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Sample records for adaptive processing stap

  1. Adaptive OFDM waveform design for spatio-temporal-sparsity exploited STAP radar

    NASA Astrophysics Data System (ADS)

    Sen, Satyabrata; Barhen, Jacob

    2015-05-01

    We propose a sparsity-based space-time adaptive processing (STAP) algorithm to detect a slowly-moving target using an orthogonal frequency division multiplexing (OFDM) radar. The motivation of employing an OFDM signal is that it improves the target-detectability from the interfering signals by increasing the frequency diversity of the system. However, due to the addition of one extra dimension in terms of frequency, the adaptive degrees-of- freedom in an OFDM-STAP also increases. Therefore, to avoid the construction a fully-adaptive OFDM-STAP, we propose a sparsity-based STAP algorithm. We observe that the interference spectrum is inherently sparse in the spatio-temporal domain, as the clutter responses occupy only a diagonal ridge on the spatio-temporal plane and the jammer signals interfere only from a few spatial directions. Hence, we exploit that sparsity to develop an efficient STAP technique that utilizes considerably lesser number of secondary data compared to the other existing STAP techniques, and produces nearly optimum STAP performance. In addition to designing the STAP filter, we propose to optimally design the transmit OFDM signals by maximizing the output signal- to-interference-plus-noise ratio (SINR) in order to improve the STAP-performance. The computation of output SINR depends on the estimated value of the interference covariance matrix, which we obtain by applying the sparse recovery algorithm. Therefore, we analytically assess the effects of the synthesized OFDM coefficients on the sparse recovery of the interference covariance matrix by computing the coherence measure of the sparse measurement matrix. Our numerical examples demonstrate the achieved STAP-performance due to sparsity- based technique and adaptive waveform design.

  2. An Efficient Adaptive Angle-Doppler Compensation Approach for Non-Sidelooking Airborne Radar STAP.

    PubMed

    Shen, Mingwei; Yu, Jia; Wu, Di; Zhu, Daiyin

    2015-01-01

    In this study, the effects of non-sidelooking airborne radar clutter dispersion on space-time adaptive processing (STAP) is considered, and an efficient adaptive angle-Doppler compensation (EAADC) approach is proposed to improve the clutter suppression performance. In order to reduce the computational complexity, the reduced-dimension sparse reconstruction (RDSR) technique is introduced into the angle-Doppler spectrum estimation to extract the required parameters for compensating the clutter spectral center misalignment. Simulation results to demonstrate the effectiveness of the proposed algorithm are presented. PMID:26053755

  3. Non-iterative autofocus algorithm for GMTI sigma-delta STAP processing

    NASA Astrophysics Data System (ADS)

    Samczyński, P.; Pietrzyk, G.; Kulpa, K.

    2009-06-01

    The paper presents the concept of the algorithm to detect and estimate motion parameters of ground slow moving targets. Detection algorithm based on Sigma-Delta antenna with two spatial channels STAP processing. Motion parameters were estimated using novel Non Iterative Map-Drift (NIMD) technique, typically dedicated as an autofocus technique for earth imaging in SAR technique. The main goal of this paper was to extend and test NIMD technique as an algorithm for ground moving targets detected with two channels (sigma/delta) antenna.

  4. GPU implementations for fast factorizations of STAP covariance matrices

    NASA Astrophysics Data System (ADS)

    Roeder, Michael; Davis, Nolan; Furtek, Jeremy; Braunreiter, Dennis; Healy, Dennis

    2008-08-01

    One of the main goals of the STAP-BOY program has been the implementation of a space-time adaptive processing (STAP) algorithm on graphics processing units (GPUs) with the goal of reducing the processing time. Within the context of GPU implementation, we have further developed algorithms that exploit data redundancy inherent in particular STAP applications. Integration of these algorithms with GPU architecture is of primary importance for fast algorithmic processing times. STAP algorithms involve solving a linear system in which the transformation matrix is a covariance matrix. A standard method involves estimating a covariance matrix from a data matrix, computing its Cholesky factors by one of several methods, and then solving the system by substitution. Some STAP applications have redundancy in successive data matrices from which the covariance matrices are formed. For STAP applications in which a data matrix is updated with the addition of a new data row at the bottom and the elimination of the oldest data in the top of the matrix, a sequence of data matrices have multiple rows in common. Two methods have been developed for exploiting this type of data redundancy when computing Cholesky factors. These two methods are referred to as 1) Fast QR factorizations of successive data matrices 2) Fast Cholesky factorizations of successive covariance matrices. We have developed GPU implementations of these two methods. We show that these two algorithms exhibit reduced computational complexity when compared to benchmark algorithms that do not exploit data redundancy. More importantly, we show that when these algorithmic improvements are optimized for the GPU architecture, the processing times of a GPU implementation of these matrix factorization algorithms may be greatly improved.

  5. OFDM Radar Space-Time Adaptive Processing by Exploiting Spatio-Temporal Sparsity

    SciTech Connect

    Sen, Satyabrata

    2013-01-01

    We propose a sparsity-based space-time adaptive processing (STAP) algorithm to detect a slowly-moving target using an orthogonal frequency division multiplexing (OFDM) radar. We observe that the target and interference spectra are inherently sparse in the spatio-temporal domain. Hence, we exploit that sparsity to develop an efficient STAP technique that utilizes considerably lesser number of secondary data and produces an equivalent performance as the other existing STAP techniques. In addition, the use of an OFDM signal increases the frequency diversity of our system, as different scattering centers of a target resonate at different frequencies, and thus improves the target detectability. First, we formulate a realistic sparse-measurement model for an OFDM radar considering both the clutter and jammer as the interfering sources. Then, we apply a residual sparse-recovery technique based on the LASSO estimator to estimate the target and interference covariance matrices, and subsequently compute the optimal STAP-filter weights. Our numerical results demonstrate a comparative performance analysis of the proposed sparse-STAP algorithm with four other existing STAP methods. Furthermore, we discover that the OFDM-STAP filter-weights are adaptable to the frequency-variabilities of the target and interference responses, in addition to the spatio-temporal variabilities. Hence, by better utilizing the frequency variabilities, we propose an adaptive OFDM-waveform design technique, and consequently gain a significant amount of STAP-performance improvement.

  6. Frequency Adaptability and Waveform Design for OFDM Radar Space-Time Adaptive Processing

    SciTech Connect

    Sen, Satyabrata; Glover, Charles Wayne

    2012-01-01

    We propose an adaptive waveform design technique for an orthogonal frequency division multiplexing (OFDM) radar signal employing a space-time adaptive processing (STAP) technique. We observe that there are inherent variabilities of the target and interference responses in the frequency domain. Therefore, the use of an OFDM signal can not only increase the frequency diversity of our system, but also improve the target detectability by adaptively modifying the OFDM coefficients in order to exploit the frequency-variabilities of the scenario. First, we formulate a realistic OFDM-STAP measurement model considering the sparse nature of the target and interference spectra in the spatio-temporal domain. Then, we show that the optimal STAP-filter weight-vector is equal to the generalized eigenvector corresponding to the minimum generalized eigenvalue of the interference and target covariance matrices. With numerical examples we demonstrate that the resultant OFDM-STAP filter-weights are adaptable to the frequency-variabilities of the target and interference responses, in addition to the spatio-temporal variabilities. Hence, by better utilizing the frequency variabilities, we propose an adaptive OFDM-waveform design technique, and consequently gain a significant amount of STAP-performance improvement.

  7. Performance estimates of radar STAP processing on the IBM/Sony/Toshiba cell processor

    NASA Astrophysics Data System (ADS)

    Cico, Luke; Greene, Jon

    2006-05-01

    Advances in commercial off-the-shelf (COTS) embedded computing technologies have yielded impressive gains in computational throughput over the past 5-10 years. Adaptive sensor array systems utilizing real-time teraflop class machines are in wide deployment today. Gains in processor density have generally been achieved by steady improvements in semiconductor optical lithographic processes along with less frequent innovations in processor chip architectures. It is likely that the real-time embedded community is entering an era where processor architectural innovations will be bearing most of the burden for producing processing density gains as lithographic processes approach fundamental physical limitations. More and more 'systems on a chip' are emerging to address these trends. An exciting example of this technology trend is IBM's new Cell Broadband Engine (CBE) architecture which offers massive SIMD compute power on multiple computational units interconnected via a high bandwidth internal fabric. This paper explores the application of a computationally intensive adaptive nulling problem on the CBE architecture.

  8. Knowledge-Aided Multichannel Adaptive SAR/GMTI Processing: Algorithm and Experimental Results

    NASA Astrophysics Data System (ADS)

    Wu, Di; Zhu, Daiyin; Zhu, Zhaoda

    2010-12-01

    The multichannel synthetic aperture radar ground moving target indication (SAR/GMTI) technique is a simplified implementation of space-time adaptive processing (STAP), which has been proved to be feasible in the past decades. However, its detection performance will be degraded in heterogeneous environments due to the rapidly varying clutter characteristics. Knowledge-aided (KA) STAP provides an effective way to deal with the nonstationary problem in real-world clutter environment. Based on the KA STAP methods, this paper proposes a KA algorithm for adaptive SAR/GMTI processing in heterogeneous environments. It reduces sample support by its fast convergence properties and shows robust to non-stationary clutter distribution relative to the traditional adaptive SAR/GMTI scheme. Experimental clutter suppression results are employed to verify the virtue of this algorithm.

  9. A new multi-channel SAR-GMTI algorithm based on frequency STAP and FrFT

    NASA Astrophysics Data System (ADS)

    Wei, Jun; Yuan, Yunneng; Sun, Jingping; Liu, Shujun; Mao, Shiyi

    2007-11-01

    A SAR-GMTI algorithm based on space-time adaptive processing (STAP) in frequency domain by multi-channel SAR is proposed. The paper deduces the theoretical formula of the clutter suppression in-depth based on frequency STAP and finds that the output is a chirp signal and similar to the input signal of the moving targets before suppressed, so FrFT is chosen to detect them and estimate their moving parameters. The analyses in theory and simulator results show that our new algorithm is effective.

  10. An examination of the application of space time adaptive processing for the detection of maritime surface targets from high altitude airborne platforms

    NASA Astrophysics Data System (ADS)

    McDonald, Michael; Cerutti-Maori, Delphine

    2013-09-01

    An examination of the application of Space Time Adaptive Processing (STAP) techniques to real, multi-channel, medium grazing angle, radar sea clutter data is undertaken and the detection performance is quantified against simulated moving maritime surface targets. The application of sub-optimal STAP approaches to the maritime radar detection problem is shown to be complicated by non-stationarity of sea clutter and rapid variations of the sea clutter spectrum due to transient wave activity. Observed performance gains from maritime STAP are much more limited than those observed for Ground Moving Target Indication (GMTI) due to the inherent spectral width of sea clutter and the slow Doppler velocities of maritime targets. Three sub-optimal STAP processing architectures are examined and PRI-Staggered Post-Doppler is shown to provide consistently superior detection performance for the data set in question.

  11. Sparsity-Based Space-Time Adaptive Processing Using OFDM Radar

    SciTech Connect

    Sen, Satyabrata

    2012-01-01

    We propose a sparsity-based space-time adaptive processing (STAP) algorithm to detect a slowly-moving target using an orthogonal frequency division multiplexing (OFDM) radar. We observe that the target and interference spectra are inherently sparse in the spatio-temporal domain, and hence we exploit that sparsity to develop an efficient STAP technique. In addition, the use of an OFDM signal increases the frequency diversity of our system, as different scattering centers of a target resonate at different frequencies, and thus improves the target detectability. First, we formulate a realistic sparse-measurement model for an OFDM radar considering both the clutter and jammer as the interfering sources. Then, we show that the optimal STAP-filter weight-vector is equal to the generalized eigenvector corresponding to the minimum generalized eigenvalue of the interference and target covariance matrices. To estimate the target and interference covariance matrices, we apply a residual sparse-recovery technique that enables us to incorporate the partially known support of the sparse vector. Our numerical results demonstrate that the sparsity-based STAP algorithm, with considerably lesser number of secondary data, produces an equivalent performance as the other existing STAP techniques.

  12. PAPR-Constrained Pareto-Optimal Waveform Design for OFDM-STAP Radar

    SciTech Connect

    Sen, Satyabrata

    2014-01-01

    We propose a peak-to-average power ratio (PAPR) constrained Pareto-optimal waveform design approach for an orthogonal frequency division multiplexing (OFDM) radar signal to detect a target using the space-time adaptive processing (STAP) technique. The use of an OFDM signal does not only increase the frequency diversity of our system, but also enables us to adaptively design the OFDM coefficients in order to further improve the system performance. First, we develop a parametric OFDM-STAP measurement model by considering the effects of signaldependent clutter and colored noise. Then, we observe that the resulting STAP-performance can be improved by maximizing the output signal-to-interference-plus-noise ratio (SINR) with respect to the signal parameters. However, in practical scenarios, the computation of output SINR depends on the estimated values of the spatial and temporal frequencies and target scattering responses. Therefore, we formulate a PAPR-constrained multi-objective optimization (MOO) problem to design the OFDM spectral parameters by simultaneously optimizing four objective functions: maximizing the output SINR, minimizing two separate Cramer-Rao bounds (CRBs) on the normalized spatial and temporal frequencies, and minimizing the trace of CRB matrix on the target scattering coefficients estimations. We present several numerical examples to demonstrate the achieved performance improvement due to the adaptive waveform design.

  13. Low-rank matrix decomposition and spatio-temporal sparse recovery for STAP radar

    DOE PAGESBeta

    Sen, Satyabrata

    2015-08-04

    We develop space-time adaptive processing (STAP) methods by leveraging the advantages of sparse signal processing techniques in order to detect a slowly-moving target. We observe that the inherent sparse characteristics of a STAP problem can be formulated as the low-rankness of clutter covariance matrix when compared to the total adaptive degrees-of-freedom, and also as the sparse interference spectrum on the spatio-temporal domain. By exploiting these sparse properties, we propose two approaches for estimating the interference covariance matrix. In the first approach, we consider a constrained matrix rank minimization problem (RMP) to decompose the sample covariance matrix into a low-rank positivemore » semidefinite and a diagonal matrix. The solution of RMP is obtained by applying the trace minimization technique and the singular value decomposition with matrix shrinkage operator. Our second approach deals with the atomic norm minimization problem to recover the clutter response-vector that has a sparse support on the spatio-temporal plane. We use convex relaxation based standard sparse-recovery techniques to find the solutions. With extensive numerical examples, we demonstrate the performances of proposed STAP approaches with respect to both the ideal and practical scenarios, involving Doppler-ambiguous clutter ridges, spatial and temporal decorrelation effects. As a result, the low-rank matrix decomposition based solution requires secondary measurements as many as twice the clutter rank to attain a near-ideal STAP performance; whereas the spatio-temporal sparsity based approach needs a considerably small number of secondary data.« less

  14. Low-rank matrix decomposition and spatio-temporal sparse recovery for STAP radar

    SciTech Connect

    Sen, Satyabrata

    2015-08-04

    We develop space-time adaptive processing (STAP) methods by leveraging the advantages of sparse signal processing techniques in order to detect a slowly-moving target. We observe that the inherent sparse characteristics of a STAP problem can be formulated as the low-rankness of clutter covariance matrix when compared to the total adaptive degrees-of-freedom, and also as the sparse interference spectrum on the spatio-temporal domain. By exploiting these sparse properties, we propose two approaches for estimating the interference covariance matrix. In the first approach, we consider a constrained matrix rank minimization problem (RMP) to decompose the sample covariance matrix into a low-rank positive semidefinite and a diagonal matrix. The solution of RMP is obtained by applying the trace minimization technique and the singular value decomposition with matrix shrinkage operator. Our second approach deals with the atomic norm minimization problem to recover the clutter response-vector that has a sparse support on the spatio-temporal plane. We use convex relaxation based standard sparse-recovery techniques to find the solutions. With extensive numerical examples, we demonstrate the performances of proposed STAP approaches with respect to both the ideal and practical scenarios, involving Doppler-ambiguous clutter ridges, spatial and temporal decorrelation effects. As a result, the low-rank matrix decomposition based solution requires secondary measurements as many as twice the clutter rank to attain a near-ideal STAP performance; whereas the spatio-temporal sparsity based approach needs a considerably small number of secondary data.

  15. A combined STAP/DPCA algorithm for enhanced endoclutter target detection

    NASA Astrophysics Data System (ADS)

    Medl, Thomas

    2014-05-01

    Displaced Phase Center Antenna (DPCA) and Space-Time Adaptive Processing (STAP) are two general methods to cancel clutter in order to detect small, slowly moving targets that may be obscured by clutter. To detect these targets, the radar detection threshold needs to be as low as possible to ensure some minimum probability of detection (Pd). Unfortunately, lowering the radar threshold naturally results in a higher false alarm rate. Although there are standard methods such as M of N to reduce the false alarms, new techniques can potentially drive the false alarm rate down even further. Many "theoretical" papers have shown that STAP can be designed to outperform DPCA because of its potential additional "degrees-of-freedom". However, in "practice," this isn't always the case. For example, it is well known that STAP can have training issues in heterogeneous clutter. Typically, a radar signal processor will implement one method or the other to detect these small endoclutter targets. The technique being explored here is a two-fold approach in which the existing STAP code first processes the data in order to find a list of candidate targets. Next, a DPCA technique is also used to find a separate list of candidate detections from the same data. Although the algorithms are working on the same data, the processing is "independent" between them so the target lists are different. After both techniques have finished processing, the modified radar signal processing code "intelligently" combines the two detection lists into a single detection list. It will be shown that the combined list of detections from the two methods results in better detection performance than either method used separately.

  16. Power and Performance Trade-offs for Space Time Adaptive Processing

    SciTech Connect

    Gawande, Nitin A.; Manzano Franco, Joseph B.; Tumeo, Antonino; Tallent, Nathan R.; Kerbyson, Darren J.; Hoisie, Adolfy

    2015-07-27

    Computational efficiency – performance relative to power or energy – is one of the most important concerns when designing RADAR processing systems. This paper analyzes power and performance trade-offs for a typical Space Time Adaptive Processing (STAP) application. We study STAP implementations for CUDA and OpenMP on two computationally efficient architectures, Intel Haswell Core I7-4770TE and NVIDIA Kayla with a GK208 GPU. We analyze the power and performance of STAP’s computationally intensive kernels across the two hardware testbeds. We also show the impact and trade-offs of GPU optimization techniques. We show that data parallelism can be exploited for efficient implementation on the Haswell CPU architecture. The GPU architecture is able to process large size data sets without increase in power requirement. The use of shared memory has a significant impact on the power requirement for the GPU. A balance between the use of shared memory and main memory access leads to an improved performance in a typical STAP application.

  17. Augmenting synthetic aperture radar with space time adaptive processing

    NASA Astrophysics Data System (ADS)

    Riedl, Michael; Potter, Lee C.; Ertin, Emre

    2013-05-01

    Wide-area persistent radar video offers the ability to track moving targets. A shortcoming of the current technology is an inability to maintain track when Doppler shift places moving target returns co-located with strong clutter. Further, the high down-link data rate required for wide-area imaging presents a stringent system bottleneck. We present a multi-channel approach to augment the synthetic aperture radar (SAR) modality with space time adaptive processing (STAP) while constraining the down-link data rate to that of a single antenna SAR system. To this end, we adopt a multiple transmit, single receive (MISO) architecture. A frequency division design for orthogonal transmit waveforms is presented; the approach maintains coherence on clutter, achieves the maximal unaliased band of radial velocities, retains full resolution SAR images, and requires no increase in receiver data rate vis-a-vis the wide-area SAR modality. For Nt transmit antennas and N samples per pulse, the enhanced sensing provides a STAP capability with Nt times larger range bins than the SAR mode, at the cost of O(log N) more computations per pulse. The proposed MISO system and the associated signal processing are detailed, and the approach is numerically demonstrated via simulation of an airborne X-band system.

  18. S-TAP Program in Elementary Education.

    ERIC Educational Resources Information Center

    Concordia Coll., Moorhead, MN.

    In September 1971, Concordia College in Minnesota developed the Self-Teacher Actualization Program (S-TAP). This program enabled junior year elementary education majors to be involved daily with the teaching of children through clinical experiences in the public schools in five curriculum areas (reading, language arts, social studies, math, and…

  19. An application of space-time adaptive processing to airborne and spaceborne monostatic and bistatic radar systems

    NASA Astrophysics Data System (ADS)

    Czernik, Richard James

    A challenging problem faced by Ground Moving Target Indicator (GMTI) radars on both airborne and spaceborne platforms is the ability to detect slow moving targets due the presence of non-stationary and heterogeneous ground clutter returns. Space-Time Adaptive Processing techniques process both the spatial signals from an antenna array as well as radar pulses simultaneously to aid in mitigating this clutter which has an inherent Doppler shift due to radar platform motion, as well as spreading across Angle-Doppler space attributable to a variety of factors. Additional problems such as clutter aliasing, widening of the clutter notch, and range dependency add additional complexity when the radar is bistatic in nature, and vary significantly as the bistatic radar geometry changes with respect to the targeted location. The most difficult situation is that of a spaceborne radar system due to its high velocity and altitude with respect to the earth. A spaceborne system does however offer several advantages over an airborne system, such as the ability to cover wide areas and to provide access to areas denied to airborne platforms. This dissertation examines both monostatic and bistatic radar performance based upon a computer simulation developed by the author, and explores the use of both optimal STAP and reduced dimension STAP architectures to mitigate the modeled clutter returns. Factors such as broadband jamming, wind, and earth rotation are considered, along with their impact on the interference covariance matrix, constructed from sample training data. Calculation of the covariance matrix in near real time based upon extracted training data is computer processor intensive and reduced dimension STAP architectures relieve some of the computation burden. The problems resulting from extending both monostatic and bistatic radar systems to space are also simulated and studied.

  20. Riemannian mean and space-time adaptive processing using projection and inversion algorithms

    NASA Astrophysics Data System (ADS)

    Balaji, Bhashyam; Barbaresco, Frédéric

    2013-05-01

    The estimation of the covariance matrix from real data is required in the application of space-time adaptive processing (STAP) to an airborne ground moving target indication (GMTI) radar. A natural approach to estimation of the covariance matrix that is based on the information geometry has been proposed. In this paper, the output of the Riemannian mean is used in inversion and projection algorithms. It is found that the projection class of algorithms can yield very significant gains, even when the gains due to inversion-based algorithms are marginal over standard algorithms. The performance of the projection class of algorithms does not appear to be overly sensitive to the projected subspace dimension.

  1. Results of an attempt to reproduce the STAP phenomenon

    PubMed Central

    Aizawa, Shinichi

    2016-01-01

    In 2014, Obokata and colleagues reported their observation of a novel cell reprogramming phenomenon they named ‘stimulus-triggered acquisition of pluripotency’ (STAP). The most conclusive evidence for the pluripotency of so-called STAP cells was the purported ability of such cells to contribute to chimera formation. Here, I report the results of an attempt by Haruko Obokata to replicate the phenomenon under the supervision of the Scientific Validity Examination Team of RIKEN. In this follow-up study, putative STAP cells prepared by Haruko Obokata were injected into 1051 embryos, of which 591 were recovered. However, the injected cells made no significant contribution in any tissue in any of the embryos that developed. PMID:27610221

  2. Results of an attempt to reproduce the STAP phenomenon.

    PubMed

    Aizawa, Shinichi

    2016-01-01

    In 2014, Obokata and colleagues reported their observation of a novel cell reprogramming phenomenon they named 'stimulus-triggered acquisition of pluripotency' (STAP). The most conclusive evidence for the pluripotency of so-called STAP cells was the purported ability of such cells to contribute to chimera formation. Here, I report the results of an attempt by Haruko Obokata to replicate the phenomenon under the supervision of the Scientific Validity Examination Team of RIKEN. In this follow-up study, putative STAP cells prepared by Haruko Obokata were injected into 1051 embryos, of which 591 were recovered. However, the injected cells made no significant contribution in any tissue in any of the embryos that developed. PMID:27610221

  3. The Acid Test for Biological Science: STAP Cells, Trust, and Replication.

    PubMed

    Lancaster, Cheryl

    2016-02-01

    In January 2014, a letter and original research article were published in Nature describing a process whereby somatic mouse cells could be converted into stem cells by subjecting them to stress. These "stimulus-triggered acquisition of pluripotency" (STAP) cells were shown to be capable of contributing to all cell types of a developing embryo, and extra-embryonic tissues. The lead author of the publications, Haruko Obokata, became an overnight celebrity in Japan, where she was dubbed the new face of Japanese science. However, in the weeks that followed publication of the research, issues arose. Other laboratories and researchers (including authors on the original papers) found that they were unable to replicate Obokata et al.'s work. Closer scrutiny of the papers by the scientific community also suggested that there was manipulation of images that had been published, and Obokata was accused of misconduct. Those who should have been supervising her work (also her co-authors on the publications) were also heavily criticised. The STAP cell saga of 2014 is used as an example to highlight the importance of trust and replication in twenty-first century biological science. The role of trust in the scientific community is highlighted, and the effects on interactions between science and the public examined. Similarly, this essay aims to highlight the importance of replication, and how this is understood by researchers, the media, and the public. The expected behaviour of scientists in the twenty-first century is now more closely scrutinised. PMID:25649070

  4. Study Of Adaptive-Array Signal Processing

    NASA Technical Reports Server (NTRS)

    Satorius, Edgar H.; Griffiths, Lloyd

    1990-01-01

    Report describes study of adaptive signal-processing techniques for suppression of mutual satellite interference in mobile (on ground)/satellite communication system. Presents analyses and numerical simulations of performances of two approaches to signal processing for suppression of interference. One approach, known as "adaptive side lobe canceling", second called "adaptive temporal processing".

  5. The Southern Twenty-centimeter All-sky Polarization Survey (STAPS)

    NASA Astrophysics Data System (ADS)

    Haverkorn, Marijke; Gaensler, Bryan; McConnell, David; McClure-Griffiths, Naomi; Carretti, Ettore; Kesteven, Michael; Heiles, Carl

    2008-04-01

    The Southern Twenty-centimeter All-sky Polarization Survey (STAPS) is proposed as a piggyback project on the S-band Polarization All-sky Survey (P560). STAPS will survey the polarized radio continuum sky from 1300 to 1800MHz at 15' resolution to probe Galactic magnetism through Faraday rotation, mostly at higher latitudes where Faraday rotation is modest. Combination of STAPS with S-PASS will significantly enhance the quality of obtainable rotation measures, especially at high latitudes. Furthermore, STAPS is envisioned to be an essential part of a global effort to map the polarized radio sky at almost contiguous frequencies from 80MHz to 2400MHz. With this frequency coverage, individual RM components along sightlines can be deconvolved with unprecedented RM resolution and dynamic range, enabling three-dimensional mapping of the Galactic magnetic field. The 1.4GHz H-OH receiver used for STAPS is to be placed off-axis next to the 2.3GHz S-PASS receiver, so that data of both surveys can be simultaneously taken. Calculations of the radiation and instrumental polarization patterns across the beam for the off-axis receiver indicate that the expected instrumental polarization is between 0.3% and 0.9% (without corrections). We request zero observing hours this semester.

  6. The Southern Twenty-centimeter All-sky Polarization Survey (STAPS)

    NASA Astrophysics Data System (ADS)

    Haverkorn, Marijke; Gaensler, Bryan; McConnell, David; McClure-Griffiths, Naomi; Carretti, Ettore; Kesteven, Michael; Wolleben, Maik; Heiles, Carl

    2008-10-01

    The Southern Twenty-centimeter All-sky Polarization Survey (STAPS) is a piggyback project on the S-PASS survey (P560). STAPS surveys the polarized radio continuum sky from 1300 to 1800MHz at 15' resolution to probe Galactic magnetism through Faraday rotation, mostly at higher latitudes where Faraday rotation is modest. Combination of STAPS with S-PASS will significantly enhance the quality of obtainable rotation measures, especially at high latitudes. Furthermore, STAPS is envisioned to be an essential part of a global effort to map the polarized radio sky at almost contiguous frequencies from 80MHz to 2400MHz (also P617, PI Wolleben). With this frequency coverage, individual RM components along sightlines can be deconvolved with unprecedented RM resolution and dynamic range, enabling three-dimensional mapping of the Galactic magnetic field. The 1.4GHz H-OH receiver used for STAPS is placed off-axis next to the 2.3GHz S-PASS receiver, allowing simultaneous datataking in both surveys. The first observing run last semester was encouraging. On-the-fly checking of data looked good, including good performance of the quarter-wave plate across the band.

  7. Investigations in adaptive processing of multispectral data

    NASA Technical Reports Server (NTRS)

    Kriegler, F. J.; Horwitz, H. M.

    1973-01-01

    Adaptive data processing procedures are applied to the problem of classifying objects in a scene scanned by multispectral sensor. These procedures show a performance improvement over standard nonadaptive techniques. Some sources of error in classification are identified and those correctable by adaptive processing are discussed. Experiments in adaptation of signature means by decision-directed methods are described. Some of these methods assume correlation between the trajectories of different signature means; for others this assumption is not made.

  8. Investigation of the cellular reprogramming phenomenon referred to as stimulus-triggered acquisition of pluripotency (STAP)

    PubMed Central

    Niwa, Hitoshi

    2016-01-01

    In January 2014, it was reported that strong external stimuli, such as a transient low-pH stressor, was capable of inducing the reprogramming of mammalian somatic cells, resulting in the generation of pluripotent cells. This cellular reprograming event was designated ‘stimulus-triggered acquisition of pluripotency’ (STAP) by the authors of these reports. However, after multiple instances of scientific misconduct in the handling and presentation of the data were brought to light, both reports were retracted. To investigate the actual scientific significance of the purported STAP phenomenon, we sought to repeat the original experiments based on the methods presented in the retracted manuscripts and other relevant information. As a result, we have concluded that the STAP phenomenon as described in the original studies is not reproducible. PMID:27292224

  9. Optical Profilometers Using Adaptive Signal Processing

    NASA Technical Reports Server (NTRS)

    Hall, Gregory A.; Youngquist, Robert; Mikhael, Wasfy

    2006-01-01

    A method of adaptive signal processing has been proposed as the basis of a new generation of interferometric optical profilometers for measuring surfaces. The proposed profilometers would be portable, hand-held units. Sizes could be thus reduced because the adaptive-signal-processing method would make it possible to substitute lower-power coherent light sources (e.g., laser diodes) for white light sources and would eliminate the need for most of the optical components of current white-light profilometers. The adaptive-signal-processing method would make it possible to attain scanning ranges of the order of decimeters in the proposed profilometers.

  10. Adaptive filtering in biological signal processing.

    PubMed

    Iyer, V K; Ploysongsang, Y; Ramamoorthy, P A

    1990-01-01

    The high dependence of conventional optimal filtering methods on the a priori knowledge of the signal and noise statistics render them ineffective in dealing with signals whose statistics cannot be predetermined accurately. Adaptive filtering methods offer a better alternative, since the a priori knowledge of statistics is less critical, real time processing is possible, and the computations are less expensive for this approach. Adaptive filtering methods compute the filter coefficients "on-line", converging to the optimal values in the least-mean square (LMS) error sense. Adaptive filtering is therefore apt for dealing with the "unknown" statistics situation and has been applied extensively in areas like communication, speech, radar, sonar, seismology, and biological signal processing and analysis for channel equalization, interference and echo canceling, line enhancement, signal detection, system identification, spectral analysis, beamforming, modeling, control, etc. In this review article adaptive filtering in the context of biological signals is reviewed. An intuitive approach to the underlying theory of adaptive filters and its applicability are presented. Applications of the principles in biological signal processing are discussed in a manner that brings out the key ideas involved. Current and potential future directions in adaptive biological signal processing are also discussed. PMID:2180633

  11. Neural Adaptation Effects in Conceptual Processing

    PubMed Central

    Marino, Barbara F. M.; Borghi, Anna M.; Gemmi, Luca; Cacciari, Cristina; Riggio, Lucia

    2015-01-01

    We investigated the conceptual processing of nouns referring to objects characterized by a highly typical color and orientation. We used a go/no-go task in which we asked participants to categorize each noun as referring or not to natural entities (e.g., animals) after a selective adaptation of color-edge neurons in the posterior LV4 region of the visual cortex was induced by means of a McCollough effect procedure. This manipulation affected categorization: the green-vertical adaptation led to slower responses than the green-horizontal adaptation, regardless of the specific color and orientation of the to-be-categorized noun. This result suggests that the conceptual processing of natural entities may entail the activation of modality-specific neural channels with weights proportional to the reliability of the signals produced by these channels during actual perception. This finding is discussed with reference to the debate about the grounded cognition view. PMID:26264031

  12. The Southern Twenty-centimeter All-sky Polarization Survey (STAPS)

    NASA Astrophysics Data System (ADS)

    Haverkorn, Marijke; Gaensler, Bryan; McConnell, David; McClure-Griffiths, Naomi; Carretti, Ettore; Kesteven, Michael; Wolleben, Maik; Heiles, Carl

    2009-10-01

    This is the fourth semester proposal for the large project P624, the Southern Twenty-centimeter All-sky Polarization Survey (STAPS), a 1.4GHz broadband all-sky survey which started as a piggy-back survey on the 2.3GHz survey S-PASS (P560). STAPS/S-PASS take data in long azimuth scans at fixed elevation. Starting times of scans are determined exactly, so that scans cover adjacent bands across the sky, eventually resulting in a Nyquist-coverage of the southern sky. The science goals of STAPS focus on the Galactic interstellar medium and magnetism. Using rotation measure synthesis, we can disentangle synchrotron emitting and Faraday rotating sources along the line of sight, allowing a new view of the polarized radio sky. The data will be used to advance models of the large-scale Galactic magnetic field, for characterization of depolarization and interstellar turbulence and for studies of magnetism in discrete structures such as supernova remnants. On- and off-axis instrumental polarization will be characterized and removed. Initial calibration indicates on-axis instrumental polarization of about one percent, which is expected to go down using more sophisticated calibration methods.

  13. The Southern Twenty-centimeter All-sky Polarization Survey (STAPS)

    NASA Astrophysics Data System (ADS)

    Haverkorn, Marijke; Gaensler, Bryan; McConnell, David; McClure-Griffiths, Naomi; Carretti, Ettore; Kesteven, Michael; Wolleben, Maik; Heiles, Carl

    2009-04-01

    This is the third semester proposal for the large project P624, the Southern Twenty-centimeter All-sky Polarization Survey (STAPS), a 1.4GHz broadband all-sky survey piggy-backing on the 2.3GHz survey S-PASS (P560). STAPS/S-PASS take data in long azimuth scans at fixed elevation. Starting times of scans are determined exactly, so that scans cover adjacent bands across the sky, eventually resulting in a Nyquist-coverage of the southern sky. The science goals of STAPS focus on the Galactic interstellar medium and magnetism. Using rotation measure synthesis, we can disentangle synchrotron emitting and Faraday rotating sources along the line of sight, allowing a new view of the polarized radio sky. The data will be used to advance models of the large-scale Galactic magnetic field, for characterization of depolarization and interstellar turbulence and for studies of magnetism in discrete structures such as supernova remnants. On- and off-axis instrumental polarization will be characterized and removed. Initial calibration indicates on-axis instrumental polarization of about one percent, which is expected to go down using more sophisticated calibration methods.

  14. A Novel Approach for Adaptive Signal Processing

    NASA Technical Reports Server (NTRS)

    Chen, Ya-Chin; Juang, Jer-Nan

    1998-01-01

    Adaptive linear predictors have been used extensively in practice in a wide variety of forms. In the main, their theoretical development is based upon the assumption of stationarity of the signals involved, particularly with respect to the second order statistics. On this basis, the well-known normal equations can be formulated. If high- order statistical stationarity is assumed, then the equivalent normal equations involve high-order signal moments. In either case, the cross moments (second or higher) are needed. This renders the adaptive prediction procedure non-blind. A novel procedure for blind adaptive prediction has been proposed and considerable implementation has been made in our contributions in the past year. The approach is based upon a suitable interpretation of blind equalization methods that satisfy the constant modulus property and offers significant deviations from the standard prediction methods. These blind adaptive algorithms are derived by formulating Lagrange equivalents from mechanisms of constrained optimization. In this report, other new update algorithms are derived from the fundamental concepts of advanced system identification to carry out the proposed blind adaptive prediction. The results of the work can be extended to a number of control-related problems, such as disturbance identification. The basic principles are outlined in this report and differences from other existing methods are discussed. The applications implemented are speech processing, such as coding and synthesis. Simulations are included to verify the novel modelling method.

  15. Contrast Adaptation Implies Two Spatiotemporal Channels but Three Adapting Processes

    ERIC Educational Resources Information Center

    Langley, Keith; Bex, Peter J.

    2007-01-01

    The contrast gain control model of adaptation predicts that the effects of contrast adaptation correlate with contrast sensitivity. This article reports that the effects of high contrast spatiotemporal adaptors are maximum when adapting around 19 Hz, which is a factor of two or more greater than the peak in contrast sensitivity. To explain the…

  16. Coping and adaptation process during puerperium

    PubMed Central

    Muñoz de Rodríguez, Lucy; Ruiz de Cárdenas, Carmen Helena

    2012-01-01

    Introduction: The puerperium is a stage that produces changes and adaptations in women, couples and family. Effective coping, during this stage, depends on the relationship between the demands of stressful or difficult situations and the recourses that the puerperal individual has. Roy (2004), in her Middle Range Theory about the Coping and Adaptation Processing, defines Coping as the ''behavioral and cognitive efforts that a person makes to meet the environment demands''. For the puerperal individual, the correct coping is necessary to maintain her physical and mental well being, especially against situations that can be stressful like breastfeeding and return to work. According to Lazarus and Folkman (1986), a resource for coping is to have someone who receives emotional support, informative and / or tangible. Objective: To review the issue of women coping and adaptation during the puerperium stage and the strategies that enhance this adaptation. Methods: search and selection of database articles: Cochrane, Medline, Ovid, ProQuest, Scielo, and Blackwell Synergy. Other sources: unpublished documents by Roy, published books on Roy´s Model, Websites from of international health organizations. Results: the need to recognize the puerperium as a stage that requires comprehensive care is evident, where nurses must be protagonist with the care offered to women and their families, considering the specific demands of this situation and recourses that promote effective coping and the family, education and health services. PMID:24893059

  17. Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS)

    NASA Technical Reports Server (NTRS)

    Masek, Jeffrey G.

    2006-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) project is creating a record of forest disturbance and regrowth for North America from the Landsat satellite record, in support of the carbon modeling activities. LEDAPS relies on the decadal Landsat GeoCover data set supplemented by dense image time series for selected locations. Imagery is first atmospherically corrected to surface reflectance, and then change detection algorithms are used to extract disturbance area, type, and frequency. Reuse of the MODIS Land processing system (MODAPS) architecture allows rapid throughput of over 2200 MSS, TM, and ETM+ scenes. Initial ("Beta") surface reflectance products are currently available for testing, and initial continental disturbance products will be available by the middle of 2006.

  18. Adaptation of photosynthetic processes to stress.

    PubMed

    Berry, J A

    1975-05-01

    I have focused on examples of plant adaptations to environmental conditions that range from adjustments in the allocation of metabolic resources and modification of structural components to entirely separate mechanisms. The result of these modifications is more efficient performance under the stresses typically encountered in the plants' native habitats. Such adaptations, for reasons which are not entirely clear, often lead to poorer performance in other environmental conditions. This situation may be a fundamental basis for the tendency toward specialization among plants native to specific niches or habitats. The evolutionary mechanisms that have resulted in these specializations are very large-scale processes. It seems reasonable to suppose that the plants native to particular habitats are relatively efficient in terms of the limitations imposed by those habitats, and that the adaptive mechanisms these plants possess are, compared to those which have evolved in competing organisms, the most succesful biological means of coping with the environmental stresses encountered. I believe that we can learn from nature and utilize the adaptive mechanisms of these plants in agriculture to replace in part our present reliance on resources and energy to modify the environment for plant growth. By analogy with natural systems, improved resource utilization will require specialization and greater knowledge of the limitations of a particular environment and plant genotype. For example, the cultural conditions, plant architecture, and physiological responses necessary to achieve high water use efficiency from our crop species with C(4) photosynthesis probably differ from those required to achieve maximum total growth. Also, efforts to control water application to eliminate waste carry with them the risk that the crop could be injured by inadequate water. Thus, greater demands would be placed on the crop physiologist, the plant breeder, and the farmer. Planting and appropriate

  19. The Urban Adaptation and Adaptation Process of Urban Migrant Children: A Qualitative Study

    ERIC Educational Resources Information Center

    Liu, Yang; Fang, Xiaoyi; Cai, Rong; Wu, Yang; Zhang, Yaofang

    2009-01-01

    This article employs qualitative research methods to explore the urban adaptation and adaptation processes of Chinese migrant children. Through twenty-one in-depth interviews with migrant children, the researchers discovered: The participant migrant children showed a fairly high level of adaptation to the city; their process of urban adaptation…

  20. STAP-2 Protein Expression in B16F10 Melanoma Cells Positively Regulates Protein Levels of Tyrosinase, Which Determines Organs to Infiltrate in the Body*

    PubMed Central

    Sekine, Yuichi; Togi, Sumihito; Muromoto, Ryuta; Kon, Shigeyuki; Kitai, Yuichi; Yoshimura, Akihiko; Oritani, Kenji; Matsuda, Tadashi

    2015-01-01

    Melanoma is the most serious type of skin cancer, with a highly metastatic phenotype. In this report, we show that signal transducing adaptor protein 2 (STAP-2) is involved in cell migration, proliferation, and melanogenesis as well as chemokine receptor expression and tumorigenesis in B16F10 melanoma cells. This was evident in mice injected with STAP-2 shRNA (shSTAP-2)-expressing B16F10 cells, which infiltrated organs in a completely different pattern from the original cells, showing massive colonization in the liver, kidney, and neck but not in the lung. The most important finding was that STAP-2 expression determined tyrosinase protein content. STAP-2 colocalized with tyrosinase in lysosomes and protected tyrosinase from protein degradation. It is noteworthy that B16F10 cells with knocked down tyrosinase showed similar cell characteristics as shSTAP-2 cells. These results indicated that tyrosinase contributed to some cellular events beyond melanogenesis. Taken together, one possibility is that STAP-2 positively regulates the protein levels of tyrosinase, which determines tumor invasion via controlling chemokine receptor expression. PMID:26023234

  1. Linearly-Constrained Adaptive Signal Processing Methods

    NASA Astrophysics Data System (ADS)

    Griffiths, Lloyd J.

    1988-01-01

    In adaptive least-squares estimation problems, a desired signal d(n) is estimated using a linear combination of L observation values samples xi (n), x2(n), . . . , xL-1(n) and denoted by the vector X(n). The estimate is formed as the inner product of this vector with a corresponding L-dimensional weight vector W. One particular weight vector of interest is Wopt which minimizes the mean-square between d(n) and the estimate. In this context, the term `mean-square difference' is a quadratic measure such as statistical expectation or time average. The specific value of W which achieves the minimum is given by the prod-uct of the inverse data covariance matrix and the cross-correlation between the data vector and the desired signal. The latter is often referred to as the P-vector. For those cases in which time samples of both the desired and data vector signals are available, a variety of adaptive methods have been proposed which will guarantee that an iterative weight vector Wa(n) converges (in some sense) to the op-timal solution. Two which have been extensively studied are the recursive least-squares (RLS) method and the LMS gradient approximation approach. There are several problems of interest in the communication and radar environment in which the optimal least-squares weight set is of interest and in which time samples of the desired signal are not available. Examples can be found in array processing in which only the direction of arrival of the desired signal is known and in single channel filtering where the spectrum of the desired response is known a priori. One approach to these problems which has been suggested is the P-vector algorithm which is an LMS-like approximate gradient method. Although it is easy to derive the mean and variance of the weights which result with this algorithm, there has never been an identification of the corresponding underlying error surface which the procedure searches. The purpose of this paper is to suggest an alternative

  2. Reduced beamset adaptive matched field processing

    NASA Astrophysics Data System (ADS)

    Tracey, Brian; Turaga, Srinivas; Lee, Nigel

    2003-04-01

    Matched field processing (MFP) offers the possibility of improved towed array performance at endfire through range/depth discrimination of contacts. One challenge is that arrays with limited vertical aperture can often resolve only a small number of multipath arrivals. This paper explores ways to capture the array resolution by re-parametrizing the set of MFP replicas. A reduced beamset can be created by performing a singular value decomposition on the MFP replica set. Alternatively, clustering techniques can be used to generate MFP cell families, or regions of similar response. These parametrizations are applied to adaptive MFP algorithms to show speed and performance gains. The use of cell families/regions instead of individual MFP cells also provides a framework for increasing the robustness of MFP by defocusing the MFP beamforming operation. The techniques are demonstrated for shallow-water towed array scenarios. [Work sponsored by DARPA-ATO under Air Force Contract No. F19628-00-C-0002. Opinions, interpretations, conclusions, and recommendations are those of the authors and are not necessarily endorsed by the Department of Defense. Approved for Public Release, Distribution Unlimited.

  3. Flood adaptive traits and processes: an overview.

    PubMed

    Voesenek, Laurentius A C J; Bailey-Serres, Julia

    2015-04-01

    Unanticipated flooding challenges plant growth and fitness in natural and agricultural ecosystems. Here we describe mechanisms of developmental plasticity and metabolic modulation that underpin adaptive traits and acclimation responses to waterlogging of root systems and submergence of aerial tissues. This includes insights into processes that enhance ventilation of submerged organs. At the intersection between metabolism and growth, submergence survival strategies have evolved involving an ethylene-driven and gibberellin-enhanced module that regulates growth of submerged organs. Opposing regulation of this pathway is facilitated by a subgroup of ethylene-response transcription factors (ERFs), which include members that require low O₂ or low nitric oxide (NO) conditions for their stabilization. These transcription factors control genes encoding enzymes required for anaerobic metabolism as well as proteins that fine-tune their function in transcription and turnover. Other mechanisms that control metabolism and growth at seed, seedling and mature stages under flooding conditions are reviewed, as well as findings demonstrating that true endurance of submergence includes an ability to restore growth following the deluge. Finally, we highlight molecular insights obtained from natural variation of domesticated and wild species that occupy different hydrological niches, emphasizing the value of understanding natural flooding survival strategies in efforts to stabilize crop yields in flood-prone environments. PMID:25580769

  4. Adaptive, predictive controller for optimal process control

    SciTech Connect

    Brown, S.K.; Baum, C.C.; Bowling, P.S.; Buescher, K.L.; Hanagandi, V.M.; Hinde, R.F. Jr.; Jones, R.D.; Parkinson, W.J.

    1995-12-01

    One can derive a model for use in a Model Predictive Controller (MPC) from first principles or from experimental data. Until recently, both methods failed for all but the simplest processes. First principles are almost always incomplete and fitting to experimental data fails for dimensions greater than one as well as for non-linear cases. Several authors have suggested the use of a neural network to fit the experimental data to a multi-dimensional and/or non-linear model. Most networks, however, use simple sigmoid functions and backpropagation for fitting. Training of these networks generally requires large amounts of data and, consequently, very long training times. In 1993 we reported on the tuning and optimization of a negative ion source using a special neural network[2]. One of the properties of this network (CNLSnet), a modified radial basis function network, is that it is able to fit data with few basis functions. Another is that its training is linear resulting in guaranteed convergence and rapid training. We found the training to be rapid enough to support real-time control. This work has been extended to incorporate this network into an MPC using the model built by the network for predictive control. This controller has shown some remarkable capabilities in such non-linear applications as continuous stirred exothermic tank reactors and high-purity fractional distillation columns[3]. The controller is able not only to build an appropriate model from operating data but also to thin the network continuously so that the model adapts to changing plant conditions. The controller is discussed as well as its possible use in various of the difficult control problems that face this community.

  5. Modular and Adaptive Control of Sound Processing

    NASA Astrophysics Data System (ADS)

    van Nort, Douglas

    parameters. In this view, desired gestural dynamics and sonic response are achieved through modular construction of mapping layers that are themselves subject to parametric control. Complementing this view of the design process, the work concludes with an approach in which the creation of gestural control/sound dynamics are considered in the low-level of the underlying sound model. The result is an adaptive system that is specialized to noise-based transformations that are particularly relevant in an electroacoustic music context. Taken together, these different approaches to design and evaluation result in a unified framework for creation of an instrumental system. The key point is that this framework addresses the influence that mapping structure and control dynamics have on the perceived feel of the instrument. Each of the results illustrate this using either top-down or bottom-up approaches that consider musical control context, thereby pointing to the greater potential for refined sonic articulation that can be had by combining them in the design process.

  6. Adaptation Processes in Chinese: Word Formation.

    ERIC Educational Resources Information Center

    Pasierbsky, Fritz

    The typical pattern of Chinese word formation is to have native material adapt to changed circumstances. The Chinese language neither borrows nor lends words, but it does occasionally borrow concepts. The larger cultural pattern in which this occurs is that the Chinese culture borrows, if necessary, but ensures that the act of borrowing does not…

  7. Adaptive mesh refinement for stochastic reaction-diffusion processes

    SciTech Connect

    Bayati, Basil; Chatelain, Philippe; Koumoutsakos, Petros

    2011-01-01

    We present an algorithm for adaptive mesh refinement applied to mesoscopic stochastic simulations of spatially evolving reaction-diffusion processes. The transition rates for the diffusion process are derived on adaptive, locally refined structured meshes. Convergence of the diffusion process is presented and the fluctuations of the stochastic process are verified. Furthermore, a refinement criterion is proposed for the evolution of the adaptive mesh. The method is validated in simulations of reaction-diffusion processes as described by the Fisher-Kolmogorov and Gray-Scott equations.

  8. A systematic process for adaptive concept exploration

    NASA Astrophysics Data System (ADS)

    Nixon, Janel Nicole

    several common challenges to the creation of quantitative modeling and simulation environments. Namely, a greater number of alternative solutions imply a greater number of design variables as well as larger ranges on those variables. This translates to a high-dimension combinatorial problem. As the size and dimensionality of the solution space gets larger, the number of physically impossible solutions within that space greatly increases. Thus, the ratio of feasible design space to infeasible space decreases, making it much harder to not only obtain a good quantitative sample of the space, but to also make sense of that data. This is especially the case in the early stages of design, where it is not practical to dedicate a great deal of resources to performing thorough, high-fidelity analyses on all the potential solutions. To make quantitative analyses feasible in these early stages of design, a method is needed that allows for a relatively sparse set of information to be collected quickly and efficiently, and yet, that information needs to be meaningful enough with which to base a decision. The method developed to address this need uses a Systematic Process for Adaptive Concept Exploration (SPACE). In the SPACE method, design space exploration occurs in a sequential fashion; as data is acquired, the sampling scheme adapts to the specific problem at hand. Previously gathered data is used to make inferences about the nature of the problem so that future samples can be taken from the more interesting portions of the design space. Furthermore, the SPACE method identifies those analyses that have significant impacts on the relationships being modeled, so that effort can be focused on acquiring only the most pertinent information. The SPACE method uses a four-part sampling scheme to efficiently uncover the parametric relationships between the design variables and responses. Step 1 aims to identify the location of infeasible space within the region of interest using an initial

  9. Adaptive Processes in Thalamus and Cortex Revealed by Silencing of Primary Visual Cortex during Contrast Adaptation.

    PubMed

    King, Jillian L; Lowe, Matthew P; Stover, Kurt R; Wong, Aimee A; Crowder, Nathan A

    2016-05-23

    Visual adaptation illusions indicate that our perception is influenced not only by the current stimulus but also by what we have seen in the recent past. Adaptation to stimulus contrast (the relative luminance created by edges or contours in a scene) induces the perception of the stimulus fading away and increases the contrast detection threshold in psychophysical tests [1, 2]. Neural correlates of contrast adaptation have been described throughout the visual system including the retina [3], dorsal lateral geniculate nucleus (dLGN) [4, 5], primary visual cortex (V1) [6], and parietal cortex [7]. The apparent ubiquity of adaptation at all stages raises the question of how this process cascades across brain regions [8]. Focusing on V1, adaptation could be inherited from pre-cortical stages, arise from synaptic depression at the thalamo-cortical synapse [9], or develop locally, but what is the weighting of these contributions? Because contrast adaptation in mouse V1 is similar to classical animal models [10, 11], we took advantage of the optogenetic tools available in mice to disentangle the processes contributing to adaptation in V1. We disrupted cortical adaptation by optogenetically silencing V1 and found that adaptation measured in V1 now resembled that observed in dLGN. Thus, the majority of adaptation seen in V1 neurons arises through local activity-dependent processes, with smaller contributions from dLGN inheritance and synaptic depression at the thalamo-cortical synapse. Furthermore, modeling indicates that divisive scaling of the weakly adapted dLGN input can predict some of the emerging features of V1 adaptation. PMID:27112300

  10. Adaptive Constructive Processes and the Future of Memory

    ERIC Educational Resources Information Center

    Schacter, Daniel L.

    2012-01-01

    Memory serves critical functions in everyday life but is also prone to error. This article examines adaptive constructive processes, which play a functional role in memory and cognition but can also produce distortions, errors, and illusions. The article describes several types of memory errors that are produced by adaptive constructive processes…

  11. Adaptation to Work: An Exploration of Processes and Outcomes.

    ERIC Educational Resources Information Center

    Ashley, William L.; And Others

    A study of adaptation to work as both a process and an outcome was conducted. The study was conducted by personal interview that probed adaptation with respect to work's organizational, performance, interpersonal, responsibility, and affective aspects; and by questionnaire using the same aspects. The population studied consisted of persons without…

  12. Adaptive Noise Suppression Using Digital Signal Processing

    NASA Technical Reports Server (NTRS)

    Kozel, David; Nelson, Richard

    1996-01-01

    A signal to noise ratio dependent adaptive spectral subtraction algorithm is developed to eliminate noise from noise corrupted speech signals. The algorithm determines the signal to noise ratio and adjusts the spectral subtraction proportion appropriately. After spectra subtraction low amplitude signals are squelched. A single microphone is used to obtain both eh noise corrupted speech and the average noise estimate. This is done by determining if the frame of data being sampled is a voiced or unvoiced frame. During unvoice frames an estimate of the noise is obtained. A running average of the noise is used to approximate the expected value of the noise. Applications include the emergency egress vehicle and the crawler transporter.

  13. Adaptive Memory: Is Survival Processing Special?

    ERIC Educational Resources Information Center

    Nairne, James S.; Pandeirada, Josefa N. S.

    2008-01-01

    Do the operating characteristics of memory continue to bear the imprints of ancestral selection pressures? Previous work in our laboratory has shown that human memory may be specially tuned to retain information processed in terms of its survival relevance. A few seconds of survival processing in an incidental learning context can produce recall…

  14. Sensory Processing Subtypes in Autism: Association with Adaptive Behavior

    ERIC Educational Resources Information Center

    Lane, Alison E.; Young, Robyn L.; Baker, Amy E. Z.; Angley, Manya T.

    2010-01-01

    Children with autism are frequently observed to experience difficulties in sensory processing. This study examined specific patterns of sensory processing in 54 children with autistic disorder and their association with adaptive behavior. Model-based cluster analysis revealed three distinct sensory processing subtypes in autism. These subtypes…

  15. Metabolic Adaptation Processes That Converge to Optimal Biomass Flux Distributions

    PubMed Central

    Altafini, Claudio; Facchetti, Giuseppe

    2015-01-01

    In simple organisms like E.coli, the metabolic response to an external perturbation passes through a transient phase in which the activation of a number of latent pathways can guarantee survival at the expenses of growth. Growth is gradually recovered as the organism adapts to the new condition. This adaptation can be modeled as a process of repeated metabolic adjustments obtained through the resilencings of the non-essential metabolic reactions, using growth rate as selection probability for the phenotypes obtained. The resulting metabolic adaptation process tends naturally to steer the metabolic fluxes towards high growth phenotypes. Quite remarkably, when applied to the central carbon metabolism of E.coli, it follows that nearly all flux distributions converge to the flux vector representing optimal growth, i.e., the solution of the biomass optimization problem turns out to be the dominant attractor of the metabolic adaptation process. PMID:26340476

  16. On adaptive robustness approach to Anti-Jam signal processing

    NASA Astrophysics Data System (ADS)

    Poberezhskiy, Y. S.; Poberezhskiy, G. Y.

    An effective approach to exploiting statistical differences between desired and jamming signals named adaptive robustness is proposed and analyzed in this paper. It combines conventional Bayesian, adaptive, and robust approaches that are complementary to each other. This combining strengthens the advantages and mitigates the drawbacks of the conventional approaches. Adaptive robustness is equally applicable to both jammers and their victim systems. The capabilities required for realization of adaptive robustness in jammers and victim systems are determined. The employment of a specific nonlinear robust algorithm for anti-jam (AJ) processing is described and analyzed. Its effectiveness in practical situations has been proven analytically and confirmed by simulation. Since adaptive robustness can be used by both sides in electronic warfare, it is more advantageous for the fastest and most intelligent side. Many results obtained and discussed in this paper are also applicable to commercial applications such as communications in unregulated or poorly regulated frequency ranges and systems with cognitive capabilities.

  17. Adaptive constructive processes and the future of memory

    PubMed Central

    Schacter, Daniel L.

    2013-01-01

    Memory serves critical functions in everyday life, but is also prone to error. This article examines adaptive constructive processes, which play a functional role in memory and cognition but can also produce distortions, errors, or illusions. The article describes several types of memory errors that are produced by adaptive constructive processes, and focuses in particular on the process of imagining or simulating events that might occur in one’s personal future. Simulating future events relies on many of the same cognitive and neural processes as remembering past events, which may help to explain why imagination and memory can be easily confused. The article considers both pitfalls and adaptive aspects of future event simulation in the context of research on planning, prediction, problem solving, mind-wandering, prospective and retrospective memory, coping and positivity bias, and the interconnected set of brain regions known as the default network. PMID:23163437

  18. Dynamic analysis of neural encoding by point process adaptive filtering.

    PubMed

    Eden, Uri T; Frank, Loren M; Barbieri, Riccardo; Solo, Victor; Brown, Emery N

    2004-05-01

    Neural receptive fields are dynamic in that with experience, neurons change their spiking responses to relevant stimuli. To understand how neural systems adapt their representations of biological information, analyses of receptive field plasticity from experimental measurements are crucial. Adaptive signal processing, the well-established engineering discipline for characterizing the temporal evolution of system parameters, suggests a framework for studying the plasticity of receptive fields. We use the Bayes' rule Chapman-Kolmogorov paradigm with a linear state equation and point process observation models to derive adaptive filters appropriate for estimation from neural spike trains. We derive point process filter analogues of the Kalman filter, recursive least squares, and steepest-descent algorithms and describe the properties of these new filters. We illustrate our algorithms in two simulated data examples. The first is a study of slow and rapid evolution of spatial receptive fields in hippocampal neurons. The second is an adaptive decoding study in which a signal is decoded from ensemble neural spiking activity as the receptive fields of the neurons in the ensemble evolve. Our results provide a paradigm for adaptive estimation for point process observations and suggest a practical approach for constructing filtering algorithms to track neural receptive field dynamics on a millisecond timescale. PMID:15070506

  19. Adaptation.

    PubMed

    Broom, Donald M

    2006-01-01

    The term adaptation is used in biology in three different ways. It may refer to changes which occur at the cell and organ level, or at the individual level, or at the level of gene action and evolutionary processes. Adaptation by cells, especially nerve cells helps in: communication within the body, the distinguishing of stimuli, the avoidance of overload and the conservation of energy. The time course and complexity of these mechanisms varies. Adaptive characters of organisms, including adaptive behaviours, increase fitness so this adaptation is evolutionary. The major part of this paper concerns adaptation by individuals and its relationships to welfare. In complex animals, feed forward control is widely used. Individuals predict problems and adapt by acting before the environmental effect is substantial. Much of adaptation involves brain control and animals have a set of needs, located in the brain and acting largely via motivational mechanisms, to regulate life. Needs may be for resources but are also for actions and stimuli which are part of the mechanism which has evolved to obtain the resources. Hence pigs do not just need food but need to be able to carry out actions like rooting in earth or manipulating materials which are part of foraging behaviour. The welfare of an individual is its state as regards its attempts to cope with its environment. This state includes various adaptive mechanisms including feelings and those which cope with disease. The part of welfare which is concerned with coping with pathology is health. Disease, which implies some significant effect of pathology, always results in poor welfare. Welfare varies over a range from very good, when adaptation is effective and there are feelings of pleasure or contentment, to very poor. A key point concerning the concept of individual adaptation in relation to welfare is that welfare may be good or poor while adaptation is occurring. Some adaptation is very easy and energetically cheap and

  20. Applying statistical process control to the adaptive rate control problem

    NASA Astrophysics Data System (ADS)

    Manohar, Nelson R.; Willebeek-LeMair, Marc H.; Prakash, Atul

    1997-12-01

    Due to the heterogeneity and shared resource nature of today's computer network environments, the end-to-end delivery of multimedia requires adaptive mechanisms to be effective. We present a framework for the adaptive streaming of heterogeneous media. We introduce the application of online statistical process control (SPC) to the problem of dynamic rate control. In SPC, the goal is to establish (and preserve) a state of statistical quality control (i.e., controlled variability around a target mean) over a process. We consider the end-to-end streaming of multimedia content over the internet as the process to be controlled. First, at each client, we measure process performance and apply statistical quality control (SQC) with respect to application-level requirements. Then, we guide an adaptive rate control (ARC) problem at the server based on the statistical significance of trends and departures on these measurements. We show this scheme facilitates handling of heterogeneous media. Last, because SPC is designed to monitor long-term process performance, we show that our online SPC scheme could be used to adapt to various degrees of long-term (network) variability (i.e., statistically significant process shifts as opposed to short-term random fluctuations). We develop several examples and analyze its statistical behavior and guarantees.

