Science.gov

Sample records for active limb sounding

  1. A novel mission concept for upper air water vapour observations: active limb sounding with a constellation of retroreflectors

    NASA Astrophysics Data System (ADS)

    Clifford, D.; Hoffmann, A.; Weitnauer, C.; Topham, R.; Romano, P.; Lohrey, S.; Kox, S.; Krings, T.; Krejci, D.; Kern, K.; Huesing, J.; Esen, B.; Deconinck, F.; Carton, J. G.; Aulinas, J.

    2011-12-01

    The topic for the Alpbach summer school 2010 was "Missions for Understanding Climate Change''. Early career scientists and engineers from many countries formed working groups to devise new space missions to tackle this challenging subject. Following the summer school, one mission concept was chosen for further development at a subsequent workshop in Obergurgl, which is described in this paper. At the core of the mission chosen for further study was a novel active limb-sounding instrument, used as part of a multi-instrument measurement approach to observing upper air water vapour. The concept combines a LiDAR in nadir-viewing mode with a LiDAR in limb sounding by occultation geometry, designed to operate as a multiple discrete wavelength, very long path system for intergrated path differential absorption measurements. This is achieved using a monostatic transmitter-receiver spacecraft flown in formation with multiple spaceborne retroreflectors. Looking through the limb of the atmosphere, this system will sample the upper troposphere-lower stratosphere and above at high vertical resolution, with a long integration path allowing detection of the low concentrations of water vapour at this height. A secondary payload of a medium resolution multispectral radiometer allows wide-swath cloud and aerosol imaging. Active limb sounding has not yet been attempted in space, and this novel concept presents significant challenges, including the performance of the lasers in space, the tracking and locking procedure between the main spacecraft and the retroreflectors, and the design of the telescopes to achieve a high enough signal-to-noise ratio for the high precision measurements. These issues are addressed in this preliminary feasibility study, which shows promising results.

  2. The relative contributions of the prosthetic and sound limb to balance control in unilateral transtibial amputees.

    PubMed

    Curtze, Carolin; Hof, At L; Postema, Klaas; Otten, Bert

    2012-06-01

    In unilateral transtibial amputees maintenance of standing balance is compromised due to the lack of active ankle control in the prosthetic limb. The purpose of this study is to disentangle the contribution of the prosthetic and sound limb to balance control following waist-pull perturbations. We compared the contribution of the hip and ankle joints to balance control of 15 unilateral transtibial amputees and 13 able-bodied controls after been externally perturbed through release of a pulling force. Perturbations were applied in four different directions. Outcome measure was the proportion of joint moment integrated over time generated by the hip and ankle joints in order to restore static stability after perturbation. Analyses revealed that perturbations in backward/forward direction were recovered mainly by the ankle strategy. The amputees compensated for the absence of active ankle control in the prosthetic limb by increasing the ankle moment in the sound limb. Interestingly, the passive properties of the prosthetic foot contributed to balance control, which has important implications for prosthetic fitting and standing stability in lower limb amputees. Amputees and controls resisted perturbations in medio-lateral direction by generating the necessary hip moments. Finally, these findings are discussed with respect to prosthetic design and rehabilitation processes.

  3. Synergy between middle infrared and millimeter-wave limb sounding of atmospheric temperature and minor constituents

    NASA Astrophysics Data System (ADS)

    Cortesi, Ugo; Del Bianco, Samuele; Ceccherini, Simone; Gai, Marco; Dinelli, Bianca Maria; Castelli, Elisa; Oelhaf, Hermann; Woiwode, Wolfgang; Höpfner, Michael; Gerber, Daniel

    2016-05-01

    Synergistic exploitation of redundant and complementary information from independent observations of the same target remains a major issue in atmospheric remote sounding and increasing attention is devoted to investigate optimized or innovative methods for the combination of two or more measured data sets. This paper focuses on the synergy between middle infrared and millimeter-wave limb sounding measurements of atmospheric composition and temperature and reports the results of a study conducted as part of the preparatory activities of the PREMIER (Process Exploration through Measurements of Infrared and millimeter-wave Emitted Radiation) mission candidate to the Core Missions of the European Space Agency (ESA) Earth Explorer 7. The activity was based on data acquired by the MIPAS-STR (Michelson Interferometer for Passive Atmospheric Sounding - STRatospheric aircraft) and MARSCHALS (Millimetre-wave Airborne Receivers for Spectroscopic CHaracterisation in Atmospheric Limb Sounding) instruments on-board the high-altitude research aircraft M-55 Geophysica during the flight of the PremierEx (PREMIER Experiment) campaign on 10 March 2010 from Kiruna, Sweden, for observation of the Arctic upper troposphere and lower stratosphere. The cloud coverage observed along the flight provided representative test cases to evaluate the synergy in three different scenarios: low clouds in the first part, no clouds in the central part and high tropospheric clouds at the end. The calculation of synergistic profiles of four atmospheric targets (i.e., O3, HNO3, H2O and temperature) was performed using a posteriori combination of individual retrieved profiles, i.e., Level 2 (L2) data rather than simultaneous inversion of observed radiances, i.e., Level 1 (L1) data. An innovative method of data fusion, based on the Measurement Space Solution (MSS) was applied along with the standard approach of inversion of MARSCHALS spectral radiances using MIPAS-STR retrieval products as a priori

  4. Synergy between middle infrared and millimetre-wave limb sounding of atmospheric temperature and minor constituents

    NASA Astrophysics Data System (ADS)

    Cortesi, U.; Del Bianco, S.; Ceccherini, S.; Gai, M.; Dinelli, B. M.; Castelli, E.; Oelhaf, H.; Woiwode, W.; Höpfner, M.; Gerber, D.

    2015-11-01

    Synergistic exploitation of redundant and complementary information from independent observations of the same target remains a major issue in atmospheric remote-sounding and increasing attention is devoted to investigate optimised or innovative methods for the combination of two or more measured data sets. This paper is focusing on the synergy between middle infrared and millimetre-wave limb sounding measurements of atmospheric composition and temperature and reports the results of a study conducted as part of the preparatory activities of the PREMIER (Process Exploration through Measurements of Infrared and millimetre wave Emitted Radiation) mission candidate to the Core Missions of ESA Earth Explorer 7. The activity was based on data acquired by the MIPAS-STR (Michelson Interferometer for Passive Atmospheric Sounding - STRatospheric aircraft) and MARSCHALS (Millimetre-wave Airborne Receivers for Spectroscopic CHaracterisation in Atmospheric Limb Sounding) instruments onboard the high altitude research aircraft M-55 Geophysica during the flight of the PremierEx (PREMIER Experiment) campaign on 10 March 2010 from Kiruna, Sweden for observation of the Arctic upper troposphere and lower stratosphere. The cloud coverage observed along the flight provided representative test cases to evaluate the synergy in three different scenarios: low clouds in the first part, no clouds in the central part and high tropospheric clouds at the end. The calculation of synergistic profiles of four atmospheric targets (i.e., O2, HNO3, H2O and temperature) was performed using a posteriori combination of individual retrieved profiles, i.e., Level 2 (L2) data rather than simultaneous inverse processing of observed radiances, i.e., Level 1 (L1) data. An innovative method of data fusion, based on the Measurement Space Solution (MSS) was applied along with the standard approach of inverse processing of MARSCHALS spectral radiances using MIPAS-STR retrieval products as a priori information (L1

  5. Finite field of view effects on inversion of limb thermal emission observations. [balloon sounding of stratosphere

    NASA Technical Reports Server (NTRS)

    Abbas, M. M.; Guo, J.; Conrath, B. J.; Kunde, V. G.; Maguire, W. C.

    1985-01-01

    It is pointed out that the technique of thermal emission spectroscopy provides an effective means for remote sounding of stratospheric temperature structure and constituent distributions. One procedure for measuring the stratospheric infrared spectrum involves the conduction of observations along ray paths tangent to the stratospheric limb. Thermal emission limb tangent observations have certain advantages compared to other types of observations. The techniques for determining temperature and trace gas distributions from limb thermal emission radiances are based on the assumption that the bulk of opacity lies near the tangent point. Ideally, the field of view (FOV) of the observing instrument should be very small. The effect of a finite FOV is to reduce the spatial resolution of the retrieved temperature and constituent profiles. The present investigation is concerned with the effects of the FOV on the inversion of infrared thermal emission measurements for balloon platforms. Attention is given to a convenient method for determining the weighting functions.

  6. The Revised Mars Global Surveyor Thermal Emission Spectrometer Limb-Sounding Temperature Data Set

    NASA Astrophysics Data System (ADS)

    McConnochie, T. H.; Smith, M. D.

    2012-12-01

    Mars Global Surveyor Thermal Emission Spectrometer (MGS-TES) nadir-soundings have been used to derive atmospheric temperatures up to roughly 40 km [Conrath et al., JGR 105 2000, Smith et al., JGR 106, 2001], and MGS-TES limb soundings have been used to extend the atmospheric temperature data set to > 60 km in altitude [Smith et al., JGR 106, 2001]. The ~40 - ~65 km altitude range probed by the MGS-TES limb sounding is particularly important for capturing key dynamical features such as the warm winter polar mesosphere [e.g., Smith et al., JGR 106, 2001; McCleese et al., Nature Geoscience 1, 2008], and the response of thermal tides to dust opacity [e.g. Wilson and Hamilton, J. Atmos. Sci. 53, 1996]. Thus accurate and precise temperature profiles at these altitudes are particularly important for constraining global circulation models. They are also critical for interpreting observations of mesospheric condensate aerosols [e.g., Määttänen et al., Icarus 209, 2010; McConnochie et al., Icarus 210, 2010)]. We have revised the limb-sounding portion of the MGS-TES temperature retrievals to account for correlated noise components as well as a slowly variance radiance bias, both of which are significant contributions to TES limb-sounding radiances. See McConnochie and Smith [AGU Fall Meeting ,2011] for further discussion of these issues. We have reprocessed the complete limb-sounding temperature data set and will present an overview of its key features, focusing on the improvements and differences relative to the original version described by Smith et al. [JGR 106, 2001]. One important improvement is a decrease in the statistical uncertainty in individual retrievals at high altitudes. In the original version, uncertainties at the 1.5 Pascal levels increased from 5 - 10 K early in the mission (Mars Year 24) to 10 - 15 K in Mars Year 26 and 27. In the revised version, these uncertainties remain near 2 K throughout the data set. Considering averages of large numbers of

  7. Salient sounds activate human visual cortex automatically

    PubMed Central

    McDonald, John J.; Störmer, Viola S.; Martinez, Antigona; Feng, Wenfeng; Hillyard, Steven A.

    2013-01-01

    Sudden changes in the acoustic environment enhance perceptual processing of subsequent visual stimuli that appear in close spatial proximity. Little is known, however, about the neural mechanisms by which salient sounds affect visual processing. In particular, it is unclear whether such sounds automatically activate visual cortex. To shed light on this issue, the present study examined event-related brain potentials (ERPs) that were triggered either by peripheral sounds that preceded task-relevant visual targets (Experiment 1) or were presented during purely auditory tasks (Experiments 2, 3, and 4). In all experiments the sounds elicited a contralateral ERP over the occipital scalp that was localized to neural generators in extrastriate visual cortex of the ventral occipital lobe. The amplitude of this cross-modal ERP was predictive of perceptual judgments about the contrast of co-localized visual targets. These findings demonstrate that sudden, intrusive sounds reflexively activate human visual cortex in a spatially specific manner, even during purely auditory tasks when the sounds are not relevant to the ongoing task. PMID:23699530

  8. The application of spaceborne GPS to atmospheric limb sounding and global change monitoring

    NASA Technical Reports Server (NTRS)

    Melbourne, W. G.; Davis, E. S.; Duncan, C. B.; Hajj, G. A.; Hardy, K. R.; Kursinski, E. R.; Meehan, T. K.; Young, L. E.; Yunck, T. P.

    1994-01-01

    This monograph is intended for readers with minimal background in radio science who seek a relatively comprehensive treatment of the mission and technical aspects of an Earth-orbiting radio occultation satellite. Part 1 (chapters 1-6) describes mission concepts and programmatic information; Part 2 (chapters 7-12) deals with the theoretical aspects of analyzing and interpreting radio occultation measurements. In this mission concept the navigation signals from a Global Positioning System (GPS) satellite that is being occulted by the Earth's limb are observed by a GPS flight receiver on board a low Earth orbiter (LEO) satellite. This technique can be used to recover profiles of the Earth's atmospheric refractivity, pressure, and temperature using small, dedicated, and relatively low-cost space systems. Chapter 2 summarizes the basic space system concepts of the limb-sounding technique and describes a low-cost strawman demonstration mission. Chapter 3 discusses some of the scientific benefits of using radio occultation on a suite of small satellites. Chapter 4 provides a more detailed discussion of several system elements in a radio occultation mission, including the launch system for small payloads, the LEO microsat, the GPS constellation, the GPS flight receiver payload, the mission operations ground control and data receiving system, the ground-based GPS global tracking network for precision orbit determination, and the central data processing and archive system. Chapter 5 addresses the various technology readiness questions that invariably arise. Chapter 6 discusses the overall costs of a demonstration mission such as GPS/MET (meteorological) proposed by the University Navstar Consortium (UNAVCO). Chapter 7 describes a geometrical optics approach to coplanar atmospheric occultation. Chapter 8 addresses major questions regarding accuracy of the occultation techniques. Chapter 9 describes some simulations that have been performed to evaluate the sensitivity of the

  9. Brain activation associated with active and passive lower limb stepping

    PubMed Central

    Jaeger, Lukas; Marchal-Crespo, Laura; Wolf, Peter; Riener, Robert; Michels, Lars; Kollias, Spyros

    2014-01-01

    Reports about standardized and repeatable experimental procedures investigating supraspinal activation in patients with gait disorders are scarce in current neuro-imaging literature. Well-designed and executed tasks are important to gain insight into the effects of gait-rehabilitation on sensorimotor centers of the brain. The present study aims to demonstrate the feasibility of a novel imaging paradigm, combining the magnetic resonance (MR)-compatible stepping robot (MARCOS) with sparse sampling functional magnetic resonance imaging (fMRI) to measure task-related BOLD signal changes and to delineate the supraspinal contribution specific to active and passive stepping. Twenty-four healthy participants underwent fMRI during active and passive, periodic, bilateral, multi-joint, lower limb flexion and extension akin to human gait. Active and passive stepping engaged several cortical and subcortical areas of the sensorimotor network, with higher relative activation of those areas during active movement. Our results indicate that the combination of MARCOS and sparse sampling fMRI is feasible for the detection of lower limb motor related supraspinal activation. Activation of the anterior cingulate and medial frontal areas suggests motor response inhibition during passive movement in healthy participants. Our results are of relevance for understanding the neural mechanisms underlying gait in the healthy. PMID:25389396

  10. Twist1 activity thresholds define multiple functions in limb development.

    PubMed

    Krawchuk, Dayana; Weiner, Shoshana J; Chen, You-Tzung; Lu, Benson C; Costantini, Frank; Behringer, Richard R; Laufer, Ed

    2010-11-01

    The basic helix-loop-helix transcription factor Twist1 is essential for normal limb development. Twist1(-/-) embryos die at midgestation. However, studies on early limb buds found that Twist1(-/-) mutant limb mesenchyme has an impaired response to FGF signaling from the apical ectodermal ridge, which disrupts the feedback loop between the mesenchyme and AER, and reduces and shifts anteriorly Shh expression in the zone of polarizing activity. We have combined Twist1 null, hypomorph and conditional alleles to generate a Twist1 allelic series that survives to birth. As Twist1 activity is reduced, limb skeletal defects progress from preaxial polydactyly to girdle reduction combined with hypoplasia, aplasia or mirror symmetry of all limb segments. With reduced Twist1 activity there is striking and progressive upregulation of ectopic Shh expression in the anterior of the limb, combined with an anterior shift in the posterior Shh domain, which is expressed at normal intensity, and loss of the posterior AER. Consequently limb outgrowth is initially impaired, before an ectopic anterior Shh domain expands the AER, promoting additional growth and repatterning. Reducing the dosage of FGF targets of the Etv gene family, which are known repressors of Shh expression in anterior limb mesenchyme, strongly enhances the anterior skeletal phenotype. Conversely this and other phenotypes are suppressed by reducing the dosage of the Twist1 antagonist Hand2. Our data support a model whereby multiple Twist1 activity thresholds contribute to early limb bud patterning, and suggest how particular combinations of skeletal defects result from differing amounts of Twist1 activity.

  11. Twist1 activity thresholds define multiple functions in limb development

    PubMed Central

    Krawchuk, Dayana; Weiner, Shoshana J.; Chen, You-Tzung; Lu, Benson; Costantini, Frank; Behringer, Richard R.; Laufer, Ed

    2010-01-01

    Summary The basic helix-loop-helix transcription factor Twist1 is essential for normal limb development. Twist1−/− embryos die at midgestation. However, studies on early limb buds found that Twist1−/− mutant limb mesenchyme has an impaired response to FGF signaling from the apical ectodermal ridge, which disrupts the feedback loop between the mesenchyme and AER, and reduces and shifts anteriorly Shh expression in the zone of polarizing activity. We have combined Twist1 null, hypomorph and conditional alleles to generate a Twist1 allelic series that survives to birth. As Twist1 activity is reduced, limb skeletal defects progress from preaxial polydactyly to girdle reduction combined with hypoplasia, aplasia or mirror symmetry of all limb segments. With reduced Twist1 activity there is striking and progressive upregulation of ectopic Shh expression in the anterior of the limb, combined with an anterior shift in the posterior Shh domain, which is expressed at normal intensity, and loss of the posterior AER. Consequently limb outgrowth is initially impaired, before an ectopic anterior Shh domain expands the AER, promoting additional growth and repatterning. Reducing the dosage of FGF targets of the Etv gene family, which are known repressors of Shh expression in the anterior limb mesenchyme, strongly enhances the anterior skeletal phenotype. Conversely this and other phenotypes are suppressed by reducing the dosage of the Twist1 antagonist Hand2. Our data support a model whereby multiple Twist1 activity thresholds contribute to early limb bud patterning, and suggest how particular combinations of skeletal defects result from differing amounts of Twist1 activity. PMID:20732316

  12. Characteristics of lower limb muscle activity during upper limb elevation in badminton players

    PubMed Central

    Masu, Yujiro; Nagai, Masanori

    2016-01-01

    [Purpose] To clarify the characteristics of postural control in badminton players by examining their lower-limb muscle activity during upper-limb elevation. [Subjects and Methods] Fourteen badminton players and 14 non-players were studied. The subjects were instructed to perform an upper-limb elevation task in order to measure the activities of the biceps femoris and biceps brachii. [Results] When elevating the dominant hand, the mean biceps femoris integrated electromyogram showed markedly higher values in the player group, for the contralateral compared with the ipsilateral leg. Similarly, when elevating the dominant hand, the difference in the maximum integrated electromyogram response time between the ipsilateral and contralateral legs was significantly smaller in the players compared with non-players. [Conclusion] It may be possible to reduce the time needed to elevate the dominant hand by shifting lower-limb activity from the ipsilateral to the contralateral leg more quickly, while increasing the rate of rise in contralateral leg muscle activity. PMID:27799681

  13. Looking at Ozone From a New Angle: Shuttle Ozone Limb Sounding Experiment-2 (SOLSE-2)

    NASA Technical Reports Server (NTRS)

    McPeters, Richard; Hilsenrath, Ernest; Janz, Scott; Brown, Tammy (Technical Monitor)

    2002-01-01

    The ozone layer above Earth is our planet's fragile sunscreen, protecting people, vegetation, and wildlife. NASA has been measuring ozone for more than 20 years by looking down, but SOLSE-2 will show that more information is available by looking at ozone from the side, at Earth's limb or atmospheric boundary. When the ozone layer is compromised, increased ultraviolet (UV) levels from the sun cause health problems ranging from severe sunburns to skin cancer and cataracts. A concerted global effort has been made to reduce or eliminate the production of chemicals that deplete ozone, but the ozone layer is not expected to recover for many decades because these chemicals can remain active in the atmosphere for up to 100 years. We know now that ozone monitoring needs to be focused in the lower stratosphere. The discovery of the ozone hole in 1985 demonstrated that very large changes in ozone were occurring in the lower stratosphere near 20 km, instead of the upper stratosphere as first expected, and where current ozone instruments are focused. Measuring ozone from a tangential perspective that is centered at the limb provides ozone profiles concentrated in the lower stratosphere. The first flight of SOLSE proved that this technique achieves the accuracy and coverage of traditional measurements, and surpasses the altitude resolution and depth of retrieval of conventional techniques. Results from the first flight convinced the science community to design the next generation ozone monitoring satellite based on SOLSE. The Ozone Mapping and Profiling Suite (OMPS) is currently being built for the NPOESS satellite. The primary objective of SOLSE-2 is to confirm the promising results of the first flight over a wider range of viewing conditions and spectral wavelengths. Sometimes a really hard problem can be solved when you look at it from a different angle! While scientists conduct research, protect yourself by observing the UV index and spend less unprotected time outdoors.

  14. Global and seasonal variations in three-dimensional gravity wave momentum flux from satellite limb-sounding temperatures

    NASA Astrophysics Data System (ADS)

    Alexander, M. Joan

    2015-08-01

    Satellite limb-sounding methods provide the best global temperature data available for simultaneous measurement of gravity wave horizontal and vertical structures needed to estimate momentum flux and constrain wave effects on general circulation. Gravity waves vary in the three spatial dimensions and time, so the ideal measurement observes all three dimensions at high resolution nearly simultaneously. High Resolution Dynamics Limb Sounder (HIRDLS) measurements give near-simultaneous profiles in close proximity and at high vertical resolution, but these coincident profiles lie only along the plane of the measurement track. Here we combine HIRDLS and radio occultation data sets to obtain three-dimensional properties of gravity waves on a global scale as well as seasonal variations. The results show dramatic changes from previous estimates using either data set alone. Changes include much larger momentum fluxes and latitudinal variations in propagation direction that support an enhanced role for gravity wave forcing of middle atmosphere circulation.

  15. Active control of sound transmission using structural modal filters

    NASA Astrophysics Data System (ADS)

    Kaizuka, Tsutomu; Tanaka, Nobuo; Nakano, Kimihiko

    2016-10-01

    This paper addresses active sound transmission control based on structural sensors and actuators. The proposed methodology is to independently measure and control the targeted structural modes, which significantly contribute to sound transmission, with structural modal filters, i.e., modal sensors and modal actuators. The targeting is performed by using modal sound transmission coefficients before control as the criteria. The modal sound transmission coefficient enables the contribution from a structural mode to the sound transmission via the modal interaction with the other structural modes to be determined. The structural modal filters effectively facilitate decreasing the sound transmission and guarantee that the structural vibration and near-field sound, side effects of sound transmission control, will not increase. It is shown with numerical examples that sound transmission can be reduced significantly in a broad frequency band by controlling a small number of structural modes and neither the structural vibration nor near-field sound are increased.

  16. Pleiotropic patterning response to activation of Shh signaling in the limb apical ectodermal ridge.

    PubMed

    Wang, Chi-Kuang Leo; Tsugane, Mizuyo H; Scranton, Victoria; Kosher, Robert A; Pierro, Louis J; Upholt, William B; Dealy, Caroline N

    2011-05-01

    Sonic hedgehog (Shh) signaling in the limb plays a central role in coordination of limb patterning and outgrowth. Shh expression in the limb is limited to the cells of the zone of polarizing activity (ZPA), located in posterior limb bud mesoderm. Shh is not expressed by limb ectoderm or apical ectodermal ridge (AER), but recent studies suggest a role for AER-Shh signaling in limb patterning. Here, we have examined the effects of activation of Shh signaling in the AER. We find that targeted expression of Shh in the AER activates constitutive Shh signaling throughout the AER and subjacent limb mesoderm, and causes a range of limb patterning defects with progressive severity from mild polydactyly, to polysyndactyly with proximal defects, to severe oligodactyly with phocomelia and partial limb ventralization. Our studies emphasize the importance of control of the timing, level and location of Shh pathway signaling for limb anterior-posterior, proximal-distal, and dorsal-ventral patterning.

  17. Pleiotropic patterning response to activation of Shh signaling in the limb Apical Ectodermal Ridge

    PubMed Central

    Wang, Chi-Kuang Leo; Tsugane, Mizuyo H.; Scranton, Victoria; Kosher, Robert A.; Pierro, Louis J.; Upholt, William B.; Dealy, Caroline N.

    2012-01-01

    Sonic hedgehog (Shh) signaling in the limb plays a central role in coordination of limb patterning and outgrowth. Shh expression in the limb is limited to the cells of the Zone of Polarizing Activity (ZPA), located in posterior limb bud mesoderm. Shh is not expressed by limb ectoderm or AER, but recent studies suggest a role for AER-Shh signaling in limb patterning. Here, we have examined the effects of activation of Shh signaling in the AER. We find that targeted expression of Shh in the AER activates constitutive Shh signaling throughout the AER and subjacent limb mesoderm, and causes a range of limb patterning defects with progressive severity from mild polydactyly, to polysyndactyly with proximal defects, to severe oligodactyly with phocomelia and partial limb ventralization. Our studies emphasize the importance of control of the timing, level and location of Shh pathway signaling for limb AP, PD and DV patterning. PMID:21465622

  18. Spherical loudspeaker array for local active control of sound.

    PubMed

    Rafaely, Boaz

    2009-05-01

    Active control of sound has been employed to reduce noise levels around listeners' head using destructive interference from noise-canceling sound sources. Recently, spherical loudspeaker arrays have been studied as multiple-channel sound sources, capable of generating sound fields with high complexity. In this paper, the potential use of a spherical loudspeaker array for local active control of sound is investigated. A theoretical analysis of the primary and secondary sound fields around a spherical sound source reveals that the natural quiet zones for the spherical source have a shell-shape. Using numerical optimization, quiet zones with other shapes are designed, showing potential for quiet zones with extents that are significantly larger than the well-known limit of a tenth of a wavelength for monopole sources. The paper presents several simulation examples showing quiet zones in various configurations.

  19. Chlorine monoxide radical, ozone, and hydrogen peroxide - Stratospheric measurements by microwave limb sounding

    NASA Technical Reports Server (NTRS)

    Waters, J. W.; Hardy, J. C.; Jarnot, R. F.; Pickett, H. M.

    1981-01-01

    Profiles of stratospheric ozone and chlorine monoxide radical (ClO) have been obtained from balloon measurements of atmospheric limb thermal emission at millimeter wavelengths. The ClO measurements, important for assessing the predicted depletion of stratospheric ozone by chlorine from industrial sources, are in close agreement with present theory. The predicted decrease of ClO at sunset was measured. A tentative value for the stratospheric abundance of hydrogen peroxide was also determined.

  20. Characteristics of physical activity in patients with critical limb ischemia

    PubMed Central

    Sakaki, Satoko; Takahashi, Tetsuya; Matsumoto, Junichi; Kubo, Kasuya; Matsumoto, Takuya; Hishinuma, Ryo; Terabe, Yuuta; Ando, Hiroshi

    2016-01-01

    [Purpose] The purpose of this study was to evaluate the amount of physical activity of the patients with critical limb ischemia consecutively in order to clarify the characteristics of physical activity of critical limb ischemia. [Subjects and Methods] Twelve patients who were eligible for the 2 months of consecutive evaluation of the amount of physical activity were enrolled in the study (men: 11; woman: 1; mean age: 64.4 [range: 44–80]). A pedometer with an accelerometer was used for the measurement of the number of steps walked as an index of the amount of physical activity. Participants were asked to lead a regular life and no instruction was given as to the number of steps. [Results] The average number of daily steps walked was 2,323 steps (range: 404–6,505). There was no clear tendency in the number of amputation site-specific steps walked. There was also no correlation between the number of steps walked and age as well as the maximum strength of the knee-extension muscle, skin perfusion pressure of the sole and the dorsum, and QOL scores. [Conclusion] The number of steps walked of the patients with critical limb ischemia was remarkably low and no significant association with health-related QOL. PMID:28174472

  1. Active control of transmitted sound in buildings

    NASA Astrophysics Data System (ADS)

    Thompsett, Russell Harvey George

    The problem of noise from neighbours has increased dramatically over the last few years. Many of the noise complaints are due to the high level, low frequency noise from modern stereo equipment, and are often described in terms of the low frequency characteristics of the music; the repetitive, booming, bass beat. The objective of this research was to establish the feasibility of applying active noise control to alleviate this problem. The initial approach was to evaluate the possibility of exploiting the dominance of individual modes in the response of rooms at low frequency to effect global control. However, initial investigations using a modal model of the sound field revealed that this would be difficult due to the contribution of many acoustic modes excited off resonance. This conclusion was supported by measurements of acoustic room responses in typical buildings, illustrating a non-resonant characteristic. Consequently, attention was turned to the feasibility of using local active control systems to create zones of quiet by concentrating control at a specific location near the observers ears, for example in a seat headrest, or near the pillows of a bed. The lack of a reference signal in either approach requires the use of a feedback control strategy. With a typically non-resonant system, the predictability in the disturbance necessary for successful feedback control must be contained in the primary excitation, namely the music. Examples of different music styles were investigated and of those with the potential to be a nuisance surprisingly few were significantly more predictable than a random disturbance. As expected the most encouraging control performance simulations were found for modern dance music, with a strong repetitive beat. A real-time, local controller was demonstrated in the laboratory with such a disturbance signal and the properties of the quiet zone were measured. The subjective response when hearing the controller in operation was found to be

  2. A switch from low to high Shh activity regulates establishment of limb progenitors and signaling centers

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The patterning and growth of the embryonic vertebrate limb is dependent on Sonic hedgehog (Shh), a morphogen that regulates the activity of Gli transcription factors. However, "Shh" expression is not observed during the first 12 hours of limb development. During this phase, the limb bud is prepatter...

  3. Limb venous distension evokes sympathetic activation via stimulation of the limb afferents in humans.

    PubMed

    Cui, Jian; McQuillan, Patrick M; Blaha, Cheryl; Kunselman, Allen R; Sinoway, Lawrence I

    2012-08-15

    We have recently shown that a saline infusion in the veins of an arterially occluded human forearm evokes a systemic response with increases in muscle sympathetic nerve activity (MSNA) and blood pressure. In this report, we examined whether this response was a reflex that was due to venous distension. Blood pressure (Finometer), heart rate, and MSNA (microneurography) were assessed in 14 young healthy subjects. In the saline trial (n = 14), 5% forearm volume normal saline was infused in an arterially occluded arm. To block afferents in the limb, 90 mg of lidocaine were added to the same volume of saline in six subjects during a separate visit. To examine whether interstitial perfusion of normal saline alone induced the responses, the same volume of albumin solution (5% concentration) was infused in 11 subjects in separate studies. Lidocaine abolished the MSNA and blood pressure responses seen with saline infusion. Moreover, compared with the saline infusion, an albumin infusion induced a larger (MSNA: Δ14.3 ± 2.7 vs. Δ8.5 ± 1.3 bursts/min, P < 0.01) and more sustained MSNA and blood pressure responses. These data suggest that venous distension activates afferent nerves and evokes a powerful systemic sympathoexcitatory reflex. We posit that the venous distension plays an important role in evoking the autonomic adjustments seen with postural stress in human subjects.

  4. Visual Feedback of the Non-Moving Limb Improves Active Joint-Position Sense of the Impaired Limb in Spastic Hemiparetic Cerebral Palsy

    ERIC Educational Resources Information Center

    Smorenburg, Ana R. P.; Ledebt, Annick; Deconinck, Frederik J. A.; Savelsbergh, Geert J. P.

    2011-01-01

    This study examined the active joint-position sense in children with Spastic Hemiparetic Cerebral Palsy (SHCP) and the effect of static visual feedback and static mirror visual feedback, of the non-moving limb, on the joint-position sense. Participants were asked to match the position of one upper limb with that of the contralateral limb. The task…

  5. Magnetic field measurements in and above a limb active region

    NASA Astrophysics Data System (ADS)

    Philip, Judge

    2013-07-01

    We analyze spectropolarimetric data of a limb active region (NOAA 11302) obtained on September 22nd 2011 using the Facility Infrared Spectrometer (FIRS) at the Dunn Solar Telescope (DST). Stokes profiles including lines of Si I 1028.7 nm and He I 1083 nm were obtained in three scans over a 45"x75" area. Simultaneous narrow band Ca II K and G-band intensity data were acquired with a cadence of 5s at the DST. The He I data show not only typical active region polarization signatures, but also signatures in plumes -- cool post flare loops -- which extend many Mm into the corona across the visible limb. The plumes have remarkably uniform brightness, and the plume plasma is significantly Doppler shifted as it drains from the corona. Using carefully constructed observing and calibration sequences and applying Principal Component Analysis to remove instrumental artifacts, we achieved a polarization sensitivity approaching 0.02%. With this sensitivity we attempt to diagnose the vector magnetic fields and plasma properties of chromospheric and cool coronal material in and above NOAA 11302. Inversions using various radiative transfer models in the HAZEL code are remarkably consistent with the idea that plume spectra are formed in a simple, slab-like geometry, but that the ``disk'' spectra are formed under more traditional models (Milne-Eddington). The inverted magnetic data of He I lines are compared with photospheric inversions of DST Si I and Fe I data from the Solar Dynamics Observatory.

  6. Physical activity, functional capacity, and step variability during walking in people with lower-limb amputation.

    PubMed

    Lin, Suh-Jen; Winston, Katie D; Mitchell, Jill; Girlinghouse, Jacob; Crochet, Karleigh

    2014-01-01

    Physical activity is important for general health. For an individual with amputation to sustain physical activity, certain functional capacity might be needed. Gait variability is related to the incidence of falls. This study explored the relationship between physical activity and a few common performance measures (six-minute walk test, step length variability, step width variability, and comfortable walking speed) in individuals with unilateral lower-limb amputation. Twenty individuals completed the study (age: 50±11yrs). Twelve of them had transtibial amputation, seven had transfemoral amputation, and one had through-knee amputation. Gait data was collected by the GaitRite instrumented walkway while participants performed a 3-min comfortable walking trial followed by a six-minute walk test. Physical activity was indicated by the mean of 7-day step counts via a pedometer. Gait variability was calculated by the coefficient of variation. Pearson correlation analysis was conducted between physical activity level and the 4 performance measures. Significance level was set at 0.05. Physical activity correlates strongly to comfortable walking speed (r=0.76), six-minute walk distance (r=0.67), and correlates fairly to step width variability (r=0.44). On the contrary, physical activity is inversely related to step length variability of the prosthetic leg (r=-0.46) and of the sound leg (r=-0.47). Having better functional capacity and lateral stability might enable an individual with lower-limb amputation to engage in a higher physical activity level, or vise versa. However, our conclusions are only preliminary as limited by the small sample size.

  7. Peripheral sounds rapidly activate visual cortex: evidence from electrocorticography.

    PubMed

    Brang, David; Towle, Vernon L; Suzuki, Satoru; Hillyard, Steven A; Di Tusa, Senneca; Dai, Zhongtian; Tao, James; Wu, Shasha; Grabowecky, Marcia

    2015-11-01

    Neurophysiological studies with animals suggest that sounds modulate activity in primary visual cortex in the presence of concurrent visual stimulation. Noninvasive neuroimaging studies in humans have similarly shown that sounds modulate activity in visual areas even in the absence of visual stimuli or visual task demands. However, the spatial and temporal limitations of these noninvasive methods prevent the determination of how rapidly sounds activate early visual cortex and what information about the sounds is relayed there. Using spatially and temporally precise measures of local synaptic activity acquired from depth electrodes in humans, we demonstrate that peripherally presented sounds evoke activity in the anterior portion of the contralateral, but not ipsilateral, calcarine sulcus within 28 ms of sound onset. These results suggest that auditory stimuli rapidly evoke spatially specific activity in visual cortex even in the absence of concurrent visual stimulation or visual task demands. This rapid auditory-evoked activation of primary visual cortex is likely to be mediated by subcortical pathways or direct cortical projections from auditory to visual areas.

  8. Shared Enhancer Activity in the Limbs and Phallus and Functional Divergence of a Limb-Genital cis-Regulatory Element in Snakes.

    PubMed

    Infante, Carlos R; Mihala, Alexandra G; Park, Sungdae; Wang, Jialiang S; Johnson, Kenji K; Lauderdale, James D; Menke, Douglas B

    2015-10-12

    The amniote phallus and limbs differ dramatically in their morphologies but share patterns of signaling and gene expression in early development. Thus far, the extent to which genital and limb transcriptional networks also share cis-regulatory elements has remained unexplored. We show that many limb enhancers are retained in snake genomes, suggesting that these elements may function in non-limb tissues. Consistent with this, our analysis of cis-regulatory activity in mice and Anolis lizards reveals that patterns of enhancer activity in embryonic limbs and genitalia overlap heavily. In mice, deletion of HLEB, an enhancer of Tbx4, produces defects in hindlimbs and genitalia, establishing the importance of this limb-genital enhancer for development of these different appendages. Further analyses demonstrate that the HLEB of snakes has lost hindlimb enhancer function while retaining genital activity. Our findings identify roles for Tbx4 in genital development and highlight deep similarities in cis-regulatory activity between limbs and genitalia.

  9. Passive resting state and history of antagonist muscle activity shape active extensions in an insect limb

    PubMed Central

    Ache, Jan M.

    2012-01-01

    Limb movements can be driven by muscle contractions, external forces, or intrinsic passive forces. For lightweight limbs like those of insects or small vertebrates, passive forces can be large enough to overcome the effects of gravity and may even generate limb movements in the absence of active muscle contractions. Understanding the sources and actions of such forces is therefore important in understanding motor control. We describe passive properties of the femur-tibia joint of the locust hind leg. The resting angle is determined primarily by passive properties of the relatively large extensor tibiae muscle and is influenced by the history of activation of the fast extensor tibiae motor neuron. The resting angle is therefore better described as a history-dependent resting state. We selectively stimulated different flexor tibiae motor neurons to generate a range of isometric contractions of the flexor tibiae muscle and then stimulated the fast extensor tibiae motor neuron to elicit active tibial extensions. Residual forces in the flexor muscle have only a small effect on subsequent active extensions, but the effect is larger for distal than for proximal flexor motor neurons and varies with the strength of flexor activation. We conclude that passive properties of a lightweight limb make substantial and complex contributions to the resting state of the limb that must be taken into account in the patterning of neuronal control signals driving its active movements. Low variability in the effects of the passive forces may permit the nervous system to accurately predict their contributions to behavior. PMID:22357791

  10. Active control of excessive sound emission on a mobile device.

    PubMed

    Jeon, Se-Woon; Youn, Dae Hee; Park, Young-cheol; Lee, Gun-Woo

    2015-04-01

    During a phone conversation, loud vocal emission from the far-end to the near-end space can disturb nearby people. In this paper, the possibility of actively controlling such unwanted sound emission using a control source placed on the mobile device is investigated. Two different approaches are tested: Global control, minimizing the potential energy measured along a volumetric space surface, and local control, minimizing the squared sound pressure at a discrete point on the phone. From the test results, both approaches can reduce the unwanted sound emission by more than 6 dB in the frequency range up to 2 kHz.

  11. Remote Sounding of the Earth's Atmospheric Limb From a Micro-Satellite Platform: a Feasibility Study of the ALTIUS Mission

    NASA Astrophysics Data System (ADS)

    Vrancken, D.; Paijmans, B.; Fussen, D.; Neefs, E.; Loodts, N.; Dekemper, E.; Vahellemont, F.; Devos, L.; Moelans, W.; Nevejans, D.; Schroeven-Deceuninck, H.; Bernaerts, D.; Zender, J.

    2008-08-01

    There is more and more interest in the understanding and the monitoring of the physics and chemistry of the Earth's atmosphere and its impact on the climate change. Currently a significantly high number of sounders provide the required data to monitor the changes in atmosphere composition, but a dramatic drop in operational atmosphere monitoring missions is expected around 2010. This drop is mainly visible in sounders capable of a high vertical resolution. Currently, instruments on ENVISAT and METOP provide relevant data but this is envisaged to be insufficient to ensure full spatial and temporal coverage and redundancy in the measurement data set. ALTIUS (Atmospheric Limb Tracker for the Investigation of the Upcoming Stratosphere) is a remote sounding experiment proposed by the Belgian Institute for Space Aeronomy (BIRA/IASB) for which a feasibility study was initiated with BELSPO (Belgian Science Policy) and ESA support. The main objective of this study phase was to establish a mission concept, to define the required payload and to establish a satellite platform design. The study was led by the BIRA/IASB team and performed in close collaboration with OIP (payload developer) and Verhaert Space (spacecraft developer). The mission scenario includes bright limb observations in basically all directions, solar occultations around the terminator passages and star occultations during eclipse. These observation modes allow imaging the atmosphere with a high vertical resolution. The spacecraft will be operated in a 10:00 sun-synchronous orbit at an altitude of 695 km, allowing a 3-day revisit time. The envisaged payload for the ALTIUS mission is an imaging spectrometer, observing in the UV, the VIS and the NIR spectral ranges. For each spectral range, an AOTF (Acousto-Optical Tunable Filter) will permit to perform observations of selectable small wavelength domains. A typical set of 10 wavelengths will be recorded within 1 second. The different operational modes impose a

  12. Artificial Limbs

    MedlinePlus

    ... you are missing an arm or leg, an artificial limb can sometimes replace it. The device, which is ... activities such as walking, eating, or dressing. Some artificial limbs let you function nearly as well as before.

  13. Salamander limb regeneration involves the activation of a multipotent skeletal muscle satellite cell population.

    PubMed

    Morrison, Jamie I; Lööf, Sara; He, Pingping; Simon, András

    2006-01-30

    In contrast to mammals, salamanders can regenerate complex structures after injury, including entire limbs. A central question is whether the generation of progenitor cells during limb regeneration and mammalian tissue repair occur via separate or overlapping mechanisms. Limb regeneration depends on the formation of a blastema, from which the new appendage develops. Dedifferentiation of stump tissues, such as skeletal muscle, precedes blastema formation, but it was not known whether dedifferentiation involves stem cell activation. We describe a multipotent Pax7+ satellite cell population located within the skeletal muscle of the salamander limb. We demonstrate that skeletal muscle dedifferentiation involves satellite cell activation and that these cells can contribute to new limb tissues. Activation of salamander satellite cells occurs in an analogous manner to how the mammalian myofiber mobilizes stem cells during skeletal muscle tissue repair. Thus, limb regeneration and mammalian tissue repair share common cellular and molecular programs. Our findings also identify satellite cells as potential targets in promoting mammalian blastema formation.

  14. Sounds activate visual cortex and improve visual discrimination.

    PubMed

    Feng, Wenfeng; Störmer, Viola S; Martinez, Antigona; McDonald, John J; Hillyard, Steven A

    2014-07-16

    A recent study in humans (McDonald et al., 2013) found that peripheral, task-irrelevant sounds activated contralateral visual cortex automatically as revealed by an auditory-evoked contralateral occipital positivity (ACOP) recorded from the scalp. The present study investigated the functional significance of this cross-modal activation of visual cortex, in particular whether the sound-evoked ACOP is predictive of improved perceptual processing of a subsequent visual target. A trial-by-trial analysis showed that the ACOP amplitude was markedly larger preceding correct than incorrect pattern discriminations of visual targets that were colocalized with the preceding sound. Dipole modeling of the scalp topography of the ACOP localized its neural generators to the ventrolateral extrastriate visual cortex. These results provide direct evidence that the cross-modal activation of contralateral visual cortex by a spatially nonpredictive but salient sound facilitates the discriminative processing of a subsequent visual target event at the location of the sound. Recordings of event-related potentials to the targets support the hypothesis that the ACOP is a neural consequence of the automatic orienting of visual attention to the location of the sound.

  15. Sounds Activate Visual Cortex and Improve Visual Discrimination

    PubMed Central

    Störmer, Viola S.; Martinez, Antigona; McDonald, John J.; Hillyard, Steven A.

    2014-01-01

    A recent study in humans (McDonald et al., 2013) found that peripheral, task-irrelevant sounds activated contralateral visual cortex automatically as revealed by an auditory-evoked contralateral occipital positivity (ACOP) recorded from the scalp. The present study investigated the functional significance of this cross-modal activation of visual cortex, in particular whether the sound-evoked ACOP is predictive of improved perceptual processing of a subsequent visual target. A trial-by-trial analysis showed that the ACOP amplitude was markedly larger preceding correct than incorrect pattern discriminations of visual targets that were colocalized with the preceding sound. Dipole modeling of the scalp topography of the ACOP localized its neural generators to the ventrolateral extrastriate visual cortex. These results provide direct evidence that the cross-modal activation of contralateral visual cortex by a spatially nonpredictive but salient sound facilitates the discriminative processing of a subsequent visual target event at the location of the sound. Recordings of event-related potentials to the targets support the hypothesis that the ACOP is a neural consequence of the automatic orienting of visual attention to the location of the sound. PMID:25031419

  16. New facilities for magnetotelluric sounding and electromagnetic sounding with active sources

    NASA Astrophysics Data System (ADS)

    Klymovych, Y.; Rakhlin, L.; Tregubenko, V.

    2003-04-01

    Magnetotelluric (MT) sounding and investigations that use electromagnetic sounding with active sources (SAS) are wide spread in many branch of geophysics. The main goal of their application is Earth geoelectric cross-section parameters definition. For MT sounding it was possible to carry out it mostly till the time intervals less, than 10000 sec, that does not permitted to get the sections for the depth more than some first kilometres. Last years in LCISR the new generation of MT and facilities for deep electromagnetic sounding in ultra-low frequencies periods up to 200,000 sec were designed. It became possible after the development of highly stable devices for DC magnetic and telluric measurements. The long term stability of newly created magnetometers now is better than 0.5 nT per month and temperature stability about 0.1 nT/oC. For telluric currents measurements highly stable non-polarized electrodes with long term stability better than 60 mV per month, and temperature stability about 10 mV/oC were designed. Implementation of such facilities made it possible to realize the magnetotelluric sounding to the depth 400-600 km and the experimental results have good agreement with global magnetotelluric curve. Such MT stations (LEMI-404 model) were used in BEAR (Baltic Electromagnetic Array Research) and several others projects. Their use made it possible also to prove with very high probability the existence of low-depth astenosphere in Dnepre-Donetsk Basin (Ukraine). Now a batch of these MT stations is manufactured and used in Ukrainian magnetotelluric net. This net was intended firstly for investigation of electromagnetic earthquake precursors, but after its further development - for geoelectric section circular changes too. Recently two new MT stations are developed. First one low-frequency (DC 1 Hz) inexpensive station LEMI-411 which, having as high metrological parameters as the wide-band one, costs considerebly lower. Second one is multifunctional SAS station

  17. Stepwise rehabilitation of the triple amputee combined with dysfunction of the sound limb.

    PubMed

    Shin, Ji Cheol; Yang, Hye Eun; Yu, Su Jin; Kim, Na Young; Yoon, Seo Yeon

    2014-02-01

    To find a multiple amputee more severe than a triple amputee is not easy. This is a report of a 36-year-old patient with right knee disarticulation, left trans-femoral amputation and right elbow disarticulation due to peripheral ischemic necrosis, when he was applied vasopressor in septic shock condition. His left hand was also 2nd, 3rd, 4th, and 5th distal interphalangeal joint disarticulation status, and it was more difficult for him to do rehabilitation program, such as donning and doffing the prostheses. For more efficient rehabilitation training program, we first focused on upper extremities function, since we believed that he might need a walking aid for gait training later. After 13 weeks of rehabilitation program, he has become sit to stand and walk short distance independently with an anterior walker. Although he still needs some assistance with activities of daily living, his Functional Independence Measure score improved from 48 to 90 during the course of 13 weeks.

  18. 75 FR 61857 - Statement on Sound Practices Concerning Elevated Risk Complex Structured Finance Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-10-06

    ... Office of Thrift Supervision Statement on Sound Practices Concerning Elevated Risk Complex Structured... concerning the following information collection. Title of Proposal: Statement on Sound Practices Concerning...: Statement on Sound Practices Concerning Elevated Risk Complex Structured Finance Activities describes...

  19. Brain Activity during Lower-Limb Movement with Manual Facilitation: An fMRI Study

    PubMed Central

    de Almeida, Patrícia Maria Duarte; Vieira, Ana Isabel Correia Matos de Ferreira; Canário, Nádia Isabel Silva; Castelo-Branco, Miguel; de Castro Caldas, Alexandre Lemos

    2015-01-01

    Brain activity knowledge of healthy subjects is an important reference in the context of motor control and reeducation. While the normal brain behavior for upper-limb motor control has been widely explored, the same is not true for lower-limb control. Also the effects that different stimuli can evoke on movement and respective brain activity are important in the context of motor potentialization and reeducation. For a better understanding of these processes, a functional magnetic resonance imaging (fMRI) was used to collect data of 10 healthy subjects performing lower-limb multijoint functional movement under three stimuli: verbal stimulus, manual facilitation, and verbal + manual facilitation. Results showed that, with verbal stimulus, both lower limbs elicit bilateral cortical brain activation; with manual facilitation, only the left lower limb (LLL) elicits bilateral activation while the right lower limb (RLL) elicits contralateral activation; verbal + manual facilitation elicits bilateral activation for the LLL and contralateral activation for the RLL. Manual facilitation also elicits subcortical activation in white matter, the thalamus, pons, and cerebellum. Deactivations were also found for lower-limb movement. Manual facilitation is stimulus capable of generating brain activity in healthy subjects. Stimuli need to be specific for bilateral activation and regarding which brain areas we aim to activate. PMID:25722890

  20. Active Noise Control Experiments using Sound Energy Flu

    NASA Astrophysics Data System (ADS)

    Krause, Uli

    2015-03-01

    This paper reports on the latest results concerning the active noise control approach using net flow of acoustic energy. The test set-up consists of two loudspeakers simulating the engine noise and two smaller loudspeakers which belong to the active noise system. The system is completed by two acceleration sensors and one microphone per loudspeaker. The microphones are located in the near sound field of the loudspeakers. The control algorithm including the update equation of the feed-forward controller is introduced. Numerical simulations are performed with a comparison to a state of the art method minimising the radiated sound power. The proposed approach is experimentally validated.

  1. Sound

    NASA Astrophysics Data System (ADS)

    Capstick, J. W.

    2013-01-01

    1. The nature of sound; 2. Elasticity and vibrations; 3. Transverse waves; 4. Longitudinal waves; 5. Velocity of longitudinal waves; 6. Reflection and refraction. Doppler's principle; 7. Interference. Beats. Combination tones; 8. Resonance and forced vibrations; 9. Quality of musical notes; 10. Organ pipes; 11. Rods. Plates. Bells; 12. Acoustical measurements; 13. The phonograph, microphone and telephone; 14. Consonance; 15. Definition of intervals. Scales. Temperament; 16. Musical instruments; 17. Application of acoustical principles to military purposes; Questions; Answers to questions; Index.

  2. Annoyance resulting from intrusion of aircraft sounds upon various activities

    NASA Technical Reports Server (NTRS)

    Gunn, W. J.; Shepherd, W. T.; Fletcher, J. L.

    1975-01-01

    An experiment was conducted in which subjects were engaged in TV viewing, telephone listening, or reverie (no activity) for a 1/2-hour session. During the session, they were exposed to a series of recorded aircraft sounds at the rate of one flight every 2 minutes. Within each session, four levels of flyover noise, separated by dB increments, were presented several times in a Latin Square balanced sequence. The peak level of the noisiest flyover in any session was fixed at 95, 90, 85, 75, or 70 dBA. At the end of the test session, subjects recorded their responses to the aircraft sounds, using a bipolar scale which covered the range from very pleasant to extremely annoying. Responses to aircraft noises were found to be significantly affected by the particular activity in which the subjects were engaged. Not all subjects found the aircraft sounds to be annoying.

  3. Sounding rocket activities of Japan in 2003 and 2004

    NASA Astrophysics Data System (ADS)

    Ishii, Nobuaki; Inatani, Yoshifumi; Nonaka, Satoshi; Nakajima, Takashi; Takumi, Abe; Yuichi, Tsuda; Yamagami, Takamasa

    2005-08-01

    In October 2003, a new space agency, JAXA (Japan Aerospace Exploration Agency) was reorganized and started as a primary space agency to promote all space activities in Japan. The Institute of Space and Astronautical Science (ISAS) belonged to JAXA and continued to promote space science and technologies using unique scientific satellites, sounding rockets and balloons. This paper summarizes sounding rocket and ballooning activities of ISAS in the fiscal year of 2003 and 2004, associated with satellite launch programs. In this time period, three sounding rockets and nineteen balloons were launched by ISAS. One of the sounding rocket, S-310-35 was an international collaboration between Japan and Norway, which was launched from Andoya Rocket Range (ARR), Andenes, Norway, so as to study the upper atmospheric dynamics and energetics associated with the auroral energy in the polar lower thermosphere. Through the combination with the national researchers and the cooperation with international organizations, ISAS will keep its own flight opportunities and be able to obtain many new scientific findings.

  4. Temperatures and aerosol opacities of the Mars atmosphere at aphelion: Validation and inter-comparison of limb sounding profiles from MRO/MCS and MGS/TES

    NASA Astrophysics Data System (ADS)

    Shirley, James H.; McConnochie, Timothy H.; Kass, David M.; Kleinböhl, Armin; Schofield, John T.; Heavens, Nicholas G.; McCleese, Daniel J.; Benson, Jennifer; Hinson, David P.; Bandfield, Joshua L.

    2015-05-01

    We exploit the relative stability and repeatability of the Mars atmosphere at aphelion for an inter-comparison of Mars Global Surveyor/Thermal Emission Spectrometer (MGS/TES) and Mars Reconnaissance Orbiter/Mars Climate Sounder (MRO/MCS) nighttime temperature profiles and aerosol opacity profiles in Mars years 25, 26, 29, 30, and 31. Cross-calibration of these datasets is important, as they together provide an extended climatology for this planetary atmosphere. As a standard of comparison we employ temperature profiles obtained by radio occultation methods during the MGS mission in Mars years 24, 25, and 26. We first compare both zonal mean TES limb sounding profiles and zonal mean MCS limb sounding profiles with zonal means of radio occultation temperature profiles for the same season (Ls = 70-80°) and latitudes (55-70°N). We employ a statistical z test for quantifying the degree of agreement of temperature profiles by pressure level. For pressures less than 610 Pa (altitudes > 3 km), the ensemble mean temperature difference between the radio occultation and TES limb sounding profiles found in these comparisons was 1.7 ± 0.7 K. The ensemble mean temperature difference between radio occultation and MCS profiles was 1.4 ± 1.0 K. These differences fall within the formal error estimates for both TES and MCS, validating the accuracy of the instruments and their respective retrieval algorithms. In the second phase of our investigation, we compare aphelion season zonal mean TES limb sounding temperature, water ice opacity, and dust opacity profiles with those obtained at the same latitudes in different years by MCS. The ensemble mean temperature difference found for three comparisons between TES and MCS zonal mean temperature profiles was 2.8 ± 2.1 K. MCS and TES temperatures between 610 Pa and 5 Pa from 55 to 70°N are largely in agreement (with differences < 2 K) when water ice aerosol opacities are comparable. Temperature differences increase when the opacities

  5. [Actuator placement for active sound and vibration control

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Two refereed journal publications and ten talks given at conferences, seminars, and colloquia resulted from research supported by NASA. They are itemized in this report. The two publications were entitled "Reactive Tabu and Search Sensor Selection in Active Structural Acoustic Control Problems" and "Quelling Cabin Noise in Turboprop Aircraft via Active Control." The conference presentations covered various aspects of actuator placement, including location problems, for active sound and vibration control of cylinders, of commuter jets, of propeller driven or turboprop aircraft, and for quelling aircraft cabin or interior noise.

  6. Decoding of the sound frequency from the steady-state neural activities in rat auditory cortex.

    PubMed

    Shiramatsu, Tomoyo I; Noda, Takahiro; Kanzaki, Ryohei; Takahashi, Hirokazu

    2013-01-01

    In the auditory cortex, onset activities have been extensively investigated as a cortical representation of sound information such as sound frequency. Yet, less attention has been paid to date to steady-state activities following the onset activities. In this study, we used machine learning to investigate whether steady-state activities in the presence of continuous sounds represent the sound frequency. Sparse Logistic Regression (SLR) decoded the sound frequency from band specific power or phase locking value (PLV) of local field potentials (LFP) from the fourth layer of the auditory cortex of anesthetized rats. Consequently, we found that SLR was able to decode the sound frequency from steady-state neural activities as well as onset activities. This result demonstrates that the steady-state activities contain information about the sound such as sound frequency.

  7. Limb sounders tracking topographic gravity wave activity from the stratosphere to the ionosphere around midlatitude Andes

    NASA Astrophysics Data System (ADS)

    Alexander, P.; Torre, A.; Schmidt, T.; Llamedo, P.; Hierro, R.

    2015-10-01

    Several studies have shown that the surroundings of the highest Andes mountains at midlatitudes in the Southern Hemisphere exhibit gravity waves (GWs) generated by diverse sources which may traverse the troposphere and then penetrate the upper layers if conditions are favorable. There is a specific latitude band where that mountain range is nearly perfectly aligned with the north-south direction, which favors the generation of wavefronts parallel to this orientation. This fact may allow an optimization of procedures to identify topographic GW in some of the observations. We analyze data per season to the east and west of these Andes latitudes to find possible significant differences in GW activity between both sectors. GW effects generated by topography and convection are expected essentially on the eastern side. We use satellite data from two different limb sounding methods: the Global Positioning System radio occultation (RO) technique and the Sounding of the Atmosphere using Broadband Emission Radiometry instrument, which are complementary with respect to the height intervals, in order to study the effects of GW from the stratosphere to the ionosphere. Activity becomes quantified by the GW average potential energy in the stratosphere and mesosphere and by the electron density variance content in the ionosphere. Consistent larger GW activity on the eastern sector is observed from the stratosphere to the ionosphere (night values). However, this fact remains statistically significant at the 90% significance level only during winter, when GWs generated by topography dominate the eastern sector. On the contrary, it is usually assumed that orographic GWs have nearly zero horizontal phase speed and will therefore probably be filtered at some height in the neutral atmosphere. However, this scheme relies on the assumption that the wind is uniform and constant. Our results also suggest that it is advisable to separate night and day cases to study GWs in the ionosphere, as

  8. The effects of prism glasses and intensive upper limb exercise on hemineglect, upper limb function, and activities of daily living in stroke patients: a case series

    PubMed Central

    Oh, Se-Il; Kim, Jin-Kyung; Park, So-Yeon

    2015-01-01

    [Purpose] This study aimed to examine the effects of visual field with prism glasses, and intensive upper limb functional training on reduction of hemineglect and improvement in upper limb function and activities of daily living in three stroke patients with hemineglect. [Subjects] This study included three stroke patients hospitalized in a sanatorium. [Methods] Intervention treatment involving prism glass use for 12 hours and 30 minutes and paretic side upper limb training was conducted 5 days a week for 15 weeks. Three upper limb training tasks (hitting a balloon, passing through a ring, and reading a newspaper) were performed for 10 minutes each session, for a total of 30 minutes. Line by Section, Motor-Free Visual Perception Test-3 (MVPT-3), Manual Function Test (MFT), Box & Block Test (BBT), and Assessment of Motor and Process Skills (AMPS) were conducted before and after intervention. [Results] Subjects’ hemineglect decreased and upper limb function on the paretic side improved after intervention, which enhanced activities of daily living. [Conclusion] Prism glass use and paretic upper limb functional training effectively ameliorated stroke patients’ hemineglect and improved upper limb function. Future research should focus on prism glasses that provide a wide visual field for use in patients with different conditions. PMID:26834386

  9. Retrotransposon long interspersed nucleotide element-1 (LINE-1) is activated during salamander limb regeneration.

    PubMed

    Zhu, Wei; Kuo, Dwight; Nathanson, Jason; Satoh, Akira; Pao, Gerald M; Yeo, Gene W; Bryant, Susan V; Voss, S Randal; Gardiner, David M; Hunter, Tony

    2012-09-01

    Salamanders possess an extraordinary capacity for tissue and organ regeneration when compared to mammals. In our effort to characterize the unique transcriptional fingerprint emerging during the early phase of salamander limb regeneration, we identified transcriptional activation of some germline-specific genes within the Mexican axolotl (Ambystoma mexicanum) that is indicative of cellular reprogramming of differentiated cells into a germline-like state. In this work, we focus on one of these genes, the long interspersed nucleotide element-1 (LINE-1) retrotransposon, which is usually active in germ cells and silent in most of the somatic tissues in other organisms. LINE-1 was found to be dramatically upregulated during regeneration. In addition, higher genomic LINE-1 content was also detected in the limb regenerate when compared to that before amputation indicating that LINE-1 retrotransposition is indeed active during regeneration. Active LINE-1 retrotransposition has been suggested to have a potentially deleterious impact on genomic integrity. Silencing of activated LINE-1 by small RNAs has been reported to be part of the machinery aiming to maintain genomic integrity. Indeed, we were able to identify putative LINE-1-related piRNAs in the limb blastema. Transposable element-related piRNAs have been identified frequently in the germline in other organisms. Thus, we present here a scenario in which a unique germline-like state is established during axolotl limb regeneration, and the re-activation of LINE-1 may serve as a marker for cellular dedifferentiation in the early-stage of limb regeneration.

  10. Active and passive electromagnetic sounding on comets and moons

    NASA Astrophysics Data System (ADS)

    Przyklenk, Anita; Auster, Hans-Ulrich

    We want to present the method of electromagnetic sounding on small extraterrestrial bodies to determine interior structures of those. Our sensors are perfectly suited for rover or lander missions, because they do not weight much (sum of all devices is approximately 600g) and can be easily installed at the bottom of a rover or at lander feet. The aim is to measure the material-specific complex resistivity, which depends on the electrical resistivity and electrical permittivity, for various sounding depth. This penetration depth depends on the 2 different operating modes. In the active mode, that is the so called Capacitive Resistivity (CR) method, the sounding depth is around a few meters. The CR is a purely electrical field measurement and works with a 4 electrode array. 2 of them are transmitter electrodes. They inject AC signals with frequencies between 100 Hz and 100 kHz into the subsurface. Then 2 receiver electrodes pick up the generated potentials. And a 4-point impedance can be calculated that depends on the electrical parameters among others [Grard, 1990a and b] [Kuras, 2002]. The second operating mode is the passive one. In the so called magneto telluric method the penetration depth depends on electrical parameters and can be in range of several 100m to km. Here, for excitation natural magnetic field variations are used. The magnetic field components are measured with our Fluxgate Magnetometer (FGM) (flight heritage: Rosetta, Venus Express, Themis,…). Induced electrical field components are measured again with the CR electrode array. Then the electromagnetic impedance can be derived, which depends on electrical resistivity among others. In the end, we want to discuss advantages and disadvantages of investigations during space missions compared to surveys on earth. As examples we have a closer look at the jovian moon Ganymede, the earth moon and the comet 67P/Churyumov-Gerasimenko and consider the applicability of electromagnetic sounding on this objects

  11. A climatological study of the composition of Titan upper atmosphere from VIMS-IR soundings in limb geometry has been carried out for HCN, C_2H_2 and CH_4

    NASA Astrophysics Data System (ADS)

    Moriconi, M. L.; Adriani, A.; Dinelli, B. M.; Lopez-Puertas, M.; Filacchione, G.; D'Aversa, E.

    A climatological study of the composition of Titan upper atmosphere from VIMS-IR soundings in limb geometry has been carried out for (HCN), (C_2H_2) and (CH_4). The results of this study are here presented for the 2004-2012 period.

  12. Antagonist muscle co-activation of limbs in human infant crawling: A pilot study.

    PubMed

    Xiong, Qi L; Wu, Xiao Y; Xiao, Nong; Zeng, Si Y; Wan, Xiao P; Zheng, Xiao L; Hou, Wen S

    2015-01-01

    Muscle Co-activation (MCo) is the simultaneous muscular activation of agonist and antagonist muscle groups, which provides adequate joint stability, movement accuracy during movement. Infant crawling is an important stage of motor function development that manifests non-synchronization growth and development of upper and lower limbs due to the well-known gross motor development principle of head to toe. However, the effect of MCo level for agonist and antagonist muscle groups on motor function development of limbs has not been previously reported. In this paper, sEMG signals were collected from triceps brachii (TB) and biceps brachii (BB), quadriceps femoris (QF) and hamstrings (HS) of limbs when fourteen infants were crawling at their self-selected speed. Antagonist muscle co-activation was evaluated by measuring two common indexes (co-activation index and Pearson's correlation coefficient).A significant difference was observed between upper limbs and lower limbs, but the relationship between MCo and speed of crawling was poor. This study is an opening for further investigation including a longitudinal study and compare against infant with CNS disorders.

  13. Comparison of laterality index of upper and lower limb movement using brain activated fMRI

    NASA Astrophysics Data System (ADS)

    Harirchian, Mohammad Hossein; Oghabian, Mohammad Ali; Rezvanizadeh, Alireza; Bolandzadeh, Niousha

    2008-03-01

    Asymmetry of bilateral cerebral function, i.e. laterality, is an important phenomenon in many brain actions such as motor functions. This asymmetry maybe altered in some clinical conditions such as Multiple Sclerosis (MS). The aim of this study was to delineate the laterality differences for upper and lower limbs in healthy subjects to compare this pattern with subjects suffering from MS in advance. Hence 9 Male healthy subjects underwent fMRI assessment, while they were asked to move their limbs in a predetermined pattern. The results showed that hands movement activates the brain with a significant lateralization in pre-motor cortex in comparison with lower limb. Also, dominant hands activate brain more lateralized than the non-dominant hand. In addition, Left basal ganglia were observed to be activated regardless of the hand used, While, These patterns of Brain activation was not detected in lower limbs. We hypothesize that this difference might be attributed to this point that hand is usually responsible for precise and fine voluntary movements, whereas lower limb joints are mainly responsible for locomotion, a function integrating voluntary and automatic bilateral movements.

  14. 75 FR 77047 - Statement on Sound Practices Concerning Elevated Risk Complex Structured Finance Activities

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-12-10

    ... Office of Thrift Supervision Statement on Sound Practices Concerning Elevated Risk Complex Structured.... Title of Proposal: Statement on Sound Practices Concerning Elevated Risk Complex Structured Finance Activities. OMB Number: 1550-0111. Form Number: N/A. Description: Statement on Sound Practices...

  15. The effect of different skin-ankle brace application pressures on quiet single-limb balance and electromyographic activation onset of lower limb muscles

    PubMed Central

    Papadopoulos, Emmanuel S; Nikolopoulos, Christos; Badekas, Athanasios; Vagenas, George; Papadakis, Stamatios A; Athanasopoulos, Spyros

    2007-01-01

    Background Several studies have been carried out in order to investigate the effect of ankle bracing on ankle joint function and performance. However, no study so far has examined the role of skin-brace interface pressure in neuromuscular control. The aim of this study was to investigate the effect of different skin-ankle brace interface pressures on quiet single limb balance and the electromyographic (EMG) activation sequence of four lower limb muscles. Methods Thirty three male physical education students who volunteered to take part in the study were measured under three ankle brace conditions: i) without brace, ii) with brace and 30 kPa application pressure and iii) with brace and 60 kPa application pressure. Single limb balance (anteroposterior and mediolateral parameter) was assessed on the dominant lower limb, with open and closed eyes, on a force platform, simultaneously with the EMG recording of four lower lower limb muscles' (gastrocnemius, peroneus longus, rectus femoris and biceps femoris) activation onset. Results The results showed that overall balance (total stability parameter) was not significantly affected in any of the three ankle brace conditions. However, the anteroposterior centre of pressure excursion and centre of pressure excursion velocity were significantly increased with the application of ankle brace, both with 30 and 60 kPa application pressures. Furthermore, it was found that single limb balance was significantly worse with closed eyes compared to open eyes. EMG measurements showed that the sequence of lower limb activation onset was not affected in any of the three ankle brace application conditions. The results of this study showed that the application of an ankle brace with two different skin-brace interface pressures had no effect on overall single limb balance and the sequence of lower limb muscle activation. Conclusion These findings suggest that peripheral joint receptors are either not adequately stimulated by the brace

  16. Activation of Auditory Cortex by Anticipating and Hearing Emotional Sounds: An MEG Study

    PubMed Central

    Yokosawa, Koichi; Pamilo, Siina; Hirvenkari, Lotta; Hari, Riitta; Pihko, Elina

    2013-01-01

    To study how auditory cortical processing is affected by anticipating and hearing of long emotional sounds, we recorded auditory evoked magnetic fields with a whole-scalp MEG device from 15 healthy adults who were listening to emotional or neutral sounds. Pleasant, unpleasant, or neutral sounds, each lasting for 6 s, were played in a random order, preceded by 100-ms cue tones (0.5, 1, or 2 kHz) 2 s before the onset of the sound. The cue tones, indicating the valence of the upcoming emotional sounds, evoked typical transient N100m responses in the auditory cortex. During the rest of the anticipation period (until the beginning of the emotional sound), auditory cortices of both hemispheres generated slow shifts of the same polarity as N100m. During anticipation, the relative strengths of the auditory-cortex signals depended on the upcoming sound: towards the end of the anticipation period the activity became stronger when the subject was anticipating emotional rather than neutral sounds. During the actual emotional and neutral sounds, sustained fields were predominant in the left hemisphere for all sounds. The measured DC MEG signals during both anticipation and hearing of emotional sounds implied that following the cue that indicates the valence of the upcoming sound, the auditory-cortex activity is modulated by the upcoming sound category during the anticipation period. PMID:24278270

  17. Modification of per- and postrotational responses by voluntary motor activity of the limbs.

    PubMed

    Guedry, F E; Benson, A J

    1983-01-01

    In order to explore interactive effects of voluntarily generated rotational stimuli on evoked vestibular responses, experiments were performed using a rotation chair in which the subject either controlled the angular motion by voluntary movement of his upper and lower limbs, or was passive-rotation being controlled by a servomotor and electromagnetic brake. In two experiments, carried out on 8 and 9 subjects respectively, it was found that cessation of sustained passive rotation by voluntary limb actions strongly suppressed the postrotational turning sensation but did not alter the evoked nystagmus. Limb movements that were directionally concordant with muscle torque in generating body rotation yielded arthrokinetic effects which augmented perrotational nystagmus and sustained the sensation of turning. The postrotational sensation of turning and postrotational nystagmus produced by voluntary cessation of active rotation were reduced relative to responses produced by passive turning and stopping. The Purkinje effect induced by postrotational head movements was similarly reduced following voluntary cessation of active rotation.

