942 resultados para Vocal nodules
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We introduce "BU-MIA," a Medical Image Analysis system that integrates various advanced chest image analysis methods for detection, estimation, segmentation, and registration. BU-MIA evaluates repeated computed tomography (CT) scans of the same patient to facilitate identification and evaluation of pulmonary nodules for interval growth. It provides a user-friendly graphical user interface with a number of interaction tools for development, evaluation, and validation of chest image analysis methods. The structures that BU-MIA processes include the thorax, lungs, and trachea, pulmonary structures, such as lobes, fissures, nodules, and vessels, and bones, such as sternum, vertebrae, and ribs.
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This paper describes a model of speech production called DIVA that highlights issues of self-organization and motor equivalent production of phonological units. The model uses a circular reaction strategy to learn two mappings between three levels of representation. Data on the plasticity of phonemic perceptual boundaries motivates a learned mapping between phoneme representations and vocal tract variables. A second mapping between vocal tract variables and articulator movements is also learned. To achieve the flexible control made possible by the redundancy of this mapping, desired directions in vocal tract configuration space are mapped into articulator velocity commands. Because each vocal tract direction cell learns to activate several articulator velocities during babbling, the model provides a natural account of the formation of coordinative structures. Model simulations show automatic compensation for unexpected constraints despite no previous experience or learning under these constraints.
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This article describes a neural network model that addresses the acquisition of speaking skills by infants and subsequent motor equivalent production of speech sounds. The model learns two mappings during a babbling phase. A phonetic-to-orosensory mapping specifies a vocal tract target for each speech sound; these targets take the form of convex regions in orosensory coordinates defining the shape of the vocal tract. The babbling process wherein these convex region targets are formed explains how an infant can learn phoneme-specific and language-specific limits on acceptable variability of articulator movements. The model also learns an orosensory-to-articulatory mapping wherein cells coding desired movement directions in orosensory space learn articulator movements that achieve these orosensory movement directions. The resulting mapping provides a natural explanation for the formation of coordinative structures. This mapping also makes efficient use of redundancy in the articulator system, thereby providing the model with motor equivalent capabilities. Simulations verify the model's ability to compensate for constraints or perturbations applied to the articulators automatically and without new learning and to explain contextual variability seen in human speech production.
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Communication is important for social and other behavioural interactions in most marine mammal species. The bottlenose dolphin (Tursiops truncatus, Montagu, 1821) is a highly social species that use whistles as communication calls to express identity and to initiate and maintain contact between socially interactive individuals. In this thesis, the degree of variability in whistle behaviour and whistle characteristics was examined between different habitats on a range of spatial scales. The whistle characteristics that best discriminated between different communities were investigated, along with exploration of whistle variation in relation to habitat type, levels of social interaction and relatedness. Finally, the use and variability of individually distinctive calls (signature whistles) within and between Irish and US waters were also examined. Relatively high levels of whistle variation were found within a genetically and socially isolated population of dolphins in the Shannon Estuary, reflecting the need for individual identification and distinctive whistles in a population with long term site fidelity and high levels of social cohesion. Variation between reproductively separate communities in Irish waters was relatively small except between animals in inshore compared with continental shelf waters. The greatest differences in whistle structure overall were evident between dolphins using inshore and offshore US waters, likely reflecting social isolation of the two distinct ecotypes that occur in these waters but also variation in behaviour or habitat conditions. Variation found among inshore communities in US waters reflected similarities in habitat use and levels of social interaction. These findings suggest that vocal variation is socially mediated, behaviourally maintained and dependent on levels of social contact between individuals. The findings contribute to our understanding of the interaction of factors influencing vocalisation behaviour in this behaviourally complex and ecologically plastic species.
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In an attempt to provide an analytical entry point into my compositional practice, I have identified eight themes which are significantly recurrent: reduction – the selection of a small number of elements; imperfection – a damaged or warped characteristic of sound; hierarchy – a concern with the roles of instruments with regard to their relative prominence; motion – apparently static sound masses consist of fine internal movement; listener perception – expectations for change influence the experience of affect; translation – the transitioning of electronic sounds to the acoustic realm, and vice versa; immersion – the creation of an accommodating soundscape; blurring – smearing and overlapping sounds or genres. Each of these eight factors is associated with relevant precedents in the history and theory of music that have been influential on my work. These include the minimalist compositions of Steve Reich and Arvo Pärt; the lo-fi aesthetic of Boards of Canada and My Bloody Valentine; concerns with political hierarchy in the work of Louis Andriessen; the variations of dynamics and microtonal shifts of Giacinto Scelsi; Leonard B. Meyer's account of expectation in music; cross-fertilisation of the acoustic and electronic in pieces by Gérard Grisey and Gyorgy Ligeti; the immersive technique of Brian Eno's ambient music; and the overlapping sounds of Aphex Twin. These eight factors are variously applicable to the eleven submitted pieces, which are individually analysed with reference to the most significant of the categories. Together they form a musical language that sustains the interaction of a variety of techniques, concepts and genres.