  1. Prism adaptation in virtual and natural contexts: Evidence for a flexible adaptive process.

    PubMed

    Veilleux, Louis-Nicolas; Proteau, Luc

    2015-01-01

    Prism exposure when aiming at a visual target in a virtual condition (e.g., when the hand is represented by a video representation) produces no or only small adaptations (after-effects), whereas prism exposure in a natural condition produces large after-effects. Some researchers suggested that this difference may arise from distinct adaptive processes, but other studies suggested a unique process. The present study reconciled these conflicting interpretations. Forty participants were divided into two groups: One group used visual feedback of their hand (natural context), and the other group used computer-generated representational feedback (virtual context). Visual feedback during adaptation was concurrent or terminal. All participants underwent laterally displacing prism perturbation. The results showed that the after-effects were twice as large in the "natural context" than in the "virtual context". No significant differences were observed between the concurrent and terminal feedback conditions. The after-effects generalized to untested targets and workspace. These results suggest that prism adaptation in virtual and natural contexts involves the same process. The smaller after-effects in the virtual context suggest that the depth of adaptation is a function of the degree of convergence between the proprioceptive and visual information that arises from the hand. PMID:25338188

  2. Behavioral training promotes multiple adaptive processes following acute hearing loss

    PubMed Central

    Keating, Peter; Rosenior-Patten, Onayomi; Dahmen, Johannes C; Bell, Olivia; King, Andrew J

    2016-01-01

    The brain possesses a remarkable capacity to compensate for changes in inputs resulting from a range of sensory impairments. Developmental studies of sound localization have shown that adaptation to asymmetric hearing loss can be achieved either by reinterpreting altered spatial cues or by relying more on those cues that remain intact. Adaptation to monaural deprivation in adulthood is also possible, but appears to lack such flexibility. Here we show, however, that appropriate behavioral training enables monaurally-deprived adult humans to exploit both of these adaptive processes. Moreover, cortical recordings in ferrets reared with asymmetric hearing loss suggest that these forms of plasticity have distinct neural substrates. An ability to adapt to asymmetric hearing loss using multiple adaptive processes is therefore shared by different species and may persist throughout the lifespan. This highlights the fundamental flexibility of neural systems, and may also point toward novel therapeutic strategies for treating sensory disorders. DOI: http://dx.doi.org/10.7554/eLife.12264.001 PMID:27008181

  3. Assessing the Process of Marital Adaptation: The Marital Coping Inventory.

    ERIC Educational Resources Information Center

    Zborowski, Lydia L.; Berman, William H.

    Studies on coping with life events identify marriage as a distinct situational stressor, in which a wide range of coping strategies specific to the marital relationship are employed. This study examined the process of martial adaptation, identified as a style of coping, in 116 married volunteers. Subjects completed a demographic questionnaire, the…

  4. Adaptive control of surface finish in automated turning processes

    NASA Astrophysics Data System (ADS)

    García-Plaza, E.; Núñez, P. J.; Martín, A. R.; Sanz, A.

    2012-04-01

    The primary aim of this study was to design and develop an on-line control system of finished surfaces in automated machining process by CNC turning. The control system consisted of two basic phases: during the first phase, surface roughness was monitored through cutting force signals; the second phase involved a closed-loop adaptive control system based on data obtained during the monitoring of the cutting process. The system ensures that surfaces roughness is maintained at optimum values by adjusting the feed rate through communication with the PLC of the CNC machine. A monitoring and adaptive control system has been developed that enables the real-time monitoring of surface roughness during CNC turning operations. The system detects and prevents faults in automated turning processes, and applies corrective measures during the cutting process that raise quality and reliability reducing the need for quality control.

  5. Adaptive process control using fuzzy logic and genetic algorithms

    NASA Technical Reports Server (NTRS)

    Karr, C. L.

    1993-01-01

    Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented.

  6. Adaptive Process Control with Fuzzy Logic and Genetic Algorithms

    NASA Technical Reports Server (NTRS)

    Karr, C. L.

    1993-01-01

    Researchers at the U.S. Bureau of Mines have developed adaptive process control systems in which genetic algorithms (GA's) are used to augment fuzzy logic controllers (FLC's). GA's are search algorithms that rapidly locate near-optimum solutions to a wide spectrum of problems by modeling the search procedures of natural genetics. FLC's are rule based systems that efficiently manipulate a problem environment by modeling the 'rule-of-thumb' strategy used in human decision-making. Together, GA's and FLC's possess the capabilities necessary to produce powerful, efficient, and robust adaptive control systems. To perform efficiently, such control systems require a control element to manipulate the problem environment, an analysis element to recognize changes in the problem environment, and a learning element to adjust to the changes in the problem environment. Details of an overall adaptive control system are discussed. A specific laboratory acid-base pH system is used to demonstrate the ideas presented.

  7. Epidemic processes over adaptive state-dependent networks

    NASA Astrophysics Data System (ADS)

    Ogura, Masaki; Preciado, Victor M.

    2016-06-01

    In this paper we study the dynamics of epidemic processes taking place in adaptive networks of arbitrary topology. We focus our study on the adaptive susceptible-infected-susceptible (ASIS) model, where healthy individuals are allowed to temporarily cut edges connecting them to infected nodes in order to prevent the spread of the infection. In this paper we derive a closed-form expression for a lower bound on the epidemic threshold of the ASIS model in arbitrary networks with heterogeneous node and edge dynamics. For networks with homogeneous node and edge dynamics, we show that the resulting lower bound is proportional to the epidemic threshold of the standard SIS model over static networks, with a proportionality constant that depends on the adaptation rates. Furthermore, based on our results, we propose an efficient algorithm to optimally tune the adaptation rates in order to eradicate epidemic outbreaks in arbitrary networks. We confirm the tightness of the proposed lower bounds with several numerical simulations and compare our optimal adaptation rates with popular centrality measures.

  8. Epidemic processes over adaptive state-dependent networks.

    PubMed

    Ogura, Masaki; Preciado, Victor M

    2016-06-01

    In this paper we study the dynamics of epidemic processes taking place in adaptive networks of arbitrary topology. We focus our study on the adaptive susceptible-infected-susceptible (ASIS) model, where healthy individuals are allowed to temporarily cut edges connecting them to infected nodes in order to prevent the spread of the infection. In this paper we derive a closed-form expression for a lower bound on the epidemic threshold of the ASIS model in arbitrary networks with heterogeneous node and edge dynamics. For networks with homogeneous node and edge dynamics, we show that the resulting lower bound is proportional to the epidemic threshold of the standard SIS model over static networks, with a proportionality constant that depends on the adaptation rates. Furthermore, based on our results, we propose an efficient algorithm to optimally tune the adaptation rates in order to eradicate epidemic outbreaks in arbitrary networks. We confirm the tightness of the proposed lower bounds with several numerical simulations and compare our optimal adaptation rates with popular centrality measures. PMID:27415289

  9. Thermodynamic Costs of Information Processing in Sensory Adaptation

    PubMed Central

    Sartori, Pablo; Granger, Léo; Lee, Chiu Fan; Horowitz, Jordan M.

    2014-01-01

    Biological sensory systems react to changes in their surroundings. They are characterized by fast response and slow adaptation to varying environmental cues. Insofar as sensory adaptive systems map environmental changes to changes of their internal degrees of freedom, they can be regarded as computational devices manipulating information. Landauer established that information is ultimately physical, and its manipulation subject to the entropic and energetic bounds of thermodynamics. Thus the fundamental costs of biological sensory adaptation can be elucidated by tracking how the information the system has about its environment is altered. These bounds are particularly relevant for small organisms, which unlike everyday computers, operate at very low energies. In this paper, we establish a general framework for the thermodynamics of information processing in sensing. With it, we quantify how during sensory adaptation information about the past is erased, while information about the present is gathered. This process produces entropy larger than the amount of old information erased and has an energetic cost bounded by the amount of new information written to memory. We apply these principles to the E. coli's chemotaxis pathway during binary ligand concentration changes. In this regime, we quantify the amount of information stored by each methyl group and show that receptors consume energy in the range of the information-theoretic minimum. Our work provides a basis for further inquiries into more complex phenomena, such as gradient sensing and frequency response. PMID:25503948

  10. Adaptive Sampling for Learning Gaussian Processes Using Mobile Sensor Networks

    PubMed Central

    Xu, Yunfei; Choi, Jongeun

    2011-01-01

    This paper presents a novel class of self-organizing sensing agents that adaptively learn an anisotropic, spatio-temporal Gaussian process using noisy measurements and move in order to improve the quality of the estimated covariance function. This approach is based on a class of anisotropic covariance functions of Gaussian processes introduced to model a broad range of spatio-temporal physical phenomena. The covariance function is assumed to be unknown a priori. Hence, it is estimated by the maximum a posteriori probability (MAP) estimator. The prediction of the field of interest is then obtained based on the MAP estimate of the covariance function. An optimal sampling strategy is proposed to minimize the information-theoretic cost function of the Fisher Information Matrix. Simulation results demonstrate the effectiveness and the adaptability of the proposed scheme. PMID:22163785

  11. Adoption: biological and social processes linked to adaptation.

    PubMed

    Grotevant, Harold D; McDermott, Jennifer M

    2014-01-01

    Children join adoptive families through domestic adoption from the public child welfare system, infant adoption through private agencies, and international adoption. Each pathway presents distinctive developmental opportunities and challenges. Adopted children are at higher risk than the general population for problems with adaptation, especially externalizing, internalizing, and attention problems. This review moves beyond the field's emphasis on adoptee-nonadoptee differences to highlight biological and social processes that affect adaptation of adoptees across time. The experience of stress, whether prenatal, postnatal/preadoption, or during the adoption transition, can have significant impacts on the developing neuroendocrine system. These effects can contribute to problems with physical growth, brain development, and sleep, activating cascading effects on social, emotional, and cognitive development. Family processes involving contact between adoptive and birth family members, co-parenting in gay and lesbian adoptive families, and racial socialization in transracially adoptive families affect social development of adopted children into adulthood. PMID:24016275

  12. Addressing the need for adaptable decision processes within healthcare software.

    PubMed

    Miseldine, P; Taleb-Bendiab, A; England, D; Randles, M

    2007-03-01

    In the healthcare sector, where the decisions made by software aid in the direct treatment of patients, software requires high levels of assurance to ensure the correct interpretation of the tasks it is automating. This paper argues that introducing adaptable decision processes within eHealthcare initiatives can reduce software-maintenance complexity and, due to the instantaneous, distributed deployment of decision models, allow for quicker updates of current best practice, thereby improving patient care. The paper provides a description of a collection of technologies and tools that can be used to provide the required adaptation in a decision process. These tools are evaluated against two case studies that individually highlight different requirements in eHealthcare: a breast-cancer decision-support system, in partnership with several of the UK's leading cancer hospitals, and a dental triage in partnership with the Royal Liverpool Hospital which both show how the complete process flow of software can be abstracted and adapted, and the benefits that arise as a result. PMID:17365643

  13. An SDR-Based Real-Time Testbed for GNSS Adaptive Array Anti-Jamming Algorithms Accelerated by GPU.

    PubMed

    Xu, Hailong; Cui, Xiaowei; Lu, Mingquan

    2016-01-01

    Nowadays, software-defined radio (SDR) has become a common approach to evaluate new algorithms. However, in the field of Global Navigation Satellite System (GNSS) adaptive array anti-jamming, previous work has been limited due to the high computational power demanded by adaptive algorithms, and often lack flexibility and configurability. In this paper, the design and implementation of an SDR-based real-time testbed for GNSS adaptive array anti-jamming accelerated by a Graphics Processing Unit (GPU) are documented. This testbed highlights itself as a feature-rich and extendible platform with great flexibility and configurability, as well as high computational performance. Both Space-Time Adaptive Processing (STAP) and Space-Frequency Adaptive Processing (SFAP) are implemented with a wide range of parameters. Raw data from as many as eight antenna elements can be processed in real-time in either an adaptive nulling or beamforming mode. To fully take advantage of the parallelism resource provided by the GPU, a batched method in programming is proposed. Tests and experiments are conducted to evaluate both the computational and anti-jamming performance. This platform can be used for research and prototyping, as well as a real product in certain applications. PMID:26978363

  14. An SDR-Based Real-Time Testbed for GNSS Adaptive Array Anti-Jamming Algorithms Accelerated by GPU

    PubMed Central

    Xu, Hailong; Cui, Xiaowei; Lu, Mingquan

    2016-01-01

    Nowadays, software-defined radio (SDR) has become a common approach to evaluate new algorithms. However, in the field of Global Navigation Satellite System (GNSS) adaptive array anti-jamming, previous work has been limited due to the high computational power demanded by adaptive algorithms, and often lack flexibility and configurability. In this paper, the design and implementation of an SDR-based real-time testbed for GNSS adaptive array anti-jamming accelerated by a Graphics Processing Unit (GPU) are documented. This testbed highlights itself as a feature-rich and extendible platform with great flexibility and configurability, as well as high computational performance. Both Space-Time Adaptive Processing (STAP) and Space-Frequency Adaptive Processing (SFAP) are implemented with a wide range of parameters. Raw data from as many as eight antenna elements can be processed in real-time in either an adaptive nulling or beamforming mode. To fully take advantage of the parallelism resource provided by the GPU, a batched method in programming is proposed. Tests and experiments are conducted to evaluate both the computational and anti-jamming performance. This platform can be used for research and prototyping, as well as a real product in certain applications. PMID:26978363

  15. Studying the star formation process with adaptive optics

    NASA Astrophysics Data System (ADS)

    Menard, Francois; Dougados, Catherine; Duchene, Gaspard; Bouvier, Jerome; Duvert, Gilles; Lavalley, Claudia; Monin, Jean-Louis; Beuzit, Jean-Luc

    2000-07-01

    Young Stellar Objects (YSOs) are the builders of worlds. During its infancy, a star transforms ordinary interstellar dust particles into astronomical gold: planets to say the process is complex, and largely unknown to data. Yet, violent and spectacular events of mass ejection are witnessed, disks in keplerian rotation are detected, multiple stars dancing around each other are found. These are as many traces of the stellar and planet formation process. The high angular resolution provided by adaptive optics, and the related gain in sensitivity, have allowed major breakthrough discoveries to be made in each of these specific fields and our understanding of the various physical processes involved in the formation of a star has leaped forward tremendously over the last few years. In the following, meant as a report of the progress made recently in star formation due to adaptive optics, we will describe new results obtained at optical and near- infrared wavelengths, in imaging and spectroscopic modes. Our images of accretion disks and ionized stellar jets permit direct measurements of many physical parameters and shed light into the physics of the accretion and ejection processes. Although the accretion/ejection process so fundamental to star formation is usually studied around single objects, most of young stars form as part of multiple systems. We also present our findings on how the fraction of stars in binary systems evolves with age. The implications of these results on the conditions under which these stars must have formed are discussed.

  16. Parallel Processing of Adaptive Meshes with Load Balancing

    NASA Technical Reports Server (NTRS)

    Das, Sajal K.; Harvey, Daniel J.; Biswas, Rupak; Biegel, Bryan (Technical Monitor)

    2001-01-01

    Many scientific applications involve grids that lack a uniform underlying structure. These applications are often also dynamic in nature in that the grid structure significantly changes between successive phases of execution. In parallel computing environments, mesh adaptation of unstructured grids through selective refinement/coarsening has proven to be an effective approach. However, achieving load balance while minimizing interprocessor communication and redistribution costs is a difficult problem. Traditional dynamic load balancers are mostly inadequate because they lack a global view of system loads across processors. In this paper, we propose a novel and general-purpose load balancer that utilizes symmetric broadcast networks (SBN) as the underlying communication topology, and compare its performance with a successful global load balancing environment, called PLUM, specifically created to handle adaptive unstructured applications. Our experimental results on an IBM SP2 demonstrate that the SBN-based load balancer achieves lower redistribution costs than that under PLUM by overlapping processing and data migration.

  17. Optimal and adaptive methods of processing hydroacoustic signals (review)

    NASA Astrophysics Data System (ADS)

    Malyshkin, G. S.; Sidel'nikov, G. B.

    2014-09-01

    Different methods of optimal and adaptive processing of hydroacoustic signals for multipath propagation and scattering are considered. Advantages and drawbacks of the classical adaptive (Capon, MUSIC, and Johnson) algorithms and "fast" projection algorithms are analyzed for the case of multipath propagation and scattering of strong signals. The classical optimal approaches to detecting multipath signals are presented. A mechanism of controlled normalization of strong signals is proposed to automatically detect weak signals. The results of simulating the operation of different detection algorithms for a linear equidistant array under multipath propagation and scattering are presented. An automatic detector is analyzed, which is based on classical or fast projection algorithms, which estimates the background proceeding from median filtering or the method of bilateral spatial contrast.

  18. Adaptive neural information processing with dynamical electrical synapses

    PubMed Central

    Xiao, Lei; Zhang, Dan-ke; Li, Yuan-qing; Liang, Pei-ji; Wu, Si

    2013-01-01

    The present study investigates a potential computational role of dynamical electrical synapses in neural information process. Compared with chemical synapses, electrical synapses are more efficient in modulating the concerted activity of neurons. Based on the experimental data, we propose a phenomenological model for short-term facilitation of electrical synapses. The model satisfactorily reproduces the phenomenon that the neuronal correlation increases although the neuronal firing rates attenuate during the luminance adaptation. We explore how the stimulus information is encoded in parallel by firing rates and correlated activity of neurons, and find that dynamical electrical synapses mediate a transition from the firing rate code to the correlation one during the luminance adaptation. The latter encodes the stimulus information by using the concerted, but lower neuronal firing rate, and hence is economically more efficient. PMID:23596413

  19. Adaptive-optics optical coherence tomography processing using a graphics processing unit.

    PubMed

    Shafer, Brandon A; Kriske, Jeffery E; Kocaoglu, Omer P; Turner, Timothy L; Liu, Zhuolin; Lee, John Jaehwan; Miller, Donald T

    2014-01-01

    Graphics processing units are increasingly being used for scientific computing for their powerful parallel processing abilities, and moderate price compared to super computers and computing grids. In this paper we have used a general purpose graphics processing unit to process adaptive-optics optical coherence tomography (AOOCT) images in real time. Increasing the processing speed of AOOCT is an essential step in moving the super high resolution technology closer to clinical viability. PMID:25570838

  20. On Cognition, Structured Sequence Processing, and Adaptive Dynamical Systems

    NASA Astrophysics Data System (ADS)

    Petersson, Karl Magnus

    2008-11-01

    Cognitive neuroscience approaches the brain as a cognitive system: a system that functionally is conceptualized in terms of information processing. We outline some aspects of this concept and consider a physical system to be an information processing device when a subclass of its physical states can be viewed as representational/cognitive and transitions between these can be conceptualized as a process operating on these states by implementing operations on the corresponding representational structures. We identify a generic and fundamental problem in cognition: sequentially organized structured processing. Structured sequence processing provides the brain, in an essential sense, with its processing logic. In an approach addressing this problem, we illustrate how to integrate levels of analysis within a framework of adaptive dynamical systems. We note that the dynamical system framework lends itself to a description of asynchronous event-driven devices, which is likely to be important in cognition because the brain appears to be an asynchronous processing system. We use the human language faculty and natural language processing as a concrete example through out.

  1. Adaptive ocean acoustic processing for a shallow ocean experiment

    SciTech Connect

    Candy, J.V.; Sullivan, E.J.

    1995-07-19

    A model-based approach is developed to solve an adaptive ocean acoustic signal processing problem. Here we investigate the design of model-based identifier (MBID) for a normal-mode model developed from a shallow water ocean experiment and then apply it to a set of experimental data demonstrating the feasibility of this approach. In this problem we show how the processor can be structured to estimate the horizontal wave numbers directly from measured pressure sound speed thereby eliminating the need for synthetic aperture processing or a propagation model solution. Ocean acoustic signal processing has made great strides over the past decade necessitated by the development of quieter submarines and the recent proliferation of diesel powered vessels.

  2. [Super sweet corn hybrids adaptability for industrial processing. I freezing].

    PubMed

    Alfonzo, Braunnier; Camacho, Candelario; Ortiz de Bertorelli, Ligia; De Venanzi, Frank

    2002-09-01

    With the purpose of evaluating adaptability to the freezing process of super sweet corn sh2 hybrids Krispy King, Victor and 324, 100 cobs of each type were frozen at -18 degrees C. After 120 days of storage, their chemical, microbiological and sensorial characteristics were compared with a sweet corn su. Industrial quality of the process of freezing and length and number of rows in cobs were also determined. Results revealed yields above 60% in frozen corns. Length and number of rows in cobs were acceptable. Most of the chemical characteristics of super sweet hybrids were not different from the sweet corn assayed at the 5% significance level. Moisture content and soluble solids of hybrid Victor, as well as total sugars of hybrid 324 were statistically different. All sh2 corns had higher pH values. During freezing, soluble solids concentration, sugars and acids decreased whereas pH increased. Frozen cobs exhibited acceptable microbiological rank, with low activities of mesophiles and total coliforms, absence of psychrophiles and fecal coliforms, and an appreciable amount of molds. In conclusion, sh2 hybrids adapted with no problems to the freezing process, they had lower contents of soluble solids and higher contents of total sugars, which almost doubled the amount of su corn; flavor, texture, sweetness and appearance of kernels were also better. Hybrid Victor was preferred by the evaluating panel and had an outstanding performance due to its yield and sensorial characteristics. PMID:12448345

  3. Motion compensation for adaptive horizontal line array processing

    NASA Astrophysics Data System (ADS)

    Yang, T. C.

    2003-01-01

    Large aperture horizontal line arrays have small resolution cells and can be used to separate a target signal from an interference signal by array beamforming. High-resolution adaptive array processing can be used to place a null at the interference signal so that the array gain can be much higher than that of conventional beamforming. But these nice features are significantly degraded by the source motion, which reduces the time period under which the environment can be considered stationary from the array processing point of view. For adaptive array processing, a large number of data samples are generally required to minimize the variance of the cross-spectral density, or the covariance matrix, between the array elements. For a moving source and interference, the penalty of integrating over a large number of samples is the spread of signal and interference energy to more than one or two eigenvalues. The signal and interference are no longer clearly identified by the eigenvectors and, consequently, the ability to suppress the interference suffers. We show in this paper that the effect of source motion can be compensated for the (signal) beam covariance matrix, thus allowing integration over a large number of data samples without loss in the signal beam power. We employ an equivalent of a rotating coordinate frame to track the signal bearing change and use the waveguide invariant theory to compensate the signal range change by frequency shifting.

  4. Prediction and control of chaotic processes using nonlinear adaptive networks

    SciTech Connect

    Jones, R.D.; Barnes, C.W.; Flake, G.W.; Lee, K.; Lewis, P.S.; O'Rouke, M.K.; Qian, S.

    1990-01-01

    We present the theory of nonlinear adaptive networks and discuss a few applications. In particular, we review the theory of feedforward backpropagation networks. We then present the theory of the Connectionist Normalized Linear Spline network in both its feedforward and iterated modes. Also, we briefly discuss the theory of stochastic cellular automata. We then discuss applications to chaotic time series, tidal prediction in Venice lagoon, finite differencing, sonar transient detection, control of nonlinear processes, control of a negative ion source, balancing a double inverted pendulum and design advice for free electron lasers and laser fusion targets.

  5. Landsat ecosystem disturbance adaptive processing system (LEDAPS) algorithm description

    USGS Publications Warehouse

    Schmidt, Gail; Jenkerson, Calli; Masek, Jeffrey; Vermote, Eric; Gao, Feng

    2013-01-01

    The Landsat Ecosystem Disturbance Adaptive Processing System (LEDAPS) software was originally developed by the National Aeronautics and Space Administration–Goddard Space Flight Center and the University of Maryland to produce top-of-atmosphere reflectance from LandsatThematic Mapper and Enhanced Thematic Mapper Plus Level 1 digital numbers and to apply atmospheric corrections to generate a surface-reflectance product.The U.S. Geological Survey (USGS) has adopted the LEDAPS algorithm for producing the Landsat Surface Reflectance Climate Data Record.This report discusses the LEDAPS algorithm, which was implemented by the USGS.

  6. Simulation of dynamic processes with adaptive neural networks.

    SciTech Connect

    Tzanos, C. P.

    1998-02-03

    Many industrial processes are highly non-linear and complex. Their simulation with first-principle or conventional input-output correlation models is not satisfactory, either because the process physics is not well understood, or it is so complex that direct simulation is either not adequately accurate, or it requires excessive computation time, especially for on-line applications. Artificial intelligence techniques (neural networks, expert systems, fuzzy logic) or their combination with simple process-physics models can be effectively used for the simulation of such processes. Feedforward (static) neural networks (FNNs) can be used effectively to model steady-state processes. They have also been used to model dynamic (time-varying) processes by adding to the network input layer input nodes that represent values of input variables at previous time steps. The number of previous time steps is problem dependent and, in general, can be determined after extensive testing. This work demonstrates that for dynamic processes that do not vary fast with respect to the retraining time of the neural network, an adaptive feedforward neural network can be an effective simulator that is free of the complexities introduced by the use of input values at previous time steps.

  7. Polymer Solidification and Stabilization: Adaptable Processes for Atypical Wastes

    SciTech Connect

    Jensen, C.

    2007-07-01

    Vinyl Ester Styrene (VES) and Advanced Polymer Solidification (APS{sup TM}) processes are used to solidify, stabilize, and immobilize radioactive, pyrophoric and hazardous wastes at US Department of Energy (DOE) and Department of Defense (DOD) sites, and commercial nuclear facilities. A wide range of projects have been accomplished, including in situ immobilization of ion exchange resin and carbon filter media in decommissioned submarines; underwater solidification of zirconium and hafnium machining swarf; solidification of uranium chips; impregnation of depth filters; immobilization of mercury, lead and other hazardous wastes (including paint chips and blasting media); and in situ solidification of submerged demineralizers. Discussion of the adaptability of the VES and APS{sup TM} processes is timely, given the decommissioning work at government sites, and efforts by commercial nuclear plants to reduce inventories of one-of-a-kind wastes. The VES and APS{sup TM} media and processes are highly adaptable to a wide range of waste forms, including liquids, slurries, bead and granular media; as well as metal fines, particles and larger pieces. With the ability to solidify/stabilize liquid wastes using high-speed mixing; wet sludges and solids by low-speed mixing; or bead and granular materials through in situ processing, these polymer will produce a stable, rock-hard product that has the ability to sequester many hazardous waste components and create Class B and C stabilized waste forms for disposal. Technical assessment and approval of these solidification processes and final waste forms have been greatly simplified by exhaustive waste form testing, as well as multiple NRC and CRCPD waste form approvals. (authors)

  8. Adaptive memory: enhanced location memory after survival processing.

    PubMed

    Nairne, James S; Vanarsdall, Joshua E; Pandeirada, Josefa N S; Blunt, Janell R

    2012-03-01

    Two experiments investigated whether survival processing enhances memory for location. From an adaptive perspective, remembering that food has been located in a particular area, or that potential predators are likely to be found in a given territory, should increase the chances of subsequent survival. Participants were shown pictures of food or animals located at various positions on a computer screen. The task was to rate the ease of collecting the food or capturing the animals relative to a central fixation point. Surprise retention tests revealed that people remembered the locations of the items better when the collection or capturing task was described as relevant to survival. These data extend the generality of survival processing advantages to a new domain (location memory) by means of a task that does not involve rating the relevance of words to a scenario. PMID:22004268

  9. Adapting the transtheoretical model of change to the bereavement process.

    PubMed

    Calderwood, Kimberly A

    2011-04-01

    Theorists currently believe that bereaved people undergo some transformation of self rather than returning to their original state. To advance our understanding of this process, this article presents an adaptation of Prochaska and DiClemente's transtheoretical model of change as it could be applied to the journey that bereaved individuals experience. This theory is unique because it addresses attitudes, intentions, and behavioral processes at each stage; it allows for a focus on a broader range of emotions than just anger and depression; it allows for the recognition of two periods of regression during the bereavement process; and it adds a maintenance stage, which other theories lack. This theory can benefit bereaved individuals directly and through the increased awareness among counselors, family, friends, employers, and society at large. This theory may also be used as a tool for bereavement programs to consider whether they are meeting clients' needs throughout the transformation change bereavement process rather than only focusing on the initial stages characterized by intense emotion. PMID:21553574

  10. Adaptive model predictive process control using neural networks

    DOEpatents

    Buescher, K.L.; Baum, C.C.; Jones, R.D.

    1997-08-19

    A control system for controlling the output of at least one plant process output parameter is implemented by adaptive model predictive control using a neural network. An improved method and apparatus provides for sampling plant output and control input at a first sampling rate to provide control inputs at the fast rate. The MPC system is, however, provided with a network state vector that is constructed at a second, slower rate so that the input control values used by the MPC system are averaged over a gapped time period. Another improvement is a provision for on-line training that may include difference training, curvature training, and basis center adjustment to maintain the weights and basis centers of the neural in an updated state that can follow changes in the plant operation apart from initial off-line training data. 46 figs.

  11. Adaptive model predictive process control using neural networks

    DOEpatents

    Buescher, Kevin L.; Baum, Christopher C.; Jones, Roger D.

    1997-01-01

    A control system for controlling the output of at least one plant process output parameter is implemented by adaptive model predictive control using a neural network. An improved method and apparatus provides for sampling plant output and control input at a first sampling rate to provide control inputs at the fast rate. The MPC system is, however, provided with a network state vector that is constructed at a second, slower rate so that the input control values used by the MPC system are averaged over a gapped time period. Another improvement is a provision for on-line training that may include difference training, curvature training, and basis center adjustment to maintain the weights and basis centers of the neural in an updated state that can follow changes in the plant operation apart from initial off-line training data.

  12. Similarities in error processing establish a link between saccade prediction at baseline and adaptation performance

    PubMed Central

    Shelhamer, Mark

    2014-01-01

    Adaptive processes are crucial in maintaining the accuracy of body movements and rely on error storage and processing mechanisms. Although classically studied with adaptation paradigms, evidence of these ongoing error-correction mechanisms should also be detectable in other movements. Despite this connection, current adaptation models are challenged when forecasting adaptation ability with measures of baseline behavior. On the other hand, we have previously identified an error-correction process present in a particular form of baseline behavior, the generation of predictive saccades. This process exhibits long-term intertrial correlations that decay gradually (as a power law) and are best characterized with the tools of fractal time series analysis. Since this baseline task and adaptation both involve error storage and processing, we sought to find a link between the intertrial correlations of the error-correction process in predictive saccades and the ability of subjects to alter their saccade amplitudes during an adaptation task. Here we find just such a relationship: the stronger the intertrial correlations during prediction, the more rapid the acquisition of adaptation. This reinforces the links found previously between prediction and adaptation in motor control and suggests that current adaptation models are inadequate to capture the complete dynamics of these error-correction processes. A better understanding of the similarities in error processing between prediction and adaptation might provide the means to forecast adaptation ability with a baseline task. This would have many potential uses in physical therapy and the general design of paradigms of motor adaptation. PMID:24598520

  13. Recasting Hope: a process of adaptation following fetal anomaly diagnosis.

    PubMed

    Lalor, Joan; Begley, Cecily M; Galavan, Eoin

    2009-02-01

    Recent decades have seen ultrasound revolutionise the management of pregnancy and its possible complications. However, somewhat less consideration has been given to the psychosocial consequences of mass screening resulting in fetal anomaly detection in low-risk populations, particularly in contexts where termination of pregnancy services are not readily accessible. A grounded theory study was conducted exploring forty-one women's experiences of ultrasound diagnosis of fetal abnormality up to and beyond the birth in the Republic of Ireland. Thirty-one women chose to continue the pregnancy and ten women accessed termination of pregnancy services outside the state. Data were collected using repeated in-depth individual interviews pre- and post-birth and analysed using the constant comparative method. Recasting Hope, the process of adaptation following diagnosis is represented temporally as four phases: 'Assume Normal', 'Shock', 'Gaining Meaning' and 'Rebuilding'. Some mothers expressed a sense of incredulity when informed of the anomaly and the 'Assume Normal' phase provides an improved understanding as to why women remain unprepared for an adverse diagnosis. Transition to phase 2, 'Shock,' is characterised by receiving the diagnosis and makes explicit women's initial reactions. Once the diagnosis is confirmed, a process of 'Gaining Meaning' commences, whereby an attempt to make sense of this ostensibly negative event begins. 'Rebuilding', the final stage in the process, is concerned with the extent to which women recover from the loss and resolve the inconsistency between their experience and their previous expectations of pregnancy in particular and beliefs in the world in general. This theory contributes to the theoretical field of thanatology as applied to the process of grieving associated with the loss of an ideal child. The framework of Recasting Hope is intended for use as a tool to assist health professionals through offering simple yet effective

  14. Adaptive memory: evaluating alternative forms of fitness-relevant processing in the survival processing paradigm.

    PubMed

    Sandry, Joshua; Trafimow, David; Marks, Michael J; Rice, Stephen

    2013-01-01

    Memory may have evolved to preserve information processed in terms of its fitness-relevance. Based on the assumption that the human mind comprises different fitness-relevant adaptive mechanisms contributing to survival and reproductive success, we compared alternative fitness-relevant processing scenarios with survival processing. Participants rated words for relevancy to fitness-relevant and control conditions followed by a delay and surprise recall test (Experiment 1a). Participants recalled more words processed for their relevance to a survival situation. We replicated these findings in an online study (Experiment 2) and a study using revised fitness-relevant scenarios (Experiment 3). Across all experiments, we did not find a mnemonic benefit for alternative fitness-relevant processing scenarios, questioning assumptions associated with an evolutionary account of remembering. Based on these results, fitness-relevance seems to be too wide-ranging of a construct to account for the memory findings associated with survival processing. We propose that memory may be hierarchically sensitive to fitness-relevant processing instructions. We encourage future researchers to investigate the underlying mechanisms responsible for survival processing effects and work toward developing a taxonomy of adaptive memory. PMID:23585858

  15. Adaptive Memory: Evaluating Alternative Forms of Fitness-Relevant Processing in the Survival Processing Paradigm

    PubMed Central

    Sandry, Joshua; Trafimow, David; Marks, Michael J.; Rice, Stephen

    2013-01-01

    Memory may have evolved to preserve information processed in terms of its fitness-relevance. Based on the assumption that the human mind comprises different fitness-relevant adaptive mechanisms contributing to survival and reproductive success, we compared alternative fitness-relevant processing scenarios with survival processing. Participants rated words for relevancy to fitness-relevant and control conditions followed by a delay and surprise recall test (Experiment 1a). Participants recalled more words processed for their relevance to a survival situation. We replicated these findings in an online study (Experiment 2) and a study using revised fitness-relevant scenarios (Experiment 3). Across all experiments, we did not find a mnemonic benefit for alternative fitness-relevant processing scenarios, questioning assumptions associated with an evolutionary account of remembering. Based on these results, fitness-relevance seems to be too wide-ranging of a construct to account for the memory findings associated with survival processing. We propose that memory may be hierarchically sensitive to fitness-relevant processing instructions. We encourage future researchers to investigate the underlying mechanisms responsible for survival processing effects and work toward developing a taxonomy of adaptive memory. PMID:23585858

  16. Intermarriages between Western Women and Palestinian Men: Multidirectional Adaptation Processes

    ERIC Educational Resources Information Center

    Roer-Strier, Dorit; Ezra, Dina Ben

    2006-01-01

    This article addresses cultural adaptation of Western-Palestinian intermarried couples. Using in-depth interviews, information was gathered from 16 participants, 7 Western women and 9 Palestinian men, living in Palestinian cities in the West Bank. Adaptation strategies are typified by the extent to which each spouse embraces the partner's culture.…

  17. Analysis of dynamic deformation processes with adaptive KALMAN-filtering

    NASA Astrophysics Data System (ADS)

    Eichhorn, Andreas

    2007-05-01

    In this paper the approach of a full system analysis is shown quantifying a dynamic structural ("white-box"-) model for the calculation of thermal deformations of bar-shaped machine elements. The task was motivated from mechanical engineering searching new methods for the precise prediction and computational compensation of thermal influences in the heating and cooling phases of machine tools (i.e. robot arms, etc.). The quantification of thermal deformations under variable dynamic loads requires the modelling of the non-stationary spatial temperature distribution inside the object. Based upon FOURIERS law of heat flow the high-grade non-linear temperature gradient is represented by a system of partial differential equations within the framework of a dynamic Finite Element topology. It is shown that adaptive KALMAN-filtering is suitable to quantify relevant disturbance influences and to identify thermal parameters (i.e. thermal diffusivity) with a deviation of only 0,2%. As result an identified (and verified) parametric model for the realistic prediction respectively simulation of dynamic temperature processes is presented. Classifying the thermal bend as the main deformation quantity of bar-shaped machine tools, the temperature model is extended to a temperature deformation model. In lab tests thermal load steps are applied to an aluminum column. Independent control measurements show that the identified model can be used to predict the columns bend with a mean deviation (r.m.s.) smaller than 10 mgon. These results show that the deformation model is a precise predictor and suitable for realistic simulations of thermal deformations. Experiments with modified heat sources will be necessary to verify the model in further frequency spectra of dynamic thermal loads.

  18. Adaptivity and Autonomy Development in a Learning Personalization Process

    ERIC Educational Resources Information Center

    Verpoorten, D.

    2009-01-01

    Within the iClass (Integrated Project 507922) and Enhanced Learning Experience and Knowledge Transfer (ELEKTRA; Specific Targeted Research or Innovation Project 027986) European projects, the author was requested to harness his pedagogical knowledge to the production of educational adaptive systems. The article identifies and documents the…

  19. Neural Adaptation and Behavioral Measures of Temporal Processing and Speech Perception in Cochlear Implant Recipients

    PubMed Central

    Zhang, Fawen; Benson, Chelsea; Murphy, Dora; Boian, Melissa; Scott, Michael; Keith, Robert; Xiang, Jing; Abbas, Paul

    2013-01-01

    The objective was to determine if one of the neural temporal features, neural adaptation, can account for the across-subject variability in behavioral measures of temporal processing and speech perception performance in cochlear implant (CI) recipients. Neural adaptation is the phenomenon in which neural responses are the strongest at the beginning of the stimulus and decline following stimulus repetition (e.g., stimulus trains). It is unclear how this temporal property of neural responses relates to psychophysical measures of temporal processing (e.g., gap detection) or speech perception. The adaptation of the electrical compound action potential (ECAP) was obtained using 1000 pulses per second (pps) biphasic pulse trains presented directly to the electrode. The adaptation of the late auditory evoked potential (LAEP) was obtained using a sequence of 1-kHz tone bursts presented acoustically, through the cochlear implant. Behavioral temporal processing was measured using the Random Gap Detection Test at the most comfortable listening level. Consonant nucleus consonant (CNC) word and AzBio sentences were also tested. The results showed that both ECAP and LAEP display adaptive patterns, with a substantial across-subject variability in the amount of adaptation. No correlations between the amount of neural adaptation and gap detection thresholds (GDTs) or speech perception scores were found. The correlations between the degree of neural adaptation and demographic factors showed that CI users having more LAEP adaptation were likely to be those implanted at a younger age than CI users with less LAEP adaptation. The results suggested that neural adaptation, at least this feature alone, cannot account for the across-subject variability in temporal processing ability in the CI users. However, the finding that the LAEP adaptive pattern was less prominent in the CI group compared to the normal hearing group may suggest the important role of normal adaptation pattern at the

  20. In Experts, underlying processes that drive visuomotor adaptation are different than in Novices

    PubMed Central

    Leukel, Christian; Gollhofer, Albert; Taube, Wolfgang

    2015-01-01

    Processes responsible for improvements in motor performance are often contrasted in an explicit and an implicit part. Explicit learning enables task success by using strategic (declarative) knowledge. Implicit learning refers to a change in motor performance without conscious effort. In this study, we tested the contribution of explicit and implicit processes in a visuomotor adaptation task in subjects with different expertise in the task they were asked to adapt. Thirty handball players (Experts) and 30 subjects without handball experience (Novices) participated. Three experiments tested visuomotor adaptation of a free throw in team handball using prismatic glasses. The difference between experiments was that in Experiment 2 and 3, contribution of explicit processes was prevented, whereas Experiment 1 allowed contribution of explicit and implicit processes. Retention was assessed in Experiment 3. There were three main findings: (i) contribution of explicit processes to adaptation was stronger in Experts than Novices (Experiment 1); (ii) adaptation took longer in Experts when preventing contribution of explicit processes (Experiment 2); and (iii) retention was stronger in Experts (Experiment 3). This study shows that learning processes involved in visuomotor adaptation change by expertise, with more involvement of explicit processes and most likely other implicit processes to adaptation in Experts. PMID:25713526

  1. Flight data processing with the F-8 adaptive algorithm

    NASA Technical Reports Server (NTRS)

    Hartmann, G.; Stein, G.; Petersen, K.

    1977-01-01

    An explicit adaptive control algorithm based on maximum likelihood estimation of parameters has been designed for NASA's DFBW F-8 aircraft. To avoid iterative calculations, the algorithm uses parallel channels of Kalman filters operating at fixed locations in parameter space. This algorithm has been implemented in NASA/DFRC's Remotely Augmented Vehicle (RAV) facility. Real-time sensor outputs (rate gyro, accelerometer and surface position) are telemetered to a ground computer which sends new gain values to an on-board system. Ground test data and flight records were used to establish design values of noise statistics and to verify the ground-based adaptive software. The software and its performance evaluation based on flight data are described

  2. Adapt

    NASA Astrophysics Data System (ADS)

    Bargatze, L. F.

    2015-12-01

    Active Data Archive Product Tracking (ADAPT) is a collection of software routines that permits one to generate XML metadata files to describe and register data products in support of the NASA Heliophysics Virtual Observatory VxO effort. ADAPT is also a philosophy. The ADAPT concept is to use any and all available metadata associated with scientific data to produce XML metadata descriptions in a consistent, uniform, and organized fashion to provide blanket access to the full complement of data stored on a targeted data server. In this poster, we present an application of ADAPT to describe all of the data products that are stored by using the Common Data File (CDF) format served out by the CDAWEB and SPDF data servers hosted at the NASA Goddard Space Flight Center. These data servers are the primary repositories for NASA Heliophysics data. For this purpose, the ADAPT routines have been used to generate data resource descriptions by using an XML schema named Space Physics Archive, Search, and Extract (SPASE). SPASE is the designated standard for documenting Heliophysics data products, as adopted by the Heliophysics Data and Model Consortium. The set of SPASE XML resource descriptions produced by ADAPT includes high-level descriptions of numerical data products, display data products, or catalogs and also includes low-level "Granule" descriptions. A SPASE Granule is effectively a universal access metadata resource; a Granule associates an individual data file (e.g. a CDF file) with a "parent" high-level data resource description, assigns a resource identifier to the file, and lists the corresponding assess URL(s). The CDAWEB and SPDF file systems were queried to provide the input required by the ADAPT software to create an initial set of SPASE metadata resource descriptions. Then, the CDAWEB and SPDF data repositories were queried subsequently on a nightly basis and the CDF file lists were checked for any changes such as the occurrence of new, modified, or deleted

  3. Adaptation as a Political Process: Adjusting to Drought and Conflict in Kenya's Drylands

    NASA Astrophysics Data System (ADS)

    Eriksen, Siri; Lind, Jeremy

    2009-05-01

    In this article, we argue that people’s adjustments to multiple shocks and changes, such as conflict and drought, are intrinsically political processes that have uneven outcomes. Strengthening local adaptive capacity is a critical component of adapting to climate change. Based on fieldwork in two areas in Kenya, we investigate how people seek to access livelihood adjustment options and promote particular adaptation interests through forming social relations and political alliances to influence collective decision-making. First, we find that, in the face of drought and conflict, relations are formed among individuals, politicians, customary institutions, and government administration aimed at retaining or strengthening power bases in addition to securing material means of survival. Second, national economic and political structures and processes affect local adaptive capacity in fundamental ways, such as through the unequal allocation of resources across regions, development policy biased against pastoralism, and competition for elected political positions. Third, conflict is part and parcel of the adaptation process, not just an external factor inhibiting local adaptation strategies. Fourth, there are relative winners and losers of adaptation, but whether or not local adjustments to drought and conflict compound existing inequalities depends on power relations at multiple geographic scales that shape how conflicting interests are negotiated locally. Climate change adaptation policies are unlikely to be successful or minimize inequity unless the political dimensions of local adaptation are considered; however, existing power structures and conflicts of interests represent political obstacles to developing such policies.

  4. Structural Technology and Analysis Program (STAP) Delivery Order 0004: Durability Patch

    NASA Astrophysics Data System (ADS)

    Ikegami, Roy; Haugse, Eric; Trego, Angela; Rogers, Lynn; Maly, Joe

    2001-06-01

    Structural cracks in secondary structure, resulting from a high cycle fatigue (HCF) environment, are often referred to as nuisance cracks. This type of damage can result in costly inspections and repair. The repairs often do not last long because the repaired structure continues to respond in a resonant fashion to the environment. Although the use of materials for passive damping applications is well understood, there are few applications to high-cycle fatigue problems. This is because design information characterization temperature, resonant response frequency and strain levels are difficult to determine. The Durability Patch and Damage Dosimeter Program addressed these problems by: (1) Developing a damped repair design process which includes a methodology for designing the material and application characteristics required to optimally damp the repair. (2) Designing and developing a rugged, small, and lightweight data acquisition unit called the damage dosimeter. This is a battery operated, single board computer, capable of collecting three channels of strain and one channel of temperature, processing this data by user developed algorithms written in the C programming language, and storing the processed data in resident memory. The dosimeter is used to provide flight data needed to characterize the vibration environment. The vibration environment is then used to design the damping material characteristics and repair. The repair design methodology and dosimeter were demonstrated on B-52, C-130, and F-15 aircraft applications.

  5. Context-Aware Design for Process Flexibility and Adaptation

    ERIC Educational Resources Information Center

    Yao, Wen

    2012-01-01

    Today's organizations face continuous and unprecedented changes in their business environment. Traditional process design tools tend to be inflexible and can only support rigidly defined processes (e.g., order processing in the supply chain). This considerably restricts their real-world applications value, especially in the dynamic and…

  6. Adaptive information processing in auditory cortex. Annual report, 1 June 1987-31 May 1988

    SciTech Connect

    Weinberger, N.M.

    1988-05-31

    The fact that learning induces frequency-specific modification of receptive fields in auditory cortex implies that the functional organization of auditory (and perhaps other sensory) cortex comprises an adaptively-constituted information base. This project initiates the first systematic investigation of adaptive information processing in cerebral cortex. A major goal is to determine the circumstances under which adaptive information processing is induced by experience. This project also addresses central hypotheses about rules that govern adaptive information processing, at three levels of spatial scale: (a) parallel processing in different auditory fields: (b) modular processing in different cortical lamina within fields; (c) local processing in different neurons within the same locus within lamina. The author emphasized determining the learning circumstances under which adaptive information processing is invoked by the brain. Current studies reveal that the frequency receptive fields of neurons in the auditory cortex, and the physiologically plastic magnocellular medial geniculate nucleus, develop frequency-specific modification such that maximal shifts in tuning are at or adjacent to the signal frequency. Further, this adaptive re-tuning of neurons develops rapidly during habituation, classical conditioning, and instrumental avoidance conditioning. The generality of re-tuning has established that AIP during learning represents a general brain strategy for the acquisition and subsequent processing of information.

  7. Concurrent processing adaptation of aeroplastic analysis of propfans

    NASA Technical Reports Server (NTRS)

    Janetzke, David C.; Murthy, Durbha V.

    1990-01-01

    Discussed here is a study involving the adaptation of an advanced aeroelastic analysis program to run concurrently on a shared memory multiple processor computer. The program uses a three-dimensional compressible unsteady aerodynamic model and blade normal modes to calculate aeroelastic stability and response of propfan blades. The identification of the computational parallelism within the sequential code and the scheduling of the concurrent subtasks to minimize processor idle time are discussed. Processor idle time in the calculation of the unsteady aerodynamic coefficients was reduced by the simple strategy of appropriately ordering the computations. Speedup and efficiency results are presented for the calculation of the matched flutter point of an experimental propfan model. The results show that efficiencies above 70 percent can be obtained using the present implementation with 7 processors. The parallel computational strategy described here is also applicable to other aeroelastic analysis procedures based on panel methods.

  8. A single-rate context-dependent learning process underlies rapid adaptation to familiar object dynamics.

    PubMed

    Ingram, James N; Howard, Ian S; Flanagan, J Randall; Wolpert, Daniel M

    2011-09-01

    Motor learning has been extensively studied using dynamic (force-field) perturbations. These induce movement errors that result in adaptive changes to the motor commands. Several state-space models have been developed to explain how trial-by-trial errors drive the progressive adaptation observed in such studies. These models have been applied to adaptation involving novel dynamics, which typically occurs over tens to hundreds of trials, and which appears to be mediated by a dual-rate adaptation process. In contrast, when manipulating objects with familiar dynamics, subjects adapt rapidly within a few trials. Here, we apply state-space models to familiar dynamics, asking whether adaptation is mediated by a single-rate or dual-rate process. Previously, we reported a task in which subjects rotate an object with known dynamics. By presenting the object at different visual orientations, adaptation was shown to be context-specific, with limited generalization to novel orientations. Here we show that a multiple-context state-space model, with a generalization function tuned to visual object orientation, can reproduce the time-course of adaptation and de-adaptation as well as the observed context-dependent behavior. In contrast to the dual-rate process associated with novel dynamics, we show that a single-rate process mediates adaptation to familiar object dynamics. The model predicts that during exposure to the object across multiple orientations, there will be a degree of independence for adaptation and de-adaptation within each context, and that the states associated with all contexts will slowly de-adapt during exposure in one particular context. We confirm these predictions in two new experiments. Results of the current study thus highlight similarities and differences in the processes engaged during exposure to novel versus familiar dynamics. In both cases, adaptation is mediated by multiple context-specific representations. In the case of familiar object dynamics

  9. Adaptable Particle-in-Cell Algorithms for Graphical Processing Units

    NASA Astrophysics Data System (ADS)

    Decyk, Viktor; Singh, Tajendra

    2010-11-01

    Emerging computer architectures consist of an increasing number of shared memory computing cores in a chip, often with vector (SIMD) co-processors. Future exascale high performance systems will consist of a hierarchy of such nodes, which will require different algorithms at different levels. Since no one knows exactly how the future will evolve, we have begun development of an adaptable Particle-in-Cell (PIC) code, whose parameters can match different hardware configurations. The data structures reflect three levels of parallelism, contiguous vectors and non-contiguous blocks of vectors, which can share memory, and groups of blocks which do not. Particles are kept ordered at each time step, and the size of a sorting cell is an adjustable parameter. We have implemented a simple 2D electrostatic skeleton code whose inner loop (containing 6 subroutines) runs entirely on the NVIDIA Tesla C1060. We obtained speedups of about 16-25 compared to a 2.66 GHz Intel i7 (Nehalem), depending on the plasma temperature, with an asymptotic limit of 40 for a frozen plasma. We expect speedups of about 70 for an 2D electromagnetic code and about 100 for a 3D electromagnetic code, which have higher computational intensities (more flops/memory access).

  10. Parallel Block Structured Adaptive Mesh Refinement on Graphics Processing Units

    SciTech Connect

    Beckingsale, D. A.; Gaudin, W. P.; Hornung, R. D.; Gunney, B. T.; Gamblin, T.; Herdman, J. A.; Jarvis, S. A.

    2014-11-17

    Block-structured adaptive mesh refinement is a technique that can be used when solving partial differential equations to reduce the number of zones necessary to achieve the required accuracy in areas of interest. These areas (shock fronts, material interfaces, etc.) are recursively covered with finer mesh patches that are grouped into a hierarchy of refinement levels. Despite the potential for large savings in computational requirements and memory usage without a corresponding reduction in accuracy, AMR adds overhead in managing the mesh hierarchy, adding complex communication and data movement requirements to a simulation. In this paper, we describe the design and implementation of a native GPU-based AMR library, including: the classes used to manage data on a mesh patch, the routines used for transferring data between GPUs on different nodes, and the data-parallel operators developed to coarsen and refine mesh data. We validate the performance and accuracy of our implementation using three test problems and two architectures: an eight-node cluster, and over four thousand nodes of Oak Ridge National Laboratory’s Titan supercomputer. Our GPU-based AMR hydrodynamics code performs up to 4.87× faster than the CPU-based implementation, and has been scaled to over four thousand GPUs using a combination of MPI and CUDA.

  11. Local adaptation in Trinidadian guppies alters ecosystem processes.

    PubMed

    Bassar, Ronald D; Marshall, Michael C; López-Sepulcre, Andrés; Zandonà, Eugenia; Auer, Sonya K; Travis, Joseph; Pringle, Catherine M; Flecker, Alexander S; Thomas, Steven A; Fraser, Douglas F; Reznick, David N

    2010-02-23

    Theory suggests evolutionary change can significantly influence and act in tandem with ecological forces via ecological-evolutionary feedbacks. This theory assumes that significant evolutionary change occurs over ecologically relevant timescales and that phenotypes have differential effects on the environment. Here we test the hypothesis that local adaptation causes ecosystem structure and function to diverge. We demonstrate that populations of Trinidadian guppies (Poecilia reticulata), characterized by differences in phenotypic and population-level traits, differ in their impact on ecosystem properties. We report results from a replicated, common garden mesocosm experiment and show that differences between guppy phenotypes result in the divergence of ecosystem structure (algal, invertebrate, and detrital standing stocks) and function (gross primary productivity, leaf decomposition rates, and nutrient flux). These phenotypic effects are further modified by effects of guppy density. We evaluated the generality of these effects by replicating the experiment using guppies derived from two independent origins of the phenotype. Finally, we tested the ability of multiple guppy traits to explain observed differences in the mesocosms. Our findings demonstrate that evolution can significantly affect both ecosystem structure and function. The ecosystem differences reported here are consistent with patterns observed across natural streams and argue that guppies play a significant role in shaping these ecosystems. PMID:20133670

  12. Process- and controller-adaptations determine the physiological effects of cold acclimation.

    PubMed

    Werner, Jürgen

    2008-09-01

    Experimental results on physiological effects of cold adaptation seem confusing and apparently incompatible with one another. This paper will explain that a substantial part of such a variety of results may be deduced from a common functional concept. A core/shell treatment ("model") of the thermoregulatory system is used with mean body temperature as the controlled variable. Adaptation, as a higher control level, is introduced into the system. Due to persistent stressors, either the (heat transfer) process or the controller properties (parameters) are adjusted (or both). It is convenient to call the one "process adaptation" and the other "controller adaptation". The most commonly demonstrated effect of autonomic cold acclimation is a change in the controller threshold. The analysis shows that this necessarily means a lowering of body temperature because of a lowered metabolic rate. This explains experimental results on both Europeans in the climatic chamber and Australian Aborigines in a natural environment. Exclusive autonomic process adaptation occurs in the form of a better insulation. The analysis explains why the post-adaptive steady-state can only be achieved, if the controller system reduces metabolism and why in spite of this the new state is inevitably characterized by a rise in body temperature. If both process and controller adaptations are simultaneously present, there may be not any change of body temperature at all, e.g., as demonstrated in animal experiments. Whether this kind of adaptation delivers a decrease, an increase or no change of mean body temperature, depends on the proportion of process and controller adaptation. PMID:18026979

  13. Effects of Crowding and Attention on High-Levels of Motion Processing and Motion Adaptation

    PubMed Central

    Pavan, Andrea; Greenlee, Mark W.

    2015-01-01

    The motion after-effect (MAE) persists in crowding conditions, i.e., when the adaptation direction cannot be reliably perceived. The MAE originating from complex moving patterns spreads into non-adapted sectors of a multi-sector adapting display (i.e., phantom MAE). In the present study we used global rotating patterns to measure the strength of the conventional and phantom MAEs in crowded and non-crowded conditions, and when attention was directed to the adapting stimulus and when it was diverted away from the adapting stimulus. The results show that: (i) the phantom MAE is weaker than the conventional MAE, for both non-crowded and crowded conditions, and when attention was focused on the adapting stimulus and when it was diverted from it, (ii) conventional and phantom MAEs in the crowded condition are weaker than in the non-crowded condition. Analysis conducted to assess the effect of crowding on high-level of motion adaptation suggests that crowding is likely to affect the awareness of the adapting stimulus rather than degrading its sensory representation, (iii) for high-level of motion processing the attentional manipulation does not affect the strength of either conventional or phantom MAEs, neither in the non-crowded nor in the crowded conditions. These results suggest that high-level MAEs do not depend on attention and that at high-level of motion adaptation the effects of crowding are not modulated by attention. PMID:25615577

  14. Adaptive Memory: The Evolutionary Significance of Survival Processing.

    PubMed

    Nairne, James S; Pandeirada, Josefa N S

    2016-07-01

    A few seconds of survival processing, during which people assess the relevance of information to a survival situation, produces particularly good retention. One interpretation of this benefit is that our memory systems are optimized to process and retain fitness-relevant information. Such a "tuning" may exist, in part, because our memory systems were shaped by natural selection, using a fitness-based criterion. However, recent research suggests that traditional mnemonic processes, such as elaborative processing, may play an important role in producing the empirical benefit. Boundary conditions have been demonstrated as well, leading some to dismiss evolutionary interpretations of the phenomenon. In this article, we discuss the current state of the evolutionary account and provide a general framework for evaluating evolutionary and purportedly nonevolutionary interpretations of mnemonic phenomena. We suggest that survival processing effects are best viewed within the context of a general survival optimization system, designed by nature to help organisms deal with survival challenges. An important component of survival optimization is the ability to simulate activities that help to prevent or escape from future threats which, in turn, depends in an important way on accurate retrospective remembering of survival-relevant information. PMID:27474137

  15. A multilevel examination of the relationships among training outcomes, mediating regulatory processes, and adaptive performance.

    PubMed

    Chen, Gilad; Thomas, Brian; Wallace, J Craig

    2005-09-01

    This study examined whether cognitive, affective-motivational, and behavioral training outcomes relate to posttraining regulatory processes and adaptive performance similarly at the individual and team levels of analysis. Longitudinal data were collected from 156 individuals composing 78 teams who were trained on and then performed a simulated flight task. Results showed that posttraining regulation processes related similarly to adaptive performance across levels. Also, regulation processes fully mediated the influences of self- and collective efficacy beliefs on individual and team adaptive performance. Finally, knowledge and skill more strongly and directly related to adaptive performance at the individual than the team level of analysis. Implications to theory and practice, limitations, and future directions are discussed. PMID:16162057

  16. The Adapted Dance Process: Planning, Partnering, and Performing

    ERIC Educational Resources Information Center

    Block, Betty A.; Johnson, Peggy V.

    2011-01-01

    This article contains specific planning, partnering, and performing techniques for fully integrating dancers with special needs into a dance pedagogy program. Each aspect is discussed within the context of the domains of learning. Fundamental partnering strategies are related to each domain as part of the integration process. The authors recommend…

  17. Adaptive healthcare processes for personalized emergency clinical pathways.

    PubMed

    Poulymenopoulou, M; Papakonstantinou, D; Malamateniou, F; Vassilacopoulos, G

    2014-01-01

    Pre-hospital and in-hospital emergency healthcare delivery involves a variety of activities and people that should be coordinated in order effectively to create an emergency care plan. Emergency care provided by emergency healthcare professionals can be improved by personalized emergency clinical pathways that are instances of relevant emergency clinical guidelines based on emergency case needs as well as on ambulance and hospital resource availability, while also enabling better resource use. Business Process Management Systems (BPMSs) in conjunction with semantic technologies can be used to support personalized emergency clinical pathways by incorporating clinical guidelines logic into the emergency healthcare processes at run-time according to emergency care context information (current emergency case and resource information). On these grounds, a framework is proposed that uses ontology to model knowledge on emergency case medical history, on healthcare resource availability, on relevant clinical guidelines and on process logic; this is inferred to result in the most suitable process model for the case, in line with relevant clinical guidelines. PMID:25160219

  18. Computer simulation program is adaptable to industrial processes

    NASA Technical Reports Server (NTRS)

    Schultz, F. E.

    1966-01-01

    The Reaction kinetics ablation program /REKAP/, developed to simulate ablation of various materials, provides mathematical formulations for computer programs which can simulate certain industrial processes. The programs are based on the use of nonsymmetrical difference equations that are employed to solve complex partial differential equation systems.

  19. Adaptive control technique for accelerators using digital signal processing

    SciTech Connect

    Eaton, L.; Jachim, S.; Natter, E.

    1987-01-01

    The use of present Digital Signal Processing (DSP) techniques can drastically reduce the residual rf amplitude and phase error in an accelerating rf cavity. Accelerator beam loading contributes greatly to this residual error, and the low-level rf field control loops cannot completely absorb the fast transient of the error. A feedforward technique using DSP is required to maintain the very stringent rf field amplitude and phase specifications. 7 refs.

  20. The influence of negative stimulus features on conflict adaption: evidence from fluency of processing.

    PubMed

    Fritz, Julia; Fischer, Rico; Dreisbach, Gesine

    2015-01-01

    Cognitive control enables adaptive behavior in a dynamically changing environment. In this context, one prominent adaptation effect is the sequential conflict adjustment, i.e., the observation of reduced response interference on trials following conflict trials. Increasing evidence suggests that such response conflicts are registered as aversive signals. So far, however, the functional role of this aversive signal for conflict adaptation to occur has not been put to test directly. In two experiments, the affective valence of conflict stimuli was manipulated by fluency of processing (stimulus contrast). Experiment 1 used a flanker interference task, Experiment 2 a color-word Stroop task. In both experiments, conflict adaptation effects were only present in fluent, but absent in disfluent trials. Results thus speak against the simple idea that any aversive stimulus feature is suited to promote specific conflict adjustments. Two alternative but not mutually exclusive accounts, namely resource competition and adaptation-by-motivation, will be discussed. PMID:25767453

  1. The influence of negative stimulus features on conflict adaption: evidence from fluency of processing

    PubMed Central

    Fritz, Julia; Fischer, Rico; Dreisbach, Gesine

    2015-01-01

    Cognitive control enables adaptive behavior in a dynamically changing environment. In this context, one prominent adaptation effect is the sequential conflict adjustment, i.e., the observation of reduced response interference on trials following conflict trials. Increasing evidence suggests that such response conflicts are registered as aversive signals. So far, however, the functional role of this aversive signal for conflict adaptation to occur has not been put to test directly. In two experiments, the affective valence of conflict stimuli was manipulated by fluency of processing (stimulus contrast). Experiment 1 used a flanker interference task, Experiment 2 a color-word Stroop task. In both experiments, conflict adaptation effects were only present in fluent, but absent in disfluent trials. Results thus speak against the simple idea that any aversive stimulus feature is suited to promote specific conflict adjustments. Two alternative but not mutually exclusive accounts, namely resource competition and adaptation-by-motivation, will be discussed. PMID:25767453

  2. [Peculiarities of adaptive hemodynamic processes during high-frequency jet lung ventilation].

