962 resultados para Gwyn, Nell, 1650-1687.


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The application of inverse filtering techniques for high-quality singing voice analysis/synthesis is discussed. In the context of source-filter models, inverse filtering provides a noninvasive method to extract the voice source, and thus to study voice quality. Although this approach is widely used in speech synthesis, this is not the case in singing voice. Several studies have proved that inverse filtering techniques fail in the case of singing voice, the reasons being unclear. In order to shed light on this problem, we will consider here an additional feature of singing voice, not present in speech: the vibrato. Vibrato has been traditionally studied by sinusoidal modeling. As an alternative, we will introduce here a novel noninteractive source filter model that incorporates the mechanisms of vibrato generation. This model will also allow the comparison of the results produced by inverse filtering techniques and by sinusoidal modeling, as they apply to singing voice and not to speech. In this way, the limitations of these conventional techniques, described in previous literature, will be explained. Both synthetic signals and singer recordings are used to validate and compare the techniques presented in the paper.

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Signaturas: *6, A-F4, G2, H-Z4, 2A-2Z4, 3A-3Z4, 4A-4Z4, 5A-5D4, 5E2, 5F4 ; *5, A-Z4, 2A-2Z4, 3A-3Y4, Z2, 4A4 ; *5, A-Z4, 2A-2Z4, 3A-3Z4, 4A-4N4, 4O5 ; *5, A-Z4, 2A-2Z4, 3A-3Z4, 4A-4O4, 4P2, 4Q1, 4R4 ; *5, A-Z4, 2A-2Z4, 3A-3M4, *2, A-S4.

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The SafeWeb anonymizing system has been lauded by the press and loved by its users; self-described as "the most widely used online privacy service in the world," it served over 3,000,000 page views per day at its peak. SafeWeb was designed to defeat content blocking by firewalls and to defeat Web server attempts to identify users, all without degrading Web site behavior or requiring users to install specialized software. In this article we describe how these fundamentally incompatible requirements were realized in SafeWeb's architecture, resulting in spectacular failure modes under simple JavaScript attacks. These exploits allow adversaries to turn SafeWeb into a weapon against its users, inflicting more damage on them than would have been possible if they had never relied on SafeWeb technology. By bringing these problems to light, we hope to remind readers of the chasm that continues to separate popular and technical notions of security.

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The goal of this work is to learn a parsimonious and informative representation for high-dimensional time series. Conceptually, this comprises two distinct yet tightly coupled tasks: learning a low-dimensional manifold and modeling the dynamical process. These two tasks have a complementary relationship as the temporal constraints provide valuable neighborhood information for dimensionality reduction and conversely, the low-dimensional space allows dynamics to be learnt efficiently. Solving these two tasks simultaneously allows important information to be exchanged mutually. If nonlinear models are required to capture the rich complexity of time series, then the learning problem becomes harder as the nonlinearities in both tasks are coupled. The proposed solution approximates the nonlinear manifold and dynamics using piecewise linear models. The interactions among the linear models are captured in a graphical model. By exploiting the model structure, efficient inference and learning algorithms are obtained without oversimplifying the model of the underlying dynamical process. Evaluation of the proposed framework with competing approaches is conducted in three sets of experiments: dimensionality reduction and reconstruction using synthetic time series, video synthesis using a dynamic texture database, and human motion synthesis, classification and tracking on a benchmark data set. In all experiments, the proposed approach provides superior performance.

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Enterprise Ireland (Project CFTD07325). European Commission (EU Framework 7 project Nanofunction, (Beyond CMOS Nanodevices for Adding Functionalities to CMOS) www.Nanofunction.eu EU ICT Network of Excellence, Grant No.257375)

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This paper describes implementations of two mobile cloud applications, file synchronisation and intensive data processing, using the Context Aware Mobile Cloud Services middleware, and the Cloud Personal Assistant. Both are part of the same mobile cloud project, actively developed and currently at the second version. We describe recent changes to the middleware, along with our experimental results of the two application models. We discuss challenges faced during the development of the middleware and their implications. The paper includes performance analysis of the CPA support for the two applications in respect to existing solutions.

