charlotte; Leroy, Yves; Ben Miloud, Camille

    2017-04-01

    A methodology is proposed to construct the stress history of a complex fault-related fold in which the deformation mechanisms are essentially frictional. To illustrate the approach, fours steps of the deformation of an initially horizontally layered sand/silicone laboratory experiment (Driehaus et al., J. of Struc. Geol., 65, 2014) are analysed with the kinematic approach of limit analysis (LA). The stress, conjugate to the virtual velocity gradient in the sense of mechanicam power, is a proxy for the true statically admmissible stress field which prevailed over the structure. The material properties, friction angles and cohesion, including their time evolution are selected such that the deformation pattern predicted by the LA is consistent with the two main thrusting events, the first forward and the second backward once the layers have sufficiently rotated. The fractures associated to the stress field determined at each step are convected on today configuration to define the complete pattern which should be observed. The end results are presented along virtual vertical wells and could be used within the oil industry at an early phase of exploration to prepare drealing operations.

  2. The Numerical FEM Model of the Kinematics of the Vibratory Shot Peening Process

    Directory of Open Access Journals (Sweden)

    Stanisław Bławucki

    2017-12-01

    Full Text Available The paper presents the results of numerical calculations, with the finite element method in the ABAQUS program environment, of the vibratory shot peening process with loose peening elements. The behaviour of shot peening elements was analysed in the kinematic aspect. The impact of the initial deployment of vibratory shot peening elements on their behaviour during processing was investigated, including the displacement, velocity, acceleration and the number of collisions. The way of determining the effectiveness of the processing with the vibratory shot peening was illustrated.

  3. The Complexity of Folding Self-Folding Origami

    Directory of Open Access Journals (Sweden)

    Menachem Stern

    2017-12-01

    Full Text Available Why is it difficult to refold a previously folded sheet of paper? We show that even crease patterns with only one designed folding motion inevitably contain an exponential number of “distractor” folding branches accessible from a bifurcation at the flat state. Consequently, refolding a sheet requires finding the ground state in a glassy energy landscape with an exponential number of other attractors of higher energy, much like in models of protein folding (Levinthal’s paradox and other NP-hard satisfiability (SAT problems. As in these problems, we find that refolding a sheet requires actuation at multiple carefully chosen creases. We show that seeding successful folding in this way can be understood in terms of subpatterns that fold when cut out (“folding islands”. Besides providing guidelines for the placement of active hinges in origami applications, our results point to fundamental limits on the programmability of energy landscapes in sheets.

  4. The Complexity of Folding Self-Folding Origami

    Science.gov (United States)

    Stern, Menachem; Pinson, Matthew B.; Murugan, Arvind

    2017-10-01

    Why is it difficult to refold a previously folded sheet of paper? We show that even crease patterns with only one designed folding motion inevitably contain an exponential number of "distractor" folding branches accessible from a bifurcation at the flat state. Consequently, refolding a sheet requires finding the ground state in a glassy energy landscape with an exponential number of other attractors of higher energy, much like in models of protein folding (Levinthal's paradox) and other NP-hard satisfiability (SAT) problems. As in these problems, we find that refolding a sheet requires actuation at multiple carefully chosen creases. We show that seeding successful folding in this way can be understood in terms of subpatterns that fold when cut out ("folding islands"). Besides providing guidelines for the placement of active hinges in origami applications, our results point to fundamental limits on the programmability of energy landscapes in sheets.

  5. A Review on Solidification and Change in Mechanical Properties Under Vibratory Welding Condition

    OpenAIRE

    Jyoti Prakash; Dr. S.P. Tewari; Bipin Kumar Srivastava

    2010-01-01

    Welding has been applied to various industries in particular, automotive, aerospace and microelectronics. Thermal cycle produced near weld line generates residual stress and inhomogeneous plastic deformation in weldments. However there are many methods for welding the workpieces and one of the method among these is vibratory welding. It has the advantages of less investment, more convenient operation, less pollution and shorter manufacturing period. In vibratory welding, workpiece vibrates in...

  6. Alternate rhythmic vibratory stimulation of trunk muscles affects walking cadence and velocity in Parkinson's disease.

    Science.gov (United States)

    De Nunzio, Alessandro M; Grasso, Margherita; Nardone, Antonio; Godi, Marco; Schieppati, Marco

    2010-02-01

    During the administration of timed bilateral alternate vibration to homonymous leg or trunk muscles during quiet upright stance, Parkinsonian (PD) patients undergo cyclic antero-posterior and medio-lateral transfers of the centre of foot pressure. This event might be potentially exploited for improving gait in these patients. Here, we tested this hypothesis by applying alternate muscle vibration during walking in PD. Fifteen patients and 15 healthy subjects walked on an instrumented walkway under four conditions: no vibration (no-Vib), and vibration of tibialis anterior (TA-Vib), soleus (Sol-Vib) and erector spinae (ES-Vib) muscles of both sides. Trains of vibration (internal frequency 100 Hz) were delivered to right and left side at alternating frequency of 10% above preferred step cadence. During vibration, stride length, cadence and velocity increased in both patients and healthy subjects, significantly so for ES-Vib. Stance and swing time tended to decrease. Width of support base increased with Sol-Vib or TA-Vib, but was unaffected by ES-Vib. Alternate ES vibration enhances gait velocity in PD. The stronger effect of ES over leg muscle vibration might depend on the relevance of the proprioceptive inflow from the trunk muscles and on the absence of adverse effects on the support base width. Trunk control is defective in PD. The effect of timed vibratory stimulation on gait suggests the potential use of trunk proprioceptive stimulation for tuning the central pattern generators for locomotion in PD. Copyright (c) 2009 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  7. Vocal Fold Paralysis

    Science.gov (United States)

    ... here Home » Health Info » Voice, Speech, and Language Vocal Fold Paralysis On this page: What is vocal fold ... Where can I get additional information? What is vocal fold paralysis? Structures involved in speech and voice production ...

  8. Construction and characterization of a novel vocal fold bioreactor.

    Science.gov (United States)

    Zerdoum, Aidan B; Tong, Zhixiang; Bachman, Brendan; Jia, Xinqiao

    2014-08-01

    In vitro engineering of mechanically active tissues requires the presentation of physiologically relevant mechanical conditions to cultured cells. To emulate the dynamic environment of vocal folds, a novel vocal fold bioreactor capable of producing vibratory stimulations at fundamental phonation frequencies is constructed and characterized. The device is composed of a function generator, a power amplifier, a speaker selector and parallel vibration chambers. Individual vibration chambers are created by sandwiching a custom-made silicone membrane between a pair of acrylic blocks. The silicone membrane not only serves as the bottom of the chamber but also provides a mechanism for securing the cell-laden scaffold. Vibration signals, generated by a speaker mounted underneath the bottom acrylic block, are transmitted to the membrane aerodynamically by the oscillating air. Eight identical vibration modules, fixed on two stationary metal bars, are housed in an anti-humidity chamber for long-term operation in a cell culture incubator. The vibration characteristics of the vocal fold bioreactor are analyzed non-destructively using a Laser Doppler Vibrometer (LDV). The utility of the dynamic culture device is demonstrated by culturing cellular constructs in the presence of 200-Hz sinusoidal vibrations with a mid-membrane displacement of 40 µm. Mesenchymal stem cells cultured in the bioreactor respond to the vibratory signals by altering the synthesis and degradation of vocal fold-relevant, extracellular matrix components. The novel bioreactor system presented herein offers an excellent in vitro platform for studying vibration-induced mechanotransduction and for the engineering of functional vocal fold tissues.

  9. Asymmetric hindwing foldings in rove beetles.

    Science.gov (United States)

    Saito, Kazuya; Yamamoto, Shuhei; Maruyama, Munetoshi; Okabe, Yoji

    2014-11-18

    Foldable wings of insects are the ultimate deployable structures and have attracted the interest of aerospace engineering scientists as well as entomologists. Rove beetles are known to fold their wings in the most sophisticated ways that have right-left asymmetric patterns. However, the specific folding process and the reason for this asymmetry remain unclear. This study reveals how these asymmetric patterns emerge as a result of the folding process of rove beetles. A high-speed camera was used to reveal the details of the wing-folding movement. The results show that these characteristic asymmetrical patterns emerge as a result of simultaneous folding of overlapped wings. The revealed folding mechanisms can achieve not only highly compact wing storage but also immediate deployment. In addition, the right and left crease patterns are interchangeable, and thus each wing internalizes two crease patterns and can be folded in two different ways. This two-way folding gives freedom of choice for the folding direction to a rove beetle. The use of asymmetric patterns and the capability of two-way folding are unique features not found in artificial structures. These features have great potential to extend the design possibilities for all deployable structures, from space structures to articles of daily use.

  10. Influence of pre-tectonic carbonate facies architecture on deformation patterns of syntectonic turbidites, an example from the central Mexican fold-thrust belt

    Science.gov (United States)

    Vásquez Serrano, Alberto; Tolson, Gustavo; Fitz Diaz, Elisa; Chávez Cabello, Gabriel

    2018-04-01

    The Mexican fold-thrust belt in central México excellently exposes relatively well preserved syntectonic deposits that overlay rocks with lateral lithostratigraphic changes across the belt. We consider the deformational effects of these changes by investigating the geometry, kinematics and strain distribution within syntectonic turbidites, which are deposited on top of Albian-Cenomanian shallow and deep water carbonate layers. Field observations and detailed structural analysis at different stratigraphic and structural levels of the Late Cretaceous syntectonic formation are compared with the deformation as a function of lithological and structural variations in the underlying carbonate units, to better understand the effect of these lithostratigraphic variations on deformation, kinematics, strain distribution and propagation of deformation. From our kinematic analyses, we conclude that the syntectonic strata are pervasively affected by folding in all areas and that deformation partitioning localized shear zones at the boundaries of this unit, particularly along the contact with massive carbonates. At the boundaries with massive platformal carbonates, the turbidites are strongly deformed by isoclinal folding with a pervasive sub-horizontal axial plane cleavage and 70-60% shortening. In contrast, contacts with thinly-bedded carbonate layers (basinal facies), do not show strain localization, and have horizontal shortening of 50-40% that is accommodated by buckle folds with a less pervasive, steeply dipping cleavage. The mechanical properties variations in the underlying pre-tectonic units as a function of changes in lithostratigraphy fundamentally control the deformation in the overlying syntectonic strata, which is an effect that could be expected to occur in any deformed sedimentary sequence with such variations.

  11. ANALYSIS OF VIBRATORY PROTECTION SYSTEM VIBRATION DURING HARMONIC AND POLYHARMONIC EXCITATIONS

    Directory of Open Access Journals (Sweden)

    T. N. Mikulik

    2011-01-01

    Full Text Available The paper considers a mathematical model of local «driver-seat» system and an algorithm for vibratory loading formation at external actions. Results of the investigations on the system vibration according to minimum vibration acceleration depending on transfer force factor acting on the seat and a vibration isolation factor are presented in the paper.

  12. Penile vibratory stimulation in the treatment of post-prostatectomy incontinence

    DEFF Research Database (Denmark)

    Fode, Mikkel; Sønksen, Jens

    2015-01-01

    AIMS: To examine penile vibratory stimulation (PVS) in the treatment of post-prostatectomy urinary incontinence (UI). METHODS: Patients with post-prostatectomy UI were included in a 12-week trial. A 24-hr pad test and a 72-hr voiding diary were collected at baseline. Participants were randomized ...

  13. Procedures for evaluation of vibratory ground motions of soil deposits at nuclear power plant sites

    International Nuclear Information System (INIS)

    1975-06-01

    According to USNRC requirements set forth in Appendix A, 10 CFR, Part 100, vibratory ground motion criteria for a nuclear plant must be based on local soil conditions, as well as on the seismicity, geology, and tectonics of the region. This report describes how such criteria can be developed by applying the latest technology associated with analytical predictions of site-dependent ground motions and with the use of composite spectra obtained from the current library of strong motion records. Recommended procedures for defining vibratory ground motion criteria contain the following steps: (1) geologic and seismologic studies; (2) site soils investigations; (3) site response sensitivity studies; (4) evaluation of local site response characteristics; (5) selection of site-matched records; and (6) appraisal and selection of seismic input criteria. An in-depth discussion of the engineering characteristics of earthquake ground motions including parameters used to characterize earthquakes and strong motion records, geologic factors that influence ground shaking, the current strong motion data base, and case histories of the effects of past earthquake events is presented. Next, geotechnical investigations of the seismologic, geologic, and site soil conditions required to develop vibratory motion criteria are briefly summarized. The current technology for establishing vibratory ground motion criteria at nuclear plant sites, including site-independent and site-dependent procedures that use data from strong motion records and from soil response analyses is described. (auth)

  14. On dynamics and control of vibratory gyroscopes with special spherical symmetry

    CSIR Research Space (South Africa)

    Shatalov, M

    2006-05-01

    Full Text Available It was shown in 1985 by Acad. V. Zhuravlev that the angular rate of a pure vibrating mode excited in a vibratory gyroscope with spherical symmetry is proportional to an inertial angular rate of the gyroscope. The effect is three dimensional...

  15. Can vibratory feedback be used to improve postural stability in persons with transtibial limb loss?

    Science.gov (United States)

    Rusaw, David; Hagberg, Kerstin; Nolan, Lee; Ramstrand, Nerrolyn

    2012-01-01

    The use of vibration as a feedback modality to convey motion of the body has been shown to improve measures of postural stability in some groups of patients. Because individuals using transtibial prostheses lack sensation distal to the amputation, vibratory feedback could possibly be used to improve their postural stability. The current investigation provided transtibial prosthesis users (n = 24, mean age 48 yr) with vibratory feedback proportional to the signal received from force transducers located under the prosthetic foot. Postural stability was evaluated by measuring center of pressure (CoP) movement, limits of stability, and rhythmic weight shift while participants stood on a force platform capable of rotations in the pitch plane (toes up/toes down). The results showed that the vibratory feedback increased the mediolateral displacement amplitude of CoP in standing balance and reduced the response time to rapid voluntary movements of the center of gravity. The results suggest that the use of vibratory feedback in an experimental setting leads to improvements in fast open-loop mechanisms of postural control in transtibial prosthesis users.

  16. Wave radiation from vibratory and impact pile driving in a layered acousto-elastic medium

    NARCIS (Netherlands)

    Tsouvalas, A.; Metrikine, A.

    2014-01-01

    A steel monopile is the most common foundation type of a wind turbine installed offshore and is driven into place with the help of vibratory or impact hammers. Underwater noise generated during the installation of steel monopiles has recently received considerable attention from international

  17. Deceptive vibratory communication: pupae of a beetle exploit the freeze response of larvae to protect themselves.

    Science.gov (United States)

    Kojima, Wataru; Ishikawa, Yukio; Takanashi, Takuma

    2012-10-23

    It is argued that animal signals may have evolved so as to manipulate the response of receivers in a way that increases the fitness of the signallers. In deceptive communication, receivers incur costs by responding to false signals. Recently, we reported that pupae of the soil-inhabiting Japanese rhinoceros beetle Trypoxylus dichotoma produce vibratory signals to deter burrowing larvae, thereby protecting themselves. In the present study, monitoring of vibrations associated with larval movement revealed that T. dichotoma larvae remained motionless for ca 10 min when pupal vibratory signals were played back transiently (freeze response). Furthermore, pupal signals of T. dichotoma elicited a freeze response in three other scarabaeid species, whose pupae do not produce vibratory signals. This indicates that the freeze response to certain types of vibration evolved before the divergence of these species and has been evolutionarily conserved, presumably because of the fitness advantage in avoiding predators. Pupae of T. dichotoma have probably exploited pre-existing anti-predator responses of conspecific larvae to protect themselves by emitting deceptive vibratory signals.

  18. Flips for 3-folds and 4-folds

    CERN Document Server

    Corti, Alessio

    2007-01-01

    This edited collection of chapters, authored by leading experts, provides a complete and essentially self-contained construction of 3-fold and 4-fold klt flips. A large part of the text is a digest of Shokurov's work in the field and a concise, complete and pedagogical proof of the existence of 3-fold flips is presented. The text includes a ten page glossary and is accessible to students and researchers in algebraic geometry.

  19. Control of Vibratory Energy Harvesters in the Presence of Nonlinearities and Power-Flow Constraints

    Science.gov (United States)

    Cassidy, Ian L.

    Over the past decade, a significant amount of research activity has been devoted to developing electromechanical systems that can convert ambient mechanical vibrations into usable electric power. Such systems, referred to as vibratory energy harvesters, have a number of useful of applications, ranging in scale from self-powered wireless sensors for structural health monitoring in bridges and buildings to energy harvesting from ocean waves. One of the most challenging aspects of this technology concerns the efficient extraction and transmission of power from transducer to storage. Maximizing the rate of power extraction from vibratory energy harvesters is further complicated by the stochastic nature of the disturbance. The primary purpose of this dissertation is to develop feedback control algorithms which optimize the average power generated from stochastically-excited vibratory energy harvesters. This dissertation will illustrate the performance of various controllers using two vibratory energy harvesting systems: an electromagnetic transducer embedded within a flexible structure, and a piezoelectric bimorph cantilever beam. Compared with piezoelectric systems, large-scale electromagnetic systems have received much less attention in the literature despite their ability to generate power at the watt--kilowatt scale. Motivated by this observation, the first part of this dissertation focuses on developing an experimentally validated predictive model of an actively controlled electromagnetic transducer. Following this experimental analysis, linear-quadratic-Gaussian control theory is used to compute unconstrained state feedback controllers for two ideal vibratory energy harvesting systems. This theory is then augmented to account for competing objectives, nonlinearities in the harvester dynamics, and non-quadratic transmission loss models in the electronics. In many vibratory energy harvesting applications, employing a bi-directional power electronic drive to actively

  20. Covering folded shapes

    Directory of Open Access Journals (Sweden)

    Oswin Aichholzer

    2014-05-01

    Full Text Available Can folding a piece of paper flat make it larger? We explore whether a shape S must be scaled to cover a flat-folded copy of itself. We consider both single folds and arbitrary folds (continuous piecewise isometries \\(S\\to\\mathbb{R}^2\\. The underlying problem is motivated by computational origami, and is related to other covering and fixturing problems, such as Lebesgue's universal cover problem and force closure grasps. In addition to considering special shapes (squares, equilateral triangles, polygons and disks, we give upper and lower bounds on scale factors for single folds of convex objects and arbitrary folds of simply connected objects.

  1. Vibratory-compacted (vipac/sphere-pac) nuclear fuels - a comparison with pelletized nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Chidester, K.; Rubin, J. [Los Alamos National Lab., NM (United States); Thompson, M

    2001-07-01

    In order to achieve the packing densities required for nuclear fuel stability, economy and performance, the fuel material must be densified. This has traditionally been performed by high-temperature sintering. (At one time, fuel densification was investigated using cold/hot swaging. However, this fabrication method has become uncommon.) Alternatively, fuel can be densified by vibratory compaction (VIPAC). During the late 1950's and into the 1970's, in the U.S., vibratory compaction fuel was fabricated and test irradiated to evaluate its applicability compared to the more traditional pelletized fuel for nuclear reactors. These activities were primarily focused on light water reactors (LWR) but some work was performed for fast reactors. This paper attempts to summarize these evaluations and proposes to reconsider VIPAC fuel for future use. (author)

  2. IMPACT OF VIBRATORY AND ROTATIONAL SHOT PEENING ONTO SELECTED PROPERTIES OF TITANIUM ALLOY SURFACE LAYER

    Directory of Open Access Journals (Sweden)

    Kazimierz Zaleski

    2014-06-01

    Full Text Available This study presents the results of tests on impact of vibratory and rotational shot peening of the Ti6A12Mo2Cr titanium alloy onto the processed object surface roughness and surface layer microhardness. The external surfaces of ring-shaped samples were shot peened. The preceding process consisted of turning with a cubic boron nitride blade knife. Steel beads, having a diameter of 6 mm, were used as a processing medium. The variable parameters of shot peening were vibrator amplitude and shot peening time. The range of recommended technological parameters for vibratory and rotational shot peening was determined. As a result of shot peening, the surface roughness could be reduced by approximately 4 times and the surface layer could be hardened to the depth of approximately 0.4 mm.

  3. Vibratory-compacted (vipac/sphere-pac) nuclear fuels - a comparison with pelletized nuclear fuels

    International Nuclear Information System (INIS)

    Chidester, K.; Rubin, J.; Thompson, M.

    2001-01-01

    In order to achieve the packing densities required for nuclear fuel stability, economy and performance, the fuel material must be densified. This has traditionally been performed by high-temperature sintering. (At one time, fuel densification was investigated using cold/hot swaging. However, this fabrication method has become uncommon.) Alternatively, fuel can be densified by vibratory compaction (VIPAC). During the late 1950's and into the 1970's, in the U.S., vibratory compaction fuel was fabricated and test irradiated to evaluate its applicability compared to the more traditional pelletized fuel for nuclear reactors. These activities were primarily focused on light water reactors (LWR) but some work was performed for fast reactors. This paper attempts to summarize these evaluations and proposes to reconsider VIPAC fuel for future use. (author)

  4. Effects of Vocal Fold Nodules on Glottal Cycle Measurements Derived from High-Speed Videoendoscopy in Children

    Science.gov (United States)

    2016-01-01

    The goal of this study is to quantify the effects of vocal fold nodules on vibratory motion in children using high-speed videoendoscopy. Differences in vibratory motion were evaluated in 20 children with vocal fold nodules (5–11 years) and 20 age and gender matched typically developing children (5–11 years) during sustained phonation at typical pitch and loudness. Normalized kinematic features of vocal fold displacements from the mid-membranous vocal fold point were extracted from the steady-state high-speed video. A total of 12 kinematic features representing spatial and temporal characteristics of vibratory motion were calculated. Average values and standard deviations (cycle-to-cycle variability) of the following kinematic features were computed: normalized peak displacement, normalized average opening velocity, normalized average closing velocity, normalized peak closing velocity, speed quotient, and open quotient. Group differences between children with and without vocal fold nodules were statistically investigated. While a moderate effect size was observed for the spatial feature of speed quotient, and the temporal feature of normalized average closing velocity in children with nodules compared to vocally normal children, none of the features were statistically significant between the groups after Bonferroni correction. The kinematic analysis of the mid-membranous vocal fold displacement revealed that children with nodules primarily differ from typically developing children in closing phase kinematics of the glottal cycle, whereas the opening phase kinematics are similar. Higher speed quotients and similar opening phase velocities suggest greater relative forces are acting on vocal fold in the closing phase. These findings suggest that future large-scale studies should focus on spatial and temporal features related to the closing phase of the glottal cycle for differentiating the kinematics of children with and without vocal fold nodules. PMID:27124157

  5. Mechanical Assessment of the Drip Shield Subject to Vibratory Motion and Dynamic and Static Rock Loading

    International Nuclear Information System (INIS)

    R.C. Quittmeyer

    2005-01-01

    The purpose of the drip shield (DS) is to divert water that may seep into emplacement drifts from contacting the waste packages, and to protect the waste packages from impact or static loading from rockfall. The objective of this document is to summarize, into one location, the results of a series of supporting engineering calculations that were developed to study the effect of static and dynamic loads on the mechanical performance of the DS. The potential DS loads are a result of: (1) Potential earthquake vibratory ground motion, and resulting interaction of the DS, waste package and pallet, and drift invert; (2) Dynamic impacts of rockfall resulting from emplacement drift damage as a result of earthquake vibratory motion; and (3) Static load of the caved rock rubble that may come to rest on the DS as a result of vibratory motion or from time-dependent yielding of the rock mass surrounding the emplacement drift. The potential mechanical failure mechanisms that may result from these loads include: (1) Overturning and/or separation of the interlocking DS segments; (2) Loss of structural integrity and stability of the DS, including excessive deformation or buckling; and (3) Localized damage to the top and side-wall plates of the DS. The scope of this document is limited to summarizing results presented in the supporting calculations in the areas of analysis of the potential for DS collapse, and determination of the damaged surface area of the DS plates. New calculations are presented to determine whether or not separation of DSs occur under vibratory motion

  6. Teleoperation of steerable flexible needles by combining kinesthetic and vibratory feedback.

    Science.gov (United States)

    Pacchierotti, Claudio; Abayazid, Momen; Misra, Sarthak; Prattichizzo, Domenico

    2014-01-01

    Needle insertion in soft-tissue is a minimally invasive surgical procedure that demands high accuracy. In this respect, robotic systems with autonomous control algorithms have been exploited as the main tool to achieve high accuracy and reliability. However, for reasons of safety and responsibility, autonomous robotic control is often not desirable. Therefore, it is necessary to focus also on techniques enabling clinicians to directly control the motion of the surgical tools. In this work, we address that challenge and present a novel teleoperated robotic system able to steer flexible needles. The proposed system tracks the position of the needle using an ultrasound imaging system and computes needle's ideal position and orientation to reach a given target. The master haptic interface then provides the clinician with mixed kinesthetic-vibratory navigation cues to guide the needle toward the computed ideal position and orientation. Twenty participants carried out an experiment of teleoperated needle insertion into a soft-tissue phantom, considering four different experimental conditions. Participants were provided with either mixed kinesthetic-vibratory feedback or mixed kinesthetic-visual feedback. Moreover, we considered two different ways of computing ideal position and orientation of the needle: with or without set-points. Vibratory feedback was found more effective than visual feedback in conveying navigation cues, with a mean targeting error of 0.72 mm when using set-points, and of 1.10 mm without set-points.

  7. Effects of vibratory stimulation-induced kinesthetic illusions on the neural activities of patients with stroke.

    Science.gov (United States)

    Kodama, Takayuki; Nakano, Hideki; Ohsugi, Hironori; Murata, Shin

    2016-01-01

    [Purpose] This study evaluated the influence of vibratory stimulation-induced kinesthetic illusion on brain function after stroke. [Subjects] Twelve healthy individuals and 13 stroke patients without motor or sensory loss participated. [Methods] Electroencephalograms were taken at rest and during vibratory stimulation. As a neurophysiological index of brain function, we measured the μ-rhythm, which is present mainly in the kinesthetic cortex and is attenuated by movement or motor imagery and compared the data using source localization analyses in the Standardized Low Resolution Brain Electromagnetic Tomography (sLORETA) program. [Results] At rest, μ-rhythms appeared in the sensorimotor and supplementary motor cortices in both healthy controls and stroke patients. Under vibratory stimulation, no μ-rhythm appeared in the sensorimotor cortex of either group. Moreover, in the supplementary motor area, which stores the motor imagery required for kinesthetic illusions, the μ-rhythms of patients were significantly stronger than those of the controls, although the μ-rhythms of both groups were reduced. Thus, differences in neural activity in the supplementary motor area were apparent between the subject groups. [Conclusion] Kinesthetic illusions do occur in patients with motor deficits due to stroke. The neural basis of the supplementary motor area in stroke patients may be functionally different from that found in healthy controls.

  8. Vocal Fold Hyperplastic Lesions: an Evaluation of Surgical Outcome with Videolaryngostroboscopy

    Directory of Open Access Journals (Sweden)

    Melek Kezban Gürbüz

    2013-06-01

    Full Text Available Background: Vocal fold hyperplastic lesions are premalignant lesions that can be treated effectively by removal of the lesions surgically. Aims: The aim of this study was to discuss the success of surgery in patients with vocal fold hyperplastic lesions in terms of preserving vibratory function by comparing the preoperative and postoperative videolaryngostroboscopy findings. Study Design: The medical charts and videolaryngostroboscopic recordings of patients diagnosed with hyperplastic lesions on the vocal folds were reviewed retrospectively. Methods: Twenty seven patients with unilateral lesions who underwent type1 subepithelial cordectomy were enrolled in the study. The videolaryngostroboscopic recordings were evaluated by three raters who were not the operating surgeon and who were blinded to the histology of patients. To evaluate the videolaryngostroboscopic findings, a form, which is a modification of criteria described by Hirano and Bless, was used. Preoperative and 6th month postoperative videolaryngostroboscopic recordings were compared with each other and with recordings of the control group, which included 50 healthy volunteers. Results: All videolaryngostroboscopic findings, except false cord vibration, were significantly improved after surgery. Conclusion: The principle of vocal fold surgery in patients with benign lesions is to preserve the vibratory tissue. This principle also applies to patients with hyperplastic lesions that are premalignant. The hydrodissection technique may be beneficial for this purpose.

  9. Self-folding origami at any energy scale

    Science.gov (United States)

    Pinson, Matthew B.; Stern, Menachem; Carruthers Ferrero, Alexandra; Witten, Thomas A.; Chen, Elizabeth; Murugan, Arvind

    2017-05-01

    Programmable stiff sheets with a single low-energy folding motion have been sought in fields ranging from the ancient art of origami to modern meta-materials research. Despite such attention, only two extreme classes of crease patterns are usually studied; special Miura-Ori-based zero-energy patterns, in which crease folding requires no sheet bending, and random patterns with high-energy folding, in which the sheet bends as much as creases fold. We present a physical approach that allows systematic exploration of the entire space of crease patterns as a function of the folding energy. Consequently, we uncover statistical results in origami, finding the entropy of crease patterns of given folding energy. Notably, we identify three classes of Mountain-Valley choices that have widely varying `typical' folding energies. Our work opens up a wealth of experimentally relevant self-folding origami designs not reliant on Miura-Ori, the Kawasaki condition or any special symmetry in space.

  10. Drug delivery system of basic fibroblast growth factor using gelatin hydrogel for restoration of acute vocal fold scar.

    Science.gov (United States)

    Kobayashi, Toshiki; Mizuta, Masanobu; Hiwatashi, Nao; Kishimoto, Yo; Nakamura, Tatsuo; Kanemaru, Shin-Ichi; Hirano, Shigeru

    2017-02-01

    There continue to be therapeutic challenges in the management of vocal fold scarring. We previously showed that basic fibroblast growth factor (bFGF) injection has therapeutic potential for vocal fold scarring. However, the working time of bFGF is relatively short, and multiple injections were required in many cases to obtain the regenerative effect. An efficacious delivery system for bFGF has yet to be established. We designed a method of sustained drug delivery system (DDS) of bFGF by using a gelatin hydrogel. Hydrogel has been developed for targeted delivery and controlled release of bFGF. Hydrogel of the particle type is also injectable and commercially available. The current study aims to investigate the effects of a single injection of bFGF-DDS on acute vocal fold scarring using a canine model. Vocal folds from eight beagles were unilaterally scarred by stripping the lamina propria. One month later, hydrogels (0.5ml) containing 10μg of bFGF were injected into the scarred vocal folds of four beagles (FGF-hydrogel group). Saline (0.5ml) was injected into the other four beagles (sham group). Vibratory and histological examination of excised larynges was performed 5 months after treatment. Comparative analysis between the current data and our previous data with repeated injection of bFGF solution was also completed. Vibratory examination demonstrated significantly improved vibration in the bFGF hydrogel-treated group. Histological examination of the bFGF hydrogel group showed restoration of hyaluronic acid in the lamina propria as compared to sham. Comparison between the DDS system and our previous bFGF solution injection indicated better effects of the DDS system on vibratory amplitude. A single injection of bFGF hydrogel has regenerative effects on acute vocal fold scarring, which is at least similar to repeated injection of bFGF solution. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

  11. Three-dimensional optical reconstruction of vocal fold kinematics using high-speed video with a laser projection system

    Science.gov (United States)

    Luegmair, Georg; Mehta, Daryush D.; Kobler, James B.; Döllinger, Michael

    2015-01-01

    Vocal fold kinematics and its interaction with aerodynamic characteristics play a primary role in acoustic sound production of the human voice. Investigating the temporal details of these kinematics using high-speed videoendoscopic imaging techniques has proven challenging in part due to the limitations of quantifying complex vocal fold vibratory behavior using only two spatial dimensions. Thus, we propose an optical method of reconstructing the superior vocal fold surface in three spatial dimensions using a high-speed video camera and laser projection system. Using stereo-triangulation principles, we extend the camera-laser projector method and present an efficient image processing workflow to generate the three-dimensional vocal fold surfaces during phonation captured at 4000 frames per second. Initial results are provided for airflow-driven vibration of an ex vivo vocal fold model in which at least 75% of visible laser points contributed to the reconstructed surface. The method captures the vertical motion of the vocal folds at a high accuracy to allow for the computation of three-dimensional mucosal wave features such as vibratory amplitude, velocity, and asymmetry. PMID:26087485

  12. Folding control in cyclic peptides through N-methylation pattern selection: formation of antiparallel beta-sheet dimers, double reverse turns and supramolecular helices by 3alpha,gamma cyclic peptides.

    Science.gov (United States)

    Amorín, Manuel; Castedo, Luis; Granja, Juan R

    2008-01-01

    Peptide foldamers constitute a growing class of nanomaterials with potential applications in a wide variety of chemical, medical and technological fields. Here we describe the preparation and structural characteristics of a new class of cyclic peptide foldamers (3alpha,gamma-CPs) that, depending on their backbone N-methylation patterns and the medium, can either remain as flat rings that dimerize through arrays of hydrogen bonds of antiparallel beta-sheet type, or can fold into twisted double reverse turns that, in the case of double gamma-turns, associate in nonpolar solvents to form helical supramolecular structures. A 3alpha,gamma-CP consists of a number of multiples of a repeat unit made up of four amino acid residues of alternating chirality: three corresponding to alpha-amino acids and one to a gamma-amino acid (a cis-3-aminocycloalkanecarboxylic acid).

  13. Research on Bell-Shaped Vibratory Angular Rate Gyro’s Character of Resonator

    Directory of Open Access Journals (Sweden)

    Hong Liu

    2013-04-01

    Full Text Available Bell-shaped vibratory angular rate gyro (abbreviated as BVG is a new type Coriolis vibratory gyro that was inspired by Chinese traditional clocks. The resonator fuses based on a variable thickness axisymmetric multicurved surface shell. Its characteristics can directly influence the performance of BVG. The BVG structure not only has capabilities of bearing high overload, high impact and, compared with the tuning fork, vibrating beam, shell and a comb structure, but also a higher frequency to overcome the influence of the disturbance of the exterior environment than the same sized hemispherical resonator gyroscope (HRG and the traditional cylinder vibratory gyroscope. It can be widely applied in high dynamic low precision angular rate measurement occasions. The main work is as follows: the issue mainly analyzes the structure and basic principle, and investigates the bell-shaped resonator’s mathematical model. The reasonable structural parameters are obtained from finite element analysis and an intelligent platform. Using the current solid vibration gyro theory analyzes the structural characteristics and principles of BVG. The bell-shaped resonator is simplified as a paraboloid of the revolution mechanical model, which has a fixed closed end and a free opened end. It obtains the natural frequency and vibration modes based on the theory of elasticity. The structural parameters are obtained from the orthogonal method by the research on the structural parameters of the resonator analysis. It obtains the modal analysis, stress analysis and impact analysis with the chosen parameters. Finally, using the turntable experiment verifies the gyro effect of the BVG.

  14. Background matters: Minor vibratory stimulation during motor skill acquisition selectively reduces off-line memory consolidation.

    Science.gov (United States)

    Korman, Maria; Herling, Zohar; Levy, Ishay; Egbarieh, Nebal; Engel-Yeger, Batya; Karni, Avi

    2017-04-01

    Although a ubiquitous situation, it is not clear how effective is a learning experience when task-irrelevant, sensory noise occurs in the background. Here, young adults were trained on the finger opposition sequence task, in a well-established training and testing protocol affording measures for online as well as off-line learning. During the training session, one group experienced a minor background vibratory stimulation to the trunk by the means of vibrating cushion, while the second group experienced recorded sound vibrations. A control group was trained with no extra sensory stimulation. Sensory stimulation during training had no effect on the online within-session gains, but dampened the expression of the off-line, consolidation phase, gains in the two sensory stimulation groups. These results suggest that background sensory stimulation can selectively modify off-line, procedural memory consolidation processes, despite well-preserved on-line learning. Classical studies have shown that neural plasticity in sensory systems is modulated by motor input. The current results extend this notion and suggest that some types of task-irrelevant sensory stimulation, concurrent with motor training, may constitute a 'gating' factor - modulating the triggering of long-term procedural memory consolidation processes. Thus, vibratory stimulation may be considered as a behavioral counterpart of pharmacological interventions that do not interfere with short term neural plasticity but block long-term plasticity. Copyright © 2017 Elsevier Inc. All rights reserved.

  15. Obtention of hydroxyapatite submicrometric of bovine origin by vibratory grinding for rapid prototyping

    International Nuclear Information System (INIS)

    Meira, C.R.; Purquerio, B.M.; Fortulan, C.A.

    2011-01-01

    Submicron bovine hydroxyapatite was obtained for rapid prototyping. Hydroxyapatite structure originated from bovine mineral bone has great importance among the biomaterials and biocompatibility due to its great similarity with the human bone structure. This study aims to obtain powder for manufacture by rapid prototyping of scaffolds. This technique manufacture requires highly reactive powders to compensate for the absence of pressure forming. Hydroxyapatite was milled in a ball mill and vibratory mill, and analyzed for their average equivalent spherical diameter and surface area. Test specimens were isostatically pressed at 100 MPa and machined into cylindrical test specimens. These specimens were sintered at several temperatures to determine the optimal sintering temperature based on densification and chemistry stability. In grinding ball mill was obtained particles of equivalent diameter of 0.74 micron in vibratory mill of 0.46 micrometers. An average flexural strength of 100 MPa and 99,8% of real density was attained for the sample sintered at 1300 deg C/2h, signaling potential for use in rapid prototyping. (author)

  16. Structural-acoustic coupling effects on the non-vacuum packaging vibratory cylinder gyroscope.

    Science.gov (United States)

    Xi, Xiang; Wu, Xuezhong; Wu, Yulie; Zhang, Yongmeng; Tao, Yi; Zheng, Yu; Xiao, Dingbang

    2013-12-13

    The resonant shells of vibratory cylinder gyroscopes are commonly packaged in metallic caps. In order to lower the production cost, a portion of vibratory cylinder gyroscopes do not employ vacuum packaging. However, under non-vacuum packaging conditions there can be internal acoustic noise leading to considerable acoustic pressure which is exerted on the resonant shell. Based on the theory of the structural-acoustic coupling, the dynamical behavior of the resonant shell under acoustic pressure is presented in this paper. A finite element (FE) model is introduced to quantitatively analyze the effect of the structural-acoustic coupling. Several main factors, such as sealing cap sizes and degree of vacuum which directly affect the vibration of the resonant shell, are studied. The results indicate that the vibration amplitude and the operating frequency of the resonant shell will be changed when the effect of structural-acoustic coupling is taken into account. In addition, an experiment was set up to study the effect of structural-acoustic coupling on the sensitivity of the gyroscope. A 32.4 mV/°/s increase of the scale factor and a 6.2 Hz variation of the operating frequency were observed when the radial gap size between the resonant shell and the sealing cap was changed from 0.5 mm to 20 mm.

  17. Structural-Acoustic Coupling Effects on the Non-Vacuum Packaging Vibratory Cylinder Gyroscope

    Directory of Open Access Journals (Sweden)

    Xiang Xi

    2013-12-01

    Full Text Available The resonant shells of vibratory cylinder gyroscopes are commonly packaged in metallic caps. In order to lower the production cost, a portion of vibratory cylinder gyroscopes do not employ vacuum packaging. However, under non-vacuum packaging conditions there can be internal acoustic noise leading to considerable acoustic pressure which is exerted on the resonant shell. Based on the theory of the structural-acoustic coupling, the dynamical behavior of the resonant shell under acoustic pressure is presented in this paper. A finite element (FE model is introduced to quantitatively analyze the effect of the structural-acoustic coupling. Several main factors, such as sealing cap sizes and degree of vacuum which directly affect the vibration of the resonant shell, are studied. The results indicate that the vibration amplitude and the operating frequency of the resonant shell will be changed when the effect of structural-acoustic coupling is taken into account. In addition, an experiment was set up to study the effect of structural-acoustic coupling on the sensitivity of the gyroscope. A 32.4 mV/°/s increase of the scale factor and a 6.2 Hz variation of the operating frequency were observed when the radial gap size between the resonant shell and the sealing cap was changed from 0.5 mm to 20 mm.

  18. Spherical images and inextensible curved folding

    Science.gov (United States)

    Seffen, Keith A.

    2018-02-01

    In their study, Duncan and Duncan [Proc. R. Soc. London A 383, 191 (1982), 10.1098/rspa.1982.0126] calculate the shape of an inextensible surface folded in two about a general curve. They find the analytical relationships between pairs of generators linked across the fold curve, the shape of the original path, and the fold angle variation along it. They present two special cases of generator layouts for which the fold angle is uniform or the folded curve remains planar, for simplifying practical folding in sheet-metal processes. We verify their special cases by a graphical treatment according to a method of Gauss. We replace the fold curve by a piecewise linear path, which connects vertices of intersecting pairs of hinge lines. Inspired by the d-cone analysis by Farmer and Calladine [Int. J. Mech. Sci. 47, 509 (2005), 10.1016/j.ijmecsci.2005.02.013], we construct the spherical images for developable folding of successive vertices: the operating conditions of the special cases in Duncan and Duncan are then revealed straightforwardly by the geometric relationships between the images. Our approach may be used to synthesize folding patterns for novel deployable and shape-changing surfaces without need of complex calculation.

  19. Frustration in Condensed Matter and Protein Folding

    Science.gov (United States)

    Li, Z.; Tanner, S.; Conroy, B.; Owens, F.; Tran, M. M.; Boekema, C.

    2014-03-01

    By means of computer modeling, we are studying frustration in condensed matter and protein folding, including the influence of temperature and Thomson-figure formation. Frustration is due to competing interactions in a disordered state. The key issue is how the particles interact to reach the lowest frustration. The relaxation for frustration is mostly a power function (randomly assigned pattern) or an exponential function (regular patterns like Thomson figures). For the atomic Thomson model, frustration is predicted to decrease with the formation of Thomson figures at zero kelvin. We attempt to apply our frustration modeling to protein folding and dynamics. We investigate the homogeneous protein frustration that would cause the speed of the protein folding to increase. Increase of protein frustration (where frustration and hydrophobicity interplay with protein folding) may lead to a protein mutation. Research is supported by WiSE@SJSU and AFC San Jose.

  20. Melody discrimination and protein fold classification

    Directory of Open Access Journals (Sweden)

    Robert P. Bywater

    2016-10-01

    Full Text Available One of the greatest challenges in theoretical biophysics and bioinformatics is the identification of protein folds from sequence data. This can be regarded as a pattern recognition problem. In this paper we report the use of a melody generation software where the inputs are derived from calculations of evolutionary information, secondary structure, flexibility, hydropathy and solvent accessibility from multiple sequence alignment data. The melodies so generated are derived from the sequence, and by inference, of the fold, in ways that give each fold a sound representation that may facilitate analysis, recognition, or comparison with other sequences.

  1. A bidirectional shape memory alloy folding actuator

    International Nuclear Information System (INIS)

    Paik, Jamie K; Wood, Robert J

    2012-01-01

    This paper presents a low-profile bidirectional folding actuator based on annealed shape memory alloy sheets applicable for meso- and microscale systems. Despite the advantages of shape memory alloys—high strain, silent operation, and mechanical simplicity—their application is often limited to unidirectional operation. We present a bidirectional folding actuator that produces two opposing 180° motions. A laser-patterned nickel alloy (Inconel 600) heater localizes actuation to the folding sections. The actuator has a thin ( < 1 mm) profile, making it appropriate for use in robotic origami. Various design parameters and fabrication variants are described and experimentally explored in the actuator prototype. (paper)

  2. Coarsely resolved topography along protein folding pathways

    Science.gov (United States)

    Fernández, Ariel; Kostov, Konstantin S.; Berry, R. Stephen

    2000-03-01

    The kinetic data from the coarse representation of polypeptide torsional dynamics described in the preceding paper [Fernandez and Berry, J. Chem. Phys. 112, 5212 (2000), preceding paper] is inverted by using detailed balance to obtain a topographic description of the potential-energy surface (PES) along the dominant folding pathway of the bovine pancreatic trypsin inhibitor (BPTI). The topography is represented as a sequence of minima and effective saddle points. The dominant folding pathway displays an overall monotonic decrease in energy with a large number of staircaselike steps, a clear signature of a good structure-seeker. The diversity and availability of alternative folding pathways is analyzed in terms of the Shannon entropy σ(t) associated with the time-dependent probability distribution over the kinetic ensemble of contact patterns. Several stages in the folding process are evident. Initially misfolded states form and dismantle revealing no definite pattern in the topography and exhibiting high Shannon entropy. Passage down a sequence of staircase steps then leads to the formation of a nativelike intermediate, for which σ(t) is much lower and fairly constant. Finally, the structure of the intermediate is refined to produce the native state of BPTI. We also examine how different levels of tolerance to mismatches of side chain contacts influence the folding kinetics, the topography of the dominant folding pathway, and the Shannon entropy. This analysis yields upper and lower bounds of the frustration tolerance required for the expeditious and robust folding of BPTI.

  3. Vibratory perception threshold in young and middle-aged patients at high risk of knee osteoarthritis compared to controls

    DEFF Research Database (Denmark)

    Thorlund, Jonas Bloch; Shakoor, Najia; Ageberg, Eva

    2012-01-01

    Vibratory perception threshold (VPT) is impaired in patients with knee osteoarthritis (OA). It is, however, not known if sensory deficits precede or follow as a consequence of OA. The aim of this study was to investigate VPT in 2 independent groups of patients with high risk of future OA (young a...

  4. Modal Damping Ratio and Optimal Elastic Moduli of Human Body Segments for Anthropometric Vibratory Model of Standing Subjects.

    Science.gov (United States)

    Gupta, Manoj; Gupta, T C

    2017-10-01

    The present study aims to accurately estimate inertial, physical, and dynamic parameters of human body vibratory model consistent with physical structure of the human body that also replicates its dynamic response. A 13 degree-of-freedom (DOF) lumped parameter model for standing person subjected to support excitation is established. Model parameters are determined from anthropometric measurements, uniform mass density, elastic modulus of individual body segments, and modal damping ratios. Elastic moduli of ellipsoidal body segments are initially estimated by comparing stiffness of spring elements, calculated from a detailed scheme, and values available in literature for same. These values are further optimized by minimizing difference between theoretically calculated platform-to-head transmissibility ratio (TR) and experimental measurements. Modal damping ratios are estimated from experimental transmissibility response using two dominant peaks in the frequency range of 0-25 Hz. From comparison between dynamic response determined form modal analysis and experimental results, a set of elastic moduli for different segments of human body and a novel scheme to determine modal damping ratios from TR plots, are established. Acceptable match between transmissibility values calculated from the vibratory model and experimental measurements for 50th percentile U.S. male, except at very low frequencies, establishes the human body model developed. Also, reasonable agreement obtained between theoretical response curve and experimental response envelop for average Indian male, affirms the technique used for constructing vibratory model of a standing person. Present work attempts to develop effective technique for constructing subject specific damped vibratory model based on its physical measurements.

  5. Vocal Fold Collision Modeling

    DEFF Research Database (Denmark)

    Granados, Alba; Brunskog, Jonas; Misztal, M. K.

    2015-01-01

    When vocal folds vibrate at normal speaking frequencies, collisions occurs. The numerics and formulations behind a position-based continuum model of contact is an active field of research in the contact mechanics community. In this paper, a frictionless three-dimensional finite element model...

  6. Folding worlds between pages

    CERN Multimedia

    Meier, Matthias

    2010-01-01

    "We all remember pop-up books form our childhood. As fascinated as we were back then, we probably never imagined how much engineering know-how went into these books. Pop-up engineer Anton Radevsky has even managed to fold a 27-kilometre particle accelerator into a book" (4 pages)

  7. Folds and Etudes

    Science.gov (United States)

    Bean, Robert

    2007-01-01

    In this article, the author talks about "Folds" and "Etudes" which are images derived from anonymous typing exercises that he found in a used copy of "Touch Typing Made Simple". "Etudes" refers to the musical tradition of studies for a solo instrument, which is a typewriter. Typing exercises are repetitive attempts to type words and phrases…

  8. Characterization of vibratory turning in cutting zone using a pneumatic quick-stop device

    Directory of Open Access Journals (Sweden)

    Saeid Amini

    2017-04-01

    Full Text Available Shear angle and sticking length are two crucial parameters in mechanics of metal cutting. These two parameters directly influence machinability factors such as cutting forces. Thus, shear angle and sticking length were investigated in vibratory turning process by using a pneumatic quick-stop device which was designed and fabricated, in this study. After preparation of ultrasonic assisted turning set-up, experimental tests have been carried out on two types of steel: AISI-1060 and AISI 304. Accordingly, the process of chip formation in each particular cutting test was quickly stopped when deformed chip was still in contact with workpiece. As a result, it was revealed that added linear vibration leads the turning operation to be improved by increase of shear angle and decrease of sticking length. Moreover, the effect of ultrasonic vibration on cutting force and chip micro-hardness is evaluated.

  9. Application of vibratory-percussion crusher for disintegration of supertough materials

    Science.gov (United States)

    Shishkin, E. V.; Kazakov, S. V.

    2017-10-01

    This article describes the results of theoretical and experimental studies of a vibratory-percussion crusher, which is driven from a pair of self-synchronizing vibration exciters, attached to the shell symmetrically about its vertical axis. In addition to that, crusher’s dynamic model is symmetrical and balanced. Forced oscillation laws for crusher working members and their amplitude-frequency characteristics have been inducted. Domains of existence of synchronous opposite-phase oscillations of crusher working members (crusher’s operating mode) and crusher capabilities have been identified. The results of mechanical and technological tests of a pilot crusher presented in the article show that this crusher may be viewed as an advanced machine for disintegration of supertough materials with minimum regrinding of finished products.

  10. Specific modes of vibratory technological machines: mathematical models, peculiarities of interaction of system elements

    Science.gov (United States)

    Eliseev, A. V.; Sitov, I. S.; Eliseev, S. V.

    2018-03-01

    The methodological basis of constructing mathematical models of vibratory technological machines is developed in the article. An approach is proposed that makes it possible to introduce a vibration table in a specific mode that provides conditions for the dynamic damping of oscillations for the zone of placement of a vibration exciter while providing specified vibration parameters in the working zone of the vibration table. The aim of the work is to develop methods of mathematical modeling, oriented to technological processes with long cycles. The technologies of structural mathematical modeling are used with structural schemes, transfer functions and amplitude-frequency characteristics. The concept of the work is to test the possibilities of combining the conditions for reducing loads with working components of a vibration exciter while simultaneously maintaining sufficiently wide limits in variating the parameters of the vibrational field.

  11. Anti-control of chaos of a permanent magnet DC motor system for vibratory compactors

    International Nuclear Information System (INIS)

    Wang Zheng; Chau, K.T.

    2008-01-01

    The purpose of this paper is to employ time-delay feedback to anti-control a permanent magnet DC (PMDC) motor system for vibratory compactors, and hence implement a new electrically chaotic compactor. Firstly, the dynamic model of the anti-controlled PMDC motor system and the proposed electrically chaotic compactor are formulated. Secondly, a nonlinear map is derived to analyze the chaotic criterion of the anti-controlled PMDC motor system. Then, numerical computations are used to investigate the dynamics of the proposed electrically chaotic compactor. Finally, a series of simulations are conducted to verify that the proposed electrically chaotic compactor not only offers better compaction effects than the conventional one, but also provides higher flexibility than the mechanically chaotic compactor

  12. Understanding the role of nonlinearities in the transduction of vibratory energy harvesters

    Science.gov (United States)

    Masana, Ravindra Shiva Charan

    The last two decades have witnessed several advances in micro-fabrication technologies and electronics, leading to the development of small, low-power devices for wireless sensing, data transmission, actuation, and medical implants. Unfortunately, the actual implementation of such devices in their respective environment has been hindered by the lack of scalable energy sources that are necessary to power and maintain them. Batteries, which remain the most commonly used power source, have not kept pace with the demands of these devices, especially in terms of energy density. In light of this challenge, the concept of vibratory energy harvesting has flourished in recent years as a possible alternative to power and maintain low-power electronics. While linear vibratory energy harvesters have received the majority of the literature's attention, a significant body of the current research activity is focused on the concept of purposeful inclusion of nonlinearities for broadband transduction. When compared to their linear resonant counterparts, nonlinear energy harvesters have a wider steady-state frequency bandwidth, leading to the common belief that they can be utilized to improve performance especially in random and non-stationary vibratory environments. This dissertation aims to critically investigate this belief by drawing a clearer picture of the role of nonlinearities in the transduction of energy harvesters and by defining the conditions under which nonlinearities can be used to enhance performance. To achieve this goal, the Thesis is divided into three parts. The first part investigates the performance of mono- and bi-stable energy harvesters under harmonic excitations and carries a detailed analysis of their relative performance. The second part investigates their response to broadband and narrowband random excitations and again analyzes their relative behavior. The third part exploits the super-harmonic resonance bands of bi-stable energy harvesters for the

  13. Study on the Effect of Steel Wheel and Ground on Single Steel Vibratory Roller

    Science.gov (United States)

    Li, Jiabo; You, Guanghui; Qiao, Jiabin; Ye, Min; Guo, Jin; Zhang, Hongyang

    2018-03-01

    In the compacting operation of single drum vibratory roller, the forces acting on the foundation of drum include the weight of the drum, the weight of the frame, the exciting force and so on. Based on the theoretical study of ground mechanics, this paper analyzes and calculates the forces acting on the steel wheel and the ground, and obtains the distribution of the laminar stress in the ground when the working plane vibrates. Derive the formula of dynamic compressive stress and static compressive stress in the foundation during vibration compaction. Through the compaction test of the soil trough of 20T single drum roller, the compressive stress data of the soil hydraulic field are obtained. The data of the dynamic compressive stress and the static compressive stress of each layer during the third compaction are obtained, and the theoretical research is verified.

  14. Optimal Draft requirement for vibratory tillage equipment using Genetic Algorithm Technique

    Science.gov (United States)

    Rao, Gowripathi; Chaudhary, Himanshu; Singh, Prem

    2018-03-01

    Agriculture is an important sector of Indian economy. Primary and secondary tillage operations are required for any land preparation process. Conventionally different tractor-drawn implements such as mouldboard plough, disc plough, subsoiler, cultivator and disc harrow, etc. are used for primary and secondary manipulations of soils. Among them, oscillatory tillage equipment is one such type which uses vibratory motion for tillage purpose. Several investigators have reported that the requirement for draft consumption in primary tillage implements is more as compared to oscillating one because they are always in contact with soil. Therefore in this paper, an attempt is made to find out the optimal parameters from the experimental data available in the literature to obtain minimum draft consumption through genetic algorithm technique.

  15. Vibratory synchronization transmission of a cylindrical roller in a vibrating mechanical system excited by two exciters

    Science.gov (United States)

    Zhang, Xueliang; Wen, Bangchun; Zhao, Chunyu

    2017-11-01

    In present work vibratory synchronization transmission (VST) of a cylindrical roller with dry friction in a vibrating mechanical system excited by two exciters, is studied. Using the average method, the criterion of implementing synchronization of two exciters and that of ensuring VST of a roller, are achieved. The criterion of stability of the synchronous states satisfies the Routh-Hurwitz principle. The influences of the structural parameters of the system to synchronization and stability, are discussed numerically, which can be served as the theoretical foundation for engineering designs. An experiment is carried out, which approximately verify the validity of the theoretical and numerical results, as well as the feasibility of the method used. Utilizing the VST theory of a roller, some types of vibrating crushing or grinding equipments, etc., can be designed.

  16. A novel oscillation control for MEMS vibratory gyroscopes using a modified electromechanical amplitude modulation technique

    International Nuclear Information System (INIS)

    Ma, Wei; Lin, Yiyu; Liu, Siqi; Zheng, Xudong; Jin, Zhonghe

    2017-01-01

    This paper reports a novel oscillation control algorithm for MEMS vibratory gyroscopes using a modified electromechanical amplitude modulation (MEAM) technique, which enhances the robustness against the frequency variation of the driving mode, compared to the conventional EAM (CEAM) scheme. In this approach, the carrier voltage exerted on the proof mass is frequency-modulated by the drive resonant frequency. Accordingly, the pick-up signal from the interface circuit involves a constant-frequency component that contains the amplitude and phase information of the vibration displacement. In other words, this informational detection signal is independent of the mechanical resonant frequency, which varies due to different batches, imprecise micro-fabrication and changing environmental temperature. In this paper, the automatic gain control loop together with the phase-locked loop are simultaneously analyzed using the averaging method and Routh–Hurwitz criterion, deriving the stability condition and the parameter optimization rules of the transient response. Then, a simulation model based on the real system is set up to evaluate the control algorithm. Further, the proposed MEAM method is tested using a field-programmable-gate-array based digital platform on a capacitive vibratory gyroscope. By optimizing the control parameters, the transient response of the drive amplitude reveals a settling time of 45.2 ms without overshoot, according well with the theoretical prediction and simulation results. The first measurement results show that the amplitude variance of the drive displacement is 12 ppm in an hour while the phase standard deviation is as low as 0.0004°. The mode-split gyroscope operating under atmospheric pressure demonstrates an outstanding performance. By virtue of the proposed MEAM method, the bias instability and angle random walk are measured to be 0.9° h −1 (improved by 2.4 times compared to the CEAM method) and 0.068° (√h) −1 (improved by 1

  17. Physics of protein folding

    Science.gov (United States)

    Finkelstein, A. V.; Galzitskaya, O. V.

    2004-04-01

    Protein physics is grounded on three fundamental experimental facts: protein, this long heteropolymer, has a well defined compact three-dimensional structure; this structure can spontaneously arise from the unfolded protein chain in appropriate environment; and this structure is separated from the unfolded state of the chain by the “all-or-none” phase transition, which ensures robustness of protein structure and therefore of its action. The aim of this review is to consider modern understanding of physical principles of self-organization of protein structures and to overview such important features of this process, as finding out the unique protein structure among zillions alternatives, nucleation of the folding process and metastable folding intermediates. Towards this end we will consider the main experimental facts and simple, mostly phenomenological theoretical models. We will concentrate on relatively small (single-domain) water-soluble globular proteins (whose structure and especially folding are much better studied and understood than those of large or membrane and fibrous proteins) and consider kinetic and structural aspects of transition of initially unfolded protein chains into their final solid (“native”) 3D structures.