    PubMed

    Zislin, B D; Astakhov, A A; Pankov, N E; Kontorovich, M B

    2009-01-01

    This study concerns poorly known features of adaptive hemodynamic reactions of the heart pump function during traditional and high-frequency jet lung ventilation. Spectral analysis of slow-wave oscillations of stroke volume and left ventricular diastolic filling wave in 36 patients with craniocerebral injury and acute cerebral insufficiency showed that beneficial adaptive reactions were realized through a rise in the general spectrum power and entropy. High-frequency jet lung ventilation ensured better effect on the adaptive processes than the traditional technique. PMID:19642544

  3. [Adaptability of sweet corn ears to a frozen process].

    PubMed

    Ramírez Matheus, Alejandra O; Martínez, Norelkys Maribel; de Bertorelli, Ligia O; De Venanzi, Frank

    2004-12-01

    The effects of frozen condition on the quality of three sweet corn ears (2038, 2010, 2004) and the pattern (Bonanza), were evaluated. Biometrics characteristics like ear size, ear diameter, row and kernel deep were measured as well as chemical and physical measurement in fresh and frozen states. The corn ears were frozen at -95 degrees C by 7 minutes. The yield and stability of the frozen ears were evaluated at 45 and 90 days of frozen storage (-18 degrees C). The average commercial yield as frozen corn ear for all the hybrids was 54.2%. The industry has a similar value range of 48% to 54%. The ear size average was 21.57 cm, row number was 15, ear diameter 45.54 mm and the kernel corn deep was 8.57 mm. All these measurements were found not different from commercial values found for the industry. All corn samples evaluated showed good stability despites the frozen processing and storage. Hybrid 2038 ranked higher in quality. PMID:15969270

  4. Interacting Adaptive Processes with Different Timescales Underlie Short-Term Motor Learning

    PubMed Central

    Ghazizadeh, Ali; Shadmehr, Reza

    2006-01-01

    Multiple processes may contribute to motor skill acquisition, but it is thought that many of these processes require sleep or the passage of long periods of time ranging from several hours to many days or weeks. Here we demonstrate that within a timescale of minutes, two distinct fast-acting processes drive motor adaptation. One process responds weakly to error but retains information well, whereas the other responds strongly but has poor retention. This two-state learning system makes the surprising prediction of spontaneous recovery (or adaptation rebound) if error feedback is clamped at zero following an adaptation-extinction training episode. We used a novel paradigm to experimentally confirm this prediction in human motor learning of reaching, and we show that the interaction between the learning processes in this simple two-state system provides a unifying explanation for several different, apparently unrelated, phenomena in motor adaptation including savings, anterograde interference, spontaneous recovery, and rapid unlearning. Our results suggest that motor adaptation depends on at least two distinct neural systems that have different sensitivity to error and retain information at different rates. PMID:16700627

  5. Incorporating Midbrain Adaptation to Mean Sound Level Improves Models of Auditory Cortical Processing

    PubMed Central

    Schoppe, Oliver; King, Andrew J.; Schnupp, Jan W.H.; Harper, Nicol S.

    2016-01-01

    Adaptation to stimulus statistics, such as the mean level and contrast of recently heard sounds, has been demonstrated at various levels of the auditory pathway. It allows the nervous system to operate over the wide range of intensities and contrasts found in the natural world. Yet current standard models of the response properties of auditory neurons do not incorporate such adaptation. Here we present a model of neural responses in the ferret auditory cortex (the IC Adaptation model), which takes into account adaptation to mean sound level at a lower level of processing: the inferior colliculus (IC). The model performs high-pass filtering with frequency-dependent time constants on the sound spectrogram, followed by half-wave rectification, and passes the output to a standard linear–nonlinear (LN) model. We find that the IC Adaptation model consistently predicts cortical responses better than the standard LN model for a range of synthetic and natural stimuli. The IC Adaptation model introduces no extra free parameters, so it improves predictions without sacrificing parsimony. Furthermore, the time constants of adaptation in the IC appear to be matched to the statistics of natural sounds, suggesting that neurons in the auditory midbrain predict the mean level of future sounds and adapt their responses appropriately. SIGNIFICANCE STATEMENT An ability to accurately predict how sensory neurons respond to novel stimuli is critical if we are to fully characterize their response properties. Attempts to model these responses have had a distinguished history, but it has proven difficult to improve their predictive power significantly beyond that of simple, mostly linear receptive field models. Here we show that auditory cortex receptive field models benefit from a nonlinear preprocessing stage that replicates known adaptation properties of the auditory midbrain. This improves their predictive power across a wide range of stimuli but keeps model complexity low as it

  6. Geophysical Inversion with Adaptive Array Processing of Ambient Noise

    NASA Astrophysics Data System (ADS)

    Traer, James

    2011-12-01

    Land-based seismic observations of microseisms generated during Tropical Storms Ernesto and Florence are dominated by signals in the 0.15--0.5Hz band. Data from seafloor hydrophones in shallow water (70m depth, 130 km off the New Jersey coast) show dominant signals in the gravity-wave frequency band, 0.02--0.18Hz and low amplitudes from 0.18--0.3Hz, suggesting significant opposing wave components necessary for DF microseism generation were negligible at the site. Both storms produced similar spectra, despite differing sizes, suggesting near-coastal shallow water as the dominant region for observed microseism generation. A mathematical explanation for a sign-inversion induced to the passive fathometer response by minimum variance distortionless response (MVDR) beamforming is presented. This shows that, in the region containing the bottom reflection, the MVDR fathometer response is identical to that obtained with conventional processing multiplied by a negative factor. A model is presented for the complete passive fathometer response to ocean surface noise, interfering discrete noise sources, and locally uncorrelated noise in an ideal waveguide. The leading order term of the ocean surface noise produces the cross-correlation of vertical multipaths and yields the depth of sub-bottom reflectors. Discrete noise incident on the array via multipaths give multiple peaks in the fathometer response. These peaks may obscure the sub-bottom reflections but can be attenuated with use of Minimum Variance Distortionless Response (MVDR) steering vectors. A theory is presented for the Signal-to-Noise-Ratio (SNR) for the seabed reflection peak in the passive fathometer response as a function of seabed depth, seabed reflection coefficient, averaging time, bandwidth and spatial directivity of the noise field. The passive fathometer algorithm was applied to data from two drifting array experiments in the Mediterranean, Boundary 2003 and 2004, with 0.34s of averaging time. In the 2004

  7. The process of adapting a universal dating abuse prevention program to adolescents exposed to domestic violence.

    PubMed

    Foshee, Vangie A; Dixon, Kimberly S; Ennett, Susan T; Moracco, Kathryn E; Bowling, J Michael; Chang, Ling-Yin; Moss, Jennifer L

    2015-07-01

    Adolescents exposed to domestic violence are at increased risk of dating abuse, yet no evaluated dating abuse prevention programs have been designed specifically for this high-risk population. This article describes the process of adapting Families for Safe Dates (FSD), an evidenced-based universal dating abuse prevention program, to this high-risk population, including conducting 12 focus groups and 107 interviews with the target audience. FSD includes six booklets of dating abuse prevention information, and activities for parents and adolescents to do together at home. We adapted FSD for mothers who were victims of domestic violence, but who no longer lived with the abuser, to do with their adolescents who had been exposed to the violence. Through the adaptation process, we learned that families liked the program structure and valued being offered the program and that some of our initial assumptions about this population were incorrect. We identified practices and beliefs of mother victims and attributes of these adolescents that might increase their risk of dating abuse that we had not previously considered. In addition, we learned that some of the content of the original program generated negative family interactions for some. The findings demonstrate the utility of using a careful process to adapt evidence-based interventions (EBIs) to cultural sub-groups, particularly the importance of obtaining feedback on the program from the target audience. Others can follow this process to adapt EBIs to groups other than the ones for which the original EBI was designed. PMID:25287405

  8. Prism adaptation reverses the local processing bias in patients with right temporo-parietal junction lesions

    PubMed Central

    Rafal, Robert D.; List, Alexandra

    2009-01-01

    Lesions to the right temporo-parietal cortex commonly result in hemispatial neglect. Lesions to the same area are also associated with hyperattention to local details of a scene and difficulty perceiving the global structure. This local processing bias is an important factor contributing to neglect and may contribute to the higher prevalence of the disorder following right compared with left hemisphere strokes. In recent years, visuomotor adaptation to rightward-shifting prisms has been introduced as a promising treatment for hemispatial neglect. Explanations for these improvements have generally described a leftward realignment of attention, however, the present investigation provides evidence that prism adaptation reduces the local processing bias. Five patients with right temporal-parietal junction lesions were asked to identify the global or local levels of hierarchical figures before and after visuomotor adaptation to rightward-shifting prisms. Prior to prism adaptation the patients had difficulty ignoring the local elements when identifying the global component. Following prism adaptation, however, this pattern was reversed, with greater global interference during local level identification. The results suggest that prism adaptation may improve non-spatially lateralized deficits that contribute to the neglect syndrome. PMID:19416951

  9. Robust Brain-Machine Interface Design Using Optimal Feedback Control Modeling and Adaptive Point Process Filtering

    PubMed Central

    Carmena, Jose M.

    2016-01-01

    Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman filters and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon optimal feedback-control (OFC) model of the brain’s behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user’s motor intention during CLDA—a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to

  10. Robust Brain-Machine Interface Design Using Optimal Feedback Control Modeling and Adaptive Point Process Filtering.

    PubMed

    Shanechi, Maryam M; Orsborn, Amy L; Carmena, Jose M

    2016-04-01

    Much progress has been made in brain-machine interfaces (BMI) using decoders such as Kalman filters and finding their parameters with closed-loop decoder adaptation (CLDA). However, current decoders do not model the spikes directly, and hence may limit the processing time-scale of BMI control and adaptation. Moreover, while specialized CLDA techniques for intention estimation and assisted training exist, a unified and systematic CLDA framework that generalizes across different setups is lacking. Here we develop a novel closed-loop BMI training architecture that allows for processing, control, and adaptation using spike events, enables robust control and extends to various tasks. Moreover, we develop a unified control-theoretic CLDA framework within which intention estimation, assisted training, and adaptation are performed. The architecture incorporates an infinite-horizon optimal feedback-control (OFC) model of the brain's behavior in closed-loop BMI control, and a point process model of spikes. The OFC model infers the user's motor intention during CLDA-a process termed intention estimation. OFC is also used to design an autonomous and dynamic assisted training technique. The point process model allows for neural processing, control and decoder adaptation with every spike event and at a faster time-scale than current decoders; it also enables dynamic spike-event-based parameter adaptation unlike current CLDA methods that use batch-based adaptation on much slower adaptation time-scales. We conducted closed-loop experiments in a non-human primate over tens of days to dissociate the effects of these novel CLDA components. The OFC intention estimation improved BMI performance compared with current intention estimation techniques. OFC assisted training allowed the subject to consistently achieve proficient control. Spike-event-based adaptation resulted in faster and more consistent performance convergence compared with batch-based methods, and was robust to parameter

  11. Application of the adaptive subspace detector to Raman spectra for biological threat detection

    NASA Astrophysics Data System (ADS)

    Russell, Thomas A.; Borchardt, Steven; Anderson, Richard; Treado, Patrick; Neiss, Jason

    2006-10-01

    Effective application of point detectors in the field to monitor the air for biological attack imposes a challenging set of requirements on threat detection algorithms. Raman spectra exhibit features that discriminate between threats and non-threats, and such spectra can be collected quickly, offering a potential solution given the appropriate algorithm. The algorithm must attempt to match to known threat signatures, while suppressing the background clutter in order to produce acceptable Receiver Operating Characteristic (ROC) curves. The radar space-time adaptive processing (STAP) community offers a set of tools appropriate to this problem, and these have recently crossed over into hyperspectral imaging (HSI) applications. The Adaptive Subspace Detector (ASD) is the Generalized Likelihood Ratio Test (GLRT) detector for structured backgrounds (which we expect for Raman background spectra) and mixed pixels, and supports the necessary adaptation to varying background environments. The structured background model reduces the training required for that adaptation, and the number of statistical assumptions required. We applied the ASD to large Raman spectral databases collected by ChemImage, developed spectral libraries of threat signatures and several backgrounds, and tested the algorithm against individual and mixture spectra, including in blind tests. The algorithm was successful in detecting threats, however, in order to maintain the desired false alarm rate, it was necessary to shift the decision threshold so as to give up some detection sensitivity. This was due to excess spread of the detector histograms, apparently related to variability in the signatures not captured by the subspaces, and evidenced by non-Gaussian residuals. We present here performance modeling, test data, algorithm and sensor performance results, and model validation conclusions.

  12. An adaptive algorithm for simulation of stochastic reaction-diffusion processes

    SciTech Connect

    Ferm, Lars Hellander, Andreas Loetstedt, Per

    2010-01-20

    We propose an adaptive hybrid method suitable for stochastic simulation of diffusion dominated reaction-diffusion processes. For such systems, simulation of the diffusion requires the predominant part of the computing time. In order to reduce the computational work, the diffusion in parts of the domain is treated macroscopically, in other parts with the tau-leap method and in the remaining parts with Gillespie's stochastic simulation algorithm (SSA) as implemented in the next subvolume method (NSM). The chemical reactions are handled by SSA everywhere in the computational domain. A trajectory of the process is advanced in time by an operator splitting technique and the timesteps are chosen adaptively. The spatial adaptation is based on estimates of the errors in the tau-leap method and the macroscopic diffusion. The accuracy and efficiency of the method are demonstrated in examples from molecular biology where the domain is discretized by unstructured meshes.

  13. A mixed signal ECG processing platform with an adaptive sampling ADC for portable monitoring applications.

    PubMed

    Kim, Hyejung; Van Hoof, Chris; Yazicioglu, Refet Firat

    2011-01-01

    This paper describes a mixed-signal ECG processing platform with an 12-bit ADC architecture that can adapt its sampling rate according to the input signals rate of change. This enables the sampling of ECG signals with significantly reduced data rate without loss of information. The presented adaptive sampling scheme reduces the ADC power consumption, enables the processing of ECG signals with lower power consumption, and reduces the power consumption of the radio while streaming the ECG signals. The test results show that running a CWT-based R peak detection algorithm using the adaptively sampled ECG signals consumes only 45.6 μW and it leads to 36% less overall system power consumption. PMID:22254775

  14. Access to Learning for Handicapped Children: A Handbook on the Instructional Adaptation Process. Field Test Version.

    ERIC Educational Resources Information Center

    Changar, Jerilynn; And Others

    The manual describes the results of a 36 month project to determine ways to modify existing curricula to meet the needs of special needs students in the mainstream. The handbook is designed in the main for administrators and facilitators as well as for teacher-adaptors. Each of eight steps in the adaptation process is broken down according to…

  15. Chinese Students and Scholars in the U.S.: An Intercultural Adaptation Process.

    ERIC Educational Resources Information Center

    Zhong, Mei

    An ethnographic study examined the culture of the Chinese students and scholars in America with a specific focus on their experiences in the cultural adaptation process. Subjects were three Chinese nationals (one female and two males) living in the area of a large midwestern university. Subjects were interviewed for about an hour each, with…

  16. Cognitive Process Development as Measured by an Adapted Version of Wechsler's Similarities Test

    ERIC Educational Resources Information Center

    Rozencwajg, Paulette

    2007-01-01

    This paper studies the development of taxonomic processing as measured by an adapted version of the Wechsler Similarities subtest, which distinguishes between categorization of concrete and abstract words. Two factors--age and concreteness--are also tested by a recall task. The results show an age-related increase in taxonomic categorization,…

  17. Factors associated with the process of adaptation among Pakistani adolescent females living in United States.

    PubMed

    Khuwaja, Salma A; Selwyn, Beatrice J; Mgbere, Osaro; Khuwaja, Alam; Kapadia, Asha; McCurdy, Sheryl; Hsu, Chiehwen E

    2013-04-01

    This study explored post-migration experiences of recently migrated Pakistani Muslim adolescent females residing in the United States. In-depth, semi-structured interviews were conducted with thirty Pakistani Muslim adolescent females between the ages of 15 and 18 years living with their families in Houston, Texas. Data obtained from the interviews were evaluated using discourse analysis to identify major reoccurring themes. Participants discussed factors associated with the process of adaptation to the American culture. The results revealed that the main factors associated with adaptation process included positive motivation for migration, family bonding, social support networks, inter-familial communication, aspiration of adolescents to learn other cultures, availability of English-as-second-language programs, participation in community rebuilding activities, and faith practices, English proficiency, peer pressure, and inter-generational conflicts. This study provided much needed information on factors associated with adaptation process of Pakistani Muslim adolescent females in the United States. The results have important implications for improving the adaptation process of this group and offer potential directions for intervention and counseling services. PMID:22940911

  18. A fuzzy model based adaptive PID controller design for nonlinear and uncertain processes.

    PubMed

    Savran, Aydogan; Kahraman, Gokalp

    2014-03-01

    We develop a novel adaptive tuning method for classical proportional-integral-derivative (PID) controller to control nonlinear processes to adjust PID gains, a problem which is very difficult to overcome in the classical PID controllers. By incorporating classical PID control, which is well-known in industry, to the control of nonlinear processes, we introduce a method which can readily be used by the industry. In this method, controller design does not require a first principal model of the process which is usually very difficult to obtain. Instead, it depends on a fuzzy process model which is constructed from the measured input-output data of the process. A soft limiter is used to impose industrial limits on the control input. The performance of the system is successfully tested on the bioreactor, a highly nonlinear process involving instabilities. Several tests showed the method's success in tracking, robustness to noise, and adaptation properties. We as well compared our system's performance to those of a plant with altered parameters with measurement noise, and obtained less ringing and better tracking. To conclude, we present a novel adaptive control method that is built upon the well-known PID architecture that successfully controls highly nonlinear industrial processes, even under conditions such as strong parameter variations, noise, and instabilities. PMID:24140160

  19. An Adaptive Altitude Information Fusion Method for Autonomous Landing Processes of Small Unmanned Aerial Rotorcraft

    PubMed Central

    Lei, Xusheng; Li, Jingjing

    2012-01-01

    This paper presents an adaptive information fusion method to improve the accuracy and reliability of the altitude measurement information for small unmanned aerial rotorcraft during the landing process. Focusing on the low measurement performance of sensors mounted on small unmanned aerial rotorcraft, a wavelet filter is applied as a pre-filter to attenuate the high frequency noises in the sensor output. Furthermore, to improve altitude information, an adaptive extended Kalman filter based on a maximum a posteriori criterion is proposed to estimate measurement noise covariance matrix in real time. Finally, the effectiveness of the proposed method is proved by static tests, hovering flight and autonomous landing flight tests. PMID:23201993

  20. Signal subspace analysis for decoherent processes during interferometric fiber-optic gyroscopes using synchronous adaptive filters.

    PubMed

    Li, Yongxiao; Wang, Zinan; Peng, Chao; Li, Zhengbin

    2014-10-10

    Conventional signal processing methods for improving the random walk coefficient and the bias stability of interferometric fiber-optic gyroscopes are usually implemented in one-dimension sequence. In this paper, as a comparison, we allocated synchronous adaptive filters with the calculations of correlations of multidimensional signals in the perspective of the signal subspace. First, two synchronous independent channels are obtained through quadrature demodulation. Next, synchronous adaptive filters were carried out in order to project the original channels to the high related error channels and the approximation channels. The error channel signals were then processed by principal component analysis for suppressing coherent noises. Finally, an optimal state estimation of these error channels and approximation channels based on the Kalman gain coefficient was operated. Experimental results show that this signal processing method improved the raw measurements' variance from 0.0630 [(°/h)2] to 0.0103 [(°/h)2]. PMID:25322393

  1. Adaptive passive fathometer processing using ambient noise received by vertical nested array

    NASA Astrophysics Data System (ADS)

    Kim, Junghun; Cho, Sungho; Choi, Jee Woong

    2015-07-01

    A passive fathometer technique utilizes surface-generated ambient noise received by a vertical line array as a sound source to estimate the depths of water-sediment interface and sub-bottom layers. Ambient noise was measured using a 24-channel, vertical nested line array consisting of four sub-arrays, in shallow water off the eastern coast of Korea. In this paper, nested array processing is applied to passive fathometer technique to improve the performance. Passive fathometer processing is performed for each sub-array, and the results are then combined to form a passive fathometer output for broadband ambient noise. Three types of beamforming technique, including conventional and two adaptive methods, are used in passive fathometer processing. The results are compared to the depths of water-sediment interface measured by an echo sounder. As a result, it is found that the adaptive methods have better performance than the conventional method.

  2. A new hypothesis: some metastases are the result of inflammatory processes by adapted cells, especially adapted immune cells at sites of inflammation

    PubMed Central

    Shahriyari, Leili

    2016-01-01

    There is an old hypothesis that metastasis is the result of migration of tumor cells from the tumor to a distant site. In this article, we propose another mechanism for metastasis, for cancers that are initiated at the site of chronic inflammation. We suggest that cells at the site of chronic inflammation might become adapted to the inflammatory process, and these adaptations may lead to the initiation of an inflammatory tumor. For example, in an inflammatory tumor immune cells might be adapted to send signals of proliferation or angiogenesis, and epithelial cells might be adapted to proliferation (like inactivation of tumor suppressor genes). Therefore, we hypothesize that metastasis could be the result of an inflammatory process by adapted cells, especially adapted immune cells at the site of inflammation, as well as the migration of tumor cells with the help of activated platelets, which travel between sites of inflammation.  If this hypothesis is correct, then any treatment causing necrotic cell death may not be a good solution. Because necrotic cells in the tumor micro-environment or anywhere in the body activate the immune system to initiate the inflammatory process, and the involvement of adapted immune cells in the inflammatory processes leads to the formation and progression of tumors. Adapted activated immune cells send more signals of proliferation and/or angiogenesis than normal cells. Moreover, if there were adapted epithelial cells, they would divide at a much higher rate in response to the proliferation signals than normal cells. Thus, not only would the tumor come back after the treatment, but it would also grow more aggressively. PMID:27158448

  3. Small Sample Properties of an Adaptive Filter with Application to Low Volume Statistical Process Control

    SciTech Connect

    CROWDER, STEPHEN V.

    1999-09-01

    In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards while building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper we address the issue of low volume statistical process control. We investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. We develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, we study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. We show that far fewer data values are needed than is typically recommended for process control applications. We also demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.

  4. Small sample properties of an adaptive filter with application to low volume statistical process control

    SciTech Connect

    Crowder, S.V.; Eshleman, L.

    1998-08-01

    In many manufacturing environments such as the nuclear weapons complex, emphasis has shifted from the regular production and delivery of large orders to infrequent small orders. However, the challenge to maintain the same high quality and reliability standards white building much smaller lot sizes remains. To meet this challenge, specific areas need more attention, including fast and on-target process start-up, low volume statistical process control, process characterization with small experiments, and estimating reliability given few actual performance tests of the product. In this paper the authors address the issue of low volume statistical process control. They investigate an adaptive filtering approach to process monitoring with a relatively short time series of autocorrelated data. The emphasis is on estimation and minimization of mean squared error rather than the traditional hypothesis testing and run length analyses associated with process control charting. The authors develop an adaptive filtering technique that assumes initial process parameters are unknown, and updates the parameters as more data become available. Using simulation techniques, they study the data requirements (the length of a time series of autocorrelated data) necessary to adequately estimate process parameters. They show that far fewer data values are needed than is typically recommended for process control applications. And they demonstrate the techniques with a case study from the nuclear weapons manufacturing complex.

  5. Signal processing through a generalized module of adaptation and spatial sensing.

    PubMed

    Krishnan, J

    2009-07-01

    Signal transduction in many cellular processes is accompanied by the feature of adaptation, which allows certain key signalling components to respond to temporal and/or spatial variation of external signals, independent of the absolute value of the signal. We extend and formulate a more general module which accounts for robust temporal adaptation and spatial response. In this setting, we examine various aspects of spatial and temporal signalling, as well as the signalling consequences and restrictions imposed by virtue of adaptation. This module is able to exhibit a variety of behaviour in response to temporal, spatial and spatio-temporal inputs. We carefully examine the roles of various parameters in this module and how they affect signal processing and propagation. Overall, we demonstrate how a simple module can account for a range downstream responses to a variety of input signals, and how elucidating the downstream response of many cellular components in systems with such adaptive signalling can be consequently very non-trivial. PMID:19254728

  6. Three-dimensional region-based adaptive image processing techniques for volume visualization applications

    NASA Astrophysics Data System (ADS)

    de Deus Lopes, Roseli; Zuffo, Marcelo K.; Rangayyan, Rangaraj M.

    1996-04-01

    Recent advances in three-dimensional (3D) imaging techniques have expanded the scope of applications of volume visualization to many areas such as medical imaging, scientific visualization, robotic vision, and virtual reality. Advanced image filtering, enhancement, and analysis techniques are being developed in parallel in the field of digital image processing. Although the fields cited have many aspects in common, it appears that many of the latest developments in image processing are not being applied to the fullest extent possible in visualization. It is common to encounter the use of rather simple and elementary image pre- processing operations being used in visualization and 3D imaging applications. The purpose of this paper is to present an overview of selected topics from recent developments in adaptive image processing and demonstrate or suggest their applications in volume visualization. The techniques include adaptive noise removal; improvement of contrast and visibility of objects; space-variant deblurring and restoration; segmentation-based lossless coding for data compression; and perception-based measures for analysis, enhancement, and rendering. The techniques share the common base of identification of adaptive regions by region growing, which lends them a perceptual basis related to the human visual system. Preliminary results obtained with some of the techniques implemented so far are used to illustrate the concepts involved, and to indicate potential performance capabilities of the methods.

  7. Adapting School-Based Substance Use Prevention Curriculum Through Cultural Grounding: A Review and Exemplar of Adaptation Processes for Rural Schools

    PubMed Central

    Colby, Margaret; Hecht, Michael L.; Miller-Day, Michelle; Krieger, Janice L.; Syvertsen, Amy K.; Graham, John W.; Pettigrew, Jonathan

    2014-01-01

    A central challenge facing twenty-first century community-based researchers and prevention scientists is curriculum adaptation processes. While early prevention efforts sought to develop effective programs, taking programs to scale implies that they will be adapted, especially as programs are implemented with populations other than those with whom they were developed or tested. The principle of cultural grounding, which argues that health message adaptation should be informed by knowledge of the target population and by cultural insiders, provides a theoretical rational for cultural regrounding and presents an illustrative case of methods used to reground the keepin’ it REAL substance use prevention curriculum for a rural adolescent population. We argue that adaptation processes like those presented should be incorporated into the design and dissemination of prevention interventions. PMID:22961604

  8. ADAPT: A knowledge-based synthesis tool for digital signal processing system design

    SciTech Connect

    Cooley, E.S.

    1988-01-01

    A computer aided synthesis tool for expansion, compression, and filtration of digital images is described. ADAPT, the Autonomous Digital Array Programming Tool, uses an extensive design knowledge base to synthesize a digital signal processing (DSP) system. Input to ADAPT can be either a behavioral description in English, or a block level specification via Petri Nets. The output from ADAPT comprises code to implement the DSP system on an array of processors. ADAPT is constructed using C, Prolog, and X Windows on a SUN 3/280 workstation. ADAPT knowledge encompasses DSP component information and the design algorithms and heuristics of a competent DSP designer. The knowledge is used to form queries for design capture, to generate design constraints from the user's responses, and to examine the design constraints. These constraints direct the search for possible DSP components and target architectures. Constraints are also used for partitioning the target systems into less complex subsystems. The subsystems correspond to architectural building blocks of the DSP design. These subsystems inherit design constraints and DSP characteristics from their parent blocks. Thus, a DSP subsystem or parent block, as designed by ADAPT, must meet the user's design constraints. Design solutions are sought by searching the Components section of the design knowledge base. Component behavior which matches or is similar to that required by the DSP subsystems is sought. Each match, which corresponds to a design alternative, is evaluated in terms of its behavior. When a design is sufficiently close to the behavior required by the user, detailed mathematical simulations may be performed to accurately determine exact behavior.

  9. A Low Processing Cost Adaptive Algorithm Identifying Nonlinear Unknown System with Piecewise Linear Curve

    NASA Astrophysics Data System (ADS)

    Fujii, Kensaku; Aoki, Ryo; Muneyasu, Mitsuji

    This paper proposes an adaptive algorithm for identifying unknown systems containing nonlinear amplitude characteristics. Usually, the nonlinearity is so small as to be negligible. However, in low cost systems, such as acoustic echo canceller using a small loudspeaker, the nonlinearity deteriorates the performance of the identification. Several methods preventing the deterioration, polynomial or Volterra series approximations, have been hence proposed and studied. However, the conventional methods require high processing cost. In this paper, we propose a method approximating the nonlinear characteristics with a piecewise linear curve and show using computer simulations that the performance can be extremely improved. The proposed method can also reduce the processing cost to only about twice that of the linear adaptive filter system.

  10. The Information Adaptive System - A demonstration of real-time onboard image processing

    NASA Technical Reports Server (NTRS)

    Thomas, G. L.; Carney, P. C.; Meredith, B. D.

    1983-01-01

    The Information Adaptive System (IAS) program has the objective to develop and demonstrate, at the brassboard level, an architecture which can be used to perform advanced signal procesing functions on board the spacecraft. Particular attention is given to the processing of high-speed multispectral imaging data in real-time, and the development of advanced technology which could be employed for future space applications. An IAS functional description is provided, and questions of radiometric correction are examined. Problems of data packetization are considered along with data selection, a distortion coefficient processor, an adaptive system controller, an image processing demonstration system, a sensor simulator and output data buffer, a test support and demonstration controller, and IAS demonstration operating modes.

  11. Adapting existing natural language processing resources for cardiovascular risk factors identification in clinical notes.

    PubMed

    Khalifa, Abdulrahman; Meystre, Stéphane

    2015-12-01

    The 2014 i2b2 natural language processing shared task focused on identifying cardiovascular risk factors such as high blood pressure, high cholesterol levels, obesity and smoking status among other factors found in health records of diabetic patients. In addition, the task involved detecting medications, and time information associated with the extracted data. This paper presents the development and evaluation of a natural language processing (NLP) application conceived for this i2b2 shared task. For increased efficiency, the application main components were adapted from two existing NLP tools implemented in the Apache UIMA framework: Textractor (for dictionary-based lookup) and cTAKES (for preprocessing and smoking status detection). The application achieved a final (micro-averaged) F1-measure of 87.5% on the final evaluation test set. Our attempt was mostly based on existing tools adapted with minimal changes and allowed for satisfying performance with limited development efforts. PMID:26318122

  12. Spectroscopic analyses of chemical adaptation processes within microalgal biomass in response to changing environments.

    PubMed

    Vogt, Frank; White, Lauren

    2015-03-31

    Via photosynthesis, marine phytoplankton transforms large quantities of inorganic compounds into biomass. This has considerable environmental impacts as microalgae contribute for instance to counter-balancing anthropogenic releases of the greenhouse gas CO2. On the other hand, high concentrations of nitrogen compounds in an ecosystem can lead to harmful algae blooms. In previous investigations it was found that the chemical composition of microalgal biomass is strongly dependent on the nutrient availability. Therefore, it is expected that algae's sequestration capabilities and productivity are also determined by the cells' chemical environments. For investigating this hypothesis, novel analytical methodologies are required which are capable of monitoring live cells exposed to chemically shifting environments followed by chemometric modeling of their chemical adaptation dynamics. FTIR-ATR experiments have been developed for acquiring spectroscopic time series of live Dunaliella parva cultures adapting to different nutrient situations. Comparing experimental data from acclimated cultures to those exposed to a chemically shifted nutrient situation reveals insights in which analyte groups participate in modifications of microalgal biomass and on what time scales. For a chemometric description of these processes, a data model has been deduced which explains the chemical adaptation dynamics explicitly rather than empirically. First results show that this approach is feasible and derives information about the chemical biomass adaptations. Future investigations will utilize these instrumental and chemometric methodologies for quantitative investigations of the relation between chemical environments and microalgal sequestration capabilities. PMID:25813024

  13. Ultrasound nondestructive evaluation (NDE) imaging with transducer arrays and adaptive processing.

    PubMed

    Li, Minghui; Hayward, Gordon

    2012-01-01

    This paper addresses the challenging problem of ultrasonic non-destructive evaluation (NDE) imaging with adaptive transducer arrays. In NDE applications, most materials like concrete, stainless steel and carbon-reinforced composites used extensively in industries and civil engineering exhibit heterogeneous internal structure. When inspected using ultrasound, the signals from defects are significantly corrupted by the echoes form randomly distributed scatterers, even defects that are much larger than these random reflectors are difficult to detect with the conventional delay-and-sum operation. We propose to apply adaptive beamforming to the received data samples to reduce the interference and clutter noise. Beamforming is to manipulate the array beam pattern by appropriately weighting the per-element delayed data samples prior to summing them. The adaptive weights are computed from the statistical analysis of the data samples. This delay-weight-and-sum process can be explained as applying a lateral spatial filter to the signals across the probe aperture. Simulations show that the clutter noise is reduced by more than 30 dB and the lateral resolution is enhanced simultaneously when adaptive beamforming is applied. In experiments inspecting a steel block with side-drilled holes, good quantitative agreement with simulation results is demonstrated. PMID:22368457

  14. The Contextualized Technology Adaptation Process (CTAP): Optimizing Health Information Technology to Improve Mental Health Systems.

    PubMed

    Lyon, Aaron R; Wasse, Jessica Knaster; Ludwig, Kristy; Zachry, Mark; Bruns, Eric J; Unützer, Jürgen; McCauley, Elizabeth

    2016-05-01

    Health information technologies have become a central fixture in the mental healthcare landscape, but few frameworks exist to guide their adaptation to novel settings. This paper introduces the contextualized technology adaptation process (CTAP) and presents data collected during Phase 1 of its application to measurement feedback system development in school mental health. The CTAP is built on models of human-centered design and implementation science and incorporates repeated mixed methods assessments to guide the design of technologies to ensure high compatibility with a destination setting. CTAP phases include: (1) Contextual evaluation, (2) Evaluation of the unadapted technology, (3) Trialing and evaluation of the adapted technology, (4) Refinement and larger-scale implementation, and (5) Sustainment through ongoing evaluation and system revision. Qualitative findings from school-based practitioner focus groups are presented, which provided information for CTAP Phase 1, contextual evaluation, surrounding education sector clinicians' workflows, types of technologies currently available, and influences on technology use. Discussion focuses on how findings will inform subsequent CTAP phases, as well as their implications for future technology adaptation across content domains and service sectors. PMID:25677251

  15. Low Temperature Adaptation Is Not the Opposite Process of High Temperature Adaptation in Terms of Changes in Amino Acid Composition

    PubMed Central

    Yang, Ling-Ling; Tang, Shu-Kun; Huang, Ying; Zhi, Xiao-Yang

    2015-01-01

    Previous studies focused on psychrophilic adaptation generally have demonstrated that multiple mechanisms work together to increase protein flexibility and activity, as well as to decrease the thermostability of proteins. However, the relationship between high and low temperature adaptations remains unclear. To investigate this issue, we collected the available predicted whole proteome sequences of species with different optimal growth temperatures, and analyzed amino acid variations and substitutional asymmetry in pairs of homologous proteins from related species. We found that changes in amino acid composition associated with low temperature adaptation did not exhibit a coherent opposite trend when compared with changes in amino acid composition associated with high temperature adaptation. This result indicates that during their evolutionary histories the proteome-scale evolutionary patterns associated with prokaryotes exposed to low temperature environments were distinct from the proteome-scale evolutionary patterns associated with prokaryotes exposed to high temperature environments in terms of changes in amino acid composition of the proteins. PMID:26614525

  16. A review of culturally adapted versions of the Oswestry Disability Index: the adaptation process, construct validity, test-retest reliability and internal consistency.

    PubMed

    Sheahan, Peter J; Nelson-Wong, Erika J; Fischer, Steven L

    2015-12-01

    The Oswestry Disability Index (ODI) is a self-report-based outcome measure used to quantify the extent of disability related to low back pain (LBP), a substantial contributor to workplace absenteeism. The ODI tool has been adapted for use by patients in several non-English speaking nations. It is unclear, however, if these adapted versions of the ODI are as credible as the original ODI developed for English-speaking nations. The objective of this study was to conduct a review of the literature to identify culturally adapted versions of the ODI and to report on the adaptation process, construct validity, test-retest reliability and internal consistency of these ODIs. Following a pragmatic review process, data were extracted from each study with regard to these four outcomes. While most studies applied adaptation processes in accordance with best-practice guidelines, there were some deviations. However, all studies reported high-quality psychometric properties: group mean construct validity was 0.734 ± 0.094 (indicated via a correlation coefficient), test-retest reliability was 0.937 ± 0.032 (indicated via an intraclass correlation coefficient) and internal consistency was 0.876 ± 0.047 (indicated via Cronbach's alpha). Researchers can be confident when using any of these culturally adapted ODIs, or when comparing and contrasting results between cultures where these versions were employed. Implications for Rehabilitation Low back pain is the second leading cause of disability in the world, behind only cancer. The Oswestry Disability Index (ODI) has been developed as a self-report outcome measure of low back pain for administration to patients. An understanding of the various cross-cultural adaptations of the ODI is important for more concerted multi-national research efforts. This review examines 16 cross-cultural adaptations of the ODI and should inform the work of health care and rehabilitation professionals. PMID:25738913

  17. Adaptive constructive processes and memory accuracy: Consequences of counterfactual simulations in young and older adults

    PubMed Central

    Gerlach, Kathy D.; Dornblaser, David W.; Schacter, Daniel L.

    2013-01-01

    People frequently engage in counterfactual thinking: mental simulations of alternative outcomes to past events. Like simulations of future events, counterfactual simulations serve adaptive functions. However, future simulation can also result in various kinds of distortions and has thus been characterized as an adaptive constructive process. Here we approach counterfactual thinking as such and examine whether it can distort memory for actual events. In Experiments 1a/b, young and older adults imagined themselves experiencing different scenarios. Participants then imagined the same scenario again, engaged in no further simulation of a scenario, or imagined a counterfactual outcome. On a subsequent recognition test, participants were more likely to make false alarms to counterfactual lures than novel scenarios. Older adults were more prone to these memory errors than younger adults. In Experiment 2, younger and older participants selected and performed different actions, then recalled performing some of those actions, imagined performing alternative actions to some of the selected actions, and did not imagine others. Participants, especially older adults, were more likely to falsely remember counterfactual actions than novel actions as previously performed. The findings suggest that counterfactual thinking can cause source confusion based on internally generated misinformation, consistent with its characterization as an adaptive constructive process. PMID:23560477

  18. Adaptive optimal control of highly dissipative nonlinear spatially distributed processes with neuro-dynamic programming.

    PubMed

    Luo, Biao; Wu, Huai-Ning; Li, Han-Xiong

    2015-04-01

    Highly dissipative nonlinear partial differential equations (PDEs) are widely employed to describe the system dynamics of industrial spatially distributed processes (SDPs). In this paper, we consider the optimal control problem of the general highly dissipative SDPs, and propose an adaptive optimal control approach based on neuro-dynamic programming (NDP). Initially, Karhunen-Loève decomposition is employed to compute empirical eigenfunctions (EEFs) of the SDP based on the method of snapshots. These EEFs together with singular perturbation technique are then used to obtain a finite-dimensional slow subsystem of ordinary differential equations that accurately describes the dominant dynamics of the PDE system. Subsequently, the optimal control problem is reformulated on the basis of the slow subsystem, which is further converted to solve a Hamilton-Jacobi-Bellman (HJB) equation. HJB equation is a nonlinear PDE that has proven to be impossible to solve analytically. Thus, an adaptive optimal control method is developed via NDP that solves the HJB equation online using neural network (NN) for approximating the value function; and an online NN weight tuning law is proposed without requiring an initial stabilizing control policy. Moreover, by involving the NN estimation error, we prove that the original closed-loop PDE system with the adaptive optimal control policy is semiglobally uniformly ultimately bounded. Finally, the developed method is tested on a nonlinear diffusion-convection-reaction process and applied to a temperature cooling fin of high-speed aerospace vehicle, and the achieved results show its effectiveness. PMID:25794375

  19. Coevolution of information processing and topology in hierarchical adaptive random Boolean networks

    NASA Astrophysics Data System (ADS)

    Górski, Piotr J.; Czaplicka, Agnieszka; Hołyst, Janusz A.

    2016-02-01

    Random Boolean Networks (RBNs) are frequently used for modeling complex systems driven by information processing, e.g. for gene regulatory networks (GRNs). Here we propose a hierarchical adaptive random Boolean Network (HARBN) as a system consisting of distinct adaptive RBNs (ARBNs) - subnetworks - connected by a set of permanent interlinks. We investigate mean node information, mean edge information as well as mean node degree. Information measures and internal subnetworks topology of HARBN coevolve and reach steady-states that are specific for a given network structure. The main natural feature of ARBNs, i.e. their adaptability, is preserved in HARBNs and they evolve towards critical configurations which is documented by power law distributions of network attractor lengths. The mean information processed by a single node or a single link increases with the number of interlinks added to the system. The mean length of network attractors and the mean steady-state connectivity possess minima for certain specific values of the quotient between the density of interlinks and the density of all links in networks. It means that the modular network displays extremal values of its observables when subnetworks are connected with a density a few times lower than a mean density of all links.

  20. ADAPT: building conceptual models of the physical and biological processes across permafrost landscapes

    NASA Astrophysics Data System (ADS)

    Allard, M.; Vincent, W. F.; Lemay, M.

    2012-12-01

    Fundamental and applied permafrost research is called upon in Canada in support of environmental protection, economic development and for contributing to the international efforts in understanding climatic and ecological feedbacks of permafrost thawing under a warming climate. The five year "Arctic Development and Adaptation to Permafrost in Transition" program (ADAPT) funded by NSERC brings together 14 scientists from 10 Canadian universities and involves numerous collaborators from academia, territorial and provincial governments, Inuit communities and industry. The geographical coverage of the program encompasses all of the permafrost regions of Canada. Field research at a series of sites across the country is being coordinated. A common protocol for measuring ground thermal and moisture regime, characterizing terrain conditions (vegetation, topography, surface water regime and soil organic matter contents) is being applied in order to provide inputs for designing a general model to provide an understanding of transfers of energy and matter in permafrost terrain, and the implications for biological and human systems. The ADAPT mission is to produce an 'Integrated Permafrost Systems Science' framework that will be used to help generate sustainable development and adaptation strategies for the North in the context of rapid socio-economic and climate change. ADAPT has three major objectives: to examine how changing precipitation and warming temperatures affect permafrost geosystems and ecosystems, specifically by testing hypotheses concerning the influence of the snowpack, the effects of water as a conveyor of heat, sediments, and carbon in warming permafrost terrain and the processes of permafrost decay; to interact directly with Inuit communities, the public sector and the private sector for development and adaptation to changes in permafrost environments; and to train the new generation of experts and scientists in this critical domain of research in Canada

  1. Performance-Based Adaptive Fuzzy Tracking Control for Networked Industrial Processes.

    PubMed

    Wang, Tong; Qiu, Jianbin; Yin, Shen; Gao, Huijun; Fan, Jialu; Chai, Tianyou

    2016-08-01

    In this paper, the performance-based control design problem for double-layer networked industrial processes is investigated. At the device layer, the prescribed performance functions are first given to describe the output tracking performance, and then by using backstepping technique, new adaptive fuzzy controllers are designed to guarantee the tracking performance under the effects of input dead-zone and the constraint of prescribed tracking performance functions. At operation layer, by considering the stochastic disturbance, actual index value, target index value, and index prediction simultaneously, an adaptive inverse optimal controller in discrete-time form is designed to optimize the overall performance and stabilize the overall nonlinear system. Finally, a simulation example of continuous stirred tank reactor system is presented to show the effectiveness of the proposed control method. PMID:27168605

  2. Two Adaptation Processes in Auditory Hair Cells Together Can Provide an Active Amplifier

    PubMed Central

    Vilfan, Andrej; Duke, Thomas

    2003-01-01

    The hair cells of the vertebrate inner ear convert mechanical stimuli to electrical signals. Two adaptation mechanisms are known to modify the ionic current flowing through the transduction channels of the hair bundles: a rapid process involves Ca2+ ions binding to the channels; and a slower adaptation is associated with the movement of myosin motors. We present a mathematical model of the hair cell which demonstrates that the combination of these two mechanisms can produce “self-tuned critical oscillations”, i.e., maintain the hair bundle at the threshold of an oscillatory instability. The characteristic frequency depends on the geometry of the bundle and on the Ca2+ dynamics, but is independent of channel kinetics. Poised on the verge of vibrating, the hair bundle acts as an active amplifier. However, if the hair cell is sufficiently perturbed, other dynamical regimes can occur. These include slow relaxation oscillations which resemble the hair bundle motion observed in some experimental preparations. PMID:12829475

  3. Improved electromagnetic induction processing with novel adaptive matched filter and matched subspace detection

    NASA Astrophysics Data System (ADS)

    Hayes, Charles E.; McClellan, James H.; Scott, Waymond R.; Kerr, Andrew J.

    2016-05-01

    This work introduces two advances in wide-band electromagnetic induction (EMI) processing: a novel adaptive matched filter (AMF) and matched subspace detection methods. Both advances make use of recent work with a subspace SVD approach to separating the signal, soil, and noise subspaces of the frequency measurements The proposed AMF provides a direct approach to removing the EMI self-response while improving the signal to noise ratio of the data. Unlike previous EMI adaptive downtrack filters, this new filter will not erroneously optimize the EMI soil response instead of the EMI target response because these two responses are projected into separate frequency subspaces. The EMI detection methods in this work elaborate on how the signal and noise subspaces in the frequency measurements are ideal for creating the matched subspace detection (MSD) and constant false alarm rate matched subspace detection (CFAR) metrics developed by Scharf The CFAR detection metric has been shown to be the uniformly most powerful invariant detector.

  4. ERP and Adaptive Autoregressive identification with spectral power decomposition to study rapid auditory processing in infants.

    PubMed

    Piazza, C; Cantiani, C; Tacchino, G; Molteni, M; Reni, G; Bianchi, A M

    2014-01-01

    The ability to process rapidly-occurring auditory stimuli plays an important role in the mechanisms of language acquisition. For this reason, the research community has begun to investigate infant auditory processing, particularly using the Event Related Potentials (ERP) technique. In this paper we approach this issue by means of time domain and time-frequency domain analysis. For the latter, we propose the use of Adaptive Autoregressive (AAR) identification with spectral power decomposition. Results show EEG delta-theta oscillation enhancement related to the processing of acoustic frequency and duration changes, suggesting that, as expected, power modulation encodes rapid auditory processing (RAP) in infants and that the time-frequency analysis method proposed is able to identify this modulation. PMID:25571014

  5. Maternal migration and child health: An analysis of disruption and adaptation processes in Benin

    PubMed Central

    Smith-Greenaway, Emily; Madhavan, Sangeetha

    2016-01-01

    Children of migrant mothers have lower vaccination rates compared to their peers with non-migrant mothers in low-income countries. Explanations for this finding are typically grounded in the disruption and adaptation perspectives of migration. Researchers argue that migration is a disruptive process that interferes with women’s economic well-being and social networks, and ultimately their health-seeking behaviors. With time, however, migrant women adapt to their new settings, and their health behaviors improve. Despite prominence in the literature, no research tests the salience of these perspectives to the relationship between maternal migration and child vaccination. We innovatively leverage Demographic and Health Survey data to test the extent to which disruption and adaptation processes underlie the relationship between maternal migration and child vaccination in the context of Benin—a West African country where migration is common and child vaccination rates have declined in recent years. By disaggregating children of migrants according to whether they were born before or after their mother’s migration, we confirm that migration does not lower children’s vaccination rates in Benin. In fact, children born after migration enjoy a higher likelihood of vaccination, whereas their peers born in the community from which their mother eventually migrates are less likely to be vaccinated. Although we find no support for the disruption perspective of migration, we do find evidence of adaptation: children born after migration have an increased likelihood of vaccination the longer their mother resides in the destination community prior to their birth. PMID:26463540

  6. Evolutionary adaptations for the temporal processing of natural sounds by the anuran peripheral auditory system.

    PubMed

    Schrode, Katrina M; Bee, Mark A

    2015-03-01

    Sensory systems function most efficiently when processing natural stimuli, such as vocalizations, and it is thought that this reflects evolutionary adaptation. Among the best-described examples of evolutionary adaptation in the auditory system are the frequent matches between spectral tuning in both the peripheral and central auditory systems of anurans (frogs and toads) and the frequency spectra of conspecific calls. Tuning to the temporal properties of conspecific calls is less well established, and in anurans has so far been documented only in the central auditory system. Using auditory-evoked potentials, we asked whether there are species-specific or sex-specific adaptations of the auditory systems of gray treefrogs (Hyla chrysoscelis) and green treefrogs (H. cinerea) to the temporal modulations present in conspecific calls. Modulation rate transfer functions (MRTFs) constructed from auditory steady-state responses revealed that each species was more sensitive than the other to the modulation rates typical of conspecific advertisement calls. In addition, auditory brainstem responses (ABRs) to paired clicks indicated relatively better temporal resolution in green treefrogs, which could represent an adaptation to the faster modulation rates present in the calls of this species. MRTFs and recovery of ABRs to paired clicks were generally similar between the sexes, and we found no evidence that males were more sensitive than females to the temporal modulation patterns characteristic of the aggressive calls used in male-male competition. Together, our results suggest that efficient processing of the temporal properties of behaviorally relevant sounds begins at potentially very early stages of the anuran auditory system that include the periphery. PMID:25617467

  7. Evolutionary adaptations for the temporal processing of natural sounds by the anuran peripheral auditory system

    PubMed Central

    Schrode, Katrina M.; Bee, Mark A.

    2015-01-01

    ABSTRACT Sensory systems function most efficiently when processing natural stimuli, such as vocalizations, and it is thought that this reflects evolutionary adaptation. Among the best-described examples of evolutionary adaptation in the auditory system are the frequent matches between spectral tuning in both the peripheral and central auditory systems of anurans (frogs and toads) and the frequency spectra of conspecific calls. Tuning to the temporal properties of conspecific calls is less well established, and in anurans has so far been documented only in the central auditory system. Using auditory-evoked potentials, we asked whether there are species-specific or sex-specific adaptations of the auditory systems of gray treefrogs (Hyla chrysoscelis) and green treefrogs (H. cinerea) to the temporal modulations present in conspecific calls. Modulation rate transfer functions (MRTFs) constructed from auditory steady-state responses revealed that each species was more sensitive than the other to the modulation rates typical of conspecific advertisement calls. In addition, auditory brainstem responses (ABRs) to paired clicks indicated relatively better temporal resolution in green treefrogs, which could represent an adaptation to the faster modulation rates present in the calls of this species. MRTFs and recovery of ABRs to paired clicks were generally similar between the sexes, and we found no evidence that males were more sensitive than females to the temporal modulation patterns characteristic of the aggressive calls used in male–male competition. Together, our results suggest that efficient processing of the temporal properties of behaviorally relevant sounds begins at potentially very early stages of the anuran auditory system that include the periphery. PMID:25617467

  8. Flexible Description and Adaptive Processing of Earth Observation Data through the BigEarth Platform

    NASA Astrophysics Data System (ADS)

    Gorgan, Dorian; Bacu, Victor; Stefanut, Teodor; Nandra, Cosmin; Mihon, Danut

    2016-04-01

    The Earth Observation data repositories extending periodically by several terabytes become a critical issue for organizations. The management of the storage capacity of such big datasets, accessing policy, data protection, searching, and complex processing require high costs that impose efficient solutions to balance the cost and value of data. Data can create value only when it is used, and the data protection has to be oriented toward allowing innovation that sometimes depends on creative people, which achieve unexpected valuable results through a flexible and adaptive manner. The users need to describe and experiment themselves different complex algorithms through analytics in order to valorize data. The analytics uses descriptive and predictive models to gain valuable knowledge and information from data analysis. Possible solutions for advanced processing of big Earth Observation data are given by the HPC platforms such as cloud. With platforms becoming more complex and heterogeneous, the developing of applications is even harder and the efficient mapping of these applications to a suitable and optimum platform, working on huge distributed data repositories, is challenging and complex as well, even by using specialized software services. From the user point of view, an optimum environment gives acceptable execution times, offers a high level of usability by hiding the complexity of computing infrastructure, and supports an open accessibility and control to application entities and functionality. The BigEarth platform [1] supports the entire flow of flexible description of processing by basic operators and adaptive execution over cloud infrastructure [2]. The basic modules of the pipeline such as the KEOPS [3] set of basic operators, the WorDeL language [4], the Planner for sequential and parallel processing, and the Executor through virtual machines, are detailed as the main components of the BigEarth platform [5]. The presentation exemplifies the development

  9. Can survival processing enhance story memory? Testing the generalizability of the adaptive memory framework.

    PubMed

    Seamon, John G; Bohn, Justin M; Coddington, Inslee E; Ebling, Maritza C; Grund, Ethan M; Haring, Catherine T; Jang, Sue-Jung; Kim, Daniel; Liong, Christopher; Paley, Frances M; Pang, Luke K; Siddique, Ashik H

    2012-07-01

    Research from the adaptive memory framework shows that thinking about words in terms of their survival value in an incidental learning task enhances their free recall relative to other semantic encoding strategies and intentional learning (Nairne, Pandeirada, & Thompson, 2008). We found similar results. When participants used incidental survival encoding for a list of words (e.g., "Will this object enhance my survival if I were stranded in the grasslands of a foreign land?"), they produced better free recall on a surprise test than did participants who intentionally tried to remember those words (Experiment 1). We also found this survival processing advantage when the words were presented within the context of a survival or neutral story (Experiment 2). However, this advantage did not extent to memory for a story's factual content, regardless of whether the participants were tested by cued recall (Experiment 3) or free recall (Experiments 4-5). Listening to a story for understanding under intentional or incidental learning conditions was just as good as survival processing for remembering story content. The functionalist approach to thinking about memory as an evolutionary adaptation designed to solve reproductive fitness problems provides a different theoretical framework for research, but it is not yet clear if survival processing has general applicability or is effective only for processing discrete stimuli in terms of fitness-relevant scenarios from our past. PMID:22288816

  10. Adaptive phase estimation and its application in EEG analysis of word processing.

    PubMed

    Schack, B; Rappelsberger, P; Weiss, S; Möller, E

    1999-10-30

    Oscillations are a general phenomenon of neuronal activity during information processing. Mostly, widespread networks are involved in brain functioning. In order to investigate network activity coherence analysis turned out to be a useful tool for examining the functional relationship between different cortical areas. This parameter allows the investigation of synchronisation phenomena with regard to defined frequencies or frequency bands. Coherence and cross phase are closely connected spectral parameters. Coherence may be understood as a measure of phase stability. Whereas coherence describes the amount of information transfer, the corresponding phase, from which time delays can be computed, hints at the direction of information transfer. Mental processes can be very brief and coupling between different areas may be highly dynamic. For this reason a two-dimensional approach of adaptive filtering was developed to estimate coherence and phase continuously in time. Statistical and dynamic properties of instantaneous phase are discussed. In order to demonstrate the value of this method for studying higher cognitive processes the method was applied to EEG recorded during word processing. During visual presentation of abstract nouns an information transfer from visual areas to frontal association areas in the Alpha1 frequency band could be verified within the first 400 ms. The Alpha1 band predominately seems to reflect sensory processing and attentional processes. In addition to conventional coherence analyses during word processing phase estimations may yield valuable new insights into the physiological mechanisms during word processing. PMID:10598864

  11. Adapting Semantic Natural Language Processing Technology to Address Information Overload in Influenza Epidemic Management

    PubMed Central

    Keselman, Alla; Rosemblat, Graciela; Kilicoglu, Halil; Fiszman, Marcelo; Jin, Honglan; Shin, Dongwook; Rindflesch, Thomas C.

    2013-01-01

    Explosion of disaster health information results in information overload among response professionals. The objective of this project was to determine the feasibility of applying semantic natural language processing (NLP) technology to addressing this overload. The project characterizes concepts and relationships commonly used in disaster health-related documents on influenza pandemics, as the basis for adapting an existing semantic summarizer to the domain. Methods include human review and semantic NLP analysis of a set of relevant documents. This is followed by a pilot-test in which two information specialists use the adapted application for a realistic information seeking task. According to the results, the ontology of influenza epidemics management can be described via a manageable number of semantic relationships that involve concepts from a limited number of semantic types. Test users demonstrate several ways to engage with the application to obtain useful information. This suggests that existing semantic NLP algorithms can be adapted to support information summarization and visualization in influenza epidemics and other disaster health areas. However, additional research is needed in the areas of terminology development (as many relevant relationships and terms are not part of existing standardized vocabularies), NLP, and user interface design. PMID:24311971

  12. Adapting Semantic Natural Language Processing Technology to Address Information Overload in Influenza Epidemic Management.

    PubMed

    Keselman, Alla; Rosemblat, Graciela; Kilicoglu, Halil; Fiszman, Marcelo; Jin, Honglan; Shin, Dongwook; Rindflesch, Thomas C

    2010-12-01

    Explosion of disaster health information results in information overload among response professionals. The objective of this project was to determine the feasibility of applying semantic natural language processing (NLP) technology to addressing this overload. The project characterizes concepts and relationships commonly used in disaster health-related documents on influenza pandemics, as the basis for adapting an existing semantic summarizer to the domain. Methods include human review and semantic NLP analysis of a set of relevant documents. This is followed by a pilot-test in which two information specialists use the adapted application for a realistic information seeking task. According to the results, the ontology of influenza epidemics management can be described via a manageable number of semantic relationships that involve concepts from a limited number of semantic types. Test users demonstrate several ways to engage with the application to obtain useful information. This suggests that existing semantic NLP algorithms can be adapted to support information summarization and visualization in influenza epidemics and other disaster health areas. However, additional research is needed in the areas of terminology development (as many relevant relationships and terms are not part of existing standardized vocabularies), NLP, and user interface design. PMID:24311971

  13. Serum testosterone levels and excessive erythrocytosis during the process of adaptation to high altitudes

    PubMed Central

    Gonzales, Gustavo F

    2013-01-01

    Populations living at high altitudes (HAs), particularly in the Peruvian Andes, are characterized by a mixture of subjects with erythrocytosis (16 g dl−121 g dl−1). Elevated haemoglobin values (EE) are associated with chronic mountain sickness, a condition reflecting the lack of adaptation to HA. According to current data, native men from regions of HA are not adequately adapted to live at such altitudes if they have elevated serum testosterone levels. This seems to be due to an increased conversion of dehydroepiandrosterone sulphate (DHEAS) to testosterone. Men with erythrocytosis at HAs show higher serum androstenedione levels and a lower testosterone/androstenedione ratio than men with EE, suggesting reduced 17beta-hydroxysteroid dehydrogenase (17beta-HSD) activity. Lower 17beta-HSD activity via Δ4-steroid production in men with erythrocytosis at HA may protect against elevated serum testosterone levels, thus preventing EE. The higher conversion of DHEAS to testosterone in subjects with EE indicates increased 17beta-HSD activity via the Δ5-pathway. Currently, there are various situations in which people live (human biodiversity) with low or high haemoglobin levels at HA. Antiquity could be an important adaptation component for life at HA, and testosterone seems to participate in this process. PMID:23524530

  14. Adaptive Sparse Signal Processing for Discrimination of Satellite-based Radiofrequency (RF) Recordings of Lightning Events

    NASA Astrophysics Data System (ADS)

    Moody, D. I.; Smith, D. A.; Heavner, M.; Hamlin, T.

    2014-12-01

    Ongoing research at Los Alamos National Laboratory studies the Earth's radiofrequency (RF) background utilizing satellite-based RF observations of terrestrial lightning. The Fast On-orbit Recording of Transient Events (FORTE) satellite, launched in 1997, provided a rich RF lightning database. Application of modern pattern recognition techniques to this dataset may further lightning research in the scientific community, and potentially improve on-orbit processing and event discrimination capabilities for future satellite payloads. We extend sparse signal processing techniques to radiofrequency (RF) transient signals, and specifically focus on improved signature extraction using sparse representations in data-adaptive dictionaries. We present various processing options and classification results for on-board discharges, and discuss robustness and potential for capability development.

  15. Adaptation of the IBM ECR (electric cantilever robot) robot to plutonium processing applications

    SciTech Connect

    Armantrout, G.A.; Pedrotti, L.R. ); Halter, E.A.; Crossfield, M. )

    1990-12-01

    The changing regulatory climate in the US is adding increasing incentive to reduce operator dose and TRU waste for DOE plutonium processing operations. To help achieve that goal the authors have begun adapting a small commercial overhead gantry robot, the IBM electric cantilever robot (ECR), to plutonium processing applications. Steps are being taken to harden this robot to withstand the dry, often abrasive, environment within a plutonium glove box and to protect the electronic components against alpha radiation. A mock-up processing system for the reduction of the oxide to a metal was prepared and successfully demonstrated. Design of a working prototype is now underway using the results of this mock-up study. 7 figs., 4 tabs.

  16. High-quality laser cutting of ceramics through adapted process techniques

    NASA Astrophysics Data System (ADS)

    Toenshoff, Hans K.; Gonschior, Martin

    1994-02-01

    Laser cutting of ceramics is a promising alternative to conventional machining methods. In this paper, processing results using several lasers and beam guidance optics to cut different oxide and non-oxide ceramics are presented. Adapted process parameters in pulsed mode operation provide high quality cut surfaces at acceptable feed rates. Especially Nd:YAG lasers can be used for cutting extremely brittle ceramics. The use of fiber optics for beam guidance, however, is limited to certain ceramics with high fracture toughness, due to a loss in beam quality. In laser cutting of ceramics, thermally-induced crack damage is one of the main problems preventing a wider use of this method in industry. Several methods were investigated in order to reduce crack formation. Adapted pulse parameters, calculated by a theoretical model, and also a newly-developed process control system lead to a remarkable reduction of crack damage. Crack-free cutting can be obtained by preheating the workpiece above a temperature of 1.100 degree(s)C. Based on these investigations, requirements on laser systems for ceramics cutting are worked out.

