922 research outputs found

    Seeing Music? What musicians need to know about vision

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    Music is inherently an auditory art form, rooted in sound, and generally analyzed in terms of its acoustic properties. However, as the process of hearing is affected by seeing, visual information does in fact play an important role in the musical experience. Vision influences many aspects of music – from evaluations of performance quality and audience interest to the perception of loudness, timbre, and note duration. Moreover, it can be used to achieve musical goals that are in fact acoustically impossible. As such, understanding the benefits of embracing (and the costs of ignoring) vision’s role is essential for all musicians. Furthermore, since music represents a pervasive and ubiquitous human practice, this topic serves as an ideal case study for understanding how auditory and visual information are integrated. Given that some musically-based studies have challenged and even contributed to updating psychological theories of sensory integration, this topic represents a rich area of research, relevant to musicians and psychologists alike

    Cytoplasmic and mitochondrial genetic effects on economic traits in dairy cattle

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    Maternal lineage effects on milk production traits, considered indicative of cytoplasmic inheritance, were evaluated with animal models. Cattle were from a selection experiment begun in 1968. Maternal pedigrees were traced to the first female member in the Holstein-Friesian Herd Book, and foundation females were assigned to maternal lineage groups. All models accounted for year-season of calving, parity, and selection lines. Maternal lineage effects were included in a repeated records model with cow effects and preadjustment for sire and maternal grandsire transmitting abilities. Maternal lineage accounted for 5.2, 4.1, and 10.5 percent of phenotypic variation in milk yield, fat yield, and fat percentage, respectively. Maternal lineage was evaluated as a fixed effect in an animal model including random animal and permanent environmental effects. Ranges of maternal lineage estimates were 2934 kg milk, 154 kg fat, and.907 percent fat. Maternal lineage significantly affected fat percentage. Maternal genetic (nuclear) effects and their covariance with additive animal effects did not significantly account for additional variation nor did they influence maternal lineage estimates. Maternal lineage also affected calculated net energy of milk;Mitochondrial DNA (mtDNA) displacement-loop (D-loop) sequence polymorphism information from 36 maternal lineages was evaluated. Of 17 base pair substitutions evaluated, several were significantly associated with milk, fat, and solids-not-fat production. Another marked a large impact on fat percentage and net energy concentration. Positive and negative effects on all production traits were observed. One base pair substitution was related to a large favorable decrease in days open, number of breedings, and reproductive costs;Maternal lineage groups defined by several methods of classification using mtDNA sequence characteristics were evaluated with animal models. Groups defined as those maternal lineages with or without base pair substitution at nucleotide 169 accounted for increased milk fat and estimated milk energy production. Clustering the 36 maternal lineages using 17 mtDNA D-loop sequence differences produced groups with significant effect on fat percentage and energy concentration

    Magnetic antivortex-core reversal by circular-rotational spin currents

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    Topological singularities occur as antivortices in ferromagnetic thin-film microstructures. Antivortices behave as two-dimensional oscillators with a gyrotropic eigenmode which can be excited resonantly by spin currents and magnetic fields. We show that the two excitation types couple in an opposing sense of rotation in the case of resonant antivortex excitation with circular-rotational currents. If the sense of rotation of the current coincides with the intrinsic sense of gyration of the antivortex, the coupling to the Oersted fields is suppressed and only the spin-torque contribution locks into the gyrotropic eigenmode. We report on the experimental observation of purely spin-torque induced antivortex-core reversal. The dynamic response of an isolated antivortex is imaged by time-resolved scanning transmission x-ray microscopy on its genuine time and length scale

    SOFT TISSUE ARTEFACTS CAUSE AN UNDERESTIMATION IN KNEE FLEXION ANGLE IN SKINMARKER BASED SQUAT SIMULATIONS

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    Simulated muscle forces provide crucial knowledge for rehabilitation and training exercise design. To accurately simulate the internal loading conditions, input kinematics of the skeletal structures without soft tissue artefact (STA) are required. The aim of this study was to evaluate the ability of two numerical approaches to reduce STA for squat kinematics. Squat repetitions of 6 elderly subjects were examined using skin markers and video-fluoroscopy. Kinematic analysis was performed with a segmental and musculoskeletal simulation approach and compared to fluoroscopic data. The averaged RMS errors relative to the maximum knee range of motion were 8.8%, 32% and 49% for flexion/extension, ab-/adduction, and internal/external rotation, respectively. Skin marker based underestimation of the flexion angle could be corrected with a linear factor of 1.15

    Nonreciprocal Spin Waves in Nanoscale Domain Walls Detected by Scanning X-ray Microscopy in Perpendicular Magnetic Anisotropic Fe/Gd Multilayers

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    Spin wave nonreciprocity in domain walls (DWs) allows for unidirectional signal processing in reconfigurable magnonic circuits. Using scanning transmission x-ray microscopy (STXM), we examined coherently-excited magnons propagating in Bloch-like DWs in amorphous Fe/Gd multilayers with perpendicular magnetic anisotropy (PMA). Near 1 GHz we detected magnons with short wavelengths down to λ=281\lambda = 281 nm in DWs whose minimum width amounted to ΎDW=52\delta_{\rm DW} = 52 nm. Consistent with micromagnetic simulations, the STXM data reveal their nonreciprocal magnon band structures. We identified Bloch points which disrupted the phase evolution of magnons and induced different λ\lambda adjacent to the topological defects. Our observations provide direct evidence of nonreciprocal spin waves within Bloch-like DWs, serving as programmable waveguides in magnonic devices with directed information flow