  18. Functional and Histological Evaluation following Canine Vocal Fold Reconstruction Using Composite Thyroid Ala Perichondrium Flaps.

    Science.gov (United States)

    Hoffman, Matthew R; Glab, Rachel; Gunderson, McLean; Maytag, Allison L; Yang, David T; Jiang, Jack J; Dailey, Seth H

    2015-07-01

    We evaluated the effects of vocal fold reconstruction using a composite thyroid ala perichondrium flap (CTAP) after unilateral vocal fold stripping in beagles. We hypothesized that CTAP would improve glottic closure, decrease phonation threshold pressure, and decrease perturbation. In addition, vocal folds with CTAP would exhibit neovascularization and fat with increased von Willebrand factor (vWF) and smooth muscle actin (SMA), reflecting neoangiogenesis and flap viability. Randomized controlled trial using beagles. University laboratory. Ten beagles underwent unilateral vocal fold stripping. Dogs in the scar-only group (n = 5) were sacrificed at 1 month. Dogs in the CTAP group (n = 5) underwent ipsilateral reconstruction with CTAP at 1 month and were sacrificed at 2 months. Excised larynx experiments evaluated vocal fold vibration using aerodynamic, acoustic, and mucosal wave measurements. Qualitative evaluation of vocal fold morphology and quantitative analysis of elastin, collagen, glycosaminoglycans, vWF, SMA, and hyaluronic acid were performed. Phonation threshold pressure (P = .005), percent jitter (P = .010), percent shimmer (P = .007), and open quotient (P = .007) were lower in the CTAP group. Neovascularization (P = .0079) and fat (P = .1667) occurred more with CTAP, although the difference in fat was not significant. von Willebrand factor was higher with CTAP vs contralateral normal fold (P = .110), although not statistically significant. Smooth muscle actin was higher with CTAP vs contralateral normal fold (P = .038) and scarred vocal folds (P = .022). Composite thyroid ala perichondrium flap restored glottic closure and vibratory periodicity following vocal fold scarring. Additional investigation on biologic response is warranted. Composite thyroid ala perichondrium flap offers an autologous, vascularized implant that can improve both vocal fold structure and function. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  19. Vocal Fold Epithelial Barrier in Health and Injury A Research Review

    Science.gov (United States)

    Levendoski, Elizabeth Erickson; Leydon, Ciara; Thibeault, Susan L.

    2015-01-01

    Purpose Vocal fold epithelium is composed of layers of individual epithelial cells joined by junctional complexes constituting a unique interface with the external environment. This barrier provides structural stability to the vocal folds and protects underlying connective tissue from injury while being nearly continuously exposed to potentially hazardous insults including environmental or systemic-based irritants such as pollutants and reflux, surgical procedures, and vibratory trauma. Small disruptions in the epithelial barrier may have a large impact on susceptibility to injury and overall vocal health. The purpose of this article is to provide a broad-based review of our current knowledge of the vocal fold epithelial barrier. Methods A comprehensive review of the literature was conducted. Details of the structure of the vocal fold epithelial barrier are presented and evaluated in the context of function in injury and pathology. The importance of the epithelial-associated vocal fold mucus barrier is also introduced. Results/Conclusions Information presented in this review is valuable for clinicians and researchers as it highlights the importance of this understudied portion of the vocal folds to overall vocal health and disease. Prevention and treatment of injury to the epithelial barrier is a significant area awaiting further investigation. PMID:24686981

  20. Characterizing the Effective Bandwidth of Nonlinear Vibratory Energy Harvesters Possessing Multiple Stable Equilibria

    Science.gov (United States)

    Panyam Mohan Ram, Meghashyam

    In the last few years, advances in micro-fabrication technologies have lead to the development of low-power electronic devices spanning critical fields related to sensing, data transmission, and medical implants. Unfortunately, effective utilization of these devices is currently hindered by their reliance on batteries. In many of these applications, batteries may not be a viable choice as they have a fixed storage capacity and need to be constantly replaced or recharged. In light of such challenges, several novel concepts for micro-power generation have been recently introduced to harness, otherwise, wasted ambient energy from the environment and maintain these low-power devices. Vibratory energy harvesting is one such concept which has received significant attention in recent years. While linear vibratory energy harvesters have been well studied in the literature and their performance metrics have been established, recent research has focused on deliberate introduction of stiffness nonlinearities into the design of these devices. It has been shown that, nonlinear energy harvesters have a wider steady-state frequency bandwidth as compared to their linear counterparts, leading to the premise that they can used to improve performance, and decrease sensitivity to variations in the design and excitation parameters. This dissertation aims to investigate this premise by developing an analytical framework to study the influence of stiffness nonlinearities on the performance and effective bandwidth of nonlinear vibratory energy harvesters. To achieve this goal, the dissertation is divided into three parts. The first part investigates the performance of bi-stable energy harvesters possessing a symmetric quartic potential energy function under harmonic excitations and carries out a detailed analysis to define their effective frequency bandwidth. The second part investigates the relative performance of mono- and bi-stable energy harvesters under optimal electric loading

  1. Analysis of rabbit intervertebral disc physiology based on water metabolism. II. Changes in normal intervertebral discs under axial vibratory load

    International Nuclear Information System (INIS)

    Hirano, N.; Tsuji, H.; Ohshima, H.; Kitano, S.; Itoh, T.; Sano, A.

    1988-01-01

    Metabolic changes induced by axial vibratory load to the spine were investigated based on water metabolism in normal intervertebral discs of rabbits with or without pentobarbital anesthesia. Tritiated water concentration in the intervertebral discs of unanesthetized rabbits was reduced remarkably by axial vibration for 30 minutes using the vibration machine developed for this study. Repeated vibratory load for 18 and 42 hours duration showed the recovery of 3 H 2 O concentration of the intervertebral disc without anesthesia. Computer simulation suggested a reduction of blood flow surrounding the intervertebral disc following the vibration stress. However, no reduction of the 3 H 2 O concentration in the intervertebral disc was noted under anesthesia. Emotional stress cannot be excluded as a factor in water metabolism in the intervertebral disc

  2. SAVIT: a dymanic model to predict vibratory motion within a spent fuel shipping cask; rail car system

    International Nuclear Information System (INIS)

    Fields, S.R.

    1978-03-01

    A dynamic model of a spent fuel shipping cask-rail car system has been developed to provide estimates of the vibratory motion of LWR spent fuel assemblies during transport and to estimate the effects of this motion on the condition of the assemblies when they arrive at receiving and storage facilities. Results of preliminary test computations are presented to illustrate the capabilities of the model

  3. Psychomotor Battery Approaches to Performance Prediction and Evaluation in Hyperbaric, Thermal and Vibratory Environments: Annotated Bibliographies and Integrative Review

    Science.gov (United States)

    1980-10-01

    W77-Mar78 and Vibratory Environments: Annotated Biblia - 4.-EFRIGOO EOT*_1 graphies and Integrative Review. I. CONTRACT OR GRANT NUMSER(a) David J...Papers In the third phase of the effort, the final version of the three speciai-environrneni performance battery bibliographies was corriiled and the...performance at much lower pressu. (e.g. 3 to 4 ATA when nitrogen is involved). The following sections will integrate the available liter - ature on the effects

  4. Non-cylindrical fold growth in the Zagros fold and thrust belt (Kurdistan, NE-Iraq)

    Science.gov (United States)

    Bartl, Nikolaus; Bretis, Bernhard; Grasemann, Bernhard; Lockhart, Duncan

    2010-05-01

    The Zagros mountains extends over 1800 km from Kurdistan in N-Iraq to the Strait of Hormuz in Iran and is one of the world most promising regions for the future hydrocarbon exploration. The Zagros Mountains started to form as a result of the collision between the Eurasian and Arabian Plates, whose convergence began in the Late Cretaceous as part of the Alpine-Himalayan orogenic system. Geodetic and seismological data document that both plates are still converging and that the fold and thrust belt of the Zagros is actively growing. Extensive hydrocarbon exploration mainly focuses on the antiforms of this fold and thrust belt and therefore the growth history of the folds is of great importance. This work investigates by means of structural field work and quantitative geomorphological techniques the progressive fold growth of the Permam, Bana Bawi- and Safeen- Anticlines located in the NE of the city of Erbil in the Kurdistan region of Northern Iraq. This part of the Zagros fold and thrust belt belongs to the so-called Simply Folded Belt, which is dominated by gentle to open folding. Faults or fault related folds have only minor importance. The mechanical anisotropy of the formations consisting of a succession of relatively competent (massive dolomite and limestone) and incompetent (claystone and siltstone) sediments essentially controls the deformation pattern with open to gentle parallel folding of the competent layers and flexural flow folding of the incompetent layers. The characteristic wavelength of the fold trains is around 10 km. Due to faster erosion of the softer rock layers in the folded sequence, the more competent lithologies form sharp ridges with steeply sloping sides along the eroded flanks of the anticlines. Using an ASTER digital elevation model in combination with geological field data we quantified 250 drainage basins along the different limbs of the subcylindrical Permam, Bana Bawi- and Safeen- Anticlines. Geomorphological indices of the drainage

  5. Vibratory response of a mirror support/positioning system for the Advanced Photon Source project at Argonne National Laboratory

    International Nuclear Information System (INIS)

    Basdogan, I.; Shu, Deming; Kuzay, T.M.; Royston, T.J.; Shabana, A.A.

    1996-01-01

    The vibratory response of a typical mirror support/positioning system used at the experimental station of the Advanced Photon Source (APS) project at Argonne National Laboratory is investigated. Positioning precision and stability are especially critical when the supported mirror directs a high-intensity beam aimed at a distant target. Stability may be compromised by low level, low frequency seismic and facility-originated vibrations traveling through the ground and/or vibrations caused by flow-structure interactions in the mirror cooling system. The example case system has five positioning degrees of freedom through the use of precision actuators and rotary and linear bearings. These linkage devices result in complex, multi-dimensional vibratory behavior that is a function of the range of positioning configurations. A rigorous multibody dynamical approach is used for the development of the system equations. Initial results of the study, including estimates of natural frequencies and mode shapes, as well as limited parametric design studies, are presented. While the results reported here are for a particular system, the developed vibratory analysis approach is applicable to the wide range of high-precision optical positioning systems encountered at the APS and at other comparable facilities

  6. Folding of multidomain proteins: biophysical consequences of tethering even in apparently independent folding.

    Science.gov (United States)

    Arviv, Oshrit; Levy, Yaakov

    2012-12-01

    Most eukaryotic and a substantial fraction of prokaryotic proteins are composed of more than one domain. The tethering of these evolutionary, structural, and functional units raises, among others, questions regarding the folding process of conjugated domains. Studying the folding of multidomain proteins in silico enables one to identify and isolate the tethering-induced biophysical determinants that govern crosstalks generated between neighboring domains. For this purpose, we carried out coarse-grained and atomistic molecular dynamics simulations of two two-domain constructs from the immunoglobulin-like β-sandwich fold. Each of these was experimentally shown to behave as the "sum of its parts," that is, the thermodynamic and kinetic folding behavior of the constituent domains of these constructs seems to occur independently, with the folding of each domain uncoupled from the folding of its partner in the two-domain construct. We show that the properties of the individual domains can be significantly affected by conjugation to another domain. The tethering may be accompanied by stabilizing as well as destabilizing factors whose magnitude depends on the size of the interface, the length, and the flexibility of the linker, and the relative stability of the domains. Accordingly, the folding of a multidomain protein should not be viewed as the sum of the folding patterns of each of its parts, but rather, it involves abrogating several effects that lead to this outcome. An imbalance between these effects may result in either stabilization or destabilization owing to the tethering. Copyright © 2012 Wiley Periodicals, Inc.

  7. The review on tessellation origami inspired folded structure

    Science.gov (United States)

    Chu, Chai Chen; Keong, Choong Kok

    2017-10-01

    Existence of folds enhances the load carrying capacity of a folded structure which makes it suitable to be used for application where large open space is required such as large span roof structures and façade. Folded structure is closely related to origami especially the tessellation origami. Tessellation origami provides a folded configuration with facetted surface as a result from repeated folding pattern. Besides that, tessellation origami has flexible folding mechanism that produced a variety of 3-dimensional folded configurations. Despite the direct relationship between fold in origami and folded structure, the idea of origami inspired folded structure is not properly reviewed in the relevant engineering field. Hence, this paper aims to present the current studies from related discipline which has direct relation with application of tessellation origami in folded structure. First, tessellation origami is properly introduced and defined. Then, the review covers the topic on the origami tessellation design suitable for folded structure, its modeling and simulation method, and existing studies and applications of origami as folded structure is presented. The paper also includes the discussion on the current issues related to each topic.

  8. Vibratory Machining Effect on the Properties of the Aaluminum Alloys Surface

    Directory of Open Access Journals (Sweden)

    Bańkowski D.

    2017-12-01

    Full Text Available The article presents an example of finishing treatment for aluminum alloys with the use of vibration machining, with loose abrasive media in a closed tumbler. For the analysis of selected properties of the surface layer prepared flat samples of aluminum alloy PA6/2017 in the state after recrystallization. The samples in the first stage were subjected to a treatment of deburring using ceramic media. In a second step polishing process performed with a strengthening metal media. In addition, for comparative purposes was considered. only the case of metal polishing. The prepared samples were subjected to hardness tests and a tangential tensile test. As a result of finishing with vibratory machining, it was possible to remove burrs, flash, rounding sharp edges, smoothing and lightening the surface of objects made. The basic parameters of the surface geometry were obtained using the Talysurf CCI Lite - Taylor Hobson optical profiler. As a result of the tests it can be stated that the greatest reduction of surface roughness and mass loss occurs in the first minutes of the process. Mechanical tests have shown that the most advantageous high values of tensile strength and hardness are obtained with two-stage vibration treatment, - combination of deburring and polishing. Moreover the use of metal media resulted in the strengthening of the surface by pressure deburring with metal media.

  9. A high-efficiency self-powered wireless sensor node for monitoring concerning vibratory events

    Science.gov (United States)

    Xu, Dacheng; Li, Suiqiong; Li, Mengyang; Xie, Danpeng; Dong, Chuan; Li, Xinxin

    2017-09-01

    This paper presents a self-powered wireless alarming sensor node (SWASN), which was designed to monitor the occurrence of concerning vibratory events. The major components of the sensor node include a vibration-threshold-triggered energy harvester (VTTEH) that powers the sensor node, a dual threshold voltage control circuit (DTVCC) for power management and a radio frequency (RF) signal transmitting module. The VTTEH generates significant electric energy only when the input vibration reaches certain amplitude. Thus, the VTTEH serves as both the power source and the vibration-event-sensing element for the sensor node. The DTVCC was specifically designed to utilize the limited power supply from the VTTEH to operate the sensor node. Constructed with only voltage detectors and MOSFETs, the DTVCC achieved low power consumption, which was 65% lower compared with the power management circuit designed in our previous work. Meanwhile, a RF transmit circuit was constructed based on the commercially available CC1110-F32 wireless transceiver chip and a compact planar antenna was designed to improve the signal transmission distance. The sensor node was fabricated and was characterized both in the laboratory and in the field. Experimental results showed that the SWASN could automatically send out alarming signals when the simulated concerning event occurred. The waiting time between two consecutive transmission periods is less than 125 s and the transmission distance can reach 1.31 km. The SWASN will have broad applications in field surveillances.

  10. Two Novel Measurements for the Drive-Mode Resonant Frequency of a Micromachined Vibratory Gyroscope

    Directory of Open Access Journals (Sweden)

    Ancheng Wang

    2013-11-01

    Full Text Available To investigate the drive-mode resonance frequency of a micromachined vibratory gyroscope (MVG, one needs to measure it accurately and efficiently. The conventional approach to measure the resonant frequency is by performing a sweep frequency test and spectrum analysis. The method is time-consuming and inconvenient because of the requirements of many test points, a lot of data storage and off-line analyses. In this paper, we propose two novel measurement methods, the search method and track method, respectively. The former is based on the magnitude-frequency characteristics of the drive mode, utilizing a one-dimensional search technique. The latter is based on the phase-frequency characteristics, applying a feedback control loop. Their performances in precision, noise resistivity and efficiency are analyzed through detailed simulations. A test system is implemented based on a field programmable gate array (FPGA and experiments are carried out. By comparing with the common approach, feasibility and superiorities of the proposed methods are validated. In particular, significant efficiency improvements are achieved whereby the conventional frequency method consumes nearly 5,000 s to finish a measurement, while only 5 s is needed for the track method and 1 s for the search method.

  11. Preduction of the vibratory behaviour of a multistage gaseous diffusion plant

    International Nuclear Information System (INIS)

    Descleve, P.; Bertaut, C.; Briot, P.

    1979-01-01

    A study has been made to predict the vibratory behaviour of the rotating machinery of a gaseous diffusion plant starting from the results obtained for a single machine. TRICASTIN gaseous diffusion plant uses several hundred of enrichment stages but only three different sizes of machine are used. Each individual machine is a vertical assembly of a compressor heat exchanger and diffusion barriers, this column is supported on four lugs on a concrete slab. This slab must accomodate thermal expansion and is placed on neoprene pads. Due to the compactness of the system the mass of concrete is relatively small. Typically the mass of a machine of the intermediate size is 84 T, the mass of associated concrete is 55 T. Furthermore this supporting slab is flexible, meaning that a dynamic analysis of the slab shows several frequencies below the compressor rotational speed. Extensive dynamic tests have been conducted on a machine supported on a rigid foundation. These tests have shown that the main source of mechanical excitation was caused at 50 Hz by the unbalance of the electrical motor rotor. Then the problem remained to predict the behaviour of a group of twenty machines in the plant itself. (orig.)

  12. Design and simulation of origami structures with smooth folds.

    Science.gov (United States)

    Peraza Hernandez, E A; Hartl, D J; Lagoudas, D C

    2017-04-01

    Origami has enabled new approaches to the fabrication and functionality of multiple structures. Current methods for origami design are restricted to the idealization of folds as creases of zeroth-order geometric continuity. Such an idealization is not proper for origami structures of non-negligible fold thickness or maximum curvature at the folds restricted by material limitations. For such structures, folds are not properly represented as creases but rather as bent regions of higher-order geometric continuity. Such fold regions of arbitrary order of continuity are termed as smooth folds . This paper presents a method for solving the following origami design problem: given a goal shape represented as a polygonal mesh (termed as the goal mesh ), find the geometry of a single planar sheet, its pattern of smooth folds, and the history of folding motion allowing the sheet to approximate the goal mesh. The parametrization of the planar sheet and the constraints that allow for a valid pattern of smooth folds are presented. The method is tested against various goal meshes having diverse geometries. The results show that every determined sheet approximates its corresponding goal mesh in a known folded configuration having fold angles obtained from the geometry of the goal mesh.

  13. Impact of Perioperative Voice Therapy on Outcomes in the Surgical Management of Vocal Fold Cysts.

    Science.gov (United States)

    Tibbetts, Kathleen M; Dominguez, Laura M; Simpson, C Blake

    2018-05-01

    Vocal fold cysts are benign mid-membranous lesions of the true vocal fold, classified as mucus retention or epidermal inclusion cysts. Treatment is surgical excision with or without postoperative voice therapy. A retrospective review was performed of the demographics, treatment approach, and outcomes of patients treated for vocal fold cysts between 2009 and 2014. Voice Handicap Index (VHI)-10 scores before and after treatment were compared using the Wilcoxon Rank-Sum test and the two-tailed Student's t test. Videostroboscopy examinations were reviewed for posttreatment changes in vibratory characteristics of the vocal folds. Twenty-five patients were identified, and one was excluded for incomplete records. Mean age was 41.9 years (66.7% female), and mean follow-up time was 5.58 months. Microflap excision was pursued by 21/24 (87.5%) patients, with 14 patients (58.3%) undergoing perioperative voice therapy. One cyst recurred. Two patients elected for observation, and their cysts persisted. VHI-10 decreased from 23.8 to 6.6 (P Vocal fold cysts impact mucosal wave and glottic closure. Surgical excision resulted in low rates of recurrence, and in improvement in the mucosal wave and VHI-10. Perioperative voice therapy did not offer a significant benefit. Mucus retention cysts were the majority, in contrast to other published studies. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  14. Extreme Mechanics: Self-Folding Origami

    Science.gov (United States)

    Santangelo, Christian D.

    2017-03-01

    Origami has emerged as a tool for designing three-dimensional structures from flat films. Because they can be fabricated by lithographic or roll-to-roll processing techniques, they have great potential for the manufacture of complicated geometries and devices. This article discusses the mechanics of origami and kirigami with a view toward understanding how to design self-folding origami structures. Whether an origami structure can be made to fold autonomously depends strongly on the geometry and kinematics of the origami fold pattern. This article collects some of the results on origami rigidity into a single framework, and discusses how these aspects affect the foldability of origami. Despite recent progress, most problems in origami and origami design remain completely open.

  15. Objective Quantification of Pre-and Postphonosurgery Vocal Fold Vibratory Characteristics Using High-Speed Videoendoscopy and a Harmonic Waveform Model

    Science.gov (United States)

    Ikuma, Takeshi; Kunduk, Melda; McWhorter, Andrew J.

    2014-01-01

    Purpose: The model-based quantitative analysis of high-speed videoendoscopy (HSV) data at a low frame rate of 2,000 frames per second was assessed for its clinical adequacy. Stepwise regression was employed to evaluate the HSV parameters using harmonic models and their relationships to the Voice Handicap Index (VHI). Also, the model-based HSV…

  16. RNA folding: structure prediction, folding kinetics and ion electrostatics.

    Science.gov (United States)

    Tan, Zhijie; Zhang, Wenbing; Shi, Yazhou; Wang, Fenghua

    2015-01-01

    Beyond the "traditional" functions such as gene storage, transport and protein synthesis, recent discoveries reveal that RNAs have important "new" biological functions including the RNA silence and gene regulation of riboswitch. Such functions of noncoding RNAs are strongly coupled to the RNA structures and proper structure change, which naturally leads to the RNA folding problem including structure prediction and folding kinetics. Due to the polyanionic nature of RNAs, RNA folding structure, stability and kinetics are strongly coupled to the ion condition of solution. The main focus of this chapter is to review the recent progress in the three major aspects in RNA folding problem: structure prediction, folding kinetics and ion electrostatics. This chapter will introduce both the recent experimental and theoretical progress, while emphasize the theoretical modelling on the three aspects in RNA folding.

  17. Self-folding graphene-polymer bilayers

    Energy Technology Data Exchange (ETDEWEB)

    Deng, Tao [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China); Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Yoon, ChangKyu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Jin, Qianru [Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Li, Mingen [Department of Physics, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Liu, Zewen [Institute of Microelectronics, Tsinghua University, Beijing 100084 (China); Gracias, David H., E-mail: dgracias@jhu.edu [Department of Materials Science and Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Department of Chemical and Biomolecular Engineering, Johns Hopkins University, Baltimore, Maryland 21218 (United States)

    2015-05-18

    In order to incorporate the extraordinary intrinsic thermal, electrical, mechanical, and optical properties of graphene with three dimensional (3D) flexible substrates, we introduce a solvent-driven self-folding approach using graphene-polymer bilayers. A polymer (SU-8) film was spin coated atop chemically vapor deposited graphene films on wafer substrates and graphene-polymer bilayers were patterned with or without metal electrodes using photolithography, thin film deposition, and etching. After patterning, the bilayers were released from the substrates and they self-folded to form fully integrated, curved, and folded structures. In contrast to planar graphene sensors on rigid substrates, we assembled curved and folded sensors that are flexible and they feature smaller form factors due to their 3D geometry and large surface areas due to their multiple rolled architectures. We believe that this approach could be used to assemble a range of high performance 3D electronic and optical devices of relevance to sensing, diagnostics, wearables, and energy harvesting.

  18. Alternative measures to observe and record vocal fold vibrations

    NARCIS (Netherlands)

    Schutte, HK; McCafferty, G; Coman, W; Carroll, R

    1996-01-01

    Vocal fold vibration patterns form the basis for the production of vocal sound. Over the years much effort has been spend to optimize the ways to visualize and give a description of these patterns. Before video possibilities became available the description of the patterns was Very time-consuming.

  19. Self-folding micropatterned polymeric containers.

    Science.gov (United States)

    Azam, Anum; Laflin, Kate E; Jamal, Mustapha; Fernandes, Rohan; Gracias, David H

    2011-02-01

    We demonstrate self-folding of precisely patterned, optically transparent, all-polymeric containers and describe their utility in mammalian cell and microorganism encapsulation and culture. The polyhedral containers, with SU-8 faces and biodegradable polycaprolactone (PCL) hinges, spontaneously assembled on heating. Self-folding was driven by a minimization of surface area of the liquefying PCL hinges within lithographically patterned two-dimensional (2D) templates. The strategy allowed for the fabrication of containers with variable polyhedral shapes, sizes and precisely defined porosities in all three dimensions. We provide proof-of-concept for the use of these polymeric containers as encapsulants for beads, chemicals, mammalian cells and bacteria. We also compare accelerated hinge degradation rates in alkaline solutions of varying pH. These optically transparent containers resemble three-dimensional (3D) micro-Petri dishes and can be utilized to sustain, monitor and deliver living biological components.

  20. Angular circulation speed of tablets in a vibratory tablet coating pan.

    Science.gov (United States)

    Kumar, Rahul; Wassgren, Carl

    2013-03-01

    In this work, a single tablet model and a discrete element method (DEM) computer simulation are developed to obtain the angular circulation speed of tablets in a vibratory tablet coating pan for range of vibration frequencies and amplitudes. The models identify three important dimensionless parameters that influence the speed of the tablets: the dimensionless amplitude ratio (a/R), the Froude number (aω2/g), and the tablet-wall friction coefficient, where a is the peak vibration amplitude at the drum center, ω is the vibration angular frequency, R is the drum radius, and g is the acceleration due to gravity. The models predict that the angular circulation speed of tablets increases with an increase in each of these parameters. The rate of increase in the angular circulation speed is observed to decrease for larger values of a/R. The angular circulation speed reaches an asymptote beyond a tablet-wall friction coefficient value of about 0.4. Furthermore, it is found that the Froude number should be greater than one for the tablets to start circulating. The angular circulation speed increases as Froude number increases but then does not change significantly at larger values of the Froude number. Period doubling, where the motion of the bed is repeated every two cycles, occurs at a Froude number larger than five. The single tablet model, although much simpler than the DEM model, is able to predict the maximum circulation speed (the limiting case for a large value of tablet-wall friction coefficient) as well as the transition to period doubling.

  1. Vibratory shear enhanced membrane process and its application in starch wastewater recycle

    Directory of Open Access Journals (Sweden)

    Kazi Sarwar Hasan

    2002-11-01

    Full Text Available Membrane application in wastewater is gaining significant popularity. Selecting the right membrane and filtration technique is an important consideration to ensure a successful system development and long term performance. A new type of membrane filtration technology known as ‘Vibratory Shear Enhanced Process’ (VSEP is introduced in this paper with some test results that has been conducted with VSEP pilot unit to recycle starch wastewater. Conventional cross flow membrane process used in wastewater application always led to rapid fouling. This loss in throughput capacity is primarily due to the formation of a layer that builds up naturally on the membranes surface during the filtration process. In addition to cutting down on the flux performance of the membrane, this boundary or gel layer acts as a secondary membrane reducing the native design selectivity of the membrane in use. This inability to handle the buildup of solids has also limited the use of membranes to low-solids feed streams. In a VSEP system, an additional shear wave produced by the membrane’s vibration cause solids and foulants to be lifted off the membrane surface and remixed with the bulk material flowing through the membrane stack. This high shear processing exposes the membrane pores for maximum throughput that is typically between 3 to10 times the throughput of conventional cross-flow systems. The short term results with raw starch wastewater shows very stable flux rate of 110 lmh using the VSEP system and selecting the PVDF ultrafiltration membrane with no pre-filtration.

  2. Development and evaluation of a vibratory-pneumatic pomegranate arils extractor

    Directory of Open Access Journals (Sweden)

    S. M Nassiri

    2017-05-01

    Full Text Available Introduction Iran is a frontier of pomegranate fruit production in the world (with almost 40 % of the world`s production. However due to traditional processing operations is not ranked as the largest pomegranate exporter. Saveh, Neyriz and Ferdows are the top pomegranate producing cities in Iran. Pomegranate is consumed as a fresh fruit as well as processed product as food additive, paste, syrup, jelly, pectin, jam, beverage, essence, vinegar and concentrate. Aril extraction is the first and essential postharvest operation for pomegranate processing. Arils are mostly extracted manually even in large scales for fresh and processed consumption. This labor intensive operation is rational when aril quality is an important index for consumer. But whenever pomegranate juice is desired, the aril quality has no priority for consumer, and therefore arils can be extracted with less care. Sarig (1985 was the first inventor of a pomegranate aril extractor who employed air jet force to extract the arils. Later, other researchers employed the same method as well as water jet to extract fruit juice and sac. In the present study, fabrication and evaluation of vibratory aril extractor augmented with air system was conducted. Materials and Methods The study was conducted using Rabab cultivar samples which were manually harvested from an orchard in Neyriz town, Fars province. Samples were kept in refrigerator at 5 0C till experimental trials. Initial moisture content of fruit skin, arils and internal fleshes were measured by gravimetric method as 31.7±2.6 %, 61.5±1.8 % and 42.8±1.4 %, respectively and for a whole fruit was measured 45.3±11.5 % (w.b.. For conducting laboratory tests, an aril extraction unit was designed and fabricated. It comprised a steel main frame, a 746 W electric motor, drive mechanism (eccentric and shaft, sample retentive unit, air jet unit, aril tank, and an air compressor-tank assembly. Sample retentive unit was designed in such a

  3. Vocal fold injection medialization laryngoplasty.

    Science.gov (United States)

    Modi, Vikash K

    2012-01-01

    Unilateral vocal fold paralysis (UVFP) can cause glottic insufficiency that can result in hoarseness, chronic cough, dysphagia, and/or aspiration. In rare circumstances, UVFP can cause airway obstruction necessitating a tracheostomy. The treatment options for UVFP include observation, speech therapy, vocal fold injection medialization laryngoplasty, thyroplasty, and laryngeal reinnervation. In this chapter, the author will discuss the technique of vocal fold injection for medialization of a UVFP. Copyright © 2012 S. Karger AG, Basel.

  4. A phase I/II exploratory clinical trial for intracordal injection of recombinant hepatocyte growth factor for vocal fold scar and sulcus.

    Science.gov (United States)

    Hirano, Shigeru; Kawamoto, Atsuhiko; Tateya, Ichiro; Mizuta, Masanobu; Kishimoto, Yo; Hiwatashi, Nao; Kawai, Yoshitaka; Tsuji, Takuya; Suzuki, Ryo; Kaneko, Mami; Naito, Yasushi; Kagimura, Tatsuo; Nakamura, Tatsuo; Kanemaru, Shin-Ichi

    2018-04-01

    Vocal fold scar and sulcus are intractable diseases with no effective established treatments. Hepatocyte growth factor (HGF) has preclinically proven to have potent antifibrotic and regenerative effects on vocal fold scar. The current Phase I/II clinical trial aims to examine the safety and effectiveness of intracordal injection of a recombinant human HGF drug for patients with vocal fold scar or sulcus. This is an open-label, dose-escalating, first-in-human clinical trial. Eighteen patients with bilateral vocal fold scar or sulcus were enrolled and divided into three groups: Step I received 1 μg of HGF per vocal fold; Step II received 3 μg of HGF; and Step III received 10 μg of HGF. Injections were administered once weekly for 4 weeks. The protocol treatment was performed starting with Step I and escalating to Step III. Patients were followed for 6 months post-treatment. Local and systemic safety aspects were examined as primary endpoints, and therapeutic effects were assessed as secondary endpoints using voice handicap index-10; maximum phonation time; vocal fold vibratory amplitude; grade, rough, breathy, asthenic, strained scale; and jitter. The results indicated no serious drug-related adverse events in either the systemic or local examinations. In whole-subject analysis, voice handicap index-10, vocal fold vibratory amplitude, and grade, rough, breathy, asthenic, strained scale were significantly improved at 6 months, whereas maximum phonation time and jitter varied. There were no significant differences in phonatory data between the step groups. In conclusion, intracordal injection of a recombinant human HGF drug was safe, feasible, and potentially effective for human patients with vocal fold scar or sulcus. Copyright © 2017 John Wiley & Sons, Ltd.

  5. Static-transmission-error vibratory-excitation contributions from plastically deformed gear teeth caused by tooth bending-fatigue damage

    Science.gov (United States)

    Mark, W. D.; Reagor, C. P.

    2007-02-01

    To assess gear health and detect gear-tooth damage, the vibratory response from meshing gear-pair excitations is commonly monitored by accelerometers. In an earlier paper, strong evidence was presented suggesting that, in the case of tooth bending-fatigue damage, the principal source of detectable damage is whole-tooth plastic deformation; i.e. yielding, rather than changes in tooth stiffness caused by tooth-root cracks. Such plastic deformations are geometric deviation contributions to the "static-transmission-error" (STE) vibratory excitation caused by meshing gear pairs. The STE contributions caused by two likely occurring forms of such plastic deformations on a single tooth are derived, and displayed in the time domain as a function of involute "roll distance." Example calculations are provided for transverse contact ratios of Qt=1.4 and 1.8, for spur gears and for helical-gear axial contact ratios ranging from Qa=1.2 to Qa=3.6. Low-pass- and band-pass-filtered versions of these same STE contributions also are computed and displayed in the time domain. Several calculations, consisting of superposition of the computed STE tooth-meshing fundamental harmonic contribution and the band-pass STE contribution caused by a plastically deformed tooth, exhibit the amplitude and frequency or phase modulation character commonly observed in accelerometer-response waveforms caused by damaged teeth. General formulas are provided that enable computation of these STE vibratory-excitation contributions for any form of plastic deformation on any number of teeth for spur and helical gears with any contact ratios.

  6. Implementation of the resonant vibratory feeders control algorithm on Simatic S7-1200 from MATLAB Simulink enviroment

    Directory of Open Access Journals (Sweden)

    Mitrović Radomir B.

    2016-01-01

    Full Text Available Simulink is an important tool for modeling and simulation of process and control algorithms. It's expansion, PLC Coder, enables direct conversion of model subsystem into SCL, structured text code, which is then used by PLC IDE to create function blocks. This shortens developing time of algorithms for PLC controller. Also, this reduces possibility for a coding error. This paper describes Simulink PLC Coder and workflow for developing PID control algorithm for Siemens Simatic S7-1200 PLC. Control object used here is resonant vibratory feeder having electromagnetic drive.

  7. How old is your fold?

    NARCIS (Netherlands)

    Winstanley, Henry F.; Abeln, Sanne; Deane, Charlotte M.

    Motivation: At present there exists no age estimate for the different protein structures found in nature. It has become clear from occurrence studies that different folds arose at different points in evolutionary time. An estimation of the age of different folds would be a starting point for many

  8. Teaching computers to fold proteins

    DEFF Research Database (Denmark)

    Winther, Ole; Krogh, Anders Stærmose

    2004-01-01

    A new general algorithm for optimization of potential functions for protein folding is introduced. It is based upon gradient optimization of the thermodynamic stability of native folds of a training set of proteins with known structure. The iterative update rule contains two thermodynamic averages...

  9. Periodic folding of viscous sheets

    Science.gov (United States)

    Ribe, Neil M.

    2003-09-01

    The periodic folding of a sheet of viscous fluid falling upon a rigid surface is a common fluid mechanical instability that occurs in contexts ranging from food processing to geophysics. Asymptotic thin-layer equations for the combined stretching-bending deformation of a two-dimensional sheet are solved numerically to determine the folding frequency as a function of the sheet’s initial thickness, the pouring speed, the height of fall, and the fluid properties. As the buoyancy increases, the system bifurcates from “forced” folding driven kinematically by fluid extrusion to “free” folding in which viscous resistance to bending is balanced by buoyancy. The systematics of the numerically predicted folding frequency are in good agreement with laboratory experiments.

  10. A study on the contribution of body vibrations to the vibratory sensation induced by high-level, complex low-frequency noise

    Directory of Open Access Journals (Sweden)

    Yukio Takahashi

    2011-01-01

    Full Text Available To investigate the contribution of body vibrations to the vibratory sensation induced by high-level, complex low-frequency noise, we conducted two experiments. In Experiment 1, eight male subjects were exposed to seven types of low-frequency noise stimuli: two pure tones [a 31.5-Hz, 100-dB(SPL tone and a 50-Hz, 100-dB(SPL tone] and five complex noises composed of the pure tones. For the complex noise stimuli, the sound pressure level of one tonal component was 100 dB(SPL and that of another one was either 90, 95, or 100 dB(SPL. Vibration induced on the body surface was measured at five locations, and the correlation with the subjective rating of the vibratory sensation at each site of measurement was examined. In Experiment 2, the correlation between the body surface vibration and the vibratory sensation was similarly examined using seven types of noise stimuli composed of a 25-Hz tone and a 50-Hz tone. In both the experiments, we found that at the chest and the abdomen, the rating of the vibratory sensation was in close correlation with the vibration acceleration level (VAL of the body surface vibration measured at each corresponding location. This was consistent with our previous results and suggested that at the trunk of the body (the chest and the abdomen, the mechanoreception of body vibrations plays an important role in the experience of the vibratory sensation in persons exposed to high-level low-frequency noise. At the head, however, no close correlation was found between the rating of the vibratory sensation and the VAL of body surface vibration. This suggested that at the head, the perceptual mechanisms of vibration induced by high-level low-frequency noise were different from those in the trunk of the body.

  11. Sleep improvement for restless legs syndrome patients. Part IV: meta-analysis comparison of effect sizes of vibratory stimulation sham pads and placebo pills

    Directory of Open Access Journals (Sweden)

    Burbank F

    2014-02-01

    Full Text Available Fred Burbank Salt Creek International Women's Health Foundation, San Clemente, CA, USA Purpose: To determine whether sham pads used as controls in randomized clinical trials of vibratory stimulation to treat patients with sleep loss associated with restless legs syndrome perform differently than placebo pills used in comparable restless legs syndrome drug trials. Patients and methods: Sham pad effect sizes from 66 control patients in two randomized clinical trials of vibratory stimulation were compared with placebo responses from 1,024 control patients in 12 randomized clinical drug trials reporting subjective sleep measurement scales. Control patient responses were measured as the standardized difference in means corrected for correlation between beginning and ending scores and for small sample sizes. Results: For parallel randomized clinical trials, sham effects in vibratory stimulation trials were not significantly different from placebo effects in drug trials (0.37 and 0.31, respectively, Qbetween subgroups =0.25, PQ≥0.62. Placebo effect sizes were significantly smaller in crossover drug trials than sham effect sizes in parallel vibratory stimulation trials (0.07 versus 0.37, respectively, Qbetween subgroups =4.59, PQ≤0.03 and placebo effect sizes in parallel drug trials (0.07 versus 0.31, respectively, Qbetween subgroups =5.50, PQ≤0.02. Conclusion: For subjective sleep loss assessments in parallel trials, sham pads in vibratory stimulation trials performed similarly to placebo pills in drug trials. Trial design (parallel versus crossover had a large influence on control effect sizes. Placebo pills in crossover drug trials had significantly smaller effect sizes than sham pads in parallel vibratory stimulation trials or placebo pills in parallel drug trials. Keywords: sham effect, placebo effect, trial design, crossover study, parallel study, counterstimulation

  12. Offshore wind turbine foundations. Development of a special vibratory hammer with enhanced function; Gruendung von Offshore Windenergieanlagen. Entwicklung einer speziellen Vibrationsramme mit erweiterter Funktion

    Energy Technology Data Exchange (ETDEWEB)

    Koecher, Johannes; Ulrich, Dirk [ThyssenKrupp Tiefbautechnik GmbH, Alsfeld (Germany)

    2013-11-01

    To ensure that steel jacket foundations for offshore wind turbines are securely anchored, they are fixed to the seabed by means of ''pins''. The pins consist of pipe piles weighing up to 140 metric tons, and are driven into the seabed by a vibratory hammer and then anchored by impact driving. ThyssenKrupp Tiefbautechnik has modified a vibratory hammer so that it can pick up the piles horizontally directly from the working ship or pontoon and then vibrate them vertically into the ground. This significantly reduces installation times and foundation costs. (orig.)

  13. Intraoperative handheld probe for 3D imaging of pediatric benign vocal fold lesions using optical coherence tomography (Conference Presentation)

    Science.gov (United States)

    Benboujja, Fouzi; Garcia, Jordan; Beaudette, Kathy; Strupler, Mathias; Hartnick, Christopher J.; Boudoux, Caroline

    2016-02-01

    Excessive and repetitive force applied on vocal fold tissue can induce benign vocal fold lesions. Children affected suffer from chronic hoarseness. In this instance, the vibratory ability of the folds, a complex layered microanatomy, becomes impaired. Histological findings have shown that lesions produce a remodeling of sup-epithelial vocal fold layers. However, our understanding of lesion features and development is still limited. Indeed, conventional imaging techniques do not allow a non-invasive assessment of sub-epithelial integrity of the vocal fold. Furthermore, it remains challenging to differentiate these sub-epithelial lesions (such as bilateral nodules, polyps and cysts) from a clinical perspective, as their outer surfaces are relatively similar. As treatment strategy differs for each lesion type, it is critical to efficiently differentiate sub-epithelial alterations involved in benign lesions. In this study, we developed an optical coherence tomography (OCT) based handheld probe suitable for pediatric laryngological imaging. The probe allows for rapid three-dimensional imaging of vocal fold lesions. The system is adapted to allow for high-resolution intra-operative imaging. We imaged 20 patients undergoing direct laryngoscopy during which we looked at different benign pediatric pathologies such as bilateral nodules, cysts and laryngeal papillomatosis and compared them to healthy tissue. We qualitatively and quantitatively characterized laryngeal pathologies and demonstrated the added advantage of using 3D OCT imaging for lesion discrimination and margin assessment. OCT evaluation of the integrity of the vocal cord could yield to a better pediatric management of laryngeal diseases.

  14. Assessment of Real-Time Compaction Quality Test Indexes for Rockfill Material Based on Roller Vibratory Acceleration Analysis

    Directory of Open Access Journals (Sweden)

    Tianbo Hua

    2018-01-01

    Full Text Available Compaction quality is directly related to the structure and seepage stability of a rockfill dam. To timely and accurately test the compaction quality of the rockfill material, four real-time test indexes were chosen to characterize the soil compaction degree based on the analysis of roller vibratory acceleration, including acceleration peak value (ap, acceleration root mean square value (arms, crest factor value (CF, and compaction meter value (CMV. To determine which of these indexes is the most appropriate, a two-part field compaction experiment was conducted using a vibratory roller in different filling zones of the dam body. Data on rolling parameters, real-time test indexes, and compaction quality indexes were collected to perform statistical regression analyses. Combined with the spectrum analysis of the acceleration signal, it was found that the CF index best characterizes the compaction degree of the rockfill material among the four indexes. Furthermore, the quantitative relations between the real-time index and compaction quality index were established to determine the control criterion of CF, which can instruct the site work of compaction quality control in the rockfill rolling process.

  15. Curved Folded Plate Timber Structures

    OpenAIRE

    Buri, Hans Ulrich; Stotz, Ivo; Weinand, Yves

    2011-01-01

    This work investigates the development of a Curved Origami Prototype made with timber panels. In the last fifteen years the timber industry has developed new, large size, timber panels. Composition and dimensions of these panels and the possibility of milling them with Computer Numerical Controlled machines shows great potential for folded plate structures. To generate the form of these structures we were inspired by Origami, the Japanese art of paper folding. Common paper tessellations are c...

  16. Effects of repeated vibratory stimulation of wrist and elbow flexors on hand dexterity, strength, and sensory function in patients with chronic stroke: a pilot study.

    Science.gov (United States)

    Choi, Won-Ho

    2017-04-01

    [Purpose] The aim of this study was to investigate the effects of repeated vibratory stimulation to muscles related to hand functions on dexterity, strength, and sensory function in patients with chronic stroke. [Subjects and Methods] A total of 10 stroke patients with hemiplegia participated in this study. They were divided into two groups: a) Experimental and b) Control, with five randomly selected subjects for each group. The experimental group received vibratory stimulation, while the control group received the traditional physical therapy. Both interventions were performed for 30 minutes each session, three times a week for four weeks. [Results] There was a significant within-group improvement in the box and block test results in both groups for dexterity. Grip strength improved in both groups but the improvement was not statistically significant. [Conclusion] The vibratory stimulation activated the biceps brachii and flexor carpi radialis, which increased dexterity to grasp and lift the box and block from the surface. Therefore, repeated vibratory stimulation to muscles related to hand functions improved hand dexterity equality to the traditional physical therapy in patients with chronic stroke.

  17. Deformation and kinematics of the central Kirthar Fold Belt, Pakistan

    Science.gov (United States)

    Hinsch, Ralph; Hagedorn, Peter; Asmar, Chloé; Nasim, Muhammad; Aamir Rasheed, Muhammad; Kiely, James M.

    2017-04-01

    The Kirthar Fold Belt is part of the lateral mountain belts in Pakistan linking the Himalaya orogeny with the Makran accretionary wedge. This region is deforming very oblique/nearly parallel to the regional plate motion vector. The study area is situated between the prominent Chaman strike-slip fault in the West and the un-deformed foreland (Kirthar Foredeep/Middle Indus Basin) in the East. The Kirthar Fold Belt is subdivided into several crustal blocks/units based on structural orientation and deformation style (e.g. Kallat, Khuzdar, frontal Kirthar). This study uses newly acquired and depth-migrated 2D seismic lines, surface geology observations and Google Earth assessments to construct three balanced cross sections for the frontal part of the fold belt. Further work was done in order to insure the coherency of the built cross-sections by taking a closer look at the regional context inferred from published data, simple analogue modelling, and constructed regional sketch sections. The Khuzdar area and the frontal Kirthar Fold Belt are dominated by folding. Large thrusts with major stratigraphic repetitions are not observed. Furthermore, strike-slip faults in the Khuzdar area are scarce and not observed in the frontal Kirthar Fold Belt. The regional structural elevation rises from the foreland across the Kirthar Fold Belt towards the hinterland (Khuzdar area). These observations indicate that basement-involved deformation is present at depth. The domination of folding indicates a weak decollement below the folds (soft-linked deformation). The fold pattern in the Khuzdar area is complex, whereas the large folds of the central Kirthar Fold Belt trend SSW-NNE to N-S and are best described as large detachment folds that have been slightly uplifted by basement involved transpressive deformation underneath. Towards the foreland, the deformation is apparently more hard-linked and involves fault-propagation folding and a small triangle zone in Cretaceous sediments

  18. Wrinkles, folds, and plasticity in granular rafts

    Science.gov (United States)

    Jambon-Puillet, Etienne; Josserand, Christophe; Protière, Suzie

    2017-09-01

    We investigate the mechanical response of a compressed monolayer of large and dense particles at a liquid-fluid interface: a granular raft. Upon compression, rafts first wrinkle; then, as the confinement increases, the deformation localizes in a unique fold. This characteristic buckling pattern is usually associated with floating elastic sheets, and as a result, particle laden interfaces are often modeled as such. Here, we push this analogy to its limits by comparing quantitative measurements of the raft morphology to a theoretical continuous elastic model of the interface. We show that, although powerful to describe the wrinkle wavelength, the wrinkle-to-fold transition, and the fold shape, this elastic description does not capture the finer details of the experiment. We describe an unpredicted secondary wavelength, a compression discrepancy with the model, and a hysteretic behavior during compression cycles, all of which are a signature of the intrinsic discrete and frictional nature of granular rafts. It suggests also that these composite materials exhibit both plastic transition and jamming dynamics.

  19. Penile vibratory stimulation in the recovery of urinary continence and erectile function after nerve-sparing radical prostatectomy

    DEFF Research Database (Denmark)

    Fode, Mikkel; Borre, Michael; Ohl, Dana A

    2014-01-01

    OBJECTIVE: To examine the effect of penile vibratory stimulation (PVS) in the preservation and restoration of erectile function and urinary continence in conjunction with nerve-sparing radical prostatectomy (RP). PATIENTS AND METHODS: The present study was conducted between July 2010 and March 2013...... were instructed in using a PVS device (FERTI CARE(®) vibrator). Stimulation was performed at the frenulum once daily by the patients in their own homes for at least 1 week before surgery. After catheter removal, daily PVS was re-initiated for a period of 6 weeks. Participants were evaluated at 3, 6...... for analyses (30 patients randomized to PVS and 38 patients randomized to the control group). The IIEF-5 score was highest in the PVS group at all time points after surgery with a median score of 18 vs 7.5 in the control group at 12 months (P = 0.09), but the difference only reached borderline significance...

  20. Development and assessment of two decontamination processes: closed electropolishing system for decontamination of underwater surfaces -vibratory decontamination with abrasives

    International Nuclear Information System (INIS)

    Benavides, E.; Fajardo, M.

    1992-01-01

    Two decontamination processes have been developed to decontaminate the stainless steel components of nuclear power plants. The first process uses an underwater closed electropolishing system for the decontamination of large stainless steel surfaces in flooded systems without loss of electrolyte. Large underwater contaminated areas can be treated with an electropolishing head covering an area of 2 m 2 in one step. The decontamination factors achieved with this technique range between 100 and 1000. The second process consists in the decontamination of nuclear components using vibratory equipment with self-cleaning abrasives generating a minimum quantity of waste. This technique may reach contamination factors similar to those obtained with other abrasive methods (brush abrasion, abrasive blasting, etc...). The obtained decontamination factors range between 5 and 50. Only a small quantity of waste is generated, which is treated and reduced in volume by filtration and evaporation

  1. Development of Cell Culture Microdevice Actuated by Piezoelectric Thin Films for Delivering Mechanical Vibratory Stimuli to Cells

    International Nuclear Information System (INIS)

    Yamada, Y; Umegaki, G; Kawashima, T; Nagai, M; Shibata, T; Masuzawa, T; Kimura, T; Kishida, A

    2012-01-01

    In order to realize a cell culture microdevice actuated by piezoelectric thin films for on-chip regulation of cell functions, this paper reported on a feasibility study by using the microdevice with KOH-etched cavities surrounded by four (111) sidewalls as microchambers in order to introduce cells to be cultured. As a result, the vibration characteristic of the PZT actuator was improved by using an electric field -150 kV/cm at 70 C for 30 min in poling process. A feasibility study on cell culture for delivering mechanical vibratory stimuli to cells revealed the microdevice could be applicable to the culture with actual biological cells. In addition, it was found that O 2 -plasma treated parylene-C process could be applicable for obtaining homogeneous surface of cell culture microdevice.

  2. NoFold: RNA structure clustering without folding or alignment.

    Science.gov (United States)

    Middleton, Sarah A; Kim, Junhyong

    2014-11-01

    Structures that recur across multiple different transcripts, called structure motifs, often perform a similar function-for example, recruiting a specific RNA-binding protein that then regulates translation, splicing, or subcellular localization. Identifying common motifs between coregulated transcripts may therefore yield significant insight into their binding partners and mechanism of regulation. However, as most methods for clustering structures are based on folding individual sequences or doing many pairwise alignments, this results in a tradeoff between speed and accuracy that can be problematic for large-scale data sets. Here we describe a novel method for comparing and characterizing RNA secondary structures that does not require folding or pairwise alignment of the input sequences. Our method uses the idea of constructing a distance function between two objects by their respective distances to a collection of empirical examples or models, which in our case consists of 1973 Rfam family covariance models. Using this as a basis for measuring structural similarity, we developed a clustering pipeline called NoFold to automatically identify and annotate structure motifs within large sequence data sets. We demonstrate that NoFold can simultaneously identify multiple structure motifs with an average sensitivity of 0.80 and precision of 0.98 and generally exceeds the performance of existing methods. We also perform a cross-validation analysis of the entire set of Rfam families, achieving an average sensitivity of 0.57. We apply NoFold to identify motifs enriched in dendritically localized transcripts and report 213 enriched motifs, including both known and novel structures. © 2014 Middleton and Kim; Published by Cold Spring Harbor Laboratory Press for the RNA Society.

  3. Variação da intensidade vocal: estudo da vibração das pregas vocais em seres humanos com videoquimografia Vocal intensity variation: a study of vocal folds vibration in humans with videokymography

    Directory of Open Access Journals (Sweden)

    Henry U. Koishi

    2003-08-01

    functional disorders, like adductor spasmodic dysphonia and hyperfunctional dysphonia, even during soft phonation. AIM: To evaluate the vibratory pattern of the vocal folds in subjects with normal voice according to intensity variation, in order to establish standard values for the vibratory cycle phases. These values may improve the diagnosis and the follow up of those disorders. STUDY DESIGN: Clinical prospective. SUBJECTS AND METHODS: Fifty-eight adults were evaluated during habitual (soft and loud phonation. Vocal folds vibration patterns were analyzed with videokymography. Vocal intensity variation was studied with acoustic analysis software, comparing the intensity levels during habitual phonation and loud phonation. RESULTS: The results showed a spontaneous fundamental frequency (F0 rise as vocal intensity grew and a decrease of the open quotient at loud intensity phonation. CONCLUSION: Sound intensity levels were established at habitual (63,46 dB and loud phonation (72,55dB. Open quotient (OQ values were also established for those intensity phonation levels.

  4. Recoverable and Programmable Collapse from Folding Pressurized Origami Cellular Solids.

    Science.gov (United States)

    Li, S; Fang, H; Wang, K W

    2016-09-09

    We report a unique collapse mechanism by exploiting the negative stiffness observed in the folding of an origami solid, which consists of pressurized cells made by stacking origami sheets. Such a collapse mechanism is recoverable, since it only involves rigid folding of the origami sheets and it is programmable by pressure control and the custom design of the crease pattern. The collapse mechanism features many attractive characteristics for applications such as energy absorption. The reported results also suggest a new branch of origami study focused on its nonlinear mechanics associated with folding.

  5. The role of the mesenchyme in cranial neural fold elevation

    International Nuclear Information System (INIS)

    Morris-Wiman, J.A.

    1988-01-01

    It has been previously postulated that the expansion of an hyaluronate-rich extracellular matrix in the fold mesenchyme is responsible for neural fold elevation. In this study we provide evidence that such expansions may play an important role in cranial neural fold elevation by pushing the folds towards the dorsal midline to assist in their elevation. For mesenchymal expansion to result in fold elevation, hyaluronate (HA) and mesenchymal cells must be non-randomly distributed within the mesenchyme. Patterns of mesenchymal cell distribution and cell proliferation were analyzed using the computer-assisted method of smoothed spatial averaging. The distribution of Alcian blue-stained and 3 H-glucosamine-labelled HA was also analyzed during cranial neural fold elevation using established image processing techniques. Analysis of the distribution of 3 H-thymidine-labelled mesenchymal cells indicated that differential mitotic activity was not responsible for decreased mesenchymal cell density. Likewise, analysis of distribution patterns of 3 H-glucosamine-labelled HA indicated that decreased HA concentration was not produced by regional differences in HA synthesis. These results suggest that decreases in mesenchymal cell density and HA concentration that occur during neural fold elevation are produced by mesenchymal expansion

  6. Unraveling metamaterial properties in zigzag-base folded sheets.

    Science.gov (United States)

    Eidini, Maryam; Paulino, Glaucio H

    2015-09-01

    Creating complex spatial objects from a flat sheet of material using origami folding techniques has attracted attention in science and engineering. In the present work, we use the geometric properties of partially folded zigzag strips to better describe the kinematics of known zigzag/herringbone-base folded sheet metamaterials such as Miura-ori. Inspired by the kinematics of a one-degree of freedom zigzag strip, we introduce a class of cellular folded mechanical metamaterials comprising different scales of zigzag strips. This class of patterns combines origami folding techniques with kirigami. Using analytical and numerical models, we study the key mechanical properties of the folded materials. We show that our class of patterns, by expanding on the design space of Miura-ori, is appropriate for a wide range of applications from mechanical metamaterials to deployable structures at small and large scales. We further show that, depending on the geometry, these materials exhibit either negative or positive in-plane Poisson's ratios. By introducing a class of zigzag-base materials in the current study, we unify the concept of in-plane Poisson's ratio for similar materials in the literature and extend it to the class of zigzag-base folded sheet materials.

  7. Self-Folding Textiles through Manipulation of Knit Stitch Architecture

    Directory of Open Access Journals (Sweden)

    Chelsea E. Knittel

    2015-12-01

    Full Text Available This research presents a preliminary study on finding predictable methods of controlling the self-folding behaviors of weft knit textiles for use in the development of smart textiles and garment devices, such as those with shape memory, auxetic behavior or transformation abilities. In this work, Shima Seiki SDS-One Apex computer-aided knitting technology, Shima Seiki industrial knitting machines, and the study of paper origami tessellation patterns were used as tools to understand and predict the self-folding abilities of weft knit textiles. A wide range of self-folding weft knit structures was produced, and relationships between the angles and ratios of the knit and purl stitch types were determined. Mechanical testing was used as a means to characterize differences produced by stitch patterns, and to further understand the relationships between angles and folding abilities. By defining a formulaic method for predicting the nature of the folds that occur due to stitch architecture patterns, we can better design self-folding fabrics for smart textile applications.

  8. The four-fold way

    International Nuclear Information System (INIS)

    Terazawa, H.

