A practical approach to the study of sound for musicians

This account of the beginning of music might equally well be applied to man\u27s discovery of sounds produced by the stretched string on his hunting-bow, or skins stretched across wooden frames. Pure fancy though it may be, the account serves to illustrate the dependence of music on the universal principles of science. Sound, the medium of expression, the vehicle, of music, is purely physical phenomenon. All aspects of its production, its transmission, and its ultimate reception are based invariable on physical laws. All musical instruments operate under these laws, as do the tones and combinations of tones which the instruments produce. Since that time when our prehistoric man made his discoveries, all musicians have had to depend upon scientific principles in producing the various sounds with which they work In order to deal most effectively with these tones, it is necessary that the musician understand some of the principles governing their production and their various relationships. It is with this necessity in mind that this thesis is being written. In the thesis an attempt is made to present those physical aspects of sound which will be of the most practical use to the musician and which will give him a better understanding of the materials with which he works. As often as it is possible and practical, direct illustration of the applications to the musician\u27s work of the principles discussed are given. this thesis is not intended to be a study of sound. The subject is covered thoroughly in a number of text-books. lt is rather an attempt to show how the Science of Sound is related to the Art of Music, to demonstrate in what ways the latter is dependent upon the former, and to outline an approach to a study of the physical principles of sound for the musician

Age-related differentiation of sensorimotor control strategies during pursuit and compensatory tracking

Motor control deficits during aging have been well-documented. Various causes of neuromotor decline, including both peripheral and central neurological deficits, have been hypothesized. Here, we use a model of closed-loop sensorimotor control to examine the functional causes of motor control deficits during aging. We recruited 14 subjects aged 19-61 years old to participate in a study in which they performed single-joint compensatory and pursuit tracking tasks with their dominant hand. We found that visual response delay and visual noise increased with age, while reliance on visual feedback, especially during compensatory tracking decreased. Increases in visual noise were also positively correlated with increases in movement error during a reach and hold task. The results suggest an increase in noise within the visuomotor control system may contribute to the decline in motor performance during early aging

Visual and Proprioceptive Contributions to Compensatory and Pursuit Tracking Movements in Humans

An ongoing debate in the field of motor control considers how the brain uses sensory information to guide the formation of motor commands to regulate movement accuracy. Recent research has shown that the brain may use visual and proprioceptive information differently for stabilization of limb posture (compensatory movements) and for controlling goal-directed limb trajectory (pursuit movements). Using a series of five experiments and linear systems identification techniques, we modeled and estimated the sensorimotor control parameters that characterize the human motor response to kinematic performance errors during continuous compensatory and pursuit tracking tasks. Our findings further support the idea that pursuit and compensatory movements of the limbs are differentially controlled

Intention Tremor and Deficits of Sensory Feedback Control in Multiple Sclerosis: a Pilot Study

Background Intention tremor and dysmetria are leading causes of upper extremity disability in Multiple Sclerosis (MS). The development of effective therapies to reduce tremor and dysmetria is hampered by insufficient understanding of how the distributed, multi-focal lesions associated with MS impact sensorimotor control in the brain. Here we describe a systems-level approach to characterizing sensorimotor control and use this approach to examine how sensory and motor processes are differentially impacted by MS. Methods Eight subjects with MS and eight age- and gender-matched healthy control subjects performed visually-guided flexion/extension tasks about the elbow to characterize a sensory feedback control model that includes three sensory feedback pathways (one for vision, another for proprioception and a third providing an internal prediction of the sensory consequences of action). The model allows us to characterize impairments in sensory feedback control that contributed to each MS subject’s tremor. Results Models derived from MS subject performance differed from those obtained for control subjects in two ways. First, subjects with MS exhibited markedly increased visual feedback delays, which were uncompensated by internal adaptive mechanisms; stabilization performance in individuals with the longest delays differed most from control subject performance. Second, subjects with MS exhibited misestimates of arm dynamics in a way that was correlated with tremor power. Subject-specific models accurately predicted kinematic performance in a reach and hold task for neurologically-intact control subjects while simulated performance of MS patients had shorter movement intervals and larger endpoint errors than actual subject responses. This difference between simulated and actual performance is consistent with a strategic compensatory trade-off of movement speed for endpoint accuracy. Conclusions Our results suggest that tremor and dysmetria may be caused by limitations in the brain’s ability to adapt sensory feedback mechanisms to compensate for increases in visual information processing time, as well as by errors in compensatory adaptations of internal estimates of arm dynamics

