Flexibility of expressive timing in repeated musical performances

Performances by soloists in the Western classical tradition are normally highly prepared, yet must sound fresh and spontaneous. How do musicians manage this? We tested the hypothesis that they achieve the necessary spontaneity by varying the musical gestures that express their interpretation of a piece. We examined the tempo arches produced by final slowing at the ends of phrases in performances of J. S. Bach’s No. 6 (Prelude) for solo cello (12 performances) and the Italian Concerto (Presto) for solo piano (eight performances). The performances were given by two experienced concert soloists during a short time period (3½ months for the Prelude, 2 weeks for the Presto) after completing their preparations for public performance. We measured the tempo of each bar or half-bar, and the stability of tempo across performances (difference of the tempo of each bar/half bar from each of the other performances). There were phrase arches for both tempo and stability with slower, less stable tempi at beginnings and ends of phrases and faster, more stable tempi mid-phrase. The effects of practice were complex. Tempo decreased overall with practice, while stability increased in some bars and decreased in others. One effect of practice may be to imbue well-learned, automatic motor sequences with freshness and spontaneity through cognitive control at phrase boundaries where slower tempi and decreased stability provide opportunities for slower cognitive processes to modulate rapid automatic motor sequences

Training thought and action for virtuoso performance

The skills needed to play fast, challenging music with passion and conviction are much the same as the skills needed to play reliably from memory. We illustrate the relationship between virtuosic performance and memorization by describing how an experienced cellist (the first author) prepared the Prelude from J. S. Bach’s Suite No. 6 (BWV 1012) for solo cello for public performance in more than 30 hours of practice, and then taught a student pianist to memorize by showing her how to practice in a similar fashion. The cellist’s practice was guided by her artistic image of how the piece should sound, which directed her attention during practice to important musical transitions. These transitions were the location of performance cues (PCs), thoughts about musical intentions and technical choices that the cellist reported attending to during performance. These PCs served as retrieval cues, providing places where the cellist could recover from a memory failure, making it possible for her to perform from memory. They also affected expressive timing, reminding the cellist to “breathe” between phrases, with the result that tempo arches were taller and more tilted in phrases that started with a PC than in phrases that did not. Thus, attending to musical goals during practice made it possible to play from memory and with passion and conviction

A longitudinal study of the development of expressive timing

Tempo arches have often been reported in polished music performances, but their development during the learning of a new piece has not been studied. We examined the development of expressive timing at three levels of musical structure (piece, section, phrase) as an experienced concert soloist (the second author) prepared the Prelude from J. S. Bach’s Suite No. 6 for solo cello for public performance. We used mixed effect models to assess the development of expressive timing and the effects of the performance cues (PCs) that the cellist used as mental landmarks to guide her performance. Tempo arches appeared early in practice at all three levels of musical structure and changed over time in complex ways, first becoming more pronounced and more asymmetrical and then shrinking somewhat in later performances. Arches were also more pronounced in phrases that contained PCs, suggesting that PCs reminded the cellist where to “breathe” between phrases. The early development of tempo arches suggests that they were an automatic product of basic cognitive or motor processes. The complex trajectory of their later development appeared to be the result, at least in part, of a deliberate communicative strategy intended to draw listeners’ attention to some musical boundaries more than others

Rebeliões de extinção

The article analyses how different environmentalist groups confront issues regarding climate justice and racial inequalities in the wake of climate emergency and the emergence of the Anthropocene, by presenting artworks that mobilize related matters.O presente artigo analisa como diferentes grupos ambientalistas encaram questões de justiça climática e desigualdades raciais em face da emergência climática e da emergência do Antropoceno, apresentando produções artísticas que mobilizam questões afins

Microscopy with ultraviolet surface excitation for rapid slide-free histology.