    1986-01-01

    The four-fold way is proposed in a minimal composite model of quarks and leptons. Various new pictures and consequences are presented and discussed. They include 1) generation, 2) quark-lepton mass spectrum, 3) quark mixing, 4) supersymmetry, 5) effective gauge theory. (author)

  9. Quantification of fold growth of frontal antiforms in the Zagros fold and thrust belt (Kurdistan, NE Iraq)

    Science.gov (United States)

    Bretis, Bernhard; Bartl, Nikolaus; Graseman, Bernhard; Lockhart, Duncan

    2010-05-01

    The Zagros fold and thrust belt is a seismically active orogen, where actual kinematic models based on GPS networks suggest a north-south shortening between Arabian and Eurasian in the order of 1.5-2.5 cm/yr. Most of this deformation is partitioned in south-southwest oriented folding and thrusting with northwest-southeast to north-south trending dextral strike slip faults. The Zagros fold and thrust belt is of great economic interest because it has been estimated that this area contains about 15% of the global recoverable hydrocarbons. Whereas the SE parts of the Zagros have been investigated by detailed geological studies, the NW extent being part of the Republic of Iraq have experienced considerably less attention. In this study we combine field work and remote sensing techniques in order to investigate the interaction of erosion and fold growth in the area NE of Erbil (Kurdistan, Iraq). In particular we focus on the interaction of the transient development of drainage patterns along growing antiforms, which directly reflects the kinematics of progressive fold growth. Detailed geomorphological studies of the Bana Bawi-, Permam- and Safeen fold trains show that these anticlines have not developed from subcylindrical embryonic folds but they have merged from different fold segments that joined laterally during fold amplification. This fold segments with length between 5 and 25 km have been detected by mapping ancient and modern river courses that initially cut the nose of growing folds and eventually got defeated leaving behind a wind gap. Fold segments, propagating in different directions force rivers to join resulting in steep gorges, which dissect the merging fold noses. Along rapidly lateral growing folds (e.g. at the SE end of the Bana Bawi Anticline) we observed "curved wind gaps", a new type of abandoned river course, where form of the wind gap mimics a formed nose of a growing antiform. The inherited curved segments of uplifted curved river courses strongly

  10. Force generation by titin folding.

    Science.gov (United States)

    Mártonfalvi, Zsolt; Bianco, Pasquale; Naftz, Katalin; Ferenczy, György G; Kellermayer, Miklós

    2017-07-01

    Titin is a giant protein that provides elasticity to muscle. As the sarcomere is stretched, titin extends hierarchically according to the mechanics of its segments. Whether titin's globular domains unfold during this process and how such unfolded domains might contribute to muscle contractility are strongly debated. To explore the force-dependent folding mechanisms, here we manipulated skeletal-muscle titin molecules with high-resolution optical tweezers. In force-clamp mode, after quenching the force (force trace contained rapid fluctuations and a gradual increase of average force, indicating that titin can develop force via dynamic transitions between its structural states en route to the native conformation. In 4 M urea, which destabilizes H-bonds hence the consolidated native domain structure, the net force increase disappeared but the fluctuations persisted. Thus, whereas net force generation is caused by the ensemble folding of the elastically-coupled domains, force fluctuations arise due to a dynamic equilibrium between unfolded and molten-globule states. Monte-Carlo simulations incorporating a compact molten-globule intermediate in the folding landscape recovered all features of our nanomechanics results. The ensemble molten-globule dynamics delivers significant added contractility that may assist sarcomere mechanics, and it may reduce the dissipative energy loss associated with titin unfolding/refolding during muscle contraction/relaxation cycles. © 2017 The Protein Society.

  11. Quantitative Study for the Surface Dehydration of Vocal Folds Based on High-Speed Imaging.

    Science.gov (United States)

    Li, Lin; Zhang, Yu; Maytag, Allison L; Jiang, Jack J

    2015-07-01

    From the perspective of the glottal area and mucosal wave, quantitatively estimate the differences of vocal fold on laryngeal activity during phonation at three different dehydration levels. Controlled three sets of tests. A dehydration experiment for 10 excised canine larynges was conducted at 16 cm H2O. According to the dehydration cycle time (H), dehydration levels were divided into three degrees (0% H, 50% H, 75% H). The glottal area and mucosal wave under three dehydration levels were extracted from high-speed images and digital videokymography (DKG) image sequences. Direct and non-direct amplitude components were derived from glottal areas. The amplitude and frequency of mucosal wave were calculated from DKG image sequences. These parameters in condition of three dehydration levels were compared for statistical analysis. The results showed a significant difference in direct (P = 0.001; P = 0.005) and non-direct (P = 0.005; P = 0.016) components of glottal areas between every two different dehydration levels. Considering the right-upper, right-lower, left-upper, and left-lower of vocal fold, the amplitudes of mucosal waves consistently decreased with increasing of dehydration levels. But, there was no significant difference in frequency. Surface dehydration could give rise to complex variation of vocal fold on tissues and vibratory mechanism, which should need analyzing from multiple perspectives. The results suggested that the combination of glottal area and mucosal wave could be better to research the change of vocal fold at different dehydrations. It would become a better crucial research tool for the clinical treatment of dehydration-induced laryngeal pathologies. Copyright © 2015 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  12. Origami-Inspired Folding of Thick, Rigid Panels

    Science.gov (United States)

    Trease, Brian P.; Thomson, Mark W.; Sigel, Deborah A.; Walkemeyer, Phillip E.; Zirbel, Shannon; Howell, Larry; Lang, Robert

    2014-01-01

    To achieve power of 250 kW or greater, a large compression ratio of stowed-to-deployed area is needed. Origami folding patterns were used to inspire the folding of a solar array to achieve synchronous deployment; however, origami models are generally created for near-zero-thickness material. Panel thickness is one of the main challenges of origami-inspired design. Three origami-inspired folding techniques (flasher, square twist, and map fold) were created with rigid panels and hinges. Hinge components are added to the model to enable folding of thick, rigid materials. Origami models are created assuming zero (or near zero) thickness. When a material with finite thickness is used, the panels are required to bend around an increasingly thick fold as they move away from the center of the model. The two approaches for dealing with material thickness are to use membrane hinges to connect the panels, or to add panel hinges, or hinges of the same thickness, at an appropriate width to enable folding.

  13. Synovial folds in equine articular process joints

    DEFF Research Database (Denmark)

    Thomsen, Line Nymann; Berg, Lise Charlotte; Markussen, Bo

    2013-01-01

    Cervical synovial folds have been suggested as a potential cause of neck pain in humans. Little is known about the extent and characteristics of cervical synovial folds in horses.......Cervical synovial folds have been suggested as a potential cause of neck pain in humans. Little is known about the extent and characteristics of cervical synovial folds in horses....

  14. [Skull vibratory test in partial vestibular lesions--influence of the stimulus frequency on the nystagmus direction].

    Science.gov (United States)

    Dumas, G; Perrin, P; Morel, N; N'Guyen, D Q; Schmerber, S

    2005-01-01

    Results of the skull vibratory test (SVT) in partial unilateral vestibular peripheral lesions (PUVL) are different from the results in total vestibular lesions (TUVL). To reveal a correlation between the results of the analysis of the skull vibratory nystagmus (SVN) horizontal component and the side of the lesion; to correlate these results with the stimulus frequency. To find out a predictive correlation between the SVN horizontal and vertical components and the topography of a vestibular lesion. To appreciate the degree of vestibular deafferentation (extended to high frequencies) provoked by gentamicin labyrinthectomy and its efficiency in Meniere's disease. 53 patients with a SVN and a PUVL were included and compared with 10 TUVL and 10 normal subjects. Protocol included a HST (2 Hz), a SVT at 30, 60 and 100 Hz and a caloric test. Recordings were performed with a 2D and 3D VNG device. In PUVL, SVN at 30, 60 and 100 Hz was obtained in 80, 90 and 90% of cases respectively. SVN is correlated with the side of the lesion at 30, 60 and 100 Hz respectively in 65%, 63%, 80% of cases. SVN is not correlated with the side of the lesion in 20% of Meniere's disease, in 8% of vestibular neuritis and in 6% of vestibular schwannoma. In PUVL HSN is correlated with the side of the lesion in 69% of cases. The direction of the HSN and of the SVN was different in 23% when the nystagmus attended at the same time for both tests. In PUVL the direction of the SVN is different at 100 Hz and 30 Hz in 16% of cases when they are concomittant on the same patient. After Gentamicine labyrinthectomy, the coherence of the results in caloric test, HSN and SVN (areflexy and lesional nystagmus beating toward the safe side) was correlated with the efficiency of the therapy. A SVN vertical component was met in 10% of PUVL (essentially in anterior canal dehiscence and few cases of partial labyrinthitis). The horizontal SVN SPV is significantly slower in PUVL than in TUVL patients (p=0.0004). The SVT

  15. A nomenclature paradigm for benign midmembranous vocal fold lesions.

    Science.gov (United States)

    Rosen, Clark A; Gartner-Schmidt, Jackie; Hathaway, Bridget; Simpson, C Blake; Postma, Gregory N; Courey, Mark; Sataloff, Robert T

    2012-06-01

    There is a significant lack of uniform agreement regarding nomenclature for benign vocal fold lesions (BVFLs). This confusion results in difficulty for clinicians communicating with their patients and with each other. In addition, BVFL research and comparison of treatment methods are hampered by the lack of a detailed and uniform BVFL nomenclature. Clinical consensus conferences were held to develop an initial BVFL nomenclature paradigm. Perceptual video analysis was performed to validate the stroboscopy component of the paradigm. The culmination of the consensus conferences and the video-perceptual analysis was used to evaluate the BVFL nomenclature paradigm using a retrospective review of patients with BVFL. An initial BVFL nomenclature paradigm was proposed utilizing detailed definitions relating to vocal fold lesion morphology, stroboscopy, response to voice therapy and intraoperative findings. Video-perceptual analysis of stroboscopy demonstrated that the proposed binary stroboscopy system used in the BVFL nomenclature paradigm was valid and widely applicable. Retrospective review of 45 patients with BVFL followed to the conclusion of treatment demonstrated that slight modifications of the initial BVFL nomenclature paradigm were required. With the modified BVFL nomenclature paradigm, 96% of the patients fit into the predicted pattern and definitions of the BVFL nomenclature system. This study has validated a multidimensional BVFL nomenclature paradigm. This vocal fold nomenclature paradigm includes nine distinct vocal fold lesions: vocal fold nodules, vocal fold polyp, pseudocyst, vocal fold cyst (subepithelial or ligament), nonspecific vocal fold lesion, vocal fold fibrous mass (subepithelial or ligament), and reactive lesion. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

  16. Further Examination of the Vibratory Loads Reduction Results from the NASA/ARMY/MIT Active Twist Rotor Test

    Science.gov (United States)

    Wilbur, Matthew L.; Yeager, William T., Jr.; Sekula, Martin K.

    2002-01-01

    The vibration reduction capabilities of a model rotor system utilizing controlled, strain-induced blade twisting are examined. The model rotor blades, which utilize piezoelectric active fiber composite actuators, were tested in the NASA Langley Transonic Dynamics Tunnel using open-loop control to determine the effect of active-twist on rotor vibratory loads. The results of this testing have been encouraging, and have demonstrated that active-twist rotor designs offer the potential for significant load reductions in future helicopter rotor systems. Active twist control was found to use less than 1% of the power necessary to operate the rotor system and had a pronounced effect on both rotating- and fixed-system loads, offering reductions in individual harmonic loads of up to 100%. A review of the vibration reduction results obtained is presented, which includes a limited set of comparisons with results generated using the second-generation version of the Comprehensive Analytical Model of Rotorcraft Aerodynamics and Dynamics (CAMRAD II) rotorcraft comprehensive analysis.

  17. [Relationship between vibratory sense threshold and blood lead concentration in ceramic color workers and transfer printing manufacturers].

    Science.gov (United States)

    Fukaya, Y; Matsumoto, T; Fujiwara, N; Tokudome, S

    1995-08-01

    We measured vibratory sense thresholds (VSTs) at 63Hz and 125Hz on the third fingertip of the right hand and on the third toe of the right foot of 74 male workers. The subjects were workers engaged in manufacturing ceramic color and transfer printing paper, whose blood lead (Pb-B) levels were 2-58 micrograms/dl. They were divided into three groups according to the Pb-B levels, namely, below 9, 10-19, and 20 micrograms/dl or more. For statistical analysis, simple and partial correlations, and Scheffé's multiple comparison between the least squares means were used. The VSTs on the fingertip as well as on the toe showed a significant correlation with age. The VSTs at 125Hz on the fingertip were also significantly correlated with alcohol consumption and cigarette smoking. Controlling for age, systolic blood pressure, alcohol consumption and smoking habit, a significant dose-effect relationship was observed between the VSTs at not only 63Hz but at 125Hz on the fingertip, and each of the corresponding Pb-B levels. A similar tendency was also observed at the two frequencies on the toe. The measurement of VSTs was considered to be an effective screening test for sensory nerve disorders caused by lead poisoning.

  18. Theory of vibratory mobilization and break-up of non-wetting fluids entrapped in pore constrictions

    Science.gov (United States)

    Beresnev, I.; Li, W.; Vigil, D.

    2006-12-01

    Quantitative dynamics of a non-wetting (e. g., NAPL) ganglion entrapped in a pore constriction and subjected to vibrations can be approximated by the equation of motion of an oscillator moving under the effect of the external pressure gradient, inertial oscillatory force, and restoring capillary force. The solution of the equation provides the conditions under which the droplet experiences forced oscillations without being mobilized or is liberated upon the acceleration of the wall exceeding an "unplugging" threshold. This solution provides a quantitative tool for the estimation of the parameters of vibratory fields needed to liberate entrapped non-wetting fluids. For typical pore sizes encountered in reservoirs and aquifers, wall accelerations must exceed at least several m/sec2 and even higher levels to mobilize the droplets of NAPL; however, in the populations of ganglia entrapped in natural porous environments, many may reside very near their mobilization thresholds and may be mobilized by extremely low accelerations as well. For given acceleration, lower seismic frequencies are more efficient. The ganglia may also break up into smaller pieces when passing through pore constrictions. The snap-off is governed by the geometry only; for constrictions with sinusoidal profile (spatial wavelength of L and maximum and minimum radii of rmax and rmin, the break-up occurs if L > 2π(rmin rmax)1/2. Computational fluid dynamics shows the details of the break-up process.

  19. Understanding ensemble protein folding at atomic detail

    International Nuclear Information System (INIS)

    Wallin, Stefan; Shakhnovich, Eugene I

    2008-01-01

    Although far from routine, simulating the folding of specific short protein chains on the computer, at a detailed atomic level, is starting to become a reality. This remarkable progress, which has been made over the last decade or so, allows a fundamental aspect of the protein folding process to be addressed, namely its statistical nature. In order to make quantitative comparisons with experimental kinetic data a complete ensemble view of folding must be achieved, with key observables averaged over the large number of microscopically different folding trajectories available to a protein chain. Here we review recent advances in atomic-level protein folding simulations and the new insight provided by them into the protein folding process. An important element in understanding ensemble folding kinetics are methods for analyzing many separate folding trajectories, and we discuss techniques developed to condense the large amount of information contained in an ensemble of trajectories into a manageable picture of the folding process. (topical review)

  20. Effects of gravity in folding

    Science.gov (United States)

    Minkel, Donald Howe

    Effects of gravity on buckle folding are studied using a Newtonian fluid finite element model of a single layer embedded between two thicker less viscous layers. The methods allow arbitrary density jumps, surface tension coefficients, resistance to slip at the interfaces, and tracking of fold growth to a large amplitudes. When density increases downward in two equal jumps, a layer buckles less and thickens more than with uniform density. When density increases upward in two equal jumps, it buckles more and thickens less. A low density layer with periodic thickness variations buckles more, sometimes explosively. Thickness variations form, even if not present initially. These effects are greater with; smaller viscosities, larger density jump, larger length scale, and slower shortening rate. They also depend on wavelength and amplitude, and these dependencies are described in detail. The model is applied to the explosive growth of the salt anticlines of the Paradox Basin, Colorado and Utah. There, shale (higher density) overlies salt (lower density). Methods for simulating realistic earth surface erosion and deposition conditions are introduced. Growth rates increase both with ease of slip at the salt-shale interface, and when earth surface relief stays low due to erosion and deposition. Model anticlines grow explosively, attaining growth rates and amplitudes close to those of the field examples. Fastest growing wavelengths are the same as seen in the field. It is concluded that a combination of partial-slip at the salt-shale interface, with reasonable earth surface conditions, promotes sufficiently fast buckling of the salt-shale interface due to density inversion alone. Neither basement faulting, nor tectonic shortening is required to account for the observed structures. Of fundamental importance is the strong tendency of gravity to promote buckling in low density layers with thickness variations. These develop, even if not present initially. folds

  1. Solitons and protein folding: An In Silico experiment

    International Nuclear Information System (INIS)

    Ilieva, N.; Dai, J.; Sieradzan, A.; Niemi, A.

    2015-01-01

    Protein folding [1] is the process of formation of a functional 3D structure from a random coil — the shape in which amino-acid chains leave the ribosome. Anfinsen’s dogma states that the native 3D shape of a protein is completely determined by protein’s amino acid sequence. Despite the progress in understanding the process rate and the success in folding prediction for some small proteins, with presently available physics-based methods it is not yet possible to reliably deduce the shape of a biologically active protein from its amino acid sequence. The protein-folding problem endures as one of the most important unresolved problems in science; it addresses the origin of life itself. Furthermore, a wrong fold is a common cause for a protein to lose its function or even endanger the living organism. Soliton solutions of a generalized discrete non-linear Schrödinger equation (GDNLSE) obtained from the energy function in terms of bond and torsion angles κ and τ provide a constructive theoretical framework for describing protein folds and folding patterns [2]. Here we study the dynamics of this process by means of molecular-dynamics simulations. The soliton manifestation is the pattern helix–loop–helix in the secondary structure of the protein, which explains the importance of understanding loop formation in helical proteins. We performed in silico experiments for unfolding one subunit of the core structure of gp41 from the HIV envelope glycoprotein (PDB ID: 1AIK [3]) by molecular-dynamics simulations with the MD package GROMACS. We analyzed 80 ns trajectories, obtained with one united-atom and two different all-atom force fields, to justify the side-chain orientation quantification scheme adopted in the studies and to eliminate force-field based artifacts. Our results are compatible with the soliton model of protein folding and provide first insight into soliton-formation dynamics

  2. Solitons and protein folding: An In Silico experiment

    Energy Technology Data Exchange (ETDEWEB)

    Ilieva, N., E-mail: nevena.ilieva@parallel.bas.bg [Institute of Information and Communication Technologies, Bulgarian Aacademy of Sciences, Sofia (Bulgaria); Dai, J., E-mail: daijing491@gmail.com [School of Physics, Beijing Institute of Technology, Beijing (China); Sieradzan, A., E-mail: adams86@wp.pl [Faculty of Chemistry, University of Gdańsk, Gdańsk (Poland); Niemi, A., E-mail: Antti.Niemi@physics.uu.se [Department of Physics and Astronomy, Uppsala University, Uppsala (Sweden); LMPT–CNRS, Université de Tours, Tours (France)

    2015-10-28

    Protein folding [1] is the process of formation of a functional 3D structure from a random coil — the shape in which amino-acid chains leave the ribosome. Anfinsen’s dogma states that the native 3D shape of a protein is completely determined by protein’s amino acid sequence. Despite the progress in understanding the process rate and the success in folding prediction for some small proteins, with presently available physics-based methods it is not yet possible to reliably deduce the shape of a biologically active protein from its amino acid sequence. The protein-folding problem endures as one of the most important unresolved problems in science; it addresses the origin of life itself. Furthermore, a wrong fold is a common cause for a protein to lose its function or even endanger the living organism. Soliton solutions of a generalized discrete non-linear Schrödinger equation (GDNLSE) obtained from the energy function in terms of bond and torsion angles κ and τ provide a constructive theoretical framework for describing protein folds and folding patterns [2]. Here we study the dynamics of this process by means of molecular-dynamics simulations. The soliton manifestation is the pattern helix–loop–helix in the secondary structure of the protein, which explains the importance of understanding loop formation in helical proteins. We performed in silico experiments for unfolding one subunit of the core structure of gp41 from the HIV envelope glycoprotein (PDB ID: 1AIK [3]) by molecular-dynamics simulations with the MD package GROMACS. We analyzed 80 ns trajectories, obtained with one united-atom and two different all-atom force fields, to justify the side-chain orientation quantification scheme adopted in the studies and to eliminate force-field based artifacts. Our results are compatible with the soliton model of protein folding and provide first insight into soliton-formation dynamics.

  3. Protein folding and wring resonances

    DEFF Research Database (Denmark)

    Bohr, Jakob; Bohr, Henrik; Brunak, Søren

    1997-01-01

    The polypeptide chain of a protein is shown to obey topological contraints which enable long range excitations in the form of wring modes of the protein backbone. Wring modes of proteins of specific lengths can therefore resonate with molecular modes present in the cell. It is suggested that prot......The polypeptide chain of a protein is shown to obey topological contraints which enable long range excitations in the form of wring modes of the protein backbone. Wring modes of proteins of specific lengths can therefore resonate with molecular modes present in the cell. It is suggested...... that protein folding takes place when the amplitude of a wring excitation becomes so large that it is energetically favorable to bend the protein backbone. The condition under which such structural transformations can occur is found, and it is shown that both cold and hot denaturation (the unfolding...

  4. Dynamics of Folds in the Plane

    Science.gov (United States)

    Krylov, Nikolai A.; Rogers, Edwin L.

    2011-01-01

    Take a strip of paper and fold a crease intersecting the long edges, creating two angles. Choose one edge and consider the angle with the crease. Fold the opposite edge along the crease, creating a new crease that bisects the angle. Fold again, this time using the newly created crease and the initial edge, creating a new angle along the chosen…

  5. Anatomy and Histology of an Epicanthal Fold.

    Science.gov (United States)

    Park, Jae Woo; Hwang, Kun

    2016-06-01

    The aim of this study is to elucidate the precise anatomical and histological detail of the epicanthal fold.Thirty-two hemifaces of 16 Korean adult cadavers were used in this study (30 hemifaces with an epicanthal fold, 2 without an epicanthal fold). In 2 patients who had an epicanthoplasty, the epicanthal folds were sampled.In a dissection, the periorbital skin and subcutaneous tissues were removed and the epicanthal fold was observed in relation to each part of the orbicularis oculi muscle. Specimens including the epicanthal fold were embeddedin in paraffin, sectioned at 10 um, and stained with Hematoxylin-Eosin. The horizontal section in the level of the paplebral fissure was made and the prepared slides were observed under a light microscope.In the specimens without an epicanthal fold, no connection between the upper preseptal muscle and the lower preseptal muscle was found. In the specimens with an epicanthal fold, a connection of the upper preseptal muscle to the lower preseptal muscle was observed. It was present in all 15 hemifaces (100%). There was no connection between the pretarsal muscles. In a horizontal section, the epicanthal fold was composed of 3 compartments: an outer skin lining, a core structure, and an innerskin lining. The core structure was mainly composed of muscular fibers and fibrotic tissue and they were intermingled.Surgeons should be aware of the anatomical details of an epicanthal fold. In removing or reconstructing an epicanthal fold, the fibromuscular core band should also be removed or reconstructed.

  6. Kinetic partitioning mechanism of HDV ribozyme folding

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Jiawen; Gong, Sha; Wang, Yujie; Zhang, Wenbing, E-mail: wbzhang@whu.edu.cn [Department of Physics, Wuhan University, Wuhan, Hubei 430072 (China)

    2014-01-14

    RNA folding kinetics is directly tied to RNA biological functions. We introduce here a new approach for predicting the folding kinetics of RNA secondary structure with pseudoknots. This approach is based on our previous established helix-based method for predicting the folding kinetics of RNA secondary structure. In this approach, the transition rates for an elementary step: (1) formation, (2) disruption of a helix stem, and (3) helix formation with concomitant partial melting of an incompatible helix, are calculated with the free energy landscape. The folding kinetics of the Hepatitis delta virus (HDV) ribozyme and the mutated sequences are studied with this method. The folding pathways are identified by recursive searching the states with high net flux-in(out) population starting from the native state. The theory results are in good agreement with that of the experiments. The results indicate that the bi-phasic folding kinetics for the wt HDV sequence is ascribed to the kinetic partitioning mechanism: Part of the population will quickly fold to the native state along the fast pathway, while another part of the population will fold along the slow pathway, in which the population is trapped in a non-native state. Single mutation not only changes the folding rate but also the folding pathway.

  7. Developing guinea pig brain as a model for cortical folding.

    Science.gov (United States)

    Hatakeyama, Jun; Sato, Haruka; Shimamura, Kenji

    2017-05-01

    The cerebral cortex in mammals, the neocortex specifically, is highly diverse among species with respect to its size and morphology, likely reflecting the immense adaptiveness of this lineage. In particular, the pattern and number of convoluted ridges and fissures, called gyri and sulci, respectively, on the surface of the cortex are variable among species and even individuals. However, little is known about the mechanism of cortical folding, although there have been several hypotheses proposed. Recent studies on embryonic neurogenesis revealed the differences in cortical progenitors as a critical factor of the process of gyrification. Here, we investigated the gyrification processes using developing guinea pig brains that form a simple but fundamental pattern of gyri. In addition, we established an electroporation-mediated gene transfer method for guinea pig embryos. We introduce the guinea pig brain as a useful model system to understand the mechanisms and basic principle of cortical folding. © 2017 Japanese Society of Developmental Biologists.

  8. Adaptive Origami for Efficiently Folded Structures

    Science.gov (United States)

    2016-02-01

    heating. Although a large fold angle at a high temperature is desirable in order to extrapolate the origami geometry toward closure, more emphasis is...AFRL-RQ-WP-TR-2016-0020 ADAPTIVE ORIGAMI FOR EFFICIENTLY FOLDED STRUCTURES James J. Joo and Greg Reich Design and Analysis Branch... ORIGAMI FOR EFFICIENTLY FOLDED STRUCTURES 5a. CONTRACT NUMBER In-house 5b. GRANT NUMBER 5c. PROGRAM ELEMENT NUMBER 61102F 6. AUTHOR(S) James J

  9. Vocal fold paralysis secondary to phonotrauma.

    Science.gov (United States)

    Klein, Travis A L; Gaziano, Joy E; Ridley, Marion B

    2014-01-01

    A unique case of acute onset vocal fold paralysis secondary to phonotrauma is presented. The cause was forceful vocalization by a drill instructor on a firearm range. Imaging studies revealed extensive intralaryngeal and retropharyngeal hemorrhage. Laryngoscopy showed a complete left vocal fold paralysis. Relative voice rest was recommended, and the patient regained normal vocal fold mobility and function after approximately 12 weeks. Copyright © 2014 The Voice Foundation. All rights reserved.

  10. On the functioning of folded dipole antennas on conducting masts

    CSIR Research Space (South Africa)

    Mcnamara, DA

    1993-11-01

    Full Text Available dimensions (e.g., d/X) in order to maximize forward gain, or to determine the number and directions of the unwanted pattern maxima there might be once the antenna is mounted in place. Manuscript received July 23, 1991; revised March 15, 1993. D... as the forward gain is concerned. The levels of the pattern maxima decrease for increasing separation. The forward gain curves eventually converge to the gain of a folded dipole in free space (i.e., without a conducting mast present...

  11. Quantification of Porcine Vocal Fold Geometry.

    Science.gov (United States)

    Stevens, Kimberly A; Thomson, Scott L; Jetté, Marie E; Thibeault, Susan L

    2016-07-01

    The aim of this study was to quantify porcine vocal fold medial surface geometry and three-dimensional geometric distortion induced by freezing the larynx, especially in the region of the vocal folds. The medial surface geometries of five excised porcine larynges were quantified and reported. Five porcine larynges were imaged in a micro-CT scanner, frozen, and rescanned. Segmentations and three-dimensional reconstructions were used to quantify and characterize geometric features. Comparisons were made with geometry data previously obtained using canine and human vocal folds as well as geometries of selected synthetic vocal fold models. Freezing induced an overall expansion of approximately 5% in the transverse plane and comparable levels of nonuniform distortion in sagittal and coronal planes. The medial surface of the porcine vocal folds was found to compare reasonably well with other geometries, although the compared geometries exhibited a notable discrepancy with one set of published human female vocal fold geometry. Porcine vocal folds are qualitatively geometrically similar to data available for canine and human vocal folds, as well as commonly used models. Freezing of tissue in the larynx causes distortion of around 5%. The data can provide direction in estimating uncertainty due to bulk distortion of tissue caused by freezing, as well as quantitative geometric data that can be directly used in developing vocal fold models. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  12. Guiding the folding pathway of DNA origami.

    Science.gov (United States)

    Dunn, Katherine E; Dannenberg, Frits; Ouldridge, Thomas E; Kwiatkowska, Marta; Turberfield, Andrew J; Bath, Jonathan

    2015-09-03

    DNA origami is a robust assembly technique that folds a single-stranded DNA template into a target structure by annealing it with hundreds of short 'staple' strands. Its guiding design principle is that the target structure is the single most stable configuration. The folding transition is cooperative and, as in the case of proteins, is governed by information encoded in the polymer sequence. A typical origami folds primarily into the desired shape, but misfolded structures can kinetically trap the system and reduce the yield. Although adjusting assembly conditions or following empirical design rules can improve yield, well-folded origami often need to be separated from misfolded structures. The problem could in principle be avoided if assembly pathway and kinetics were fully understood and then rationally optimized. To this end, here we present a DNA origami system with the unusual property of being able to form a small set of distinguishable and well-folded shapes that represent discrete and approximately degenerate energy minima in a vast folding landscape, thus allowing us to probe the assembly process. The obtained high yield of well-folded origami structures confirms the existence of efficient folding pathways, while the shape distribution provides information about individual trajectories through the folding landscape. We find that, similarly to protein folding, the assembly of DNA origami is highly cooperative; that reversible bond formation is important in recovering from transient misfoldings; and that the early formation of long-range connections can very effectively enforce particular folds. We use these insights to inform the design of the system so as to steer assembly towards desired structures. Expanding the rational design process to include the assembly pathway should thus enable more reproducible synthesis, particularly when targeting more complex structures. We anticipate that this expansion will be essential if DNA origami is to continue its

  13. The effects of vibratory stimulation employed to forearm and arm flexor muscles on upper limb function in patients with chronic stroke.

    Science.gov (United States)

    Jung, Sang-Mi

    2017-09-01

    [Purpose] The purpose of this study was to investigate not only the effects of stimulatory vibration but also the retained effects 2 weeks after the last session of the intervention. [Subjects and Methods] Ten subjects with post-stroke hemiplegia were recruited in this study. The experimental group (EG) received vibratory stimulation for 30 minutes in each session, three times a week for 2 weeks. Grip strength (GS), box-and-block test (BBT), and Weinstein monofilament were used to assess hand strength, dexterity, and sensory in the affected hand, respectively. [Results] A significant difference was found between the pre- and post-follow-up BBT. Significant differences were found among the pre-posttest, post-follow-up test, and pre-follow-up test results for GS and BBT. [Conclusion] This study was conducted with 10 subjects, without a control group, to verify the pure effect of the intervention. As a result, significant positive effects were observed in the post-test and follow-up test of GS and BBT. Therefore, repeated vibratory stimulation influenced GS and BBT after the 2-week intervention and retained the effect for 2 more weeks.

  14. Obtention of hydroxyapatite submicrometric of bovine origin by vibratory grinding for rapid prototyping; Obtencao de hidroxiapatita submicrometrica de origem bovina por moagem vibratoria visando prototipagem rapida

    Energy Technology Data Exchange (ETDEWEB)

    Meira, C.R.; Purquerio, B.M.; Fortulan, C.A., E-mail: camilameira@sc.usp.br [Universidade de Sao Paulo (USP), Sao Carlos, SP (Brazil). Escola de Engenharia; Braga, F.J.C. [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)

    2011-07-01

    Submicron bovine hydroxyapatite was obtained for rapid prototyping. Hydroxyapatite structure originated from bovine mineral bone has great importance among the biomaterials and biocompatibility due to its great similarity with the human bone structure. This study aims to obtain powder for manufacture by rapid prototyping of scaffolds. This technique manufacture requires highly reactive powders to compensate for the absence of pressure forming. Hydroxyapatite was milled in a ball mill and vibratory mill, and analyzed for their average equivalent spherical diameter and surface area. Test specimens were isostatically pressed at 100 MPa and machined into cylindrical test specimens. These specimens were sintered at several temperatures to determine the optimal sintering temperature based on densification and chemistry stability. In grinding ball mill was obtained particles of equivalent diameter of 0.74 micron in vibratory mill of 0.46 micrometers. An average flexural strength of 100 MPa and 99,8% of real density was attained for the sample sintered at 1300 deg C/2h, signaling potential for use in rapid prototyping. (author)

  15. In vitro evaluation of a basic fibroblast growth factor-containing hydrogel toward vocal fold lamina propria scar treatment.

    Science.gov (United States)

    Erndt-Marino, Josh D; Jimenez-Vergara, Andrea C; Diaz-Rodriguez, Patricia; Kulwatno, Jonathan; Diaz-Quiroz, Juan Felipe; Thibeault, Susan; Hahn, Mariah S

    2018-04-01

    Scarring of the vocal fold lamina propria can lead to debilitating voice disorders that can significantly impair quality of life. The reduced pliability of the scar tissue-which diminishes proper vocal fold vibratory efficiency-results in part from abnormal extracellular matrix (ECM) deposition by vocal fold fibroblasts (VFF) that have taken on a fibrotic phenotype. To address this issue, bioactive materials containing cytokines and/or growth factors may provide a platform to transition fibrotic VFF within the scarred tissue toward an anti-fibrotic phenotype, thereby improving the quality of ECM within the scar tissue. However, for such an approach to be most effective, the acute host response resulting from biomaterial insertion/injection likely also needs to be considered. The goal of the present work was to evaluate the anti-fibrotic and anti-inflammatory capacity of an injectable hydrogel containing tethered basic fibroblast growth factor (bFGF) in the dual context of scar and biomaterial-induced acute inflammation. An in vitro co-culture system was utilized containing both activated, fibrotic VFF and activated, pro-inflammatory macrophages (MΦ) within a 3D poly(ethylene glycol) diacrylate (PEGDA) hydrogel containing tethered bFGF. Following 72 h of culture, alterations in VFF and macrophage phenotype were evaluated relative to mono-culture and co-culture controls. In our co-culture system, bFGF reduced the production of fibrotic markers collagen type I, α smooth muscle actin, and biglycan by activated VFF and promoted wound-healing/anti-inflammatory marker expression in activated MΦ. Cumulatively, these data indicate that bFGF-containing hydrogels warrant further investigation for the treatment of vocal fold lamina propria scar. © 2017 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 106B: 1258-1267, 2018. © 2017 Wiley Periodicals, Inc.

  16. Approaching climate-adaptive facades with foldings

    DEFF Research Database (Denmark)

    Sack-Nielsen, Torsten

    2014-01-01

    envelopes based on folding principles such as origami. Three major aspects cover the project’s interest in this topic: Shape, kinetics and the application of new multi-functional materials form the interdisciplinary framework of this research. Shape// Initially small paper sketch models demonstrate folding...

  17. Monadic Maps and Folds for Arbitrary Datatypes

    NARCIS (Netherlands)

    Fokkinga, M.M.

    Each datatype constructor comes equiped not only with a so-called map and fold (catamorphism), as is widely known, but, under some condition, also with a kind of map and fold that are related to an arbitrary given monad. This result follows from the preservation of initiality under lifting

  18. Fold and Fit: Space Conserving Shape Editing

    KAUST Repository

    Ibrahim, Mohamed; Yan, Dong-Ming

    2017-01-01

    We present a framework that folds man-made objects in a structure-aware manner for space-conserving storage and transportation. Given a segmented 3D mesh of a man-made object, our framework jointly optimizes for joint locations, the folding order

  19. Merging monads and folds for functional programming

    NARCIS (Netherlands)

    Meijer, E.; Jeuring, J.T.

    1995-01-01

    These notes discuss the simultaneous use of generalised fold operators and monads to structure functional programs. Generalised fold operators structure programs after the decomposition of the value they consume. Monads structure programs after the computation of the value they produce. Our programs

  20. Theoretical study of the folded waveguide

    International Nuclear Information System (INIS)

    Chen, G.L.; Owens, T.L.; Whealton, J.H.

    1988-01-01

    We have applied a three-dimensional (3-D) algorithm for solving Maxwell's equations to the analysis of foleded waveguides used for fusion plasma heating at the ion cyclotron resonance frequency. A rigorous analysis of the magnetic field structure in the folded waveguide is presented. The results are compared to experimenntal measurements. Optimum conditions for the folded waveguide are discussed. 6 refs., 10 figs

  1. Experimental investigation into the mechanism of folding

    NARCIS (Netherlands)

    Kuenen, Ph.H.; Sitter, de L.U.

    1938-01-01

    The investigation of geological structures due to folding led de Sitter to form an opinion on the mechanical problems involved (Bibl. 7). His principal contention is that in simple cases the relative movements of particles with respect to eachother during deformation leading to a fold, have been

  2. A comparison of RNA folding measures

    Directory of Open Access Journals (Sweden)

    Gardner Paul P

    2005-10-01

    Full Text Available Abstract Background In the last few decades there has been a great deal of discussion concerning whether or not noncoding RNA sequences (ncRNAs fold in a more well-defined manner than random sequences. In this paper, we investigate several existing measures for how well an RNA sequence folds, and compare the behaviour of these measures over a large range of Rfam ncRNA families. Such measures can be useful in, for example, identifying novel ncRNAs, and indicating the presence of alternate RNA foldings. Results Our analysis shows that ncRNAs, but not mRNAs, in general have lower minimal free energy (MFE than random sequences with the same dinucleotide frequency. Moreover, even when the MFE is significant, many ncRNAs appear to not have a unique fold, but rather several alternative folds, at least when folded in silico. Furthermore, we find that the six investigated measures are correlated to varying degrees. Conclusion Due to the correlations between the different measures we find that it is sufficient to use only two of them in RNA folding studies, one to test if the sequence in question has lower energy than a random sequence with the same dinucleotide frequency (the Z-score and the other to see if the sequence has a unique fold (the average base-pair distance, D.

  3. Muscular anatomy of the human ventricular folds.

    Science.gov (United States)

    Moon, Jerald; Alipour, Fariborz

    2013-09-01

    Our purpose in this study was to better understand the muscular anatomy of the ventricular folds in order to help improve biomechanical modeling of phonation and to better understand the role of these muscles during phonatory and nonphonatory tasks. Four human larynges were decalcified, sectioned coronally from posterior to anterior by a CryoJane tape transfer system, and stained with Masson's trichrome. The total and relative areas of muscles observed in each section were calculated and used for characterizing the muscle distribution within the ventricular folds. The ventricular folds contained anteriorly coursing thyroarytenoid and ventricularis muscle fibers that were in the lower half of the ventricular fold posteriorly, and some ventricularis muscle was evident in the upper and lateral portions of the fold more anteriorly. Very little muscle tissue was observed in the medial half of the fold, and the anterior half of the ventricular fold was largely devoid of any muscle tissue. All 4 larynges contained muscle bundles that coursed superiorly and medially through the upper half of the fold, toward the lateral margin of the epiglottis. Although variability of expression was evident, a well-defined thyroarytenoid muscle was readily apparent lateral to the arytenoid cartilage in all specimens.

  4. Graph-representation of oxidative folding pathways

    Directory of Open Access Journals (Sweden)

    Kaján László

    2005-01-01

    Full Text Available Abstract Background The process of oxidative folding combines the formation of native disulfide bond with conformational folding resulting in the native three-dimensional fold. Oxidative folding pathways can be described in terms of disulfide intermediate species (DIS which can also be isolated and characterized. Each DIS corresponds to a family of folding states (conformations that the given DIS can adopt in three dimensions. Results The oxidative folding space can be represented as a network of DIS states interconnected by disulfide interchange reactions that can either create/abolish or rearrange disulfide bridges. We propose a simple 3D representation wherein the states having the same number of disulfide bridges are placed on separate planes. In this representation, the shuffling transitions are within the planes, and the redox edges connect adjacent planes. In a number of experimentally studied cases (bovine pancreatic trypsin inhibitor, insulin-like growth factor and epidermal growth factor, the observed intermediates appear as part of contiguous oxidative folding pathways. Conclusions Such networks can be used to visualize folding pathways in terms of the experimentally observed intermediates. A simple visualization template written for the Tulip package http://www.tulip-software.org/ can be obtained from V.A.

  5. Self-folding polymeric containers for encapsulation and delivery of drugs.

    Science.gov (United States)

    Fernandes, Rohan; Gracias, David H

    2012-11-01

    Self-folding broadly refers to self-assembly processes wherein thin films or interconnected planar templates curve, roll-up or fold into three dimensional (3D) structures such as cylindrical tubes, spirals, corrugated sheets or polyhedra. The process has been demonstrated with metallic, semiconducting and polymeric films and has been used to curve tubes with diameters as small as 2nm and fold polyhedra as small as 100nm, with a surface patterning resolution of 15nm. Self-folding methods are important for drug delivery applications since they provide a means to realize 3D, biocompatible, all-polymeric containers with well-tailored composition, size, shape, wall thickness, porosity, surface patterns and chemistry. Self-folding is also a highly parallel process, and it is possible to encapsulate or self-load therapeutic cargo during assembly. A variety of therapeutic cargos such as small molecules, peptides, proteins, bacteria, fungi and mammalian cells have been encapsulated in self-folded polymeric containers. In this review, we focus on self-folding of all-polymeric containers. We discuss the mechanistic aspects of self-folding of polymeric containers driven by differential stresses or surface tension forces, the applications of self-folding polymers in drug delivery and we outline future challenges. Copyright © 2012 Elsevier B.V. All rights reserved.

  6. Geometric U-folds in four dimensions

    Science.gov (United States)

    Lazaroiu, C. I.; Shahbazi, C. S.

    2018-01-01

    We describe a general construction of geometric U-folds compatible with a non-trivial extension of the global formulation of four-dimensional extended supergravity on a differentiable spin manifold. The topology of geometric U-folds depends on certain flat fiber bundles which encode how supergravity fields are globally glued together. We show that smooth non-trivial U-folds of this type can exist only in theories where both the scalar and space-time manifolds have non-trivial fundamental group and in addition the scalar map of the solution is homotopically non-trivial. Consistency with string theory requires smooth geometric U-folds to be glued using subgroups of the effective discrete U-duality group, implying that the fundamental group of the scalar manifold of such solutions must be a subgroup of the latter. We construct simple examples of geometric U-folds in a generalization of the axion-dilaton model of \

  7. Fold and Fit: Space Conserving Shape Editing

    KAUST Repository

    Ibrahim, Mohamed

    2017-09-01

    We present a framework that folds man-made objects in a structure-aware manner for space-conserving storage and transportation. Given a segmented 3D mesh of a man-made object, our framework jointly optimizes for joint locations, the folding order, and folding angles for each part of the model, enabling it to transform into a spatially efficient configuration while keeping its original functionality as intact as possible. That is, if a model is supposed to withstand several forces in its initial state to serve its functionality, our framework places the joints between the parts of the model such that the model can withstand forces with magnitudes that are comparable to the magnitudes applied on the unedited model. Furthermore, if the folded shape is not compact, our framework proposes further segmentation of the model to improve its compactness in its folded state.

  8. [Clinical analysis of vocal fold firbrous mass].

    Science.gov (United States)

    Chen, Hao; Sun, Jing Wu; Wan, Guang Lun; Hu, Yan Ming

    2018-03-01

    To explore the character of laryngoscopy finding, voice, and therapy of vocal fold fibrous mass. Clinical data, morphology, voice character, surgery and pathology of 15 cases with vocal fold fibrous mass were analyzed. The morbidity of vocal fold fibrous mass might be related to overuse of voice and laryngopharyngeal reflex. Laryngoscopy revealed shuttle line appearance, smoothness and decreased mucosal wave of vocal fold. These patients were invalid for voice training and might be improved by surgery, but recovery is slow. The morbidity of vocal fold fibrous mass might be related to overuse of voice and laryngopharyngeal reflex. Conservative treatment is ineffective for this disease, and surgery might improve. Copyright© by the Editorial Department of Journal of Clinical Otorhinolaryngology Head and Neck Surgery.

  9. Sarcoidosis Presenting as Bilateral Vocal Fold Immobility.

    Science.gov (United States)

    Hintze, Justin M; Gnagi, Sharon H; Lott, David G

    2018-05-01

    Bilateral true vocal fold paralysis is rarely attributable to inflammatory diseases. Sarcoidosis is a rare but important etiology of bilateral true vocal fold paralysis by compressive lymphadenopathy, granulomatous infiltration, and neural involvement. We describe the first reported case of sarcoidosis presenting as bilateral vocal fold immobility caused by direct fixation by granulomatous infiltration severe enough to necessitate tracheostomy insertion. In addition, we discuss the presentation, the pathophysiology, and the treatment of this disease with a review of the literature of previously reported cases of sarcoidosis-related vocal fold immobility. Sarcoidosis should therefore be an important consideration for the otolaryngologist's differential diagnosis of true vocal fold immobility. Copyright © 2018 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  10. Eye and sheath folds in turbidite convolute lamination: Aberystwyth Grits Group, Wales

    Science.gov (United States)

    McClelland, H. L. O.; Woodcock, N. H.; Gladstone, C.

    2011-07-01

    Eye and sheath folds are described from the turbidites of the Aberystwyth Group, in the Silurian of west Wales. They have been studied at outcrop and on high resolution optical scans of cut surfaces. The folds are not tectonic in origin. They occur as part of the convolute-laminated interval of each sand-mud turbidite bed. The thickness of this interval is most commonly between 20 and 100 mm. Lamination patterns confirm previous interpretations that convolute lamination nucleated on ripples and grew during continued sedimentation of the bed. The folds amplified vertically and were sheared horizontally by continuing turbidity flow, but only to average values of about γ = 1. The strongly curvilinear fold hinges are due not to high shear strains, but to nucleation on sinuous or linguoid ripples. The Aberystwyth Group structures provide a warning that not all eye folds in sedimentary or metasedimentary rocks should be interpreted as sections through high shear strain sheath folds.

  11. Kinematics, structural mechanics, and design of origami structures with smooth folds

    Science.gov (United States)

    Peraza Hernandez, Edwin Alexander

    Origami provides novel approaches to the fabrication, assembly, and functionality of engineering structures in various fields such as aerospace, robotics, etc. With the increase in complexity of the geometry and materials for origami structures that provide engineering utility, computational models and design methods for such structures have become essential. Currently available models and design methods for origami structures are generally limited to the idealization of the folds as creases of zeroth-order geometric continuity. Such an idealization is not proper for origami structures having non-negligible thickness or maximum curvature at the folds restricted by material limitations. Thus, for general structures, creased folds of merely zeroth-order geometric continuity are not appropriate representations of structural response and a new approach is needed. The first contribution of this dissertation is a model for the kinematics of origami structures having realistic folds of non-zero surface area and exhibiting higher-order geometric continuity, here termed smooth folds. The geometry of the smooth folds and the constraints on their associated kinematic variables are presented. A numerical implementation of the model allowing for kinematic simulation of structures having arbitrary fold patterns is also described. Examples illustrating the capability of the model to capture realistic structural folding response are provided. Subsequently, a method for solving the origami design problem of determining the geometry of a single planar sheet and its pattern of smooth folds that morphs into a given three-dimensional goal shape, discretized as a polygonal mesh, is presented. The design parameterization of the planar sheet and the constraints that allow for a valid pattern of smooth folds and approximation of the goal shape in a known folded configuration are presented. Various testing examples considering goal shapes of diverse geometries are provided. Afterwards, a

  12. The mechanics of fault-bend folding and tear-fault systems in the Niger Delta

    Science.gov (United States)

    Benesh, Nathan Philip

    This dissertation investigates the mechanics of fault-bend folding using the discrete element method (DEM) and explores the nature of tear-fault systems in the deep-water Niger Delta fold-and-thrust belt. In Chapter 1, we employ the DEM to investigate the development of growth structures in anticlinal fault-bend folds. This work was inspired by observations that growth strata in active folds show a pronounced upward decrease in bed dip, in contrast to traditional kinematic fault-bend fold models. Our analysis shows that the modeled folds grow largely by parallel folding as specified by the kinematic theory; however, the process of folding over a broad axial surface zone yields a component of fold growth by limb rotation that is consistent with the patterns observed in natural folds. This result has important implications for how growth structures can he used to constrain slip and paleo-earthquake ages on active blind-thrust faults. In Chapter 2, we expand our DEM study to investigate the development of a wider range of fault-bend folds. We examine the influence of mechanical stratigraphy and quantitatively compare our models with the relationships between fold and fault shape prescribed by the kinematic theory. While the synclinal fault-bend models closely match the kinematic theory, the modeled anticlinal fault-bend folds show robust behavior that is distinct from the kinematic theory. Specifically, we observe that modeled structures maintain a linear relationship between fold shape (gamma) and fault-horizon cutoff angle (theta), rather than expressing the non-linear relationship with two distinct modes of anticlinal folding that is prescribed by the kinematic theory. These observations lead to a revised quantitative relationship for fault-bend folds that can serve as a useful interpretation tool. Finally, in Chapter 3, we examine the 3D relationships of tear- and thrust-fault systems in the western, deep-water Niger Delta. Using 3D seismic reflection data and new

  13. Folded Plate Structures as Building Envelopes

    DEFF Research Database (Denmark)

    Falk, Andreas; Buelow, Peter von; Kirkegaard, Poul Henning

    2012-01-01

    This paper treats applications of cross-laminated timber (CLT) in structural systems for folded façade solutions. Previous work on CLT-based systems for folded roofs has shown a widening range of structural possibilities to develop timber-based shells. Geometric and material properties play...... CLT-based systems, which are studied and analysed by using a combination of digital tools for structural and environmental design and analysis. The results show gainful, rational properties of folded systems and beneficial effects from an integration of architectural and environmental performance...... criteria in the design of CLT-based façades....

  14. Mechanical Models of Fault-Related Folding

    Energy Technology Data Exchange (ETDEWEB)

    Johnson, A. M.

    2003-01-09

    The subject of the proposed research is fault-related folding and ground deformation. The results are relevant to oil-producing structures throughout the world, to understanding of damage that has been observed along and near earthquake ruptures, and to earthquake-producing structures in California and other tectonically-active areas. The objectives of the proposed research were to provide both a unified, mechanical infrastructure for studies of fault-related foldings and to present the results in computer programs that have graphical users interfaces (GUIs) so that structural geologists and geophysicists can model a wide variety of fault-related folds (FaRFs).

  15. The distribution of deformation in parallel fault-related folds with migrating axial surfaces: comparison between fault-propagation and fault-bend folding

    Science.gov (United States)

    Salvini, Francesco; Storti, Fabrizio

    2001-01-01

    In fault-related folds that form by axial surface migration, rocks undergo deformation as they pass through axial surfaces. The distribution and intensity of deformation in these structures has been impacted by the history of axial surface migration. Upon fold initiation, unique dip panels develop, each with a characteristic deformation intensity, depending on their history. During fold growth, rocks that pass through axial surfaces are transported between dip panels and accumulate additional deformation. By tracking the pattern of axial surface migration in model folds, we predict the distribution of relative deformation intensity in simple-step, parallel fault-bend and fault-propagation anticlines. In both cases the deformation is partitioned into unique domains we call deformation panels. For a given rheology of the folded multilayer, deformation intensity will be homogeneously distributed in each deformation panel. Fold limbs are always deformed. The flat crests of fault-propagation anticlines are always undeformed. Two asymmetric deformation panels develop in fault-propagation folds above ramp angles exceeding 29°. For lower ramp angles, an additional, more intensely-deformed panel develops at the transition between the crest and the forelimb. Deformation in the flat crests of fault-bend anticlines occurs when fault displacement exceeds the length of the footwall ramp, but is never found immediately hinterland of the crest to forelimb transition. In environments dominated by brittle deformation, our models may serve as a first-order approximation of the distribution of fractures in fault-related folds.

  16. Designing cooperatively folded abiotic uni- and multimolecular helix bundles

    Science.gov (United States)

    de, Soumen; Chi, Bo; Granier, Thierry; Qi, Ting; Maurizot, Victor; Huc, Ivan

    2018-01-01

    Abiotic foldamers, that is foldamers that have backbones chemically remote from peptidic and nucleotidic skeletons, may give access to shapes and functions different to those of peptides and nucleotides. However, design methodologies towards abiotic tertiary and quaternary structures are yet to be developed. Here we report rationally designed interactional patterns to guide the folding and assembly of abiotic helix bundles. Computational design facilitated the introduction of hydrogen-bonding functionalities at defined locations on the aromatic amide backbones that promote cooperative folding into helix-turn-helix motifs in organic solvents. The hydrogen-bond-directed aggregation of helices not linked by a turn unit produced several thermodynamically and kinetically stable homochiral dimeric and trimeric bundles with structures that are distinct from the designed helix-turn-helix. Relative helix orientation within the bundles may be changed from parallel to tilted on subtle solvent variations. Altogether, these results prefigure the richness and uniqueness of abiotic tertiary structure behaviour.

  17. Topology Explains Why Automobile Sunshades Fold Oddly

    Science.gov (United States)

    Feist, Curtis; Naimi, Ramin

    2009-01-01

    Automobile sunshades always fold into an "odd" number of loops. The explanation why involves elementary topology (braid theory and linking number, both explained in detail here with definitions and examples), and an elementary fact from algebra about symmetric group.

  18. Reinke Edema: Watch For Vocal Fold Cysts.

    Science.gov (United States)

    Tüzüner, Arzu; Demirci, Sule; Yavanoglu, Ahmet; Kurkcuoglu, Melih; Arslan, Necmi

    2015-06-01

    Reinke edema is one of the common cause of dysphonia middle-aged population, and severe thickening of vocal folds require surgical treatment. Smoking plays a major role on etiology. Vocal fold cysts are also benign lesions and vocal trauma blamed for acquired cysts. We would like to present 3 cases with vocal fold cyst related with Reinke edema. First case had a subepidermal epidermoid cyst with Reinke edema, which could be easily observed before surgery during laryngostroboscopy. Second case had a mucous retention cyst into the edematous Reinke tissue, which was detected during surgical intervention, and third case had a epidermoid cyst that occurred 2 months after before microlaryngeal operation regarding Reinke edema reduction. These 3 cases revealed that surgical management of Reinke edema needs a careful dissection and close follow-up after surgery for presence of vocal fold cysts.

  19. Origami: Paper Folding--The Algorithmic Way.

    Science.gov (United States)

    Heukerott, Pamela Beth

    1988-01-01

    Describes origami, the oriental art of paper folding as an activity to teach upper elementary students concepts and skills in geometry involving polygons, angles, measurement, symmetry, and congruence. (PK)

  20. Self-folding miniature elastic electric devices

    International Nuclear Information System (INIS)

    Miyashita, Shuhei; Meeker, Laura; Rus, Daniela; Tolley, Michael T; Wood, Robert J

    2014-01-01

    Printing functional materials represents a considerable impact on the access to manufacturing technology. In this paper we present a methodology and validation of print-and-self-fold miniature electric devices. Polyvinyl chloride laminated sheets based on metalized polyester film show reliable self-folding processes under a heat application, and it configures 3D electric devices. We exemplify this technique by fabricating fundamental electric devices, namely a resistor, capacitor, and inductor. Namely, we show the development of a self-folded stretchable resistor, variable resistor, capacitive strain sensor, and an actuation mechanism consisting of a folded contractible solenoid coil. Because of their pre-defined kinematic design, these devices feature elasticity, making them suitable as sensors and actuators in flexible circuits. Finally, an RLC circuit obtained from the integration of developed devices is demonstrated, in which the coil based actuator is controlled by reading a capacitive strain sensor. (paper)

  1. Rigid Origami via Optical Programming and Deferred Self-Folding of a Two-Stage Photopolymer.

    Science.gov (United States)

    Glugla, David J; Alim, Marvin D; Byars, Keaton D; Nair, Devatha P; Bowman, Christopher N; Maute, Kurt K; McLeod, Robert R

    2016-11-02

    We demonstrate the formation of shape-programmed, glassy origami structures using a single-layer photopolymer with two mechanically distinct phases. The latent origami pattern consisting of rigid, high cross-link density panels and flexible, low cross-link density creases is fabricated using a series of photomask exposures. Strong optical absorption of the polymer formulation creates depth-wise gradients in the cross-link density of the creases, enforcing directed folding which enables programming of both mountain and valley folds within the same sheet. These multiple photomask patterns can be sequentially applied because the sheet remains flat until immersed into a photopolymerizable monomer solution that differentially swells the polymer to fold and form the origami structure. After folding, a uniform photoexposure polymerizes the absorbed solution, permanently fixing the shape of the folded structure while simultaneously increasing the modulus of the folds. This approach creates sharp folds by mimicking the stiff panels and flexible creases of paper origami while overcoming the traditional trade-off of self-actuated materials that require low modulus for folding and high modulus for mechanical robustness. Using this process, we demonstrate a waterbomb base capable of supporting 1500 times its own weight.

  2. Folding of non-Euclidean curved shells

    Science.gov (United States)

    Bende, Nakul; Evans, Arthur; Innes-Gold, Sarah; Marin, Luis; Cohen, Itai; Santangelo, Christian; Hayward, Ryan

    2015-03-01

    Origami-based folding of 2D sheets has been of recent interest for a variety of applications ranging from deployable structures to self-folding robots. Though folding of planar sheets follows well-established principles, folding of curved shells involves an added level of complexity due to the inherent influence of curvature on mechanics. In this study, we use principles from differential geometry and thin shell mechanics to establish fundamental rules that govern folding of prototypical creased shells. In particular, we show how the normal curvature of a crease line controls whether the deformation is smooth or discontinuous, and investigate the influence of shell thickness and boundary conditions. We show that snap-folding of shells provides a route to rapid actuation on time-scales dictated by the speed of sound. The simple geometric design principles developed can be applied at any length-scale, offering potential for bio-inspired soft actuators for tunable optics, microfluidics, and robotics. This work was funded by the National Science Foundation through EFRI ODISSEI-1240441 with additional support to S.I.-G. through the UMass MRSEC DMR-0820506 REU program.

  3. Vocal fold hemorrhage: factors predicting recurrence.

    Science.gov (United States)

    Lennon, Christen J; Murry, Thomas; Sulica, Lucian

    2014-01-01

    Vocal fold hemorrhage is an acute phonotraumatic injury treated with voice rest; recurrence is a generally accepted indication for surgical intervention. This study aims to identify factors predictive of recurrence based on outcomes of a large clinical series. Retrospective cohort. Retrospective review of cases of vocal fold hemorrhage presenting to a university laryngology service. Demographic information was compiled. Videostroboscopic exams were evaluated for hemorrhage extent, presence of varix, mucosal lesion, and/or vocal fold paresis. Vocal fold hemorrhage recurrence was the main outcome measure. Follow-up telephone survey was used to complement clinical data. Forty-seven instances of vocal fold hemorrhage were evaluated (25M:22F; 32 professional voice users). Twelve of the 47 (26%) patients experienced recurrence. Only the presence of varix demonstrated significant association with recurrence (P = 0.0089) on multivariate logistic regression. Vocal fold hemorrhage recurred in approximately 26% of patients. Varix was a predictor of recurrence, with 48% of those with varix experiencing recurrence. Monitoring, behavioral management and/or surgical intervention may be indicated to treat patients with such characteristics. © 2013 The American Laryngological, Rhinological and Otological Society, Inc.