CTD observations on the North Brazil shelf during a multidisciplinary Amazon Shelf Sediment Study, AMASSEDS, August 1989

CTD and acoustic Doppler current profiler (ADCP) observations were made on the North Brazil shelf adjacent to the mouth of the Amazon River during R/V Iselin cruise I8909 August 3-14, 1989 as part of A Multidisciplinary Amazon Shelf SEDiment Study (AMASSEDS). These observations were obtained during a large-scale survey in support of geological and geochemical sampling, an anchored time series station consisting of 26 hourly CTD casts, and one transect which was repeated off the mouth of the Amazon River. The maximum sampling depth at each station was within two meters of the bottom. The primary objectives of the AMASSEDS hydrographic measurement program were to (a) observe and characterize the temperature, salinity, density, oxygen, fluorescence and light transmission fields and their spatial variability on the north Brazilian shelf directly influenced by the Amazon River discharge, (b) resolve the seaward extent and vertical structure of the surface plume of low salinity Amazon River water during different stages of river discharge, (c) describe the spatial structure of the turbidity and associated suspended sediment distributions across the shelf, (d) characterize the properties of the Amazon shelf water beneath the surface plume and their seasonal variability, and (e) describe the landward penetration of the North Brazil Current (NBC) with respect to water properties and shelf currents. This report represents a summary in graphic and tabular form of the hydrographic observations made during the first AMASSEDS cruise (I8909) on the R/V Iselin.Funding was provided by the National Science Foundation through Grant Number OCE 88-1291

CTD observations off northern California during the Shelf Mixed Layer Experiment, SMILE, May 1989

CTD observations were made off the northern California coast during R/V Wecoma cruise W8905 May 5-14, 1989 as part of the Shelf Mixed Layer Experiment (SMILE). The surveys consisted of two sampling plans - a large-scale grid of four cross-shelf transects extending to both sides of Point Arena and Point Reyes, and a small-scale grid of six cross-shelf transects located near the central SMILE mooring site. All of the cross-shelf transects extended beyond the shelf break and the maximum sampling depth at each station was near-bottom or 1500 m. The average along-shelf separation between cross-shelf transects was about 15 km for the small-scale surveys and 50 km for the large-scale grid. The primary objectives of the hydrographic measurement program were to observe and characterize the temperature, salinity, density, and light transmission fields and their temporal and spatial variability in the surface boundary layer along the continental shelf and slope near the SMILE moored array, and to acquire estimates of the cross- and along-shelf scales over which the mixed-layer depth varies. This report presents a summary in graphic and tabular form of the hydrographic observations made during cruise W8905 on the R/V Wecoma.Funding was provided by the National Science Foundation through Grant Number OCE 87-1693

CTD observations off northern California during the Shelf Mixed Layer Experiment, SMILE, November 1988

CTD observations on the R/V Wecoma cruise W8811 were made off the northern California coast November 13-24, 1988 as part of the .S.helf Mlxed Layer Experiment (SMILE). The survey consisted of repeated mappings of the central transect (C) through the SMILE moored array, and two synoptic sampling surveys-a large-scale grid of four cross-shelf transects extending to both sides ofPoint Arena and Point Reyes, and a small-scale grid of five cross-shelf transects located near the central SMILE mooring site. The small-scale hydrographic survey had a much higher spatial resolution of CTD stations than the large-scale survey. The primary objectives of the hydrographic measurement program were to observe and characterize the temperature, salinity, density, and light transmission fields and their temporal and spatial variability in the surface boundary layer along the continental shelf and slope near the SMILE moored array, and to acquire an estimate of the cross-shelf and along-shelf scales over which the mixed-layer depth varies. All of the cross-shelf transects extended beyond the shelf break and the maximum sampling depth at each station was near-bottom or 600 m. This report presents a summary in graphic and tabular form of the hydrographic observations made during cruise W8811 on the RN Wecoma.Funding was provided by the National Science Foundation through grant Number OCE 87-1693