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Little is known about the biology of the softshell clam in Europe, despite it being identified as a potential species to culture for food in the future. Monthly samples of the softshell clam, Mya arenaria, were collected intertidally from Co. Wexford, Ireland, over a period of sixteen months. The mean weight of sampled individuals was 7 4 ± 4 . 9  g and mean length was 8 . 2 ± 0 . 2  cm. Histological examination revealed a female-to-male ratio of 1 : 1.15. In 2010, M. arenaria at this site matured over the summer months, with both sexes either ripe or spawning by August. A single spawning event was recorded in 2010, completed by November. Two unusually cold winters, followed by a warmer-than-average spring, appear to have affected M. arenaria gametogenesis in this area, potentially affecting the time of spawning, fertilisation success, and recruitment of this species. No hermaphrodites were observed in the samples collected, nor were any pathogens observed. Timing of development and spawning is compared with the coasts of eastern North America and with other European coasts.

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Prostate cancer (PC) is the second leading cause of cancer death in men. Recent reports suggest that excess of nutrients involved in the one-carbon metabolism pathway increases PC risk; however, empirical data are lacking. Veteran American men (272 controls and 144 PC cases) who attended the Durham Veteran American Medical Center between 2004-2009 were enrolled into a case-control study. Intake of folate, vitamin B12, B6, and methionine were measured using a food frequency questionnaire. Regression models were used to evaluate the association among one-carbon cycle nutrients, MTHFR genetic variants, and prostate cancer. Higher dietary methionine intake was associated with PC risk (OR = 2.1; 95%CI 1.1-3.9) The risk was most pronounced in men with Gleason sum <7 (OR = 2.75; 95%CI 1.32- 5.73). The association of higher methionine intake and PC risk was only apparent in men who carried at least one MTHFR A1298C allele (OR = 6.7; 95%CI = 1.6-27.8), compared to MTHFR A1298A noncarrier men (OR = 0.9; 95%CI = 0.24-3.92) (p-interaction = 0.045). There was no evidence for associations between B vitamins (folate, B12, and B6) and PC risk. Our results suggest that carrying the MTHFR A1298C variants modifies the association between high methionine intake and PC risk. Larger studies are required to validate these findings.

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In most multicellular organisms, the decision to undergo programmed cell death in response to cellular damage or developmental cues is typically transmitted through mitochondria. It has been suggested that an exception is the apoptotic pathway of Drosophila melanogaster, in which the role of mitochondria remains unclear. Although IAP antagonists in Drosophila such as Reaper, Hid and Grim may induce cell death without mitochondrial membrane permeabilization, it is surprising that all three localize to mitochondria. Moreover, induction of Reaper and Hid appears to result in mitochondrial fragmentation during Drosophila cell death. Most importantly, disruption of mitochondrial fission can inhibit Reaper and Hid-induced cell death, suggesting that alterations in mitochondrial dynamics can modulate cell death in fly cells. We report here that Drosophila Reaper can induce mitochondrial fragmentation by binding to and inhibiting the pro-fusion protein MFN2 and its Drosophila counterpart dMFN/Marf. Our in vitro and in vivo analyses reveal that dMFN overexpression can inhibit cell death induced by Reaper or γ-irradiation. In addition, knockdown of dMFN causes a striking loss of adult wing tissue and significant apoptosis in the developing wing discs. Our findings are consistent with a growing body of work describing a role for mitochondrial fission and fusion machinery in the decision of cells to die.

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Background. Thoracic epidural catheters provide the best quality postoperative pain relief for major abdominal and thoracic surgical procedures, but placement is one of the most challenging procedures in the repertoire of an anesthesiologist. Most patients presenting for a procedure that would benefit from a thoracic epidural catheter have already had high resolution imaging that may be useful to assist placement of a catheter. Methods. This retrospective study used data from 168 patients to examine the association and predictive power of epidural-skin distance (ESD) on computed tomography (CT) to determine loss of resistance depth acquired during epidural placement. Additionally, the ability of anesthesiologists to measure this distance was compared to a radiologist, who specializes in spine imaging. Results. There was a strong association between CT measurement and loss of resistance depth (P < 0.0001); the presence of morbid obesity (BMI > 35) changed this relationship (P = 0.007). The ability of anesthesiologists to make CT measurements was similar to a gold standard radiologist (all individual ICCs > 0.9). Conclusions. Overall, this study supports the examination of a recent CT scan to aid in the placement of a thoracic epidural catheter. Making use of these scans may lead to faster epidural placements, fewer accidental dural punctures, and better epidural blockade.