  4. Videokymography. Imaging and quantification of regular and irregular vocal fold vibrations

    NARCIS (Netherlands)

    Schutte, HK; Svec, JG; Sram, F; McCafferty, G; Coman, W; Carroll, R

    1996-01-01

    A newly developed imaging technique makes it possible to observe the vocal fold vibration pattern also under unstable conditions. In contrast to stroboscopy, which strongly relies on the regularity of the vibration under study videokymography enables the study of irregular patterns as well. The

  5. Axons Pull on the Brain, But Tension Does Not Drive Cortical Folding

    Science.gov (United States)

    Xu, Gang; Knutsen, Andrew K.; Dikranian, Krikor; Kroenke, Christopher D.; Bayly, Philip V.; Taber, Larry A.

    2011-01-01

    During human brain development, the cerebral cortex undergoes substantial folding, leading to its characteristic highly convoluted form. Folding is necessary to accommodate the expansion of the cerbral cortex; abnormal cortical folding is linked to various neurological disorders, including schizophrenia, epilepsy, autism and mental retardation. Although this process requires mechanical forces, the specific force-generating mechanisms that drive folding remain unclear. The two most widely accepted hypotheses are (1) folding is caused by differential growth of the cortex and (2) folding is caused by mechanical tension generated in axons. Direct evidence supporting either theory, however, is lacking. Here we show that axons are indeed under considerable tension in the developing ferret brain, but the patterns of tissue stress are not consistent with a causal role for axonal tension. In particular, microdissection assays reveal that significant tension exists along axons aligned circumferentially in subcortical white matter tracts, as well as those aligned radially inside developing gyri (outward folds). Contrary to previous speculation, however, axonal tension is not directed across developing gyri, suggesting that axon tension does not drive folding. On the other hand, using computational (finite element) models, we show that differential cortical growth accompanied by remodeling of the subplate leads to outward folds and stress fields that are consistent with our microdissection experiments, supporting a mechanism involving differential growth. Local perturbations, such as temporal differences in the initiation of cortical growth, can ensure consistent folding patterns. This study shows that a combination of experimental and computational mechanics can be used to evaluate competing hypotheses of morphogenesis, and illuminate the biomechanics of cortical folding. PMID:20590291

  6. Technical Work Plan For: Calculation of Waste Package and Drip Shield Response to Vibratory Ground Motion and Revision of the Seismic Consequence Abstraction

    International Nuclear Information System (INIS)

    M. Gross

    2006-01-01

    The overall objective of the work scope covered by this technical work plan (TWP) is to develop new damage abstractions for the seismic scenario class in total system performance assessment (TSPA). The new abstractions will be based on a new set of waste package and drip shield damage calculations in response to vibratory ground motion and fault displacement. The new damage calculations, which are collectively referred to as damage models in this TWP, are required to represent recent changes in waste form packaging and in the regulatory time frame. The new damage models also respond to comments from the Independent Validation Review Team (IVRT) postvalidation review of the draft TSPA model regarding performance of the drip shield and to an Additional Information Need (AIN) from the U.S. Nuclear Regulatory Commission (NRC)

  7. Technical Work Plan For: Calculation of Waste Packave and Drip Shield Response to Vibratory Ground Motion and Revision of the Seismic Consequence Abstraction

    Energy Technology Data Exchange (ETDEWEB)

    M. Gross

    2006-12-08

    The overall objective of the work scope covered by this technical work plan (TWP) is to develop new damage abstractions for the seismic scenario class in total system performance assessment (TSPA). The new abstractions will be based on a new set of waste package and drip shield damage calculations in response to vibratory ground motion and fault displacement. The new damage calculations, which are collectively referred to as damage models in this TWP, are required to represent recent changes in waste form packaging and in the regulatory time frame. The new damage models also respond to comments from the Independent Validation Review Team (IVRT) postvalidation review of the draft TSPA model regarding performance of the drip shield and to an Additional Information Need (AIN) from the U.S. Nuclear Regulatory Commission (NRC).

  8. Experimental investigation of protein folding and misfolding.

    Science.gov (United States)

    Dobson, Christopher M

    2004-09-01

    Newly synthesised proteins need to fold, often to intricate and close-packed structures, in order to function. The underlying mechanism by which this complex process takes place both in vitro and in vivo is now becoming understood, at least in general terms, as a result of the application of a wide range of biophysical and computational methods used in combination with the techniques of biochemistry and protein engineering. It is increasingly apparent, however, that folding is not only crucial for generating biological activity, but that it is also coupled to a wide range of processes within the cell, ranging from the trafficking of proteins to specific organelles to the regulation of cell growth and differentiation. Not surprisingly, therefore, the failure of proteins to fold appropriately, or to remain correctly folded, is associated with a large number of cellular malfunctions that give rise to disease. Misfolding, and its consequences such as aggregation, can be investigated by extending the types of techniques used to study the normal folding process. Application of these techniques is enabling the development of a unified description of the interconversion and regulation of the different conformational states available to proteins in living systems. Such a description proves a generic basis for understanding the fundamental links between protein misfolding and its associated clinical disorders, such as Alzheimer's disease and Type II diabetes, and for exploring novel therapeutic strategies directed at their prevention and treatment on a rational basis.

  9. Kinetics and Thermodynamics of Membrane Protein Folding

    Directory of Open Access Journals (Sweden)

    Ernesto A. Roman

    2014-03-01

    Full Text Available Understanding protein folding has been one of the great challenges in biochemistry and molecular biophysics. Over the past 50 years, many thermodynamic and kinetic studies have been performed addressing the stability of globular proteins. In comparison, advances in the membrane protein folding field lag far behind. Although membrane proteins constitute about a third of the proteins encoded in known genomes, stability studies on membrane proteins have been impaired due to experimental limitations. Furthermore, no systematic experimental strategies are available for folding these biomolecules in vitro. Common denaturing agents such as chaotropes usually do not work on helical membrane proteins, and ionic detergents have been successful denaturants only in few cases. Refolding a membrane protein seems to be a craftsman work, which is relatively straightforward for transmembrane β-barrel proteins but challenging for α-helical membrane proteins. Additional complexities emerge in multidomain membrane proteins, data interpretation being one of the most critical. In this review, we will describe some recent efforts in understanding the folding mechanism of membrane proteins that have been reversibly refolded allowing both thermodynamic and kinetic analysis. This information will be discussed in the context of current paradigms in the protein folding field.

  10. Bifurcation of self-folded polygonal bilayers

    Science.gov (United States)

    Abdullah, Arif M.; Braun, Paul V.; Hsia, K. Jimmy

    2017-09-01

    Motivated by the self-assembly of natural systems, researchers have investigated the stimulus-responsive curving of thin-shell structures, which is also known as self-folding. Self-folding strategies not only offer possibilities to realize complicated shapes but also promise actuation at small length scales. Biaxial mismatch strain driven self-folding bilayers demonstrate bifurcation of equilibrium shapes (from quasi-axisymmetric doubly curved to approximately singly curved) during their stimulus-responsive morphing behavior. Being a structurally instable, bifurcation could be used to tune the self-folding behavior, and hence, a detailed understanding of this phenomenon is appealing from both fundamental and practical perspectives. In this work, we investigated the bifurcation behavior of self-folding bilayer polygons. For the mechanistic understanding, we developed finite element models of planar bilayers (consisting of a stimulus-responsive and a passive layer of material) that transform into 3D curved configurations. Our experiments with cross-linked Polydimethylsiloxane samples that change shapes in organic solvents confirmed our model predictions. Finally, we explored a design scheme to generate gripper-like architectures by avoiding the bifurcation of stimulus-responsive bilayers. Our research contributes to the broad field of self-assembly as the findings could motivate functional devices across multiple disciplines such as robotics, artificial muscles, therapeutic cargos, and reconfigurable biomedical devices.

  11. Self-folding origami: shape memory composites activated by uniform heating

    International Nuclear Information System (INIS)

    Tolley, Michael T; Felton, Samuel M; Aukes, Daniel; Wood, Robert J; Miyashita, Shuhei; Rus, Daniela

    2014-01-01

    Self-folding is an approach used frequently in nature for the efficient fabrication of structures, but is seldom used in engineered systems. Here, self-folding origami are presented, which consist of shape memory composites that are activated with uniform heating in an oven. These composites are rapidly fabricated using inexpensive materials and tools. The folding mechanism based on the in-plane contraction of a sheet of shape memory polymer is modeled, and parameters for the design of composites that self-fold into target shapes are characterized. Four self-folding shapes are demonstrated: a cube, an icosahedron, a flower, and a Miura pattern; each of which is activated in an oven in less than 4 min. Self-sealing is also investigated using hot melt adhesive, and the resulting structures are found to bear up to twice the load of unsealed structures. (paper)

  12. The Risk of Vocal Fold Atrophy after Serial Corticosteroid Injections of the Vocal Fold.

    Science.gov (United States)

    Shi, Lucy L; Giraldez-Rodriguez, Laureano A; Johns, Michael M

    2016-11-01

    The aim of this study was to illustrate the risk of vocal fold atrophy in patients who receive serial subepithelial steroid injections for vocal fold scar. This study is a retrospective case report of two patients who underwent a series of weekly subepithelial infusions of 10 mg/mL dexamethasone for benign vocal fold lesion. Shortly after the procedures, both patients developed a weak and breathy voice. The first patient was a 53-year-old man with radiation-induced vocal fold stiffness. Six injections were performed unilaterally, and 1 week later, he developed unilateral vocal fold atrophy with new glottal insufficiency. The second patient was a 67-year-old woman with severe vocal fold inflammation related to laryngitis and calcinosis, Raynaud's phenomenon, esophagean dysmotility, sclerodactyly, and telangiectasia (CREST) syndrome. Five injections were performed bilaterally, and 1 week later, she developed bilateral vocal fold atrophy with a large midline glottal gap during phonation. In both cases, the steroid-induced vocal atrophy resolved spontaneously after 4 months. Serial subepithelial steroid infusions of the vocal folds, although safe in the majority of patients, carry the risk of causing temporary vocal fold atrophy when given at short intervals. Copyright © 2016 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  13. Improvement of a Vocal Fold Imaging System

    Energy Technology Data Exchange (ETDEWEB)

    Krauter, K. G. [Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)

    2017-02-01

    Medical professionals can better serve their patients through continual update of their imaging tools. A wide range of pathologies and disease may afflict human vocal cords or, as they’re also known, vocal folds. These diseases can affect human speech hampering the ability of the patient to communicate. Vocal folds must be opened for breathing and the closed to produce speech. Currently methodologies to image markers of potential pathologies are difficult to use and often fail to detect early signs of disease. These current methodologies rely on a strobe light and slower frame rate camera in an attempt to obtain images as the vocal folds travel over the full extent of their motion.

  14. Analysis of high-fold gamma data

    International Nuclear Information System (INIS)

    Radford, D. C.; Cromaz, M.; Beyer, C. J.

    1999-01-01

    Historically, γ-γ and γ-γ-γ coincidence spectra were utilized to build nuclear level schemes. With the development of large detector arrays, it has became possible to analyze higher fold coincidence data sets. This paper briefly reports on software to analyze 4-fold coincidence data sets that allows creation of 4-fold histograms (hypercubes) of at least 1024 channels per side (corresponding to a 43 gigachannel data space) that will fit onto a few gigabytes of disk space, and extraction of triple-gated spectra in a few seconds. Future detector arrays may have even much higher efficiencies, and detect as many as 15 or 20 γ rays simultaneously; such data will require very different algorithms for storage and analysis. Difficulties inherent in the analysis of such data are discussed, and two possible new solutions are presented, namely adaptive list-mode systems and 'list-list-mode' storage

  15. In vitro folding of inclusion body proteins.

    Science.gov (United States)

    Rudolph, R; Lilie, H

    1996-01-01

    Insoluble, inactive inclusion bodies are frequently formed upon recombinant protein production in transformed microorganisms. These inclusion bodies, which contain the recombinant protein in an highly enriched form, can be isolated by solid/liquid separation. After solubilization, native proteins can be generated from the inactive material by using in vitro folding techniques. New folding procedures have been developed for efficient in vitro reconstitution of complex hydrophobic, multidomain, oligomeric, or highly disulfide-bonded proteins. These protocols take into account process parameters such as protein concentration, catalysis of disulfide bond formation, temperature, pH, and ionic strength, as well as specific solvent ingredients that reduce unproductive side reactions. Modification of the protein sequence has been exploited to improve in vitro folding.

  16. Solvent Effects on Protein Folding/Unfolding

    Science.gov (United States)

    García, A. E.; Hillson, N.; Onuchic, J. N.

    Pressure effects on the hydrophobic potential of mean force led Hummer et al. to postulate a model for pressure denaturation of proteins in which denaturation occurs by means of water penetration into the protein interior, rather than by exposing the protein hydrophobic core to the solvent --- commonly used to describe temperature denaturation. We study the effects of pressure in protein folding/unfolding kinetics in an off-lattice minimalist model of a protein in which pressure effects have been incorporated by means of the pair-wise potential of mean force of hydrophobic groups in water. We show that pressure slows down the kinetics of folding by decreasing the reconfigurational diffusion coefficient and moves the location of the folding transition state.

  17. Exact folded-band chaotic oscillator.

    Science.gov (United States)

    Corron, Ned J; Blakely, Jonathan N

    2012-06-01

    An exactly solvable chaotic oscillator with folded-band dynamics is shown. The oscillator is a hybrid dynamical system containing a linear ordinary differential equation and a nonlinear switching condition. Bounded oscillations are provably chaotic, and successive waveform maxima yield a one-dimensional piecewise-linear return map with segments of both positive and negative slopes. Continuous-time dynamics exhibit a folded-band topology similar to Rössler's oscillator. An exact solution is written as a linear convolution of a fixed basis pulse and a discrete binary sequence, from which an equivalent symbolic dynamics is obtained. The folded-band topology is shown to be dependent on the symbol grammar.

  18. SDEM modelling of fault-propagation folding

    DEFF Research Database (Denmark)

    Clausen, O.R.; Egholm, D.L.; Poulsen, Jane Bang

    2009-01-01

    and variations in Mohr-Coulomb parameters including internal friction. Using SDEM modelling, we have mapped the propagation of the tip-line of the fault, as well as the evolution of the fold geometry across sedimentary layers of contrasting rheological parameters, as a function of the increased offset......Understanding the dynamics and kinematics of fault-propagation-folding is important for evaluating the associated hydrocarbon play, for accomplishing reliable section balancing (structural reconstruction), and for assessing seismic hazards. Accordingly, the deformation style of fault-propagation...... a precise indication of when faults develop and hence also the sequential evolution of secondary faults. Here we focus on the generation of a fault -propagated fold with a reverse sense of motion at the master fault, and varying only the dip of the master fault and the mechanical behaviour of the deformed...

  19. Heterochiral Knottin Protein: Folding and Solution Structure.

    Science.gov (United States)

    Mong, Surin K; Cochran, Frank V; Yu, Hongtao; Graziano, Zachary; Lin, Yu-Shan; Cochran, Jennifer R; Pentelute, Bradley L

    2017-10-31

    Homochirality is a general feature of biological macromolecules, and Nature includes few examples of heterochiral proteins. Herein, we report on the design, chemical synthesis, and structural characterization of heterochiral proteins possessing loops of amino acids of chirality opposite to that of the rest of a protein scaffold. Using the protein Ecballium elaterium trypsin inhibitor II, we discover that selective β-alanine substitution favors the efficient folding of our heterochiral constructs. Solution nuclear magnetic resonance spectroscopy of one such heterochiral protein reveals a homogeneous global fold. Additionally, steered molecular dynamics simulation indicate β-alanine reduces the free energy required to fold the protein. We also find these heterochiral proteins to be more resistant to proteolysis than homochiral l-proteins. This work informs the design of heterochiral protein architectures containing stretches of both d- and l-amino acids.

  20. Vascular lesions of the vocal fold.

    Science.gov (United States)

    Gökcan, Kürşat Mustafa; Dursun, Gürsel

    2009-04-01

    The aim of the study was to present symptoms, laryngological findings, clinical course, management modalities, and consequences of vascular lesions of vocal fold. This study examined 162 patients, the majority professional voice users, with vascular lesions regarding their presenting symptoms, laryngological findings, clinical courses and treatment results. The most common complaint was sudden hoarseness with hemorrhagic polyp. Microlaryngoscopic surgery was performed in 108 cases and the main indication of surgery was the presence of vocal fold mass or development of vocal polyp during clinical course. Cold microsurgery was utilized for removal of vocal fold masses and feeding vessels cauterized using low power, pulsed CO(2) laser. Acoustic analysis of patients revealed a significant improvement of jitter, shimmer and harmonics/noise ratio values after treatment. Depending on our clinical findings, we propose treatment algorithm where voice rest and behavioral therapy is the integral part and indications of surgery are individualized for each patient.

  1. Natural triple beta-stranded fibrous folds.

    Science.gov (United States)

    Mitraki, Anna; Papanikolopoulou, Katerina; Van Raaij, Mark J

    2006-01-01

    A distinctive family of beta-structured folds has recently been described for fibrous proteins from viruses. Virus fibers are usually involved in specific host-cell recognition. They are asymmetric homotrimeric proteins consisting of an N-terminal virus-binding tail, a central shaft or stalk domain, and a C-terminal globular receptor-binding domain. Often they are entirely or nearly entirely composed of beta-structure. Apart from their biological relevance and possible gene therapy applications, their shape, stability, and rigidity suggest they may be useful as blueprints for biomechanical design. Folding and unfolding studies suggest their globular C-terminal domain may fold first, followed by a "zipping-up" of the shaft domains. The C-terminal domains appear to be important for registration because peptides corresponding to shaft domains alone aggregate into nonnative fibers and/or amyloid structures. C-terminal domains can be exchanged between different fibers and the resulting chimeric proteins are useful as a way to solve structures of unknown parts of the shaft domains. The following natural triple beta-stranded fibrous folds have been discovered by X-ray crystallography: the triple beta-spiral, triple beta-helix, and T4 short tail fiber fold. All have a central longitudinal hydrophobic core and extensive intermonomer polar and nonpolar interactions. Now that a reasonable body of structural and folding knowledge has been assembled about these fibrous proteins, the next challenge and opportunity is to start using this information in medical and industrial applications such as gene therapy and nanotechnology.

  2. Folding models for elastic and inelastic scattering

    International Nuclear Information System (INIS)

    Satchler, G.R.

    1982-01-01

    The most widely used models are the optical model potential (OMP) for elastic scattering, and its generalization to non-spherical shapes, the deformed optical model potential (DOMP) for inelastic scattering. These models are simple and phenomenological; their parameters are adjusted so as to reproduce empirical data. Nonetheless, there are certain, not always well-defined, constraints to be imposed. The potential shapes and their parameter values must be reasonable and should vary in a smooth and systematic way with the masses of the colliding nuclei and their energy. One way of satisfying these constraints, without going back to a much more fundamental theory, is through the use of folding models. The basic justification for using potentials of the Woods-Saxon shape for nucleon-nucleus scattering, for example, is our knowledge that a nuclear density distribution is more-or-less constant in the nuclear interior with a diffuse surface. When this is folded with a short-range nucleon-nucleon interaction, the result is a similar shape with a more diffuse surface. Folding procedures allow us to incorporate many aspects of nuclear structure (although the nuclear size is one of the most important), as well as theoretical ideas about the effective interaction of two nucleons within nuclear matter. It also provides us with a means of linking information obtained from nuclear (hadronic) interactions with that from other sources, as well as correlating that from the use of different hadronic probes. Folding model potentials, single-folded potentials, and the double-folding model including applications to heavy-ion scattering are discussed

  3. Stretching and folding mechanism in foams

    International Nuclear Information System (INIS)

    Tufaile, Alberto; Pedrosa Biscaia Tufaile, Adriana

    2008-01-01

    We have described the stretching and folding of foams in a vertical Hele-Shaw cell containing air and a surfactant solution, from a sequence of upside-down flips. Besides the fractal dimension of the foam, we have observed the logistic growth for the soap film length. The stretching and folding mechanism is present during the foam formation, and this mechanism is observed even after the foam has reached its respective maximum fractal dimension. Observing the motion of bubbles inside the foam, large bubbles present power spectrum associated with random walk motion in both directions, while the small bubbles are scattered like balls in a Galton board

  4. Assessment of thyroplasty for vocal fold paralysis

    DEFF Research Database (Denmark)

    Grøntved, Ågot Møller; Faber, Christian; Jakobsen, John

    2009-01-01

    INTRODUCTION: Thyroplasty with silicone rubber implantation is a surgical procedure for treatment of patients with vocal fold paralysis. The aim of the present study was to evaluate the outcome of the operation and to monitor which of the analyses were the more beneficial. MATERIAL AND METHODS...... because it offers a quantitative measure of the voice capacity and intensity, which are the major problems experienced by patients with vocal fold paralysis. Used together, these tools are highly instrumental in guiding the patient's choice of surgery or no surgery. Udgivelsesdato: 2009-Jan-12...

  5. Stretching and folding mechanism in foams

    Energy Technology Data Exchange (ETDEWEB)

    Tufaile, Alberto [Escola de Artes, Ciencias e Humanidades, Soft Matter Laboratory, Universidade de Sao Paulo, 03828-000 Sao Paulo, SP (Brazil)], E-mail: tufaile@usp.br; Pedrosa Biscaia Tufaile, Adriana [Escola de Artes, Ciencias e Humanidades, Soft Matter Laboratory, Universidade de Sao Paulo, 03828-000 Sao Paulo, SP (Brazil)

    2008-10-13

    We have described the stretching and folding of foams in a vertical Hele-Shaw cell containing air and a surfactant solution, from a sequence of upside-down flips. Besides the fractal dimension of the foam, we have observed the logistic growth for the soap film length. The stretching and folding mechanism is present during the foam formation, and this mechanism is observed even after the foam has reached its respective maximum fractal dimension. Observing the motion of bubbles inside the foam, large bubbles present power spectrum associated with random walk motion in both directions, while the small bubbles are scattered like balls in a Galton board.

  6. The efficacy of a novel collagen-gelatin scaffold with basic fibroblast growth factor for the treatment of vocal fold scar.

    Science.gov (United States)

    Hiwatashi, Nao; Hirano, Shigeru; Mizuta, Masanobu; Kobayashi, Toshiki; Kawai, Yoshitaka; Kanemaru, Shin-Ichi; Nakamura, Tatsuo; Ito, Juichi; Kawai, Katsuya; Suzuki, Shigehiko

    2017-05-01

    Vocal fold scar remains a therapeutic challenge. Basic fibroblast growth factor (bFGF) was reported to have regenerative effects for vocal fold scar, although it has the disadvantage of rapid absorption in vivo. A collagen-gelatin sponge (CGS) can compensate for the disadvantage by providing a sustained release system. The current study evaluated the efficacy of CGS combined with bFGF on vocal fold scar, using rat fibroblasts for an in vitro model and a canine in vivo model. We prepared fibroblasts from scarred vocal folds (sVFs) in rats and showed that bFGF accelerated cell proliferation and suppressed expression levels of cleaved caspase 3 and α-smooth muscle actin. Has 1, Has 3, Fgf2, Hgf and Vegfa mRNA levels were significantly upregulated, while Col1a1 and Col3a1 were dose-dependently downregulated, with a maximum effect at 100 ng/ml bFGF. In an in vivo assay, 6 weeks after lamina propria stripping, beagles were divided into three groups: CGS alone (CGS group); CGS with bFGF (7 µg/cm 2 ; CGS + bFGF group); or a sham-treated group. Vibratory examination revealed that the glottal gap was significantly reduced in the bFGF group and the two implanted groups, whereas the CGS + bFGF group showed higher mucosal wave amplitude. Histological examination revealed significantly restored hyaluronic acid and elastin redistribution in the CGS + bFGF group and reductions in dense collagen deposition. These results provide evidence that CGS and bFGF combination therapy may have therapeutic potential and could be a promising tool for treating vocal fold scar. Copyright © 2015 John Wiley & Sons, Ltd. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Self-organization and mismatch tolerance in protein folding: General theory and an application

    Science.gov (United States)

    Fernández, Ariel; Berry, R. Stephen

    2000-03-01

    The folding of a protein is a process both expeditious and robust. The analysis of this process presented here uses a coarse, discretized representation of the evolving form of the backbone chain, based on its torsional states. This coarse description consists of discretizing the torsional coordinates modulo the Ramachandran basins in the local softmode dynamics. Whenever the representation exhibits "contact patterns" that correspond to topological compatibilities with particular structural forms, secondary and then tertiary, the elements constituting the pattern are effectively entrained by a reduction of their rates of exploration of their discretized configuration space. The properties "expeditious and robust" imply that the folding protein must have some tolerance to both torsional "frustrated" and side-chain contact mismatches which may occur during the folding process. The energy-entropy consequences of the staircase or funnel topography of the potential surface should allow the folding protein to correct these mismatches, eventually. This tolerance lends itself to an iterative pattern-recognition-and-feedback description of the folding process that reflects mismatched local torsional states and hydrophobic/polar contacts. The predictive potential of our algorithm is tested by application to the folding of bovine pancreatic trypsin inhibitor (BPTI), a protein whose ability to form its active structure is contingent upon its frustration tolerance.

  8. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, W.K.; Hanks, C.L.; Whalen, M.T.; Jensen, J.; Atkinson, P.K.; Brinton, J.S.

    2001-01-09

    The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding and lithostratigraphy on fracture patterns, (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics, and (4) The influence of lithostratigraphy and deformation on fluid flow.

  9. Entropic formulation for the protein folding process: Hydrophobic stability correlates with folding rates

    Science.gov (United States)

    Dal Molin, J. P.; Caliri, A.

    2018-01-01

    Here we focus on the conformational search for the native structure when it is ruled by the hydrophobic effect and steric specificities coming from amino acids. Our main tool of investigation is a 3D lattice model provided by a ten-letter alphabet, the stereochemical model. This minimalist model was conceived for Monte Carlo (MC) simulations when one keeps in mind the kinetic behavior of protein-like chains in solution. We have three central goals here. The first one is to characterize the folding time (τ) by two distinct sampling methods, so we present two sets of 103 MC simulations for a fast protein-like sequence. The resulting sets of characteristic folding times, τ and τq were obtained by the application of the standard Metropolis algorithm (MA), as well as by an enhanced algorithm (Mq A). The finding for τq shows two things: (i) the chain-solvent hydrophobic interactions {hk } plus a set of inter-residues steric constraints {ci,j } are able to emulate the conformational search for the native structure. For each one of the 103MC performed simulations, the target is always found within a finite time window; (ii) the ratio τq / τ ≅ 1 / 10 suggests that the effect of local thermal fluctuations, encompassed by the Tsallis weight, provides to the chain an innate efficiency to escape from energetic and steric traps. We performed additional MC simulations with variations of our design rule to attest this first result, both algorithms the MA and the Mq A were applied to a restricted set of targets, a physical insight is provided. Our second finding was obtained by a set of 600 independent MC simulations, only performed with the Mq A applied to an extended set of 200 representative targets, our native structures. The results show how structural patterns should modulate τq, which cover four orders of magnitude; this finding is our second goal. The third, and last result, was obtained with a special kind of simulation performed with the purpose to explore a

  10. Crosstalk properties of 36-fold segmented symmetric hexagonal HPGe detectors

    International Nuclear Information System (INIS)

    Bruyneel, Bart; Reiter, Peter; Wiens, Andreas; Eberth, Juergen; Hess, Herbert; Pascovici, Gheorghe; Warr, Nigel; Weisshaar, Dirk

    2009-01-01

    Crosstalk properties of three 36-fold segmented, symmetric, large volume, HPGe detectors from the AGATA Collaboration were deduced from coincidence measurements performed with digitized segment and core signals after interaction of γ rays with energies of 1.33 MeV. The mean energy values measured by the core signal fluctuate for γ-ray interactions with energy deposited in two segments. A regular pattern is observed depending on the hit segment combinations. The core energy shifts deviate 0.03-0.06% from the average energy calibration. The segment-sum energy is reduced with respect to the core energy as a function of the decoupling capacitance and the segment multiplicity. The deviation of the segment-sum energies from multiplicity two events fluctuates within an interval of less than 0.1% depending on the different segment combinations. The energy shifts caused by crosstalk for the core and segment signals are comparable for all three detectors. A linear electronic model of the detector and preamplifier assembly was developed to evaluate the results. The fold-dependent energy shifts of the segment-sum energies are reproduced. The model yields a constant shift in all segments, proportional to the core signal. The measured crosstalk pattern and its intensity variation in the segments agree well with the calculated values. The regular variation observed in the core energies cannot be directly related to crosstalk and may be caused by other effects like electron trapping.

  11. A comparison of RNA folding measures

    DEFF Research Database (Denmark)

    Freyhult, E.; Gardner, P. P.; Moulton, V.

    2005-01-01

    the behaviour of these measures over a large range of Rfam ncRNA families. Such measures can be useful in, for example, identifying novel ncRNAs, and indicating the presence of alternate RNA foldings. Results Our analysis shows that ncRNAs, but not mRNAs, in general have lower minimal free energy (MFE) than....... Conclusion Due to the correlations between the different measures we find that it is sufficient to use only two of them in RNA folding studies, one to test if the sequence in question has lower energy than a random sequence with the same dinucleotide frequency (the Z-score) and the other to see......Background In the last few decades there has been a great deal of discussion concerning whether or not noncoding RNA sequences (ncRNAs) fold in a more well-defined manner than random sequences. In this paper, we investigate several existing measures for how well an RNA sequence folds, and compare...

  12. Mapping the universe of RNA tetraloop folds

    DEFF Research Database (Denmark)

    Bottaro, Sandro; Lindorff-Larsen, Kresten

    2017-01-01

    We report a map of RNA tetraloop conformations constructed by calculating pairwise distances among all experimentally determined four-nucleotide hairpin loops. Tetraloops with similar structures are clustered together and, as expected, the two largest clusters are the canonical GNRA and UNCG fold...

  13. Fold in Origami and Unfold Math

    Science.gov (United States)

    Georgeson, Joseph

    2011-01-01

    Students enjoy origami and like making everything from paper cranes to footballs out of small, colorful squares of paper. They can invent their own shapes and are intrigued by the polyhedrons that they can construct. Paper folding is fun, but where is the math? Unless teachers develop lessons that address mathematical objectives, origami could be…

  14. Targeted transtracheal stimulation for vocal fold closure.

    Science.gov (United States)

    Hadley, Aaron J; Thompson, Paul; Kolb, Ilya; Hahn, Elizabeth C; Tyler, Dustin J

    2014-06-01

    Paralysis of the structures in the head and neck due to stroke or other neurological disorder often causes dysphagia (difficulty in swallowing). Patients with dysphagia have a significantly higher incidence of aspiration pneumonia and death. The recurrent laryngeal nerve (RLN), which innervates the intrinsic laryngeal muscles that control the vocal folds, travels superiorly in parallel to the trachea in the tracheoesophageal groove. This study tests the hypothesis that functional electrical stimulation (FES) applied via transtracheal electrodes can produce controlled vocal fold adduction. Bipolar electrodes were placed at 15° intervals around the interior mucosal surface of the canine trachea, and current was applied to the tissue while electromyography (EMG) from the intrinsic laryngeal muscles and vocal fold movement visualization via laryngoscopy were recorded. The lowest EMG thresholds were found at an average location of 100° to the left of the ventral midsagittal line and 128° to the right. A rotatable pair of bipolar electrodes spaced 230° apart were able to stimulate bilaterally both RLNs in every subject. Laryngoscopy showed complete glottal closure with transtracheal stimulation in six of the eight subjects, and this closure was maintained under simultaneous FES-induced laryngeal elevation. Transtracheal stimulation is an effective tool for minimally invasive application of FES to induce vocal fold adduction, providing an alternative mechanism to study airway protection.

  15. Amylose folding under the influence of lipids

    NARCIS (Netherlands)

    Lopez, Cesar A.; de Vries, Alex H.; Marrink, Siewert J.

    2012-01-01

    The molecular dynamics simulation technique was used to study the folding and complexation process of a short amylose fragment in the presence of lipids. In aqueous solution, the amylose chain remains as an extended left-handed helix. After the addition of lipids in the system, however, we observe

  16. MARATHON DESPITE UNILATERAL VOCAL FOLD PARALYSIS

    Directory of Open Access Journals (Sweden)

    Matthias Echternach

    2008-06-01

    Full Text Available The principal symptoms of unilateral vocal fold paralysis are hoarseness and difficulty in swallowing. Dyspnea is comparatively rare (Laccourreye et al., 2003. The extent to which unilateral vocal fold paralysis may lead to respiratory problems at all - in contrast to bilateral vocal fold paralysis- has not yet well been determined. On the one hand, inspiration is impaired with unilateral vocal fold paralysis; on the other hand, neither the position of the vocal fold paralysis nor the degree of breathiness correlates with respiratory parameters (Cantarella et al., 2003; 2005. The question of what respiratory stress a patient with a vocal fold paresis can endure has not yet been dealt with.A 43 year-old female patient was suffering from recurrent unspecific respiratory complaints for four months after physical activity. During training for a marathon, she experienced no difficulty in breathing. These unspecific respiratory complaints occurred only after athletic activity and persisted for hours. The patient observed neither an increased coughing nor a stridor. Her voice remained unaltered during the attacks, nor were there any signs of a symptomatic gastroesophageal reflux or infectious disease. A cardio-pulmonary and a radiological examination by means of an X-ray of the thorax also revealed no pathological phenomena. As antiallergic and antiobstructive therapy remained unsuccessful, a laryngological examination was performed in order to exclude a vocal cord dysfunction.Surprisingly enough, the laryngostroboscopy showed, as an initial description, a vocal fold paralysis of the left vocal fold in median position (Figure 1. The anamnestic background for the cause was unclear. The only clue was a thoracotomy on the left side due to a pleuritis in childhood. A subsequent laryngoscopic examination had never been performed. Good mucosa waves and amplitudes were shown bilateral with complete glottal closure. Neither in the acoustic analysis, nor in the

  17. Towards a systematic classification of protein folds

    DEFF Research Database (Denmark)

    Lindgård, Per-Anker; Bohr, Henrik

    1997-01-01

    structures are given a unique name, which simultaneously represent a linear string of physical coupling constants describing hinge spin interactions. We have defined a metric and a precise distance measure between the fold classes. An automated procedure is constructed in which any protein structure...

  18. Vocal fold submucosal infusion technique in phonomicrosurgery.

    Science.gov (United States)

    Kass, E S; Hillman, R E; Zeitels, S M

    1996-05-01

    Phonomicrosurgery is optimized by maximally preserving the vocal fold's layered microstructure (laminae propriae). The technique of submucosal infusion of saline and epinephrine into the superficial lamina propria (SLP) was examined to delineate how, when, and why it was helpful toward this surgical goal. A retrospective review revealed that the submucosal infusion technique was used to enhance the surgery in 75 of 152 vocal fold procedures that were performed over the last 2 years. The vocal fold epithelium was noted to be adherent to the vocal ligament in 29 of the 75 cases: 19 from previous surgical scarring, 4 from cancer, 3 from sulcus vocalis, 2 from chronic hemorrhage, and 1 from radiotherapy. The submucosal infusion technique was most helpful when the vocal fold epithelium required resection and/or when extensive dissection in the SLP was necessary. The infusion enhanced the surgery by vasoconstriction of the microvasculature in the SLP, which improved visualization during cold-instrument tangential dissection. Improved visualization facilitated maximal preservation of the SLP, which is necessary for optimal pliability of the overlying epithelium. The infusion also improved the placement of incisions at the perimeter of benign, premalignant, and malignant lesions, and thereby helped preserve epithelium uninvolved by the disorder.

  19. Folding and Fracturing of Rocks: the background

    Science.gov (United States)

    Ramsay, John G.

    2017-04-01

    This book was generated by structural geology teaching classes at Imperial College. I was appointed lecturer during 1957 and worked together with Dr Gilbert Wilson teaching basic structural geology at B.Sc level. I became convinced that the subject, being essentially based on geometric field observations, required a firm mathematical basis for its future development. In particular it seemed to me to require a very sound understanding of stress and strain. My field experience suggested that a knowledge of two- and three-demensional strain was critical in understanding natural tectonic processes. I found a rich confirmation for this in early publications of deformed fossils, oolitic limestones and spotted slates made by several geologists around the beginning of the 20th century (Sorby, Philips, Haughton, Harker) often using surprisingly sophisticated mathematical methods. These methods were discussed and elaborated in Folding and Fracturing of Rocks in a practical way. The geometric features of folds were related to folding mechanisms and the fold related small scale structures such as cleavage, schistosity and lineation explained in terms of rock strain. My work in the Scottish Highlands had shown just how repeated fold superposition could produce very complex geometric features, while further work in other localities suggested that such geometric complications are common in many orogenic zones. From the development of structural geological studies over the past decades it seems that the readers of this book have found many of the ideas set out are still of practical application. The mapping of these outcrop-scale structures should be emphasised in all field studies because they can be seen as ''fingerprints'' of regional scale tectonic processes. My own understanding of structural geology has been inspired by field work and I am of the opinion that future progress in understanding will be likewise based on careful observation and measurement of the features of

  20. ETIOLOGICAL FACTORS FOR VOCAL FOLD POLYP FORMATION

    Directory of Open Access Journals (Sweden)

    DAŠA GLUVAJIĆ

    2016-05-01

    Full Text Available Background: Vocal fold polyp is one of the most common causes for hoarseness. Many different etiological factors contribute to vocal fold polyp formation. The aim of the study was to find out whether the etiological factors for polyp formation have changed in the last 30 years.Methods: Eighty-one patients with unilateral vocal fold polyp were included in the study. A control group was composed of 50 volunteers without voice problems who matched the patients by age and gender. The data about etiological factors and the findings of phoniatric examination were obtained from the patients' medical documentation and from the questionnaires for the control group. The incidence of etiological factors was compared between the two groups. The program SPSS, Version 18 was used for statistical analysis.Results: The most frequent etiological factors were occupational voice load, GER, allergy and smoking. In 79% of patients 2 – 6 contemporary acting risk factors were found. Occupational voice load (p=0,018 and GER (p=0,004 were significantly more frequent in the patients than in the controls. The other factors did not significantly influence the polyp formation.Conclusions: There are several factors involved simultaneously in the formation of vocal fold polyps both nowadays and 30 years ago. Some of the most common factors remain the same (voice load, smoking, others are new (GER, allergy, which is probably due to the different lifestyle and working conditions than 30 years ago. Occupational voice load and GER were significantly more frequently present in the patients with polyp than in the control group. Regarding the given results it is important to instruct workers with professional vocal load about etiological factors for vocal fold polyp formation.

  1. Inverse folding of RNA pseudoknot structures

    Directory of Open Access Journals (Sweden)

    Li Linda YM

    2010-06-01

    Full Text Available Abstract Background RNA exhibits a variety of structural configurations. Here we consider a structure to be tantamount to the noncrossing Watson-Crick and G-U-base pairings (secondary structure and additional cross-serial base pairs. These interactions are called pseudoknots and are observed across the whole spectrum of RNA functionalities. In the context of studying natural RNA structures, searching for new ribozymes and designing artificial RNA, it is of interest to find RNA sequences folding into a specific structure and to analyze their induced neutral networks. Since the established inverse folding algorithms, RNAinverse, RNA-SSD as well as INFO-RNA are limited to RNA secondary structures, we present in this paper the inverse folding algorithm Inv which can deal with 3-noncrossing, canonical pseudoknot structures. Results In this paper we present the inverse folding algorithm Inv. We give a detailed analysis of Inv, including pseudocodes. We show that Inv allows to design in particular 3-noncrossing nonplanar RNA pseudoknot 3-noncrossing RNA structures-a class which is difficult to construct via dynamic programming routines. Inv is freely available at http://www.combinatorics.cn/cbpc/inv.html. Conclusions The algorithm Inv extends inverse folding capabilities to RNA pseudoknot structures. In comparison with RNAinverse it uses new ideas, for instance by considering sets of competing structures. As a result, Inv is not only able to find novel sequences even for RNA secondary structures, it does so in the context of competing structures that potentially exhibit cross-serial interactions.

  2. Improving protein fold recognition by extracting fold-specific features from predicted residue-residue contacts.

    Science.gov (United States)

    Zhu, Jianwei; Zhang, Haicang; Li, Shuai Cheng; Wang, Chao; Kong, Lupeng; Sun, Shiwei; Zheng, Wei-Mou; Bu, Dongbo

    2017-12-01

    Accurate recognition of protein fold types is a key step for template-based prediction of protein structures. The existing approaches to fold recognition mainly exploit the features derived from alignments of query protein against templates. These approaches have been shown to be successful for fold recognition at family level, but usually failed at superfamily/fold levels. To overcome this limitation, one of the key points is to explore more structurally informative features of proteins. Although residue-residue contacts carry abundant structural information, how to thoroughly exploit these information for fold recognition still remains a challenge. In this study, we present an approach (called DeepFR) to improve fold recognition at superfamily/fold levels. The basic idea of our approach is to extract fold-specific features from predicted residue-residue contacts of proteins using deep convolutional neural network (DCNN) technique. Based on these fold-specific features, we calculated similarity between query protein and templates, and then assigned query protein with fold type of the most similar template. DCNN has showed excellent performance in image feature extraction and image recognition; the rational underlying the application of DCNN for fold recognition is that contact likelihood maps are essentially analogy to images, as they both display compositional hierarchy. Experimental results on the LINDAHL dataset suggest that even using the extracted fold-specific features alone, our approach achieved success rate comparable to the state-of-the-art approaches. When further combining these features with traditional alignment-related features, the success rate of our approach increased to 92.3%, 82.5% and 78.8% at family, superfamily and fold levels, respectively, which is about 18% higher than the state-of-the-art approach at fold level, 6% higher at superfamily level and 1% higher at family level. An independent assessment on SCOP_TEST dataset showed consistent

  3. Fracture zones constrained by neutral surfaces in a fault-related fold: Insights from the Kelasu tectonic zone, Kuqa Depression

    Science.gov (United States)

    Sun, Shuai; Hou, Guiting; Zheng, Chunfang

    2017-11-01

    Stress variation associated with folding is one of the controlling factors in the development of tectonic fractures, however, little attention has been paid to the influence of neutral surfaces during folding on fracture distribution in a fault-related fold. In this study, we take the Cretaceous Bashijiqike Formation in the Kuqa Depression as an example and analyze the distribution of tectonic fractures in fault-related folds by core observation and logging data analysis. Three fracture zones are identified in a fault-related fold: a tensile zone, a transition zone and a compressive zone, which may be constrained by two neutral surfaces of fold. Well correlation reveals that the tensile zone and the transition zone reach the maximum thickness at the fold hinge and get thinner in the fold limbs. A 2D viscoelastic stress field model of a fault-related fold was constructed to further investigate the mechanism of fracturing. Statistical and numerical analysis reveal that the tensile zone and the transition zone become thicker with decreasing interlimb angle. Stress variation associated with folding is the first level of control over the general pattern of fracture distribution while faulting is a secondary control over the development of local fractures in a fault-related fold.

  4. Ca-Dependent Folding of Human Calumenin

    Science.gov (United States)

    Mazzorana, Marco; Hussain, Rohanah; Sorensen, Thomas

    2016-01-01

    Human calumenin (hCALU) is a six EF-hand protein belonging to the CREC family. As other members of the family, it is localized in the secretory pathway and regulates the activity of SERCA2a and of the ryanodine receptor in the endoplasmic reticulum (ER). We have studied the effects of Ca2+ binding to the protein and found it to attain a more compact structure upon ion binding. Circular Dichroism (CD) measurements suggest a major rearrangement of the protein secondary structure, which reversibly switches from disordered at low Ca2+ concentrations to predominantly alpha-helical when Ca2+ is added. SAXS experiments confirm the transition from an unfolded to a compact structure, which matches the structural prediction of a trilobal fold. Overall our experiments suggest that calumenin is a Ca2+ sensor, which folds into a compact structure, capable of interacting with its molecular partners, when Ca2+ concentration within the ER reaches the millimolar range. PMID:26991433

  5. Dynamics in thin folded polymer films

    Science.gov (United States)

    Croll, Andrew; Rozairo, Damith

    Origami and Kirigami inspired structures depend on a complex interplay between geometry and material properties. While clearly important to the overall function, very little attention has focused on how extreme curvatures and singularities in real materials influence the overall dynamic behaviour of folded structures. In this work we use a set of three polymer thin films in order to closely examine the interaction of material and geometry. Specifically, we use polydimethylsiloxane (PDMS), polystyrene (PS) and polycarbonate (PC) thin films which we subject to loading in several model geometries of varying complexity. Depending on the material, vastly different responses are noted in our experiments; D-cones can annihilate, cut or lead to a crumpling cascade when pushed through a film. Remarkably, order can be generated with additional perturbation. Finally, the role of adhesion in complex folded structures can be addressed. AFOSR under the Young Investigator Program (FA9550-15-1-0168).

  6. Folding pathways explored with artificial potential functions

    International Nuclear Information System (INIS)

    Ulutaş, B; Bozma, I; Haliloglu, T

    2009-01-01

    This paper considers the generation of trajectories to a given protein conformation and presents a novel approach based on artificial potential functions—originally proposed for multi-robot navigation. The artificial potential function corresponds to a simplified energy model, but with the novelty that—motivated by work on robotic navigation—a nonlinear compositional scheme of constructing the energy model is adapted instead of an additive formulation. The artificial potential naturally gives rise to a dynamic system for the protein structure that ensures collision-free motion to an equilibrium point. In cases where the equilibrium point is the native conformation, the motion trajectory corresponds to the folding pathway. This framework is used to investigate folding in a variety of protein structures, and the results are compared with those of other approaches including experimental studies

  7. Folded membrane dialyzer with mechanically sealed edges

    Energy Technology Data Exchange (ETDEWEB)

    Markley, F.W.

    A semipermeable membrane is folded in accordion fashion to form a stack of pleats and the edges are sealed so as to isolate the opposite surfaces of the membrane. The stack is contained within a case that provides ports for flow of blood in contact with one surface of the membrane through channels formed by the pleats and also provides ports for flow of a dialysate through channels formed by the pleats in contact with the other surface of the membrane. The serpentine side edges of the membrane are sealed by a solidified plastic material, whereas effective mechanical means are provided to seal the end edges of the folded membrane. The mechanical means include a clamping strip which biases case sealing flanges into a sealed relationship with end portions of the membrane near the end edges, which portions extend from the stack and between the sealing flanges.

  8. PREFACE Protein folding: lessons learned and new frontiers Protein folding: lessons learned and new frontiers

    Science.gov (United States)

    Pappu, Rohit V.; Nussinov, Ruth

    2009-03-01

    In appropriate physiological milieux proteins spontaneously fold into their functional three-dimensional structures. The amino acid sequences of functional proteins contain all the information necessary to specify the folds. This remarkable observation has spawned research aimed at answering two major questions. (1) Of all the conceivable structures that a protein can adopt, why is the ensemble of native-like structures the most favorable? (2) What are the paths by which proteins manage to robustly and reproducibly fold into their native structures? Anfinsen's thermodynamic hypothesis has guided the pursuit of answers to the first question whereas Levinthal's paradox has influenced the development of models for protein folding dynamics. Decades of work have led to significant advances in the folding problem. Mean-field models have been developed to capture our current, coarse grain understanding of the driving forces for protein folding. These models are being used to predict three-dimensional protein structures from sequence and stability profiles as a function of thermodynamic and chemical perturbations. Impressive strides have also been made in the field of protein design, also known as the inverse folding problem, thereby testing our understanding of the determinants of the fold specificities of different sequences. Early work on protein folding pathways focused on the specific sequence of events that could lead to a simplification of the search process. However, unifying principles proved to be elusive. Proteins that show reversible two-state folding-unfolding transitions turned out to be a gift of natural selection. Focusing on these simple systems helped researchers to uncover general principles regarding the origins of cooperativity in protein folding thermodynamics and kinetics. On the theoretical front, concepts borrowed from polymer physics and the physics of spin glasses led to the development of a framework based on energy landscape theories. These

  9. Image Analysis for Nail-fold Capillaroscopy

    OpenAIRE

    Vucic, Vladimir

    2015-01-01

    Detection of diseases in an early stage is very important since it can make the treatment of patients easier, safer and more ecient. For the detection of rheumatic diseases, and even prediction of tendencies towards such diseases, capillaroscopy is becoming an increasingly recognized method. Nail-fold capillaroscopy is a non-invasive imaging technique that is used for analysis of microcirculation abnormalities that may lead todisease like systematic sclerosis, Reynauds phenomenon and others. ...

  10. Coherent topological phenomena in protein folding

    DEFF Research Database (Denmark)

    Bohr, Henrik; Brunak, Søren; Bohr, Jakob

    1997-01-01

    A theory is presented for coherent topological phenomena in protein dynamics with implications for protein folding and stability. We discuss the relationship to the writhing number used in knot diagrams of DNA. The winding state defines a long-range order along the backbone of a protein with long......-range excitations, `wring' modes, that play an important role in protein denaturation and stability. Energy can be pumped into these excitations, either thermally or by an external force....

  11. Evolution of a protein folding nucleus.

    Science.gov (United States)

    Xia, Xue; Longo, Liam M; Sutherland, Mason A; Blaber, Michael

    2016-07-01

    The folding nucleus (FN) is a cryptic element within protein primary structure that enables an efficient folding pathway and is the postulated heritable element in the evolution of protein architecture; however, almost nothing is known regarding how the FN structurally changes as complex protein architecture evolves from simpler peptide motifs. We report characterization of the FN of a designed purely symmetric β-trefoil protein by ϕ-value analysis. We compare the structure and folding properties of key foldable intermediates along the evolutionary trajectory of the β-trefoil. The results show structural acquisition of the FN during gene fusion events, incorporating novel turn structure created by gene fusion. Furthermore, the FN is adjusted by circular permutation in response to destabilizing functional mutation. FN plasticity by way of circular permutation is made possible by the intrinsic C3 cyclic symmetry of the β-trefoil architecture, identifying a possible selective advantage that helps explain the prevalence of cyclic structural symmetry in the proteome. © 2015 The Protein Society.

  12. Folding Membrane Proteins by Deep Transfer Learning

    KAUST Repository

    Wang, Sheng

    2017-08-29

    Computational elucidation of membrane protein (MP) structures is challenging partially due to lack of sufficient solved structures for homology modeling. Here, we describe a high-throughput deep transfer learning method that first predicts MP contacts by learning from non-MPs and then predicts 3D structure models using the predicted contacts as distance restraints. Tested on 510 non-redundant MPs, our method has contact prediction accuracy at least 0.18 better than existing methods, predicts correct folds for 218 MPs, and generates 3D models with root-mean-square deviation (RMSD) less than 4 and 5 Å for 57 and 108 MPs, respectively. A rigorous blind test in the continuous automated model evaluation project shows that our method predicted high-resolution 3D models for two recent test MPs of 210 residues with RMSD ∼2 Å. We estimated that our method could predict correct folds for 1,345–1,871 reviewed human multi-pass MPs including a few hundred new folds, which shall facilitate the discovery of drugs targeting at MPs.

  13. Protein Folding: Search for Basic Physical Models

    Directory of Open Access Journals (Sweden)

    Ivan Y. Torshin

    2003-01-01

    Full Text Available How a unique three-dimensional structure is rapidly formed from the linear sequence of a polypeptide is one of the important questions in contemporary science. Apart from biological context of in vivo protein folding (which has been studied only for a few proteins, the roles of the fundamental physical forces in the in vitro folding remain largely unstudied. Despite a degree of success in using descriptions based on statistical and/or thermodynamic approaches, few of the current models explicitly include more basic physical forces (such as electrostatics and Van Der Waals forces. Moreover, the present-day models rarely take into account that the protein folding is, essentially, a rapid process that produces a highly specific architecture. This review considers several physical models that may provide more direct links between sequence and tertiary structure in terms of the physical forces. In particular, elaboration of such simple models is likely to produce extremely effective computational techniques with value for modern genomics.

  14. Hierarchical Diagnosis of Vocal Fold Disorders

    Science.gov (United States)

    Nikkhah-Bahrami, Mansour; Ahmadi-Noubari, Hossein; Seyed Aghazadeh, Babak; Khadivi Heris, Hossein

    This paper explores the use of hierarchical structure for diagnosis of vocal fold disorders. The hierarchical structure is initially used to train different second-level classifiers. At the first level normal and pathological signals have been distinguished. Next, pathological signals have been classified into neurogenic and organic vocal fold disorders. At the final level, vocal fold nodules have been distinguished from polyps in organic disorders category. For feature selection at each level of hierarchy, the reconstructed signal at each wavelet packet decomposition sub-band in 5 levels of decomposition with mother wavelet of (db10) is used to extract the nonlinear features of self-similarity and approximate entropy. Also, wavelet packet coefficients are used to measure energy and Shannon entropy features at different spectral sub-bands. Davies-Bouldin criterion has been employed to find the most discriminant features. Finally, support vector machines have been adopted as classifiers at each level of hierarchy resulting in the diagnosis accuracy of 92%.

  15. Thermostability in endoglucanases is fold-specific

    Science.gov (United States)

    2011-01-01

    Background Endoglucanases are usually considered to be synergistically involved in the initial stages of cellulose breakdown-an essential step in the bioprocessing of lignocellulosic plant materials into bioethanol. Despite their economic importance, we currently lack a basic understanding of how some endoglucanases can sustain their ability to function at elevated temperatures required for bioprocessing, while others cannot. In this study, we present a detailed comparative analysis of both thermophilic and mesophilic endoglucanases in order to gain insights into origins of thermostability. We analyzed the sequences and structures for sets of endoglucanase proteins drawn from the Carbohydrate-Active enZymes (CAZy) database. Results Our results demonstrate that thermophilic endoglucanases and their mesophilic counterparts differ significantly in their amino acid compositions. Strikingly, these compositional differences are specific to protein folds and enzyme families, and lead to differences in intramolecular interactions in a fold-dependent fashion. Conclusions Here, we provide fold-specific guidelines to control thermostability in endoglucanases that will aid in making production of biofuels from plant biomass more efficient. PMID:21291533

  16. Thermostability in endoglucanases is fold-specific

    Directory of Open Access Journals (Sweden)

    Wolt Jeffrey D

    2011-02-01

    Full Text Available Abstract Background Endoglucanases are usually considered to be synergistically involved in the initial stages of cellulose breakdown-an essential step in the bioprocessing of lignocellulosic plant materials into bioethanol. Despite their economic importance, we currently lack a basic understanding of how some endoglucanases can sustain their ability to function at elevated temperatures required for bioprocessing, while others cannot. In this study, we present a detailed comparative analysis of both thermophilic and mesophilic endoglucanases in order to gain insights into origins of thermostability. We analyzed the sequences and structures for sets of endoglucanase proteins drawn from the Carbohydrate-Active enZymes (CAZy database. Results Our results demonstrate that thermophilic endoglucanases and their mesophilic counterparts differ significantly in their amino acid compositions. Strikingly, these compositional differences are specific to protein folds and enzyme families, and lead to differences in intramolecular interactions in a fold-dependent fashion. Conclusions Here, we provide fold-specific guidelines to control thermostability in endoglucanases that will aid in making production of biofuels from plant biomass more efficient.

  17. Araguaia fold belt, new geochronological data

    International Nuclear Information System (INIS)

    Lafon, J.M.; Macambira, J.B.; Macambira, M.J.B.; Moura, C.A.V.; Souza, A.C.C.

    1990-01-01

    The northern part of the Araguaia Fold Belt (AFB) outcrops in a N-S direction for about 400 km in the state of Tocantins. Dome-like structures occur in this fold belt also in a N-S direction. Both deformation and metamorphism increase from the West to the East. The basement of the AFB consist of Colmeia complex and Cantao gneiss, which crop out mainly in the core of the dome-like structures. The supracrustals rocks of the fold belt belongs to the Baixo Araguaia supergroup which is divided into the lower Estrondo group and the upper Tocantins group. Preliminary Sm-Nd data from the Colmeia complex (Grota Rica dome) gave Archean model ages of 2.8 Ga (TNd sub(DM)) while Rb-Sr data in the same rocks give an age of 2530 ± 200 Ma. In the others dome-like structures, the Rb-Sr systematics gave ages for the Colmeia a complex of 2239 ± 47 Ma (Colmeia structure) and 1972 ± 46 Ma (Lontra structure). These younger ages are believed to represent partial to total isotopic resetting of the Rb-Sr system during the Transamazonian Event. The Rb-Sr studies of the Cantao gneiss gave an age of 1774 ± 31 Ma. (author)

  18. The Influence of Fold and Fracture Development on Reservoir Behavior of the Lisburne Group of Northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wallace, Wesley K.; Hanks, Catherine L.; Whalen, Michael T.; Jensen1, Jerry; Shackleton, J. Ryan; Jadamec, Margarete A.; McGee, Michelle M.; Karpov1, Alexandre V.

    2001-07-23

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively underformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults, (2) The influence of folding on fracture patterns, (3) The influence of deformation on fluid flow, and (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics.

  19. Orogen-transverse tectonic window in the Eastern Himalayan fold belt: A superposed buckling model

    Science.gov (United States)

    Bose, Santanu; Mandal, Nibir; Acharyya, S. K.; Ghosh, Subhajit; Saha, Puspendu

    2014-09-01

    The Eastern Lesser Himalayan fold-thrust belt is punctuated by a row of orogen-transverse domal tectonic windows. To evaluate their origin, a variety of thrust-stack models have been proposed, assuming that the crustal shortening occurred dominantly by brittle deformations. However, the Rangit Window (RW) in the Darjeeling-Sikkim Himalaya (DSH) shows unequivocal structural imprints of ductile deformations of multiple episodes. Based on new structural maps, coupled with outcrop-scale field observations, we recognize at least four major episodes of folding in the litho-tectonic units of DSH. The last episode has produced regionally orogen-transverse upright folds (F4), the interference of which with the third-generation (F3) orogen-parallel folds has shaped the large-scale structural patterns in DSH. We propose a new genetic model for the RW, invoking the mechanics of superposed buckling in the mechanically stratified litho-tectonic systems. We substantiate this superposed buckling model with results obtained from analogue experiments. The model explains contrasting F3-F4 interferences in the Lesser Himalayan Sequence (LHS). The lower-order (terrain-scale) folds have undergone superposed buckling in Mode 1, producing large-scale domes and basins, whereas the RW occurs as a relatively higher-order dome nested in the first-order Tista Dome. The Gondwana and the Proterozoic rocks within the RW underwent superposed buckling in Modes 3 and 4, leading to Type 2 fold interferences, as evident from their structural patterns.