  17. Mechanisms for Rapid Adaptive Control of Motion Processing in Macaque Visual Cortex

    PubMed Central

    Baker, Pamela M.; Ahmed, Bashir; Kohn, Adam; Bair, Wyeth

    2015-01-01

    A key feature of neural networks is their ability to rapidly adjust their function, including signal gain and temporal dynamics, in response to changes in sensory inputs. These adjustments are thought to be important for optimizing the sensitivity of the system, yet their mechanisms remain poorly understood. We studied adaptive changes in temporal integration in direction-selective cells in macaque primary visual cortex, where specific hypotheses have been proposed to account for rapid adaptation. By independently stimulating direction-specific channels, we found that the control of temporal integration of motion at one direction was independent of motion signals driven at the orthogonal direction. We also found that individual neurons can simultaneously support two different profiles of temporal integration for motion in orthogonal directions. These findings rule out a broad range of adaptive mechanisms as being key to the control of temporal integration, including untuned normalization and nonlinearities of spike generation and somatic adaptation in the recorded direction-selective cells. Such mechanisms are too broadly tuned, or occur too far downstream, to explain the channel-specific and multiplexed temporal integration that we observe in single neurons. Instead, we are compelled to conclude that parallel processing pathways are involved, and we demonstrate one such circuit using a computer model. This solution allows processing in different direction/orientation channels to be separately optimized and is sensible given that, under typical motion conditions (e.g., translation or looming), speed on the retina is a function of the orientation of image components. SIGNIFICANCE STATEMENT Many neurons in visual cortex are understood in terms of their spatial and temporal receptive fields. It is now known that the spatiotemporal integration underlying visual responses is not fixed but depends on the visual input. For example, neurons that respond selectively to

  18. Adapting high-level language programs for parallel processing using data flow

    NASA Technical Reports Server (NTRS)

    Standley, Hilda M.

    1988-01-01

    EASY-FLOW, a very high-level data flow language, is introduced for the purpose of adapting programs written in a conventional high-level language to a parallel environment. The level of parallelism provided is of the large-grained variety in which parallel activities take place between subprograms or processes. A program written in EASY-FLOW is a set of subprogram calls as units, structured by iteration, branching, and distribution constructs. A data flow graph may be deduced from an EASY-FLOW program.

  19. Motion adaptive signal integration-high dynamic range (MASI-HDR) video processing for dynamic platforms

    NASA Astrophysics Data System (ADS)

    Piacentino, Michael R.; Berends, David C.; Zhang, David C.; Gudis, Eduardo

    2013-05-01

    Two of the biggest challenges in designing U×V vision systems are properly representing high dynamic range scene content using low dynamic range components and reducing camera motion blur. SRI's MASI-HDR (Motion Adaptive Signal Integration-High Dynamic Range) is a novel technique for generating blur-reduced video using multiple captures for each displayed frame while increasing the effective camera dynamic range by four bits or more. MASI-HDR processing thus provides high performance video from rapidly moving platforms in real-world conditions in low latency real time, enabling even the most demanding applications on air, ground and water.

  20. Workload-Matched Adaptive Automation Support of Air Traffic Controller Information Processing Stages

    NASA Technical Reports Server (NTRS)

    Kaber, David B.; Prinzel, Lawrence J., III; Wright, Melanie C.; Clamann, Michael P.

    2002-01-01

    Adaptive automation (AA) has been explored as a solution to the problems associated with human-automation interaction in supervisory control environments. However, research has focused on the performance effects of dynamic control allocations of early stage sensory and information acquisition functions. The present research compares the effects of AA to the entire range of information processing stages of human operators, such as air traffic controllers. The results provide evidence that the effectiveness of AA is dependent on the stage of task performance (human-machine system information processing) that is flexibly automated. The results suggest that humans are better able to adapt to AA when applied to lower-level sensory and psychomotor functions, such as information acquisition and action implementation, as compared to AA applied to cognitive (analysis and decision-making) tasks. The results also provide support for the use of AA, as compared to completely manual control. These results are discussed in terms of implications for AA design for aviation.

  1. Effect of Margin Design and Processing Steps on Marginal Adaptation of Captek Restorations

    PubMed Central

    Shih, Amy; Flinton, Robert; Vaidyanathan, Jayalakshmi; Vaidyanathan, Tritala

    2011-01-01

    This study examined the effect of four margin designs on marginal adaptation of Captek crowns during selected processing steps. Twenty-four Captek crowns were fabricated, six each of four margin designs: shoulder (Group A), chamfer (Group B), chamfer with bevel (Group C), and shoulder with bevel (Group D). Marginal discrepancies between crowns and matching dies were measured at selected points for each sample at the coping stage (Stage 1), following porcelain application (Stage 2) and cementation (Stage 3). Digital imaging methods were used to measure marginal gap. The results indicate decreasing trend of margin gap as a function of margin design in the order A>B>C>D. Between processing steps, the trend was in the order Stage 3 < Stage 1 < Stage 2. Porcelain firing had no significant effect on marginal adaptation, but cementation decreased the marginal gap. Generally, the margin gap in Captek restorations were in all cases less than the reported acceptable range of margin gaps for ceramometal restorations. These results are clinically favorable outcomes and may be associated with the ductility and burnishability of matrix phase in Captek metal coping margins. PMID:21991488

  2. [Super sweet corn hybrid sh2 adaptability for industrial canning process].

    PubMed

    Ortiz de Bertorelli, Ligia; De Venanzi, Frank; Alfonzo, Braunnier; Camacho, Candelario

    2002-12-01

    The super sweet corns Krispy king, Victor and 324 (sh2 hybrids) were evaluated to determine their adaptabilities to the industrial canning process as whole kernels. All these hybrids and Bonanza (control) were sown in San Joaquín (Carabobo, Venezuela), harvested and canned. After 110 days storage at room temperature they were analyzed to be compared physically, chemically and sensorially with Bonanza hybrid. Results did not show significant differences among most of the physical characteristics, except for percentage of broken kernels which was higher in 324 hybrid. Chemical parameters showed significant differences (P < 0.05) comparing each super sweet hybrid with Bonanza. The super sweet hybrids presented a higher sugar content and soluble solid of the brine than Bonanza, also a lower pH. The super sweet whole kernel presented a lower soluble solids content than Bonanza but they were not significant (Krispy king and 324). Appearance, odor and overall quality were the same for super sweet hybrids and Bonanza (su). Color, flavor and sweetness were better for 324 than all the other hybrids. Super sweet hybrids presented a very good adaptation to the canning process, having as an advantage that doesn't require sugar addition in the brine and a very good texture (firm and crispy). PMID:12868279

  3. A self-adaptive parameter optimization algorithm in a real-time parallel image processing system.

    PubMed

    Li, Ge; Zhang, Xuehe; Zhao, Jie; Zhang, Hongli; Ye, Jianwei; Zhang, Weizhe

    2013-01-01

    Aiming at the stalemate that precision, speed, robustness, and other parameters constrain each other in the parallel processed vision servo system, this paper proposed an adaptive load capacity balance strategy on the servo parameters optimization algorithm (ALBPO) to improve the computing precision and to achieve high detection ratio while not reducing the servo circle. We use load capacity functions (LC) to estimate the load for each processor and then make continuous self-adaptation towards a balanced status based on the fluctuated LC results; meanwhile, we pick up a proper set of target detection and location parameters according to the results of LC. Compared with current load balance algorithm, the algorithm proposed in this paper is proceeded under an unknown informed status about the maximum load and the current load of the processors, which means it has great extensibility. Simulation results showed that the ALBPO algorithm has great merits on load balance performance, realizing the optimization of QoS for each processor, fulfilling the balance requirements of servo circle, precision, and robustness of the parallel processed vision servo system. PMID:24174920

  4. Automatic ultrasonic imaging system with adaptive-learning-network signal-processing techniques

    SciTech Connect

    O'Brien, L.J.; Aravanis, N.A.; Gouge, J.R. Jr.; Mucciardi, A.N.; Lemon, D.K.; Skorpik, J.R.

    1982-04-01

    A conventional pulse-echo imaging system has been modified to operate with a linear ultrasonic array and associated digital electronics to collect data from a series of defects fabricated in aircraft quality steel blocks. A thorough analysis of the defect responses recorded with this modified system has shown that considerable improvements over conventional imaging approaches can be obtained in the crucial areas of defect detection and characterization. A combination of advanced signal processing concepts with the Adaptive Learning Network (ALN) methodology forms the basis for these improvements. Use of established signal processing algorithms such as temporal and spatial beam-forming in concert with a sophisticated detector has provided a reliable defect detection scheme which can be implemented in a microprocessor-based system to operate in an automatic mode.

  5. Adaptive sparse signal processing for discrimination of satellite-based radiofrequency (RF) recordings of lightning events

    NASA Astrophysics Data System (ADS)

    Moody, Daniela I.; Smith, David A.

    2015-05-01

    For over two decades, Los Alamos National Laboratory programs have included an active research effort utilizing satellite observations of terrestrial lightning to learn more about the Earth's RF background. The FORTE satellite provided a rich satellite lightning database, which has been previously used for some event classification, and remains relevant for advancing lightning research. Lightning impulses are dispersed as they travel through the ionosphere, appearing as nonlinear chirps at the receiver on orbit. The data processing challenge arises from the combined complexity of the lightning source model, the propagation medium nonlinearities, and the sensor artifacts. We continue to develop modern event classification capability on the FORTE database using adaptive signal processing combined with compressive sensing techniques. The focus of our work is improved feature extraction using sparse representations in overcomplete analytical dictionaries. We explore two possible techniques for detecting lightning events, and showcase the algorithms on few representative data examples. We present preliminary results of our work and discuss future development.

  6. Combining molecular evolution and environmental genomics to unravel adaptive processes of MHC class IIB diversity in European minnows (Phoxinus phoxinus)

    PubMed Central

    Collin, Helene; Burri, Reto; Comtesse, Fabien; Fumagalli, Luca

    2013-01-01

    Abstract Host–pathogen interactions are a major evolutionary force promoting local adaptation. Genes of the major histocompatibility complex (MHC) represent unique candidates to investigate evolutionary processes driving local adaptation to parasite communities. The present study aimed at identifying the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of European minnows (Phoxinus phoxinus). To this end, we isolated and genotyped exon 2 of two MHCIIB gene duplicates (DAB1 and DAB3) and 1′665 amplified fragment length polymorphism (AFLP) markers in nine populations, and characterized local bacterial communities by 16S rDNA barcoding using 454 amplicon sequencing. Both MHCIIB loci exhibited signs of historical balancing selection. Whereas genetic differentiation exceeded that of neutral markers at both loci, the populations' genetic diversities were positively correlated with local pathogen diversities only at DAB3. Overall, our results suggest pathogen-mediated local adaptation in European minnows at both MHCIIB loci. While at DAB1 selection appears to favor different alleles among populations, this is only partially the case in DAB3, which appears to be locally adapted to pathogen communities in terms of genetic diversity. These results provide new insights into the importance of host–pathogen interactions in driving local adaptation in the European minnow, and highlight that the importance of adaptive processes driving MHCIIB gene evolution may differ among duplicates within species, presumably as a consequence of alternative selective regimes or different genomic context. Using next-generation sequencing, the present manuscript identifies the relative roles of neutral and adaptive processes driving the evolution of MHC class IIB (MHCIIB) genes in natural populations of a cyprinid fish: the European minnow (Phoxinus phoxinus). We highlight that the relative importance of neutral

  7. The Process of Adaptation of a Community-Level, Evidence-Based Intervention for HIV-Positive African American Men Who Have Sex with Men in Two Cities

    ERIC Educational Resources Information Center

    Robinson, Beatrice E.; Galbraith, Jennifer S.; Lund, Sharon M.; Hamilton, Autumn R.; Shankle, Michael D.

    2012-01-01

    We describe the process of adapting a community-level, evidence-based behavioral intervention (EBI), Community PROMISE, for HIV-positive African American men who have sex with men (AAMSM). The Centers for Disease Control and Prevention (CDC) Map of the Adaptation Process (MAP) guided the adaptation process for this new target population by two…

  8. Human Topological Task Adapted for Rats: Spatial Information Processes of the Parietal Cortex

    PubMed Central

    Goodrich-Hunsaker, Naomi J.; Howard, Brian P.; Hunsaker, Michael R.; Kesner, Raymond P.

    2008-01-01

    Human research has shown that lesions of the parietal cortex disrupt spatial information processing, specifically topological information. Similar findings have been found in nonhumans. It has been difficult to determine homologies between human and non-human mnemonic mechanisms for spatial information processing because methodologies and neuropathology differ. The first objective of the present study was to adapt a previously established human task for rats. The second objective was to better characterize the role of parietal cortex (PC) and dorsal hippocampus (dHPC) for topological spatial information processing. Rats had to distinguish whether a ball inside a ring or a ball outside a ring was the correct, rewarded object. After rats reached criterion on the task (>95%) they were randomly assigned to a lesion group (control, PC, dHPC). Animals were then re-tested. Post-surgery data show that controls were 94% correct on average, dHPC rats were 89% correct on average, and PC rats were 56% correct on average. The results from the present study suggest that the parietal cortex, but not the dHPC processes topological spatial information. The present data are the first to support comparable topological spatial information processes of the parietal cortex in humans and rats. PMID:18571941

  9. Spectral Doppler estimation utilizing 2-D spatial information and adaptive signal processing.

    PubMed

    Ekroll, Ingvild K; Torp, Hans; Løvstakken, Lasse

    2012-06-01

    The trade-off between temporal and spectral resolution in conventional pulsed wave (PW) Doppler may limit duplex/triplex quality and the depiction of rapid flow events. It is therefore desirable to reduce the required observation window (OW) of the Doppler signal while preserving the frequency resolution. This work investigates how the required observation time can be reduced by adaptive spectral estimation utilizing 2-D spatial information obtained by parallel receive beamforming. Four adaptive estimation techniques were investigated, the power spectral Capon (PSC) method, the amplitude and phase estimation (APES) technique, multiple signal classification (MUSIC), and a projection-based version of the Capon technique. By averaging radially and laterally, the required covariance matrix could successfully be estimated without temporal averaging. Useful PW spectra of high resolution and contrast could be generated from ensembles corresponding to those used in color flow imaging (CFI; OW = 10). For a given OW, the frequency resolution could be increased compared with the Welch approach, in cases in which the transit time was higher or comparable to the observation time. In such cases, using short or long pulses with unfocused or focused transmit, an increase in temporal resolution of up to 4 to 6 times could be obtained in in vivo examples. It was further shown that by using adaptive signal processing, velocity spectra may be generated without high-pass filtering the Doppler signal. With the proposed approach, spectra retrospectively calculated from CFI may become useful for unfocused as well as focused imaging. This application may provide new clinical information by inspection of velocity spectra simultaneously from several spatial locations. PMID:22711413

  10. Neuroelectric adaptations to cognitive processing in virtual environments: an exercise-related approach.

    PubMed

    Vogt, Tobias; Herpers, Rainer; Scherfgen, David; Strüder, Heiko K; Schneider, Stefan

    2015-04-01

    Recently, virtual environments (VEs) are suggested to encourage users to exercise regularly. The benefits of chronic exercise on cognitive performance are well documented in non-VE neurophysiological and behavioural studies. Based on event-related potentials (ERP) such as the N200 and P300, cognitive processing may be interpreted on a neuronal level. However, exercise-related neuroelectric adaptation in VE remains widely unclear and thus characterizes the primary aim of the present study. Twenty-two healthy participants performed active (moderate cycling exercise) and passive (no exercise) sessions in three VEs (control, front, surround), each generating a different sense of presence. Within sessions, conditions were randomly assigned, each lasting 5 min and including a choice reaction-time task to assess cognitive performance. According to the international 10:20 system, EEG with real-time triggered stimulus onset was recorded, and peaks of N200 and P300 components (amplitude, latency) were exported for analysis. Heart rate was recorded, and sense of presence assessed prior to and following each session and condition. Results revealed an increase in ERP amplitudes (N200: p < 0.001; P300: p < 0.001) and latencies (N200: p < 0.001) that were most pronounced over fronto-central and occipital electrode sites relative to an increased sense of presence (p < 0.001); however, ERP were not modulated by exercise (each p > 0.05). Hypothesized to mirror cognitive processing, decreases of cognitive performance's accuracy and reaction time failed significance. With respect to previous research, the present neuroelectric adaptation gives reason to believe in compensative neuronal resources that balance demanding cognitive processing in VE to avoid behavioural inefficiency. PMID:25630906

  11. An adaptive threshold based image processing technique for improved glaucoma detection and classification.

    PubMed

    Issac, Ashish; Partha Sarathi, M; Dutta, Malay Kishore

    2015-11-01

    Glaucoma is an optic neuropathy which is one of the main causes of permanent blindness worldwide. This paper presents an automatic image processing based method for detection of glaucoma from the digital fundus images. In this proposed work, the discriminatory parameters of glaucoma infection, such as cup to disc ratio (CDR), neuro retinal rim (NRR) area and blood vessels in different regions of the optic disc has been used as features and fed as inputs to learning algorithms for glaucoma diagnosis. These features which have discriminatory changes with the occurrence of glaucoma are strategically used for training the classifiers to improve the accuracy of identification. The segmentation of optic disc and cup based on adaptive threshold of the pixel intensities lying in the optic nerve head region. Unlike existing methods the proposed algorithm is based on an adaptive threshold that uses local features from the fundus image for segmentation of optic cup and optic disc making it invariant to the quality of the image and noise content which may find wider acceptability. The experimental results indicate that such features are more significant in comparison to the statistical or textural features as considered in existing works. The proposed work achieves an accuracy of 94.11% with a sensitivity of 100%. A comparison of the proposed work with the existing methods indicates that the proposed approach has improved accuracy of classification glaucoma from a digital fundus which may be considered clinically significant. PMID:26321351

  12. Analysis of adaptive forward-backward diffusion flows with applications in image processing

    NASA Astrophysics Data System (ADS)

    Surya Prasath, V. B.; Urbano, José Miguel; Vorotnikov, Dmitry

    2015-10-01

    The nonlinear diffusion model introduced by Perona and Malik (1990 IEEE Trans. Pattern Anal. Mach. Intell. 12 629-39) is well suited to preserve salient edges while restoring noisy images. This model overcomes well-known edge smearing effects of the heat equation by using a gradient dependent diffusion function. Despite providing better denoizing results, the analysis of the PM scheme is difficult due to the forward-backward nature of the diffusion flow. We study a related adaptive forward-backward diffusion equation which uses a mollified inverse gradient term engrafted in the diffusion term of a general nonlinear parabolic equation. We prove a series of existence, uniqueness and regularity results for viscosity, weak and dissipative solutions for such forward-backward diffusion flows. In particular, we introduce a novel functional framework for wellposedness of flows of total variation type. A set of synthetic and real image processing examples are used to illustrate the properties and advantages of the proposed adaptive forward-backward diffusion flows.

  13. Does Variation in Genome Sizes Reflect Adaptive or Neutral Processes? New Clues from Passiflora

    PubMed Central

    Fonseca, Tamara C.; Salzano, Francisco M.; Bonatto, Sandro L.; Freitas, Loreta B.

    2011-01-01

    One of the long-standing paradoxes in genomic evolution is the observation that much of the genome is composed of repetitive DNA which has been typically regarded as superfluous to the function of the genome in generating phenotypes. In this work, we used comparative phylogenetic approaches to investigate if the variations in genome sizes (GS) should be considered as adaptive or neutral processes by the comparison between GS and flower diameters (FD) of 50 Passiflora species, more specifically, within its two most species-rich subgenera, Passiflora and Decaloba. For this, we have constructed a phylogenetic tree of these species, estimated GS and FD of them, inferred the tempo and mode of evolution of these traits and their correlations, using both current and phylogenetically independent contrasted values. We found significant correlations among the traits, when considering the complete set of data or only the subgenus Passiflora, whereas no correlations were observed within Decaloba. Herein, we present convincing evidence of adaptive evolution of GS, as well as clues that this pattern is limited by a minimum genome size, which could reduce both the possibilities of changes in GS and the possibility of phenotypic responses to environment changes. PMID:21464897

  14. Therapeutic adherence and competence scales for Developmentally Adapted Cognitive Processing Therapy for adolescents with PTSD

    PubMed Central

    Gutermann, Jana; Schreiber, Franziska; Matulis, Simone; Stangier, Ulrich; Rosner, Rita; Steil, Regina

    2015-01-01

    Background The assessment of therapeutic adherence and competence is often neglected in psychotherapy research, particularly in children and adolescents; however, both variables are crucial for the interpretation of treatment effects. Objective Our aim was to develop, adapt, and pilot two scales to assess therapeutic adherence and competence in a recent innovative program, Developmentally Adapted Cognitive Processing Therapy (D-CPT), for adolescents suffering from posttraumatic stress disorder (PTSD) after childhood abuse. Method Two independent raters assessed 30 randomly selected sessions involving 12 D-CPT patients (age 13–20 years, M age=16.75, 91.67% female) treated by 11 therapists within the pilot phase of a multicenter study. Results Three experts confirmed the relevance and appropriateness of each item. All items and total scores for adherence (intraclass correlation coefficients [ICC]=0.76–1.00) and competence (ICC=0.78–0.98) yielded good to excellent inter-rater reliability. Cronbach's alpha was 0.59 for the adherence scale and 0.96 for the competence scale. Conclusions The scales reliably assess adherence and competence in D-CPT for adolescent PTSD patients. The ratings can be helpful in the interpretation of treatment effects, the assessment of mediator variables, and the identification and training of therapeutic skills that are central to achieving good treatment outcomes. Both adherence and competence will be assessed as possible predictor variables for treatment success in future D-CPT trials. PMID:25791915

  15. Application of an adaptive plan to the configuration of nonlinear image-processing algorithms

    NASA Astrophysics Data System (ADS)

    Chu, Chee-Hung H.

    1990-07-01

    The application of an adaptive plan to the design of a class of nonlinear digital image processing operators known as stack filters is presented in this paper. The adaptive plan is based on the mechanics found in genetics and natural selection. Such learning mechanisms have become known as genetic algorithms. A stack filter is characterized by the coefficients of its underlying positive Boolean function. This set of coefficients constitute a binary string, referred to as a chromosome in a genetic algorithm, that represents that particular filter configuration. A fitness value for each chromosome is computed based on the performance of the associated filter in specific tasks such as noise suppression. A population of chromosomes is maintained by the genetic algorithm, and new generations are formed by selecting mating pairs based on their fitness values. Genetic operators such as crossover or mutation are applied to the mating pairs to form offsprings. By exchanging some substrings of the two parent-chromosomes, the crossover operator can bring different blocks of genes that result in good performance together into one chromosome that yields the best performance. Empirical results show that this method is capable of configuring stack filters that are effective in impulsive noise suppression.

  16. Tug-of-war between driver and passenger mutations in cancer and other adaptive processes.

    PubMed

    McFarland, Christopher D; Mirny, Leonid A; Korolev, Kirill S

    2014-10-21

    Cancer progression is an example of a rapid adaptive process where evolving new traits is essential for survival and requires a high mutation rate. Precancerous cells acquire a few key mutations that drive rapid population growth and carcinogenesis. Cancer genomics demonstrates that these few driver mutations occur alongside thousands of random passenger mutations--a natural consequence of cancer's elevated mutation rate. Some passengers are deleterious to cancer cells, yet have been largely ignored in cancer research. In population genetics, however, the accumulation of mildly deleterious mutations has been shown to cause population meltdown. Here we develop a stochastic population model where beneficial drivers engage in a tug-of-war with frequent mildly deleterious passengers. These passengers present a barrier to cancer progression describable by a critical population size, below which most lesions fail to progress, and a critical mutation rate, above which cancers melt down. We find support for this model in cancer age-incidence and cancer genomics data that also allow us to estimate the fitness advantage of drivers and fitness costs of passengers. We identify two regimes of adaptive evolutionary dynamics and use these regimes to understand successes and failures of different treatment strategies. A tumor's load of deleterious passengers can explain previously paradoxical treatment outcomes and suggest that it could potentially serve as a biomarker of response to mutagenic therapies. The collective deleterious effect of passengers is currently an unexploited therapeutic target. We discuss how their effects might be exacerbated by current and future therapies. PMID:25277973

  17. Algorithms and architectures for adaptive least squares signal processing, with applications in magnetoencephalography

    SciTech Connect

    Lewis, P.S.

    1988-10-01

    Least squares techniques are widely used in adaptive signal processing. While algorithms based on least squares are robust and offer rapid convergence properties, they also tend to be complex and computationally intensive. To enable the use of least squares techniques in real-time applications, it is necessary to develop adaptive algorithms that are efficient and numerically stable, and can be readily implemented in hardware. The first part of this work presents a uniform development of general recursive least squares (RLS) algorithms, and multichannel least squares lattice (LSL) algorithms. RLS algorithms are developed for both direct estimators, in which a desired signal is present, and for mixed estimators, in which no desired signal is available, but the signal-to-data cross-correlation is known. In the second part of this work, new and more flexible techniques of mapping algorithms to array architectures are presented. These techniques, based on the synthesis and manipulation of locally recursive algorithms (LRAs), have evolved from existing data dependence graph-based approaches, but offer the increased flexibility needed to deal with the structural complexities of the RLS and LSL algorithms. Using these techniques, various array architectures are developed for each of the RLS and LSL algorithms and the associated space/time tradeoffs presented. In the final part of this work, the application of these algorithms is demonstrated by their employment in the enhancement of single-trial auditory evoked responses in magnetoencephalography. 118 refs., 49 figs., 36 tabs.

  18. Adaptive Integrated Optical Bragg Grating in Semiconductor Waveguide Suitable for Optical Signal Processing

    NASA Astrophysics Data System (ADS)

    Moniem, T. A.

    2016-05-01

    This article presents a methodology for an integrated Bragg grating using an alloy of GaAs, AlGaAs, and InGaAs with a controllable refractive index to obtain an adaptive Bragg grating suitable for many applications on optical processing and adaptive control systems, such as limitation and filtering. The refractive index of a Bragg grating is controlled by using an external electric field for controlling periodic modulation of the refractive index of the active waveguide region. The designed Bragg grating has refractive indices programmed by using that external electric field. This article presents two approaches for designing the controllable refractive indices active region of a Bragg grating. The first approach is based on the modification of a planar micro-strip structure of the iGaAs traveling wave as the active region, and the second is based on the modification of self-assembled InAs/GaAs quantum dots of an alloy from GaAs and InGaAs with a GaP traveling wave. The overall design and results are discussed through numerical simulation by using the finite-difference time-domain, plane wave expansion, and opto-wave simulation methods to confirm its operation and feasibility.

  19. Intelligent Modeling Combining Adaptive Neuro Fuzzy Inference System and Genetic Algorithm for Optimizing Welding Process Parameters

    NASA Astrophysics Data System (ADS)

    Gowtham, K. N.; Vasudevan, M.; Maduraimuthu, V.; Jayakumar, T.

    2011-04-01

    Modified 9Cr-1Mo ferritic steel is used as a structural material for steam generator components of power plants. Generally, tungsten inert gas (TIG) welding is preferred for welding of these steels in which the depth of penetration achievable during autogenous welding is limited. Therefore, activated flux TIG (A-TIG) welding, a novel welding technique, has been developed in-house to increase the depth of penetration. In modified 9Cr-1Mo steel joints produced by the A-TIG welding process, weld bead width, depth of penetration, and heat-affected zone (HAZ) width play an important role in determining the mechanical properties as well as the performance of the weld joints during service. To obtain the desired weld bead geometry and HAZ width, it becomes important to set the welding process parameters. In this work, adaptative neuro fuzzy inference system is used to develop independent models correlating the welding process parameters like current, voltage, and torch speed with weld bead shape parameters like depth of penetration, bead width, and HAZ width. Then a genetic algorithm is employed to determine the optimum A-TIG welding process parameters to obtain the desired weld bead shape parameters and HAZ width.

  20. Usability of clinical decision support system as a facilitator for learning the assistive technology adaptation process.

    PubMed

    Danial-Saad, Alexandra; Kuflik, Tsvi; Weiss, Patrice L Tamar; Schreuer, Naomi

    2016-01-01

    The aim of this study was to evaluate the usability of Ontology Supported Computerized Assistive Technology Recommender (OSCAR), a Clinical Decision Support System (CDSS) for the assistive technology adaptation process, its impact on learning the matching process, and to determine the relationship between its usability and learnability. Two groups of expert and novice clinicians (total, n = 26) took part in this study. Each group filled out system usability scale (SUS) to evaluate OSCAR's usability. The novice group completed a learning questionnaire to assess OSCAR's effect on their ability to learn the matching process. Both groups rated OSCAR's usability as "very good", (M [SUS] = 80.7, SD = 11.6, median = 83.7) by the novices, and (M [SUS] = 81.2, SD = 6.8, median = 81.2) by the experts. The Mann-Whitney results indicated that no significant differences were found between the expert and novice groups in terms of OSCAR's usability. A significant positive correlation existed between the usability of OSCAR and the ability to learn the adaptation process (rs = 0.46, p = 0.04). Usability is an important factor in the acceptance of a system. The successful application of user-centered design principles during the development of OSCAR may serve as a case study that models the significant elements to be considered, theoretically and practically in developing other systems. Implications for Rehabilitation Creating a CDSS with a focus on its usability is an important factor for its acceptance by its users. Successful usability outcomes can impact the learning process of the subject matter in general, and the AT prescription process in particular. The successful application of User-Centered Design principles during the development of OSCAR may serve as a case study that models the significant elements to be considered, theoretically and practically. The study emphasizes the importance of close collaboration between the developers and

  1. Improving performance of natural language processing part-of-speech tagging on clinical narratives through domain adaptation

    PubMed Central

    Ferraro, Jeffrey P; Daumé, Hal; DuVall, Scott L; Chapman, Wendy W; Harkema, Henk; Haug, Peter J

    2013-01-01

    Objective Natural language processing (NLP) tasks are commonly decomposed into subtasks, chained together to form processing pipelines. The residual error produced in these subtasks propagates, adversely affecting the end objectives. Limited availability of annotated clinical data remains a barrier to reaching state-of-the-art operating characteristics using statistically based NLP tools in the clinical domain. Here we explore the unique linguistic constructions of clinical texts and demonstrate the loss in operating characteristics when out-of-the-box part-of-speech (POS) tagging tools are applied to the clinical domain. We test a domain adaptation approach integrating a novel lexical-generation probability rule used in a transformation-based learner to boost POS performance on clinical narratives. Methods Two target corpora from independent healthcare institutions were constructed from high frequency clinical narratives. Four leading POS taggers with their out-of-the-box models trained from general English and biomedical abstracts were evaluated against these clinical corpora. A high performing domain adaptation method, Easy Adapt, was compared to our newly proposed method ClinAdapt. Results The evaluated POS taggers drop in accuracy by 8.5–15% when tested on clinical narratives. The highest performing tagger reports an accuracy of 88.6%. Domain adaptation with Easy Adapt reports accuracies of 88.3–91.0% on clinical texts. ClinAdapt reports 93.2–93.9%. Conclusions ClinAdapt successfully boosts POS tagging performance through domain adaptation requiring a modest amount of annotated clinical data. Improving the performance of critical NLP subtasks is expected to reduce pipeline error propagation leading to better overall results on complex processing tasks. PMID:23486109

  2. Modeling soil processes for adapting agricultural systems to climate variability and change

    NASA Astrophysics Data System (ADS)

    Basso, B.

    2014-12-01

    Climate change, drought, and agricultural intensification are increasing the demand for enhanced resource use efficiency (water, nitrogen and radiation). There is a global consensus between climate and agricultural scientists about the need to quantify the likely impacts of climate change on crop yields due to their significant consequences on food prices as well as the global economy. Crop models have been extensively tested for yields, but their validation for soil water balance, and carbon and nitrogen cycling in agricultural systems has been limited. The objective of this research is to illustrate the importance of modeling soil processes correctly to identify management strategy that allow cropping systems to adapt to climate variability and change. Results from the first phase of the AgMIP soil and crop rotation initiative will also be discussed.

  3. Nonlinear structural response using adaptive dynamic relaxation on a massively-parallel-processing system

    NASA Technical Reports Server (NTRS)

    Oakley, David R.; Knight, Norman F., Jr.

    1994-01-01

    A parallel adaptive dynamic relaxation (ADR) algorithm has been developed for nonlinear structural analysis. This algorithm has minimal memory requirements, is easily parallelizable and scalable to many processors, and is generally very reliable and efficient for highly nonlinear problems. Performance evaluations on single-processor computers have shown that the ADR algorithm is reliable and highly vectorizable, and that it is competitive with direct solution methods for the highly nonlinear problems considered. The present algorithm is implemented on the 512-processor Intel Touchstone DELTA system at Caltech, and it is designed to minimize the extent and frequency of interprocessor communication. The algorithm has been used to solve for the nonlinear static response of two and three dimensional hyperelastic systems involving contact. Impressive relative speedups have been achieved and demonstrate the high scalability of the ADR algorithm. For the class of problems addressed, the ADR algorithm represents a very promising approach for parallel-vector processing.

  4. Multi-objective optimization of gear forging process based on adaptive surrogate meta-models

    NASA Astrophysics Data System (ADS)

    Meng, Fanjuan; Labergere, Carl; Lafon, Pascal; Daniel, Laurent

    2013-05-01

    In forging industry, net shape or near net shape forging of gears has been the subject of considerable research effort in the last few decades. So in this paper, a multi-objective optimization methodology of net shape gear forging process design has been discussed. The study is mainly done in four parts: building parametric CAD geometry model, simulating the forging process, fitting surrogate meta-models and optimizing the process by using an advanced algorithm. In order to maximally appropriate meta-models of the real response, an adaptive meta-model based design strategy has been applied. This is a continuous process: first, bui Id a preliminary version of the meta-models after the initial simulated calculations; second, improve the accuracy and update the meta-models by adding some new representative samplings. By using this iterative strategy, the number of the initial sample points for real numerical simulations is greatly decreased and the time for the forged gear design is significantly shortened. Finally, an optimal design for an industrial application of a 27-teeth gear forging process was introduced, which includes three optimization variables and two objective functions. A 3D FE nu merical simulation model is used to realize the process and an advanced thermo-elasto-visco-plastic constitutive equation is considered to represent the material behavior. The meta-model applied for this example is kriging and the optimization algorithm is NSGA-II. At last, a relatively better Pareto optimal front (POF) is gotten with gradually improving the obtained surrogate meta-models.

  5. Molecular Mechanisms Mediating the Adaptive Regulation of Intestinal Riboflavin Uptake Process

    PubMed Central

    Subramanian, Veedamali S.; Ghosal, Abhisek; Kapadia, Rubina; Nabokina, Svetlana M.; Said, Hamid M.

    2015-01-01

    The intestinal absorption process of vitamin B2 (riboflavin, RF) is carrier-mediated, and all three known human RF transporters, i.e., hRFVT-1, -2, and -3 (products of the SLC52A1, 2 & 3 genes, respectively) are expressed in the gut. We have previously shown that the intestinal RF uptake process is adaptively regulated by substrate level, but little is known about the molecular mechanism(s) involved. Using human intestinal epithelial NCM460 cells maintained under RF deficient and over-supplemented (OS) conditions, we now show that the induction in RF uptake in RF deficiency is associated with an increase in expression of the hRFVT-2 & -3 (but not hRFVT-1) at the protein and mRNA levels. Focusing on hRFVT-3, the predominant transporter in the intestine, we also observed an increase in the level of expression of its hnRNA and activity of its promoter in the RF deficiency state. An increase in the level of expression of the nuclear factor Sp1 (which is important for activity of the SLC52A3 promoter) was observed in RF deficiency, while mutating the Sp1/GC site in the SLC52A3 promoter drastically decreased the level of induction in SLC52A3 promoter activity in RF deficiency. We also observed specific epigenetic changes in the SLC52A3 promoter in RF deficiency. Finally, an increase in hRFVT-3 protein expression at the cell surface was observed in RF deficiency. Results of these investigations show, for the first time, that transcriptional and post-transcriptional mechanisms are involved in the adaptive regulation of intestinal RF uptake by the prevailing substrate level. PMID:26121134

  6. Adaptive step ODE algorithms for the 3D simulation of electric heart activity with graphics processing units.

    PubMed

    Garcia-Molla, V M; Liberos, A; Vidal, A; Guillem, M S; Millet, J; Gonzalez, A; Martinez-Zaldivar, F J; Climent, A M

    2014-01-01

    In this paper we studied the implementation and performance of adaptive step methods for large systems of ordinary differential equations systems in graphics processing units, focusing on the simulation of three-dimensional electric cardiac activity. The Rush-Larsen method was applied in all the implemented solvers to improve efficiency. We compared the adaptive methods with the fixed step methods, and we found that the fixed step methods can be faster while the adaptive step methods are better in terms of accuracy and robustness. PMID:24377685

  7. An adaptive process-based cloud infrastructure for space situational awareness applications

    NASA Astrophysics Data System (ADS)

    Liu, Bingwei; Chen, Yu; Shen, Dan; Chen, Genshe; Pham, Khanh; Blasch, Erik; Rubin, Bruce

    2014-06-01

    Space situational awareness (SSA) and defense space control capabilities are top priorities for groups that own or operate man-made spacecraft. Also, with the growing amount of space debris, there is an increase in demand for contextual understanding that necessitates the capability of collecting and processing a vast amount sensor data. Cloud computing, which features scalable and flexible storage and computing services, has been recognized as an ideal candidate that can meet the large data contextual challenges as needed by SSA. Cloud computing consists of physical service providers and middleware virtual machines together with infrastructure, platform, and software as service (IaaS, PaaS, SaaS) models. However, the typical Virtual Machine (VM) abstraction is on a per operating systems basis, which is at too low-level and limits the flexibility of a mission application architecture. In responding to this technical challenge, a novel adaptive process based cloud infrastructure for SSA applications is proposed in this paper. In addition, the details for the design rationale and a prototype is further examined. The SSA Cloud (SSAC) conceptual capability will potentially support space situation monitoring and tracking, object identification, and threat assessment. Lastly, the benefits of a more granular and flexible cloud computing resources allocation are illustrated for data processing and implementation considerations within a representative SSA system environment. We show that the container-based virtualization performs better than hypervisor-based virtualization technology in an SSA scenario.

  8. Design Process of Flight Vehicle Structures for a Common Bulkhead and an MPCV Spacecraft Adapter

    NASA Technical Reports Server (NTRS)

    Aggarwal, Pravin; Hull, Patrick V.

    2015-01-01

    Design and manufacturing space flight vehicle structures is a skillset that has grown considerably at NASA during that last several years. Beginning with the Ares program and followed by the Space Launch System (SLS); in-house designs were produced for both the Upper Stage and the SLS Multipurpose crew vehicle (MPCV) spacecraft adapter. Specifically, critical design review (CDR) level analysis and flight production drawing were produced for the above mentioned hardware. In particular, the experience of this in-house design work led to increased manufacturing infrastructure for both Marshal Space Flight Center (MSFC) and Michoud Assembly Facility (MAF), improved skillsets in both analysis and design, and hands on experience in building and testing (MSA) full scale hardware. The hardware design and development processes from initiation to CDR and finally flight; resulted in many challenges and experiences that produced valuable lessons. This paper builds on these experiences of NASA in recent years on designing and fabricating flight hardware and examines the design/development processes used, as well as the challenges and lessons learned, i.e. from the initial design, loads estimation and mass constraints to structural optimization/affordability to release of production drawing to hardware manufacturing. While there are many documented design processes which a design engineer can follow, these unique experiences can offer insight into designing hardware in current program environments and present solutions to many of the challenges experienced by the engineering team.

  9. Phoneme restoration and empirical coverage of Interactive Activation and Adaptive Resonance models of human speech processing.

    PubMed

    Grossberg, Stephen; Kazerounian, Sohrob

    2016-08-01

    Magnuson [J. Acoust. Soc. Am. 137, 1481-1492 (2015)] makes claims for Interactive Activation (IA) models and against Adaptive Resonance Theory (ART) models of speech perception. Magnuson also presents simulations that claim to show that the TRACE model can simulate phonemic restoration, which was an explanatory target of the cARTWORD ART model. The theoretical analysis and review herein show that these claims are incorrect. More generally, the TRACE and cARTWORD models illustrate two diametrically opposed types of neural models of speech and language. The TRACE model embodies core assumptions with no analog in known brain processes. The cARTWORD model defines a hierarchy of cortical processing regions whose networks embody cells in laminar cortical circuits as part of the paradigm of laminar computing. cARTWORD further develops ART speech and language models that were introduced in the 1970s. It builds upon Item-Order-Rank working memories, which activate learned list chunks that unitize sequences to represent phonemes, syllables, and words. Psychophysical and neurophysiological data support Item-Order-Rank mechanisms and contradict TRACE representations of time, temporal order, silence, and top-down processing that exhibit many anomalous properties, including hallucinations of non-occurring future phonemes. Computer simulations of the TRACE model are presented that demonstrate these failures. PMID:27586743

  10. Adaptive-weighted bilateral filtering and other pre-processing techniques for optical coherence tomography.

    PubMed

    Anantrasirichai, N; Nicholson, Lindsay; Morgan, James E; Erchova, Irina; Mortlock, Katie; North, Rachel V; Albon, Julie; Achim, Alin

    2014-09-01

    This paper presents novel pre-processing image enhancement algorithms for retinal optical coherence tomography (OCT). These images contain a large amount of speckle causing them to be grainy and of very low contrast. To make these images valuable for clinical interpretation, we propose a novel method to remove speckle, while preserving useful information contained in each retinal layer. The process starts with multi-scale despeckling based on a dual-tree complex wavelet transform (DT-CWT). We further enhance the OCT image through a smoothing process that uses a novel adaptive-weighted bilateral filter (AWBF). This offers the desirable property of preserving texture within the OCT image layers. The enhanced OCT image is then segmented to extract inner retinal layers that contain useful information for eye research. Our layer segmentation technique is also performed in the DT-CWT domain. Finally we describe an OCT/fundus image registration algorithm which is helpful when two modalities are used together for diagnosis and for information fusion. PMID:25034317

  11. Motor learning and cross-limb transfer rely upon distinct neural adaptation processes.

    PubMed

    Stöckel, Tino; Carroll, Timothy J; Summers, Jeffery J; Hinder, Mark R

    2016-08-01

    Performance benefits conferred in the untrained limb after unilateral motor practice are termed cross-limb transfer. Although the effect is robust, the neural mechanisms remain incompletely understood. In this study we used noninvasive brain stimulation to reveal that the neural adaptations that mediate motor learning in the trained limb are distinct from those that underlie cross-limb transfer to the opposite limb. Thirty-six participants practiced a ballistic motor task with their right index finger (150 trials), followed by intermittent theta-burst stimulation (iTBS) applied to the trained (contralateral) primary motor cortex (cM1 group), the untrained (ipsilateral) M1 (iM1 group), or the vertex (sham group). After stimulation, another 150 training trials were undertaken. Motor performance and corticospinal excitability were assessed before motor training, pre- and post-iTBS, and after the second training bout. For all groups, training significantly increased performance and excitability of the trained hand, and performance, but not excitability, of the untrained hand, indicating transfer at the level of task performance. The typical facilitatory effect of iTBS on MEPs was reversed for cM1, suggesting homeostatic metaplasticity, and prior performance gains in the trained hand were degraded, suggesting that iTBS interfered with learning. In stark contrast, iM1 iTBS facilitated both performance and excitability for the untrained hand. Importantly, the effects of cM1 and iM1 iTBS on behavior were exclusive to the hand contralateral to stimulation, suggesting that adaptations within the untrained M1 contribute to cross-limb transfer. However, the neural processes that mediate learning in the trained hemisphere vs. transfer in the untrained hemisphere appear distinct. PMID:27169508

  12. Tug-of-war between driver and passenger mutations in cancer and other adaptive processes

    PubMed Central

    McFarland, Christopher D.; Mirny, Leonid A.; Korolev, Kirill S.

    2014-01-01

    Cancer progression is an example of a rapid adaptive process where evolving new traits is essential for survival and requires a high mutation rate. Precancerous cells acquire a few key mutations that drive rapid population growth and carcinogenesis. Cancer genomics demonstrates that these few driver mutations occur alongside thousands of random passenger mutations—a natural consequence of cancer’s elevated mutation rate. Some passengers are deleterious to cancer cells, yet have been largely ignored in cancer research. In population genetics, however, the accumulation of mildly deleterious mutations has been shown to cause population meltdown. Here we develop a stochastic population model where beneficial drivers engage in a tug-of-war with frequent mildly deleterious passengers. These passengers present a barrier to cancer progression describable by a critical population size, below which most lesions fail to progress, and a critical mutation rate, above which cancers melt down. We find support for this model in cancer age–incidence and cancer genomics data that also allow us to estimate the fitness advantage of drivers and fitness costs of passengers. We identify two regimes of adaptive evolutionary dynamics and use these regimes to understand successes and failures of different treatment strategies. A tumor’s load of deleterious passengers can explain previously paradoxical treatment outcomes and suggest that it could potentially serve as a biomarker of response to mutagenic therapies. The collective deleterious effect of passengers is currently an unexploited therapeutic target. We discuss how their effects might be exacerbated by current and future therapies. PMID:25277973

  13. Predicting Health Care Cost Transitions Using a Multidimensional Adaptive Prediction Process.

    PubMed

    Guo, Xiaobo; Gandy, William; Coberley, Carter; Pope, James; Rula, Elizabeth; Wells, Aaron

    2015-08-01

    Managing population health requires meeting individual care needs while striving for increased efficiency and quality of care. Predictive models can integrate diverse data to provide objective assessment of individual prospective risk to identify individuals requiring more intensive health management in the present. The purpose of this research was to develop and test a predictive modeling approach, Multidimensional Adaptive Prediction Process (MAPP). MAPP is predicated on dividing the population into cost cohorts and then utilizing a collection of models and covariates to optimize future cost prediction for individuals in each cohort. MAPP was tested on 3 years of administrative health care claims starting in 2009 for health plan members (average n=25,143) with evidence of coronary heart disease. A "status quo" reference modeling methodology applied to the total annual population was established for comparative purposes. Results showed that members identified by MAPP contributed $7.9 million and $9.7 million more in 2011 health care costs than the reference model for cohorts increasing in cost or remaining high cost, respectively. Across all cohorts, the additional accurate cost capture of MAPP translated to an annual difference of $1882 per member, a 21% improvement, relative to the reference model. The results demonstrate that improved future cost prediction is achievable using a novel adaptive multiple model approach. Through accurate prospective identification of individuals whose costs are expected to increase, MAPP can help health care entities achieve efficient resource allocation while improving care quality for emergent need individuals who are intermixed among a diverse set of health care consumers. PMID:25607816

  14. Adapting Rational Unified Process (RUP) approach in designing a secure e-Tendering model

    NASA Astrophysics Data System (ADS)

    Mohd, Haslina; Robie, Muhammad Afdhal Muhammad; Baharom, Fauziah; Darus, Norida Muhd; Saip, Mohamed Ali; Yasin, Azman

    2016-08-01

    e-Tendering is an electronic processing of the tender document via internet and allow tenderer to publish, communicate, access, receive and submit all tender related information and documentation via internet. This study aims to design the e-Tendering system using Rational Unified Process approach. RUP provides a disciplined approach on how to assign tasks and responsibilities within the software development process. RUP has four phases that can assist researchers to adjust the requirements of various projects with different scope, problem and the size of projects. RUP is characterized as a use case driven, architecture centered, iterative and incremental process model. However the scope of this study only focusing on Inception and Elaboration phases as step to develop the model and perform only three of nine workflows (business modeling, requirements, analysis and design). RUP has a strong focus on documents and the activities in the inception and elaboration phases mainly concern the creation of diagrams and writing of textual descriptions. The UML notation and the software program, Star UML are used to support the design of e-Tendering. The e-Tendering design based on the RUP approach can contribute to e-Tendering developers and researchers in e-Tendering domain. In addition, this study also shows that the RUP is one of the best system development methodology that can be used as one of the research methodology in Software Engineering domain related to secured design of any observed application. This methodology has been tested in various studies in certain domains, such as in Simulation-based Decision Support, Security Requirement Engineering, Business Modeling and Secure System Requirement, and so forth. As a conclusion, these studies showed that the RUP one of a good research methodology that can be adapted in any Software Engineering (SE) research domain that required a few artifacts to be generated such as use case modeling, misuse case modeling, activity

  15. FLEXBAR—Flexible Barcode and Adapter Processing for Next-Generation Sequencing Platforms

    PubMed Central

    Dodt, Matthias; Roehr, Johannes T.; Ahmed, Rina; Dieterich, Christoph

    2012-01-01

    Quantitative and systems biology approaches benefit from the unprecedented depth of next-generation sequencing. A typical experiment yields millions of short reads, which oftentimes carry particular sequence tags. These tags may be: (a) specific to the sequencing platform and library construction method (e.g., adapter sequences); (b) have been introduced by experimental design (e.g., sample barcodes); or (c) constitute some biological signal (e.g., splice leader sequences in nematodes). Our software FLEXBAR enables accurate recognition, sorting and trimming of sequence tags with maximal flexibility, based on exact overlap sequence alignment. The software supports data formats from all current sequencing platforms, including color-space reads. FLEXBAR maintains read pairings and processes separate barcode reads on demand. Our software facilitates the fine-grained adjustment of sequence tag detection parameters and search regions. FLEXBAR is a multi-threaded software and combines speed with precision. Even complex read processing scenarios might be executed with a single command line call. We demonstrate the utility of the software in terms of read mapping applications, library demultiplexing and splice leader detection. FLEXBAR and additional information is available for academic use from the website: http://sourceforge.net/projects/flexbar/. PMID:24832523

  16. Adaptive convex combination approach for the identification of improper quaternion processes.

    PubMed

    Ujang, Bukhari Che; Jahanchahi, Cyrus; Took, Clive Cheong; Mandic, Danilo P

    2014-01-01

    Data-adaptive optimal modeling and identification of real-world vector sensor data is provided by combining the fractional tap-length (FT) approach with model order selection in the quaternion domain. To account rigorously for the generality of such processes, both second-order circular (proper) and noncircular (improper), the proposed approach in this paper combines the FT length optimization with both the strictly linear quaternion least mean square (QLMS) and widely linear QLMS (WL-QLMS). A collaborative approach based on QLMS and WL-QLMS is shown to both identify the type of processes (proper or improper) and to track their optimal parameters in real time. Analysis shows that monitoring the evolution of the convex mixing parameter within the collaborative approach allows us to track the improperness in real time. Further insight into the properties of those algorithms is provided by establishing a relationship between the steady-state error and optimal model order. The approach is supported by simulations on model order selection and identification of both strictly linear and widely linear quaternion-valued systems, such as those routinely used in renewable energy (wind) and human-centered computing (biomechanics). PMID:24806652

  17. Multispectral image sharpening using a shift-invariant wavelet transform and adaptive processing of multiresolution edges

    USGS Publications Warehouse

    Lemeshewsky, G.P.

    2002-01-01

    Enhanced false color images from mid-IR, near-IR (NIR), and visible bands of the Landsat thematic mapper (TM) are commonly used for visually interpreting land cover type. Described here is a technique for sharpening or fusion of NIR with higher resolution panchromatic (Pan) that uses a shift-invariant implementation of the discrete wavelet transform (SIDWT) and a reported pixel-based selection rule to combine coefficients. There can be contrast reversals (e.g., at soil-vegetation boundaries between NIR and visible band images) and consequently degraded sharpening and edge artifacts. To improve performance for these conditions, I used a local area-based correlation technique originally reported for comparing image-pyramid-derived edges for the adaptive processing of wavelet-derived edge data. Also, using the redundant data of the SIDWT improves edge data generation. There is additional improvement because sharpened subband imagery is used with the edge-correlation process. A reported technique for sharpening three-band spectral imagery used forward and inverse intensity, hue, and saturation transforms and wavelet-based sharpening of intensity. This technique had limitations with opposite contrast data, and in this study sharpening was applied to single-band multispectral-Pan image pairs. Sharpening used simulated 30-m NIR imagery produced by degrading the spatial resolution of a higher resolution reference. Performance, evaluated by comparison between sharpened and reference image, was improved when sharpened subband data were used with the edge correlation.

  18. Adaptive sparse signal processing of on-orbit lightning data using learned dictionaries

    NASA Astrophysics Data System (ADS)

    Moody, Daniela I.; Smith, David A.; Hamlin, Timothy D.; Light, Tess E.; Suszcynsky, David M.

    2013-05-01

    For the past two decades, there has been an ongoing research effort at Los Alamos National Laboratory to learn more about the Earth's radiofrequency (RF) background utilizing satellite-based RF observations of terrestrial lightning. The Fast On-orbit Recording of Transient Events (FORTE) satellite provided a rich RF lighting database, comprising of five years of data recorded from its two RF payloads. While some classification work has been done previously on the FORTE RF database, application of modern pattern recognition techniques may advance lightning research in the scientific community and potentially improve on-orbit processing and event discrimination capabilities for future satellite payloads. We now develop and implement new event classification capability on the FORTE database using state-of-the-art adaptive signal processing combined with compressive sensing and machine learning techniques. The focus of our work is improved feature extraction using sparse representations in learned dictionaries. Conventional localized data representations for RF transients using analytical dictionaries, such as a short-time Fourier basis or wavelets, can be suitable for analyzing some types of signals, but not others. Instead, we learn RF dictionaries directly from data, without relying on analytical constraints or additional knowledge about the signal characteristics, using several established machine learning algorithms. Sparse classification features are extracted via matching pursuit search over the learned dictionaries, and used in conjunction with a statistical classifier to distinguish between lightning types. We present preliminary results of our work and discuss classification scenarios and future development.

  19. FLEXBAR-Flexible Barcode and Adapter Processing for Next-Generation Sequencing Platforms.

    PubMed

    Dodt, Matthias; Roehr, Johannes T; Ahmed, Rina; Dieterich, Christoph

    2012-01-01

    Quantitative and systems biology approaches benefit from the unprecedented depth of next-generation sequencing. A typical experiment yields millions of short reads, which oftentimes carry particular sequence tags. These tags may be: (a) specific to the sequencing platform and library construction method (e.g., adapter sequences); (b) have been introduced by experimental design (e.g., sample barcodes); or (c) constitute some biological signal (e.g., splice leader sequences in nematodes). Our software FLEXBAR enables accurate recognition, sorting and trimming of sequence tags with maximal flexibility, based on exact overlap sequence alignment. The software supports data formats from all current sequencing platforms, including color-space reads. FLEXBAR maintains read pairings and processes separate barcode reads on demand. Our software facilitates the fine-grained adjustment of sequence tag detection parameters and search regions. FLEXBAR is a multi-threaded software and combines speed with precision. Even complex read processing scenarios might be executed with a single command line call. We demonstrate the utility of the software in terms of read mapping applications, library demultiplexing and splice leader detection. FLEXBAR and additional information is available for academic use from the website: http://sourceforge.net/projects/flexbar/. PMID:24832523

  20. High-performance brain-machine interface enabled by an adaptive optimal feedback-controlled point process decoder.

    PubMed

    Shanechi, Maryam M; Orsborn, Amy; Moorman, Helene; Gowda, Suraj; Carmena, Jose M

    2014-01-01

    Brain-machine interface (BMI) performance has been improved using Kalman filters (KF) combined with closed-loop decoder adaptation (CLDA). CLDA fits the decoder parameters during closed-loop BMI operation based on the neural activity and inferred user velocity intention. These advances have resulted in the recent ReFIT-KF and SmoothBatch-KF decoders. Here we demonstrate high-performance and robust BMI control using a novel closed-loop BMI architecture termed adaptive optimal feedback-controlled (OFC) point process filter (PPF). Adaptive OFC-PPF allows subjects to issue neural commands and receive feedback with every spike event and hence at a faster rate than the KF. Moreover, it adapts the decoder parameters with every spike event in contrast to current CLDA techniques that do so on the time-scale of minutes. Finally, unlike current methods that rotate the decoded velocity vector, adaptive OFC-PPF constructs an infinite-horizon OFC model of the brain to infer velocity intention during adaptation. Preliminary data collected in a monkey suggests that adaptive OFC-PPF improves BMI control. OFC-PPF outperformed SmoothBatch-KF in a self-paced center-out movement task with 8 targets. This improvement was due to both the PPF's increased rate of control and feedback compared with the KF, and to the OFC model suggesting that the OFC better approximates the user's strategy. Also, the spike-by-spike adaptation resulted in faster performance convergence compared to current techniques. Thus adaptive OFC-PPF enabled proficient BMI control in this monkey. PMID:25571483

  1. Learning from experience: Event-related potential correlates of reward processing, neural adaptation, and behavioral choice

    PubMed Central

    Walsh, Matthew M.; Anderson, John R.

    2012-01-01

    To behave adaptively, we must learn from the consequences of our actions. Studies using event-related potentials (ERPs) have been informative with respect to the question of how such learning occurs. These studies have revealed a frontocentral negativity termed the feedback-related negativity (FRN) that appears after negative feedback. According to one prominent theory, the FRN tracks the difference between the values of actual and expected outcomes, or reward prediction errors. As such, the FRN provides a tool for studying reward valuation and decision making. We begin this review by examining the neural significance of the FRN. We then examine its functional significance. To understand the cognitive processes that occur when the FRN is generated, we explore variables that influence its appearance and amplitude. Specifically, we evaluate four hypotheses: (1) the FRN encodes a quantitative reward prediction error; (2) the FRN is evoked by outcomes and by stimuli that predict outcomes; (3) the FRN and behavior change with experience; and (4) the system that produces the FRN is maximally engaged by volitional actions. PMID:22683741

  2. Mass Detection in Mammographic Images Using Wavelet Processing and Adaptive Threshold Technique.

    PubMed

    Vikhe, P S; Thool, V R

    2016-04-01

    Detection of mass in mammogram for early diagnosis of breast cancer is a significant assignment in the reduction of the mortality rate. However, in some cases, screening of mass is difficult task for radiologist, due to variation in contrast, fuzzy edges and noisy mammograms. Masses and micro-calcifications are the distinctive signs for diagnosis of breast cancer. This paper presents, a method for mass enhancement using piecewise linear operator in combination with wavelet processing from mammographic images. The method includes, artifact suppression and pectoral muscle removal based on morphological operations. Finally, mass segmentation for detection using adaptive threshold technique is carried out to separate the mass from background. The proposed method has been tested on 130 (45 + 85) images with 90.9 and 91 % True Positive Fraction (TPF) at 2.35 and 2.1 average False Positive Per Image(FP/I) from two different databases, namely Mammographic Image Analysis Society (MIAS) and Digital Database for Screening Mammography (DDSM). The obtained results show that, the proposed technique gives improved diagnosis in the early breast cancer detection. PMID:26811073

  3. Use of adaptive hybrid filtering process in Crohn's disease lesion detection from real capsule endoscopy videos.

    PubMed

    Charisis, Vasileios S; Hadjileontiadis, Leontios J

    2016-03-01

    The aim of this Letter is to present a new capsule endoscopy (CE) image analysis scheme for the detection of small bowel ulcers that relate to Crohn's disease. More specifically, this scheme is based on: (i) a hybrid adaptive filtering (HAF) process, that utilises genetic algorithms to the curvelet-based representation of images for efficient extraction of the lesion-related morphological characteristics, (ii) differential lacunarity (DL) analysis for texture feature extraction from the HAF-filtered images and (iii) support vector machines for robust classification performance. For the training of the proposed scheme, namely HAF-DL, an 800-image database was used and the evaluation was based on ten 30-second long endoscopic videos. Experimental results, along with comparison with other related efforts, have shown that the HAF-DL approach evidently outperforms the latter in the field of CE image analysis for automated lesion detection, providing higher classification results. The promising performance of HAF-DL paves the way for a complete computer-aided diagnosis system that could support the physicians' clinical practice. PMID:27222730

  4. An FPGA-based High Speed Parallel Signal Processing System for Adaptive Optics Testbed

    NASA Astrophysics Data System (ADS)

    Kim, H.; Choi, Y.; Yang, Y.

    In this paper a state-of-the-art FPGA (Field Programmable Gate Array) based high speed parallel signal processing system (SPS) for adaptive optics (AO) testbed with 1 kHz wavefront error (WFE) correction frequency is reported. The AO system consists of Shack-Hartmann sensor (SHS) and deformable mirror (DM), tip-tilt sensor (TTS), tip-tilt mirror (TTM) and an FPGA-based high performance SPS to correct wavefront aberrations. The SHS is composed of 400 subapertures and the DM 277 actuators with Fried geometry, requiring high speed parallel computing capability SPS. In this study, the target WFE correction speed is 1 kHz; therefore, it requires massive parallel computing capabilities as well as strict hard real time constraints on measurements from sensors, matrix computation latency for correction algorithms, and output of control signals for actuators. In order to meet them, an FPGA based real-time SPS with parallel computing capabilities is proposed. In particular, the SPS is made up of a National Instrument's (NI's) real time computer and five FPGA boards based on state-of-the-art Xilinx Kintex 7 FPGA. Programming is done with NI's LabView environment, providing flexibility when applying different algorithms for WFE correction. It also facilitates faster programming and debugging environment as compared to conventional ones. One of the five FPGA's is assigned to measure TTS and calculate control signals for TTM, while the rest four are used to receive SHS signal, calculate slops for each subaperture and correction signal for DM. With this parallel processing capabilities of the SPS the overall closed-loop WFE correction speed of 1 kHz has been achieved. System requirements, architecture and implementation issues are described; furthermore, experimental results are also given.

  5. Adaptive sparse signal processing of on-orbit lightning data using learned dictionaries

    NASA Astrophysics Data System (ADS)

    Moody, D. I.; Hamlin, T.; Light, T. E.; Loveland, R. C.; Smith, D. A.; Suszcynsky, D. M.