    Infrastructural Speculations: Tactics for Designing and Interrogating Lifeworlds

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    This paper introduces “infrastructural speculations,” an orientation toward speculative design that considers the complex and long-lived relationships of technologies with broader systems, beyond moments of immediate invention and design. As modes of speculation are increasingly used to interrogate questions of broad societal concern, it is pertinent to develop an orientation that foregrounds the “lifeworld” of artifacts—the social, perceptual, and political environment in which they exist. While speculative designs often imply a lifeworld, infrastructural speculations place lifeworlds at the center of design concern, calling attention to the cultural, regulatory, environmental, and repair conditions that enable and surround particular future visions. By articulating connections and affinities between speculative design and infrastructure studies research, we contribute a set of design tactics for producing infrastructural speculations. These tactics help design researchers interrogate the complex and ongoing entanglements among technologies, institutions, practices, and systems of power when gauging the stakes of alternate lifeworlds

    Alternative male morphs solve sperm performance/longevity trade-off in opposite directions

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    Males pursuing alternative reproductive tactics have been predicted to face a trade-off between maximizing either swimming performance or endurance of their sperm. However, empirical evidence for this trade-off is equivocal, which may be due to simplistic assumptions. In the shell-brooding cichlid fish Lamprologus callipterus, two Mendelian male morphs compete for fertilization by divergent means: Bourgeois nest males ejaculate sperm, on average, about six times farther from the unfertilized ova than do parasitic dwarf males. This asymmetry is opposite to the usual situation, in which bourgeois males typically benefit from superior fertilization opportunities, suggesting that nest males' sperm should persist longer than dwarf male sperm. The assumed trade-off between sperm swimming performance and longevity predicts that, in turn, sperm of dwarf males should outperform that of nest males in swimming efficiency. Measurement of sperm performance and endurance reveals that dwarf male spermatozoa swim straighter initially than those of nest males, but their motility declines earlier and their velocity slows down more abruptly. Nest male sperm survives longer, which relates to a larger sperm head plus midpiece, implying more mitochondria. Thus, the trade-off between sperm performance and endurance is optimized in opposite directions by alternative male morphs. We argue that the relative success of alternative sperm performance strategies can be influenced strongly by environmental factors such as the time window between gamete release and fertilization, and the position of gamete release. This is an important yet little understood aspect of gametic adaptations to sperm competition

    Seeing the way: visual sociology and the distance runner's perspective

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    Employing visual and autoethnographic data from a two‐year research project on distance runners, this article seeks to examine the activity of seeing in relation to the activity of distance running. One of its methodological aims is to develop the linkage between visual and autoethnographic data in combining an observation‐based narrative and sociological analysis with photographs. This combination aims to convey to the reader not only some of the specific subcultural knowledge and particular ways of seeing, but also something of the runner's embodied feelings and experience of momentum en route. Via the combination of narrative and photographs we seek a more effective way of communicating just how distance runners see and experience their training terrain. The importance of subjecting mundane everyday practices to detailed sociological analysis has been highlighted by many sociologists, including those of an ethnomethodological perspective. Indeed, without the competence of social actors in accomplishing these mundane, routine understandings and practices, it is argued, there would in fact be no social order

    Wakeshield WSF-02 GPS Experiment

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    Shuttle mission STS-69 was launched on September 7, 1995, 10:09 CDT, carrying the Wake Shield Facility (WSF-02). The WSF-02 spacecraft included a set of payloads provided by the Texas Space Grant Consortium, known as TexasSat. One of the TexasSat payloads was a GPS TurboRogue receiver loaned by the University Corporation for Atmospheric Research. On September 11, the WSF-02 was unberthed from the Endeavour payload bay using the remote manipulator system. The GPS receiver was powered on prior to release and the WSF-02 remained in free-flight for three days before being retrieved on September 14. All WSF-02 GPS data, which includes dual frequency pseudorange and carrier phase, were stored in an on-board recorder for post-flight analysis, but "snap- shots" of data were transmitted for 2-3 minutes at intervals of several hours, when permitted by the telemetry band- widdl The GPS experiment goals were: (1) an evaluation of precision orbit determination in a low altitude environment (400 km) where perturbations due to atmospheric drag and the Earth's gravity field are more pronounced than for higher altitude satellites with high precision orbit requirements, such as TOPEX/POSEIDON; (2) an assessment of relative positioning using the WSF GPS receiver and the Endeavour Collins receiver; and (3) determination of atmospheric temperature profiles using GPS signals passing through the atmosphere. Analysis of snap-shot telemetry data indicate that 24 hours of continuous data were stored on board, which includes high rate (50 Hz) data for atmosphere temperature profiles. Examination of the limited number of real-time navigation solutions show that at least 7 GPS satellites were tracked simultaneously and the on-board clock corrections were at the microsec level, as expected. Furthermore, a dynamical consistency test provided a further validation of the on-board navigation solutions. Complete analysis will be conducted in post-flight using the data recorded on-board
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