  20. Functional results after external vocal fold medialization thyroplasty with the titanium vocal fold medialization implant.

    Science.gov (United States)

    Schneider, Berit; Denk, Doris-Maria; Bigenzahn, Wolfgang

    2003-04-01

    A persistent insufficiency of glottal closure is mostly a consequence of a unilateral vocal fold movement impairment. It can also be caused by vocal fold atrophy or scarring processes with regular bilateral respiratory vocal fold function. Because of consequential voice, breathing, and swallowing impairments, a functional surgical treatment is required. The goal of the study was to outline the functional results after medialization thyroplasty with the titanium vocal fold medialization implant according to Friedrich. In the period of 1999 to 2001, an external vocal fold medialization using the titanium implant was performed on 28 patients (12 women and 16 men). The patients were in the age range of 19 to 84 years. Twenty-two patients had a paralysis of the left-side vocal fold, and six patients, of the right-side vocal fold. Detailed functional examinations were executed on all patients before and after the surgery: perceptive voice sound analysis according to the "roughness, breathiness, and hoarseness" method, judgment of the s/z ratio and voice dysfunction index, voice range profile measurements, videostroboscopy, and pulmonary function tests. In case of dysphagia/aspiration, videofluoroscopy of swallowing was also performed. The respective data were statistically analyzed (paired t test, Wilcoxon-test). All patients reported on improvement of voice, swallowing, and breathing functions postoperatively. Videostroboscopy revealed an almost complete glottal closure after surgery in all of the patients. All voice-related parameters showed a significant improvement. An increase of the laryngeal resistance by the medialization procedure could be excluded by analysis of the pulmonary function test. The results confirm the external medialization of the vocal folds as an adequate method in the therapy of voice, swallowing, and breathing impairment attributable to an insufficient glottal closure. The titanium implant offers, apart from good tissue tolerability, the

  1. Structural analysis of sheath folds in the Sylacauga Marble Group, Talladega slate belt, southern Appalachians

    Science.gov (United States)

    Mies, J.W.

    1993-01-01

    Remnant blocks of marble from the Moretti-Harrah dimension-stone quarry provide excellent exposure of meter-scale sheath folds. Tubular structures with elliptical cross-sections (4 ???Ryz ??? 5) are the most common expression of the folds. The tubes are elongate subparallel to stretching lineation and are defined by centimeter-scale layers of schist. Eccentrically nested elliptical patterns and opposing asymmetry of folds ('S' and 'Z') are consistent with the sheath-fold interpretation. Sheath folds are locally numerous in the Moretti-Harrah quarry but are not widely distributed in the Sylacauga Marble Group; reconnaissance in neighboring quarries provided no additional observations. The presence of sheath folds in part of the Talladega slate belt indicates a local history of plastic, non-coaxial deformation. Such a history of deformation is substantiated by petrographic study of an extracted hinge from the Moretti-Harrah quarry. The sheath folds are modeled as due to passive amplification of initial structures during simple shear, using both analytic geometry and graphic simulation. As indicated by these models, relatively large shear strains (y ??? 9) and longitudinal initial structures are required. The shear strain presumably relates to NW-directed displacement of overlying crystalline rocks during late Paleozoic orogeny. ?? 1993.

  2. Glass ionomer application for vocal fold augmentation: Histopathological analysis on rabbit vocal fold.

    Science.gov (United States)

    Demirci, Sule; Tuzuner, Arzu; Callıoglu, Elif Ersoy; Yumusak, Nihat; Arslan, Necmi; Baltacı, Bülent

    2016-04-01

    The aim of this study was to investigate the use of glass ionomer cement (GIC) as an injection material for vocal fold augmentation and to evaluate the biocompatibility of the material. Ten adult New Zealand rabbits were used. Under general anesthesia, 0.1-cc GIC was injected to one vocal fold and the augmentation of vocal fold was observed. No injection was applied to the opposite side, which was accepted as the control group. The animals were sacrificed after 3 months and the laryngeal specimens were histopathologically evaluated. The injected and the noninjected control vocal folds were analyzed. The GIC particles were observed in histological sections on the injected side, and no foreign body giant cells, granulomatous inflammation, necrosis, or marked chronic inflammation were detected around the glass ionomer particles. Mild inflammatory reactions were noticed in only two specimens. The noninjected sides of vocal folds were completely normal. The findings of this study suggest that GIC is biocompatible and may be further investigated as an alternative injection material for augmentation of the vocal fold. Further studies are required to examine the viscoelastic properties of GIC and the long-term effects in experimental studies. NA. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  3. The effect of residual stress relaxation by the vibratory stress relief technique on the textures of grains in AA 6061 aluminum alloy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Jia-Siang; Hsieh, Chih-Chun; Lin, Chi-Ming; Chen, Erh-Chiang; Kuo, Che-Wei; Wu, Weite, E-mail: wwu@dragon.nchu.edu.tw

    2014-05-01

    The textures and crystallographic orientations beneath the treatment area in AA 6061 aluminum alloy after vibratory stress relief (VSR) process were investigated by combining the electron backscatter diffraction analysis of the misoriented low- or high-angle boundaries, the (inverse) pole figures, the line scans and the various grain orientations. The relaxation effect caused by compressive residual stress in the intermediate region is superior to that of tensile residual stress on both sides of the cantilever by means of X-ray diffraction techniques. The residual stress relaxation that occurs due to vibrational stress excitation accompanies the “orientation of banding” disintegration, the decreases in the dislocation density, the strain energy, and the fraction of low-angle boundaries within each type of grain orientation, such as Copper {112} 〈111〉, S {123} 〈634〉, Goss {110} 〈001〉, and Brass {110} 〈112〉, excepting the Cube (or near-Cube) {100} 〈001〉 grain orientation. The maintained invariance in the Cube texture can be attributed to the maximum number of active primary slip systems, resulting in an interaction that results from hindered slip on intersecting families of the planes.

  4. The effect of residual stress relaxation by the vibratory stress relief technique on the textures of grains in AA 6061 aluminum alloy

    International Nuclear Information System (INIS)

    Wang, Jia-Siang; Hsieh, Chih-Chun; Lin, Chi-Ming; Chen, Erh-Chiang; Kuo, Che-Wei; Wu, Weite

    2014-01-01

    The textures and crystallographic orientations beneath the treatment area in AA 6061 aluminum alloy after vibratory stress relief (VSR) process were investigated by combining the electron backscatter diffraction analysis of the misoriented low- or high-angle boundaries, the (inverse) pole figures, the line scans and the various grain orientations. The relaxation effect caused by compressive residual stress in the intermediate region is superior to that of tensile residual stress on both sides of the cantilever by means of X-ray diffraction techniques. The residual stress relaxation that occurs due to vibrational stress excitation accompanies the “orientation of banding” disintegration, the decreases in the dislocation density, the strain energy, and the fraction of low-angle boundaries within each type of grain orientation, such as Copper {112} 〈111〉, S {123} 〈634〉, Goss {110} 〈001〉, and Brass {110} 〈112〉, excepting the Cube (or near-Cube) {100} 〈001〉 grain orientation. The maintained invariance in the Cube texture can be attributed to the maximum number of active primary slip systems, resulting in an interaction that results from hindered slip on intersecting families of the planes

  5. What determines the structures of native folds of proteins?

    International Nuclear Information System (INIS)

    Trovato, Antonio; Hoang, Trinh X; Banavar, Jayanth R; Maritan, Amos; Seno, Flavio

    2005-01-01

    We review a simple physical model (Hoang et al 2004 Proc. Natl Acad. Sci. USA 101 7960, Banavar et al 2004 Phys. Rev. E at press) which captures the essential physico-chemical ingredients that determine protein structure, such as the inherent anisotropy of a chain molecule, the geometrical and energetic constraints placed by hydrogen bonds, sterics, and hydrophobicity. Within this framework, marginally compact conformations resembling the native state folds of proteins emerge as competing minima in the free energy landscape. Here we demonstrate that a hydrophobic-polar (HP) sequence composed of regularly repeated patterns has as its ground state a β-helical structure remarkably similar to a known architecture in the Protein Data Bank

  6. The effect of vocal tract impedance on the vocal folds

    DEFF Research Database (Denmark)

    Agerkvist, Finn T.; Selamtzis, Andreas

    2011-01-01

    frontend is used to measure the electroglottograph signal which reflects the opening and closing pattern of the vocal folds. The measurements were carried out for all four modes (Neutral, Curbing, Overdrive and Edge) for the vowel [a] in three different pitches: C3(131 Hz), G3 (196 Hz) and C4 (262Hz......The importance of the interaction between the acoustic impedance of the vocal tract with the flow across the vocal cords is well established. In this paper we are investigating the changes in vocal tract impedance when using the different modes of phonation according to Sadolin [1], going from...... the soft levels of the Neutral mode to the high levels of the fully ‘metallic’ Edge mode. The acoustic impedance of vocal tract as seen from the mouth opening is measured via a microphone placed close to the mouth when exciting the system with a volume velocity source [2]. At the same time a Laryngograph...

  7. Nanoscale Dewetting Transition in Protein Complex Folding

    Science.gov (United States)

    Hua, Lan; Huang, Xuhui; Liu, Pu; Zhou, Ruhong; Berne, Bruce J.

    2011-01-01

    In a previous study, a surprising drying transition was observed to take place inside the nanoscale hydrophobic channel in the tetramer of the protein melittin. The goal of this paper is to determine if there are other protein complexes capable of displaying a dewetting transition during their final stage of folding. We searched the entire protein data bank (PDB) for all possible candidates, including protein tetramers, dimers, and two-domain proteins, and then performed the molecular dynamics (MD) simulations on the top candidates identified by a simple hydrophobic scoring function based on aligned hydrophobic surface areas. Our large scale MD simulations found several more proteins, including three tetramers, six dimers, and two two-domain proteins, which display a nanoscale dewetting transition in their final stage of folding. Even though the scoring function alone is not sufficient (i.e., a high score is necessary but not sufficient) in identifying the dewetting candidates, it does provide useful insights into the features of complex interfaces needed for dewetting. All top candidates have two features in common: (1) large aligned (matched) hydrophobic areas between two corresponding surfaces, and (2) large connected hydrophobic areas on the same surface. We have also studied the effect on dewetting of different water models and different treatments of the long-range electrostatic interactions (cutoff vs PME), and found the dewetting phenomena is fairly robust. This work presents a few proteins other than melittin tetramer for further experimental studies of the role of dewetting in the end stages of protein folding. PMID:17608515

  8. Incremental fold tests of remagnetized carbonate rocks

    Science.gov (United States)

    Van Der Voo, R.; van der Pluijm, B.

    2017-12-01

    Many unmetamorphosed carbonates all over the world are demonstrably remagnetized, with the age of the secondary magnetizations typically close to that of the nearest orogeny in space and time. This observation did not become compelling until the mid-1980's, when the incremental fold test revealed the Appalachian carbonates to carry a syn-deformational remanence of likely Permian age (Scotese et al., 1982, Phys. Earth Planet. Int., v. 30, p. 385-395; Cederquist et al., 2006, Tectonophysics v. 422, p. 41-54). Since that time scores of Appalachian and Rocky Mountain carbonate rocks have added results to the growing database of paleopoles representing remagnetizations. Late Paleozoic remagnetizations form a cloud of results surrounding the reference poles of the Laurentian APWP. Remagnetizations in other locales and with inferred ages coeval with regional orogenies (e.g., Taconic, Sevier/Laramide, Variscan, Indosinian) are also ubiquitous. To be able to transform this cornucopia into valuable anchor-points on the APWP would be highly desirable. This may indeed become feasible, as will be explained next. Recent studies of faulted and folded carbonate-shale sequences have shown that this deformation enhances the illitization of smectite (Haines & van der Pluijm, 2008, Jour. Struct. Geol., v. 30, p. 525-538; Fitz-Diaz et al., 2014, International Geol. Review, v. 56, p. 734-755). 39Ar-40Ar dating of the authigenic illite (neutralizing any detrital illite contribution by taking the intercept of a mixing line) yields, therefore, the age of the deformation. We know that this date is also the age of the syndeformational remanence; thus we have the age of the corresponding paleopole. Results so far are obtained for the Canadian and U.S. Rocky Mountains and for the Spanish Cantabrian carbonates (Tohver et al., 2008, Earth Planet. Sci. Lett., v. 274, p. 524-530) and make good sense in accord with geological knowledge. Incremental fold tests are the tools used for this

  9. Synovial folds in the knee joint

    International Nuclear Information System (INIS)

    Schaefer, H.

    1987-01-01

    Stimulated by arthroscopic insight into central abnormalities of the knee joint and by the large number of unexplained case of 'anterior knee pain', we have studied the synovia in more than 2000 contrast examinations of the joint. Surprisingly, and contrary to the views expressed in the literature, the clinically significant plica parapatellaris medialis was seen as frequently during pneumo-arthrography as during more complex procedures. Abnormalities in the synovial fold emerged as a discreet disease identified as the 'medial shelf syndrome' and should be included in the differential diagnosis of causes of pain round the lower end of the femur and patella. (orig.) [de

  10. Eight-fold quantum states blossom in a high-temperature superconductor

    CERN Multimedia

    2003-01-01

    "Researchers based at Lawrence Berkeley National Laboratory and the University of California at Berkeley have used a scanning tunneling microscope (STM) to reveal eight-fold patterns of quasiparticle interference in the high-temperature superconductor Bi-2212 (bismuth strontium calcium copper oxide)" (2 pages).

  11. Folding model analysis of alpha radioactivity

    International Nuclear Information System (INIS)

    Basu, D N

    2003-01-01

    Radioactive decay of nuclei via emission of α-particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the α-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the α nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic α-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields calculations for the half-lives of α decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations provide reasonable estimates for the lifetimes of α-radioactivity of nuclei

  12. Three-Dimensional Growth of Flexural Slip Fault-Bend and Fault-Propagation Folds and Their Geomorphic Expression

    Directory of Open Access Journals (Sweden)

    Asdrúbal Bernal

    2018-03-01

    latter mode of fold growth may be more common. The advective component of deformation (implicit in kink-band migration models of fault-bend and fault-propagation folding exerts a strong control on drainage basin development. In particular, as drainage lengthens with fold growth, more linear, parallel drainage networks are developed as compared to the dendritic patterns developed above simple uplifting structures. Over the 1 Ma of their development the folds modelled here only attain partial topographic equilibrium, as new material is continually being advected through active axial surfaces on both fold limbs and faults are propagating in both the transport and strike directions. We also find that the position of drainage divides at the Earth’s surface has a complex relationship to the underlying fold axial surface locations.

  13. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    Energy Technology Data Exchange (ETDEWEB)

    Wesley K. Wallace; Catherine L. Hanks; Michael T. Whalen; Jerry Jensen; Paul K. Atkinson; Joseph S. Brinton

    2000-05-01

    The Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding and lithostratigraphy on fracture patterns. (3) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. (4) The influence of lithostratigraphy and deformation on fluid flow. The results of field work during the summer of 1999 offer some preliminary insights: The Lisburne Limestone displays a range of symmetrical detachment fold geometries throughout the northeastern Brooks Range. The variation in fold geometry suggests a generalized progression in fold geometry with increasing shortening: Straight-limbed, narrow-crested folds at low shortening, box folds at intermediate shortening, and folds with a large height-to-width ratio and thickened hinges at high shortening. This sequence is interpreted to represent a progressive change in the dominant shortening mechanism from flexural-slip at low shortening to bulk strain at higher shortening. Structural variations in bed thickness occur throughout this progression. Parasitic folding accommodates structural thickening at low shortening and is gradually succeeded by penetrative strain as shortening increases. The amount of structural thickening at low to intermediate shortening may be inversely related to the local amount of structural thickening of the Kayak Shale, the incompetent unit that underlies the Lisburne. The Lisburne Limestone displays a different structural style in the south, across the boundary between the northeastern Brooks Range and the main axis of the Brooks Range fold

  14. SVM-Fold: a tool for discriminative multi-class protein fold and superfamily recognition.

    Science.gov (United States)

    Melvin, Iain; Ie, Eugene; Kuang, Rui; Weston, Jason; Stafford, William Noble; Leslie, Christina

    2007-05-22

    Predicting a protein's structural class from its amino acid sequence is a fundamental problem in computational biology. Much recent work has focused on developing new representations for protein sequences, called string kernels, for use with support vector machine (SVM) classifiers. However, while some of these approaches exhibit state-of-the-art performance at the binary protein classification problem, i.e. discriminating between a particular protein class and all other classes, few of these studies have addressed the real problem of multi-class superfamily or fold recognition. Moreover, there are only limited software tools and systems for SVM-based protein classification available to the bioinformatics community. We present a new multi-class SVM-based protein fold and superfamily recognition system and web server called SVM-Fold, which can be found at http://svm-fold.c2b2.columbia.edu. Our system uses an efficient implementation of a state-of-the-art string kernel for sequence profiles, called the profile kernel, where the underlying feature representation is a histogram of inexact matching k-mer frequencies. We also employ a novel machine learning approach to solve the difficult multi-class problem of classifying a sequence of amino acids into one of many known protein structural classes. Binary one-vs-the-rest SVM classifiers that are trained to recognize individual structural classes yield prediction scores that are not comparable, so that standard "one-vs-all" classification fails to perform well. Moreover, SVMs for classes at different levels of the protein structural hierarchy may make useful predictions, but one-vs-all does not try to combine these multiple predictions. To deal with these problems, our method learns relative weights between one-vs-the-rest classifiers and encodes information about the protein structural hierarchy for multi-class prediction. In large-scale benchmark results based on the SCOP database, our code weighting approach

  15. Fabrication and characterization of self-folding thermoplastic sheets using unbalanced thermal shrinkage.

    Science.gov (United States)

    Danielson, Christian; Mehrnezhad, Ali; YekrangSafakar, Ashkan; Park, Kidong

    2017-06-14

    Self-folding or micro-origami technologies are actively investigated as a novel manufacturing process to fabricate three-dimensional macro/micro-structures. In this paper, we present a simple process to produce a self-folding structure with a biaxially oriented polystyrene sheet (BOPS) or Shrinky Dinks. A BOPS sheet is known to shrink to one-third of its original size in plane, when it is heated above 160 °C. A grid pattern is engraved on one side of the BOPS film with a laser engraver to decrease the thermal shrinkage of the engraved side. The thermal shrinkage of the non-engraved side remains the same and this unbalanced thermal shrinkage causes folding of the structure as the structure shrinks at high temperature. We investigated the self-folding mechanism and characterized how the grid geometry, the grid size, and the power of the laser engraver affect the bending curvature. The developed fabrication process to locally modulate thermomechanical properties of the material by engraving the grid pattern and the demonstrated design methodology to harness the unbalanced thermal shrinkage can be applied to develop complicated self-folding macro/micro structures.

  16. Effects of thermo-mechanical behavior and hinge geometry on folding response of shape memory polymer sheets

    Science.gov (United States)

    Mailen, Russell W.; Dickey, Michael D.; Genzer, Jan; Zikry, Mohammed

    2017-11-01

    Shape memory polymer (SMP) sheets patterned with black ink hinges change shape in response to external stimuli, such as absorbed thermal energy from an infrared (IR) light. The geometry of these hinges, including size, orientation, and location, and the applied thermal loads significantly influence the final folded shape of the sheet, but these variables have not been fully investigated. We perform a systematic study on SMP sheets to fundamentally understand the effects of single and double hinge geometries, hinge orientation and spacing, initial temperature, heat flux intensity, and pattern width on the folding behavior. We have developed thermo-viscoelastic finite element models to characterize and quantify the stresses, strains, and temperatures as they relate to SMP shape changes. Our predictions indicate that hinge orientation can be used to reduce the total bending angle, which is the angle traversed by the folding face of the sheet. Two parallel hinges increase the total bending angle, and heat conduction between the hinges affects the transient folding response. IR intensity and initial temperatures can also influence the transient folding behavior. These results can provide guidelines to optimize the transient folding response and the three-dimensional folded structure obtained from self-folding polymer origami sheets that can be applied for myriad applications.

  17. Dysphonia and vocal fold telangiectasia in hereditary hemorrhagic telangiectasia.

    Science.gov (United States)

    Chang, Joseph; Yung, Katherine C

    2014-11-01

    This case report is the first documentation of dysphonia and vocal fold telangiectasia as a complication of hereditary hemorrhagic telangiectasia (HHT). Case report of a 40-year-old man with HHT presenting with 2 years of worsening hoarseness. Hoarseness corresponded with a period of anticoagulation. Endoscopy revealed vocal fold scarring, vocal fold telangiectasias, and plica ventricular is suggestive of previous submucosal vocal fold hemorrhage and subsequent counterproductive compensation with ventricular phonation. Hereditary hemorrhagic telangiectasia may present as dysphonia with vocal fold telangiectasias and place patients at risk of vocal fold hemorrhage. © The Author(s) 2014.

  18. Fluvial-Deltaic Strata as a High-Resolution Recorder of Fold Growth and Fault Slip

    Science.gov (United States)

    Anastasio, D. J.; Kodama, K. P.; Pazzaglia, F. P.

    2008-12-01

    Fluvial-deltaic systems characterize the depositional record of most wedge-top and foreland basins, where the synorogenic stratigraphy responds to interactions between sediment supply driven by tectonic uplift, climate modulated sea level change and erosion rate variability, and fold growth patterns driven by unsteady fault slip. We integrate kinematic models of fault-related folds with growth strata and fluvial terrace records to determine incremental rates of shortening, rock uplift, limb tilting, and fault slip with 104-105 year temporal resolution in the Pyrenees and Apennines. At Pico del Aguila anticline, a transverse dècollement fold along the south Pyrenean mountain front, formation-scale synorogenic deposition and clastic facies patterns in prodeltaic and slope facies reflect tectonic forcing of sediment supply, sea level variability controlling delta front position, and climate modulated changes in terrestrial runoff. Growth geometries record a pinned anticline and migrating syncline hinges during folding above the emerging Guarga thrust sheet. Lithologic and anhysteretic remanent magnetization (ARM) data series from the Eocene Arguis Fm. show cyclicity at Milankovitch frequencies allowing detailed reconstruction of unsteady fold growth. Multiple variations in limb tilting rates from roof ramp and basal dècollement. Along the northern Apennine mountain front, the age and geometry of strath terraces preserved across the Salsomaggiore anticline records the Pleistocene-Recent kinematics of the underlying fault-propagation fold as occurring with a fixed anticline hinge, a rolling syncline hinge, and along-strike variations in uplift and forelimb tilting. The uplifted intersection of terrace deposits documents syncline axial surface migration and underlying fault-tip propagation at a rate of ~1.4 cm/yr since the Middle Pleistocene. Because this record of fault slip coincides with the well-known large amplitude oscillations in global climate that contribute

  19. Investigation of hindwing folding in ladybird beetles by artificial elytron transplantation and microcomputed tomography.

    Science.gov (United States)

    Saito, Kazuya; Nomura, Shuhei; Yamamoto, Shuhei; Niiyama, Ryuma; Okabe, Yoji

    2017-05-30

    Ladybird beetles are high-mobility insects and explore broad areas by switching between walking and flying. Their excellent wing transformation systems enabling this lifestyle are expected to provide large potential for engineering applications. However, the mechanism behind the folding of their hindwings remains unclear. The reason is that ladybird beetles close the elytra ahead of wing folding, preventing the observation of detailed processes occurring under the elytra. In the present study, artificial transparent elytra were transplanted on living ladybird beetles, thereby enabling us to observe the detailed wing-folding processes. The result revealed that in addition to the abdominal movements mentioned in previous studies, the edge and ventral surface of the elytra, as well as characteristic shaped veins, play important roles in wing folding. The structures of the wing frames enabling this folding process and detailed 3D shape of the hindwing were investigated using microcomputed tomography. The results showed that the tape spring-like elastic frame plays an important role in the wing transformation mechanism. Compared with other beetles, hindwings in ladybird beetles are characterized by two seemingly incompatible properties: ( i ) the wing rigidity with relatively thick veins and ( ii ) the compactness in stored shapes with complex crease patterns. The detailed wing-folding process revealed in this study is expected to facilitate understanding of the naturally optimized system in this excellent deployable structure.

  20. Vocal Fold Immobility due to Birth Trauma: A Systematic Review and Pooled Analysis.

    Science.gov (United States)

    Jabbour, Jad; North, Lauren M; Bougie, David; Robey, Thomas

    2017-12-01

    Objectives To describe the present understanding of birth trauma-related vocal fold immobility and quantitatively compare it with idiopathic congenital vocal fold immobility to explore whether it is a discrete entity. Data Sources PubMed, Ovid, and Cochrane databases. Review Methods English-language, observational, or experimental studies involving infants with idiopathic congenital or birth trauma-related vocal fold immobility were included. Data from these studies were pooled with our institution's vocal fold immobility database, with the resultant idiopathic congenital and birth trauma cohorts compared regarding patterns and outcomes of immobility. Results The search returned 288 articles, with 24 meeting inclusion criteria. Of studies reviewing all-cause immobility, 8 of 9 (88.9%) identified birth trauma as an etiology, although birth trauma definitions and proposed mechanisms of immobility varied. The study subjects, combined with our institution's database, yielded 188 idiopathic congenital and 113 birth trauma cases. Compared with idiopathic congenital cases, birth trauma cases had a higher proportion of unilateral immobility (72 of 113 [63.7%] vs 52 of 188 [27.7%], P vocal fold immobility warrant further investigation, these findings suggest that it is distinct from idiopathic congenital vocal fold immobility, with a unique presentation and potentially more favorable outcomes. This can inform counseling and management for infants with otherwise unexplained immobility but known birth trauma.

  1. Improving decoy databases for protein folding algorithms

    KAUST Repository

    Lindsey, Aaron

    2014-01-01

    Copyright © 2014 ACM. Predicting protein structures and simulating protein folding are two of the most important problems in computational biology today. Simulation methods rely on a scoring function to distinguish the native structure (the most energetically stable) from non-native structures. Decoy databases are collections of non-native structures used to test and verify these functions. We present a method to evaluate and improve the quality of decoy databases by adding novel structures and removing redundant structures. We test our approach on 17 different decoy databases of varying size and type and show significant improvement across a variety of metrics. We also test our improved databases on a popular modern scoring function and show that they contain a greater number of native-like structures than the original databases, thereby producing a more rigorous database for testing scoring functions.

  2. Folded tandem ion accelerator facility at BARC

    International Nuclear Information System (INIS)

    Agarwal, Arun; Padmakumar, Sapna; Subrahmanyam, N.B.V.; Singh, V.P.; Bhatt, J.P.; Ware, Shailaja V.; Pol, S.S; Basu, A.; Singh, S.K.; Krishnagopal, S.; Bhagwat, P.V.

    2017-01-01

    The 5.5 MV single stage Van de Graaff (VDG) accelerator was in continuous operation at Nuclear Physics Division (NPD), Bhabha Atomic Research Centre (BARC) since its inception in 1962. During 1993-96, VDG accelerator was converted to a Folded Tandem Ion Accelerator (FOTIA). The scientists and engineers of NPD, IADD (then a part of NPD) along with several other divisions of BARC joined hands together in designing, fabrication, installation and commissioning of the FOTIA for the maximum terminal voltage of 6 MV. After experiencing the first accelerated ion beam on the target from FOTIA during April 2000, different ion species were accelerated and tested. Now this accelerator FOTIA is in continuous use for different kind of experiments

  3. Electrotransfection of Polyamine Folded DNA Origami Structures.

    Science.gov (United States)

    Chopra, Aradhana; Krishnan, Swati; Simmel, Friedrich C

    2016-10-12

    DNA origami structures are artificial molecular nanostructures in which DNA double helices are forced into a closely packed configuration by a multitude of DNA strand crossovers. We show that three different types of origami structures (a flat sheet, a hollow tube, and a compact origami block) can be formed in magnesium-free buffer solutions containing low (origami folding is proportional to the DNA concentration. At excessive amounts, the structures aggregate and precipitate. In contrast to origami structures formed in conventional buffers, the resulting structures are stable in the presence of high electric field pulses, such as those commonly used for electrotransfection experiments. We demonstrate that spermidine-stabilized structures are stable in cell lysate and can be delivered into mammalian cells via electroporation.

  4. Some physical approaches to protein folding

    Science.gov (United States)

    Bascle, J.; Garel, T.; Orland, H.

    1993-02-01

    To understand how a protein folds is a problem which has important biological implications. In this article, we would like to present a physics-oriented point of view, which is twofold. First of all, we introduce simple statistical mechanics models which display, in the thermodynamic limit, folding and related transitions. These models can be divided into (i) crude spin glass-like models (with their Mattis analogs), where one may look for possible correlations between the chain self-interactions and the folded structure, (ii) glass-like models, where one emphasizes the geometrical competition between one- or two-dimensional local order (mimicking α helix or β sheet structures), and the requirement of global compactness. Both models are too simple to predict the spatial organization of a realistic protein, but are useful for the physicist and should have some feedback in other glassy systems (glasses, collapsed polymers .... ). These remarks lead us to the second physical approach, namely a new Monte-Carlo method, where one grows the protein atom-by-atom (or residue-by-residue), using a standard form (CHARMM .... ) for the total energy. A detailed comparison with other Monte-Carlo schemes, or Molecular Dynamics calculations, is then possible; we will sketch such a comparison for poly-alanines. Our twofold approach illustrates some of the difficulties one encounters in the protein folding problem, in particular those associated with the existence of a large number of metastable states. Le repliement des protéines est un problème qui a de nombreuses implications biologiques. Dans cet article, nous présentons, de deux façons différentes, un point de vue de physicien. Nous introduisons tout d'abord des modèles simples de mécanique statistique qui exhibent, à la limite thermodynamique, des transitions de repliement. Ces modèles peuvent être divisés en (i) verres de spin (éventuellement à la Mattis), où l'on peut chercher des corrélations entre les

  5. Folded Sheet Versus Transparent Sheet Models for Human Symmetry Judgments

    Directory of Open Access Journals (Sweden)

    Jacques Ninio

    2011-07-01

    Full Text Available As a contribution to the mysteries of human symmetry perception, reaction time data were collected on the detection of symmetry or repetition violations, in the context of short term visual memory studies. The histograms for reaction time distributions are rather narrow in the case of symmetry judgments. Their analysis was performed in terms of a simple kinetic model of a mental process in two steps, a slow one for the construction of the representation of the images to be compared, and a fast one, in the 50 ms range, for the decision. There was no need for an additional ‘mental rotation’ step. Symmetry seems to facilitate the construction step. I also present here original stimuli showing a color equalization effect across a symmetry axis, and its counterpart in periodic patterns. According to a “folded sheet model”, when a shape is perceived, the brain automatically constructs a mirror-image representation of the shape. Based in part on the reaction time analysis, I present here an alternative “transparent sheet” model in which the brain constructs a single representation, which can be accessed from two sides, thus generating simultaneously a pattern and its mirror-symmetric partner. Filtering processes, implied by current models of symmetry perception could intervene at an early stage, by nucleating the propagation of similar perceptual groupings in the two symmetric images.

  6. Topologies to geometries in protein folding: Hierarchical and nonhierarchical scenarios

    Science.gov (United States)

    Fernández, Ariel; Colubri, Andrés; Berry, R. Stephen

    2001-04-01

    This work presents a method to portray protein folding dynamics at a coarse resolution, based on a pattern-recognition-and-feedback description of the evolution of torsional motions of the backbone chain in the hydrophobic collapse of the protein. The approach permits theory and computation to treat the search of conformation space from picoseconds to the millisecond time scale or longer, the time scales of adiabatic evolution of soft-mode dynamics. The procedure tracks the backbone torsional coordinates modulo the basins of attraction to which they belong in the Ramachandran maps. The state and history of the backbone are represented in a map of local torsional states and hydrophobicity/hydrophilicity matching of the residues comprising the chain, the local topology matrix (LTM). From this map, we infer allowable structural features by recognizing patterns in the LTM as topologically compatible with particular structural forms within a level of frustration tolerance. Each such 3D realization of an LTM leads to a contact map, from which one can infer one or more structures. Introduction of energetic and entropic terms allow elimination of all but the most favored of these structures at each new juncture. The method's predictive power is first established by comparing "final," stable LTMs for natural sequences of intermediate length (N⩽120) with PDB data. The method is extended further to β-lactoglobulin (β-LG, N=162), the quintessential nonhierarchical folder.

  7. Improving Protein Fold Recognition by Deep Learning Networks

    Science.gov (United States)

    Jo, Taeho; Hou, Jie; Eickholt, Jesse; Cheng, Jianlin

    2015-12-01

    For accurate recognition of protein folds, a deep learning network method (DN-Fold) was developed to predict if a given query-template protein pair belongs to the same structural fold. The input used stemmed from the protein sequence and structural features extracted from the protein pair. We evaluated the performance of DN-Fold along with 18 different methods on Lindahl’s benchmark dataset and on a large benchmark set extracted from SCOP 1.75 consisting of about one million protein pairs, at three different levels of fold recognition (i.e., protein family, superfamily, and fold) depending on the evolutionary distance between protein sequences. The correct recognition rate of ensembled DN-Fold for Top 1 predictions is 84.5%, 61.5%, and 33.6% and for Top 5 is 91.2%, 76.5%, and 60.7% at family, superfamily, and fold levels, respectively. We also evaluated the performance of single DN-Fold (DN-FoldS), which showed the comparable results at the level of family and superfamily, compared to ensemble DN-Fold. Finally, we extended the binary classification problem of fold recognition to real-value regression task, which also show a promising performance. DN-Fold is freely available through a web server at http://iris.rnet.missouri.edu/dnfold.

  8. Improving Protein Fold Recognition by Deep Learning Networks.

    Science.gov (United States)

    Jo, Taeho; Hou, Jie; Eickholt, Jesse; Cheng, Jianlin

    2015-12-04

    For accurate recognition of protein folds, a deep learning network method (DN-Fold) was developed to predict if a given query-template protein pair belongs to the same structural fold. The input used stemmed from the protein sequence and structural features extracted from the protein pair. We evaluated the performance of DN-Fold along with 18 different methods on Lindahl's benchmark dataset and on a large benchmark set extracted from SCOP 1.75 consisting of about one million protein pairs, at three different levels of fold recognition (i.e., protein family, superfamily, and fold) depending on the evolutionary distance between protein sequences. The correct recognition rate of ensembled DN-Fold for Top 1 predictions is 84.5%, 61.5%, and 33.6% and for Top 5 is 91.2%, 76.5%, and 60.7% at family, superfamily, and fold levels, respectively. We also evaluated the performance of single DN-Fold (DN-FoldS), which showed the comparable results at the level of family and superfamily, compared to ensemble DN-Fold. Finally, we extended the binary classification problem of fold recognition to real-value regression task, which also show a promising performance. DN-Fold is freely available through a web server at http://iris.rnet.missouri.edu/dnfold.

  9. RNAiFold: a web server for RNA inverse folding and molecular design.

    Science.gov (United States)

    Garcia-Martin, Juan Antonio; Clote, Peter; Dotu, Ivan

    2013-07-01

    Synthetic biology and nanotechnology are poised to make revolutionary contributions to the 21st century. In this article, we describe a new web server to support in silico RNA molecular design. Given an input target RNA secondary structure, together with optional constraints, such as requiring GC-content to lie within a certain range, requiring the number of strong (GC), weak (AU) and wobble (GU) base pairs to lie in a certain range, the RNAiFold web server determines one or more RNA sequences, whose minimum free-energy secondary structure is the target structure. RNAiFold provides access to two servers: RNA-CPdesign, which applies constraint programming, and RNA-LNSdesign, which applies the large neighborhood search heuristic; hence, it is suitable for larger input structures. Both servers can also solve the RNA inverse hybridization problem, i.e. given a representation of the desired hybridization structure, RNAiFold returns two sequences, whose minimum free-energy hybridization is the input target structure. The web server is publicly accessible at http://bioinformatics.bc.edu/clotelab/RNAiFold, which provides access to two specialized servers: RNA-CPdesign and RNA-LNSdesign. Source code for the underlying algorithms, implemented in COMET and supported on linux, can be downloaded at the server website.

  10. Glycoprotein folding and quality-control mechanisms in protein-folding diseases

    Directory of Open Access Journals (Sweden)

    Sean P. Ferris

    2014-03-01

    Full Text Available Biosynthesis of proteins – from translation to folding to export – encompasses a complex set of events that are exquisitely regulated and scrutinized to ensure the functional quality of the end products. Cells have evolved to capitalize on multiple post-translational modifications in addition to primary structure to indicate the folding status of nascent polypeptides to the chaperones and other proteins that assist in their folding and export. These modifications can also, in the case of irreversibly misfolded candidates, signal the need for dislocation and degradation. The current Review focuses on the glycoprotein quality-control (GQC system that utilizes protein N-glycosylation and N-glycan trimming to direct nascent glycopolypeptides through the folding, export and dislocation pathways in the endoplasmic reticulum (ER. A diverse set of pathological conditions rooted in defective as well as over-vigilant ER quality-control systems have been identified, underlining its importance in human health and disease. We describe the GQC pathways and highlight disease and animal models that have been instrumental in clarifying our current understanding of these processes.

  11. Effect of Vocal Fold Medialization on Dysphagia in Patients with Unilateral Vocal Fold Immobility.

    Science.gov (United States)

    Cates, Daniel J; Venkatesan, Naren N; Strong, Brandon; Kuhn, Maggie A; Belafsky, Peter C

    2016-09-01

    The effect of vocal fold medialization (VFM) on vocal improvement in persons with unilateral vocal fold immobility (UVFI) is well established. The effect of VFM on the symptom of dysphagia is uncertain. The purpose of this study is to evaluate dysphagia symptoms in patients with UVFI pre- and post-VFM. Case series with chart review. Academic tertiary care medical center. The charts of 44 persons with UVFI who underwent VFM between June 1, 2013, and December 31, 2014, were abstracted from a prospectively maintained database at the University of California, Davis, Voice and Swallowing Center. Patient demographics, indications, and type of surgical procedure were recorded. Self-reported swallowing impairment was assessed with the validated 10-item Eating Assessment Tool (EAT-10) before and after surgery. A paired samples t test was used to compare pre- and postmedialization EAT-10 scores. Forty-four patients met criteria and underwent either vocal fold injection (73%) or thyroplasty (27%). Etiologies of vocal fold paralysis were iatrogenic (55%), idiopathic (29%), benign or malignant neoplastic (9%), traumatic (5%), or related to the late effects of radiation (2%). EAT-10 (mean ± SD) scores improved from 12.2 ± 11.1 to 7.7 ± 7.2 after medialization (P dysphagia and report significant improvement in swallowing symptoms following VFM. The symptomatic improvement appears to be durable over time. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2016.

  12. A single-stranded architecture for cotranscriptional folding of RNA nanostructures

    DEFF Research Database (Denmark)

    Geary, Cody; Rothemund, Paul; Andersen, Ebbe Sloth

    2014-01-01

    Artificial DNA and RNA structures have been used as scaffolds for a variety of nanoscale devices. In comparison to DNA structures, RNA structures have been limited in size, but they also have advantages: RNA can fold during transcription and thus can be genetically encoded and expressed in cells....... We introduce an architecture for designing artificial RNA structures that fold from a single strand, in which arrays of antiparallel RNA helices are precisely organized by RNA tertiary motifs and a new type of crossover pattern. We constructed RNA tiles that assemble into hexagonal lattices...

  13. NR4A1 is an endogenous inhibitor of vocal fold fibrosis.

    Science.gov (United States)

    Hiwatashi, Nao; Bing, Renjie; Kraja, Iv; Branski, Ryan C

    2017-09-01

    NR4A1 was recently identified as an endogenous inhibitor of transforming growth factor (TGF)-β-induced fibrosis, and the role of this nuclear receptor has not been elucidated in tissue health or the response to injury in the vocal folds. Given the clinical implications of vocal fold fibrosis, we investigated NR4A1 expression during vocal fold wound healing in vivo and the regulatory roles of NR4A1 on vocal fold fibroblasts (VFFs) in vitro with the ultimate goal of developing targeted therapies for this challenging patient population. In vivo and in vitro. In vivo, the temporal pattern of NR4A1 mRNA expression was quantified following rat vocal fold injury. In vitro, the role of NR4A1 on TGF-β1-mediated transcription of genes underlying fibrosis as well as myofibroblast differentiation and collagen gel contraction was quantified in our human VFF line. Small interfering RNA was employed to alter NR4A1 expression to further elucidate this complex system. Nr4a1 mRNA increased 1 day after injury and peaked at 7 days. Knockdown of NR4A1 resulted in upregulation of COL1A1 and TGF-β1, with TGF-β1 stimulation (both P vocal fold health or disease. Upregulation of TGF-β following vocal fold injury was concurrent with increased NR4A1 expression. These data provide a foundation for the development of therapeutic strategies given persistent TGF-β signaling in vocal fold fibrosis. N/A Laryngoscope, 127:E317-E323, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Geomorphology of the Southwest Coast of County Cork, Ireland: A Look into the Rocks, Folds, and Glacial Scours

    Science.gov (United States)

    Bowden, S.; Wireman, R.; Sautter, L.; Beutel, E. K.

    2015-12-01

    Bathymetric data were collected off the southwest coast of County Cork, Ireland by the joint INFOMAR project between the Marine Institute of Ireland and the Geologic Survey of Ireland. Data were collected using a Kongsberg EM2040 multibeam sonar on the R/V Celtic Voyager, in August and September 2014, and were post-processed with CARIS HIPS and SIPS 8.1 and 9.0 software to create 2D and 3D bathymetric surfaces. From the computer generated images, some of the lithologic formations were relatively aged and observed. The studied regions range in depth from 20 to 118 m, with shallower areas to the northeast. Several large rock outcrops occur, the larger of which shows a vertical rise of nearly 20 m. These outcrops are oriented in a northeast-southwest direction, and exhibit significant bed folding, regional folding, tilted beds, and cross joints. The folds studied are plunging chevron folds. These folds have a northeast-southwest fold axis orthogonal to the cross joints and are older relative to the jointing systems. The NE-SW joints are older than the NW-SE joints due to their correlation with drainage and erosion patterns. Regional folding is the youngest feature due to its superposition on the chevron folding and jointing systems. The interaction of cross jointing and folding is consistent with the geologic history of the area, and creates a unique bathymetry worthy of further study.

  15. Kinematics of large scale asymmetric folds and associated smaller ...

    Indian Academy of Sciences (India)

    The present work reiterates the importance of analysis of ... these models is the assumption that the folds are passive folds ... applicability of these models is thus limited in the case of ...... with contrasted rheological properties, a theory for the.

  16. Phonosurgery of vocal fold polyps, cysts and nodules is beneficial

    DEFF Research Database (Denmark)

    Jensen, Jane Bjerg; Rasmussen, Niels

    2013-01-01

    This study reports our experience with microscopic phonosurgery (PS) of benign lesions of the vocal folds.......This study reports our experience with microscopic phonosurgery (PS) of benign lesions of the vocal folds....

  17. Diagnostic and therapeutic pitfalls in benign vocal fold diseases

    Science.gov (United States)

    Bohlender, Jörg

    2013-01-01

    More than half of patients presenting with hoarseness show benign vocal fold changes. The clinician should be familiar with the anatomy, physiology and functional aspects of voice disorders and also the modern diagnostic and therapeutic possibilities in order to ensure an optimal and patient specific management. This review article focuses on the diagnostic and therapeutic limitations and difficulties of treatment of benign vocal fold tumors, the management and prevention of scarred vocal folds and the issue of unilateral vocal fold paresis. PMID:24403969

  18. Folds in multilayered rocks of Proterozoic age, Rajasthan, India

    Indian Academy of Sciences (India)

    R. Narasimhan (Krishtel eMaging) 1461 1996 Oct 15 13:05:22

    Johnson and Johnson 2002 etc) shows that the fold shape modification may be brought about by buckling and flattening operating simultaneously throughout the development of fold. In the present paper a series of F1 folds devel- oped in slates with interlayered alternations with quartzite of Proterozoic age and unaffected ...

  19. Nomenclature proposal to describe vocal fold motion impairment

    NARCIS (Netherlands)

    Rosen, Clark A.; Mau, Ted; Remacle, Marc; Hess, Markus; Eckel, Hans E.; Young, VyVy N.; Hantzakos, Anastasios; Yung, Katherine C.; Dikkers, Frederik G.

    2016-01-01

    The terms used to describe vocal fold motion impairment are confusing and not standardized. This results in a failure to communicate accurately and to major limitations of interpreting research studies involving vocal fold impairment. We propose standard nomenclature for reporting vocal fold

  20. Nomenclature proposal to describe vocal fold motion impairment

    NARCIS (Netherlands)

    Rosen, Clark A.; Mau, Ted; Remacle, Marc; Hess, Markus; Eckel, Hans E.; Young, VyVy N.; Hantzakos, Anastasios; Yung, Katherine C.; Dikkers, Frederik G.

    The terms used to describe vocal fold motion impairment are confusing and not standardized. This results in a failure to communicate accurately and to major limitations of interpreting research studies involving vocal fold impairment. We propose standard nomenclature for reporting vocal fold

  1. Factors that affect coseismic folds in an overburden layer

    Science.gov (United States)

    Zeng, Shaogang; Cai, Yongen

    2018-03-01

    Coseismic folds induced by blind thrust faults have been observed in many earthquake zones, and they have received widespread attention from geologists and geophysicists. Numerous studies have been conducted regarding fold kinematics; however, few have studied fold dynamics quantitatively. In this paper, we establish a conceptual model with a thrust fault zone and tectonic stress load to study the factors that affect coseismic folds and their formation mechanisms using the finite element method. The numerical results show that the fault dip angle is a key factor that controls folding. The greater the dip angle is, the steeper the fold slope. The second most important factor is the overburden thickness. The thicker the overburden is, the more gradual the fold. In this case, folds are difficult to identify in field surveys. Therefore, if a fold can be easily identified with the naked eye, the overburden is likely shallow. The least important factors are the mechanical parameters of the overburden. The larger the Young's modulus of the overburden is, the smaller the displacement of the fold and the fold slope. Strong horizontal compression and vertical extension in the overburden near the fault zone are the main mechanisms that form coseismic folds.

  2. Technique to achieve the symmetry of the new inframammary fold

    Science.gov (United States)

    Pozzi, Marcello; Zoccali, Giovanni; Buccheri, Ernesto Maria; de Vita, Roy

    2014-01-01

    Summary The literature outlines several surgical techniques to restore inframmammary fold definition, but symmetry of the fold is often left to irreproducible procedures. We report our personal technique to restore the symmetry of the inframmammary fold during multistep breast reconstruction. PMID:25078934

  3. Folding very short peptides using molecular dynamics.

    Directory of Open Access Journals (Sweden)

    Bosco K Ho

    2006-04-01

    Full Text Available Peptides often have conformational preferences. We simulated 133 peptide 8-mer fragments from six different proteins, sampled by replica-exchange molecular dynamics using Amber7 with a GB/SA (generalized-Born/solvent-accessible electrostatic approximation to water implicit solvent. We found that 85 of the peptides have no preferred structure, while 48 of them converge to a preferred structure. In 85% of the converged cases (41 peptides, the structures found by the simulations bear some resemblance to their native structures, based on a coarse-grained backbone description. In particular, all seven of the beta hairpins in the native structures contain a fragment in the turn that is highly structured. In the eight cases where the bioinformatics-based I-sites library picks out native-like structures, the present simulations are largely in agreement. Such physics-based modeling may be useful for identifying early nuclei in folding kinetics and for assisting in protein-structure prediction methods that utilize the assembly of peptide fragments.

  4. Delayed Collapse of Wooden Folding Stairs

    Science.gov (United States)

    Krentowski, Janusz; Chyzy, Tadeusz

    2017-10-01

    During operation of folding stairs, a fastener joining the ladder hanger with the frame was torn off. A person using the stairs sustained serious injury. In several dozen other locations similar accidents were observed. As a result of inspections, some threaded parts of the screws were found in the gaps between the wooden elements of the stairs’ flaps. In the construction a hatch made of wooden strips is attached to an external frame by means of metal hangers. Laboratory strength tests were conducted on three samples made of wooden elements identical to the ones used in the damaged stairs. Due to complex load distribution mechanism acting on the base of the structure, a three-dimensional FEM model was created. An original software was used for calculations. Five computational model variants were considered. As a result of the numerical analyses, it was unquestionably shown that faulty connections were the cause of the destruction of the stairs. The weakest link in the load transmission chain were found to have been the screws connecting the hatch board with the hangers.

  5. Folding and unfolding phylogenetic trees and networks.

    Science.gov (United States)

    Huber, Katharina T; Moulton, Vincent; Steel, Mike; Wu, Taoyang

    2016-12-01

    Phylogenetic networks are rooted, labelled directed acyclic graphswhich are commonly used to represent reticulate evolution. There is a close relationship between phylogenetic networks and multi-labelled trees (MUL-trees). Indeed, any phylogenetic network N can be "unfolded" to obtain a MUL-tree U(N) and, conversely, a MUL-tree T can in certain circumstances be "folded" to obtain aphylogenetic network F(T) that exhibits T. In this paper, we study properties of the operations U and F in more detail. In particular, we introduce the class of stable networks, phylogenetic networks N for which F(U(N)) is isomorphic to N, characterise such networks, and show that they are related to the well-known class of tree-sibling networks. We also explore how the concept of displaying a tree in a network N can be related to displaying the tree in the MUL-tree U(N). To do this, we develop aphylogenetic analogue of graph fibrations. This allows us to view U(N) as the analogue of the universal cover of a digraph, and to establish a close connection between displaying trees in U(N) and reconciling phylogenetic trees with networks.

  6. Structural proteomics of minimal organisms: conservation ofprotein fold usage and evolutionary implications

    Energy Technology Data Exchange (ETDEWEB)

    Chandonia, John-Marc; Kim, Sung-Hou

    2006-03-15

    Background: Determining the complete repertoire of proteinstructures for all soluble, globular proteins in a single organism hasbeen one of the major goals of several structural genomics projects inrecent years. Results: We report that this goal has nearly been reachedfor several "minimal organisms"--parasites or symbionts with reducedgenomes--for which over 95 percent of the soluble, globular proteins maynow be assigned folds, overall 3-D backbone structures. We analyze thestructures of these proteins as they relate to cellular functions, andcompare conservation off old usage between functional categories. We alsocompare patterns in the conservation off olds among minimal organisms andthose observed between minimal organisms and other bacteria. Conclusion:We find that proteins performing essential cellular functions closelyrelated to transcription and translation exhibit a higher degree ofconservation in fold usage than proteins in other functional categories.Folds related to transcription and translation functional categories werealso over represented in minimal organisms compared to otherbacteria.

  7. An optical flow-based state-space model of the vocal folds

    DEFF Research Database (Denmark)

    Granados, Alba; Brunskog, Jonas

    2017-01-01

    High-speed movies of the vocal fold vibration are valuable data to reveal vocal fold features for voice pathology diagnosis. This work presents a suitable Bayesian model and a purely theoretical discussion for further development of a framework for continuum biomechanical features estimation. A l...... to capture different deformation patterns between the computed optical flow and the finite element deformation, controlled by the choice of the model tissue parameters........ A linear and Gaussian nonstationary state-space model is proposed and thoroughly discussed. The evolution model is based on a self-sustained three-dimensional finite element model of the vocal folds, and the observation model involves a dense optical flow algorithm. The results show that the method is able...

  8. An optical flow-based state-space model of the vocal folds.

    Science.gov (United States)

    Granados, Alba; Brunskog, Jonas

    2017-06-01

    High-speed movies of the vocal fold vibration are valuable data to reveal vocal fold features for voice pathology diagnosis. This work presents a suitable Bayesian model and a purely theoretical discussion for further development of a framework for continuum biomechanical features estimation. A linear and Gaussian nonstationary state-space model is proposed and thoroughly discussed. The evolution model is based on a self-sustained three-dimensional finite element model of the vocal folds, and the observation model involves a dense optical flow algorithm. The results show that the method is able to capture different deformation patterns between the computed optical flow and the finite element deformation, controlled by the choice of the model tissue parameters.

  9. The pathophysiology of the nodular and micronodular small bowel fold

    International Nuclear Information System (INIS)

    Olmsted, W.W.; Ros, P.R.; Moser, R.P.; Shekita, K.M.; Lichtenstein, J.E.

    1986-01-01

    The normal small bowel fold is easily seen on conventional studies of the small intestine, but visualization of the small bowel villus is at the limit of resolution of current roentgenographic technique. When the villi are enlarged, they appear radiographically as an irregularity or micronodularity of the small bowel fold. The anatomy of the fold and the pathophysiology of diseases producing fold nodularity (tumor,inflammatory disease, NLH, mastocytosis) and micronodularity (lymphangiectasia, Waldenstrom macroglobulinemia, Whipple disease) are presented, with an emphasis on radiologic-pathologic correlation. The radiologist should suggest certain diseases or conditions based on the roentgenographic characteristics of the closely analyzed small bowel fold

  10. Pathophysiology of the nodular and micronodular small bowel fold

    International Nuclear Information System (INIS)

    Olmstead, W.W.; Ros, P.R.; Moser, R.P.; Shekitka, K.M.; Lichtenstein, J.E.; Buck, J.L.

    1987-01-01

    The normal small bowel fold is easily seen on conventional studies of the small intestine, but visualization of the small bowel villus is just at the resolution of current roentgenographic technique. When the villi are enlarged, they can be seen radiographically as an irregularity or micronodularity of the small bowel fold. The anatomy of the fold and the pathophysiology of diseases producing fold nodularity (tumor, inflammatory disease, NLH, mastocytosis) and micronodularity (lymphangiectasia, Waldenstrom macroglobulinemia, Whipple disease) are presented, with an emphasis on radiologic-pathologic correlation. The radiologist should suggest certain diseases or conditions based on the roentgenographic characteristics of the closely analyzed small bowel fold

  11. The effect of a scanning flat fold mirror on a cosmic microwave background B-mode experiment.

    Science.gov (United States)

    Grainger, William F; North, Chris E; Ade, Peter A R

    2011-06-01

    We investigate the possibility of using a flat-fold beam steering mirror for a cosmic microwave background B-mode experiment. An aluminium flat-fold mirror is found to add ∼0.075% polarization, which varies in a scan synchronous way. Time-domain simulations of a realistic scanning pattern are performed, and the effect on the power-spectrum illustrated, and a possible method of correction applied. © 2011 American Institute of Physics

  12. Protein Folding Free Energy Landscape along the Committor - the Optimal Folding Coordinate.

    Science.gov (United States)

    Krivov, Sergei V

    2018-06-06

    Recent advances in simulation and experiment have led to dramatic increases in the quantity and complexity of produced data, which makes the development of automated analysis tools very important. A powerful approach to analyze dynamics contained in such data sets is to describe/approximate it by diffusion on a free energy landscape - free energy as a function of reaction coordinates (RC). For the description to be quantitatively accurate, RCs should be chosen in an optimal way. Recent theoretical results show that such an optimal RC exists; however, determining it for practical systems is a very difficult unsolved problem. Here we describe a solution to this problem. We describe an adaptive nonparametric approach to accurately determine the optimal RC (the committor) for an equilibrium trajectory of a realistic system. In contrast to alternative approaches, which require a functional form with many parameters to approximate an RC and thus extensive expertise with the system, the suggested approach is nonparametric and can approximate any RC with high accuracy without system specific information. To avoid overfitting for a realistically sampled system, the approach performs RC optimization in an adaptive manner by focusing optimization on less optimized spatiotemporal regions of the RC. The power of the approach is illustrated on a long equilibrium atomistic folding simulation of HP35 protein. We have determined the optimal folding RC - the committor, which was confirmed by passing a stringent committor validation test. It allowed us to determine a first quantitatively accurate protein folding free energy landscape. We have confirmed the recent theoretical results that diffusion on such a free energy profile can be used to compute exactly the equilibrium flux, the mean first passage times, and the mean transition path times between any two points on the profile. We have shown that the mean squared displacement along the optimal RC grows linear with time as for

  13. Single-Chain Folding of Synthetic Polymers: A Critical Update.

    Science.gov (United States)

    Altintas, Ozcan; Barner-Kowollik, Christopher

    2015-11-23

    The current contribution serves as a critical update to a previous feature article from us (Macromol. Rapid Commun. 2012, 33, 958-971), and highlights the latest advances in the preparation of single chain polymeric nanoparticles and initial-yet promising-attempts towards mimicking the structure of natural biomacromolecules via single-chain folding of well-defined linear polymers via so-called single chain selective point folding and repeat unit folding. The contribution covers selected examples from the literature published up to ca. September 2015. Our aim is not to provide an exhaustive review but rather highlight a selection of new and exciting examples for single-chain folding based on advanced macromolecular precision chemistry. Initially, the discussion focuses on the synthesis and characterization of single-chain folded structures via selective point folding. The second part of the feature article addresses the folding of well-defined single-chain polymers by means of repeat unit folding. The current state of the art in the field of single-chain folding indicates that repeat unit folding-driven nanoparticle preparation is well-advanced, while initial encouraging steps towards building selective point folding systems have been taken. In addition, a summary of the-in our view-open key questions is provided that may guide future biomimetic design efforts. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  14. Characteristics of phonation onset in a two-layer vocal fold model.