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This thesis explores the use of electromagnetics for both steering and tracking of medical instruments in minimally invasive surgeries. The end application is virtual navigation of the lung for biopsy of early stage cancer nodules. Navigation to the peripheral regions of the lung is difficult due to physical dimensions of the bronchi and current methods have low successes rates for accurate diagnosis. Firstly, the potential use of DC magnetic fields for the actuation of catheter devices with permanently magnetised distal attachments is investigated. Catheter models formed from various materials and magnetic tip formations are used to examine the usefulness of relatively low power and compact electromagnets. The force and torque that can be exerted on a small permanent magnet is shown to be extremely limited. Hence, after this initial investigation we turn our attention to electromagnetic tracking, in the development of a novel, low-cost implementation of a GPS-like system for navigating within a patient. A planar magnetic transmitter, formed on a printed circuit board for a low-profile and low cost manufacture, is used to generate a low frequency magnetic field distribution which is detected by a small induction coil sensor. The field transmitter is controlled by a novel closed-loop system that ensures a highly stable magnetic field with reduced interference from one transmitter coil to another. Efficient demodulation schemes are presented which utilise synchronous detection of each magnetic field component experienced by the sensor. The overall tracking accuracy of the system is shown to be less than 2 mm with an orientation error less than 1°. A novel demodulation implementation using a unique undersampling approach allows the use of reduced sample rates to sample the signals of interest without loss of tracking accuracy. This is advantageous for embedded microcontroller implementations of EM tracking systems. The EM tracking system is demonstrated in the pre-clinical environment of a breathing lung phantom. The airways of the phantom are successfully navigated using the system in combination with a 3D computer model rendered from CT data. Registration is achieved using both a landmark rigid registration method and a hybrid fiducial-free approach. The design of a planar magnetic shield structure for blocking the effects of metallic distortion from below the transmitter is presented which successfully blocks the impact of large ferromagnetic objects such as operating tables. A variety of shielding material are analysed with MuMetal and ferrite both providing excellent shieling performance and an increased signal to noise ratio. Finally, the effect of conductive materials and human tissue on magnetic field measurements is presented. Error due to induced eddy currents and capacitive coupling is shown to severely affect EM tracking accuracy at higher frequencies.
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The problem was to determine whether a method of aural and visual vocal training that included a program of portable electronic piano keyboard experience would be more effective in teaching sight-singing skills to novice high school chorus students than a method that included only aural and visual vocal training. A sub-problem was to determine whether novice chorus students enjoyed playing electronic keyboards in chorus as a reinforcement experience in sight-singing training. Students were randomly assigned to two treatment groups, tested with the Musical Aptitude Profile, Tonal Imagery, part A, and then trained separately. The experimental group sang repetitions of melodic patterns and utilized techniques associated with the Kodály Method while simultaneously playing keyboard. The comparison group received a similar treatment without using keyboards. The students were pre- and post-tested in sight-singing using the Vocal Sight-Reading Inventory. Results of the Analysis of Covariance using MAP scores as the covariate revealed no significant difference (p<.05) between post-test scores of the two groups. Improvement was noted in 96% of students from pre-test to post-test regardless of grouping. The repeated measures ANOVA revealed a significant relationship (p<.006) between aptitude group and post-test score. High aptitude students in both groups were found to benefit more from the training than low aptitude students. High aptitude keyboard group students achieved an average gain score that was 8.67 points higher than the comparison group. Of the total experimental group, 92% enjoyed playing keyboards in chorus. It is recommended that future research be undertaken to study the use of keyboards with advanced high school choruses and with uncertain singers in the high school chorus. Research is also needed to develop graded, valid, and reliable sight-singing tests for use in high school chorus. Techniques of the Kodály Method should be further investigated for use in high school sight-singing training.