  18. Might as Well Jump: Sound Affects Muscle Activation in Skateboarding

    PubMed Central

    Cesari, Paola; Camponogara, Ivan; Papetti, Stefano; Rocchesso, Davide; Fontana, Federico

    2014-01-01

    The aim of the study is to reveal the role of sound in action anticipation and performance, and to test whether the level of precision in action planning and execution is related to the level of sensorimotor skills and experience that listeners possess about a specific action. Individuals ranging from 18 to 75 years of age - some of them without any skills in skateboarding and others experts in this sport - were compared in their ability to anticipate and simulate a skateboarding jump by listening to the sound it produces. Only skaters were able to modulate the forces underfoot and to apply muscle synergies that closely resembled the ones that a skater would use if actually jumping on a skateboard. More importantly we showed that only skaters were able to plan the action by activating anticipatory postural adjustments about 200 ms after the jump event. We conclude that expert patterns are guided by auditory events that trigger proper anticipations of the corresponding patterns of movements. PMID:24619134

  19. Muscle activation patterns during walking from transtibial amputees recorded within the residual limb-prosthetic interface

    PubMed Central

    2012-01-01

    Background Powered lower limb prostheses could be more functional if they had access to feedforward control signals from the user’s nervous system. Myoelectric signals are one potential control source. The purpose of this study was to determine if muscle activation signals could be recorded from residual lower limb muscles within the prosthetic socket-limb interface during walking. Methods We recorded surface electromyography from three lower leg muscles (tibilias anterior, gastrocnemius medial head, gastrocnemius lateral head) and four upper leg muscles (vastus lateralis, rectus femoris, biceps femoris, and gluteus medius) of 12 unilateral transtibial amputee subjects and 12 non-amputee subjects during treadmill walking at 0.7, 1.0, 1.3, and 1.6 m/s. Muscle signals were recorded from the amputated leg of amputee subjects and the right leg of control subjects. For amputee subjects, lower leg muscle signals were recorded from within the limb-socket interface and from muscles above the knee. We quantified differences in the muscle activation profile between amputee and control groups during treadmill walking using cross-correlation analyses. We also assessed the step-to-step inter-subject variability of these profiles by calculating variance-to-signal ratios. Results We found that amputee subjects demonstrated reliable muscle recruitment signals from residual lower leg muscles recorded within the prosthetic socket during walking, which were locked to particular phases of the gait cycle. However, muscle activation profile variability was higher for amputee subjects than for control subjects. Conclusion Robotic lower limb prostheses could use myoelectric signals recorded from surface electrodes within the socket-limb interface to derive feedforward commands from the amputee’s nervous system. PMID:22882763

  20. Active sound reduction: A study of recent developments and some future possibilities

    NASA Astrophysics Data System (ADS)

    Lindqvist, E.

    1983-11-01

    It is suggested that active sound reduction is easiest to implement and most effective at low frequencies and in a duct rather than in a room or a free field. The prospects for success are considerably improved if the sound to be attenuated is periodic. Symmetry of the sound field can sometimes be exploited. The physical mechanisms of sound attenuation include reflection of sound by secondary sources, creation of higher order sources in order to reduce the energy radiated and conversion of acoustic energy. Active techniques can also be applied to prevent transmission of sound or vibrations from one sub-field to another. Microelectronics and digital filtering techniques are expected to greatly influence active sound attenuators.

  1. Ambulatory activity classification with dendogram-based support vector machine: Application in lower-limb active exoskeleton.

    PubMed

    Mazumder, Oishee; Kundu, Ananda Sankar; Lenka, Prasanna Kumar; Bhaumik, Subhasis

    2016-10-01

    Ambulatory activity classification is an active area of research for controlling and monitoring state initiation, termination, and transition in mobility assistive devices such as lower-limb exoskeletons. State transition of lower-limb exoskeletons reported thus far are achieved mostly through the use of manual switches or state machine-based logic. In this paper, we propose a postural activity classifier using a 'dendogram-based support vector machine' (DSVM) which can be used to control a lower-limb exoskeleton. A pressure sensor-based wearable insole and two six-axis inertial measurement units (IMU) have been used for recognising two static and seven dynamic postural activities: sit, stand, and sit-to-stand, stand-to-sit, level walk, fast walk, slope walk, stair ascent and stair descent. Most of the ambulatory activities are periodic in nature and have unique patterns of response. The proposed classification algorithm involves the recognition of activity patterns on the basis of the periodic shape of trajectories. Polynomial coefficients extracted from the hip angle trajectory and the centre-of-pressure (CoP) trajectory during an activity cycle are used as features to classify dynamic activities. The novelty of this paper lies in finding suitable instrumentation, developing post-processing techniques, and selecting shape-based features for ambulatory activity classification. The proposed activity classifier is used to identify the activity states of a lower-limb exoskeleton. The DSVM classifier algorithm achieved an overall classification accuracy of 95.2%.

  2. Bioelectrical activity of limb muscles during cold shivering of stimulation of the vestibular apparatus

    NASA Technical Reports Server (NTRS)

    Kuzmina, G. I.

    1980-01-01

    The effects of caloric and electric stimulation of the vestibular receptors on the EMG activity of limb muslces in anesthetized cats during cold induced shivering involved flexor muscles alone. Both types of stimulation suppressed bioelectrical activity more effectively in the ipsilateral muscles. The suppression of shivering activity seems to be due to the increased inhibitory effect of descending labyrinth pathways on the function of flexor motoneurons.

  3. Analyzing Activities in the Course of Science Education, According to Activity Theory: The Case of Sound

    ERIC Educational Resources Information Center

    Theodoraki, Xarikleia; Plakitsi, Katerina

    2013-01-01

    In the present study, we analyze activities on the topic of sound, which are performed in the science education laboratory lessons in the third-year students of the Department of Early Childhood Education at the University of Ioannina. The analysis of the activities is based on one of the most modern learning theories of CHAT (Cultural Historical…

  4. Application of subharmonics for active sound design of electric vehicles.

    PubMed

    Gwak, Doo Young; Yoon, Kiseop; Seong, Yeolwan; Lee, Soogab

    2014-12-01

    The powertrain of electric vehicles generates an unfamiliar acoustical environment for customers. This paper seeks optimal interior sound for electric vehicles based on psychoacoustic knowledge and musical harmonic theory. The concept of inserting a virtual sound, which consists of the subharmonics of an existing high-frequency component, is suggested to improve sound quality. Subjective evaluation results indicate that the impression of interior sound can be enhanced in this manner. Increased appeal is achieved through two designed stimuli, which proves the effectiveness of the method proposed.

  5. Ensemble statistics of active and reactive sound intensity in reverberation rooms.

    PubMed

    Jacobsen, Finn; Molares, Alfonso Rodríguez

    2011-01-01

    This paper examines fundamental statistical properties of the active and reactive sound intensity in reverberant enclosures driven with pure tones. The existing theory for sound intensity in a diffuse sound field, which is based on Waterhouse's random wave model and therefore limited to the region of high modal overlap, is extended to the region of low modal overlap by taking account of the random fluctuations of the sound power emitted by the source that generates the sound field. The validity of the extended model is confirmed by experimental and numerical results.

  6. Shh pathway activation is present and required within the vertebrate limb bud apical ectodermal ridge for normal autopod patterning.

    PubMed

    Bouldin, Cortney M; Gritli-Linde, Amel; Ahn, Sohyun; Harfe, Brian D

    2010-03-23

    Expression of Sonic Hedgehog (Shh) in the posterior mesenchyme of the developing limb bud regulates patterning and growth of the developing limb by activation of the Hedgehog (Hh) signaling pathway. Through the analysis of Shh and Hh signaling target genes, it has been shown that activation in the limb bud mesoderm is required for normal limb development to occur. In contrast, it has been stated that Hh signaling in the limb bud ectoderm cannot occur because components of the Hh signaling pathway and Hh target genes have not been found in this tissue. However, recent array-based data identified both the components necessary to activate the Hh signaling pathway and targets of this pathway in the limb bud ectoderm. Using immunohistochemistry and various methods of detection for targets of Hh signaling, we found that SHH protein and targets of Hh signaling are present in the limb bud ectoderm including the apex of the bud. To directly test whether ectodermal Hh signaling was required for normal limb patterning, we removed Smo, an essential component of the Hh signaling pathway, from the apical ectodermal ridge (AER). Loss of functional Hh signaling in the AER resulted in disruption of the normal digit pattern and formation of additional postaxial cartilaginous condensations. These data indicate that contrary to previous accounts, the Hh signaling pathway is present and required in the developing limb AER for normal autopod development.

  7. Peak activation of lower limb musculature during high flexion kneeling and transitional movements.

    PubMed

    Kingston, David C; Tennant, Liana M; Chong, Helen C; Acker, Stacey M

    2016-09-01

    Few studies have measured lower limb muscle activation during high knee flexion or investigated the effects of occupational safety footwear. Therefore, our understanding of injury and disease mechanisms, such as knee osteoarthritis, is limited for these high-risk postures. Peak activation was assessed in eight bilateral lower limb muscles for twelve male participants, while shod or barefoot. Transitions between standing and kneeling had peak quadriceps and tibialis anterior (TA) activations above 50% MVC. Static kneeling and simulated tasks performed when kneeling had peak TA activity above 15% MVC but below 10% MVC for remaining muscles. In three cases, peak muscle activity was significantly higher (mean 8.9% MVC) when shod. However, net compressive knee joint forces may not be significantly increased when shod. EMG should be used as a modelling input when estimating joint contact forces for these postures, considering the activation levels in the hamstrings and quadriceps muscles during transitions. Practitioner Summary: Kneeling transitional movements are used in activities of daily living and work but are linked to increased knee osteoarthritis risk. We found peak EMG activity of some lower limb muscles to be over 70% MVC during transitions and minimal influence of wearing safety footwear.

  8. Quadratic Optimization in the Problems of Active Control of Sound

    NASA Technical Reports Server (NTRS)

    Loncaric, J.; Tsynkov, S. V.; Bushnell, Dennis M. (Technical Monitor)

    2002-01-01

    We analyze the problem of suppressing the unwanted component of a time-harmonic acoustic field (noise) on a predetermined region of interest. The suppression is rendered by active means, i.e., by introducing the additional acoustic sources called controls that generate the appropriate anti-sound. Previously, we have obtained general solutions for active controls in both continuous and discrete formulations of the problem. We have also obtained optimal solutions that minimize the overall absolute acoustic source strength of active control sources. These optimal solutions happen to be particular layers of monopoles on the perimeter of the protected region. Mathematically, minimization of acoustic source strength is equivalent to minimization in the sense of L(sub 1). By contrast. in the current paper we formulate and study optimization problems that involve quadratic functions of merit. Specifically, we minimize the L(sub 2) norm of the control sources, and we consider both the unconstrained and constrained minimization. The unconstrained L(sub 2) minimization is certainly the easiest problem to address numerically. On the other hand, the constrained approach allows one to analyze sophisticated geometries. In a special case, we call compare our finite-difference optimal solutions to the continuous optimal solutions obtained previously using a semi-analytic technique. We also show that the optima obtained in the sense of L(sub 2) differ drastically from those obtained in the sense of L(sub 1).

  9. Impairment variables predicting activity limitation in individuals with lower limb amputation.

    PubMed

    Raya, Michele A; Gailey, Robert S; Fiebert, Ira M; Roach, Kathyrn E

    2010-03-01

    The purpose of this study was to determine whether measures of impairment (i.e., muscle strength, balance), personal factors (i.e., comorbidities, demographic information) and amputation specific variables (i.e., time since amputation, cause of amputation, level of amputation) were able to predict performance on the six-minute walk test, a measure of activity limitation, in individuals with lower limb amputation. A total of 72 individuals with lower limb amputation ranging in age from 21-83 were tested for balance, limb muscle strength and function. Medical comorbidities were recorded and activity limitation was measured using the six-minute walk test. Data were analyzed and multivariate relationships were examined using multiple linear regression. Impairment variables of strength, balance, subject demographics, time since amputation, cause of amputation and level of amputation were all significant predictors and explained 72% of the variance in the outcome variable. Strength of the hip extensors was the strongest predictor, accounting for 30.9% of the total variance. Multiple factors impact six minute walk scores in individuals with lower limb amputation. Impairments in hip strength and balance appear to be the two most significant. The findings of this study support the use of the six-minute walk test to underscore impairments of the musculoskeletal system that can affect ambulation ability in the amputee.

  10. Activity-related energy expenditure during lower limb cast immobilization in children.

    PubMed

    Maggio, Albane B; Martin, Xavier E; Ceroni, Dimitri

    2017-05-01

    Physical inactivity, which may result from immobilization, is recognized as a risk factor for the development of obesity. We aimed to quantify the decrease in activity-related energy expenditure (AEE) because of lower limb cast immobilization. We carried out a longitudinal matched case-control study: 34 adolescents with a first episode of lower limb fracture and 34 healthy cases. Physical activity was assessed during cast immobilization by an accelerometer from which we calculated the decrease in AEE. AEE in adolescents with lower limb fractures was estimated to be 16.0% lower than healthy controls. When converted into kcal per mean participants' weight, the difference in AEE amounted to 125 kcal/day, which corresponds to 5.2 h of slow walking. A significant reduction of AEE in adolescents with lower limb fractures may lead to a significantly positive energy balance as there is usually no compensatory reduction of energy intake. An increase of walking seems unrealistic in this situation and patients should be advised at the emergency unit to reduce their energy intake during the immobilization period.

  11. Custom design in lower limb prosthetics for athletic activity.

    PubMed

    Fergason, J R; Boone, D A

    2000-08-01

    In summary, the prosthetist is the best source of information with regard to the fast-changing lower extremity prosthetics technology for sports. The needs and desires of the amputee should be outlined and balanced with the cost of the desired components and design. In many cases, one carefully designed prosthesis can serve in dual roles for everyday ambulation and certain athletic activities. In other cases, the amputee is limited severely by a prosthesis that is not designed for a specific activity. Using a prosthesis for activities that it was not designed to accommodate can cause physical injury to the amputee as well as structural failure of the device. A properly designed and fitted prosthesis can open a whole new world of activity to the amputee and helps him or her to reach the desired a vocational goals.

  12. Comparison of stratospheric air parcel trajectories calculated from SSU and LIMS satellite data. [Stratospheric Sounding Unit/Limb Infrared Monitor of Stratosphere

    NASA Technical Reports Server (NTRS)

    Austin, J.

    1986-01-01

    Midstratospheric trajectories for February and March 1979 are calculated using geopotential analyses derived from limb infrared monitor of the stratosphere data. These trajectories are compared with the corresponding results using stratospheric sounding unit data. The trajectories are quasi-isentropic in that a radiation scheme is used to simply cross-isentrope flow. The results show that in disturbed conditions, quantitative agreement the trajectories, that is, within 25 great circle degrees (GCD) (one GCD about 110 km) may be valid for only 3 or 4 days, whereas during quiescent periods, quantitative agreement may last up to 10 days. By comparing trajectories calculated with different data some insight can be gained as to errors due to vertical resolution and horizontal resolution (due to infrequent sampling) in the analyzed geopotential height fields. For the disturbed trajectories described in this paper the horizontal resolution of the data was more important than vertical resolution; however, for the quiescent trajectories, which could be calculated accurately for a longer duration because of the absence of appreciable transients, the vertical resolution of the data was found to be more important than the horizontal resolution. It is speculated that these characteristics are also applicable to trajectories calculated during disturbed and quiescent periods in general. A review of some recently published trajectories shows that the qualitative conclusions of such works remains unaffected when the calculations are repeated using different data.

  13. Motor area activity for action-related and nonaction-related sounds in a three-dimensional sound field reproduction system.

    PubMed

    Tsuchida, Koichiro; Ueno, Kanako; Shimada, Sotaro

    2015-03-25

    The motor cortical area is often activated to auditory stimuli in the human brain. In this study, we examined whether the motor area shows differential activation for action-related and nonaction-related sounds and whether it is susceptible to the quality of the sounds. A three-dimensional sound field recording and reproduction system based on the boundary surface control principle (BoSC system) was used for this purpose. We measured brain activity during hearing action-related or nonaction-related sounds with electroencephalography using mu rhythm suppression (mu-suppression) as an index of motor cortical activation. The results showed that mu-suppression was observed when the participant heard action-related sounds, but it was not evident when hearing nonaction-related sounds. Moreover, this suppression was significantly larger in the 3D sound field (62-ch loudspeaker condition), which generates a more realistic sound field, than in the 1-ch loudspeaker condition. Our results indicate that the motor area was indeed activated for action-related sounds and that its activation was enhanced with a 3D realistic sound field. We discuss our findings in relation to the mirror neuron system and the possibility of using its activity as an objective measure that reflects the subjective sense of reality in various virtual reality settings when interacting with others.

  14. Staying in dynamic balance on a prosthetic limb: A leg to stand on?

    PubMed

    Curtze, Carolin; Hof, At L; Postema, Klaas; Otten, Bert

    2016-06-01

    With the loss of a lower limb, amputees lack the active muscle empowered control of the ankle that is important for balance control. We examined single-leg stance on prosthesis vs. sound limb balancing on narrow ridges in transtibial amputees. When balancing on the prosthetic limb, the lateral displacement of the center of pressure was reduced and was compensated by an increase in counter-rotation. We show that single-leg stance on a prosthetic limb can be compared to balancing on a narrow ridge. Standing on a prosthetic limb involves the same balance mechanisms as balancing on narrow ridges of 40-mm to 20-mm width. Yet, the ability to balance on a narrow ridge with the sound limb was only a weak predictor for an amputee's ability to stand on the prosthetic limb. Balancing in single-leg stance on a prosthetic limb is not a common activity. The ability to compensate with the sound limb may therefore be functionally more important than the ability to stay in dynamic balance on the prosthetic limb.

  15. Upper Limb Muscle and Brain Activity in Light Assembly Task on Different Load Levels

    NASA Astrophysics Data System (ADS)

    Zadry, Hilma Raimona; Dawal, Siti Zawiah Md.; Taha, Zahari

    2010-10-01

    A study was conducted to investigate the effect of load on upper limb muscles and brain activities in light assembly task. The task was conducted at two levels of load (Low and high). Surface electromyography (EMG) was used to measure upper limb muscle activities of twenty subjects. Electroencephalography (EEG) was simultaneously recorded with EMG to record brain activities from Fz, Pz, O1 and O2 channels. The EMG Mean Power Frequency (MPF) of the right brachioradialis and the left upper trapezius activities were higher on the high-load task compared to low-load task. The EMG MPF values also decrease as time increases, that reflects muscle fatigue. Mean power of the EEG alpha bands for the Fz-Pz channels were found to be higher on the high-load task compared to low-load task, while for the O1-O2 channels, they were higher on the low-load task than on the high-load task. These results indicated that the load levels effect the upper limb muscle and brain activities. The high-load task will increase muscle activities on the right brachioradialis and the left upper tapezius muscles, and will increase the awareness and motivation of the subjects. Whilst the low-load task can generate drowsiness earlier. It signified that the longer the time and the more heavy of the task, the subjects will be more fatigue physically and mentally.

  16. Chemical activation of Wnt/β-catenin signalling inhibits innervation and causes skeletal tissue malformations during axolotl limb regeneration.

    PubMed

    Wischin, Sabina; Castañeda-Patlán, Cristina; Robles-Flores, Martha; Chimal-Monroy, Jesús

    2017-02-03

    Limb regeneration involves several interrelated physiological processes in which a particular signalling pathway may play a variety of functions. Blocking the function of Wnt/β-catenin signalling during limb regeneration inhibits regeneration in axolotls (Ambystoma mexicanum). Limb development shares many features with limb regeneration, and Wnt/β-catenin activation has different effects depending on the developmental stage. The aim of this study was to evaluate whether Wnt/β-catenin signalling activation during axolotl limb regeneration has different effects when activated at different stages of regeneration. To evaluate this hypothesis, we treated amputated axolotls with a Wnt agonist chemical at different stages of limb regeneration. The results showed that limb regeneration was inhibited when the treatment began before blastema formation. Under these conditions, blastema formation was hindered, possibly due to the lack of innervation. On the other hand, when axolotls were treated after blastema formation and immediately before the onset of morphogenesis, we observed structural disorganization in skeletal formation. In conclusion, we found that limb regeneration was differentially affected depending on the stage at which the Wnt signalling pathway was activated.

  17. Differential actigraphy for monitoring asymmetry in upper limb motor activities.

    PubMed

    Rabuffetti, M; Meriggi, P; Pagliari, C; Bartolomeo, P; Ferrarin, M

    2016-09-21

    Most applications of accelerometry-based actigraphy require a single sensor, properly located onto the body, to estimate, for example, the level of activity or the energy expenditure. Some approaches adopt a multi-sensor setup to improve those analyses or to classify different types of activity. The specific case of two symmetrically placed actigraphs allowing, by some kind of differential analysis, for the assessment of asymmetric motor behaviors, has been considered in relatively few studies. This article presents a novel method for differential actigraphy, which requires the synchronized measurements of two triaxial accelerometers (programmable eZ430-Chronos, Texas Instruments, USA) placed symmetrically on both wrists. The method involved the definition of a robust epoch-related activity index and its implementation on-board the adopted programmable platform. Finally, the activity recordings from both sensors allowed us to define a novel asymmetry index AR24 h ranging from  -100% (only the left arm moves) to  +100% (only the right arm moves) with null value marking a perfect symmetrical behavior. The accuracy of the AR24 h index was 1.3%. Round-the-clock monitoring on 31 healthy participants (20-79 years old, 10 left handed) provided for the AR24 h reference data (range  -5% to 21%) and a fairly good correlation to the clinical handedness index (r  =  0.66, p  <  0.001). A subset of 20 participants repeated the monitoring one week apart evidencing an excellent test-retest reliability (r  =  0.70, p  <  0.001). Such figures support future applications of the methodology for the study of pathologies involving motor asymmetries, such as in patients with motor hemisyndromes and, in general, for those subjects for whom a quantification of the asymmetry in daily motor performances is required to complement laboratory tests.

  18. Issues in Humanoid Audition and Sound Source Localization by Active Audition

    NASA Astrophysics Data System (ADS)

    Nakadai, Kazuhiro; Okuno, Hiroshi G.; Kitano, Hiroaki

    In this paper, we present an active audition system which is implemented on the humanoid robot "SIG the humanoid". The audition system for highly intelligent humanoids localizes sound sources and recognizes auditory events in the auditory scene. Active audition reported in this paper enables SIG to track sources by integrating audition, vision, and motor movements. Given the multiple sound sources in the auditory scene, SIG actively moves its head to improve localization by aligning microphones orthogonal to the sound source and by capturing the possible sound sources by vision. However, such an active head movement inevitably creates motor noises.The system adaptively cancels motor noises using motor control signals and the cover acoustics. The experimental result demonstrates that active audition by integration of audition, vision, and motor control attains sound source tracking in variety of conditions.onditions.

  19. The evolution of lineage-specific regulatory activities in the human embryonic limb.

    PubMed

    Cotney, Justin; Leng, Jing; Yin, Jun; Reilly, Steven K; DeMare, Laura E; Emera, Deena; Ayoub, Albert E; Rakic, Pasko; Noonan, James P

    2013-07-03

    The evolution of human anatomical features likely involved changes in gene regulation during development. However, the nature and extent of human-specific developmental regulatory functions remain unknown. We obtained a genome-wide view of cis-regulatory evolution in human embryonic tissues by comparing the histone modification H3K27ac, which provides a quantitative readout of promoter and enhancer activity, during human, rhesus, and mouse limb development. Based on increased H3K27ac, we find that 13% of promoters and 11% of enhancers have gained activity on the human lineage since the human-rhesus divergence. These gains largely arose by modification of ancestral regulatory activities in the limb or potential co-option from other tissues and are likely to have heterogeneous genetic causes. Most enhancers that exhibit gain of activity in humans originated in mammals. Gains at promoters and enhancers in the human limb are associated with increased gene expression, suggesting they include molecular drivers of human morphological evolution.

  20. Quasi-3DOF Active / Passive Hybrid Rehabilitation System for Upper Limbs: "Hybrid-PLEMO"

    NASA Astrophysics Data System (ADS)

    Kikuchi, Takehito; Furusho, Junji; Jin, Ying; Fukushima, Kazuki; Akai, Hiroki

    Many kinds of actuator-based (active type) haptic device have developed and utilized as rehabilitation robots. These systems have great advantages for rehabilitative activities, for example assistive forces and so on. However, from the view point of safety, we have room to consider utilizing brake-based (passive type) haptic devices as rehabilitation-tools. The effects and roles of active / passive force feedback for rehabilitative trainings have not been clarified yet. In this study, we have developed an active / passive switchable rehabilitation system for upper limbs (Hybrid-PLEMO) to address these questions. In this paper, we describe the force-feedback mechanism of the Hybrid-PLEMO.

  1. Agency over a phantom limb and electromyographic activity on the stump depend on visuomotor synchrony: a case study.

    PubMed

    Imaizumi, Shu; Asai, Tomohisa; Kanayama, Noriaki; Kawamura, Mitsuru; Koyama, Shinichi

    2014-01-01

    Most patients, post-amputation, report the experience of a phantom limb. Some even sense voluntary movements when viewing a mirror image of the intact limb superimposed onto the phantom limb. While delayed visual feedback of an action is known to reduce a sense of agency, the effect of delayed visual feedback on phantom motor sensation (i.e., sense of controlling a phantom limb) has not been examined. Using a video-projection system, we examined the effect of delayed visual feedback on phantom motor sensation in an upper-limb amputee (male; left upper-limb amputation). He was instructed to view mirrored video images of his intact hand clasping and unclasping during a phantom limb movement. He then rated the intensity of the phantom motor sensation. Three types of hand movement images were presented as follows: synchronous, asynchronous with a 250-ms delay, and asynchronous with a 500-ms delay. Results showed that phantom motor sensation decreased when the image was delayed by 250 and 500 ms. However, when we instructed the patient to adjust the phase of phantom limb movement to that of the image with a 500-ms delay, phantom motor sensation increased. There was also a positive correlation between intensity of phantom motor sensation and electromyographic (EMG) activity on deltoids at the patient's stump. These results suggest that phantom motor sensation and EMG activity on the stump depend on visuomotor synchrony and top-down effects.

  2. Intra-session repeatability of lower limb muscles activation pattern during pedaling.

    PubMed

    Dorel, Sylvain; Couturier, Antoine; Hug, François

    2008-10-01

    Assessment of intra-session repeatability of muscle activation pattern is of considerable relevance for research settings, especially when used to determine changes over time. However, the repeatability of lower limb muscles activation pattern during pedaling is not fully established. Thus, we tested the intra-session repeatability of the activation pattern of 10 lower limb muscles during a sub-maximal cycling exercise. Eleven triathletes participated to this study. The experimental session consisted in a reference sub-maximal cycling exercise (i.e. 150 W) performed before and after a 53-min simulated training session (mean power output=200+/-12 W). Repeatability of EMG patterns was assessed in terms of muscle activity level (i.e. RMS of the mean pedaling cycle and burst) and muscle activation timing (i.e. onset and offset of the EMG burst) for the 10 following lower limb muscles: gluteus maximus (GMax), semimembranosus (SM), Biceps femoris (BF), vastus medialis (VM), rectus femoris (RF), vastus lateralis (VL), gastrocnemius medianus (GM) and lateralis (GL), soleus (SOL) and tibialis anterior (TA). No significant differences concerning the muscle activation level were found between test and retest for all the muscles investigated. Only VM, SOL and TA showed significant differences in muscle activation timing parameters. Whereas ICC and SEM values confirmed this weak repeatability, cross-correlation coefficients suggest a good repeatability of the activation timing parameters for all the studied muscles. Overall, the main finding of this work is the good repeatability of the EMG pattern during pedaling both in term of muscle activity level and muscle activation timing.

  3. Limb and back muscle activity adaptations to tripedal locomotion in dogs.

    PubMed

    Fuchs, Aniela; Anders, Alexandra; Nolte, Ingo; Schilling, Nadja

    2015-10-01

    Alterations in muscle recruitment are key to the functional plasticity of the mammalian locomotor system. One particularly challenging situation quadrupeds may face is when the functionality of a limb is reduced or lost. To better understand how mammals manage in such situations and which muscular adaptations they exhibit when locomoting on three legs, we recorded the activity patterns of two limb and one back extensor muscle in nine dogs using surface electromyography. We compared the timing and the level of recruitment before and after the loss of a hindlimb was simulated. Both the intensity and the timing of the activity changed significantly in the m. vastus lateralis of the remaining hindlimb, consistent with this limb bearing a greater proportion of the body weight as well as with previously reported kinematic changes. In accordance with the greater body weight supported by the forelimbs, the m. triceps brachii showed first and foremost an increased level of excitation. The very asymmetrical changes in the timing and the level of activity in the m. longissimus dorsi reflects the highly asymmetrical functional requirements imposed on the trunk and the pelvis when one hindlimb is no longer involved in the production of locomotor work while the other hindlimb partially compensates the loss. Integration of our electromyographical findings with kinetic and kinematic results illustrates that dogs exhibited a well-coordinated response to the functional requirements of tripedalism and underlines the importance of moment-to-moment modulation in muscular recruitment for the functional plasticity of the mammalian locomotor system.

  4. Selection and preparation of hand and foot movements: Cz activity as a marker of limb system preparation.

    PubMed

    Miller, Jeff

    2012-05-01

    Event-related potentials were used to examine the preparation of hand and foot responses in tasks using both limb systems. As in tasks using only one system, opposite lateralized readiness potentials were observed for hand and foot responses (Experiment 1). Furthermore, movement-related activity at Cz was more positive prior to hand than foot responses, revealing that Cz activity can be used to index selective movement preparation by one limb system. In Experiment 2, two responses were cued prior to stimulus onset. Cue-related activity at Cz was more positive with hand than foot cuing, reinforcing the conclusion that Cz activity is sensitive to selective preparation for one of these limb systems. Overall, the results show that it is possible to carry out motor preparation of two responses within the same limb system and that differential Cz activity is a useful index of this preparation in tasks with hand versus foot movements.

  5. Relations among pure-tone sound stimuli, neural activity, and the loudness sensation

    NASA Technical Reports Server (NTRS)

    Howes, W. L.

    1972-01-01

    Both the physiological and psychological responses to pure-tone sound stimuli are used to derive formulas which: (1) relate the loudness, loudness level, and sound-pressure level of pure tones; (2) apply continuously over most of the acoustic regime, including the loudness threshold; and (3) contain no undetermined coefficients. Some of the formulas are fundamental for calculating the loudness of any sound. Power-law formulas relating the pure-tone sound stimulus, neural activity, and loudness are derived from published data.

  6. Differential Activity-Dependent Development of Corticospinal Control of Movement and Final Limb Position During Visually Guided Locomotion

    PubMed Central

    Friel, K. M.; Drew, T.; Martin, J. H.

    2009-01-01

    Although we understand that activity- and use-dependent processes are important in determining corticospinal axon terminal development in the spinal cord, little is known about the role of these processes in development of skilled control of limb movements. In the present study we determined the effects of unilateral motor cortex activity blockade produced by muscimol infusion during the corticospinal axon terminal refinement period, between postnatal weeks 5–7, on visually guided locomotion. We examined stepping and forepaw placement on the rungs of a horizontal ladder and gait modifications as animals stepped over obstacles during treadmill walking. When cats traversed the horizontal ladder, the limb contralateral to inactivation was placed significantly farther forward on the rungs than the ipsilateral limb, indicating defective endpoint control. Similarly, when animals stepped over obstacles on a treadmill, the contralateral limb was placed farther in front of the obstacle, but only when it was the first (i.e., leading) limb to step over the obstacle, not when it was the second (i.e., trailing) limb. This is also indicative of an endpoint control deficit. In contrast, neither during ladder walking, nor when stepping over obstacles on the treadmill, was there any consistent evidence for a major impairment in limb trajectory. These results point to distinct and possibility independent corticospinal mechanisms for movement trajectory control and endpoint control. Although corticospinal activity during early postnatal development is needed to refine circuits for accurate endpoint control, this activity-dependent refinement is not needed for movement trajectory control. PMID:17376849

  7. Different categories of living and non-living sound-sources activate distinct cortical networks.

    PubMed

    Engel, Lauren R; Frum, Chris; Puce, Aina; Walker, Nathan A; Lewis, James W

    2009-10-01

    With regard to hearing perception, it remains unclear as to whether, or the extent to which, different conceptual categories of real-world sounds and related categorical knowledge are differentially represented in the brain. Semantic knowledge representations are reported to include the major divisions of living versus non-living things, plus more specific categories including animals, tools, biological motion, faces, and places-categories typically defined by their characteristic visual features. Here, we used functional magnetic resonance imaging (fMRI) to identify brain regions showing preferential activity to four categories of action sounds, which included non-vocal human and animal actions (living), plus mechanical and environmental sound-producing actions (non-living). The results showed a striking antero-posterior division in cortical representations for sounds produced by living versus non-living sources. Additionally, there were several significant differences by category, depending on whether the task was category-specific (e.g. human or not) versus non-specific (detect end-of-sound). In general, (1) human-produced sounds yielded robust activation in the bilateral posterior superior temporal sulci independent of task. Task demands modulated activation of left lateralized fronto-parietal regions, bilateral insular cortices, and sub-cortical regions previously implicated in observation-execution matching, consistent with "embodied" and mirror-neuron network representations subserving recognition. (2) Animal action sounds preferentially activated the bilateral posterior insulae. (3) Mechanical sounds activated the anterior superior temporal gyri and parahippocampal cortices. (4) Environmental sounds preferentially activated dorsal occipital and medial parietal cortices. Overall, this multi-level dissociation of networks for preferentially representing distinct sound-source categories provides novel support for grounded cognition models that may underlie

  8. Different categories of living and non-living sound-sources activate distinct cortical networks

    PubMed Central

    Engel, Lauren R.; Frum, Chris; Puce, Aina; Walker, Nathan A.; Lewis, James W.

    2009-01-01

    With regard to hearing perception, it remains unclear as to whether, or the extent to which, different conceptual categories of real-world sounds and related categorical knowledge are differentially represented in the brain. Semantic knowledge representations are reported to include the major divisions of living versus non-living things, plus more specific categories including animals, tools, biological motion, faces, and places—categories typically defined by their characteristic visual features. Here, we used functional magnetic resonance imaging (fMRI) to identify brain regions showing preferential activity to four categories of action sounds, which included non-vocal human and animal actions (living), plus mechanical and environmental sound-producing actions (non-living). The results showed a striking antero-posterior division in cortical representations for sounds produced by living versus non-living sources. Additionally, there were several significant differences by category, depending on whether the task was category-specific (e.g. human or not) versus non-specific (detect end-of-sound). In general, (1) human-produced sounds yielded robust activation in the bilateral posterior superior temporal sulci independent of task. Task demands modulated activation of left-lateralized fronto-parietal regions, bilateral insular cortices, and subcortical regions previously implicated in observation-execution matching, consistent with “embodied” and mirror-neuron network representations subserving recognition. (2) Animal action sounds preferentially activated the bilateral posterior insulae. (3) Mechanical sounds activated the anterior superior temporal gyri and parahippocampal cortices. (4) Environmental sounds preferentially activated dorsal occipital and medial parietal cortices. Overall, this multi-level dissociation of networks for preferentially representing distinct sound-source categories provides novel support for grounded cognition models that may

  9. Characteristics of the muscle activities of the elderly for various pressures in the pneumatic actuator of lower limb orthosis

    NASA Astrophysics Data System (ADS)

    Kim, Kyong; Yu, Chang-Ho; Kwon, Tae-Kyu; Hong, Chul-Un; Kim, Nam-Gyun

    2005-12-01

    There developed a lower limb orthosis with a pneumatic rubber actuator, which can assist and improve the muscular activities in the lower limb of the elderly. For this purpose, the characteristics of the lower limbs muscle activities for various pressures in the pneumatic actuator for the lower limb orthosis was investigated. To find out the characteristics of the muscle activities for various pneumatic pressures, it analyzed the flexing and extending movement of the knees, and measured the lower limbs muscular power. The subjects wearing the lower limbs orthosis were instructed to perform flexing and extending movement of the knees. The variation in the air pressure of the pneumatic actuator was varies from one kgf/cm2 to four kgf/cm2. The muscular power was measured by monitoring electromyogram using MP100 (BIOPAC Systems, Inc.) and detailed three-dimensional motions of the lower limbs were collected by APAS 3D Motion Analysis system. Through this study, it expected to find the most suitable air pressure for the improvement of the muscular power of the aged.

  10. Residual limb skin temperature and thermal comfort in people with amputation during activity in a cold environment.

    PubMed

    Segal, Ava D; Klute, Glenn K

    2016-01-01

    Thermal comfort remains a common problem for people with lower-limb amputation. Both donning a prosthesis and engaging in activity at room temperature can increase residual limb skin temperature; however, the effects of activity on skin temperature and comfort in more extreme environments remain unknown. We examined residual limb skin temperatures and perceived thermal comfort (PTC; 11-point Likert scale) of participants with unilateral transtibial amputation (n = 8) who were snowshoeing in a cold environment. Residual limb skin temperature increased by 3.9°C [3.0°C to 4.7°C] (mean difference [95% confidence interval (CI)], p < 0.001) after two 30 min exercise sessions separated by a 5 min rest session. Minimal cooling (-0.2°C [-1.1°C to 0.6°C]) occurred during the rest period. Similar changes in PTC were found for the residual limb, intact limb, and whole body, with a mean scale increase of 1.6 [1.1 to 2.1] and 1.3 [0.8 to 1.8] for the first and second exercise sessions, respectively (p < 0.001). Activity in a cold environment caused similar increases in residual limb skin temperature as those found in studies conducted at room temperature. Participants with amputation perceived warming as their skin temperature increased during exercise followed by the perception of cooling during rest, despite minimal associated decreases in skin temperature.

  11. Inexpensive Audio Activities: Earbud-based Sound Experiments

    NASA Astrophysics Data System (ADS)

    Allen, Joshua; Boucher, Alex; Meggison, Dean; Hruby, Kate; Vesenka, James

    2016-11-01

    Inexpensive alternatives to a number of classic introductory physics sound laboratories are presented including interference phenomena, resonance conditions, and frequency shifts. These can be created using earbuds, economical supplies such as Giant Pixie Stix® wrappers, and free software available for PCs and mobile devices. We describe two interference laboratories (beat frequency and two-speaker interference) and two resonance laboratories (quarter- and half-wavelength). Lastly, a Doppler laboratory using rotating earbuds is explained. The audio signal captured by all experiments is analyzed on free spectral analysis software and many of the experiments incorporate the unifying theme of measuring the speed of sound in air.

  12. Performance of active feedforward control systems in non-ideal, synthesized diffuse sound fields.

    PubMed

    Misol, Malte; Bloch, Christian; Monner, Hans Peter; Sinapius, Michael

    2014-04-01

    The acoustic performance of passive or active panel structures is usually tested in sound transmission loss facilities. A reverberant sending room, equipped with one or a number of independent sound sources, is used to generate a diffuse sound field excitation which acts as a disturbance source on the structure under investigation. The spatial correlation and coherence of such a synthesized non-ideal diffuse-sound-field excitation, however, might deviate significantly from the ideal case. This has consequences for the operation of an active feedforward control system which heavily relies on the acquisition of coherent disturbance source information. This work, therefore, evaluates the spatial correlation and coherence of ideal and non-ideal diffuse sound fields and considers the implications on the performance of a feedforward control system. The system under consideration is an aircraft-typical double panel system, equipped with an active sidewall panel (lining), which is realized in a transmission loss facility. Experimental results for different numbers of sound sources in the reverberation room are compared to simulation results of a comparable generic double panel system excited by an ideal diffuse sound field. It is shown that the number of statistically independent noise sources acting on the primary structure of the double panel system depends not only on the type of diffuse sound field but also on the sample lengths of the processed signals. The experimental results show that the number of reference sensors required for a defined control performance exhibits an inverse relationship to control filter length.

  13. Magnocellular red nucleus activity during different types of limb movement in the macaque monkey.

    PubMed Central

    Gibson, A R; Houk, J C; Kohlerman, N J

    1985-01-01

    Three hundred and thirty-four neurones located in the magnocellular division of red nucleus (r.n.m.) were studied in three alert macaque monkeys. These cells had low discharge rates at rest and produced high frequency bursts during movement. Single cells were selectively active for movement of one body part, and a motor somatotopy was evident. From dorsal to ventral we encountered cells related to movements of the face, contralateral upper limb, contralateral lower limb and, in one case, the tail. Free-form tests indicated that 76% of upper-limb cells were preferentially related to hand and finger movements, and 84% of lower limb cells were preferentially related to foot and toe movements. Quantitative tests of movement relations were based on depths of modulation in discharge rate recorded while the monkeys operated several devices that served as manipulanda in a tracking task; each device elicited a different movement. We conducted 220 tests on eighty-one cells using eleven devices. The modulation in discharge rate exceeded a 50 pulses/s criterion level in seventy-nine cases; eleven were well related to proximal movements, twenty-two to movements of the digits and forty-six to a co-ordinated hand movement elicited by a device called the twister. Both unidirectional and bidirectional patterns of bursting were frequent. A few cells showed reciprocal patterns consisting of a large increase in rate for one direction of movement and a small decrease for the other. The bursts in discharge preceded movement onset (97% of 132 cases) by an average of 135 ms. Electromyographic activity in forearm muscles preceded movement by about 55 ms. In some cases we recorded from a single cell while the monkey operated two, three or four devices. Depth of modulation on the twister device was twice that on a proximal device in nine cases whereas one case showed a proximal device preference; five cases showed overlap. Comparison between twister and digits yielded ten cases of twister

  14. Cortical Activation during Attention to Sound in Autism Spectrum Disorders

    ERIC Educational Resources Information Center

    Funabiki, Yasuko; Murai, Toshiya; Toichi, Motomi

    2012-01-01

    Individuals with autism spectrum disorders (ASDs) can demonstrate hypersensitivity to sounds as well as a lack of awareness of them. Several functional imaging studies have suggested an abnormal response in the auditory cortex of such subjects, but it is not known whether these subjects have dysfunction in the auditory cortex or are simply not…

  15. Out on a Limb: Investigating the Anatomy of Tree Limbs

    ERIC Educational Resources Information Center

    Shaw, Edward L.

    2008-01-01

    The author presents several upper elementary science activities involving tree limbs that were collected after severe weather conditions. The activities involved 3rd-grade students arranging tree limb pieces in the correct order from the trunk to the tip of the limb, measuring the pieces, determining the age of a tree limb by its rings,…

  16. Muscle activation patterns when passively stretching spastic lower limb muscles of children with cerebral palsy.

    PubMed

    Bar-On, Lynn; Aertbeliën, Erwin; Molenaers, Guy; Desloovere, Kaat

    2014-01-01

    The definition of spasticity as a velocity-dependent activation of the tonic stretch reflex during a stretch to a passive muscle is the most widely accepted. However, other mechanisms are also thought to contribute to pathological muscle activity and, in patients post-stroke and spinal cord injury can result in different activation patterns. In the lower-limbs of children with spastic cerebral palsy (CP) these distinct activation patterns have not yet been thoroughly explored. The aim of the study was to apply an instrumented assessment to quantify different muscle activation patterns in four lower-limb muscles of children with CP. Fifty-four children with CP were included (males/females n = 35/19; 10.8 ± 3.8 yrs; bilateral/unilateral involvement n =  32/22; Gross Motor Functional Classification Score I-IV) of whom ten were retested to evaluate intra-rater reliability. With the subject relaxed, single-joint, sagittal-plane movements of the hip, knee, and ankle were performed to stretch the lower-limb muscles at three increasing velocities. Muscle activity and joint motion were synchronously recorded using inertial sensors and electromyography (EMG) from the adductors, medial hamstrings, rectus femoris, and gastrocnemius. Muscles were visually categorised into activation patterns using average, normalized root mean square EMG (RMS-EMG) compared across increasing position zones and velocities. Based on the visual categorisation, quantitative parameters were defined using stretch-reflex thresholds and normalized RMS-EMG. These parameters were compared between muscles with different activation patterns. All patterns were dominated by high velocity-dependent muscle activation, but in more than half, low velocity-dependent activation was also observed. Muscle activation patterns were found to be both muscle- and subject-specific (p<0.01). The intra-rater reliability of all quantitative parameters was moderate to good. Comparing RMS-EMG between incremental position

  17. Active control of sound fields in elastic cylinders by vibrational inputs

    NASA Technical Reports Server (NTRS)

    Jones, J. D.; Fuller, C. R.

    1987-01-01

    An experiment is performed to study the mechanisms of active control of sound fields in elastic cylinders via vibrational outputs. In the present method of control, a vibrational force input was used as the secondary control input to reduce the radiated acoustic field. For the frequencies considered, the active vibration technique provided good global reduction of interior sound even though only one actuator was used.

  18. Numerical investigation of acoustic field in enclosures: Evaluation of active and reactive components of sound intensity

    NASA Astrophysics Data System (ADS)

    Meissner, Mirosław

    2015-03-01

    The paper focuses on a theoretical description and numerical evaluation of active and reactive components of sound intensity in enclosed spaces. As the study was dedicated to low-frequency room responses, a modal expansion of the sound pressure was used. Numerical simulations have shown that the presence of energy vortices whose size and distribution depend on the character of the room response is a distinctive feature of the active intensity field. When several modes with frequencies close to a source frequency are excited, the vortices within the room are positioned irregularly. However, if the response is determined by one or two dominant modes, a regular distribution of vortices in the room can be observed. The irrotational component of the active intensity was found using the Helmholtz decomposition theorem. As was evidenced by numerical simulations, the suppression of the vortical flow of sound energy in the nearfield permits obtaining a clear image of the sound source.

  19. Classification of upper limb motions from around-shoulder muscle activities: hand biofeedback.

    PubMed

    González, Jose; Horiuchi, Yuse; Yu, Wenwei

    2010-05-28

    Mining information from EMG signals to detect complex motion intention has attracted growing research attention, especially for upper-limb prosthetic hand applications. In most of the studies, recordings of forearm muscle activities were used as the signal sources, from which the intention of wrist and hand motions were detected using pattern recognition technology. However, most daily-life upper limb activities need coordination of the shoulder-arm-hand complex, therefore, relying only on the local information to recognize the body coordinated motion has many disadvantages because natural continuous arm-hand motions can't be realized. Also, achieving a dynamical coupling between the user and the prosthesis will not be possible. This study objective was to investigate whether it is possible to associate the around-shoulder muscles' Electromyogram (EMG) activities with the different hand grips and arm directions movements. Experiments were conducted to record the EMG of different arm and hand motions and the data were analyzed to decide the contribution of each sensor, in order to distinguish the arm-hand motions as a function of the reaching time. Results showed that it is possible to differentiate hand grips and arm position while doing a reaching and grasping task. Also, these results are of great importance as one step to achieve a close loop dynamical coupling between the user and the prosthesis.

  20. Distinguishing body mass and activity level from the lower limb: can entheses diagnose obesity?

    PubMed

    Godde, Kanya; Taylor, Rebecca Wilson

    2013-03-10

    The ability to estimate body size from the skeleton has broad applications, but is especially important to the forensic community when identifying unknown skeletal remains. This research investigates the utility of using entheses/muscle skeletal markers of the lower limb to estimate body size and to classify individuals into average, obese, and active categories, while using a biomechanical approach to interpret the results. Eighteen muscle attachment sites of the lower limb, known to be involved in the sit-to-stand transition, were scored for robusticity and stress in 105 white males (aged 31-81 years) from the William M. Bass Donated Skeletal Collection. Both logistic regression and log linear models were applied to the data to (1) test the utility of entheses as an indicator of body weight and activity level, and (2) to generate classification percentages that speak to the accuracy of the method. Thirteen robusticity scores differed significantly between the groups, but classification percentages were only slightly greater than chance. However, clear differences could be seen between the average and obese and the average and active groups. Stress scores showed no value in discriminating between groups. These results were interpreted in relation to biomechanical forces at the microscopic and macroscopic levels. Even though robusticity alone is not able to classify individuals well, its significance may show greater value when incorporated into a model that has multiple skeletal indicators. Further research needs to evaluate a larger sample and incorporate several lines of evidence to improve classification rates.

  1. Influence of a 12.8-km military load carriage activity on lower limb gait mechanics and muscle activity.

    PubMed

    Rice, Hannah; Fallowfield, Joanne; Allsopp, Adrian; Dixon, Sharon

    2016-07-27

    The high stress fracture occurrence in military populations has been associated with frequent load carriage activities. This study aimed to assess the influence of load carriage and of completing a load carriage training activity on gait characteristics. Thirty-two Royal Marine recruits completed a 12.8-km load carriage activity as part of their military training. Data were collected during walking in military boots, pre and post-activity, with and without the additional load (35.5 kg). Ground contact time, lower limb sagittal plane kinematics and kinetics, and electromyographic variables were obtained for each condition. When carrying load, there was increased ground contact time, increased joint flexion and joint moments, and increased plantar flexor and knee extensor muscle activity. Post-activity, there were no changes to kinematic variables, knee extensor moments were reduced, and there was evidence of plantar flexor muscle fatigue. The observed gait changes may be associated with stress fracture development. Practitioner Summary: This study identified gait changes due to load carriage and after a military load carriage training activity. Such activities are associated with lower limb stress fractures. A pre-post study design was used. Gait mechanics changed to a greater extent when carrying load, than after completion of the activity when assessed without load.

  2. Heparan sulfate proteoglycans including syndecan-3 modulate BMP activity during limb cartilage differentiation.

    PubMed

    Fisher, Melanie C; Li, Yingcui; Seghatoleslami, M Reza; Dealy, Caroline N; Kosher, Robert A

    2006-01-01

    Bone morphogenetic proteins (BMPs) are involved in multiple aspects of limb development including regulation of cartilage differentiation. Several BMPs bind strongly to heparin, and heparan sulfate proteoglycans (HSPGs) at the cell surface or in the extracellular matrix have recently been implicated as modulators of BMP signaling in some developing systems. Here we have explored the role of HSPGs in regulating BMP activity during limb chondrogenesis by evaluating the effects of exogenous heparan sulfate (HS), heparitinase treatment, and overexpression of the HSPG syndecan-3 on the ability of BMP2 to modulate the chondrogenic differentiation of limb mesenchymal cells in micromass culture. Exogenous HS dramatically enhances the ability of BMP2 to stimulate chondrogenesis and cartilage specific gene expression, and reduces the concentration of BMP2 needed to stimulate chondrogenesis. Furthermore, HS stimulates BMP2-mediated phosphorylation of Smad1, Smad5, and Smad8, transcriptional mediators of BMP2 signaling, indicating that HS enhances the interaction of BMP2 with its receptors. Pretreatment of micromass cultures with heparitinase to degrade endogenous HSPGs also enhances the chondrogenic activity of BMP2, and reduces the concentration of BMP2 needed to promote chondrogenesis. Taken together these results indicate that exogenous HS or heparitinase enhance the chondrogenic activity of BMP2 by interfering with its interaction with endogenous HSPGs that would normally restrict its interaction with its receptors. Consistent with the possibility that HSPGs are negative modulators of BMP signaling during chondrogenesis, we have found that overexpression of syndecan-3, which is one of the major HSPGs normally expressed during chondrogenesis, greatly impairs the ability of BMP2 to promote cartilage differentiation. Furthermore, retroviral overexpression of syndecan-3 inhibits BMP2-mediated Smad phosphorylation in the regions of the cultures in which chondrogenesis is

  3. Intrinsic muscle strength and voluntary activation of both lower limbs and functional performance after stroke.

    PubMed

    Horstman, Astrid M; Beltman, Marijke J; Gerrits, Karin H; Koppe, Peter; Janssen, Thomas W; Elich, Peter; de Haan, Arnold

    2008-07-01

    The objective of this study was to assess the nature of muscle weakness in both legs after stroke compared with able-bodied control individuals and to examine whether there is a relationship between the degree of muscle weakness and coactivation of knee extensors and flexors as well as voluntary activation capacity of knee extensors of both paretic and non-paretic legs and indices of functional performance. Maximal voluntary isometric torques of knee extensors (MVCe) and flexors (MVCf) were determined in 14 patients (bilaterally) and 12 able-bodied controls. Simultaneous measurements were made of torque and surface EMG from agonist and antagonist muscles. Coactivation was calculated. Supramaximal triplets were evoked with electrical stimulation to estimate maximal torque capacity and degree of voluntary activation of knee extensors. MVCs, activation and coactivation parameters were correlated to scores of seven functional performance tests. MVCe, MVCf and voluntary activation were lower in paretic lower limb (PL) compared with both non-paretic lower limb (NL) and control. Besides, all these parameters of NL were also lower than control. Electrically evoked torque capacity of knee extensors of PL was about 60% of both NL and control, which were not significantly different from each other. Strong significant correlations between strength, as well as voluntary activation, and functional performance were found. Coactivation did not correlate well with functional performance. Thus, whereas for NL activation failure can explain weakness, for PL both activation failure and reduced intrinsic torque capacity are responsible for the severe weakness. Activation capacity and muscle strength correlated strongly to functional performance, while coactivation did not.

  4. Developmental changes in brain activation involved in the production of novel speech sounds in children.

    PubMed

    Hashizume, Hiroshi; Taki, Yasuyuki; Sassa, Yuko; Thyreau, Benjamin; Asano, Michiko; Asano, Kohei; Takeuchi, Hikaru; Nouchi, Rui; Kotozaki, Yuka; Jeong, Hyeonjeong; Sugiura, Motoaki; Kawashima, Ryuta

    2014-08-01

    Older children are more successful at producing unfamiliar, non-native speech sounds than younger children during the initial stages of learning. To reveal the neuronal underpinning of the age-related increase in the accuracy of non-native speech production, we examined the developmental changes in activation involved in the production of novel speech sounds using functional magnetic resonance imaging. Healthy right-handed children (aged 6-18 years) were scanned while performing an overt repetition task and a perceptual task involving aurally presented non-native and native syllables. Productions of non-native speech sounds were recorded and evaluated by native speakers. The mouth regions in the bilateral primary sensorimotor areas were activated more significantly during the repetition task relative to the perceptual task. The hemodynamic response in the left inferior frontal gyrus pars opercularis (IFG pOp) specific to non-native speech sound production (defined by prior hypothesis) increased with age. Additionally, the accuracy of non-native speech sound production increased with age. These results provide the first evidence of developmental changes in the neural processes underlying the production of novel speech sounds. Our data further suggest that the recruitment of the left IFG pOp during the production of novel speech sounds was possibly enhanced due to the maturation of the neuronal circuits needed for speech motor planning. This, in turn, would lead to improvement in the ability to immediately imitate non-native speech.

  5. Modulation of cutaneous reflexes in human upper limb muscles during arm cycling is independent of activity in the contralateral arm.

    PubMed

    Carroll, Timothy J; Zehr, E Paul; Collins, David F

    2005-02-01

    The amplitudes and signs of cutaneous reflexes are modulated during rhythmic movements of the arms and legs (during walking and arm or leg cycling for instance). This reflex modulation is frequently independent of the background muscle activity and may involve central pattern generator (CPG) circuits. The purpose of the present study was to investigate the nature and degree of coupling between the upper limbs during arm cycling, with regard to the regulation of cutaneous reflexes. Responses to electrical stimulations of the right, superficial radial nerve (five 1 ms pulses, 300 Hz) were recorded bilaterally in six arm muscles of eight participants during arm cycling involving only the limb ipsilateral to the stimulation, only the limb contralateral to the stimulation, and bilateral movement when the limbs were both in-phase and 180 degrees out of phase. The pattern of cutaneous reflex modulation throughout the arm cycle was independent of the functional state of the limb contralateral to the recording site, irrespective of whether recordings were made ipsilateral or contralateral to the stimulation. Furthermore, cutaneous reflexes were significantly (p<0.05) modulated with arm position in only 8% of cases in which the limb containing the responding muscle was either stationary or being moved passively by the experimenter. The results show that there is relatively weak coupling between the arms with regard to the regulation of cutaneous reflexes during rhythmic, cyclical arm movements. This suggests a loose connection between the CPGs for each arm that regulate muscle activity and reflex amplitude during rhythmic movement.

  6. Effect of instability training equipment on lower limb kinematics and muscle activity.

    PubMed

    Pfusterschmied, J; Lindinger, S; Buchecker, M; Stöggl, T; Wagner, H; Müller, E

    2013-03-01

    To improve the effectiveness of training or therapy, it is important to know the benefits for each type of instability training equipment. The aim of this study was to show differences in lower limb kinematics and muscle activation during single leg standing on a slackline (SL) compared to a multi-functional rocker board (MD) and an air cushion (AC). In 14 subjects, mean angular velocity of the hip, knee and ankle, as well as the muscle activity (iEMG) from six lower limb muscles were recorded during 12 s of single leg standing task. Ankle in-/eversion and knee ab-/adduction angular velocity were highest for SL followed by MD and AC (all p < 0.05), as well as in the hip flex-/extension angular velocity with higher values for SL compared with AC (p < 0.01). Regarding iEMG, the rectus femoris muscle showed higher values for SL compared with MD (p < 0.05) and AC (p < 0.01). iEMG of biceps femoris muscle demonstrated higher values for MD compared to AC (p < 0.05), but with no difference to SL. Balancing on a SL is a more challenging exercise for the postural control system compared to MD and AC, and affects the knee and hip joint motion in particular.

  7. Sound conditioning protects hearing by activating the hypothalamic-pituitary-adrenal axis.

    PubMed

    Tahera, Yeasmin; Meltser, Inna; Johansson, Peter; Salman, Hazim; Canlon, Barbara

    2007-01-01

    Sound conditioning primes the auditory system to low levels of acoustic stimuli and reduces damage caused by a subsequent acoustic trauma. This priming activates the HPA axis resulting in the elevation of plasma corticosterone with a consequent upregulation of glucocorticoid receptors (GR) in the cochlea and the paraventricular nucleus (PVN) of the hypothalamus in the mouse. This protective effect is blocked by adrenalectomy or pharmacological treatment with RU486 + metyrapone. Sound conditioning prevents GR down-regulation induced by acoustic trauma and subsequently enhances GR activity in spiral ganglion neurons. Increased SRC-1 expression, triggered by sound conditioning, positively correlates with the upregulation of GR in the cochlea. These findings will help to define the cellular mechanisms responsible for protecting the auditory system from hearing loss by sound conditioning.

  8. Characterization of concentration gradients of a morphogenetically active retinoid in the chick limb bud

    PubMed Central

    1987-01-01

    It has long been suggested that the generation of biological patterns depends in part on gradients of diffusible substances. In an attempt to bridge the gap between this largely theoretical concept and experimental embryology, we have examined the physiology of diffusion gradients in an actual embryonic field. In particular, we have generated in the chick wing bud concentration gradients of the morphogenetically active retinoid TTNPB, (E)-4-[2-(5,6,7,8-tetrahydro- 5,5,8,8-tetramethyl-2-naphthalenyl)-1-prope nyl] benzoic acid, a synthetic vitamin A compound. Upon local application of TTNPB the normal 234 digit pattern is duplicated in a way that correlates with the geometry of the underlying TTNPB gradient; low doses of TTNPB lead to a shallow gradient and an additional digit 2, whereas higher doses result in a steep, far-reaching gradient and patterns with additional digits 3 and 4. The experimentally measured TTNPB distribution along the anteroposterior axis, can be modeled by a local source and a dispersed sink. This model correctly predicts the site of specification of digit 2, and provides an empirical estimate of the diffusion coefficient (D) of retinoids in embryonic limb tissue. The numerical value of approximately 10(-7) cm2s-1 for D suggests that retinoids are not freely diffusible in the limb rudiment, but interact with the previously identified cellular retinoic acid binding protein. In addition, D affords an estimate of the time required to establish a diffusion gradient as 3 to 4 h. This time span is in a range compatible with the time scale of pattern specification in developing vertebrate limbs. Our studies support the view that diffusion of morphogenetic substances is a plausible mechanism of pattern formation in secondary embryonic fields. PMID:3667700

  9. Effect of Kayak Ergometer Elastic Tension on Upper Limb EMG Activity and 3D Kinematics.

    PubMed

    Fleming, Neil; Donne, Bernard; Fletcher, David

    2012-01-01

    Despite the prevalence of shoulder injury in kayakers, limited published research examining associated upper limb kinematics and recruitment patterns exists. Altered muscle recruitment patterns on-ergometer vs. on-water kayaking were recently reported, however, mechanisms underlying changes remain to be elucidated. The current study assessed the effect of ergometer recoil tension on upper limb recruitment and kinematics during the kayak stroke. Male kayakers (n = 10) performed 4 by 1 min on-ergometer exercise bouts at 85%VO2max at varying elastic recoil tension; EMG, stroke force and three-dimensional 3D kinematic data were recorded. While stationary recoil forces significantly increased across investigated tensions (125% increase, p < 0.001), no significant differences were detected in assessed force variables during the stroke cycle. In contrast, increasing tension induced significantly higher Anterior Deltoid (AD) activity in the latter stages (70 to 90%) of the cycle (p < 0.05). No significant differences were observed across tension levels for Triceps Brachii or Latissimus Dorsi. Kinematic analysis revealed that overhead arm movements accounted for 39 ± 16% of the cycle. Elbow angle at stroke cycle onset was 144 ± 10°; maximal elbow angle (151 ± 7°) occurred at 78 ± 10% into the cycle. All kinematic markers moved to a more anterior position as tension increased. No significant change in wrist marker elevation was observed, while elbow and shoulder marker elevations significantly increased across tension levels (p < 0.05). In conclusion, data suggested that kayakers maintained normal upper limb kinematics via additional AD recruitment despite ergometer induced recoil forces. Key pointsKayak ergometer elastic tension significantly alters Anterior Deltoid recruitment patterns.Kayakers maintain optimal arm kinematics despite changing external forces via altered shoulder muscle recruitment.Overhead arm movements account for a high proportion of the kayak

  10. Effect of Kayak Ergometer Elastic Tension on Upper Limb EMG Activity and 3D Kinematics

    PubMed Central

    Fleming, Neil; Donne, Bernard; Fletcher, David

    2012-01-01

    Despite the prevalence of shoulder injury in kayakers, limited published research examining associated upper limb kinematics and recruitment patterns exists. Altered muscle recruitment patterns on-ergometer vs. on-water kayaking were recently reported, however, mechanisms underlying changes remain to be elucidated. The current study assessed the effect of ergometer recoil tension on upper limb recruitment and kinematics during the kayak stroke. Male kayakers (n = 10) performed 4 by 1 min on-ergometer exercise bouts at 85%VO2max at varying elastic recoil tension; EMG, stroke force and three-dimensional 3D kinematic data were recorded. While stationary recoil forces significantly increased across investigated tensions (125% increase, p < 0.001), no significant differences were detected in assessed force variables during the stroke cycle. In contrast, increasing tension induced significantly higher Anterior Deltoid (AD) activity in the latter stages (70 to 90%) of the cycle (p < 0.05). No significant differences were observed across tension levels for Triceps Brachii or Latissimus Dorsi. Kinematic analysis revealed that overhead arm movements accounted for 39 ± 16% of the cycle. Elbow angle at stroke cycle onset was 144 ± 10°; maximal elbow angle (151 ± 7°) occurred at 78 ± 10% into the cycle. All kinematic markers moved to a more anterior position as tension increased. No significant change in wrist marker elevation was observed, while elbow and shoulder marker elevations significantly increased across tension levels (p < 0.05). In conclusion, data suggested that kayakers maintained normal upper limb kinematics via additional AD recruitment despite ergometer induced recoil forces. Key pointsKayak ergometer elastic tension significantly alters Anterior Deltoid recruitment patterns.Kayakers maintain optimal arm kinematics despite changing external forces via altered shoulder muscle recruitment.Overhead arm movements account for a high proportion of the kayak

  11. Activity of protein kinase C during the differentiation of chick limb bud mesenchymal cells.

    PubMed

    Sonn, J K; Solursh, M

    1993-07-01

    To investigate the relationship between protein kinase C (PKC) and chondrogenesis, PKC activity was assayed in cultures of stage 23/24 chick limb bud mesenchymal cells under various conditions. PKC activities of cytosolic and particulate fractions were low in 1 day cultured cells. As chondrogenesis proceeds, cytosolic PKC activity increased more than twofold, while that of the particulate fraction increased only slightly. Three days' treatment of cultures with phorbol-12-myristate-13-acetate (PMA, 5 x 10(-8) M) inhibited chondrogenesis judged by the accumulation of Alcian blue bound to the extracellular matrix and depressed PKC activity in cytosolic fraction. When cells were grown for 3 days in control medium after 3 days' treatment with PMA, chondrogenesis resumed and PKC activity recovered to normal values. PKC activity in cultures plated at low density (5 x 10(6) cells/ml) where chondrogenesis is reduced was as low as that in 1 day cultured cells plated at high density (2 x 10(7) cells/ml) or that in PMA treated cells. On the other hand, staurosporine promoted chondrogenesis without affecting PKC activity. Furthermore, reversal of PMA's inhibitory effect on chondrogenesis by staurosporine was not accompanied by recovery of PKC activity. These data indicate that increases in PKC activity is closely related to chondrogenesis and that PMA inhibits chondrogenesis by depressing PKC. However, staurosporine's enhancing effect on chondrogenesis is not related to PKC activity.

  12. Adaptive wave field synthesis for active sound field reproduction: experimental results.

    PubMed

    Gauthier, Philippe-Aubert; Berry, Alain

    2008-04-01

    Sound field reproduction has applications in music reproduction, spatial audio, sound environment reproduction, and experimental acoustics. Sound field reproduction can be used to artificially reproduce the spatial character of natural hearing. The objective is then to reproduce a sound field in a real reproduction environment. Wave field synthesis (WFS) is a known open-loop technology which assumes that the reproduction environment is anechoic. The room response thus reduces the quality of the physical sound field reproduction by WFS. In recent research papers, adaptive wave field synthesis (AWFS) was defined as a potential solution to compensate for these quality reductions from which WFS objective performance suffers. In this paper, AWFS is experimentally investigated as an active sound field reproduction system with a limited number of reproduction error sensors to compensate for the response of the listening environment. Two digital signal processing algorithms for AWFS are used for comparison purposes, one of which is based on independent radiation mode control. AWFS performed propagating sound field reproduction better than WFS in three tested reproduction spaces (hemianechoic chamber, standard laboratory space, and reverberation chamber).

  13. Low-frequency sound affects active micromechanics in the human inner ear.

    PubMed

    Kugler, Kathrin; Wiegrebe, Lutz; Grothe, Benedikt; Kössl, Manfred; Gürkov, Robert; Krause, Eike; Drexl, Markus

    2014-10-01

    Noise-induced hearing loss is one of the most common auditory pathologies, resulting from overstimulation of the human cochlea, an exquisitely sensitive micromechanical device. At very low frequencies (less than 250 Hz), however, the sensitivity of human hearing, and therefore the perceived loudness is poor. The perceived loudness is mediated by the inner hair cells of the cochlea which are driven very inadequately at low frequencies. To assess the impact of low-frequency (LF) sound, we exploited a by-product of the active amplification of sound outer hair cells (OHCs) perform, so-called spontaneous otoacoustic emissions. These are faint sounds produced by the inner ear that can be used to detect changes of cochlear physiology. We show that a short exposure to perceptually unobtrusive, LF sounds significantly affects OHCs: a 90 s, 80 dB(A) LF sound induced slow, concordant and positively correlated frequency and level oscillations of spontaneous otoacoustic emissions that lasted for about 2 min after LF sound offset. LF sounds, contrary to their unobtrusive perception, strongly stimulate the human cochlea and affect amplification processes in the most sensitive and important frequency range of human hearing.

  14. Enhanced activation of motor execution networks using action observation combined with imagination of lower limb movements.

    PubMed

    Villiger, Michael; Estévez, Natalia; Hepp-Reymond, Marie-Claude; Kiper, Daniel; Kollias, Spyros S; Eng, Kynan; Hotz-Boendermaker, Sabina

    2013-01-01

    The combination of first-person observation and motor imagery, i.e. first-person observation of limbs with online motor imagination, is commonly used in interactive 3D computer gaming and in some movie scenes. These scenarios are designed to induce a cognitive process in which a subject imagines himself/herself acting as the agent in the displayed movement situation. Despite the ubiquity of this type of interaction and its therapeutic potential, its relationship to passive observation and imitation during observation has not been directly studied using an interactive paradigm. In the present study we show activation resulting from observation, coupled with online imagination and with online imitation of a goal-directed lower limb movement using functional MRI (fMRI) in a mixed block/event-related design. Healthy volunteers viewed a video (first-person perspective) of a foot kicking a ball. They were instructed to observe-only the action (O), observe and simultaneously imagine performing the action (O-MI), or imitate the action (O-IMIT). We found that when O-MI was compared to O, activation was enhanced in the ventralpremotor cortex bilaterally, left inferior parietal lobule and left insula. The O-MI and O-IMIT conditions shared many activation foci in motor relevant areas as confirmed by conjunction analysis. These results show that (i) combining observation with motor imagery (O-MI) enhances activation compared to observation-only (O) in the relevant foot motor network and in regions responsible for attention, for control of goal-directed movements and for the awareness of causing an action, and (ii) it is possible to extensively activate the motor execution network using O-MI, even in the absence of overt movement. Our results may have implications for the development of novel virtual reality interactions for neurorehabilitation interventions and other applications involving training of motor tasks.