    2012-12-01

    For the past two decades, there has been an ongoing research effort at Los Alamos National Laboratory (LANL) to learn more about the Earth's radiofrequency (RF) background utilizing satellite-based RF observations of terrestrial lightning. Arguably the richest satellite lightning database ever recorded is that from the Fast On-orbit Recording of Transient Events (FORTE) satellite, which returned at least five years of data from its two RF payloads after launch in 1997. While some classification work has been done previously on the LANL FORTE RF database, application of modern pattern recognition techniques may further lightning research in the scientific community and potentially improve on-orbit processing and event discrimination capabilities for future satellite payloads. We now develop and implement new event classification capability on the FORTE database using state-of-the-art adaptive signal processing combined with compressive sensing and machine learning techniques. The focus of our work is improved feature extraction using sparse representations in learned dictionaries. Extracting classification features from RF signals typically relies on knowledge of the application domain in order to find feature vectors unique to a signal class and robust against background noise. Conventional localized data representations for RF transients using analytical dictionaries, such as a short-time Fourier basis or wavelets, can be suitable for analyzing some types of signals, but not others. Instead, we learn RF dictionaries directly from data, without relying on analytical constraints or additional knowledge about the signal characteristics, using several established machine learning algorithms. Sparse classification features are extracted via matching pursuit search over the learned dictionaries, and used in conjunction with a statistical classifier to distinguish between lightning types. We present preliminary results of our work and discuss classification performance

  6. Incorporating Deeply Uncertain Factors into the Many Objective Search Process: Improving Adaptation to Environmental Change

    NASA Astrophysics Data System (ADS)

    Kasprzyk, J. R.; Watson, A. A.

    2014-12-01

    Deep uncertainty refers to situations in which decision makers or stakeholders do not know, or cannot fully agree upon, the full suite of risk factors within a planning problem. This phenomenon is especially important when considering scenarios of future environmental change, since there exist multiple trajectories of environmental forcings (e.g., streamflow timing and magnitude) and socioeconomic factors (e.g., population growth). This presentation first briefly reviews robust optimization and scenario approaches that have been proposed to plan for systems under deep uncertainty. One recently introduced framework is Many Objective Robust Decision Making (MORDM). MORDM combines two techniques: evolutionary algorithm search is used to generate planning alternatives, and robust decision making methods are used to sample performance over a large range of plausible factors and, subsequently, choose a robust solution. Within MORDM, Pareto approximate tradeoff sets of solutions are used to balance objectives and examine alternatives. However, MORDM does not currently incorporate the deeply uncertain scenario information into the search process itself. In this presentation, we suggest several avenues for doing so, that are focused on modifying the suite of uncertain data that is selected within the search process. Visualizations that compare tradeoff sets across different sets of assumptions can be used to guide decision makers' learning and, ultimately, their selection of several candidate solutions for further planning. For example, the baseline assumptions about probability distributions can be compared to optimization results under severe events to determine adaptive management strategies. A case study of water planning in the Lower Rio Grande Valley (LRGV) in Texas is used to demonstrate the approach. Our LRGV results compare baseline optimization with new solution sets that examine optimal management strategies under scenarios characterized by lower than average

  7. Prism Adaptation Alters Electrophysiological Markers of Attentional Processes in the Healthy Brain.

    PubMed

    Martín-Arévalo, Elisa; Laube, Inga; Koun, Eric; Farnè, Alessandro; Reilly, Karen T; Pisella, Laure

    2016-01-20

    Neglect patients typically show a rightward attentional orienting bias and a strong disengagement deficit, such that they are especially slow in responding to left-sided targets after right-sided cues (Posner et al., 1984). Prism adaptation (PA) can reduce diverse debilitating neglect symptoms and it has been hypothesized that PA's effects are so generalized that they might be mediated by attentional mechanisms (Pisella et al., 2006; Redding and Wallace, 2006). In neglect patients, performance on spatial attention tasks improves after rightward-deviating PA (Jacquin-Courtois et al., 2013). In contrast, in healthy subjects, although there is evidence that leftward-deviating PA induces neglect-like performance on some visuospatial tasks, behavioral studies of spatial attention tasks have mostly yielded negative results (Morris et al., 2004; Bultitude et al., 2013). We hypothesized that these negative behavioral findings might reflect the limitations of behavioral measures in healthy subjects. Here we exploited the sensitivity of event-related potentials to test the hypothesis that electrophysiological markers of attentional processes in the healthy human brain are affected by PA. Leftward-deviating PA generated asymmetries in attentional orienting (reflected in the cue-locked N1) and in attentional disengagement for invalidly cued left targets (reflected in the target-locked P1). This is the first electrophysiological demonstration that leftward-deviating PA in healthy subjects mimics attentional patterns typically seen in neglect patients. Significance statement: Prism adaptation (PA) is a promising tool for ameliorating many deficits in neglect patients and inducing neglect-like behavior in healthy subjects. The mechanisms underlying PA's effects are poorly understood but one hypothesis suggests that it acts by modulating attention. To date, however, there has been no successful demonstration of attentional modulation in healthy subjects. We provide the first

  8. Adaptive Lévy Processes and Area-Restricted Search in Human Foraging

    PubMed Central

    Hills, Thomas T.; Kalff, Christopher; Wiener, Jan M.

    2013-01-01

    A considerable amount of research has claimed that animals’ foraging behaviors display movement lengths with power-law distributed tails, characteristic of Lévy flights and Lévy walks. Though these claims have recently come into question, the proposal that many animals forage using Lévy processes nonetheless remains. A Lévy process does not consider when or where resources are encountered, and samples movement lengths independently of past experience. However, Lévy processes too have come into question based on the observation that in patchy resource environments resource-sensitive foraging strategies, like area-restricted search, perform better than Lévy flights yet can still generate heavy-tailed distributions of movement lengths. To investigate these questions further, we tracked humans as they searched for hidden resources in an open-field virtual environment, with either patchy or dispersed resource distributions. Supporting previous research, for both conditions logarithmic binning methods were consistent with Lévy flights and rank-frequency methods–comparing alternative distributions using maximum likelihood methods–showed the strongest support for bounded power-law distributions (truncated Lévy flights). However, goodness-of-fit tests found that even bounded power-law distributions only accurately characterized movement behavior for 4 (out of 32) participants. Moreover, paths in the patchy environment (but not the dispersed environment) showed a transition to intensive search following resource encounters, characteristic of area-restricted search. Transferring paths between environments revealed that paths generated in the patchy environment were adapted to that environment. Our results suggest that though power-law distributions do not accurately reflect human search, Lévy processes may still describe movement in dispersed environments, but not in patchy environments–where search was area-restricted. Furthermore, our results indicate that

  9. Application of Non-Kolmogorovian Probability and Quantum Adaptive Dynamics to Unconscious Inference in Visual Perception Process

    NASA Astrophysics Data System (ADS)

    Accardi, Luigi; Khrennikov, Andrei; Ohya, Masanori; Tanaka, Yoshiharu; Yamato, Ichiro

    2016-07-01

    Recently a novel quantum information formalism — quantum adaptive dynamics — was developed and applied to modelling of information processing by bio-systems including cognitive phenomena: from molecular biology (glucose-lactose metabolism for E.coli bacteria, epigenetic evolution) to cognition, psychology. From the foundational point of view quantum adaptive dynamics describes mutual adapting of the information states of two interacting systems (physical or biological) as well as adapting of co-observations performed by the systems. In this paper we apply this formalism to model unconscious inference: the process of transition from sensation to perception. The paper combines theory and experiment. Statistical data collected in an experimental study on recognition of a particular ambiguous figure, the Schröder stairs, support the viability of the quantum(-like) model of unconscious inference including modelling of biases generated by rotation-contexts. From the probabilistic point of view, we study (for concrete experimental data) the problem of contextuality of probability, its dependence on experimental contexts. Mathematically contextuality leads to non-Komogorovness: probability distributions generated by various rotation contexts cannot be treated in the Kolmogorovian framework. At the same time they can be embedded in a “big Kolmogorov space” as conditional probabilities. However, such a Kolmogorov space has too complex structure and the operational quantum formalism in the form of quantum adaptive dynamics simplifies the modelling essentially.

  10. Designing Training for Temporal and Adaptive Transfer: A Comparative Evaluation of Three Training Methods for Process Control Tasks

    ERIC Educational Resources Information Center

    Kluge, Annette; Sauer, Juergen; Burkolter, Dina; Ritzmann, Sandrina

    2010-01-01

    Training in process control environments requires operators to be prepared for temporal and adaptive transfer of skill. Three training methods were compared with regard to their effectiveness in supporting transfer: Drill & Practice (D&P), Error Training (ET), and procedure-based and error heuristics training (PHT). Communication electronics…

  11. Adaptive optics microscopy enhances image quality in deep layers of CLARITY processed brains of YFP-H mice

    NASA Astrophysics Data System (ADS)

    Reinig, Marc R.; Novack, Samuel W.; Tao, Xiaodong; Ermini, Florian; Bentolila, Laurent A.; Roberts, Dustin G.; MacKenzie-Graham, Allan; Godshalk, S. E.; Raven, M. A.; Kubby, Joel

    2016-03-01

    Optical sectioning of biological tissues has become the method of choice for three-dimensional histological analyses. This is particularly important in the brain were neurons can extend processes over large distances and often whole brain tracing of neuronal processes is desirable. To allow deeper optical penetration, which in fixed tissue is limited by scattering and refractive index mismatching, tissue-clearing procedures such as CLARITY have been developed. CLARITY processed brains have a nearly uniform refractive index and three-dimensional reconstructions at cellular resolution have been published. However, when imaging in deep layers at submicron resolution some limitations caused by residual refractive index mismatching become apparent, as the resulting wavefront aberrations distort the microscopic image. The wavefront can be corrected with adaptive optics. Here, we investigate the wavefront aberrations at different depths in CLARITY processed mouse brains and demonstrate the potential of adaptive optics to enable higher resolution and a better signal-to-noise ratio. Our adaptive optics system achieves high-speed measurement and correction of the wavefront with an open-loop control using a wave front sensor and a deformable mirror. Using adaptive optics enhanced microscopy, we demonstrate improved image quality wavefront, point spread function, and signal to noise in the cortex of YFP-H mice.

  12. Person Fit Based on Statistical Process Control in an Adaptive Testing Environment. Research Report 98-13.

    ERIC Educational Resources Information Center

    van Krimpen-Stoop, Edith M. L. A.; Meijer, Rob R.

    Person-fit research in the context of paper-and-pencil tests is reviewed, and some specific problems regarding person fit in the context of computerized adaptive testing (CAT) are discussed. Some new methods are proposed to investigate person fit in a CAT environment. These statistics are based on Statistical Process Control (SPC) theory. A…

  13. Adaptation Duration Dissociates Category-, Image-, and Person-Specific Processes on Face-Evoked Event-Related Potentials

    PubMed Central

    Zimmer, Márta; Zbanţ, Adriana; Németh, Kornél; Kovács, Gyula

    2015-01-01

    Several studies demonstrated that face perception is biased by the prior presentation of another face, a phenomenon termed as face-related after-effect (FAE). FAE is linked to a neural signal-reduction at occipito-temporal areas and it can be observed in the amplitude modulation of the early event-related potential (ERP) components. Recently, macaque single-cell recording studies suggested that manipulating the duration of the adaptor makes the selective adaptation of different visual motion processing steps possible. To date, however, only a few studies tested the effects of adaptor duration on the electrophysiological correlates of human face processing directly. The goal of the current study was to test the effect of adaptor duration on the image-, identity-, and generic category-specific face processing steps. To this end, in a two-alternative forced choice familiarity decision task we used five adaptor durations (ranging from 200–5000 ms) and four adaptor categories: adaptor and test were identical images—Repetition Suppression (RS); adaptor and test were different images of the Same Identity (SameID); adaptor and test images depicted Different Identities (DiffID); the adaptor was a Fourier phase-randomized image (No). Behaviorally, a strong priming effect was observed in both accuracy and response times for RS compared with both DiffID and No. The electrophysiological results suggest that rapid adaptation leads to a category-specific modulation of P100, N170, and N250. In addition, both identity and image-specific processes affected the N250 component during rapid adaptation. On the other hand, prolonged (5000 ms) adaptation enhanced, and extended category-specific adaptation processes over all tested ERP components. Additionally, prolonged adaptation led to the emergence of image-, and identity-specific modulations on the N170 and P2 components as well. In other words, there was a clear dissociation among category, identity-, and image

  14. Large-scale analysis of high-speed atomic force microscopy data sets using adaptive image processing

    PubMed Central

    Erickson, Blake W; Coquoz, Séverine; Adams, Jonathan D; Burns, Daniel J

    2012-01-01

    Summary Modern high-speed atomic force microscopes generate significant quantities of data in a short amount of time. Each image in the sequence has to be processed quickly and accurately in order to obtain a true representation of the sample and its changes over time. This paper presents an automated, adaptive algorithm for the required processing of AFM images. The algorithm adaptively corrects for both common one-dimensional distortions as well as the most common two-dimensional distortions. This method uses an iterative thresholded processing algorithm for rapid and accurate separation of background and surface topography. This separation prevents artificial bias from topographic features and ensures the best possible coherence between the different images in a sequence. This method is equally applicable to all channels of AFM data, and can process images in seconds. PMID:23213638

  15. Application of nonlinear absorption properties and light adaptation process in the polymer films based on bacteriorhodopsin for the low-power optical signal processing

    NASA Astrophysics Data System (ADS)

    Korchemskaya, Elena Y.; Soskin, Marat S.

    1994-01-01

    Experimental and theoretical investigations were made of the characteristics of nonlinear transmission and light adaptation processes of polymer films based on bacteriorhodopsin (BR). It was found that media containing BR can be used to enhance the contrast of low-power signals for realization of the connection structure of the neural network.

  16. Towards real-time wavefront sensorless adaptive optics using a graphical processing unit (GPU) in a line scanning system

    NASA Astrophysics Data System (ADS)

    Biss, David P.; Patel, Ankit H.; Ferguson, R. Daniel; Mujat, Mircea; Iftimia, Nicusor; Hammer, Daniel X.

    2011-03-01

    Adaptive optics ophthalmic imaging systems that rely on a standalone wave-front sensor can be costly to build and difficult for non-technical personnel to operate. As an alternative we present a simplified wavefront sensorless adaptive optics laser scanning ophthalmoscope. This sensorless system is based on deterministic search algorithms that utilize the image's spatial frequency as an optimization metric. We implement this algorithm on a NVIDIA video card to take advantage of the graphics processing unit (GPU)'s parallel architecture to reduce algorithm computation times and approach real-time correction.

  17. Application of adaptive subband coding for noisy bandlimited ECG signal processing

    NASA Astrophysics Data System (ADS)

    Aditya, Krishna; Chu, Chee-Hung H.; Szu, Harold H.

    1996-03-01

    An approach to impulsive noise suppression and background normalization of digitized bandlimited electrovcardiogram signals is presented. This approach uses adaptive wavelet filters that incorporate the band-limited a priori information and the shape information of a signal to decompose the data. Empirical results show that the new algorithm has good performance in wideband impulsive noise suppression and background normalization for subsequent wave detection, when compared with subband coding using Daubechie's D4 wavelet, without the bandlimited adaptive wavelet transform.

  18. Complementary adaptive processes contribute to the developmental plasticity of spatial hearing

    PubMed Central

    Keating, Peter; Dahmen, Johannes C.; King, Andrew J.

    2014-01-01

    Spatial hearing evolved independently in mammals and birds, and is thought to adapt to altered developmental input in different ways. We found, however, that ferrets possess multiple forms of plasticity that are expressed according to which spatial cues are available, suggesting that the basis for adaptation may be similar across species. Our results also provide insight into the way sound source location is represented by populations of cortical neurons. PMID:25581359

  19. Gene Regulatory and Metabolic Adaptation Processes of Dinoroseobacter shibae DFL12T during Oxygen Depletion*

    PubMed Central

    Laass, Sebastian; Kleist, Sarah; Bill, Nelli; Drüppel, Katharina; Kossmehl, Sebastian; Wöhlbrand, Lars; Rabus, Ralf; Klein, Johannes; Rohde, Manfred; Bartsch, Annekathrin; Wittmann, Christoph; Schmidt-Hohagen, Kerstin; Tielen, Petra; Jahn, Dieter; Schomburg, Dietmar

    2014-01-01

    Metabolic flexibility is the key to the ecological success of the marine Roseobacter clade bacteria. We investigated the metabolic adaptation and the underlying changes in gene expression of Dinoroseobacter shibae DFL12T to anoxic life by a combination of metabolome, proteome, and transcriptome analyses. Time-resolved studies during continuous oxygen depletion were performed in a chemostat using nitrate as the terminal electron acceptor. Formation of the denitrification machinery was found enhanced on the transcriptional and proteome level, indicating that D. shibae DFL12T established nitrate respiration to compensate for the depletion of the electron acceptor oxygen. In parallel, arginine fermentation was induced. During the transition state, growth and ATP concentration were found to be reduced, as reflected by a decrease of A578 values and viable cell counts. In parallel, the central metabolism, including gluconeogenesis, protein biosynthesis, and purine/pyrimidine synthesis was found transiently reduced in agreement with the decreased demand for cellular building blocks. Surprisingly, an accumulation of poly-3-hydroxybutanoate was observed during prolonged incubation under anoxic conditions. One possible explanation is the storage of accumulated metabolites and the regeneration of NADP+ from NADPH during poly-3-hydroxybutanoate synthesis (NADPH sink). Although D. shibae DFL12T was cultivated in the dark, biosynthesis of bacteriochlorophyll was increased, possibly to prepare for additional energy generation via aerobic anoxygenic photophosphorylation. Overall, oxygen depletion led to a metabolic crisis with partly blocked pathways and the accumulation of metabolites. In response, major energy-consuming processes were reduced until the alternative respiratory denitrification machinery was operative. PMID:24648520

  20. Process-based quality management for clinical implementation of adaptive radiotherapy

    PubMed Central

    Noel, Camille E.; Santanam, Lakshmi; Parikh, Parag J.; Mutic, Sasa

    2014-01-01

    Purpose: Intensity-modulated adaptive radiotherapy (ART) has been the focus of considerable research and developmental work due to its potential therapeutic benefits. However, in light of its unique quality assurance (QA) challenges, no one has described a robust framework for its clinical implementation. In fact, recent position papers by ASTRO and AAPM have firmly endorsed pretreatment patient-specific IMRT QA, which limits the feasibility of online ART. The authors aim to address these obstacles by applying failure mode and effects analysis (FMEA) to identify high-priority errors and appropriate risk-mitigation strategies for clinical implementation of intensity-modulated ART. Methods: An experienced team of two clinical medical physicists, one clinical engineer, and one radiation oncologist was assembled to perform a standard FMEA for intensity-modulated ART. A set of 216 potential radiotherapy failures composed by the forthcoming AAPM task group 100 (TG-100) was used as the basis. Of the 216 failures, 127 were identified as most relevant to an ART scheme. Using the associated TG-100 FMEA values as a baseline, the team considered how the likeliness of occurrence (O), outcome severity (S), and likeliness of failure being undetected (D) would change for ART. New risk priority numbers (RPN) were calculated. Failures characterized by RPN ≥ 200 were identified as potentially critical. Results: FMEA revealed that ART RPN increased for 38% (n = 48/127) of potential failures, with 75% (n = 36/48) attributed to failures in the segmentation and treatment planning processes. Forty-three of 127 failures were identified as potentially critical. Risk-mitigation strategies include implementing a suite of quality control and decision support software, specialty QA software/hardware tools, and an increase in specially trained personnel. Conclusions: Results of the FMEA-based risk assessment demonstrate that intensity-modulated ART introduces different (but not necessarily

  1. Process-based quality management for clinical implementation of adaptive radiotherapy

    SciTech Connect

    Noel, Camille E.; Santanam, Lakshmi; Parikh, Parag J.; Mutic, Sasa

    2014-08-15

    Purpose: Intensity-modulated adaptive radiotherapy (ART) has been the focus of considerable research and developmental work due to its potential therapeutic benefits. However, in light of its unique quality assurance (QA) challenges, no one has described a robust framework for its clinical implementation. In fact, recent position papers by ASTRO and AAPM have firmly endorsed pretreatment patient-specific IMRT QA, which limits the feasibility of online ART. The authors aim to address these obstacles by applying failure mode and effects analysis (FMEA) to identify high-priority errors and appropriate risk-mitigation strategies for clinical implementation of intensity-modulated ART. Methods: An experienced team of two clinical medical physicists, one clinical engineer, and one radiation oncologist was assembled to perform a standard FMEA for intensity-modulated ART. A set of 216 potential radiotherapy failures composed by the forthcoming AAPM task group 100 (TG-100) was used as the basis. Of the 216 failures, 127 were identified as most relevant to an ART scheme. Using the associated TG-100 FMEA values as a baseline, the team considered how the likeliness of occurrence (O), outcome severity (S), and likeliness of failure being undetected (D) would change for ART. New risk priority numbers (RPN) were calculated. Failures characterized by RPN ≥ 200 were identified as potentially critical. Results: FMEA revealed that ART RPN increased for 38% (n = 48/127) of potential failures, with 75% (n = 36/48) attributed to failures in the segmentation and treatment planning processes. Forty-three of 127 failures were identified as potentially critical. Risk-mitigation strategies include implementing a suite of quality control and decision support software, specialty QA software/hardware tools, and an increase in specially trained personnel. Conclusions: Results of the FMEA-based risk assessment demonstrate that intensity-modulated ART introduces different (but not necessarily

  2. Adaptive signal processing of on-orbit radio frequency lightning recordings using overcomplete chirplet dictionaries

    NASA Astrophysics Data System (ADS)

    Moody, D. I.; Smith, D. A.; Light, T. E.; Suszcynsky, D. M.; Heavner, M.

    2013-12-01

    Ongoing research at Los Alamos National Laboratory studies the Earth's radio frequency (RF) transient background utilizing satellite-based RF observations of terrestrial lightning. Such impulsive signals are dispersed as they travel through the ionosphere and appear as nonlinear chirps at a receiver on-orbit. Signals of interest are typically observed in the presence of additive noise and structured clutter, including gated and continuous-wave (CW) sources. Detection and classification of such non-stationary signals against a complex, non-stationary background can present challenges for standard physics-based approaches. The FORTE satellite provided a rich satellite lightning database that has been previously used for some event classification. We now develop and implement new event classification capability on the FORTE database using state-of-the-art adaptive signal processing combined with compressive sensing and machine learning techniques. The focus of our work is improved feature extraction using representations in overcomplete analytical dictionaries. We choose a dictionary based on Gabor chirplets, which is designed to represent both pulses (chirping or non-chirping) and CW signals in very few representative elements from the dictionary. One feature extraction approach is based on obtaining sparse representations of our data using a matching pursuit search of the dictionary. A second approach is based on using a frame operator on the dictionary to obtain a dense representation of our data. We explore robustness of extracted features to changes in background clutter and noise levels. Both feature extraction algorithms will be used in conjunction with statistical classifiers to explore classification performance of major lightning types. Performance will be evaluated both qualitatively, as well as quantitatively using a small validated test set. We present preliminary results of our work and discuss future areas of development.

  3. Gene regulatory and metabolic adaptation processes of Dinoroseobacter shibae DFL12T during oxygen depletion.

    PubMed

    Laass, Sebastian; Kleist, Sarah; Bill, Nelli; Drüppel, Katharina; Kossmehl, Sebastian; Wöhlbrand, Lars; Rabus, Ralf; Klein, Johannes; Rohde, Manfred; Bartsch, Annekathrin; Wittmann, Christoph; Schmidt-Hohagen, Kerstin; Tielen, Petra; Jahn, Dieter; Schomburg, Dietmar

    2014-05-01

    Metabolic flexibility is the key to the ecological success of the marine Roseobacter clade bacteria. We investigated the metabolic adaptation and the underlying changes in gene expression of Dinoroseobacter shibae DFL12(T) to anoxic life by a combination of metabolome, proteome, and transcriptome analyses. Time-resolved studies during continuous oxygen depletion were performed in a chemostat using nitrate as the terminal electron acceptor. Formation of the denitrification machinery was found enhanced on the transcriptional and proteome level, indicating that D. shibae DFL12(T) established nitrate respiration to compensate for the depletion of the electron acceptor oxygen. In parallel, arginine fermentation was induced. During the transition state, growth and ATP concentration were found to be reduced, as reflected by a decrease of A578 values and viable cell counts. In parallel, the central metabolism, including gluconeogenesis, protein biosynthesis, and purine/pyrimidine synthesis was found transiently reduced in agreement with the decreased demand for cellular building blocks. Surprisingly, an accumulation of poly-3-hydroxybutanoate was observed during prolonged incubation under anoxic conditions. One possible explanation is the storage of accumulated metabolites and the regeneration of NADP(+) from NADPH during poly-3-hydroxybutanoate synthesis (NADPH sink). Although D. shibae DFL12(T) was cultivated in the dark, biosynthesis of bacteriochlorophyll was increased, possibly to prepare for additional energy generation via aerobic anoxygenic photophosphorylation. Overall, oxygen depletion led to a metabolic crisis with partly blocked pathways and the accumulation of metabolites. In response, major energy-consuming processes were reduced until the alternative respiratory denitrification machinery was operative. PMID:24648520

  4. Adaptive Speckle Imaging Interferometry: a new technique for the analysis of microstructure dynamics, drying processes and coating formation.

    PubMed

    Brunel, L; Brun, A; Snabre, P; Cipelletti, L

    2007-11-12

    We describe an extension of multi-speckle diffusing wave spectroscopy adapted to follow the non-stationary microscopic dynamics in drying films and coatings in a very reactive way and with a high dynamic range. We call this technique "Adaptive Speckle Imaging Interferometry". We introduce an efficient tool, the inter-image distance, to evaluate the speckle dynamics, and the concept of "speckle rate" (SR, in Hz) to quantify this dynamics. The adaptive algorithm plots a simple kinetics, the time evolution of the SR, providing a non-invasive characterization of drying phenomena. A new commercial instrument, called HORUS(R), based on ASII and specialized in the analysis of film formation and drying processes is presented. PMID:19550809

  5. Adaptation and validation of indicators concerning the sterilization process of supplies in Primary Health Care services1

    PubMed Central

    Passos, Isis Pienta Batista Dias; Padoveze, Maria Clara; Roseira, Camila Eugênia; de Figueiredo, Rosely Moralez

    2015-01-01

    OBJECTIVES: to adapt and validate, by expert consensus, a set of indicators used to assess the sterilization process of dental, medical and hospital supplies to be used in PHC services. METHOD: qualitative methodological study performed in two stages. The first stage included a focal group composed of experts to adapt the indicators to be used in PHC. In the second stage, the indicators were validated using a 4-point Likert scale, which was completed by judges. A Content Validity Index of ≥ 0.75 was considered to show approval of the indicators. RESULTS: the adaptations implemented by the focal group mainly referred to the physical structure, inclusion of dental care professionals, inclusion of chemical disinfection, and replacement of the hot air and moist heat sterilization methods. The validation stage resulted in an index of 0.96, which ranged from 0.90 to 1.00, for the components of the indicators. CONCLUSION: the judges considered the indicators after adaptation to be validated. Even though there may be differences among items processed around the world, there certainly are common characteristics, especially in countries with economic and cultural environments similar to Brazil. The inclusion of these indicators to assess the safety of healthcare supplies used in PHC services should be considered. PMID:25806643

  6. Situation Awareness Implications of Adaptive Automation of Air Traffic Controller Information Processing Functions

    NASA Technical Reports Server (NTRS)

    Kaber, David B.; McClernon, Christopher K.; Perry, Carlene M.; Segall, Noa

    2004-01-01

    The goal of this research was to define a measure of situation awareness (SA) in an air traffic control (ATC) task and to assess the influence of adaptive automation (AA) of various information processing functions on controller perception, comprehension and projection. The measure was also to serve as a basis for defining and developing an approach to triggering dynamic control allocations, as part of AA, based on controller SA. To achieve these objectives, an enhanced version of an ATC simulation (Multitask (copyright)) was developed for use in two human factors experiments. The simulation captured the basic functions of Terminal Radar Approach Control (TRACON) and was capable of presenting to operators four different modes of control, including information acquisition, information analysis, decision making and action implementation automation, as well as a completely manual control mode. The SA measure that was developed as part of the research was based on the Situation Awareness Global Assessment Technique (SAGAT), previous goal-directed task analyses of enroute control and TRACON, and a separate cognitive task analysis on the ATC simulation. The results of the analysis on Multitask were used as a basis for formulating SA queries as part of the SAGAT-based approach to measuring controller SA, which was used in the experiments. A total of 16 subjects were recruited for both experiments. Half the subjects were used in Experiment #1, which focused on assessing the sensitivity and reliability of the SA measurement approach in the ATC simulation. Comparisons were made of manual versus automated control. The remaining subjects were used in the second experiment, which was intended to more completely describe the SA implications of AA applied to specific controller information processing functions, and to describe how the measure could ultimately serve as a trigger of dynamic function allocations in the application of AA to ATC. Comparisons were made of the

  7. Simpler Adaptive Optics using a Single Device for Processing and Control

    NASA Astrophysics Data System (ADS)

    Zovaro, A.; Bennet, F.; Rye, D.; D'Orgeville, C.; Rigaut, F.; Price, I.; Ritchie, I.; Smith, C.

    The management of low Earth orbit is becoming more urgent as satellite and debris densities climb, in order to avoid a Kessler syndrome. A key part of this management is to precisely measure the orbit of both active satellites and debris. The Research School of Astronomy and Astrophysics at the Australian National University have been developing an adaptive optics (AO) system to image and range orbiting objects. The AO system provides atmospheric correction for imaging and laser ranging, allowing for the detection of smaller angular targets and drastically increasing the number of detectable objects. AO systems are by nature very complex and high cost systems, often costing millions of dollars and taking years to design. It is not unusual for AO systems to comprise multiple servers, digital signal processors (DSP) and field programmable gate arrays (FPGA), with dedicated tasks such as wavefront sensor data processing or wavefront reconstruction. While this multi-platform approach has been necessary in AO systems to date due to computation and latency requirements, this may no longer be the case for those with less demanding processing needs. In recent years, large strides have been made in FPGA and microcontroller technology, with todays devices having clock speeds in excess of 200 MHz whilst using a < 5 V power supply. AO systems using a single such device for all data processing and control may present a far simpler, cheaper, smaller and more efficient solution than existing systems. A novel AO system design based around a single, low-cost controller is presented. The objective is to determine the performance which can be achieved in terms of bandwidth and correction order, with a focus on optimisation and parallelisation of AO algorithms such as wavefront measurement and reconstruction. The AO system consists of a Shack-Hartmann wavefront sensor and a deformable mirror to correct light from a 1.8 m telescope for the purpose of imaging orbiting satellites. The

  8. An Evolving Simulation/Gaming Process to Facilitate Adaptive Watershed Management in Northern Mountainous Thailand

    ERIC Educational Resources Information Center

    Barnaud, Cecile; Promburom, Tanya; Trebuil, Guy; Bousquet, Francois

    2007-01-01

    The decentralization of natural resource management provides an opportunity for communities to increase their participation in related decision making. Research should propose adapted methodologies enabling the numerous stakeholders of these complex socioecological settings to define their problems and identify agreed-on solutions. This article…

  9. Effects of Class Size and Adaptive Teaching Competency on Classroom Processes and Academic Outcome

    ERIC Educational Resources Information Center

    Bruhwiler, Christian; Blatchford, Peter

    2011-01-01

    In many studies of class size effects, teacher characteristics are missing, even though many argue it is not class size that is important but teacher quality. In the present study teachers' effectiveness on the learning progress was assessed while teaching a unit with predefined learning objectives. To measure adaptive teaching competency a…

  10. Can Survival Processing Enhance Story Memory? Testing the Generalizability of the Adaptive Memory Framework

    ERIC Educational Resources Information Center

    Seamon, John G.; Bohn, Justin M.; Coddington, Inslee E.; Ebling, Maritza C.; Grund, Ethan M.; Haring, Catherine T.; Jang, Sue-Jung; Kim, Daniel; Liong, Christopher; Paley, Frances M.; Pang, Luke K.; Siddique, Ashik H.

    2012-01-01

    Research from the adaptive memory framework shows that thinking about words in terms of their survival value in an incidental learning task enhances their free recall relative to other semantic encoding strategies and intentional learning (Nairne, Pandeirada, & Thompson, 2008). We found similar results. When participants used incidental survival…

  11. ADAPTIVE WATER SENSOR SIGNAL PROCESSING: EXPERIMENTAL RESULTS AND IMPLICATIONS FOR ONLINE CONTAMINANT WARNING SYSTEMS

    EPA Science Inventory

    A contaminant detection technique and its optimization algorithms have two principal functions. One is the adaptive signal treatment that suppresses background noise and enhances contaminant signals, leading to a promising detection of water quality changes at a false rate as low...

  12. Facial Emotion Processing and Social Adaptation in Adults with and without Autism Spectrum Disorder

    ERIC Educational Resources Information Center

    Garcia-Villamisar, Domingo; Rojahn, Johannes; Zaja, Rebecca H.; Jodra, Marina

    2010-01-01

    Individuals with autism spectrum disorder (ASD) and individuals with intellectual disabilities without ASD have limited facial emotion recognition abilities, which may adversely impact social adjustment and other adaptive behavior. This study was designed to examine this relationship in adults with and without ASD. Two groups of adults with…

  13. Rational Adaptation under Task and Processing Constraints: Implications for Testing Theories of Cognition and Action

    ERIC Educational Resources Information Center

    Howes, Andrew; Lewis, Richard L.; Vera, Alonso

    2009-01-01

    The authors assume that individuals adapt rationally to a utility function given constraints imposed by their cognitive architecture and the local task environment. This assumption underlies a new approach to modeling and understanding cognition--cognitively bounded rational analysis--that sharpens the predictive acuity of general, integrated…

  14. Adaptive Memory: Ancestral Priorities and the Mnemonic Value of Survival Processing

    ERIC Educational Resources Information Center

    Nairne, James S.; Pandeirada, Josefa N. S.

    2010-01-01

    Evolutionary psychologists often propose that humans carry around "stone-age" brains, along with a toolkit of cognitive adaptations designed originally to solve hunter-gatherer problems. This perspective predicts that optimal cognitive performance might sometimes be induced by ancestrally-based problems, those present in ancestral environments,…

  15. Considerations of Dance Transmission Processes: Adapting Bharata Natyam in a Singapore Primary School

    ERIC Educational Resources Information Center

    Lum, Chee Hoo; Gonda, Donn Emmanuel

    2014-01-01

    This qualitative case study has, for its purpose, an examination of the pedagogies and practices of a master Bharata Natyam dance instructor working within a Singapore primary school context. It explores the instructor's adaptation within an after-school weekly activity of the South Indian traditional classical dance form. Considerations of…

  16. The Emotions of Socialization-Related Learning: Understanding Workplace Adaptation as a Learning Process.

    ERIC Educational Resources Information Center

    Reio, Thomas G., Jr.

    The influence of selected discrete emotions on socialization-related learning and perception of workplace adaptation was examined in an exploratory study. Data were collected from 233 service workers in 4 small and medium-sized companies in metropolitan Washington, D.C. The sample members' average age was 32.5 years, and the sample's racial makeup…

  17. The Targeted Assessment Coaching Interview: Adapting the Assessment Process to Different Coaching Requirements

    ERIC Educational Resources Information Center

    Barner, Robert

    2006-01-01

    Purpose: The purpose of this article is to provide readers with an understanding of how the assessment protocol for executive coaching can be adapted to more effectively meet the different needs of clients who are seeking developmental, transitional, or remedial coaching. Design/methodology/approach: This article is based on the author's 20 years…

  18. Modelling of adaptation processes of crops to water and nitrogen stress

    NASA Astrophysics Data System (ADS)

    Kovács, Géza J.

    In the early 1980s the author published interpretations of his observations on special adaptation processes of crops (“Zichy” experiment). Those days it was not yet possible to include these details into a crop model. The knowledge has grown about the systems of crops and their environment, now it is appropriate to test those hypothesis by systems models. The 4M system model used in this study was developed by RISSAC modelling team lead by the author. 4M is based on CERES model family and the advices of the “father” of CERES, J.T. Ritchie. 4M aims to include a lot of results from Hungarian agricultural research. Some observations of “Zichy” experiment needed explanations but there were shortages of information on some parts of the system in order to test the hypothesis. Observations were as it follows: (1) The growth of above ground maize biomass slowed down in both years after a heavy rainy period. (2) Following the rainy period there was a fast drop of nitrate content in the soil and (3) following this time the water content of soil decreased with a fast rate approaching the wilting point. (4) When maize reacted on the emerging water stress there was a second (and even deeper) slow down of growth of above ground biomass. (5) The consequences of the stormy period was more dramatic in the second year of the experiment (1979), there was 3 t ha -1 loss of biomass and 2.5 t ha -1 loss of grain yield relative to 1978. (6) There was a significant difference in the time of stormy rain: in 1978 it occurred post-anthesis while in 1979 it occurred just prior to anthesis. Hypothesis tested here were as it follows: (1) The cause of observed growth stress reaction was a fast nitrate leaching from the rooted zone. (2) The crops cannot take up all the mineral nitrogen measured in a soil probe, the major limit is the mass flow to the roots controlled by transpiration and nitrogen concentration of soil solution. (3) “Leaching of soil by a flush of rain leads to

  19. Proteomic evidence of a paedomorphic evolutionary process within a marine snail species: a strategy for adapting to extreme ecological conditions?

    PubMed

    Diz, A P; Páez de la Cadena, M; Rolán-Alvarez, E

    2012-12-01

    The exposed and sheltered ecotypes of the marine snail Littorina saxatilis from European rocky shores are considered a key model system to study adaptation and ecological speciation. Previous studies showed that two ecotypes (RB and SU) of this species in NW Spain have adapted differently to different shore levels and microhabitats. In order to understand how this divergent adaptive process has been accomplished, we followed a quantitative proteomic approach to investigate the proteome variation in a number of different biological factors, that is, ecotype, ontogeny and their interactions. This approach allowed testing the hypothesis that one of the ecotypes has evolved by paedomorphosis, and also whether or not the molecular mechanisms related to ecotype differentiation are set up in early developmental stages. Additionally, the identification of some candidate proteins using mass spectrometry provides some functional insights into these evolutionary processes. Results from this study provided evidence of higher ontogenetic differentiation at proteome level in the RB (metamorphic) than in SU (paedomorphic) ecotype that point to the possibility of juvenile stage retention in this latter ecotype. The level of protein expression (proteome) differences between ecotypes maintained nearly constant from late embryonic stages to adulthood, although some proteins involved in these changes considerably differed in embryonic compared to other ontogenetic stages. Paedomorphosis may be the evolutionary response of the SU ecotype of solving the trade-off during sexually immaturity that is caused by the evolution of small size arising from adaptation to the wave-exposed habitat. Some potential candidate genes of adaptation related to energetic metabolism have been identified, providing a promising baseline for future functional analyses. PMID:23020901

  20. Photoreceptor Processing Speed and Input Resistance Changes during Light Adaptation Correlate with Spectral Class in the Bumblebee, Bombus impatiens

    PubMed Central

    Skorupski, Peter; Chittka, Lars

    2011-01-01

    Colour vision depends on comparison of signals from photoreceptors with different spectral sensitivities. However, response properties of photoreceptor cells may differ in ways other than spectral tuning. In insects, for example, broadband photoreceptors, with a major sensitivity peak in the green region of the spectrum (>500 nm), drive fast visual processes, which are largely blind to chromatic signals from more narrowly-tuned photoreceptors with peak sensitivities in the blue and UV regions of the spectrum. In addition, electrophysiological properties of the photoreceptor membrane may result in differences in response dynamics of photoreceptors of similar spectral class between species, and different spectral classes within a species. We used intracellular electrophysiological techniques to investigate response dynamics of the three spectral classes of photoreceptor underlying trichromatic colour vision in the bumblebee, Bombus impatiens, and we compare these with previously published data from a related species, Bombus terrestris. In both species, we found significantly faster responses in green, compared with blue- or UV-sensitive photoreceptors, although all 3 photoreceptor types are slower in B. impatiens than in B. terrestris. Integration times for light-adapted B. impatiens photoreceptors (estimated from impulse response half-width) were 11.3±1.6 ms for green photoreceptors compared with 18.6±4.4 ms and 15.6±4.4 for blue and UV, respectively. We also measured photoreceptor input resistance in dark- and light-adapted conditions. All photoreceptors showed a decrease in input resistance during light adaptation, but this decrease was considerably larger (declining to about 22% of the dark value) in green photoreceptors, compared to blue and UV (41% and 49%, respectively). Our results suggest that the conductances associated with light adaptation are largest in green photoreceptors, contributing to their greater temporal processing speed. We suggest that the

  1. Developing Coastal Adaptation to Climate Change in the New York City Infrastructure-Shed: Process, Approach, Tools, and Strategies

    NASA Technical Reports Server (NTRS)

    Rosenzweig, Cynthia; Solecki, William D.; Blake, Reginald; Bowman, Malcolm; Faris, Craig; Gornitz, Vivien; Horton, Radley; Jacob, Klaus; LeBlanc, Alice; Leichenko, Robin; Linkin, Megan; Major, David; O'Grady, Megan; Patrick, Lesley; Sussman, Edna; Yohe, Gary; Zimmerman, Rae

    2010-01-01

    While current rates of sea level rise and associated coastal flooding in the New York City region appear to be manageable by stakeholders responsible for communications, energy, transportation, and water infrastructure, projections for sea level rise and associated flooding in the future, especially those associated with rapid icemelt of the Greenland and West Antarctic Icesheets, may be beyond the range of current capacity because an extreme event might cause flooding and inundation beyond the planning and preparedness regimes. This paper describes the comprehensive process, approach, and tools developed by the New York City Panel on Climate Change (NPCC) in conjunction with the region s stakeholders who manage its critical infrastructure, much of which lies near the coast. It presents the adaptation approach and the sea-level rise and storm projections related to coastal risks developed through the stakeholder process. Climate change adaptation planning in New York City is characterized by a multi-jurisdictional stakeholder-scientist process, state-of-the-art scientific projections and mapping, and development of adaptation strategies based on a risk-management approach.

  2. A NOISE ADAPTIVE FUZZY EQUALIZATION METHOD FOR PROCESSING SOLAR EXTREME ULTRAVIOLET IMAGES

    SciTech Connect

    Druckmueller, M.

    2013-08-15

    A new image enhancement tool ideally suited for the visualization of fine structures in extreme ultraviolet images of the corona is presented in this paper. The Noise Adaptive Fuzzy Equalization method is particularly suited for the exceptionally high dynamic range images from the Atmospheric Imaging Assembly instrument on the Solar Dynamics Observatory. This method produces artifact-free images and gives significantly better results than methods based on convolution or Fourier transform which are often used for that purpose.

  3. Cardiac hypertrophy, arrhythmogenicity and the new myocardial phenotype. II. The cellular adaptational process.

    PubMed

    Swynghedauw, B; Chevalier, B; Charlemagne, D; Mansier, P; Carré, F

    1997-07-01

    Ventricular fibrosis is not the only structural determinant of arrhythmias in left ventricular hypertrophy. In an experimental model of compensatory cardiac hypertrophy (CCH) the degree of cardiac hypertrophy is also independently linked to ventricular arrhythmias. Cardiac hypertrophy reflects the level of adaptation, and matches the adaptational modifications of the myocardial phenotype. We suggest that these modifications have detrimental aspects. The increased action potential (AP) and QT duration and the prolonged calcium transient both favour spontaneous calcium oscillations, and both are potentially arrhythmogenic and linked to phenotypic changes in membrane proteins. To date, only two ionic currents have been studied in detail: Ito is depressed (likely the main determinant in AP durations), and If, the pacemaker current, is induced in the overloaded ventricular myocytes. In rat CCH, the two components of the sarcoplasmic reticulum, namely Ca(2+)-ATPase and ryanodine receptors, are down-regulated in parallel. Nevertheless, while the inward calcium current is unchanged, the functionally linked duo composed of the Na+/Ca2+ exchanged and (Na+, K+)-ATPase, is less active. Such an imbalance may explain the prolonged calcium transient. The changes in heart rate variability provide information about the state of the autonomic nervous system and has prognostic value even in CCH. Transgenic studies have demonstrated that the myocardial adrenergic and muscarinic receptor content is also a determining factor. During CCH, several phenotypic membrane changes participate in the slowing of contraction velocity and are thus adaptational. They also have a detrimental counterpart and, together with fibrosis, favour arrhythmias. PMID:9302342

  4. Environmentally adaptive processing for shallow ocean applications: A sequential Bayesian approach.

    PubMed

    Candy, J V

    2015-09-01

    The shallow ocean is a changing environment primarily due to temperature variations in its upper layers directly affecting sound propagation throughout. The need to develop processors capable of tracking these changes implies a stochastic as well as an environmentally adaptive design. Bayesian techniques have evolved to enable a class of processors capable of performing in such an uncertain, nonstationary (varying statistics), non-Gaussian, variable shallow ocean environment. A solution to this problem is addressed by developing a sequential Bayesian processor capable of providing a joint solution to the modal function tracking and environmental adaptivity problem. Here, the focus is on the development of both a particle filter and an unscented Kalman filter capable of providing reasonable performance for this problem. These processors are applied to hydrophone measurements obtained from a vertical array. The adaptivity problem is attacked by allowing the modal coefficients and/or wavenumbers to be jointly estimated from the noisy measurement data along with tracking of the modal functions while simultaneously enhancing the noisy pressure-field measurements. PMID:26428765

  5. Using adaptive genetic algorithms in the design of morphological filters in textural image processing

    NASA Astrophysics Data System (ADS)

    Li, Wei; Haese-Coat, Veronique; Ronsin, Joseph

    1996-03-01

    An adaptive GA scheme is adopted for the optimal morphological filter design problem. The adaptive crossover and mutation rate which make the GA avoid premature and at the same time assure convergence of the program are successfully used in optimal morphological filter design procedure. In the string coding step, each string (chromosome) is composed of a structuring element coding chain concatenated with a filter sequence coding chain. In decoding step, each string is divided into 3 chains which then are decoded respectively into one structuring element with a size inferior to 5 by 5 and two concatenating morphological filter operators. The fitness function in GA is based on the mean-square-error (MSE) criterion. In string selection step, a stochastic tournament procedure is used to replace the simple roulette wheel program in order to accelerate the convergence. The final convergence of our algorithm is reached by a two step converging strategy. In presented applications of noise removal from texture images, it is found that with the optimized morphological filter sequences, the obtained MSE values are smaller than those using corresponding non-adaptive morphological filters, and the optimized shapes and orientations of structuring elements take approximately the same shapes and orientations as those of the image textons.

  6. Erosive processes after tectonic uplift stimulate vicariant and adaptive speciation: evolution in an Afrotemperate-endemic paper daisy genus

    PubMed Central

    2014-01-01

    Background The role of tectonic uplift in stimulating speciation in South Africa’s only alpine zone, the Drakensberg, has not been explicitly examined. Tectonic processes may influence speciation both through the creation of novel habitats and by physically isolating plant populations. We use the Afrotemperate endemic daisy genus Macowania to explore the timing and mode (geographic versus adaptive) of speciation in this region. Between sister species pairs we expect high morphological divergence where speciation has happened in sympatry (adaptive) while with geographic (vicariant) speciation we may expect to find less morphological divergence and a greater degree of allopatry. A dated molecular phylogenetic hypothesis for Macowania elucidates species’ relationships and is used to address the potential impact of uplift on diversification. Morphological divergence of a small sample of reproductive and vegetative characters, used as a proxy for adaptive divergence, is measured against species’ range distributions to estimate mode of speciation across two subclades in the genus. Results The Macowania crown age is consistent with the hypothesis of post-uplift diversification, and we find evidence for both vicariant and adaptive speciation between the two subclades within Macowania. Both subclades exhibit strong signals of range allopatry, suggesting that geographic isolation was important in speciation. One subclade, associated with dry, rocky environments at high altitudes, shows very little morphological and ecological differentiation but high range allopatry. The other subclade occupies a greater variety of habitats and exhibits far greater morphological differentiation, but contains species with overlapping distribution ranges. Conclusions Species in Macowania are likely to have diversified in response to tectonic uplift, and we invoke uplift and uplift-mediated erosion as the main drivers of speciation. The greater relative morphological divergence in

  7. HIV-1 Adaptation to Antigen Processing Results in Population-Level Immune Evasion and Affects Subtype Diversification

    PubMed Central

    Tenzer, Stefan; Crawford, Hayley; Pymm, Phillip; Gifford, Robert; Sreenu, Vattipally B.; Weimershaus, Mirjana; de Oliveira, Tulio; Burgevin, Anne; Gerstoft, Jan; Akkad, Nadja; Lunn, Daniel; Fugger, Lars; Bell, John; Schild, Hansjörg; van Endert, Peter; Iversen, Astrid K.N.

    2014-01-01

    Summary The recent HIV-1 vaccine failures highlight the need to better understand virus-host interactions. One key question is why CD8+ T cell responses to two HIV-Gag regions are uniquely associated with delayed disease progression only in patients expressing a few rare HLA class I variants when these regions encode epitopes presented by ∼30 more common HLA variants. By combining epitope processing and computational analyses of the two HIV subtypes responsible for ∼60% of worldwide infections, we identified a hitherto unrecognized adaptation to the antigen-processing machinery through substitutions at subtype-specific motifs. Multiple HLA variants presenting epitopes situated next to a given subtype-specific motif drive selection at this subtype-specific position, and epitope abundances correlate inversely with the HLA frequency distribution in affected populations. This adaptation reflects the sum of intrapatient adaptations, is predictable, facilitates viral subtype diversification, and increases global HIV diversity. Because low epitope abundance is associated with infrequent and weak T cell responses, this most likely results in both population-level immune evasion and inadequate responses in most people vaccinated with natural HIV-1 sequence constructs. Our results suggest that artificial sequence modifications at subtype-specific positions in vitro could refocus and reverse the poor immunogenicity of HIV proteins. PMID:24726370

  8. NASA End-to-End Data System /NEEDS/ information adaptive system - Performing image processing onboard the spacecraft

    NASA Technical Reports Server (NTRS)

    Kelly, W. L.; Howle, W. M.; Meredith, B. D.

    1980-01-01

    The Information Adaptive System (IAS) is an element of the NASA End-to-End Data System (NEEDS) Phase II and is focused toward onbaord image processing. Since the IAS is a data preprocessing system which is closely coupled to the sensor system, it serves as a first step in providing a 'Smart' imaging sensor. Some of the functions planned for the IAS include sensor response nonuniformity correction, geometric correction, data set selection, data formatting, packetization, and adaptive system control. The inclusion of these sensor data preprocessing functions onboard the spacecraft will significantly improve the extraction of information from the sensor data in a timely and cost effective manner and provide the opportunity to design sensor systems which can be reconfigured in near real time for optimum performance. The purpose of this paper is to present the preliminary design of the IAS and the plans for its development.

  9. Adaptive Sensor Optimization and Cognitive Image Processing Using Autonomous Optical Neuroprocessors

    SciTech Connect

    CAMERON, STEWART M.

    2001-10-01

    Measurement and signal intelligence demands has created new requirements for information management and interoperability as they affect surveillance and situational awareness. Integration of on-board autonomous learning and adaptive control structures within a remote sensing platform architecture would substantially improve the utility of intelligence collection by facilitating real-time optimization of measurement parameters for variable field conditions. A problem faced by conventional digital implementations of intelligent systems is the conflict between a distributed parallel structure on a sequential serial interface functionally degrading bandwidth and response time. In contrast, optically designed networks exhibit the massive parallelism and interconnect density needed to perform complex cognitive functions within a dynamic asynchronous environment. Recently, all-optical self-organizing neural networks exhibiting emergent collective behavior which mimic perception, recognition, association, and contemplative learning have been realized using photorefractive holography in combination with sensory systems for feature maps, threshold decomposition, image enhancement, and nonlinear matched filters. Such hybrid information processors depart from the classical computational paradigm based on analytic rules-based algorithms and instead utilize unsupervised generalization and perceptron-like exploratory or improvisational behaviors to evolve toward optimized solutions. These systems are robust to instrumental systematics or corrupting noise and can enrich knowledge structures by allowing competition between multiple hypotheses. This property enables them to rapidly adapt or self-compensate for dynamic or imprecise conditions which would be unstable using conventional linear control models. By incorporating an intelligent optical neuroprocessor in the back plane of an imaging sensor, a broad class of high-level cognitive image analysis problems including geometric

  10. Plant cell in the process of the adaptation to simulated microgravity

    NASA Astrophysics Data System (ADS)

    Kordyum, E. L.

    Analysis of structural-and-functional rearrangements in the organelles of meristematic, differentiating and differentiated cells of pea root under microgravity demonstrated certain consistencies in their manifestation, namely: a) heterogeneity of the organelles in a cell population with respect to the degree of the rearrangements; b) coincidence of a spatial succession in development; c) increased reactivity under changes in functional load during cell growth and differentiation; d) enhanced activity when a cell loses its specific functions (replacement of functions). It is assumed that microgravity does not prevent the development of certain adaptative reactions of organisms at the cellular level.

  11. Integrated Business Process Adaptation towards Friction-Free Business-to-Business Collaboration

    ERIC Educational Resources Information Center

    Shan, Zhe

    2011-01-01

    One key issue in process-aware E-commerce collaboration is the orchestration of business processes of multiple business partners throughout a supply chain network in an automated and seamless way. Since each partner has its own internal processes with different control flow structures and message interfaces, the real challenge lies in verifying…

  12. Regulation of Emotions in Socially Challenging Learning Situations: An Instrument to Measure the Adaptive and Social Nature of the Regulation Process

    ERIC Educational Resources Information Center

    Jarvenoja, Hanna; Volet, Simone; Jarvela, Sanna

    2013-01-01

    Self-regulated learning (SRL) research has conventionally relied on measures, which treat SRL as an aptitude. To study self-regulation and motivation in learning contexts as an ongoing adaptive process, situation-specific methods are needed in addition to static measures. This article presents an "Adaptive Instrument for Regulation of Emotions"…

  13. The evolution of concepts of vestibular peripheral information processing: toward the dynamic, adaptive, parallel processing macular model.

    PubMed

    Ross, Muriel D

    2003-09-01

    In a letter to Robert Hooke, written on 5 February, 1675, Isaac Newton wrote "If I have seen further than certain other men it is by standing upon the shoulders of giants." In his context, Newton was referring to the work of Galileo and Kepler, who preceded him. However, every field has its own giants, those men and women who went before us and, often with few tools at their disposal, uncovered the facts that enabled later researchers to advance knowledge in a particular area. This review traces the history of the evolution of views from early giants in the field of vestibular research to modern concepts of vestibular organ organization and function. Emphasis will be placed on the mammalian maculae as peripheral processors of linear accelerations acting on the head. This review shows that early, correct findings were sometimes unfortunately disregarded, impeding later investigations into the structure and function of the vestibular organs. The central themes are that the macular organs are highly complex, dynamic, adaptive, distributed parallel processors of information, and that historical references can help us to understand our own place in advancing knowledge about their complicated structure and functions. PMID:14575392

  14. The evolution of concepts of vestibular peripheral information processing: toward the dynamic, adaptive, parallel processing macular model

    NASA Technical Reports Server (NTRS)

    Ross, Muriel D.

    2003-01-01

    In a letter to Robert Hooke, written on 5 February, 1675, Isaac Newton wrote "If I have seen further than certain other men it is by standing upon the shoulders of giants." In his context, Newton was referring to the work of Galileo and Kepler, who preceded him. However, every field has its own giants, those men and women who went before us and, often with few tools at their disposal, uncovered the facts that enabled later researchers to advance knowledge in a particular area. This review traces the history of the evolution of views from early giants in the field of vestibular research to modern concepts of vestibular organ organization and function. Emphasis will be placed on the mammalian maculae as peripheral processors of linear accelerations acting on the head. This review shows that early, correct findings were sometimes unfortunately disregarded, impeding later investigations into the structure and function of the vestibular organs. The central themes are that the macular organs are highly complex, dynamic, adaptive, distributed parallel processors of information, and that historical references can help us to understand our own place in advancing knowledge about their complicated structure and functions.

  15. The neural dynamics of somatosensory processing and adaptation across childhood: a high-density electrical mapping study.

    PubMed

    Uppal, Neha; Foxe, John J; Butler, John S; Acluche, Frantzy; Molholm, Sophie

    2016-03-01

    Young children are often hyperreactive to somatosensory inputs hardly noticed by adults, as exemplified by irritation to seams or labels in clothing. The neurodevelopmental mechanisms underlying changes in sensory reactivity are not well understood. Based on the idea that neurodevelopmental changes in somatosensory processing and/or changes in sensory adaptation might underlie developmental differences in somatosensory reactivity, high-density electroencephalography was used to examine how the nervous system responds and adapts to repeated vibrotactile stimulation over childhood. Participants aged 6-18 yr old were presented with 50-ms vibrotactile stimuli to the right wrist over the median nerve at 5 blocked interstimulus intervals (ranging from ∼7 to ∼1 stimulus per second). Somatosensory evoked potentials (SEPs) revealed three major phases of activation within the first 200 ms, with scalp topographies suggestive of neural generators in contralateral somatosensory cortex. Although overall SEPs were highly similar for younger, middle, and older age groups (6.1-9.8, 10.0-12.9, and 13.0-17.8 yr old), there were significant age-related amplitude differences in initial and later phases of the SEP. In contrast, robust adaptation effects for fast vs. slow presentation rates were observed that did not differ as a function of age. A greater amplitude response in the later portion of the SEP was observed for the youngest group and may be related to developmental changes in responsivity to somatosensory stimuli. These data suggest the protracted development of the somatosensory system over childhood, whereas adaptation, as assayed in this study, is largely in place by ∼7 yr of age. PMID:26763781

  16. Application of adaptive neuro-fuzzy inference system and cuckoo optimization algorithm for analyzing electro chemical machining process

    NASA Astrophysics Data System (ADS)

    Teimouri, Reza; Sohrabpoor, Hamed

    2013-12-01

    Electrochemical machining process (ECM) is increasing its importance due to some of the specific advantages which can be exploited during machining operation. The process offers several special privileges such as higher machining rate, better accuracy and control, and wider range of materials that can be machined. Contribution of too many predominate parameters in the process, makes its prediction and selection of optimal values really complex, especially while the process is programmized for machining of hard materials. In the present work in order to investigate effects of electrolyte concentration, electrolyte flow rate, applied voltage and feed rate on material removal rate (MRR) and surface roughness (SR) the adaptive neuro-fuzzy inference systems (ANFIS) have been used for creation predictive models based on experimental observations. Then the ANFIS 3D surfaces have been plotted for analyzing effects of process parameters on MRR and SR. Finally, the cuckoo optimization algorithm (COA) was used for selection solutions in which the process reaches maximum material removal rate and minimum surface roughness simultaneously. Results indicated that the ANFIS technique has superiority in modeling of MRR and SR with high prediction accuracy. Also, results obtained while applying of COA have been compared with those derived from confirmatory experiments which validate the applicability and suitability of the proposed techniques in enhancing the performance of ECM process.

  17. Costal process of the first sacral vertebra: sexual dimorphism and obstetrical adaptation.

    PubMed

    Tague, Robert G

    2007-03-01

    The human sacrum is sexually dimorphic, with males being larger than females in most dimensions. Previous studies, though, suggest that females may have a longer costal process of the first sacral vertebra (S1) than males. However, these studies neither quantified nor tested statistically the costal process of S1. This study compares S1 with the five lumbar vertebrae (L1 to L5) for a number of metric dimensions, including costal process length. Four issues are addressed, the: 1) hypothesis that females have a longer costal process of S1 than males; 2)hypothesis that homologous structures (i.e., costal processes of L1 to S1) differ in their direction of sexual dimorphism; 3) importance of the costal process of S1 to the obstetrical capacity of the pelvis; and 4) evolution of sexual dimorphism in costal process length of S1. One hundred ninety-seven individuals, including males and females of American blacks and whites, from the Hamann-Todd and Terry Collections were studied. Results show that males are significantly larger than females for most vertebral measurements, except that females have a significantly longer costal process of S1 than males. Costal process length of S1 is positively correlated with the transverse diameter and circumference of the pelvic inlet. The magnitude of sexual dimorphism in costal process length of S1 ranks this measure among the most highly dimorphic of the pelvis. Compared with the humans in this study, australopithecines have a relatively long costal process of S1, but their broad sacrum was not associated with obstetrical imperatives. PMID:17266155

  18. Adaptive Memory: Survival Processing Increases Both True and False Memory in Adults and Children

    ERIC Educational Resources Information Center

    Otgaar, Henry; Smeets, Tom

    2010-01-01

    Research has shown that processing information in a survival context can enhance the information's memorability. The current study examined whether survival processing can also decrease the susceptibility to false memories and whether the survival advantage can be found in children. In Experiment 1, adults rated semantically related words in a…

  19. Model based adaptive control of a continuous capture process for monoclonal antibodies production.

    PubMed

    Steinebach, Fabian; Angarita, Monica; Karst, Daniel J; Müller-Späth, Thomas; Morbidelli, Massimo

    2016-04-29

    A two-column capture process for continuous processing of cell-culture supernatant is presented. Similar to other multicolumn processes, this process uses sequential countercurrent loading of the target compound in order maximize resin utilization and productivity for a given product yield. The process was designed using a novel mechanistic model for affinity capture, which takes both specific adsorption as well as transport through the resin beads into account. Simulations as well as experimental results for the capture of an IgG antibody are discussed. The model was able to predict the process performance in terms of yield, productivity and capacity utilization. Compared to continuous capture with two columns operated batch wise in parallel, a 2.5-fold higher capacity utilization was obtained for the same productivity and yield. This results in an equal improvement in product concentration and reduction of buffer consumption. The developed model was used not only for the process design and optimization but also for its online control. In particular, the unit operating conditions are changed in order to maintain high product yield while optimizing the process performance in terms of capacity utilization and buffer consumption also in the presence of changing upstream conditions and resin aging. PMID:27046002

  20. Adaptive Image Processing Methods for Improving Contaminant Detection Accuracy on Poultry Carcasses

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Technical Abstract A real-time multispectral imaging system has demonstrated a science-based tool for fecal and ingesta contaminant detection during poultry processing. In order to implement this imaging system at commercial poultry processing industry, the false positives must be removed. For doi...