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Surgery is one of the most effective and widely used procedures in treating human cancers, but a major problem is that the surgeon often fails to remove the entire tumor, leaving behind tumor-positive margins, metastatic lymph nodes, and/or satellite tumor nodules. Here we report the use of a hand-held spectroscopic pen device (termed SpectroPen) and near-infrared contrast agents for intraoperative detection of malignant tumors, based on wavelength-resolved measurements of fluorescence and surface-enhanced Raman scattering (SERS) signals. The SpectroPen utilizes a near-infrared diode laser (emitting at 785 nm) coupled to a compact head unit for light excitation and collection. This pen-shaped device effectively removes silica Raman peaks from the fiber optics and attenuates the reflected excitation light, allowing sensitive analysis of both fluorescence and Raman signals. Its overall performance has been evaluated by using a fluorescent contrast agent (indocyanine green, or ICG) as well as a surface-enhanced Raman scattering (SERS) contrast agent (pegylated colloidal gold). Under in vitro conditions, the detection limits are approximately 2-5 × 10(-11) M for the indocyanine dye and 0.5-1 × 10(-13) M for the SERS contrast agent. Ex vivo tissue penetration data show attenuated but resolvable fluorescence and Raman signals when the contrast agents are buried 5-10 mm deep in fresh animal tissues. In vivo studies using mice bearing bioluminescent 4T1 breast tumors further demonstrate that the tumor borders can be precisely detected preoperatively and intraoperatively, and that the contrast signals are strongly correlated with tumor bioluminescence. After surgery, the SpectroPen device permits further evaluation of both positive and negative tumor margins around the surgical cavity, raising new possibilities for real-time tumor detection and image-guided surgery.
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The opera ION serves as my Doctoral Dissertation at the University of Maryland School of Music. The librettist of the opera is Nick Olcott, Opera Assistant Director at the University. My interest in this little-known play of Euripides began with my work with Professor Lillian Doherty of the University's Classics Department. Since I am fluent in Greek, I was able to read the play in original, becoming aware of nuances of meaning absent in the standard English translations. Professor Leon Major, Artistic Director of the University's Opera Studio, was enthusiastic about the choice of this play as the basis for an opera, and has been very generous of his time in showing me what must be done to turn a play into an opera. ION is my first complete stage work for voices and constitutes an ambitious project. The opera is scored for a small chamber orchestra, consisting of Saxophone, Percussion (many types), Piano, a Small Chorus of six singers, as well as five Soloists. An orchestra of this size is adequate for the plot, and also provides support for various new vocal techniques, alternating between singing and speaking, as well as traditional arias. In ION, I incorporate Greek folk elements, which I know first-hand from my Balkan background, as well as contemporary techniques which I have absorbed during my graduate work at Boston University and the University of Maryland. Euripides' ION has fascinated me for two reasons in particular: its connection with founding myth of Athens, and the suggestiveness of its plot, which turns on the relationship of parents to children. In my interpretation, the leading character Ion is seen as emblematic for today's teenagers. Using the setting of the classic play, I hope to create a modern transformation of a myth, not to simply retell it. To this end, hopefully a new opera form will rise, as valid for our times as Verdi and Wagner were for theirs.
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This performance dissertation traced the evolution of the Russian romance from 1800 to the present. The Russian romance is a relatively unknown and greatly neglected genre of classical art songs. It is commonly believed that the Russian romance began with Dargomizhsky and Glinka proceeding directly to Tchaikovsky and Rachmaninoff. Forgotten are the composers before Dargornizhsky and Glinka, the bridge composers, and the post-Tchaikovsky and post-Rachmaninoff composers. This may be, in part, because of the difficulties in obtaining Russian vocal scores. While most of the musical world is acquainted with the magnificent Russian instrumental music, the "true soul" of the Russian people lies in its romances. I presented examples of the two different schools of composition, reflecting their philosophical differences in thinking that came about in the 1860s: (1) Russian National school, (2) Western European school. Each school's influence on generations of Russian composers and their pupils have been represented in the recital programs. Also represented was the effect of the October Revolution on music and the voice of the Russian people, Anna Akhmatova. The amount of music that could be included in this dissertation greatly exceeds the amount of available performance time and represents a selected portion of the repertoire. The first recital included repertoire from the beginning of the romance in the early nineteenth century to the beginning of the twentieth century and the second recital focused on the music of the twentieth century, pre and post, the October Revolution. Finally, given the status of Anna Akhmatova and her contributions, the third recital was devoted entirely to her poetry. The "Russian soul" is one of deep, heartfelt emotions and sorrow. Happiness and joy are also present, but always with a touch of melancholy. The audience did not simply go through a musical journey, but took a journey through the "Russian soul". With the strong response of the audience to these recitals, my belief that this repertoire deserves a prominent place in recital programming was confirmed.