    Science.gov (United States)

    Zhang, Zhaoyan

    2009-02-01

    Characteristics of phonation onset were investigated in a two-layer body-cover continuum model of the vocal folds as a function of the biomechanical and geometric properties of the vocal folds. The analysis showed that an increase in either the body or cover stiffness generally increased the phonation threshold pressure and phonation onset frequency, although the effectiveness of varying body or cover stiffness as a pitch control mechanism varied depending on the body-cover stiffness ratio. Increasing body-cover stiffness ratio reduced the vibration amplitude of the body layer, and the vocal fold motion was gradually restricted to the medial surface, resulting in more effective flow modulation and higher sound production efficiency. The fluid-structure interaction induced synchronization of more than one group of eigenmodes so that two or more eigenmodes may be simultaneously destabilized toward phonation onset. At certain conditions, a slight change in vocal fold stiffness or geometry may cause phonation onset to occur as eigenmode synchronization due to a different pair of eigenmodes, leading to sudden changes in phonation onset frequency, vocal fold vibration pattern, and sound production efficiency. Although observed in a linear stability analysis, a similar mechanism may also play a role in register changes at finite-amplitude oscillations.

  15. Accurately controlled sequential self-folding structures by polystyrene film

    Science.gov (United States)

    Deng, Dongping; Yang, Yang; Chen, Yong; Lan, Xing; Tice, Jesse

    2017-08-01

    Four-dimensional (4D) printing overcomes the traditional fabrication limitations by designing heterogeneous materials to enable the printed structures evolve over time (the fourth dimension) under external stimuli. Here, we present a simple 4D printing of self-folding structures that can be sequentially and accurately folded. When heated above their glass transition temperature pre-strained polystyrene films shrink along the XY plane. In our process silver ink traces printed on the film are used to provide heat stimuli by conducting current to trigger the self-folding behavior. The parameters affecting the folding process are studied and discussed. Sequential folding and accurately controlled folding angles are achieved by using printed ink traces and angle lock design. Theoretical analyses are done to guide the design of the folding processes. Programmable structures such as a lock and a three-dimensional antenna are achieved to test the feasibility and potential applications of this method. These self-folding structures change their shapes after fabrication under controlled stimuli (electric current) and have potential applications in the fields of electronics, consumer devices, and robotics. Our design and fabrication method provides an easy way by using silver ink printed on polystyrene films to 4D print self-folding structures for electrically induced sequential folding with angular control.

  16. Vocal fold paresis - a debilitating and underdiagnosed condition.

    Science.gov (United States)

    Harris, G; O'Meara, C; Pemberton, C; Rough, J; Darveniza, P; Tisch, S; Cole, I

    2017-07-01

    To review the clinical signs of vocal fold paresis on laryngeal videostroboscopy, to quantify its impact on patients' quality of life and to confirm the benefit of laryngeal electromyography in its diagnosis. Twenty-nine vocal fold paresis patients were referred for laryngeal electromyography. Voice Handicap Index 10 results were compared to 43 patients diagnosed with vocal fold paralysis. Laryngeal videostroboscopy analysis was conducted to determine side of paresis. Blinded laryngeal electromyography confirmed vocal fold paresis in 92.6 per cent of cases, with vocal fold lag being the most common diagnostic sign. The laryngology team accurately predicted side of paresis in 76 per cent of cases. Total Voice Handicap Index 10 responses were not significantly different between vocal fold paralysis and vocal fold paresis groups (26.08 ± 0.21 and 22.93 ± 0.17, respectively). Vocal fold paresis has a significant impact on quality of life. This study shows that laryngeal electromyography is an important diagnostic tool. Patients with persisting dysphonia and apparently normal vocal fold movement, who fail to respond to appropriate speech therapy, should be investigated for a diagnosis of vocal fold paresis.

  17. Quantitative electromyographic characteristics of idiopathic unilateral vocal fold paralysis.

    Science.gov (United States)

    Chang, Wei-Han; Fang, Tuan-Jen; Li, Hsueh-Yu; Jaw, Fu-Shan; Wong, Alice M K; Pei, Yu-Cheng

    2016-11-01

    Unilateral vocal fold paralysis with no preceding causes is diagnosed as idiopathic unilateral vocal fold paralysis. However, comprehensive guidelines for evaluating the defining characteristics of idiopathic unilateral vocal fold paralysis are still lacking. In the present study, we hypothesized that idiopathic unilateral vocal fold paralysis may have different clinical and neurologic characteristics from unilateral vocal fold paralysis caused by surgical trauma. Retrospective, case series study. Patients with unilateral vocal fold paralysis were evaluated using quantitative laryngeal electromyography, videolaryngostroboscopy, voice acoustic analysis, the Voice Outcome Survey, and the Short Form-36 Health Survey quality-of-life questionnaire. Patients with idiopathic and iatrogenic vocal fold paralysis were compared. A total of 124 patients were recruited. Of those, 17 with no definite identified causes after evaluation and follow-up were assigned to the idiopathic group. The remaining 107 patients with surgery-induced vocal fold paralysis were assigned to the iatrogenic group. Patients in the idiopathic group had higher recruitment of the thyroarytenoid-lateral cricoarytenoid muscle complex and better quality of life compared with the iatrogenic group. Idiopathic unilateral vocal fold paralysis has a distinct clinical presentation, with relatively minor denervation changes in the involved laryngeal muscles, and less impact on quality of life compared with iatrogenic vocal fold paralysis. 4. Laryngoscope, 126:E362-E368, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  18. Evolutionary and developmental implications of asymmetric brain folding in a large primate pedigree

    OpenAIRE

    Atkinson, Elizabeth G.; Rogers, Jeffrey; Cheverud, James M.

    2016-01-01

    Bilateral symmetry is a fundamental property of the vertebrate central nervous system. Local deviations from symmetry provide various types of information about the development, evolution and function of elements within the CNS, especially the cerebral hemispheres. Here, we quantify the pattern and extent of asymmetry in cortical folding within the cerebrum of Papio baboons and assess the evolutionary and developmental implications of the findings. Analyses of directional asymmetry show a pop...

  19. Cation-induced folding of alginate-bearing bilayer gels: an unusual example of spontaneous folding along the long axis.

    Science.gov (United States)

    Athas, Jasmin C; Nguyen, Catherine P; Kummar, Shailaa; Raghavan, Srinivasa R

    2018-04-04

    The spontaneous folding of flat gel films into tubes is an interesting example of self-assembly. Typically, a rectangular film folds along its short axis when forming a tube; folding along the long axis has been seen only in rare instances when the film is constrained. Here, we report a case where the same free-swelling gel film folds along either its long or short axis depending on the concentration of a solute. Our gels are sandwiches (bilayers) of two layers: a passive layer of cross-linked N,N'-dimethylyacrylamide (DMAA) and an active layer of cross-linked DMAA that also contains chains of the biopolymer alginate. Multivalent cations like Ca2+ and Cu2+ induce these bilayer gels to fold into tubes. The folding occurs instantly when a flat film of the gel is introduced into a solution of these cations. The likely cause for folding is that the active layer stiffens and shrinks (because the alginate chains in it get cross-linked by the cations) whereas the passive layer is unaffected. The resulting mismatch in swelling degree between the two layers creates internal stresses that drive folding. Cations that are incapable of cross-linking alginate, such as Na+ and Mg2+, do not induce gel folding. Moreover, the striking aspect is the direction of folding. When the Ca2+ concentration is high (100 mM or higher), the gels fold along their long axis, whereas when the Ca2+ concentration is low (40 to 80 mM), the gels fold along their short axis. We hypothesize that the folding axis is dictated by the inhomogeneous nature of alginate-cation cross-linking, i.e., that the edges get cross-linked before the faces of the gel. At high Ca2+ concentration, the stiffer edges constrain the folding; in turn, the gel folds such that the longer edges are deformed less, which explains the folding along the long axis. At low Ca2+ concentration, the edges and the faces of the gel are more similar in their degree of cross-linking; therefore, the gel folds along its short axis. An analogy

  20. The Ventricular-Fold Dynamics in Human Phonation

    OpenAIRE

    Bailly , Lucie; Henrich Bernardoni , Nathalie; Müller , Frank; Rohlfs , Anna-Katharina; Hess , Markus

    2014-01-01

    International audience; Purpose: In this study, the authors aimed (a) to provide a classification of the ventricular-fold dynamics during voicing, (b) to study the aerodynamic impact of these motions on vocal-fold vibrations, and (c) to assess whether ventricularfold oscillations could be sustained by aerodynamic coupling with the vocal folds. Method: A 72-sample database of vocal gestures accompanying different acoustical events comprised highspeed cinematographic, audio, and electroglottogr...

  1. Comparing the Folding and Misfolding Energy Landscapes of Phosphoglycerate Kinase

    OpenAIRE

    Agocs, Gergely; Szabo, Bence T.; Koehler, Gottfried; Osvath, Szabolcs

    2012-01-01

    Partitioning of polypeptides between protein folding and amyloid formation is of outstanding pathophysiological importance. Using yeast phosphoglycerate kinase as model, here we identify the features of the energy landscape that decide the fate of the protein: folding or amyloidogenesis. Structure formation was initiated from the acid-unfolded state, and monitored by fluorescence from 10 ms to 20 days. Solvent conditions were gradually shifted between folding and amyloidogenesis, and the prop...

  2. Ligand-promoted protein folding by biased kinetic partitioning.

    Science.gov (United States)

    Hingorani, Karan S; Metcalf, Matthew C; Deming, Derrick T; Garman, Scott C; Powers, Evan T; Gierasch, Lila M

    2017-04-01

    Protein folding in cells occurs in the presence of high concentrations of endogenous binding partners, and exogenous binding partners have been exploited as pharmacological chaperones. A combined mathematical modeling and experimental approach shows that a ligand improves the folding of a destabilized protein by biasing the kinetic partitioning between folding and alternative fates (aggregation or degradation). Computationally predicted inhibition of test protein aggregation and degradation as a function of ligand concentration are validated by experiments in two disparate cellular systems.

  3. Iterative Controller Tuning for Process with Fold Bifurcations

    DEFF Research Database (Denmark)

    Huusom, Jakob Kjøbsted; Poulsen, Niels Kjølstad; Jørgensen, Sten Bay

    2007-01-01

    Processes involving fold bifurcation are notoriously difficult to control in the vicinity of the fold where most often optimal productivity is achieved . In cases with limited process insight a model based control synthesis is not possible. This paper uses a data driven approach with an improved...... version of iterative feedback tuning to optimizing a closed loop performance criterion, as a systematic tool for tuning process with fold bifurcations....

  4. Current Understanding and Future Directions for Vocal Fold Mechanobiology

    Science.gov (United States)

    Li, Nicole Y.K.; Heris, Hossein K.; Mongeau, Luc

    2013-01-01

    The vocal folds, which are located in the larynx, are the main organ of voice production for human communication. The vocal folds are under continuous biomechanical stress similar to other mechanically active organs, such as the heart, lungs, tendons and muscles. During speech and singing, the vocal folds oscillate at frequencies ranging from 20 Hz to 3 kHz with amplitudes of a few millimeters. The biomechanical stress associated with accumulated phonation is believed to alter vocal fold cell activity and tissue structure in many ways. Excessive phonatory stress can damage tissue structure and induce a cell-mediated inflammatory response, resulting in a pathological vocal fold lesion. On the other hand, phonatory stress is one major factor in the maturation of the vocal folds into a specialized tri-layer structure. One specific form of vocal fold oscillation, which involves low impact and large amplitude excursion, is prescribed therapeutically for patients with mild vocal fold injuries. Although biomechanical forces affect vocal fold physiology and pathology, there is little understanding of how mechanical forces regulate these processes at the cellular and molecular level. Research into vocal fold mechanobiology has burgeoned over the past several years. Vocal fold bioreactors are being developed in several laboratories to provide a biomimic environment that allows the systematic manipulation of physical and biological factors on the cells of interest in vitro. Computer models have been used to simulate the integrated response of cells and proteins as a function of phonation stress. The purpose of this paper is to review current research on the mechanobiology of the vocal folds as it relates to growth, pathogenesis and treatment as well as to propose specific research directions that will advance our understanding of this subject. PMID:24812638

  5. Competition between folding and glycosylation in the endoplasmic reticulum

    DEFF Research Database (Denmark)

    Holst, B; Bruun, A W; Kielland-Brandt, Morten

    1996-01-01

    Using carboxypeptidase Y in Saccharomyces cerevisiae as a model system, the in vivo relationship between protein folding and N-glycosylation was studied. Seven new sites for N-glycosylation were introduced at positions buried in the folded protein structure. The level of glycosylation of such new...... acceptor sites. In some cases, all the newly synthesized mutant protein was modified at the novel site while in others no modification took place. In the most interesting category of mutants, the level of glycosylation was dependent on the conditions for folding. This shows that folding and glycosylation...

  6. Folding System for the Clothes by a Robot and Tools

    OpenAIRE

    大澤, 文明; 関, 啓明; 神谷, 好承

    2004-01-01

    The works of a home robot has the laundering. The purpose of this study is to find a means of folding of the clothes and store the clothes in a drawer by a home robot. Because the shape of cloth tends to change in various ways depending on the situation, it is difficult for robot hands to fold the clothes. In this paper, we propose a realistic folding system for the clothes by a robot and tools. The function of a tool is folding the clothes in half by inserting the clothes using two plates. T...

  7. Thermodynamics of protein folding: a random matrix formulation.

    Science.gov (United States)

    Shukla, Pragya

    2010-10-20

    The process of protein folding from an unfolded state to a biologically active, folded conformation is governed by many parameters, e.g. the sequence of amino acids, intermolecular interactions, the solvent, temperature and chaperon molecules. Our study, based on random matrix modeling of the interactions, shows, however, that the evolution of the statistical measures, e.g. Gibbs free energy, heat capacity, and entropy, is single parametric. The information can explain the selection of specific folding pathways from an infinite number of possible ways as well as other folding characteristics observed in computer simulation studies. © 2010 IOP Publishing Ltd

  8. Specific features of vocal fold paralysis in functional computed tomography

    International Nuclear Information System (INIS)

    Laskowska, K.; Mackiewicz-Nartowicz, H.; Serafin, Z.; Nawrocka, E.

    2008-01-01

    Vocal fold paralysis is usually recognized in laryngological examination, and detailed vocal fold function may be established based on laryngovideostroboscopy. Additional imaging should exclude any morphological causes of the paresis, which should be treated pharmacologically or surgically. The aim of this paper was to analyze the computed tomography (CT) images of the larynx in patients with unilateral vocal fold paralysis. CT examinations of the larynx were performed in 10 patients with clinically defined unilateral vocal fold paralysis. The examinations consisted of unenhanced acquisition and enhanced 3-phased acquisition: during free breathing, Valsalva maneuver, and phonation. The analysis included the following morphologic features of the paresis.the deepened epiglottic vallecula, the deepened piriform recess, the thickened and medially positioned aryepiglottic fold, the widened laryngeal pouch, the anteriorly positioned arytenoid cartilage, the thickened vocal fold, and the filled infraglottic space in frontal CT reconstruction. CT images were compared to laryngovideostroboscopy. The most common symptoms of vocal cord paralysis in CT were the deepened epiglottic vallecula and piriform recess, the widened laryngeal pouch with the filled infraglottic space, and the thickened aryepiglottic fold. Regarding the efficiency of the paralysis determination, the three functional techniques of CT larynx imaging used did not differ significantly, and laryngovideostroboscopy demonstrated its advantage over CT. CT of the larynx is a supplementary examination in the diagnosis of vocal fold paralysis, which may enable topographic analysis of the fold dysfunction. The knowledge of morphological CT features of the paralysis may help to prevent false-positive diagnosis of laryngeal cancer. (author)

  9. Arytenoid and posterior vocal fold surgery for bilateral vocal fold immobility.

    Science.gov (United States)

    Young, VyVy N; Rosen, Clark A

    2011-12-01

    Many procedures exist to address the airway restriction often seen with bilateral vocal fold immobility. We review the most recent studies involving arytenoid and/or posterior vocal fold surgery to provide an update on the issues related to these procedures. Specific focus is placed on selection of the surgical approach and operative side, use of adjunctive therapies, and outcome measures including decannulation rate, revision and complication rate, and postoperative results. Ten studies were identified between 2004 and 2011. Modifications to the orginal transverse cordotomy and medial arytenoidectomy techniques continue to be investigated to seek improvement in dyspnea symptoms with minimal decline in voice and/or swallowing function. Decannulation rates for these approaches are high. Postoperative dysphagia appears to be less commonly observed but requires continued study. The use of mitomycin-C in these procedures has been poorly studied to date. Both transverse cordotomy and medial arytenoidectomy procedures result in high success rates. However, many questions related to these procedures remain unanswered, particularly with respect to preoperative and postoperative evaluations of voice quality, swallowing function, and pulmonary status. There is need for rigorous prospective clinical studies to address these many issues further.

  10. Endo-extralaryngeal Laterofixation of the Vocal Folds in Patients with Bilateral Vocal Fold Immobility.

    Science.gov (United States)

    Wiegand, Susanne; Teymoortash, Afshin; Hanschmann, Holger

    2017-01-01

    Bilateral vocal fold paralysis can result in shortness of breath and severe dyspnea which can be life-threatening. Thirty-five patients with bilateral vocal fold paralysis who underwent endo-extralaryngeal laterofixation according to Lichtenberger were retrospectively analyzed regarding etiology, symptoms, treatment and complications. In 27 patients, laterofixation of the vocal cord alone was performed. Eight patients underwent laterofixation and additional posterior chordectomy of the opposite vocal cord according to Dennis and Kashima. The time of intervention ranged from 1 day to 38 years after the onset of bilateral vocal cord immobility. The intraoperative course was uneventful in all patients. None of the patients had postoperative aspiration. Postoperative voice function was acceptable in all patients. Complications of suture laterofixation were laryngeal edema, formation of fibrin, and malposition of the suture. Laterofixation of the vocal cords according to Lichtenberger is a safe and easy method that can be used as a first-stage treatment of vocal cord paralysis. Copyright© 2017, International Institute of Anticancer Research (Dr. George J. Delinasios), All rights reserved.

  11. Incidence of vocal fold immobility in patients with dysphagia.

    Science.gov (United States)

    Leder, Steven B; Ross, Douglas A

    2005-01-01

    This study prospectively investigated the incidence of vocal fold immobility, unilateral and bilateral, and its influence on aspiration status in a referred population of 1452 patients for a dysphagia evaluation from a large, urban, tertiary-care, teaching hospital. Main outcome measures included overall incidence of vocal fold immobility and aspiration status, with specific emphasis on age, etiology, and side of vocal fold immobility, i.e., right, left, or bilateral. Overall incidence of vocal fold immobility was 5.6% (81 of 1452 patients), including 47 males (mean age 55.7 yr) and 34 females (mean age 59.7 yr). In the subgroup of patients with vocal fold immobility, 31% (25 of 81) exhibited unilateral right, 60% (49 of 81) unilateral left, and 9% (7 of 81) bilateral impairment. Overall incidence of aspiration was found to be 29% (426 of 1452) of all patients referred for a swallow evaluation. Aspiration was observed in 44% (36 of 81) of patients presenting with vocal fold immobility, i.e., 44% (11 of 25) unilateral right, 43% (21 of 49) unilateral left, and 57% (4 of 7) bilateral vocal fold immobility. Left vocal fold immobility occurred most frequently due to surgical trauma. A liquid bolus was aspirated more often than a puree bolus. Side of vocal fold immobility and age were not factors that increased incidence of aspiration. In conclusion, vocal fold immobility, with an incidence of 5.6%, is not an uncommon finding in patients referred for a dysphagia evaluation in the acute-care setting, and vocal fold immobility, when present, was associated with a 15% increased incidence of aspiration when compared with a population already being evaluated for dysphagia.

  12. In vivo measurement of vocal fold surface resistance.

    Science.gov (United States)

    Mizuta, Masanobu; Kurita, Takashi; Dillon, Neal P; Kimball, Emily E; Garrett, C Gaelyn; Sivasankar, M Preeti; Webster, Robert J; Rousseau, Bernard

    2017-10-01

    A custom-designed probe was developed to measure vocal fold surface resistance in vivo. The purpose of this study was to demonstrate proof of concept of using vocal fold surface resistance as a proxy of functional tissue integrity after acute phonotrauma using an animal model. Prospective animal study. New Zealand White breeder rabbits received 120 minutes of airflow without vocal fold approximation (control) or 120 minutes of raised intensity phonation (experimental). The probe was inserted via laryngoscope and placed on the left vocal fold under endoscopic visualization. Vocal fold surface resistance of the middle one-third of the vocal fold was measured after 0 (baseline), 60, and 120 minutes of phonation. After the phonation procedure, the larynx was harvested and prepared for transmission electron microscopy. In the control group, vocal fold surface resistance values remained stable across time points. In the experimental group, surface resistance (X% ± Y% relative to baseline) was significantly decreased after 120 minutes of raised intensity phonation. This was associated with structural changes using transmission electron microscopy, which revealed damage to the vocal fold epithelium after phonotrauma, including disruption of the epithelium and basement membrane, dilated paracellular spaces, and alterations to epithelial microprojections. In contrast, control vocal fold specimens showed well-preserved stratified squamous epithelia. These data demonstrate the feasibility of measuring vocal fold surface resistance in vivo as a means of evaluating functional vocal fold epithelial barrier integrity. Device prototypes are in development for additional testing, validation, and for clinical applications in laryngology. NA Laryngoscope, 127:E364-E370, 2017. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  13. Lateral Nail Fold Incision Technique for Venous Anastomosis in Fingertip Replantation.

    Science.gov (United States)

    Jeon, Byung-Joon; Yang, Jae-Won; Roh, Si Young; Ki, Sae Hwi; Lee, Dong Chul; Kim, Jin Soo

    2016-01-01

    Successful venous anastomosis is one of the most important factors in fingertip replantation. Volar veins in the fingertip course proximally in a random pattern, which makes it difficult to find out the exact locations. Although dorsal veins in the lateral nail fold have constant location and adequate diameter for anastomosis, they have been known as hard to dissect from the immobile subcutaneous tissue. The authors present a new lateral nail fold incision technique for venous anastomosis in the fingertip amputations. From February 2010 to October 2010, 9 replantations using the new incision and venous anastomosis technique were performed in 9 patients. The levels of amputations were from the nail base to half of the nail bed. After repairing the proper digital arteries, a skin incision was made along the junction between the lateral nail fold and nail bed. Careful dissection was performed to isolate the veins in the lateral nail fold. After evaluation of the suitability of the vessel, venous anastomosis was performed. Seven male and 2 female patients were enrolled in this study. Appropriate dorsal veins for anastomosis could be found in 8 of 9 patients. All the replanted stumps survived without venous congestion and following additional procedures. A sizable volar or dorsal vein could not be found in 1 patient. The salvage technique was required in this patient. Dorsal veins in the lateral nail fold can be found easily because of the constant anatomical location. The new incision on the lateral nail fold provides not only sufficient operative field for anastomosis but also additional opportunity of successful venous anastomosis in the selected cases. The authors, therefore, propose this technique as an effective method for an alternative venous anastomosis in the zone I replantation.

  14. Status report on the folded tandem ion accelerator at BARC

    Indian Academy of Sciences (India)

    Folded tandem ion accelerator; charged particle beams; voltage stability; Rutherford backscattering; ion optics; beam lines. Abstract. The folded tandem ion accelerator (FOTIA) facility set up at BARC has become operational. At present, it is used for elemental analysis studies using the Rutherford backscattering technique.

  15. The effect of surface electrical stimulation on vocal fold position.

    Science.gov (United States)

    Humbert, Ianessa A; Poletto, Christopher J; Saxon, Keith G; Kearney, Pamela R; Ludlow, Christy L

    2008-01-01

    Closure of the true and false vocal folds is a normal part of airway protection during swallowing. Individuals with reduced or delayed true vocal fold closure can be at risk for aspiration and may benefit from intervention to ameliorate the problem. Surface electrical stimulation is currently used during therapy for dysphagia, despite limited knowledge of its physiological effects. Prospective single effects study. The immediate physiological effect of surface stimulation on true vocal fold angle was examined at rest in 27 healthy adults using 10 different electrode placements on the submental and neck regions. Fiberoptic nasolaryngoscopic recordings during passive inspiration were used to measure change in true vocal fold angle with stimulation. Vocal fold angles changed only to a small extent during two electrode placements (P vocal fold abduction was 2.4 degrees; while horizontal placements of electrodes in the submental region produced a mean adduction of 2.8 degrees (P = .03). Surface electrical stimulation to the submental and neck regions does not produce immediate true vocal fold adduction adequate for airway protection during swallowing, and one position may produce a slight increase in true vocal fold opening.

  16. Cotranslational protein folding reveals the selective use of ...

    Indian Academy of Sciences (India)

    to fold properly by decelerating the translation rate at these sites. Thus the cotranslational protein folding is believed to be true for many proteins and is an important selection factor for the selective codon usage to optimize proper gene expres- sion and function (Komar 2009). A web server CS and S has been created by ...

  17. Vocal Fold Mucus Aggregation in Persons with Voice Disorders

    Science.gov (United States)

    Bonilha, Heather Shaw; White, Lisa; Kuckhahn, Kelsey; Gerlach, Terri Treman; Deliyski, Dimitar D.

    2012-01-01

    Mucus aggregation on the vocal folds is a common finding from laryngeal endoscopy. Patients with voice disorders report the presence of mucus aggregation. Patients also report that mucus aggregation causes them to clear their throat, a behavior believed to be harmful to vocal fold mucosa. Even though clinicians and patients report and discuss…

  18. Surfing the free energy landscape of flavodoxin folding

    NARCIS (Netherlands)

    Bollen, Y.J.M.

    2004-01-01

    The research described in this thesis has been carried out to obtain a better understanding of the fundamental rules describing protein folding. Protein folding is the process in which a linear chain of amino acids contracts to a compact state in which it is active. Flavodoxin from Azotobacter

  19. New variants of known folds: do they bring new biology?

    International Nuclear Information System (INIS)

    Koonin, Eugene V.

    2010-01-01

    New distinct versions of known protein folds provide a powerful means of protein-function prediction that complements sequence and genomic context analysis. New distinct versions of known protein folds provide a powerful means of protein-function prediction that complements sequence and genomic context analysis. These structures do not supplant direct biochemical experiments, but are indispensable for the complete characterization of proteins

  20. Acute vocal fold hemorrhage caught on video during office exam.

    Science.gov (United States)

    Carroll, Thomas L; Smith, Libby J

    2009-03-01

    This article presents a unique video of a laryngeal exam during which a vocal fold hemorrhage occurs. This patient had likely been suffering from intermittent vocal fold hemorrhages for the last decade due to a persistent vascular lesion and an underlying chronic cough.

  1. Transiently disordered tails accelerate folding of globular proteins.

    Science.gov (United States)

    Mallik, Saurav; Ray, Tanaya; Kundu, Sudip

    2017-07-01

    Numerous biological proteins exhibit intrinsic disorder at their termini, which are associated with multifarious functional roles. Here, we show the surprising result that an increased percentage of terminal short transiently disordered regions with enhanced flexibility (TstDREF) is associated with accelerated folding rates of globular proteins. Evolutionary conservation of predicted disorder at TstDREFs and drastic alteration of folding rates upon point-mutations suggest critical regulatory role(s) of TstDREFs in shaping the folding kinetics. TstDREFs are associated with long-range intramolecular interactions and the percentage of native secondary structural elements physically contacted by TstDREFs exhibit another surprising positive correlation with folding kinetics. These results allow us to infer probable molecular mechanisms behind the TstDREF-mediated regulation of folding kinetics that challenge protein biochemists to assess by direct experimental testing. © 2017 Federation of European Biochemical Societies.

  2. Method of generating ploynucleotides encoding enhanced folding variants

    Energy Technology Data Exchange (ETDEWEB)

    Bradbury, Andrew M.; Kiss, Csaba; Waldo, Geoffrey S.

    2017-05-02

    The invention provides directed evolution methods for improving the folding, solubility and stability (including thermostability) characteristics of polypeptides. In one aspect, the invention provides a method for generating folding and stability-enhanced variants of proteins, including but not limited to fluorescent proteins, chromophoric proteins and enzymes. In another aspect, the invention provides methods for generating thermostable variants of a target protein or polypeptide via an internal destabilization baiting strategy. Internally destabilization a protein of interest is achieved by inserting a heterologous, folding-destabilizing sequence (folding interference domain) within DNA encoding the protein of interest, evolving the protein sequences adjacent to the heterologous insertion to overcome the destabilization (using any number of mutagenesis methods), thereby creating a library of variants. The variants in the library are expressed, and those with enhanced folding characteristics selected.

  3. Folding propensity of intrinsically disordered proteins by osmotic stress

    International Nuclear Information System (INIS)

    Mansouri, Amanda L.; Grese, Laura N.; Rowe, Erica L.

    2016-01-01

    Proteins imparted with intrinsic disorder conduct a range of essential cellular functions. To better understand the folding and hydration properties of intrinsically disordered proteins (IDPs), we used osmotic stress to induce conformational changes in nuclear co-activator binding domain (NCBD) and activator for thyroid hormone and retinoid receptor (ACTR). Osmotic stress was applied by the addition of small and polymeric osmolytes, where we discovered that water contributions to NCBD folding always exceeded those for ACTR. Both NCBD and ACTR were found to gain a-helical structure with increasing osmotic stress, consistent with their folding upon NCBD/ACTR complex formation. Using small-angle neutron scattering (SANS), we further characterized NCBD structural changes with the osmolyte ethylene glycol. Here a large reduction in overall size initially occurred before substantial secondary structural change. In conclusion, by focusing on folding propensity, and linked hydration changes, we uncover new insights that may be important for how IDP folding contributes to binding.

  4. Ultrasonography of the larynx for diagnosis of the vocal folds mobility impairment

    Directory of Open Access Journals (Sweden)

    Petr S. Vetshev

    2017-03-01

    Full Text Available Purpose. To study a possibility of performance and diagnostic accuracy of ultrasonography (US of a larynx in identification of motility disorders of VF (vocal folds in comparison with the laryngoscope which is traditionally applied for this purpose. Materials and methods. According to the objectives of the study, two patient groups were formed. In first group of patients (n = 466 we studied acceptability of ultrasonografy to discriminate various laryngeal structures. In second group of patient (n = 432 we evaluated the diagnostic accuracy of ultrasonography in point of detection of vocal muscles paresis. Results. Laryngeal structures were available to examination by ultrasound (without taking in account age and sex in 92.7% of patients. Two patterns have been identified in the course of this part of the study: deterioration of visibility of the vocal folds with increasing patient age and better visibility of the vocal folds in women than in men. According to the comparative analysis, ultrasonography accuracy rate (in those patients who had had clearly visible vocal folds during ultrasonography did not differ from that during videolaryngoscopy. Conclusion. During the conducted research it was found that the US of the larynx is an effective and perspective method for detection of a paresis of VF with sensitivity and specificity 93,55% and 100% respectively. Among those patients who' VF are available to ultrasound evaluation the accuracy of method is comparable with a videolaryngoscopy and can be used with success in daily work of units of endocrine surgery.

  5. Elastocapillary folding of three dimensional micro-structures using water pumped through the wafer via a silicon nitride tube

    NARCIS (Netherlands)

    Legrain, A.B.H.; Berenschot, Johan W.; Sanders, Remco G.P.; Ma, Kechun; Tas, Niels Roelof; Abelmann, Leon

    2011-01-01

    In this paper we present the first investigation of a batch method for folding of threedimensional micrometer-sized silicon nitride structures by capillary forces. Silicon nitride tubes have been designed and fabricated using DRIE at the center of the planar origami patterns of the structures. Water

  6. Three-Fold Embedding: Farm Development in Relation to Its Socio-Material Context

    Directory of Open Access Journals (Sweden)

    Ron Methorst

    2017-09-01

    Full Text Available Understanding heterogeneity in farm development strategies is important in order to design effective policies and support programs to increase the sustainability of agriculture in relation to its socio-material context. Using a unique case study of 102 dairy farmers in The Netherlands, all operating in a highly similar socio-material context, this paper studies the differences in the relation of farms with the socio-material context. To this end, the concept of three-fold embedding is developed and tested using the ideal-typical characteristics of three patterns of farm development that were identified in the case study: (1 maximising total milk production; (2 optimising milk production using mainly on-farm resources; and (3 diversified on-farm production. Three-fold embedding was conceptualised in relation to the following dimensions: (1 value chain relations; (2 socio-cultural relations; and (3 natural resource relations, while using a scale ranging from a Close to a Stretched set of relations. The concept of three-fold embedding proves to be useful to identify in a non-normative and non-binary manner meaningful differences between patterns of farm development. These differences relate to differences in opportunity identification and strategic decision-making. The concept supports a relational perspective in studying farm strategy development using a sociology of entrepreneurship approach.

  7. Mapping of near surface fold structures with GPR and ERT near Steinbrunn (Northern Burgenland, Austria)

    Science.gov (United States)

    Kreutzer, Ingrid; Chwatal, Werner; Häusler, Hermann; Scheibz, Jürgen; Steirer, Fritz

    2014-05-01

    In the transition zone between the southern Vienna Basin and the Eisenstadt basin, close to Wr. Neustadt, spectacular fold structures are exposed in the former sand pit of Steinbrunn. The succession of Upper Pannonian age consists of decimetre to meter thick sandy, silty and clayey beds, which are overlain by sandstone beds (Grundtner et al., 2009). The anticline and syncline structures were interpreted as of gravitational origin by Exner et al. (2009), and reinterpreted as of tectonic origin by Häusler (2012a). In order to gain a more detailed insight to the three dimensional distribution and orientation of the folds high resolution geophysics such as electrical resistivity tomography (ERT), ground penetrating radar (GPR) and electromagnetics (EM) were applied to map the surroundings of the sandpit. The ERT- and EM-profiles show that the uppermost layer is more clayey northwest and sandier southeast of the sandpit. This is important for the GPR because clay attenuates the radar signals and therefore no clear layering of the subsurface could be mapped in these areas. In order to directly compare ERT and GPR results with the lithology of the fold structures observed in the sandpit, a reference profile on top of the 140 m long wall of the sandpit was performed. Both methods clearly reveal fold structures paralleling the folded Pannonian strata of the outcrop. While the GPR data displays boundaries and their geometry in the succession, the resistivities in the ERT portrays a more smoothened image of the observed fold structure. In almost all GPR profiles wavelike structures are visible with axes in northern direction and dome-shaped structures with axes in eastern direction, deepening towards the west. In conclusion this pattern is comparable to sections of rounded buckle folds. Although there are clayey areas wave-like and dome-like reflections can be followed in the GPR profiles over a distance of several hundred meters. This is confirmed by the ERT profiles

  8. Fluorescence of Alexa fluor dye tracks protein folding.

    Directory of Open Access Journals (Sweden)

    Simon Lindhoud

    Full Text Available Fluorescence spectroscopy is an important tool for the characterization of protein folding. Often, a protein is labeled with appropriate fluorescent donor and acceptor probes and folding-induced changes in Förster Resonance Energy Transfer (FRET are monitored. However, conformational changes of the protein potentially affect fluorescence properties of both probes, thereby profoundly complicating interpretation of FRET data. In this study, we assess the effects protein folding has on fluorescence properties of Alexa Fluor 488 (A488, which is commonly used as FRET donor. Here, A488 is covalently attached to Cys69 of apoflavodoxin from Azotobacter vinelandii. Although coupling of A488 slightly destabilizes apoflavodoxin, the three-state folding of this protein, which involves a molten globule intermediate, is unaffected. Upon folding of apoflavodoxin, fluorescence emission intensity of A488 changes significantly. To illuminate the molecular sources of this alteration, we applied steady state and time-resolved fluorescence techniques. The results obtained show that tryptophans cause folding-induced changes in quenching of Alexa dye. Compared to unfolded protein, static quenching of A488 is increased in the molten globule. Upon populating the native state both static and dynamic quenching of A488 decrease considerably. We show that fluorescence quenching of Alexa Fluor dyes is a sensitive reporter of conformational changes during protein folding.

  9. The impact of intraglottal vortices on vocal fold dynamics

    Science.gov (United States)

    Erath, Byron; Pirnia, Alireza; Peterson, Sean

    2016-11-01

    During voiced speech a critical pressure is produced in the lungs that separates the vocal folds and creates a passage (the glottis) for airflow. As air passes through the vocal folds the resulting aerodynamic loading, coupled with the tissue properties of the vocal folds, produces self-sustained oscillations. Throughout each cycle a complex flow field develops, characterized by a plethora of viscous flow phenomena. Air passing through the glottis creates a jet, with periodically-shed vortices developing due to flow separation and the Kelvin-Helmholtz instability in the shear layer. These vortices have been hypothesized to be a crucial mechanism for producing vocal fold vibrations. In this study the effect of vortices on the vocal fold dynamics is investigated experimentally by passing a vortex ring over a flexible beam with the same non-dimensional mechanical properties as the vocal folds. Synchronized particle image velocimetry data are acquired in tandem with the beam dynamics. The resulting impact of the vortex ring loading on vocal fold dynamics is discussed in detail. This work was supported by the National Science Foundation Grant CBET #1511761.

  10. Idiopathic unilateral vocal-fold paralysis in the adult.

    Science.gov (United States)

    Rubin, F; Villeneuve, A; Alciato, L; Slaïm, L; Bonfils, P; Laccourreye, O

    2018-02-02

    To analyze the characteristics of adult idiopathic unilateral vocal-fold paralysis. Retrospective study of diagnostic problems, clinical data and recovery in an inception cohort of 100 adult patients with idiopathic unilateral vocal-fold paralysis (Group A) and comparison with a cohort of 211 patients with isolated non-idiopathic non-traumatic unilateral vocal-fold paralysis (Group B). Diagnostic problems were noted in 24% of cases in Group A: eight patients with concomitant common upper aerodigestive tract infection, five patients with a concomitant condition liable to induce immunodepression and 11 patients in whom a malignant tumor occurred along the path of the ipsilateral vagus and inferior laryngeal nerves or in the ipsilateral paralyzed larynx. There was no recovery of vocal-fold motion beyond 51 months after onset of paralysis. The 5-year actuarial estimate for recovery differed significantly (Pvocal-fold paralysis. In non-traumatic vocal-fold paralysis in adult patients, without recovery of vocal-fold motion, a minimum three years' regular follow-up is recommended. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

  11. Endoscopic Anatomy of the Tensor Fold and Anterior Attic.

    Science.gov (United States)

    Li, Bin; Doan, Phi; Gruhl, Robert R; Rubini, Alessia; Marchioni, Daniele; Fina, Manuela

    2018-02-01

    Objectives The objectives of the study were to (1) study the anatomical variations of the tensor fold and its anatomic relation with transverse crest, supratubal recess, and anterior epitympanic space and (2) explore the most appropriate endoscopic surgical approach to each type of the tensor fold variants. Study Design Cadaver dissection study. Setting Temporal bone dissection laboratory. Subjects and Methods Twenty-eight human temporal bones (26 preserved and 2 fresh) were dissected through an endoscopic transcanal approach between September 2016 and June 2017. The anatomical variations of the tensor fold, transverse crest, supratubal recess, and anterior epitympanic space were studied before and after removing ossicles. Results Three different tensor fold orientations were observed: vertical (type A, 11/28, 39.3%) with attachment to the transverse crest, oblique (type B, 13/28, 46.4%) with attachment to the anterior tegmen tympani, and horizontal (type C, 4/28, 14.3%) with attachment to the tensor tympani canal. The tensor fold was a complete membrane in 20 of 28 (71.4%) specimens, preventing direct ventilation between the supratubal recess and anterior epitympanic space. We identified 3 surgical endoscopic approaches, which allowed visualization of the tensor fold without removing the ossicles. Conclusions The orientation of the tensor fold is the determining structure that dictates the conformation and limits of the epitympanic space. We propose a classification of the tensor fold based on 3 anatomical variants. We also describe 3 different minimally invasive endoscopic approaches to identify the orientation of the tensor fold while maintaining ossicular chain continuity.

  12. Radiation Fibrosis of the Vocal Fold: From Man to Mouse

    Science.gov (United States)

    Johns, Michael M.; Kolachala, Vasantha; Berg, Eric; Muller, Susan; Creighton, Frances X.; Branski, Ryan C.

    2013-01-01

    Objectives To characterize fundamental late tissue effects in the human vocal fold following radiation therapy. To develop a murine model of radiation fibrosis to ultimately develop both treatment and prevention paradigms. Design Translational study using archived human and fresh murine irradiated vocal fold tissue. Methods 1) Irradiated vocal fold tissue from patients undergoing laryngectomy for loss of function from radiation fibrosis were identified from pathology archives. Histomorphometry, immunohistochemistry, and whole-genome microarray as well as real-time transcriptional analyses was performed. 2) Focused radiation to the head and neck was delivered to mice in a survival fashion. One month following radiation, vocal fold tissue was analyzed with histomorphometry, immunohistochemistry, and real-time PCR transcriptional analysis for selected markers of fibrosis. Results Human irradiated vocal folds demonstrated increased collagen transcription with increased deposition and disorganization of collagen in both the thyroarytenoid muscle and the superficial lamina propria. Fibronectin were increased in the superficial lamina propria. Laminin decreased in the thyroarytenoid muscle. Whole genome microarray analysis demonstrated increased transcription of markers for fibrosis, oxidative stress, inflammation, glycosaminoglycan production and apoptosis. Irradiated murine vocal folds demonstrated increases in collagen and fibronectin transcription and deposition in the lamina propria. Transforming growth factor (TGF)-β increased in the lamina propria. Conclusion Human irradiated vocal folds demonstrate molecular changes leading to fibrosis that underlie loss of vocal fold pliability that occurs in patients following laryngeal irradiation. Irradiated murine tissue demonstrates similar findings, and this mouse model may have utility in creating prevention and treatment strategies for vocal fold radiation fibrosis. PMID:23242839

  13. Micro-scale truss structures with three-fold and six-fold symmetry formed from self-propagating polymer waveguides

    Energy Technology Data Exchange (ETDEWEB)

    Jacobsen, Alan J. [HRL Laboratories LLC, Sensors and Materials Laboratory, 3011 Malibu Canyon Road, Malibu, CA 90265-4797 (United States); Department of Aerospace and Mechanical Engineering, University of Southern California, Los Angeles, CA (United States)], E-mail: ajjacobsen@hrl.com; Barvosa-Carter, William [HRL Laboratories LLC, Sensors and Materials Laboratory, 3011 Malibu Canyon Road, Malibu, CA 90265-4797 (United States); Nutt, Steven [Department of Chemical Engineering and Materials Science, University of Southern California, Los Angeles, CA (United States)

    2008-06-15

    A process for interconnecting a three-dimensional pattern of self-propagating polymer waveguides was used to form micro-truss structures with two new unit cell architectures. The structures were formed using a two-dimensional mask with a hexagonal pattern of apertures. Distinct unit cell architectures were possible by exposing the mask to a different number of incident UV exposure beams, which are used to form the waveguides. One unit cell design featured three intersecting waveguides per node, resulting in a structure with three-fold symmetry. The second unit cell design had six-fold symmetry and was characterized by primary nodes with six intersecting waveguides and secondary nodes with two intersecting waveguides. Compression loading experiments were conducted on micro-truss samples with comparable relative density values ({rho}/{rho}{sub s} = 6.5%), but different unit cell architectures. The addition of secondary nodes in the structures based on the second design led to an increase in compressive modulus of up to 70% and an average increase in peak strength of 42%. The increase in compressive strength and modulus was attributed to a reduction in the truss-member slenderness ratio achieved through increased waveguide connectivity.

  14. Micro-scale truss structures with three-fold and six-fold symmetry formed from self-propagating polymer waveguides

    International Nuclear Information System (INIS)

    Jacobsen, Alan J.; Barvosa-Carter, William; Nutt, Steven

    2008-01-01

    A process for interconnecting a three-dimensional pattern of self-propagating polymer waveguides was used to form micro-truss structures with two new unit cell architectures. The structures were formed using a two-dimensional mask with a hexagonal pattern of apertures. Distinct unit cell architectures were possible by exposing the mask to a different number of incident UV exposure beams, which are used to form the waveguides. One unit cell design featured three intersecting waveguides per node, resulting in a structure with three-fold symmetry. The second unit cell design had six-fold symmetry and was characterized by primary nodes with six intersecting waveguides and secondary nodes with two intersecting waveguides. Compression loading experiments were conducted on micro-truss samples with comparable relative density values (ρ/ρ s = 6.5%), but different unit cell architectures. The addition of secondary nodes in the structures based on the second design led to an increase in compressive modulus of up to 70% and an average increase in peak strength of 42%. The increase in compressive strength and modulus was attributed to a reduction in the truss-member slenderness ratio achieved through increased waveguide connectivity

  15. Polyhedral patterns

    KAUST Repository

    Jiang, Caigui; Tang, Chengcheng; Vaxman, Amir; Wonka, Peter; Pottmann, Helmut

    2015-01-01

    We study the design and optimization of polyhedral patterns, which are patterns of planar polygonal faces on freeform surfaces. Working with polyhedral patterns is desirable in architectural geometry and industrial design. However, the classical

  16. Water dynamics clue to key residues in protein folding

    International Nuclear Information System (INIS)

    Gao, Meng; Zhu, Huaiqiu; Yao, Xin-Qiu; She, Zhen-Su

    2010-01-01

    A computational method independent of experimental protein structure information is proposed to recognize key residues in protein folding, from the study of hydration water dynamics. Based on all-atom molecular dynamics simulation, two key residues are recognized with distinct water dynamical behavior in a folding process of the Trp-cage protein. The identified key residues are shown to play an essential role in both 3D structure and hydrophobic-induced collapse. With observations on hydration water dynamics around key residues, a dynamical pathway of folding can be interpreted.

  17. Microwave-enhanced folding and denaturation of globular proteins

    DEFF Research Database (Denmark)

    Bohr, Henrik; Bohr, Jakob

    2000-01-01

    It is shown that microwave irradiation can affect the kinetics of the folding process of some globular proteins, especially beta-lactoglobulin. At low temperature the folding from the cold denatured phase of the protein is enhanced, while at a higher temperature the denaturation of the protein from...... its folded state is enhanced. In the latter case, a negative temperature gradient is needed for the denaturation process, suggesting that the effects of the microwaves are nonthermal. This supports the notion that coherent topological excitations can exist in proteins. The application of microwaves...

  18. Protein folding and the organization of the protein topology universe

    DEFF Research Database (Denmark)

    Lindorff-Larsen,, Kresten; Røgen, Peter; Paci, Emanuele

    2005-01-01

    residues and, in addition, that the topology of the transition state is closer to that of the native state than to that of any other fold in the protein universe. Here, we review the evidence for these conclusions and suggest a molecular mechanism that rationalizes these findings by presenting a view...... of protein folds that is based on the topological features of the polypeptide backbone, rather than the conventional view that depends on the arrangement of different types of secondary-structure elements. By linking the folding process to the organization of the protein structure universe, we propose...

  19. Adjustable thermal resistor by reversibly folding a graphene sheet.

    Science.gov (United States)

    Song, Qichen; An, Meng; Chen, Xiandong; Peng, Zhan; Zang, Jianfeng; Yang, Nuo

    2016-08-11

    Phononic (thermal) devices such as thermal diodes, thermal transistors, thermal logic gates, and thermal memories have been studied intensively. However, tunable thermal resistors have not been demonstrated yet. Here, we propose an instantaneously adjustable thermal resistor based on folded graphene. Through theoretical analysis and molecular dynamics simulations, we study the phonon-folding scattering effect and the dependence of thermal resistivity on the length between two folds and the overall length. Furthermore, we discuss the possibility of realizing instantaneously adjustable thermal resistors in experiment. Our studies bring new insights into designing thermal resistors and understanding the thermal modulation of 2D materials by adjusting basic structure parameters.

  20. Sex Hormone Receptor Expression in the Human Vocal Fold Subunits.

    Science.gov (United States)

    Kirgezen, Tolga; Sunter, Ahmet Volkan; Yigit, Ozgur; Huq, Gulben Erdem

    2017-07-01

    The study aimed to evaluate the existence of sex hormone receptors in the subunits of vocal fold. This is a cadaver study. The androgen, estrogen, and progesterone receptors were examined in the epithelium (EP), superficial layer of the lamina propria (SLP), vocal ligament (VL), and macula flava (MF) of the vocal folds from 42 human cadavers (21 male, 21 female) by immunohistochemical methods. Their staining ratios were scored and statistically compared. The androgen receptor score was significantly higher for the MF than for the EP and SLP (P vocal fold, mostly in the MF and VLs. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  1. Miniaturization of Multiple-Layer Folded Patch Antennas

    DEFF Research Database (Denmark)

    Zhang, Jiaying; Breinbjerg, Olav

    2009-01-01

    A new folded patch antenna with multiple layers was developed in this paper, by folding the patch in a proper way, and a highly miniaturized antenna can be realized. The multiple layer patch with 4-layer and 6-layer are designed and evaluated at 2.4 GHz, 915 MHz, and 415 MHz respectively. Then a 4...... layer patch is fabricated and measured to validate the design method. The theoretical analysis, design and simulations, fabrications, as well as the measurements are presented in this paper. All the results show that the folded patch antenna is a good candidate in making a highly miniaturized compact...

  2. Endoscopic vocal fold injection using a 25-gauge butterfly needle.

    Science.gov (United States)

    Buchanan, M A; Riffat, F; Palme, C E

    2016-04-01

    To describe a useful technique for infiltrating a bulking agent using a butterfly needle, as part of a transoral endoscopic vocal fold medialisation procedure. This paper describes the procedure of grasping the needle with phonosurgery forceps and administering the injectate to the vocal fold through careful application of the syringe plunger via a length of rubber tubing from outside the mouth. This procedure is performed routinely in our institution without complication. The advantages of this technique are discussed. This is a safe and easy method of injecting into a vocal fold.

  3. Co-evolutionary constraints of globular proteins correlate with their folding rates.

    Science.gov (United States)

    Mallik, Saurav; Kundu, Sudip

    2015-08-04

    Folding rates (lnkf) of globular proteins correlate with their biophysical properties, but relationship between lnkf and patterns of sequence evolution remains elusive. We introduce 'relative co-evolution order' (rCEO) as length-normalized average primary chain separation of co-evolving pairs (CEPs), which negatively correlates with lnkf. In addition to pairs in native 3D contact, indirectly connected and structurally remote CEPs probably also play critical roles in protein folding. Correlation between rCEO and lnkf is stronger in multi-state proteins than two-state proteins, contrasting the case of contact order (co), where stronger correlation is found in two-state proteins. Finally, rCEO, co and lnkf are fitted into a 3D linear correlation. Copyright © 2015 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

  4. Generic framework for mining cellular automata models on protein-folding simulations.

    Science.gov (United States)

    Diaz, N; Tischer, I

    2016-05-13

    Cellular automata model identification is an important way of building simplified simulation models. In this study, we describe a generic architectural framework to ease the development process of new metaheuristic-based algorithms for cellular automata model identification in protein-folding trajectories. Our framework was developed by a methodology based on design patterns that allow an improved experience for new algorithms development. The usefulness of the proposed framework is demonstrated by the implementation of four algorithms, able to obtain extremely precise cellular automata models of the protein-folding process with a protein contact map representation. Dynamic rules obtained by the proposed approach are discussed, and future use for the new tool is outlined.

  5. 100-fold but not 50-fold dystrophin overexpression aggravates electrocardiographic defects in the mdx model of Duchenne muscular dystrophy

    Directory of Open Access Journals (Sweden)

    Yongping Yue

    2016-01-01

    Full Text Available Dystrophin gene replacement holds the promise of treating Duchenne muscular dystrophy. Supraphysiological expression is a concern for all gene therapy studies. In the case of Duchenne muscular dystrophy, Chamberlain and colleagues found that 50-fold overexpression did not cause deleterious side effect in skeletal muscle. To determine whether excessive dystrophin expression in the heart is safe, we studied two lines of transgenic mdx mice that selectively expressed a therapeutic minidystrophin gene in the heart at 50-fold and 100-fold of the normal levels. In the line with 50-fold overexpression, minidystrophin showed sarcolemmal localization and electrocardiogram abnormalities were corrected. However, in the line with 100-fold overexpression, we not only detected sarcolemmal minidystrophin expression but also observed accumulation of minidystrophin vesicles in the sarcoplasm. Excessive minidystrophin expression did not correct tachycardia, a characteristic feature of Duchenne muscular dystrophy. Importantly, several electrocardiogram parameters (QT interval, QRS duration and the cardiomyopathy index became worse than that of mdx mice. Our data suggests that the mouse heart can tolerate 50-fold minidystrophin overexpression, but 100-fold overexpression leads to cardiac toxicity.

  6. Adipose-Derived Mesenchymal Stem Cells in the Regeneration of Vocal Folds: A Study on a Chronic Vocal Fold Scar

    Directory of Open Access Journals (Sweden)

    Angelou Valerie

    2016-01-01

    Full Text Available Background. The aim of the study was to assess the histological effects of autologous infusion of adipose-derived stem cells (ADSC on a chronic vocal fold scar in a rabbit model as compared to an untreated scar as well as in injection of hyaluronic acid. Study Design. Animal experiment. Method. We used 74 New Zealand rabbits. Sixteen of them were used as control/normal group. We created a bilateral vocal fold wound in the remaining 58 rabbits. After 18 months we separated our population into three groups. The first group served as control/scarred group. The second one was injected with hyaluronic acid in the vocal folds, and the third received an autologous adipose-derived stem cell infusion in the scarred vocal folds (ADSC group. We measured the variation of thickness of the lamina propria of the vocal folds and analyzed histopathologic changes in each group after three months. Results. The thickness of the lamina propria was significantly reduced in the group that received the ADSC injection, as compared to the normal/scarred group. The collagen deposition, the hyaluronic acid, the elastin levels, and the organization of elastic fibers tend to return to normal after the injection of ADSC. Conclusions. Autologous injection of adipose-derived stem cells on a vocal fold chronic scar enhanced the healing of the vocal folds and the reduction of the scar tissue, even when compared to other treatments.

  7. Adipose-Derived Mesenchymal Stem Cells in the Regeneration of Vocal Folds: A Study on a Chronic Vocal Fold Scar

    Science.gov (United States)

    Vassiliki, Kalodimou; Irini, Messini; Nikolaos, Psychalakis; Karampela, Eleftheria; Apostolos, Papalois

    2016-01-01

    Background. The aim of the study was to assess the histological effects of autologous infusion of adipose-derived stem cells (ADSC) on a chronic vocal fold scar in a rabbit model as compared to an untreated scar as well as in injection of hyaluronic acid. Study Design. Animal experiment. Method. We used 74 New Zealand rabbits. Sixteen of them were used as control/normal group. We created a bilateral vocal fold wound in the remaining 58 rabbits. After 18 months we separated our population into three groups. The first group served as control/scarred group. The second one was injected with hyaluronic acid in the vocal folds, and the third received an autologous adipose-derived stem cell infusion in the scarred vocal folds (ADSC group). We measured the variation of thickness of the lamina propria of the vocal folds and analyzed histopathologic changes in each group after three months. Results. The thickness of the lamina propria was significantly reduced in the group that received the ADSC injection, as compared to the normal/scarred group. The collagen deposition, the hyaluronic acid, the elastin levels, and the organization of elastic fibers tend to return to normal after the injection of ADSC. Conclusions. Autologous injection of adipose-derived stem cells on a vocal fold chronic scar enhanced the healing of the vocal folds and the reduction of the scar tissue, even when compared to other treatments. PMID:26933440

  8. Laryngeal ultrasound and vocal fold movement in the pediatric cardiovascular intensive care unit.

    Science.gov (United States)

    Ongkasuwan, Julina; Ocampo, Elena; Tran, Brandon

    2017-01-01

    Vocal fold motion impairment (VFMI) is a known sequela of cardiovascular surgery. The gold standard for the evaluation of vocal fold movement is flexible nasolaryngoscopy (FNL). Although safe, FNL does cause measurable physiologic changes. Noxious stimuli in cardiovascular intensive care unit (CVICU) neonates may cause imbalance between the pulmonary and systemic circulations and potentially circulatory collapse. The goals of this project were to determine the accuracy of laryngeal ultrasound (LUS) compared to FNL to identify VFMI in CVICU neonates and compare their physiologic impact. Case control. Prospective case-control study. Forty-six consecutive infants from the CVICU were recruited, 23 with VFMI and 23 without based on FNL findings. They then underwent LUS, which was subsequently reviewed by two pediatric radiologists blinded to the FNL results. Physiologic parameters were recorded before and after the procedures. Data analysis was performed with Cohen's kappa and Wilcoxon signed-rank test. Agreement between LUS and FNL was substantial (κ = 0.78). Laryngeal ultrasound had a sensitivity of 0.84 and specificity of 0.95 for identifying VFMI. In terms of physiologic impact, LUS caused statistically significantly less change in diastolic blood pressure (P = 0.01), pulse (P = 0.001), and O 2 saturation (P = 0.004) compared to FNL. Arytenoid rotation could be seen clearly, and the vocal fold-arytenoid angle in abduction was most predictive of symmetry and movement (P = 0.17). However, it was difficult to determine vocal fold closure patterns with LUS. Laryngeal ultrasound is a comparable to FNL for evaluating vocal fold mobility with less physiologic impact. 3b. Laryngoscope, 127:167-172, 2017. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  9. RNAslider: a faster engine for consecutive windows folding and its application to the analysis of genomic folding asymmetry.

    Science.gov (United States)

    Horesh, Yair; Wexler, Ydo; Lebenthal, Ilana; Ziv-Ukelson, Michal; Unger, Ron

    2009-03-04

    Scanning large genomes with a sliding window in search of locally stable RNA structures is a well motivated problem in bioinformatics. Given a predefined window size L and an RNA sequence S of size N (L free energy (MFE) for the folding of each of the L-sized substrings of S. The consecutive windows folding problem can be naively solved in O(NL3) by applying any of the classical cubic-time RNA folding algorithms to each of the N-L windows of size L. Recently an O(NL2) solution for this problem has been described. Here, we describe and implement an O(NLpsi(L)) engine for the consecutive windows folding problem, where psi(L) is shown to converge to O(1) under the assumption of a standard probabilistic polymer folding model, yielding an O(L) speedup which is experimentally confirmed. Using this tool, we note an intriguing directionality (5'-3' vs. 3'-5') folding bias, i.e. that the minimal free energy (MFE) of folding is higher in the native direction of the DNA than in the reverse direction of various genomic regions in several organisms including regions of the genomes that do not encode proteins or ncRNA. This bias largely emerges from the genomic dinucleotide bias which affects the MFE, however we see some variations in the folding bias in the different genomic regions when normalized to the dinucleotide bias. We also present results from calculating the MFE landscape of a mouse chromosome 1, characterizing the MFE of the long ncRNA molecules that reside in this chromosome. The efficient consecutive windows folding engine described in this paper allows for genome wide scans for ncRNA molecules as well as large-scale statistics. This is implemented here as a software tool, called RNAslider, and applied to the scanning of long chromosomes, leading to the observation of features that are visible only on a large scale.