  1. Adaptive Process Controls and Ultrasonics for High Temperature PEM MEA Manufacture

    SciTech Connect

    Walczyk, Daniel F.

    2015-08-26

    The purpose of this 5-year DOE-sponsored project was to address major process bottlenecks associated with fuel cell manufacturing. New technologies were developed to significantly reduce pressing cycle time for high temperature PEM membrane electrode assembly (MEA) through the use of novel, robust ultrasonic (U/S) bonding processes along with low temperature (<100°C) PEM MEAs. In addition, greater manufacturing uniformity and performance was achieved through (a) an investigation into the causes of excessive variation in ultrasonically and thermally bonded MEAs using more diagnostics applied during the entire fabrication and cell build process, and (b) development of rapid, yet simple quality control measurement techniques for use by industry.

  2. To adopt is to adapt: the process of implementing the ICF with an acute stroke multidisciplinary team in England

    PubMed Central

    Tempest, Stephanie; Harries, Priscilla; Kilbride, Cherry; De Souza, Lorraine

    2012-01-01

    Purpose: The success of the International Classifcation of Functioning, Disability and Health (ICF) depends on its uptake in clinical practice. This project aimed to explore ways the ICF could be used with an acute stroke multidisciplinary team and identify key learning from the implementation process. Method: Using an action research approach, iterative cycles of observe, plan, act and evaluate were used within three phases: exploratory; innovatory and refective. Thematic analysis was undertaken, using a model of immersion and crystallisation, on data collected via interview and focus groups, e-mail communications, minutes from relevant meetings, feld notes and a refective diary. Results: Two overall themes were determined from the data analysis which enabled implementation. There is a need to: (1) adopt the ICF in ways that meet local service needs; and (2) adapt the ICF language and format. Conclusions: The empirical fndings demonstrate how to make the ICF classifcation a clinical reality. First, we need to adopt the ICF as a vehicle to implement local service priorities e.g. to structure a multidisciplinary team report, thus enabling ownership of the implementation process. Second, we need to adapt the ICF terminology and format to make it acceptable for use by clinicians. PMID:22372376

  3. Religious adaptation of a parenting programme: process evaluation of the Family Links Islamic Values course for Muslim fathers

    PubMed Central

    Nasiruddin, Q.

    2015-01-01

    Abstract Background Amid concern about the reach and inclusivity of parenting interventions, attempts have been made to culturally adapt programmes for specific ethnic or linguistic groups. This paper describes a novel approach of the religious adaptation of a parenting programme, namely the Family Links Islamic Values course. Methods A small‐scale qualitative process evaluation was conducted on one Family Links Islamic Values course for Muslim fathers in the South of England in order to describe the intervention as implemented and its theory of change, as well as the acceptability of the programme to the participants. The data consisted of 13 semi‐structured interviews (10 with parents and three with staff), 25 h of observation and reading of programme manuals. Results A logic model is presented to describe the theoretical basis of the intervention. The programme was highly acceptable to fathers who valued the integration of religious teachings and were generally very positive about their experience of attending the course. Post‐course interviews with both fathers and mothers mentioned some positive changes in fathers as a result of their attendance. Conclusions It is important to be responsive to the needs of some British Muslims for religiously credible interventions. This small‐scale process evaluation needs to be followed by a robust evaluation of programme outcomes for parents and children. PMID:25649634

  4. Rational adaptation under task and processing constraints: implications for testing theories of cognition and action.

    PubMed

    Howes, Andrew; Lewis, Richard L; Vera, Alonso

    2009-10-01

    The authors assume that individuals adapt rationally to a utility function given constraints imposed by their cognitive architecture and the local task environment. This assumption underlies a new approach to modeling and understanding cognition-cognitively bounded rational analysis-that sharpens the predictive acuity of general, integrated theories of cognition and action. Such theories provide the necessary computational means to explain the flexible nature of human behavior but in doing so introduce extreme degrees of freedom in accounting for data. The new approach narrows the space of predicted behaviors through analysis of the payoff achieved by alternative strategies, rather than through fitting strategies and theoretical parameters to data. It extends and complements established approaches, including computational cognitive architectures, rational analysis, optimal motor control, bounded rationality, and signal detection theory. The authors illustrate the approach with a reanalysis of an existing account of psychological refractory period (PRP) dual-task performance and the development and analysis of a new theory of ordered dual-task responses. These analyses yield several novel results, including a new understanding of the role of strategic variation in existing accounts of PRP and the first predictive, quantitative account showing how the details of ordered dual-task phenomena emerge from the rational control of a cognitive system subject to the combined constraints of internal variance, motor interference, and a response selection bottleneck. PMID:19839682

  5. Adaptive and robust statistical methods for processing near-field scanning microwave microscopy images.

    PubMed

    Coakley, K J; Imtiaz, A; Wallis, T M; Weber, J C; Berweger, S; Kabos, P

    2015-03-01

    Near-field scanning microwave microscopy offers great potential to facilitate characterization, development and modeling of materials. By acquiring microwave images at multiple frequencies and amplitudes (along with the other modalities) one can study material and device physics at different lateral and depth scales. Images are typically noisy and contaminated by artifacts that can vary from scan line to scan line and planar-like trends due to sample tilt errors. Here, we level images based on an estimate of a smooth 2-d trend determined with a robust implementation of a local regression method. In this robust approach, features and outliers which are not due to the trend are automatically downweighted. We denoise images with the Adaptive Weights Smoothing method. This method smooths out additive noise while preserving edge-like features in images. We demonstrate the feasibility of our methods on topography images and microwave |S11| images. For one challenging test case, we demonstrate that our method outperforms alternative methods from the scanning probe microscopy data analysis software package Gwyddion. Our methods should be useful for massive image data sets where manual selection of landmarks or image subsets by a user is impractical. PMID:25463325

  6. A scale-based forward-and-backward diffusion process for adaptive image enhancement and denoising

    NASA Astrophysics Data System (ADS)

    Wang, Yi; Niu, Ruiqing; Zhang, Liangpei; Wu, Ke; Sahli, Hichem

    2011-12-01

    This work presents a scale-based forward-and-backward diffusion (SFABD) scheme. The main idea of this scheme is to perform local adaptive diffusion using local scale information. To this end, we propose a diffusivity function based on the Minimum Reliable Scale (MRS) of Elder and Zucker (IEEE Trans. Pattern Anal. Mach. Intell. 20(7), 699-716, 1998) to detect the details of local structures. The magnitude of the diffusion coefficient at each pixel is determined by taking into account the local property of the image through the scales. A scale-based variable weight is incorporated into the diffusivity function for balancing the forward and backward diffusion. Furthermore, as numerical scheme, we propose a modification of the Perona-Malik scheme (IEEE Trans. Pattern Anal. Mach. Intell. 12(7), 629-639, 1990) by incorporating edge orientations. The article describes the main principles of our method and illustrates image enhancement results on a set of standard images as well as simulated medical images, together with qualitative and quantitative comparisons with a variety of anisotropic diffusion schemes.

  7. A data processing system adapted to the special needs of the emergency laboratory.

    PubMed Central

    Neumeier, D; Sator, H; Rindfleisch, G E; Knedel, M

    1983-01-01

    A data processing system for the emergency laboratory was integrated in our clinical laboratory computer system, its prime objective being the service requirements of the laboratory. It included the possibility of simultaneous optical reading of request forms and on-line capturing, processing, and printing of laboratory test data. Priority request forms, which allow the clinician to specify the interval by which emergency test results must be available, are registered by an optical reader and arranged according to urgency by the computer. The production of worksheets is replaced by visual display of information required for accurate specimen analyses on a large colour TV screen. The individual processing status of all tests from as many as 30 request forms is displayed in a colour code. For process control the updated delay time for test performance is faded in. All reports are produced by direct machine transfer of verified test results. For security purposes all steps of sample processing (request, result, report) are recorded via line printers outside the emergency laboratory. The capacity of the computer for managing sample and data processing reduces the work load for technicians. This results in a reduction of the turn-round time of tests. 95% of all requested tests are performed and reported within the requested time period and in emergencies, test results are available within 5-10 min. There has been no major breakdown of the system in over one year of use. Images PMID:6875013

  8. Results from the Active for Life process evaluation: program delivery fidelity and adaptations.

    PubMed

    Griffin, Sarah F; Wilcox, Sara; Ory, Marcia G; Lattimore, Diana; Leviton, Laura; Castro, Cynthia; Carpenter, Ruth Ann; Rheaume, Carol

    2010-04-01

    Active for Life((R)) (AFL) was a large (n = 8159) translational initiative to increase physical activity (PA) in midlife and older adults. Translational research calls for a shift in emphasis from just understanding what works (efficacy) to also understanding how it works in more 'real world' settings. This article describes the process evaluation design and findings, discuss how these findings were used to better understand the translational process and provide a set of process evaluation recommendations with community-based translational research. AFL community organizations across the United States implemented one of two evidence-based PA programs (Active Living Every Day-The Cooper Institute; Human Kinetics Inc. or Active Choices-Stanford University). Both programs were based on the transtheoretical model and social cognitive theory. Overall, the process evaluation revealed high-dose delivery and implementation fidelity by quite varied community organizations serving diverse adult populations. Findings reveal most variation occurred for program elements requiring more participant engagement. Additionally, the results show how a collaborative process allowed the organizations to 'fit' the programs to their specific participant base while maintaining fidelity to essential program elements. PMID:19325031

  9. Integration of adaptive process control with computational simulation for spin-forming

    SciTech Connect

    Raboin, P. J., LLNL

    1998-03-10

    Improvements in spin-forming capabilities through upgrades to a metrology and machine control system and advances in numerical simulation techniques were studied in a two year project funded by Laboratory Directed Research and Development (LDRD) at Lawrence Livermore National Laboratory. Numerical analyses were benchmarked with spin-forming experiments and computational speeds increased sufficiently to now permit actual part forming simulations. Extensive modeling activities examined the simulation speeds and capabilities of several metal forming computer codes for modeling flat plate and cylindrical spin-forming geometries. Shape memory research created the first numerical model to describe this highly unusual deformation behavior in Uranium alloys. A spin-forming metrology assessment led to sensor and data acquisition improvements that will facilitate future process accuracy enhancements, such as a metrology frame. Finally, software improvements (SmartCAM) to the manufacturing process numerically integrate the part models to the spin-forming process and to computational simulations.

  10. Adaptive Memory: Determining the Proximate Mechanisms Responsible for the Memorial Advantages of Survival Processing

    ERIC Educational Resources Information Center

    Burns, Daniel J.; Burns, Sarah A.; Hwang, Ana J.

    2011-01-01

    J. S. Nairne, S. R. Thompson, and J. N. S. Pandeirada (2007) suggested that our memory systems may have evolved to help us remember fitness-relevant information and showed that retention of words rated for their relevance to survival is superior to that of words encoded under other deep processing conditions. The authors present 4 experiments that…

  11. Learning Effects of a Science Textbook Designed with Adapted Cognitive Process Principles on Grade 5 Students

    ERIC Educational Resources Information Center

    Cheng, Ming-Chang; Chou, Pei-I; Wang, Ya-Ting; Lin, Chih-Ho

    2015-01-01

    This study investigates how the illustrations in a science textbook, with their design modified according to cognitive process principles, affected students' learning performance. The quasi-experimental design recruited two Grade 5 groups (N?=?58) as the research participants. The treatment group (n?=?30) used the modified version of the textbook,…

  12. Information Processing and Risk Perception: An Adaptation of the Heuristic-Systematic Model.

    ERIC Educational Resources Information Center

    Trumbo, Craig W.

    2002-01-01

    Describes heuristic-systematic information-processing model and risk perception--the two major conceptual areas of the analysis. Discusses the proposed model, describing the context of the data collections (public health communication involving cancer epidemiology) and providing the results of a set of three replications using the proposed model.…

  13. Adapting the Interpersonal Process Model of Intimacy to Enhance the Co-Leader Relationship during Training

    ERIC Educational Resources Information Center

    Huffman, David D.; Fernando, Delini M.

    2012-01-01

    Group work literature acknowledges that the group co-leader relationship influences the development of group members and the group as a whole. However, little direction has been offered for supervisors of group co-leaders to facilitate the development of the co-leader relationship. Reis and Shaver's (1988) interpersonal process model of intimacy…

  14. The alkaloid gramine in the anaerobic digestion process-inhibition and adaptation of the methanogenic community.

    PubMed

    Popp, Denny; Harms, Hauke; Sträuber, Heike

    2016-08-01

    As many plant secondary metabolites have antimicrobial activity, microorganisms of the anaerobic digestion process might be affected when plant material rich in these compounds is digested. Hitherto, the effects of plant secondary metabolites on the anaerobic digestion process are poorly investigated. In this study, the alkaloid gramine, a constituent of reed canary grass, was added daily to a continuous co-digestion of grass silage and cow manure. A transient decrease of the methane yield by 17 % and a subsequent recovery was observed, but no effect on other process parameters. When gramine was infrequently spiked in higher amounts, the observed inhibitory effect was even more pronounced including a 53 % decrease of the methane yield and an increase of acetic acid concentrations up to 96 mM. However, the process recovered and the process parameters were finally at initial values (methane yield around 255 LN CH4 per gram volatile solids of substrate and acetic acid concentration lower than 2 mM). The bacterial communities of the reactors remained stable upon gramine addition. In contrast, the methanogenic community changed from a well-balanced mixture of five phylotypes towards a strong dominance of Methanosarcina (more than two thirds of the methanogenic community) while Methanosaeta disappeared. Batch inhibition assays revealed that acetic acid was only converted to methane via acetoclastic methanogenesis which was more strongly affected by gramine than hydrogenotrophic methanogenesis and acetogenesis. Hence, when acetoclastic methanogenesis is the dominant pathway, a shift of the methanogenic community is necessary to digest gramine-rich plant material. PMID:27138201

  15. Variation in genes involved in epigenetic processes offers insights into tropically adapted cattle diversity.

    PubMed

    Porto-Neto, Laercio R; Fortes, Marina R S; McWilliam, Sean M; Lehnert, Sigrid A; Reverter, Antonio

    2014-01-01

    We evaluated the relevance of the BovineHD Illumina SNP chip with respect to genes involved in epigenetic processes. Genotypes for 729,068 SNP on two tropical cattle breeds of Australia were used: Brahman (n = 2112) and Tropical Composite (n = 2550). We used data mining approaches to compile a list of bovine protein-coding genes involved in epigenetic processes. These genes represent 9 functional categories that contain between one (histone demethylases) and 99 (chromatin remodeling factors) genes. A total of 3091 SNP mapped to positions within 3000 bp of the 193 coding regions of those genes, including 113 SNP in transcribed regions, 2738 in intronic regions and 240 in up- or down-stream regions. For all these SNP categories, we observed differences in the allelic frequencies between Brahman and Tropical Composite cattle. These differences were larger than those observed for the entire set of 729,068 SNP (P = 1.79 x 10(-5)). A multidimensional scaling analysis using only the 113 SNP in transcribed regions allowed for the separation of the two populations and this separation was comparable to the one obtained with a random set of 113 SNP (Principal Component 1 r (2) > 0.84). To further characterize the differences between the breeds we defined a gene-differentiation metric based on the average genotypic frequencies of SNP connected to each gene and compared both cattle populations. The 10% most differentiated genes were distributed across 10 chromosomes, with significant (P < 0.05) enrichment on BTA 3 and 10. The 10% most conserved genes were located in 12 chromosomes. We conclude that there is variation between cattle populations in genes connected to epigenetic processes, and this variation can be used to differentiate cattle breeds. More research is needed to fully characterize the use of these SNP and its potential as means to further our understanding of biological variation and epigenetic processes. PMID:24795751

  16. Variation in genes involved in epigenetic processes offers insights into tropically adapted cattle diversity

    PubMed Central

    Porto-Neto, Laercio R.; Fortes, Marina R. S.; McWilliam, Sean M.; Lehnert, Sigrid A.; Reverter, Antonio

    2014-01-01

    We evaluated the relevance of the BovineHD Illumina SNP chip with respect to genes involved in epigenetic processes. Genotypes for 729,068 SNP on two tropical cattle breeds of Australia were used: Brahman (n = 2112) and Tropical Composite (n = 2550). We used data mining approaches to compile a list of bovine protein-coding genes involved in epigenetic processes. These genes represent 9 functional categories that contain between one (histone demethylases) and 99 (chromatin remodeling factors) genes. A total of 3091 SNP mapped to positions within 3000 bp of the 193 coding regions of those genes, including 113 SNP in transcribed regions, 2738 in intronic regions and 240 in up- or down-stream regions. For all these SNP categories, we observed differences in the allelic frequencies between Brahman and Tropical Composite cattle. These differences were larger than those observed for the entire set of 729,068 SNP (P = 1.79 x 10−5). A multidimensional scaling analysis using only the 113 SNP in transcribed regions allowed for the separation of the two populations and this separation was comparable to the one obtained with a random set of 113 SNP (Principal Component 1 r2 > 0.84). To further characterize the differences between the breeds we defined a gene-differentiation metric based on the average genotypic frequencies of SNP connected to each gene and compared both cattle populations. The 10% most differentiated genes were distributed across 10 chromosomes, with significant (P < 0.05) enrichment on BTA 3 and 10. The 10% most conserved genes were located in 12 chromosomes. We conclude that there is variation between cattle populations in genes connected to epigenetic processes, and this variation can be used to differentiate cattle breeds. More research is needed to fully characterize the use of these SNP and its potential as means to further our understanding of biological variation and epigenetic processes. PMID:24795751

  17. Bayesian Treed Multivariate Gaussian Process with Adaptive Design: Application to a Carbon Capture Unit

    SciTech Connect

    Konomi, Bledar A.; Karagiannis, Georgios; Sarkar, Avik; Sun, Xin; Lin, Guang

    2014-05-16

    Computer experiments (numerical simulations) are widely used in scientific research to study and predict the behavior of complex systems, which usually have responses consisting of a set of distinct outputs. The computational cost of the simulations at high resolution are often expensive and become impractical for parametric studies at different input values. To overcome these difficulties we develop a Bayesian treed multivariate Gaussian process (BTMGP) as an extension of the Bayesian treed Gaussian process (BTGP) in order to model and evaluate a multivariate process. A suitable choice of covariance function and the prior distributions facilitates the different Markov chain Monte Carlo (MCMC) movements. We utilize this model to sequentially sample the input space for the most informative values, taking into account model uncertainty and expertise gained. A simulation study demonstrates the use of the proposed method and compares it with alternative approaches. We apply the sequential sampling technique and BTMGP to model the multiphase flow in a full scale regenerator of a carbon capture unit. The application presented in this paper is an important tool for research into carbon dioxide emissions from thermal power plants.

  18. Population Processes at Multiple Spatial Scales Maintain Diversity and Adaptation in the Linum marginale - Melampsora lini Association

    PubMed Central

    Nemri, Adnane; Barrett, Luke G.; Laine, Anna-Liisa; Burdon, Jeremy J.; Thrall, Peter H.

    2012-01-01

    Host-pathogen coevolution is a major driver of species diversity, with an essential role in the generation and maintenance of genetic variation in host resistance and pathogen infectivity. Little is known about how resistance and infectivity are structured across multiple geographic scales and what eco-evolutionary processes drive these patterns. Across southern Australia, the wild flax Linum marginale is frequently attacked by its rust fungus Melampsora lini. Here, we compare the genetic and phenotypic structure of resistance and infectivity among population pairs from two regions where environmental differences associate with specific life histories and mating systems. We find that both host and pathogen populations are genetically distinct between these regions. The region with outcrossing hosts and pathogens that go through asexual cycles followed by sexual reproduction showed greater diversity of resistance and infectivity phenotypes, higher levels of resistance and less clumped within-population spatial distribution of resistance. However, in the region where asexual pathogens infect selfing hosts, pathogens were more infective and better adapted to sympatric hosts. Our findings largely agree with expectations based on the distinctly different host mating systems in the two regions, with a likely advantage for hosts undergoing recombination. For the pathogen in this system, sexual reproduction may primarily be a survival mechanism in the region where it is observed. While it appears to potentially have adverse effects on local adaptation in the short term, it may be necessary for longer-term coevolution with outcrossing hosts. PMID:22859978

  19. Collective Signal Processing in Cluster Chemotaxis: Roles of Adaptation, Amplification, and Co-attraction in Collective Guidance

    PubMed Central

    Camley, Brian A.; Zimmermann, Juliane; Levine, Herbert; Rappel, Wouter-Jan

    2016-01-01

    Single eukaryotic cells commonly sense and follow chemical gradients, performing chemotaxis. Recent experiments and theories, however, show that even when single cells do not chemotax, clusters of cells may, if their interactions are regulated by the chemoattractant. We study this general mechanism of “collective guidance” computationally with models that integrate stochastic dynamics for individual cells with biochemical reactions within the cells, and diffusion of chemical signals between the cells. We show that if clusters of cells use the well-known local excitation, global inhibition (LEGI) mechanism to sense chemoattractant gradients, the speed of the cell cluster becomes non-monotonic in the cluster’s size—clusters either larger or smaller than an optimal size will have lower speed. We argue that the cell cluster speed is a crucial readout of how the cluster processes chemotactic signals; both amplification and adaptation will alter the behavior of cluster speed as a function of size. We also show that, contrary to the assumptions of earlier theories, collective guidance does not require persistent cell-cell contacts and strong short range adhesion. If cell-cell adhesion is absent, and the cluster cohesion is instead provided by a co-attraction mechanism, e.g. chemotaxis toward a secreted molecule, collective guidance may still function. However, new behaviors, such as cluster rotation, may also appear in this case. Co-attraction and adaptation allow for collective guidance that is robust to varying chemoattractant concentrations while not requiring strong cell-cell adhesion. PMID:27367541

  20. Cognitive flexibility in adolescence: neural and behavioral mechanisms of reward prediction error processing in adaptive decision making during development.

    PubMed

    Hauser, Tobias U; Iannaccone, Reto; Walitza, Susanne; Brandeis, Daniel; Brem, Silvia

    2015-01-01

    Adolescence is associated with quickly changing environmental demands which require excellent adaptive skills and high cognitive flexibility. Feedback-guided adaptive learning and cognitive flexibility are driven by reward prediction error (RPE) signals, which indicate the accuracy of expectations and can be estimated using computational models. Despite the importance of cognitive flexibility during adolescence, only little is known about how RPE processing in cognitive flexibility deviates between adolescence and adulthood. In this study, we investigated the developmental aspects of cognitive flexibility by means of computational models and functional magnetic resonance imaging (fMRI). We compared the neural and behavioral correlates of cognitive flexibility in healthy adolescents (12-16years) to adults performing a probabilistic reversal learning task. Using a modified risk-sensitive reinforcement learning model, we found that adolescents learned faster from negative RPEs than adults. The fMRI analysis revealed that within the RPE network, the adolescents had a significantly altered RPE-response in the anterior insula. This effect seemed to be mainly driven by increased responses to negative prediction errors. In summary, our findings indicate that decision making in adolescence goes beyond merely increased reward-seeking behavior and provides a developmental perspective to the behavioral and neural mechanisms underlying cognitive flexibility in the context of reinforcement learning. PMID:25234119

  1. Real-time atmospheric imaging and processing with hybrid adaptive optics and hardware accelerated lucky-region fusion (LRF) algorithm

    NASA Astrophysics Data System (ADS)

    Liu, Jony Jiang; Carhart, Gary W.; Beresnev, Leonid A.; Aubailly, Mathieu; Jackson, Christopher R.; Ejzak, Garrett; Kiamilev, Fouad E.

    2014-09-01

    Atmospheric turbulences can significantly deteriorate the performance of long-range conventional imaging systems and create difficulties for target identification and recognition. Our in-house developed adaptive optics (AO) system, which contains high-performance deformable mirrors (DMs) and the fast stochastic parallel gradient decent (SPGD) control mechanism, allows effective compensation of such turbulence-induced wavefront aberrations and result in significant improvement on the image quality. In addition, we developed advanced digital synthetic imaging and processing technique, "lucky-region" fusion (LRF), to mitigate the image degradation over large field-of-view (FOV). The LRF algorithm extracts sharp regions from each image obtained from a series of short exposure frames and fuses them into a final improved image. We further implemented such algorithm into a VIRTEX-7 field programmable gate array (FPGA) and achieved real-time video processing. Experiments were performed by combining both AO and hardware implemented LRF processing technique over a near-horizontal 2.3km atmospheric propagation path. Our approach can also generate a universal real-time imaging and processing system with a general camera link input, a user controller interface, and a DVI video output.

  2. “Vulnerability, Resiliency, and Adaptation: The Health of Latin Americans during the Migration Process to the United States”*

    PubMed Central

    Riosmena, Fernando; Jochem, Warren C.

    2013-01-01

    In this paper, we offer a general outlook of the health of Latin Americans (with a special emphasis on Mexicans) during the different stages of the migration process to the U.S. given the usefulness of the social vulnerability concept and given that said vulnerability varies conspicuously across the different stages of the migration process. Severe migrant vulnerability during the transit and crossing has serious negative health consequences. Yet, upon their arrival to the U.S., migrant health is favorable in outcomes such as mortality by many causes of death and in several chronic conditions and risk factors, though these apparent advantages seem to disappear during the process of adaptation to the host society. We discuss potential explanations for the initial health advantage and the sources of vulnerability that explain its erosion, with special emphasis in systematic timely access to health care. Given that migration can affect social vulnerability processes in sending areas, we discuss the potential health consequences for these places and conclude by considering the immigration and health policy implications of these issues for the United States and sending countries, with emphasis on Mexico. PMID:24660053

  3. ERP evidence of adaptive changes in error processing and attentional control during rhythm synchronization learning.

    PubMed

    Padrão, Gonçalo; Penhune, Virginia; de Diego-Balaguer, Ruth; Marco-Pallares, Josep; Rodriguez-Fornells, Antoni

    2014-10-15

    The ability to detect and use information from errors is essential during the acquisition of new skills. There is now a wealth of evidence about the brain mechanisms involved in error processing. However, the extent to which those mechanisms are engaged during the acquisition of new motor skills remains elusive. Here we examined rhythm synchronization learning across 12 blocks of practice in musically naïve individuals and tracked changes in ERP signals associated with error-monitoring and error-awareness across distinct learning stages. Synchronization performance improved with practice, and performance improvements were accompanied by dynamic changes in ERP components related to error-monitoring and error-awareness. Early in learning, when performance was poor and the internal representations of the rhythms were weaker we observed a larger error-related negativity (ERN) following errors compared to later learning. The larger ERN during early learning likely results from greater conflict between competing motor responses, leading to greater engagement of medial-frontal conflict monitoring processes and attentional control. Later in learning, when performance had improved, we observed a smaller ERN accompanied by an enhancement of a centroparietal positive component resembling the P3. This centroparietal positive component was predictive of participant's performance accuracy, suggesting a relation between error saliency, error awareness and the consolidation of internal templates of the practiced rhythms. Moreover, we showed that during rhythm learning errors led to larger auditory evoked responses related to attention orientation which were triggered automatically and which were independent of the learning stage. The present study provides crucial new information about how the electrophysiological signatures related to error-monitoring and error-awareness change during the acquisition of new skills, extending previous work on error processing and cognitive

  4. Low Light Adaptation: Energy Transfer Processes in Different Types of Light Harvesting Complexes from Rhodopseudomonas palustris

    PubMed Central

    Moulisová, Vladimíra; Luer, Larry; Hoseinkhani, Sajjad; Brotosudarmo, Tatas H.P.; Collins, Aaron M.; Lanzani, Guglielmo; Blankenship, Robert E.; Cogdell, Richard J.

    2009-01-01

    Abstract Energy transfer processes in photosynthetic light harvesting 2 (LH2) complexes isolated from purple bacterium Rhodopseudomonas palustris grown at different light intensities were studied by ground state and transient absorption spectroscopy. The decomposition of ground state absorption spectra shows contributions from B800 and B850 bacteriochlorophyll (BChl) a rings, the latter component splitting into a low energy and a high energy band in samples grown under low light (LL) conditions. A spectral analysis reveals strong inhomogeneity of the B850 excitons in the LL samples that is well reproduced by an exponential-type distribution. Transient spectra show a bleach of both the low energy and high energy bands, together with the respective blue-shifted exciton-to-biexciton transitions. The different spectral evolutions were analyzed by a global fitting procedure. Energy transfer from B800 to B850 occurs in a mono-exponential process and the rate of this process is only slightly reduced in LL compared to high light samples. In LL samples, spectral relaxation of the B850 exciton follows strongly nonexponential kinetics that can be described by a reduction of the bleach of the high energy excitonic component and a red-shift of the low energetic one. We explain these spectral changes by picosecond exciton relaxation caused by a small coupling parameter of the excitonic splitting of the BChl a molecules to the surrounding bath. The splitting of exciton energy into two excitonic bands in LL complex is most probably caused by heterogenous composition of LH2 apoproteins that gives some of the BChls in the B850 ring B820-like site energies, and causes a disorder in LH2 structure. PMID:19948132

  5. Process Optimization through Adaptation of Shielding Gas Selection and Feeding during Laser Beam Welding

    NASA Astrophysics Data System (ADS)

    Patschger, Andreas; Sahib, Christoffer; Bergmann, Jean Pierre; Bastick, André

    For this paper the influence of the shielding gas itself as well as the feeding method on austenitic welding joints was examined with thin sheets frequently used in the household appliance industry. The composition of the shielding gas mixture with active and/or inert gases was varied in the examination, and the effect on the weld seam could be made clear. By comparing different shielding gas feeding concepts, the process was optimized with regard to seam formation. Moreover, the influence of oxygen on the seam shape was examined in the deep welding regime on a specific example.

  6. Morphological adaptation of the calamistrum to the cribellate spinning process in Deinopoidae (Uloboridae, Deinopidae).

    PubMed

    Joel, Anna-Christin; Scholz, Ingo; Orth, Linda; Kappel, Peter; Baumgartner, Werner

    2016-02-01

    Spiders are famous for their silk with fascinating mechanical properties. However, some can further produce, process and handle nano fibres, which are used as capture threads. These 'cribellate spiders' bear a specialized setae comb on their metatarsus (calamistrum), which modifies cribellate nano fibres to assemble a puffy structure within the capture thread. Among different species, the calamistrum morphology can differ remarkably. Although a model of thread production has been established for Uloborus plumipes, it is not resolved if/how different shaped calamistra influence the production process. We were able to transfer the model without restrictions to spiders with different shaped calamistra. Fibres are not locked between setae but are passing across a rather smooth surface-like area on the calamistrum. This area can be relocated, explaining the first morphological difference between calamistra, without changing the influence of the calamistrum on fibres. By performing an elongated leg movement, contact between fibres and calamistrum could be adjusted after finishing thread production. This movement has to bring the thread in contact with the second morphological peculiarity: cribellate teeth. We suggest these teeth are used to handle the thread independently of the spinnerets, a feature only necessary for spiders, which do not move during web construction. PMID:26998332

  7. Hydrology and hydraulics expertise in participatory processes for climate change adaptation in the Dutch Meuse.

    PubMed

    Wesselink, Anna; de Vriend, Huib; Barneveld, Hermjan; Krol, Maarten; Bijker, Wiebe

    2009-01-01

    Many scientists feel that scientific outcomes are not sufficiently taken into account in policy-making. The research reported in this paper shows what happens with scientific information during such a process. In 2001 the Dutch Ministry of Transport, Public Works and Water Management commissioned their regional office in Limburg to assess how flood management objectives could be achieved in future in the Dutch Meuse valley, assuming climate change will increase peak discharges. To ensure political support, regional discussion rounds were to help assess the measures previously identified. This paper discusses the ways in which hydrological and hydraulic expertise was input, understood and used in this assessment process. Project participants as a group had no trouble contesting assumptions and outcomes. Nevertheless, water expertise was generally accepted as providing facts, once basic choices such as starting situation had been discussed and agreed. The technical constraints determined that politically unacceptable measures would have to be selected to achieve the legally binding flood management objective. As a result, no additional space will be set aside for future flood management beyond the already reserved floodplain. In this case, political arguments clearly prevail over policy objectives, with hydraulic expertise providing decisive arbitration between the two. PMID:19657153

  8. Back-propagation neural network adaptive control of a continuous wastewater treatment process

    SciTech Connect

    Syu, J.J.; Chen, B.C.

    1998-09-01

    Wastewater treatment processes and technology have been investigated for several decades and have almost been completed up to date. In this study, a chemical method was applied to treat the wastewater. Instead of real wastewater, benzoic acid and water were mixed as the wastewater since different concentrations of dissolved benzoic acid could result in different chemical oxygen demands (COD). Hydrogen peroxide and ferrous chloride were both added to treat the wastewater in order to meet the standards of 1998 environmental regulation in Taiwan. pH was found to be a major factor affecting the coagulation condition of the suspended particles during the treatment process. Back-propagation neural network was applied, and the purpose of the control was to provide the minimum amount of reagents to reach the required COD. The pump rates for adding hydrogen peroxide and ferrous chloride were controlled. The neural network was of a time-delayed mode, and its structure was properly determined, with the only output node being the predicted H{sub 2}O{sub 2}. The concentration of the added reagents was compared as well.

  9. Morphological adaptation of the calamistrum to the cribellate spinning process in Deinopoidae (Uloboridae, Deinopidae)

    PubMed Central

    Joel, Anna-Christin; Scholz, Ingo; Orth, Linda; Kappel, Peter; Baumgartner, Werner

    2016-01-01

    Spiders are famous for their silk with fascinating mechanical properties. However, some can further produce, process and handle nano fibres, which are used as capture threads. These ‘cribellate spiders’ bear a specialized setae comb on their metatarsus (calamistrum), which modifies cribellate nano fibres to assemble a puffy structure within the capture thread. Among different species, the calamistrum morphology can differ remarkably. Although a model of thread production has been established for Uloborus plumipes, it is not resolved if/how different shaped calamistra influence the production process. We were able to transfer the model without restrictions to spiders with different shaped calamistra. Fibres are not locked between setae but are passing across a rather smooth surface-like area on the calamistrum. This area can be relocated, explaining the first morphological difference between calamistra, without changing the influence of the calamistrum on fibres. By performing an elongated leg movement, contact between fibres and calamistrum could be adjusted after finishing thread production. This movement has to bring the thread in contact with the second morphological peculiarity: cribellate teeth. We suggest these teeth are used to handle the thread independently of the spinnerets, a feature only necessary for spiders, which do not move during web construction. PMID:26998332

  10. Adaptation of a Control Center Development Environment for Industrial Process Control

    NASA Technical Reports Server (NTRS)

    Killough, Ronnie L.; Malik, James M.

    1994-01-01

    In the control center, raw telemetry data is received for storage, display, and analysis. This raw data must be combined and manipulated in various ways by mathematical computations to facilitate analysis, provide diversified fault detection mechanisms, and enhance display readability. A development tool called the Graphical Computation Builder (GCB) has been implemented which provides flight controllers with the capability to implement computations for use in the control center. The GCB provides a language that contains both general programming constructs and language elements specifically tailored for the control center environment. The GCB concept allows staff who are not skilled in computer programming to author and maintain computer programs. The GCB user is isolated from the details of external subsystem interfaces and has access to high-level functions such as matrix operators, trigonometric functions, and unit conversion macros. The GCB provides a high level of feedback during computation development that improves upon the often cryptic errors produced by computer language compilers. An equivalent need can be identified in the industrial data acquisition and process control domain: that of an integrated graphical development tool tailored to the application to hide the operating system, computer language, and data acquisition interface details. The GCB features a modular design which makes it suitable for technology transfer without significant rework. Control center-specific language elements can be replaced by elements specific to industrial process control.

  11. Adaptive algorithms of position and energy reconstruction in Anger-camera type detectors: experimental data processing in ANTS

    NASA Astrophysics Data System (ADS)

    Morozov, A.; Defendi, I.; Engels, R.; Fraga, F. A. F.; Fraga, M. M. F. R.; Gongadze, A.; Guerard, B.; Jurkovic, M.; Kemmerling, G.; Manzin, G.; Margato, L. M. S.; Niko, H.; Pereira, L.; Petrillo, C.; Peyaud, A.; Piscitelli, F.; Raspino, D.; Rhodes, N. J.; Sacchetti, F.; Schooneveld, E. M.; Solovov, V.; Van Esch, P.; Zeitelhack, K.

    2013-05-01

    The software package ANTS (Anger-camera type Neutron detector: Toolkit for Simulations), developed for simulation of Anger-type gaseous detectors for thermal neutron imaging was extended to include a module for experimental data processing. Data recorded with a sensor array containing up to 100 photomultiplier tubes (PMT) or silicon photomultipliers (SiPM) in a custom configuration can be loaded and the positions and energies of the events can be reconstructed using the Center-of-Gravity, Maximum Likelihood or Least Squares algorithm. A particular strength of the new module is the ability to reconstruct the light response functions and relative gains of the photomultipliers from flood field illumination data using adaptive algorithms. The performance of the module is demonstrated with simulated data generated in ANTS and experimental data recorded with a 19 PMT neutron detector. The package executables are publicly available at http://coimbra.lip.pt/~andrei/

  12. "Research protocol: a synthesis of qualitative studies on the process of adaptation to dependency in elderly persons and their families"

    PubMed Central

    2010-01-01

    Background Dealing with dependency in the elderly and their families leads us to explore the life experience of those involved together with the processes of adaptation to this condition. A number of original studies have been published which, following a qualitative methodology, have dealt with both dimensions. Methods/Design Objectives: 1) To present a synthesis of the qualitative evidence available on the process of adaptation to dependency in elderly persons and their families; 2) to conduct an in-depth study into the experiences and strategies developed by both to optimise their living conditions; 3) to enable standards of action/intervention to be developed in the caregiving environment. A synthesis of qualitative studies is projected with an extensive and inclusive bibliography search strategy. The primary search will focus on the major databases (CINAHL, MEDLINE, EMBASE, PsycInfo, PSICODOC, Cochrane Library, JBI, EMBASE, LILACS, CUIDEN, CUIDEN qualitative, CUIDATGE, British Nursing Index, SSCI). The secondary search will be conducted in articles taken from the references to studies identified in the articles and reports and the manual search in congresses and foundation papers. Article quality will be assessed by the guide proposed by Sandelowski & Barroso and data extraction done using the QARI data extraction form proposed by the Joanna Briggs Institute for Evidence-Based Practice. The synthesis of the findings will be based on the principles and procedures of grounded theory: coding, identification and relationship between categories, and synthesis using constant comparison as a strategy. Discussion This synthesis of qualitative evidence will enable us to detect health needs as perceived by the receivers in their own interaction contexts. PMID:20738846

  13. Assembly Processes under Severe Abiotic Filtering: Adaptation Mechanisms of Weed Vegetation to the Gradient of Soil Constraints

    PubMed Central

    Nikolic, Nina; Böcker, Reinhard; Kostic-Kravljanac, Ljiljana; Nikolic, Miroslav

    2014-01-01

    Questions Effects of soil on vegetation patterns are commonly obscured by other environmental factors; clear and general relationships are difficult to find. How would community assembly processes be affected by a substantial change in soil characteristics when all other relevant factors are held constant? In particular, can we identify some functional adaptations which would underpin such soil-induced vegetation response? Location Eastern Serbia: fields partially damaged by long-term and large-scale fluvial deposition of sulphidic waste from a Cu mine; subcontinental/submediterranean climate. Methods We analysed the multivariate response of cereal weed assemblages (including biomass and foliar analyses) to a strong man-made soil gradient (from highly calcareous to highly acidic, nutrient-poor soils) over short distances (field scale). Results The soil gradient favoured a substitution of calcicoles by calcifuges, and an increase in abundance of pseudometallophytes, with preferences for Atlantic climate, broad geographical distribution, hemicryptophytic life form, adapted to low-nutrient and acidic soils, with lower concentrations of Ca, and very narrow range of Cu concentrations in leaves. The trends of abundance of the different ecological groups of indicator species along the soil gradient were systematically reflected in the maintenance of leaf P concentrations, and strong homeostasis in biomass N:P ratio. Conclusion Using annual weed vegetation at the field scale as a fairly simple model, we demonstrated links between gradients in soil properties (pH, nutrient availability) and floristic composition that are normally encountered over large geographic distances. We showed that leaf nutrient status, in particular the maintenance of leaf P concentrations and strong homeostasis of biomass N:P ratio, underpinned a clear functional response of vegetation to mineral stress. These findings can help to understand assembly processes leading to unusual, novel combinations

  14. Adaptive, maladaptive, mediational, and bidirectional processes of relational and physical aggression, relational and physical victimization, and peer liking.

    PubMed

    Kawabata, Yoshito; Tseng, Wan-Ling; Crick, Nicki R

    2014-01-01

    A three-wave longitudinal study among ethnically diverse preadolescents (N = 597 at Time 1, ages 9-11) was conducted to examine adaptive, maladaptive, mediational, and bidirectional processes of relational and physical aggression, victimization, and peer liking indexed by peer acceptance and friendships. A series of nested structural equation models tested the hypothesized links among these peer-domain factors. It was hypothesized that (1) relational aggression trails both adaptive and maladaptive processes, linking to more peer victimization and more peer liking, whereas physical aggression is maladaptive, resulting in more peer victimization and less peer liking; (2) physical and relational victimization is maladaptive, relating to more aggression and less peer liking; (3) peer liking may be the social context that promotes relational aggression (not physical aggression), whereas peer liking may protect against peer victimization, regardless of its type; and (4) peer liking mediates the link between forms of aggression and forms of peer victimization. Results showed that higher levels of peer liking predicted relative increases in relational aggression (not physical aggression), which in turn led to more peer liking. On the other hand, more peer liking was predictive of relative decreases in relational aggression and relational victimization in transition to the next grade (i.e., fifth grade). In addition, relational victimization predicted relative increases in relational aggression and relative decreases in peer liking. Similarly, physical aggression was consistently and concurrently associated more physical victimization and was marginally predictive of relative increases in physical victimization in transition to the next grade. More peer liking predicted relative decreases in physical victimization, which resulted in lower levels of peer liking. The directionality and magnitude of these paths did not differ between boys and girls. PMID:24318459

  15. Using adaptive sampling and triangular meshes for the processing and inversion of potential field data

    NASA Astrophysics Data System (ADS)

    Foks, Nathan Leon

    The interpretation of geophysical data plays an important role in the analysis of potential field data in resource exploration industries. Two categories of interpretation techniques are discussed in this thesis; boundary detection and geophysical inversion. Fault or boundary detection is a method to interpret the locations of subsurface boundaries from measured data, while inversion is a computationally intensive method that provides 3D information about subsurface structure. My research focuses on these two aspects of interpretation techniques. First, I develop a method to aid in the interpretation of faults and boundaries from magnetic data. These processes are traditionally carried out using raster grid and image processing techniques. Instead, I use unstructured meshes of triangular facets that can extract inferred boundaries using mesh edges. Next, to address the computational issues of geophysical inversion, I develop an approach to reduce the number of data in a data set. The approach selects the data points according to a user specified proxy for its signal content. The approach is performed in the data domain and requires no modification to existing inversion codes. This technique adds to the existing suite of compressive inversion algorithms. Finally, I develop an algorithm to invert gravity data for an interfacing surface using an unstructured mesh of triangular facets. A pertinent property of unstructured meshes is their flexibility at representing oblique, or arbitrarily oriented structures. This flexibility makes unstructured meshes an ideal candidate for geometry based interface inversions. The approaches I have developed provide a suite of algorithms geared towards large-scale interpretation of potential field data, by using an unstructured representation of both the data and model parameters.

  16. Adapting the Reconfigurable SpaceCube Processing System for Multiple Mission Applications

    NASA Technical Reports Server (NTRS)

    Petrick, Dave

    2014-01-01

    This paper will detail the use of SpaceCube in multiple space flight applications including the Hubble Space Telescope Servicing Mission 4 (HST-SM4), an International Space Station (ISS) radiation test bed experiment, and the main avionics subsystem for two separate ISS attached payloads. Each mission has had varying degrees of data processing complexities, performance requirements, and external interfaces. We will show the methodology used to minimize the changes required to the physical hardware, FPGA designs, embedded software interfaces, and testing.This paper will summarize significant results as they apply to each mission application. In the HST-SM4 application we utilized the FPGA resources to accelerate portions of the image processing algorithms more than 25 times faster than a standard space processor in order to meet computational speed requirements. For the ISS radiation on-orbit demonstration, the main goal is to show that we can rely on the commercial FPGAs and processors in a space environment. We describe our FPGA and processor radiation mitigation strategies that have resulted in our eight PowerPCs being available and error free for more than 99.99 of the time over the period of four years. This positive data and proven reliability of the SpaceCube on ISS resulted in the Department of Defense (DoD) selecting SpaceCube, which is replacing an older and slower computer currently used on ISS, as the main avionics for two upcoming ISS experiment campaigns. This paper will show how we quickly reconfigured the SpaceCube system to meet the more stringent reliability requirements

  17. Adapting of the Background-Oriented Schlieren (BOS) Technique in the Characterization of the Flow Regimes in Thermal Spraying Processes

    NASA Astrophysics Data System (ADS)

    Tillmann, W.; Abdulgader, M.; Rademacher, H. G.; Anjami, N.; Hagen, L.

    2014-01-01

    In thermal spraying technique, the changes in the in-flight particle velocities are considered to be only a function of the drag forces caused by the dominating flow regimes in the spray jet. Therefore, the correct understanding of the aerodynamic phenomena occurred at nozzle out let and at the substrate interface is an important task in the targeted improvement in the nozzle and air-cap design as well as in the spraying process in total. The presented work deals with the adapting of an innovative technique for the flow characterization called background-oriented Schlieren. The flow regimes in twin wire arc spraying (TWAS) and high velocity oxygen fuel (HVOF) were analyzed with this technique. The interfering of the atomization gas flow with the intersected wires causes in case of TWAS process a deformation of the jet shape. It leads also to areas with different aero dynamic forces. The configurations of the outlet air-caps in TWAS effect predominantly the outlet flow characteristics. The ratio between fuel and oxygen determine the dominating flow regimes in the HVOF spraying jet. Enhanced understanding of the aerodynamics at outlet and at the substrate interface could lead to a targeted improvement in thermal spraying processes.

  18. Adaptive Data Processing Technique for Lidar-Assisted Control to Bridge the Gap between Lidar Systems and Wind Turbines: Preprint

    SciTech Connect

    Schlipf, David; Raach, Steffen; Haizmann, Florian; Cheng, Po Wen; Fleming, Paul; Scholbrock, Andrew, Krishnamurthy, Raghu; Boquet, Mathieu

    2015-12-14

    This paper presents first steps toward an adaptive lidar data processing technique crucial for lidar-assisted control in wind turbines. The prediction time and the quality of the wind preview from lidar measurements depend on several factors and are not constant. If the data processing is not continually adjusted, the benefit of lidar-assisted control cannot be fully exploited, or can even result in harmful control action. An online analysis of the lidar and turbine data are necessary to continually reassess the prediction time and lidar data quality. In this work, a structured process to develop an analysis tool for the prediction time and a new hardware setup for lidar-assisted control are presented. The tool consists of an online estimation of the rotor effective wind speed from lidar and turbine data and the implementation of an online cross correlation to determine the time shift between both signals. Further, initial results from an ongoing campaign in which this system was employed for providing lidar preview for feed-forward pitch control are presented.

  19. Influence of microbial adaption and supplementation of nutrients on the biodegradation of ionic liquids in sewage sludge treatment processes.

    PubMed

    Markiewicz, Marta; Stolte, Stefan; Lustig, Zofia; Łuczak, Justyna; Skup, Michał; Hupka, Jan; Jungnickel, Christian

    2011-11-15

    As ionic liquids are winning more attention from industry as a replacement of more hazardous chemicals, some of their structures have the potential to become persistent pollutants due to high stability towards abiotic and biotic degradation processes. Therefore it is important to determine the hazard associated with the presence of ILs in the environment, for example biodegradation under real conditions. Standard biodegradation testing procedures generally permit pre-conditioning of inoculum but do not allow for pre-exposition to the test substance. These are usually conducted in a mineral medium which does not provide additional organic nutrients. Though very valuable, as a point of reference, these tests do not fully represent real conditions. In in situ conditions, for example in wastewater treatment plants or natural soils and water bodies, the presence of readily available sources of energy and nutrients as well as the process of adaptation may often alter the fate and metabolic pathways of xenobiotics. Our results have shown that these are the opposing processes influencing the biodegradation rate of ILs in sewage sludge. The results have significant practical implications with respect to the assessment of biodegradability and environmental fate of ILs and other xenobiotics in environmental conditions and their potential remediation options. PMID:21907490

  20. Identifying vegetation's influence on multi-scale fluvial processes based on plant trait adaptations

    NASA Astrophysics Data System (ADS)

    Manners, R.; Merritt, D. M.; Wilcox, A. C.; Scott, M.

    2015-12-01

    Riparian vegetation-geomorphic interactions are critical to the physical and biological function of riparian ecosystems, yet we lack a mechanistic understanding of these interactions and predictive ability at the reach to watershed scale. Plant functional groups, or groupings of species that have similar traits, either in terms of a plant's life history strategy (e.g., drought tolerance) or morphology (e.g., growth form), may provide an expression of vegetation-geomorphic interactions. We are developing an approach that 1) identifies where along a river corridor plant functional groups exist and 2) links the traits that define functional groups and their impact on fluvial processes. The Green and Yampa Rivers in Dinosaur National Monument have wide variations in hydrology, hydraulics, and channel morphology, as well as a large dataset of species presence. For these rivers, we build a predictive model of the probable presence of plant functional groups based on site-specific aspects of the flow regime (e.g., inundation probability and duration), hydraulic characteristics (e.g., velocity), and substrate size. Functional group traits are collected from the literature and measured in the field. We found that life-history traits more strongly predicted functional group presence than did morphological traits. However, some life-history traits, important for determining the likelihood of a plant existing along an environmental gradient, are directly related to the morphological properties of the plant, important for the plant's impact on fluvial processes. For example, stem density (i.e., dry mass divided by volume of stem) is positively correlated to drought tolerance and is also related to the modulus of elasticity. Growth form, which is related to the plant's susceptibility to biomass-removing fluvial disturbances, is also related to frontal area. Using this approach, we can identify how plant community composition and distribution shifts with a change to the flow

  1. Phoneme restoration and empirical coverage of interactive activation and adaptive resonance models of human speech processing

    PubMed Central

    Magnuson, James S.

    2015-01-01

    Grossberg and Kazerounian [(2011). J. Acoust. Soc. Am. 130, 440–460] present a model of sequence representation for spoken word recognition, the cARTWORD model, which simulates essential aspects of phoneme restoration. Grossberg and Kazerounian also include simulations with the TRACE model presented by McClelland and Elman [(1986). Cognit. Psychol. 18, 1–86] that seem to indicate that TRACE cannot simulate phoneme restoration. Grossberg and Kazerounian also claim cARTWORD should be preferred to TRACE because of TRACE's implausible approach to sequence representation (reduplication of time-specific units) and use of non-modulatory feedback (i.e., without position-specific bottom-up support). This paper responds to Grossberg and Kazerounian first with TRACE simulations that account for phoneme restoration when appropriately constructed noise is used (and with minor changes to TRACE phoneme definitions), then reviews the case for reduplicated units and feedback as implemented in TRACE, as well as TRACE's broad and deep coverage of empirical data. Finally, it is argued that cARTWORD is not comparable to TRACE because cARTWORD cannot represent sequences with repeated elements, has only been implemented with small phoneme and lexical inventories, and has been applied to only one phenomenon (phoneme restoration). Without evidence that cARTWORD captures a similar range and detail of human spoken language processing as alternative models, it is premature to prefer cARTWORD to TRACE. PMID:25786959

  2. Self-adaptive optimal control of dry dual clutch transmission (DCT) during starting process

    NASA Astrophysics Data System (ADS)

    Zhao, Zhiguo; He, Lu; Zheng, Zhengxing; Yang, Yunyun; Wu, Chaochun

    2016-02-01

    An optimal control based on the minimum principle is proposed to solve the problems with the starting process of the self-developed five-speed dry dual clutch transmission (DCT). For the slipping phase, the minimum principle and improved engine constant speed control are adopted to obtain the optimal clutch and engine torques and their rotating speeds, with the minimum jerk intensity and friction work as optimization indices. For the stable running phase, the engine torque is converted to the driver's level of demand. The Matlab/Simulink software platform was used to simulate the DCT vehicle in the starting stage. The simulation and related analysis were conducted for different engine speeds and intentions of the driver. The results showed that the proposed clutch starting control strategy not only reduces the level of jerk and the frictional energy loss but also follows the different starting intentions of the driver. The optimum clutch engagement principle was transformed into the clutch position principle, and a test was carried out on the test bench to validate the effectiveness of the optimum clutch position curve.

  3. [Adaptive reactions of dehydrogenation processes in root voles during additional impacts of the physical nature].

    PubMed

    Kudiasheva, A G; Taskaev, A I

    2011-01-01

    Variations of the dehydrogenation enzyme activity (succinate dehydrogenase, pyruvate dehydrogenase, lactate dehydrogenase) in the heart muscle, liver and brain of root voles (Microtus oeconomus Pall.) and their progeny associated with additional stress effects (chronic low-level gamma-irradiation, short-term exposure to cold) have been studied. Root voles (parents) were caught in the areas with a normal and high-level natural radioactivity in the Republic of Komi. It has been revealed that the direction of shifts of the dehydrogenation enzyme activity in response to the factors of the physical nature is determined by the initial level of the oxidation process in tissues of root voles and their progeny that haven't been subjected to these actions. The reaction of root voles and their progeny (1-3 generations) from the radium zone has lower reserve functional possibilities in relation to the additional exposure as compared with the animals from the control zone. In some cases, chronic low-level irradiation and short-term cooling lead to leveling of differences between groups of animals which initially varied from each other in biochemical indexes. PMID:22279768

  4. Adaptive sparse signal processing of satellite-based radio frequency (RF) recordings of lightning events

    NASA Astrophysics Data System (ADS)

    Moody, Daniela I.; Smith, David A.

    2014-05-01

    Ongoing research at Los Alamos National Laboratory studies the Earth's radio frequency (RF) background utilizing satellite-based RF observations of terrestrial lightning. Such impulsive events are dispersed through the ionosphere and appear as broadband nonlinear chirps at a receiver on-orbit. They occur in the presence of additive noise and structured clutter, making their classification challenging. The Fast On-orbit Recording of Transient Events (FORTE) satellite provided a rich RF lightning database. Application of modern pattern recognition techniques to this database may further lightning research in the scientific community, and potentially improve on-orbit processing and event discrimination capabilities for future satellite payloads. Conventional feature extraction techniques using analytical dictionaries, such as a short-time Fourier basis or wavelets, are not comprehensively suitable for analyzing the broadband RF pulses under consideration here. We explore an alternative approach based on non-analytical dictionaries learned directly from data, and extend two dictionary learning algorithms, K-SVD and Hebbian, for use with satellite RF data. Both algorithms allow us to learn features without relying on analytical constraints or additional knowledge about the expected signal characteristics. We then use a pursuit search over the learned dictionaries to generate sparse classification features, and discuss their performance in terms of event classification. We also use principal component analysis to analyze and compare the respective learned dictionary spaces to the real data space.

  5. An adaptive image segmentation process for the classification of lung biopsy images

    NASA Astrophysics Data System (ADS)

    McKee, Daniel W.; Land, Walker H., Jr.; Zhukov, Tatyana; Song, Dansheng; Qian, Wei

    2006-03-01

    The purpose of this study was to develop a computer-based second opinion diagnostic tool that could read microscope images of lung tissue and classify the tissue sample as normal or cancerous. This problem can be broken down into three areas: segmentation, feature extraction and measurement, and classification. We introduce a kernel-based extension of fuzzy c-means to provide a coarse initial segmentation, with heuristically-based mechanisms to improve the accuracy of the segmentation. The segmented image is then processed to extract and quantify features. Finally, the measured features are used by a Support Vector Machine (SVM) to classify the tissue sample. The performance of this approach was tested using a database of 85 images collected at the Moffitt Cancer Center and Research Institute. These images represent a wide variety of normal lung tissue samples, as well as multiple types of lung cancer. When used with a subset of the data containing images from the normal and adenocarcinoma classes, we were able to correctly classify 78% of the images, with a ROC A Z of 0.758.

  6. Multiresolution stroke sketch adaptive representation and neural network processing system for gray-level image recognition

    NASA Astrophysics Data System (ADS)

    Meystel, Alexander M.; Rybak, Ilya A.; Bhasin, Sanjay

    1992-11-01

    This paper describes a method for multiresolutional representation of gray-level images as hierarchial sets of strokes characterizing forms of objects with different degrees of generalization depending on the context of the image. This method transforms the original image into a hierarchical graph which allows for efficient coding in order to store, retrieve, and recognize the image. The method which is described is based upon finding the resolution levels for each image which minimizes the computations required. This becomes possible because of the use of a special image representation technique called Multiresolutional Attentional Representation for Recognition, based upon a feature which the authors call a stroke. This feature turns out to be efficient in the process of finding the appropriate system of resolutions and construction of the relational graph. Multiresolutional Attentional Representation for Recognition (MARR) is formed by a multi-layer neural network with recurrent inhibitory connections between neurons, the receptive fields of which are selectively tuned to detect the orientation of local contrasts in parts of the image with appropriate degree of generalization. This method simulates the 'coarse-to-fine' algorithm which an artist usually uses, making at attentional sketch of real images. The method, algorithms, and neural network architecture in this system can be used in many machine-vision systems with AI properties; in particular, robotic vision. We expect that systems with MARR can become a component of intelligent control systems for autonomous robots. Their architectures are mostly multiresolutional and match well with the multiple resolutions of the MARR structure.

  7. Temperature Adaptations in the Terminal Processes of Anaerobic Decomposition of Yellowstone National Park and Icelandic Hot Spring Microbial Mats

    PubMed Central

    Sandbeck, Kenneth A.; Ward, David M.

    1982-01-01

    The optimum temperatures for methanogenesis in microbial mats of four neutral to alkaline, low-sulfate hot springs in Yellowstone National Park were between 50 and 60°C, which was 13 to 23°C lower than the upper temperature for mat development. Significant methanogenesis at 65°C was only observed in one of the springs. Methane production in samples collected at a 51 or 62°C site in Octopus Spring was increased by incubation at higher temperatures and was maximal at 70°C. Strains of Methanobacterium thermoautotrophicum were isolated from 50, 55, 60, and 65°C sites in Octopus Spring at the temperatures of the collection sites. The optimum temperature for growth and methanogenesis of each isolate was 65°C. Similar results were found for the potential rate of sulfate reduction in an Icelandic hot spring microbial mat in which sulfate reduction dominated methane production as a terminal process in anaerobic decomposition. The potential rate of sulfate reduction along the thermal gradient of the mat was greatest at 50°C, but incubation at 60°C of the samples obtained at 50°C increased the rate. Adaptation to different mat temperatures, common among various microorganisms and processes in the mats, did not appear to occur in the processes and microorganisms which terminate the anaerobic food chain. Other factors must explain why the maximal rates of these processes are restricted to moderate temperatures of the mat ecosystem. PMID:16346109

  8. The adaptive metabolic response involves specific protein glutathionylation during the filamentation process in the pathogen Candida albicans.

    PubMed

    Gergondey, R; Garcia, C; Serre, V; Camadro, J M; Auchère, F

    2016-07-01

    Candida albicans is an opportunist pathogen responsible for a large spectrum of infections, from superficial mycosis to the systemic disease candidiasis. Its ability to adopt various morphological forms, such as unicellular yeasts, filamentous pseudohyphae and hyphae, contributes to its ability to survive within the host. It has been suggested that the antioxidant glutathione is involved in the filamentation process. We investigated S-glutathionylation, the reversible binding of glutathione to proteins, and the functional consequences on C. albicans metabolic remodeling during the yeast-to-hyphae transition. Our work provided evidence for the specific glutathionylation of mitochondrial proteins involved in bioenergetics pathways in filamentous forms and a regulation of the main enzyme of the glyoxylate cycle, isocitrate lyase, by glutathionylation. Isocitrate lyase inactivation in the hyphal forms was reversed by glutaredoxin treatment, in agreement with a glutathionylation process, which was confirmed by proteomic data showing the binding of one glutathione molecule to the enzyme (data are available via ProteomeXchange with identifier PXD003685). We also assessed the effect of alternative carbon sources on glutathione levels and isocitrate lyase activity. Changes in nutrient availability led to morphological flexibility and were related to perturbations in glutathione levels and isocitrate lyase activity, confirming the key role of the maintenance of intracellular redox status in the adaptive metabolic strategy of the pathogen. PMID:27083931

  9. Adapting the SpaceCube v2.0 Data Processing System for Mission-Unique Application Requirements

    NASA Technical Reports Server (NTRS)

    Petrick, David; Gill, Nat; Hasouneh, Munther; Stone, Robert; Winternitz, Luke; Thomas, Luke; Davis, Milton; Sparacino, Pietro; Flatley, Thomas

    2015-01-01

    The SpaceCube (sup TM) v2.0 system is a superior high performance, reconfigurable, hybrid data processing system that can be used in a multitude of applications including those that require a radiation hardened and reliable solution. This paper provides an overview of the design architecture, flexibility, and the advantages of the modular SpaceCube v2.0 high performance data processing system for space applications. The current state of the proven SpaceCube technology is based on nine years of engineering and operations. Five systems have been successfully operated in space starting in 2008 with four more to be delivered for launch vehicle integration in 2015. The SpaceCube v2.0 system is also baselined as the avionics solution for five additional flight projects and is always a top consideration as the core avionics for new instruments or spacecraft control. This paper will highlight how this multipurpose system is currently being used to solve design challenges of three independent applications. The SpaceCube hardware adapts to new system requirements by allowing for application-unique interface cards that are utilized by reconfiguring the underlying programmable elements on the core processor card. We will show how this system is being used to improve on a heritage NASA GPS technology, enable a cutting-edge LiDAR instrument, and serve as a typical command and data handling (C&DH) computer for a space robotics technology demonstration.