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A relatively unexplored area of the harpsichord repertoire is the group of transcriptions made by J.S. Bach (1685-1750), Jean Henry d'Anglebert (1629-1691), and Jean-Baptiste Forqueray (1699-1782). These transcriptions are valuable and worth exploring and performing. Studying them provides unique insights into their composer‘s musical thinking. By comparing transcriptions with their original sources, the transcriber's decisions and priorities can be observed. The performance component of this dissertation comprises three recitals. The first features works of Johann Sebastian Bach: two transcriptions of violin concerti by Antonio Vivaldi (1678-1741), and two transcriptions of trio sonatas by Johann Adam Reinken (1643-1722). The most salient feature of Bach‘s transcriptions is his addition of musical material: ornamenting slow movements, adding diminutions and idiomatic keyboard figurations throughout, and recomposing and expanding fugal movements. The second recital features works of Jean Henry d'Anglebert and Jean-Baptiste Forqueray, two French composer/performers. From d'Anglebert‘s many transcriptions, I assembled two key-related suites: the first comprised of lute pieces by Ennemond Gaultier (c. 1575-1651), and the second comprised of movements from operas by Jean-Baptiste Lully (1632-1687). Forqueray's transcriptions are of suites for viola da gamba and continuo, composed by his father, Antoine Forqueray (1671-1745). Creative and varied ornamentation, along with the style brisé of arpeggiated chords, are the most important features of d‘Anglebert‘s transcriptions. Forqueray‘s transcriptions are highly virtuosic and often feature the tenor and bass range of the harpsichord. The third recital features my own transcriptions: the first suite for solo cello by J.S. Bach, excerpts from the opera La Descente d’Orphée aux Enfers by Marc-Antoine Charpentier (1643-1704), and two violin pieces by Nicola Matteis (fl. c. 1670-c. 1698). In these transcriptions, I demonstrate what I have learned from studying and performing the works in the first two recitals. These recitals were performed in the Leah Smith Hall at the University of Maryland on May 4, 2010; May 11, 2010; and October 7, 2010. They were recorded on compact discs and are archived within the Digital Repository at the University of Maryland (DRUM).

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La comunidad de investigación en educación matemática se ha venido preocupando recientemente por el problema del escalamiento: el proceso de reproducir en gran escala experiencias innovadoras que, en contextos concretos, han demostrado ser eficaces para la mejora del rendimiento de los escolares en matemáticas. En este documento caracterizamos la noción de escalamiento, describimos cuatro proyectos de escalamiento en educación matemática, identificamos los elementos claves comunes a estos proyectos y reflexionamos sobre la problemática de diseñar e implementar este tipo de proyectos en el contexto de un país latinoamericano.

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El presente artículo tiene como objetivo presentar los resultados de la investigación realizada con alumnos jóvenes y adultos en una escuela pública en la ciudad de Uberlandia/MG (Brasil), tratando de reflexionar y aprender a percibir la presencia de conocimientos africanos en matemáticas por manifestaciones de tradiciones afro-brasileñas, además de identificar que los estudiantes contemplando la cuestión de la raza, apodos y la imagen que tienen de las matemáticas y de las tradiciones afro-brasileñas, con miras a desarrollar una educación enraizada en los fundamentos de nociones, que busca reforzar la producción de conocimientos matemáticos a otros grupos sociales para una matemática crítica e incluyente. La encuesta también trató de contribuir al desarrollo de acciones educativas basadas en la ley brasileña 10.639/03. La enseñanza de las matemáticas, teniendo debidamente en cuenta los cultivos afro brasileños también tienen mucho que contribuir a la comprensión del mundo como una posibilidad para desarrollar valores y ampliar conceptos.