Histologic examination of tissues is central to the diagnosis and management of neoplasms and many other diseases, and is a foundational technique for preclinical and basic research. However, commonly used bright-field microscopy requires prior preparation of micrometre-thick tissue sections mounted on glass slides, a process that can require hours or days, that contributes to cost, and that delays access to critical information. Here, we introduce a simple, non-destructive slide-free technique that within minutes provides high-resolution diagnostic histological images resembling those obtained from conventional haematoxylin-and-eosin-histology. The approach, which we named microscopy with ultraviolet surface excitation (MUSE), can also generate shape and colour-contrast information. MUSE relies on ~280-nm ultraviolet light to restrict the excitation of conventional fluorescent stains to tissue surfaces, and it has no significant effects on downstream molecular assays (including fluorescence in situ hybridization and RNA-seq). MUSE promises to improve the speed and efficiency of patient care in both state-of-the-art and low-resource settings, and to provide opportunities for rapid histology in research

Medial Temporal Lobe BOLD Activity at Rest Predicts Individual Differences in Memory Ability in Hhealthy Young Adults

Human beings differ in their ability to form and retrieve lasting long-term memories. To explore the source of these individual differences, we used functional magnetic resonance imaging to measure blood-oxygen-level-dependent (BOLD) activity in healthy young adults (n = 50) during periods of resting fixation that were interleaved with periods of simple cognitive tasks. We report that medial temporal lobe BOLD activity during periods of rest predicts individual differences in memory ability. Specifically, individuals who exhibited greater magnitudes of task-induced deactivations in medial temporal lobe BOLD signal (as compared to periods of rest) demonstrated superior memory during offline testing. This relationship was independent of differences in general cognitive function and persisted across different control tasks (i.e., number judgment versus checkerboard detection) and experimental designs (i.e., blocked versus event-related). These results offer a neurophysiological basis for the variability in mnemonic ability that is present amongst healthy young adults and may help to guide strategies aimed at early detection and intervention of neurological and mnemonic impairment

Medial Temporal Lobe BOLD Activity at Rest Predicts Individual Differences in Memory Ability in Hhealthy Young Adults

Human beings differ in their ability to form and retrieve lasting long-term memories. To explore the source of these individual differences, we used functional magnetic resonance imaging to measure blood-oxygen-level-dependent (BOLD) activity in healthy young adults (n = 50) during periods of resting fixation that were interleaved with periods of simple cognitive tasks. We report that medial temporal lobe BOLD activity during periods of rest predicts individual differences in memory ability. Specifically, individuals who exhibited greater magnitudes of task-induced deactivations in medial temporal lobe BOLD signal (as compared to periods of rest) demonstrated superior memory during offline testing. This relationship was independent of differences in general cognitive function and persisted across different control tasks (i.e., number judgment versus checkerboard detection) and experimental designs (i.e., blocked versus event-related). These results offer a neurophysiological basis for the variability in mnemonic ability that is present amongst healthy young adults and may help to guide strategies aimed at early detection and intervention of neurological and mnemonic impairment

High-temperature kinetic study for the reactive ion etching of InP in BCl 3 /Ar/O 2

The reactive ion etching kinetics of InP studied uses BCl 3 /Ar and BCl 3 /Ar/O 2 as etchants. High-temperature etching using BCl 3 and Ar increases the etch rate negligibly. However, the addition of 30% oxygen in the gas feed increases etch rates by a factor of 10,000 up to 1.5 micron/min at wafer temperatures of 250°C. X-ray photoelectron spectroscopy analysis reveals that oxygen removes the boron species adsorbing on the InP surface by scavenging the boron to form volatile boron oxides. To study the gas-phase chemistry, optical emission spectroscopy is used to monitor atomic chlorine intensity at different gas mixtures. The chlorine intensity shows a Gaussian-type dependence with oxygen addition, which is similar to the etch rate dependence. Two regimes of etching found are: at temperatures below 150°C, the etching is limited by the removal of indium chlorides; above 180°C, the etching is reaction-limited. The surface morphology shows that the etch profile becomes rougher as a result of increased chemical etching. At high power densities (0.21 W/cm 2 ) and intermediate temperatures (150°C), near vertical wall shapes are obtained. A kinetic model for the high-temperature etching is developed, as well as a rate law based on the InCl formation reaction. The rate law compares favorably with experimental etch rate results.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/37431/1/690410322_ftp.pd

Linear-Accelerator Program

Contains reports on one research project