  10. Botulinum toxin in the treatment of vocal fold nodules.

    Science.gov (United States)

    Allen, Jacqui E; Belafsky, Peter C

    2009-12-01

    Promising new techniques in the management of vocal fold nodules have been developed in the past 2 years. Simultaneously, the therapeutic use of botulinum toxin has rapidly expanded. This review explores the use of botulinum toxin in treatment of vocal nodules and summarizes current therapeutic concepts. New microsurgical instruments and techniques, refinements in laser technology, radiosurgical excision and steroid intralesional injections are all promising new techniques in the management of vocal nodules. Botulinum toxin-induced 'voice rest' is a new technique we have employed in patients with recalcitrant nodules. Successful resolution of nodules is possible with this technique, without the risk of vocal fold scarring inherent in dissection/excision techniques. Botulinum toxin usage is exponentially increasing, and large-scale, long-term studies demonstrate its safety profile. Targeted vocal fold temporary paralysis induced by botulinum toxin injection is a new, well tolerated and efficacious treatment in patients with persistent vocal fold nodules.

  11. New Analysis and Theory of Deployable Folded Structures, Phase II

    Data.gov (United States)

    National Aeronautics and Space Administration — A recently developed mathematical folding theory has great value for deployable space structures and in situ manufacture of large beams, panels and cylinders. The...

  12. RNA inverse folding using Monte Carlo tree search.

    Science.gov (United States)

    Yang, Xiufeng; Yoshizoe, Kazuki; Taneda, Akito; Tsuda, Koji

    2017-11-06

    Artificially synthesized RNA molecules provide important ways for creating a variety of novel functional molecules. State-of-the-art RNA inverse folding algorithms can design simple and short RNA sequences of specific GC content, that fold into the target RNA structure. However, their performance is not satisfactory in complicated cases. We present a new inverse folding algorithm called MCTS-RNA, which uses Monte Carlo tree search (MCTS), a technique that has shown exceptional performance in Computer Go recently, to represent and discover the essential part of the sequence space. To obtain high accuracy, initial sequences generated by MCTS are further improved by a series of local updates. Our algorithm has an ability to control the GC content precisely and can deal with pseudoknot structures. Using common benchmark datasets for evaluation, MCTS-RNA showed a lot of promise as a standard method of RNA inverse folding. MCTS-RNA is available at https://github.com/tsudalab/MCTS-RNA .

  13. Folding two dimensional crystals by swift heavy ion irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Ochedowski, Oliver; Bukowska, Hanna [Fakultät für Physik and CENIDE, Universität Duisburg-Essen, D-47048 Duisburg (Germany); Freire Soler, Victor M. [Fakultät für Physik and CENIDE, Universität Duisburg-Essen, D-47048 Duisburg (Germany); Departament de Fisica Aplicada i Optica, Universitat de Barcelona, E08028 Barcelona (Spain); Brökers, Lara [Fakultät für Physik and CENIDE, Universität Duisburg-Essen, D-47048 Duisburg (Germany); Ban-d' Etat, Brigitte; Lebius, Henning [CIMAP (CEA-CNRS-ENSICAEN-UCBN), 14070 Caen Cedex 5 (France); Schleberger, Marika, E-mail: marika.schleberger@uni-due.de [Fakultät für Physik and CENIDE, Universität Duisburg-Essen, D-47048 Duisburg (Germany)

    2014-12-01

    Ion irradiation of graphene, the showcase model of two dimensional crystals, has been successfully applied to induce various modifications in the graphene crystal. One of these modifications is the formation of origami like foldings in graphene which are created by swift heavy ion irradiation under glancing incidence angle. These foldings can be applied to locally alter the physical properties of graphene like mechanical strength or chemical reactivity. In this work we show that the formation of foldings in two dimensional crystals is not restricted to graphene but can be applied for other materials like MoS{sub 2} and hexagonal BN as well. Further we show that chemical vapour deposited graphene forms foldings after swift heavy ion irradiation while chemical vapour deposited MoS{sub 2} does not.

  14. Folding two dimensional crystals by swift heavy ion irradiation

    International Nuclear Information System (INIS)

    Ochedowski, Oliver; Bukowska, Hanna; Freire Soler, Victor M.; Brökers, Lara; Ban-d'Etat, Brigitte; Lebius, Henning; Schleberger, Marika

    2014-01-01

    Ion irradiation of graphene, the showcase model of two dimensional crystals, has been successfully applied to induce various modifications in the graphene crystal. One of these modifications is the formation of origami like foldings in graphene which are created by swift heavy ion irradiation under glancing incidence angle. These foldings can be applied to locally alter the physical properties of graphene like mechanical strength or chemical reactivity. In this work we show that the formation of foldings in two dimensional crystals is not restricted to graphene but can be applied for other materials like MoS 2 and hexagonal BN as well. Further we show that chemical vapour deposited graphene forms foldings after swift heavy ion irradiation while chemical vapour deposited MoS 2 does not

  15. Evidence for multiphase folding of the central Indian Ocean lithosphere

    Digital Repository Service at National Institute of Oceanography (India)

    Krishna, K.S.; Bull, J.M.; Scrutton, R.A.

    Long-wavelength (100-300 km) folding in the central Indian Ocean associated with the diffuse plate boundary separating the Indian, Australian, and Capricorn plates is Earth's most convincing example of organized large-scale lithospheric deformation...

  16. Nonlinear vs. linear biasing in Trp-cage folding simulations

    Energy Technology Data Exchange (ETDEWEB)

    Spiwok, Vojtěch, E-mail: spiwokv@vscht.cz; Oborský, Pavel; Králová, Blanka [Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 3, Prague 6 166 28 (Czech Republic); Pazúriková, Jana [Institute of Computer Science, Masaryk University, Botanická 554/68a, 602 00 Brno (Czech Republic); Křenek, Aleš [Institute of Computer Science, Masaryk University, Botanická 554/68a, 602 00 Brno (Czech Republic); Center CERIT-SC, Masaryk Univerzity, Šumavská 416/15, 602 00 Brno (Czech Republic)

    2015-03-21

    Biased simulations have great potential for the study of slow processes, including protein folding. Atomic motions in molecules are nonlinear, which suggests that simulations with enhanced sampling of collective motions traced by nonlinear dimensionality reduction methods may perform better than linear ones. In this study, we compare an unbiased folding simulation of the Trp-cage miniprotein with metadynamics simulations using both linear (principle component analysis) and nonlinear (Isomap) low dimensional embeddings as collective variables. Folding of the mini-protein was successfully simulated in 200 ns simulation with linear biasing and non-linear motion biasing. The folded state was correctly predicted as the free energy minimum in both simulations. We found that the advantage of linear motion biasing is that it can sample a larger conformational space, whereas the advantage of nonlinear motion biasing lies in slightly better resolution of the resulting free energy surface. In terms of sampling efficiency, both methods are comparable.

  17. Trends in Utilization of Vocal Fold Injection Procedures.

    Science.gov (United States)

    Rosow, David E

    2015-11-01

    Office-based vocal fold injections have become increasingly popular over the past 15 years. Examination of trends in procedure coding for vocal fold injections in the United States from 2000 to 2012 was undertaken to see if they reflect this shift. The US Part B Medicare claims database was queried from 2000 through 2012 for multiple Current Procedural Terminology codes. Over the period studied, the number of nonoperative laryngoscopic injections (31513, 31570) and operative medialization laryngoplasties (31588) remained constant. Operative vocal fold injection (31571) demonstrated marked linear growth over the 12-year study period, from 744 procedures in 2000 to 4788 in 2012-an increase >640%. The dramatic increased incidence in the use of code 31571 reflects an increasing share of vocal fold injections being performed in the operating room and not in an office setting, running counter to the prevailing trend toward awake, office-based injection procedures. © American Academy of Otolaryngology—Head and Neck Surgery Foundation 2015.

  18. Traumatic chorioretinal folds treated with intra-vitreal triamcinolone injection

    Directory of Open Access Journals (Sweden)

    Kook Young Kim

    2013-01-01

    Full Text Available A 34-year-old male visited the hospital due to decreased visual acuity in the left eye following an injury from a car accident. In the left eye, best-corrected visual acuity (BCVA was hand motion and intraocular pressure (IOP was 8 mmHg. Choroidal vasodilation and chorioretinal folds were observed by spectral domain-optical coherence tomography (SD-OCT. Topical and systemic steroid treatments did not improve the chorioretinal folds. Twelve months after the injury, intra-vitreal triamcinolone (4 mg/0.1 ml was injected. Six months after intra-vitreal triamcinolone injection, BCVA in the left eye had improved to 20/100. Fundus examination showed improvement in retinal vascular tortuosity and SD-OCT revealed improvements in choroidal vasodilation and chorioretinal folds. Intra-vitreal triamcinolone injection (IVTI was effective against traumatic chorioretinal folds with no recurrence based on objective observation by fundus photography and SD-OCT.

  19. Phonosurgery of the vocal folds : a classification proposal

    NARCIS (Netherlands)

    Remacle, M; Friedrich, G; Dikkers, FG; de Jong, F

    The Phonosurgery Committee of the European Laryngological Society (ELS) has examined the definition and technical description of phonosurgical procedures. Based on this review, the committee has proposed a working classification. The current presentation is restricted to vocal fold surgery (VFS)

  20. Protein folding and misfolding shining light by infrared spectroscopy

    CERN Document Server

    Fabian, Heinz

    2012-01-01

    Infrared spectroscopy is a new and innovative technology to study protein folding/misfolding events in the broad arsenal of techniques conventionally used in this field. The progress in understanding protein folding and misfolding is primarily due to the development of biophysical methods which permit to probe conformational changes with high kinetic and structural resolution. The most commonly used approaches rely on rapid mixing methods to initiate the folding event via a sudden change in solvent conditions. Traditionally, techniques such as fluorescence, circular dichroism or visible absorption are applied to probe the process. In contrast to these techniques, infrared spectroscopy came into play only very recently, and the progress made in this field up to date which now permits to probe folding events over the time scale from picoseconds to minutes has not yet been discussed in a book. The aim of this book is to provide an overview of the developments as seen by some of the main contributors to the field...

  1. Thermal analysis for folded solar array of spacecraft in orbit

    International Nuclear Information System (INIS)

    Yang, W.H.; Cheng, H.E.; Cai, A.

    2004-01-01

    The combined radiation-conduction heat transfer in folded solar array was considered as a three-dimensional anisotropic conduction without inner heat source. The three-dimensional equivalent conductivity in cell plate were obtained. The especially discrete equation coefficients of the nodes on the surfaces of adjacent cell plates were deduced by utilizing the simplified radiation network among the two adjacent cell plate surfaces and the deep cold space. All the thermal influence factors on the temperature response of the folded solar array were considered carefully. SIP method was used to solve the discrete equation. By comparing the calculation results under three cases, the temperature response and the maximum average difference of the folded solar array was obtained during the period of throw-radome of the launch vehicle and spread of the folded solar array. The obtained result is a valuable reference for the selection of the launch time of the spacecraft

  2. Cell origami: self-folding of three-dimensional cell-laden microstructures driven by cell traction force.

    Directory of Open Access Journals (Sweden)

    Kaori Kuribayashi-Shigetomi

    Full Text Available This paper describes a method of generating three-dimensional (3D cell-laden microstructures by applying the principle of origami folding technique and cell traction force (CTF. We harness the CTF as a biological driving force to fold the microstructures. Cells stretch and adhere across multiple microplates. Upon detaching the microplates from a substrate, CTF causes the plates to lift and fold according to a prescribed pattern. This self-folding technique using cells is highly biocompatible and does not involve special material requirements for the microplates and hinges to induce folding. We successfully produced various 3D cell-laden microstructures by just changing the geometry of the patterned 2D plates. We also achieved mass-production of the 3D cell-laden microstructures without causing damage to the cells. We believe that our methods will be useful for biotechnology applications that require analysis of cells in 3D configurations and for self-assembly of cell-based micro-medical devices.

  3. Cell origami: self-folding of three-dimensional cell-laden microstructures driven by cell traction force.

    Science.gov (United States)

    Kuribayashi-Shigetomi, Kaori; Onoe, Hiroaki; Takeuchi, Shoji

    2012-01-01

    This paper describes a method of generating three-dimensional (3D) cell-laden microstructures by applying the principle of origami folding technique and cell traction force (CTF). We harness the CTF as a biological driving force to fold the microstructures. Cells stretch and adhere across multiple microplates. Upon detaching the microplates from a substrate, CTF causes the plates to lift and fold according to a prescribed pattern. This self-folding technique using cells is highly biocompatible and does not involve special material requirements for the microplates and hinges to induce folding. We successfully produced various 3D cell-laden microstructures by just changing the geometry of the patterned 2D plates. We also achieved mass-production of the 3D cell-laden microstructures without causing damage to the cells. We believe that our methods will be useful for biotechnology applications that require analysis of cells in 3D configurations and for self-assembly of cell-based micro-medical devices.

  4. Space-time evolution of a growth fold (Betic Cordillera, Spain). Evidences from 3D geometrical modelling

    Science.gov (United States)

    Martin-Rojas, Ivan; Alfaro, Pedro; Estévez, Antonio

    2014-05-01

    We present a study that encompasses several software tools (iGIS©, ArcGIS©, Autocad©, etc.) and data (geological mapping, high resolution digital topographic data, high resolution aerial photographs, etc.) to create a detailed 3D geometric model of an active fault propagation growth fold. This 3D model clearly shows structural features of the analysed fold, as well as growth relationships and sedimentary patterns. The results obtained permit us to discuss the kinematics and structural evolution of the fold and the fault in time and space. The study fault propagation fold is the Crevillente syncline. This fold represents the northern limit of the Bajo Segura Basin, an intermontane basin in the Eastern Betic Cordillera (SE Spain) developed from upper Miocene on. 3D features of the Crevillente syncline, including growth pattern, indicate that limb rotation and, consequently, fault activity was higher during Messinian than during Tortonian; consequently, fault activity was also higher. From Pliocene on our data point that limb rotation and fault activity steadies or probably decreases. This in time evolution of the Crevillente syncline is not the same all along the structure; actually the 3D geometric model indicates that observed lateral heterogeneity is related to along strike variation of fault displacement.

  5. Morphometric Study of Vocal Folds in Indian Cadavers

    Directory of Open Access Journals (Sweden)

    Rawal J.D.

    2015-06-01

    Full Text Available Introduction: -The larynx is an air passage and a sphincteric device used in respiration and phonation. The larynx, from inside outwards has a framework of mucosa surrounded by fibro-elastic membrane which in turn is surrounded by cartilages and then a layer of muscles. Vocal folds are intrinsic ligament of larynx covered by mucosal folds. Larynx generates sound through rhythmic opening and closing of the vocal folds. The perceived pitch of human voice mainly depends upon fundamental frequency of sound generated by larynx. Aim: - The aim of present study is to measure various dimensions of vocal folds in Indian cadavers. Material & Methods: - 50 larynx were obtained from embalmed cadavers, of which 10 larynx were of females. Vocal cords were dissected from the larynx and morphometric analysis was done. Results and Conclusions: - The average total length of the vocal folds was found to be 16.11 mm. ± 2.62 mm. in male and 14.10 mm. ± 1.54 mm. in female cadavers. The average width of the vocal folds was found to be 4.38 mm. ± 0.74 mm. in male and 3.60 mm. ± 0.64 mm. in female cadavers. The average total length of the membranous part of the vocal folds was found to be 11.90 mm. ± 1.86 mm. in male and 10.45 mm. ± 1.81 mm. in female cadavers. The average ratio of the length of the membranous and the cartilaginous parts of the vocal folds was calculated to be 3.10 ± 0.96in male and 2.85 ± 0.73in female cadavers.

  6. WW Domain Folding Complexity Revealed by Infrared Spectroscopy

    OpenAIRE

    Davis, Caitlin M.; Dyer, R. Brian

    2014-01-01

    Although the intrinsic tryptophan fluorescence of proteins offers a convenient probe of protein folding, interpretation of the fluorescence spectrum is often difficult because it is sensitive to both global and local changes. Infrared (IR) spectroscopy offers a complementary measure of structural changes involved in protein folding, because it probes changes in the secondary structure of the protein backbone. Here we demonstrate the advantages of using multiple probes, infrared and fluorescen...

  7. Cervical osteophytes presenting as unilateral vocal fold paralysis and dysphagia.

    Science.gov (United States)

    Yoskovitch, A; Kantor, S

    2001-05-01

    Any process involving either the vagus nerve, its recurrent laryngeal branch or the external branch of the superior laryngeal nerve may cause paralysis of the vocal fold. The most common cause is neoplasm. Clinically, the patients often present with a hoarse, breathy voice as well as symptoms of aspiration. The following represents a unique case of unilateral vocal fold paralysis and dysphagia caused by a degenerative disease of the cervical spine, resluting in extrinsic compression of the recurrent laryngeal nerve.

  8. Double folded Yukawa interaction potential between two heavy ions

    International Nuclear Information System (INIS)

    Bulgac, A.; Carstoiu, F.; Dumitrescu, O.

    1980-02-01

    A simple semi-analytical formula for the heavy ion interaction potential within the double-folding model approximation is obtained. The folded interaction is assumed to be expressed in Yukawa terms or the derivatives of them. The densities used can be both experimental or theoretical (of simple ''step-wise'', ''Fermi-Saxon-Woods'' or complicated ''shell model'' structure) densities. A way of inserting the exchange terms is discussed. Numerical calculations for some colliding partners are reported. (author)

  9. The Arterial Folding Point During Flexion of the Hip Joint

    International Nuclear Information System (INIS)

    Park, Sung Il; Won, Je Hwan; Kim, Byung Moon; Kim, Jae Keun; Lee, Do Yun

    2005-01-01

    Purpose: Endovascular stents placed in periarticular vessels may be at a greater risk of neointimal hyperplasia and eventual occlusion than those placed in non-periarticular vessels. The purpose of this study was to investigate the location of maximal conformational change along the iliac and femoral artery, the folding point, during flexion of the hip joint and its location relative to the hip joint and the inguinal ligament. Methods: Seventy patients undergoing femoral artery catheterization were evaluated. The patients were 47 men and 23 women and ranged in age from 26 to 75 years (mean 54 years). The arteries (right:left = 34:36) were measured using a marked catheter for sizing vessels. Fluoroscopic images were obtained in anteroposterior and lateral projections in neutral position, and in the lateral projection in flexed position of the hip joint. The folding point was determined by comparing the lateral projection images in the neutral and flexed positions. The distance from the acetabular roof to the folding point and the distance from the inguinal ligament to the folding point was evaluated. Results: : The folding point was located 42.8 ± 28.6 mm cranial to the acetabular roof and 35.1 ± 30.1 mm cranial to the inguinal ligament. As the patient’s age increased, the folding point was located more cranially (p < 0.001). Conclusions: The folding point during flexion of the hip joint was located 42.8 ± 28.6 mm cranial to the acetabular roof and 35.1 ± 30.1 mm cranial to the inguinal ligament. As the patient's age increased, the folding point was located more cranially. When a stent is inserted over this region, more attention may be needed during follow-up to monitor possible occlusion and stent failure.

  10. Oral and vocal fold diadochokinesis in dysphonic women

    OpenAIRE

    Louzada,Talita; Beraldinelle,Roberta; Berretin-Felix,Giédre; Brasolotto,Alcione Ghedini

    2011-01-01

    The evaluation of oral and vocal fold diadochokinesis (DDK) in individuals with voice disorders may contribute to the understanding of factors that affect the balanced vocal production. Scientific studies that make use of this assessment tool support the knowledge advance of this area, reflecting the development of more appropriate therapeutic planning. Objective: To compare the results of oral and vocal fold DDK in dysphonic women and in women without vocal disorders. Material and methods: F...

  11. Vocal fold ion transport and mucin expression following acrolein exposure.

    Science.gov (United States)

    Levendoski, Elizabeth Erickson; Sivasankar, M Preeti

    2014-05-01

    The vocal fold epithelium is exposed to inhaled particulates including pollutants during breathing in everyday environments. Yet, our understanding of the effects of pollutants on vocal fold epithelial function is extremely limited. The objective of this study was to investigate the effect of the pollutant acrolein on two vocal fold epithelial mechanisms: ion transport and mucin (MUC) synthesis. These mechanisms were chosen as each plays a critical role in vocal defense and in maintaining surface hydration which is necessary for optimal voice production. Healthy, native porcine vocal folds (N = 85) were excised and exposed to an acrolein or sham challenge. A 60-min acrolein, but not sham challenge significantly reduced ion transport and inhibited cyclic adenosine monophosphate-dependent, increases in ion transport. Decreases in ion transport were associated with reduced sodium absorption. Within the same timeline, no significant acrolein-induced changes in MUC gene or protein expression were observed. These results improve our understanding of the effects of acrolein on key vocal fold epithelial functions and inform the development of future investigations that seek to elucidate the impact of a wide range of pollutant exposures on vocal fold health.

  12. Protein solubility and folding enhancement by interaction with RNA.

    Directory of Open Access Journals (Sweden)

    Seong Il Choi

    Full Text Available While basic mechanisms of several major molecular chaperones are well understood, this machinery has been known to be involved in folding of only limited number of proteins inside the cells. Here, we report a chaperone type of protein folding facilitated by interaction with RNA. When an RNA-binding module is placed at the N-terminus of aggregation-prone target proteins, this module, upon binding with RNA, further promotes the solubility of passenger proteins, potentially leading to enhancement of proper protein folding. Studies on in vitro refolding in the presence of RNA, coexpression of RNA molecules in vivo and the mutants with impaired RNA binding ability suggests that RNA can exert chaperoning effect on their bound proteins. The results suggest that RNA binding could affect the overall kinetic network of protein folding pathway in favor of productive folding over off-pathway aggregation. In addition, the RNA binding-mediated solubility enhancement is extremely robust for increasing soluble yield of passenger proteins and could be usefully implemented for high-throughput protein expression for functional and structural genomic research initiatives. The RNA-mediated chaperone type presented here would give new insights into de novo folding in vivo.

  13. Multi-crease Self-folding by Global Heating.

    Science.gov (United States)

    Miyashita, Shuhei; Onal, Cagdas D; Rus, Daniela

    2015-01-01

    This study demonstrates a new approach to autonomous folding for the body of a 3D robot from a 2D sheet, using heat. We approach this challenge by folding a 0.27-mm sheetlike material into a structure. We utilize the thermal deformation of a contractive sheet sandwiched by rigid structural layers. During this baking process, the heat applied on the entire sheet induces contraction of the contracting layer and thus forms an instructed bend in the sheet. To attain the targeted folding angles, the V-fold spans method is used. The targeted angle θout can be kinematically encoded into crease geometry. The realization of this angle in the folded structure can be approximately controlled by a contraction angle θin. The process is non-reversible, is reliable, and is relatively fast. Our method can be applied simultaneously to all the folds in multi-crease origami structures. We demonstrate the use of this method to create a lightweight mobile robot.

  14. Synthetic oligorotaxanes exert high forces when folding under mechanical load

    Science.gov (United States)

    Sluysmans, Damien; Hubert, Sandrine; Bruns, Carson J.; Zhu, Zhixue; Stoddart, J. Fraser; Duwez, Anne-Sophie

    2018-01-01

    Folding is a ubiquitous process that nature uses to control the conformations of its molecular machines, allowing them to perform chemical and mechanical tasks. Over the years, chemists have synthesized foldamers that adopt well-defined and stable folded architectures, mimicking the control expressed by natural systems1,2. Mechanically interlocked molecules, such as rotaxanes and catenanes, are prototypical molecular machines that enable the controlled movement and positioning of their component parts3-5. Recently, combining the exquisite complexity of these two classes of molecules, donor-acceptor oligorotaxane foldamers have been synthesized, in which interactions between the mechanically interlocked component parts dictate the single-molecule assembly into a folded secondary structure6-8. Here we report on the mechanochemical properties of these molecules. We use atomic force microscopy-based single-molecule force spectroscopy to mechanically unfold oligorotaxanes, made of oligomeric dumbbells incorporating 1,5-dioxynaphthalene units encircled by cyclobis(paraquat-p-phenylene) rings. Real-time capture of fluctuations between unfolded and folded states reveals that the molecules exert forces of up to 50 pN against a mechanical load of up to 150 pN, and displays transition times of less than 10 μs. While the folding is at least as fast as that observed in proteins, it is remarkably more robust, thanks to the mechanically interlocked structure. Our results show that synthetic oligorotaxanes have the potential to exceed the performance of natural folding proteins.

  15. The influence of material anisotropy on vibration at onset in a three-dimensional vocal fold model

    Science.gov (United States)

    Zhang, Zhaoyan

    2014-01-01

    Although vocal folds are known to be anisotropic, the influence of material anisotropy on vocal fold vibration remains largely unknown. Using a linear stability analysis, phonation onset characteristics were investigated in a three-dimensional anisotropic vocal fold model. The results showed that isotropic models had a tendency to vibrate in a swing-like motion, with vibration primarily along the superior-inferior direction. Anterior-posterior (AP) out-of-phase motion was also observed and large vocal fold vibration was confined to the middle third region along the AP length. In contrast, increasing anisotropy or increasing AP-transverse stiffness ratio suppressed this swing-like motion and allowed the vocal fold to vibrate in a more wave-like motion with strong medial-lateral motion over the entire medial surface. Increasing anisotropy also suppressed the AP out-of-phase motion, allowing the vocal fold to vibrate in phase along the entire AP length. Results also showed that such improvement in vibration pattern was the most effective with large anisotropy in the cover layer alone. These numerical predictions were consistent with previous experimental observations using self-oscillating physical models. It was further hypothesized that these differences may facilitate complete glottal closure in finite-amplitude vibration of anisotropic models as observed in recent experiments. PMID:24606284

  16. Bending, wrinkling, and folding of thin polymer film/elastomer interfaces

    Science.gov (United States)

    Ebata, Yuri

    This work focuses on understanding the buckling deformation mechanisms of bending, wrinkling, and folding that occur on the surfaces and interfaces of polymer systems. We gained fundamental insight into the formation mechanism of these buckled structures for thin glassy films placed on an elastomeric substrate. By taking advantage of geometric confinement, we demonstrated new strategies in controlling wrinkling morphologies. We were able to achieve surfaces with controlled patterned structures which will have a broad impact in optical, adhesive, microelectronics, and microfluidics applications. Wrinkles and strain localized features, such as delaminations and folds, are observed in many natural systems and are useful for a wide range of patterning applications. However, the transition from sinusoidal wrinkles to more complex strain localized structures is not well understood. We investigated the onset of wrinkling and strain localizations under uniaxial strain. We show that careful measurement of feature amplitude allowed not only the determination of wrinkle, fold, or delamination onset, but also allowed clear distinction between each feature. The folds observed in this experiment have an outward morphology from the surface in contrast to folds that form into the plane, as observed in a film floating on a liquid substrate. A critical strain map was constructed, where the critical strain was measured experimentally for wrinkling, folding, and delamination with varying film thickness and modulus. Wrinkle morphologies, i.e. amplitude and wavelength of wrinkles, affect properties such as electron transport in stretchable electronics and adhesion properties of smart surfaces. To gain an understanding of how the wrinkle morphology can be controlled, we introduced a geometrical confinement in the form of rigid boundaries. Upon straining, we found that wrinkles started near the rigid boundaries where maximum local strain occurred and propagated towards the middle as more

  17. In vivo labelling of proteins associated with folded chromosomes of yeast

    International Nuclear Information System (INIS)

    Litske Petersen, J.G.; Pinon, R.

    1980-01-01

    Proteins associated with the pre-replicative (g 1 ) and post-replicative (g 2 ) folded chromosomes of Saccharomyces cerevisiae can be labelled in vivo by growing cells in acetate vegetative medium containing [ 35 S]methionine. In both sporulating (MATa/MATα) and non-sporulating (MATa/MATa, MATα/MATα) diploids proteins associated with the resting stage genome (g 0 ) can be labelled with [ 35 S]methionine during nitrogen starvation and in sporulation medium. In addition, in MATa/MATα diploids proteins associated with the meiotic replication form (r) can also be labelled. SDS-polyacrylamide gel electrophoresis and autoradiography of the labelled proteins from the various folded genome forms showed that the g 1 and g 2 patterns are, with the exception of one polypeptide band, essentially identical. Several differences distinguished the r and g 0 patterns from those of the g 1 and g 2 structures. At least four polypeptide bands distinguish the r and g 0 patterns. No significant differences were observed between the g 0 proteins of sporulating and non-sporulating diploids. (author)

  18. Study of wire electrical discharge machined folded-up corner cube retroreflector with a tunable cantilever beam

    Science.gov (United States)

    Chen, Yu-Fan; Wang, Yen-Hung; Tsai, Jui-che

    2018-03-01

    This work has developed an approach to construct a corner cube retroreflector (CCR). A two-dimensional cutout pattern is first fabricated with wire electrical discharge machining process. It is then folded up into a three-dimensional CCR suspended on a cantilever beam. The folded-up CCR may be driven through external actuators for optical modulation; it can also mechanically respond to perturbation, acceleration, etc., to function as a sensor. Mechanical (static and dynamic modeling) and optical (ray tracing) analyses are also performed.

  19. Narrow-band imaging (NBI for improving the assessment of vocal fold leukoplakia and overcoming the umbrella effect.

    Directory of Open Access Journals (Sweden)

    H Klimza

    Full Text Available It is crucial to find a balance between functional and oncological outcome when choosing an adequate method for the management of vocal fold leukoplakia. Therefore, a detailed examination is a milestone in the decision-making process.To examine whether narrow-band imaging (NBI can be helpful in vocal fold assessment in the case of leukoplakia and how to overcome the "umbrella effect"- understood as the submucosal vascular pattern hidden under the plaque.Prospective cohort of 41 consecutive patients. Inclusion criteria: vocal fold leukoplakia, no previous procedures (surgery, radiotherapy, and preoperative endoscopy with an optical filter for NBI. Two groups: "suspicious" and "normal", according to the submucosal microvascular pattern of peripheral regions of the mucosa surrounding the plaque, were distinguished. Patients were qualified for a full-thickness or partial-thickness biopsy, respectively. Criteria defining suspected characters were well-demarcated brownish areas with scattered brown spots corresponding to type IV, Va, Vb, and Vc NI classifications.In 22/41 (53.7% patients with "suspected" microvascular pattern, full-thickness biopsy was performed. Moderate and severe dysplasia was revealed in 15 type IV and 7 type Va NI patients. In 19/41 (46.3% patients with proper NBI vessel pattern treated by partial-thickness biopsy, hyperkeratosis was diagnosed. There was a strong correlation between the NBI pattern and final histology: Chi2 (2 = 41.0 (p = 0.0000.The results demonstrate that NBI endoscopic assessment of the submucosal microvascular pattern of mucosa surrounding the plaque can be an effective method to categorise the risk in vocal fold leukoplakia prior to treatment.

  20. RNA folding kinetics using Monte Carlo and Gillespie algorithms.

    Science.gov (United States)

    Clote, Peter; Bayegan, Amir H

    2018-04-01

    RNA secondary structure folding kinetics is known to be important for the biological function of certain processes, such as the hok/sok system in E. coli. Although linear algebra provides an exact computational solution of secondary structure folding kinetics with respect to the Turner energy model for tiny ([Formula: see text]20 nt) RNA sequences, the folding kinetics for larger sequences can only be approximated by binning structures into macrostates in a coarse-grained model, or by repeatedly simulating secondary structure folding with either the Monte Carlo algorithm or the Gillespie algorithm. Here we investigate the relation between the Monte Carlo algorithm and the Gillespie algorithm. We prove that asymptotically, the expected time for a K-step trajectory of the Monte Carlo algorithm is equal to [Formula: see text] times that of the Gillespie algorithm, where [Formula: see text] denotes the Boltzmann expected network degree. If the network is regular (i.e. every node has the same degree), then the mean first passage time (MFPT) computed by the Monte Carlo algorithm is equal to MFPT computed by the Gillespie algorithm multiplied by [Formula: see text]; however, this is not true for non-regular networks. In particular, RNA secondary structure folding kinetics, as computed by the Monte Carlo algorithm, is not equal to the folding kinetics, as computed by the Gillespie algorithm, although the mean first passage times are roughly correlated. Simulation software for RNA secondary structure folding according to the Monte Carlo and Gillespie algorithms is publicly available, as is our software to compute the expected degree of the network of secondary structures of a given RNA sequence-see http://bioinformatics.bc.edu/clote/RNAexpNumNbors .

  1. Visualization of protein folding funnels in lattice models.

    Directory of Open Access Journals (Sweden)

    Antonio B Oliveira

    Full Text Available Protein folding occurs in a very high dimensional phase space with an exponentially large number of states, and according to the energy landscape theory it exhibits a topology resembling a funnel. In this statistical approach, the folding mechanism is unveiled by describing the local minima in an effective one-dimensional representation. Other approaches based on potential energy landscapes address the hierarchical structure of local energy minima through disconnectivity graphs. In this paper, we introduce a metric to describe the distance between any two conformations, which also allows us to go beyond the one-dimensional representation and visualize the folding funnel in 2D and 3D. In this way it is possible to assess the folding process in detail, e.g., by identifying the connectivity between conformations and establishing the paths to reach the native state, in addition to regions where trapping may occur. Unlike the disconnectivity maps method, which is based on the kinetic connections between states, our methodology is based on structural similarities inferred from the new metric. The method was developed in a 27-mer protein lattice model, folded into a 3×3×3 cube. Five sequences were studied and distinct funnels were generated in an analysis restricted to conformations from the transition-state to the native configuration. Consistent with the expected results from the energy landscape theory, folding routes can be visualized to probe different regions of the phase space, as well as determine the difficulty in folding of the distinct sequences. Changes in the landscape due to mutations were visualized, with the comparison between wild and mutated local minima in a single map, which serves to identify different trapping regions. The extension of this approach to more realistic models and its use in combination with other approaches are discussed.

  2. The nature of folded states of globular proteins.

    Science.gov (United States)

    Honeycutt, J D; Thirumalai, D

    1992-06-01

    We suggest, using dynamical simulations of a simple heteropolymer modelling the alpha-carbon sequence in a protein, that generically the folded states of globular proteins correspond to statistically well-defined metastable states. This hypothesis, called the metastability hypothesis, states that there are several free energy minima separated by barriers of various heights such that the folded conformations of a polypeptide chain in each of the minima have similar structural characteristics but have different energies from one another. The calculated structural characteristics, such as bond angle and dihedral angle distribution functions, are assumed to arise from only those configurations belonging to a given minimum. The validity of this hypothesis is illustrated by simulations of a continuum model of a heteropolymer whose low temperature state is a well-defined beta-barrel structure. The simulations were done using a molecular dynamics algorithm (referred to as the "noisy" molecular dynamics method) containing both friction and noise terms. It is shown that for this model there are several distinct metastable minima in which the structural features are similar. Several new methods of analyzing fluctuations in structures belonging to two distinct minima are introduced. The most notable one is a dynamic measure of compactness that can in principle provide the time required for maximal compactness to be achieved. The analysis shows that for a given metastable state in which the protein has a well-defined folded structure the transition to a state of higher compactness occurs very slowly, lending credence to the notion that the system encounters a late barrier in the process of folding to the most compact structure. The examination of the fluctuations in the structures near the unfolding----folding transition temperature indicates that the transition state for the unfolding to folding process occurs closer to the folded state.

  3. THE INFLUENCE OF FOLD AND FRACTURE DEVELOPMENT ON RESERVOIR BEHAVIOR OF THE LISBURNE GROUP OF NORTHERN ALASKA

    Energy Technology Data Exchange (ETDEWEB)

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen; Michael T. Whalen

    2002-01-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is detachment folded where it is exposed throughout the northeastern Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study are to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of detachment folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. The Lisburne in the main axis of the Brooks Range is characteristically deformed into imbricate thrust sheets with asymmetrical hanging wall anticlines and footwall synclines. In contrast, the Lisburne in the northeastern Brooks Range is characterized by symmetrical detachment folds. The focus of our 2000 field studies was at the boundary between these structural styles in the vicinity of Porcupine Lake, in the Arctic National Wildlife Refuge. The northern edge of thrust-truncated folds in Lisburne is marked by a local range front that likely represents an eastward continuation of the central Brooks Range front. This is bounded to the north by a gently dipping panel of Lisburne with local asymmetrical folds. The leading edge of the flat panel is thrust over Permian to Cretaceous rocks in a synclinal depression. These younger rocks overlie symmetrically detachment-folded Lisburne, as is extensively exposed to the north. Six partial sections were measured in the Lisburne of the flat panel and local range front. The Lisburne here is about 700 m thick and is interpreted to consist primarily of the Wachsmuth and Alapah Limestones, with only a thin veneer of Wahoo Limestone. The Wachsmuth (200 m) is gradational between the underlying Missippian Kayak Shale and the overlying Mississippian Alapah, and

  4. Vocal Fold Injection: Review of Indications, Techniques, and Materials for Augmentation

    OpenAIRE

    Mallur, Pavan S.; Rosen, Clark A.

    2010-01-01

    Vocal fold injection is a procedure that has over a 100 year history but was rarely done as short as 20 years ago. A renaissance has occurred with respect to vocal fold injection due to new technologies (visualization and materials) and new injection approaches. Awake, un-sedated vocal fold injection offers many distinct advantages for the treatment of glottal insufficiency (vocal fold paralysis, vocal fold paresis, vocal fold atrophy and vocal fold scar). A review of materials available and ...

  5. WW domain folding complexity revealed by infrared spectroscopy.

    Science.gov (United States)

    Davis, Caitlin M; Dyer, R Brian

    2014-09-02

    Although the intrinsic tryptophan fluorescence of proteins offers a convenient probe of protein folding, interpretation of the fluorescence spectrum is often difficult because it is sensitive to both global and local changes. Infrared (IR) spectroscopy offers a complementary measure of structural changes involved in protein folding, because it probes changes in the secondary structure of the protein backbone. Here we demonstrate the advantages of using multiple probes, infrared and fluorescence spectroscopy, to study the folding of the FBP28 WW domain. Laser-induced temperature jumps coupled with fluorescence or infrared spectroscopy have been used to probe changes in the peptide backbone on the submillisecond time scale. The relaxation dynamics of the β-sheets and β-turn were measured independently by probing the corresponding IR bands assigned in the amide I region. Using these wavelength-dependent measurements, we observe three kinetics phases, with the fastest process corresponding to the relaxation kinetics of the turns. In contrast, fluorescence measurements of the wild-type WW domain and tryptophan mutants exhibit single-exponential kinetics with a lifetime that corresponds to the slowest phase observed by infrared spectroscopy. Mutant sequences provide evidence of an intermediate dry molten globule state. The slowest step in the folding of this WW domain is the tight packing of the side chains in the transition from the dry molten globule intermediate to the native structure. This study demonstrates that using multiple complementary probes enhances the interpretation of protein folding dynamics.

  6. Intermediates and the folding of proteins L and G

    Energy Technology Data Exchange (ETDEWEB)

    Brown, Scott; Head-Gordon, Teresa

    2003-07-01

    We use a minimalist protein model, in combination with a sequence design strategy, to determine differences in primary structure for proteins L and G that are responsible for the two proteins folding through distinctly different folding mechanisms. We find that the folding of proteins L and G are consistent with a nucleation-condensation mechanism, each of which is described as helix-assisted {beta}-1 and {beta}-2 hairpin formation, respectively. We determine that the model for protein G exhibits an early intermediate that precedes the rate-limiting barrier of folding and which draws together misaligned secondary structure elements that are stabilized by hydrophobic core contacts involving the third {beta}-strand, and presages the later transition state in which the correct strand alignment of these same secondary structure elements is restored. Finally the validity of the targeted intermediate ensemble for protein G was analyzed by fitting the kinetic data to a two-step first order reversible reaction, proving that protein G folding involves an on-pathway early intermediate, and should be populated and therefore observable by experiment.

  7. Fold maps and positive topological quantum field theories

    Energy Technology Data Exchange (ETDEWEB)

    Wrazidlo, Dominik Johannes

    2017-04-12

    The notion of positive TFT as coined by Banagl is specified by an axiomatic system based on Atiyah's original axioms for TFTs. By virtue of a general framework that is based on the concept of Eilenberg completeness of semirings from computer science, a positive TFT can be produced rigorously via quantization of systems of fields and action functionals - a process inspired by Feynman's path integral from classical quantum field theory. The purpose of the present dissertation thesis is to investigate a new differential topological invariant for smooth manifolds that arises as the state sum of the fold map TFT, which has been constructed by Banagl as a example of a positive TFT. By eliminating an internal technical assumption on the fields of the fold map TFT, we are able to express the informational content of the state sum in terms of an extension problem for fold maps from cobordisms into the plane. Next, we use the general theory of generic smooth maps into the plane to improve known results about the structure of the state sum in arbitrary dimensions, and to determine it completely in dimension two. The aggregate invariant of a homotopy sphere, which is derived from the state sum, naturally leads us to define a filtration of the group of homotopy spheres in order to understand the role of indefinite fold lines beyond a theorem of Saeki. As an application, we show how Kervaire spheres can be characterized by indefinite fold lines in certain dimensions.

  8. HEMATOMA OF THE PROXIMAL NAIL FOLD. REPORT OF 41 CASES

    Directory of Open Access Journals (Sweden)

    Chang Patricia

    2011-04-01

    Full Text Available Background: The proximal fold is an important part of the nail apparatus it contributes to the formation of the nail plate and through the cuticle acts as an impermeable barrier protecting it from any cause.Objective: To know the proximal nail fold hematoma caused by the use of pulse oximeter.Material and Methods: A descriptive study was conducted in 41 patients with proximal nail hematoma secondary to the use of oximetry in patients hospitalized in the Intermediate and Intensive Care Unit at the Hospital General de Enfermedades from December 1, 2007 to December 31, 2010.Results: We studied 41 patients with proximal nail fold hematoma secondary to the use of oximeter, 30 (73.1% were males and 11 (26.8% females. The numbers of fingers affected by pulse oximeter were in one digit. 30 (73.1% cases, in two digits 6 (14.6%, in three digits 3 (7.3%, in 4 digits 1 (2.4% and in 5 digits 1 (2.4% case. The most affected proximal nail fold was right index: 24 (58.5%, right middle 11 (26.8%, right ring 6 (14.6%, left index 12 (29.2%, and left middle 6 (14.6% cases.Conclusions: Hematomas of the proximal nail fold may be caused by different traumatisms. The use of pulse oximeter is one of them.

  9. Recurrence of vocal fold leukoplakia after carbon dioxide laser therapy.

    Science.gov (United States)

    Chen, Min; Chen, Jian; Cheng, Lei; Wu, Haitao

    2017-09-01

    This work aims to analyze the recurrence of vocal fold leukoplakia after carbon dioxide (CO 2 ) laser resection. In this retrospective study, all patients undergoing CO 2 laser resection of vocal fold leukoplakia were followed up for at least 2 years. Recurrence was diagnosed as any presence of leukoplakia in the vocal cord subsequent to previous successful complete resection. A total of 326 patients with complete resection of vocal fold leukoplakia and follow-up subsequent surveillance laryngoscopy were studied. The recurrence rate, the recurrence time, and risk factors were evaluated. Of these, 52 (16.0%) patients experienced recurrence with a mean follow-up time of 50.5 ± 15.4 months. The mean time to recurrence was 16.2 ± 14.1 months. Univariate analysis showed that the size of lesion (P vocal fold leukoplakia, long-term follow-up is required after CO 2 laser resection. In conclusion, the size of lesion combined with the pathological grade are important risk factors that predict vocal fold leukoplakia recurrence.

  10. Possible association between Helicobacter pylori infection and vocal fold leukoplakia.

    Science.gov (United States)

    Chen, Min; Chen, Jian; Yang, Yue; Cheng, Lei; Wu, Hai-Tao

    2018-03-06

    Several studies have indicated the larynx as possible Helicobacter pylori (H. pylori) reservoirs. This study explored the association between H. pylori and vocal fold leukoplakia. The case-control study involved 51 patients with vocal fold leukoplakia and 35 control patients with vocal polyps. Helicobacter pylori was detected in tissues by the rapid urease test, nested polymerase chain reaction (PCR), and single-step PCR. The H. pylori-specific immunoglobulin antibodies were detected in plasma by enzyme-linked immunosorbent assay (ELISA). Helicobacter pylori-positive rate of vocal fold leukoplakia and vocal polyps was 23.5% versus 11.4% (P = .157), 37.2% versus 14.3% (P = .020), 27.5% versus 8.6% (P = .031), and 70.6% versus 68.6% (P = .841) detected by rapid urease test, nested PCR, single-step PCR, and ELISA, respectively. Regression analysis indicated that H. pylori infection (P = .044) was the independent risk factor for vocal fold leukoplakia. Helicobacter pylori infection exists in the larynx and may be associated with vocal fold leukoplakia. © 2018 Wiley Periodicals, Inc.

  11. Sulfated glycosaminoglycans in human vocal fold lamina propria

    Directory of Open Access Journals (Sweden)

    Sung Woo Park

    Full Text Available Abstract Introduction: The distribution, concentration and function of glycosaminoglycans in the various vocal fold tissues are still unclear. Objective: To evaluate the distribution and concentration of sulfated glycosaminoglycans in different layers of the human vocal fold according to gender and age. Methods: We used 11 vocal folds obtained from cadavers (7 men and 4 women with no laryngeal lesion, less than 12 h after death, and aged between 35 and 98 years. The folds underwent glycosaminoglycans extraction from the cover and ligament, and post-electrophoresis analysis. Data were compared according to the layer, age and gender. Results: The concentration of dermatan sulfate was significantly higher in all layers. No differences were observed in the total concentrations of glycosaminoglycans in layers studied according to gender. It is significantly lower in the cover of individuals aged below 60 years. Conclusion: Dermatan sulfate, chondroitin sulfate, and heparan sulfate were observed in the human vocal folds cover and ligament of both genders, with the concentration of dermatan sulfate being significantly higher in all layers. Glycosaminoglycans concentration on the cover is significantly lower in individuals below 60 years compared with elderly.

  12. Modeling Vocal Fold Intravascular Flow using Synthetic Replicas

    Science.gov (United States)

    Terry, Aaron D.; Ricks, Matthew T.; Thomson, Scott L.

    2017-11-01

    Vocal fold vibration that is induced by air flowing from the lungs is believed to decrease blood flow through the vocal folds. This is important due to the critical role of blood flow in maintaining tissue health. However, the precise mechanical relationships between vocal fold vibration and blood perfusion remain understudied. A platform for studying liquid perfusion in a synthetic, life-size, self-oscillating vocal fold replica has recently been developed. The replicas are fabricated using molded silicone with material properties comparable to those of human vocal fold tissues and that include embedded microchannels through which liquid is perfused. The replicas are mounted on an air flow supply tube to initiate flow-induced vibration. A liquid reservoir is attached to the microchannel to cause liquid to perfuse through replica in the anterior-posterior direction. As replica vibration is initiated and amplitude increases, perfusion flow rate decreases. In this presentation, the replica design will be presented, along with data quantifying the relationships between parameters such as replica vibration amplitude, stiffness, microchannel diameter, and perfusion flow rate. This work was supported by Grant NIDCD R01DC005788 from the National Institutes of Health.

  13. Recovery of Vocal Fold Epithelium after Acute Phonotrauma.

    Science.gov (United States)

    Rousseau, Bernard; Kojima, Tsuyoshi; Novaleski, Carolyn K; Kimball, Emily E; Valenzuela, Carla V; Mizuta, Masanobu; Daniero, James J; Garrett, C Gaelyn; Sivasankar, M Preeti

    2017-01-01

    We investigated the timeline of tissue repair of vocal fold epithelium after acute vibration exposure using an in vivo rabbit model. Sixty-five New Zealand white breeder rabbits were randomized to 120 min of modal- or raised-intensity phonation. After the larynges were harvested at 0, 4, 8, and 24 h, and at 3 and 7 days, the vocal fold tissue was evaluated using electron microscopy and quantitative real-time polymerase chain reaction. There was an immediate decrease in the microprojection depth and height following raised-intensity phonation, paired with upregulation of cyclooxygenase-2. This initial 24-h period was also characterized by the significant downregulation of junction proteins. Interleukin 1β and transforming growth factor β1 were upregulated for 3 and 7 days, respectively, followed by an increase in epithelial cell surface depth at 3 and 7 days. These data appear to demonstrate a shift from inflammatory response to the initiation of a restorative process in the vocal fold epithelium between 24 h and 3 days. Despite the initial damage from raised-intensity phonation, the vocal fold epithelium demonstrates a remarkable capacity for the expeditious recovery of structural changes from transient episodes of acute phonotrauma. While structurally intact, the return of functional barrier integrity may be delayed by repeated episodes of phonotrauma and may also play an important role in the pathophysiology of vocal fold lesions. © 2017 S. Karger AG, Basel.

  14. Bilateral Vocal Fold Medialization: A Treatment for Abductor Spasmodic Dysphonia.

    Science.gov (United States)

    Dewan, Karuna; Berke, Gerald S

    2017-11-10

    Abductor spasmodic dysphonia, a difficult-to-treat laryngologic condition, is characterized by spasms causing the vocal folds to remain abducted despite efforts to adduct them during phonation. Traditional treatment for abductor spasmodic dysphonia-botulinum toxin injection into the posterior cricoarytenoid muscle-can be both technically challenging and uncomfortable. Due to the difficulty of needle placement, it is often unsuccessful. The purpose of this investigation is to present a previously undescribed treatment for abductor spasmodic dysphonia-bilateral vocal fold medialization. A retrospective case review of all cases of abductor spasmodic dysphonia treated in a tertiary care laryngology practice with bilateral vocal fold medialization over a 10-year period was performed. The Voice Handicap Index and the Voice-Related Quality of Life surveys were utilized to assess patient satisfaction with voice outcome. Six patients with abductor spasmodic dysphonia treated with bilateral vocal fold medialization were identified. Disease severity ranged from mild to severe. All six patients reported statistically significant improvement in nearly all Voice Handicap Index and Voice-Related Quality of Life parameters. They reported fewer voice breaks and greater ease of communication. Results were noted immediately and symptoms continue to be well controlled for many years following medialization. Bilateral vocal fold medialization is a safe and effective treatment for abductor spasmodic dysphonia. It is performed under local anesthesia and provides phonation improvement in the short and long term. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. Probabilistic analysis for identifying the driving force of protein folding

    Science.gov (United States)

    Tokunaga, Yoshihiko; Yamamori, Yu; Matubayasi, Nobuyuki

    2018-03-01

    Toward identifying the driving force of protein folding, energetics was analyzed in water for Trp-cage (20 residues), protein G (56 residues), and ubiquitin (76 residues) at their native (folded) and heat-denatured (unfolded) states. All-atom molecular dynamics simulation was conducted, and the hydration effect was quantified by the solvation free energy. The free-energy calculation was done by employing the solution theory in the energy representation, and it was seen that the sum of the protein intramolecular (structural) energy and the solvation free energy is more favorable for a folded structure than for an unfolded one generated by heat. Probabilistic arguments were then developed to determine which of the electrostatic, van der Waals, and excluded-volume components of the interactions in the protein-water system governs the relative stabilities between the folded and unfolded structures. It was found that the electrostatic interaction does not correspond to the preference order of the two structures. The van der Waals and excluded-volume components were shown, on the other hand, to provide the right order of preference at probabilities of almost unity, and it is argued that a useful modeling of protein folding is possible on the basis of the excluded-volume effect.

  16. Polyhedral patterns

    KAUST Repository

    Jiang, Caigui

    2015-10-27

    We study the design and optimization of polyhedral patterns, which are patterns of planar polygonal faces on freeform surfaces. Working with polyhedral patterns is desirable in architectural geometry and industrial design. However, the classical tiling patterns on the plane must take on various shapes in order to faithfully and feasibly approximate curved surfaces. We define and analyze the deformations these tiles must undertake to account for curvature, and discover the symmetries that remain invariant under such deformations. We propose a novel method to regularize polyhedral patterns while maintaining these symmetries into a plethora of aesthetic and feasible patterns.

  17. FRAN and RBF-PSO as two components of a hyper framework to recognize protein folds.

    Science.gov (United States)

    Abbasi, Elham; Ghatee, Mehdi; Shiri, M E

    2013-09-01

    In this paper, an intelligent hyper framework is proposed to recognize protein folds from its amino acid sequence which is a fundamental problem in bioinformatics. This framework includes some statistical and intelligent algorithms for proteins classification. The main components of the proposed framework are the Fuzzy Resource-Allocating Network (FRAN) and the Radial Bases Function based on Particle Swarm Optimization (RBF-PSO). FRAN applies a dynamic method to tune up the RBF network parameters. Due to the patterns complexity captured in protein dataset, FRAN classifies the proteins under fuzzy conditions. Also, RBF-PSO applies PSO to tune up the RBF classifier. Experimental results demonstrate that FRAN improves prediction accuracy up to 51% and achieves acceptable multi-class results for protein fold prediction. Although RBF-PSO provides reasonable results for protein fold recognition up to 48%, it is weaker than FRAN in some cases. However the proposed hyper framework provides an opportunity to use a great range of intelligent methods and can learn from previous experiences. Thus it can avoid the weakness of some intelligent methods in terms of memory, computational time and static structure. Furthermore, the performance of this system can be enhanced throughout the system life-cycle. Copyright © 2013 Elsevier Ltd. All rights reserved.

  18. Cave development in an uplifting fold-and-thrust belt of the Tatra Mountains, Poland

    Directory of Open Access Journals (Sweden)

    Jacek Szczygiel

    2015-09-01

    Full Text Available Detailed structural analysis and geomorphological observations supplemented by the analysis of the distribution of karst conduit directions have been performed in 23 morphologically diverse caves in the Tatra Mountains. Based on these studies, a development scheme of vadose cave passages has been proposed for the most common geological settings in the fold-and-thrust-belt: (1 single-plain faults, (2 multiple fault cores, (3 bedding plane fractures and (4 hinge zones of recumbent folds. Results indicate that the dynamics of the massif (local gravity sliding in the nearby slope zone and regional stress fields, along with the structural pattern, influences the predisposition of structural and stratigraphic discontinuities to karst drainage. Constant tectonic stress fields affected the massif during the entire speleogenesis. This led to the rejuvenation of the same displacements in successive tectonic events, which resulted in promoting this reactivated structures in successive speleogenetic phases. Structures along which older cave levels had developed were also utilized later by vadose and phreatic drainage, leading to the intersection of the vadose passages with elevated paleo-phreatic cave levels. Independently, formation of entirely vadose caves, guided by the same group of weak and rejuvenated planes, was enabled. In the Tatras, the concentric and recumbent geometry of the main folds resulted in steep dipping of the bedding planes over a distance up to a few hundred meters which makes the bedding plane fractures subject to karst water circulation in these geologic and geodynamic settings.

  19. Structural analysis of Bacillus pumilus phenolic acid decarboxylase, a lipocalin-fold enzyme

    International Nuclear Information System (INIS)

    Matte, Allan; Grosse, Stephan; Bergeron, Hélène; Abokitse, Kofi; Lau, Peter C. K.

    2010-01-01

    The crystal structure of phenolic acid decarboxylase from B. pumilus strain UI-670 has been determined and refined at 1.69 Å resolution. The enzyme is a dimer, with each subunit adopting a β-barrel structure belonging to the lipocalin fold. The decarboxylation of phenolic acids, including ferulic and p-coumaric acids, to their corresponding vinyl derivatives is of importance in the flavouring and polymer industries. Here, the crystal structure of phenolic acid decarboxylase (PAD) from Bacillus pumilus strain UI-670 is reported. The enzyme is a 161-residue polypeptide that forms dimers both in the crystal and in solution. The structure of PAD as determined by X-ray crystallography revealed a β-barrel structure and two α-helices, with a cleft formed at one edge of the barrel. The PAD structure resembles those of the lipocalin-fold proteins, which often bind hydrophobic ligands. Superposition of structurally related proteins bound to their cognate ligands shows that they and PAD bind their ligands in a conserved location within the β-barrel. Analysis of the residue-conservation pattern for PAD-related sequences mapped onto the PAD structure reveals that the conservation mainly includes residues found within the hydrophobic core of the protein, defining a common lipocalin-like fold for this enzyme family. A narrow cleft containing several conserved amino acids was observed as a structural feature and a potential ligand-binding site

  20. RNAslider: a faster engine for consecutive windows folding and its application to the analysis of genomic folding asymmetry

    Directory of Open Access Journals (Sweden)

    Ziv-Ukelson Michal

    2009-03-01

    Full Text Available Abstract Background Scanning large genomes with a sliding window in search of locally stable RNA structures is a well motivated problem in bioinformatics. Given a predefined window size L and an RNA sequence S of size N (L 3 by applying any of the classical cubic-time RNA folding algorithms to each of the N-L windows of size L. Recently an O(NL2 solution for this problem has been described. Results Here, we describe and implement an O(NLψ(L engine for the consecutive windows folding problem, where ψ(L is shown to converge to O(1 under the assumption of a standard probabilistic polymer folding model, yielding an O(L speedup which is experimentally confirmed. Using this tool, we note an intriguing directionality (5'-3' vs. 3'-5' folding bias, i.e. that the minimal free energy (MFE of folding is higher in the native direction of the DNA than in the reverse direction of various genomic regions in several organisms including regions of the genomes that do not encode proteins or ncRNA. This bias largely emerges from the genomic dinucleotide bias which affects the MFE, however we see some variations in the folding bias in the different genomic regions when normalized to the dinucleotide bias. We also present results from calculating the MFE landscape of a mouse chromosome 1, characterizing the MFE of the long ncRNA molecules that reside in this chromosome. Conclusion The efficient consecutive windows folding engine described in this paper allows for genome wide scans for ncRNA molecules as well as large-scale statistics. This is implemented here as a software tool, called RNAslider, and applied to the scanning of long chromosomes, leading to the observation of features that are visible only on a large scale.