  15. Real-World Affected Upper Limb Activity in Chronic Stroke: An Examination of Potential Modifying Factors

    PubMed Central

    Bailey, Ryan R.; Birkenmeier, Rebecca L.; Lang, Catherine E.

    2015-01-01

    BACKGROUND Despite improvement in motor function after intervention, adults with chronic stroke experience disability in everyday activity. Factors other than motor function may influence affected upper limb (UL) activity. OBJECTIVE To characterize affected UL activity and examine potential modifying factors of affected UL activity in community-dwelling adults with chronic stroke. METHODS Forty-six adults with chronic stroke wore accelerometers on both ULs for 25 hours and provided information about potential modifying factors (time spent in sedentary activity, cognitive impairment, depressive symptomatology, number of comorbidities, motor dysfunction of the affected UL, age, activities of daily living (ADL) status, and living arrangement). Accelerometry was used to quantify duration of affected and unaffected UL activity. The ratio of affected-to-unaffected UL activity was also calculated. Associations within and between accelerometry-derived variables and potential modifying factors were examined. RESULTS Mean hours of affected and unaffected UL activity were 5.0 ± 2.2 and 7.6 ± 2.1 hours, respectively. The ratio of affected-to-unaffected UL activity was 0.64 ± 0.19, and hours of affected and unaffected UL activity were strongly correlated (r=0.78). Increased severity of motor dysfunction and dependence in ADLs were associated with decreased affected UL activity. No other factors were associated with affected UL activity. CONCLUSIONS Severity of motor dysfunction and ADL status should be taken into consideration when setting goals for UL activity in people with chronic stroke. Given the strong, positive correlation between affected and unaffected UL activity, encouragement to increase activity of the unaffected UL may increase affected UL activity. PMID:25776118

  16. Effects of indoor slippers on plantar pressure and lower limb EMG activity in older women.

    PubMed

    Yick, K L; Tse, L T; Lo, W T; Ng, S P; Yip, J

    2016-09-01

    Open-toe mule slippers are popular footwear worn at home especially by older women. However, their biomechanical effects are still poorly understood. The objective of this study is to therefore evaluate the physical properties of two typical types of open-toe mule slippers and the changes in plantar pressure and lower limb muscle activity of older women when wearing these slippers. Five walking trials have been carried out by ten healthy women. The results indicate that compared to barefoot, wearing slippers results in significant increases in the contact area of the mid-foot regions which lead to plantar pressure redistribution from metatarsal heads 2-3 and the lateral heel to the midfoot regions. However, there is no significant difference in the selected muscle activity across all conditions. The findings enhance our understanding of slipper features associated with changes in biomechanical measures thereby providing the basis of slipper designs for better foot protection and comfort.

  17. Physical activity and quality of life: A study of a lower-limb amputee population.

    PubMed

    Deans, Sarah A; McFadyen, Angus K; Rowe, Philip J

    2008-06-01

    This cross-sectional descriptive study was initiated to investigate the relationship between physical activity and perceived quality of life in a lower-limb amputee population. The objective was to show which aspects of physical activity were most strongly linked to quality-of-life factors in this special patient group. The outcome measurements were two questionnaires: a section of the Trinity Amputation and Prosthetic Experience Scales (TAPES) and the World Health Organization Quality-of-Life Scale (WHOQOL-Bref). The former measures activity restriction and has Athletic, Functional, and Social subscales. The latter includes Physical, Psychological, Social, and Environmental domains, and measures the individual's perception of their quality of life. The two questionnaires were sent by post to 75 male and female participants with either trans-tibial or trans-femoral amputation who were receiving prosthetic care from a Glasgow-based rehabilitation and mobility centre and who met the inclusion criteria. All participants were over 18 years of age (mean age 66 years). In total, 25 participants returned the questionnaires-a response rate of 33%. According to analysis, 8 of the 12 relationships found were statistically significant. There was a very strong correlation between scores on the social elements of each questionnaire. The correlations between scores on the functional and athletic elements of the TAPES questionnaire and scores on the social element of the WHOQOL-Bref questionnaire were less strong. Our findings support the need for greater acknowledgement by healthcare professionals involved in the care of those with amputation about the importance of the patient's social relationships with friends and family. Education about the importance of increasing and maintaining a level of physical activity conducive to health benefits should be implemented within a supportive sociable environment for the patient with lower-limb amputation.

  18. Assisting people with attention deficit hyperactivity disorder by actively reducing limb hyperactive behavior with a gyration air mouse through a controlled environmental stimulation.

    PubMed

    Shih, Ching-Hsiang

    2011-01-01

    The latest researches have adopted software technology turning the gyration air mouse into a high performance limb movement detector, and have assessed whether two persons with multiple disabilities would be able to control an environmental stimulation using limb movement. This study extends gyration air mouse functionality by actively reducing limb hyperactive behavior to assess whether two persons with attention deficit hyperactivity disorder (ADHD) would be able to actively reduce their limb hyperactive behavior by controlling their favorite stimulation on/off using a gyration air mouse with a newly developed actively limb hyperactive behavior reducing program (ALHBRP). The study was performed according to an ABAB design, in which A represented the baseline and B represented intervention phases. Data showed that both participants significantly increased their time duration of maintaining a static limb posture (TDMSLP) to activate the control system in order to produce environmental stimulation during the intervention phases. Practical and developmental implications of the findings are discussed.

  19. An Acute Bout of Barefoot Running Alters Lower-limb Muscle Activation for Minimalist Shoe Users.

    PubMed

    Snow, N J; Basset, F A; Byrne, J

    2016-05-01

    Despite the abundance of barefoot running-related research, there have been no electromyography studies evaluating the effects of this mode of exercise on habitual users of minimalist footwear. The present study investigated differences in muscle activation during acute bouts of barefoot and shod running, in minimalist shoe users. 8 male participants ran on a motorized treadmill for 10 min under both conditions, at 70% maximal aerobic speed. Electromyographic data were sampled from the biceps femoris, gluteus maximus, gastrocnemius medialis, tibialis anterior, and vastus lateralis during both swing and stance. Root-mean-square analysis of electromyographic data was conducted to compare muscle activation between conditions. During stance, barefoot running resulted in greater muscle activity in gastrocnemius medialis and gluteus maximus, and lower muscle activity in tibialis anterior. During swing, barefoot running resulted in increased muscle activity in vastus lateralis and gastrocnemius medialus. These results indicate that, for minimalist shoe users, an acute bout of barefoot running results in significantly different lower-limb muscle activity. Increased activation in the above muscles presents a possible mechanism for injury, which should be considered during exercise prescription.

  20. Active/Passive Control of Sound Radiation from Panels using Constrained Layer Damping

    NASA Technical Reports Server (NTRS)

    Gibbs, Gary P.; Cabell, Randolph H.

    2003-01-01

    A hybrid passive/active noise control system utilizing constrained layer damping and model predictive feedback control is presented. This system is used to control the sound radiation of panels due to broadband disturbances. To facilitate the hybrid system design, a methodology for placement of constrained layer damping which targets selected modes based on their relative radiated sound power is developed. The placement methodology is utilized to determine two constrained layer damping configurations for experimental evaluation of a hybrid system. The first configuration targets the (4,1) panel mode which is not controllable by the piezoelectric control actuator, and the (2,3) and (5,2) panel modes. The second configuration targets the (1,1) and (3,1) modes. The experimental results demonstrate the improved reduction of radiated sound power using the hybrid passive/active control system as compared to the active control system alone.

  1. Oscillatory pallidal local field potential activity inversely correlates with limb dyskinesias in Parkinson's disease.

    PubMed

    Silberstein, Paul; Oliviero, Antonio; Di Lazzaro, Vincenzo; Insola, Angelo; Mazzone, Paolo; Brown, Peter

    2005-08-01

    Levodopa induced dyskinesias (LIDs) are poorly understood and yet are a major cause of disability in Parkinson's disease (PD). The activity of neurons in the basal ganglia of patients with PD tends to be strongly synchronized at frequencies under 30 Hz, leading to oscillatory local field potentials (LFPs). As dopaminergic therapy acutely suppresses this synchronization, we investigated whether this suppression may contribute to LIDs. Accordingly, we sought an inverse correlation between oscillatory synchronization and dyskinesia activity across time. To this end, we recorded pallidal LFPs in two Parkinsonian subjects exhibiting LIDs following surgery for deep brain stimulation. We correlated LFP power with simultaneously recorded EMG from the dyskinetic contralateral upper limb. We found highly significant inverse correlations between the oscillatory LFP activity under 30 Hz and dyskinetic EMG (maximum r = -0.65, P < 0.001 and r = -0.33, P < 0.001 for activities over 13-30 Hz in each subject). The inverse relationship between oscillatory pallidal LFP activity and dyskinetic EMG was maintained over time periods of a few seconds and was focal. This observation links the suppression of oscillatory synchronization in the pallidum with dyskinetic muscle activity in PD.

  2. Physical activity barriers and enablers in older Veterans with lower-limb amputation.

    PubMed

    Littman, Alyson J; Boyko, Edward J; Thompson, Mary Lou; Haselkorn, Jodie K; Sangeorzan, Bruce J; Arterburn, David E

    2014-01-01

    Little is known about the types of physical activities that older individuals with lower-limb loss perform, correlates of regular physical activity (PA), and barriers and facilitators to PA. We conducted an exploratory study in 158 older Veterans from the Pacific Northwest with a partial foot (35%), below-knee (39%) and above-knee (26%) amputation. Ninety-eight percent of survey respondents were male, on average 65 yr of age and 15 yr postamputation; 36% of amputations were trauma-related. The most commonly reported physical activities were muscle strengthening (42%), yard work and/or gardening (30%), and bicycling (11%). Forty-three percent were classified as physically active based on weekly moderate- and vigorous-intensity PA. History of vigorous preamputation PA was positively associated with being active, while low wealth and watching ≥5 h/d of television/videos were inversely associated. While pain- and resource-related barriers to PA were most frequently reported, only knowledge-related and interest/motivation-related barriers were inversely associated with being active. Family support and financial assistance to join a gym were the most commonly reported factors that would facilitate PA. To increase PA in the older amputee population, interventions should address motivational issues, knowledge gaps, and television watching; reduce financial barriers to exercising; and consider involving family members.

  3. Muscular activity of lower limb muscles associated with working on inclined surfaces

    PubMed Central

    Lu, Ming-Lun; Kincl, Laurel; Lowe, Brian; Succop, Paul; Bhattacharya, Amit

    2015-01-01

    This study investigated effects of visual cues, muscular fatigue, task performance and experience of working on inclined surfaces on activity of postural muscles in the lower limbs associated with maintaining balance on three inclined surfaces—0°, 14° and 26°. Normalized electromyographic (NEMG) data were collected on 44 professional roofers bilaterally from the rectus femoris, biceps femoris, tibialii anterior, and gastrocnemii medial muscle groups. The 50th and 95th percentile normalized EMG amplitudes were used as EMG variables. Results showed that inclination angle and task performance caused a significant increase in the NEMG amplitudes of all postural muscles. Visual cues were significantly associated with a decrease in the 95th percentile EMG amplitude for the right gastrocnemius medial and tibialis anterior. Fatigue was related to a significant decrease in the NEMG amplitude for the rectus femoris. Experience of working on inclined surfaces did not have a significant effect on the NEMG amplitude. PMID:25331562

  4. Intratympanic manganese administration revealed sound intensity and frequency dependent functional activity in rat auditory pathway.

    PubMed

    Jin, Seong-Uk; Lee, Jae-Jun; Hong, Kwan Soo; Han, Mun; Park, Jang-Woo; Lee, Hui Joong; Lee, Sangheun; Lee, Kyu-Yup; Shin, Kyung Min; Cho, Jin Ho; Cheong, Chaejoon; Chang, Yongmin

    2013-09-01

    The cochlear plays a vital role in the sense and sensitivity of hearing; however, there is currently a lack of knowledge regarding the relationships between mechanical transduction of sound at different intensities and frequencies in the cochlear and the neurochemical processes that lead to neuronal responses in the central auditory system. In the current study, we introduced manganese-enhanced MRI (MEMRI), a convenient in vivo imaging method, for investigation of how sound, at different intensities and frequencies, is propagated from the cochlear to the central auditory system. Using MEMRI with intratympanic administration, we demonstrated differential manganese signal enhancements according to sound intensity and frequencies in the ascending auditory pathway of the rat after administration of intratympanic MnCl2.Compared to signal enhancement without explicit sound stimuli, auditory structures in the ascending auditory pathway showed stronger signal enhancement in rats who received sound stimuli of 10 and 40 kHz. In addition, signal enhancement with a stimulation frequency of 40 kHz was stronger than that with 10 kHz. Therefore, the results of this study seem to suggest that, in order to achieve an effective response to high sound intensity or frequency, more firing of auditory neurons, or firing of many auditory neurons together for the pooled neural activity is needed.

  5. Foot posture influences the electromyographic activity of selected lower limb muscles during gait

    PubMed Central

    2009-01-01

    Background Some studies have found that flat-arched foot posture is related to altered lower limb muscle function compared to normal- or high-arched feet. However, the results from these studies were based on highly selected populations such as those with rheumatoid arthritis. Therefore, the objective of this study was to compare lower limb muscle function of normal and flat-arched feet in people without pain or disease. Methods Sixty adults aged 18 to 47 years were recruited to this study. Of these, 30 had normal-arched feet (15 male and 15 female) and 30 had flat-arched feet (15 male and 15 female). Foot posture was classified using two clinical measurements (the arch index and navicular height) and four skeletal alignment measurements from weightbearing foot x-rays. Intramuscular fine-wire electrodes were inserted into tibialis posterior and peroneus longus under ultrasound guidance, and surface EMG activity was recorded from tibialis anterior and medial gastrocnemius while participants walked barefoot at their self-selected comfortable walking speed. Time of peak amplitude, peak and root mean square (RMS) amplitude were assessed from stance phase EMG data. Independent samples t-tests were performed to assess for significant differences between the normal- and flat-arched foot posture groups. Results During contact phase, the flat-arched group exhibited increased activity of tibialis anterior (peak amplitude; 65 versus 46% of maximum voluntary isometric contraction) and decreased activity of peroneus longus (peak amplitude; 24 versus 37% of maximum voluntary isometric contraction). During midstance/propulsion, the flat-arched group exhibited increased activity of tibialis posterior (peak amplitude; 86 versus 60% of maximum voluntary isometric contraction) and decreased activity of peroneus longus (RMS amplitude; 25 versus 39% of maximum voluntary isometric contraction). Effect sizes for these significant findings ranged from 0.48 to 1.3, representing moderate to

  6. Neuromuscular Activity of Upper and Lower Limbs during two Backstroke Swimming Start Variants

    PubMed Central

    De Jesus, Karla; De Jesus, Kelly; Medeiros, Alexandre I. A.; Gonçalves, Pedro; Figueiredo, Pedro; Fernandes, Ricardo J.; Vilas-Boas, João Paulo

    2015-01-01

    A proficient start is decisive in sprint competitive swimming events and requires swimmers’ to exert maximal forces in a short period to complete the task successfully. The aim of this study was to compare the electromyographic (EMG) activity in-between the backstroke start with feet positioned parallel and partially emerged performed with the hands on the highest horizontal and on the vertical handgrip at hands-off, take-off, flight and entry start phases. EMG comparisons between starting variants were supported by upper and lower limb joint angles at starting position and 15 m start time data. Following a four-week start training to familiarize participants with each start variant, 10 male competitive backstroke swimmers performed randomly six 15 m maximal trials, being three of each start variant. Surface EMG of Biceps Brachii, Triceps Brachii, Rectus Femoris, Biceps Femoris, Gastrocnemius Medialis and Tibialis Anterior was recorded and processed using the time integral EMG (iEMG). Eight video cameras (four surface and four underwater) were used to determine backstroke start phases and joint angles at starting position. EMG, joint angles and temporal parameters have not evidenced changes due to the different handgrips. Nevertheless, clear differences were observed in both variants for upper and lower limb muscles activity among starting phases (e.g. Biceps Brachii at take-off vs. flight phase, 15.17% ± 2.76% and 22.38% ± 4.25%; 14.24% ± 7.11% and 25.90% ± 8.65%, for variant with hands horizontal and vertically positioned, respectively). It was concluded that different handgrips did not affect EMG, kinematics and temporal profile in backstroke start. Despite coaches might plan similar strength training for both start variants, further attention should be given on the selection of proper exercises to maximize the contribution of relevant muscles at different starting phases. Key points An effective swim start component (from the starting signal until the

  7. Psychoacoustic active noise control with ITU-R 468 noise weighting and its sound quality analysis.

    PubMed

    Bao, Hua; Panahi, Issa M S

    2010-01-01

    Non-uniform frequency response of human hearing system requires conventional active noise control (ANC) system to be modified. Psychoacoustic active noise control (PANC) system based on filtered-E least-mean-square (FELMS) structure aims to improve the noise attenuation performance in terms of hearing perception. ITU-R 468 noise weighting reflects human hearing response to random noise. In this paper we incorporate ITU-R 468 noise weighting into PANC system. Sound quality analysis is conducted for attenuated noise with a predictive pleasantness model which combines four psychoacoustic parameters (loudness, sharpness, roughness and tonality). Simulation on realistic MRI acoustic noise shows improvement of sound quality in the new system.

  8. Anticipated Effectiveness of Active Noise Control in Propeller Aircraft Interiors as Determined by Sound Quality Tests

    NASA Technical Reports Server (NTRS)

    Powell, Clemans A.; Sullivan, Brenda M.

    2004-01-01

    Two experiments were conducted, using sound quality engineering practices, to determine the subjective effectiveness of hypothetical active noise control systems in a range of propeller aircraft. The two tests differed by the type of judgments made by the subjects: pair comparisons in the first test and numerical category scaling in the second. Although the results of the two tests were in general agreement that the hypothetical active control measures improved the interior noise environments, the pair comparison method appears to be more sensitive to subtle changes in the characteristics of the sounds which are related to passenger preference.

  9. Muscular activity and physical interaction forces during lower limb exoskeleton use.

    PubMed

    Wilcox, Matthew; Rathore, Ashish; Morgado Ramirez, Dafne Zuleima; Loureiro, Rui C V; Carlson, Tom

    2016-12-01

    Spinal cord injury (SCI) typically manifests with a loss of sensorimotor control of the lower limbs. In order to overcome some of the disadvantages of chronic wheelchair use by such patients, robotic exoskeletons are an emerging technology that has the potential to transform the lives of patients. However, there are a number of points of contact between the robot and the user, which lead to interaction forces. In a recent study, the authors have shown that peak interaction forces are particularly prominent at the anterior aspect of the right leg. This study uses a similar experimental protocol with additional electromyography (EMG) analysis to examine whether such interaction forces are due to the muscular activity of the participant or the movement of the exoskeleton itself. Interestingly, the authors found that peak forces preceded peak EMG activity. This study did not find a significant correlation between EMG activity and force data, which would indicate that the interaction forces can largely be attributed to the movement of the exoskeleton itself. However, we also report significantly higher correlation coefficients in muscle/force pairs located at the anterior aspect of the right leg. In their previous research, the authors have shown peak interaction forces at the same locations, which suggests that muscular activity of the participant makes a more significant contribution to the interaction forces at these locations. The findings of this study are of significance for incomplete SCI patients, for whom EMG activity may provide an important input to an intuitive control schema.

  10. Influence of 14-day hind limb unloading on isolated muscle spindle activity in rats.

    PubMed

    Zhao, Xue Hong; Fan, Xiao Li; Song, Xin Ai; Wu, Su Di; Ren, Jun Chan; Chen, Ming Xia

    2010-09-01

    During hind limb unloading (HU), the soleus is often in a shortened position and the natural physiological stimulus of muscle spindles is altered, such that muscle spindle activity also changes. Using isolated spindle conditions, the present study investigates the electrophysiological activity and ultrastructure of muscle spindles following HU. Results show that muscle spindle discharges fall into either of two main patterns, single spikes or spike clusters in shortened positions, with a steady frequency of 18-38 spikes/s (mean 29.08 +/- 2.45) in an extended position. Following 14-day HU, afferent discharge activity was significantly altered in soleus muscle spindles. Duration of individual spikes was significantly prolonged, from 0.54 +/- 0.05 ms for control rats to 1.53 +/- 0.25 ms for rats in the HU group. In a shortened position, regular rhythm afferent discharges were obviously depressed, and the majority of muscle spindles became silent, while in an extended position, the discharges remained continuous but with decreased frequency. Results also show that the ultrastructure of muscle spindles experience degenerative changes during HU. Altered muscle spindle afference could possibly modify the activity of motor neurons and further affect the activity of extrafusal fibers.

  11. Multiunit Activity-Based Real-Time Limb-State Estimation from Dorsal Root Ganglion Recordings

    PubMed Central

    Han, Sungmin; Chu, Jun-Uk; Kim, Hyungmin; Park, Jong Woong; Youn, Inchan

    2017-01-01

    Proprioceptive afferent activities could be useful for providing sensory feedback signals for closed-loop control during functional electrical stimulation (FES). However, most previous studies have used the single-unit activity of individual neurons to extract sensory information from proprioceptive afferents. This study proposes a new decoding method to estimate ankle and knee joint angles using multiunit activity data. Proprioceptive afferent signals were recorded from a dorsal root ganglion with a single-shank microelectrode during passive movements of the ankle and knee joints, and joint angles were measured as kinematic data. The mean absolute value (MAV) was extracted from the multiunit activity data, and a dynamically driven recurrent neural network (DDRNN) was used to estimate ankle and knee joint angles. The multiunit activity-based MAV feature was sufficiently informative to estimate limb states, and the DDRNN showed a better decoding performance than conventional linear estimators. In addition, processing time delay satisfied real-time constraints. These results demonstrated that the proposed method could be applicable for providing real-time sensory feedback signals in closed-loop FES systems. PMID:28276474

  12. Active Outer Hair Cells Affect the Sound-Evoked Vibration of the Reticular Lamina

    NASA Astrophysics Data System (ADS)

    Jacob, Stefan; Fridberger, Anders

    2011-11-01

    It is well established that the organ of Corti uses active mechanisms to enhance its sensitivity and frequency selectivity. Two possible mechanisms have been identified, both capable of producing mechanical forces, which can alter the sound-evoked vibration of the hearing organ. However, little is known about the effect of these forces on the sound-evoked vibration pattern of the reticular lamina. Current injections into scala media were used to alter the amplitude of the active mechanisms in the apex of the guinea pig temporal bone. We used time-resolved confocal imaging to access the vibration pattern of individual outer hair cells. During positive current injection the the sound-evoked vibration of outer hair cell row three increased while row one showed a small decrease. Negative currents reversed the observed effect. We conclude that the outer hair cell mediated modification of reticular lamina vibration patterns could contribute to the inner hair cell stimulation.

  13. Predictive Factors of Dependency in Activities of Daily Living Following Limb Trauma in the Elderly

    PubMed Central

    Safa, Azade; Masoudi Alavi, Negin; Abedzadeh-Kalahroudi, Masoumeh

    2016-01-01

    Background Traumatic injuries in the elderly often lead to permanent disabilities and long-term treatments that can adversely influence their activities of daily of living (ADL). The effect on ADL is an important outcome in elderly trauma. Objectives The present study was designed to evaluate the predictive factors of dependency in ADL following limb trauma in elderly referred to Shahid Beheshti Hospital, Kashan, Iran, in 2013. Patients and Methods This descriptive study was conducted on 200 traumatic patients admitted to the trauma emergency ward of Shahid Beheshti hospital in 2013. The questionnaire used in this study had three parts: demographic data, information related to trauma, and an independence scale of ADL (ISADL). The ISADL was completed in the emergency ward to declare pre-traumatic status; it was also completed one and three months after trauma. Statistical analysis was conducted by the t-test and analysis of variance (ANOVA). The repeated measure was used to study the trend of the ISADL and other demographic variables. The multiple regression analysis was also used to declare the predictive variables related to the ISADL. Results The study population consisted of 81 males (40.5%) and 119 females (59.5%). The participants’ average age was 70.57 ± 9.05 years. In total, 80.5% of the elderly were completely independent in ADL before trauma; this decreased to 13.5% one month after trauma. The repeated measure analysis showed a significant improvement in the ISADL three months after trauma. Gender, age, and education had significant interaction with the ISADL. The multiple regression analysis showed that type of trauma and location of injured organ had predictive values related to the ISADL, one and three months after trauma. The place and cause of trauma, and having surgery showed a significant relationship with the ISADL three months after trauma. Conclusions Many factors, such as gender, age, education, type of trauma, and location of injured organ

  14. Semi-Supervised Active Learning for Sound Classification in Hybrid Learning Environments

    PubMed Central

    Han, Wenjing; Coutinho, Eduardo; Li, Haifeng; Schuller, Björn; Yu, Xiaojie; Zhu, Xuan

    2016-01-01

    Coping with scarcity of labeled data is a common problem in sound classification tasks. Approaches for classifying sounds are commonly based on supervised learning algorithms, which require labeled data which is often scarce and leads to models that do not generalize well. In this paper, we make an efficient combination of confidence-based Active Learning and Self-Training with the aim of minimizing the need for human annotation for sound classification model training. The proposed method pre-processes the instances that are ready for labeling by calculating their classifier confidence scores, and then delivers the candidates with lower scores to human annotators, and those with high scores are automatically labeled by the machine. We demonstrate the feasibility and efficacy of this method in two practical scenarios: pool-based and stream-based processing. Extensive experimental results indicate that our approach requires significantly less labeled instances to reach the same performance in both scenarios compared to Passive Learning, Active Learning and Self-Training. A reduction of 52.2% in human labeled instances is achieved in both of the pool-based and stream-based scenarios on a sound classification task considering 16,930 sound instances. PMID:27627768

  15. Diversity in sound pressure levels and estimated active space of resident killer whale vocalizations.

    PubMed

    Miller, Patrick J O

    2006-05-01

    Signal source intensity and detection range, which integrates source intensity with propagation loss, background noise and receiver hearing abilities, are important characteristics of communication signals. Apparent source levels were calculated for 819 pulsed calls and 24 whistles produced by free-ranging resident killer whales by triangulating the angles-of-arrival of sounds on two beamforming arrays towed in series. Levels in the 1-20 kHz band ranged from 131 to 168 dB re 1 microPa at 1 m, with differences in the means of different sound classes (whistles: 140.2+/-4.1 dB; variable calls: 146.6+/-6.6 dB; stereotyped calls: 152.6+/-5.9 dB), and among stereotyped call types. Repertoire diversity carried through to estimates of active space, with "long-range" stereotyped calls all containing overlapping, independently-modulated high-frequency components (mean estimated active space of 10-16 km in sea state zero) and "short-range" sounds (5-9 km) included all stereotyped calls without a high-frequency component, whistles, and variable calls. Short-range sounds are reported to be more common during social and resting behaviors, while long-range stereotyped calls predominate in dispersed travel and foraging behaviors. These results suggest that variability in sound pressure levels may reflect diverse social and ecological functions of the acoustic repertoire of killer whales.

  16. Active control of harmonic sound transmission into an acoustic enclosure using both structural and acoustic actuators

    PubMed

    Kim; Brennan

    2000-05-01

    This paper describes an analytical and experimental investigation into the active control of harmonic sound transmission in a structural-acoustic coupled system. A rectangular enclosure is considered that has five acoustically rigid walls and a flexible plate on the remaining side through which a harmonic sound wave is transmitted into the enclosure. The control system is designed to globally reduce the sound field inside the enclosure, and the roles of structural and acoustic actuators are of particular interest. Three control configurations, classified by the type of actuators, are compared and discussed. They are: (i) use of a single point-force actuator, (ii) use of a single acoustic piston source, and (iii) simultaneous use of both a point-force actuator and an acoustic piston source. It is shown both analytically and experimentally that the point-force actuator is effective in controlling plate-dominated modes while the acoustic source is effective in controlling cavity-dominated modes. Since the transmitted sound field is governed by both plate- and cavity-dominated modes, the hybrid use of both types of actuators is shown to be a desirable configuration for the active control of sound transmission into a structural-acoustic coupled system.

  17. Experience-based Auditory Predictions Modulate Brain Activity to Silence as do Real Sounds.

    PubMed

    Chouiter, Leila; Tzovara, Athina; Dieguez, Sebastian; Annoni, Jean-Marie; Magezi, David; De Lucia, Marzia; Spierer, Lucas

    2015-10-01

    Interactions between stimuli's acoustic features and experience-based internal models of the environment enable listeners to compensate for the disruptions in auditory streams that are regularly encountered in noisy environments. However, whether auditory gaps are filled in predictively or restored a posteriori remains unclear. The current lack of positive statistical evidence that internal models can actually shape brain activity as would real sounds precludes accepting predictive accounts of filling-in phenomenon. We investigated the neurophysiological effects of internal models by testing whether single-trial electrophysiological responses to omitted sounds in a rule-based sequence of tones with varying pitch could be decoded from the responses to real sounds and by analyzing the ERPs to the omissions with data-driven electrical neuroimaging methods. The decoding of the brain responses to different expected, but omitted, tones in both passive and active listening conditions was above chance based on the responses to the real sound in active listening conditions. Topographic ERP analyses and electrical source estimations revealed that, in the absence of any stimulation, experience-based internal models elicit an electrophysiological activity different from noise and that the temporal dynamics of this activity depend on attention. We further found that the expected change in pitch direction of omitted tones modulated the activity of left posterior temporal areas 140-200 msec after the onset of omissions. Collectively, our results indicate that, even in the absence of any stimulation, internal models modulate brain activity as do real sounds, indicating that auditory filling in can be accounted for by predictive activity.

  18. V1 and v2b interneurons secure the alternating flexor-extensor motor activity mice require for limbed locomotion.

    PubMed

    Zhang, Jingming; Lanuza, Guillermo M; Britz, Olivier; Wang, Zhi; Siembab, Valerie C; Zhang, Ying; Velasquez, Tomoko; Alvarez, Francisco J; Frank, Eric; Goulding, Martyn

    2014-04-02

    Reciprocal activation of flexor and extensor muscles constitutes the fundamental mechanism that tetrapod vertebrates use for locomotion and limb-driven reflex behaviors. This aspect of motor coordination is controlled by inhibitory neurons in the spinal cord; however, the identity of the spinal interneurons that serve this function is not known. Here, we show that the production of an alternating flexor-extensor motor rhythm depends on the composite activities of two classes of ventrally located inhibitory neurons, V1 and V2b interneurons (INs). Abrogating V1 and V2b IN-derived neurotransmission in the isolated spinal cord results in a synchronous pattern of L2 flexor-related and L5 extensor-related locomotor activity. Mice lacking V1 and V2b inhibition are unable to articulate their limb joints and display marked deficits in limb-driven reflex movements. Taken together, these findings identify V1- and V2b-derived neurons as the core interneuronal components of the limb central pattern generator (CPG) that coordinate flexor-extensor motor activity.

  19. Investigation of spherical loudspeaker arrays for local active control of sound.

    PubMed

    Peleg, Tomer; Rafaely, Boaz

    2011-10-01

    Active control of sound can be employed globally to reduce noise levels in an entire enclosure, or locally around a listener's head. Recently, spherical loudspeaker arrays have been studied as multiple-channel sources for local active control of sound, presenting the fundamental theory and several active control configurations. In this paper, important aspects of using a spherical loudspeaker array for local active control of sound are further investigated. First, the feasibility of creating sphere-shaped quiet zones away from the source is studied both theoretically and numerically, showing that these quiet zones are associated with sound amplification and poor system robustness. To mitigate the latter, the design of shell-shaped quiet zones around the source is investigated. A combination of two spherical sources is then studied with the aim of enlarging the quiet zone. The two sources are employed to generate quiet zones that surround a rigid sphere, investigating the application of active control around a listener's head. A significant improvement in performance is demonstrated in this case over a conventional headrest-type system that uses two monopole secondary sources. Finally, several simulations are presented to support the theoretical work and to demonstrate the performance and limitations of the system.

  20. Control of sound radiation with active/adaptive structures

    NASA Technical Reports Server (NTRS)

    Fuller, C. R.; Rogers, C. A.; Robertshaw, H. H.

    1992-01-01

    Recent research is discussed in the area of active structural acoustic control with active/adaptive structures. Progress in the areas of structural acoustics, actuators, sensors, and control approaches is presented. Considerable effort has been given to the interaction of these areas with each other due to the coupled nature of the problem. A discussion is presented on actuators bonded to or embedded in the structure itself. The actuators discussed are piezoceramic actuators and shape memory alloy actuators. The sensors discussed are optical fiber sensors, Nitinol fiber sensors, piezoceramics, and polyvinylidene fluoride sensors. The active control techniques considered are state feedback control techniques and least mean square adaptive algorithms. Results presented show that significant progress has been made towards controlling structurally radiated noise by active/adaptive means applied directly to the structure.

  1. Active control and sound synthesis--two different ways to investigate the influence of the modal parameters of a guitar on its sound.

    PubMed

    Benacchio, Simon; Mamou-Mani, Adrien; Chomette, Baptiste; Finel, Victor

    2016-03-01

    The vibrational behavior of musical instruments is usually studied using physical modeling and simulations. Recently, active control has proven its efficiency to experimentally modify the dynamical behavior of musical instruments. This approach could also be used as an experimental tool to systematically study fine physical phenomena. This paper proposes to use modal active control as an alternative to sound simulation to study the complex case of the coupling between classical guitar strings and soundboard. A comparison between modal active control and sound simulation investigates the advantages, the drawbacks, and the limits of these two approaches.

  2. Activation of back and lower limb muscles during squat exercises with different trunk flexion

    PubMed Central

    Lee, Tae-Sik; Song, Min-Young; Kwon, Yu-Jeong

    2016-01-01

    [Purpose] The purpose of this study was to investigate the activation of back and lower limb muscles in subjects who were performing a squat exercise at different angles of trunk flexion. [Subjects and Methods] Twenty healthy subjects (age 21.1± 1.8 years, height 168.7 ± 8.2 cm, weight 66.1 ± 12.3 kg) volunteered. The activation of the erector spinae muscle, rectus femoris muscle, gluteus maximus muscle and biceps femoris muscle was observed while the subjects performed squat exercises with a trunk flexion of 0°, 15°, and 30°. [Results] The erector spinae muscle, gluteus maximus muscle, and biceps femoris muscle were activated more during the squat exercise with the trunk flexion at 30° than the exercise with the trunk flexion at 0°. The rectus femoris muscle showed a tendency to decrease as the truck flexion increased. [Conclusion] Squat exercise be executed while maintaining an erect trunk posture if one wishes to strengthen the quadriceps muscle while reducing the load on the lower back. PMID:28174462

  3. Active lower limb prosthetics: a systematic review of design issues and solutions.

    PubMed

    Windrich, Michael; Grimmer, Martin; Christ, Oliver; Rinderknecht, Stephan; Beckerle, Philipp

    2016-12-19

    This paper presents a review on design issues and solutions found in active lower limb prostheses. This review is based on a systematic literature search with a methodical search strategy. The search was carried out across four major technical databases and the retrieved records were screened for their relevance. A total of 21 different active prostheses, including 8 above-knee, 9 below-knee and 4 combined knee-ankle prostheses were identified. While an active prosthesis may help to restore the functional performance of an amputee, the requirements regarding the actuation unit as well as for the control system are high and the development becomes a challenging task. Regarding mechanical design and the actuation unit high force/torque delivery, high efficiency, low size and low weight are conflicting goals. The actuation principle and variable impedance actuators are discussed. The control system is paramount for a "natural functioning" of the prosthesis. The control system has to enable locomotion and should react to the amputee's intent. For this, multi-level control approaches are reviewed.

  4. Temporal and spatial patterns of cortical activation during assisted lower limb movement.

    PubMed

    Wieser, M; Haefeli, J; Bütler, L; Jäncke, L; Riener, R; Koeneke, S

    2010-05-01

    Human gait is a complex process in the central nervous system that results from the integrity of various mechanisms, including different cortical and subcortical structures. In the present study, we investigated cortical activity during lower limb movement using EEG. Assisted by a dynamic tilt table, all subjects performed standardized stepping movements in an upright position. Source localization of the movement-related potential in relation to spontaneous EEG showed activity in brain regions classically associated with human gait such as the primary motor cortex, the premotor cortex, the supplementary motor cortex, the cingulate cortex, the primary somatosensory cortex and the somatosensory association cortex. Further, we observed a task-related power decrease in the alpha and beta frequency band at electrodes overlying the leg motor area. A temporal activation and deactivation of the involved brain regions as well as the chronological sequence of the movement-related potential could be mapped to specific phases of the gait-like leg movement. We showed that most cortical capacity is needed for changing the direction between the flexion and extension phase. An enhanced understanding of the human gait will provide a basis to improve applications in the field of neurorehabilitation and brain-computer interfaces.

  5. EUV analysis of an active region. [of solar corona in limb region

    NASA Technical Reports Server (NTRS)

    Raghavan, N.; Withbroe, G. L.

    1975-01-01

    A sequence of extreme-ultraviolet (EUV) spectroheliograms of McMath region No. 10283 were obtained by OSO-6. The lines O VI (1032 A) Mg X (625 A), Si XII (499 A), and Fe XVI (335 A) were used to determine coronal temperatures and densities above the active region. A comparison of theoretical and observed line ratios yielded coronal temperatures of 2.2 to 2.3 million K above the active region and 2.0 to 2.1 million K in the surrounding area. The temperatures derived from ratios involving the O VI intensities are systematically higher than the others. This is attributed to an error in the theoretical O VI intensities. The intensities observed above the limb are compared with intensities predicted by a simple model based on cylindrical geometry. The overall agreement shows that the assumption of an isothermal corona in hydrostatic equilibrium above the active region is a resonable working hypothesis and that the adopted geometrical model for the electron density distribution is adequate.

  6. Study on development of active-passive rehabilitation system for upper limbs: Hybrid-PLEMO

    NASA Astrophysics Data System (ADS)

    Kikuchi, T.; Jin, Y.; Fukushima, K.; Akai, H.; Furusho, J.

    2009-02-01

    In recent years, many researchers have studied the potential of using robotics technology to assist and quantify the motor functions for neuron-rehabilitation. Some kinds of haptic devices have been developed and evaluated its efficiency with clinical tests, for example, upper limb training for patients with spasticity after stroke. Active-type (motor-driven) haptic devices can realize a lot of varieties of haptics. But they basically require high-cost safety system. On the other hand, passive-type (brake-based) haptic devices have inherent safety. However, the passive robot system has strong limitation on varieties of haptics. There are not sufficient evidences to clarify how the passive/active haptics effect to the rehabilitation of motor skills. In this paper, we developed an active-passive-switchable rehabilitation system with ER clutch/brake device named "Hybrid-PLEMO" in order to address these problems. In this paper, basic structures and haptic control methods of the Hybrid-PLEMO are described.

  7. Activation of back and lower limb muscles during squat exercises with different trunk flexion.

    PubMed

    Lee, Tae-Sik; Song, Min-Young; Kwon, Yu-Jeong

    2016-12-01

    [Purpose] The purpose of this study was to investigate the activation of back and lower limb muscles in subjects who were performing a squat exercise at different angles of trunk flexion. [Subjects and Methods] Twenty healthy subjects (age 21.1± 1.8 years, height 168.7 ± 8.2 cm, weight 66.1 ± 12.3 kg) volunteered. The activation of the erector spinae muscle, rectus femoris muscle, gluteus maximus muscle and biceps femoris muscle was observed while the subjects performed squat exercises with a trunk flexion of 0°, 15°, and 30°. [Results] The erector spinae muscle, gluteus maximus muscle, and biceps femoris muscle were activated more during the squat exercise with the trunk flexion at 30° than the exercise with the trunk flexion at 0°. The rectus femoris muscle showed a tendency to decrease as the truck flexion increased. [Conclusion] Squat exercise be executed while maintaining an erect trunk posture if one wishes to strengthen the quadriceps muscle while reducing the load on the lower back.

  8. Performances of Student Activism: Sound, Silence, Gender, and Dis/ability

    ERIC Educational Resources Information Center

    Pasque, Penny A.; Vargas, Juanita Gamez

    2014-01-01

    This chapter explores the various performances of activism by students through sound, silence, gender, and dis/ability and how these performances connect to social change efforts around issues such as human trafficking, homeless children, hunger, and children with varying abilities.

  9. Early Fishing Peoples of Puget Sound. Ocean Related Curriculum Activities. Revised Edition.

    ERIC Educational Resources Information Center

    McNutt, Nan

    The ocean affects all of our lives. Therefore, awareness of and information about the interconnections between humans and oceans are prerequisites to making sound decisions for the future. Project ORCA (Ocean Related Curriculum Activities) has developed interdisciplinary curriculum materials designed to meet the needs of students and teachers…

  10. Feedforward control of sound transmission using an active acoustic metamaterial

    NASA Astrophysics Data System (ADS)

    Cheer, Jordan; Daley, Stephen; McCormick, Cameron

    2017-02-01

    Metamaterials have received significant interest in recent years due to their potential ability to exhibit behaviour not found in naturally occurring materials. This includes the generation of band gaps, which are frequency regions with high levels of wave attenuation. In the context of acoustics, these band gaps can be tuned to occur at low frequencies where the acoustic wavelength is large compared to the material, and where the performance of traditional passive noise control treatments is limited. Therefore, such acoustic metamaterials have been shown to offer a significant performance advantage compared to traditional passive control treatments, however, due to their resonant behaviour, the band gaps tend to occur over a relatively narrow frequency range. A similar long wavelength performance advantage can be achieved using active noise control, but the systems in this case do not rely on resonant behaviour. This paper demonstrates how the performance of an acoustic metamaterial, consisting of an array of Helmholtz resonators, can be significantly enhanced by the integration of an active control mechanism that is facilitated by embedding loudspeakers into the resonators. Crucially, it is then also shown how the active acoustic metamaterial significantly outperforms an equivalent traditional active noise control system. In both cases a broadband feedforward control strategy is employed to minimise the transmitted pressure in a one-dimensional acoustic control problem and a new method of weighting the control effort over a targeted frequency range is described.

  11. Spatial Effects of Sound on Visual Activity in Human Newborns.

    ERIC Educational Resources Information Center

    Mendelson, Morton J.; Haith, Marshall M.

    This study investigated the possibility of a functional relation between the auditory and visual systems in the human newborn beyond reflexive organization. Visual activity was monitored in 16 newborns through the use of infrared corneal reflection video tape recording. Infants were observed in total darkness and while monocularly viewing a…

  12. Sounds Like Fun: Activities for Developing Phonological Awareness, Revised Edition

    ERIC Educational Resources Information Center

    Spector, Cecile Cyrul

    2009-01-01

    Kids love jokes--and teachers and SLPs love fast and easy ways to improve students' phonological awareness. That's why every elementary and middle-school SLP and educator needs this playful, effective activity book, packed with jokes and riddles that increase students' awareness of the phonemes that make up words. The perfect way to avoid "drill…

  13. Perceptual demand modulates activation of human auditory cortex in response to task-irrelevant sounds.

    PubMed

    Sabri, Merav; Humphries, Colin; Verber, Matthew; Mangalathu, Jain; Desai, Anjali; Binder, Jeffrey R; Liebenthal, Einat

    2013-09-01

    In the visual modality, perceptual demand on a goal-directed task has been shown to modulate the extent to which irrelevant information can be disregarded at a sensory-perceptual stage of processing. In the auditory modality, the effect of perceptual demand on neural representations of task-irrelevant sounds is unclear. We compared simultaneous ERPs and fMRI responses associated with task-irrelevant sounds across parametrically modulated perceptual task demands in a dichotic-listening paradigm. Participants performed a signal detection task in one ear (Attend ear) while ignoring task-irrelevant syllable sounds in the other ear (Ignore ear). Results revealed modulation of syllable processing by auditory perceptual demand in an ROI in middle left superior temporal gyrus and in negative ERP activity 130-230 msec post stimulus onset. Increasing the perceptual demand in the Attend ear was associated with a reduced neural response in both fMRI and ERP to task-irrelevant sounds. These findings are in support of a selection model whereby ongoing perceptual demands modulate task-irrelevant sound processing in auditory cortex.

  14. [SOUND SIGNALS OF DANGER ACTIVATE THE NITRERGIC SYSTEM OF THE MEDIAL PREFRONTAL CORTEX].

    PubMed

    Sudorgina, P V; Saulskaya, N B

    2015-07-01

    In Sprague-Dawley rats by means of in vivo microdialysis, we have shown that presentation to rats-during conditioned fear expression of a sound conditioned stimulus previously paired with footshock (CS+) produces an increase in extracellular levels of citrulline (an NO co-product) in the medial prefrontal cortex. Presentation to the same rats of a different sound stimulus (not associated with footshock) (CS-) causes a very small increase in extracellular citrulline level. CS+ induced citrulline increase is prevented by infusions into the medial prefrontal cortex of Nomega-propyl-L-arginine (1 mM), a neuronal NO synthase inhibitor and it is not observed in control rats (same procedure, no footshock). These data indicate for the first time that sound signals of danger, but not safety signals activate nitrergic system of the medial prefrontal cortex.

  15. Active control of low-frequency sound radiation by cylindrical shell with piezoelectric stack force actuators

    NASA Astrophysics Data System (ADS)

    Cao, Yin; Sun, Hongling; An, Fengyan; Li, Xiaodong

    2012-05-01

    A novel active control method of sound radiation from a cylindrical shell under axial excitations is proposed and theoretically analyzed. This control method is based on a pair of piezoelectric stack force actuators which are installed on the shell and parallel to the axial direction. The actuators are driven in phase and generate the same forces to control the vibration and the sound radiation of the cylindrical shell. The model considered is a fluid-loaded finite stiffened cylindrical shell with rigid end-caps and only low-frequency axial vibration modes are involved. Numerical simulations are performed to explore the required control forces and the optimal mounting positions of actuators under different cost functions. The results show that the proposed force actuators can reduce the radiated sound pressure of low-frequency axial modes in all directions.

  16. Active control of sound transmission/radiation from elastic plates by vibration inputs. II - Experiments

    NASA Technical Reports Server (NTRS)

    Metcalf, V. L.; Fuller, C. R.; Silcox, R. J.; Brown, D. E.

    1992-01-01

    Actively controlled harmonic force inputs were applied experimentally to reduce the sound transmitted through an elastic circular plate. The control implementation used a time domain least mean square adaptive algorithm with two error sensors. The control forces were applied directly to the plate by point force vibration inputs, while the error information and performance were measured in the radiated acoustic field by microphones. Test cases were also performed in which the error sensors were accelerometers mounted on the plate. When accelerometers were used as error sensors, the controller performance was degraded; leading to the conclusion that minimizing plate motion does not necessarily lead to an associated decrease in radiated sound levels. In contrast, the results show excellent attenuation of the transmitted sound field when microphone error sensors were used. This result was consistent over a range of frequencies. In addition, the experimental results are compared to previously derived analytical results and the effect of using a point or global minimization scheme is discussed.

  17. Active control of structurally-coupled sound fields in elastic cylinders by vibrational force inputs

    NASA Technical Reports Server (NTRS)

    Jones, J. D.; Fuller, C. R.

    1990-01-01

    Active control of structurally-coupled sound fields in elastic cylinders is analytically and experimentally studied. The primary (noise) field in the cylinder model is generated by the coupled dynamic response of the shell under loading by a single exterior acoustic source. Control of the interior sound field is achieved by applying vibrational force inputs directly to the shell wall. Action of the point controllers serve to increase the input impedance of select structural modes of the shell which are well-coupled to the interior acoustic cavity, thus substantially reducing sound transmission into the cavity. Spatially-averaged noise reductions in excess of 30 dB are demonstrated for acoustic resonant conditions within the cavity. Twin controller configurations are presented which demonstrate the ability to independently control orthogonal modes of the interior acoustic space. Benefits and drawbacks of this new methodology for noise control are discussed and clearly demonstrated.

  18. Case studies of the impact of orbital sampling on stratospheric trend detection and derivation of tropical vertical velocities: solar occultation vs. limb emission sounding

    NASA Astrophysics Data System (ADS)

    Millán, Luis F.; Livesey, Nathaniel J.; Santee, Michelle L.; Neu, Jessica L.; Manney, Gloria L.; Fuller, Ryan A.

    2016-09-01

    This study investigates the representativeness of two types of orbital sampling applied to stratospheric temperature and trace gas fields. Model fields are sampled using real sampling patterns from the Aura Microwave Limb Sounder (MLS), the HALogen Occultation Experiment (HALOE) and the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS). The MLS sampling acts as a proxy for a dense uniform sampling pattern typical of limb emission sounders, while HALOE and ACE-FTS represent coarse nonuniform sampling patterns characteristic of solar occultation instruments. First, this study revisits the impact of sampling patterns in terms of the sampling bias, as previous studies have done. Then, it quantifies the impact of different sampling patterns on the estimation of trends and their associated detectability. In general, we find that coarse nonuniform sampling patterns may introduce non-negligible errors in the inferred magnitude of temperature and trace gas trends and necessitate considerably longer records for their definitive detection. Lastly, we explore the impact of these sampling patterns on tropical vertical velocities derived from stratospheric water vapor measurements. We find that coarse nonuniform sampling may lead to a biased depiction of the tropical vertical velocities and, hence, to a biased estimation of the impact of the mechanisms that modulate these velocities. These case studies suggest that dense uniform sampling such as that available from limb emission sounders provides much greater fidelity in detecting signals of stratospheric change (for example, fingerprints of greenhouse gas warming and stratospheric ozone recovery) than coarse nonuniform sampling such as that of solar occultation instruments.

  19. Activation of germline-specific genes is required for limb regeneration in the Mexican axolotl.

    PubMed

    Zhu, Wei; Pao, Gerald M; Satoh, Akira; Cummings, Gillian; Monaghan, James R; Harkins, Timothy T; Bryant, Susan V; Randal Voss, S; Gardiner, David M; Hunter, Tony

    2012-10-01

    The capacity for tissue and organ regeneration in humans is dwarfed by comparison to that of salamanders. Emerging evidence suggests that mechanisms learned from the early phase of salamander limb regeneration-wound healing, cellular dedifferentiation and blastemal formation-will reveal therapeutic approaches for tissue regeneration in humans. Here we describe a unique transcriptional fingerprint of regenerating limb tissue in the Mexican axolotl (Ambystoma mexicanum) that is indicative of cellular reprogramming of differentiated cells to a germline-like state. Two genes that are required for self-renewal of germ cells in mice and flies, Piwi-like 1 (PL1) and Piwi-like 2 (PL2), are expressed in limb blastemal cells, the basal layer keratinocytes and the thickened apical epithelial cap in the wound epidermis in the regenerating limb. Depletion of PL1 and PL2 by morpholino oligonucleotides decreased cell proliferation and increased cell death in the blastema leading to a significant retardation of regeneration. Examination of key molecules that are known to be required for limb development or regeneration further revealed that FGF8 is transcriptionally downregulated in the presence of the morpholino oligos, indicating PL1 and PL2 might participate in FGF signaling during limb regeneration. Given the requirement for FGF signaling in limb development and regeneration, the results suggest that PL1 and PL2 function to establish a unique germline-like state that is associated with successful regeneration.

  20. Active control of multi-dimensional random sound in ducts

    NASA Technical Reports Server (NTRS)

    Silcox, R. J.; Elliott, S. J.

    1990-01-01

    Previous work has demonstrated how active control may be applied to the control of random noise in ducts. These implementations, however, have been restricted to frequencies where only plane waves are propagating in the duct. In spite of this, the need for this technology at low frequencies has progressed to the point where commercial products that apply these concepts are currently available. Extending the frequency range of this technology requires the extension of current single channel controllers to multi-variate control systems as well as addressing the problems inherent in controlling higher order modes. The application of active control in the multi-dimensional propagation of random noise in waveguides is examined. An adaptive system is implemented using measured system frequency response functions. Experimental results are presented illustrating attained suppressions of 15 to 30 dB for random noise propagating in multiple modes.

  1. THE EFFECT OF DOUBLE VERSUS SINGLE OSCILLATING EXERCISE DEVICES ON TRUNK AND LIMB MUSCLE ACTIVATION

    PubMed Central

    Arora, Shruti; Button, Duane C.; Basset, Fabien A.

    2013-01-01

    muscular activity for trunk and shoulder muscle activation but does not provide an advantage for limb activation. Overall, oscillating the devices in the transverse plane provided greater muscular activation of the anterior deltoid, TA/IO and LSES than use of the devices during frontal or sagittal plane movements. Level of evidence: 2c: Outcomes research. PMID:24175124

  2. Range of Motion Requirements for Upper-Limb Activities of Daily Living

    PubMed Central

    Walters, Lisa Smurr; Cowley, Jeffrey; Wilken, Jason M.; Resnik, Linda

    2016-01-01

    OBJECTIVE. We quantified the range of motion (ROM) required for eight upper-extremity activities of daily living (ADLs) in healthy participants. METHOD. Fifteen right-handed participants completed several bimanual and unilateral basic ADLs while joint kinematics were monitored using a motion capture system. Peak motions of the pelvis, trunk, shoulder, elbow, and wrist were quantified for each task. RESULTS. To complete all activities tested, participants needed a minimum ROM of −65°/0°/105° for humeral plane angle (horizontal abduction–adduction), 0°–108° for humeral elevation, −55°/0°/79° for humeral rotation, 0°–121° for elbow flexion, −53°/0°/13° for forearm rotation, −40°/0°/38° for wrist flexion–extension, and −28°/0°/38° for wrist ulnar–radial deviation. Peak trunk ROM was 23° lean, 32° axial rotation, and 59° flexion–extension. CONCLUSION. Full upper-limb kinematics were calculated for several ADLs. This methodology can be used in future studies as a basis for developing normative databases of upper-extremity motions and evaluating pathology in populations. PMID:26709433

  3. The use of an active controlled enclosure to attenuate sound radiation from a heavy radiator

    NASA Astrophysics Data System (ADS)

    Sun, Yao; Yang, Tiejun; Zhu, Minggang; Pan, Jie

    2017-03-01

    Active structural acoustical control usually experiences difficulty in the control of heavy sources or sources where direct applications of control forces are not practical. To overcome this difficulty, an active controlled enclosure, which forms a cavity with both flexible and open boundary, is employed. This configuration permits indirect implementation of active control in which the control inputs can be applied to subsidiary structures other than the sources. To determine the control effectiveness of the configuration, the vibro-acoustic behavior of the system, which consists of a top plate with an open, a sound cavity and a source panel, is investigated in this paper. A complete mathematical model of the system is formulated involving modified Fourier series formulations and the governing equations are solved using the Rayleigh-Ritz method. The coupling mechanisms of a partly opened cavity and a plate are analysed in terms of modal responses and directivity patterns. Furthermore, to attenuate sound power radiated from both the top panel and the open, two strategies are studied: minimizing the total radiated power and the cancellation of volume velocity. Moreover, three control configurations are compared, using a point force on the control panel (structural control), using a sound source in the cavity (acoustical control) and applying hybrid structural-acoustical control. In addition, the effects of boundary condition of the control panel on the sound radiation and control performance are discussed.

  4. On the electric activity of superfluid helium at the excitation of first and second sound waves

    SciTech Connect

    Pashitskii, E. A. Gurin, A. A.

    2010-01-15

    We show that the electric activity of superfluid helium (HeII) observed in the experiments [3] during the excitation of standing second sound waves in an acoustic resonator can be described in terms of the phenomenological mechanism of the inertial polarization of atoms in a dielectric, in particular, in HeII, when the polarization field induced in the medium is proportional to the mechanical acceleration, by analogy with the Stewart-Tolman effect. The variable relative velocity w = v{sub n} - v{sub s} of the normal and superfluid HeII components that emerges in the second sound wave determines the mean group velocity of rotons, V{sub g} Almost-Equal-To w, with the density of the normal component related to their equilibrium number density in the temperature range 1.3 K {<=} T {<=} 2 K. Therefore, the acceleration of the 4He atoms involved in the formation of a roton excitation is proportional to the time derivative of the relative velocity.w. In this case, the linear local relations between the variable values of the electric induction, electric field strength, and polarization vector should be taken into account. As a result, the variable displacement current induced in the bulk of HeII and the corresponding potential difference do not depend on the anomalously low polarizability of liquid helium. This allows the ratio of the amplitudes of the temperature and potential oscillations in the second sound wave, which is almost independent of T in the above temperature range, consistent with experimental data to be obtained. At the same time, the absence of an electric response during the excitation of first sound waves in the linear regime is related to an insufficient power of the sound oscillations. Based on the experimental data on the excitation of first and second sounds, we have obtained estimates for the phenomenological coefficient of proportionality between the polarization vector and acceleration and for the drag coefficient of helium atoms by rotons in the

  5. Spontaneous brain activity predicts learning ability of foreign sounds.

    PubMed

    Ventura-Campos, Noelia; Sanjuán, Ana; González, Julio; Palomar-García, María-Ángeles; Rodríguez-Pujadas, Aina; Sebastián-Gallés, Núria; Deco, Gustavo; Ávila, César

    2013-05-29

    Can learning capacity of the human brain be predicted from initial spontaneous functional connectivity (FC) between brain areas involved in a task? We combined task-related functional magnetic resonance imaging (fMRI) and resting-state fMRI (rs-fMRI) before and after training with a Hindi dental-retroflex nonnative contrast. Previous fMRI results were replicated, demonstrating that this learning recruited the left insula/frontal operculum and the left superior parietal lobe, among other areas of the brain. Crucially, resting-state FC (rs-FC) between these two areas at pretraining predicted individual differences in learning outcomes after distributed (Experiment 1) and intensive training (Experiment 2). Furthermore, this rs-FC was reduced at posttraining, a change that may also account for learning. Finally, resting-state network analyses showed that the mechanism underlying this reduction of rs-FC was mainly a transfer in intrinsic activity of the left frontal operculum/anterior insula from the left frontoparietal network to the salience network. Thus, rs-FC may contribute to predict learning ability and to understand how learning modifies the functioning of the brain. The discovery of this correspondence between initial spontaneous brain activity in task-related areas and posttraining performance opens new avenues to find predictors of learning capacities in the brain using task-related fMRI and rs-fMRI combined.

  6. Sound Localization with Communications Headsets: Comparison of Passive and Active Systems

    DTIC Science & Technology

    2007-12-01

    communications muffs in active noise reduction (ANR) and talk-through-circuitry (TTC) modes and Nacre QUIETPRO communications earplugs in off (passive...UK) in active noise reduction (ANR) and talk-through circuitry (TTC) modes ofoperation and Nacre QU’IETPRO communications earplugs ( Nacre , Trondheim...externally mounted microphones [Figure 2a]. Sound level is limited to 85 dBA. The Nacre QUIETPRO device comprises two ear pieces (transducer housing

  7. Reduction of interior sound fields in flexible cylinders by active vibration control

    NASA Technical Reports Server (NTRS)

    Jones, J. D.; Fuller, C. R.

    1988-01-01

    The mechanisms of interior sound reduction through active control of a thin flexible shell's vibrational response are presently evaluated in view of an analytical model. The noise source is a single exterior acoustic monopole. The active control model is evaluated for harmonic excitation; the results obtained indicate spatially-averaged noise reductions in excess of 20 dB over the source plane, for acoustic resonant conditions inside the cavity.

  8. Modifications in activation of lower limb muscles as a function of initial foot position in cycling.

    PubMed

    Padulo, Johnny; Powell, Douglas W; Ardigò, Luca P; Viggiano, Davide

    2015-08-01

    Cyclic movements, such as walking/cycling, require the activity of spinal-circuits, the central-pattern-generators (CPG). To our knowledge little work has been done to investigate the activation of these circuits, e.g., the muscular and kinematic activity during cycling initiation. This study aims to detail the muscle output properties as a function of the initial lower limb-position using a simple cycling paradigm. Therefore, subjects were required to pedal on a cycle-ergometer in seated position starting at different-crank-angles (0-150°). Surface-electromyography was recorded from the gluteus major (GL), vastus lateralis (VL), and gastrocnemius medialis (GM), while crank position was recorded using a linear-encoder. Gluteus major peak-activity (PA) occurred at 65.0±12.4° when starting with 0° initial crank position (ICP), while occurred maximally at 110.5±2.9 when starting with 70° ICP. Vastus lateralis PA occurred at 40.7±8.8° with 0° ICP, whereas with 70° ICP PA occurred at 103.4±4.0°. Similarly, GM PA occurred at 112.0±10.7° with 0° ICP, whereas with 70° ICP PA occurred at 142.5±4.2° PA. Gluteus major and gastrocnemius medialis showed similar PA phase shifts, which may suggest they are controlled by same local circuitry, in agreement with their common spinal origin, i.e., motoneurons pool in S1-S2.

  9. Fatigue-related firing of muscle nociceptors reduces voluntary activation of ipsilateral but not contralateral lower limb muscles.

    PubMed

    Kennedy, David S; Fitzpatrick, Siobhan C; Gandevia, Simon C; Taylor, Janet L

    2015-02-15

    During fatiguing upper limb exercise, maintained firing of group III/IV muscle afferents can limit voluntary drive to muscles within the same limb. It is not known if this effect occurs in the lower limb. We investigated the effects of group III/IV muscle afferent firing from fatigued ipsilateral and contralateral extensor muscles and ipsilateral flexor muscles of the knee on voluntary activation of the knee extensors. In three experiments, we examined voluntary activation of the knee extensors by measuring changes in superimposed twitches evoked by femoral nerve stimulation. Subjects attended on 2 days for each experiment. On one day a sphygmomanometer cuff occluded blood flow of the fatigued muscles to maintain firing of group III/IV muscle afferents. After a 2-min extensor contraction (experiment 1; n = 9), mean voluntary activation was lower with than without maintained ischemia (47 ± 19% vs. 87 ± 8%, respectively; P < 0.001). After a 2-min knee flexor maximal voluntary contraction (MVC) (experiment 2; n = 8), mean voluntary activation was also lower with than without ischemia (59 ± 21% vs. 79 ± 9%; P < 0.01). After the contralateral (left) MVC (experiment 3; n = 8), mean voluntary activation of the right leg was similar with or without ischemia (92 ± 6% vs. 93 ± 4%; P = 0.65). After fatiguing exercise, activity in group III/IV muscle afferents reduces voluntary activation of the fatigued muscle and nonfatigued antagonist muscles in the same leg. However, group III/IV muscle afferents from the fatigued left leg had no effect on the unfatigued right leg. This suggests that any "crossover" of central fatigue in the lower limbs is not mediated by group III/IV muscle afferents.

  10. Assisting People with Attention Deficit Hyperactivity Disorder by Actively Reducing Limb Hyperactive Behavior with a Gyration Air Mouse through a Controlled Environmental Stimulation

    ERIC Educational Resources Information Center

    Shih, Ching-Hsiang

    2011-01-01

    The latest researches have adopted software technology turning the gyration air mouse into a high performance limb movement detector, and have assessed whether two persons with multiple disabilities would be able to control an environmental stimulation using limb movement. This study extends gyration air mouse functionality by actively reducing…

  11. Aircraft panel with sensorless active sound power reduction capabilities through virtual mechanical impedances

    NASA Astrophysics Data System (ADS)

    Boulandet, R.; Michau, M.; Micheau, P.; Berry, A.

    2016-01-01

    This paper deals with an active structural acoustic control approach to reduce the transmission of tonal noise in aircraft cabins. The focus is on the practical implementation of the virtual mechanical impedances method by using sensoriactuators instead of conventional control units composed of separate sensors and actuators. The experimental setup includes two sensoriactuators developed from the electrodynamic inertial exciter and distributed over an aircraft trim panel which is subject to a time-harmonic diffuse sound field. The target mechanical impedances are first defined by solving a linear optimization problem from sound power measurements before being applied to the test panel using a complex envelope controller. Measured data are compared to results obtained with sensor-actuator pairs consisting of an accelerometer and an inertial exciter, particularly as regards sound power reduction. It is shown that the two types of control unit provide similar performance, and that here virtual impedance control stands apart from conventional active damping. In particular, it is clear from this study that extra vibrational energy must be provided by the actuators for optimal sound power reduction, mainly due to the high structural damping in the aircraft trim panel. Concluding remarks on the benefits of using these electrodynamic sensoriactuators to control tonal disturbances are also provided.

  12. Active Control of Turbulent Boundary Layer Induced Sound Radiation from Multiple Aircraft Panels

    NASA Technical Reports Server (NTRS)

    Gibbs, Gary P.; Cabell, Randolph H.

    2002-01-01

    The objective of this work is to experimentally investigate active structural acoustic control of turbulent boundary layer (TBL) induced sound radiation from multiple panels on an aircraft sidewall. One possible approach for controlling sound radiation from multiple panels is a multi-input/multi-output scheme which considers dynamic coupling between the panels. Unfortunately, this is difficult for more than a few panels, and is impractical for a typical aircraft which contains several hundred such panels. An alternative is to implement a large number of independent control systems. Results from the current work demonstrate the feasibility of reducing broadband radiation from multiple panels utilizing a single-input/single-output (SISO) controller per bay, and is the first known demonstration of active control of TBL induced sound radiation on more than two bays simultaneously. The paper compares sound reduction for fully coupled control of six panels versus independent control on each panel. An online adaptive control scheme for independent control is also demonstrated. This scheme will adjust for slow time varying dynamic systems such as fuselage response changes due to aircraft pressurization, etc.

  13. Active control of turbulent boundary layer sound transmission into a vehicle interior

    NASA Astrophysics Data System (ADS)

    Caiazzo, A.; Alujević, N.; Pluymers, B.; Desmet, W.

    2016-09-01

    In high speed automotive, aerospace, and railway transportation, the turbulent boundary layer (TBL) is one of the most important sources of interior noise. The stochastic pressure distribution associated with the turbulence is able to excite significantly structural vibration of vehicle exterior panels. They radiate sound into the vehicle through the interior panels. Therefore, the air flow noise becomes very influential when it comes to the noise vibration and harshness assessment of a vehicle, in particular at low frequencies. Normally, passive solutions, such as sound absorbing materials, are used for reducing the TBL-induced noise transmission into a vehicle interior, which generally improve the structure sound isolation performance. These can achieve excellent isolation performance at higher frequencies, but are unable to deal with the low-frequency interior noise components. In this paper, active control of TBL noise transmission through an acoustically coupled double panel system into a rectangular cavity is examined theoretically. The Corcos model of the TBL pressure distribution is used to model the disturbance. The disturbance is rejected by an active vibration isolation unit reacting between the exterior and the interior panels. Significant reductions of the low-frequency vibrations of the interior panel and the sound pressure in the cavity are observed.

  14. Inhibition of PHOSPHO1 activity results in impaired skeletal mineralization during limb development of the chick.

    PubMed

    Macrae, Vicky E; Davey, Megan G; McTeir, Lynn; Narisawa, Sonoko; Yadav, Manisha C; Millan, Jose Luis; Farquharson, Colin

    2010-04-01

    PHOSPHO1 is a bone-specific phosphatase implicated in the initiation of inorganic phosphate generation for matrix mineralization. The control of mineralization is attributed to the actions of tissue-nonspecific alkaline phosphatase (TNAP). However, matrix vesicles (MVs) containing apatite crystals are present in patients with hypophosphatasia as well as TNAP null (Akp2(-/-)) mice. It is therefore likely that other phosphatases work with TNAP to regulate matrix mineralization. Although PHOSPHO1 and TNAP expression is associated with MVs, it is not known if PHOSPHO1 and TNAP are coexpressed during the early stages of limb development. Furthermore, the functional in vivo role of PHOSPHO1 in matrix mineralization has yet to be established. Here, we studied the temporal expression and functional role of PHOSPHO1 within chick limb bud mesenchymal micromass cultures and also in wild-type and talpid(3) chick mutants. These mutants are characterized by defective hedgehog signalling and the absence of endochondral mineralization. The ability of in vitro micromass cultures to differentiate and mineralize their matrix was temporally associated with increased expression of PHOSPHO1 and TNAP. Comparable changes in expression were noted in developing embryonic legs (developmental stages 23-36HH). Micromass cultures treated with lansoprazole, a small-molecule inhibitor of PHOSPHO1 activity, or FGF2, an inhibitor of chondrocyte differentiation, resulted in reduced alizarin red staining (P<0.05). FGF2 treatment also caused a reduction in PHOSPHO1 (P<0.001) and TNAP (P<0.001) expression. Expression analysis by whole-mount RNA in situ hybridization correlated with qPCR micromass data and demonstrated the existence of a tightly regulated pattern of Phospho1 and Tnap expression which precedes mineralization. Treatment of developing embryos for 5 days with lansoprazole completely inhibited mineralization of all leg and wing long bones as assessed by alcian blue/alizarin red staining

  15. Shoes influence lower limb muscle activity and may predispose the wearer to lateral ankle ligament injury.

    PubMed

    Kerr, Robin; Arnold, Graham P; Drew, Tim S; Cochrane, Lynda A; Abboud, Rami J

    2009-03-01

    Lateral ankle ligaments are injured by hyperinversion of the foot. Foot position is controlled by the lower limb muscles. Awareness of foot position is impaired by wearing shoes. We aimed to determine the influence of wearing shoes upon muscle activity. Sixty-two healthy subjects underwent the same measurements, barefoot and with standardized shoes in a random order. Electromyography (EMG) was recorded from the peroneus longus muscle in response to sudden and unanticipated inversion of the ipsilateral foot. Following foot inversion, the EMG signal showed an initial peak muscle contraction followed by a sustained smaller contraction. Both changes were significantly greater in shoes compared to the barefoot condition for all tested degrees of inversion. Muscle contraction following sudden inversion of the foot was significantly greater when wearing shoes. This greater muscular contraction may be an intrinsic mechanism to oppose the increased moment created by the inverted foot/shoe condition, and hence, may counter balance the increased tendency to injure the lateral ankle ligaments created by wearing shoes.