  10. Adapting the SpaceCube v2.0 Data Processing System for Mission-Unique Application Requirements

    NASA Technical Reports Server (NTRS)

    Petrick, David

    2015-01-01

    The SpaceCubeTM v2.0 system is a superior high performance, reconfigurable, hybrid data processing system that can be used in a multitude of applications including those that require a radiation hardened and reliable solution. This paper provides an overview of the design architecture, flexibility, and the advantages of the modular SpaceCube v2.0 high performance data processing system for space applications. The current state of the proven SpaceCube technology is based on nine years of engineering and operations. Five systems have been successfully operated in space starting in 2008 with four more to be delivered for launch vehicle integration in 2015. The SpaceCube v2.0 system is also baselined as the avionics solution for five additional flight projects and is always a top consideration as the core avionics for new instruments or spacecraft control. This paper will highlight how this multipurpose system is currently being used to solve design challenges of three independent applications. The SpaceCube hardware adapts to new system requirements by allowing for application-unique interface cards that are utilized by reconfiguring the underlying programmable elements on the core processor card. We will show how this system is being used to improve on a heritage NASA GPS technology, enable a cutting-edge LiDAR instrument, and serve as a typical command and data handling (CDH) computer for a space robotics technology demonstration.

  11. Adaptation to recent conflict in the classical color-word Stroop-task mainly involves facilitation of processing of task-relevant information.

    PubMed

    Purmann, Sascha; Pollmann, Stefan

    2015-01-01

    To process information selectively and to continuously fine-tune selectivity of information processing are important abilities for successful goal-directed behavior. One phenomenon thought to represent this fine-tuning are conflict adaptation effects in interference tasks, i.e., reduction of interference after an incompatible trial and when incompatible trials are frequent. The neurocognitive mechanisms of these effects are currently only partly understood and results from brainimaging studies so far are mixed. In our study we validate and extend recent findings by examining adaption to recent conflict in the classical Stroop task using functional magnetic resonance imaging. Consistent with previous research we found increased activity in a fronto-parietal network comprising the medial prefrontal cortex, ventro-lateral prefrontal cortex, and posterior parietal cortex when contrasting incompatible with compatible trials. These areas have been associated with attentional processes and might reflect increased cognitive conflict and resolution thereof during incompatible trials. While carefully controlling for non-attentional sequential effects we found smaller Stroop interference after an incompatible trial (conflict adaptation effect). These behavioral conflict adaptation effects were accompanied by changes in activity in visual color-selective areas (V4, V4α), while there was no modulation by previous trial compatibility in a visual word-selective area (VWFA). Our results provide further evidence for the notion, that adaptation to recent conflict seems to be based mainly on enhancement of processing of the task-relevant information. PMID:25784868

  12. Adaptation to recent conflict in the classical color-word Stroop-task mainly involves facilitation of processing of task-relevant information

    PubMed Central

    Purmann, Sascha; Pollmann, Stefan

    2015-01-01

    To process information selectively and to continuously fine-tune selectivity of information processing are important abilities for successful goal-directed behavior. One phenomenon thought to represent this fine-tuning are conflict adaptation effects in interference tasks, i.e., reduction of interference after an incompatible trial and when incompatible trials are frequent. The neurocognitive mechanisms of these effects are currently only partly understood and results from brainimaging studies so far are mixed. In our study we validate and extend recent findings by examining adaption to recent conflict in the classical Stroop task using functional magnetic resonance imaging. Consistent with previous research we found increased activity in a fronto-parietal network comprising the medial prefrontal cortex, ventro-lateral prefrontal cortex, and posterior parietal cortex when contrasting incompatible with compatible trials. These areas have been associated with attentional processes and might reflect increased cognitive conflict and resolution thereof during incompatible trials. While carefully controlling for non-attentional sequential effects we found smaller Stroop interference after an incompatible trial (conflict adaptation effect). These behavioral conflict adaptation effects were accompanied by changes in activity in visual color-selective areas (V4, V4α), while there was no modulation by previous trial compatibility in a visual word-selective area (VWFA). Our results provide further evidence for the notion, that adaptation to recent conflict seems to be based mainly on enhancement of processing of the task-relevant information. PMID:25784868

  13. ADAPT-NMR 3.0: utilization of BEST-type triple-resonance NMR experiments to accelerate the process of data collection and assignment

    PubMed Central

    Dashti, Hesam; Tonelli, Marco

    2015-01-01

    ADAPT-NMR (Assignment-directed Data collection Algorithm utilizing a Probabilistic Toolkit in NMR) is a software package whose Bayesian core uses on-the-fly chemical shift assignments to guide data acquisition by non-uniform sampling from a panel of through-bond NMR experiments. The new version of ADAPT-NMR (ADAPT-NMR v3.0) has the option of utilizing 2D tilted-plane versions of 3D fast spectral acquisition with BEST-type pulse sequences, while also retaining the capability of acquiring and processing data from tilted-plane versions of conventional sensitivity-enhanced experiments. The use of BEST experiments significantly reduces data collection times and leads to enhanced performance by ADAPT-NMR. PMID:26021595

  14. ADAPT-NMR 3.0: utilization of BEST-type triple-resonance NMR experiments to accelerate the process of data collection and assignment.

    PubMed

    Dashti, Hesam; Tonelli, Marco; Markley, John L

    2015-07-01

    ADAPT-NMR (Assignment-directed Data collection Algorithm utilizing a Probabilistic Toolkit in NMR) is a software package whose Bayesian core uses on-the-fly chemical shift assignments to guide data acquisition by non-uniform sampling from a panel of through-bond NMR experiments. The new version of ADAPT-NMR (ADAPT-NMR v3.0) has the option of utilizing 2D tilted-plane versions of 3D fast spectral acquisition with BEST-type pulse sequences, while also retaining the capability of acquiring and processing data from tilted-plane versions of conventional sensitivity-enhanced experiments. The use of BEST experiments significantly reduces data collection times and leads to enhanced performance by ADAPT-NMR. PMID:26021595

  15. Use of the LIGA process for the production of pyramid wavefront sensors for adaptive optics in astronomy

    NASA Astrophysics Data System (ADS)

    Ghigo, Mauro; Diolaiti, Emiliano; Perennes, Frederic; Ragazzoni, Roberto

    2003-12-01

    Nowadays many groups in the world are developing adaptive optics (AO) systems for the real time correction of the aberrations introduced by the turbolence of the atmosphere in the field of view of the astronomical telescopes. The Shack-Hartmann wavefront sensor has been often used for the detection of the optical aberrations but over the past few years an alternative wavefront sensor with pyramidic shape has being developed. The properties of this sensor have been extensively investigated both theoretically and experimentally (for example in the AO module of the Italian "Telescopio Nazionale Galileo"). Important features of this pyramidal sensor are that it offers the advantage of either variable gain against the wavefront deformation and tunable sampling of the telescope pupil. These features translate into a considerable gain in the limiting magnitude of the reference star when compared to the classical Shack-Hartmann sensor. The manufacturing of single pyramid prototypes has been initially accomplished using the classical figuring and polishing technique, a time consuming procedure. Since the multi-conjugated adaptive optics (MCAO) that are under study, foresee the use of a large number of identical pyramids, it has been investigated and developed an alternative method for the mass production of this optical component. Using a lithography-dedicated beamline already operating at the ELETTRA Synchrotron in Trieste, a manufacturing technique has been implemented that uses a process named LIGA [Lithography, electroplating (German: Galvanik) and molding (German: Abformung)]. With this method is it possible to create a master pyramid made of a polymeric material and having the characteristics requested. The master is then used to create a metallic mold by means of electroforming. In the end the mold is used for the molding of a number of identical pyramids made in a suitable amorphous optical polymer, using the technique of the hot embossing. This technique produce

  16. The process of adaptation of a community-level, evidence-based intervention for HIV-positive African American men who have sex with men in two cities.

    PubMed

    Robinson, Beatrice E; Galbraith, Jennifer S; Lund, Sharon M; Hamilton, Autumn R; Shankle, Michael D

    2012-06-01

    We describe the process of adapting a community-level, evidence-based behavioral intervention (EBI), Community PROMISE, for HIV-positive African American men who have sex with men (AAMSM). The Centers for Disease Control and Prevention (CDC) Map of the Adaptation Process (MAP) guided the adaptation process for this new target population by two community-based organizations (CBOs) working in partnership with two research organizations. We describe five steps of the MAP, assessment, selection, preparation, pilot, and implementation, and the use of qualitative interviews, field observations, and a cross-sectional survey. We recommend: (1) development of a centralized interactive website, listserv, or other resources where agencies adapting EBIs can share tools, materials, experiences, lessons learned, and best practices; (2) strengthening Funding Opportunity Announcements by funding incrementally in phases linked to the MAP; and (3) research should examine (a) whether EBIs adapted by CBOs remain efficacious and (b) the best "fit" between the cultural and climate characteristics of effective collaborations between community- and research-based organizations. PMID:22676461

  17. Introduction of new technologies and decision making processes: a framework to adapt a Local Health Technology Decision Support Program for other local settings

    PubMed Central

    Poulin, Paule; Austen, Lea; Scott, Catherine M; Poulin, Michelle; Gall, Nadine; Seidel, Judy; Lafrenière, René

    2013-01-01

    Purpose Introducing new health technologies, including medical devices, into a local setting in a safe, effective, and transparent manner is a complex process, involving many disciplines and players within an organization. Decision making should be systematic, consistent, and transparent. It should involve translating and integrating scientific evidence, such as health technology assessment (HTA) reports, with context-sensitive evidence to develop recommendations on whether and under what conditions a new technology will be introduced. However, the development of a program to support such decision making can require considerable time and resources. An alternative is to adapt a preexisting program to the new setting. Materials and methods We describe a framework for adapting the Local HTA Decision Support Program, originally developed by the Department of Surgery and Surgical Services (Calgary, AB, Canada), for use by other departments. The framework consists of six steps: 1) development of a program review and adaptation manual, 2) education and readiness assessment of interested departments, 3) evaluation of the program by individual departments, 4) joint evaluation via retreats, 5) synthesis of feedback and program revision, and 6) evaluation of the adaptation process. Results Nine departments revised the Local HTA Decision Support Program and expressed strong satisfaction with the adaptation process. Key elements for success were identified. Conclusion Adaptation of a preexisting program may reduce duplication of effort, save resources, raise the health care providers’ awareness of HTA, and foster constructive stakeholder engagement, which enhances the legitimacy of evidence-informed recommendations for introducing new health technologies. We encourage others to use this framework for program adaptation and to report their experiences. PMID:24273415

  18. Seam tracking with adaptive image capture for fine-tuning of a high power laser welding process

    NASA Astrophysics Data System (ADS)

    Lahdenoja, Olli; Säntti, Tero; Laiho, Mika; Paasio, Ari; Poikonen, Jonne K.

    2015-02-01

    This paper presents the development of methods for real-time fine-tuning of a high power laser welding process of thick steel by using a compact smart camera system. When performing welding in butt-joint configuration, the laser beam's location needs to be adjusted exactly according to the seam line in order to allow the injected energy to be absorbed uniformly into both steel sheets. In this paper, on-line extraction of seam parameters is targeted by taking advantage of a combination of dynamic image intensity compression, image segmentation with a focal-plane processor ASIC, and Hough transform on an associated FPGA. Additional filtering of Hough line candidates based on temporal windowing is further applied to reduce unrealistic frame-to-frame tracking variations. The proposed methods are implemented in Matlab by using image data captured with adaptive integration time. The simulations are performed in a hardware oriented way to allow real-time implementation of the algorithms on the smart camera system.

  19. When the sense of smell meets emotion: anxiety-state-dependent olfactory processing and neural circuitry adaptation.

    PubMed

    Krusemark, Elizabeth A; Novak, Lucas R; Gitelman, Darren R; Li, Wen

    2013-09-25

    Phylogenetically the most ancient sense, olfaction is characterized by a unique intimacy with the emotion system. However, mechanisms underlying olfaction-emotion interaction remain unclear, especially in an ever-changing environment and dynamic internal milieu. Perturbing the internal state with anxiety induction in human subjects, we interrogated emotion-state-dependent olfactory processing in a functional magnetic resonance imaging (fMRI) study. Following anxiety induction, initially neutral odors become unpleasant and take longer to detect, accompanied by augmented response to these odors in the olfactory (anterior piriform and orbitofrontal) cortices and emotion-relevant pregenual anterior cingulate cortex. In parallel, the olfactory sensory relay adapts with increased anxiety, incorporating amygdala as an integral step via strengthened (afferent or efferent) connections between amygdala and all levels of the olfactory cortical hierarchy. This anxiety-state-dependent neural circuitry thus enables cumulative infusion of limbic affective information throughout the olfactory sensory progression, thereby driving affectively charged olfactory perception. These findings could constitute an olfactory etiology model of emotional disorders, as exaggerated emotion-olfaction interaction in negative mood states turns innocuous odors aversive, fueling anxiety and depression with rising ambient sensory stress. PMID:24068799

  20. Adaptive covariance estimation of non-stationary processes and its application to infer dynamic connectivity from fMRI.

    PubMed

    Fu, Zening; Chan, Shing-Chow; Di, Xin; Biswal, Bharat; Zhang, Zhiguo

    2014-04-01

    Time-varying covariance is an important metric to measure the statistical dependence between non-stationary biological processes. Time-varying covariance is conventionally estimated from short-time data segments within a window having a certain bandwidth, but it is difficult to choose an appropriate bandwidth to estimate covariance with different degrees of non-stationarity. This paper introduces a local polynomial regression (LPR) method to estimate time-varying covariance and performs an asymptotic analysis of the LPR covariance estimator to show that both the estimation bias and variance are functions of the bandwidth and there exists an optimal bandwidth to minimize the mean square error (MSE) locally. A data-driven variable bandwidth selection method, namely the intersection of confidence intervals (ICI), is adopted in LPR for adaptively determining the local optimal bandwidth that minimizes the MSE. Experimental results on simulated signals show that the LPR-ICI method can achieve robust and reliable performance in estimating time-varying covariance with different degrees of variations and under different noise scenarios, making it a powerful tool to study the dynamic relationship between non-stationary biomedical signals. Further, we apply the LPR-ICI method to estimate time-varying covariance of functional magnetic resonance imaging (fMRI) signals in a visual task for the inference of dynamic functional brain connectivity. The results show that the LPR-ICI method can effectively capture the transient connectivity patterns from fMRI. PMID:24760946

  1. Reconstruction of a probable ancestral form of conger eel galectins revealed their rapid adaptive evolution process for specific carbohydrate recognition.

    PubMed

    Konno, Ayumu; Ogawa, Tomohisa; Shirai, Tsuyoshi; Muramoto, Koji

    2007-11-01

    Recently, many cases of rapid adaptive evolution, which is characterized by the higher substitution rates of nonsynonymous substitutions to synonymous ones, have been identified in the various genes of venomous and biodefense proteins, including the conger eel galectins, congerins I and II (ConI and ConII). To understand the evolutionary process of congerins, we prepared a probable ancestral form, Con-anc, corresponding to the putative amino acid sequence at the divergence of ConI and ConII in phylogenetic tree with 76% and 61% sequence identities to the current proteins, respectively. Con-anc and ConII had comparable thermostability and similar carbohydrate specificities in general, whereas ConI was more thermostable and showed different carbohydrate specificities. Con-anc showed decreased specificity to oligosaccharides with alpha 2,3-sialyl galactose moieties. These suggest that ConI and ConII have evolved via accelerated evolution under significant selective pressure to increase the thermostability and to acquire the activity to bind to alpha2,3-sialyl galactose present in pathogenic bacteria, respectively. Furthermore, comparative mutagenesis analyses of Con-anc and congerins revealed the structural basis for specific recognition of ConII to alpha2,3-sialyl galactose moiety, and strong binding ability of ConI to oligosaccharides including lacto-N-biosyl (Galbeta1-3GlcNAc) or lacto-N-neobiosyl (Galbeta1-4GlcNAc) residues, respectively. Thus, protein engineering using a probable ancestral form presented here is a powerful approach not only to determine the evolutionary process but also to investigate the structure-activity relationships of proteins. PMID:17827170

  2. Adaptation to elastic loads and BMI robot controls during rat locomotion examined with point-process GLMs.

    PubMed

    Song, Weiguo; Cajigas, Iahn; Brown, Emery N; Giszter, Simon F

    2015-01-01

    Currently little is known about how a mechanically coupled BMI system's actions are integrated into ongoing body dynamics. We tested a locomotor task augmented with a BMI system driving a robot mechanically interacting with a rat under three conditions: control locomotion (BL), "simple elastic load" (E) and "BMI with elastic load" (BMI/E). The effect of the BMI was to allow compensation of the elastic load as a function of the neural drive. Neurons recorded here were close to one another in cortex, all within a 200 micron diameter horizontal distance of one another. The interactions of these close assemblies of neurons may differ from those among neurons at longer distances in BMI tasks and thus are important to explore. A point process generalized linear model (GLM), was used to examine connectivity at two different binning timescales (1 ms vs. 10 ms). We used GLM models to fit non-Poisson neural dynamics solely using other neurons' prior neural activity as covariates. Models at different timescales were compared based on Kolmogorov-Smirnov (KS) goodness-of-fit and parsimony. About 15% of cells with non-Poisson firing were well fitted with the neuron-to-neuron models alone. More such cells were fitted at the 1 ms binning than 10 ms. Positive connection parameters ("excitation" ~70%) exceeded negative parameters ("inhibition" ~30%). Significant connectivity changes in the GLM determined networks of well-fitted neurons occurred between the conditions. However, a common core of connections comprising at least ~15% of connections persisted between any two of the three conditions. Significantly almost twice as many connections were in common between the two load conditions (~27%), compared to between either load condition and the baseline. This local point process GLM identified neural correlation structure and the changes seen across task conditions in the rats in this neural subset may be intrinsic to cortex or due to feedback and input reorganization in adaptation

  3. Geochemical diversity in S processes mediated by culture-adapted and environmental-enrichments of Acidithiobacillus spp.

    NASA Astrophysics Data System (ADS)

    Bernier, Luc; Warren, Lesley A.

    2007-12-01

    Coupled S speciation and acid generation resulting from S processing associated with five different microbial treatments, all primarily Acidithiobacillus spp. (i.e. autotrophic S-oxidizers) were evaluated in batch laboratory experiments. Microbial treatments included two culture-adapted strains, Acidithiobacillus ferrooxidans and Acidithiobacillus thiooxidans, their consortia and two environmental enrichments from a mine tailings lake that were determined to be >95% Acidithiobacillus spp., by whole-cell fluorescent hybridization. Using batch experiments simulating acidic mine waters with no carbon amendments, acid generation, and S speciation associated with the oxidation of three S substrates (thiosulfate, tetrathionate, and elemental S) were evaluated. Aseptic controls showed no observable pH decrease over the experimental time course (1 month) for all three S compounds examined. In contrast, pH decreased in all microbial treatments from starting pH values of 4 to 2 or less for all three S substrates. Results show a non-linear relationship between the pH dynamics of the batch cultures and their corresponding sulfate concentrations, and indicate how known microbial S processing pathways have opposite impacts, ultimately on pH dynamics. Associated geochemical modeling indicated negligible abiogenic processes contributing to the observed results, indicating strong microbial control of acid generation extending over pH ranges from 4 to less than 2. However, the observed acid generation rates and associated S speciation were both microbial treatment and substrate-specific. Results reveal a number of novel insights regarding microbial catalysis of S oxidation: (1) metabolic diversity in S processing, as evidenced by the observed geochemical signatures in S chemical speciation and rates of acid generation amongst phylogenetically similar organisms (to the genus level); (2) consortial impacts differ from those of individual strain members; (3) environmental enrichments

  4. Digital computer modeling of the process of reduction of redundancy in multichannel telemetry information by the method of adaptive discretization with associative sorting

    NASA Technical Reports Server (NTRS)

    Tolmadzheva, T. A.; Kantor, A. V.; Rozhkovskiy, L. V.

    1974-01-01

    Digital computer modeling of the process of adaptive discretization with associative sorting of actual multichannel telemetry information is discussed. The main task in modeling is production of initial data for determination of dependences describing the operation of the on-board information compression device. Conclusions are presented including the shortcomings of telemetric information used in modeling.

  5. Development of a Computerized Adaptive Testing for Diagnosing the Cognitive Process of Grade 7 Students in Learning Algebra, Using Multidimensional Item Response Theory

    ERIC Educational Resources Information Center

    Senarat, Somprasong; Tayraukham, Sombat; Piyapimonsit, Chatsiri; Tongkhambanjong, Sakesan

    2013-01-01

    The purpose of this research is to develop a multidimensional computerized adaptive test for diagnosing the cognitive process of grade 7 students in learning algebra by applying multidimensional item response theory. The research is divided into 4 steps: 1) the development of item bank of algebra, 2) the development of the multidimensional…

  6. Investigating the Substantive Aspect of Construct Validity for the Satisfaction with Life Scale Adapted for Children: A Focus on Cognitive Processes

    ERIC Educational Resources Information Center

    Gadermann, Anne M.; Guhn, Martin; Zumbo, Bruno D.

    2011-01-01

    The objective of this study was to investigate the substantive aspect of construct validity of the Satisfaction with Life Scale adapted for Children (SWLS-C; Gadermann et al. in Soc Indic Res 96:229-247, "2010"). Specifically, the study examined the cognitive processes of children when responding to the items of the SWLS-C to find out how they…

  7. The Use of Statistical Process Control-Charts for Person-Fit Analysis on Computerized Adaptive Testing. LSAC Research Report Series.

    ERIC Educational Resources Information Center

    Meijer, Rob R.; van Krimpen-Stoop, Edith M. L. A.

    In this study a cumulative-sum (CUSUM) procedure from the theory of Statistical Process Control was modified and applied in the context of person-fit analysis in a computerized adaptive testing (CAT) environment. Six person-fit statistics were proposed using the CUSUM procedure, and three of them could be used to investigate the CAT in online test…

  8. The influence of regional urbanization and abnormal weather conditions on the processes of human climatic adaptation on mountain resorts

    NASA Astrophysics Data System (ADS)

    Artamonova, M.; Golitsyn, G.; Senik, I.; Safronov, A.; Babyakin, A.; Efimenko, N.; Povolotskaya, N.; Topuriya, D.; Chalaya, E.

    2012-04-01

    This work is a further development in the study of weather pathogenic index (WPI) and negative influence of urbanization processes on the state of people's health with adaptation disorder. This problem is socially significant. According to the data of the WHO, in the world there are from 20 to 45% of healthy people and from 40 to 80% of people with chronic diseases who suffer from the raised meteosensitivity. As a result of our researches of meteosensitivity of people during their short-duration on mountain resorts there were used negative adaptive reactions (NAR) under 26 routine tests, stress-reactions under L.H. Garkavi's hemogram, vegetative indices, tests of neuro-vascular reactivity, signs of imbalance of vegetative and neurohumoral regulation according to the data of biorhythm fractal analysis and sudden aggravations of diseases (SAD) as an indicator of negative climatic and urbanization influence. In 2010-2011 the Caucasian mountain resorts were having long periods of climatic anomalies, strengthening of anthropogenic emissions and forest fires when record-breaking high waves of NAR and SAD were noticed. There have also been specified indices ranks of weather pathogenicity from results of comparison of health characteristics with indicators of synoptico-dynamic processes according to Weather Research and Forecasting model (WRF); air ionization N+, N-, N+/N- spectra of aerosol particles (the size from 500 to 20000 nanometers) and concentrations of chemically active gases (O3, NO, NO2, ), volatile phytoorganic substances in the surface atmosphere, bactericidal characteristics of vegetation by criterion χ2 (not above 0,05). It has allowed us to develop new physiological optimum borders, norm and pessimum, to classify emergency ecologo-weather situations, to develop a new techniques of their forecasting and prevention of meteopathic reactions with meteosensitive patients (Method of treatment and the early (emergency) and planned prevention meteopatic reactions

  9. Adaptive Iterative Dose Reduction Using Three Dimensional Processing (AIDR3D) Improves Chest CT Image Quality and Reduces Radiation Exposure

    PubMed Central

    Yamashiro, Tsuneo; Miyara, Tetsuhiro; Honda, Osamu; Kamiya, Hisashi; Murata, Kiyoshi; Ohno, Yoshiharu; Tomiyama, Noriyuki; Moriya, Hiroshi; Koyama, Mitsuhiro; Noma, Satoshi; Kamiya, Ayano; Tanaka, Yuko; Murayama, Sadayuki

    2014-01-01

    Objective To assess the advantages of Adaptive Iterative Dose Reduction using Three Dimensional Processing (AIDR3D) for image quality improvement and dose reduction for chest computed tomography (CT). Methods Institutional Review Boards approved this study and informed consent was obtained. Eighty-eight subjects underwent chest CT at five institutions using identical scanners and protocols. During a single visit, each subject was scanned using different tube currents: 240, 120, and 60 mA. Scan data were converted to images using AIDR3D and a conventional reconstruction mode (without AIDR3D). Using a 5-point scale from 1 (non-diagnostic) to 5 (excellent), three blinded observers independently evaluated image quality for three lung zones, four patterns of lung disease (nodule/mass, emphysema, bronchiolitis, and diffuse lung disease), and three mediastinal measurements (small structure visibility, streak artifacts, and shoulder artifacts). Differences in these scores were assessed by Scheffe's test. Results At each tube current, scans using AIDR3D had higher scores than those without AIDR3D, which were significant for lung zones (p<0.0001) and all mediastinal measurements (p<0.01). For lung diseases, significant improvements with AIDR3D were frequently observed at 120 and 60 mA. Scans with AIDR3D at 120 mA had significantly higher scores than those without AIDR3D at 240 mA for lung zones and mediastinal streak artifacts (p<0.0001), and slightly higher or equal scores for all other measurements. Scans with AIDR3D at 60 mA were also judged superior or equivalent to those without AIDR3D at 120 mA. Conclusion For chest CT, AIDR3D provides better image quality and can reduce radiation exposure by 50%. PMID:25153797

  10. Processes Driving the Adaptive Radiation of a Tropical Tree (Diospyros, Ebenaceae) in New Caledonia, a Biodiversity Hotspot.

    PubMed

    Paun, Ovidiu; Turner, Barbara; Trucchi, Emiliano; Munzinger, Jérôme; Chase, Mark W; Samuel, Rosabelle

    2016-03-01

    Due to its special geological history, the New Caledonian Archipelago is a mosaic of soil types, and in combination with climatic conditions this results in a heterogeneous environment across relatively small distances. A group of over 20 endemic species of Diospyros (Ebenaceae) has rapidly and recently radiated on the archipelago after a single long-distance dispersal event. Most of the Diospyros species in the radiating group are morphologically and ecologically well differentiated, but they exhibit low levels of DNA variability. To investigate the processes that shaped the diversification of this group we employed restriction site associated DNA sequencing (RADseq). Over 8400 filtered SNPs generally confirm species delimitations and produce a well-supported phylogenetic tree. Our analyses document local introgression, but only a limited potential for gene flow over longer distances. The phylogenetic relationships point to an early regional clustering among populations and species, indicating that allopatric speciation with respect to macrohabitat (i.e., climatic conditions) may have had a role in the initial differentiation within the group. A later, more rapid radiation involved divergence with respect to microhabitat (i.e., soil preference). Several sister species in the group show a parallel divergence in edaphic preference. Searches for genomic regions that are systematically differentiated in this replicated phenotypic divergence pointed to loci potentially involved in ion binding and cellular transport. These loci appear meaningful in the context of adaptations to soil types that differ in heavy-metal and mineral content. Identical nucleotide changes affected only two of these loci, indicating that introgression may have played a limited role in their evolution. Our results suggest that both allopatric diversification and (parapatric) ecological divergence shaped successive rounds of speciation in the Diospyros radiation on New Caledonia. PMID:26430059

  11. Processes Driving the Adaptive Radiation of a Tropical Tree (Diospyros, Ebenaceae) in New Caledonia, a Biodiversity Hotspot

    PubMed Central

    Paun, Ovidiu; Turner, Barbara; Trucchi, Emiliano; Munzinger, Jérôme; Chase, Mark W.; Samuel, Rosabelle

    2016-01-01

    Due to its special geological history, the New Caledonian Archipelago is a mosaic of soil types, and in combination with climatic conditions this results in a heterogeneous environment across relatively small distances. A group of over 20 endemic species of Diospyros (Ebenaceae) has rapidly and recently radiated on the archipelago after a single long-distance dispersal event. Most of the Diospyros species in the radiating group are morphologically and ecologically well differentiated, but they exhibit low levels of DNA variability. To investigate the processes that shaped the diversification of this group we employed restriction site associated DNA sequencing (RADseq). Over 8400 filtered SNPs generally confirm species delimitations and produce a well-supported phylogenetic tree. Our analyses document local introgression, but only a limited potential for gene flow over longer distances. The phylogenetic relationships point to an early regional clustering among populations and species, indicating that allopatric speciation with respect to macrohabitat (i.e., climatic conditions) may have had a role in the initial differentiation within the group. A later, more rapid radiation involved divergence with respect to microhabitat (i.e., soil preference). Several sister species in the group show a parallel divergence in edaphic preference. Searches for genomic regions that are systematically differentiated in this replicated phenotypic divergence pointed to loci potentially involved in ion binding and cellular transport. These loci appear meaningful in the context of adaptations to soil types that differ in heavy-metal and mineral content. Identical nucleotide changes affected only two of these loci, indicating that introgression may have played a limited role in their evolution. Our results suggest that both allopatric diversification and (parapatric) ecological divergence shaped successive rounds of speciation in the Diospyros radiation on New Caledonia. PMID:26430059

  12. Orthopaedic Surgery Under National Health Reform: An Analysis of Power, Process, Adaptation, and Leadership: AOA Critical Issues.

    PubMed

    Callahan, Charles D; Adair, Daniel; Bozic, Kevin J; Manning, Blaine T; Saleh, Jamal K; Saleh, Khaled J

    2014-07-01

    Morrison argued that demography, economy, and technology drive the evolution of industries from a formative first-generation state ("First Curve") to a radically different way of doing things ("Second Curve") that is marked by new skills, strategies, and partners. The current health-reform movement in the United States reflects these three key evolutionary trends: surging medical needs of an aging population, dramatic expansion of Medicare spending, and care delivery systems optimized through powerful information technology. Successful transition from a formative first-generation state (First Curve) to a radically different way of doing things (Second Curve) will require new skills, strategies, and partners. In a new world that is value-driven, community-centric (versus hospital-centric), and prevention-focused, orthopaedic surgeons and health-care administrators must form new alliances to reduce the cost of care and improve durable outcomes for musculoskeletal problems. The greatest barrier to success in the Second Curve stems not from lack of empirical support for integrated models of care, but rather from resistance by those who would execute them. Porter's five forces of competitive strategy and the behavioral analysis of change provide insights into the predictable forms of resistance that undermine clinical and economic success in the new environment of care. This paper analyzes the components that will differentiate orthopaedic care provision for the Second Curve. It also provides recommendations for future-focused orthopaedic surgery and health-care administrative leaders to consider as they design newly adaptive, mutually reinforcing, and economically viable musculoskeletal care processes that drive the level of orthopaedic care that our nation deserves-at a cost that it can afford. PMID:24990985

  13. Implications of Childhood Experiences for the Health and Adaptation of Lesbian, Gay, and Bisexual Individuals: Sensitivity to Developmental Process in Future Research

    PubMed Central

    Rosario, Margaret

    2015-01-01

    The empirical literature on lesbian, gay, and bisexual (LGB) individuals has predominantly focused on sexual-orientation disparities between LGB and heterosexual individuals on health and adaptation, as well as on the role of gay-related or minority stress in the health and adaptation of LGB individuals. Aside from demographic control variables, the initial predictor is a marker of sexual orientation or LGB-related experience (e.g., minority stress). Missing are potential strengths and vulnerabilities that LGB individuals develop over time and bring to bear on their sexual identity development and other LGB-related experiences. Those strengths and vulnerabilities may have profound consequences for the sexual identity development, health, and adaptation of LGB individuals. Here, I focus on one such set of strengths and vulnerabilities derived from attachment. I conclude by emphasizing the importance of attachment in the lives of LGB individuals and the need to identify other developmental processes that may be equally consequential. PMID:26900586

  14. Evaluation of an Adaptive Game that Uses EEG Measures Validated during the Design Process as Inputs to a Biocybernetic Loop

    PubMed Central

    Ewing, Kate C.; Fairclough, Stephen H.; Gilleade, Kiel

    2016-01-01

    Biocybernetic adaptation is a form of physiological computing whereby real-time data streaming from the brain and body is used by a negative control loop to adapt the user interface. This article describes the development of an adaptive game system that is designed to maximize player engagement by utilizing changes in real-time electroencephalography (EEG) to adjust the level of game demand. The research consists of four main stages: (1) the development of a conceptual framework upon which to model the interaction between person and system; (2) the validation of the psychophysiological inference underpinning the loop; (3) the construction of a working prototype; and (4) an evaluation of the adaptive game. Two studies are reported. The first demonstrates the sensitivity of EEG power in the (frontal) theta and (parietal) alpha bands to changing levels of game demand. These variables were then reformulated within the working biocybernetic control loop designed to maximize player engagement. The second study evaluated the performance of an adaptive game of Tetris with respect to system behavior and user experience. Important issues for the design and evaluation of closed-loop interfaces are discussed. PMID:27242486

  15. Evaluation of an Adaptive Game that Uses EEG Measures Validated during the Design Process as Inputs to a Biocybernetic Loop.

    PubMed

    Ewing, Kate C; Fairclough, Stephen H; Gilleade, Kiel

    2016-01-01

    Biocybernetic adaptation is a form of physiological computing whereby real-time data streaming from the brain and body is used by a negative control loop to adapt the user interface. This article describes the development of an adaptive game system that is designed to maximize player engagement by utilizing changes in real-time electroencephalography (EEG) to adjust the level of game demand. The research consists of four main stages: (1) the development of a conceptual framework upon which to model the interaction between person and system; (2) the validation of the psychophysiological inference underpinning the loop; (3) the construction of a working prototype; and (4) an evaluation of the adaptive game. Two studies are reported. The first demonstrates the sensitivity of EEG power in the (frontal) theta and (parietal) alpha bands to changing levels of game demand. These variables were then reformulated within the working biocybernetic control loop designed to maximize player engagement. The second study evaluated the performance of an adaptive game of Tetris with respect to system behavior and user experience. Important issues for the design and evaluation of closed-loop interfaces are discussed. PMID:27242486

  16. Learning from the value of your mistakes: evidence for a risk-sensitive process in movement adaptation

    PubMed Central

    Trent, Michael C.; Ahmed, Alaa A.

    2013-01-01

    Risk frames nearly every decision we make. Yet, remarkably little is known about whether risk influences how we learn new movements. Risk-sensitivity can emerge when there is a distortion between the absolute magnitude (actual value) and how much an individual values (subjective value) a given outcome. In movement, this translates to the difference between a given movement error and its consequences. Surprisingly, how movement learning can be influenced by the consequences associated with an error is not well-understood. It is traditionally assumed that all errors are created equal, i.e., that adaptation is proportional to an error experienced. However, not all movement errors of a given magnitude have the same subjective value. Here we examined whether the subjective value of error influenced how participants adapted their control from movement to movement. Seated human participants grasped the handle of a force-generating robotic arm and made horizontal reaching movements in two novel dynamic environments that penalized errors of the same magnitude differently, changing the subjective value of the errors. We expected that adaptation in response to errors of the same magnitude would differ between these environments. In the first environment, Stable, errors were not penalized. In the second environment, Unstable, rightward errors were penalized with the threat of unstable, cliff-like forces. We found that adaptation indeed differed. Specifically, in the Unstable environment, we observed reduced adaptation to leftward errors, an appropriate strategy that reduced the chance of a penalizing rightward error. These results demonstrate that adaptation is influenced by the subjective value of error, rather than solely the magnitude of error, and therefore is risk-sensitive. In other words, we may not simply learn from our mistakes, we may also learn from the value of our mistakes. PMID:23986693

  17. An Engineered Approach to Stem Cell Culture: Automating the Decision Process for Real-Time Adaptive Subculture of Stem Cells

    PubMed Central

    Ker, Dai Fei Elmer; Weiss, Lee E.; Junkers, Silvina N.; Chen, Mei; Yin, Zhaozheng; Sandbothe, Michael F.; Huh, Seung-il; Eom, Sungeun; Bise, Ryoma; Osuna-Highley, Elvira; Kanade, Takeo; Campbell, Phil G.

    2011-01-01

    Current cell culture practices are dependent upon human operators and remain laborious and highly subjective, resulting in large variations and inconsistent outcomes, especially when using visual assessments of cell confluency to determine the appropriate time to subculture cells. Although efforts to automate cell culture with robotic systems are underway, the majority of such systems still require human intervention to determine when to subculture. Thus, it is necessary to accurately and objectively determine the appropriate time for cell passaging. Optimal stem cell culturing that maintains cell pluripotency while maximizing cell yields will be especially important for efficient, cost-effective stem cell-based therapies. Toward this goal we developed a real-time computer vision-based system that monitors the degree of cell confluency with a precision of 0.791±0.031 and recall of 0.559±0.043. The system consists of an automated phase-contrast time-lapse microscope and a server. Multiple dishes are sequentially imaged and the data is uploaded to the server that performs computer vision processing, predicts when cells will exceed a pre-defined threshold for optimal cell confluency, and provides a Web-based interface for remote cell culture monitoring. Human operators are also notified via text messaging and e-mail 4 hours prior to reaching this threshold and immediately upon reaching this threshold. This system was successfully used to direct the expansion of a paradigm stem cell population, C2C12 cells. Computer-directed and human-directed control subcultures required 3 serial cultures to achieve the theoretical target cell yield of 50 million C2C12 cells and showed no difference for myogenic and osteogenic differentiation. This automated vision-based system has potential as a tool toward adaptive real-time control of subculturing, cell culture optimization and quality assurance/quality control, and it could be integrated with current and developing robotic cell

  18. KnowledgePuzzle: A Browsing Tool to Adapt the Web Navigation Process to the Learner's Mental Model

    ERIC Educational Resources Information Center

    AlAgha, Iyad

    2012-01-01

    This article presents KnowledgePuzzle, a browsing tool for knowledge construction from the web. It aims to adapt the structure of web content to the learner's information needs regardless of how the web content is originally delivered. Learners are provided with a meta-cognitive space (e.g., a concept mapping tool) that enables them to plan…

  19. The Cultural Adaptation Process of Agricultural and Life Sciences Students on Short-Term Study Abroad Experiences

    ERIC Educational Resources Information Center

    Conner, Nathan William

    2013-01-01

    The purpose of this study was to explore how undergraduate students in a college of agricultural and life sciences experienced cultural adaptation during short-term study abroad programs. The specific objectives of this study were to describe how undergraduate students in the college of agricultural and life sciences experienced culture throughout…

  20. Adaptation Processes of Recent Immigrants to the United States: A Review of the Demographic and Social Aspects. Policy Discussion Paper.

    ERIC Educational Resources Information Center

    Goodis, Tracy Ann

    This paper reviews the recent literature on the demographic and social aspects of immigrant adaptation. Demographic information includes age and family structure, fertility behavior, intermarriage, and residential segregation. Social dimensions refer to native-language retention, English-language acquisition, and educational attainment. Most…

  1. Development of a new pre- and post-processing tool (SADAPT-TRAN) for nonlinear mixed-effects modeling in S-ADAPT.

    PubMed

    Bulitta, Jurgen Bernd; Bingölbali, Ayhan; Shin, Beom Soo; Landersdorfer, Cornelia Barbara

    2011-06-01

    Mechanistic modeling greatly benefits from automated pre- and post-processing of model code and modeling results. While S-ADAPT provides many state-of-the-art parametric population estimation methods, its pre- and post-processing capabilities are limited. Our objective was to develop a fully automated, open-source pre- and post-processor for nonlinear mixed-effects modeling in S-ADAPT. We developed a new translator tool (SADAPT-TRAN) based on Perl scripts. These scripts (a) automatically translate the core model components into robust Fortran code, (b) perform extensive mutual error checks across all input files and the raw dataset, (c) extend the options of the Monte Carlo Parametric Expectation Maximization (MC-PEM) algorithm, and (d) improve the numerical robustness of the model code. The post-processing scripts automatically summarize the results of one or multiple models as tables and, by generating problem specific R scripts, provide an extended series of standard and covariate-stratified diagnostic plots. The SADAPT-TRAN package substantially improved the efficiency to specify, debug, and evaluate models and enhanced the flexibility of using the MC-PEM algorithm for parallelized estimation in S-ADAPT. The parameter variability model can take any combination of normally, log-normally, or logistically distributed parameters and the SADAPT-TRAN package can automatically generate the Fortran code required to specify between occasion variability. Extended estimation features are available to avoid local minima, estimate means with negligible variances, and estimate variances for fixed means. The SADAPT-TRAN package significantly facilitated model development in S-ADAPT, reduced model specification errors, and provided useful error messages for beginner and advanced users. This benefit was greatest for complex mechanistic models. PMID:21369876

  2. Local and global solution for a nonlocal Fokker-Planck equation related to the adaptive biasing force process

    NASA Astrophysics Data System (ADS)

    Alrachid, Houssam; Lelièvre, Tony; Talhouk, Raafat

    2016-05-01

    We prove global existence, uniqueness and regularity of the mild, Lp and classical solution of a non-linear Fokker-Planck equation arising in an adaptive importance sampling method for molecular dynamics calculations. The non-linear term is related to a conditional expectation, and is thus non-local. The proof uses tools from the theory of semigroups of linear operators for the local existence result, and an a priori estimate based on a supersolution for the global existence result.

  3. From sounds to words: a neurocomputational model of adaptation, inhibition and memory processes in auditory change detection.

    PubMed

    Garagnani, Max; Pulvermüller, Friedemann

    2011-01-01

    Most animals detect sudden changes in trains of repeated stimuli but only some can learn a wide range of sensory patterns and recognise them later, a skill crucial for the evolutionary success of higher mammals. Here we use a neural model mimicking the cortical anatomy of sensory and motor areas and their connections to explain brain activity indexing auditory change and memory access. Our simulations indicate that while neuronal adaptation and local inhibition of cortical activity can explain aspects of change detection as observed when a repeated unfamiliar sound changes in frequency, the brain dynamics elicited by auditory stimulation with well-known patterns (such as meaningful words) cannot be accounted for on the basis of adaptation and inhibition alone. Specifically, we show that the stronger brain responses observed to familiar stimuli in passive oddball tasks are best explained in terms of activation of memory circuits that emerged in the cortex during the learning of these stimuli. Such memory circuits, and the activation enhancement they entail, are absent for unfamiliar stimuli. The model illustrates how basic neurobiological mechanisms, including neuronal adaptation, lateral inhibition, and Hebbian learning, underlie neuronal assembly formation and dynamics, and differentially contribute to the brain's major change detection response, the mismatch negativity. PMID:20728545

  4. Exploring the Nature of the Intention, Meaning and Perception Process of the Neuro-occupation Model to Understand Adaptation to Change.

    PubMed

    Derakhshanrad, Seyed Alireza; Piven, Emily; Hosseini, Seyed Ali; Shahboulaghi, Farahnaz Mohammadi; Nazeran, Homer; Rassafiani, Mehdi

    2016-03-01

    The theoretical model of neuro-occupation, intention, meaning and perception, sought to describe the symbiotic relationship between occupation and the brain, as a chaotic, self-organized, complex system. Lack of evidence has limited its applicability to practice. The aim of this study was to track the postulates of the model within the daily experiences of subjects. Structured matrices were created for content analysis, using a qualitative multiple-case-study design, typically used for testing models. An underpinning principle of the model, defined a circular causality feedback process, which was confirmed as described through tracing the repetitive processes within the lived experience of two Iranian men. The process suggested that continual adaptation occurred in lives interrupted by cerebrovascular accident, which enabled the subjects to return to expression of meaning through purposeful occupation and continually re-shaped their perceptions. The primary limitation of this study was that it was the earliest attempt to test the model and to substantiate the process by comparing the similarities and differences between too few subjects. Future research should identify the same process in more subjects and validate a practical assessment tool for clients. These findings may inform practitioners about intentional use of occupational challenges to elicit adaptive behaviours in clients. PMID:26234718

  5. Adaptive parallel logic networks

    NASA Technical Reports Server (NTRS)

    Martinez, Tony R.; Vidal, Jacques J.

    1988-01-01

    Adaptive, self-organizing concurrent systems (ASOCS) that combine self-organization with massive parallelism for such applications as adaptive logic devices, robotics, process control, and system malfunction management, are presently discussed. In ASOCS, an adaptive network composed of many simple computing elements operating in combinational and asynchronous fashion is used and problems are specified by presenting if-then rules to the system in the form of Boolean conjunctions. During data processing, which is a different operational phase from adaptation, the network acts as a parallel hardware circuit.

  6. Adaptive GSA-based optimal tuning of PI controlled servo systems with reduced process parametric sensitivity, robust stability and controller robustness.

    PubMed

    Precup, Radu-Emil; David, Radu-Codrut; Petriu, Emil M; Radac, Mircea-Bogdan; Preitl, Stefan

    2014-11-01

    This paper suggests a new generation of optimal PI controllers for a class of servo systems characterized by saturation and dead zone static nonlinearities and second-order models with an integral component. The objective functions are expressed as the integral of time multiplied by absolute error plus the weighted sum of the integrals of output sensitivity functions of the state sensitivity models with respect to two process parametric variations. The PI controller tuning conditions applied to a simplified linear process model involve a single design parameter specific to the extended symmetrical optimum (ESO) method which offers the desired tradeoff to several control system performance indices. An original back-calculation and tracking anti-windup scheme is proposed in order to prevent the integrator wind-up and to compensate for the dead zone nonlinearity of the process. The minimization of the objective functions is carried out in the framework of optimization problems with inequality constraints which guarantee the robust stability with respect to the process parametric variations and the controller robustness. An adaptive gravitational search algorithm (GSA) solves the optimization problems focused on the optimal tuning of the design parameter specific to the ESO method and of the anti-windup tracking gain. A tuning method for PI controllers is proposed as an efficient approach to the design of resilient control systems. The tuning method and the PI controllers are experimentally validated by the adaptive GSA-based tuning of PI controllers for the angular position control of a laboratory servo system. PMID:25330468

  7. Genomic analysis of snub-nosed monkeys (Rhinopithecus) identifies genes and processes related to high-altitude adaptation.

    PubMed

    Yu, Li; Wang, Guo-Dong; Ruan, Jue; Chen, Yong-Bin; Yang, Cui-Ping; Cao, Xue; Wu, Hong; Liu, Yan-Hu; Du, Zheng-Lin; Wang, Xiao-Ping; Yang, Jing; Cheng, Shao-Chen; Zhong, Li; Wang, Lu; Wang, Xuan; Hu, Jing-Yang; Fang, Lu; Bai, Bing; Wang, Kai-Le; Yuan, Na; Wu, Shi-Fang; Li, Bao-Guo; Zhang, Jin-Guo; Yang, Ye-Qin; Zhang, Cheng-Lin; Long, Yong-Cheng; Li, Hai-Shu; Yang, Jing-Yuan; Irwin, David M; Ryder, Oliver A; Li, Ying; Wu, Chung-I; Zhang, Ya-Ping

    2016-08-01

    The snub-nosed monkey genus Rhinopithecus includes five closely related species distributed across altitudinal gradients from 800 to 4,500 m. Rhinopithecus bieti, Rhinopithecus roxellana, and Rhinopithecus strykeri inhabit high-altitude habitats, whereas Rhinopithecus brelichi and Rhinopithecus avunculus inhabit lowland regions. We report the de novo whole-genome sequence of R. bieti and genomic sequences for the four other species. Eight shared substitutions were found in six genes related to lung function, DNA repair, and angiogenesis in the high-altitude snub-nosed monkeys. Functional assays showed that the high-altitude variant of CDT1 (Ala537Val) renders cells more resistant to UV irradiation, and the high-altitude variants of RNASE4 (Asn89Lys and Thr128Ile) confer enhanced ability to induce endothelial tube formation in vitro. Genomic scans in the R. bieti and R. roxellana populations identified signatures of selection between and within populations at genes involved in functions relevant to high-altitude adaptation. These results provide valuable insights into the adaptation to high altitude in the snub-nosed monkeys. PMID:27399969

  8. The specificity of neural responses to music and their relation to voice processing: an fMRI-adaptation study.

    PubMed

    Armony, Jorge L; Aubé, William; Angulo-Perkins, Arafat; Peretz, Isabelle; Concha, Luis

    2015-04-23

    Several studies have identified, using functional magnetic resonance imaging (fMRI), a region within the superior temporal gyrus that preferentially responds to musical stimuli. However, in most cases, significant responses to other complex stimuli, particularly human voice, were also observed. Thus, it remains unknown if the same neurons respond to both stimulus types, albeit with different strengths, or whether the responses observed with fMRI are generated by distinct, overlapping neural populations. To address this question, we conducted an fMRI experiment in which short music excerpts and human vocalizations were presented in a pseudo-random order. Critically, we performed an adaptation-based analysis in which responses to the stimuli were analyzed taking into account the category of the preceding stimulus. Our results confirm the presence of a region in the anterior STG that responds more strongly to music than voice. Moreover, we found a music-specific adaptation effect in this area, consistent with the existence of music-preferred neurons. Lack of differences between musicians and non-musicians argues against an expertise effect. These findings provide further support for neural separability between music and speech within the temporal lobe. PMID:25766754

  9. The association of physical activity to neural adaptability during visuo-spatial processing in healthy elderly adults: A multiscale entropy analysis.

    PubMed

    Wang, Chun-Hao; Tsai, Chia-Liang; Tseng, Philip; Yang, Albert C; Lo, Men-Tzung; Peng, Chung-Kang; Wang, Hsin-Yi; Muggleton, Neil G; Juan, Chi-Hung; Liang, Wei-Kuang

    2014-10-29

    Physical activity has been shown to benefit brain and cognition in late adulthood. However, this effect is still unexplored in terms of brain signal complexity, which reflects the level of neural adaptability and efficiency during cognitive processing that cannot be acquired via averaged neuroelectric signals. Here we employed multiscale entropy analysis (MSE) of electroencephalography (EEG), a new approach that conveys important information related to the temporal dynamics of brain signal complexity across multiple time scales, to reveal the association of physical activity with neural adaptability and efficiency in elderly adults. A between-subjects design that included 24 participants (aged 66.63±1.31years; female=12) with high physical activity and 24 age- and gender-matched low physical activity participants (aged 67.29±1.20years) was conducted to examine differences related to physical activity in performance and MSE of EEG signals during a visuo-spatial cognition task. We observed that physically active elderly adults had better accuracy on both visuo-spatial attention and working memory conditions relative to their sedentary counterparts. Additionally, these physically active elderly adults displayed greater MSE values at larger time scales at the Fz electrode in both attention and memory conditions. The results suggest that physical activity may be beneficial for adaptability of brain systems in tasks involving visuo-spatial information. MSE thus might be a promising approach to test the effects of the benefits of exercise on cognition. PMID:25463141

  10. Use of adaptive signal-processing techniques to discriminate between coal cutting and rock cutting. Information Circular/1991

    SciTech Connect

    Pazuchanics, M.J.; Mowrey, G.L.

    1991-01-01

    The report presents results from an ongoing investigation of the use of adaptive signal discriminating methods to distinguish between cutting coal and cutting mine rock. Cutting bit forces and tool vibration were measured in the laboratory as a linear cutting apparatus made constant-depth cuts in coal, sandstone, and shale test specimens. A portion of the collected data has been analyzed and some preliminary results are given here. The influence of data bandwidth, data window size, number of signal features, and voting among classifiers on classification performance are noted. Results to date based on ideal cutting conditions and simple geologic materials indicate that of the four classifiers tested there appears to be no single best classifier. In most cases, classification accuracy showed slight improvement as the number of features considered for classification increased. The highest classification accuracies were achieved when voting was conducted among classifiers followed by voting among force components.

  11. Global change effects on biogeochemical processes of Argentinian estuaries: an overview of vulnerabilities and ecohydrological adaptive outlooks.

    PubMed

    Kopprio, Germán A; Biancalana, Florencia; Fricke, Anna; Garzón Cardona, John E; Martínez, Ana; Lara, Rubén J

    2015-02-28

    The aims of this work are to provide an overview of the current stresses of estuaries in Argentina and to propose adaptation strategies from an ecohydrological approach. Several Argentinian estuaries are impacted by pollutants, derived mainly from sewage discharge and agricultural or industrial activities. Anthropogenic impacts are expected to rise with increasing human population. Climate-driven warmer temperature and hydrological changes will alter stratification, residence time, oxygen content, salinity, pollutant distribution, organism physiology and ecology, and nutrient dynamics. Good water quality is essential in enhancing estuarine ecological resilience to disturbances brought on by global change. The preservation, restoration, and creation of wetlands will help to protect the coast from erosion, increase sediment accretion rates, and improve water quality by removing excess nutrients and pollutants. The capacity of hydrologic basin ecosystems to absorb human and natural impacts can be improved through holistic management, which should consider social vulnerability in complex human-natural systems. PMID:25194878

  12. 'Newness-struggle-success' continuum: a qualitative examination of the cultural adaptation process experienced by overseas-qualified dentists in Australia.

    PubMed

    Balasubramanian, Madhan; Brennan, David S; Spencer, A John; Short, Stephanie D

    2016-04-01

    Objectives Overseas-qualified dentists constitute a significant proportion of the Australian dental workforce (approximately one in four). The aim of the present study was to provide a better understanding of the cultural adaptation process of overseas-qualified dentists in Australia, so as to facilitate their integration into the Australian way of life and improve their contribution to Australian healthcare, economy and society. Methods Life stories of 49 overseas-qualified dentists from 22 countries were analysed for significant themes and patterns. We focused on their settlement experience, which relates to their social and cultural experience in Australia. This analysis was consistent with a hermeneutic phenomenological approach to qualitative social scientific research. Results Many participants noted that encounters with 'the Australian accent' and 'slang' influenced their cultural experience in Australia. Most of the participants expressed 'fascination' with the people and lifestyle in Australia, primarily with regard to the relaxed way of life, cultural diversity and the freedom one usually experiences living in Australia. Few participants expressed 'shock' at not being able to find a community of similar religious faith in Australia, as they are used to in their home countries. These issues were analysed in two themes; (1) language and communication; and (2) people, religion and lifestyle. The cultural adaptation process of overseas-qualified dentists in Australia is described as a continuum or superordinate theme, which we have entitled the 'newness-struggle-success' continuum. This overarching theme supersedes and incorporates all subthemes. Conclusion Family, friends, community and organisational structures (universities and public sector) play a vital role in the cultural learning process, affecting overseas-qualified dentist's ability to progress successfully through the cultural continuum. What is known about the topic? Australia is a popular host

  13. Changes in glutathione-dependent redox status and mitochondrial energetic strategies are part of the adaptive response during the filamentation process in Candida albicans.

    PubMed

    Hala, Guedouari; Rachel, Gergondey; Arthur, Bourdais; Océane, Vanparis; Anne-Laure, Bulteau; Jean-Michel, Camadro; Françoise, Auchère

    2014-10-01

    Candia albicans is an opportunist pathogen responsible for a large spectrum of infections, from superficial mycosis to systemic diseases called candidiasis. Its ability to grow in various morphological forms, such as unicellular budding yeast, filamentous pseudohyphae and hyphae, contributes to its survival in the diverse microenvironments it encounters in the host. During infection in vivo, C. albicans is faced with high levels of ROS generated by phagocytes, and the thiol-dependent redox status of the cells reflects their levels of oxidative stress. We investigated the role of glutathione during the transition between the yeast and hyphal forms of the pathogen, in relation to possible changes in mitochondrial bioenergetic pathways. Using various growth media and selective mutations affecting the filamentation process, we showed that C. albicans filamentation was always associated with a depletion of intracellular glutathione levels. Moreover, the induction of hypha formation resulted in general changes in thiol metabolism, including the oxidation of cell surface -SH groups and glutathione excretion. Metabolic adaptation involved TCA cycle activation, acceleration of mitochondrial respiration and a redistribution of electron transfer pathways, with an increase in the contribution of the alternative oxidase and rotenone-insensitive dehydrogenase. Changes in redox status and apparent oxidative stress may be necessary to the shift to adaptive metabolic pathways, ensuring normal mitochondrial function and ATP levels. The consumption of intracellular glutathione levels during the filamentation process may thus be the price paid by C. albicans for survival in the conditions encountered in the host. PMID:26461308

  14. Energy Landscape Reveals That the Budding Yeast Cell Cycle Is a Robust and Adaptive Multi-stage Process

    PubMed Central

    Lv, Cheng; Li, Xiaoguang; Li, Fangting; Li, Tiejun

    2015-01-01

    Quantitatively understanding the robustness, adaptivity and efficiency of cell cycle dynamics under the influence of noise is a fundamental but difficult question to answer for most eukaryotic organisms. Using a simplified budding yeast cell cycle model perturbed by intrinsic noise, we systematically explore these issues from an energy landscape point of view by constructing an energy landscape for the considered system based on large deviation theory. Analysis shows that the cell cycle trajectory is sharply confined by the ambient energy barrier, and the landscape along this trajectory exhibits a generally flat shape. We explain the evolution of the system on this flat path by incorporating its non-gradient nature. Furthermore, we illustrate how this global landscape changes in response to external signals, observing a nice transformation of the landscapes as the excitable system approaches a limit cycle system when nutrients are sufficient, as well as the formation of additional energy wells when the DNA replication checkpoint is activated. By taking into account the finite volume effect, we find additional pits along the flat cycle path in the landscape associated with the checkpoint mechanism of the cell cycle. The difference between the landscapes induced by intrinsic and extrinsic noise is also discussed. In our opinion, this meticulous structure of the energy landscape for our simplified model is of general interest to other cell cycle dynamics, and the proposed methods can be applied to study similar biological systems. PMID:25794282

  15. Adaptive Management

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management where knowledge is incomplete, and when, despite inherent uncertainty, managers and policymakers must act. Unlike a traditional trial and error approach, adaptive managem...

  16. Estimation of the most influential factors on the laser cutting process heat affected zone (HAZ) by adaptive neuro-fuzzy technique

    NASA Astrophysics Data System (ADS)

    Petković, Dalibor; Nikolić, Vlastimir; Milovančević, Miloš; Lazov, Lyubomir

    2016-07-01

    Heat affected zone (HAZ) of the laser cutting process may be developed on the basis on combination of different factors. In this investigation was analyzed the HAZ forecasting based on the different laser cutting parameters. The main aim in this article was to analyze the influence of three inputs on the HAZ of the laser cutting process. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data in order to select the most influential factors for HAZ forecasting. Three inputs are considered: laser power, cutting speed and gas pressure. According the results the cutting speed has the highest influence on the HAZ forecasting (RMSE: 0.0553). Gas pressure has the smallest influence on the HAZ forecasting (RMSE: 0.0801). The results can be used in order to simplify HAZ prediction and analyzing.

  17. Origins of adaptive immunity.

    PubMed

    Liongue, Clifford; John, Liza B; Ward, Alister

    2011-01-01

    Adaptive immunity, involving distinctive antibody- and cell-mediated responses to specific antigens based on "memory" of previous exposure, is a hallmark of higher vertebrates. It has been argued that adaptive immunity arose rapidly, as articulated in the "big bang theory" surrounding its origins, which stresses the importance of coincident whole-genome duplications. Through a close examination of the key molecules and molecular processes underpinning adaptive immunity, this review suggests a less-extreme model, in which adaptive immunity emerged as part of longer evolutionary journey. Clearly, whole-genome duplications provided additional raw genetic materials that were vital to the emergence of adaptive immunity, but a variety of other genetic events were also required to generate some of the key molecules, whereas others were preexisting and simply co-opted into adaptive immunity. PMID:21395512

  18. Technology transfer for adaptation

    NASA Astrophysics Data System (ADS)

    Biagini, Bonizella; Kuhl, Laura; Gallagher, Kelly Sims; Ortiz, Claudia

    2014-09-01

    Technology alone will not be able to solve adaptation challenges, but it is likely to play an important role. As a result of the role of technology in adaptation and the importance of international collaboration for climate change, technology transfer for adaptation is a critical but understudied issue. Through an analysis of Global Environment Facility-managed adaptation projects, we find there is significantly more technology transfer occurring in adaptation projects than might be expected given the pessimistic rhetoric surrounding technology transfer for adaptation. Most projects focused on demonstration and early deployment/niche formation for existing technologies rather than earlier stages of innovation, which is understandable considering the pilot nature of the projects. Key challenges for the transfer process, including technology selection and appropriateness under climate change, markets and access to technology, and diffusion strategies are discussed in more detail.

  19. Complementary processing of haptic information by slowly and rapidly adapting neurons in the trigeminothalamic pathway. Electrophysiology, mathematical modeling and simulations of vibrissae-related neurons

    PubMed Central

    Sanchez-Jimenez, Abel; Torets, Carlos; Panetsos, Fivos

    2013-01-01

    Tonic (slowly adapting) and phasic (rapidly adapting) primary afferents convey complementary aspects of haptic information to the central nervous system: object location and texture the former, shape the latter. Tonic and phasic neural responses are also recorded in all relay stations of the somatosensory pathway, yet it is unknown their role in both, information processing and information transmission to the cortex: we don't know if tonic and phasic neurons process complementary aspects of haptic information and/or if these two types constitute two separate channels that convey complementary aspects of tactile information to the cortex. Here we propose to elucidate these two questions in the fast trigeminal pathway of the rat (PrV-VPM: principal trigeminal nucleus-ventroposteromedial thalamic nucleus). We analyze early and global behavior, latencies and stability of the responses of individual cells in PrV and medial lemniscus under 1–40 Hz stimulation of the whiskers in control and decorticated animals and we use stochastic spiking models and extensive simulations. Our results strongly suggest that in the first relay station of the somatosensory system (PrV): (1) tonic and phasic neurons process complementary aspects of whisker-related tactile information (2) tonic and phasic responses are not originated from two different types of neurons (3) the two responses are generated by the differential action of the somatosensory cortex on a unique type of PrV cell (4) tonic and phasic neurons do not belong to two different channels for the transmission of tactile information to the thalamus (5) trigeminothalamic transmission is exclusively performed by tonically firing neurons and (6) all aspects of haptic information are coded into low-pass, band-pass, and high-pass filtering profiles of tonically firing neurons. Our results are important for both, basic research on neural circuits and information processing, and development of sensory neuroprostheses. PMID:23761732

  20. The Limits to Adaptation; A Systems Approach

    EPA Science Inventory

    The Limits to Adaptation: A Systems Approach. The ability to adapt to climate change is delineated by capacity thresholds, after which climate damages begin to overwhelm the adaptation response. Such thresholds depend upon physical properties (natural processes and engineering...