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This performance project will cover performing issues in terms of technique in the scherzo. The Dictionary of Musical Terms defines technique as "the system of creating music, the musical slull to show personality by controlling tones that is not an abstract theory but a practical ability in composition or performance." My project focuses on techniques in fast tempos, specifically those found in the scherzo form and in concertos containing a scherzo character. The term scherzo has varied in its meaning and form throughout history. In the Baroque period, a scherzo was a work of light vocal or instrumental character. In the Classical period, scherzo still meant light in style, but it also indicated a quick tempo, often in 2/4 time. The scherzo was usually a single movement in a suite or multi-movement work. Like the minuet form, the scherzo contained a contrasting trio section. The scherzo was also standard in Romantic and post-Romantic symphonies and related genres. Because of the high degree of subjectivity in Romantic music, genres that stressed emotional content over abstract form developed rapidly. Some composers even wrote one-movement pieces entitled scherzo. These pieces became very important because they usually expressed a particular character or mood. The objective of my dissertation project is to research scherzo-like concertos, scherzo as single movements in larger forms, and scherzo as independent works. My first recital will consist of two concertos with a scherzo-like character. These are Mozart's Piano Concerto No. 9 i ?nl Major; K. 271 and Ravel's Piano Concerto in G Major. I will perform these works in December 2002 with a second piano. In addition, I will perform the Ravel with an orchestra in 2003. My second recital will consist of two parts. The fxst half presents multi-movement works with scherzo movements. The pieces are Haydn's Piano Sonata No. 3 in F Majol; Hob. WI/9, Beethoven's Piano Sonata No. 10 in G Major; Op. 14, No. 2. The second half presents independent four scherzi by Chopin. The final program will also include multi-movement works containing scherzo and independent scherzo. These are Prokofiev's Piano Sonata No. 2 in D minor, Op. 14, Grieg Lyric Pieces Op. 54, Schubert Zwei Scherzi D. 593 and Copland Scherzo humoristique; Le Chat et la Souris (The Cat and the Mouse).
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The term 'sonata' arose in the early seventeenth-century Baroque period and was originally used to distinguish instrumental (sonata) music from vocal music. Later. the sonata style, as a reliable yet flexible compositional framework, was extensively shaped and utilized throughout the Classical period. Subsequently, in the Romantic period, freer creative, individualistic. and expressive musical elements began to be preferred by composers in their use of harmonj., tone color, form, and rhythm. However, even during the revolutionary Romantic period in music. the compositions which did not have a pre-defined format (character pieces, etc) were often comfortably framed and limited within the recognizable boundaries provided by the Classical sonata style. The sonata format, when used as a tool in musical composition, provides logical boundaries that may serve to organize any unexpected emotional expressions on the part of the composer. Yet the sonata framework is also flexible enough to allow freedom of expression. In the Romantic period and beyond, composers had relied, some more than others, upon the sonata's adaptable blend of stability and flexibility. In my opinion, it is more persuasive to express oneself musically within the framework of an established musical style. Thus, I have chosen my dissertation topic as the performance of six pieces incorporating elements of the reliable and flexible sonata style. The sonata of each composer that I have selected clearly demonstrates a tension between logic and emotion expressed within the sonata framework. However, the compositions can be divided interestingly into two groups, such as 'conservative' and 'progressive' group. The 'conservative' group consists of composers who seemed to strive for greater freedom of self-expression within the constraints of the traditional sonata form. On the other hand, the 'progressive' group consists of composers who seemed more to rely upon the sonata form to rein in and add stability to their highly individual and emotional musical ideas. It is my hope that this project will provide a stimulating viewpoint from which to consider the evolution and utilization of the sonata style especially as it is applied to the composition and performance of these six diverse and interesting pieces.