  16. Affection of Fundamental Brain Activity By Using Sounds For Patients With Prosodic Disorders: A Pilot Study

    NASA Astrophysics Data System (ADS)

    Imai, Emiko; Katagiri, Yoshitada; Seki, Keiko; Kawamata, Toshio

    2011-06-01

    We present a neural model of the production of modulated speech streams in the brain, referred to as prosody, which indicates the limbic structure essential for producing prosody both linguistically and emotionally. This model suggests that activating the fundamental brain including monoamine neurons at the basal ganglia will potentially contribute to helping patients with prosodic disorders coming from functional defects of the fundamental brain to overcome their speech problem. To establish effective clinical treatment for such prosodic disorders, we examine how sounds affect the fundamental activity by using electroencephalographic measurements. Throughout examinations with various melodious sounds, we found that some melodies with lilting rhythms successfully give rise to the fast alpha rhythms at the electroencephalogram which reflect the fundamental brain activity without any negative feelings.

  17. Actuator placement for active sound and vibration control of cylinders

    NASA Technical Reports Server (NTRS)

    Kincaid, Rex K.

    1995-01-01

    Active structural acoustic control is a method in which the control inputs (used to reduce interior noise) are applied directly to a vibrating structural acoustic system. The control concept modeled in this work is the application of in-plane force inputs to piezoceramic patches bonded to the wall of a vibrating cylinder. The cylinder is excited by an exterior noise source -- an acoustic monopole -- located near the outside of the cylinder wall. The goal is to determine the force inputs and sites for the piezoelectric actuators so that (1) the interior noise is effectively damped; (2) the level of vibration of the cylinder shell is not increased; and (3) the power requirements needed to drive the actuators are not excessive. We studied external monopole excitations at two frequencies. A cylinder resonance of 100 Hz, where the interior acoustic field is driven in multiple, off-resonance cylinder cavity modes, and a cylinder resonance of 200 Hz are characterized by both near and off-resonance cylinder vibration modes which couple effectively with a single, dominant, low-order acoustic cavity mode at resonance. Previous work has focused almost exclusively on meeting objective (1) and solving a complex least-squares problem to arrive at an optimal force vector for a given set of actuator sites. In addition, it has been noted that when the cavity mode couples with cylinder vibration modes (our 200 Hz case) control spillover may occur in higher order cylinder shell vibrational modes. How to determine the best set of actuator sites to meet objectives (1)-(3) is the main contribution of our research effort. The selection of the best set of actuator sites from a set of potential sites is done via two metaheuristics -- simulated annealing and tabu search. Each of these metaheuristics partitions the set of potential actuator sites into two disjoint sets: those that are selected to control the noise (on) and those that are not (off). Next, each metaheuristic attempts to

  18. Decoding Lower Limb Muscle Activity and Kinematics from Cortical Neural Spike Trains during Monkey Performing Stand and Squat Movements

    PubMed Central

    Ma, Xuan; Ma, Chaolin; Huang, Jian; Zhang, Peng; Xu, Jiang; He, Jiping

    2017-01-01

    Extensive literatures have shown approaches for decoding upper limb kinematics or muscle activity using multichannel cortical spike recordings toward brain machine interface (BMI) applications. However, similar topics regarding lower limb remain relatively scarce. We previously reported a system for training monkeys to perform visually guided stand and squat tasks. The current study, as a follow-up extension, investigates whether lower limb kinematics and muscle activity characterized by electromyography (EMG) signals during monkey performing stand/squat movements can be accurately decoded from neural spike trains in primary motor cortex (M1). Two monkeys were used in this study. Subdermal intramuscular EMG electrodes were implanted to 8 right leg/thigh muscles. With ample data collected from neurons from a large brain area, we performed a spike triggered average (SpTA) analysis and got a series of density contours which revealed the spatial distributions of different muscle-innervating neurons corresponding to each given muscle. Based on the guidance of these results, we identified the locations optimal for chronic electrode implantation and subsequently carried on chronic neural data recordings. A recursive Bayesian estimation framework was proposed for decoding EMG signals together with kinematics from M1 spike trains. Two specific algorithms were implemented: a standard Kalman filter and an unscented Kalman filter. For the latter one, an artificial neural network was incorporated to deal with the nonlinearity in neural tuning. High correlation coefficient and signal to noise ratio between the predicted and the actual data were achieved for both EMG signals and kinematics on both monkeys. Higher decoding accuracy and faster convergence rate could be achieved with the unscented Kalman filter. These results demonstrate that lower limb EMG signals and kinematics during monkey stand/squat can be accurately decoded from a group of M1 neurons with the proposed

  19. Decoding Lower Limb Muscle Activity and Kinematics from Cortical Neural Spike Trains during Monkey Performing Stand and Squat Movements.

    PubMed

    Ma, Xuan; Ma, Chaolin; Huang, Jian; Zhang, Peng; Xu, Jiang; He, Jiping

    2017-01-01

    Extensive literatures have shown approaches for decoding upper limb kinematics or muscle activity using multichannel cortical spike recordings toward brain machine interface (BMI) applications. However, similar topics regarding lower limb remain relatively scarce. We previously reported a system for training monkeys to perform visually guided stand and squat tasks. The current study, as a follow-up extension, investigates whether lower limb kinematics and muscle activity characterized by electromyography (EMG) signals during monkey performing stand/squat movements can be accurately decoded from neural spike trains in primary motor cortex (M1). Two monkeys were used in this study. Subdermal intramuscular EMG electrodes were implanted to 8 right leg/thigh muscles. With ample data collected from neurons from a large brain area, we performed a spike triggered average (SpTA) analysis and got a series of density contours which revealed the spatial distributions of different muscle-innervating neurons corresponding to each given muscle. Based on the guidance of these results, we identified the locations optimal for chronic electrode implantation and subsequently carried on chronic neural data recordings. A recursive Bayesian estimation framework was proposed for decoding EMG signals together with kinematics from M1 spike trains. Two specific algorithms were implemented: a standard Kalman filter and an unscented Kalman filter. For the latter one, an artificial neural network was incorporated to deal with the nonlinearity in neural tuning. High correlation coefficient and signal to noise ratio between the predicted and the actual data were achieved for both EMG signals and kinematics on both monkeys. Higher decoding accuracy and faster convergence rate could be achieved with the unscented Kalman filter. These results demonstrate that lower limb EMG signals and kinematics during monkey stand/squat can be accurately decoded from a group of M1 neurons with the proposed

  20. Assisting children with Attention Deficit Hyperactivity Disorder actively reduces limb hyperactive behavior with a Nintendo Wii Remote Controller through controlling environmental stimulation.

    PubMed

    Shih, Ching-Hsiang; Yeh, Jui-Chi; Shih, Ching-Tien; Chang, Man-Ling

    2011-01-01

    The latest studies have adopted software technology which turns the Wii Remote Controller into a high-performance limb action detector, we assessed whether two persons with multiple disabilities would be able to control an environmental stimulus through limb action. This study extends the functionality of the Wii Remote Controller to the correction of limb hyperactive behavior to assess whether two children with Attention Deficit Hyperactivity Disorder (ADHD) would be able to actively reduce their limb hyperactive behavior through controlling their favorite stimuli by turning them on/off using a Wii Remote Controller. An ABAB design, in which A represented the baseline and B represented intervention phases, was adopted in this study. Result showed that both participants significantly increased their time duration of maintaining a static limb posture (TDMSLP) to activate the control system in order to produce environmental stimulation in the intervention phases. Practical and developmental implications of the findings are discussed.

  1. Effect of a fluid layer on the sound radiation of a plate and its active control

    NASA Astrophysics Data System (ADS)

    Sun, Yao; Pan, Jie; Yang, Tiejun

    2015-11-01

    In this paper, a baffled plate facing a layer of fluid is used to investigate the effects of the radiating environment on the plate's sound radiation and its active control. By varying the thickness of the fluid layer, different radiation environments are presented to the plate, resulting in a variation in the efficiencies and shapes of the radiation modes of the plate. As the design of feed-forward control of the radiated sound power and of feedback control of the vibration velocity or volume velocity is limited by the properties of the secondary control path (an open-loop frequency response function), the performance of the control system may be deteriorated if a controller optimally designed for one radiation environment is used for a different environment. The effects of radiation environment on the properties of the secondary control path and performance of active control are investigated.

  2. Active control of sound radiated by a submarine in bending vibration

    NASA Astrophysics Data System (ADS)

    Caresta, Mauro

    2011-02-01

    This paper theoretically investigates the use of inertial actuators to reduce the sound radiated by a submarine hull in bending vibration under harmonic excitation from the propeller. The radial forces from the propeller are tonal at the blade passing frequency and are transmitted to the hull through the stern end cone. The hull is modelled as a fluid loaded cylindrical shell with ring stiffeners and two equally spaced bulkheads. The cylinder is closed by end-plates and conical end caps. The actuators are arranged in circumferential arrays and attached to the prow end cone. Both Active Vibration Control and Active Structural Acoustic Control are analysed. The inertial actuators can provide control forces with a magnitude large enough to reduce the sound radiated by the vibrations of the hull in some frequency ranges.

  3. Activation patterns of embryonic chick hind limb muscles recorded in ovo and in an isolated spinal cord preparation.

    PubMed

    Landmesser, L T; O'Donovan, M J

    1984-02-01

    Muscle activation patterns of embryonic chick hind limb muscles were determined from electromyographic (e.m.g.) recordings in an isolated spinal cord/hind limb preparation of stage 34-36 embryos, and were compared with in ovo e.m.g. activity from similarly staged embryos. Muscle activity in ovo consisted of periodically recurring sequences of bursts during which antagonistic muscles often alternated and synergistic muscles were co-active, as compatible with their mature function. However, more variable behaviour was also observed. Burst sequences in ovo were often initiated by a short-duration, high-amplitude discharge that occurred synchronously in all muscles studied, and which was followed by a period of electrical silence that was longest in the flexor muscles. This type of activity has not been described previously in mature animals. In ovo movement sequences were generally initiated by extensor activity which progressively declined in duration and intensity throughout the sequence, while flexor activity progressively intensified. The onset of activity in extensor muscles was accompanied by an abrupt decrease in flexor activity, whereas the converse was not observed. Spontaneous movement sequences also occurred when the spinal cord and hind limb were isolated and maintained in oxygenated Tyrode solution for several hours. Deafferentation experiments indicated that the motor pattern in this preparation was generated centrally by circuits within the spinal cord. Activity from the isolated cord was less variable than that occurring in ovo, consisting of sequences of highly regular recurring bursts. Each burst began with a brief high-amplitude discharge that occurred synchronously in all muscles and which was similar to that observed in ovo. This was followed by a silent period, which was longest in the flexors, and then by a more prolonged burst. Although its behaviour differs from that in ovo in some respects, it is concluded that the isolated cord maintained in

  4. Activation patterns of embryonic chick hind limb muscles recorded in ovo and in an isolated spinal cord preparation.

    PubMed Central

    Landmesser, L T; O'Donovan, M J

    1984-01-01

    Muscle activation patterns of embryonic chick hind limb muscles were determined from electromyographic (e.m.g.) recordings in an isolated spinal cord/hind limb preparation of stage 34-36 embryos, and were compared with in ovo e.m.g. activity from similarly staged embryos. Muscle activity in ovo consisted of periodically recurring sequences of bursts during which antagonistic muscles often alternated and synergistic muscles were co-active, as compatible with their mature function. However, more variable behaviour was also observed. Burst sequences in ovo were often initiated by a short-duration, high-amplitude discharge that occurred synchronously in all muscles studied, and which was followed by a period of electrical silence that was longest in the flexor muscles. This type of activity has not been described previously in mature animals. In ovo movement sequences were generally initiated by extensor activity which progressively declined in duration and intensity throughout the sequence, while flexor activity progressively intensified. The onset of activity in extensor muscles was accompanied by an abrupt decrease in flexor activity, whereas the converse was not observed. Spontaneous movement sequences also occurred when the spinal cord and hind limb were isolated and maintained in oxygenated Tyrode solution for several hours. Deafferentation experiments indicated that the motor pattern in this preparation was generated centrally by circuits within the spinal cord. Activity from the isolated cord was less variable than that occurring in ovo, consisting of sequences of highly regular recurring bursts. Each burst began with a brief high-amplitude discharge that occurred synchronously in all muscles and which was similar to that observed in ovo. This was followed by a silent period, which was longest in the flexors, and then by a more prolonged burst. Although its behaviour differs from that in ovo in some respects, it is concluded that the isolated cord maintained in

  5. Effect of sound wave stress on antioxidant enzyme activities and lipid peroxidation of Dendrobium candidum.

    PubMed

    Li, Biao; Wei, Jinmin; Wei, Xiaolan; Tang, Kun; Liang, Yilong; Shu, Kunxian; Wang, Bochu

    2008-06-01

    The effect of sound wave stress on important medicinal plant, Dendrobium candidum Wall. ex Lindl, was investigated, including the responses on malondialdehyde (MDA) content, the activities change of superoxide dismutase (SOD), catalase (CAT), peroxidase (POD) and ascorbate peroxidase (APX). Results were found that the activities of SOD, CAT, POD and APX enhanced totally in different organs of D. candidum, as leaves, stems and roots, in response to the stress. Furthermore there happened similar shift of antioxidant enzymes activities, which increased in the initial stimulation and decreased afterwards. Data showed SOD, CAT, POD and APX activities ascended to max at day 9, 6, 9 and 12 in leaves, at day 9, 6, 12 and 9 in stems, and at day 12, 6, 9 and 9 in roots, respectively. As a lipid peroxidation parameter, MDA content in different organs increased in the beginning, dropped afterward, and increased again in the late. Anyway the total trend was the rise of MDA level compared to the control. It was interesting that the MDA content appeared the lowest levels almost when the antioxidant enzymes activities were up to the highest. Our results demonstrated the different organs of D. candidum might produce accumulation of active oxygen species (AOS) under initial treatment of sound wave stress. Later AOS might start to reduce due to the enhancement of antioxidant enzymes activities treated by the stress. The data revealed that the antioxidant metabolism was to be important in determining the ability of plants to survive in sound stress, and the up regulation of these enzymes activities would help to reduce the build up of AOS, which could protect plant cells from oxidative damage. Moreover, different cell compartments might activate different defensive system to reduce excessive amount of AOS. Finally the mechanism of this action was also discussed simply.

  6. Effect of the Mandibular Orthopedic Repositioning Appliance on Trunk and Upper Limb Muscle Activation during Maximum Isometric Contraction.

    PubMed

    Lee, Sang-Yeol; Hong, Min-Ho; Park, Min-Chull; Choi, Sung-Min

    2013-11-01

    [Purpose] The purpose of this study was to measure the muscle activities of the trunk muscles and upper limb muscles during maximum isometric contraction when temporomandibular joint alignment was achieved with a mandibular orthopedic repositioning appliance in order provide basic data on the effects of mandibular orthopedic repositioning appliance on the entire body. [Subjects] The present study was conducted with healthy Korean adults in their 20s (males=10, females=10). [Methods] An 8 channel surface electromyography system was used to measure the muscle activities of the upper limb muscles and neck muscles of the subjects during maximum isometric contraction with and without use of a mandibular orthopedic repositioning appliance. [Results] The maximum isometric contractions of the trunk and upper limb muscles when mandibular orthopedic repositioning appliance were used were compared with those when no mandibular orthopedic repositioning appliance was used. The results showed that the sternocleidomastoid muscle, cervical and lumbar erector spinae, upper trapezius, biceps, triceps, rectus abdominis and internal oblique and external oblique muscles all showed significant increases in maximum isometric contractions with a mandibular orthopedic repositioning appliance. [Conclusion] The use of a mandibular orthopedic repositioning appliance is considered to be a method for normal adults to improve the stability of the entire body with the improvement of the stability of the TMJ. The proximal improvement in stability improves of the proximal thereby improving not only muscle strength with increased muscle activation but also stability during exercises.

  7. A Sit-to-Stand Training Robot and Its Performance Evaluation: Dynamic Analysis in Lower Limb Rehabilitation Activities

    NASA Astrophysics Data System (ADS)

    Cao, Enguo; Inoue, Yoshio; Liu, Tao; Shibata, Kyoko

    In many countries in which the phenomenon of population aging is being experienced, motor function recovery activities have aroused much interest. In this paper, a sit-to-stand rehabilitation robot utilizing a double-rope system was developed, and the performance of the robot was evaluated by analyzing the dynamic parameters of human lower limbs. For the robot control program, an impedance control method with a training game was developed to increase the effectiveness and frequency of rehabilitation activities, and a calculation method was developed for evaluating the joint moments of hip, knee, and ankle. Test experiments were designed, and four subjects were requested to stand up from a chair with assistance from the rehabilitation robot. In the experiments, body segment rotational angles, trunk movement trajectories, rope tensile forces, ground reaction forces (GRF) and centers of pressure (COP) were measured by sensors, and the moments of ankle, knee and hip joint were real-time calculated using the sensor-measured data. The experiment results showed that the sit-to-stand rehabilitation robot with impedance control method could maintain the comfortable training postures of users, decrease the moments of limb joints, and enhance training effectiveness. Furthermore, the game control method could encourage collaboration between the brain and limbs, and allow for an increase in the frequency and intensity of rehabilitation activities.

  8. Active control of sound transmission through partitions composed of discretely controlled modules

    NASA Astrophysics Data System (ADS)

    Leishman, Timothy W.

    This thesis provides a detailed theoretical and experimental investigation of active segmented partitions (ASPs) for the control of sound transmission. ASPs are physically segmented arrays of interconnected acoustically and structurally small modules that are discretely controlled using electronic controllers. Theoretical analyses of the thesis first address physical principles fundamental to ASP modeling and experimental measurement techniques. Next, they explore specific module configurations, primarily using equivalent circuits. Measured normal-incidence transmission losses and related properties of experimental ASPs are determined using plane wave tubes and the two-microphone transfer function technique. A scanning laser vibrometer is also used to evaluate distributed transmitting surface vibrations. ASPs have the inherent potential to provide excellent active sound transmission control (ASTC) through lightweight structures, using very practical control strategies. The thesis analyzes several unique ASP configurations and evaluates their abilities to produce high transmission losses via global minimization of normal transmitting surface vibrations. A novel dual diaphragm configuration is shown to employ this strategy particularly well. It uses an important combination of acoustical actuation and mechano-acoustical segmentation to produce exceptionally high transmission loss (e.g., 50 to 80 dB) over a broad frequency range-including lower audible frequencies. Such performance is shown to be comparable to that produced by much more massive partitions composed of thick layers of steel or concrete and sand. The configuration uses only simple localized error sensors and actuators, permitting effective use of independent single-channel controllers in a decentralized format. This work counteracts the commonly accepted notion that active vibration control of partitions is an ineffective means of controlling sound transmission. With appropriate construction, actuation

  9. Semi-active control of piezoelectric coating's underwater sound absorption by combining design of the shunt impedances

    NASA Astrophysics Data System (ADS)

    Sun, Yang; Li, Zhaohui; Huang, Aigen; Li, Qihu

    2015-10-01

    Piezoelectric shunt damping technology has been applied in the field of underwater sound absorption in recent years. In order to achieve broadband echo reduction, semi-active control of sound absorption of multi-layered piezoelectric coating by shunt damping is significant. In this paper, a practical method is proposed to control the underwater sound absorption coefficients of piezoelectric coating layers by combining design of the shunt impedance that allows certain sound absorption coefficients at setting frequencies. A one-dimensional electro-acoustic model of the piezoelectric coating and the backing is established based on the Mason equivalent circuit theory. First, the shunt impedance of the coating is derived under the constraint of sound absorption coefficient at one frequency. Then, taking the 1-3 piezoelectric composite coating as an example, the sound absorption properties of the coating shunted to the designed shunt impedance are investigated. Next, on the basis of that, an iterative method for two constrained frequencies and an optimizing algorithm for multiple constrained frequencies are provided for combining design of the shunt impedances. At last, an experimental sample with four piezoelectric material layers is manufactured, of which the sound absorption coefficients are measured in an impedance tube. The experimental results show good agreement with the finite element simulation results. It is proved that a serial R-L circuit can control the peak frequency, maximum and bandwidth of the sound absorption coefficient and the combining R-L circuits shunted to multiple layers can control the sound absorption coefficients at multiple frequencies.

  10. Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

    NASA Technical Reports Server (NTRS)

    Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

    1994-01-01

    An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

  11. Active control of aircraft engine inlet noise using compact sound sources and distributed error sensors

    NASA Technical Reports Server (NTRS)

    Burdisso, Ricardo (Inventor); Fuller, Chris R. (Inventor); O'Brien, Walter F. (Inventor); Thomas, Russell H. (Inventor); Dungan, Mary E. (Inventor)

    1996-01-01

    An active noise control system using a compact sound source is effective to reduce aircraft engine duct noise. The fan noise from a turbofan engine is controlled using an adaptive filtered-x LMS algorithm. Single multi channel control systems are used to control the fan blade passage frequency (BPF) tone and the BPF tone and the first harmonic of the BPF tone for a plane wave excitation. A multi channel control system is used to control any spinning mode. The multi channel control system to control both fan tones and a high pressure compressor BPF tone simultaneously. In order to make active control of turbofan inlet noise a viable technology, a compact sound source is employed to generate the control field. This control field sound source consists of an array of identical thin, cylindrically curved panels with an inner radius of curvature corresponding to that of the engine inlet. These panels are flush mounted inside the inlet duct and sealed on all edges to prevent leakage around the panel and to minimize the aerodynamic losses created by the addition of the panels. Each panel is driven by one or more piezoelectric force transducers mounted on the surface of the panel. The response of the panel to excitation is maximized when it is driven at its resonance; therefore, the panel is designed such that its fundamental frequency is near the tone to be canceled, typically 2000-4000 Hz.

  12. Analogy electromagnetism-acoustics: Validation and application to local impedance active control for sound absorption

    NASA Astrophysics Data System (ADS)

    Nicolas, L.; Furstoss, M.; Galland, M. A.

    1998-10-01

    An analogy between electromagnetism and acoustics is presented in 2D. The propagation of sound in presence of absorbing material is modeled using an open boundary microwave package. Validation is performed through analytical and experimental results. Application to local impedance active control for free field sound absorption is finally described. Une analogie entre acoustique et électromagnétisme est présentée en 2D, afin de modéliser la propagation d'ondes acoustiques, en présence de matériau absorbant et à l'aide d'un logiciel de micro-ondes en domaine ouvert. Cette analogie est validée par des résultats analytiques et expérimentaux. Une application au contrôle actif de l'impédance acoustique de surface de matériaux poreux est finalement décrite.

  13. Prediction of prognosis of ALS: Importance of active denervation findings of the cervical-upper limb area and trunk area.

    PubMed

    Sato, Yoko; Nakatani, Eiji; Watanabe, Yasuhiro; Fukushima, Masanori; Nakashima, Kenji; Kannagi, Mari; Kanatani, Yasuhiro; Mizushima, Hiroshi

    2015-11-01

    Amyotrophic lateral sclerosis (ALS) is a motor neuron disease characterized by serious muscle atrophy and weakness. The purpose of this study was to find prognostic factors in patients with mild ALS using application forms for the Specified Disease Treatment Research Program in Japan. We classified ALS as mild, moderate and severe. The subjects consisted of 363 patients with mild ALS who underwent needle electromyography at registration and were followed for more than one year. Time to progression to severe ALS and time to deterioration of activities of daily living such as speech dysfunction, upper limb dysfunction, and walking disability were used as outcomes. Cox proportional hazards model analysis was performed to identify prognostic factors. Of the patients with initially mild ALS, 38.3% (139/363) had progressed severe ALS at the last follow-up. In multivariate analysis of time to progression to severe ALS, bulbar onset (hazard ratio [95% confidence interval]: 1.68 [1.13-2.49], p = 0.010), tongue atrophy (1.69 [1.14-2.51], p = 0.009), dyspnea (1.57 [1.02-2.41], p = 0.042) and active denervation findings (ADFs) of the cervical-upper limb area (1.81 [1.25-2.63], p = 0.002) emerged as prognostic factors. Furthermore ADFs in the trunk area were prognostic factors for upper limb dysfunction and walking disability (1.72 [1.05-2.81], p = 0.031, and 1.97 [1.09-3.59], p = 0.026). In conclusion ADFs of the cervical-upper limb area and trunk area were prognostic factors in ALS patients.

  14. Prediction of prognosis of ALS: Importance of active denervation findings of the cervical-upper limb area and trunk area

    PubMed Central

    Sato, Yoko; Nakatani, Eiji; Watanabe, Yasuhiro; Fukushima, Masanori; Nakashima, Kenji; Kannagi, Mari; Kanatani, Yasuhiro; Mizushima, Hiroshi

    2015-01-01

    Summary Amyotrophic lateral sclerosis (ALS) is a motor neuron disease characterized by serious muscle atrophy and weakness. The purpose of this study was to find prognostic factors in patients with mild ALS using application forms for the Specified Disease Treatment Research Program in Japan. We classified ALS as mild, moderate and severe. The subjects consisted of 363 patients with mild ALS who underwent needle electromyography at registration and were followed for more than one year. Time to progression to severe ALS and time to deterioration of activities of daily living such as speech dysfunction, upper limb dysfunction, and walking disability were used as outcomes. Cox proportional hazards model analysis was performed to identify prognostic factors. Of the patients with initially mild ALS, 38.3% (139/363) had progressed severe ALS at the last follow-up. In multivariate analysis of time to progression to severe ALS, bulbar onset (hazard ratio [95% confidence interval]: 1.68 [1.13–2.49], p = 0.010), tongue atrophy (1.69 [1.14–2.51], p = 0.009), dyspnea (1.57 [1.02–2.41], p = 0.042) and active denervation findings (ADFs) of the cervical-upper limb area (1.81 [1.25–2.63], p = 0.002) emerged as prognostic factors. Furthermore ADFs in the trunk area were prognostic factors for upper limb dysfunction and walking disability (1.72 [1.05–2.81], p = 0.031, and 1.97 [1.09–3.59], p = 0.026). In conclusion ADFs of the cervical-upper limb area and trunk area were prognostic factors in ALS patients. PMID:26668778

  15. Improved training of neural networks for the nonlinear active control of sound and vibration.

    PubMed

    Bouchard, M; Paillard, B; Le Dinh, C T

    1999-01-01

    Active control of sound and vibration has been the subject of a lot of research in recent years, and examples of applications are now numerous. However, few practical implementations of nonlinear active controllers have been realized. Nonlinear active controllers may be required in cases where the actuators used in active control systems exhibit nonlinear characteristics, or in cases when the structure to be controlled exhibits a nonlinear behavior. A multilayer perceptron neural-network based control structure was previously introduced as a nonlinear active controller, with a training algorithm based on an extended backpropagation scheme. This paper introduces new heuristical training algorithms for the same neural-network control structure. The objective is to develop new algorithms with faster convergence speed (by using nonlinear recursive-least-squares algorithms) and/or lower computational loads (by using an alternative approach to compute the instantaneous gradient of the cost function). Experimental results of active sound control using a nonlinear actuator with linear and nonlinear controllers are presented. The results show that some of the new algorithms can greatly improve the learning rate of the neural-network control structure, and that for the considered experimental setup a neural-network controller can outperform linear controllers.

  16. [160 activities analyzed by the risk of biomechanical overload on the upper limbs in small industry, handicrafts, services and agriculture].

    PubMed

    Caselli, Ugo; Breschi, Chiara; Compagnonil, Raffaella; De Filippo, Laura; Gogliettino, Maria Angela; Guerrera, Elena; Mameli, Marina; Mastrominico, Eleonora; Mochi, Silvia; Sarto, Daniela

    2014-01-01

    We analyzed 160 work activities in the sectors of small industries, handicrafts, services and agriculture to evaluate the risk of biomnechanical overload of the upper limbs with the OCRA Checklist. The aim was to provide a tool available for the risk assessment in activities generally underestimnated for this risk and typical of the Italian production. The information was provided in the form of cards containing easily accessible data, risk scenarios in different timing, along with some of the key prevention interventions that can be realized.

  17. Single low-threshold afferents innervating the skin of the human foot modulate ongoing muscle activity in the upper limbs.

    PubMed

    Bent, Leah R; Lowrey, Catherine R

    2013-03-01

    We have shown for the first time that single cutaneous afferents in the foot dorsum have significant reflex coupling to motoneurons supplying muscles in the upper limb, particularly posterior deltoid and triceps brachii. These observations strengthen what we know from whole nerve stimulation, that skin on the foot and ankle can contribute to the modulation of interlimb muscles in distant innervation territories. The current work provides evidence of the mechanism behind the reflex, where one single skin afferent can evoke a reflex response, rather than a population. Nineteen of forty-one (46%) single cutaneous afferents isolated in the dorsum or plantar surface of the foot elicited a significant modulation of muscle activity in the upper limb. Identification of single afferents in this reflex indicates the strength of the connection and, ultimately, the importance of foot skin in interlimb coordination. The median response magnitude was 2.29% of background EMG, and the size of the evoked response did not significantly differ among the four mechanoreceptor classes (P > 0.1). Interestingly, although the distribution of afferents types did not differ across the foot dorsum, there was a significantly greater coupling response from receptors located on the medial aspect of the foot dorsum (P < 0.01). Furthermore, the most consistent coupling with upper limb muscles was demonstrated by type I afferents (fast and slowly adapting). This work contributes to the current literature on receptor specificity, supporting the view that individual classes of cutaneous afferents may subserve specific roles in kinesthesia, reflexes, and tactile perception.

  18. Impact of decline-board squat exercises and knee joint angles on the muscle activity of the lower limbs.

    PubMed

    Lee, Daehee; Lee, Sangyong; Park, Jungseo

    2015-08-01

    [Purpose] This study aims to investigate how squat exercises on a decline board and how the knee joint angles affect the muscle activity of the lower limbs. [Subjects] The subjects were 26 normal adults. [Methods] A Tumble Forms wedge device was used as the decline board, and the knee joint angles were measured with a goniometer. To examine the muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior of the lower limbs, a comparison analysis with electromyography was conducted. [Results] The muscle activity of the biceps femoris, rectus femoris, gastrocnemius lateralis, and tibialis anterior increased with increased knee joint angles, both for squat exercises on the decline board and on a flat floor. When the knee joint angle was 45°, 60°, and 90°, the muscle activity of the rectus femoris was significantly higher and that of the tibialis anterior was significantly lower during squat exercises on the decline board than on the flat floor. When the knee joint angle was 90°, the muscle activity of the gastrocnemius lateralis was significantly lower. [Conclusion] Squat exercises on a decline board are an effective intervention to increase the muscle activity of the rectus femoris with increased knee joint angles.

  19. Stretch and shortening of skeletal muscles activated along the ascending limb of the force-length relation.

    PubMed

    Rassier, Dilson E; Pun, Clara

    2010-01-01

    There is a history dependence of skeletal muscle contraction. When muscles are activated and subsequently stretched, they produce a long lasting force enhancement. When muscles are activated and subsequently shortened, they produce a long-lasting force depression. The purposes of the studies shown in this chapter were (1) to evaluate if force enhancement and force depression are present along the ascending limb of the force-length (FL) relation, (2) to evaluate if the history-dependent properties of force production are associated with sarcomere length (SL) non-uniformity, and (3) to determine the effects of cross-bridge (de)activation on force depression. Isolated myofibrils were activated by either Ca²(+) or MgADP and were subjected to consecutive stretches or shortenings along the ascending limb of the FL relation, separated by periods (approximately 5 s) of isometric contraction. Force after stretch was higher than force after shortening when the contractions were produced at similar SLs. The difference in force could not be explained by SL non-uniformity. After shortening, MgADP activation produced forces that were higher than Ca²(+) activation. Since MgADP induces the formation of strongly bound cross-bridges, the result suggests that force depression following shortening is associated with cross-bridge deactivation.

  20. Context-Dependent Neural Activation: Internally and Externally Guided Rhythmic Lower Limb Movement in Individuals With and Without Neurodegenerative Disease.

    PubMed

    Hackney, Madeleine E; Lee, Ho Lim; Battisto, Jessica; Crosson, Bruce; McGregor, Keith M

    2015-01-01

    Parkinson's disease is a neurodegenerative disorder that has received considerable attention in allopathic medicine over the past decades. However, it is clear that, to date, pharmacological and surgical interventions do not fully address symptoms of PD and patients' quality of life. As both an alternative therapy and as an adjuvant to conventional approaches, several types of rhythmic movement (e.g., movement strategies, dance, tandem biking, and Tai Chi) have shown improvements to motor symptoms, lower limb control, and postural stability in people with PD (1-6). However, while these programs are increasing in number, still little is known about the neural mechanisms underlying motor improvements attained with such interventions. Studying limb motor control under task-specific contexts can help determine the mechanisms of rehabilitation effectiveness. Both internally guided (IG) and externally guided (EG) movement strategies have evidence to support their use in rehabilitative programs. However, there appears to be a degree of differentiation in the neural substrates involved in IG vs. EG designs. Because of the potential task-specific benefits of rhythmic training within a rehabilitative context, this report will consider the use of IG and EG movement strategies, and observations produced by functional magnetic resonance imaging and other imaging techniques. This review will present findings from lower limb imaging studies, under IG and EG conditions for populations with and without movement disorders. We will discuss how these studies might inform movement disorders rehabilitation (in the form of rhythmic, music-based movement training) and highlight research gaps. We believe better understanding of lower limb neural activity with respect to PD impairment during rhythmic IG and EG movement will facilitate the development of novel and effective therapeutic approaches to mobility limitations and postural instability.

  1. Context-Dependent Neural Activation: Internally and Externally Guided Rhythmic Lower Limb Movement in Individuals With and Without Neurodegenerative Disease

    PubMed Central

    Hackney, Madeleine E.; Lee, Ho Lim; Battisto, Jessica; Crosson, Bruce; McGregor, Keith M.

    2015-01-01

    Parkinson’s disease is a neurodegenerative disorder that has received considerable attention in allopathic medicine over the past decades. However, it is clear that, to date, pharmacological and surgical interventions do not fully address symptoms of PD and patients’ quality of life. As both an alternative therapy and as an adjuvant to conventional approaches, several types of rhythmic movement (e.g., movement strategies, dance, tandem biking, and Tai Chi) have shown improvements to motor symptoms, lower limb control, and postural stability in people with PD (1–6). However, while these programs are increasing in number, still little is known about the neural mechanisms underlying motor improvements attained with such interventions. Studying limb motor control under task-specific contexts can help determine the mechanisms of rehabilitation effectiveness. Both internally guided (IG) and externally guided (EG) movement strategies have evidence to support their use in rehabilitative programs. However, there appears to be a degree of differentiation in the neural substrates involved in IG vs. EG designs. Because of the potential task-specific benefits of rhythmic training within a rehabilitative context, this report will consider the use of IG and EG movement strategies, and observations produced by functional magnetic resonance imaging and other imaging techniques. This review will present findings from lower limb imaging studies, under IG and EG conditions for populations with and without movement disorders. We will discuss how these studies might inform movement disorders rehabilitation (in the form of rhythmic, music-based movement training) and highlight research gaps. We believe better understanding of lower limb neural activity with respect to PD impairment during rhythmic IG and EG movement will facilitate the development of novel and effective therapeutic approaches to mobility limitations and postural instability. PMID:26696952

  2. Sound production by North Atlantic right whales (Eubalaena glacialis) in surface active groups.

    PubMed

    Parks, Susan E; Tyack, Peter L

    2005-05-01

    The surface active group (SAG) is the most commonly observed surface social behavior of North Atlantic right whales. Recordings were made from 52 SAGs in the Bay of Fundy, Canada between July and September, from 1999 to 2002. The call types recorded from these groups were similar to those described previously for Southern right whales (Eubalaena australis), with six major call types being termed scream, gunshot, blow, upcall, warble, and downcall. The percentage of total calls of each call type depended on the group size and composition. The most common call type recorded was the scream call. The scream calls were produced by the focal female in a SAG. Production of other sound types can be attributed to whales other than the focal female, with gunshot and upcalls produced by males, and warble calls produced by female calves. The source levels for these sounds range from 137 to 162 dB rms re 1 ,tPa-m for tonal calls and 174 to 192 dB rms for broadband gunshot sounds.

  3. Sound production by North Atlantic right whales (Eubalaena glacialis) in surface active groups

    NASA Astrophysics Data System (ADS)

    Parks, Susan E.; Tyack, Peter L.

    2005-05-01

    The surface active group (SAG) is the most commonly observed surface social behavior of North Atlantic right whales. Recordings were made from 52 SAGs in the Bay of Fundy, Canada between July and September, from 1999 to 2002. The call types recorded from these groups were similar to those described previously for Southern right whales (Eubalaena australis), with six major call types being termed scream, gunshot, blow, upcall, warble, and downcall. The percentage of total calls of each call type depended on the group size and composition. The most common call type recorded was the scream call. The scream calls were produced by the focal female in a SAG. Production of other sound types can be attributed to whales other than the focal female, with gunshot and upcalls produced by males, and warble calls produced by female calves. The source levels for these sounds range from 137 to 162 dB rms re 1 μPa-m for tonal calls and 174 to 192 dB rms for broadband gunshot sounds. .

  4. Control strategies and mechanisms for active control of sound transmission into a vibro-acoustic enclosure

    NASA Astrophysics Data System (ADS)

    Jin, Guoyong; Feng, Na; Yang, Tiejun

    2011-06-01

    An analytical study was presented on active control of sound transmission into a vibro-acoustic enclosure comprising two flexible plates. Two types of actuators were used, i.e. acoustic actuator and distributed lead zirconate titanate piezoelectric (PZT) actuator instead of point force actuator. Using the modal acoustic transfer impedance-mobility matrices, the excitation and interaction in the coupled sound transmission system can be described with clear physical significance. With the control system designed to globally reduce the sound field, different control system configurations were considered, including the structural actuator on the incident plate, actuator on the receiving plate, acoustic actuator on the cavity, and their combinations. The effectiveness and performance of the control strategy corresponding to each system configuration were compared and discussed. The role and control mechanism of each type of actuator were of particular interest. It was shown that the incident plate actuator is effective in controlling the cavity-dominated modes and the structural modes dominated by the incident plate and receiving plate. Two main control mechanisms are involved in this control configuration, i.e., modal suppressing and modal rearrangement. For control system configuration with only acoustic actuator in the enclosure, the mechanism involved in this arrangement is purely modal suppression. Desirable placements of structural actuators in terms of total potential energy reduction were also discussed.

  5. Speed of sound estimation with active PZT element for thermal monitoring during ablation therapy: feasibility study

    NASA Astrophysics Data System (ADS)

    Kim, Younsu; Guo, Xiaoyu; Cheng, Alexis; Boctor, Emad M.

    2016-04-01

    Controlling the thermal dose during ablation therapy is instrumental to successfully removing the tumor while preserving the surrounding healthy tissue. In the practical scenario, surgeons must be able to determine the ablation completeness in the tumor region. Various methods have been proposed to monitor it, one of which uses ultrasound since it is a common intraoperative imaging modality due to its non-invasive, cost-effective, and convenient natures. In our approach, we propose to use time of flight (ToF) information to estimate speed of sound changes. Accurate speed of sound estimation is crucial because it is directly correlated with temperature change and subsequent determination of ablation completeness. We divide the region of interest in a circular fashion with a variable radius from the ablator tip. We introduce the concept of effective speed of sound in each of the sub-regions. Our active PZT element control system facilitates this unique approach by allowing us to acquire one-way ToF information between the PZT element and each of the ultrasound elements. We performed a simulation and an experiment to verify feasibility of this method. The simulation result showed that we could compute the effective speed of sound within 0.02m/s error in our discrete model. We also perform a sensitivity analysis for this model. Most of the experimental results had less than 1% error. Simulation using a Gaussian continuous model with multiple PZT elements is also demonstrated. We simulate the effect of the element location one the optimization result.

  6. Limb Loss

    MedlinePlus

    ... limb. Learning how to use it takes time. Physical therapy can help you adapt. Recovery from the loss of a limb can be hard. Sadness, anger, and frustration are common. If you are having a tough time, talk to your doctor. Treatment with medicine or counseling can help.

  7. The effect of exercise types for rotator cuff repair patients on activities of shoulder muscles and upper limb disability

    PubMed Central

    Kang, Jeong-Il; Moon, Young-Jun; Choi, Hyun; Jeong, Dae-Keun; Kwon, Hye-Min; Park, Jun-Su

    2016-01-01

    [Purpose] This study investigated the effect on activities, shoulder muscle fatigue, upper limb disability of two exercise types performed by patients in the post- immobilization period of rotator cuff repair. [Subjects and Methods] The intervention program was performed by 20 patients from 6 weeks after rotator cuff repair. Ten subjects each were randomly allocated to a group performing open kinetic chain exercise and a group preforming closed kinetic chain exercise. Muscle activity and median frequency were measured by using sEMG and the Upper Extremity Function Assessment before and after conducting the intervention and changes in the results were compared. [Results] There was a significant within group increases in the activities of the shoulder muscles, except for the posterior deltoid. The median power frequencies (MFD) of the supraspinatus, infraspinatus and anterior deltoid significantly increased in the open kinetic chain exercise group, but that of the posterior deltoid decreased. There were significant differences in the changes in the upper limb disability scores of the two groups, in the shoulder muscle activities, except for that of the posterior deltoid, in the comparison of the change in the muscle activities of the two groups, and in the MDFs of all shoulder muscles. [Conclusion] The Median power frequencies of all these muscles after closed kinetic chain exercise increased indicating that muscle fatigue decreased. Therefore, research into exercise programs using closed kinetic chain exercises will be needed to establish exercise methods for reducing muscle fatigue. PMID:27821933

  8. The Effectiveness of Lower-Limb Wearable Technology for Improving Activity and Participation in Adult Stroke Survivors: A Systematic Review

    PubMed Central

    Parker, Jack; Martyn St-James, Marrissa; Mawson, Susan

    2016-01-01

    Background With advances in technology, the adoption of wearable devices has become a viable adjunct in poststroke rehabilitation. Regaining ambulation is a top priority for an increasing number of stroke survivors. However, despite an increase in research exploring these devices for lower limb rehabilitation, little is known of the effectiveness. Objective This review aims to assess the effectiveness of lower limb wearable technology for improving activity and participation in adult stroke survivors. Methods Randomized controlled trials (RCTs) of lower limb wearable technology for poststroke rehabilitation were included. Primary outcome measures were validated measures of activity and participation as defined by the International Classification of Functioning, Disability and Health. Databases searched were MEDLINE, Web of Science (Core collection), CINAHL, and the Cochrane Library. The Cochrane Risk of Bias Tool was used to assess the methodological quality of the RCTs. Results In the review, we included 11 RCTs with collectively 550 participants at baseline and 474 participants at final follow-up including control groups and participants post stroke. Participants' stroke type and severity varied. Only one study found significant between-group differences for systems functioning and activity. Across the included RCTs, the lowest number of participants was 12 and the highest was 151 with a mean of 49 participants. The lowest number of participants to drop out of an RCT was zero in two of the studies and 19 in one study. Significant between-group differences were found across three of the 11 included trials. Out of the activity and participation measures alone, P values ranged from P=.87 to P ≤.001. Conclusions This review has highlighted a number of reasons for insignificant findings in this area including low sample sizes, appropriateness of the RCT methodology for complex interventions, a lack of appropriate analysis of outcome data, and participant stroke

  9. Maintenance of neuronal size gradient in MNTB requires sound-evoked activity

    PubMed Central

    Weatherstone, Jessica H.; Pilati, Nadia; Wang, Yuan; Forsythe, Ian D.; Rubel, Edwin W.; Tempel, Bruce L.

    2016-01-01

    The medial nucleus of the trapezoid body (MNTB) is an important source of inhibition during the computation of sound location. It transmits fast and precisely timed action potentials at high frequencies; this requires an efficient calcium clearance mechanism, in which plasma membrane calcium ATPase 2 (PMCA2) is a key component. Deafwaddler (dfw2J) mutant mice have a null mutation in PMCA2 causing deafness in homozygotes (dfw2J/dfw2J) and high-frequency hearing loss in heterozygotes (+/dfw2J). Despite the deafness phenotype, no significant differences in MNTB volume or cell number were observed in dfw2J homozygous mutants, suggesting that PMCA2 is not required for MNTB neuron survival. The MNTB tonotopic axis encodes high to low sound frequencies across the medial to lateral dimension. We discovered a cell size gradient along this axis: lateral neuronal somata are significantly larger than medially located somata. This size gradient is decreased in +/dfw2J and absent in dfw2J/dfw2J. The lack of acoustically driven input suggests that sound-evoked activity is required for maintenance of the cell size gradient. This hypothesis was corroborated by selective elimination of auditory hair cell activity with either hair cell elimination in Pou4f3 DTR mice or inner ear tetrodotoxin (TTX) treatment. The change in soma size was reversible and recovered within 7 days of TTX treatment, suggesting that regulation of the gradient is dependent on synaptic activity and that these changes are plastic rather than permanent. NEW & NOTEWORTHY Neurons of the medial nucleus of the trapezoid body (MNTB) act as fast-spiking inhibitory interneurons within the auditory brain stem. The MNTB is topographically organized, with low sound frequencies encoded laterally and high frequencies medially. We discovered a cell size gradient along this axis: lateral neurons are larger than medial neurons. The absence of this gradient in deaf mice lacking plasma membrane calcium ATPase 2 suggests an

  10. Maintenance of neuronal size gradient in MNTB requires sound-evoked activity.

    PubMed

    Weatherstone, Jessica H; Kopp-Scheinpflug, Conny; Pilati, Nadia; Wang, Yuan; Forsythe, Ian D; Rubel, Edwin W; Tempel, Bruce L

    2017-02-01

    The medial nucleus of the trapezoid body (MNTB) is an important source of inhibition during the computation of sound location. It transmits fast and precisely timed action potentials at high frequencies; this requires an efficient calcium clearance mechanism, in which plasma membrane calcium ATPase 2 (PMCA2) is a key component. Deafwaddler (dfw(2J) ) mutant mice have a null mutation in PMCA2 causing deafness in homozygotes (dfw(2J) /dfw(2J) ) and high-frequency hearing loss in heterozygotes (+/dfw(2J) ). Despite the deafness phenotype, no significant differences in MNTB volume or cell number were observed in dfw(2J) homozygous mutants, suggesting that PMCA2 is not required for MNTB neuron survival. The MNTB tonotopic axis encodes high to low sound frequencies across the medial to lateral dimension. We discovered a cell size gradient along this axis: lateral neuronal somata are significantly larger than medially located somata. This size gradient is decreased in +/dfw(2J) and absent in dfw(2J) /dfw(2J) The lack of acoustically driven input suggests that sound-evoked activity is required for maintenance of the cell size gradient. This hypothesis was corroborated by selective elimination of auditory hair cell activity with either hair cell elimination in Pou4f3 DTR mice or inner ear tetrodotoxin (TTX) treatment. The change in soma size was reversible and recovered within 7 days of TTX treatment, suggesting that regulation of the gradient is dependent on synaptic activity and that these changes are plastic rather than permanent.NEW & NOTEWORTHY Neurons of the medial nucleus of the trapezoid body (MNTB) act as fast-spiking inhibitory interneurons within the auditory brain stem. The MNTB is topographically organized, with low sound frequencies encoded laterally and high frequencies medially. We discovered a cell size gradient along this axis: lateral neurons are larger than medial neurons. The absence of this gradient in deaf mice lacking plasma membrane calcium ATPase 2

  11. How does high-frequency sound or vibration activate vestibular receptors?

    PubMed

    Curthoys, I S; Grant, J W

    2015-03-01

    The mechanism by which vestibular neural phase locking occurs and how it relates to classical otolith mechanics is unclear. Here, we put forward the hypothesis that sound and vibration both cause fluid pressure waves in the inner ear and that it is these pressure waves which displace the hair bundles on vestibular receptor hair cells and result in activation of type I receptor hair cells and phase locking of the action potentials in the irregular vestibular afferents, which synapse on type I receptors. This idea has been suggested since the early neural recordings and recent results give it greater credibility.

  12. Persistent responsiveness of long-latency auditory cortical activities in response to repeated stimuli of musical timbre and vowel sounds.

    PubMed

    Kuriki, Shinya; Ohta, Keisuke; Koyama, Sachiko

    2007-11-01

    Long-latency auditory-evoked magnetic field and potential show strong attenuation of N1m/N1 responses when an identical stimulus is presented repeatedly due to adaptation of auditory cortical neurons. This adaptation is weak in subsequently occurring P2m/P2 responses, being weaker for piano chords than single piano notes. The adaptation of P2m is more suppressed in musicians having long-term musical training than in nonmusicians, whereas the amplitude of P2 is enhanced preferentially in musicians as the spectral complexity of musical tones increases. To address the key issues of whether such high responsiveness of P2m/P2 responses to complex sounds is intrinsic and common to nonmusical sounds, we conducted a magnetoencephalographic study on participants who had no experience of musical training, using consecutive trains of piano and vowel sounds. The dipole moment of the P2m sources located in the auditory cortex indicated significantly suppressed adaptation in the right hemisphere both to piano and vowel sounds. Thus, the persistent responsiveness of the P2m activity may be inherent, not induced by intensive training, and common to spectrally complex sounds. The right hemisphere dominance of the responsiveness to musical and speech sounds suggests analysis of acoustic features of object sounds to be a significant function of P2m activity.

  13. Influence of shoes increasing dorsiflexion and decreasing metatarsus flexion on lower limb muscular activity during fitness exercises, walking, and running.

    PubMed

    Bourgit, David; Millet, Guillaume Y; Fuchslocher, Jörg

    2008-05-01

    The aim of the present study was to compare electromyographic activity during fitness exercises, walking, and running among 3 different dorsiflexion shoes (+2 degrees , +4 degrees , and +10 degrees ) and standard shoes (-4 degrees ). The 3 different dorsiflexion shoes tested in this study have a curvature placed in the middle of the sole. This design was specially projected to decrease the metatarsus flexion. Electromyographic activity of 9 lower limb muscles was measured on 12 healthy female subjects during 5 fitness exercises (unload squat, side and front step, submaximal ballistic plantar flexion, and lunge exercise), and during running (10 km x h(-1)) and walking (4.5 km x h(-1)) on a treadmill. EMG signal was analyzed with the root mean square (RMS) and integrated EMG. All RMS data measured during these exercises were expressed as percentages of maximum voluntary isometric contraction. The results show that dorsiflexion affects muscle recruitment and reorganizes the motor pattern. The general tendency was that the tibialis anterior activity increased with dorsiflexion. However, an optimal dorsiflexion existed for various exercises. It is concluded that shoes with moderate dorsiflexion can activate lower limb muscles differently compared with both standard shoes and shoes with large dorsiflexion during submaximal exercises and locomotion.

  14. Sulfoxide stimulation of chondrogenesis in limb mesenchyme is accompanied by an increase in type II collagen enhancer activity

    SciTech Connect

    Horton, W.E. Jr.; Higginbotham, J.D. )

    1991-05-01

    We have utilized a modification of the limb bud mesenchyme micromass culture system to screen compounds that might stimulate chondrogenesis. Two compounds in the sulfoxide family (methylphenylsulfoxide and p-chlorophenyl methyl sulfoxide) were stimulatory at 10(-2) M and 10(-3) M, respectively; whereas other sulfoxides and organic solvents were not active at these concentrations. In addition, specific growth factors (basic FGF, IGF-I, IGF-II) were not chondroinductive at concentrations that are active in other cell systems. Both sulfoxide compounds stimulated cartilage nodule formation, ({sup 35}S)sulfate incorporation, and activity of the regulatory sequences of the collagen II gene. In contrast, transforming growth factor beta-1 (10 ng/ml) stimulated sulfate incorporation but produced only a diffuse deposition of cartilage matrix and reduced the ability of the cells to utilize the regulatory sequences of the collagen II gene. The sulfoxides appear to promote the differentiation of limb bud cells to chondrocytes and thus exhibit chondroinductive activity.

  15. Physical mechanisms of active control of sound transmission through rib stiffened double-panel structure

    NASA Astrophysics Data System (ADS)

    Ma, Xiyue; Chen, Kean; Ding, Shaohu; Yu, Haoxin

    2016-06-01

    This paper presents an analytical investigation on physical mechanisms of actively controlling sound transmission through a rib stiffened double-panel structure using point source in the cavity. The combined modal expansion and vibro-acoustic coupling methods are applied to establish the theoretical model of such active structure. Under the condition of minimizing radiated power of the radiating ribbed plate, the physical mechanisms are interpreted in detail from the point of view of modal couplings similar as that used in existed literatures. Results obtained demonstrate that the rule of sound energy transmission and the physical mechanisms for the rib stiffened double-panel structure are all changed, and affected by the coupling effects of the rib when compared with the analytical results obtained for unribbed double-panel case. By taking the coupling effects of the rib into considerations, the cavity modal suppression and rearrangement mechanisms obtained in existed investigations are modified and supplemented for the ribbed plate case, which gives a clear interpretation for the physical nature involved in the active rib stiffened double-panel structure.

  16. Dynamics of sensorimotor cortex activation to spatial sounds precueing ipsi- versus contralateral manual responses.

    PubMed

    Kaiser, Jochen; Ulrich, Rolf; Lutzenberger, Werner

    2003-10-01

    Spatially informative visual precues give rise to event-related potential asymmetries with higher negativities over the contralateral hemisphere. However the attribution of these potentials to sensorimotor areas is still unclear. The present magnetoencephalography study assessed movement preparation processes to auditory spatial precues. Event-related desynchronization (ERD) was measured to test the hypothesis that lateralized sounds would give rise to a fast, stimulus-driven activation of motor networks independent of the precued response side. The lateralized vowels /a/ and /e/ served as precues for either ipsi- or contralateral responses, respectively, which had to be executed when an imperative stimulus was presented 1 s after precue onset. Two separate experiments were conducted with either blocked or mixed presentation of ipsi- and contralateral precues. Beta ERD over sensorimotor regions representing the stimulus side was elicited by both types of precues approximately 200 ms after their onset. For contralateral precues, a switch of beta ERD to the response hemisphere took place approximately 400 ms after trial-onset, peaking prior to the imperative stimulus (approximately 800 ms post trial-onset). Signal subspace projection demonstrated a high topographical correspondence between the early precue-related ERD and the pattern immediately preceding the response, suggesting that both were generated in similar motor networks. Apparently lateralized sounds give rise to an early activation of contralateral motor networks independent of the precued response. This suggests strong associations between space processing and action preparation networks, with fast activations preceding a detailed cortical analysis of stimulus meaning.

  17. Control of a pneumatic power active lower-limb orthosis with filter-based iterative learning control

    NASA Astrophysics Data System (ADS)

    Huang, Chia-En; Chen, Jian-Shiang

    2014-05-01

    A filter-based iterative learning control (FILC) scheme is developed in this paper, which consists in a proportional-derivative (PD) feedback controller and a feedforward filter. Moreover, based on two-dimensional system theory, the stability of the FILC system is proven. The design criteria for a wavelet transform filter (WTF) - chosen as the feedforward filter - and the PD feedback controller are also given. Finally, using a pneumatic power active lower-limb orthosis (PPALO) as the controlled plant, the wavelet-based iterative learning control (WILC) implementation and the orchestration of a trajectory tracking control simulation are given in detail and the overall tracking performance is validated.

  18. Warm-up with weighted bat and adjustment of upper limb muscle activity in bat swinging under movement correction conditions.

    PubMed

    Ohta, Yoichi; Ishii, Yasumitsu; Ikudome, Sachi; Nakamoto, Hiroki

    2014-02-01

    The effects of weighted bat warm-up on adjustment of upper limb muscle activity were investigated during baseball bat swinging under dynamic conditions that require a spatial and temporal adjustment of the swinging to hit a moving target. Seven male college baseball players participated in this study. Using a batting simulator, the task was to swing the standard bat coincident with the arrival timing and position of a moving target after three warm-up swings using a standard or weighted bat. There was no significant effect of weighted bat warm-up on muscle activity before impact associated with temporal or spatial movement corrections. However, lower inhibition of the extensor carpi ulnaris muscle activity was observed in a velocity-changed condition in the weighted bat warm-up, as compared to a standard bat warm-up. It is suggested that weighted bat warm-up decreases the adjustment ability associated with inhibition of muscle activation under movement correction conditions.

  19. Mobile Gait Analysis System for Lower Limb Amputee High-Level Activity Rehabilitation

    DTIC Science & Technology

    2012-09-01

    individual sensor boards which go on either the foot or limb segments (right) and enclosure with sensor board connected to the F/M foot sensor attached...performed the necessary testing. They are now on the latest iteration which will be manufactured in October 2012 and will go through mechanical...Indoors Barefoot . Am J Phys Med Rehabil. 2003:82(2), 96-100. 19. Dou P, Jia X, Suo S, Wang R, Zhang M. Pressure distribution at the stump/socket

  20. Historical Patterns and Drivers of Spatial Changes in Recreational Fishing Activity in Puget Sound, Washington

    PubMed Central

    Beaudreau, Anne H.; Whitney, Emily J.

    2016-01-01

    Small-scale fisheries are the primary users of many coastal fish stocks; yet, spatial and temporal patterns of recreational and subsistence fishing in coastal marine ecosystems are poorly documented. Knowledge about the spatial distribution of fishing activities can inform place-based management that balances species conservation with opportunities for recreation and subsistence. We used a participatory mapping approach to document changes in spatial fishing patterns of 80 boat-based recreational anglers from 1950 to 2010 in Puget Sound, Washington, USA. Hand-drawn fishing areas for salmon, rockfishes, flatfishes, and crabs were digitized and analyzed in a Geographic Information System. We found that recreational fishing has spanned the majority of Puget Sound since the 1950s, with the heaviest use limited to small areas of central and northern Puget Sound. People are still fishing in the same places they were decades ago, with relatively little change in specific locations despite widespread declines in salmon and bottomfish populations during the second half of the 20th century. While the location of core fishing areas remained consistent, the size of those areas and intensity of use changed over time. The size of fishing areas increased through the 2000s for salmon but declined after the 1970s and 1980s for rockfishes, flatfishes, and crabs. Our results suggest that the spatial extent of recreational bottomfishing increased after the 1960s, when the availability of motorized vessels and advanced fish-finding technologies allowed anglers to expand their scope beyond localized angling from piers and boathouses. Respondents offered a wide range of reasons for shifts in fishing areas over time, reflecting substantial individual variation in motivations and behaviors. Changes in fishing areas were most commonly attributed to changes in residence and declines in target species and least tied to fishery regulations, despite the implementation of at least 25 marine

  1. National Report Switzerland: Sounding Rocket and Balloon Activities and Related Research in Switzerland 2013-2015

    NASA Astrophysics Data System (ADS)

    Egli, M.

    2015-09-01

    , particularly in 2014. In order to keep the stations attractive to researchers from all over the world, investment in infrastructure is necessary. New instruments were recently installed at the Jungfrau East Ridge, for example, that now allow for the recording of additional climate and environmental data. A short summary of a few Swiss projects within the framework of sounding rocket and balloon activities and related research performed between 2013 and 2015 is provided in the following paragraphs.

  2. Assessing Acoustic Sound Levels Associated with Active Source Seismic Surveys in Shallow Marine Environments

    NASA Astrophysics Data System (ADS)

    Bohnenstiehl, D. R.; Tolstoy, M.; Thode, A.; Diebold, J. B.; Webb, S. C.

    2004-12-01

    The potential effect of active source seismic research on marine mammal populations is a topic of increasing concern, and controversy surrounding such operations has begun to impact the planning and permitting of academic surveys [e.g., Malakoff, 2002 Science]. Although no causal relationship between marine mammal strandings and seismic exploration has been proven, any circumstantial evidence must be thoroughly investigated. A 2002 stranding of two beaked whales in the Gulf of California within 50 km of a R/V Ewing seismic survey has been a subject of concern for both marine seismologists and environmentalists. In order to better understand possible received levels for whales in the vicinity of these operations, modeling is combined with ground-truth calibration measurements. A wide-angle parabolic equation model, which is capable of including shear within the sediment and basement layers, is used to generate predictive models of low-frequency transmission loss within the Gulf of California. This work incorporates range-dependent bathymetry, sediment thickness, sound velocity structure and sub-bottom properties. Oceanic sounds speed profiles are derived from the U.S. Navy's seasonal GDEM model and sediment thicknesses are taken from NOAA's worldwide database. The spectral content of the Ewing's 20-airgun seismic array is constrained by field calibration in the spring of 2003 [Tolstoy et al., 2004 GRL], indicating peak energies at frequencies below a few hundred Hz, with energy spectral density showing an approximate power-law decrease at higher frequencies (being ~40 dB below peak at 1 kHz). Transmission loss is estimated along a series of radials extending from multiple positions along the ship's track, with the directivity of the array accounted for by phase-shifting point sources that are scaled by the cube root of the individual airgun volumes. This allows the time-space history of low-frequency received levels to be reconstructed within the Gulf of California

  3. Stimulus intensity affects early sensory processing: sound intensity modulates auditory evoked gamma-band activity in human EEG.

    PubMed

    Schadow, Jeanette; Lenz, Daniel; Thaerig, Stefanie; Busch, Niko A; Fründ, Ingo; Herrmann, Christoph S

    2007-08-01

    We studied the effect of different sound intensities on the auditory evoked gamma-band response (GBR). Previous studies observed oscillatory gamma activity in the auditory cortex of animals and humans. For the visual modality, it has been demonstrated that the GBR can be modulated by top-down (attention, memory) as well as bottom-up factors (stimulus properties). Therefore, we expected to find a sound intensity modulation for the auditory GBR. 21 healthy participants without hearing deficits were investigated in a forced-choice discrimination task. Sinusoidal tones were presented at three systematically varied sound intensities (30, 45, 60 dB hearing level). The results of the auditory evoked potentials were predominantly consistent with previous studies. Furthermore, we observed an augmentation of the evoked GBR with increasing sound intensity. The analysis indicated that this intensity difference in the GBR amplitude most likely arises from increased phase-locking. The results demonstrate a distinct dependency between sound intensity and gamma-band oscillations. Future experiments that investigate the relationship between auditory evoked GBRs and higher cognitive processes should therefore select stimuli with an adequate sound intensity and control this variable to avoid confounding effects. In addition, it seems that gamma-band activity is more sensitive to exogenous stimulus parameters than evoked potentials.

  4. Adaptive wave field synthesis for broadband active sound field reproduction: signal processing.

    PubMed

    Gauthier, Philippe-Aubert; Berry, Alain

    2008-04-01

    Sound field reproduction is a physical approach to the reproduction of the natural spatial character of hearing. It is also useful in experimental acoustics and psychoacoustics. Wave field synthesis (WFS) is a known open-loop technology which assumes that the reproduction environment is anechoic. A real reflective reproduction space thus reduces the objective accuracy of WFS. Recently, adaptive wave field synthesis (AWFS) was defined as a combination of WFS and active compensation. AWFS is based on the minimization of reproduction errors and on the penalization of departure from the WFS solution. This paper focuses on signal processing for AWFS. A classical adaptive algorithm is modified for AWFS: filtered-reference least-mean-square. This modified algorithm and the classical equivalent leaky algorithm have similar convergence properties except that the WFS solution influences the adaptation rule of the modified algorithm. The paper also introduces signal processing for independent radiation mode control of AWFS on the basis of plant decoupling. Simulation results for AWFS are introduced for free-field and reflective spaces. The two algorithms effectively reproduce the sound field and compensate for the reproduction errors at the error sensors. The independent radiation mode control allows a more flexible tuning of the algorithm.

  5. Double panel with skyhook active damping control units for control of sound radiation.

    PubMed

    Gardonio, Paolo; Alujević, Neven

    2010-09-01

    This paper presents an experimental study on decentralized velocity feedback control on a double panel consisting of an external aluminum panel and a honeycomb trim panel. The decentralized feedback loops are formed by a 3x3 array of coil-magnet electrodynamic actuators that react off the trim panel and a lightweight stiff frame structure located in the air gap between the two panels. Microelectromechanical systems (MEMS) accelerometers are located on the opposite side of the trim panel in correspondence to the electrodynamic actuators. The grid structure is designed to provide an inertial reference to the actuators. In this way the velocity feedback control loops produce skyhook active damping on the double panel, which minimizes the vibrational response and sound radiation of the trim panel at low audio frequencies. Two configurations are considered where the grid structure is either weakly coupled or strongly coupled to the external panel. Both stability and control performance of the two configurations are analyzed experimentally. The study shows that the control configuration with the weakly coupled grid structure enables the implementation of larger stable feedback control gains, which lead to reductions of the sound radiated by the trim panel between 10 and 30 dB for the first seven resonance peaks.

  6. Frequencies of Inaudible High-Frequency Sounds Differentially Affect Brain Activity: Positive and Negative Hypersonic Effects

    PubMed Central

    Fukushima, Ariko; Yagi, Reiko; Kawai, Norie; Honda, Manabu; Nishina, Emi; Oohashi, Tsutomu

    2014-01-01

    The hypersonic effect is a phenomenon in which sounds containing significant quantities of non-stationary high-frequency components (HFCs) above the human audible range (max. 20 kHz) activate the midbrain and diencephalon and evoke various physiological, psychological and behavioral responses. Yet important issues remain unverified, especially the relationship existing between the frequency of HFCs and the emergence of the hypersonic effect. In this study, to investigate the relationship between the hypersonic effect and HFC frequencies, we divided an HFC (above 16 kHz) of recorded gamelan music into 12 band components and applied them to subjects along with an audible component (below 16 kHz) to observe changes in the alpha2 frequency component (10–13 Hz) of spontaneous EEGs measured from centro-parieto-occipital regions (Alpha-2 EEG), which we previously reported as an index of the hypersonic effect. Our results showed reciprocal directional changes in Alpha-2 EEGs depending on the frequency of the HFCs presented with audible low-frequency component (LFC). When an HFC above approximately 32 kHz was applied, Alpha-2 EEG increased significantly compared to when only audible sound was applied (positive hypersonic effect), while, when an HFC below approximately 32 kHz was applied, the Alpha-2 EEG decreased (negative hypersonic effect). These findings suggest that the emergence of the hypersonic effect depends on the frequencies of inaudible HFC. PMID:24788141

  7. Measurement of energetic radiation caused by thunderstorm activities by a sounding balloon and ground observation

    NASA Astrophysics Data System (ADS)

    Torii, T.

    2015-12-01

    Energetic radiation caused by thunderstorm activity is observed at various places, such as the ground, high mountain areas, and artificial satellites. In order to investigate the radiation source and its energy distribution, we measured energetic radiation by a sounding balloon, and the ground observation. On the measurement inside/above the thundercloud, we conducted a sounding observation using a radiosonde mounted two GM tubes (for gamma-rays, and for beta/gamma-rays), in addition to meteorological instruments. The balloon passed through a region of strong echoes in a thundercloud shown by radar image, at which time an increase in counting rate of the GM tube about 2 orders of magnitude occurred at the altitude from 5 km to 7.5 km. Furthermore, the counting rate of two GM tubes indicated the tendency different depending on movement of a balloon. This result suggests that the ratio for the gamma-rays (energetic photons) of the beta-rays (energetic electrons) varies according to the place in the thundercloud. Furthermore, we carried out a ground observation of the energetic gamma rays during winter thunderstorm at a coastal area facing the Sea of Japan. Two types of the energetic radiation have been observed at this time. We report the outline of these measurements and analysis in the session of the AGU meeting.

  8. Sound localization with communications headsets: comparison of passive and active systems.

    PubMed

    Abel, Sharon M; Tsang, Suzanne; Boyne, Stephen

    2007-01-01

    Studies have demonstrated that conventional hearing protectors interfere with sound localization. This research examines possible benefits from advanced communications devices. Horizontal plane sound localization was compared in normal-hearing males with the ears unoccluded and fitted with Peltor H10A passive attenuation earmuffs, Racal Slimgard II communications muffs in active noise reduction (ANR) and talk-through-circuitry (TTC) modes and Nacre QUIETPRO TM communications earplugs in off (passive attenuation) and push-to-talk (PTT) modes. Localization was assessed using an array of eight loudspeakers, two in each spatial quadrant. The stimulus was 75 dB SPL, 300-ms broadband noise. One block of 120 forced-choice loudspeaker identification trials was presented in each condition. Subjects responded using a laptop response box with a set of eight microswitches in the same configuration as the speaker array. A repeated measures ANOVA was applied to the dataset. The results reveal that the overall percent correct response was highest in the unoccluded condition (94%). A significant reduction of 24% was observed for the communications devices in TTC and PTT modes and a reduction of 49% for the passive muff and plug and muff with ANR. Disruption in performance was due to an increase in front-back reversal errors for mirror image spatial positions. The results support the conclusion that communications devices with advanced technologies are less detrimental to directional hearing than conventional, passive, limited amplification and ANR devices.

  9. Knowledge About Sounds-Context-Specific Meaning Differently Activates Cortical Hemispheres, Auditory Cortical Fields, and Layers in House Mice.