CTD observations off Northern California during the Shelf Mixed Layer Experiment, SMILE, February/March 1989

CTD observations were made off the northern California coast during R/V Wecoma cruise W8902 February 22- March 10, 1989 as part of the Shelf Mixed Layer Experiment (SMILE). The surveys consisted of three sampling plans- a large-scale grid of four cross-shelf transects extending to both sides of Point Arena and Point Reyes, a small-scale grid of five cross-shelf transects located near the central SMILE mooring site, and an expanded small-scale grid of nine cross-shelf transects. All of the cross-shelf transects extended beyond the shelf break and the maximum sampling depth at each station was near-bottom or 1000 m. The average along-shelf separation between cross-shelf transects was about 15 km for the small-scale surveys and 50 km for the large-scale grid. The primary objectives of the hydrographic measurement program were to observe and characterize the temperature, salinity, density, and light transmission fields and their temporal and spatial variability in the surface boundary layer along the continental shelf and slope near the SMILE moored array, and to acquire estimates of the cross- and along-shelf scales over which the mixed-layer depth varies. This report presents a summary in graphic and tabular form of the hydrographic observations made during cruise W8902 on the R/V Wecoma.Funding was provided by the National Science Foundation through Grant Number OCE 87-1693

CTD observations on the North Brazil shelf during a multidisciplinary Amazon Shelf Sediment Study, AMASSEDS, May-June 1990

Hydrographic (CTD) and acoustic Doppler current profiler (ADCP) observations were made on the North Brazil shelf adjacent to the mouth of the Amazon River during R/V Iselin cruise I9004 May 23-June 13, 1990 as part of A Multidisciplinary Amazon Shelf SEDiment Study (AMASSEDS). These observations were obtained during a small-scale survey on Leg 1 in support of mooring deployment operations, during a large-scale survey on Leg 3 in support of geological and geochemical sampling, during a frontal zone survey on Leg 4 consisting of 12 and 24 hourly CTD casts at anchored stations, and during a bottom tripod recovery on Leg 5. The maximum sampling depth at each station was within two meters of the bottom. The primary objectives of the AMASSEDS hydrographic measurement program were (a) to observe and characterize the temperature, salinity, density, oxygen, fluorescence and light transmission fields and their spatial variabilty on the North Brazilian shelf directly influenced by the Amazon River discharge, (b) to resolve the seaward extend and vertical structure of the surface plume of low salinity Amazon River water during different stages of river discharge, (c) to describe the spatial structure of the turbidity and associate suspended sediment distributions across the shelf, (d) to characterize the properties of the Amazon shelf water beneath the surface plume and their seasonal variabilty, and (e) to describe the landward penetration of the North Brazil Current with respect to water properties and shelf currents. This report represents a summary in graphic and tabular form of the hydrographic observations made during the third AMASSEDS cruise (I9004) on the R/V Iselin.Funding was provided by the National Science Foundation through Grant No. OCE 88-12917

An estimate of the cross-frontal transport at the shelf break of the East China Sea with the Finite Volume Coastal Ocean Model

Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 111 (2006): C03012, doi:10.1029/2005JC003290.The Finite Volume Coastal Ocean Model (FVCOM) is used to estimate the onshore cross-frontal transport at the shelf break of the East China Sea. Boundary conditions of FVCOM are provided by the Princeton Ocean Model simulating ocean currents in the Yellow Sea and East China Sea realistically. One advantage of this study is that the unstructured triangular cell grid of FVCOM resolves complex bottom topography that may trigger Kuroshio frontal waves. It is anticipated that these nonlinear frontal waves enhance the exchange of seawater between the Kuroshio and shelf regions. Kuroshio frontal waves in the model are excited around the location where the bottom slope changes abruptly, and have the phase speed and amplitude consistent with those observed in the East China Sea. In addition, the model reproduces the onshore transport associated with growing frontal waves in the upper and lower layers. On the basis of passive tracer experiments, the annually averaged onshore-transport integrated along the shelf break is estimated to be 0.85 × 106 m3/s.This study was carried out when A. I. stayed at WHOI with the grant of Overseas Advanced Educational Research Practice Support Program supported by the Ministry of Education, Science and Culture, Japan. In addition, the Japan Society for the Promotion of Science supported this study through Grant-in-Aid for Scientific Research