  1. The use of folding structures in fusion reactors

    International Nuclear Information System (INIS)

    Haines, T.

    1992-01-01

    Folding structures can be used with advantage in fusion machines. They have been used in Space for decades to extend antennas, sensors and solar panels; terrestrial versions have been used as retractable antennas and antennas masts. They have also been used in the Joint European Torus (JET) and other nuclear applications. In this paper, three types are described, together with concepts for use in fusion machines. The Storable Tubular Extendible Member (STEM) was conceived by the National Research Council of Canada and developed by Spar Aerospace Limited. The Astromast is a folding truss developed by Astro Aerospace Corporation, a US subsidiary of Spar. The X-Beam is an ultra-stiff folding truss

  2. Self-organized critical model for protein folding

    Science.gov (United States)

    Moret, M. A.

    2011-09-01

    The major factor that drives a protein toward collapse and folding is the hydrophobic effect. At the folding process a hydrophobic core is shielded by the solvent-accessible surface area of the protein. We study the fractal behavior of 5526 protein structures present in the Brookhaven Protein Data Bank. Power laws of protein mass, volume and solvent-accessible surface area are measured independently. The present findings indicate that self-organized criticality is an alternative explanation for the protein folding. Also we note that the protein packing is an independent and constant value because the self-similar behavior of the volumes and protein masses have the same fractal dimension. This power law guarantees that a protein is a complex system. From the analyzed data, q-Gaussian distributions seem to fit well this class of systems.

  3. A biomorphic origami actuator fabricated by folding a conducting paper

    Energy Technology Data Exchange (ETDEWEB)

    Okuzaki, H; Saido, T; Suzuki, H; Hara, Y; Yan, H [Laboratory of Organic Robotics, Interdisciplinary Graduate School of Medicine and Engineering, University of Yamanashi, 4-4-37 Takeda, 400-8511 (Japan)], E-mail: okuzaki@yamanashi.ac.jp

    2008-08-15

    Cooperation between the electrical conductivity and hygroscopic nature of conducting polymers can provide an insight into the development of a new class of electro-active polymer (EAP) actuators or soft robots working in ambient air. In this paper, we describe an 'origami' actuator fabricated by folding a sheet of conducting 'paper'. The principle lies in the electrically induced changes in the elastic modulus of a humidosensitive conducting polymer film through reversible sorption and desorption of water vapor molecules, which is responsible for amplifying a contraction of the film ({approx} 1%) to more than a 100-fold expansion (> 100%) of the origami actuator. Utilizing the origami technique, we have fabricated a biomorphic origami robot by folding an electrochemically synthesized polypyrrole film into the figure of an accordion shape, which can move with a caterpillar-like motion by repeated expansion and contraction at a velocity of 2 cm min{sup -1}.

  4. A biomorphic origami actuator fabricated by folding a conducting paper

    International Nuclear Information System (INIS)

    Okuzaki, H; Saido, T; Suzuki, H; Hara, Y; Yan, H

    2008-01-01

    Cooperation between the electrical conductivity and hygroscopic nature of conducting polymers can provide an insight into the development of a new class of electro-active polymer (EAP) actuators or soft robots working in ambient air. In this paper, we describe an 'origami' actuator fabricated by folding a sheet of conducting 'paper'. The principle lies in the electrically induced changes in the elastic modulus of a humidosensitive conducting polymer film through reversible sorption and desorption of water vapor molecules, which is responsible for amplifying a contraction of the film (∼ 1%) to more than a 100-fold expansion (> 100%) of the origami actuator. Utilizing the origami technique, we have fabricated a biomorphic origami robot by folding an electrochemically synthesized polypyrrole film into the figure of an accordion shape, which can move with a caterpillar-like motion by repeated expansion and contraction at a velocity of 2 cm min -1 .

  5. IMPAIRED MOBILITY OF VOCAL FOLDS - etiology and symptoms

    Directory of Open Access Journals (Sweden)

    Karlo Pintarić

    2015-06-01

    Full Text Available Paresis or paralysis of one or both vocal cords affects some significant aspects of a human life: breathing, swallowing and speech. The major causes for reduced mobility or even immobility are innervation damage, less often fixation of vocal cord or impaired mobility of crycoarytenoid joint. An injury of the superior or/and inferior laryngeal nerve can be a consequence of different medical procedures, tumor growth, trauma, infection, neurological disorders, radiation exposure, toxic damage, impaired circulation of the area or it is idiopathic. The symptoms are different in the case of unilateral and bilateral paresis of the vocal folds. They also depend on the cause for the impaired mobility. In the patients with unilateral vocal fold paresis, hoarseness and aspiration during swallowing are the leading symptoms. In the bilateral vocal fold paralysis, dyspnea prevails. 

  6. Peptide folding in the presence of interacting protein crowders

    Energy Technology Data Exchange (ETDEWEB)

    Bille, Anna, E-mail: anna.bille@thep.lu.se; Irbäck, Anders, E-mail: anders@thep.lu.se [Computational Biology and Biological Physics, Department of Astronomy and Theoretical Physics, Lund University, Sölvegatan 14A, SE-223 62 Lund (Sweden); Mohanty, Sandipan, E-mail: s.mohanty@fz-juelich.de [Jülich Supercomputing Centre, Institute for Advanced Simulation, Forschungszentrum Jülich, D-52425 Jülich (Germany)

    2016-05-07

    Using Monte Carlo methods, we explore and compare the effects of two protein crowders, BPTI and GB1, on the folding thermodynamics of two peptides, the compact helical trp-cage and the β-hairpin-forming GB1m3. The thermally highly stable crowder proteins are modeled using a fixed backbone and rotatable side-chains, whereas the peptides are free to fold and unfold. In the simulations, the crowder proteins tend to distort the trp-cage fold, while having a stabilizing effect on GB1m3. The extent of the effects on a given peptide depends on the crowder type. Due to a sticky patch on its surface, BPTI causes larger changes than GB1 in the melting properties of the peptides. The observed effects on the peptides stem largely from attractive and specific interactions with the crowder surfaces, and differ from those seen in reference simulations with purely steric crowder particles.

  7. Dermofat graft in deep nasolabial fold and facial rhytidectomy.

    Science.gov (United States)

    Hwang, Kun; Han, Jin Yi; Kim, Dae Joong

    2003-01-01

    Fat and dermis or the combined tissues are used commonly in augmentation of the nasolabial fold. Guyuron obtained the dermofat graft from either the suprapubic or the groin region. The thickness of the preauricular skin was measured in seven Korean cadavers, five male and two female. We used the dermofat graft out of the preauricular skin remnant after facial rhytidectomy to augment the deep nasolabial fold in a patient. The average thickness of the epidermis was 56 +/- 12 microm, the dermis was 1820 +/- 265 microm thick, and the subcutaneous tissue was 4783 +/- 137 microm. More dense connective tissues, such as SMAS, are seen in the preauricular skin. The dermofat graft was easily obtained and prepared from the leftover preauricular skin after dissection of the lax skin in face lifting. This technique could be employed effectively and successfully to alleviate a deep nasolabial fold and concomitant facial rhytidectomy in an Asian with a thick preauricular skin.

  8. Making a diagnosis of different lesions of vocal fold mucosa by contact endoscopy: The first usage in our clinical practice

    Directory of Open Access Journals (Sweden)

    Jovanović Milan B.

    2005-01-01

    Full Text Available During laryngomicroscopy, the superficial layers of vocal fold epithelium can be examined in vivo and in situ by contact endoscopy. Methylene blue is applied initially to stain the epihelial cells of the vocal folds. When in contact with mucosal tissue, this endoscope provides 60 and 150 times magnification and clear visualization of cellular patterns of the superficial epithelial layers. For the first time in our laryngological clinical practice, we confirmed a number of previously established parametars such as regularity and arrangement of the epithelium, nucleus contour, and nucleus-cytoplasm ratio, what all enable recognition and easy evaluation of different clinical conditions such as chronic laryngitis, Reinke.s edema, papiloma dyspiasia or vocal fold carcinoma. The advantage of con- tact endoscopy in vivo and in situ allows for detailed scan and mapping of all cell changes of the whole mucosa surface. All these features definitely classify the contact endoscopy into additional diagnostic methods in laryngology.

  9. Specialization Patterns

    DEFF Research Database (Denmark)

    Schultz, Ulrik Pagh; Lawall, Julia Laetitia; Consel, Charles

    2000-01-01

    Design patterns offer many advantages for software development, but can introduce inefficiency into the final program. Program specialization can eliminate such overheads, but is most effective when targeted by the user to specific bottlenecks. Consequently, we propose that these concepts...... are complementary. Program specialization can optimize programs written using design patterns, and design patterns provide information about the program structure that can guide specialization. Concretely, we propose specialization patterns, which describe how to apply program specialization to optimize uses...... of design patterns. In this paper, we analyze the specialization opportunities provided by specific uses of design patterns. Based on the analysis of each design pattern, we define the associated specialization pattern. These specialization opportunities can be declared using the specialization classes...

  10. Modulating Phonation Through Alteration of Vocal Fold Medial Surface Contour

    Science.gov (United States)

    Mau, Ted; Muhlestein, Joseph; Callahan, Sean; Chan, Roger W.

    2012-01-01

    Objectives 1. To test whether alteration of the vocal fold medial surface contour can improve phonation. 2. To demonstrate that implant material properties affect vibration even when implant is deep to the vocal fold lamina propria. Study Design Induced phonation of excised human larynges. Methods Thirteen larynges were harvested within 24 hours post-mortem. Phonation threshold pressure (PTP) and flow (PTF) were measured before and after vocal fold injections using either calcium hydroxylapatite (CaHA) or hyaluronic acid (HA). Small-volume injections (median 0.0625 mL) were targeted to the infero-medial aspect of the thyroarytenoid (TA) muscle. Implant locations were assessed histologically. Results The effect of implantation on PTP was material-dependent. CaHA tended to increase PTP, whereas HA tended to decrease PTP (Wilcoxon test P = 0.00013 for onset). In contrast, the effect of implantation on PTF was similar, with both materials tending to decrease PTF (P = 0.16 for onset). Histology confirmed implant presence in the inferior half of the vocal fold vertical thickness. Conclusions Taken together, these data suggested the implants may have altered the vocal fold medial surface contour, potentially resulting in a less convergent or more rectangular glottal geometry as a means to improve phonation. An implant with a closer viscoelastic match to vocal fold cover is desirable for this purpose, as material properties can affect vibration even when the implant is not placed within the lamina propria. This result is consistent with theoretical predictions and implies greater need for surgical precision in implant placement and care in material selection. PMID:22865592

  11. Fabrication of ten-fold photonic quasicrystalline structures

    Directory of Open Access Journals (Sweden)

    XiaoHong Sun

    2015-05-01

    Full Text Available Compared to periodic crystals, quasicrystals have higher point group symmetry and are more favorable in achieving complete band-gaps. In this report, a top-cut prism interferometer is designed to fabricate ten-fold photonic quasicrystalline structures. By optimizing the exposing conditions and material characteristics, appropriate quasicrystals have been obtained in the SU8 photoresist films. Atomic Force Microscopy and laser diffraction are used to characterize the fabricated structures. The measurement results show the consistence between the theoretical design and experiments. This will provide guidance for the large-area and fast production of ten-fold quasicrystalline structures with high quality.

  12. Vocal fold composition and early glottic carcinoma infiltration

    Directory of Open Access Journals (Sweden)

    Fang Qin

    2012-08-01

    Full Text Available Abstract Background Current imaging techniques provide only limited information pertaining to the extent of infiltration of laryngeal carcinomas into vocal fold tissue layers. Therefore, it is needed to seek the contribute to the body of knowledge surrounding examination and characterization in laryngeal carcinoma infiltration. Methods Excised larynges were collected from 30 male laryngectomy patients with an average age of 43.5 years (ranging 36 to 55 years and history of smoking (≥10 years exhibiting T1, T2, or subglottal (normal vocal fold carcinomas. Vocal folds were preserved via freezing or immersion in paraffin. The depth of the mucosa, submucosa, and muscular layers in both normal vocal folds and tumor tissues of afflicted vocal folds was measured. Results The average depths of the mucosa, submucosa, and muscular layers in normal vocal folds were 0.15 ± 0.06 mm, 2.30 ± 0.59 mm, and 2.87 ± 0.88 mm, respectively. Infiltration measurements of T1 tumors showed a depth of 1.62 ± 0.51 mm and 1.32 ± 0.49 mm in frozen sections and paraffin-embedded samples, respectively. Similarly, T2 tumors showed a depth of 2.87 ± 0.68 mm and 2.58 ± 0.67 mm in frozen sections and paraffin-embedded samples, respectively. T1 and T2 tumors occupied 24.8 ± 10 and 48.5 ± 15 percent of the normal vocal fold depth, respectively. Conclusion This data provides a baseline for estimating infiltration of laryngeal carcinomas in vocal fold tissue layers, of particular interest to surgeons. This information may be used to assess typical depths of infiltration, thus allowing for more appropriate selection of surgical procedures based on individual patient assessment.

  13. A folding algorithm for extended RNA secondary structures.

    Science.gov (United States)

    Höner zu Siederdissen, Christian; Bernhart, Stephan H; Stadler, Peter F; Hofacker, Ivo L

    2011-07-01

    RNA secondary structure contains many non-canonical base pairs of different pair families. Successful prediction of these structural features leads to improved secondary structures with applications in tertiary structure prediction and simultaneous folding and alignment. We present a theoretical model capturing both RNA pair families and extended secondary structure motifs with shared nucleotides using 2-diagrams. We accompany this model with a number of programs for parameter optimization and structure prediction. All sources (optimization routines, RNA folding, RNA evaluation, extended secondary structure visualization) are published under the GPLv3 and available at www.tbi.univie.ac.at/software/rnawolf/.

  14. An efficient and low resistant circumferential overlap trisection helical baffle heat exchanger with folded baffles

    International Nuclear Information System (INIS)

    Dong, Cong; Li, Dongshuang; Zheng, Youqu; Li, Guoneng; Suo, Yange; Chen, Yaping

    2016-01-01

    Highlights: • The novel cothHXf with circumferential overlap and folded baffles is first proposed. • The key sections of cylindrical and dumbbell are constructed to analyze local flow field characteristics. • The restricted leakage, easier to install and low resistant characteristics are emphasized. • The enhanced heat transfer mechanism of Dean Vortex secondary flow is analyzed. • A variety of comprehensive efficiency assessments are used. - Abstract: An efficient and low resistant circumferential overlap trisection helical baffle shell-and-tube heat exchanger with folded baffles (cothHXf) is presented. It is a modified trisection helical baffle heat exchanger with folded helical baffles for setting rods-and-spanning sleeves. It not only inherits all the merits of circumferential overlap helical baffle scheme, but also adds many additional advantages, such as supporting the inclined baffles with the least rods, simplifying the manufacturing process of spanning tubes and effectively inhibiting the reverse leakage at triangular areas between adjacent baffles. The improved flow characteristic and heat transfer enhancement mechanism of this heat exchanger were numerically investigated in comparison with conventional segmental baffles shell-and-tube heat exchanger (segHX). The flow fields within triangular area of adjacent baffles and nearby regions were depicted. The impacts of the folded baffles on shell-side helical flow, secondary vortex flow, and leakage pattern were analyzed. The distribution configurations of fields of velocity, pressure, temperature and local heat flow rate were revealed. The results show that the heat transfer performance and comprehensive performance evaluation indexes of the cothHXf are much better than those of the segHX while the pressure drop of the cothHXf is much lower than that of the segHX. The numerical simulation results of vivid distributions of flow and thermal fields of the cothHXf can provide theoretical basis for an

  15. Distinguishing thrust sequences in gravity-driven fold and thrust belts

    Science.gov (United States)

    Alsop, G. I.; Weinberger, R.; Marco, S.

    2018-04-01

    Piggyback or foreland-propagating thrust sequences, where younger thrusts develop in the footwalls of existing thrusts, are generally assumed to be the typical order of thrust development in most orogenic settings. However, overstep or 'break-back' sequences, where later thrusts develop above and in the hangingwalls of earlier thrusts, may potentially form during cessation of movement in gravity-driven mass transport deposits (MTDs). In this study, we provide a detailed outcrop-based analysis of such an overstep thrust sequence developed in an MTD in the southern Dead Sea Basin. Evidence that may be used to discriminate overstep thrusting from piggyback thrust sequences within the gravity-driven fold and thrust belt includes upright folds and forethrusts that are cut by younger overlying thrusts. Backthrusts form ideal markers that are also clearly offset and cut by overlying younger forethrusts. Portions of the basal detachment to the thrust system are folded and locally imbricated in footwall synclines below forethrust ramps, and these geometries also support an overstep sequence. However, new 'short-cut' basal detachments develop below these synclines, indicating that movement continued on the basal detachment rather than it being abandoned as in classic overstep sequences. Further evidence for 'synchronous thrusting', where movement on more than one thrust occurs at the same time, is provided by displacement patterns on sequences of thrust ramp imbricates that systematically increases downslope towards the toe of the MTD. Older thrusts that initiate downslope in the broadly overstep sequence continue to move and therefore accrue greater displacements during synchronous thrusting. Our study provides a template to help distinguish different thrust sequences in both orogenic settings and gravity-driven surficial systems, with displacement patterns potentially being imaged in seismic sections across offshore MTDs.

  16. Single injection of basic fibroblast growth factor to treat severe vocal fold lesions and vocal fold paralysis.

    Science.gov (United States)

    Kanazawa, Takeharu; Komazawa, Daigo; Indo, Kanako; Akagi, Yusuke; Lee, Yogaku; Nakamura, Kazuhiro; Matsushima, Koji; Kunieda, Chikako; Misawa, Kiyoshi; Nishino, Hiroshi; Watanabe, Yusuke

    2015-10-01

    Severe vocal fold lesions such as vocal fold sulcus, scars, and atrophy induce a communication disorder due to severe hoarseness, but a treatment has not been established. Basic fibroblast growth factor (bFGF) therapies by either four-time repeated local injections or regenerative surgery for vocal fold scar and sulcus have previously been reported, and favorable outcomes have been observed. In this study, we modified bFGF therapy using a single of bFGF injection, which may potentially be used in office procedures. Retrospective chart review. Five cases of vocal fold sulcus, six cases of scars, seven cases of paralysis, and 17 cases of atrophy were treated by a local injection of bFGF. The injection regimen involved injecting 50 µg of bFGF dissolved in 0.5 mL saline only once into the superficial lamina propria using a 23-gauge injection needle. Two months to 3 months after the injection, phonological outcomes were evaluated. The maximum phonation time (MPT), mean airflow rate, pitch range, speech fundamental frequency, jitter, and voice handicap index improved significantly after the bFGF injection. Furthermore, improvement in the MPT was significantly greater in patients with (in increasing order) vocal fold atrophy, scar, and paralysis. The improvement in the MPT among all patients was significantly correlated with age; the MPT improved more greatly in younger patients. Regenerative treatments by bFGF injection—even a single injection—effectively improve vocal function in vocal fold lesions. 4 © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

  17. The Influence of fold and fracture development on reservoir behavior of the Lisburne Group of northern Alaska

    Energy Technology Data Exchange (ETDEWEB)

    Wesley K. Wallace; Catherine L. Hanks; Jerry Jensen: Michael T. Whalen; Paul Atkinson; Joseph Brinton; Thang Bui; Margarete Jadamec; Alexandre Karpov; John Lorenz; Michelle M. McGee; T.M. Parris; Ryan Shackleton

    2004-07-01

    The Carboniferous Lisburne Group is a major carbonate reservoir unit in northern Alaska. The Lisburne is folded and thrust faulted where it is exposed throughout the Brooks Range, but is relatively undeformed in areas of current production in the subsurface of the North Slope. The objectives of this study were to develop a better understanding of four major aspects of the Lisburne: (1) The geometry and kinematics of folds and their truncation by thrust faults. (2) The influence of folding on fracture patterns. (3) The influence of deformation on fluid flow. (4) Lithostratigraphy and its influence on folding, faulting, fracturing, and reservoir characteristics. Symmetrical detachment folds characterize the Lisburne in the northeastern Brooks Range. In contrast, Lisburne in the main axis of the Brooks Range is deformed into imbricate thrust sheets with asymmetrical hangingwall anticlines and footwall synclines. The Continental Divide thrust front separates these different structural styles in the Lisburne and also marks the southern boundary of the northeastern Brooks Range. Field studies were conducted for this project during 1999 to 2001 in various locations in the northeastern Brooks Range and in the vicinity of Porcupine Lake, immediately south of the Continental Divide thrust front. Results are summarized below for the four main subject areas of the study.

  18. Longitudinal development of cortical thickness, folding, and fiber density networks in the first 2 years of life.

    Science.gov (United States)

    Nie, Jingxin; Li, Gang; Wang, Li; Shi, Feng; Lin, Weili; Gilmore, John H; Shen, Dinggang

    2014-08-01

    Quantitatively characterizing the development of cortical anatomical networks during the early stage of life plays an important role in revealing the relationship between cortical structural connection and high-level functional development. The development of correlation networks of cortical-thickness, cortical folding, and fiber-density is systematically analyzed in this article to study the relationship between different anatomical properties during the first 2 years of life. Specifically, longitudinal MR images of 73 healthy subjects from birth to 2 year old are used. For each subject at each time point, its measures of cortical thickness, cortical folding, and fiber density are projected to its cortical surface that has been partitioned into 78 cortical regions. Then, the correlation matrices for cortical thickness, cortical folding, and fiber density at each time point can be constructed, respectively, by computing the inter-regional Pearson correlation coefficient (of any pair of ROIs) across all 73 subjects. Finally, the presence/absence pattern (i.e., binary pattern) of the connection network is constructed from each inter-regional correlation matrix, and its statistical and anatomical properties are adopted to analyze the longitudinal development of anatomical networks. The results show that the development of anatomical network could be characterized differently by using different anatomical properties (i.e., using cortical thickness, cortical folding, or fiber density). Copyright © 2013 Wiley Periodicals, Inc.

  19. Landforms along transverse faults parallel to axial zone of folded ...

    Indian Academy of Sciences (India)

    Himalaya, along the Kali River valley, is defined by folded hanging wall ... role of transverse fault tectonics in the formation of the curvature cannot be ruled out. 1. .... Piedmont surface is made up of gravelliferous and ... made to compute the wedge failure analysis (Hoek .... (∼T2) is at the elevation of ∼272 m asl measured.

  20. A history of folding in mathematics mathematizing the margins

    CERN Document Server

    Friedman, Michael

    2018-01-01

    While it is well known that the Delian problems are impossible to solve with a straightedge and compass – for example, it is impossible to construct a segment whose length is ∛2 with these instruments – the Italian mathematician Margherita Beloch Piazzolla's discovery in 1934 that one can in fact construct a segment of length ∛2 with a single paper fold was completely ignored (till the end of the 1980s). This comes as no surprise, since with few exceptions paper folding was seldom considered as a mathematical practice, let alone as a mathematical procedure of inference or proof that could prompt novel mathematical discoveries. A few question immediately arise: Why did paper folding become a non-instrument? What caused the marginalisation of this technique? And how was the mathematical knowledge, which was nevertheless transmitted and prompted by paper folding, later treated and conceptualised? Aiming to answer these questions, this volume provides, for the first time, an extensive historical study...

  1. Five-fold local symmetry in metallic liquids and glasses

    International Nuclear Information System (INIS)

    Li M Z; Li F X; Zhang H P; Peng H L; Hu Y C; Wang W H

    2017-01-01

    The structure of metallic glasses has been a long-standing mystery. Owing to the disordered nature of atomic structures in metallic glasses, it is a great challenge to find a simple structural description, such as periodicity for crystals, for establishing the structure–property relationship in amorphous materials. In this paper, we briefly review the recent developments of the five-fold local symmetry in metallic liquids and glasses and the understanding of the structure–property relationship based on this parameter. Experimental evidence demonstrates that five-fold local symmetry is found to be general in metallic liquids and glasses. Comprehensive molecular dynamics simulations show that the temperature evolution of five-fold local symmetry reflects the structural evolution in glass transition in cooling process, and the structure–property relationship such as relaxation dynamics, dynamic crossover phenomena, glass transition, and mechanical deformation in metallic liquids and glasses can be well understood base on the simple and general structure parameter of five-fold local symmetry. (paper)

  2. 77 FR 74513 - Folding Gift Boxes From China

    Science.gov (United States)

    2012-12-14

    ... From China Determination On the basis of the record \\1\\ developed in the subject five-year review, the... boxes from China would be likely to lead to continuation or recurrence of material injury to an industry... Publication 4365 (November 2012), entitled Folding Gift Boxes from China: Investigation No. 731-TA-921 (Second...

  3. The Boundary-Hopf-Fold Bifurcation in Filippov Systems

    NARCIS (Netherlands)

    Efstathiou, Konstantinos; Liu, Xia; Broer, Henk W.

    2015-01-01

    This paper studies the codimension-3 boundary-Hopf-fold (BHF) bifurcation of planar Filippov systems. Filippov systems consist of at least one discontinuity boundary locally separating the phase space to disjoint components with different dynamics. Such systems find applications in several fields,

  4. Examining a Thermodynamic Order Parameter of Protein Folding.

    Science.gov (United States)

    Chong, Song-Ho; Ham, Sihyun

    2018-05-08

    Dimensionality reduction with a suitable choice of order parameters or reaction coordinates is commonly used for analyzing high-dimensional time-series data generated by atomistic biomolecular simulations. So far, geometric order parameters, such as the root mean square deviation, fraction of native amino acid contacts, and collective coordinates that best characterize rare or large conformational transitions, have been prevailing in protein folding studies. Here, we show that the solvent-averaged effective energy, which is a thermodynamic quantity but unambiguously defined for individual protein conformations, serves as a good order parameter of protein folding. This is illustrated through the application to the folding-unfolding simulation trajectory of villin headpiece subdomain. We rationalize the suitability of the effective energy as an order parameter by the funneledness of the underlying protein free energy landscape. We also demonstrate that an improved conformational space discretization is achieved by incorporating the effective energy. The most distinctive feature of this thermodynamic order parameter is that it works in pointing to near-native folded structures even when the knowledge of the native structure is lacking, and the use of the effective energy will also find applications in combination with methods of protein structure prediction.

  5. Nonintegrability of the unfolding of the fold-Hopf bifurcation

    Science.gov (United States)

    Yagasaki, Kazuyuki

    2018-02-01

    We consider the unfolding of the codimension-two fold-Hopf bifurcation and prove its meromorphic nonintegrability in the meaning of Bogoyavlenskij for almost all parameter values. Our proof is based on a generalized version of the Morales-Ramis-Simó theory for non-Hamiltonian systems and related variational equations up to second order are used.

  6. Periodic and stochastic thermal modulation of protein folding kinetics.

    Science.gov (United States)

    Platkov, Max; Gruebele, Martin

    2014-07-21

    Chemical reactions are usually observed either by relaxation of a bulk sample after applying a sudden external perturbation, or by intrinsic fluctuations of a few molecules. Here we show that the two ideas can be combined to measure protein folding kinetics, either by periodic thermal modulation, or by creating artificial thermal noise that greatly exceeds natural thermal fluctuations. We study the folding reaction of the enzyme phosphoglycerate kinase driven by periodic temperature waveforms. As the temperature waveform unfolds and refolds the protein, its fluorescence color changes due to FRET (Förster resonant Energy Transfer) of two donor/acceptor fluorophores labeling the protein. We adapt a simple model of periodically driven kinetics that nicely fits the data at all temperatures and driving frequencies: The phase shifts of the periodic donor and acceptor fluorescence signals as a function of driving frequency reveal reaction rates. We also drive the reaction with stochastic temperature waveforms that produce thermal fluctuations much greater than natural fluctuations in the bulk. Such artificial thermal noise allows the recovery of weak underlying signals due to protein folding kinetics. This opens up the possibility for future detection of a stochastic resonance for protein folding subject to noise with controllable amplitude.

  7. Measurement of flow separation in a human vocal folds model

    Czech Academy of Sciences Publication Activity Database

    Šidlof, Petr; Doaré, O.; Cadot, O.; Chaigne, A.

    2011-01-01

    Roč. 51, č. 1 (2011), s. 123-136 ISSN 0723-4864 R&D Projects: GA AV ČR KJB200760801 Institutional research plan: CEZ:AV0Z20760514 Keywords : vocal folds * flow separation * physical model Subject RIV: BI - Acoustics Impact factor: 1.735, year: 2011 http://www.springerlink.com/content/t81114611760jp23/

  8. Energy Landscapes: From Protein Folding to Molecular Assembly

    Science.gov (United States)

    Databases National Security Education Center (NSEC) Center for Nonlinear Studies Engineering Institute assembly is very common in biology and in nanotechnology. Simple examples of self-assembly are the folding efflux pump machinery, ATP synthase, the ribosome, and many others. In nanotechnology, self-assembly has

  9. Conceptual Transformation and Cognitive Processes in Origami Paper Folding

    Science.gov (United States)

    Tenbrink, Thora; Taylor, Holly A.

    2015-01-01

    Research on problem solving typically does not address tasks that involve following detailed and/or illustrated step-by-step instructions. Such tasks are not seen as cognitively challenging problems to be solved. In this paper, we challenge this assumption by analyzing verbal protocols collected during an Origami folding task. Participants…

  10. 76 FR 74704 - Folded Self-Mailers and Unenveloped Mailpieces

    Science.gov (United States)

    2011-12-01

    ... self-mailers (FSM) and unenveloped mailpieces that are mailed at automation or machinable prices. To... and construction of folded self-mailers and unenveloped mailpieces that are mailed at automation or machinable prices. The proposed standards were issued after two years of collaborative work with mailers to...

  11. Biosimulation of inflammation and healing in surgically injured vocal folds.

    Science.gov (United States)

    Li, Nicole Y K; Vodovotz, Yoram; Hebda, Patricia A; Abbott, Katherine Verdolini

    2010-06-01

    The pathogenesis of vocal fold scarring is complex and remains to be deciphered. The current study is part of research endeavors aimed at applying systems biology approaches to address the complex biological processes involved in the pathogenesis of vocal fold scarring and other lesions affecting the larynx. We developed a computational agent-based model (ABM) to quantitatively characterize multiple cellular and molecular interactions involved in inflammation and healing in vocal fold mucosa after surgical trauma. The ABM was calibrated with empirical data on inflammatory mediators (eg, tumor necrosis factor) and extracellular matrix components (eg, hyaluronan) from published studies on surgical vocal fold injury in the rat population. The simulation results reproduced and predicted trajectories seen in the empirical data from the animals. Moreover, the ABM studies suggested that hyaluronan fragments might be the clinical surrogate of tissue damage, a key variable that in these simulations both is enhanced by and further induces inflammation. A relatively simple ABM such as the one reported in this study can provide new understanding of laryngeal wound healing and generate working hypotheses for further wet-lab studies.

  12. 76 FR 50438 - Folded Self-Mailers and Unenveloped Mailpieces

    Science.gov (United States)

    2011-08-15

    ... orientation. Thickness of attachments or enclosures within a mailpiece. Flap size, style, and orientation... style, and includes closure methods and optional elements that may be incorporated into a basic folded... 111 is proposed to be amended as follows: PART 111--[AMENDED] 1. The authority citation for 39 CFR...

  13. A folded plate clamped along one side only

    Science.gov (United States)

    Nazarov, Serguei A.; Slutskij, Andrey S.

    2017-12-01

    An asymptotic model of a folded thin elastic plate is posed on two plane domains and contains transmission conditions at the common line segment of their boundaries. These conditions become non-local and inhomogeneous if only one side of the plate is fixed. Solvability and smoothness results and error estimates for the model are derived. xml:lang="fr"

  14. Laryngeal Electromyography for Prognosis of Vocal Fold Paralysis.

    Science.gov (United States)

    Pardo-Maza, Adriana; García-Lopez, Isabel; Santiago-Pérez, Susana; Gavilán, Javier

    2017-01-01

    This study aimed to determine the value of laryngeal electromyography in the prognosis of vocal fold paralysis. This is a retrospective descriptive study. This study included 80 patients diagnosed with unilateral or bilateral vocal fold paralysis on flexible laryngoscopy between 2002 and 2014 in a tertiary medical center. Laryngeal electromyography using a standardized protocol was performed; the outcome measures were classified and analyzed into two groups according to the degree of injury. Group 1 included patients with mild to moderate injury, and group 2 included patients with severe to complete injury. Prognosis was correlated with vocal fold motion recovery status with a minimum of 6 months of follow-up since the symptoms onset using positive and negative predictive values. Sixty patients showed acute or chronic recurrent laryngeal neuropathy in laryngeal electromyography. Twelve of 41 patients included in group 1 recovered motion, and 30 of 35 patients included in group 2 did not recover, resulting in 88.2% of positive predictive value and 35.7% of negative predictive value. Our data confirm that laryngeal electromyography is a useful clinical tool in predicting poor recovery in patients with vocal fold paralysis. It allows identification of candidates for early intervention. Copyright © 2017 The Voice Foundation. Published by Elsevier Inc. All rights reserved.

  15. Laryngeal Electromyographic findings in patients with vocal fold motion asymmetry.

    Science.gov (United States)

    Woo, Peak; Isseroff, Tova F; Parasher, Arjun; Richards, Amanda; Sivak, Mark

    2016-08-01

    Vocal fold motion asymmetry (VFMA) is often attributed to vocal fold paresis or an anatomical variant. Although laryngeal electromyography (LEMG) may be used to evaluate patients with vocal fold paresis, electrodiagnostic findings in VFMA have not been well defined. Review of a case series Twenty-five symptomatic patients with VFMA were examined by LEMG, and the findings were analyzed. Although all were thought to have unilateral recurrent laryngeal nerve paresis, LEMG showed only nine to have unilateral recurrent nerve paresis. There were nine with both ipsilateral recurrent laryngeal nerve and superior laryngeal nerve paresis, four with bilateral paresis, and three were normal. Reduced total number of units, reduced recruitment, motor units firing fast, and polyphasic units were more common, whereas fibrillation potentials, fasciculation, positive sharp waves, and complex repetitive discharges were uncommon. The LEMG findings are most consistent with old, healed neuropathy. McNemar's test for the acute versus chronic denervation potentials showed significant differences. VFMA has a high incidence of vocal fold paresis that can be better defined by LEMG. The site and side of paresis is often wrong based on laryngoscopy findings alone. The LEMG findings of VFMA appear to be consistent with old, healed neuropathy 4 Laryngoscope, 126:E273-E277, 2016. © 2016 The American Laryngological, Rhinological and Otological Society, Inc.

  16. Radiology findings in adult patients with vocal fold paralysis

    Energy Technology Data Exchange (ETDEWEB)

    Robinson, S. [Helsinki Medical Imaging Centre, University of Helsinki, Haartmaninkatu, Helsinki (Finland)]. E-mail: s.robinson@dzu.at; Pitkaeranta, A. [Department of Otorhinolaryngology, Haartmaninkatu, Helsinki (Finland)

    2006-10-15

    Aim: To compile imaging findings in patients with vocal fold paralysis. Materials and methods: A retrospective analysis of the medical charts of 100 consecutive patients, admitted to our department with vocal fold paralysis was undertaken. After laryngoscopy, patients were referred for radiological work-up depending on their clinical history and clinical findings. Ultrasound of the neck and/or contrast-enhanced spiral computed tomography (CT) of the neck and mediastinum was performed, extending to include the whole chest if necessary. In one patient, CT of the brain and in two patients, magnetic resonance angiography was undertaken. Analysis of the clinical and radiological data was performed to assess the most frequent causes for vocal fold paralysis. Results: In 66% of patients, the paralysis was related to previous surgery. Thirty-four percent of cases were labelled idiopathic after clinical examination. After imaging and follow-up, only 8% remained unexplained. Nine patients suffered from neoplasms, four from vascular disease, and 12 from infections. One patient developed encephalomyelitis disseminata on follow-up. Conclusion: Thorough radiological work-up helps to reduce the amount of idiopathic cases of vocal fold paralysis and guides appropriate therapy.

  17. A new generation videokymography for routine clinical vocal fold examination

    NARCIS (Netherlands)

    Qiu, Qingjun; Schutte, Harm K.

    2006-01-01

    Objective. This study aims to introduce a new-generation videokymographic system, which provides simultaneous laryngoscopic and kymographic image, for routine clinical vocal fold examination. Study Design: The authors explored a new imaging method for diagnosis and evaluation of voice disorders.

  18. Radiology findings in adult patients with vocal fold paralysis

    International Nuclear Information System (INIS)

    Robinson, S.; Pitkaeranta, A.

    2006-01-01

    Aim: To compile imaging findings in patients with vocal fold paralysis. Materials and methods: A retrospective analysis of the medical charts of 100 consecutive patients, admitted to our department with vocal fold paralysis was undertaken. After laryngoscopy, patients were referred for radiological work-up depending on their clinical history and clinical findings. Ultrasound of the neck and/or contrast-enhanced spiral computed tomography (CT) of the neck and mediastinum was performed, extending to include the whole chest if necessary. In one patient, CT of the brain and in two patients, magnetic resonance angiography was undertaken. Analysis of the clinical and radiological data was performed to assess the most frequent causes for vocal fold paralysis. Results: In 66% of patients, the paralysis was related to previous surgery. Thirty-four percent of cases were labelled idiopathic after clinical examination. After imaging and follow-up, only 8% remained unexplained. Nine patients suffered from neoplasms, four from vascular disease, and 12 from infections. One patient developed encephalomyelitis disseminata on follow-up. Conclusion: Thorough radiological work-up helps to reduce the amount of idiopathic cases of vocal fold paralysis and guides appropriate therapy

  19. Vocal Fold Epithelial Response to Luminal Osmotic Perturbation

    Science.gov (United States)

    Sivasankar, Mahalakshmi; Fisher, Kimberly V.

    2007-01-01

    Purpose: Dry-air challenges increase the osmolarity of fluid lining the luminal surface of the proximal airway. The homeostasis of surface fluid is thought to be essential for voice production and laryngeal defense. Therefore, the authors hypothesized that viable vocal fold epithelium would generate a water flux to reduce an osmotic challenge (150…

  20. Degradation of extracytoplasmic catalysts for protein folding in Bacillus subtilis

    NARCIS (Netherlands)

    Krishnappa, Laxmi; Monteferrante, Carmine G; Neef, Jolanda; Dreisbach, Annette; van Dijl, Jan Maarten

    The general protein secretion pathway of Bacillus subtilis has a high capacity for protein export from the cytoplasm, which is exploited in the biotechnological production of a wide range of enzymes. These exported proteins pass the membrane in an unfolded state, and accordingly, they have to fold

  1. Simply folded band chaos in a VHF microstrip oscillator

    Energy Technology Data Exchange (ETDEWEB)

    Blakely, Jonathan N. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States)]. E-mail: jonathan.blakely@us.army.mil; Holder, J. Darryl [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States); Corron, Ned J. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States); Pethel, Shawn D. [US Army Research, Development, and Engineering Command, AMSRD-AMR-WS-ST, Redstone Arsenal, AL 35898 (United States)

    2005-10-10

    We present experimental observations of a microstrip circuit that produces Roessler-like chaos with center frequency of 175 MHz. A simply folded band chaotic attractor is created through a period doubling route. The circuit provides an experimental realization of a chaotic neutral delay differential equation, a largely unexplored type of nonlinear dynamical system.

  2. Mechanical Modeling and Computer Simulation of Protein Folding

    Science.gov (United States)

    Prigozhin, Maxim B.; Scott, Gregory E.; Denos, Sharlene

    2014-01-01

    In this activity, science education and modern technology are bridged to teach students at the high school and undergraduate levels about protein folding and to strengthen their model building skills. Students are guided from a textbook picture of a protein as a rigid crystal structure to a more realistic view: proteins are highly dynamic…

  3. Folding and insertion thermodynamics of the transmembrane WALP peptide

    NARCIS (Netherlands)

    Bereau, T.; Bennett, W.F.D.; Pfaendtner, J.; Deserno, M.; Karttunen, M.E.J.

    2015-01-01

    The anchor of most integral membrane proteins consists of one or several helices spanning the lipid bilayer. The WALP peptide, GWW(LA)$_n$(L)WWA, is a common model helix to study the fundamentals of protein insertion and folding, as well as helix-helix association in the membrane. Its structural

  4. Folding and insertion thermodynamics of the transmembrane WALP peptide

    NARCIS (Netherlands)

    Bereau, T.; Bennett, W.F.D. Drew; Pfaendtner, J.; Deserno, M.; Karttunen, M.

    2015-01-01

    The anchor of most integral membrane proteins consists of one or several helices spanning the lipid bilayer. The WALP peptide, GWW(LA)n (L)WWA, is a common model helix to study the fundamentals of protein insertion and folding, as well as helix-helix association in the membrane. Its structural

  5. Approximate self-similarity in models of geological folding

    NARCIS (Netherlands)

    Budd, C.J.; Peletier, M.A.

    2000-01-01

    We propose a model for the folding of rock under the compression of tectonic plates. This models an elastic rock layer imbedded in a viscous foundation by a fourth-order parabolic equation with a nonlinear constraint. The large-time behavior of solutions of this problem is examined and found to be

  6. Anatomical study of minor alterations in neonate vocal folds.

    Science.gov (United States)

    Silva, Adriano Rezende; Machado, Almiro José; Crespo, Agrício Nubiato

    2014-01-01

    Minor structural alterations of the vocal fold cover are frequent causes of voice abnormalities. They may be difficult to diagnose, and are expressed in different manners. Cases of intracordal cysts, sulcus vocalis, mucosal bridge, and laryngeal micro-diaphragm form the group of minor structural alterations of the vocal fold cover investigated in the present study. The etiopathogenesis and epidemiology of these alterations are poorly known. To evaluate the existence and anatomical characterization of minor structural alterations in the vocal folds of newborns. 56 larynxes excised from neonates of both genders were studied. They were examined fresh, or defrosted after conservation via freezing, under a microscope at magnifications of 25× and 40×. The vocal folds were inspected and palpated by two examiners, with the aim of finding minor structural alterations similar to those described classically, and other undetermined minor structural alterations. Larynges presenting abnormalities were submitted to histological examination. Six cases of abnormalities were found in different larynges: one (1.79%) compatible with a sulcus vocalis and five (8.93%) compatible with a laryngeal micro-diaphragm. No cases of cysts or mucosal bridges were found. The observed abnormalities had characteristics similar to those described in other age groups. Abnormalities similar to sulcus vocalis or micro-diaphragm may be present at birth. Copyright © 2014 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  7. Computing the Fréchet distance between folded polygons

    NARCIS (Netherlands)

    Cook IV, A.F.; Driemel, A.; Sherette, J.; Wenk, C.

    2015-01-01

    Computing the Fréchet distance for surfaces is a surprisingly hard problem and the only known polynomial-time algorithm is limited to computing it between flat surfaces. We study the problem of computing the Fréchet distance for a class of non-flat surfaces called folded polygons. We present a

  8. Acute dysphonia secondary to vocal fold hemorrhage after vardenafil use.

    Science.gov (United States)

    Singh, Vikas; Cohen, Seth M; Rousseau, Bernard; Noordzij, J Pieter; Garrett, C Gaelyn; Ossoff, Robert H

    2010-06-01

    Owing to their vasodilatory effects, the phosphodiesterase-5 inhibitors have become widely used for the treatment of erectile dysfunction. Among the reported adverse events of these agents are epistaxis, variceal bleeding, intracranial hemorrhage, and hemorrhoidal bleeding. We report a case of vocal fold hemorrhage that occurred after vardenafil use in a 31-year-old man who was a professional singer.

  9. Thermodynamic properties of an extremely rapid protein folding reaction.

    Science.gov (United States)

    Schindler, T; Schmid, F X

    1996-12-24

    The cold-shock protein CspB from Bacillus subtilis is a very small beta-barrel protein, which folds with a time constant of 1 ms (at 25 degrees C) in a U reversible N two-state reaction. To elucidate the energetics of this extremely fast reaction we investigated the folding kinetics of CspB as a function of both temperature and denaturant concentration between 2 and 45 degrees C and between 1 and 8 M urea. Under all these conditions unfolding and refolding were reversible monoexponential reactions. By using transition state theory, data from 327 kinetic curves were jointly analyzed to determine the thermodynamic activation parameters delta H H2O++, delta S H2O++, delta G H2O++, and delta C p H2O++ for unfolding and refolding and their dependences on the urea concentration. 90% of the total change in heat capacity and 96% of the change in the m value (m = d delta G/d[urea]) occur between the unfolded state and the activated state. This suggests that for CspB the activated state of folding is unusually well structured and almost equivalent to the native protein in its interactions with the solvent. As a consequence of this native-like activated state a strong temperature-dependent enthalpy/entropy compensation is observed for the refolding kinetics, and the barrier to refolding shifts from being largely enthalpic at low temperature to largely entropic at high temperature. This shift originates not from the changes in the folding protein chains itself, but from the changes in the protein-solvent interactions. We speculate that the absence of intermediates and the native-like activated state in the folding of CspB are correlated with the small size and the structural type of this protein. The stabilization of a small beta-sheet as in CspB requires extensive non-local interactions, and therefore incomplete sheets are unstable. As a consequence, the critical activated state is reached only very late in folding. The instability of partially folded structure is a means to

  10. Swallowing function in pediatric patients with bilateral vocal fold immobility.

    Science.gov (United States)

    Hsu, Jeffrey; Tibbetts, Kathleen M; Wu, Derek; Nassar, Michel; Tan, Melin

    2017-02-01

    Infants with bilateral vocal fold immobility (BVFI) often have poor swallow function in addition to potential airway compromise. While there are several reports on BVFI and its effect on patients' airway status, little is known about long term swallow function. We aim to characterize the swallowing function over time in pediatric patients with bilateral vocal fold immobility. A retrospective review of medical records of infants diagnosed with BVFI at a tertiary care children's hospital between 2005 and 2014 was conducted. Patient demographics, nature and etiology of immobility, laryngoscopy findings, comorbidities, and swallow outcomes at diagnosis and follow-up were recorded. Swallowing outcomes as measured by presence or absence of a gastrostomy tube were compared by etiology, vocal fold status, and normal or developmentally delay using the Fisher's exact test. 110 patients with a diagnosis of vocal fold immobility were identified. Twenty-nine (26%) had BVFI and twenty-three had complete medical records. Etiologies of vocal fold immobility include cardiac related in 13% (3/23), idiopathic in 30% (7/23) prolonged intubation in 26% (6/23) central neurologic in 22% (5/23), trauma in 4% (1/23), and infection in 4% (1/23). Average follow-up time was 44 months (range 5-94 months). Ten patients (56.5%) required a gastrostomy tube at time of diagnosis. Of this cohort who received gastrostomy tubes, three (30%) ultimately transitioned to complete oral feeds. Return of vocal fold mobility did not correlate with swallow function. In those with non-neurologic etiologies, the need for gastrostomy tube at end of follow up was unlikely. There was a statistically significant difference in the percentage of gastrostomy tube-free children at most recent follow up in patients who were normally developed (86%) versus those who were developmentally delayed (33%) (p = 0.02). We characterized the swallowing function of 23 pediatric patients with BVFI. Comorbidities are significant

  11. Single-molecule studies of the Im7 folding landscape.

    Science.gov (United States)

    Pugh, Sara D; Gell, Christopher; Smith, D Alastair; Radford, Sheena E; Brockwell, David J

    2010-04-23

    Under appropriate conditions, the four-helical Im7 (immunity protein 7) folds from an ensemble of unfolded conformers to a highly compact native state via an on-pathway intermediate. Here, we investigate the unfolded, intermediate, and native states populated during folding using diffusion single-pair fluorescence resonance energy transfer by measuring the efficiency of energy transfer (or proximity or P ratio) between pairs of fluorophores introduced into the side chains of cysteine residues placed in the center of helices 1 and 4, 1 and 3, or 2 and 4. We show that while the native states of each variant give rise to a single narrow distribution with high P values, the distributions of the intermediates trapped at equilibrium (denoted I(eqm)) are fitted by two Gaussian distributions. Modulation of the folding conditions from those that stabilize the intermediate to those that destabilize the intermediate enabled the distribution of lower P value to be assigned to the population of the unfolded ensemble in equilibrium with the intermediate state. The reduced stability of the I(eqm) variants allowed analysis of the effect of denaturant concentration on the compaction and breadth of the unfolded state ensemble to be quantified from 0 to 6 M urea. Significant compaction is observed as the concentration of urea is decreased in both the presence and absence of sodium sulfate, as previously reported for a variety of proteins. In the presence of Na(2)SO(4) in 0 M urea, the P value of the unfolded state ensemble approaches that of the native state. Concurrent with compaction, the ensemble displays increased peak width of P values, possibly reflecting a reduction in the rate of conformational exchange among iso-energetic unfolded, but compact conformations. The results provide new insights into the initial stages of folding of Im7 and suggest that the unfolded state is highly conformationally constrained at the outset of folding. (c) 2010 Elsevier Ltd. All rights reserved.

  12. Stretched versus compressed exponential kinetics in α-helix folding

    International Nuclear Information System (INIS)

    Hamm, Peter; Helbing, Jan; Bredenbeck, Jens

    2006-01-01

    In a recent paper (J. Bredenbeck, J. Helbing, J.R. Kumita, G.A. Woolley, P. Hamm, α-helix formation in a photoswitchable peptide tracked from picoseconds to microseconds by time resolved IR spectroscopy, Proc. Natl. Acad. Sci USA 102 (2005) 2379), we have investigated the folding of a photo-switchable α-helix with a kinetics that could be fit by a stretched exponential function exp(-(t/τ) β ). The stretching factor β became smaller as the temperature was lowered, a result which has been interpreted in terms of activated diffusion on a rugged energy surface. In the present paper, we discuss under which conditions diffusion problems occur with stretched exponential kinetics (β 1). We show that diffusion problems do have a strong tendency to yield stretched exponential kinetics, yet, that there are conditions (strong perturbation from equilibrium, performing the experiment in the folding direction) under which compressed exponential kinetics would be expected instead. We discuss the kinetics on free energy surfaces predicted by simple initiation-propagation models (zipper models) of α-helix folding, as well as by folding funnel models. We show that our recent experiment has been performed under condition for which models with strong downhill driving force, such as the zipper model, would predict compressed, rather than stretched exponential kinetics, in disagreement with the experimental observation. We therefore propose that the free energy surface along a reaction coordinate that governs the folding kinetics must be relatively flat and has a shape similar to a 1D golf course. We discuss how this conclusion can be unified with the thermodynamically well established zipper model by introducing an additional kinetic reaction coordinate

  13. Time course of recovery of idiopathic vocal fold paralysis.

    Science.gov (United States)

    Husain, Solomon; Sadoughi, Babak; Mor, Niv; Levin, Ariana M; Sulica, Lucian

    2018-01-01

    To clarify the time course of recovery in patients with idiopathic vocal fold paralysis. Retrospective chart review. Medical records for all patients with idiopathic vocal fold paralysis over a 10-year period were reviewed to obtain demographic and clinical information, including onset of disease and recovery of vocal function. Stroboscopic exams of patients who recovered voice were reviewed blindly to assess return of vocal fold motion. Thirty-eight of 55 patients (69%) recovered vocal function. Time course of recovery could be assessed in 34 patients who did not undergo injection augmentation. The mean time to recovery was 152.8 ± 109.3 days (left, 179.8 ± 111.3 days; right, 105.3 ± 93.7 days; P = .088). Two-thirds of patients recovered within 6 months. Probability of recovery declined over time. Five of 22 patients who recovered voice had return of vocal fold motion; 17 did not. The mean time to recovery did not differ between these groups (return of motion, 127.4 ± 132.3 days; no return of motion, 160.1 ± 105.1 days; P = .290). Sixty-nine percent of patients with idiopathic vocal fold paralysis recovered vocal function, two-thirds doing so within 6 months of onset. Age, gender, laterality, use of injection augmentation did not influence recovery rate. Declining probability of recovery over time leads us to consider framework surgery after 6 months in patients with idiopathic paralysis. 4. Laryngoscope, 128:148-152, 2018. © 2017 The American Laryngological, Rhinological and Otological Society, Inc.

  14. Experimental Analysis of Steady-State Maneuvering Effects on Transmission Vibration Patterns Recorded in an AH-1 Cobra Helicopter

    Science.gov (United States)

    Huff, Edward M.; Dzwonczyk, Mark; Norvig, Peter (Technical Monitor)

    2000-01-01

    Flight experiment was designed primarily to determine the extent to which steady-state maneuvers influence characteristic vibration patterns measured at the input pinion and output annulus gear locations of the main transmission. If results were to indicate that maneuvers systematically influence vibration patterns, more extensive studies would be planned to explore the response surface. It was also designed to collect baseline data for comparison with experimental data to be recorded at a later date from test stands at Glenn Research Center. Finally, because this was the first vibration flight study on the Cobra aircraft, considerable energy was invested in developing an in-flight recording apparatus, as well as exploring acceleration mounting methods, and generally learning about the overall vibratory characteristics of the aircraft itself.

  15. Detachments in Shale: Controlling Characteristics on Fold-Thrust Belt Style

    Science.gov (United States)

    Hansberry, Rowan; King, Ros; Collins, Alan; Morley, Chris

    2013-04-01

    Fold-thrust belts occur across multiple tectonic settings where thin-skinned deformation is accommodated by one or more detachment zones, both basal and within the fold-thrust belt. These fold-thrust belts exhibit considerable variation in structural style and vergence depending on the characteristics (e.g. strength, thickness, and lithology) and number of detachment zones. Shale as a detachment lithology is intrinsically weaker than more competent silts and sands; however, it can be further weakened by high pore pressures, reducing resistance to sliding and; high temperatures, altering the rheology of the detachment. Despite the implications for petroleum exploration and natural hazard assessment the precise nature by which detachments in shale control and are involved in deformation in fold-thrust belts is poorly understood. Present-day active basal detachment zones are usually located in inaccessible submarine regions. Therefore, this project employs field observations and sample analysis of ancient, exhumed analogues to document the nature of shale detachments (e.g. thickness, lithology, dip and dip direction, deformational temperature and thrust propagation rates) at field sites in Thailand, Norway and New Zealand. X-ray diffraction analysis of illite crystallinity and oxygen stable isotopes analysis are used as a proxy for deformational temperature whilst electron-backscatter diffraction analysis is used to constrain microstructural deformational patterns. K-Ar dating of synkinematic clay fault gouges is being applied to date the final stages of activity on individual faults with a view to constraining thrust activation sequences. It is not possible to directly measure palaeo-data for some key detachment parameters, such as pore pressure and coefficients of friction. However, the use of critical taper wedge theory has been used to successfully infer internal and basal coefficients of friction and depth-normalized pore pressure within a wedge and at its base

  16. Two- and three-dimensional folding of thin film single-crystalline silicon for photovoltaic power applications

    OpenAIRE

    Guo, Xiaoying; Li, Huan; Yeop Ahn, Bok; Duoss, Eric B.; Hsia, K. Jimmy; Lewis, Jennifer A.; Nuzzo, Ralph G.

    2009-01-01

    Fabrication of 3D electronic structures in the micrometer-to-millimeter range is extremely challenging due to the inherently 2D nature of most conventional wafer-based fabrication methods. Self-assembly, and the related method of self-folding of planar patterned membranes, provide a promising means to solve this problem. Here, we investigate self-assembly processes driven by wetting interactions to shape the contour of a functional, nonplanar photovoltaic (PV) device. A mechanics model based ...

  17. The influence of thyroarytenoid and cricothyroid muscle activation on vocal fold stiffness and eigenfrequencies

    OpenAIRE

    Yin, Jun; Zhang, Zhaoyan

    2013-01-01

    The influence of the thyroarytenoid (TA) and cricothyroid (CT) muscle activation on vocal fold stiffness and eigenfrequencies was investigated in a muscularly controlled continuum model of the vocal folds. Unlike the general understanding that vocal fold fundamental frequency was determined by vocal fold tension, this study showed that vocal fold eigenfrequencies were primarily determined by vocal fold stiffness. This study further showed that, with reference to the resting state of zero stra...

  18. Transient intermediates are populated in the folding pathways of single-domain two-state folding protein L

    Science.gov (United States)

    Maity, Hiranmay; Reddy, Govardhan

    2018-04-01

    Small single-domain globular proteins, which are believed to be dominantly two-state folders, played an important role in elucidating various aspects of the protein folding mechanism. However, recent single molecule fluorescence resonance energy transfer experiments [H. Y. Aviram et al. J. Chem. Phys. 148, 123303 (2018)] on a single-domain two-state folding protein L showed evidence for the population of an intermediate state and it was suggested that in this state, a β-hairpin present near the C-terminal of the native protein state is unfolded. We performed molecular dynamics simulations using a coarse-grained self-organized-polymer model with side chains to study the folding pathways of protein L. In agreement with the experiments, an intermediate is populated in the simulation folding pathways where the C-terminal β-hairpin detaches from the rest of the protein structure. The lifetime of this intermediate structure increased with the decrease in temperature. In low temperature conditions, we also observed a second intermediate state, which is globular with a significant fraction of the native-like tertiary contacts satisfying the features of a dry molten globule.

  19. The pro region required for folding of carboxypeptidase Y is a partially folded domain with little regular structural core

    DEFF Research Database (Denmark)

    Sørensen, P; Winther, Jakob R.; Kaarsholm, N C

    1993-01-01

    The pro region of carboxypeptidase Y (CPY) from yeast is necessary for the correct folding of the enzyme [Winther, J. R., & Sørensen P. (1991) Proc. Natl. Acad. Sci. U.S.A. 88, 9330-9334]. Using fluorescence, circular dichroism, and heteronuclear NMR analyses, it is demonstrated that the isolated...

  20. Specialization Patterns

    OpenAIRE

    Schultz , Ulrik Pagh; Lawall , Julia ,; Consel , Charles

    1999-01-01

    Design patterns offer numerous advantages for software development, but can introduce inefficiency into the finished program. Program specialization can eliminate such overheads, but is most effective when targeted by the user to specific bottlenecks. Consequently, we propose to consider program specialization and design patterns as complementary concepts. On the one hand, program specialization can optimize object-oriented programs written using design patterns. On the other hand, design pat...