    PubMed

    Geissler, Diana B; Schmidt, H Sabine; Ehret, Günter

    2016-01-01

    Activation of the auditory cortex (AC) by a given sound pattern is plastic, depending, in largely unknown ways, on the physiological state and the behavioral context of the receiving animal and on the receiver's experience with the sounds. Such plasticity can be inferred when house mouse mothers respond maternally to pup ultrasounds right after parturition and naïve females have to learn to respond. Here we use c-FOS immunocytochemistry to quantify highly activated neurons in the AC fields and layers of seven groups of mothers and naïve females who have different knowledge about and are differently motivated to respond to acoustic models of pup ultrasounds of different behavioral significance. Profiles of FOS-positive cells in the AC primary fields (AI, AAF), the ultrasonic field (UF), the secondary field (AII), and the dorsoposterior field (DP) suggest that activation reflects in AI, AAF, and UF the integration of sound properties with animal state-dependent factors, in the higher-order field AII the news value of a given sound in the behavioral context, and in the higher-order field DP the level of maternal motivation and, by left-hemisphere activation advantage, the recognition of the meaning of sounds in the given context. Anesthesia reduced activation in all fields, especially in cortical layers 2/3. Thus, plasticity in the AC is field-specific preparing different output of AC fields in the process of perception, recognition and responding to communication sounds. Further, the activation profiles of the auditory cortical fields suggest the differentiation between brains hormonally primed to know (mothers) and brains which acquired knowledge via implicit learning (naïve females). In this way, auditory cortical activation discriminates between instinctive (mothers) and learned (naïve females) cognition.

  10. Spectroscopic study of a dark lane and a cool loop in a solar limb active region by Hinode/EIS

    SciTech Connect

    Lee, Kyoung-Sun; Imada, S.; Moon, Y.-J.; Lee, Jin-Yi

    2014-01-10

    We investigated a cool loop and a dark lane over a limb active region on 2007 March 14 using the Hinode/EUV Imaging Spectrometer. The cool loop is clearly seen in the spectral lines formed at the transition region temperature. The dark lane is characterized by an elongated faint structure in the coronal spectral lines and is rooted on a bright point. We examined their electron densities, Doppler velocities, and nonthermal velocities as a function of distance from the limb. We derived electron densities using the density sensitive line pairs of Mg VII, Si X, Fe XII, Fe XIII, and Fe XIV spectra. We also compared the observed density scale heights with the calculated scale heights from each peak formation temperatures of the spectral lines under the hydrostatic equilibrium. We noted that the observed density scale heights of the cool loop are consistent with the calculated heights, with the exception of one observed cooler temperature; we also found that the observed scale heights of the dark lane are much lower than their calculated scale heights. The nonthermal velocity in the cool loop slightly decreases along the loop, while nonthermal velocity in the dark lane sharply falls off with height. Such a decrease in the nonthermal velocity may be explained by wave damping near the solar surface or by turbulence due to magnetic reconnection near the bright point.

  11. It's More Fun than It Sounds--Enhancing Science Concepts through Hands-on Activities for Young Children

    ERIC Educational Resources Information Center

    Guha, Smita

    2012-01-01

    To teach young children, teachers choose topics in science that children are curious about. Children's inquisitive nature is reflected through the activities as they make repetitive sounds to find the cause and effect relationship. Teachers can make best use of those invaluable moments by incorporating those activities into science lessons on…

  12. The production and perception of emotionally expressive walking sounds: similarities between musical performance and everyday motor activity.

    PubMed

    Giordano, Bruno L; Egermann, Hauke; Bresin, Roberto

    2014-01-01

    Several studies have investigated the encoding and perception of emotional expressivity in music performance. A relevant question concerns how the ability to communicate emotions in music performance is acquired. In accordance with recent theories on the embodiment of emotion, we suggest here that both the expression and recognition of emotion in music might at least in part rely on knowledge about the sounds of expressive body movements. We test this hypothesis by drawing parallels between musical expression of emotions and expression of emotions in sounds associated with a non-musical motor activity: walking. In a combined production-perception design, two experiments were conducted, and expressive acoustical features were compared across modalities. An initial performance experiment tested for similar feature use in walking sounds and music performance, and revealed that strong similarities exist. Features related to sound intensity, tempo and tempo regularity were identified as been used similarly in both domains. Participants in a subsequent perception experiment were able to recognize both non-emotional and emotional properties of the sound-generating walkers. An analysis of the acoustical correlates of behavioral data revealed that variations in sound intensity, tempo, and tempo regularity were likely used to recognize expressed emotions. Taken together, these results lend support the motor origin hypothesis for the musical expression of emotions.

  13. The Production and Perception of Emotionally Expressive Walking Sounds: Similarities between Musical Performance and Everyday Motor Activity

    PubMed Central

    Giordano, Bruno L.; Egermann, Hauke; Bresin, Roberto

    2014-01-01

    Several studies have investigated the encoding and perception of emotional expressivity in music performance. A relevant question concerns how the ability to communicate emotions in music performance is acquired. In accordance with recent theories on the embodiment of emotion, we suggest here that both the expression and recognition of emotion in music might at least in part rely on knowledge about the sounds of expressive body movements. We test this hypothesis by drawing parallels between musical expression of emotions and expression of emotions in sounds associated with a non-musical motor activity: walking. In a combined production-perception design, two experiments were conducted, and expressive acoustical features were compared across modalities. An initial performance experiment tested for similar feature use in walking sounds and music performance, and revealed that strong similarities exist. Features related to sound intensity, tempo and tempo regularity were identified as been used similarly in both domains. Participants in a subsequent perception experiment were able to recognize both non-emotional and emotional properties of the sound-generating walkers. An analysis of the acoustical correlates of behavioral data revealed that variations in sound intensity, tempo, and tempo regularity were likely used to recognize expressed emotions. Taken together, these results lend support the motor origin hypothesis for the musical expression of emotions. PMID:25551392

  14. A novel BK channel-targeted peptide suppresses sound evoked activity in the mouse inferior colliculus

    PubMed Central

    Scott, L. L.; Brecht, E. J.; Philpo, A.; Iyer, S.; Wu, N. S.; Mihic, S. J.; Aldrich, R. W.; Pierce, J.; Walton, J. P.

    2017-01-01

    Large conductance calcium-activated (BK) channels are broadly expressed in neurons and muscle where they modulate cellular activity. Decades of research support an interest in pharmaceutical applications for modulating BK channel function. Here we report a novel BK channel-targeted peptide with functional activity in vitro and in vivo. This 9-amino acid peptide, LS3, has a unique action, suppressing channel gating rather than blocking the pore of heterologously expressed human BK channels. With an IC50 in the high picomolar range, the apparent affinity is higher than known high affinity BK channel toxins. LS3 suppresses locomotor activity via a BK channel-specific mechanism in wild-type or BK channel-humanized Caenorhabditis elegans. Topical application on the dural surface of the auditory midbrain in mouse suppresses sound evoked neural activity, similar to a well-characterized pore blocker of the BK channel. Moreover, this novel ion channel-targeted peptide rapidly crosses the BBB after systemic delivery to modulate auditory processing. Thus, a potent BK channel peptide modulator is open to neurological applications, such as preventing audiogenic seizures that originate in the auditory midbrain. PMID:28195225

  15. Active control of sound transmission through stiff lightweight composite fuselage constructions

    NASA Technical Reports Server (NTRS)

    Thomas, D. R.; Nelson, P. A.; Pinnington, R. J.; Elliott, S. J.

    1992-01-01

    Work was performed on the active control of sound transmission in composite structures. First, a model was outlined of a vibrating plate with arbitrary boundary conditions. Second, the far field was minimized to radiate acoustic power using secondary force inputs. Third, a model of a simple case of freely mounted stiff lightweight panels was used. Fourth, experimental results for aluminum honeycomb composite panels is presented. Fifth, experimental results are presented for the combination of a clamped steel plate and an aluminum honeycomb panel with secondary forces acting between the partitions. Finally, experimental results for the combination of a clamped steel plate with four secondary aluminum honeycomb panels is presented. All materials are shown in viewgraph format.

  16. AB296. SPR-23 Aberrant bladder reflexes can drive hind limb locomotor activity following complete suprasacral spinal cord injury

    PubMed Central

    Inouye, Brian M.; Brooks, Jillene M.; Degoski, Danielle J.; Hughes, Francis M.; Purves, J. Todd; Fraser, Matthew O.

    2016-01-01

    Objective Many rats with chronic suprasacral spinal cord injury (SCI) demonstrate hind limb locomotor activity (HLLA) in response to external crede or high pressure contractions during cystometry. We propose that this aberrant, pressure-driven bladder reflex pathway may be harnessed to facilitate walking in SCI patients. As a first step in exploring this possibility, we examined the relationship between intravesical pressure (IVP) and HLLA in chronic suprasacral SCI rats. Methods Female rats (4 weeks post-SCI at T9-10, n=16) were anesthetized with isoflurane and fitted with transvesical catheters and right quadriceps EMG electrodes to monitor bladder and hind limb locomotor activities, respectively. The animals were mounted in Ballman restraint cages to which they had been previously acclimated. The catheter was connected to a pressure transducer, an infusion pump, and a saline-filled reservoir mounted on a metered vertical pole (pressure clamp). After 30 min of recovery from anesthesia, the bladder was filled at 0.1 mL/min with saline to verify bladder-to-bladder reflex activity for 30 min. IVP was then increased in an interrupted stepwise fashion from 0–120 cmH2O at 10 cmH2O increments. Each step consisted of five minutes: 3 minutes at the new pressure followed by 2 minutes at 0 cmH2O. IVP and the number of HLLA events (as defined by rhythmic EMG discharges of 3–10 cycles/event) were recorded for each pressure step. This process was repeated for two more trials for each rat to assess the durability of the reflex. Data were analyzed using ANOVA with repeated measures both within and across pressure escalation trials. P<0.05 was considered significant. Results ANOVA revealed that locomotor events increased with increasing IVP and decreased with the number of escalation trials (P<0.0001 for both effects). The increase in the number of locomotor events with increasing IVP appeared to plateau at ~50–60 cmH2O (P<0.05 for all). The average of the maximal number of

  17. Relationship Between Lower Limb Muscle Activity and Platform Acceleration During Whole-Body Vibration Exercise.

    PubMed

    Lienhard, Karin; Vienneau, Jordyn; Nigg, Sandro; Meste, Olivier; Colson, Serge S; Nigg, Benno M

    2015-10-01

    The purpose of this study was to identify the influence of different magnitudes and directions of the vibration platform acceleration on surface electromyography (sEMG) during whole-body vibration (WBV) exercises. Therefore, a WBV platform was used that delivers vertical vibrations by a side-alternating mode, horizontal vibrations by a circular mode, and vibrations in all 3 planes by a dual mode. Surface electromyography signals of selected lower limb muscles were measured in 30 individuals while they performed a static squat on a vibration platform. The WBV trials included 2 side-alternating trials (Side-L: 6 Hz, 2.5 mm; Side-H: 16 Hz, 4 mm), 2 circular trials (Circ-L: 14 Hz, 0.8 mm; Circ-H: 43 Hz, 0.8 mm), and 4 dual-mode trials that were the combinations of the single-mode trials (Side-L/Circ-L, Side-L/Circ-H, Side-H/Circ-L, Side-H/Circ-H). Furthermore, control trials without vibration were assessed, and 3-dimensional platform acceleration was quantified during the vibration. Significant increases in the root mean square of the sEMG (sEMGRMS) compared with the control trial were found in most muscles for Side-L/Circ-H (+17 to +63%, p ≤ 0.05), Side-H/Circ-L (+7 to +227%, p ≤ 0.05), and Side-H/Circ-H (+21 to +207%, p < 0.01) and in the lower leg muscles for Side-H (+35 to +138%, p ≤ 0.05). Furthermore, only the vertical platform acceleration showed a linear relationship (r = 0.970, p < 0.001) with the averaged sEMGRMS of the lower limb muscles. Significant increases in sEMGRMS were found with a vertical acceleration threshold of 18 m·s(-2) and higher. The present results emphasize that WBV exercises should be performed on a platform that induces vertical accelerations of 18 m·s(-2) and higher.

  18. Fingernails Yield Clues to Limb Regeneration

    MedlinePlus

    ... embryonic development, as well as limb regeneration in amphibians. They found that the Wnt pathway was active ... nerve cells was crucial for limb regeneration in amphibians, so they wanted to examine their role in ...

  19. Relationship between lower limb position and pelvic floor muscle surface electromyography activity in menopausal women: a prospective observational study

    PubMed Central

    Halski, Tomasz; Ptaszkowski, Kuba; Słupska, Lucyna; Dymarek, Robert; Paprocka-Borowicz, Małgorzata

    2017-01-01

    Objectives In physiotherapeutic practice, special attention is being given to the reciprocal anatomical, physiological, and biomechanical relationship of the pelvis and the structures connected to it. However, the scientific literature shows mainly the theoretical information about their mutual connections. The lack of information about these relations from a practical aspect coupled with the paucity of scientific papers on the impact of posture changes on the pelvic floor led the authors to conduct this study. The primary aim of this study was to compare the resting and functional bioelectrical activities of pelvic floor muscles (PFMs) depending on three different positions of the lower limbs (positions A, B, and C) in the supine position. Materials and methods This was a prospective observational study evaluating resting and functional activities of the PFM depending on the position of the lower limbs. The study was carried out at the Department and Clinic of Urology, University Hospital in Wroclaw, Poland and the target group were women in the menopausal period. Bioelectrical activity of PFM was recorded using a surface electromyographic instrument in the supine position. Results of the values obtained in A, B, and C positions were compared using a one-way analysis of variance. Results In position A, the average resting surface electromyography (sEMG) activity of PFM was 6.9±2.6 µV; in position B, the result was 6.9±2.5 µV and in position C, the resting sEMG activity was 5.7±1.8 µV (P=0.0102). The results of the functional bioelectrical activity of PFM were as follows: position A – 20.3±11.8 µV, position B – 19.9±10.6 µV, and position C – 25.3±10.9 µV (P=0.0104). Conclusion The results showed that in the supine position, the PFM achieved the lowest resting activity and the highest functional activity. Therefore, the supine position can be recommended for the diagnosis and therapy of weakened PFM. PMID:28115836

  20. Superior analgesic effect of an active distraction versus pleasant unfamiliar sounds and music: the influence of emotion and cognitive style.

    PubMed

    Villarreal, Eduardo A Garza; Brattico, Elvira; Vase, Lene; Østergaard, Leif; Vuust, Peter

    2012-01-01

    Listening to music has been found to reduce acute and chronic pain. The underlying mechanisms are poorly understood; however, emotion and cognitive mechanisms have been suggested to influence the analgesic effect of music. In this study we investigated the influence of familiarity, emotional and cognitive features, and cognitive style on music-induced analgesia. Forty-eight healthy participants were divided into three groups (empathizers, systemizers and balanced) and received acute pain induced by heat while listening to different sounds. Participants listened to unfamiliar Mozart music rated with high valence and low arousal, unfamiliar environmental sounds with similar valence and arousal as the music, an active distraction task (mental arithmetic) and a control, and rated the pain. Data showed that the active distraction led to significantly less pain than did the music or sounds. Both unfamiliar music and sounds reduced pain significantly when compared to the control condition; however, music was no more effective than sound to reduce pain. Furthermore, we found correlations between pain and emotion ratings. Finally, systemizers reported less pain during the mental arithmetic compared with the other two groups. These findings suggest that familiarity may be key in the influence of the cognitive and emotional mechanisms of music-induced analgesia, and that cognitive styles may influence pain perception.

  1. Muscle activity in the lower limbs during push-down movement with a new active-exercise apparatus for the leg

    PubMed Central

    Tanaka, Kenta; Kamada, Hiroshi; Shimizu, Yukiyo; Aikawa, Shizu; Irie, Shun; Ochiai, Naoyuki; Sakane, Masataka; Yamazaki, Masashi

    2016-01-01

    [Purpose] Lower-limb deep vein thrombosis is a complication of orthopedic surgery. A leg-exercise apparatus named “LEX” was developed as a novel active-exercise apparatus for deep vein thrombosis prevention. Muscle activity was evaluated to assess the effectiveness of exercise with LEX in the prevention. [Subjects] Eight healthy volunteers participated in this study. [Methods] Muscle activities were determined through electromyography during exercise with LEX [LEX (+)] and during active ankle movements [LEX (−)]. The end points were peak % maximum voluntary contraction and % integrated electromyogram of rectus femoris, vastus lateralis, biceps femoris, tibialis anterior, gastrocnemius, and soleus. [Results] LEX (+) resulted in higher average values in all muscles except the tibialis anterior. Significant differences were noted in the peak of the biceps femoris and gastrocnemius and in the integrated electromyogram of the rectus femoris, vastus lateralis, gastrocnemius, and soleus. The LEX (+)/LEX (−) ratio of the peak was 2.2 for the biceps femoris and 2.0 for the gastrocnemius . The integrated electromyogram was 1.8 for the gastrocnemius, 1.5 for the rectus femoris, 1.4 for the vastus lateralis, and 1.2 for the soleus. [Conclusion] Higher muscle activity was observed with LEX (+). LEX might be a good tool for increasing lower-limb blood flow and deep vein thrombosis prevention. PMID:27134410

  2. The Impact of Anthropogenic Activities on Ecosystems of Long Island Sound, N.Y.

    NASA Astrophysics Data System (ADS)

    Lauture, E.; McHugh, C. M.; Nitsche, F. O.; Kenna, T. C.

    2015-12-01

    Long Island Sound (LIS) is a tide-dominated estuary located along heavily populated regions on the eastern coast of the US. Western LIS has been impacted by heavy metals and is susceptible to hypoxic and anoxic conditions since the 1900's. As part of the Long Island Sound Cable Fund and the National Science Foundation programs, we surveyed the western and central regions of LIS in 2006 and 2013, respectively. From the R/V Hugh Sharp and the R/V Seawolf, we collected high-resolution subbottom profiles, multibeam bathymetry, sediment cores, and grabs in distinct sedimentary environments such as channels, terraces, and river mouths. The goal was to evaluate the impact of anthropogenic activities as they relate to physical processes and populated regions. Along western LIS, total organic carbon (TOC) and heavy metal concentrations are higher from the 1850s to the present, especially along locations of known high organic waste. Pre-industrial concentrations of TOC average 2.22% with maximum values of 4.75%. A similar trend is observed with heavy metals. For example, lead (Pb) increased from background levels of ~10 to 20 ppm to over 200 ppm. Benthic foraminifers seem to be influenced by these trends with changes in ecosystems. The dominant assemblage, Elphidium excavatum clavatum remains dominant with a slight decrease in their abundance during anthropogenic times. From ~1850's to the present Ammonia beccarii becomes more abundant. These shifts in foraminifer species to assemblages that tolerate low oxygen conditions reflect the increasing hypoxic conditions. In central LIS, surface sediments average TOC of 1.34% with highest values of 5.21% near the Housatonic River that drains industrialized portions of Connecticut, and lowest values of 0.073% near the Long Island coastline. Understanding the evolution of hypoxia as well as the sources of heavy metals can lead to important implications for restoration of marine ecosystems.

  3. Expert athletes activate somatosensory and motor planning regions of the brain when passively listening to familiar sports sounds.

    PubMed

    Woods, Elizabeth A; Hernandez, Arturo E; Wagner, Victoria E; Beilock, Sian L

    2014-06-01

    The present functional magnetic resonance imaging study examined the neural response to familiar and unfamiliar, sport and non-sport environmental sounds in expert and novice athletes. Results revealed differential neural responses dependent on sports expertise. Experts had greater neural activation than novices in focal sensorimotor areas such as the supplementary motor area, and pre- and postcentral gyri. Novices showed greater activation than experts in widespread areas involved in perception (i.e. supramarginal, middle occipital, and calcarine gyri; precuneus; inferior and superior parietal lobules), and motor planning and processing (i.e. inferior frontal, middle frontal, and middle temporal gyri). These between-group neural differences also appeared as an expertise effect within specific conditions. Experts showed greater activation than novices during the sport familiar condition in regions responsible for auditory and motor planning, including the inferior frontal gyrus and the parietal operculum. Novices only showed greater activation than experts in the supramarginal gyrus and pons during the non-sport unfamiliar condition, and in the middle frontal gyrus during the sport unfamiliar condition. These results are consistent with the view that expert athletes are attuned to only the most familiar, highly relevant sounds and tune out unfamiliar, irrelevant sounds. Furthermore, these findings that athletes show activation in areas known to be involved in action planning when passively listening to sounds suggests that auditory perception of action can lead to the re-instantiation of neural areas involved in producing these actions, especially if someone has expertise performing the actions.

  4. Inferring Meal Eating Activities in Real World Settings from Ambient Sounds: A Feasibility Study

    PubMed Central

    Thomaz, Edison; Zhang, Cheng; Essa, Irfan; Abowd, Gregory D.

    2015-01-01

    Dietary self-monitoring has been shown to be an effective method for weight-loss, but it remains an onerous task despite recent advances in food journaling systems. Semi-automated food journaling can reduce the effort of logging, but often requires that eating activities be detected automatically. In this work we describe results from a feasibility study conducted in-the-wild where eating activities were inferred from ambient sounds captured with a wrist-mounted device; twenty participants wore the device during one day for an average of 5 hours while performing normal everyday activities. Our system was able to identify meal eating with an F-score of 79.8% in a person-dependent evaluation, and with 86.6% accuracy in a person-independent evaluation. Our approach is intended to be practical, leveraging off-the-shelf devices with audio sensing capabilities in contrast to systems for automated dietary assessment based on specialized sensors. PMID:25859566

  5. Comparison of neck and upper-limb muscle activities between able-bodied and paraplegic individuals during wheelchair propulsion on the ground.

    PubMed

    Kim, Sang Jin; Park, So Hyun; Lee, Chang-Ryeol

    2015-05-01

    [Purpose] This study compared the muscle activities of the neck and upper-limb muscles between able-bodied individuals and persons with paraplegia during wheelchair propulsion on the ground. [Subjects and Methods] The muscle activities of the neck and upper-limb muscles of 8 normal individuals and 8 individuals with paraplegia were analyzed during wheelchair propulsion. The activities of the latissimus dorsi, pectoralis major, anterior/posterior deltoids, triceps brachii, extensor carpi radialis, and sternocleidomastoid muscles were assessed. [Results] The paraplegic group showed significantly higher sternocleidomastoid activity than the normal group. Latissimus dorsi activity was also higher in the paraplegia group than in the normal group, but the difference was not significant. There were no significant differences in the other muscle activities between groups. [Conclusion] Paraplegic patients tend to use the sternocleidomastoid and latissimus dorsi muscles with greater degrees of activity. Therefore, physiotherapists should not overlook the treatment of these muscles for paraplegic patients who are long-term wheelchair users.

  6. Listening to an Audio Drama Activates Two Processing Networks, One for All Sounds, Another Exclusively for Speech

    PubMed Central

    Boldt, Robert; Malinen, Sanna; Seppä, Mika; Tikka, Pia; Savolainen, Petri; Hari, Riitta; Carlson, Synnöve

    2013-01-01

    Earlier studies have shown considerable intersubject synchronization of brain activity when subjects watch the same movie or listen to the same story. Here we investigated the across-subjects similarity of brain responses to speech and non-speech sounds in a continuous audio drama designed for blind people. Thirteen healthy adults listened for ∼19 min to the audio drama while their brain activity was measured with 3 T functional magnetic resonance imaging (fMRI). An intersubject-correlation (ISC) map, computed across the whole experiment to assess the stimulus-driven extrinsic brain network, indicated statistically significant ISC in temporal, frontal and parietal cortices, cingulate cortex, and amygdala. Group-level independent component (IC) analysis was used to parcel out the brain signals into functionally coupled networks, and the dependence of the ICs on external stimuli was tested by comparing them with the ISC map. This procedure revealed four extrinsic ICs of which two–covering non-overlapping areas of the auditory cortex–were modulated by both speech and non-speech sounds. The two other extrinsic ICs, one left-hemisphere-lateralized and the other right-hemisphere-lateralized, were speech-related and comprised the superior and middle temporal gyri, temporal poles, and the left angular and inferior orbital gyri. In areas of low ISC four ICs that were defined intrinsic fluctuated similarly as the time-courses of either the speech-sound-related or all-sounds-related extrinsic ICs. These ICs included the superior temporal gyrus, the anterior insula, and the frontal, parietal and midline occipital cortices. Taken together, substantial intersubject synchronization of cortical activity was observed in subjects listening to an audio drama, with results suggesting that speech is processed in two separate networks, one dedicated to the processing of speech sounds and the other to both speech and non-speech sounds. PMID:23734202

  7. Listening to an audio drama activates two processing networks, one for all sounds, another exclusively for speech.

    PubMed

    Boldt, Robert; Malinen, Sanna; Seppä, Mika; Tikka, Pia; Savolainen, Petri; Hari, Riitta; Carlson, Synnöve

    2013-01-01

    Earlier studies have shown considerable intersubject synchronization of brain activity when subjects watch the same movie or listen to the same story. Here we investigated the across-subjects similarity of brain responses to speech and non-speech sounds in a continuous audio drama designed for blind people. Thirteen healthy adults listened for ∼19 min to the audio drama while their brain activity was measured with 3 T functional magnetic resonance imaging (fMRI). An intersubject-correlation (ISC) map, computed across the whole experiment to assess the stimulus-driven extrinsic brain network, indicated statistically significant ISC in temporal, frontal and parietal cortices, cingulate cortex, and amygdala. Group-level independent component (IC) analysis was used to parcel out the brain signals into functionally coupled networks, and the dependence of the ICs on external stimuli was tested by comparing them with the ISC map. This procedure revealed four extrinsic ICs of which two-covering non-overlapping areas of the auditory cortex-were modulated by both speech and non-speech sounds. The two other extrinsic ICs, one left-hemisphere-lateralized and the other right-hemisphere-lateralized, were speech-related and comprised the superior and middle temporal gyri, temporal poles, and the left angular and inferior orbital gyri. In areas of low ISC four ICs that were defined intrinsic fluctuated similarly as the time-courses of either the speech-sound-related or all-sounds-related extrinsic ICs. These ICs included the superior temporal gyrus, the anterior insula, and the frontal, parietal and midline occipital cortices. Taken together, substantial intersubject synchronization of cortical activity was observed in subjects listening to an audio drama, with results suggesting that speech is processed in two separate networks, one dedicated to the processing of speech sounds and the other to both speech and non-speech sounds.

  8. Solar C: Scatter-Free Observatory for Limb Active Regions and Coronae

    NASA Technical Reports Server (NTRS)

    2004-01-01

    The SOLARC observatory is a 0.5m off-axis reflecting coronagraph. NASA SRT funding has allowed the completion of this telescope facility, which we believe is now the world's largest operational coronagraph. We have achieved our proposal goals both in the development of the new technology for this facility and in the demonstration of its scientific and educational potential: 1) The SOLARC engineering development was successful and has spawned other similar instruments. The off-axis design of ATST (a new 4m telescope) has benefited from the SOLARC development. The off-axis 1.6m NST facility at BBSO is also now under construction and will be the world's largest solar disk observing telescope until ATST is completed. Both of these telescope designs are derivatives of the SOLARC 0.5m off-axis. Some of this technical development is described in the publications. 2) The most important scientific goal of SOLARC has been to demonstrate that coronal magnetic fields can be measured using infrared spectropolarimetry techniques. With the completion of the optical fiber-bundle imaging spectropolarimeter we have measured the coronal field strength with a sensitivity to the line-of-sight field component of 2G at 150,OOOkm above the limb. We believe this capability opens new opportunities for space weather, and coronal physics research. In particular we have demonstrated a new tool for understanding the effect of the Sun on the terrestrial space environment. A paper reporting these results has recently been submitted to the Astrophysical Journal Letters.

  9. Is Two Better than One? Limb Activation Treatment Combined with Contralesional Arm Vibration to Ameliorate Signs of Left Neglect

    PubMed Central

    Pitteri, Marco; Arcara, Giorgio; Passarini, Laura; Meneghello, Francesca; Priftis, Konstantinos

    2013-01-01

    In the present study, we evaluated the effects of the Limb Activation Treatment (LAT) alone and in combination with the Contralateral Arm Vibration (CAV) on left neglect (LN) rehabilitation. We conceived them as techniques that both prompt the activation of the lesioned right hemisphere because of the activation (with the LAT as an active technique) and the stimulation (with the CAV as a passive technique) of the left hemibody. To test the effect of the simultaneous use of these two techniques (i.e., LAT and CAV) on visuo-spatial aspects of LN, we described the case of an LN patient (GR), who showed high intra-individual variability (IIV) in performance. Given the high IIV of GR, we used an ABAB repeated-measures design to better define the effectiveness of the combined application of LAT and CAV, as a function of time. The results showed an improvement of GR’s performance on the Bells test following the combined application of LAT and CAV, with respect to the application of LAT alone. We did not find, however, significant effects of treatment on two other LN tests (i.e., Line bisection and Picture scanning). We propose that the combined application of LAT and CAV can be beneficial for some aspects of LN. PMID:23966926

  10. Muscular Activity and Fatigue in Lower-Limb and Trunk Muscles during Different Sit-To-Stand Tests

    PubMed Central

    Roldán-Jiménez, Cristina; Bennett, Paul; Cuesta-Vargas, Antonio I.

    2015-01-01

    Sit-to-stand (STS) tests measure the ability to get up from a chair, reproducing an important component of daily living activity. As this functional task is essential for human independence, STS performance has been studied in the past decades using several methods, including electromyography. The aim of this study was to measure muscular activity and fatigue during different repetitions and speeds of STS tasks using surface electromyography in lower-limb and trunk muscles. This cross-sectional study recruited 30 healthy young adults. Average muscle activation, percentage of maximum voluntary contraction, muscle involvement in motion and fatigue were measured using surface electrodes placed on the medial gastrocnemius (MG), biceps femoris (BF), vastus medialis of the quadriceps (QM), the abdominal rectus (AR), erector spinae (ES), rectus femoris (RF), soleus (SO) and the tibialis anterior (TA). Five-repetition STS, 10-repetition STS and 30-second STS variants were performed. MG, BF, QM, ES and RF muscles showed differences in muscle activation, while QM, AR and ES muscles showed significant differences in MVC percentage. Also, significant differences in fatigue were found in QM muscle between different STS tests. There was no statistically significant fatigue in the BF, MG and SO muscles of the leg although there appeared to be a trend of increasing fatigue. These results could be useful in describing the functional movements of the STS test used in rehabilitation programs, notwithstanding that they were measured in healthy young subjects. PMID:26506612

  11. Coronal Radio Sounding Experiments with Mars Express: Scintillation Spectra during Low Solar Activity

    SciTech Connect

    Efimov, A. I.; Lukanina, L. A.; Samoznaev, L. N.; Rudash, V. K.; Chashei, I. V.; Bird, M. K.; Paetzold, M.; Tellmann, S.

    2010-03-25

    Coronal radio sounding observations were carried out with the radio science experiment MaRS on the ESA spacecraft Mars Express during the period from 25 August to 22 October 2004. Differential frequency and log-amplitude fluctuations of the dual-frequency signals were recorded during a period of low solar activity. The data are applicable to low heliographic latitudes, i.e. to slow solar wind. The mean frequency fluctuation and power law index of the frequency fluctuation temporal spectra are determined as a function of heliocentric distance. The radial dependence of the frequency fluctuation spectral index alpha reflects the previously documented flattening of the scintillation power spectra in the solar wind acceleration region. Temporal spectra of S-band and X-band normalized log-amplitude fluctuations were investigated over the range of fluctuation frequencies 0.01 Hzactivity. Ranging measurements are presented and compared with frequency and log-amplitude scintillation data. Evidence for a weak increase in the fractional electron density turbulence level is obtained in the range 10-40 solar radii.

  12. Age-Specific Effects of Mirror-Muscle Activity on Cross-Limb Adaptations Under Mirror and Non-Mirror Visual Feedback Conditions.

    PubMed

    Reissig, Paola; Stöckel, Tino; Garry, Michael I; Summers, Jeffery J; Hinder, Mark R

    2015-01-01

    Cross-limb transfer (CLT) describes the observation of bilateral performance gains due to unilateral motor practice. Previous research has suggested that CLT may be reduced, or absent, in older adults, possibly due to age-related structural and functional brain changes. Based on research showing increases in CLT due to the provision of mirror visual feedback (MVF) during task execution in young adults, our study aimed to investigate whether MVF can facilitate CLT in older adults, who are known to be more reliant on visual feedback for accurate motor performance. Participants (N = 53) engaged in a short-term training regime (300 movements) involving a ballistic finger task using their dominant hand, while being provided with either visual feedback of their active limb, or a mirror reflection of their active limb (superimposed over the quiescent limb). Performance in both limbs was examined before, during and following the unilateral training. Furthermore, we measured corticospinal excitability (using TMS) at these time points, and assessed muscle activity bilaterally during the task via EMG; these parameters were used to investigate the mechanisms mediating and predicting CLT. Training resulted in significant bilateral performance gains that did not differ as a result of age or visual feedback (both p > 0.1). Training also elicited bilateral increases in corticospinal excitability (p < 0.05). For younger adults, CLT was significantly predicted by performance gains in the trained hand (β = 0.47), whereas for older adults it was significantly predicted by mirror activity in the untrained hand during training (β = 0.60). The present study suggests that older adults are capable of exhibiting CLT to a similar degree to younger adults. The prominent role of mirror activity in the untrained hand for CLT in older adults indicates that bilateral cortical activity during unilateral motor tasks is a compensatory mechanism. In this particular task, MVF did not facilitate the

  13. Enhanced auditory evoked activity to self-generated sounds is mediated by primary and supplementary motor cortices.

    PubMed

    Reznik, Daniel; Ossmy, Ori; Mukamel, Roy

    2015-02-04

    Accumulating evidence demonstrates that responses in auditory cortex to auditory consequences of self-generated actions are modified relative to the responses evoked by identical sounds generated by an external source. Such modifications have been suggested to occur through a corollary discharge sent from the motor system, although the exact neuroanatomical origin is unknown. Furthermore, since tactile input has also been shown to modify responses in auditory cortex, it is not even clear whether the source of such modifications is motor output or somatosensory feedback. We recorded functional magnetic resonance imaging (fMRI) data from healthy human subjects (n = 11) while manipulating the rate at which they performed sound-producing actions with their right hand. In addition, we manipulated the amount of tactile feedback to examine the relative roles of motor and somatosensory cortices in modifying evoked activity in auditory cortex (superior temporal gyrus). We found an enhanced fMRI signal in left auditory cortex during perception of self-generated sounds relative to passive listening to identical sounds. Moreover, the signal difference between active and passive conditions in left auditory cortex covaried with the rate of sound-producing actions and was invariant to the amount of tactile feedback. Together with functional connectivity analysis, our results suggest motor output from supplementary motor area and left primary motor cortex as the source of signal modification in auditory cortex during perception of self-generated sounds. Motor signals from these regions could represent a predictive signal of the expected auditory consequences of the performed action.

  14. Difference in Activity in the Supplementary Motor Area Depending on Limb Combination of Hand-Foot Coordinated Movements.

    PubMed

    Nakagawa, Kento; Kawashima, Saeko; Mizuguchi, Nobuaki; Kanosue, Kazuyuki

    2016-01-01

    Periodic interlimb coordination shows lower performance when the ipsilateral hand and foot (e.g., right hand and right foot) are simultaneously moved than when the contralateral hand and foot (e.g., right hand and left foot) are simultaneously moved. The present study aimed to investigate how brain activity that is related to the dependence of hand-foot coordination on limb combination, using functional magnetic imaging. Twenty-one right-handed subjects performed periodic coordinated movements of the ipsilateral or contralateral hand and foot in the same or opposite direction in the sagittal plane. Kinematic data showed that performance was lower for the ipsilateral hand-foot coordination than for the contralateral one. A comparison of brain activity between the same and opposite directions showed that there was a greater activation of supplementary motor area for ipsilateral hand-foot coordination as compared to that seen during contralateral hand-foot coordination. We speculate that this might reflect a difference in the degree of inhibition of the neural circuit that disrupts opposite directional movements between ipsilateral and contralateral hand-foot coordinated movements.

  15. Comparing brain activation associated with isolated upper and lower limb movement across corresponding joints.

    PubMed

    Luft, Andreas R; Smith, Gerald V; Forrester, Larry; Whitall, Jill; Macko, Richard F; Hauser, Till-Karsten; Goldberg, Andrew P; Hanley, Daniel F

    2002-10-01

    It was shown recently that functional activation across brain motor areas during locomotion and foot movements are similar but differ substantially from activation related to upper extremity movement (Miyai [2001]: Neuroimage 14:1186-1192). The activation pattern may be a function of the behavioral context of the movement rather than of its mechanical properties. We compare motor system activation patterns associated with isolated single-joint movement of corresponding joints in arm and leg carried out in equal frequency and range. Eleven healthy volunteers underwent BOLD-weighted fMRI while performing repetitive elbow or knee extension/flexion. To relate elbow and knee activation to the well-described patterns of finger movement, serial finger-to-thumb opposition was assessed in addition. After identifying task-related voxels using statistical parametric mapping, activation was measured in five regions of interest (ROI; primary motor [M1] and somatosensory cortex [S1], premotor cortex, supplementary motor area [SMA] divided into preSMA and SMA-proper, and cerebellum). Differences in the degree of activation across ROIs were found between elbow and knee movement. SMA-proper activation was prominent for knee, but almost absent for elbow movement (P < 0.05); finger movement produced small but constant SMA-proper activation. Ipsilateral M1 activation was detected during knee and finger movement, but was absent for the elbow task (P < 0.05). Knee movement showed less lateralization in M1 and S1 than other tasks (P < 0.05). The data demonstrate that central motor structures contribute differently to isolated elbow and knee movement. Activation during knee movement shows similarities to gait-related activation patterns.

  16. Effect of head and limb orientation on trunk muscle activation during abdominal hollowing in chronic low back pain

    PubMed Central

    2014-01-01

    Background Individuals with chronic low back pain (CLBP) have altered activations patterns of the anterior trunk musculature when performing the abdominal hollowing manœuvre (attempt to pull umbilicus inward and upward towards the spine). There is a subgroup of individuals with CLBP who have high neurocognitive and sensory motor deficits with associated primitive reflexes (PR). The objective of the study was to determine if orienting the head and extremities to positions, which mimic PR patterns would alter anterior trunk musculature activation during the hollowing manoeuvre. Methods This study compared surface electromyography (EMG) of bilateral rectus abdominis (RA), external oblique (EO), and internal obliques (IO) of 11 individuals with CLBP and evident PR to 9 healthy controls during the hollowing manoeuvre in seven positions of the upper quarter. Results Using magnitude based inferences it was likely (>75%) that controls had a higher ratio of left IO:RA activation with supine (cervical neutral), asymmetrical tonic neck reflex (ATNR) left and right, right cervical rotation and cervical extension positions. A higher ratio of right IO:RA was detected in the cervical neutral and ATNR left position for the control group. The CLBP group were more likely to show higher activation of the left RA in the cervical neutral, ATNR left and right, right cervical rotation and cervical flexion positions as well as in the cervical neutral and cervical flexion position for the right RA. Conclusions Individuals with CLBP and PR manifested altered activation patterns during the hollowing maneuver compared to healthy controls and that altering cervical and upper extremity position can diminish the group differences. Altered cervical and limb positions can change the activation levels of the IO and EO in both groups. PMID:24558971

  17. Fatigue-related firing of distal muscle nociceptors reduces voluntary activation of proximal muscles of the same limb.

    PubMed

    Kennedy, David S; McNeil, Chris J; Gandevia, Simon C; Taylor, Janet L

    2014-02-15

    With fatiguing exercise, firing of group III/IV muscle afferents reduces voluntary activation and force of the exercised muscles. These afferents can also act across agonist/antagonist pairs, reducing voluntary activation and force in nonfatigued muscles. We hypothesized that maintained firing of group III/IV muscle afferents after a fatiguing adductor pollicis (AP) contraction would decrease voluntary activation and force of AP and ipsilateral elbow flexors. In two experiments (n = 10) we examined voluntary activation of AP and elbow flexors by measuring changes in superimposed twitches evoked by ulnar nerve stimulation and transcranial magnetic stimulation of the motor cortex, respectively. Inflation of a sphygmomanometer cuff after a 2-min AP maximal voluntary contraction (MVC) blocked circulation of the hand for 2 min and maintained firing of group III/IV muscle afferents. After a 2-min AP MVC, maximal AP voluntary activation was lower with than without ischemia (56.2 ± 17.7% vs. 76.3 ± 14.6%; mean ± SD; P < 0.05) as was force (40.3 ± 12.8% vs. 57.1 ± 13.8% peak MVC; P < 0.05). Likewise, after a 2-min AP MVC, elbow flexion voluntary activation was lower with than without ischemia (88.3 ± 7.5% vs. 93.6 ± 3.9%; P < 0.05) as was torque (80.2 ± 4.6% vs. 86.6 ± 1.0% peak MVC; P < 0.05). Pain during ischemia was reported as Moderate to Very Strong. Postfatigue firing of group III/IV muscle afferents from the hand decreased voluntary drive and force of AP. Moreover, this effect decreased voluntary drive and torque of proximal unfatigued muscles, the elbow flexors. Fatigue-sensitive group III/IV muscle nociceptors act to limit voluntary drive not only to fatigued muscles but also to unfatigued muscles within the same limb.

  18. Active listening room compensation for massive multichannel sound reproduction systems using wave-domain adaptive filtering.

    PubMed

    Spors, Sascha; Buchner, Herbert; Rabenstein, Rudolf; Herbordt, Wolfgang

    2007-07-01

    The acoustic theory for multichannel sound reproduction systems usually assumes free-field conditions for the listening environment. However, their performance in real-world listening environments may be impaired by reflections at the walls. This impairment can be reduced by suitable compensation measures. For systems with many channels, active compensation is an option, since the compensating waves can be created by the reproduction loudspeakers. Due to the time-varying nature of room acoustics, the compensation signals have to be determined by an adaptive system. The problems associated with the successful operation of multichannel adaptive systems are addressed in this contribution. First, a method for decoupling the adaptation problem is introduced. It is based on a generalized singular value decomposition and is called eigenspace adaptive filtering. Unfortunately, it cannot be implemented in its pure form, since the continuous adaptation of the generalized singular value decomposition matrices to the variable room acoustics is numerically very demanding. However, a combination of this mathematical technique with the physical description of wave propagation yields a realizable multichannel adaptation method with good decoupling properties. It is called wave domain adaptive filtering and is discussed here in the context of wave field synthesis.

  19. Numerical investigation of sound transmission through double wall cylinders with respect to active noise control

    NASA Technical Reports Server (NTRS)

    Coats, T. J.; Silcox, R. J.; Lester, H. C.

    1993-01-01

    Market pressure for more fuel efficient air travel has led to increased use of turboprop and higher bypass turbofan engines. The low frequency components of propeller, jet and boundary layer noise are difficult to attenuate with conventional passive techniques. Weight and geometric restrictions for sound absorbing meterials limit the amount and type of treatment that may be applied. An active noise control (ANC) method is providing to be an attractive alternative. The approach taken in this paper uses a numerical finite/boundary element method (FEM/BEM) that may be easilty adapted to arbitrary geometries. A double walled cylinder is modeled using commercially available software. The outer shell is modeled as an aluminum cylinder, similar to that of aircraft skins. The inner shell is modeled as a composite material representative of a lightweight, stiff trim panel. Two different inner shell materials are used. The first is representative of current trim structure, the second a much stiffer composite. The primary source is generated by an exterior acoustic monopole. Control fields are generated using normal force inputs to the inner cylindrical shell. A linear least mean square (LMS) algorithm is used to determine amplitudes of control forces that minimize the interior acoustic field. Coupling of acoustic and structural modes and noise reductions are discussed for each of the inner shell materials.

  20. Numerical investigation of sound transmission through double wall cylinders with respect to active noise control

    NASA Astrophysics Data System (ADS)

    Coats, T. J.; Silcox, R. J.; Lester, H. C.

    Market pressure for more fuel efficient air travel has led to increased use of turboprop and higher bypass turbofan engines. The low frequency components of propeller, jet and boundary layer noise are difficult to attenuate with conventional passive techniques. Weight and geometric restrictions for sound absorbing meterials limit the amount and type of treatment that may be applied. An active noise control (ANC) method is providing to be an attractive alternative. The approach taken in this paper uses a numerical finite/boundary element method (FEM/BEM) that may be easilty adapted to arbitrary geometries. A double walled cylinder is modeled using commercially available software. The outer shell is modeled as an aluminum cylinder, similar to that of aircraft skins. The inner shell is modeled as a composite material representative of a lightweight, stiff trim panel. Two different inner shell materials are used. The first is representative of current trim structure, the second a much stiffer composite. The primary source is generated by an exterior acoustic monopole. Control fields are generated using normal force inputs to the inner cylindrical shell. A linear least mean square (LMS) algorithm is used to determine amplitudes of control forces that minimize the interior acoustic field. Coupling of acoustic and structural modes and noise reductions are discussed for each of the inner shell materials.

  1. Effects of Active and Passive Hearing Protection Devices on Sound Source Localization, Speech Recognition, and Tone Detection

    PubMed Central

    Brown, Andrew D.; Beemer, Brianne T.; Greene, Nathaniel T.; Argo, Theodore; Meegan, G. Douglas; Tollin, Daniel J.

    2015-01-01

    Hearing protection devices (HPDs) such as earplugs offer to mitigate noise exposure and reduce the incidence of hearing loss among persons frequently exposed to intense sound. However, distortions of spatial acoustic information and reduced audibility of low-intensity sounds caused by many existing HPDs can make their use untenable in high-risk (e.g., military or law enforcement) environments where auditory situational awareness is imperative. Here we assessed (1) sound source localization accuracy using a head-turning paradigm, (2) speech-in-noise recognition using a modified version of the QuickSIN test, and (3) tone detection thresholds using a two-alternative forced-choice task. Subjects were 10 young normal-hearing males. Four different HPDs were tested (two active, two passive), including two new and previously untested devices. Relative to unoccluded (control) performance, all tested HPDs significantly degraded performance across tasks, although one active HPD slightly improved high-frequency tone detection thresholds and did not degrade speech recognition. Behavioral data were examined with respect to head-related transfer functions measured using a binaural manikin with and without tested HPDs in place. Data reinforce previous reports that HPDs significantly compromise a variety of auditory perceptual facilities, particularly sound localization due to distortions of high-frequency spectral cues that are important for the avoidance of front-back confusions. PMID:26313145

  2. Activity recognition in patients with lower limb impairments: do we need training data from each patient?

    PubMed

    Lonini, Luca; Gupta, Aakash; Kording, Konrad; Jayaraman, Arun

    2016-08-01

    Machine learning allows detecting specific physical activities using data from wearable sensors. Such a quantification of patient mobility over time promises to accurately inform clinical decisions for physical rehabilitation. There are two strategies of setting up the machine learning problem: detect one patient's activities using data from the same patient (personal model) or detect their activities using data from other patients (global model), and we currently do not know if personal models are necessary. Here we consider the problem of detecting physical activities from a waist-worn accelerometer in patients who use a knee-ankle-foot orthosis (KAFO) to walk. We show that while a model based on healthy subjects has low accuracy, the global model performs as well as the personal model. This is encouraging because it suggests that condition-specific activity recognition algorithms are sufficient and that no data from individual patients is necessary.

  3. Impact of Active Ankle Movement Frequency on Velocity of Lower Limb Venous Flow following Total Hip Arthroplasty

    PubMed Central

    Nakayama, Tsutomu; Hiyama, Takayuki; Yamada, Tatsuya; Hirasawa, Naoyuki

    2016-01-01

    Background. Although active ankle movement plays a predominant role in mechanical thromboprophylaxis following total hip arthroplasty (THA), the most effective frequency of movement remains unclear. Materials and Methods. In 29 consecutive patients undergoing THA, the velocity of blood flow in the profunda femoris was measured after various frequencies of ankle movement two days after THA using a pulse wave Doppler ultrasound system. To test the interobserver reliabilities for the velocity measured with Doppler ultrasound system, the intraclass correlation coefficient was calculated based on the measurement in 10 limbs of healthy volunteers. Results. At 0, 1, and 2 minutes after ankle movement, the velocity after movement at 60 contractions per minute was significantly faster than that after movement at 40 or 80 contractions per minute (p = 0.0007, repeated-measures analysis of variance). The intraclass correlation coefficient score in two investigators was 0.849 (95% confidence interval, 0.428 to 0.962). Conclusions. Active ankle movement at 60 contractions per minute is recommended in patients receiving THA to obtain optimal venous blood flow. PMID:27999685

  4. Using the MAVEN EUV Monitor to Validate Far-Side and Over-The-Limb Solar Activity Predictions

    NASA Astrophysics Data System (ADS)

    Eparvier, F. G.; Thiemann, E.; Chamberlin, P. C.; Woods, T. N.

    2015-12-01

    The Extreme Ultraviolet Monitor (EUVM) on the Mars Atmosphere and Volatile EvolutioN (MAVEN) mission measures the solar irradiance from the vantage point of Mars in three broad wavelength bands (0-7 nm, 17-22 nm, and 121-122 nm) at a cadence of 1-sec. Normal operations at Mars began in mid-November, 2014 and continue to the present. In November, 2014 the sub-Mars point on the Sun was approximately on the east limb of the solar disk as seen from Earth. Through the mission so far, the MAVEN EUVM has been measuring the EUV irradiance from a solar disk that has been decreasingly less observable from Earth. In June 2015, Mars and MAVEN were in conjunction from Earth, observing irradiance from a solar disk completely unviewable from Earth. The EUVM observations during this period show variability from active regions rotating and from flares. At many other times through the MAVEN mission, the EUVM has observed flares not visible from Earth. The MAVEN solar observations provide a unique opportunity to study the solar variability from multiple vantage points at both daily and sub-daily time scales. MAVEN EUVM observations of far side solar activity will be compared with predictions based on interpolation from Earth and from various far side imaging techniques such as helioseismic and H Ly-alpha backscatter imaging.

  5. Upper limb function and activity in people with facioscapulohumeral muscular dystrophy: a web-based survey.

    PubMed

    Bergsma, Arjen; Cup, Edith H C; Janssen, Mariska M H P; Geurts, Alexander C H; de Groot, Imelda J M

    2017-02-01

    Purpose To investigate the upper extremity (UE) at the level of impairments and related activity limitations and participation restrictions in people with facioscapulohumeral muscular dystrophy (FSHD). Methods The study was conducted using web-based questionnaires that were distributed amongst people with FSHD in the Netherlands. Eighty-eight respondents started the survey, and 71 completed it. The questionnaires covered the following dimensions: Function, Activity and Participation of the International Classification of Functioning Disability and Health. Results More than 40% of the respondents experienced pain in one arm or both the arms. Increased pain and stiffness scores and longer disease duration were associated with increased limitation scores. For basic activities, lifting the arm above shoulder-level was most frequently reported as most limited, coherent with the clinical picture of FSHD. Among the respondents, 50% indicated restrictions at school, 78% indicated restrictions at work and more than 80% indicated restrictions whilst participating in sports, hobbies, household activities and romantic relationships. Conclusions This study has shown that alongside the well-known problem of lifting the arms above shoulder-level, UE activities below shoulder height during vocational and occupational activities are also problematic in patients with FSHD. Alongside disease duration, pain and stiffness are associated with UE activity limitations. Implications for Rehabilitation Attention is needed for pain and experienced stiffness in the upper extremity as it is frequently present in patients with FSHD. Rehabilitation professionals need to be aware that patients with FSHD not only experience problems with activities above shoulder height, but also with activities below shoulder height. At least 50% of the patients with FSHD experience restrictions in participation as a result of limitations in their UE.

  6. PREFACE: Aerodynamic sound Aerodynamic sound

    NASA Astrophysics Data System (ADS)

    Akishita, Sadao

    2010-02-01

    reduction of bluff-body noise. Xiaoyu Wang and Xiaofeng Sun discuss the interaction of fan stator and acoustic treatments using the transfer element method. S Saito and his colleagues in JAXA report the development of active devices for reducing helicopter noise. The paper by A Tamura and M Tsutahara proposes a brand new methodology for aerodynamic sound by applying the lattice Boltzmann finite difference method. As the method solves the fluctuation of air density directly, it has the advantage of not requiring modeling of the sound generation. M A Langthjem and M Nakano solve the hole-tone feedback cycle in jet flow by a numerical method. Y Ogami and S Akishita propose the application of a line-vortex method to the three-dimensional separated flow from a bluff body. I hope that a second issue on aerodynamic sound will be published in FDR in the not too distant future.

  7. Enzymatic activities in limb muscles subjected to external fixation with ring-hybrid frames.

    PubMed

    Reznick, Abraham Z; Coleman, Raymond; Stein, Haim

    2007-04-01

    Enzymatic activities, which originate in the muscle envelope of tibiae with an experimental segmental bone loss, provide additional evidence for the intimate bone-muscle interrelationships in new bone formation.

  8. Comparison of Lower Limb Muscle Activity during Eccentric and Concentric Exercises in Runners with Achilles Tendinopathy

    PubMed Central

    Yu, Jaeho

    2014-01-01

    [Purpose] This study aimed to identify changes in muscle activation by comparing muscle activities of the affected side (AS) and non-affected side (NAS) during eccentric and concentric exercises in runners with unilateral Achilles tendinopathy. [Subjects] The study included 18 participants consisting of men and women with chronic Achilles tendinopathy in a single leg who had more than 1 year of running experience. [Methods] All subjects performed concentric and eccentric exercise with the Achilles tendon moving from full plantar flexion to full dorsiflexion for 8 seconds, and electromyography data was obtained. [Results] All muscles examined showed a significant increase in %maximal voluntary contraction (MVC) with concentric exercise compared with eccentric exercise. Compared with the NAS, the AS showed significant increases in %MVC of the rectus femoris, tibialis anterior, and lateral gastrocnemius. All interaction effects of exercise methods and injuries showed statistically significant changes. [Conclusion] Runners with Achilles tendinopathy show increases in medial gastrocnemius activity when performing eccentric exercise. PMID:25276014

  9. Proposal of Method for Control of Muscle Activation Level for Limbs during Motion and Application of this Method in Strength Training

    NASA Astrophysics Data System (ADS)

    Komada, Satoshi; Murakami, Yosuke; Hirai, Junji

    With an increase in the number of elderly people in our society, the need for equipments that ensure activities of daily living and that can be used in strength training for reducing the need for nursing care is increasing. In this paper, we propose a method for controlling the level of muscle activation for a particular muscle group without EMG sensors; the force exerted by the tips of the limbs during motion is used to control the level of muscle activation. The method is based on a musculoskeletal model for limbs called functionally different effective muscles of three antagonistic pairs of six muscles in 2D space. Hill's equation is incorporated in the method to consider force-velocity characteristics of muscles. EMG measurement results for two muscles under isokinetic contraction in the lower limbs of a subject show that difference between the achieved activation level and the desired activation level is less than the error of the output force distribution. Moreover, the control method is applied to strength training. A manipulator that can facilitate the isokinetic contraction with more than the desired activation level for a specific muscle group is developed.

  10. Sound Symbolism.

    ERIC Educational Resources Information Center

    Hinton, Leanne, Ed.; And Others

    Sound symbolism is the study of the relationship between the sound of an utterance and its meaning. In this interdisciplinary collection of new studies, 24 leading scholars discuss the role of sound symbolism in a theory of language. Contributions and authors include the following: "Sound-Symbolic Processes" (Leanne Hinton, Johanna…

  11. Hair cells use active zones with different voltage dependence of Ca2+ influx to decompose sounds into complementary neural codes

    PubMed Central

    Ohn, Tzu-Lun; Rutherford, Mark A.; Jing, Zhizi; Jung, Sangyong; Duque-Afonso, Carlos J.; Hoch, Gerhard; Picher, Maria Magdalena; Scharinger, Anja; Strenzke, Nicola; Moser, Tobias

    2016-01-01

    For sounds of a given frequency, spiral ganglion neurons (SGNs) with different thresholds and dynamic ranges collectively encode the wide range of audible sound pressures. Heterogeneity of synapses between inner hair cells (IHCs) and SGNs is an attractive candidate mechanism for generating complementary neural codes covering the entire dynamic range. Here, we quantified active zone (AZ) properties as a function of AZ position within mouse IHCs by combining patch clamp and imaging of presynaptic Ca2+ influx and by immunohistochemistry. We report substantial AZ heterogeneity whereby the voltage of half-maximal activation of Ca2+ influx ranged over ∼20 mV. Ca2+ influx at AZs facing away from the ganglion activated at weaker depolarizations. Estimates of AZ size and Ca2+ channel number were correlated and larger when AZs faced the ganglion. Disruption of the deafness gene GIPC3 in mice shifted the activation of presynaptic Ca2+ influx to more hyperpolarized potentials and increased the spontaneous SGN discharge. Moreover, Gipc3 disruption enhanced Ca2+ influx and exocytosis in IHCs, reversed the spatial gradient of maximal Ca2+ influx in IHCs, and increased the maximal firing rate of SGNs at sound onset. We propose that IHCs diversify Ca2+ channel properties among AZs and thereby contribute to decomposing auditory information into complementary representations in SGNs. PMID:27462107

  12. Vocalisation Repertoire of Female Bluefin Gurnard (Chelidonichthys kumu) in Captivity: Sound Structure, Context and Vocal Activity.

    PubMed

    Radford, Craig A; Ghazali, Shahriman M; Montgomery, John C; Jeffs, Andrew G

    2016-01-01

    Fish vocalisation is often a major component of underwater soundscapes. Therefore, interpretation of these soundscapes requires an understanding of the vocalisation characteristics of common soniferous fish species. This study of captive female bluefin gurnard, Chelidonichthys kumu, aims to formally characterise their vocalisation sounds and daily pattern of sound production. Four types of sound were produced and characterised, twice as many as previously reported in this species. These sounds fit two aural categories; grunt and growl, the mean peak frequencies for which ranged between 129 to 215 Hz. This species vocalized throughout the 24 hour period at an average rate of (18.5 ± 2.0 sounds fish-1 h-1) with an increase in vocalization rate at dawn and dusk. Competitive feeding did not elevate vocalisation as has been found in other gurnard species. Bluefin gurnard are common in coastal waters of New Zealand, Australia and Japan and, given their vocalization rate, are likely to be significant contributors to ambient underwater soundscape in these areas.

  13. Vocalisation Repertoire of Female Bluefin Gurnard (Chelidonichthys kumu) in Captivity: Sound Structure, Context and Vocal Activity

    PubMed Central

    Radford, Craig A.; Ghazali, Shahriman M.; Montgomery, John C.; Jeffs, Andrew G.

    2016-01-01

    Fish vocalisation is often a major component of underwater soundscapes. Therefore, interpretation of these soundscapes requires an understanding of the vocalisation characteristics of common soniferous fish species. This study of captive female bluefin gurnard, Chelidonichthys kumu, aims to formally characterise their vocalisation sounds and daily pattern of sound production. Four types of sound were produced and characterised, twice as many as previously reported in this species. These sounds fit two aural categories; grunt and growl, the mean peak frequencies for which ranged between 129 to 215 Hz. This species vocalized throughout the 24 hour period at an average rate of (18.5 ± 2.0 sounds fish-1 h-1) with an increase in vocalization rate at dawn and dusk. Competitive feeding did not elevate vocalisation as has been found in other gurnard species. Bluefin gurnard are common in coastal waters of New Zealand, Australia and Japan and, given their vocalization rate, are likely to be significant contributors to ambient underwater soundscape in these areas. PMID:26890124

  14. Similar electromyographic activities of lower limbs between squatting on a reebok core board and ground.

    PubMed

    Li, Yongming; Cao, Chunmei; Chen, Xiaoping

    2013-05-01

    Reebok Core Boards (RCB) used as a platform in training provide an unstable environment for resistance training. The objective of this study was to examine the effect of unstable surface on muscle electromyographic (EMG) activities during a deep squat task. Thirteen male subjects participated in the study. Electromyographic activities of soleus (SO), vastus lateralis (VL), vastus medialis (VM), rectus femoris (RF), biceps femoris (BF), gluteus maximus (GMa), gluteus medius (GMe), and upper lumbar erector spinae (ULES) muscles were collected when subjects were performing a deep squat task on a RCB and ground with different weight loads (body weight, 30%RM (repetition maximum) and 60%RM). No significant difference was observed for all muscle EMG between unstable and stable surface during all weight load conditions (p > 0.05). Muscle EMG significantly increased when the weight load increased (p < 0.05). Similar muscle activities were observed when subjects performed a deep squat task on a stable and unstable surface. Simply applying unstable surface might not provide extra stimulation to the superficial muscles during squatting in resistance-trained students.

  15. EMG activation of trunk and upper limb muscles following experimentally-induced overpronation and oversupination of the feet in quiet standing.

    PubMed

    Ntousis, Theodoros; Mandalidis, Dimitris; Chronopoulos, Efstathios; Athanasopoulos, Spyros

    2013-02-01

    Kinematic studies have shown that experimentally-induced overpronation or oversupination of the subtalar joint may alter the position of the legs, hips and pelvis and consequently the trunk and upper limb. The purpose of the present study was to examine whether such foot deformity affects the activity of muscles that act on the trunk and upper limb. Twenty-eight healthy individuals (11 males and 17 females) 21.4±1.9 years of age without skeletal deformity, leg length discrepancy (LLD), overpronated or oversupinated feet or excessive lateral pelvic inclination volunteered for the study. Bilateral EMG recordings of the latissimus dorsi, pectoralis major and rectus abdominis were undertaken for 30-s with each subject in the relaxed standing position and at 5° and 10° bilateral or unilateral overpronation or oversupination of the foot on the dominant side using wooden wedge-shape blocks. The recorded EMG activity was normalised based on the EMG activity produced by the muscles under investigation during maximum isometric voluntary contraction. The findings of the present study revealed that neither bilateral nor unilateral overpronation/oversupination of the feet induced a significant alteration of the EMG activity of the latissimus dorsi, pectoralis major and rectus abdominis on either the dominant or non-dominant side. These findings suggest that in the absence of other major structural deformity bilateral or unilateral foot overpronation or oversupination does not affect the EMG activity of muscles that act on the trunk and upper limb in quiet standing.

  16. Auditory learning through active engagement with sound: biological impact of community music lessons in at-risk children

    PubMed Central

    Kraus, Nina; Slater, Jessica; Thompson, Elaine C.; Hornickel, Jane; Strait, Dana L.; Nicol, Trent; White-Schwoch, Travis

    2014-01-01

    The young nervous system is primed for sensory learning, facilitating the acquisition of language and communication skills. Social and linguistic impoverishment can limit these learning opportunities, eventually leading to language-related challenges such as poor reading. Music training offers a promising auditory learning strategy by directing attention to meaningful acoustic elements of the soundscape. In light of evidence that music training improves auditory skills and their neural substrates, there are increasing efforts to enact community-based programs to provide music instruction to at-risk children. Harmony Project is a community foundation that has provided free music instruction to over 1000 children from Los Angeles gang-reduction zones over the past decade. We conducted an independent evaluation of biological effects of participating in Harmony Project by following a cohort of children for 1 year. Here we focus on a comparison between students who actively engaged with sound through instrumental music training vs. students who took music appreciation classes. All children began with an introductory music appreciation class, but midway through the year half of the children transitioned to the instrumental training. After the year of training, the children who actively engaged with sound through instrumental music training had faster and more robust neural processing of speech than the children who stayed in the music appreciation class, observed in neural responses to a speech sound /d/. The neurophysiological measures found to be enhanced in the instrumentally-trained children have been previously linked to reading ability, suggesting a gain in neural processes important for literacy stemming from active auditory learning. Despite intrinsic constraints on our study imposed by a community setting, these findings speak to the potential of active engagement with sound (i.e., music-making) to engender experience-dependent neuroplasticity and may inform the

  17. Auditory learning through active engagement with sound: biological impact of community music lessons in at-risk children.

    PubMed

    Kraus, Nina; Slater, Jessica; Thompson, Elaine C; Hornickel, Jane; Strait, Dana L; Nicol, Trent; White-Schwoch, Travis

    2014-01-01

    The young nervous system is primed for sensory learning, facilitating the acquisition of language and communication skills. Social and linguistic impoverishment can limit these learning opportunities, eventually leading to language-related challenges such as poor reading. Music training offers a promising auditory learning strategy by directing attention to meaningful acoustic elements of the soundscape. In light of evidence that music training improves auditory skills and their neural substrates, there are increasing efforts to enact community-based programs to provide music instruction to at-risk children. Harmony Project is a community foundation that has provided free music instruction to over 1000 children from Los Angeles gang-reduction zones over the past decade. We conducted an independent evaluation of biological effects of participating in Harmony Project by following a cohort of children for 1 year. Here we focus on a comparison between students who actively engaged with sound through instrumental music training vs. students who took music appreciation classes. All children began with an introductory music appreciation class, but midway through the year half of the children transitioned to the instrumental training. After the year of training, the children who actively engaged with sound through instrumental music training had faster and more robust neural processing of speech than the children who stayed in the music appreciation class, observed in neural responses to a speech sound /d/. The neurophysiological measures found to be enhanced in the instrumentally-trained children have been previously linked to reading ability, suggesting a gain in neural processes important for literacy stemming from active auditory learning. Despite intrinsic constraints on our study imposed by a community setting, these findings speak to the potential of active engagement with sound (i.e., music-making) to engender experience-dependent neuroplasticity and may inform the

  18. Behavioural physical activity interventions in participants with lower-limb osteoarthritis: a systematic review with meta-analysis

    PubMed Central

    Williamson, Wilby; Kluzek, Stefan; Roberts, Nia; Richards, Justin; Arden, Nigel; Leeson, Paul; Newton, Julia; Foster, Charlie

    2015-01-01

    behavioural lifestyle interventions for lower limb osteoarthritis populations would benefit from consensus on methodology and outcome reporting. This includes use of validated physical activity reporting tools and planning for long-term follow-up. PMID:26260348

  19. Dopamine transporter is essential for the maintenance of spontaneous activity of auditory nerve neurones and their responsiveness to sound stimulation.

    PubMed

    Ruel, Jérôme; Wang, Jing; Demêmes, Danielle; Gobaille, Serge; Puel, Jean-Luc; Rebillard, Guy

    2006-04-01

    Dopamine, a neurotransmitter released by the lateral olivocochlear efferents, has been shown tonically to inhibit the spontaneous and sound-evoked activity of auditory nerve fibres. This permanent inhibition probably requires the presence of an efficient transporter to remove dopamine from the synaptic cleft. Here, we report that the dopamine transporter is located in the lateral efferent fibres both below the inner hair cells and in the inner spiral bundle. Perilymphatic perfusion of the dopamine transporter inhibitors nomifensine and N-[1-(2-benzo[b]thiophenyl)cyclohexyl]piperidine into the cochlea reduced the spontaneous neural noise and the sound-evoked compound action potential of the auditory nerve in a dose-dependent manner, leading to both neural responses being completely abolished. We observed no significant change in cochlear responses generated by sensory hair cells (cochlear microphonic, summating potential, distortion products otoacoustic emissions) or in the endocochlear potential reflecting the functional state of the stria vascularis. This is consistent with a selective action of dopamine transporter inhibitors on auditory nerve activity. Capillary electrophoresis with laser-induced fluorescence (EC-LIF) measurements showed that nomifensine-induced inhibition of auditory nerve responses was due to increased extracellular dopamine levels in the cochlea. Altogether, these results show that the dopamine transporter is essential for maintaining the spontaneous activity of auditory nerve neurones and their responsiveness to sound stimulation.

  20. Bone speed of sound and physical activity levels of overweight and normal-weight girls and adolescents.

    PubMed

    Yao, Mathew; Ludwa, Izabella; Corbett, Lauren; Klentrou, Panagiota; Bonsu, Peter; Gammage, Kimberley; Falk, Bareket

    2011-02-01

    Bone properties, reflected by speed of sound (SOS), and physical activity levels were examined in overweight (OW) girls (n = 19) and adolescents (n = 22), in comparison with normal-weight (NW) girls (n = 21) and adolescents (n = 13). Moderate-to-vigorous physical activity (MVPA) was higher in NW than in OW in both age groups. Tibial SOS was lower in OW compared with NW in both age groups. MVPA correlated with tibial SOS, once age was partialed out. The results suggest that overweight girls and adolescents are characterized by low tibial SOS, which may be partially attributed to lower physical activity levels.

  1. Comparison of lower limb muscle activation with ballet movements (releve and demi-plie) and general movements (heel rise and squat) in healthy adults

    PubMed Central

    Kim, Min-Ju; Kim, Joong-Hwi

    2016-01-01

    [Purpose] The aim of this study was to demonstrate therapeutic grounds for rehabilitation exercise approach by comparing and analyzing muscular activities of Ballet movements: the releve movement (RM) and the demi-plie movement (DM). [Methods] Four types of movements such as RM vs. heel rise (HM) and DM vs. squat movement (SM) were randomized and applied in 30 healthy male and female individuals while measuring 10-s lower limb muscular activities (gluteus maximus [GMa], gluteus medius [GMe], rectus femoris [RF], adductor longus [AL], medial gastrocnemius [MG], and lateral gastrocnemius [LG]) by using surface electromyography (EMG). [Results] Significant differences were found in GMa, GMe, AL and MG activities for DM and in all of the six muscles for RM, in particular when the two groups were compared (RM vs HM and DM vs SM). [Conclusion] The RM and DM have a greater effect on lower limb muscular force activities compared to HM and SM and could be recommended as clinical therapeutic exercises for lower limb muscle enhancement. PMID:26957762

  2. Optimization of Muscle Activity for Task-Level Goals Predicts Complex Changes in Limb Forces across Biomechanical Contexts

    PubMed Central

    McKay, J. Lucas; Ting, Lena H.