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This dissertation project consisted of performances of three diverse operatic roles. The goal was to examine the challenges and benefits of performing diverse repertoire (baroque, classical, and romantic opera, in this case) and to observe how vocal and acting techniques might adjust to different styles and voice classifications. On December 3, 5, 11, and 13,2003, I performed a composite role in Fatal Song, directed by Leon Major, in the Robert & Arlene Kogod Theatre. This opera pastiche, premiered in 1996, contains spoken dialogue, and the music originates from famous eighteenth and nineteenth-century operas. I explored the challenges and benefits of playing three different, well-known opera characters within the same opera, performing four different languages within the same opera, and performing spoken dialogue in an opera. My roles in this pastiche of famous opera included Lucia from Lucia di Lammermoor by Gaetano Donizetti, Manon from Manon by Jules Massenet, and Pamina from Die ZauberJlote by W.A. Mozart. On January 28 and 29, 2005, I performed the role of Nice in Eurilla e Alcindo, a serenata by Antonio Vivaldi, in Homer Ulrich Recital Hall; musical direction by Joseph Gascho and stage direction by Kate Vetter Cain. I explored the challenges and benefits of preparing baroque ornamentation, singing without a conductor, performing an unknown work, staging a work that is not traditionally staged, singing with minimal sets and costumes, and singing with period instruments. On April 16,20, and 24,2005, I performed the role of Musetta in Giacomo Puccini's La BohBme, directed by Pat Diamond and conducted by Jeffrey Rink, in the Ina & Jack Kay Theatre. I examined the challenges and benefits of singing with a large orchestra of modem instruments, singing Puccini rubato and coordinating this with the conductor, and singing a role in one of the most well-known operas in today's repertoire. As a result of this investigation, I concluded that singing different styles, and singing outside one's voice classification, within reason, is beneficial. The knowledge, skill, confidence and insight I acquired by becoming more versatile benefited me as a performer and as a teacher.
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© 2013 The Association for the Study of Animal Behaviour.Social complexity, often estimated by group size, is seen as driving the complexity of vocal signals, but its relation to olfactory signals, which arguably arose to function in nonsocial realms, remains underappreciated. That olfactory signals also may mediate within-group interaction, vary with social complexity and promote social cohesion underscores a potentially crucial link with sociality. To examine that link, we integrated chemical and behavioural analyses to ask whether olfactory signals facilitate reproductive coordination in a strepsirrhine primate, the Coquerel's sifaka, Propithecus coquereli. Belonging to a clade comprising primarily solitary, nocturnal species, the diurnal, group-living sifaka represents an interesting test case. Convergent with diurnal, group-living lemurids, sifakas expressed chemically rich scent signals, consistent with the social complexity hypothesis for communication. These signals minimally encoded the sex of the signaller and varied with female reproductive state. Likewise, sex and female fertility were reflected in within-group scent investigation, scent marking and overmarking. We further asked whether, within breeding pairs, the stability or quality of the pair's bond influences the composition of glandular signals and patterns of investigatory or scent-marking behaviour. Indeed, reproductively successful pairs tended to show greater similarity in their scent signals than did reproductively unsuccessful pairs, potentially through chemical convergence. Moreover, scent marking was temporally coordinated within breeding pairs and was influenced by past reproductive success. That olfactory signalling reflects social bondedness or reproductive history lends support to recent suggestions that the quality of relationships may be a more valuable proxy than group size for estimating social complexity. We suggest that olfactory signalling in sifakas is more complex than previously recognized and, as in other socially integrated species, can be a crucial mechanism for promoting group cohesion and maintaining social bonds. Thus, the evolution of sociality may well be reflected in the complexity of olfactory signalling.
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Like humans, birds that exhibit vocal learning have relatively delayed telencephalon maturation, resulting in a disproportionately smaller brain prenatally but enlarged telencephalon in adulthood relative to vocal non-learning birds. To determine if this size difference results from evolutionary changes in cell-autonomous or cell-interdependent developmental processes, we transplanted telencephala from zebra finch donors (a vocal-learning species) into Japanese quail hosts (a vocal non-learning species) during the early neural tube stage (day 2 of incubation), and harvested the chimeras at later embryonic stages (between 9-12 days of incubation). The donor and host tissues fused well with each other, with known major fiber pathways connecting the zebra finch and quail parts of the brain. However, the overall sizes of chimeric finch telencephala were larger than non-transplanted finch telencephala at the same developmental stages, even though the proportional sizes of telencephalic subregions and fiber tracts were similar to normal finches. There were no significant changes in the size of chimeric quail host midbrains, even though they were innervated by the physically smaller zebra finch brain, including the smaller retinae of the finch eyes. Chimeric zebra finch telencephala had a decreased cell density relative to normal finches. However, cell nucleus size differences between each species were maintained as in normal birds. These results suggest that telencephalic size development is partially cell-interdependent, and that the mechanisms controlling the size of different brain regions may be functionally independent.