    2012-01-01

    Optimality principles have been proposed as a general framework for understanding motor control in animals and humans largely based on their ability to predict general features movement in idealized motor tasks. However, generalizing these concepts past proof-of-principle to understand the neuromechanical transformation from task-level control to detailed execution-level muscle activity and forces during behaviorally-relevant motor tasks has proved difficult. In an unrestrained balance task in cats, we demonstrate that achieving task-level constraints center of mass forces and moments while minimizing control effort predicts detailed patterns of muscle activity and ground reaction forces in an anatomically-realistic musculoskeletal model. Whereas optimization is typically used to resolve redundancy at a single level of the motor hierarchy, we simultaneously resolved redundancy across both muscles and limbs and directly compared predictions to experimental measures across multiple perturbation directions that elicit different intra- and interlimb coordination patterns. Further, although some candidate task-level variables and cost functions generated indistinguishable predictions in a single biomechanical context, we identified a common optimization framework that could predict up to 48 experimental conditions per animal (n = 3) across both perturbation directions and different biomechanical contexts created by altering animals' postural configuration. Predictions were further improved by imposing experimentally-derived muscle synergy constraints, suggesting additional task variables or costs that may be relevant to the neural control of balance. These results suggested that reduced-dimension neural control mechanisms such as muscle synergies can achieve similar kinetics to the optimal solution, but with increased control effort (≈2×) compared to individual muscle control. Our results are consistent with the idea that hierarchical, task-level neural control

  3. Inflammation, oxidative stress and platelet activation in aspirin-treated critical limb ischaemia: beneficial effects of iloprost.

    PubMed

    Lessiani, Gianfranco; Vazzana, Natale; Cuccurullo, Chiara; Di Michele, Dario; Laurora, Giuseppe; Sgrò, Giuseppe; Di Ruscio, Paolo; Simeone, Emilio; Di Iorio, Pierangelo; Lattanzio, Stefano; Liani, Rossella; Ferrante, Elisabetta; Davì, Giovanni

    2011-02-01

    Platelets critically contribute to atherothrombosis and worsening ischaemia in patients with peripheral arterial disease (PAD), eventually leading to critical limb ischaemia (CLI). Furthermore, persistent platelet activation despite antiplatelet therapy has been reported in this setting. The prostacyclin analogue iloprost is currently recommended in CLI patients for its effects in relieving symptoms by promoting local perfusion. In this study, we investigated the effects of iloprost infusion on urinary 11-dehydro-TXB₂ and 8-iso-PGF(₂α) excretion rate, as in vivo indexes of thromboxane-dependent platelet activation and lipid peroxidation, respectively, and on platelet-derived proinflammatory sCD40L and nitric oxide bioavailability in 44 patients with CLI while on chronic treatment with low-dose aspirin. Daily iloprost infusion for one-week significantly decreased urinary 11-dehydro-TXB₂ [499 (277-807) vs. 380 (189-560) pg/mg creatinine, p < 0.0001] and 8-iso-PGF(₂α) [533 (316-842) vs. 334 (196-540) pg/mg creatinine, p < 0.0001] as well as plasma sCD40L [1540 (1005-3015) vs. 948 (845-2030) pg/ml, p < 0.0001]. Furthermore, a significant increase in plasma nitrate plus nitrite levels has been observed [26.8 (18.8-35.9) vs. 43.7 (33.0-75.5) μM, p < 0.0001]. A significant direct correlation was also found between urinary 8-iso-PGF(₂α) and 11-dehydro-TXB2 before and after iloprost treatment (Rho = 0.695, p < 0.0001). In conclusion, we report that a short-term course of iloprost is able to significantly reduce residual thromboxane biosynthesis, oxidative stress, endothelial dysfunction and platelet-derived inflammation in low-dose aspirin treated patients with CLI.

  4. Peripheral muscle dysfunction in COPD: lower limbs versus upper limbs.

    PubMed

    Miranda, Eduardo Foschini; Malaguti, Carla; Corso, Simone Dal

    2011-01-01

    In patients with COPD, the degree of functional impairment appears to differ between the upper and lower limbs. Significant dyspnea and fatigue have been reported by these patients when performing tasks with unsupported upper limbs and two mechanisms have been proposed to explain this fact: neuromechanical dysfunction of respiratory muscles; and changes in lung volume during such activities. The neuromechanical dysfunction seen in COPD patients during this type of exercise is related to changes in the breathing pattern, as well as to the simultaneity of afferent and efferent muscle stimuli, resulting in respiratory muscle asynchrony. In addition, the increased ventilation during upper limb exercise in patients with COPD leads to dynamic hyperinflation at different workloads. During lower limb exercises, the strength and endurance of the quadriceps muscle is lower in COPD patients than in healthy subjects. This could by explained by abnormal muscle metabolism (decreased aerobic capacity), dependence on glycolytic metabolism, and rapid accumulation of lactate during exercise. In comparison with lower limb exercises, upper limb exercises result in higher metabolic and ventilatory demands, as well as in a more intense sensation of dyspnea and greater fatigue. Because there are differences between the upper and lower limb muscles in terms of the morphological and functional adaptations in COPD patients, specific protocols for strength training and endurance should be developed and tested for the corresponding muscle groups.

  5. A myocontrolled neuroprosthesis integrated with a passive exoskeleton to support upper limb activities.

    PubMed

    Ambrosini, Emilia; Ferrante, Simona; Schauer, Thomas; Klauer, Christian; Gaffuri, Marina; Ferrigno, Giancarlo; Pedrocchi, Alessandra

    2014-04-01

    This work aimed at designing a myocontrolled arm neuroprosthesis for both assistive and rehabilitative purposes. The performance of an adaptive linear prediction filter and a high-pass filter to estimate the volitional EMG was evaluated on healthy subjects (N=10) and neurological patients (N=8) during dynamic hybrid biceps contractions. A significant effect of filter (p=0.017 for healthy; p<0.001 for patients) was obtained. The post hoc analysis revealed that for both groups only the adaptive filter was able to reliably detect the presence of a small volitional contribution. An on/off non-linear controller integrated with an exoskeleton for weight support was developed. The controller allowed the patient to activate/deactivate the stimulation intensity based on the residual EMG estimated by the adaptive filter. Two healthy subjects and 3 people with Spinal Cord Injury were asked to flex the elbow while tracking a trapezoidal target with and without myocontrolled-NMES support. Both healthy subjects and patients easily understood how to use the controller in a single session. Two patients reduced their tracking error by more than 60% with NMES support, while the last patient obtained a tracking error always comparable to the healthy subjects performance (<4°). This study proposes a reliable and feasible solution to combine NMES with voluntary effort.

  6. Sound science-A simple and robust hands-on loudspeaker activity

    NASA Astrophysics Data System (ADS)

    Johnson, Molly; Stonick, Virginia

    1999-09-01

    This article describes a simple and very robust loudspeaker, comprising nothing more than a cream-cheese tub with lid, a screw, a magnet, wire, and tape. When plugged into a boom-box speaker output, it generates "high-fidelity" sound and much student enthusiasm.

  7. The Effect of Immediate Post-Training Active and Passive Recovery Interventions on Anaerobic Performance and Lower Limb Flexibility in Professional Soccer Players

    PubMed Central

    Rey, Ezequiel; Lago-Peñas, Carlos; Casáis, Luis; Lago-Ballesteros, Joaquín

    2012-01-01

    The capacity to recover from intense training, competition and matches is considered an important determinant in soccer performance. At present, there is no consensus on the effect of post-training recovery interventions on subsequent training session. The aim of this study was to determine the effectiveness of active (12 min submaximal running and 8 min of static stretching) and passive recovery (20 min sitting on a bench) interventions performed immediately after a training session on anaerobic performances (CMJ, 20 m sprint and Balsom agility test) and lower limb flexibility 24 h after the training. During two experimental sessions, 31 professional soccer players participated in a randomized fully controlled trial design. The first session was designed to evaluate the player’s anaerobic performances and lower limb flexibility (pretest). After baseline measurements, participants performed a standardized soccer training during which heart rate and RPE were recorded to evaluate the training load. At the end of the training unit all players were randomly assigned to the active recovery group and the passive recovery group. A second experimental session was organized to obtain the posttest values. Players performed the same test, administered in the same order than in the first trial. No significant differences between groups were observed in heart rate and RPE. No significant effect due to recovery interventions was found on lower limb flexibility and anaerobic performances except CMJ that posttest value was significantly greater in the active recovery group than in the passive group (p < 0.05). PMID:23486836

  8. The effect of immediate post-training active and passive recovery interventions on anaerobic performance and lower limb flexibility in professional soccer players.

    PubMed

    Rey, Ezequiel; Lago-Peñas, Carlos; Casáis, Luis; Lago-Ballesteros, Joaquín

    2012-03-01

    The capacity to recover from intense training, competition and matches is considered an important determinant in soccer performance. At present, there is no consensus on the effect of post-training recovery interventions on subsequent training session. The aim of this study was to determine the effectiveness of active (12 min submaximal running and 8 min of static stretching) and passive recovery (20 min sitting on a bench) interventions performed immediately after a training session on anaerobic performances (CMJ, 20 m sprint and Balsom agility test) and lower limb flexibility 24 h after the training. During two experimental sessions, 31 professional soccer players participated in a randomized fully controlled trial design. The first session was designed to evaluate the player's anaerobic performances and lower limb flexibility (pretest). After baseline measurements, participants performed a standardized soccer training during which heart rate and RPE were recorded to evaluate the training load. At the end of the training unit all players were randomly assigned to the active recovery group and the passive recovery group. A second experimental session was organized to obtain the posttest values. Players performed the same test, administered in the same order than in the first trial. No significant differences between groups were observed in heart rate and RPE. No significant effect due to recovery interventions was found on lower limb flexibility and anaerobic performances except CMJ that posttest value was significantly greater in the active recovery group than in the passive group (p < 0.05).

  9. Abdominal sounds

    MedlinePlus

    ... may be a sign of early bowel obstruction. Causes Most of the sounds you hear in your stomach and intestines are ... a list of more serious conditions that can cause abnormal bowel sounds. Hyperactive, hypoactive, or missing bowel sounds may be ...

  10. Exploring Noise: Sound Pollution.

    ERIC Educational Resources Information Center

    Rillo, Thomas J.

    1979-01-01

    Part one of a three-part series about noise pollution and its effects on humans. This section presents the background information for teachers who are preparing a unit on sound. The next issues will offer learning activities for measuring the effects of sound and some references. (SA)

  11. Inferring Human Activity Recognition with Ambient Sound on Wireless Sensor Nodes

    PubMed Central

    Salomons, Etto L.; Havinga, Paul J. M.; van Leeuwen, Henk

    2016-01-01

    A wireless sensor network that consists of nodes with a sound sensor can be used to obtain context awareness in home environments. However, the limited processing power of wireless nodes offers a challenge when extracting features from the signal, and subsequently, classifying the source. Although multiple papers can be found on different methods of sound classification, none of these are aimed at limited hardware or take the efficiency of the algorithms into account. In this paper, we compare and evaluate several classification methods on a real sensor platform using different feature types and classifiers, in order to find an approach that results in a good classifier that can run on limited hardware. To be as realistic as possible, we trained our classifiers using sound waves from many different sources. We conclude that despite the fact that the classifiers are often of low quality due to the highly restricted hardware resources, sufficient performance can be achieved when (1) the window length for our classifiers is increased, and (2) if we apply a two-step approach that uses a refined classification after a global classification has been performed. PMID:27690026

  12. Activation of Smad2 but not Smad3 is required to mediate TGF-β signaling during axolotl limb regeneration.

    PubMed

    Denis, Jean-François; Sader, Fadi; Gatien, Samuel; Villiard, Éric; Philip, Anie; Roy, Stéphane

    2016-10-01

    Axolotls are unique among vertebrates in their ability to regenerate tissues, such as limbs, tail and skin. The axolotl limb is the most studied regenerating structure. The process is well characterized morphologically; however, it is not well understood at the molecular level. We demonstrate that TGF-β1 is highly upregulated during regeneration and that TGF-β signaling is necessary for the regenerative process. We show that the basement membrane is not prematurely formed in animals treated with the TGF-β antagonist SB-431542. More importantly, Smad2 and Smad3 are differentially regulated post-translationally during the preparation phase of limb regeneration. Using specific antagonists for Smad2 and Smad3 we demonstrate that Smad2 is responsible for the action of TGF-β during regeneration, whereas Smad3 is not required. Smad2 target genes (Mmp2 and Mmp9) are inhibited in SB-431542-treated limbs, whereas non-canonical TGF-β targets (e.g. Mmp13) are unaffected. This is the first study to show that Smad2 and Smad3 are differentially regulated during regeneration and places Smad2 at the heart of TGF-β signaling supporting the regenerative process.

  13. Effects of anthropogenic sound on digging behavior, metabolism, Ca2+/Mg2+ ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta

    PubMed Central

    Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

    2016-01-01

    Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca2+/Mg2+-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams. PMID:27063002

  14. Effects of anthropogenic sound on digging behavior, metabolism, Ca2+/Mg2+ ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta

    NASA Astrophysics Data System (ADS)

    Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

    2016-04-01

    Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca2+/Mg2+-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams.

  15. Effects of anthropogenic sound on digging behavior, metabolism, Ca(2+)/Mg(2+) ATPase activity, and metabolism-related gene expression of the bivalve Sinonovacula constricta.

    PubMed

    Peng, Chao; Zhao, Xinguo; Liu, Saixi; Shi, Wei; Han, Yu; Guo, Cheng; Jiang, Jingang; Wan, Haibo; Shen, Tiedong; Liu, Guangxu

    2016-04-11

    Anthropogenic sound has increased significantly in the past decade. However, only a few studies to date have investigated its effects on marine bivalves, with little known about the underlying physiological and molecular mechanisms. In the present study, the effects of different types, frequencies, and intensities of anthropogenic sounds on the digging behavior of razor clams (Sinonovacula constricta) were investigated. The results showed that variations in sound intensity induced deeper digging. Furthermore, anthropogenic sound exposure led to an alteration in the O:N ratios and the expression of ten metabolism-related genes from the glycolysis, fatty acid biosynthesis, tryptophan metabolism, and Tricarboxylic Acid Cycle (TCA cycle) pathways. Expression of all genes under investigation was induced upon exposure to anthropogenic sound at ~80 dB re 1 μPa and repressed at ~100 dB re 1 μPa sound. In addition, the activity of Ca(2+)/Mg(2+)-ATPase in the feet tissues, which is directly related to muscular contraction and subsequently to digging behavior, was also found to be affected by anthropogenic sound intensity. The findings suggest that sound may be perceived by bivalves as changes in the water particle motion and lead to the subsequent reactions detected in razor clams.

  16. Physiographic and land cover attributes of the Puget Lowland and the active streamflow gaging network, Puget Sound Basin

    USGS Publications Warehouse

    Konrad, Christopher; Sevier, Maria

    2014-01-01

    Geospatial information for the active streamflow gaging network in the Puget Sound Basin was compiled to support regional monitoring of stormwater effects to small streams. The compilation includes drainage area boundaries and physiographic and land use attributes that affect hydrologic processes. Three types of boundaries were used to tabulate attributes: Puget Sound Watershed Characterization analysis units (AU); the drainage area of active streamflow gages; and the catchments of Regional Stream Monitoring Program (RSMP) sites. The active streamflow gaging network generally includes sites that represent the ranges of attributes for lowland AUs, although there are few sites with low elevations (less than 60 meters), low precipitation (less than 1 meter year), or high stream density (greater than 5 kilometers per square kilometers). The active streamflow gaging network can serve to provide streamflow information in some AUs and RSMP sites, particularly where the streamflow gage measures streamflow generated from a part of the AU or that drains to the RSMP site, and that part of the AU or RSMP site is a significant fraction of the drainage area of the streamgage. The maximum fraction of each AU or RSMP catchment upstream of a streamflow gage and the maximum fraction of any one gaged basin in an AU or RSMP along with corresponding codes are provided in the attribute tables.

  17. The effectiveness of a work style intervention and a lifestyle physical activity intervention on the recovery from neck and upper limb symptoms in computer workers.

    PubMed

    Bernaards, Claire M; Ariëns, Geertje A M; Knol, Dirk L; Hildebrandt, Vincent H

    2007-11-01

    This study assessed the effectiveness of a single intervention targeting work style and a combined intervention targeting work style and physical activity on the recovery from neck and upper limb symptoms. Computer workers with frequent or long-term neck and upper limb symptoms were randomised into the work style group (WS, n=152), work style and physical activity group (WSPA, n=156), or usual care group (n=158). The WS and WSPA group attended six group meetings. All meetings focused on behavioural change with regard to body posture, workplace adjustment, breaks and coping with high work demands (WS and WSPA group) and physical activity (WSPA group). Pain, disability at work, days with symptoms and months without symptoms were measured at baseline and after 6 (T1) and 12 months (T2). Self-reported recovery was assessed at T1/T2. Both interventions were ineffective in improving recovery. The work style intervention but not the combined intervention was effective in reducing all pain measures. These effects were present in the neck/shoulder, not in the arm/wrist/hand. For the neck/shoulder, the work style intervention group also showed an increased recovery-rate. Total physical activity increased in all study groups but no differences between groups were observed. To conclude, a group-based work style intervention focused on behavioural change was effective in improving recovery from neck/shoulder symptoms and reducing pain on the long-term. The combined intervention was ineffective in increasing total physical activity. Therefore we cannot draw conclusions on the effect of increasing physical activity on the recovery from neck and upper limb symptoms.

  18. The expression pattern of the Distal-less homeobox-containing gene Dlx-5 in the developing chick limb bud suggests its involvement in apical ectodermal ridge activity, pattern formation, and cartilage differentiation.

    PubMed

    Ferrari, D; Sumoy, L; Gannon, J; Sun, H; Brown, A M; Upholt, W B; Kosher, R A

    1995-08-01

    Here we report the isolation from a chick limb bud cDNA library of a cDNA that contains the full coding sequence of chicken Dlx-5, a member of the Distal-less (Dlx) family of homeobox-containing genes that encode homeodomains highly similar to that of the Drosophila Distal-less gene, a gene that is required for limb development in the Drosophila embryo. The expression pattern of Dlx-5 in the developing chick limb bud suggests that it may be involved in several aspects of limb morphogenesis. Dlx-5 is expressed in the apical ectodermal ridge (AER) which directs the outgrowth and patterning of underlying limb mesoderm. During early limb development Dlx-5 is also expressed in the mesoderm at the anterior margin of the limb bud and in a discrete group of mesodermal cells at the mid-proximal posterior margin that corresponds to the posterior necrotic zone. These mesodermal domains of Dlx-5 expression roughly correspond to the anterior and posterior boundaries of the progress zone, the group of highly proliferating undifferentiated mesodermal cells underneath the AER that will give rise to the skeletal elements of the limb and associated structures. The AER and anterior and posterior mesodermal domains of Dlx-5 expression are regions in which the homeobox-containing gene Msx-2 is also highly expressed, suggesting that Dlx-5 and Msx-2 might be involved in regulatory networks that control AER activity and demarcate the progress zone. In addition, Dlx-5 is expressed in high amounts by the differentiating cartilaginous skeletal elements of the limb, suggesting it may be involved in regulating the onset of limb cartilage differentiation.

  19. Masked priming of conceptual features reveals differential brain activation during unconscious access to conceptual action and sound information.

    PubMed

    Trumpp, Natalie M; Traub, Felix; Kiefer, Markus

    2013-01-01

    Previous neuroimaging studies suggested an involvement of sensory-motor brain systems during conceptual processing in support of grounded cognition theories of conceptual memory. However, in these studies with visible stimuli, contributions of strategic imagery or semantic elaboration processes to observed sensory-motor activity cannot be entirely excluded. In the present study, we therefore investigated the electrophysiological correlates of unconscious feature-specific priming of action- and sound-related concepts within a novel feature-priming paradigm to specifically probe automatic processing of conceptual features without the contribution of possibly confounding factors such as orthographic similarity or response congruency. Participants were presented with a masked subliminal prime word and a subsequent visible target word. In the feature-priming conditions primes as well as targets belonged to the same conceptual feature dimension (action or sound, e.g., typewriter or radio) whereas in the two non-priming conditions, either the primes or the targets consisted of matched control words with low feature relevance (e.g., butterfly or candle). Event-related potential analyses revealed unconscious feature-specific priming effects at fronto-central electrodes within 100 to 180 ms after target stimulus onset that differed with regard to topography and underlying neural generators. In congruency with previous findings under visible stimulation conditions, these differential subliminal ERP feature-priming effects demonstrate an unconscious automatic access to action versus sound features of concepts. The present results therefore support grounded cognition theory suggesting that activity in sensory and motor areas during conceptual processing can also occur unconsciously and is not mandatorily accompanied by a vivid conscious experience of the conceptual content such as in imagery.

  20. The emotional symbolism of two English e-sounds: /i/ as in "cheap" is pleasant and /I/ as in "chip" active.

    PubMed

    Whissell, Cynthia

    2003-02-01

    This article aligns the symbolism of the long (/i/) and short (/I/) e sounds in English with the two dimensions of emotional space-Pleasantness and Activation. On the basis of this alignment, the four quadrants of emotional space are labelled Cheerful (high /i/, high /I/), Cheerless (low /i/, low /I/), Tough (low /i/, high /I/), and Tender (high /i/, low /I/). In four phases, data from over 50 samples (mainly, poetry, song lyrics, and names) were plotted and compared in terms of their use of the two e sounds. Significant and meaningful differences among samples were discovered in all phases. The placement of samples in quadrants was additionally informative. Data samples including many long e sounds (/i/) tended to be more Pleasant and those including many short e sounds (/I/) tended to be more Active.

  1. National Report Germany: Sounding Rocket and Balloon Research Activities Supported by the German Space Programme in 2013-2015

    NASA Astrophysics Data System (ADS)

    Kuhl, R.; Gritzner, C.; Friedrichs, D.

    2015-09-01

    Mainly sounding rockets but also stratospheric balloons have played a crucial role in implementing the German Space Programme since many years. Research activities were conducted in the fields of Microgravity Research, Space Science, Earth Observation, Space Technology Development, and Education. Currently, the mesosphere and ionosphere of the Earth and the photosphere and chromosphere of the Sun are in the focus of German research activities in the field of Space Science. Microgravity related topics are studied in the disciplines of Life and Physical Sciences during ballistic TEXUS and MAPHEUS rocket flights. A lot of student activities are currently supported by the agencies SNSB and DLR under the auspices of the Swedish-German programme REXUS/BEXUS.

  2. Sound Absorbers

    NASA Astrophysics Data System (ADS)

    Fuchs, H. V.; Möser, M.

    Sound absorption indicates the transformation of sound energy into heat. It is, for instance, employed to design the acoustics in rooms. The noise emitted by machinery and plants shall be reduced before arriving at a workplace; auditoria such as lecture rooms or concert halls require a certain reverberation time. Such design goals are realised by installing absorbing components at the walls with well-defined absorption characteristics, which are adjusted for corresponding demands. Sound absorbers also play an important role in acoustic capsules, ducts and screens to avoid sound immission from noise intensive environments into the neighbourhood.

  3. Global navigation satellite sounding of the atmosphere and GNSS altimetry : prospects for geosciences

    NASA Technical Reports Server (NTRS)

    Yunck, Tom P.; Hajj, George A.

    2003-01-01

    The vast illuminating power of the Global Positioning System (GPS), which transformed space geodesy in the 199Os, is now serving to probe the earth's fluid envelope in unique ways. Three distinct techniques have emerged: ground-based sensing of the integrated atmospheric moisture; space-based profiling of atmospheric refractivity, pressure, temperature, moisture, and other properties by active limb sounding; and surface (ocean and ice) altimetry and scatterometry with reflected signals detected from space. Ground-based GPS moisture sensing is already in provisional use for numerical weather prediction. Limb sounding, while less mature, offers a bevy of attractions, including high accuracy, stability, and vertical resolution; all-weather operation; and exceptionally low cost. GPS bistatic radar, r 'reflectometry,' is the least advanced but shows promise for a number of niche applications.

  4. Human amygdala activation by the sound produced during dental treatment: A fMRI study.

    PubMed

    Yu, Jen-Fang; Lee, Kun-Che; Hong, Hsiang-Hsi; Kuo, Song-Bor; Wu, Chung-De; Wai, Yau-Yau; Chen, Yi-Fen; Peng, Ying-Chin

    2015-01-01

    During dental treatments, patients may experience negative emotions associated with the procedure. This study was conducted with the aim of using functional magnetic resonance imaging (fMRI) to visualize cerebral cortical stimulation among dental patients in response to auditory stimuli produced by ultrasonic scaling and power suction equipment. Subjects (n = 7) aged 23-35 years were recruited for this study. All were right-handed and underwent clinical pure-tone audiometry testing to reveal a normal hearing threshold below 20 dB hearing level (HL). As part of the study, subjects initially underwent a dental calculus removal treatment. During the treatment, subjects were exposed to ultrasonic auditory stimuli originating from the scaling handpiece and salivary suction instruments. After dental treatment, subjects were imaged with fMRI while being exposed to recordings of the noise from the same dental instrument so that cerebral cortical stimulation in response to aversive auditory stimulation could be observed. The independent sample confirmatory t-test was used. Subjects also showed stimulation in the amygdala and prefrontal cortex, indicating that the ultrasonic auditory stimuli elicited an unpleasant response in the subjects. Patients experienced unpleasant sensations caused by contact stimuli in the treatment procedure. In addition, this study has demonstrated that aversive auditory stimuli such as sounds from the ultrasonic scaling handpiece also cause aversive emotions. This study was indicated by observed stimulation of the auditory cortex as well as the amygdala, indicating that noise from the ultrasonic scaling handpiece was perceived as an aversive auditory stimulus by the subjects. Subjects can experience unpleasant sensations caused by the sounds from the ultrasonic scaling handpiece based on their auditory stimuli.

  5. Sound Waves Induce Neural Differentiation of Human Bone Marrow-Derived Mesenchymal Stem Cells via Ryanodine Receptor-Induced Calcium Release and Pyk2 Activation.

    PubMed

    Choi, Yura; Park, Jeong-Eun; Jeong, Jong Seob; Park, Jung-Keug; Kim, Jongpil; Jeon, Songhee

    2016-10-01

    Mesenchymal stem cells (MSCs) have shown considerable promise as an adaptable cell source for use in tissue engineering and other therapeutic applications. The aims of this study were to develop methods to test the hypothesis that human MSCs could be differentiated using sound wave stimulation alone and to find the underlying mechanism. Human bone marrow (hBM)-MSCs were stimulated with sound waves (1 kHz, 81 dB) for 7 days and the expression of neural markers were analyzed. Sound waves induced neural differentiation of hBM-MSC at 1 kHz and 81 dB but not at 1 kHz and 100 dB. To determine the signaling pathways involved in the neural differentiation of hBM-MSCs by sound wave stimulation, we examined the Pyk2 and CREB phosphorylation. Sound wave induced an increase in the phosphorylation of Pyk2 and CREB at 45 min and 90 min, respectively, in hBM-MSCs. To find out the upstream activator of Pyk2, we examined the intracellular calcium source that was released by sound wave stimulation. When we used ryanodine as a ryanodine receptor antagonist, sound wave-induced calcium release was suppressed. Moreover, pre-treatment with a Pyk2 inhibitor, PF431396, prevented the phosphorylation of Pyk2 and suppressed sound wave-induced neural differentiation in hBM-MSCs. These results suggest that specific sound wave stimulation could be used as a neural differentiation inducer of hBM-MSCs.

  6. Mangling upper limb injuries in industry.

    PubMed

    Ring, D; Jupiter, J B

    1999-01-01

    The salvage of upper limbs mangled by industrial machinery became possible with the development of predictable techniques of vascular and microvascular anastamosis. Unfortunately, many of these salvaged limbs are associated with fair and poor functional outcomes. The quality of the skeletal fixation can have a substantial effect on the functional outcome and should be a major focus of the limb repair process. Internal plate fixation facilitates wound care and limb mobilization without tethering muscle-tendon units and is safe in the majority of severe upper limb injuries provided that all devitalized tissue is debrided and, if necessary, reconstructed using microvascular tissue transfers. Injury patterns, especially those which involve associated injury of the elbow or forearm ligaments, must be identified and treated appropriately. Internal fixation should restore anatomical alignment and provide sufficient stability to allow immediate active mobilization of the limb without contributing to devascularization of the soft tissues or skeleton.

  7. Critical Limb Ischemia: Reporting Outcomes and Quality

    PubMed Central

    2012-01-01

    The impetus to pursue quality in limb salvage is high in the current economic environment. This has been spurred on by the diffusion of multiple technologies, the lack of well-defined cost-effectiveness benchmarks, and the paucity of process and structure benchmarks. Furthermore, no national database exists to capture current activity and trends, and lead structure and process changes that could analyze outcomes and improve standards in peripheral interventions for limb salvage. This manuscript examines the challenges in measuring outcomes and quality in limb salvage and explores the components necessary for ensuring quality in limb salvage interventions. PMID:23342183

  8. Saunders's framework for understanding limb development as a platform for investigating limb evolution.

    PubMed

    Young, John J; Tabin, Clifford J

    2016-11-11

    John W. Saunders, Jr. made seminal discoveries unveiling how chick embryos develop their limbs. He discovered the apical ectodermal ridge (AER), the zone of polarizing activity (ZPA), and the domains of interdigital cell death within the developing limb and determined their function through experimental analysis. These discoveries provided the basis for subsequent molecular understanding of how vertebrate limbs are induced, patterned, and differentiated. These mechanisms are strongly conserved among the vast diversity of tetrapod limbs suggesting that relatively minor changes and tweaks to the molecular cascades are responsible for the diversity observed in nature. Analysis of the pathway systems first identified by Saunders in the context of animals displaying limb reduction show how alterations in these pathways have resulted in multiple mechanisms of limb and digit loss. Other classes of modification to these same patterning systems are seen at the root of other, novel limb morphological alterations and elaborations.

  9. Convergence in Reflex Pathways from Multiple Cutaneous Nerves Innervating the Foot Depends upon the Number of Rhythmically Active Limbs during Locomotion

    PubMed Central

    Nakajima, Tsuyoshi; Mezzarane, Rinaldo A.; Hundza, Sandra R.; Komiyama, Tomoyoshi; Zehr, E. Paul

    2014-01-01

    Neural output from the locomotor system for each arm and leg influences the spinal motoneuronal pools directly and indirectly through interneuronal (IN) reflex networks. While well documented in other species, less is known about the functions and features of convergence in common IN reflex system from cutaneous afferents innervating different foot regions during remote arm and leg movement in humans. The purpose of the present study was to use spatial facilitation to examine possible convergence in common reflex pathways during rhythmic locomotor limb movements. Cutaneous reflexes were evoked in ipsilateral tibialis anterior muscle by stimulating (in random order) the sural nerve (SUR), the distal tibial nerve (TIB), and combined simultaneous stimulation of both nerves (TIB&SUR). Reflexes were evoked while participants performed rhythmic stepping and arm swinging movement with both arms and the leg contralateral to stimulation (ARM&LEG), with just arm movement (ARM) and with just contralateral leg movement (LEG). Stimulation intensities were just below threshold for evoking early latency (<80 ms to peak) reflexes. For each stimulus condition, rectified EMG signals were averaged while participants held static contractions in the stationary (stimulated) leg. During ARM&LEG movement, amplitudes of cutaneous reflexes evoked by combined TIB&SUR stimulation were significantly larger than simple mathematical summation of the amplitudes evoked by SUR or TIB alone. Interestingly, this extra facilitation seen during combined nerve stimulation was significantly reduced when performing ARM or LEG compared to ARM&LEG. We conclude that locomotor rhythmic limb movement induces excitation of common IN reflex pathways from cutaneous afferents innervating different foot regions. Importantly, activity in this pathway is most facilitated during ARM&LEG movement. These results suggest that transmission in IN reflex pathways is weighted according to the number of limbs directly engaged

  10. Convergence in reflex pathways from multiple cutaneous nerves innervating the foot depends upon the number of rhythmically active limbs during locomotion.

    PubMed

    Nakajima, Tsuyoshi; Mezzarane, Rinaldo A; Hundza, Sandra R; Komiyama, Tomoyoshi; Zehr, E Paul

    2014-01-01

    Neural output from the locomotor system for each arm and leg influences the spinal motoneuronal pools directly and indirectly through interneuronal (IN) reflex networks. While well documented in other species, less is known about the functions and features of convergence in common IN reflex system from cutaneous afferents innervating different foot regions during remote arm and leg movement in humans. The purpose of the present study was to use spatial facilitation to examine possible convergence in common reflex pathways during rhythmic locomotor limb movements. Cutaneous reflexes were evoked in ipsilateral tibialis anterior muscle by stimulating (in random order) the sural nerve (SUR), the distal tibial nerve (TIB), and combined simultaneous stimulation of both nerves (TIB&SUR). Reflexes were evoked while participants performed rhythmic stepping and arm swinging movement with both arms and the leg contralateral to stimulation (ARM&LEG), with just arm movement (ARM) and with just contralateral leg movement (LEG). Stimulation intensities were just below threshold for evoking early latency (<80 ms to peak) reflexes. For each stimulus condition, rectified EMG signals were averaged while participants held static contractions in the stationary (stimulated) leg. During ARM&LEG movement, amplitudes of cutaneous reflexes evoked by combined TIB&SUR stimulation were significantly larger than simple mathematical summation of the amplitudes evoked by SUR or TIB alone. Interestingly, this extra facilitation seen during combined nerve stimulation was significantly reduced when performing ARM or LEG compared to ARM&LEG. We conclude that locomotor rhythmic limb movement induces excitation of common IN reflex pathways from cutaneous afferents innervating different foot regions. Importantly, activity in this pathway is most facilitated during ARM&LEG movement. These results suggest that transmission in IN reflex pathways is weighted according to the number of limbs directly engaged

  11. Field validation of sound mitigation models and air pollutant emission testing in support of missile motor disposal activities.

    PubMed

    McFarland, Michael J; Palmer, Glenn R; Kordich, Micheal M; Pollet, Dean A; Jensen, James A; Lindsay, Mitchell H

    2005-08-01

    The U.S. Department of Defense approved activities conducted at the Utah Test and Training Range (UTTR) include both operational readiness test firing of intercontinental ballistic missile motors as well as the destruction of obsolete or otherwise unusable intercontinental ballistic missile motors through open burn/open detonation (OB/ OD). Within the Utah Division of Air Quality, these activities have been identified as having the potential to generate unacceptable noise levels, as well as significant amounts of hazardous air pollutants. Hill Air Force Base, UT, has completed a series of field tests at the UTTR in which sound-monitoring surveillance of OB/OD activities was conducted to validate the Sound Intensity Prediction System (SIPS) model. Using results generated by the SIPS model to support the decision to detonate, the UTTR successfully disposed of missile motors having an aggregate net explosive weight (NEW) of 56,500 lbs without generating adverse noise levels within populated areas. These results suggest that, under appropriate conditions, missile motors of even larger NEW may be detonated without exceeding regulatory noise limits. In conjunction with collecting noise monitoring data, air quality data was collected to support the development of air emission factors for both static missile motor firings and OB/OD activities. Through the installation of 15 ground-based air samplers, the generation of combustion fixed gases, hazardous air pollutants, and chlorides were monitored during the 56,500-lb NEW detonation event. Comparison of field measurements to predictions generated from the U.S. Navy's energetic combustion pollutant formation model, POLU4WN, indicated that, as the detonation fireball expanded from ground zero, organic compounds as well as carbon monoxide continued to oxidize as the hot gases reacted with ambient air. Hazardous air pollutant analysis of air samplers confirmed the presence of chloromethane, benzene, toluene, 1,2-propadiene, and

  12. Field verification of sound attenuation modeling and air emission testing in support of missile motor disposal activities.

    PubMed

    McFarland, Michael J; Palmer, Glenn R; Rasmussen, Steve L; Kordich, Micheal M; Pollet, Dean A; Jensen, James A; Lindsay, Mitchell H

    2006-07-01

    The U.S. Department of Defense-approved activities conducted at the Utah Test and Training Range (UTTR) include both operational readiness test firing of intercontinental ballistic missile (ICBM) motors, as well as the destruction of obsolete or otherwise unusable ICBM motors through open burn/open detonation (OB/OD). Within the Utah Division of Air Quality, these activities have been identified as having the potential to generate unacceptable noise levels, as well as significant amounts of volatile organic compounds (VOCs). Hill Air Force Base, UT, has completed a series of field tests at the UTTR in which sound-monitoring surveillance of OB/OD activities was conducted to validate the Sound Intensity Prediction System (SIPS) model. Using results generated by the SIPS model to support the decision to detonate, the UTTR successfully disposed of missile motors having an aggregate net explosive weight (NEW) of 81,374 lb without generating adverse noise levels within populated areas. In conjunction with collecting noise-monitoring data, air emissions were collected to support the development of air emission factors for both static missile motor firings and OB/OD activities. Through the installation of 15 ground-based air samplers, the generation of combustion-fixed gases, VOCs, and chlorides was monitored during the 81,374-lb NEW detonation event. Comparison of field measurements to predictions generated from the US Navy energetic combustion pollutant formation model, POLU4WN, indicated that, as the detonation fire ball expanded, organic compounds, as well as CO, continued to oxidize as the combustion gases mixed with ambient air. VOC analysis of air samplers confirmed the presence of chloromethane, vinyl chloride, benzene, toluene, and 2-methyl-1-propene. Qualitative chloride analysis indicated that gaseous HCl was generated at low concentrations, if at all.

  13. Limb Prosthetics

    MedlinePlus

    ... For example, some go skydiving, climb mountains, run marathons, complete triathlons, participate fully in sports, or return ... only for activities at home or for a marathon, the prosthesis can provide profound psychologic benefits. How ...

  14. Horizontal coherence of low-frequency fixed-path sound in a continental shelf region with internal-wave activity.

    PubMed

    Duda, Timothy F; Collis, Jon M; Lin, Ying-Tsong; Newhall, Arthur E; Lynch, James F; DeFerrari, Harry A

    2012-02-01

    Sound at 85 to 450 Hz propagating in approximately 80-m depth water from fixed sources to a joint horizontal/vertical line array (HLA/VLA) is analyzed. The data are from a continental shelf area east of Delaware Bay (USA) populated with tidally generated long- and short-wavelength internal waves. Sound paths are 19 km in the along-shore (along internal-wave crest) direction and 30 km in the cross-shore direction. Spatial statistics of HLA arrivals are computed as functions of beam steering angle and time. These include array gain, horizontally lagged spatial correlation function, and coherent beam power. These quantities vary widely in magnitude, and vary over a broad range of time scales. For example, correlation scale can change rapidly from forty to five wavelengths, and correlation-scale behavior is anisotropic. In addition, the vertical array can be used to predict correlation expected for adiabatic propagation with cylindrical symmetry, forming a benchmark. Observed variations are in concert with internal-wave activity. Temporal variations of three coherence measures, horizontal correlation length, array gain, and ratio of actual correlation length to predicted adiabatic-mode correlation length, are very strong, varying by almost a factor of ten as internal waves pass.

  15. Skeletal limb abnormalities

    MedlinePlus

    ... medlineplus.gov/ency/article/003170.htm Skeletal limb abnormalities To use the sharing features on this page, please enable JavaScript. Skeletal limb abnormalities refers to a variety of bone structure problems ...

  16. Critical Limb Ischemia (CLI)

    MedlinePlus

    ... High blood pressure Family history of vascular disease Warning Signs You may have critical limb ischemia if ... blood flow to the limb. Other treatments include laser atherectomy, where small bits of plaque are vaporized ...

  17. GPS Sounding Rocket Developments

    NASA Technical Reports Server (NTRS)

    Bull, Barton

    1999-01-01

    Sounding rockets are suborbital launch vehicles capable of carrying scientific payloads several hundred miles in altitude. These missions return a variety of scientific data including; chemical makeup and physical processes taking place in the atmosphere, natural radiation surrounding the Earth, data on the Sun, stars, galaxies and many other phenomena. In addition, sounding rockets provide a reasonably economical means of conducting engineering tests for instruments and devices used on satellites and other spacecraft prior to their use in more expensive activities. This paper addresses the NASA Wallops Island history of GPS Sounding Rocket experience since 1994 and the development of highly accurate and useful system.

  18. Active sound radiation control of a thick piezolaminated smart rectangular plate

    NASA Astrophysics Data System (ADS)

    Hasheminejad, Seyyed M.; Keshavarzpour, Hemad

    2013-09-01

    A spatial state-space formulation based on the linear three-dimensional piezoelasticity theory in conjunction with the classical Rayleigh integral acoustic radiation model is employed to obtain a semi-analytic solution for the coupled vibroacoustic response of a simply supported, arbitrarily thick, piezolaminated rectangular plate, set in an infinite rigid baffle. The smart structure is composed of an orthotropic supporting core layer integrated with matched volume velocity spatially distributed piezoelectric sensor and uniform force actuator layers. To assist controller design, a frequency-domain subspace-based identification technique is applied to estimate the coupled fluid-structure dynamics of the system. A standard linear quadratic Gaussian (LQG) optimal controller is subsequently synthesized and simulated based on the identified model and the optimal control input voltage for minimizing the estimated net volume velocity (total radiated power) of the panel is calculated in both frequency and time domains. Numerical simulations demonstrate the effectiveness of the adopted volumetric sensing/actuation technique in conjunction with the optimal control strategy for suppressing the predicted sound radiation response of a three-layered (NaNb5O15/Al/PZT4) sandwich panel in both frequency and time domains. The trade-off between dynamic performance and control effort penalty is examined for two different types of loading (i.e., impulsive and broadband random disturbances). Validity of the results is demonstrated by comparison with a commercial finite element package, as well as with the data available in the literature.

  19. Target-depth estimation in active sonar: Cramer-Rao bounds for a bilinear sound-speed profile.

    PubMed

    Mours, Alexis; Ioana, Cornel; Mars, Jérôme I; Josso, Nicolas F; Doisy, Yves

    2016-09-01

    This paper develops a localization method to estimate the depth of a target in the context of active sonar, at long ranges. The target depth is tactical information for both strategy and classification purposes. The Cramer-Rao lower bounds for the target position as range and depth are derived for a bilinear profile. The influence of sonar parameters on the standard deviations of the target range and depth are studied. A localization method based on ray back-propagation with a probabilistic approach is then investigated. Monte-Carlo simulations applied to a summer Mediterranean sound-speed profile are performed to evaluate the efficiency of the estimator. This method is finally validated on data in an experimental tank.

  20. Effects of Listening to Music versus Environmental Sounds in Passive and Active Situations on Levels of Pain and Fatigue in Fibromyalgia.

    PubMed

    Mercadíe, Lolita; Mick, Gérard; Guétin, Stéphane; Bigand, Emmanuel

    2015-10-01

    In fibromyalgia, pain symptoms such as hyperalgesia and allodynia are associated with fatigue. Mechanisms underlying such symptoms can be modulated by listening to pleasant music. We expected that listening to music, because of its emotional impact, would have a greater modulating effect on the perception of pain and fatigue in patients with fibromyalgia than listening to nonmusical sounds. To investigate this hypothesis, we carried out a 4-week study in which patients with fibromyalgia listened to either preselected musical pieces or environmental sounds when they experienced pain in active (while carrying out a physical activity) or passive (at rest) situations. Concomitant changes of pain and fatigue levels were evaluated. When patients listened to music or environmental sounds at rest, pain and fatigue levels were significantly reduced after 20 minutes of listening, with no difference of effect magnitude between the two stimuli. This improvement persisted 10 minutes after the end of the listening session. In active situations, pain did not increase in presence of the two stimuli. Contrary to our expectations, music and environmental sounds produced a similar relieving effect on pain and fatigue, with no benefit gained by listening to pleasant music over environmental sounds.

  1. Letter Recognition and Sound Identification.

    ERIC Educational Resources Information Center

    Prior, Jennifer

    This lesson, which is most appropriate for kindergartners, reviews letter names and their sounds through a group letter recognition activity, a picture book activity, and alphabet practice with several online activities. During three 30-minute sessions, students will: identify the letters of the alphabet; identify the sounds of letters; identify…

  2. Active learning of novel sound-producing objects: motor reactivation and enhancement of visuo-motor connectivity.

    PubMed

    Butler, Andrew J; James, Karin Harman

    2013-02-01

    Our experience with the world commonly involves physical interaction with objects enabling us to learn associations between multisensory information perceived during an event and our actions that create an event. The interplay among active interactions during learning and multisensory integration of object properties is not well understood. To better understand how action might enhance multisensory associative recognition, we investigated the interplay among motor and perceptual systems after active learning. Fifteen participants were included in an fMRI study during which they learned visuo-auditory-motor associations between novel objects and the sounds they produce, either through self-generated actions on the objects (active learning) or by observing an experimenter produce the actions (passive learning). Immediately after learning, behavioral and BOLD fMRI measures were collected while perceiving the objects used during unisensory and multisensory training in associative perception and recognition tasks. Active learning was faster and led to more accurate recognition of audiovisual associations than passive learning. Functional ROI analyses showed that in motor, somatosensory, and cerebellar regions there was greater activation during both the perception and recognition of actively learned associations. Finally, functional connectivity between visual- and motor-related processing regions was enhanced during the presentation of actively learned audiovisual associations. Overall, the results of the current study clarify and extend our own previous work [Butler, A. J., James, T. W., & Harman James, K. Enhanced multisensory integration and motor reactivation after active motor learning of audiovisual associations. Journal of Cognitive Neuroscience, 23, 3515-3528, 2011] by providing several novel findings and highlighting the task-based nature of motor reactivation and retrieval after active learning.

  3. Breath sounds

    MedlinePlus

    ... are believed to occur when air opens closed air spaces. Rales can be further described as moist, dry, fine, and coarse. Rhonchi. Sounds that resemble snoring. They occur when air is blocked or air flow becomes rough through ...

  4. Sound Advice.

    ERIC Educational Resources Information Center

    Popke, Michael

    2000-01-01

    Discusses the planning and decision-making process in acquiring sound equipment for sports stadiums that will help make the experience of fans more pleasurable. The bidding process and use of consultants is explored. (GR)

  5. Development of Activity-Related Muscle Fatigue during Robot-Mediated Upper Limb Rehabilitation Training in Persons with Multiple Sclerosis: A Pilot Trial.

    PubMed

    Octavia, Johanna Renny; Feys, Peter; Coninx, Karin

    2015-01-01

    Robot-assisted rehabilitation facilitates high-intensity training of the impaired upper limb in neurological rehabilitation. It has been clinically observed that persons with Multiple Sclerosis (MS) have difficulties in sustaining the training intensity during a session due to the development of activity-related muscle fatigue. An experimental observational pilot study was conducted to examine whether or not the muscle fatigue develops in MS patients during one session of robot-assisted training within a virtual learning environment. Six MS patients with upper limb impairment (motricity index ranging from 50 to 91/100) and six healthy persons completed five training bouts of three minutes each performing lifting tasks, while EMG signals of anterior deltoid and lower trapezius muscles were measured and their subjective perceptions on muscle fatigue were registered. Decreased performance and higher subjective fatigue perception were present in the MS group. Increased mean EMG amplitudes and subjective perception levels on muscle fatigue were observed in both groups. Muscle fatigue development during 15' training has been demonstrated in the arm of MS patients, which influences the sustainability of training intensity in MS patients. To optimize the training performance, adaptivity based on the detection of MS patient's muscle fatigue could be provided by means of training program adjustment.

  6. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1989-08-15

    The subject of this report is progress during the quarter for Phase I -- Design and Permitting, Phase II -- Coolside/LIMB Construction, Start-Up and Phase III -- Operation, Data Collection, Reporting and Disposition. Under Phase I, Task 2, Consol Technology Transfer, Consol R D continued to review the status of the Coolside installation and identified construction details which required additional action. Activities in Task 4.0 -- Permitting and Licensing have focused on finalizing a subcontract agreement for trucking the DOE Coolside/LIMB ash to a solid waste landfill. Under Phase II, Task 1, Project Management, purchase orders were placed with two (2) lime suppliers for supplying the specified hydrated lime to be used for the Coolside test program. For Subtask 2.2 -- Sorbent Feed System Installation, the construction and installation of the sorbent feed system has been completed. Under Phase III, Subtask 2.1, Optimization of the Coolside sorbent feed system, the ash recycle system and the caustic injection system were initiated. 3 figs.

  7. Reduction of the Radiating Sound of a Submerged Finite Cylindrical Shell Structure by Active Vibration Control

    PubMed Central

    Kim, Heung Soo; Sohn, Jung Woo; Jeon, Juncheol; Choi, Seung-Bok

    2013-01-01

    In this work, active vibration control of an underwater cylindrical shell structure was investigated, to suppress structural vibration and structure-borne noise in water. Finite element modeling of the submerged cylindrical shell structure was developed, and experimentally evaluated. Modal reduction was conducted to obtain the reduced system equation for the active feedback control algorithm. Three Macro Fiber Composites (MFCs) were used as actuators and sensors. One MFC was used as an exciter. The optimum control algorithm was designed based on the reduced system equations. The active control performance was then evaluated using the lab scale underwater cylindrical shell structure. Structural vibration and structure-borne noise of the underwater cylindrical shell structure were reduced significantly by activating the optimal controller associated with the MFC actuators. The results provide that active vibration control of the underwater structure is a useful means to reduce structure-borne noise in water. PMID:23389344

  8. Reduction of the radiating sound of a submerged finite cylindrical shell structure by active vibration control.

    PubMed

    Kim, Heung Soo; Sohn, Jung Woo; Jeon, Juncheol; Choi, Seung-Bok

    2013-02-06

    In this work, active vibration control of an underwater cylindrical shell structure was investigated, to suppress structural vibration and structure-borne noise in water. Finite element modeling of the submerged cylindrical shell structure was developed, and experimentally evaluated. Modal reduction was conducted to obtain the reduced system equation for the active feedback control algorithm. Three Macro Fiber Composites (MFCs) were used as actuators and sensors. One MFC was used as an exciter. The optimum control algorithm was designed based on the reduced system equations. The active control performance was then evaluated using the lab scale underwater cylindrical shell structure. Structural vibration and structure-borne noise of the underwater cylindrical shell structure were reduced significantly by activating the optimal controller associated with the MFC actuators. The results provide that active vibration control of the underwater structure is a useful means to reduce structure-borne noise in water.

  9. Sound Guard

    NASA Technical Reports Server (NTRS)

    1978-01-01

    Lubrication technology originally developed for a series of NASA satellites has produced a commercial product for protecting the sound fidelity of phonograph records. Called Sound Guard, the preservative is a spray-on fluid that deposits a microscopically thin protective coating which reduces friction and prevents the hard diamond stylus from wearing away the softer vinyl material of the disc. It is marketed by the Consumer Products Division of Ball Corporation, Muncie, Indiana. The lubricant technology on which Sound Guard is based originated with NASA's Orbiting Solar Observatory (OSO), an Earth-orbiting satellite designed and built by Ball Brothers Research Corporation, Boulder, Colorado, also a division of Ball Corporation. Ball Brothers engineers found a problem early in the OSO program: known lubricants were unsuitable for use on satellite moving parts that would be exposed to the vacuum of space for several months. So the company conducted research on the properties of materials needed for long life in space and developed new lubricants. They worked successfully on seven OSO flights and attracted considerable attention among other aerospace contractors. Ball Brothers now supplies its "Vac Kote" lubricants and coatings to both aerospace and non-aerospace industries and the company has produced several hundred variations of the original technology. Ball Corporation expanded its product line to include consumer products, of which Sound Guard is one of the most recent. In addition to protecting record grooves, Sound Guard's anti-static quality also retards particle accumulation on the stylus. During comparison study by a leading U.S. electronic laboratory, a record not treated by Sound Guard had to be cleaned after 50 plays and the stylus had collected a considerable number of small vinyl particles. The Sound Guard-treated disc was still clean after 100 plays, as was its stylus.

  10. Concurrent Acoustic Activation of the Medial Olivocochlear System Modifies the After-Effects of Intense Low-Frequency Sound on the Human Inner Ear.

    PubMed

    Kugler, Kathrin; Wiegrebe, Lutz; Gürkov, Robert; Krause, Eike; Drexl, Markus

    2015-12-01

    >Human hearing is rather insensitive for very low frequencies (i.e. below 100 Hz). Despite this insensitivity, low-frequency sound can cause oscillating changes of cochlear gain in inner ear regions processing even much higher frequencies. These alterations outlast the duration of the low-frequency stimulation by several minutes, for which the term 'bounce phenomenon' has been coined. Previously, we have shown that the bounce can be traced by monitoring frequency and level changes of spontaneous otoacoustic emissions (SOAEs) over time. It has been suggested elsewhere that large receptor potentials elicited by low-frequency stimulation produce a net Ca(2+) influx and associated gain decrease in outer hair cells. The bounce presumably reflects an underdamped, homeostatic readjustment of increased Ca(2+) concentrations and related gain changes after low-frequency sound offset. Here, we test this hypothesis by activating the medial olivocochlear efferent system during presentation of the bounce-evoking low-frequency (LF) sound. The efferent system is known to modulate outer hair cell Ca(2+) concentrations and receptor potentials, and therefore, it should modulate the characteristics of the bounce phenomenon. We show that simultaneous presentation of contralateral broadband noise (100 Hz-8 kHz, 65 and 70 dB SPL, 90 s, activating the efferent system) and ipsilateral low-frequency sound (30 Hz, 120 dB SPL, 90 s, inducing the bounce) affects the characteristics of bouncing SOAEs recorded after low-frequency sound offset. Specifically, the decay time constant of the SOAE level changes is shorter, and the transient SOAE suppression is less pronounced. Moreover, the number of new, transient SOAEs as they are seen during the bounce, are reduced. Taken together, activation of the medial olivocochlear system during induction of the bounce phenomenon with low-frequency sound results in changed characteristics of the bounce phenomenon. Thus, our data provide experimental support

  11. The functional anatomy of suggested limb paralysis.

    PubMed

    Deeley, Quinton; Oakley, David A; Toone, Brian; Bell, Vaughan; Walsh, Eamonn; Marquand, Andre F; Giampietro, Vincent; Brammer, Michael J; Williams, Steven C R; Mehta, Mitul A; Halligan, Peter W

    2013-02-01

    Suggestions of limb paralysis in highly hypnotically suggestible subjects have been employed to successfully model conversion disorders, revealing similar patterns of brain activation associated with attempted movement of the affected limb. However, previous studies differ with regard to the executive regions involved during involuntary inhibition of the affected limb. This difference may have arisen as previous studies did not control for differences in hypnosis depth between conditions and/or include subjective measures to explore the experience of suggested paralysis. In the current study we employed functional magnetic resonance imaging (fMRI) to examine the functional anatomy of left and right upper limb movements in eight healthy subjects selected for high hypnotic suggestibility during (i) hypnosis (NORMAL) and (ii) attempted movement following additional left upper limb paralysis suggestions (PARALYSIS). Contrast of left upper limb motor function during NORMAL relative to PARALYSIS conditions revealed greater activation of contralateral M1/S1 and ipsilateral cerebellum, consistent with the engagement of these regions in the completion of movements. By contrast, two significant observations were noted in PARALYSIS relative to NORMAL conditions. In conjunction with reports of attempts to move the paralysed limb, greater supplementary motor area (SMA) activation was observed, a finding consistent with the role of SMA in motor intention and planning. The anterior cingulate cortex (ACC, BA 24) was also significantly more active in PARALYSIS relative to NORMAL conditions - suggesting that ACC (BA 24) may be implicated in involuntary, as well as voluntary inhibition of prepotent motor responses.

  12. Slow Movements of Bio-Inspired Limbs

    NASA Astrophysics Data System (ADS)

    Babikian, Sarine; Valero-Cuevas, Francisco J.; Kanso, Eva

    2016-10-01

    Slow and accurate finger and limb movements are essential to daily activities, but the underlying mechanics is relatively unexplored. Here, we develop a mathematical framework to examine slow movements of tendon-driven limbs that are produced by modulating the tendons' stiffness parameters. Slow limb movements are driftless in the sense that movement stops when actuations stop. We demonstrate, in the context of a planar tendon-driven system representing a finger, that the control of stiffness suffices to produce stable and accurate limb postures and quasi-static (slow) transitions among them. We prove, however, that stable postures are achievable only when tendons are pretensioned, i.e., they cannot become slack. Our results further indicate that a non-smoothness in slow movements arises because the precision with which individual stiffnesses need to be altered changes substantially throughout the limb's motion.

  13. Planar cell polarity in vertebrate limb morphogenesis.

    PubMed

    Gao, Bo; Yang, Yingzi

    2013-08-01

    Studies of the vertebrate limb development have contributed significantly to understanding the fundamental mechanisms underlying growth, patterning, and morphogenesis of a complex multicellular organism. In the limb, well-defined signaling centers interact to coordinate limb growth and patterning along the three axes. Recent analyses of live imaging and mathematical modeling have provided evidence that polarized cell behaviors governed by morphogen gradients play an important role in shaping the limb bud. Furthermore, the Wnt/planar cell polarity (PCP) pathway that controls uniformly polarized cell behaviors in a field of cells has emerged to be critical for directional morphogenesis in the developing limb. Directional information coded in the morphogen gradient may be interpreted by responding cells through regulating the activities of PCP components in a Wnt morphogen dose-dependent manner.

  14. Planar Cell Polarity in vertebrate limb morphogenesis

    PubMed Central

    Gao, Bo; Yang, Yingzi

    2013-01-01

    Studies of the vertebrate limb development have contributed significantly to understanding the fundamental mechanisms underlying growth, patterning and morphogenesis of a complex multicellular organism. In the limb, well-defined signaling centers interact to coordinate limb growth and patterning along the three axes. Recent analyses of live imaging and mathematical modeling have provided evidence that polarized cell behaviors governed by morphogen gradients play an important role in shaping the limb bud. Furthermore, the Wnt/Planar Cell Polarity (PCP) pathway that controls uniformly polarized cellular behaviors in a field of cells has emerged to be critical for directional morphogenesis in the developing limb. Directional information coded in the morphogen gradient may be interpreted by responding cells through regulating the activities of PCP components in a Wnt morphogen dose-dependent manner. PMID:23747034

  15. Variation in the emission rate of sounds in a captive group of false killer whales Pseudorca crassidens during feedings: possible food anticipatory vocal activity?

    NASA Astrophysics Data System (ADS)

    Platto, Sara; Wang, Ding; Wang, Kexiong

    2016-11-01

    This study examines whether a group of captive false killer whales ( Pseudorca crassidens ) showed variations in the vocal rate around feeding times. The high level of motivation to express appetitive behaviors in captive animals may lead them to respond with changes of the behavioral activities during the time prior to food deliveries which are referred to as food anticipatory activity. False killer whales at Qingdao Polar Ocean World (Qingdao, China) showed significant variations of the rates of both the total sounds and sound classes (whistles, clicks, and burst pulses) around feedings. Precisely, from the Transition interval that recorded the lowest vocalization rate (3.40 s/m/d), the whales increased their acoustic emissions upon trainers' arrival (13.08 s/m/d). The high rate was maintained or intensified throughout the food delivery (25.12 s/m/d), and then reduced immediately after the animals were fed (9.91 s/m/d). These changes in the false killer whales sound production rates around feeding times supports the hypothesis of the presence of a food anticipatory vocal activity. Although sound rates may not give detailed information regarding referential aspects of the animal communication it might still shed light about the arousal levels of the individuals during different social or environmental conditions. Further experiments should be performed to assess if variations of the time of feeding routines may affect the vocal activity of cetaceans in captivity as well as their welfare.

  16. Chronic Pain Associated with Upper-Limb Loss

    PubMed Central

    Hanley, Marisol A.; Ehde, Dawn M.; Jensen, Mark; Czerniecki, Joseph; Smith, Douglas G.; Robinson, Lawrence R.

    2011-01-01

    Objective To describe the prevalence, intensity, and functional impact of the following types of pain associated with upper-limb loss: phantom limb, residual limb, back, neck, and nonamputated-limb pain. Design Cross-sectional survey; 104 respondents with upper-limb loss at least 6 months postamputation completed measures of pain intensity, interference, disability, and health-related quality-of-life. Results Nearly all (90%) of the respondents reported pain, with 76% reporting more than one pain type. Phantom-limb pain and residual-limb pain were the most prevalent (79% and 71%, respectively), followed by back (52%), neck (43%), and nonamputated-limb pain (33%). Although nonamputated-limb pain was least prevalent, it was reported to cause the highest levels of interference and pain-related disability days. Self-reported quality-of-life was significantly lower for individuals with each type of pain compared with those without any pain. Age, time since amputation, and cause of amputation were not associated with pain. Conclusions In addition to pain in the phantom and residual limb, back, neck, and nonamputated-limb pain are also common after upper-limb loss. All of these pain types are associated with significant disability and activity interference for some individuals, suggesting that assessment of multiple pain types in persons with upper-limb amputation may be important. PMID:19692791

  17. Effects of multiple congruent cues on concurrent sound segregation during passive and active listening: an event-related potential (ERP) study.

    PubMed

    Kocsis, Zsuzsanna; Winkler, István; Szalárdy, Orsolya; Bendixen, Alexandra

    2014-07-01

    In two experiments, we assessed the effects of combining different cues of concurrent sound segregation on the object-related negativity (ORN) and the P400 event-related potential components. Participants were presented with sequences of complex tones, half of which contained some manipulation: one or two harmonic partials were mistuned, delayed, or presented from a different location than the rest. In separate conditions, one, two, or three of these manipulations were combined. Participants watched a silent movie (passive listening) or reported after each tone whether they perceived one or two concurrent sounds (active listening). ORN was found in almost all conditions except for location difference alone during passive listening. Combining several cues or manipulating more than one partial consistently led to sub-additive effects on the ORN amplitude. These results support the view that ORN reflects a combined, feature-unspecific assessment of the auditory system regarding the contribution of two sources to the incoming sound.

  18. A mobile system for the multifrequency Doppler sounding of the modified ionosphere in active experiments

    NASA Astrophysics Data System (ADS)

    Bagno, Iu. D.; Kim, V. Iu.; Namazov, S. A.; Panchenko, V. N.; Khar'kov, I. P.

    1993-01-01

    The paper presents a description of a mobile multichannel Doppler system designed for shipboard studies of the modified ionosphere. The system was used for the diagnostics of the modified ionosphere in active experiments carried out in equatorial and low-latitude regions using the MR-20 geophysical rockets as well as in satellite experiments in the framework of the CRRES project. The data processing method is discussed, and experimental data are presented.

  19. Identification of Sound Source Azimuth with Active and Passive Hearing Protectors

    DTIC Science & Technology

    1982-09-01

    dichotic or independent input to the two ears; the DH-140 provides a diotic or completely correlated input to both ears. Auditory localizatio’i ’r a...in the data for subject F. Model 6 resembles the serpentine pattern seen with the dichotic active protector (Figure 11). However, closer examination...Even when aware of this enhancement of head shadow effect, subjects were unable to assign perceptual loci to the left or right. With a dichotic

  20. Geophysical Sounding

    NASA Astrophysics Data System (ADS)

    Blake, E.

    1998-01-01

    Of the many geophysical remote-sensing techniques available today, a few are suitable for the water ice-rich, layered material expected at the north martian ice cap. Radio echo sounding has been used for several decades to determine ice thickness and internal structure. Selection of operating frequency is a tradeoff between signal attenuation (which typically increases with frequency and ice temperature) and resolution (which is proportional to wavelength). Antenna configuration and size will be additional considerations for a mission to Mars. Several configurations for ice-penetrating radar systems are discussed: these include orbiter-borne sounders, sounding antennas trailed by balloons and penetrators, and lander-borne systems. Lander-borne systems could include short-wave systems capable of resolving fine structure and layering in the upper meters beneath the lander. Spread-spectrum and deconvolution techniques can be used to increase the depth capability of a radar system. If soundings over several locations are available (e.g., with balloons, rovers, or panning short-wave systems), then it will be easier to resolve internal layering, variations in basal reflection coefficient (from which material properties may be inferred), and the geometry of nonhorizontal features. Sonic sounding has a long history in oil and gas exploration. It is, however, unlikely that large explosive charges, or even swept-frequency techniques such as Vibroseis, would be suitable for a Polar lander -- these systems are capable of penetrating several kilometers of material at frequencies of 10-200 Hz, but the energy required to generate the sound waves is large and potentially destructive. The use of audio-frequency and ultrasonic sound generated by piezoelectric crystals is discussed as a possible method to explore layering and fine features in the upper meters of the ice cap. Appropriate choice of transducer(s) will permit operation over a range of fixed or modulated frequencies

  1. The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses

    PubMed Central

    TAKAHASHI, Toshiyuki; MATSUI, Akira; MUKAI, Kazutaka; OHMURA, Hajime; HIRAGA, Atsushi; AIDA, Hiroko

    2014-01-01

    ABSTRACT It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from −6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles. PMID:25558180

  2. The Effects of Inclination (Up and Down) of the Treadmill on the Electromyogram Activities of the Forelimb and Hind limb Muscles at a Walk and a Trot in Thoroughbred Horses.

    PubMed

    Takahashi, Toshiyuki; Matsui, Akira; Mukai, Kazutaka; Ohmura, Hajime; Hiraga, Atsushi; Aida, Hiroko

    2014-01-01

    It is important to know the effects of the inclination of a slope on the activity of each muscle, because training by running on a sloped track is commonly used for Thoroughbred racehorses. The effects of incline (from -6 to +6%) on the forelimbs and hind limbs during walking and trotting on a treadmill were evaluated by an integrated electromyogram (iEMG). The muscle activities in the forelimbs (5 horses) and hind limbs (4 horses) were measured separately. Two stainless steel wires were inserted into each of the brachiocephalicus (Bc), biceps brachii (BB), splenius (Sp), and pectoralis descendens (PD) in the forelimb experiment and into the longissimus dorsi (LD), vastus lateralis (VL), gluteus medius (GM), and biceps femoris (BF) in the hind limb experiment. The EMG recordings were taken at a sampling rate of 1,000 Hz. At a walk, the iEMG values for the forelimb were not significantly different under any of the inclinations. In the hind limb, the iEMG values for the GM and BF significantly decreased as the inclination decreased. At a trot, the iEMG values for the Bc in the forelimb significantly decreased as the inclination of the treadmill decreased. In the hind limb, the iEMG values for the LD, GM, and BF significantly decreased as the inclination decreased. Uphill exercise increased the iEMG values for the Bc, LD, GM, and BF, while downhill exercise resulted in little increase in the iEMG values. It was concluded that the effects of inclination on the muscle activities were larger for the uphill exercises, and for the hind limb muscles compared with the forelimb muscles.

  3. The Sound of Silence: Activating Silent Biosynthetic Gene Clusters in Marine Microorganisms.

    PubMed

    Reen, F Jerry; Romano, Stefano; Dobson, Alan D W; O'Gara, Fergal

    2015-07-31

    Unlocking the rich harvest of marine microbial ecosystems has the potential to both safeguard the existence of our species for the future, while also presenting significant lifestyle benefits for commercial gain. However, while significant advances have been made in the field of marine biodiscovery, leading to the introduction of new classes of therapeutics for clinical medicine, cosmetics and industrial products, much of what this natural ecosystem has to offer is locked in, and essentially hidden from our screening methods. Releasing this silent potential represents a significant technological challenge, the key to which is a comprehensive understanding of what controls these systems. Heterologous expression systems have been successful in awakening a number of these cryptic marine biosynthetic gene clusters (BGCs). However, this approach is limited by the typically large size of the encoding sequences. More recently, focus has shifted to the regulatory proteins associated with each BGC, many of which are signal responsive raising the possibility of exogenous activation. Abundant among these are the LysR-type family of transcriptional regulators, which are known to control production of microbial aromatic systems. Although the environmental signals that activate these regulatory systems remain unknown, it offers the exciting possibility of evoking mimic molecules and synthetic expression systems to drive production of potentially novel natural products in microorganisms. Success in this field has the potential to provide a quantum leap forward in medical and industrial bio-product development. To achieve these new endpoints, it is clear that the integrated efforts of bioinformaticians and natural product chemists will be required as we strive to uncover new and potentially unique structures from silent or cryptic marine gene clusters.

  4. The Sound of Silence: Activating Silent Biosynthetic Gene Clusters in Marine Microorganisms

    PubMed Central

    Reen, F. Jerry; Romano, Stefano; Dobson, Alan D.W.; O’Gara, Fergal

    2015-01-01

    Unlocking the rich harvest of marine microbial ecosystems has the potential to both safeguard the existence of our species for the future, while also presenting significant lifestyle benefits for commercial gain. However, while significant advances have been made in the field of marine biodiscovery, leading to the introduction of new classes of therapeutics for clinical medicine, cosmetics and industrial products, much of what this natural ecosystem has to offer is locked in, and essentially hidden from our screening methods. Releasing this silent potential represents a significant technological challenge, the key to which is a comprehensive understanding of what controls these systems. Heterologous expression systems have been successful in awakening a number of these cryptic marine biosynthetic gene clusters (BGCs). However, this approach is limited by the typically large size of the encoding sequences. More recently, focus has shifted to the regulatory proteins associated with each BGC, many of which are signal responsive raising the possibility of exogenous activation. Abundant among these are the LysR-type family of transcriptional regulators, which are known to control production of microbial aromatic systems. Although the environmental signals that activate these regulatory systems remain unknown, it offers the exciting possibility of evoking mimic molecules and synthetic expression systems to drive production of potentially novel natural products in microorganisms. Success in this field has the potential to provide a quantum leap forward in medical and industrial bio-product development. To achieve these new endpoints, it is clear that the integrated efforts of bioinformaticians and natural product chemists will be required as we strive to uncover new and potentially unique structures from silent or cryptic marine gene clusters. PMID:26264003

  5. Relation of Neurological Findings on Decoupling of Brain Activity from Limb Movement to Piagetian Ideas on the Origin of Thought

    ERIC Educational Resources Information Center

    Becker, Joe

    2006-01-01

    Neurological research has demonstrated that brain activity in animals originally dedicated to the production and regulation of physical activity can be decoupled from that physical activity. Furthermore, animals can use the brain activity in this new condition to achieve particular results such as moving a cursor on a screen. These findings are…

  6. Sound Solutions

    ERIC Educational Resources Information Center

    Starkman, Neal

    2007-01-01

    Poor classroom acoustics are impairing students' hearing and their ability to learn. However, technology has come up with a solution: tools that focus voices in a way that minimizes intrusive ambient noise and gets to the intended receiver--not merely amplifying the sound, but also clarifying and directing it. One provider of classroom audio…

  7. Sonic Hedgehog Signaling in Limb Development

    PubMed Central

    Tickle, Cheryll; Towers, Matthew

    2017-01-01

    The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e.g., shoulder to digits axis) of the limb. It has been shown that Shh signaling can specify antero-posterior positional values in limb buds in both a concentration- (paracrine) and time-dependent (autocrine) fashion. Currently there are several models for how Shh specifies positional values over time in the limb buds of chick and mouse embryos and how this is integrated with growth. Extensive work has elucidated downstream transcriptional targets of Shh signaling. Nevertheless, it remains unclear how antero-posterior positional values are encoded and then interpreted to give the particular structure appropriate to that position, for example, the type of digit. A distant cis-regulatory enhancer controls limb-bud-specific expression of Shh and the discovery of increasing numbers of interacting transcription factors indicate complex spatiotemporal regulation. Altered Shh signaling is implicated in clinical conditions with congenital limb defects and in the evolution of the morphological diversity of vertebrate limbs. PMID:28293554

  8. Sonic Hedgehog Signaling in Limb Development.

    PubMed

    Tickle, Cheryll; Towers, Matthew

    2017-01-01

    The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e.g., shoulder to digits axis) of the limb. It has been shown that Shh signaling can specify antero-posterior positional values in limb buds in both a concentration- (paracrine) and time-dependent (autocrine) fashion. Currently there are several models for how Shh specifies positional values over time in the limb buds of chick and mouse embryos and how this is integrated with growth. Extensive work has elucidated downstream transcriptional targets of Shh signaling. Nevertheless, it remains unclear how antero-posterior positional values are encoded and then interpreted to give the particular structure appropriate to that position, for example, the type of digit. A distant cis-regulatory enhancer controls limb-bud-specific expression of Shh and the discovery of increasing numbers of interacting transcription factors indicate complex spatiotemporal regulation. Altered Shh signaling is implicated in clinical conditions with congenital limb defects and in the evolution of the morphological diversity of vertebrate limbs.

  9. Structural sensing of interior sound for active control of noise in structural-acoustic cavities.

    PubMed

    Bagha, Ashok K; Modak, S V

    2015-07-01

    This paper proposes a method for structural sensing of acoustic potential energy for active control of noise in a structural-acoustic cavity. The sensing strategy aims at global control and works with a fewer number of sensors. It is based on the established concept of radiation modes and hence does not add too many states to the order of the system. Acoustic potential energy is sensed using a combination of a Kalman filter and a frequency weighting filter with the structural response measurements as the inputs. The use of Kalman filter also makes the system robust against measurement noise. The formulation of the strategy is presented using finite element models of the system including that of sensors and actuators so that it can be easily applied to practical systems. The sensing strategy is numerically evaluated in the framework of Linear Quadratic Gaussian based feedback control of interior noise in a rectangular box cavity with a flexible plate with single and multiple pairs of piezoelectric sensor-actuator patches when broadband disturbances act on the plate. The performance is compared with an "acoustic filter" that models the complete transfer function from the structure to the acoustic domain. The sensing performance is also compared with a direct estimation strategy.

  10. Assisting Children with Attention Deficit Hyperactivity Disorder Actively Reduces Limb Hyperactive Behavior with a Nintendo Wii Remote Controller through Controlling Environmental Stimulation

    ERIC Educational Resources Information Center

    Shih, Ching-Hsiang; Yeh, Jui-Chi; Shih, Ching-Tien; Chang, Man-Ling

    2011-01-01

    The latest studies have adopted software technology which turns the Wii Remote Controller into a high-performance limb action detector, we assessed whether two persons with multiple disabilities would be able to control an environmental stimulus through limb action. This study extends the functionality of the Wii Remote Controller to the…

  11. Wave field synthesis, adaptive wave field synthesis and ambisonics using decentralized transformed control: Potential applications to sound field reproduction and active noise control

    NASA Astrophysics Data System (ADS)

    Gauthier, Philippe-Aubert; Berry, Alain; Woszczyk, Wieslaw

    2005-09-01

    Sound field reproduction finds applications in listening to prerecorded music or in synthesizing virtual acoustics. The objective is to recreate a sound field in a listening environment. Wave field synthesis (WFS) is a known open-loop technology which assumes that the reproduction environment is anechoic. Classical WFS, therefore, does not perform well in a real reproduction space such as room. Previous work has suggested that it is physically possible to reproduce a progressive wave field in-room situation using active control approaches. In this paper, a formulation of adaptive wave field synthesis (AWFS) introduces practical possibilities for an adaptive sound field reproduction combining WFS and active control (with WFS departure penalization) with a limited number of error sensors. AWFS includes WFS and closed-loop ``Ambisonics'' as limiting cases. This leads to the modification of the multichannel filtered-reference least-mean-square (FXLMS) and the filtered-error LMS (FELMS) adaptive algorithms for AWFS. Decentralization of AWFS for sound field reproduction is introduced on the basis of sources' and sensors' radiation modes. Such decoupling may lead to decentralized control of source strength distributions and may reduce computational burden of the FXLMS and the FELMS algorithms used for AWFS. [Work funded by NSERC, NATEQ, Université de Sherbrooke and VRQ.] Ultrasound/Bioresponse to

  12. Multipoint observations of nightside auroral activity: the Cascades2 sounding rocket mission

    NASA Astrophysics Data System (ADS)

    Lynch, K. A.; Mella, M. R.; Kintner, P. M.; Lundberg, E. T.; Lessard, M.; Jones, S.; Stenbaek-Nielsen, H. C.; Hampton, D. L.; Ivchenko, N. V.; Dahlgren, H.

    2009-12-01

    Cascades2 was launched from Poker Flat Alaska on 20 Mar 2009 at 11:04 UT (roughly 30 minutes premidnight magnetic local time.) The 12 minute 43 second flight reached an apogee of 564 km over the northern coast of Alaska at 11:11:11 UT, and entered the polar cap at 11:14:40 UT before atmospheric reentry at 11:16:42 UT. The experiment array included a 5-payload suite of in situ instrumentation, ground cameras of various fields of view at three different points under the trajectory, various ground magnetometers, the PFISR radar at the launch site, and the THEMIS spacecraft in the magnetotail. The array design was chosen to address questions about (1) shears in ionospheric electric fields and their ability to drive waves; (2) proper motion of auroral structures with respect to the ambient ionosphere; and (3) quantifying parameters of dispersive Alfven wave phenomena and their effects on auroral fluxtubes. The successful flight was due to the sustained and dedicated effort of the many and varied members of our team. The Cascades2 trajectory passed through several parts of a poleward boundary intensification event, with both inverted-V type aurora and sustained Alfvenic activity seen. Other presentations will detail the ground camera, onboard DC electric fields, and onboard multipoint electron data. In this presentation we show onboard magnetometer results of current signatures both compressional and transverse. Also we present ion data showing the complex motion of low and medium energy ions in these poleward boundary events; ions are seen to be both moving upward along the field line, and then precipitating back down at higher energies with dispersion signatures.

  13. Active tectonics of the Seattle fault and central Puget sound, Washington - Implications for earthquake hazards

    USGS Publications Warehouse

    Johnson, S.Y.; Dadisman, S.V.; Childs, J. R.; Stanley, W.D.

    1999-01-01

    We use an extensive network of marine high-resolution and conventional industry seismic-reflection data to constrain the location, shallow structure, and displacement rates of the Seattle fault zone and crosscutting high-angle faults in the Puget Lowland of western Washington. Analysis of seismic profiles extending 50 km across the Puget Lowland from Lake Washington to Hood Canal indicates that the west-trending Seattle fault comprises a broad (4-6 km) zone of three or more south-dipping reverse faults. Quaternary sediment has been folded and faulted along all faults in the zone but is clearly most pronounced along fault A, the northernmost fault, which forms the boundary between the Seattle uplift and Seattle basin. Analysis of growth strata deposited across fault A indicate minimum Quaternary slip rates of about 0.6 mm/yr. Slip rates across the entire zone are estimated to be 0.7-1.1 mm/yr. The Seattle fault is cut into two main segments by an active, north-trending, high-angle, strike-slip fault zone with cumulative dextral displacement of about 2.4 km. Faults in this zone truncate and warp reflections in Tertiary and Quaternary strata and locally coincide with bathymetric lineaments. Cumulative slip rates on these faults may exceed 0.2 mm/yr. Assuming no other crosscutting faults, this north-trending fault zone divides the Seattle fault into 30-40-km-long western and eastern segments. Although this geometry could limit the area ruptured in some Seattle fault earthquakes, a large event ca. A.D. 900 appears to have involved both segments. Regional seismic-hazard assessments must (1) incorporate new information on fault length, geometry, and displacement rates on the Seattle fault, and (2) consider the hazard presented by the previously unrecognized, north-trending fault zone.

  14. Generation of pattern and form in the developing limb.

    PubMed

    Towers, Matthew; Tickle, Cheryll

    2009-01-01

    The developing limb is a major model for pattern formation in vertebrate embryos. Many of the seminal discoveries of the mechanisms involved in patterning have been made using chick embryos because of the ease of manipulating their developing limbs. More recently, the molecular basis of limb pattern formation has been increasingly uncovered and now, with the availability of genomic resources, the genetic approaches available are even more powerful. Nevertheless, since the limb is ultimately built of cells, gene action must ultimately be translated into cell behaviour and a major challenge will be to integrate genetics with molecular and cellular biology. In this review, we will first outline the stages in limb development, the major interacting signalling pathways that pattern the limb and the molecules involved. We will describe fate maps of the developing limb, and discuss what is known about cellular activities including proliferation, death, adhesiveness, communication and migration during the patterning process. Finally we will explore how these cell activities produce form.

  15. Simultaneously active pre-attentive representations of local and global rules for sound sequences in the human brain.

    PubMed

    Horváth, J; Czigler, I; Sussman, E; Winkler, I

    2001-08-01

    Regular sequences of sounds (i.e., non-random) can usually be described by several, equally valid rules. Rules allowing extrapolation from one sound to the next are termed local rules, those that define relations between temporally non-adjacent sounds are termed global rules. The aim of the present study was to determine whether both local and global rules can be simultaneously extracted from a sound sequence even when attention is directed away from the auditory stimuli. The pre-attentive representation of a sequence of two alternating tones (differing only in frequency) was investigated using the mismatch negativity (MMN) auditory event-related potential. Both local- and global-rule violations of tone alternation elicited the MMN component while subjects ignored the auditory stimuli. This finding suggests that (a) pre-attentive auditory processes can extract both local and global rules from sound sequences, and (b) that several regularity representations of a sound sequence are simultaneously maintained during the pre-attentive phase of auditory stimulus processing.

  16. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1988-03-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full-scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO{sub x} and NO{sub x} emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  17. LIMB Demonstration Project Extension

    SciTech Connect

    Not Available

    1988-09-15

    The basic goal of the Limestone Injection Multistage Burner (LIMB) demonstration is to extend LIMB technology development to a full-scale application on a representative wall-fired utility boiler. The successful retrofit of LIMB to an existing boiler is expected to demonstrate that (a) reductions of 50 percent or greater in SO and NO emissions can be achieved at a fraction of the cost of add-on FGD systems, (b) boiler reliability, operability, and steam production can be maintained at levels existing prior to LIMB retrofit, and (c) technical difficulties attributable to LIMB operation, such as additional slagging and fouling, changes in ash disposal requirements, and an increased particulate load, can be resolved in a cost-effective manner. The primary fuel to be used will be an Ohio bituminous coal having a nominal sulfur content of 3 percent or greater.

  18. p75(NTR)-dependent activation of NF-κB regulates microRNA-503 transcription and pericyte-endothelial crosstalk in diabetes after limb ischaemia.

    PubMed

    Caporali, Andrea; Meloni, Marco; Nailor, Audrey; Mitić, Tijana; Shantikumar, Saran; Riu, Federica; Sala-Newby, Graciela B; Rose, Lorraine; Besnier, Marie; Katare, Rajesh; Voellenkle, Christine; Verkade, Paul; Martelli, Fabio; Madeddu, Paolo; Emanueli, Costanza

    2015-08-13

    The communication between vascular endothelial cells (ECs) and pericytes in the microvasculature is fundamental for vascular growth and homeostasis; however, these processes are disrupted by diabetes. Here we show that modulation of p75(NTR) expression in ECs exposed to high glucose activates transcription of miR-503, which negatively affects pericyte function. p75(NTR) activates NF-κB to bind the miR-503 promoter and upregulate miR-503 expression in ECs. NF-κB further induces activation of Rho kinase and shedding of endothelial microparticles carrying miR-503, which transfer miR-503 from ECs to vascular pericytes. The integrin-mediated uptake of miR-503 in the recipient pericytes reduces expression of EFNB2 and VEGFA, resulting in impaired migration and proliferation. We confirm operation of the above mechanisms in mouse models of diabetes, in which EC-derived miR-503 reduces pericyte coverage of capillaries, increased permeability and impaired post-ischaemic angiogenesis in limb muscles. Collectively, our data demonstrate that miR-503 regulates pericyte-endothelial crosstalk in microvascular diabetic complications.

  19. Applications of Sound Spectrum Analysis

    ERIC Educational Resources Information Center

    Moran, Timothy

    2007-01-01

    The physics of sound is often studied in introductory physics class experiments involving a tube of resonating air. In typical setups, pistons control the length of a cylindrical space or a microphone is moved within a tube. While these activities are useful and can be made very quantitative, they don't directly demonstrate the sounds that are…

  20. Exploring Sound with Insects

    ERIC Educational Resources Information Center

    Robertson, Laura; Meyer, John R.

    2010-01-01

    Differences in insect morphology and movement during singing provide a fascinating opportunity for students to investigate insects while learning about the characteristics of sound. In the activities described here, students use a free online computer software program to explore the songs of the major singing insects and experiment with making…

  1. Crossmodal enhancement of visual orientation discrimination by looming sounds requires functional activation of primary visual areas: a case study.

    PubMed

    Cecere, Roberto; Romei, Vincenzo; Bertini, Caterina; Làdavas, Elisabetta

    2014-04-01

    Approaching or looming sounds are salient, potentially threatening stimuli with particular impact on visual processing. The early crossmodal effects by looming sounds (Romei, Murray, Cappe, & Thut, 2009) and their selective impact on visual orientation discrimination (Leo, Romei, Freeman, Ladavas, & Driver, 2011) suggest that these multisensory interactions may take place already within low-level visual cortices. To investigate this hypothesis, we tested a patient (SDV) with bilateral occipital lesion and spared residual portions of V1/V2. Accordingly, SDV׳s visual perimetry revealed blindness of the central visual field with some residual peripheral vision. In two experiments we tested for the influence of looming vs. receding and stationary sounds on SDV׳s line orientation discrimination (orientation discrimination experiment) and visual detection abilities (detection experiment) in the preserved or blind portions of the visual field, corresponding to spared and lesioned areas of V1, respectively. In the visual orientation discrimination experiment we found that SDV visual orientation sensitivity significantly improved for visual targets paired with looming sounds but only for lines presented in the partially preserved visual field. In the visual detection experiment, where SDV was required to simply detect the same stimuli presented in the orientation discrimination experiment, a generalised sound-induced visual improvement both in the intact and in blind portion of the visual field was observed. These results provide direct evidence that early visual areas are critically involved in crossmodal modulation of visual orientation sensitivity by looming sounds. Thus, a lesion in V1 prevents the enhancement of visual orientation sensitivity. In contrast, the same lesion does not prevent the visual detection enhancement by a sound, probably due to alternative visual pathways (e.g. retino-colliculo-extrastriate) which are usually spared in these patients and able to

  2. A synchrony-dependent influence of sounds on activity in visual cortex measured using functional near-infrared spectroscopy (fNIRS).

    PubMed

    Wiggins, Ian M; Hartley, Douglas E H

    2015-01-01

    Evidence from human neuroimaging and animal electrophysiological studies suggests that signals from different sensory modalities interact early in cortical processing, including in primary sensory cortices. The present study aimed to test whether functional near-infrared spectroscopy (fNIRS), an emerging, non-invasive neuroimaging technique, is capable of measuring such multisensory interactions. Specifically, we tested for a modulatory influence of sounds on activity in visual cortex, while varying the temporal synchrony between trains of transient auditory and visual events. Related fMRI studies have consistently reported enhanced activation in response to synchronous compared to asynchronous audiovisual stimulation. Unexpectedly, we found that synchronous sounds significantly reduced the fNIRS response from visual cortex, compared both to asynchronous sounds and to a visual-only baseline. It is possible that this suppressive effect of synchronous sounds reflects the use of an efficacious visual stimulus, chosen for consistency with previous fNIRS studies. Discrepant results may also be explained by differences between studies in how attention was deployed to the auditory and visual modalities. The presence and relative timing of sounds did not significantly affect performance in a simultaneously conducted behavioral task, although the data were suggestive of a positive relationship between the strength of the fNIRS response from visual cortex and the accuracy of visual target detection. Overall, the present findings indicate that fNIRS is capable of measuring multisensory cortical interactions. In multisensory research, fNIRS can offer complementary information to the more established neuroimaging modalities, and may prove advantageous for testing in naturalistic environments and with infant and clinical populations.

  3. GPS Sounding Rocket Developments

    NASA Technical Reports Server (NTRS)

    Bull, Barton

    1999-01-01

    Sounding rockets are suborbital launch vehicles capable of carrying scientific payloads several hundred miles in altitude. These missions return a variety of scientific data including; chemical makeup and physical processes taking place In the atmosphere, natural radiation surrounding the Earth, data on the Sun, stars, galaxies and many other phenomena. In addition, sounding rockets provide a reasonably economical means of conducting engineering tests for instruments and devices used on satellites and other spacecraft prior to their use in more expensive activities. The NASA Sounding Rocket Program is managed by personnel from Goddard Space Flight Center Wallops Flight Facility (GSFC/WFF) in Virginia. Typically around thirty of these rockets are launched each year, either from established ranges at Wallops Island, Virginia, Poker Flat Research Range, Alaska; White Sands Missile Range, New Mexico or from Canada, Norway and Sweden. Many times launches are conducted from temporary launch ranges in remote parts of the world requi6ng considerable expense to transport and operate tracking radars. An inverse differential GPS system has been developed for Sounding Rocket. This paper addresses the NASA Wallops Island history of GPS Sounding Rocket experience since 1994 and the development of a high accurate and useful system.

  4. Hybrid Active/Passive Control of Sound Radiation from Panels with Constrained Layer Damping and Model Predictive Feedback Control

    NASA Technical Reports Server (NTRS)

    Cabell, Randolph H.; Gibbs, Gary P.

    2000-01-01

    make the controller adaptive. For example, a mathematical model of the plant could be periodically updated as the plant changes, and the feedback gains recomputed from the updated model. To be practical, this approach requires a simple plant model that can be updated quickly with reasonable computational requirements. A recent paper by the authors discussed one way to simplify a feedback controller, by reducing the number of actuators and sensors needed for good performance. The work was done on a tensioned aircraft-style panel excited on one side by TBL flow in a low speed wind tunnel. Actuation was provided by a piezoelectric (PZT) actuator mounted on the center of the panel. For sensing, the responses of four accelerometers, positioned to approximate the response of the first radiation mode of the panel, were summed and fed back through the controller. This single input-single output topology was found to have nearly the same noise reduction performance as a controller with fifteen accelerometers and three PZT patches. This paper extends the previous results by looking at how constrained layer damping (CLD) on a panel can be used to enhance the performance of the feedback controller thus providing a more robust and efficient hybrid active/passive system. The eventual goal is to use the CLD to reduce sound radiation at high frequencies, then implement a very simple, reduced order, low sample rate adaptive controller to attenuate sound radiation at low frequencies. Additionally this added damping smoothes phase transitions over the bandwidth which promotes robustness to natural frequency shifts. Experiments were conducted in a transmission loss facility on a clamped-clamped aluminum panel driven on one side by a loudspeaker. A generalized predictive control (GPC) algorithm, which is suited to online adaptation of its parameters, was used in single input-single output and multiple input-single output configurations. Because this was a preliminary look at the potential

  5. Sound preferences in urban open public spaces

    NASA Astrophysics Data System (ADS)

    Kang, Jian; Yang, Wei

    2003-10-01

    This paper studies people's perception of sound, based on an intensive questionnaire survey in fourteen urban open public spaces of five European countries. The questionnaire includes identification of recognized sounds, classification of sound preference, and indication of wanted and unwanted sounds. The results indicate three facets to people's sound preferences. First, people generally prefer natural and culture-related sounds rather than artificial sounds. Vehicle sounds and construction sounds are regarded as the most unpopular, whereas sounds from human activities are normally rated as neutral. Second, cultural background and long-term environmental experience play an important role in people's judgment of sound preference. People from a similar environment may show a similar tendency on their sound preferences, which can be defined as macro-preference. Third, personal differences, such as age and gender, further influence people's sound preference, which can be defined as micro-preference. For example, with increasing age, a higher percentage of people are favorable to, or tolerate, sounds relating to nature, culture or human activities. Male and female exhibit only slight differences. [Work supported by the European Commission.

  6. Experimental Simulation of Active Control With On-line System Identification on Sound Transmission Through an Elastic Plate

    NASA Technical Reports Server (NTRS)

    1998-01-01

    An adaptive control algorithm with on-line system identification capability has been developed. One of the great advantages of this scheme is that an additional system identification mechanism such as an additional uncorrelated random signal generator as the source of system identification is not required. A time-varying plate-cavity system is used to demonstrate the control performance of this algorithm. The time-varying system consists of a stainless-steel plate which is bolted down on a rigid cavity opening where the cavity depth was changed with respect to time. For a given externally located harmonic sound excitation, the system identification and the control are simultaneously executed to minimize the transmitted sound in the cavity. The control performance of the algorithm is examined for two cases. First, all the water was drained, the external disturbance frequency is swept with 1 Hz/sec. The result shows an excellent frequency tracking capability with cavity internal sound suppression of 40 dB. For the second case, the water level is initially empty and then raised to 3/20 full in 60 seconds while the external sound excitation is fixed with a frequency. Hence, the cavity resonant frequency decreases and passes the external sound excitation frequency. The algorithm shows 40 dB transmitted noise suppression without compromising the system identification tracking capability.

  7. Spectral analysis of ionospheric disturbances in the phase delay and radio signal amplitude at limb paths according to the COSMIC data in periods of solar activity

    NASA Astrophysics Data System (ADS)

    Shmakov, A. V.; Gorbunov, M. E.

    2016-07-01

    Based on more than 4500 sessions of radio transillumination of Earth's atmosphere along the satellite-atmosphere-satellite path obtained in the COSMIC experiment, the distribution along latitude and over local time of the spatial spectra of variations in the ionospheric phase delay and signal amplitude has been analyzed. The spatial spectra have been calculated for two height ranges, i.e., 60-80 and 80-100 km. In the phase signal spectrum within the height range 80-100 km, the second maximum in the vicinity of a frequency of 7-8 rad/km is clearly seen. Its diurnal and latitudinal behavior and its decrease towards high latitudes in both hemispheres can also be seen. In the height range of 60-80 km, this maximum is hardly observed. Although solar flares can lead to substantial local changes in the electron concentration, no substantial difference in the behavior of the spectral densities of the amplitude and phase delay at long limb paths was observed within these two height ranges on days of active and quiet sun. The latter fact makes it possible to develop a united algorithm of optimal ionospheric correction of the radio occultation data independent of solar activity.

  8. Earth Limb Radiance Transformation.

    DTIC Science & Technology

    1981-03-02

    AD-A097 523 AEROSPACE CORP EL SEGUNDO CA CHEMISTRY AND PHYSICS LAB F/G 4/1 EARTH LIMB RADIANCE TRANSFORMATION (U) MAR AI S 4 YOUNG F0701-80 -C-0081... Earth Limb Radiance Trafisformation Prepared by S. J. YOUNG Chemistr and Physics Laboratory Laboratory Operations The Aerospace Corporation S.El...ITLEK (and Subtitle) TYPE OF REPORT & P53100 COVERED Earth Limb Radiance Transformation. ( Interim ./ / /TR-OJ081(697j7-g4)-l-- i7.Step hen J. Young

  9. Imparting regenerative capacity to limbs by progenitor cell transplantation

    PubMed Central

    Lin, Gufa; Chen, Ying; Slack, Jonathan M.W.

    2012-01-01

    Summary The frog Xenopus can normally regenerate its limbs at early developmental stages but loses the ability during metamorphosis. This behavior provides a potential gain-of-function model for measures that can enhance limb regeneration. Here we show that frog limbs can be caused to form multidigit regenerates after receiving transplants of larval limb progenitor cells. It is necessary to activate Wnt/β -catenin signaling in the cells, and to add Sonic hedgehog, FGF10 and thymosin β4. These factors promote survival and growth of the grafted cells and also provide pattern information. The eventual regenerates are not composed solely of donor tissue; the host cells also make a substantial contribution despite their lack of regeneration-competence. Cells from adult frog legs or from regenerating tadpole tails do not promote limb regeneration, demonstrating the necessity for limb progenitor cells. These findings have obvious implications for the development of a technology to promote limb regeneration in mammals. PMID:23273877

  10. Active vehicle charging measurements in sounding rocket and space shuttle orbiter environments at Low Earth Orbit (LEO) altitude

    NASA Technical Reports Server (NTRS)

    Raitt, W. J.; Eccles, J. V.; Myers, N. B.; Thompson, D. C.; Banks, P. M.; Williamson, P. R.; Bush, R. I.; Hawkins, J.; Sasaki, S.; Oyama, K.-I.

    1987-01-01

    It was concluded that for electron beam emission up to 100mA, vehicle charging is not a significant problem with the Space Shuttle Orbiter. Similarly, sounding rocket payloads have no serious charging problems up to this level of beam current, provided that the maximum amount of the rocket skin is available to collect ionospheric electrons from the LEO altitude range. However, sounding rockets are marginal in their collecting area capability and other effects may occur to balance the beam current when operated at lower altitudes during the night.

  11. Hydrogen Sulfide Levels and Nuclear Factor-Erythroid 2-Related Factor 2 (NRF2) Activity Are Attenuated in the Setting of Critical Limb Ischemia (CLI)

    PubMed Central

    Islam, Kazi N; Polhemus, David J; Donnarumma, Erminia; Brewster, Luke P; Lefer, David J

    2015-01-01

    Background Cystathionine γ-lyase, cystathionine β-synthase, and 3-mercaptopyruvate sulfurtransferase are endogenous enzymatic sources of hydrogen sulfide (H2S). Functions of H2S are mediated by several targets including ion channels and signaling proteins. Nuclear factor-erythroid 2-related factor 2 is responsible for the expression of antioxidant response element–regulated genes and is known to be upregulated by H2S. We examined the levels of H2S, H2S-producing enzymes, and nuclear factor-erythroid 2-related factor 2 activation status in skeletal muscle obtained from critical limb ischemia (CLI) patients. Methods and Results Gastrocnemius tissues were attained postamputation from human CLI and healthy control patients. We found mRNA and protein levels of cystathionine γ-lyase, cystathionine β-synthase, and 3-mercaptopyruvate sulfurtransferase were significantly decreased in skeletal muscle of CLI patients as compared to control. H2S and sulfane sulfur levels were significantly decreased in skeletal muscle of CLI patients. We also observed significant reductions in nuclear factor-erythroid 2-related factor 2 activation as well as antioxidant proteins, such as Cu, Zn-superoxide dismutase, catalase, and glutathione peroxidase in skeletal muscle of CLI patients. Biomarkers of oxidative stress, such as malondialdehyde and protein carbonyl formation, were significantly increased in skeletal muscle of CLI patients as compared to healthy controls. Conclusions The data demonstrate that H2S bioavailability and nuclear factor-erythroid 2-related factor 2 activation are both attenuated in CLI tissues concomitant with significantly increased oxidative stress. Reductions in the activity of H2S-producing enzymes may contribute to the pathogenesis of CLI. PMID:25977470

  12. Skeletal muscle dedifferentiation during salamander limb regeneration.

    PubMed

    Wang, Heng; Simon, András

    2016-10-01

    Salamanders can regenerate entire limbs throughout their life. A critical step during limb regeneration is formation of a blastema, which gives rise to the new extremity. Salamander limb regeneration has historically been tightly linked to the term dedifferentiation, however, with refined research tools it is important to revisit the definition of dedifferentiation in the context. To what extent do differentiated cells revert their differentiated phenotypes? To what extent do progeny from differentiated cells cross lineage boundaries during regeneration? How do cell cycle plasticity and lineage plasticity relate to each other? What is the relationship between dedifferentiation of specialized cells and activation of tissue resident stem cells in terms of their contribution to the new limb? Here we highlight these problems through the case of skeletal muscle.

  13. Phantom limb pain

    MedlinePlus

    ... Philadelphia, PA: Elsevier; 2015:chap 54. Nikolajsen L, Springer JS, Haroutiunian S. Phantom limb pain. In: Benzon HT, ... medical conditions. Call 911 for all medical emergencies. Links to other sites are provided for information only -- ...

  14. Comparison of muscular activities in the abdomen and lower limbs while performing sit-up and leg-raise.

    PubMed

    Kim, Kanghoon; Lee, Taesik

    2016-01-01

    [Purpose] This study compared the muscle activities of sit-up and leg-raise. [Subjects and Methods] The subjects of this study were healthy students in their 20s. For electromyography of sit-ups and leg-raises in the supine position, 5 muscle groups of the abdomen were selected for the attachment of sensors: the upper and lower rectus abdominis, external oblique, rectus femoris, and the iliopsoas. SPSS 20.0 was used for the statistical analysis. One-way ANOVA with repeated measures of all factors was performed to verify the statistical significance of the measurements taken for the muscle activities and follow-up verification was made with the Bonferroni post hoc test. [Results] Sit-up and leg raise showed a significant difference. The eccentric sit-up exercise elicited a significant increase in the activation of the abdominal muscle. The leg raise and eccentric sit-up exercises elicited significant increases in the activation of hip flexor muscle. [Conclusion] The eccentric sit-up had the most outstanding effect on the abdominal muscles involved in stability of the trunk.

  15. Comparison of muscular activities in the abdomen and lower limbs while performing sit-up and leg-raise

    PubMed Central

    Kim, Kanghoon; Lee, Taesik

    2016-01-01

    [Purpose] This study compared the muscle activities of sit-up and leg-raise. [Subjects and Methods] The subjects of this study were healthy students in their 20s. For electromyography of sit-ups and leg-raises in the supine position, 5 muscle groups of the abdomen were selected for the attachment of sensors: the upper and lower rectus abdominis, external oblique, rectus femoris, and the iliopsoas. SPSS 20.0 was used for the statistical analysis. One-way ANOVA with repeated measures of all factors was performed to verify the statistical significance of the measurements taken for the muscle activities and follow-up verification was made with the Bonferroni post hoc test. [Results] Sit-up and leg raise showed a significant difference. The eccentric sit-up exercise elicited a significant increase in the activation of the abdominal muscle. The leg raise and eccentric sit-up exercises elicited significant increases in the activation of hip flexor muscle. [Conclusion] The eccentric sit-up had the most outstanding effect on the abdominal muscles involved in stability of the trunk. PMID:27065536

  16. Hyaluronan in limb morphogenesis.

    PubMed

    Li, Yingcui; Toole, Bryan P; Dealy, Caroline N; Kosher, Robert A

    2007-05-15

    Hyaluronan (HA) is a large glycosaminoglycan that is not only a structural component of extracellular matrices, but also interacts with cell surface receptors to promote cell proliferation, migration, and intracellular signaling. HA is a major component of the extracellular matrix of the distal subapical mesenchymal cells of the developing limb bud that are undergoing proliferation, directed migration, and patterning in response to the apical ectodermal ridge (AER), and has the functional potential to be involved in these processes. Here we show that the HA synthase Has2 is abundantly expressed by the distal subridge mesodermal cells of the chick limb bud and also by the AER itself. Has2 expression and HA production are downregulated in the proximal central core of the limb bud during the formation of the precartilage condensations of the skeletal elements, suggesting that downregulation of HA may be necessary for the close juxtaposition of cells and the resulting cell-cell interactions that trigger cartilage differentiation during condensation. Overexpression of Has2 in the mesoderm of the chick limb bud in vivo results in the formation of shortened and severely malformed limbs that lack one or more skeletal elements. Skeletal elements that do form in limbs overexpressing Has2 are reduced in length, exhibit abnormal morphology, and are positioned inappropriately. We also demonstrate that sustained HA production in micromass cultures of limb mesenchymal cells inhibits formation of precartilage condensations and subsequent chondrogenesis, indicating that downregulation of HA is indeed necessary for formation of the precartilage condensations that trigger cartilage differentiation. Taken together these results suggest involvement of HA in various aspects of limb morphogenesis.

  17. Limb regeneration: a new development?

    PubMed

    Nacu, Eugen; Tanaka, Elly M

    2011-01-01

    Salamander limb regeneration is a classical model of tissue morphogenesis and patterning. Through recent advances in cell labeling and molecular analysis, a more precise, mechanistic understanding of this process has started to emerge. Long-standing questions include to what extent limb regeneration recapitulates the events observed in mammalian limb development and to what extent are adult- or salamander- specific aspects deployed. Historically, researchers studying limb development and limb regeneration have proposed different models of pattern formation. Here we discuss recent data on limb regeneration and limb development to argue that although patterning mechanisms are likely to be similar, cell plasticity and signaling from nerves play regeneration-specific roles.

  18. Sound Sequence Discrimination Learning Motivated by Reward Requires Dopaminergic D2 Receptor Activation in the Rat Auditory Cortex

    ERIC Educational Resources Information Center

    Kudoh, Masaharu; Shibuki, Katsuei

    2006-01-01

    We have previously reported that sound sequence discrimination learning requires cholinergic inputs to the auditory cortex (AC) in rats. In that study, reward was used for motivating discrimination behavior in rats. Therefore, dopaminergic inputs mediating reward signals may have an important role in the learning. We tested the possibility in the…

  19. Depolarized inactivation overcomes impaired activation to produce DRG neuron hyperexcitability in a Nav1.7 mutation in a patient with distal limb pain.

    PubMed

    Huang, Jianying; Yang, Yang; Dib-Hajj, Sulayman D; van Es, Michael; Zhao, Peng; Salomon, Jody; Drenth, Joost P H; Waxman, Stephen G

    2014-09-10

    Sodium channel Nav1.7, encoded by SCN9A, is expressed in DRG neurons and regulates their excitability. Genetic and functional studies have established a critical contribution of Nav1.7 to human pain disorders. We have now characterized a novel Nav1.7 mutation (R1279P) from a female human subject with distal limb pain, in which depolarized fast inactivation overrides impaired activation to produce hyperexcitability and spontaneous firing in DRG neurons. Whole-cell voltage-clamp recordings in human embryonic kidney (HEK) 293 cells demonstrated that R1279P significantly depolarizes steady-state fast-, slow-, and closed-state inactivation. It accelerates deactivation, decelerates inactivation, and facilitates repriming. The mutation increases ramp currents in response to slow depolarizations. Our voltage-clamp analysis showed that R1279P depolarizes channel activation, a change that was supported by our multistate structural modeling. Because this mutation confers both gain-of-function and loss-of-function attributes on the Nav1.7 channel, we tested the impact of R1279P expression on DRG neuron excitability. Current-clamp studies reveal that R1279P depolarizes resting membrane potential, decreases current threshold, and increases firing frequency of evoked action potentials within small DRG neurons. The populations of spontaneously firing and repetitively firing neurons were increased by expressing R1279P. These observations indicate that the dominant proexcitatory gating changes associated with this mutation, including depolarized steady-state fast-, slow-, and closed-state inactivation, faster repriming, and larger ramp currents, override the depolarizing shift of activation, to produce hyperexcitability and spontaneous firing of nociceptive neurons that underlie pain.

  20. Statins induce immunosuppressive effect on heterotopic limb allografts in rat through inhibiting T cell activation and proliferation.

    PubMed

    Nie, Chunlei; Yang, Daping; Liu, Guofeng; Dong, Deli; Ma, Zhiqiang; Fu, Hailiang; Zhao, Zhengyu; Sun, Zhiyong

    2009-01-05

    Long-term use of immunosuppressive agents could bring many side effects. Recently, 3-Hydroxy-3-methyl-gutaryl coenzyme A reductase inhibitors (statins) have been reported to be immunomodulatory besides lowering serum cholesterol level. The aim of this study was to investigate the effects of statins on composite tissue allografts and T lymphocyte in vivo and in vitro. Rats were divided into 5 groups: syngeneic transplantation group (Lewis-Lewis); allogeneic control group (Brown Norway-Lewis, no treatment); low-dose statins group (15 mg /kg); high-dose statins group (30 mg /kg) and cyclosporin A group. In vivo, treatment of statins significantly prolonged allografts survival as compared to control group. Histological findings further supported these clinical results and demonstrated less extent of rejection. Immunohistochemical analysis showed that there was a remarkably reduced T cells infiltration in statins groups. Moreover, the serum levels of IL-2 and IFN-gamma were decreased after statins therapy, while these in control group increased significantly. Meanwhile, transcriptional activities of IL-2 and IFN-gamma were also dramatically down-regulated after statins treatment. In vitro, mixed lymphocyte reaction assay was performed and the results revealed lymphocyte proliferation was inhibited by statins in a dose-dependent manner. Furthermore, administration of statins exhibited inhibitory effects on CD3/CD28 mediated T cell activation and proliferation. Besides, the results demonstrated that statins significantly down-regulated mRNA expression and suppress cytokine production of IL-2 and IFN-gamma in vitro. In conclusion, our data demonstrated that application of statins could induce immunosuppressive effect and prolong allografts survival through inhibiting activation and proliferation of T cell and reducing production of IL-2 and IFN-gamma.

  1. Limb-specific representation for reaching in the posterior parietal cortex.

    PubMed

    Chang, Steve W C; Dickinson, Anthony R; Snyder, Lawrence H

    2008-06-11

    To reach for something we see, the brain must integrate the target location with the limb to be used for reaching. Neuronal activity in the parietal reach region (PRR) located in the posterior parietal cortex represents targets for reaching. Does this representation depend on the limb to be used? We found a continuum of limb-dependent and limb-independent responses: some neurons represented targets for movements of either limb, whereas others represented only contralateral-limb targets. Only a few cells represented ipsilateral-limb targets. Furthermore, these representations were not dependent on preferred direction. Additional experiments provide evidence that the PRR is specifically involved in contralateral-limb movements: firing rates are correlated with contralateral- but not ipsilateral-limb reaction times. The current study therefore provides novel evidence that the PRR operates as a limb-dependent stage that lies further along the sensory-motor transformation for visually guided reaching than previously expected.

  2. Signal transducer and activator of transcription 2 (STAT2) metabolism coupling postmitotic outgrowth to visual and sound perception network in human left cerebrum by biocomputation.

    PubMed

    Wang, Lin; Huang, Juxiang; Jiang, Minghu; Lin, Hong

    2012-07-01

    We constructed the high-expression signal transducer and activator of transcription 2 (STAT2) metabolism coupling postmitotic outgrowth to visual and sound perception network in human left cerebrum compared with low-expression (fold change ≥2) chimpanzee left cerebrum in GEO data set by using integration of gene regulatory network inference method with gene ontology (GO) analysis of STAT2-activated up- and downstream network. Our result showed that upstream RECQL, PDIA2, ENOSF1, THBS4, RASGRP1, PER2, PDE8A, ORC2L, DCI, OGG1_2, SMA4, GPD1, etc. activated STAT2, and downstream STAT2-activated GSTM3_1, GOSR1, SH3BGR, OSBPL8, PHYH, SAPS2, C21orf33, PDIA2, TRAPPC6A, ENOSF1, CAMTA1, GTF2I_2, etc. in human left cerebrum. STAT2-activated network enhanced regulation of small GTPase-mediated signal transduction, regulation of transcription, regulation of mitosis, regulation of cell growth, positive regulation of phosphoinositide 3-kinase cascade, positive regulation of fat cell differentiation, negative regulation of DNA replication, negative regulation of progression through cell cycle, cyclic nucleotide metabolism, lipid metabolism, carbohydrate metabolism, vitamin A metabolism, N-acetylglucosamine metabolism, UDP-N-acetylgalactosamine metabolism, fatty acid transport, intracellular protein transport, vesicle-mediated transport, lipid transport, retrograde transport, Ras protein signal transduction, Wnt receptor signaling pathway, nervous system development, cell extension, cell adhesion, cell differentiation, circadian rhythm, generation of precursor metabolites and energy, establishment of blood-nerve barrier, visual perception, sensory perception of sound, and poly-N-acetyllactosamine biosynthesis, as a result of inducing metabolism coupling postmitotic outgrowth to visual and sound perception in human left cerebrum.

  3. Method of sound synthesis

    DOEpatents

    Miner, Nadine E.; Caudell, Thomas P.

    2004-06-08

    A sound synthesis method for modeling and synthesizing dynamic, parameterized sounds. The sound synthesis method yields perceptually convincing sounds and provides flexibility through model parameterization. By manipulating model parameters, a variety of related, but perceptually different sounds can be generated. The result is subtle changes in sounds, in addition to synthesis of a variety of sounds, all from a small set of models. The sound models can change dynamically according to changes in the simulation environment. The method is applicable to both stochastic (impulse-based) and non-stochastic (pitched) sounds.

  4. Comparison of three computer office workstations offering forearm support: impact on upper limb posture and muscle activation.

    PubMed

    Delisle, Alain; Larivière, Christian; Plamondon, André; Imbeau, Daniel

    2006-02-10

    The aims of the study were: 1) to determine whether resting the forearms on the work surface, as compared to chair armrests, reduces muscular activation; 2) to compare the sensitivity of different electromyographic (EMG) summary parameters. Eighteen healthy subjects performed computer work (with keyboard and mouse alternately) for 20 min while resting their forearms on a work surface adjustable in height (Workstation A), on the chair's armrests with an adjustable workstation (Workstation B) or on their chair's armrests with a non-adjustable workstation (Workstation C). The EMG amplitude of the trapezius and deltoid muscles was little influenced by the workstations, whereas their EMG variability increased with Workstation A, which was interpreted as a positive effect. However, the EMG amplitude of the mouse-side extensor digitorum muscle was higher with Workstation A. Alternating between resting the forearms on the work surface and on the chairs' armrests could solicit different muscles during computer work, and could be considered as a strategy for preventing musculoskeletal disorders. The new exposure variation analysis summary parameters used were sensitive to small workstation changes, thus supporting their use in future studies.

  5. Prevention and Treatment of Lower Limb Deep Vein Thrombosis after Radiofrequency Catheter Ablation: Results of a Prospective active controlled Study

    PubMed Central

    Li, Lan; Zhang, Bao-jian; Zhang, Bao-ku; Ma, Jun; Liu, Xu-zheng; Jiang, Shu-bin

    2016-01-01

    We conducted a prospective, single-center, active controlled study from July 2013 to January 2015, in Chinese patients with rapid ventricular arrhythmia who had received radiofrequency catheter ablation (RFCA) treatment to determine formation of lower extremity deep vein thrombosis (LDVT) post RFCA procedure, and evaluated the effect of rivaroxaban on LDVT. Patients with asymptomatic pulmonary thromboembolism who had not received any other anticoagulant and had received no more than 36 hours of treatment with unfractionated heparin were included. Post RFCA procedure, patients received either rivaroxaban (10 mg/d for 14 days beginning 2–3 hours post-operation; n = 86) or aspirin (100 mg/d for 3 months beginning 2–3 hours post-operation; n = 90). The primary outcome was a composite of LDVT occurrence, change in diameter of femoral veins, and safety outcomes that were analyzed based on major or minor bleeding events. In addition, blood flow velocity was determined. No complete occlusive thrombus or bleeding events were reported with either of the group. The lower incidence rate of non-occluded thrombus in rivaroxaban (5.8%) compared to the aspirin group (16.7%) indicates rivaroxaban may be administered post-RFCA to prevent and treat femoral venous thrombosis in a secure and effective way with a faster inset of action than standard aspirin therapy. PMID:27329582

  6. Changes in unilateral upper limb muscular strength and EMG activity following a 16 week strength training intervention survivors of breast cancer.

    PubMed

    Hagstrom, Amanda D; Shorter, Kathleen A; Marshall, Paul W M

    2017-03-08

    Upper limb strength deficits are frequently observed following breast cancer and its treatments. It is currently unknown whether these unilateral deficits can be corrected by a standard bilateral strength training intervention. Twenty three survivors of breast cancer were included in this analysis. Fourteen performed a 16 week resistance training (RT) intervention, 9 were assigned to a usual care waitlist control group. Electromyographic (EMG) analysis of the pectoralis major and triceps brachii were monitored during three maximal isometric contractions and a fatiguing endurance task. Muscular strength was significantly different between limbs at the start of the intervention (p = 0.02). EMG amplitude and median frequency did not differ between limbs at the start of the intervention. Muscular strength was significantly different between limbs in the RT group at the end of the intervention (p = 0.01). EMG amplitude did not differ between limbs or groups at the end of the intervention. Bilateral strength training did not correct the unilateral strength deficit observed in this group of survivors of breast cancer. Periods of unilateral strength training should be implemented into periodised RT programs in this cohort.

  7. Cellular proliferation in the skin of X-rayed newt limbs (with a note on x-ray-induced limb regression)

    SciTech Connect

    Wertz, R.L.

    1982-07-01

    Left hind limbs, including the pelvis, of adult newts (Notophthalmus viridescens) were locally irradiated with a dose of x-rays that inhibited regeneration (2,000 R). This x-ray dose and other doses (700-2,000 R) capable of inhibiting limb regeneration also cause limb regression prior to amputation. Before limb regression occurred, there was a latent period of 3 to 6 weeks. Limb regression was characterized by necrotic wasting and resorption of distal elements. The degree of loss was variable and dependent upon dosage. After this further degenerative changes were not noted. Proliferation of epidermal cells was examined 4 days after irradiation prior to limb regression or after x-ray-induced degeneration of the limbs had ended. Proliferative activity in x-rayed limbs was also compared at various stages of contralateral control limb regeneration. Limbs examined after x-ray-induced limb regression had ended showed levels of (/sup 3/H)-thymidine incorporation into DNA comparable to normal epidermis. In contrast, limbs examined 4 days after irradiation had lower levels of DNA synthesis (P much less than 0.01). Amputation of limbs in both groups caused an increase in DNA synthesis (P much less than 0.01). Histological examination showed that cellular proliferation was associated primarily with the epidermis. These results indicate that epidermal cell proliferation was not resistant to x-rays. However, levels of normal cell division were observed after amputation of after cessation of x-ray-induced limb regression.

  8. Using therapeutic sound with progressive audiologic tinnitus management.

    PubMed

    Henry, James A; Zaugg, Tara L; Myers, Paula J; Schechter, Martin A

    2008-09-01

    Management of tinnitus generally involves educational counseling, stress reduction, and/or the use of therapeutic sound. This article focuses on therapeutic sound, which can involve three objectives: (a) producing a sense of relief from tinnitus-associated stress (using soothing sound); (b) passively diverting attention away from tinnitus by reducing contrast between tinnitus and the acoustic environment (using background sound); and (c) actively diverting attention away from tinnitus (using interesting sound). Each of these goals can be accomplished using three different types of sound-broadly categorized as environmental sound, music, and speech-resulting in nine combinations of uses of sound and types of sound to manage tinnitus. The authors explain the uses and types of sound, how they can be combined, and how the different combinations are used with Progressive Audiologic Tinnitus Management. They also describe how sound is used with other sound-based methods of tinnitus management (Tinnitus Masking, Tinnitus Retraining Therapy, and Neuromonics).

  9. Sound sensitivity of neurons in rat hippocampus during performance of a sound-guided task.

    PubMed

    Itskov, Pavel M; Vinnik, Ekaterina; Honey, Christian; Schnupp, Jan; Diamond, Mathew E

    2012-04-01

    To investigate how hippocampal neurons encode sound stimuli, and the conjunction of sound stimuli with the animal's position in space, we recorded from neurons in the CA1 region of hippocampus in rats while they performed a sound discrimination task. Four different sounds were used, two associated with water reward on the right side of the animal and the other two with water reward on the left side. This allowed us to separate neuronal activity related to sound identity from activity related to response direction. To test the effect of spatial context on sound coding, we trained rats to carry out the task on two identical testing platforms at different locations in the same room. Twenty-one percent of the recorded neurons exhibited sensitivity to sound identity, as quantified by the difference in firing rate for the two sounds associated with the same response direction. Sensitivity to sound identity was often observed on only one of the two testing platforms, indicating an effect of spatial context on sensory responses. Forty-three percent of the neurons were sensitive to response direction, and the probability that any one neuron was sensitive to response direction was statistically independent from its sensitivity to sound identity. There was no significant coding for sound identity when the rats heard the same sounds outside the behavioral task. These results suggest that CA1 neurons encode sound stimuli, but only when those sounds are associated with actions.

  10. Io with Loki Plume on Bright Limb

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Voyager 1 image of Io showing active plume of Loki on limb. Heart-shaped feature southeast of Loki consists of fallout deposits from active plume Pele. The images that make up this mosaic were taken from an average distance of approximately 490,000 kilometers (340,000 miles).

  11. Sounds of Space

    NASA Astrophysics Data System (ADS)

    Gurnett, D. A.

    2005-12-01

    Starting in the early 1960s, spacecraft-borne plasma wave instruments revealed that space is filled with an astonishing variety of radio and plasma wave sounds, which have come to be called "sounds of space." For over forty years these sounds have been collected and played to a wide variety of audiences, often as the result of press conferences or press releases involving various NASA projects for which the University of Iowa has provided plasma wave instruments. This activity has led to many interviews on local and national radio programs, and occasionally on programs haviang world-wide coverage, such as the BBC. As a result of this media coverage, we have been approached many times by composers requesting copies of our space sounds for use in their various projects, many of which involve electronic synthesis of music. One of these collaborations led to "Sun Rings," which is a musical event produced by the Kronos Quartet that has played to large audiences all over the world. With the availability of modern computer graphic techniques we have recently been attempting to integrate some of these sound of space into an educational audio/video web site that illustrates the scientific principles involved in the origin of space plasma waves. Typically I try to emphasize that a substantial gas pressure exists everywhere in space in the form of an ionized gas called a plasma, and that this plasma can lead to a wide variety of wave phenomenon. Examples of some of this audio/video material will be presented.

  12. Limb salvage surgery

    PubMed Central

    Kadam, Dinesh

    2013-01-01

    The threat of lower limb loss is seen commonly in severe crush injury, cancer ablation, diabetes, peripheral vascular disease and neuropathy. The primary goal of limb salvage is to restore and maintain stability and ambulation. Reconstructive strategies differ in each condition such as: Meticulous debridement and early coverage in trauma, replacing lost functional units in cancer ablation, improving vascularity in ischaemic leg and providing stable walking surface for trophic ulcer. The decision to salvage the critically injured limb is multifactorial and should be individualised along with laid down definitive indications. Early cover remains the standard of care, delayed wound coverage not necessarily affect the final outcome. Limb salvage is more cost-effective than amputations in a long run. Limb salvage is the choice of procedure over amputation in 95% of limb sarcoma without affecting the survival. Compound flaps with different tissue components, skeletal reconstruction; tendon transfer/reconstruction helps to restore function. Adjuvant radiation alters tissue characters and calls for modification in reconstructive plan. Neuropathic ulcers are wide and deep often complicated by osteomyelitis. Free flap reconstruction aids in faster healing and provides superior surface for offloading. Diabetic wounds are primarily due to neuropathy and leads to six-fold increase in ulcerations. Control of infections, aggressive debridement and vascular cover are the mainstay of management. Endovascular procedures are gaining importance and have reduced extent of surgery and increased amputation free survival period. Though the standard approach remains utilising best option in the reconstruction ladder, the recent trend shows running down the ladder of reconstruction with newer reliable local flaps and negative wound pressure therapy. PMID:24501463

  13. A New ERA in Global Temperature Monitoring with the Advanced Microwave Sounding Unit (AMSU)

    NASA Technical Reports Server (NTRS)

    Spencer, Roy W.; Braswell, William D.; Christy, John R.

    1999-01-01

    The launch of the first Advanced Microwave Sounding Unit (AMSU) on the NOAA-15 spacecraft on 13 May 1998 marked a significant advance in our ability to monitor global temperatures. Compared to the Microwave Sounding Units (MSU) flying since 1978 on the TIROS-N series of NOAA polar orbiters, the AMSU offers better horizontal, vertical, and radiometric resolutions. It will allow routine monitoring of 1 1 (mostly) separate layers, compared to 2 or 3 with the MSU, including layers in the middle and upper stratosphere (2.5 hPa) where increasing carbon dioxide concentrations should be causing a cooling rate of about 1 deg. C per decade. More precise limb corrections combined with low noise will allow identification of subtle spatial temperature patterns associated with global cyclone activity.

  14. [Limb edema and lymphoscintigraphy].

    PubMed

    Bourgeois, P; Munck, D; Belgrado, J P; Leduc, O; Leduc, A

    2003-02-01

    Lymphoscintigraphic investigations represent techniques of nuclear medicine very contributive for the management and treatment of the limb edemas, either primary or secundary. Their principle is presented and methodologies proposed in the literature are reviewed. Their diagnostic contributions are detailed. The sensitivities and specificities of several protocols of investigation are reported. Some limitations of these examinations are analyzed and discussed. Clinical indications for their use are proposed and their interest with regard to the various treatments that can be applied to these limb edemas is discussed.

  15. JKTLD: Limb darkening coefficients

    NASA Astrophysics Data System (ADS)

    Southworth, John

    2015-11-01

    JKTLD outputs theoretically-calculated limb darkening (LD) strengths for equations (LD laws) which predict the amount of LD as a function of the part of the star being observed. The coefficients of these laws are obtained by bilinear interpolation (in effective temperature and surface gravity) in published tables of coefficients calculated from stellar model atmospheres by several researchers. Many observations of stars require the strength of limb darkening (LD) to be estimated, which can be done using theoretical models of stellar atmospheres; JKTLD can help in these circumstances.

  16. Neural correlates of sound externalization.

    PubMed

    Callan, Akiko; Callan, Daniel E; Ando, Hiroshi

    2013-02-01

    When we listen to sounds through headphones without utilizing special transforms, sound sources seem to be located inside our heads. The sound sources are said to be lateralized to one side or the other to varying degree. This internal lateralization is different than sound source localization in the natural environment in which the sound is localized distal to the head. We used fMRI to investigate difference in neural responses between lateralization and localization. Individualized binaural recordings were used as externalized auditory stimuli and stereo recordings were used as internalized auditory stimuli. Brain activity was measured while 14 participants performed an active auditory localization task and while 12 participants performed a stimulus type identification task. Irrespective of the task condition, we observed enhanced activity in the bilateral posterior temporal gyri (pSTG) for the externalized stimuli relative to the internalized stimuli. Region of interest analysis indicated that both left and right pSTG were more sensitive to sound sources in contra- than ipsilateral hemifields. Moreover, greater back than front activity was also found in the left pSTG. Compared to impoverished spatial auditory stimuli, realistic spatial auditory stimuli enhance neural responses in the pSTG. This may be why we could observe contralateral hemifield preference in bilateral pSTG that many previous studies have failed to observe. Overall, the results indicate the importance of using ecologically valid stimuli for investigating neural processes in human cortex.

  17. Application of sonic hedgehog to the developing chick limb.

    PubMed

    Tiecke, Eva; Tickle, Cheryll

    2007-01-01

    Here, we describe methods for applying Sonic hedgehog (Shh) to developing chick limbs. The Sonic hedgehog gene is expressed in the polarizing region, a signaling region at the posterior margin of the limb bud and application of Shh-expressing cells or Shh protein to early limb buds mimics polarizing region signaling. The polarizing region (or zone of polarizing activity) is involved in one of the best known cell-cell interactions in vertebrate embryos and is pivotal in controlling digit number and pattern. At later stages of limb development, the application of Shh protein to the regions between digit primordia can induce changes in digit morphogenesis.

  18. Absence of Small Conductance K+ Channel (SK) Activity in Apical Membranes of Thick Ascending Limb and Cortical Collecting Duct in ROMK (Bartter’s) Knockout Mice*

    PubMed Central

    Lu, Ming; Wang, Tong; Yan, Qingshang; Yang, Xinbo; Dong, Ke; Knepper, Mark A.; Wang, WenHui; Giebisch, Gerhard; Shull, Gary E.; Hebert, Steven C.

    2015-01-01

    The ROMK (Kir1.1; Kcnj1) gene is believed to encode the apical small conductance K+ channels (SK) of the thick ascending limb (TAL) and cortical collecting duct (CCD). Loss-of-function mutations in the human ROMK gene cause Bartter’s syndrome with renal Na+ wasting, consistent with the role of this channel in apical K+ recycling in the TAL that is crucial for NaCl reabsorption. However, the mechanism of renal K+ wasting and hypokalemia that develop in individuals with ROMK Bartter’s syndrome is not apparent given the proposed loss of the collecting duct SK channel. Thus, we generated a colony of ROMK null mice with ~25% survival to adulthood that provides a good model for ROMK Bartter’s syndrome. The remaining 75% of null mice die in less than 14 days after birth. The surviving ROMK null mice have normal gross renal morphology with no evidence of significant hydronephrosis, whereas non-surviving null mice exhibit marked hydronephrosis. ROMK protein expression was absent in TAL and CCD from null mice but exhibited normal abundance and localization in wild-type littermates. ROMK null mice were polyuric and natriuretic with an elevated hematocrit consistent with mild extracellular volume depletion. SK channel activity in TAL and CCD was assessed by patch clamp analysis in ROMK wild-type ROMK(+/+), heterozygous ROMK(+/−), and null ROMK(−/−) mice. In 313 patches with successful seals from the three ROMK genotypes, SK channel activity in ROMK (+/+ and +/−) exhibited normal single channel kinetics. The expression frequencies are as follows: 67 (TAL) and 58% (CCD) in ROMK(+/+); about half that of the wild-type in ROMK(+/−), being 38 (TAL) and 25% (CCD); absent in both TAL or CCD in ROMK(−/−) between 2 and 5 weeks in 15 mice (61 and 66 patches, respectively). The absence of SK channel activity in ROMK null mice demonstrates that ROMK is essential for functional expression of SK channels in both TAL and CCD. Despite loss of ROMK expression, the

  19. Artificial limb connection

    NASA Technical Reports Server (NTRS)

    Owens, L. J.

    1974-01-01

    Connection simplifies and eases donning and removing artificial limb; eliminates harnesses and clamps; and reduces skin pressures by allowing bone to carry all tensile and part of compressive loads between prosthesis and stump. Because connection is modular, it is easily modified to suit individual needs.

  20. [Active epidemiological surveillance and prevention of diseases caused by biomechanical overload of the upper limbs: experience at a territorial service of occupational medicine].

    PubMed

    Barbieri, P G; Pezzotti, C; Rocco, A

    2001-01-01

    Nowadays in the western countries, the Work Musculoscheletal Disorders (WMSDs) are the most relevant work-related diseases either for the large number of at-risk workers and for the high prevalence of cases among them. Among WMSDs, the Carpal Tunnel Syndrome (CTS) is considered a sentinel event in occupational medicine and epidemiological surveillance systems were set up to study its temporal occurrence and spatial spread. Surprisingly enough, in our country the epidemiology of the WMSDs is still unknown; although observations of important clusters of cases are increasing, these pathologies are still largely underreported by medical doctors. In the high industrialised province of Brescia, Northwestern Italy, only 1% of the 25.000 occupational disease, collected by the occupational medicine and prevention service of the National Health Service (SPSAL) since 1989 to 1997, were coded as WMSDs. Even if the notification of these work-related disorders is compulsory by low since 1973, up-to-now very few cases were reported to SPSALs, and consequently active prevention programs were very few too. For that reason, a project of active surveillance of WMSDs diagnosed on the general population was carried out to improve their identification and to evaluate the work-related etiological fraction as well as to address primary prevention projects. During 1997-1999 618 upper limb musculoskeletal disorders were collected from 2 orthopaedic hospital divisions where cases underwent surgical treatment. 369 of them were interviewed by telephone (253 female, 116 man) and 128 cases (34%) were classified as probable professionally exposed to some known hazard. Female were prevalent (71%), involved particularly in textile, garments, plastic, food production and domestic services. Among men, construction, metallurgic and mechanic were the more frequent jobs. 116 WMSDs were reported to the National Insurance Institute (INAIL). The collection of these WMSDs was the basis for specific

  1. Calculating Speed of Sound

    NASA Astrophysics Data System (ADS)

    Bhatnagar, Shalabh

    2017-01-01

    Sound is an emerging source of renewable energy but it has some limitations. The main limitation is, the amount of energy that can be extracted from sound is very less and that is because of the velocity of the sound. The velocity of sound changes as per medium. If we could increase the velocity of the sound in a medium we would be probably able to extract more amount of energy from sound and will be able to transfer it at a higher rate. To increase the velocity of sound we should know the speed of sound. If we go by the theory of classic mechanics speed is the distance travelled by a particle divided by time whereas velocity is the displacement of particle divided by time. The speed of sound in dry air at 20 °C (68 °F) is considered to be 343.2 meters per second and it won't be wrong in saying that 342.2 meters is the velocity of sound not the speed as it's the displacement of the sound not the total distance sound wave covered. Sound travels in the form of mechanical wave, so while calculating the speed of sound the whole path of wave should be considered not just the distance traveled by sound. In this paper I would like to focus on calculating the actual speed of sound wave which can help us to extract more energy and make sound travel with faster velocity.

  2. Intensity of activation and timing of deactivation modulate elastic energy storage and release in a pennate muscle and account for gait-specific initiation of limb protraction in the horse.

    PubMed

    Lichtwark, Glen A; Watson, Johanna C; Mavrommatis, Sophia; Wilson, Alan M

    2009-08-01

    The equine biceps brachii (biceps) initiates rapid limb protraction through a catapult mechanism. Elastic strain energy is slowly stored in an internal tendon and is then rapidly released to protract the forelimb. The muscle fibres are short, have little scope for length change and can therefore only shorten slowly compared with the speed at which the whole muscle must shorten, which makes them poor candidates for driving rapid limb protraction. We suggest that the muscle fibres in the biceps act to modulate the elastic energy output of the muscle-tendon unit (MTU) to meet the demands of locomotion under different conditions. We hypothesise that more elastic strain energy is stored and released from the biceps MTU during higher speed locomotion to accommodate the increase in energy required to protract the limb and that this can be achieved by varying the length change and activation conditions of the muscle. We examined the work performed by the biceps during trot and canter using an inverse dynamics analysis (IDA). We then used excised biceps muscles to determine how much work could be performed by the muscle in active and passive stretch-shorten cycles. A muscle model was developed to investigate the influence of changes in activation parameters on energy storage and energy return from the biceps MTU. Increased biceps MTU length change and increased work performed by the biceps MTU were found at canter compared with at trot. More work was performed by the ex vivo biceps MTU following activation of the muscle and by increasing muscle length change. However, the ratio of active to passive work diminished with increasing length change. The muscle model demonstrated that duration and timing of activation during stretch-shorten cycles could modulate the elastic energy storage and return from the biceps. We conclude that the equine biceps MTU acts as a tuneable spring and the contractile component functions to modulate the energy required for rapid forelimb

  3. Opposing RA and FGF signals control proximodistal vertebrate limb development through regulation of Meis genes.

    PubMed

    Mercader, N; Leonardo, E; Piedra, M E; Martínez-A, C; Ros, M A; Torres, M

    2000-09-01

    Vertebrate limbs develop in a temporal proximodistal sequence, with proximal regions specified and generated earlier than distal ones. Whereas considerable information is available on the mechanisms promoting limb growth, those involved in determining the proximodistal identity of limb parts remain largely unknown. We show here that retinoic acid (RA) is an upstream activator of the proximal determinant genes Meis1 and Meis2. RA promotes proximalization of limb cells and endogenous RA signaling is required to maintain the proximal Meis domain in the limb. RA synthesis and signaling range, which initially span the entire lateral plate mesoderm, become restricted to proximal limb domains by the apical ectodermal ridge (AER) activity following limb initiation. We identify fibroblast growth factor (FGF) as the main molecule responsible for this AER activity and propose a model integrating the role of FGF in limb cell proliferation, with a specific function in promoting distalization through inhibition of RA production and signaling.

  4. Using Therapeutic Sound With Progressive Audiologic Tinnitus Management

    PubMed Central

    Henry, James A.; Zaugg, Tara L.; Myers, Paula J.; Schechter, Martin A.

    2008-01-01

    Management of tinnitus generally involves educational counseling, stress reduction, and/or the use of therapeutic sound. This article focuses on therapeutic sound, which can involve three objectives: (a) producing a sense of relief from tinnitus-associated stress (using soothing sound); (b) passively diverting attention away from tinnitus by reducing contrast between tinnitus and the acoustic environment (using background sound); and (c) actively diverting attention away from tinnitus (using interesting sound). Each of these goals can be accomplished using three different types of sound—broadly categorized as environmental sound, music, and speech—resulting in nine combinations of uses of sound and types of sound to manage tinnitus. The authors explain the uses and types of sound, how they can be combined, and how the different combinations are used with Progressive Audiologic Tinnitus Management. They also describe how sound is used with other sound-based methods of tinnitus management (Tinnitus Masking, Tinnitus Retraining Therapy, and Neuromonics). PMID:18664499

  5. Neck muscle fatigue alters upper limb proprioception.

    PubMed

    Zabihhosseinian, Mahboobeh; Holmes, Michael W R; Murphy, Bernadette

    2015-05-01

    Limb proprioception is an awareness by the central nervous system (CNS) of the location of a limb in three-dimensional space and is essential for movement and postural control. The CNS uses the position of the head and neck when interpreting the position of the upper limb, and altered input from neck muscles may affect the sensory inputs to the CNS and consequently may impair the awareness of upper limb joint position. The purpose of this study was to determine whether fatigue of the cervical extensors muscles (CEM) using a submaximal fatigue protocol alters the ability to recreate a previously presented elbow angle with the head in a neutral position. Twelve healthy individuals participated. CEM activity was examined bilaterally using surface electromyography, and kinematics of the elbow joint was measured. The fatigue protocol included an isometric neck extension task at 70 % of maximum until failure. Joint position error increased following fatigue, demonstrating a significant main effect of time (F 2, 18 = 19.41, p ≤ 0.0001) for absolute error. No significant differences were found for variable error (F 2, 18 = 0.27, p = 0.76) or constant error (F 2, 18 = 1.16 of time, p ≤ 0.33). This study confirms that fatigue of the CEM can reduce the accuracy of elbow joint position matching. This suggests that altered afferent input from the neck subsequent to fatigue may impair upper limb proprioception.

  6. Active Region Soft X-Ray Spectra as Observed Using Sounding Rocket Measurements from the Solar Aspect Monitor (SAM), - a Modified SDO/EVE Instrument

    NASA Astrophysics Data System (ADS)

    Wieman, S. R.; Didkovsky, L. V.; Woods, T. N.; Jones, A. R.; Caspi, A.; Warren, H. P.

    2015-12-01

    Observations of solar active regions (ARs) in the soft x-ray spectral range (0.5 to 3.0 nm) were made on sounding rocket flight NASA 36.290 using a modified Solar Aspect Monitor (SAM), a pinhole camera on the EUV Variability Experiment (EVE) sounding rocket instrument. The suite of EVE rocket instruments is designed for under-flight calibrations of the orbital EVE on SDO. While the sounding rocket EVE instrument is for the most part a duplicate of the EVE on SDO, the SAM channel on the rocket version was modified in 2012 to include a free-standing transmission grating so that it could provide spectrally resolved images of the solar disk with the best signal to noise ratio for the brightest features on it, such as ARs. Calibrations of the EVE sounding rocket instrument at the National Institute of Standards and Technology Synchrotron Ultraviolet Radiation Facility (NIST SURF) have provided a measurement of the SAM absolute spectral response function and a mapping of wavelength separation in the grating diffraction pattern. For solar observations, this spectral separation is on a similar scale to the spatial size of the AR on the CCD, so dispersed AR images associated with emission lines of similar wavelength tend to overlap. Furthermore, SAM shares a CCD detector with MEGS-A, a separate EVE spectrometer channel, and artifacts of the MEGS-A signal (a set of bright spectral lines) appear in the SAM images. For these reasons some processing and analysis of the solar images obtained by SAM must be performed in order to determine spectra of the observed ARs. We present a method for determining AR spectra from the SAM rocket images and report initial soft X-ray spectra for two of the major active regions (AR11877 and AR11875) observed on flight 36.290 on 21 October 2013 at about 18:30 UT. We also compare our results with concurrent measurements from other solar soft x-ray instrumentation.

  7. Sound Insulation in Buildings

    NASA Astrophysics Data System (ADS)

    Gösele, K.; Schröder, E.

    Sound insulation between the different rooms inside a building or to the outside is a very complex problem. First, the airborne sound insulation of ceilings, walls, doors and windows is important. Second, a sufficient structure-borne sound insulation, also called impact sound insulation, for the ceilings, has to be provided especially. Finally, the service equipment should be sufficiently quiet.

  8. Sounds Exaggerate Visual Shape

    ERIC Educational Resources Information Center

    Sweeny, Timothy D.; Guzman-Martinez, Emmanuel; Ortega, Laura; Grabowecky, Marcia; Suzuki, Satoru

    2012-01-01

    While perceiving speech, people see mouth shapes that are systematically associated with sounds. In particular, a vertically stretched mouth produces a /woo/ sound, whereas a horizontally stretched mouth produces a /wee/ sound. We demonstrate that hearing these speech sounds alters how we see aspect ratio, a basic visual feature that contributes…

  9. The Sound of Science

    ERIC Educational Resources Information Center

    Merwade, Venkatesh; Eichinger, David; Harriger, Bradley; Doherty, Erin; Habben, Ryan

    2014-01-01

    While the science of sound can be taught by explaining the concept of sound waves and vibrations, the authors of this article focused their efforts on creating a more engaging way to teach the science of sound--through engineering design. In this article they share the experience of teaching sound to third graders through an engineering challenge…

  10. Making Sound Connections

    ERIC Educational Resources Information Center

    Deal, Walter F., III

    2007-01-01

    Sound provides and offers amazing insights into the world. Sound waves may be defined as mechanical energy that moves through air or other medium as a longitudinal wave and consists of pressure fluctuations. Humans and animals alike use sound as a means of communication and a tool for survival. Mammals, such as bats, use ultrasonic sound waves to…

  11. Glucose uptake and glycogen synthesis in muscles from immobilized limbs

    NASA Technical Reports Server (NTRS)

    Nicholson, W. F.; Watson, P. A.; Booth, F. W.

    1984-01-01

    Defects in glucose metabolism in muscles of immobilized limbs of mice were related to alterations in insulin binding, insulin responsiveness, glucose supply, and insulin activation of glycogen synthase. These were tested by in vitro methodology. A significant lessening in the insulin-induced maximal response of 2-deoxyglucose uptake into the mouse soleus muscle occurred between the 3rd and 8th h of limb immobilization, suggesting a decreased insulin responsiveness. Lack of change in the specific binding of insulin to muscles of 24-h immobilized limbs indicates that a change in insulin receptor number did not play a role in the failure of insulin to stimulate glucose metabolism. Its inability to stimulate glycogen synthesis in muscle from immobilized limbs is due, in part, to a lack of glucose supply to glycogen synthesis and also to the ineffectiveness of insulin to increase the percentage of glycogen synthase in its active form in muscles from 24-h immobilized limbs.

  12. Regeneration inducers in limb regeneration.

    PubMed

    Satoh, Akira; Mitogawa, Kazumasa; Makanae, Aki

    2015-08-01

    Limb regeneration ability, which can be observed in amphibians, has been investigated as a representative phenomenon of organ regeneration. Recently, an alternative experimental system called the accessory limb model was developed to investigate early regulation of amphibian limb regeneration. The accessory limb model contributed to identification of limb regeneration inducers in urodele amphibians. Furthermore, the accessory limb model may be applied to other species to explore universality of regeneration mechanisms. This review aims to connect the insights recently gained to emboss universality of regeneration mechanisms among species. The defined molecules (BMP7 (or2) + FGF2 + FGF8) can transform skin wound healing to organ (limb) regeneration responses. The same molecules can initiate regeneration responses in some species.

  13. Development of a control system for artificially rehabilitated limbs: a review.

    PubMed

    Bhuiyan, M S H; Choudhury, I A; Dahari, M

    2015-04-01

    Development of an advanced control system for prostheses (artificial limbs) is necessary to provide functionality, effectiveness, and preferably the feeling of a sound living limb. The development of the control system has introduced varieties of control strategies depending on the application. This paper reviews some control systems used for prosthetics, orthotics, and exoskeletons. The advantages and limitations of different control systems for particular applications have been discussed and presented in a comparative manner to help in deciding the appropriate method for pertinent application.

  14. Lower-limb amputee recovery response to an imposed error in mediolateral foot placement.

    PubMed

    Segal, Ava D; Klute, Glenn K

    2014-09-22

    Despite walking with a wider step width, amputees remain 20% more likely to fall than non-amputees. Since mediolateral (ML) balance is critical for ambulation and contingent on ML foot placement, we used a ML disturbance to perturb walking balance and explore the influence of prosthetic foot stiffness on balance recovery. Ten transtibial amputees were fit with two commonly prescribed prosthetic feet with differing stiffness characteristics; 12 non-amputees also participated. A perturbation device that released an air burst just before heel strike imposed a repeatable medial or lateral disturbance in foot placement. After a medial disturbance, the first recovery step width was narrowed (p<0.0001) for the prosthetic limb (-103%), the sound limb (-51%) and non-amputees (-41%) and more than twice as variable. The ML inclination angle remained reduced (-109%) for the prosthetic limb, while the sound limb and non-amputees approached undisturbed levels (p<0.0004). Amputees required five steps to return to undisturbed step width after a prosthetic medial disturbance versus two steps for the sound limb and for non-amputees. After a lateral disturbance, the first recovery step was widened for the prosthetic limb (+82%), sound limb (+75%), and wider than non-amputees (+51%; p<0.0001), with all participants requiring three steps to return to undisturbed step width. Amputees also exhibited a similar upper torso response compared to the non-amputees for both disturbances. Prosthetic feet with different stiffness properties did not have a significant effect. In conclusion, amputee balance was particularly challenged by medial disturbances to the prosthetic limb implying a need for improved interventions that address these balance deficits.

  15. Suppressive competition: how sounds may cheat sight.

    PubMed

    Kayser, Christoph; Remedios, Ryan

    2012-02-23

    In this issue of Neuron, Iurilli et al. (2012) demonstrate that auditory cortex activation directly engages local GABAergic circuits in V1 to induce sound-driven hyperpolarizations in layer 2/3 and layer 6 pyramidal neurons. Thereby, sounds can directly suppress V1 activity and visual driven behavior.

  16. [Critical limb ischemia--update].

    PubMed

    Melamed, Eitan; Kotyba, Baydousi; Galili, Offer; Karmeli, Ron

    2010-12-01

    Critical limb ischemia (CLI) is the most severe manifestation of peripheral artery occlusive disease. Without timely diagnosis and revascularization, patients with CLI are at risk of devastating complications including loss of limb and life. Therapeutic goals in treating patients with CLI include reducing cardiovascular risk factors, relieving ischemic pain, heating ulcers, preventing major amputation, improving quality of life and increasing survival. These aims may be achieved through medical therapy, revascularization or amputation. The past decade has seen substantial growth in endovascular therapies and options now exist for treating long segment occlusive disease, but surgical bypass may still yield more durable results. Patients who are younger, more active, and at low risk for surgery, may have better outcomes undergoing an operation. This is also indicated for endovascular failures, which may include technical failures or late occlusions after stents or other procedures. In contrast, frail patients with a limited life expectancy may experience better outcomes with endovascular therapy. For patients who are non-ambulatory, demented, or unfit to undergo revascularization, an amputation should be considered.

  17. Moth hearing and sound communication.

    PubMed

    Nakano, Ryo; Takanashi, Takuma; Surlykke, Annemarie

    2015-01-01

    Active echolocation enables bats to orient and hunt the night sky for insects. As a counter-measure against the severe predation pressure many nocturnal insects have evolved ears sensitive to ultrasonic bat calls. In moths bat-detection was the principal purpose of hearing, as evidenced by comparable hearing physiology with best sensitivity in the bat echolocation range, 20-60 kHz, across moths in spite of diverse ear morphology. Some eared moths subsequently developed sound-producing organs to warn/startle/jam attacking bats and/or to communicate intraspecifically with sound. Not only the sounds for interaction with bats, but also mating signals are within the frequency range where bats echolocate, indicating that sound communication developed after hearing by "sensory exploitation". Recent findings on moth sound communication reveal that close-range (~ a few cm) communication with low-intensity ultrasounds "whispered" by males during courtship is not uncommon, contrary to the general notion of moths predominantly being silent. Sexual sound communication in moths may apply to many eared moths, perhaps even a majority. The low intensities and high frequencies explain that this was overlooked, revealing a bias towards what humans can sense, when studying (acoustic) communication in animals.

  18. Controlling sound with acoustic metamaterials

    NASA Astrophysics Data System (ADS)

    Cummer, Steven A.; Christensen, Johan; Alù, Andrea

    2016-03-01

    Acoustic metamaterials can manipulate and control sound waves in ways that are not possible in conventional materials. Metamaterials with zero, or even negative, refractive index for sound offer new possibilities for acoustic imaging and for the control of sound at subwavelength scales. The combination of transformation acoustics theory and highly anisotropic acoustic metamaterials enables precise control over the deformation of sound fields, which can be used, for example, to hide or cloak objects from incident acoustic energy. Active acoustic metamaterials use external control to create effective material properties that are not possible with passive structures and have led to the development of dynamically reconfigurable, loss-compensating and parity-time-symmetric materials for sound manipulation. Challenges remain, including the development of efficient techniques for fabricating large-scale metamaterial structures and converting laboratory experiments into useful devices. In this Review, we outline the designs and properties of materials with unusual acoustic parameters (for example, negative refractive index), discuss examples of extreme manipulation of sound and, finally, provide an overview of future directions in the field.

  19. Sonic hedgehog: restricted expression and limb dysmorphologies.

    PubMed

    Hill, Robert E; Heaney, Simon J H; Lettice, Laura A

    2003-01-01

    Sonic hedgehog, SHH, is required for patterning the limb. The array of skeletal elements that compose the hands and feet, and the ordered arrangement of these bones to form the pattern of fingers and toes are dependent on SHH. The mechanism of action of SHH in the limb is not fully understood; however, an aspect that appears to be important is the localized, asymmetric expression of Shh. Shh is expressed in the posterior margin of the limb bud in a region defined as the zone of polarizing activity (ZPA). Analysis of mouse mutants which have polydactyly (extra toes) shows that asymmetric expression of Shh is lost due to the appearance of an ectopic domain of expression in the anterior limb margin. One such polydactylous mouse mutant, sasquatch (Ssq), maps to the corresponding chromosomal region of the human condition pre-axial polydactyly (PPD) and thus represents a model for this condition. The mutation responsible for Ssq is located 1 Mb away from the Shh gene; however, the mutation disrupts a long-range cis-acting regulator of Shh expression. By inference, human pre-axial polydactyly results from a similar disruption of Shh expression. Other human congenital abnormalities also map near the pre-axial polydactyly locus, suggesting a major chromosomal region for limb dysmorphologies. The distinct phenotypes range from loss of all bones of the hands and feet to syndactyly of the soft tissue and fusion of the digits. We discuss the role played by Shh expression in mouse mutant phenotypes and the human limb dysmorphologies.

  20. Sonic hedgehog: restricted expression and limb dysmorphologies

    PubMed Central

    Hill, Robert E; Heaney, Simon JH; Lettice, Laura A

    2003-01-01

    Sonic hedgehog, SHH, is required for patterning the limb. The array of skeletal elements that compose the hands and feet, and the ordered arrangement of these bones to form the pattern of fingers and toes are dependent on SHH. The mechanism of action of SHH in the limb is not fully understood; however, an aspect that appears to be important is the localized, asymmetric expression of Shh. Shh is expressed in the posterior margin of the limb bud in a region defined as the zone of polarizing activity (ZPA). Analysis of mouse mutants which have polydactyly (extra toes) shows that asymmetric expression of Shh is lost due to the appearance of an ectopic domain of expression in the anterior limb margin. One such polydactylous mouse mutant, sasquatch (Ssq), maps to the corresponding chromosomal region of the human condition pre-axial polydactyly (PPD) and thus represents a model for this condition. The mutation responsible for Ssq is located 1 Mb away from the Shh gene; however, the mutation disrupts a long-range cis-acting regulator of Shh expression. By inference, human pre-axial polydactyly results from a similar disruption of Shh expression. Other human congenital abnormalities also map near the pre-axial polydactyly locus, suggesting a major chromosomal region for limb dysmorphologies. The distinct phenotypes range from loss of all bones of the hands and feet to syndactyly of the soft tissue and fusion of the digits. We discuss the role played by Shh expression in mouse mutant phenotypes and the human limb dysmorphologies. PMID:12587915

  1. Off-limb coronal loop dynamics as seen from CDS, EIT and TRACE

    NASA Astrophysics Data System (ADS)

    Banerjee, D.; O'Shea, E.; Doyle, J. G.

    Observations have revealed the existence of weak transient disturbances in extended coronal loop systems These propagating disturbances PDs originate from small scale brightenings at the footpoints of the loops and propagate upward along the loops In all cases observed the projected propagation speed is close to but below the expected sound speed in the loops This suggest that the PDs could be interpreted as slow mode MHD waves Interpreting the oscillation in terms of different wave modes and or plasma motions always depend on the line of sight as we observe in the limb or on the center of the disk The JOP 165 campaign will address some of these questions MDI and TRACE photospheric and UV imaging of TRACE and SPIRIT have been acquired simultaneously with high temporal and spatial coverage along with the spectroscopic data from CDS EIT was operated in the shutterless mode to achieve high Cadence Some of the off-limb active region dynamics and oscillations observed during this JOP campaign will be focussed in this presentation Plasma condensations and temporal variations in active region loops will be also addressed

  2. Exploring HF-induced ionospheric turbulence by Doppler sounding and stimulated electromagnetic emissions at the High Frequency Active Auroral Research Program heating facility

    NASA Astrophysics Data System (ADS)

    Sergeev, Evgeny N.; Shindin, Alexey V.; Grach, Savely M.; Milikh, Gennady M.; Mishin, Evgeny V.; Bernhardt, Paul A.; Siefring, Carl L.; Briczinski, Stanley J.; McCarrick, Michael J.

    2016-07-01

    We report on the features of the F region plasma perturbations during HF heating experiments at the High Frequency Active Auroral Research Program facility in March-April 2011 and May-June 2014. The diagnostics included multifrequency Doppler (phase) sounding (MDS) and stimulated electromagnetic emission (SEE). The results concern modification of the electron density profile near the reflection and upper hybrid heights, as well as correlation of the density modification with temporal behavior of narrow continuum, downshifted maximum, and broad continuum SEE spectral features. We reveal also a new SEE spectral feature which appears in the SEE spectra for the pump frequency f0 near the third and fourth electron gyroharmonics. It is located in the SEE spectrum well below the pump wave frequency, f - f0 -(40-220) kHz, occupies a wide frequency range till 100-150 kHz, and is termed the broad downshifted emission.

  3. Utility of aeromagnetic studies for mapping of potentially active faults in two forearc basins: Puget Sound, Washington, and Cook Inlet, Alaska

    USGS Publications Warehouse

    Saltus, R.W.; Blakely, R.J.; Haeussler, P.J.; Wells, R.E.

    2005-01-01

    High-resolution aeromagnetic surveys over forearc basins can detect faults and folds in weakly magnetized sediments, thus providing geologic constraints on tectonic evolution and improved understanding of seismic hazards in convergent-margin settings. Puget Sound, Washington, and Cook Inlet, Alaska, provide two case histories. In each lowland region, shallow-source magnetic anomalies are related to active folds and/or faults. Mapping these structures is critical for understanding seismic hazards that face the urban regions of Seattle, Washington, and Anchorage, Alaska. Similarities in aeromagnetic anomaly patterns and magnetic stratigraphy between the two regions suggest that we can expect the aeromagnetic method to yield useful structural information that may contribute to earth-hazard and energy resource investigations in other forearc basins.

  4. Active Region Soft X-Ray Spectra and Temperature Analyses based on Sounding Rocket Measurements from the Solar Aspect Monitor (SAM), - a Modified SDO/EVE Instrument

    NASA Astrophysics Data System (ADS)

    Didkovsky, Leonid V.; Wieman, Seth; Woods, Thomas N.; Jones, Andrew; Moore, Christopher

    2016-05-01

    Some initial results of soft x-ray spectral (0.5 to 3.0 nm) observations of active regions (AR11877 and AR11875) from a sounding rocket flight NASA 36.290 on 21 October 2013 at about 18:30 UT are reported. These observations were made by a Solar Aspect Monitor (SAM), a rocket version of the EUV Variability Experiment’s (EVE) channel, a pinhole camera modified for EVE rocket suite of instruments to include a free-standing transmission grating (200 nm period), which provided spectrally-resolved images of the solar disk. Intensity ratios for strong emission lines extracted from temporally averaged SAM spectral profiles of the ARs were compared to appropriately convolved modeled CHIANTI spectra. These ratios represent the AR’s temperature structures, which are compared to the structures derived from some other observations and temperature models.

  5. Demography and function of children with limb loss.

    PubMed

    Yigiter, K; Ulger, O; Sener, G; Akdogan, S; Erbahçeci, F; Bayar, K

    2005-08-01

    This retrospective study was designed for the period 1982-2002 to collect the basic data on the demography, level and side of the amputation, involved limbs, age, gender, and prosthetic functional level in children with limb loss. A total of 232 children were assessed through their prosthetic records. Seventy-two percent (195 children) presented lower-limb involvement, and 28% (77 children) had upper-limb loss. The age of the children varied between 1 and 15 years with a mean age of 9.90 +/- 2.32 years. Results of the study revealed that the leading amputation cause in children was congenital limb absence. The most frequent levels were determined as trans-tibial and trans-radial in lower and upper limbs, respectively. Findings showed that more boys (60%) were affected, and 84% of all amputations were found to be unilateral. It was also seen that right-side amputations (54%) were more common than left-side amputations (46%). The outcome of the study showed that 96% of children with lower-limb loss reached a functional gait pattern without any aids, while the percentage of independence in activities of daily living was found to be 88% in upper-limb loss.

  6. Limb lengthening in achondroplasia

    PubMed Central

    Chilbule, Sanjay K; Dutt, Vivek; Madhuri, Vrisha

    2016-01-01

    Background: Stature lengthening in skeletal dysplasia is a contentious issue. Specific guidelines regarding the age and sequence of surgery, methods and extent of lengthening at each stage are not uniform around the world. Despite the need for multiple surgeries, with their attendant complications, parents demanding stature lengthening are not rare, due to the social bias and psychological effects experienced by these patients. This study describes the outcome and complications of extensive stature lengthening performed at our center. Materials and Methods: Eight achondroplasic and one hypochondroplasic patient underwent bilateral transverse lengthening for tibiae, humeri and femora. Tibia lengthening was carried out using a ring fixator and bifocal corticotomy, while a monolateral pediatric limb reconstruction system with unifocal corticotomy was used for the femur and humerus. Lengthening of each bone segment, height gain, healing index and complications were assessed. Subgroup analysis was carried out to assess the effect of age and bone segment on the healing index. Results: Nine patients aged five to 25 years (mean age 10.2 years) underwent limb lengthening procedures for 18 tibiae, 10 femora and 8 humeri. Four patients underwent bilateral lengthening of all three segments. The mean length gain for the tibia, femur and humerus was 15.4 cm (100.7%), 9.9 cm (52.8%) and 9.6 cm (77.9%), respectively. Healing index was 25.7, 25.6 and 20.6 days/cm, respectively, for the tibia, femur and humerus. An average of 33.3% height gain was attained. Lengthening of both tibia and femur added to projected height achieved as the 3rd percentile of standard height in three out of four patients. In all, 33 complications were encountered (0.9 complications per segment). Healing index was not affected by age or bone segment. Conclusion: Extensive limb lengthening (more than 50% over initial length) carries significant risk and should be undertaken only after due consideration. PMID

  7. Early sound symbolism for vowel sounds.

    PubMed

    Spector, Ferrinne; Maurer, Daphne

    2013-01-01

    Children and adults consistently match some words (e.g., kiki) to jagged shapes and other words (e.g., bouba) to rounded shapes, providing evidence for non-arbitrary sound-shape mapping. In this study, we investigated the influence of vowels on sound-shape matching in toddlers, using four contrasting pairs of nonsense words differing in vowel sound (/i/ as in feet vs. /o/ as in boat) and four rounded-jagged shape pairs. Crucially, we used reduplicated syllables (e.g., kiki vs. koko) rather than confounding vowel sound with consonant context and syllable variability (e.g., kiki vs. bouba). Toddlers consistently matched words with /o/ to rounded shapes and words with /i/ to jagged shapes (p < 0.01). The results suggest that there may be naturally biased correspondences between vowel sound and shape.

  8. Lipotyphla limb myology comparison.

    PubMed

    Neveu, Pauline; Gasc, Jean-Pierre

    2002-05-01

    Fore- and hindlimb muscles were dissected in four species of Lipotyphla: the western European hedgehog Erinaceus europaeus (Erinaceidae, Erinaceinae); the moonrat Echinosorex gymnura (Erinaceidae, Hylomyinae or Galericinae); the tailless tenrec Tenrec ecaudatus (Tenrecidae, Tenrecinae); and the common European white-toothed shrew Crocidura russula (Soricidae, Soricinae). This work completely reviews the limb musculature of these walking mammals. Twelve myological characters were evaluated in order to disclose phylogenetic relationships. The cladogram obtained supported previous ones based on cranial and dental characters. This study shows that myological characters are valuable in phylogenetic analyses.

  9. Sound wave transmission (image)

    MedlinePlus

    When sounds waves reach the ear, they are translated into nerve impulses. These impulses then travel to the brain where they are interpreted by the brain as sound. The hearing mechanisms within the inner ear, can ...

  10. Sounds in the Ocean at 1-100 Hz

    NASA Astrophysics Data System (ADS)

    Wilcock, William S. D.; Stafford, Kathleen M.; Andrew, Rex K.; Odom, Robert I.

    2014-01-01

    Very-low-frequency sounds between 1 and 100 Hz propagate large distances in the ocean sound channel. Weather conditions, earthquakes, marine mammals, and anthropogenic activities influence sound levels in this band. Weather-related sounds result from interactions between waves, bubbles entrained by breaking waves, and the deformation of sea ice. Earthquakes generate sound in geologically active regions, and earthquake T waves propagate throughout the oceans. Blue and fin whales generate long bouts of sounds near 20 Hz that can dominate regional ambient noise levels seasonally. Anthropogenic sound sources include ship propellers, energy extraction, and seismic air guns and have been growing steadily. The increasing availability of long-term records of ocean sound will provide new opportunities for a deeper understanding of natural and anthropogenic sound sources and potential interactions between them.

  11. Sounds in the ocean at 1-100 Hz.

    PubMed

    Wilcock, William S D; Stafford, Kathleen M; Andrew, Rex K; Odom, Robert I

    2014-01-01

    Very-low-frequency sounds between 1 and 100 Hz propagate large distances in the ocean sound channel. Weather conditions, earthquakes, marine mammals, and anthropogenic activities influence sound levels in this band. Weather-related sounds result from interactions between waves, bubbles entrained by breaking waves, and the deformation of sea ice. Earthquakes generate sound in geologically active regions, and earthquake T waves propagate throughout the oceans. Blue and fin whales generate long bouts of sounds near 20 Hz that can dominate regional ambient noise levels seasonally. Anthropogenic sound sources include ship propellers, energy extraction, and seismic air guns and have been growing steadily. The increasing availability of long-term records of ocean sound will provide new opportunities for a deeper understanding of natural and anthropogenic sound sources and potential interactions between them.

  12. FGF8 and SHH substitute for anterior-posterior tissue interactions to induce limb regeneration.

    PubMed

    Nacu, Eugeniu; Gromberg, Elena; Oliveira, Catarina R; Drechsel, David; Tanaka, Elly M

    2016-05-19

    In salamanders, grafting of a left limb blastema onto a right limb stump yields regeneration of three limbs, the normal limb and two 'supernumerary' limbs. This experiment and other research have shown that the juxtaposition of anterior and posterior limb tissue plus innervation are necessary and sufficient to induce complete limb regeneration in salamanders. However, the cellular and molecular basis of the requirement for anterior-posterior tissue interactions were unknown. Here we have clarified the molecular basis of the requirement for both anterior and posterior tissue during limb regeneration and supernumerary limb formation in axolotls (Ambystoma mexicanum). We show that the two tissues provide complementary cross-inductive signals that are required for limb outgrowth. A blastema composed solely of anterior tissue normally regresses rather than forming a limb, but activation of hedgehog (HH) signalling was sufficient to drive regeneration of an anterior blastema to completion owing to its ability to maintain fibroblast growth factor (FGF) expression, the key signalling activity responsible for blastema outgrowth. In blastemas composed solely of posterior tissue, HH signalling was not sufficient to drive regeneration; however, ectopic expression of FGF8 together with endogenous HH signalling was sufficient. In axolotls, FGF8 is expressed only in the anterior mesenchyme and maintenance of its expression depends on sonic hedgehog (SHH) signalling from posterior tissue. Together, our findings identify key anteriorly and posteriorly localized signals that promote limb regeneration and show that these single factors are sufficient to drive non-regenerating blastemas to complete regeneration with full elaboration of skeletal elements.

  13. Objectively assessed physical activity and lower limb function and prospective associations with mortality and newly diagnosed disease in UK older adults: an OPAL four-year follow-up study

    PubMed Central

    Fox, Kenneth R.; Ku, Po-Wen; Hillsdon, Melvyn; Davis, Mark G.; Simmonds, Bethany A. J.; Thompson, Janice L.; Stathi, Afroditi; Gray, Selena F.; Sharp, Deborah J.; Coulson, Joanne C.

    2015-01-01

    Background: objective measures of physical activity and function with a diverse cohort of UK adults in their 70s and 80s were used to investigate relative risk of all-cause mortality and diagnoses of new diseases over a 4-year period. Participants: two hundred and forty older adults were randomly recruited from 12 general practices in urban and suburban areas of a city in the United Kingdom. Follow-up included 213 of the baseline sample. Methods: socio-demographic variables, height and weight, and self-reported diagnosed diseases were recorded at baseline. Seven-day accelerometry was used to assess total physical activity, moderate-to-vigorous activity and sedentary time. A log recorded trips from home. Lower limb function was assessed using the Short Physical Performance Battery. Medical records were accessed on average 50 months post baseline, when new diseases and deaths were recorded. Analyses: ANOVAs were used to assess socio-demographic, physical activity and lower limb function group differences in diseases at baseline and new diseases during follow-up. Regression models were constructed to assess the prospective associations between physical activity and function with mortality and new disease. Results: for every 1,000 steps walked per day, the risk of mortality was 36% lower (hazard ratios 0.64, 95% confidence interval (CI) 0.44–0.91, P = 0.013). Low levels of moderate-to-vigorous physical activity (incident rate ratio (IRR) 1.67, 95% CI 1.04–2.68, P = 0.030) and low frequency of trips from home (IRR 1.41, 95% CI 0.98–2.05, P = 0.045) were associated with diagnoses of more new diseases. Conclusion: physical activity should be supported for adults in their 70s and 80s, as it is associated with reduced risk of mortality and new disease development. PMID:25377744

  14. Development of an Upper Limb Motorized Assistive-Rehabilitative Robot

    NASA Astrophysics Data System (ADS)

    Amiri, Masoud; Casolo, Federico

    While the number of people requiring help for the activities of daily living are increasing, several studies have been shown the effectiveness of robot training for upper limb functionality recovery. The robotic system described in this paper is an active end-effector based robot which can be used for assisting and rehabilitating of human upper limb. The robot is able to take into account desire of the patient for the support that patient needs to complete the task.

  15. Altitude Registration of Limb-Scattered Radiation

    NASA Technical Reports Server (NTRS)

    Moy, Leslie; Bhartia, Pawan K.; Jaross, Glen; Loughman, Robert; Kramarova, Natalya; Chen, Zhong; Taha, Ghassan; Chen, Grace; Xu, Philippe

    2017-01-01

    One of the largest constraints to the retrieval of accurate ozone profiles from UV backscatter limb sounding sensors is altitude registration. Two methods, the Rayleigh scattering attitude sensing (RSAS) and absolute radiance residual method (ARRM), are able to determine altitude registration to the accuracy necessary for long-term ozone monitoring. The methods compare model calculations of radiances to measured radiances and are independent of onboard tracking devices. RSAS determines absolute altitude errors, but, because the method is susceptible to aerosol interference, it is limited to latitudes and time periods with minimal aerosol contamination. ARRM, a new technique introduced in this paper, can be applied across all seasons and altitudes. However, it is only appropriate for relative altitude error estimates. The application of RSAS to Limb Profiler (LP) measurements from the Ozone Mapping and Profiler Suite (OMPS) on board the Suomi NPP (SNPP) satellite indicates tangent height (TH) errors greater than 1 km with an absolute accuracy of +/-200 m. Results using ARRM indicate a approx. 300 to 400m intra-orbital TH change varying seasonally +/-100 m, likely due to either errors in the spacecraft pointing or in the geopotential height (GPH) data that we use in our analysis. ARRM shows a change of approx. 200m over 5 years with a relative accuracy (a long-term accuracy) of 100m outside the polar regions.

  16. Altitude registration of limb-scattered radiation

    NASA Astrophysics Data System (ADS)

    Moy, Leslie; Bhartia, Pawan K.; Jaross, Glen; Loughman, Robert; Kramarova, Natalya; Chen, Zhong; Taha, Ghassan; Chen, Grace; Xu, Philippe

    2017-01-01

    One of the largest constraints to the retrieval of accurate ozone profiles from UV backscatter limb sounding sensors is altitude registration. Two methods, the Rayleigh scattering attitude sensing (RSAS) and absolute radiance residual method (ARRM), are able to determine altitude registration to the accuracy necessary for long-term ozone monitoring. The methods compare model calculations of radiances to measured radiances and are independent of onboard tracking devices. RSAS determines absolute altitude errors, but, because the method is susceptible to aerosol interference, it is limited to latitudes and time periods with minimal aerosol contamination. ARRM, a new technique introduced in this paper, can be applied across all seasons and altitudes. However, it is only appropriate for relative altitude error estimates. The application of RSAS to Limb Profiler (LP) measurements from the Ozone Mapping and Profiler Suite (OMPS) on board the Suomi NPP (SNPP) satellite indicates tangent height (TH) errors greater than 1 km with an absolute accuracy of ±200 m. Results using ARRM indicate a ˜ 300 to 400 m intra-orbital TH change varying seasonally ±100 m, likely due to either errors in the spacecraft pointing or in the geopotential height (GPH) data that we use in our analysis. ARRM shows a change of ˜ 200 m over ˜ 5 years with a relative accuracy (a long-term accuracy) of ±100 m outside the polar regions.

  17. Myopathy phenotype of transgenic mice expressing active site-mutated inactive p94 skeletal muscle-specific calpain, the gene product responsible for limb girdle muscular dystrophy type 2A.

    PubMed

    Tagawa, K; Taya, C; Hayashi, Y; Nakagawa, M; Ono, Y; Fukuda, R; Karasuyama, H; Toyama-Sorimachi, N; Katsui, Y; Hata, S; Ishiura, S; Nonaka, I; Seyama, Y; Arahata, K; Yonekawa, H; Sorimachi, H; Suzuki, K

    2000-05-22

    A defect of the gene for p94 (calpain 3), a skeletal muscle-specific calpain, is responsible for limb girdle muscular dystrophy type 2A (LGMD2A), or 'calpainopathy', which is an autosomal recessive and progressive neuromuscular disorder. To study the relationships between the physiological functions of p94 and the etiology of LGMD2A, we created transgenic mice that express an inactive mutant of p94, in which the active site Cys129 is replaced by Ser (p94:C129S). Three lines of transgenic mice expressing p94:C129S mRNA at various levels showed significantly decreased grip strength. Sections of soleus and extensor digitorum longus (EDL) muscles of the aged transgenic mice showed increased numbers of lobulated and split fibers, respectively, which are often observed in limb girdle muscular dystrophy muscles. Centrally placed nuclei were also frequently found in the EDL muscle of the transgenic mice, whereas wild-type mice of the same age had almost none. There was more p94 protein produced in aged transgenic mice muscles and it showed significantly less autolytic degradation activity than that of wild-type mice. Although no necrotic-regenerative fibers were observed, the age and p94:C129S expression dependence of the phenotypes strongly suggest that accumulation of p94:C129S protein causes these myopathy phenotypes. The p94:C129S transgenic mice could provide us with crucial information on the molecular mech-anism of LGMD2A.

  18. Vasospastic Limb Ischemia Presenting Acute and Chronic Limb Ischemia

    PubMed Central

    2014-01-01

    Vasospastic limb ischemia might have been underappreciated compared to vasospasm in other territories such as heart and brain. However, an increasing awareness of this vascular disorder can be translated to an improved patients’ care. Herein, we report a case of vasospasm presenting acute and chronic limb ischemia in four extremities. PMID:24995065

  19. LDTK: Limb Darkening Toolkit

    NASA Astrophysics Data System (ADS)

    Parviainen, H.; Aigrain, S.

    2015-11-01

    We present a PYTHON package LDTK that automates the calculation of custom stellar limb-darkening (LD) profiles and model-specific limb-darkening coefficients using the library of PHOENIX-generated specific intensity spectra by Husser et al. The aim of the package is to facilitate analyses requiring custom generated LD profiles, such as the studies of exoplanet transits - especially transmission spectroscopy, where the transit modelling is carried out for custom narrow passbands - eclipsing binaries, interferometry, and microlensing events. First, LDTK can be used to compute custom LD profiles with uncertainties propagated from the uncertainties in the stellar parameter estimates. Secondly, LDTK can be used to estimate the LD-model-specific coefficients with uncertainties for the most common LD models. Thirdly, LDTK can be directly integrated into the log posterior computation of any pre-existing modelling code with minimal modifications. The last approach can be used to constrain the LD model parameter space directly by the LD profile, allowing for the marginalization over the LD parameter space without the need to approximate the constraint from the LD profile using a prior.

  20. Sound Levels in East Texas Schools.

    ERIC Educational Resources Information Center

    Turner, Aaron Lynn

    A survey of sound levels was taken in several Texas schools to determine the amount of noise and sound present by size of class, type of activity, location of building, and the presence of air conditioning and large amounts of glass. The data indicate that class size and relative amounts of glass have no significant bearing on the production of…

  1. The role of hind limb flexor muscles during swimming in the toad, Bufo marinus.

    PubMed

    Gillis, Gary B

    2007-01-01

    Most work examining muscle function during anuran locomotion has focused largely on the roles of major hind limb extensors during jumping and swimming. Nevertheless, the recovery phase of anuran locomotion likely plays a critical role in locomotor performance, especially in the aquatic environment, where flexing limbs can increase drag on the swimming animal. In this study, I use kinematic and electromyographic analyses to explore the roles of four anatomical flexor muscles in the hind limb of Bufo marinus during swimming: m. iliacus externus, a hip flexor; mm. iliofibularis and semitendinosus, knee flexors; and m. tibialis anticus longus, an ankle flexor. Two general questions are addressed: (1) What role, if any, do these flexors play during limb extension? and (2) How do limb flexors control limb flexion? Musculus iliacus externus exhibits a large burst of EMG activity early in limb extension and shows low levels of activity during recovery. Both m. iliofibularis and m. semitendinosus are biphasically active, with relatively short but intense bursts during limb extension followed by longer and typically weaker secondary bursts during recovery. Musculus tibialis anticus longus becomes active mid way through recovery and remains active through the start of extension in the next stroke. In conclusion, flexors at all three joints exhibit some activity during limb extension, indicating that they play a role in mediating limb movements during propulsion. Further, recovery is controlled by a complex pattern of flexor activation timing, but muscle intensities are generally lower, suggesting relatively low force requirements during this phase of swimming.

  2. Rocket ozone sounding network data

    NASA Technical Reports Server (NTRS)

    Wright, D. U.; Krueger, A. J.; Foster, G. M.

    1978-01-01

    During the period December 1976 through February 1977, three regular monthly ozone profiles were measured at Wallops Flight Center, two special soundings were taken at Antigua, West Indies, and at the Churchill Research Range, monthly activities were initiated to establish stratospheric ozone climatology. This report presents the data results and flight profiles for the period covered.

  3. Sounds like Team Spirit

    NASA Technical Reports Server (NTRS)

    Hoffman, Edward

    2002-01-01

    I recently accompanied my son Dan to one of his guitar lessons. As I sat in a separate room, I focused on the music he was playing and the beautiful, robust sound that comes from a well-played guitar. Later that night, I woke up around 3 am. I tend to have my best thoughts at this hour. The trouble is I usually roll over and fall back asleep. This time I was still awake an hour later, so I got up and jotted some notes down in my study. I was thinking about the pure, honest sound of a well-played instrument. From there my mind wandered into the realm of high-performance teams and successful projects. (I know this sounds weird, but this is the sort of thing I think about at 3 am. Maybe you have your own weird thoughts around that time.) Consider a team in relation to music. It seems to me that a crack team can achieve a beautiful, perfect unity in the same way that a band of brilliant musicians can when they're in harmony with one another. With more than a little satisfaction I have to admit, I started to think about the great work performed for you by the Knowledge Sharing team, including this magazine you are reading. Over the past two years I personally have received some of my greatest pleasures as the APPL Director from the Knowledge Sharing activities - the Masters Forums, NASA Center visits, ASK Magazine. The Knowledge Sharing team expresses such passion for their work, just like great musicians convey their passion in the music they play. In the case of Knowledge Sharing, there are many factors that have made this so enjoyable (and hopefully worthwhile for NASA). Three ingredients come to mind -- ingredients that have produced a signature sound. First, through the crazy, passionate playing of Alex Laufer, Michelle Collins, Denise Lee, and Todd Post, I always know that something startling and original is going to come out of their activities. This team has consistently done things that are unique and innovative. For me, best of all is that they are always

  4. Sound of sonoluminescence

    NASA Astrophysics Data System (ADS)

    Elze, H.-Thomas; Kodama, Takeshi; Rafelski, Johann

    1998-04-01

    We consider an air bubble in water under conditions of single-bubble sonoluminescence (SBSL) and evaluate the emitted sound field nonperturbatively for subsonic gas-liquid interface motion. Sound emission being the dominant damping mechanism, we also implement the nonperturbative sound damping in the Rayleigh-Plesset equation for the interface motion. We evaluate numerically the sound pulse emitted during bubble collapse and compare the nonperturbative and perturbative results, showing that the usual perturbative description leads to an overestimate of the maximal surface velocity and maximal sound pressure. The radius vs time relation for a full SBSL cycle remains deceptively unaffected.

  5. Evaluation of Limb-Girdle Muscular Dystrophy

    ClinicalTrials.gov

    2014-03-06

    Becker Muscular Dystrophy; Limb-Girdle Muscular Dystrophy, Type 2A (Calpain-3 Deficiency); Limb-Girdle Muscular Dystrophy, Type 2B (Miyoshi Myopathy, Dysferlin Deficiency); Limb-Girdle Muscular Dystrophy, Type 2I (FKRP-deficiency)

  6. Priming Gestures with Sounds

    PubMed Central

    Lemaitre, Guillaume; Heller, Laurie M.; Navolio, Nicole; Zúñiga-Peñaranda, Nicolas

    2015-01-01

    We report a series of experiments about a little-studied type of compatibility effect between a stimulus and a response: the priming of manual gestures via sounds associated with these gestures. The goal was to investigate the plasticity of the gesture-sound associations mediating this type of priming. Five experiments used a primed choice-reaction task. Participants were cued by a stimulus to perform response gestures that produced response sounds; those sounds were also used as primes before the response cues. We compared arbitrary associations between gestures and sounds (key lifts and pure tones) created during the experiment (i.e. no pre-existing knowledge) with ecological associations corresponding to the structure of the world (tapping gestures and sounds, scraping gestures and sounds) learned through the entire life of the participant (thus existing prior to the experiment). Two results were found. First, the priming effect exists for ecological as well as arbitrary associations between gestures and sounds. Second, the priming effect is greatly reduced for ecologically existing associations and is eliminated for arbitrary associations when the response gesture stops producing the associated sounds. These results provide evidence that auditory-motor priming is mainly created by rapid learning of the association between sounds and the gestures that produce them. Auditory-motor priming is therefore mediated by short-term associations between gestures and sounds that can be readily reconfigured regardless of prior knowledge. PMID:26544884

  7. Visual Presentation Effects on Identification of Multiple Environmental Sounds

    PubMed Central

    Masakura, Yuko; Ichikawa, Makoto; Shimono, Koichi; Nakatsuka, Reio

    2016-01-01

    This study examined how the contents and timing of a visual stimulus affect the identification of mixed sounds recorded in a daily life environment. For experiments, we presented four environment sounds as auditory stimuli for 5 s along with a picture or a written word as a visual stimulus that might or might not denote the source of one of the four sounds. Three conditions of temporal relations between the visual stimuli and sounds were used. The visual stimulus was presented either: (a) for 5 s simultaneously with the sound; (b) for 5 s, 1 s before the sound (SOA between the audio and visual stimuli was 6 s); or (c) for 33 ms, 1 s before the sound (SOA was 1033 ms). Participants reported all identifiable sounds for those audio–visual stimuli. To characterize the effects of visual stimuli on sound identification, the following were used: the identification rates of sounds for which the visual stimulus denoted its sound source, the rates of other sounds for which the visual stimulus did not denote the sound source, and the frequency of false hearing of a sound that was not presented for each sound set. Results of the four experiments demonstrated that a picture or a written word promoted identification of the sound when it was related to the sound, particularly when the visual stimulus was presented for 5 s simultaneously with the sounds. However, a visual stimulus preceding the sounds had a benefit only for the picture, not for the written word. Furthermore, presentation with a picture denoting a sound simultaneously with the sound reduced the frequency of false hearing. These results suggest three ways that presenting a visual stimulus affects identification of the auditory stimulus. First, activation of the visual representation extracted directly from the picture promotes identification of the denoted sound and suppresses the processing of sounds for which the visual stimulus did not denote the sound source. Second, effects based on processing of the

  8. SPORTS INJURIES OF THE UPPER LIMBS

    PubMed Central

    da Silva, Rogerio Teixeira

    2015-01-01

    Sports injuries of the upper limbs are very common in physical activities and therefore, they need to be studied in detail, taking into consideration specific aspects of the types of sports practiced. Special attention should be paid to the dynamics of the shoulder girdle and the entire scapular belt, since the most appropriate treatment for athletes can only be provided in this manner. This can also help to prevent recurrences, which can occur in some cases because athletes always seek to return to their pre-injury level of sports activity. This article will focus primarily on the management of upper-limb tendon injuries, from the physiopathology through to the new methods of injury treatment that are more prevalent in sports practice in Brazil. PMID:27022529

  9. Analysis of environmental sounds

    NASA Astrophysics Data System (ADS)

    Lee, Keansub

    Environmental sound archives - casual recordings of people's daily life - are easily collected by MPS players or camcorders with low cost and high reliability, and shared in the web-sites. There are two kinds of user generated recordings we would like to be able to handle in this thesis: Continuous long-duration personal audio and Soundtracks of short consumer video clips. These environmental recordings contain a lot of useful information (semantic concepts) related with activity, location, occasion and content. As a consequence, the environment archives present many new opportunities for the automatic extraction of information that can be used in intelligent browsing systems. This thesis proposes systems for detecting these interesting concepts on a collection of these real-world recordings. The first system is to segment and label personal audio archives - continuous recordings of an individual's everyday experiences - into 'episodes' (relatively consistent acoustic situations lasting a few minutes or more) using the Bayesian Information Criterion and spectral clustering. The second system is for identifying regions of speech or music in the kinds of energetic and highly-variable noise present in this real-world sound. Motivated by psychoacoustic evidence that pitch is crucial in the perception and organization of sound, we develop a noise-robust pitch detection algorithm to locate speech or music-like regions. To avoid false alarms resulting from background noise with strong periodic components (such as air-conditioning), a new scheme is added in order to suppress these noises in the domain of autocorrelogram. In addition, the third system is to automatically detect a large set of interesting semantic concepts; which we chose for being both informative and useful to users, as well as being technically feasible. These 25 concepts are associated with people's activities, locations, occasions, objects, scenes and sounds, and are based on a large collection of

  10. The Surface Microlayer: Review of Literature and Evaluation of Potential Effects of Dredge Activities in Puget Sound.

    DTIC Science & Technology

    1987-01-01

    Heyrand. 1975. Polonium - 210 - Its vertical oceanic transport by zoo- plankton metabolic activity. Marine Chemistry 3:105-110. Collins, J. 1974. Oil and...F.A. Aulicino. 1985. Comparison of methods to detect fecal streptococci in marine waters. Water, Air and Soil 26:201- 210 . Waggott, A., and A.B

  11. Distinct cortical pathways for processing tool versus animal sounds.

    PubMed

    Lewis, James W; Brefczynski, Julie A; Phinney, Raymond E; Janik, John J; DeYoe, Edgar A

    2005-05-25

    Human listeners can effortlessly categorize a wide range of environmental sounds. Whereas categorizing visual object classes (e.g., faces, tools, houses, etc.) preferentially activates different regions of visually sensitive cortex, it is not known whether the auditory system exhibits a similar organization for different types or categories of complex sounds outside of human speech. Using functional magnetic resonance imaging, we show that hearing and correctly or incorrectly categorizing animal vocalizations (as opposed to hand-manipulated tool sounds) preferentially activated middle portions of the left and right superior temporal gyri (mSTG). On average, the vocalization sounds had much greater harmonic and phase-coupling content (acoustically similar to human speech sounds), which may represent some of the signal attributes that preferentially activate the mSTG regions. In contrast, correctly categorized tool sounds (and even animal sounds that were miscategorized as being tool-related sounds) preferentially activated a widespread, predominantly left hemisphere cortical "mirror network." This network directly overlapped substantial portions of motor-related cortices that were independently activated when participants pantomimed tool manipulations with their right (dominant) hand. These data suggest that the recognition processing for some sounds involves a causal reasoning mechanism (a high-level auditory "how" pathway), automatically evoked when attending to hand-manipulated tool sounds, that effectively associates the dynamic motor actions likely to have produced the sound(s).

  12. Sounding Rocket Observations of Active Region Soft X-Ray Spectra Between 0.5 and 2.5 nm Using a Modified SDO/EVE Instrument

    NASA Astrophysics Data System (ADS)

    Wieman, Seth; Didkovsky, Leonid; Woods, Thomas; Jones, Andrew; Moore, Christopher

    2016-12-01

    Spectrally resolved measurements of individual solar active regions (ARs) in the soft X-ray (SXR) range are important for studying dynamic processes in the solar corona and their associated effects on the Earth's upper atmosphere. They are also a means of evaluating atomic data and elemental abundances used in physics-based solar spectral models. However, very few such measurements are available. We present spectral measurements of two individual ARs in the 0.5 to 2.5 nm range obtained on the NASA 36.290 sounding rocket flight of 21 October 2013 (at about 18:30 UT) using the Solar Aspect Monitor (SAM), a channel of the Extreme Ultaviolet Variability Experiment (EVE) payload designed for underflight calibrations of the orbital EVE on the Solar Dynamics Observatory (SDO). The EVE rocket instrument is a duplicate of the EVE on SDO, except the SAM channel on the rocket version was modified in 2012 to include a freestanding transmission grating to provide spectrally resolved images of the solar disk with the best signal to noise ratio for the brightest features, such as ARs. Calibrations of the EVE sounding rocket instrument at the National Institute of Standards and Technology Synchrotron Ultraviolet Radiation Facility (NIST/SURF) have provided a measurement of the SAM absolute spectral response function and a mapping of wavelength separation in the grating diffraction pattern. We discuss techniques (incorporating the NIST/SURF data) for determining SXR spectra from the dispersed AR images as well as the resulting spectra for NOAA ARs 11877 and 11875 observed on the 2013 rocket flight. In comparisons with physics-based spectral models using the CHIANTI v8 atomic database we find that both AR spectra are in good agreement with isothermal spectra (4 MK), as well as spectra based on an AR differential emission measure (DEM) included with the CHIANTI distribution, with the exception of the relative intensities of strong Fe xvii lines associated with 2p6-2p53{s} and 2p6-2p

  13. Rainsticks: Integrating Culture, Folklore, and the Physics of Sound

    ERIC Educational Resources Information Center

    Moseley, Christine; Fies, Carmen

    2007-01-01

    The purpose of this activity is for students to build a rainstick out of materials in their own environment and imitate the sound of rain while investigating the physical principles of sound. Students will be able to relate the sound produced by an instrument to the type and quantity of materials used in its construction.

  14. Simulation of Upper Limb Movements

    NASA Astrophysics Data System (ADS)

    Uherčík, Filip; Hučko, Branislav

    2011-12-01

    The paper deals with controlling an upper limb prosthesis based on the measurement of myoelectric signals (MES) while drinking. MES signals have been measured on healthy limbs to obtain the same response for the prosthesis. To simulate the drinking motion of a healthy upper limb, the program ADAMS was used, with all degrees of freedom and a hand after trans-radial amputation with an existing hand prosthesis. Modification of the simulation has the exact same logic of control, where the muscle does not have to be strenuous all the time, but it is the impulse of the muscle which drives the motor even though the impulse disappears and passed away.

  15. Management of Major Limb Injuries

    PubMed Central

    Langer, Vijay

    2014-01-01

    Management of major limb injuries is a daunting challenge, especially as many of these patients have severe associated injuries. In trying to save life, often the limb is sacrificed. The existing guidelines on managing such trauma are often confusing. There is scope to lay down such protocols along with the need for urgent transfer of such patients to a multispecialty center equipped to salvage life and limb for maximizing outcome. This review article comprehensively deals with the issue of managing such major injuries. PMID:24511296

  16. Map showing recent and historic landslide activity on coastal bluffs of Puget Sound between Shilshole Bay and Everett, Washington

    USGS Publications Warehouse

    Baum, R.L.; Harp, E.L.; Hultman, W.A.

    2000-01-01

    Many landslides occurred on the coastal bluffs between Seattle and Everett, Washington during the winters of 1996 and 1997. Shallow earth slides and debris flows were the most common, but a few deep-seated rotational earth slides also occurred. The landslides caused significant property damage and interfered with rail traffic; future landslides in the area pose significant hazards to property and public safety. Field observations indicate that ground-water seepage, runoff concentration, and dumping at the tops of the bluffs all contributed to instability of the bluffs. Most landslides in the study area occurred in colluvium, residuum, and landslide deposits derived from the Vashon Drift, particularly the advance outwash. In the northern part of the area, colluvium derived from the Pleistocene Whidbey Formation was also involved in shallow landslides. Comparison of recent activity with historic records in the southern part of the map area indicates that landslides tend to occur in many of the same areas as previous landslides.

  17. Prevalence and Characteristics of Phantom Limb Pain and Residual Limb Pain in the Long Term after Upper Limb Amputation

    ERIC Educational Resources Information Center

    Desmond, Deirdre M.; MacLachlan, Malcolm

    2010-01-01

    This study aims to describe the prevalence and characteristics of phantom limb pain and residual limb pain after upper limb amputation. One-hundred and forty-one participants (139 males; mean age 74.8 years; mean time since amputation 50.1 years) completed a self-report questionnaire assessing residual and phantom limb pain experience. Prevalence…

  18. Sound Power Determination Using Sound Intensity Measurements: Applications and Extensions

    NASA Astrophysics Data System (ADS)

    Yang, Shaobo

    1995-01-01

    The determination of sound power using sound intensity measurements is one of the most important developments in acoustics since the advent of digital signal processing techniques and FFT (fast Fourier transform) techniques in 1970's. Sound power determination using sound intensity measurements is the only way to precisely determine the sound power of noise sources in operating conditions when other noise sources are operating simultaneously. Sound power determination from sound intensity measurements largely obviates the need for special purpose test facilities, such as an anechoic room or a reverberation room. The determination of sound power from sound intensity measurements has many distinct advantages over the traditional determination of the sound power from sound pressure, and it will soon become the dominant method in the determination of the sound power of noise sources in-situ. Sound intensity measurements have been successfully applied to the determination of the sound power levels of noise sources in laboratory conditions, and of small machinery noise sources. The full scale application of this new technique to industrial machinery noise sources is certainly of importance for practical purposes. This dissertation mainly describes progress made in research on the application of sound intensity measurements for the determination of the sound power of noise sources. Results concerning the sound power determination from sound intensity measurements in the following areas are discussed: sound power determination from sound intensity measurements at low frequency, error analysis of sound intensity estimates at low frequency, and sound power determination from sound intensity measurements in the presence of air flow, sound power determination from sound intensity measurements in the presence of strong background noise and some practical considerations on the application of the sound intensity technique to in-situ sound power determination.

  19. Sound presentation during different respiration phases alters the sound-induced vasoconstriction mediated by the sympathetic nerve.

    PubMed

    Sato, Takashi G; Ooishi, Yuuki

    2012-07-11

    The sympathetic orienting response induced by sound has been widely studied and utilized as an index of sound-induced emotions and other mental phenomena. Since sympathetic activity has its own oscillation that is synchronized with the respiration rhythm (sympatho-respiratory coupling), it is possible that the sound-induced orienting response of sympathetic activity varies depending on the respiration phase. In this study, the sound presentations were timed to coincide with the onset of inspiration or expiration. 10 experimental sounds were presented to 12 males aged 21-35 years. Respiration was monitored with an elastic chest band. Vasoconstriction at a finger was measured with laser Doppler flowmetry as a sympathetic orienting response. We found that the sound-induced vasoconstriction was larger for sounds presented in the inspiration phase than for those presented in the expiration phase, suggesting that the respiration network-derived sympathetic tone works as a gate for the sound-induced sympathetic tone.

  20. Lower-Limb Rehabilitation Robot Design

    NASA Astrophysics Data System (ADS)

    Bouhabba, E. M.; Shafie, A. A.; Khan, M. R.; Ariffin, K.

    2013-12-01

    It is a general assumption that robotics will play an important role in therapy activities within rehabilitation treatment. In the last decade, the interest in the field has grown exponentially mainly due to the initial success of the early systems and the growing demand caused by increasing numbers of stroke patients and their associate rehabilitation costs. As a result, robot therapy systems have been developed worldwide for training of both the upper and lower extremities. This paper investigates and proposes a lower-limb rehabilitation robot that is used to help patients with lower-limb paralysis to improve and resume physical functions. The proposed rehabilitation robot features three rotary joints forced by electric motors providing linear motions. The paper covers mechanism design and optimization, kinematics analysis, trajectory planning, wearable sensors, and the control system design. The design and control system demonstrate that the proposed rehabilitation robot is safe and reliable with the effective design and better kinematic performance.

  1. FINAL REPORT OF FY 1999, 2000, AND 2001 ACTIVITIES: CONTINUED DEVELOPMENT OF AN INTEGRATED SOUNDING SYSTEM IN SUPPORT OF THE DOE/ARM EXPERIMENTAL PROGRAM

    SciTech Connect

    Ed R. Westwater CIRES, University of Colorado /NOAA Environmental Technology Laboratory 325 Broadway MS R/E/ET1 Boulder, Colorado 80305

    2002-04-30

    OAK B188 FINAL REPORT OF FY 1999, 2000, AND 2001 ACTIVITIES: CONTINUED DEVELOPMENT OF AN INTEGRATED SOUNDING SYSTEM IN SUPPORT OF THE DOE/ARM EXPERIMENTAL PROGRAM The basic goals of the research are to develop and test algorithms and deploy instruments that improve measurements of atmospheric quantities relevant to radiative transfer and climate research. Primary among these atmospheric variables are integrated amounts of water vapor and cloud liquid, as well as profiles of temperature, water vapor and cloud liquid. A primary thrust of this research is to combine data from instruments available to ARM to maximize their importance in radiative transfer and climate research. To gather data relevant to these studies, participation in field experiments, especially intensive operating periods, as well as the subsequent analysis and dissemination of collected data, is of primary importance. Examples of relevant experiments include several Water Vapor Intensive Operating Periods at the Southern Great Plains Cloud And Radiation Testbed site, experiments in the Tropical Western Pacific such as PROBE and Nauru'99, and experiments at the North Slope of Alaska/Adjacent Arctic Ocean site. This final report describes our analyses of data taken during these field experiments.

  2. Evaluation and comparison of effective connectivity during simple and compound limb motor imagery.

    PubMed

    Yi, Weibo; Zhang, Lixin; Wang, Kun; Xiao, Xiaolin; He, Feng; Zhao, Xin; Qi, Hongzhi; Zhou, Peng; Wan, Baikun; Ming, Dong

    2014-01-01

    Motor imagery (MI) has been demonstrated beneficial in motor rehabilitation in patients with movement disorders. In contrast with simple limb motor imagery, less work was reported about the effective connectivity networks of compound limb motor imagery which involves several parts of limbs. This work aimed to investigate the differences of information flow patterns between simple limb motor imagery and compound limb motor imagery. Ten subjects participated in the experiment involving three tasks of simple limb motor imagery (left hand, right hand, feet) and three tasks of compound limb motor imagery (both hands, left hand combined with right foot, right hand combined with left foot). The causal interactions among different neural regions were evaluated by Short-time Directed Transfer Function (SDTF). Quite different from the networks of simple limb motor imagery, more effective interactions overlying larger brain regions were observed during compound limb motor imagery. These results imply that there exist significant differences in the patterns of EEG activity flow between simple limb motor imagery and compound limb motor imagery, which present more complex networks and could be utilized in motor rehabilitation for more benefit in patients with movement disorders.

  3. An investigation into the bilateral functional differences of the lower limb muscles in standing and walking

    PubMed Central

    Liang, Shengyun; Xu, Jiali; wang, Lei

    2016-01-01

    To date, most studies use surface electromyographic (sEMG) signals as the control source on active rehabilitation robots, and unilateral data are collected based on the gait symmetry hypothesis, which has caused much controversy. The purpose of this study is to quantitatively evaluate the sEMG activity asymmetry of bilateral muscles in lower extremities during functional tasks. Nine participants were instructed to perform static and dynamic steady state tests. sEMG signals from the tibialis anterior, soleus, medial gastrocnemius and lateral gastrocnemius muscles of bilateral lower extremities were recorded in the experiments. Muscle activities are quantified in terms of sEMG amplitude. We investigated whether characteristics of left limb and the one of the right limb have the same statistical characteristics during functional tasks using The Wilcoxon rank-sum test, and studied dynamic signal irregularity degree for sEMG activities via sample entropy. The total of muscle activities showed significant differences between left limb and right limb during the static steady state (p = 0.000). For dynamic steady states, there were significant differences for most muscle activities between left limb and right limb at different speeds (p = 0.000). Nevertheless, there was no difference between the lateral gastrocnemius for bilateral limb at 2.0 kilometers per hour (p = 0.060). For medial gastrocnemius, differences were not found between left limb and right limb at 1.0 and 3.0 kilometers per hours (p = 0.390 and p = 0.085, respectively). Similarly, there was no difference for soleus at 3.0 kilometers per hour (p = 0.115). The importance of the differences in muscle activities between left limb and right limb were found. These results can potentially be used for evaluating lower limb extremity function of special populations (elderly people or stroke patients) in an objective and simple method. PMID:27602282

  4. Limb patterning: from signaling gradients to molecular oscillations.

    PubMed

    Sheeba, Caroline J; Andrade, Raquel P; Palmeirim, Isabel

    2014-02-20

    The developing forelimb is patterned along the proximal-distal and anterior-posterior axes by opposing gradients of retinoic acid and fibroblast growth factors and by graded sonic hedgehog signaling, respectively. However, how coordinated patterning along both axes is accomplished with temporal precision remains unknown. The limb molecular oscillator hairy2 was recently shown to be a direct readout of the combined signaling activities of retinoic acid, fibroblast growth factor and sonic hedgehog in the limb mesenchyme. Herein, an integrated time-space model is presented to conciliate the progress zone and two-signal models for limb patterning. We propose that the limb clock may allow temporal information to be decoded into positional information when the distance between opposing signaling gradients is no longer sufficient to provide distinct cell fate specification.

  5. Improved decoding of limb-state feedback from natural sensors.

    PubMed

    Wagenaar, J B; Ventura, V; Weber, D J

    2009-01-01

    Limb state feedback is of great importance for achieving stable and adaptive control of FES neuroprostheses. A natural way to determine limb state is to measure and decode the activity of primary afferent neurons in the limb. The feasibility of doing so has been demonstrated by [1] and [2]. Despite positive results, some drawbacks in these works are associated with the application of reverse regression techniques for decoding the afferent neuronal signals. Decoding methods that are based on direct regression are now favored over reverse regression for decoding neural responses in higher regions in the central nervous system [3]. In this paper, we apply a direct regression approach to decode the movement of the hind limb of a cat from a population of primary afferent neurons. We show that this approach is more principled, more efficient, and more generalizable than reverse regression.

  6. Myoelectric control of artificial limb inspired by quantum information processing

    NASA Astrophysics Data System (ADS)

    Siomau, Michael; Jiang, Ning

    2015-03-01

    Precise and elegant coordination of a prosthesis across many degrees of freedom represents a significant challenge to efficient rehabilitation of people with limb deficiency. Processing the electrical neural signals collected from the surface of the remnant muscles of the stump is a common way to initiate and control the different movements available to the artificial limb. Based on the assumption that there are distinguishable and repeatable signal patterns among different types of muscular activation, the problem of prosthesis control reduces to one of pattern recognition. Widely accepted classical methods for pattern recognition, however, cannot provide simultaneous and proportional control of the artificial limb. Here we show that, in principle, quantum information processing of the neural signals allows us to overcome the above-mentioned difficulties, suggesting a very simple scheme for myoelectric control of artificial limb with advanced functionalities.

  7. Limb displacement and brightness seismology

    NASA Astrophysics Data System (ADS)

    Emilio, Marcelo; Cunnyngham, Ian; Kuhn, Jeff; Mehret, Leandro; Bush, Rock; Scholl, Isabelle

    2015-08-01

    The Helioseismic and Magnetic Imager (HMI) abord the Solar Dynamics Observatory (SDO) has been used to obtain the most sensitive spectrally resolved observation of individual p-modes at the extreme solar limb. Such oscillation observations of the limb displacement and brightness for some spatial and temporal regimes are even competitive in signal-to-noise to full-disk doppler measurements of the p-mode spectrum. Limb measurements of 5-min p-modes, while having many similarities to full-disk doppler observations, have significantly different sensitivities to the solar rotation and the 5-min mode solar atmospheric structure. These may provide information about the solar structure which is complementary to full-disk measurements. In this work we present results from Individual spherical harmonic p-modes that were detected around solar limb with amplitudes at the micro-arcsecond level.

  8. Pediatric limb differences and amputations.

    PubMed

    Le, Joan T; Scott-Wyard, Phoebe R

    2015-02-01

    Congenital limb differences are uncommon birth defects that may go undetected even with prenatal screening ultrasound scans and often go undetected until birth. For children with congenital limb differences, a diagnostic evaluation should be done to rule out syndromes involving other organ systems or known associations. The most common etiology of acquired amputation is trauma. Postamputation complications include pain and terminal bony overgrowth. A multidisciplinary approach to management with the child and family can lead to a successful, functional, and fulfilling life.

  9. EUVS Sounding Rocket Payload

    NASA Technical Reports Server (NTRS)

    Stern, Alan S.

    1996-01-01

    During the first half of this year (CY 1996), the EUVS project began preparations of the EUVS payload for the upcoming NASA sounding rocket flight 36.148CL, slated for launch on July 26, 1996 to observe and record a high-resolution (approx. 2 A FWHM) EUV spectrum of the planet Venus. These preparations were designed to improve the spectral resolution and sensitivity performance of the EUVS payload as well as prepare the payload for this upcoming mission. The following is a list of the EUVS project activities that have taken place since the beginning of this CY: (1) Applied a fresh, new SiC optical coating to our existing 2400 groove/mm grating to boost its reflectivity; (2) modified the Ranicon science detector to boost its detective quantum efficiency with the addition of a repeller grid; (3) constructed a new entrance slit plane to achieve 2 A FWHM spectral resolution; (4) prepared and held the Payload Initiation Conference (PIC) with the assigned NASA support team from Wallops Island for the upcoming 36.148CL flight (PIC held on March 8, 1996; see Attachment A); (5) began wavelength calibration activities of EUVS in the laboratory; (6) made arrangements for travel to WSMR to begin integration activities in preparation for the July 1996 launch; (7) paper detailing our previous EUVS Venus mission (NASA flight 36.117CL) published in Icarus (see Attachment B); and (8) continued data analysis of the previous EUVS mission 36.137CL (Spica occultation flight).

  10. Limb proportions show developmental plasticity in response to embryo movement

    PubMed Central

    Pollard, A. S.; Charlton, B. G.; Hutchinson, J. R.; Gustafsson, T.; McGonnell, I. M.; Timmons, J. A.; Pitsillides, A. A.

    2017-01-01

    Animals have evolved limb proportions adapted to different environments, but it is not yet clear to what extent these proportions are directly influenced by the environment during prenatal development. The developing skeleton experiences mechanical loading resulting from embryo movement. We tested the hypothesis that environmentally-induced changes in prenatal movement influence embryonic limb growth to alter proportions. We show that incubation temperature influences motility and limb bone growth in West African Dwarf crocodiles, producing altered limb proportions which may, influence post-hatching performance. Pharmacological immobilisation of embryonic chickens revealed that altered motility, independent of temperature, may underpin this growth regulation. Use of the chick also allowed us to merge histological, immunochemical and cell proliferation labelling studies to evaluate changes in growth plate organisation, and unbiased array profiling to identify specific cellular and transcriptional targets of embryo movement. This disclosed that movement alters limb proportions and regulates chondrocyte proliferation in only specific growth plates. This selective targeting is related to intrinsic mTOR (mechanistic target of rapamycin) pathway activity in individual growth plates. Our findings provide new insights into how environmental factors can be integrated to influence cellular activity in growing bones and ultimately gross limb morphology, to generate phenotypic variation during prenatal development. PMID:28165010

  11. Limb proportions show developmental plasticity in response to embryo movement.

    PubMed

    Pollard, A S; Charlton, B G; Hutchinson, J R; Gustafsson, T; McGonnell, I M; Timmons, J A; Pitsillides, A A

    2017-02-06

    Animals have evolved limb proportions adapted to different environments, but it is not yet clear to what extent these proportions are directly influenced by the environment during prenatal development. The developing skeleton experiences mechanical loading resulting from embryo movement. We tested the hypothesis that environmentally-induced changes in prenatal movement influence embryonic limb growth to alter proportions. We show that incubation temperature influences motility and limb bone growth in West African Dwarf crocodiles, producing altered limb proportions which may, influence post-hatching performance. Pharmacological immobilisation of embryonic chickens revealed that altered motility, independent of temperature, may underpin this growth regulation. Use of the chick also allowed us to merge histological, immunochemical and cell proliferation labelling studies to evaluate changes in growth plate organisation, and unbiased array profiling to identify specific cellular and transcriptional targets of embryo movement. This disclosed that movement alters limb proportions and regulates chondrocyte proliferation in only specific growth plates. This selective targeting is related to intrinsic mTOR (mechanistic target of rapamycin) pathway activity in individual growth plates. Our findings provide new insights into how environmental factors can be integrated to influence cellular activity in growing bones and ultimately gross limb morphology, to generate phenotypic variation during prenatal development.

  12. Organization of the upper limb movement for piano key-depression differs between expert pianists and novice players.

    PubMed

    Furuya, Shinichi; Kinoshita, Hiroshi

    2008-03-01

    The present study investigated the expert-novice difference in the organization of upper-limb movement for the key-depression on the piano. Kinematic and electromyographic recordings were made while experts (N = 7) and novices (N = 7) of classical-piano players performed a right hand octave keystroke to produce four different sound dynamics. The joint torque generated at the key-bottom moment (key-force torque) was also estimated. At all sound dynamics, the experts showed a larger finger attack angle, more flexed shoulder, wrist, and MP joints, more extended elbow joint, and smaller key-force torque at the MP joint than the novices. The level of co-activation in the finger flexor-extensor muscles during the period prior to the key-bottom moment was also lower for the experts. To attain the large attack angle by the experts, as the fingertip depressed the key to the bottom, their shoulder was actively flexed, the forearm was thrust forward, and the hand was rotated forward. The novices, on the other hand, actively extended their shoulder to move the forearm and hand downward to depress the key. These results confirmed a substantial difference in the key-depression movement organization between the experts and novices. These findings also suggest that experts use a synergistically organized multi-joint limb motion that allows them to minimize the biomechanical load and muscular effort to the distal muscles. The novices, on the other hand, tend to rely on a rudimentary synergy of joint motion developed through daily experience.

  13. Breaking the Sound Barrier

    ERIC Educational Resources Information Center

    Brown, Tom; Boehringer, Kim

    2007-01-01

    Students in a fourth-grade class participated in a series of dynamic sound learning centers followed by a dramatic capstone event--an exploration of the amazing Trashcan Whoosh Waves. It's a notoriously difficult subject to teach, but this hands-on, exploratory approach ignited student interest in sound, promoted language acquisition, and built…

  14. Operational sounding algorithms

    NASA Technical Reports Server (NTRS)

    Smith, W. L.

    1980-01-01

    The analytical equations used to interpret TIROS-N sounding radiances for operational applications are presented. Both the National Environmental Satellite System (NESS) Global Operational Synoptic Scale and the NESS/University of Wisconsin (UW) North American Mesoscale Sounding Production Systems are considered.

  15. Categorization of Sounds

    ERIC Educational Resources Information Center

    Smits, Roel; Sereno, Joan; Jongman, Allard

    2006-01-01

    The authors conducted 4 experiments to test the decision-bound, prototype, and distribution theories for the categorization of sounds. They used as stimuli sounds varying in either resonance frequency or duration. They created different experimental conditions by varying the variance and overlap of 2 stimulus distributions used in a training phase…

  16. The Bosstown Sound.

    ERIC Educational Resources Information Center

    Burns, Gary

    Based on the argument that (contrary to critical opinion) the musicians in the various bands associated with Bosstown Sound were indeed talented, cohesive individuals and that the bands' lack of renown was partially a result of ill-treatment by record companies and the press, this paper traces the development of the Bosstown Sound from its…

  17. Are fixed limb inertial models valid for dynamic simulations of human movement?

    PubMed

    Clark, Timothy; Hawkins, David

    2010-10-19

    During human movement, muscle activation and limb movement result in subtle changes in muscle mass distribution. Muscle mass redistribution can affect limb inertial properties and limb dynamics, but it is not currently known to what extent. The objectives of this study were to investigate: (1) how physiological alterations of muscle and tendon length affect limb inertial characteristics, and (2) how such changes affect dynamic simulations of human movement. To achieve these objectives, a digital model of a human leg, custom software, and Software for interactive musculoskeletal modeling were used to simulate mass redistribution of muscle-tendon structures within a limb segment during muscle activation and joint movement. Thigh and s