  1. How to Make a Non-Antigenic Protein (Auto) Antigenic: Molecular Complementarity Alters Antigen Processing and Activates Adaptive-Innate Immunity Synergy.

    PubMed

    Root-Bernstein, Robert

    2015-01-01

    Evidence is reviewed that complementary proteins and peptides form complexes with increased antigenicity and/or autoimmunogenicity. Five case studies are highlighted: 1) diphtheria toxin-antitoxin (antibody), which induces immunity to the normally non-antigenic toxin, and autoimmune neuritis; 2) tryptophan peptide of myelin basic protein and muramyl dipeptide ("adjuvant peptide"), which form a complex that induces experimental allergic encephalomyelitis; 3) an insulin and glucagon complex that is far more antigenic than either component individually; 4) various causes of experimental autoimmune myocarditis such as C protein in combination with its antibody, or coxsackie B virus in combination with the coxsackie and adenovirus receptor; 5) influenza A virus haemagglutinin with the outer membrane protein of the Haemophilus influenzae, which increases antigenicity. Several mechanisms cooperate to alter immunogenicity. Complexation alters antigen processing, protecting the components against proteolysis, altering fragmentation and presenting novel antigens to the immune system. Complementary antigens induce complementary adaptive immune responses (complementary antibodies and/or T cell receptors) that produce circulating immune complexes (CIC). CIC stimulate innate immunity. Concurrently, complementary antigens stimulate multiple Toll-like receptors that synergize to over-produce cytokines, which further stimulate adaptive immunity. Thus innate and adaptive immunity form a positive feedback loop. If components of the complex mimic a host protein, then autoimmunity may result. Enhanced antigenicity for production of improved vaccines and/or therapeutic autoimmunity (e.g., against cancer cells) might be achieved by using information from antibody or TCR recognition sites to complement an antigen; by panning for complements in randomized peptide libraries; or using antisense peptide strategies to design complements. PMID:26179268

  2. Theory of psychological adaptive modes.

    PubMed

    Lehti, Juha

    2016-05-01

    When an individual is facing a stressor and normal stress-response mechanism cannot guarantee sufficient adaptation, special emotional states, adaptive modes, are activated (for example a depressive reaction). Adaptive modes are involuntary states of mind, they are of comprehensive nature, they interfere with normal functioning, and they cannot be repressed or controlled the same way as many emotions. Their transformational nature differentiates them from other emotional states. The object of the adaptive mode is to optimize the problem-solving abilities according to the situation that has provoked the mode. Cognitions and emotions during the adaptive mode are different than in a normal mental state. These altered cognitions and emotional reactions guide the individual to use the correct coping skills in order to deal with the stressor. Successful adaptation will cause the adaptive mode to fade off since the adaptive mode is no longer necessary, and the process as a whole will lead to raised well-being. However, if the adaptation process is inadequate, then the transformation period is prolonged, and the adaptive mode will turn into a dysfunctional state. Many psychiatric disorders are such maladaptive processes. The maladaptive processes can be turned into functional ones by using adaptive skills that are used in functional adaptive processes. PMID:27063089

  3. Changes in Endosymbiotic Bacteria of Brown Planthoppers During the Process of Adaptation to Different Resistant Rice Varieties.

    PubMed

    Hong-Xing, Xu; Xu-Song, Zheng; Ya-Jun, Yang; Jun-Ce, Tian; Qiang, Fu; Gong-Yin, Ye; Zhong-Xian, Lu

    2015-06-01

    The specific primers of five species of endosymbiotic bacteria were designed to determine their numbers in three virulent populations of brown planthopper, Nilapavata lugens Stål, and to assess changes during adaptation to different resistant varieties using fluorescent quantitative PCR. The results showed that Chryseobacterium was the dominant bacteria in all three populations of brown planthopper, followed by Acinetobacter in TN1 population, Arsenophonus and Serratia in Mudgo population, and Arthrobacter and Acinetobacter in ASD7 population. When the TN1 population of brown planthopper was transferred to ASD7 (with resistant gene bph2) rice plants, Chryseobacterium was still the dominant bacteria, but the originally subdominant Acinetobacter declined to a level that was not significantly different from that of other endosymbiotic bacteria. After they were transferred to Mudgo (with resistant gene Bph1), Serratia and Arsenophonus increased significantly and became the dominant bacteria. However, they declined to a level that was not significantly different from that of the three other species after two generations. When ASD7 and Mudgo populations of brown planthopper were transferred to the susceptible variety TN1, the community of endosymbiotic bacteria in the ASD7 population of brown planthopper showed no significant changes. However, the numbers of Acinetobacter and Arthrobacter in the Mudgo population of brown planthopper exhibited a transient increase and returned to their original levels after two generations. After the Mudgo population of brown planthopper was transferred to ASD7 rice plants, the quantity of endosymbiotic bacteria fluctuated, but the bacterial structure did not change significantly. However, after the ASD7 population of brown planthopper was transferred to the Mudgo rice plants, the bacterial structure changed significantly. Serratia and Arsenophonus increased significantly and became dominant. Although Serratia and Arsenophonus decreased

  4. Evolution of adaptation mechanisms: Adaptation energy, stress, and oscillating death.

    PubMed

    Gorban, Alexander N; Tyukina, Tatiana A; Smirnova, Elena V; Pokidysheva, Lyudmila I

    2016-09-21

    In 1938, Selye proposed the notion of adaptation energy and published 'Experimental evidence supporting the conception of adaptation energy.' Adaptation of an animal to different factors appears as the spending of one resource. Adaptation energy is a hypothetical extensive quantity spent for adaptation. This term causes much debate when one takes it literally, as a physical quantity, i.e. a sort of energy. The controversial points of view impede the systematic use of the notion of adaptation energy despite experimental evidence. Nevertheless, the response to many harmful factors often has general non-specific form and we suggest that the mechanisms of physiological adaptation admit a very general and nonspecific description. We aim to demonstrate that Selye׳s adaptation energy is the cornerstone of the top-down approach to modelling of non-specific adaptation processes. We analyze Selye׳s axioms of adaptation energy together with Goldstone׳s modifications and propose a series of models for interpretation of these axioms. Adaptation energy is considered as an internal coordinate on the 'dominant path' in the model of adaptation. The phenomena of 'oscillating death' and 'oscillating remission' are predicted on the base of the dynamical models of adaptation. Natural selection plays a key role in the evolution of mechanisms of physiological adaptation. We use the fitness optimization approach to study of the distribution of resources for neutralization of harmful factors, during adaptation to a multifactor environment, and analyze the optimal strategies for different systems of factors. PMID:26801872

  5. Selection of the most influential factors on the water-jet assisted underwater laser process by adaptive neuro-fuzzy technique

    NASA Astrophysics Data System (ADS)

    Nikolić, Vlastimir; Petković, Dalibor; Lazov, Lyubomir; Milovančević, Miloš

    2016-07-01

    Water-jet assisted underwater laser cutting has shown some advantages as it produces much less turbulence, gas bubble and aerosols, resulting in a more gentle process. However, this process has relatively low efficiency due to different losses in water. It is important to determine which parameters are the most important for the process. In this investigation was analyzed the water-jet assisted underwater laser cutting parameters forecasting based on the different parameters. The method of ANFIS (adaptive neuro fuzzy inference system) was applied to the data in order to select the most influential factors for water-jet assisted underwater laser cutting parameters forecasting. Three inputs are considered: laser power, cutting speed and water-jet speed. The ANFIS process for variable selection was also implemented in order to detect the predominant factors affecting the forecasting of the water-jet assisted underwater laser cutting parameters. According to the results the combination of laser power cutting speed forms the most influential combination foe the prediction of water-jet assisted underwater laser cutting parameters. The best prediction was observed for the bottom kerf-width (R2 = 0.9653). The worst prediction was observed for dross area per unit length (R2 = 0.6804). According to the results, a greater improvement in estimation accuracy can be achieved by removing the unnecessary parameter.

  6. Laser Raman detection for oral cancer based on an adaptive Gaussian process classification method with posterior probabilities

    NASA Astrophysics Data System (ADS)

    Du, Zhanwei; Yang, Yongjian; Bai, Yuan; Wang, Lijun; Su, Le; Chen, Yong; Li, Xianchang; Zhou, Xiaodong; Jia, Jun; Shen, Aiguo; Hu, Jiming

    2013-03-01

    The existing methods for early and differential diagnosis of oral cancer are limited due to the unapparent early symptoms and the imperfect imaging examination methods. In this paper, the classification models of oral adenocarcinoma, carcinoma tissues and a control group with just four features are established by utilizing the hybrid Gaussian process (HGP) classification algorithm, with the introduction of the mechanisms of noise reduction and posterior probability. HGP shows much better performance in the experimental results. During the experimental process, oral tissues were divided into three groups, adenocarcinoma (n = 87), carcinoma (n = 100) and the control group (n = 134). The spectral data for these groups were collected. The prospective application of the proposed HGP classification method improved the diagnostic sensitivity to 56.35% and the specificity to about 70.00%, and resulted in a Matthews correlation coefficient (MCC) of 0.36. It is proved that the utilization of HGP in LRS detection analysis for the diagnosis of oral cancer gives accurate results. The prospect of application is also satisfactory.

  7. An evaluation of Admedus' tissue engineering process-treated (ADAPT) bovine pericardium patch (CardioCel) for the repair of cardiac and vascular defects.

    PubMed

    Strange, Geoff; Brizard, Christian; Karl, Tom R; Neethling, Leon

    2015-03-01

    Tissue engineers have been seeking the 'Holy Grail' solution to calcification and cytotoxicity of implanted tissue for decades. Tissues with all of the desired qualities for surgical repair of congenital heart disease (CHD) are lacking. An anti-calcification tissue engineering process (ADAPT TEP) has been developed and applied to bovine pericardium (BP) tissue (CardioCel, AdmedusRegen Pty Ltd, Perth, WA, Australia) to eliminate cytotoxicity, improve resistance to acute and chronic inflammation, reduce calcification and facilitate controlled tissue remodeling. Clinical data in pediatric patients, and additional pre-market authorized prescriber data demonstrate that CardioCel performs extremely well in the short term and is safe and effective for a range of congenital heart deformations. These data are supported by animal studies which have shown no more than normal physiologic levels of calcification, with good durability, biocompatibility and controlled healing. PMID:25431988

  8. Adaptive SPECT

    PubMed Central

    Barrett, Harrison H.; Furenlid, Lars R.; Freed, Melanie; Hesterman, Jacob Y.; Kupinski, Matthew A.; Clarkson, Eric; Whitaker, Meredith K.

    2008-01-01

    Adaptive imaging systems alter their data-acquisition configuration or protocol in response to the image information received. An adaptive pinhole single-photon emission computed tomography (SPECT) system might acquire an initial scout image to obtain preliminary information about the radiotracer distribution and then adjust the configuration or sizes of the pinholes, the magnifications, or the projection angles in order to improve performance. This paper briefly describes two small-animal SPECT systems that allow this flexibility and then presents a framework for evaluating adaptive systems in general, and adaptive SPECT systems in particular. The evaluation is in terms of the performance of linear observers on detection or estimation tasks. Expressions are derived for the ideal linear (Hotelling) observer and the ideal linear (Wiener) estimator with adaptive imaging. Detailed expressions for the performance figures of merit are given, and possible adaptation rules are discussed. PMID:18541485

  9. Inhibitory function of adapter-related protein complex 2 alpha 1 subunit in the process of nuclear translocation of human immunodeficiency virus type 1 genome

    SciTech Connect

    Kitagawa, Yukiko; Kameoka, Masanori Shoji-Kawata, Sanae; Iwabu, Yukie; Mizuta, Hiroyuki; Tokunaga, Kenzo; Fujino, Masato; Natori, Yukikazu; Yura, Yoshiaki; Ikuta, Kazuyoshi

    2008-03-30

    The transfection of human cells with siRNA against adapter-related protein complex 2 alpha 1 subunit (AP2{alpha}) was revealed to significantly up-regulate the replication of human immunodeficiency virus type 1 (HIV-1). This effect was confirmed by cell infection with vesicular stomatitis virus G protein-pseudotyped HIV-1 as well as CXCR4-tropic and CCR5-tropic HIV-1. Viral adsorption, viral entry and reverse transcription processes were not affected by cell transfection with siRNA against AP2{alpha}. In contrast, viral nuclear translocation as well as the integration process was significantly up-regulated in cells transfected with siRNA against AP2{alpha}. Confocal fluorescence microscopy revealed that a subpopulation of AP2{alpha} was not only localized in the cytoplasm but was also partly co-localized with lamin B, importin {beta} and Nup153, implying that AP2{alpha} negatively regulates HIV-1 replication in the process of nuclear translocation of viral DNA in the cytoplasm or the perinuclear region. We propose that AP2{alpha} may be a novel target for disrupting HIV-1 replication in the early stage of the viral life cycle.

  10. Adaptation is automatic.

    PubMed

    Samuel, A G; Kat, D

    1998-04-01

    Two experiments were used to test whether selective adaptation for speech occurs automatically or instead requires attentional resources. A control condition demonstrated the usual large identification shifts caused by repeatedly presenting an adapting sound (/wa/, with listeners identifying members of a /ba/-/wa/ test series). Two types of distractor tasks were used: (1) Subjects did a rapid series of arithmetic problems during the adaptation periods (Experiments 1 and 2), or (2) they made a series of rhyming judgments, requiring phonetic coding (Experiment 2). A control experiment (Experiment 3) demonstrated that these tasks normally impose a heavy attentional cost on phonetic processing. Despite this, for both experimental conditions, the observed adaptation effect was just as large as in the control condition. This result indicates that adaptation is automatic, operating at an early, preattentive level. The implications of these results for current models of speech perception are discussed. PMID:9599999

  11. Adaptive parallel logic networks

    SciTech Connect

    Martinez, T.R.; Vidal, J.J.

    1988-02-01

    This paper presents a novel class of special purpose processors referred to as ASOCS (adaptive self-organizing concurrent systems). Intended applications include adaptive logic devices, robotics, process control, system malfunction management, and in general, applications of logic reasoning. ASOCS combines massive parallelism with self-organization to attain a distributed mechanism for adaptation. The ASOCS approach is based on an adaptive network composed of many simple computing elements (nodes) which operate in a combinational and asynchronous fashion. Problem specification (programming) is obtained by presenting to the system if-then rules expressed as Boolean conjunctions. New rules are added incrementally. In the current model, when conflicts occur, precedence is given to the most recent inputs. With each rule, desired network response is simply presented to the system, following which the network adjusts itself to maintain consistency and parsimony of representation. Data processing and adaptation form two separate phases of operation. During processing, the network acts as a parallel hardware circuit. Control of the adaptive process is distributed among the network nodes and efficiently exploits parallelism.

  12. Uncertainty in adaptive capacity

    NASA Astrophysics Data System (ADS)

    Adger, W. Neil; Vincent, Katharine

    2005-03-01

    The capacity to adapt is a critical element of the process of adaptation: it is the vector of resources that represent the asset base from which adaptation actions can be made. Adaptive capacity can in theory be identified and measured at various scales, from the individual to the nation. The assessment of uncertainty within such measures comes from the contested knowledge domain and theories surrounding the nature of the determinants of adaptive capacity and the human action of adaptation. While generic adaptive capacity at the national level, for example, is often postulated as being dependent on health, governance and political rights, and literacy, and economic well-being, the determinants of these variables at national levels are not widely understood. We outline the nature of this uncertainty for the major elements of adaptive capacity and illustrate these issues with the example of a social vulnerability index for countries in Africa. To cite this article: W.N. Adger, K. Vincent, C. R. Geoscience 337 (2005).

  13. Reconfigurable environmentally adaptive computing

    NASA Technical Reports Server (NTRS)

    Coxe, Robin L. (Inventor); Galica, Gary E. (Inventor)

    2008-01-01

    Described are methods and apparatus, including computer program products, for reconfigurable environmentally adaptive computing technology. An environmental signal representative of an external environmental condition is received. A processing configuration is automatically selected, based on the environmental signal, from a plurality of processing configurations. A reconfigurable processing element is reconfigured to operate according to the selected processing configuration. In some examples, the environmental condition is detected and the environmental signal is generated based on the detected condition.

  14. Estimation of breast percent density in raw and processed full field digital mammography images via adaptive fuzzy c-means clustering and support vector machine segmentation

    SciTech Connect

    Keller, Brad M.; Nathan, Diane L.; Wang Yan; Zheng Yuanjie; Gee, James C.; Conant, Emily F.; Kontos, Despina

    2012-08-15

    Purpose: The amount of fibroglandular tissue content in the breast as estimated mammographically, commonly referred to as breast percent density (PD%), is one of the most significant risk factors for developing breast cancer. Approaches to quantify breast density commonly focus on either semiautomated methods or visual assessment, both of which are highly subjective. Furthermore, most studies published to date investigating computer-aided assessment of breast PD% have been performed using digitized screen-film mammograms, while digital mammography is increasingly replacing screen-film mammography in breast cancer screening protocols. Digital mammography imaging generates two types of images for analysis, raw (i.e., 'FOR PROCESSING') and vendor postprocessed (i.e., 'FOR PRESENTATION'), of which postprocessed images are commonly used in clinical practice. Development of an algorithm which effectively estimates breast PD% in both raw and postprocessed digital mammography images would be beneficial in terms of direct clinical application and retrospective analysis. Methods: This work proposes a new algorithm for fully automated quantification of breast PD% based on adaptive multiclass fuzzy c-means (FCM) clustering and support vector machine (SVM) classification, optimized for the imaging characteristics of both raw and processed digital mammography images as well as for individual patient and image characteristics. Our algorithm first delineates the breast region within the mammogram via an automated thresholding scheme to identify background air followed by a straight line Hough transform to extract the pectoral muscle region. The algorithm then applies adaptive FCM clustering based on an optimal number of clusters derived from image properties of the specific mammogram to subdivide the breast into regions of similar gray-level intensity. Finally, a SVM classifier is trained to identify which clusters within the breast tissue are likely fibroglandular, which are then

  15. Estimation of breast percent density in raw and processed full field digital mammography images via adaptive fuzzy c-means clustering and support vector machine segmentation

    PubMed Central

    Keller, Brad M.; Nathan, Diane L.; Wang, Yan; Zheng, Yuanjie; Gee, James C.; Conant, Emily F.; Kontos, Despina

    2012-01-01

    Purpose: The amount of fibroglandular tissue content in the breast as estimated mammographically, commonly referred to as breast percent density (PD%), is one of the most significant risk factors for developing breast cancer. Approaches to quantify breast density commonly focus on either semiautomated methods or visual assessment, both of which are highly subjective. Furthermore, most studies published to date investigating computer-aided assessment of breast PD% have been performed using digitized screen-film mammograms, while digital mammography is increasingly replacing screen-film mammography in breast cancer screening protocols. Digital mammography imaging generates two types of images for analysis, raw (i.e., “FOR PROCESSING”) and vendor postprocessed (i.e., “FOR PRESENTATION”), of which postprocessed images are commonly used in clinical practice. Development of an algorithm which effectively estimates breast PD% in both raw and postprocessed digital mammography images would be beneficial in terms of direct clinical application and retrospective analysis. Methods: This work proposes a new algorithm for fully automated quantification of breast PD% based on adaptive multiclass fuzzy c-means (FCM) clustering and support vector machine (SVM) classification, optimized for the imaging characteristics of both raw and processed digital mammography images as well as for individual patient and image characteristics. Our algorithm first delineates the breast region within the mammogram via an automated thresholding scheme to identify background air followed by a straight line Hough transform to extract the pectoral muscle region. The algorithm then applies adaptive FCM clustering based on an optimal number of clusters derived from image properties of the specific mammogram to subdivide the breast into regions of similar gray-level intensity. Finally, a SVM classifier is trained to identify which clusters within the breast tissue are likely fibroglandular, which

  16. Application of Self Adaptive Unsupervised Neural Networks for Processing of VLF-LF signals to detect Seismic-Ionospheric Precursor Phenomena.

    NASA Astrophysics Data System (ADS)

    Skeberis, C.; Xenos, T. D.; Hadjileontiadis, L.; Contadakis, M. E.; Arabelos, D.

    2012-04-01

    This paper investigates the development and application of artificial neural networks (ANN) based on Predictive Modular Neural Networks (PREMONNs) to provide a self adaptive unsupervised method for detecting disturbances that can be attributed to seismic-ionospheric precursor phenomena using VLF radio signals. As such, the neural network is applied to bring forth and adaptively discriminate different characteristics in the received signals, in real time, in order to provide data segments of interest that can be correlated to subsequent seismic phenomena. PREMONNs have been developed for time series prediction and through that for source switching detection in a time series; they are constituted by two modules. The first tier is a module consisting of a dynamic array of neural networks following the data stream in order to predict the next value of a time series whereas the second is a decision one utilizing a Bayes probability equation to decide on source switching. That module is responsible for electing and appropriately training the closest fitting NN or switching to a new NN if a source switch is apparent. For the purpose of this paper, VLF signals transmitted by a number of European VLF transmitters are monitored for over a year in Thessaloniki (40.69N 22.78E) and the data from December 2010 to December 2011 are used. The received signals are sampled and stored for off line processing. The receiver was developed by Elettronika Srl, and is part of the International Network for Frontier Research on Earthquake Precursors (INFREP). Signals received from the 20.27KHz ICV station in Tavolara, Italy (Lat 40.923,Lon. 9.731) were used. The received VLF signal was normalized and then processed using the Empirical Mode Decomposition Method (EMD). The resulting data are used to train the unsupervised ANN and the performance of the developed network is then evaluated. The efficacy of different layouts of the PREMONN is evaluated and the application of a self

  17. Process and experience of cross-cultural adaptation of a quality of life measure (CHO-KLAT) for boys with haemophilia in Brazil.

    PubMed

    Villaça, P R; Carneiro, J D A; D'Amico, E A; Blanchette, V; Brandão, L R; Cassis, F R M Y; Santos, V N; Sandoval, E P N; Burke, T A; Young, N L

    2013-11-01

    Health-related quality of life (HRQoL) is an important outcome from the perspective of boys with haemophilia and their parents. Few studies have captured the HRQoL of boys with haemophilia in developing countries. This article reports on the cross-cultural adaptation of the Canadian Haemophilia Outcomes - Kids Life Assessment Tool (CHO-KLAT) for use in São Paulo, Brazil. The CHO-KLAT(2.0) was translated into Portuguese, and then translated back into English. The original English and back-translation versions were compared by a group of three clinicians, whose first language was Portuguese. The resulting Portuguese version was assessed through a series of cognitive debriefing interviews with children and their parents. This process identified concepts that were not clear and revised items to ensure appropriate understanding through an iterative process. The initial back-translation was not discrepant from the original English version. We made changes to 66% of the CHO-KLAT(2.0) items based on clinical expert review and 26% of the items based on cognitive debriefings. In addition, two new items were added to the final Portuguese version to reflect the local cultural context. The final result had good face validity. This process was found to be extremely valuable in ensuring the items were accurately interpreted by the boys/parents in São Paulo Brazil. The results suggest that professional translators, clinical experts and cognitive debriefing are all required to achieve a culturally appropriate instrument. The Portuguese CHO-KLAT(2.0) is well understood by Sao Paulo boys/parents. The next step will be to test its validity and reliability locally. PMID:23786255

  18. Dynamical Adaptation in Photoreceptors

    PubMed Central

    Clark, Damon A.; Benichou, Raphael; Meister, Markus; Azeredo da Silveira, Rava

    2013-01-01

    Adaptation is at the heart of sensation and nowhere is it more salient than in early visual processing. Light adaptation in photoreceptors is doubly dynamical: it depends upon the temporal structure of the input and it affects the temporal structure of the response. We introduce a non-linear dynamical adaptation model of photoreceptors. It is simple enough that it can be solved exactly and simulated with ease; analytical and numerical approaches combined provide both intuition on the behavior of dynamical adaptation and quantitative results to be compared with data. Yet the model is rich enough to capture intricate phenomenology. First, we show that it reproduces the known phenomenology of light response and short-term adaptation. Second, we present new recordings and demonstrate that the model reproduces cone response with great precision. Third, we derive a number of predictions on the response of photoreceptors to sophisticated stimuli such as periodic inputs, various forms of flickering inputs, and natural inputs. In particular, we demonstrate that photoreceptors undergo rapid adaptation of response gain and time scale, over ∼ 300 ms—i. e., over the time scale of the response itself—and we confirm this prediction with data. For natural inputs, this fast adaptation can modulate the response gain more than tenfold and is hence physiologically relevant. PMID:24244119

  19. Simulation of Electron Diffusion Region processes in magnetospheric current layers with the new semi-implicit adaptive Multi Level Multi Domain method

    NASA Astrophysics Data System (ADS)

    Innocenti, M. E.; Beck, A.; Markidis, S.; Lapenta, G.

    2014-12-01

    Magnetic reconnection is the magnetosphere is characterized by the complex interplay of microscopic and macroscopic scale: processes originating at the electron scales may eventually produce noticeable effects at the macroscopic scales also. A suitable example is the acceleration of electron jets to electron Alfvén speed in the inner Electron Diffusion Region (EDR) (Drake08): the accelerated electrons then evolve into an outer EDR with length of the order of the ion skin depth (Karimabadi07).This same example highlights the challenges entailed in numerical simulations of magnetic reconnection. Large domains have to be simulated to appreciate the large scale reconnection dynamics, but at the same time electron scale resolution has to be used, at least locally, to allow microscale processes to develop. This dramatically increases the computational costs of simulations, especially if a realistic mass ratio between the particle species is used. We show here simulations of large domain magnetic reconnection processes with electron scale resolution. These simulations are made possible at a moderate computational cost by the use of the newly developed semi-implicit Multi Level Multi Domain method (Innocenti13, Beck13), which combines the advantages of implicit algorithms (Vu92) and adaptivity. With the MLMD method, a domain larger than the Ion Diffusion Region is simulated with realistic mass ratio and with ion scale resolution. The EDR is then simulated also with higher spatial and temporal resolution, to allow electron scale, faster processes to develop there. Since electron scale resolution is used only in a small part of the total domain, the computational cost of MLMD simulations is dramatically lowered with respect to fully resolved simulations. Comparable levels of physical details is delivered (Innocenti14, submitted). To prove this, we show here that the MLMD method can capture characteristic EDR electron scale processes such as the formation of an inversion

  20. Implementing Process-Oriented, Guided-Inquiry Learning for the First Time: Adaptations and Short-Term Impacts on Students' Attitude and Performance

    ERIC Educational Resources Information Center

    Chase, Anthony; Pakhira, Deblina; Stains, Marilyne

    2013-01-01

    Innovative, research-based instructional practices are critical to transforming the conventional undergraduate instructional landscape into a student-centered learning environment. Research on dissemination of innovation indicates that instructors often adapt rather than adopt these practices. These adaptations can lead to the loss of critical…

  1. Adapting the Electrospinning Process to Provide Three Unique Environments for a Tri-layered In Vitro Model of the Airway Wall.

    PubMed

    Bridge, Jack C; Aylott, Jonathan W; Brightling, Christopher E; Ghaemmaghami, Amir M; Knox, Alan J; Lewis, Mark P; Rose, Felicity R A J; Morris, Gavin E

    2015-01-01

    Electrospinning is a highly adaptable method producing porous 3D fibrous scaffolds that can be exploited in in vitro cell culture. Alterations to intrinsic parameters within the process allow a high degree of control over scaffold characteristics including fiber diameter, alignment and porosity. By developing scaffolds with similar dimensions and topographies to organ- or tissue-specific extracellular matrices (ECM), micro-environments representative to those that cells are exposed to in situ can be created. The airway bronchiole wall, comprised of three main micro-environments, was selected as a model tissue. Using decellularized airway ECM as a guide, we electrospun the non-degradable polymer, polyethylene terephthalate (PET), by three different protocols to produce three individual electrospun scaffolds optimized for epithelial, fibroblast or smooth muscle cell-culture. Using a commercially available bioreactor system, we stably co-cultured the three cell-types to provide an in vitro model of the airway wall over an extended time period. This model highlights the potential for such methods being employed in in vitro diagnostic studies investigating important inter-cellular cross-talk mechanisms or assessing novel pharmaceutical targets, by providing a relevant platform to allow the culture of fully differentiated adult cells within 3D, tissue-specific environments. PMID:26275100

  2. Genome Features of the Endophytic Actinobacterium Micromonospora lupini Strain Lupac 08: On the Process of Adaptation to an Endophytic Life Style?

    PubMed Central

    Trujillo, Martha E.; Bacigalupe, Rodrigo; Pujic, Petar; Igarashi, Yasuhiro; Benito, Patricia; Riesco, Raúl; Médigue, Claudine; Normand, Philippe

    2014-01-01

    Endophytic microorganisms live inside plants for at least part of their life cycle. According to their life strategies, bacterial endophytes can be classified as “obligate” or “facultative”. Reports that members of the genus Micromonospora, Gram-positive Actinobacteria, are normal occupants of nitrogen-fixing nodules has opened up a question as to what is the ecological role of these bacteria in interactions with nitrogen-fixing plants and whether it is in a process of adaptation from a terrestrial to a facultative endophytic life. The aim of this work was to analyse the genome sequence of Micromonospora lupini Lupac 08 isolated from a nitrogen fixing nodule of the legume Lupinus angustifolius and to identify genomic traits that provide information on this new plant-microbe interaction. The genome of M. lupini contains a diverse array of genes that may help its survival in soil or in plant tissues, while the high number of putative plant degrading enzyme genes identified is quite surprising since this bacterium is not considered a plant-pathogen. Functionality of several of these genes was demonstrated in vitro, showing that Lupac 08 degraded carboxymethylcellulose, starch and xylan. In addition, the production of chitinases detected in vitro, indicates that strain Lupac 08 may also confer protection to the plant. Micromonospora species appears as new candidates in plant-microbe interactions with an important potential in agriculture and biotechnology. The current data strongly suggests that a beneficial effect is produced on the host-plant. PMID:25268993

  3. Adapting the Electrospinning Process to Provide Three Unique Environments for a Tri-layered In Vitro Model of the Airway Wall

    PubMed Central

    Bridge, Jack C.; Aylott, Jonathan W.; Brightling, Christopher E.; Ghaemmaghami, Amir M.; Knox, Alan J.; Lewis, Mark P.; Rose, Felicity R.A.J.; Morris, Gavin E.

    2015-01-01

    Electrospinning is a highly adaptable method producing porous 3D fibrous scaffolds that can be exploited in in vitro cell culture. Alterations to intrinsic parameters within the process allow a high degree of control over scaffold characteristics including fiber diameter, alignment and porosity. By developing scaffolds with similar dimensions and topographies to organ- or tissue-specific extracellular matrices (ECM), micro-environments representative to those that cells are exposed to in situ can be created. The airway bronchiole wall, comprised of three main micro-environments, was selected as a model tissue. Using decellularized airway ECM as a guide, we electrospun the non-degradable polymer, polyethylene terephthalate (PET), by three different protocols to produce three individual electrospun scaffolds optimized for epithelial, fibroblast or smooth muscle cell-culture. Using a commercially available bioreactor system, we stably co-cultured the three cell-types to provide an in vitro model of the airway wall over an extended time period. This model highlights the potential for such methods being employed in in vitro diagnostic studies investigating important inter-cellular cross-talk mechanisms or assessing novel pharmaceutical targets, by providing a relevant platform to allow the culture of fully differentiated adult cells within 3D, tissue-specific environments. PMID:26275100

  4. Laser Raman detection of platelets for early and differential diagnosis of Alzheimer’s disease based on an adaptive Gaussian process classification algorithm

    NASA Astrophysics Data System (ADS)

    Luo, Yusheng; Du, Z. W.; Yang, Y. J.; Chen, P.; Tian, Q.; Shang, X. L.; Liu, Z. C.; Yao, X. Q.; Wang, J. Z.; Wang, X. H.; Cheng, Y.; Peng, J.; Shen, A. G.; Hu, J. M.

    2013-04-01

    Early and differential diagnosis of Alzheimer’s disease (AD) has puzzled many clinicians. In this work, laser Raman spectroscopy (LRS) was developed to diagnose AD from platelet samples from AD transgenic mice and non-transgenic controls of different ages. An adaptive Gaussian process (GP) classification algorithm was used to re-establish the classification models of early AD, advanced AD and the control group with just two features and the capacity for noise reduction. Compared with the previous multilayer perceptron network method, the GP showed much better classification performance with the same feature set. Besides, spectra of platelets isolated from AD and Parkinson’s disease (PD) mice were also discriminated. Spectral data from 4 month AD (n = 39) and 12 month AD (n = 104) platelets, as well as control data (n = 135), were collected. Prospective application of the algorithm to the data set resulted in a sensitivity of 80%, a specificity of about 100% and a Matthews correlation coefficient of 0.81. Samples from PD (n = 120) platelets were also collected for differentiation from 12 month AD. The results suggest that platelet LRS detection analysis with the GP appears to be an easier and more accurate method than current ones for early and differential diagnosis of AD.

  5. The genomics of adaptation.

    PubMed

    Radwan, Jacek; Babik, Wiesław

    2012-12-22

    The amount and nature of genetic variation available to natural selection affect the rate, course and outcome of evolution. Consequently, the study of the genetic basis of adaptive evolutionary change has occupied biologists for decades, but progress has been hampered by the lack of resolution and the absence of a genome-level perspective. Technological advances in recent years should now allow us to answer many long-standing questions about the nature of adaptation. The data gathered so far are beginning to challenge some widespread views of the way in which natural selection operates at the genomic level. Papers in this Special Feature of Proceedings of the Royal Society B illustrate various aspects of the broad field of adaptation genomics. This introductory article sets up a context and, on the basis of a few selected examples, discusses how genomic data can advance our understanding of the process of adaptation. PMID:23097510

  6. Adaptations, exaptations, and spandrels.

    PubMed

    Buss, D M; Haselton, M G; Shackelford, T K; Bleske, A L; Wakefield, J C

    1998-05-01

    Adaptation and natural selection are central concepts in the emerging science of evolutionary psychology. Natural selection is the only known causal process capable of producing complex functional organic mechanisms. These adaptations, along with their incidental by-products and a residue of noise, comprise all forms of life. Recently, S. J. Gould (1991) proposed that exaptations and spandrels may be more important than adaptations for evolutionary psychology. These refer to features that did not originally arise for their current use but rather were co-opted for new purposes. He suggested that many important phenomena--such as art, language, commerce, and war--although evolutionary in origin, are incidental spandrels of the large human brain. The authors outline the conceptual and evidentiary standards that apply to adaptations, exaptations, and spandrels and discuss the relative utility of these concepts for psychological science. PMID:9612136

  7. Role of osmolytes in adaptation of osmotically stressed and chill-stressed Listeria monocytogenes grown in liquid media and on processed meat surfaces.

    PubMed Central

    Smith, L T

    1996-01-01

    Listeria monocytogenes is a food-borne pathogen that is widely distributed in nature and is found in many kinds of fresh and processed foods. The pervasiveness of this organism is due, in part, to its ability to tolerate environments with elevated osmolarity and reduced temperatures. Previously, we showed that L. monocytogenes adapts to osmotic and chill stress by transporting the osmolyte glycine betaine from the environment and accumulating it intracellularly (R. Ko, L. T. Smith, and G. M. Smith, J. Bacteriol. 176:426-431, 1994). In the present study, the influence of various environmental conditions on the accumulation of glycine betaine and another osmolyte, carnitine, was investigated. Carnitine was shown to confer both chill and osmotic tolerance to the pathogen but was less effective than glycine betaine. The absolute amount of each osmolyte accumulated by the cell was dependent on the temperature, the osmolarity of the medium, and the phase of growth of the culture. L. monocytogenes also accumulated high levels of osmolytes when grown on a variety of processed meats at reduced temperatures. However, the contribution of carnitine to the total intracellular osmolyte concentration was much greater in samples grown on meat than in those grown in liquid media. While the amount of each osmolyte in meat was less than 1 nmol/mg (fresh weight), the overall levels of osmolytes in L. monocytogenes grown on meat were about the same as those in liquid samples, from about 200 to 1,000 nmol/mg of cell protein for each osmolyte. This finding suggests that the accumulation of osmolytes is as important in the survival of L. monocytogenes in meat as it is in liquid media. PMID:8795194

  8. Developmentally adapted cognitive processing therapy for adolescents and young adults with PTSD symptoms after physical and sexual abuse: study protocol for a randomized controlled trial

    PubMed Central

    2014-01-01

    Background Although childhood sexual and/or physical abuse (CSA/CPA) is known to have severe psychopathological consequences, there is little evidence on psychotherapeutic interventions for adolescents and young adults suffering from post-traumatic stress disorder (PTSD). Equally sparse are data on moderators of treatment response on PTSD-related epigenetic changes, health care costs and loss of productivity, alterations in cognitive processing, and on how successful interventions affect all of these factors. Early treatment may prevent later (co)morbidity. In this paper, we present a study protocol for the evaluation of a newly developed psychotherapeutic manual for PTSD after CSA/CPA in adolescents and young adults – the Developmentally Adapted Cognitive Processing Therapy (D-CPT). Methods/design In a multicenter randomized controlled trial (RCT) D-CPT is compared to treatment as usual (TAU). A sample of 90 adolescent outpatients aged 14 to 21 years will be randomized to one of these conditions. Four assessments will be carried out at baseline, at end of treatment, and 3 and 6 months after end of therapy. Each time, patients will be assessed via clinical interviews and a wide range of questionnaires. In addition to PTSD symptoms and comorbidities, we will evaluate moderators of treatment response, epigenetic profiles, direct and indirect costs of this disorder, and neurophysiological processing of threat cues in PTSD and their respective changes in the course of these two treatments (D-CPT and TAU). Discussion The study will provide new insights in the understudied field of PTSD in adolescents and young adults. A newly developed intervention will be evaluated in this therapeutically underserved population. Results will provide data on treatment efficacy, direct and indirect treatment costs, as well as on associations of treatment outcome and PTSD intensity both to epigenetic profiles and to the neurobiological processing of threat cues. Besides, they will

  9. A local coastal adaptation pathway

    NASA Astrophysics Data System (ADS)

    Barnett, J.; Graham, S.; Mortreux, C.; Fincher, R.; Waters, E.; Hurlimann, A.

    2014-12-01

    Local governments are not adapting to sea-level rise because it is difficult to build consensus on the need for change and the best way to implement it. In theory, adaptation pathways can resolve this impasse. Adaptation pathways are a sequence of linked strategies that are triggered by a change in environmental conditions, and in which initial decisions can have low regrets and preserve options for future generations. We report on a project that sought to empirically test the relevance and feasibility of a local pathway for adapting to sea-level rise. We find that triggers of change that have social impacts are salient to local people, and developing a local adaptation pathway helps build consensus among diverse constituencies. Our results show that adaptation pathways are feasible at the local scale, offering a low-risk, low-cost way to begin the long process of adaptation to sea-level rise.

  10. Adaptive Development

    NASA Technical Reports Server (NTRS)

    2005-01-01

    The goal of this research is to develop and demonstrate innovative adaptive seal technologies that can lead to dramatic improvements in engine performance, life, range, and emissions, and enhance operability for next generation gas turbine engines. This work is concentrated on the development of self-adaptive clearance control systems for gas turbine engines. Researchers have targeted the high-pressure turbine (HPT) blade tip seal location for following reasons: Current active clearance control (ACC) systems (e.g., thermal case-cooling schemes) cannot respond to blade tip clearance changes due to mechanical, thermal, and aerodynamic loads. As such they are prone to wear due to the required tight running clearances during operation. Blade tip seal wear (increased clearances) reduces engine efficiency, performance, and service life. Adaptive sealing technology research has inherent impact on all envisioned 21st century propulsion systems (e.g. distributed vectored, hybrid and electric drive propulsion concepts).

  11. Adaptation and perceptual norms

    NASA Astrophysics Data System (ADS)

    Webster, Michael A.; Yasuda, Maiko; Haber, Sara; Leonard, Deanne; Ballardini, Nicole

    2007-02-01

    We used adaptation to examine the relationship between perceptual norms--the stimuli observers describe as psychologically neutral, and response norms--the stimulus levels that leave visual sensitivity in a neutral or balanced state. Adapting to stimuli on opposite sides of a neutral point (e.g. redder or greener than white) biases appearance in opposite ways. Thus the adapting stimulus can be titrated to find the unique adapting level that does not bias appearance. We compared these response norms to subjectively defined neutral points both within the same observer (at different retinal eccentricities) and between observers. These comparisons were made for visual judgments of color, image focus, and human faces, stimuli that are very different and may depend on very different levels of processing, yet which share the property that for each there is a well defined and perceptually salient norm. In each case the adaptation aftereffects were consistent with an underlying sensitivity basis for the perceptual norm. Specifically, response norms were similar to and thus covaried with the perceptual norm, and under common adaptation differences between subjectively defined norms were reduced. These results are consistent with models of norm-based codes and suggest that these codes underlie an important link between visual coding and visual experience.

  12. Effects of starvation, refeeding, and insulin on energy-linked metabolic processes in catfish (Rhamdia hilarii) adapted to a carbohydrate-rich diet

    SciTech Connect

    Machado, C.R.; Garofalo, M.A.; Roselino, J.E.; Kettelhut, I.C.; Migliorini, R.H.

    1988-09-01

    The effects of starvation and of a short period of refeeding on energy-linked metabolic processes, as well as the effects of insulin administration, were investigated in an omnivorous fish (catfish, Rhamdia hilarii) previously adapted to a carbohydrate-rich diet. Following food deprivation blood sugar levels declined progressively to about 50% of fed values after 30 days. During the same period plasma free fatty acid (FFA) concentration increased twofold. Starvation resulted in reduced concentrations of lipid and glycogen in the liver and of glycogen, lipid, and protein in white muscle. However, taking into account the initial and final concentrations of tissue constituents, the liver weight, and the large fractions of body weight represented by muscle, it could be estimated that most of the energy utilized during starvation derived from the catabolism of muscle lipid and protein. Refeeding starved fishes for 48 hr induced several-fold increases in the rates of in vivo and in vitro incorporation of (14C)glucose into liver and muscle lipid and of (14C)glycine into liver and muscle protein. Incorporation of (14C)glucose into liver glycogen was also increased. However; refeeding did not affect the incorporation of labeled glucose into muscle glycogen, neither in vivo nor in vitro. Administration of pharmacological doses of insulin to normally fed catfishes resulted in marked increases in the in vivo incorporation of 14C from glucose into lipid and protein in both liver and muscle. In contrast, labeled glucose incorporation into muscle glycogen was not affected by insulin and label incorporation into liver glycogen was actually lower than that in noninjected controls.

  13. Understanding hydrologic budgets, dynamics in an arid basin and explore spatial scaling properties using Process-based Adaptive Watershed Simulator (PAWS)

    NASA Astrophysics Data System (ADS)

    Fang, K.; Shen, C.; Salve, R.

    2013-12-01

    The Southern California hot desert hosts a fragile ecosystem as well as a range of human economic activities, primarily mining, energy production and recreation. This inland arid landscape is characterized by occasional intensive precipitation events and year-round strong potential evapotranspiration. In this landscape, water and especially groundwater is vital for ecosystem functions and human use. However, the impact of recent development on the sustainability of groundwater resources in the area has not been thoroughly investigated. We apply an integrated, physically-based hydrologic-land surface model, the Process-based Adaptive Watershed Simulator + Community Land Model (PAWS+CLM) to evaluate the sustainability of the groundwater resources in the area. We elucidate the spatio-temporal patterns of hydrologic fluxes and budgets. The modeling results indicate that mountain front recharge is the essential recharging mechanism for the alluvial aquifer. Although pumping activities do not exceed annual-average recharge values, they are still expected to contribute significantly to groundwater drawdown in business-as-usual scenario. The impact of groundwater withdrawals is significant on the desert ecosystem. The relative importance of groundwater flow on NPP rises significantly as compared to other ecosystems. We further evaluate the fractal scaling properties of soil moisture in this very arid system and found the relationship to be much more static in time than that found in a humid continental climate system. The scaling exponents can be predicted using simple functions of the mean. Therefore, multi-scale model based on coarse-resolution surrogate model is expected to perform well in this system. The modeling result is also important for assessing the groundwater sustainability and impact of human activities in the desert environment.

  14. Adapting Animals.

    ERIC Educational Resources Information Center

    Wedman, John; Wedman, Judy

    1985-01-01

    The "Animals" program found on the Apple II and IIe system master disk can be adapted for use in the mathematics classroom. Instructions for making the necessary changes and suggestions for using it in lessons related to geometric shapes are provided. (JN)

  15. Adaptive Thresholds

    SciTech Connect

    Bremer, P. -T.

    2014-08-26

    ADAPT is a topological analysis code that allow to compute local threshold, in particular relevance based thresholds for features defined in scalar fields. The initial target application is vortex detection but the software is more generally applicable to all threshold based feature definitions.

  16. Adaptive homeostasis.

    PubMed

    Davies, Kelvin J A

    2016-06-01

    Homeostasis is a central pillar of modern Physiology. The term homeostasis was invented by Walter Bradford Cannon in an attempt to extend and codify the principle of 'milieu intérieur,' or a constant interior bodily environment, that had previously been postulated by Claude Bernard. Clearly, 'milieu intérieur' and homeostasis have served us well for over a century. Nevertheless, research on signal transduction systems that regulate gene expression, or that cause biochemical alterations to existing enzymes, in response to external and internal stimuli, makes it clear that biological systems are continuously making short-term adaptations both to set-points, and to the range of 'normal' capacity. These transient adaptations typically occur in response to relatively mild changes in conditions, to programs of exercise training, or to sub-toxic, non-damaging levels of chemical agents; thus, the terms hormesis, heterostasis, and allostasis are not accurate descriptors. Therefore, an operational adjustment to our understanding of homeostasis suggests that the modified term, Adaptive Homeostasis, may be useful especially in studies of stress, toxicology, disease, and aging. Adaptive Homeostasis may be defined as follows: 'The transient expansion or contraction of the homeostatic range in response to exposure to sub-toxic, non-damaging, signaling molecules or events, or the removal or cessation of such molecules or events.' PMID:27112802

  17. Generalization of Prism Adaptation

    ERIC Educational Resources Information Center

    Redding, Gordon M.; Wallace, Benjamin

    2006-01-01

    Prism exposure produces 2 kinds of adaptive response. Recalibration is ordinary strategic remapping of spatially coded movement commands to rapidly reduce performance error. Realignment is the extraordinary process of transforming spatial maps to bring the origins of coordinate systems into correspondence. Realignment occurs when spatial…

  18. The Worker as Proteus: Understanding Occupational Adaptability.

    ERIC Educational Resources Information Center

    Faddis, Constance R.

    The purpose of this paper is to review and synthesize what is known about occupational adaptability and to propose a heuristic model of the process(es) of adaptation in work. Following an introductory chapter, three chapters contain a review of literature that draws from many disciplines and presents an overview of human adaptation in general, as…

  19. Theoretical predications of the effects of temperature on simulated adaptive processes in human motor nerve axons at 20°C-42°C.

    PubMed

    Stephanova, D I; Daskalova, M

    2014-09-01

    The effects of temperature on conducting and accommodative processes in the myelinated human motor nerve fiber were previously studied by us in the range of 20°C-42°C. To complete the cycle of our studies on adaptive processes in the fiber, the temperature effects on strength-duration time constant, rheobasic current and recovery cycle are investigated. The computations use our temperature dependent multi-layered model of the fiber and the temperature is increased from 20°C to 42°C. The results show that these excitability parameters are more sensitive to the hypothermia (≤ 25°C) and are most sensitive to the hyperthermia (≥ 40°C), especially at 42°C, than at temperatures in the range of 28°C-37°C. With the increase of temperature from 20°C to 42°C, the strength-duration time constant decreases ~ 8.8 times, while it decreases ~ 2.7% per °C in the range of 28°C-37°C. Conversely, the rheobasic current increases ~ 4.4 times from 20°C to 42°C, while it increases ~ 2.3% per °C in the range of 28°C-37°C. The behavior of relative refractory period and axonal superexcitability in a 100 ms recovery cycle is complex with the increase of temperature. The axonal superexcitability decreases with the increase of temperature during hypothermia. However, it increases rapidly with the increase of temperature during hyperthermia, especially at 42°C and a block of each applied third testing stimulus is obtained. The superexcitability period is followed by a late subexcitability period when the temperatures are in the physiological range of 32°C-37°C. The present results are essential for the interpretation of mechanisms of excitability parameter changes obtained here and measured in healthy subjects with symptoms of cooling, warming and fever, which can result from alterations in body temperature. Our present and previous results confirm that 42°C is the highest critical temperature for healthy subjects. PMID:25164362

  20. The Limits to Adaptation: A Systems Approach

    EPA Science Inventory

    The ability to adapt to climate change is delineated by capacity thresholds, after which climate damages begin to overwhelm the adaptation response. Such thresholds depend upon physical properties (natural processes and engineering parameters), resource constraints (expressed th...

  1. A holistic strategy for adaptive land management

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Adaptive management is widely applied to natural resources management. Adaptive management can be generally defined as an iterative decision-making process that incorporates formulation of management objectives, actions designed to address these objectives, monitoring of results, and repeated adapta...

  2. Adaptive Assessments Using Open Specifications

    ERIC Educational Resources Information Center

    Leon, Hector Barbosa; Garcia-Penalvo, Francisco J.; Rodriguez-Conde, Maria Jose; Morales, Erla M.; de Pablos, Patricia Ordonez

    2012-01-01

    Evaluation is a key element in formal education processes; it must be constructed in a way that the item questions within help students understand by adapting them to the learning style as well. The focus of the present research work specifically in the convenience to adapt an associated multimedia material in each single question besides the…

  3. Adaptive triangular mesh generation

    NASA Technical Reports Server (NTRS)

    Erlebacher, G.; Eiseman, P. R.

    1984-01-01

    A general adaptive grid algorithm is developed on triangular grids. The adaptivity is provided by a combination of node addition, dynamic node connectivity and a simple node movement strategy. While the local restructuring process and the node addition mechanism take place in the physical plane, the nodes are displaced on a monitor surface, constructed from the salient features of the physical problem. An approximation to mean curvature detects changes in the direction of the monitor surface, and provides the pulling force on the nodes. Solutions to the axisymmetric Grad-Shafranov equation demonstrate the capturing, by triangles, of the plasma-vacuum interface in a free-boundary equilibrium configuration.

  4. Connector adapter

    NASA Technical Reports Server (NTRS)

    Hacker, Scott C. (Inventor); Dean, Richard J. (Inventor); Burge, Scott W. (Inventor); Dartez, Toby W. (Inventor)

    2007-01-01

    An adapter for installing a connector to a terminal post, wherein the connector is attached to a cable, is presented. In an embodiment, the adapter is comprised of an elongated collet member having a longitudinal axis comprised of a first collet member end, a second collet member end, an outer collet member surface, and an inner collet member surface. The inner collet member surface at the first collet member end is used to engage the connector. The outer collet member surface at the first collet member end is tapered for a predetermined first length at a predetermined taper angle. The collet includes a longitudinal slot that extends along the longitudinal axis initiating at the first collet member end for a predetermined second length. The first collet member end is formed of a predetermined number of sections segregated by a predetermined number of channels and the longitudinal slot.

  5. Adaptive sampler

    DOEpatents

    Watson, Bobby L.; Aeby, Ian

    1982-01-01

    An adaptive data compression device for compressing data having variable frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  6. Adaptive sampler

    DOEpatents

    Watson, B.L.; Aeby, I.

    1980-08-26

    An adaptive data compression device for compressing data is described. The device has a frequency content, including a plurality of digital filters for analyzing the content of the data over a plurality of frequency regions, a memory, and a control logic circuit for generating a variable rate memory clock corresponding to the analyzed frequency content of the data in the frequency region and for clocking the data into the memory in response to the variable rate memory clock.

  7. Adaptive antennas

    NASA Astrophysics Data System (ADS)

    Barton, P.

    1987-04-01

    The basic principles of adaptive antennas are outlined in terms of the Wiener-Hopf expression for maximizing signal to noise ratio in an arbitrary noise environment; the analogy with generalized matched filter theory provides a useful aid to understanding. For many applications, there is insufficient information to achieve the above solution and thus non-optimum constrained null steering algorithms are also described, together with a summary of methods for preventing wanted signals being nulled by the adaptive system. The three generic approaches to adaptive weight control are discussed; correlation steepest descent, weight perturbation and direct solutions based on sample matrix conversion. The tradeoffs between hardware complexity and performance in terms of null depth and convergence rate are outlined. The sidelobe cancellor technique is described. Performance variation with jammer power and angular distribution is summarized and the key performance limitations identified. The configuration and performance characteristics of both multiple beam and phase scan array antennas are covered, with a brief discussion of performance factors.

  8. Toward reflexive climate adaptation research

    DOE PAGESBeta

    Preston, Benjamin L.; Rickards, Lauren; Fünfgeld, Hartmut; Keenan, Rodney J.

    2015-06-22

    Climate adaptation research is expanding very quickly within an increasingly reflexive society where the relationship between academia and other social institutions is in a state of flux. Tensions exist between the two dominant research orientations of research about and research for adaptation. In particular, the research community is challenged to develop processes for successfully executing transdisciplinary research for adaptation when academic institutions and researchers are largely structured around traditional, disciplinary expertise and funding models. One tool for helping to manage this tension is a third, more reflexive, orientation toward adaptation research that is emerging in the literature. Finally, this newmore » ‘research on adaptation research’ promises to help enhance understanding of the research enterprise itself and how it can become more adaptive.« less

  9. Toward reflexive climate adaptation research

    SciTech Connect

    Preston, Benjamin L.; Rickards, Lauren; Fünfgeld, Hartmut; Keenan, Rodney J.

    2015-06-22

    Climate adaptation research is expanding very quickly within an increasingly reflexive society where the relationship between academia and other social institutions is in a state of flux. Tensions exist between the two dominant research orientations of research about and research for adaptation. In particular, the research community is challenged to develop processes for successfully executing transdisciplinary research for adaptation when academic institutions and researchers are largely structured around traditional, disciplinary expertise and funding models. One tool for helping to manage this tension is a third, more reflexive, orientation toward adaptation research that is emerging in the literature. Finally, this new ‘research on adaptation research’ promises to help enhance understanding of the research enterprise itself and how it can become more adaptive.

  10. Adaptive challenges in medical practices.

    PubMed

    Daiker, Barbara L

    2013-01-01

    The purpose of this qualitative grounded theory study was to describe the theoretical structures of the strategies used by medical practices to navigate adaptive challenges. The process of responding to adaptive challenges in five medical practices was studied using a grounded theory approach, collecting data from interviews with the organizations' leaders and managers. The leadership of these medical practices had successfully navigated adaptive challenges within two years of the study. The analysis revealed a model that describes the key elements in finding solutions to adaptive challenges. The model was named the Adaptation Solution Dynamic, which explains the elements of Rational Tools, Relationship Commitment, and Achievement Drive. The findings from the results of this study provide a theoretical basis for studying how leaders support identifying solutions to adaptive challenges. PMID:23866647

  11. EEG Theta Dynamics within Frontal and Parietal Cortices for Error Processing during Reaching Movements in a Prism Adaptation Study Altering Visuo-Motor Predictive Planning

    PubMed Central

    Bonfiglio, Luca; Minichilli, Fabrizio; Cantore, Nicoletta; Carboncini, Maria Chiara; Piccotti, Emily; Rossi, Bruno

    2016-01-01

    Modulation of frontal midline theta (fmθ) is observed during error commission, but little is known about the role of theta oscillations in correcting motor behaviours. We investigate EEG activity of healthy partipants executing a reaching task under variable degrees of prism-induced visuo-motor distortion and visual occlusion of the initial arm trajectory. This task introduces directional errors of different magnitudes. The discrepancy between predicted and actual movement directions (i.e. the error), at the time when visual feedback (hand appearance) became available, elicits a signal that triggers on-line movement correction. Analysis were performed on 25 EEG channels. For each participant, the median value of the angular error of all reaching trials was used to partition the EEG epochs into high- and low-error conditions. We computed event-related spectral perturbations (ERSP) time-locked either to visual feedback or to the onset of movement correction. ERSP time-locked to the onset of visual feedback showed that fmθ increased in the high- but not in the low-error condition with an approximate time lag of 200 ms. Moreover, when single epochs were sorted by the degree of motor error, fmθ started to increase when a certain level of error was exceeded and, then, scaled with error magnitude. When ERSP were time-locked to the onset of movement correction, the fmθ increase anticipated this event with an approximate time lead of 50 ms. During successive trials, an error reduction was observed which was associated with indices of adaptations (i.e., aftereffects) suggesting the need to explore if theta oscillations may facilitate learning. To our knowledge this is the first study where the EEG signal recorded during reaching movements was time-locked to the onset of the error visual feedback. This allowed us to conclude that theta oscillations putatively generated by anterior cingulate cortex activation are implicated in error processing in semi-naturalistic motor

  12. An Inter-Disciplinary Approach to Assess Adaptation Processes Resulting From a Long-Term Drainage Disturbance of a Permafrost Ecosystem

    NASA Astrophysics Data System (ADS)

    Goeckede, M.; Kwon, M. J.; Kittler, F.; Burjack, I.; Heimann, M.; Zimov, N.; Zimov, S. A.

    2014-12-01

    Hydrology plays a pivotal role for the sustainability of the permafrost carbon reservoir in the Northern high latitudes under climate change. Changes in moisture conditions may significantly carbon pools and fluxes, and in addition trigger secondary shifts in biogeochemical and biogeophysical ecosystem properties, with feedbacks to the carbon cycle. The net impact of hydrologic disturbance, e.g. as a result of changes in drainage conditions, on the links between carbon processes and climate is therefore highly uncertain. This study presents findings from an interdisciplinary experiment established on the floodplain of the Kolyma River near Chersky, Northeast Siberia. Parts of our study site have been artificially drained by ditches since 2004, simulating the formation of a channel system triggered by the thawing of ice wedges in ice-rich permafrost. Observations from this area are directly compared to data from a nearby undisturbed reference site. CO2 and CH4 flux measurements are available from 2 eddy-covariance towers operated year-round, and a distributed array of soil chambers. Additional observations target e.g. microbial and vegetation community structures, radiocarbon signals, nutrient availability and seasonal dynamics in phenology. Drainage has lowered average soil water levels by about 20cm, resulting in systematic shifts in e.g. soil temperature regime and snow cover. These dryer and warmer conditions have shifted the vegetation structure away from the formerly dominating cotton grasses towards tussock-forming sedges and shrubs. Microbial communities were found to have adapted to the new environment, e.g. concerning the dominating orders of methanogenetic archaea. Radiocarbon signals indicate that the drainage has unlocked older carbon pools from deeper layers. The combined effects of these changes reduce the CO2 uptake and significantly lower the CH4 emissions in the drained area, resulting in a higher net carbon sink compared to the reference. Seasonal

  13. The Adaptation of a School-Based Health Promotion Programme for Youth with Intellectual and Developmental Disabilities: A Community-Engaged Research Process

    ERIC Educational Resources Information Center

    Hubbard, Kristie L.; Bandini, Linda G.; Folta, Sara C.; Wansink, Brian; Must, Aviva

    2014-01-01

    Background: Evidenced-based health promotion programmes for youth with intellectual and developmental disabilities (I/DD) are notably absent. Barriers include a lack of understanding of how to adapt existing evidence-based programmes to their needs, maximize inclusion and support mutual goals of health and autonomy. Methods: We undertook a…

  14. Adapted Intervention Mapping: A Strategic Planning Process for Increasing Physical Activity and Healthy Eating Opportunities in Schools via Environment and Policy Change

    ERIC Educational Resources Information Center

    Belansky, Elaine S.; Cutforth, Nick; Chavez, Robert; Crane, Lori A.; Waters, Emily; Marshall, Julie A.

    2013-01-01

    Background: School environment and policy changes have increased healthy eating and physical activity; however, there has been modest success in translating research ?ndings to practice. The School Environment Project tested whether an adapted version of Intervention Mapping (AIM) resulted in school change. Methods: Using a pair randomized design,…

  15. WISC-IV Profile in High-Functioning Autism Spectrum Disorders: Impaired Processing Speed Is Associated with Increased Autism Communication Symptoms and Decreased Adaptive Communication Abilities

    ERIC Educational Resources Information Center

    Oliveras-Rentas, Rafael E.; Kenworthy, Lauren; Roberson, Richard B.; Martin, Alex; Wallace, Gregory L.

    2012-01-01

    Changes in the Wechsler Intelligence Scales for Children-IV (WISC-IV) may affect the IQ profile characteristic of autism spectrum disorders (ASD). Moreover, the association of particular component cognitive abilities (unlike overall IQ) with symptomatology and adaptive functioning in ASD remains unclear. This archival study characterizes the…

  16. Hydropower, adaptive management, and Biodiversity

    NASA Astrophysics Data System (ADS)

    Wieringa, Mark J.; Morton, Anthony G.

    1996-11-01

    Adaptive management is a policy framework within which an iterative process of decision making is followed based on the observed responses to and effectiveness of previous decisions. The use of adaptive management allows science-based research and monitoring of natural resource and ecological community responses, in conjunction with societal values and goals, to guide decisions concerning man's activities. The adaptive management process has been proposed for application to hydropower operations at Glen Canyon Dam on the Colorado River, a situation that requires complex balancing of natural resources requirements and competing human uses. This example is representative of the general increase in public interest in the operation of hydropower facilities and possible effects on downstream natural resources and of the growing conflicts between uses and users of river-based resources. This paper describes the adaptive management process, using the Glen Canyon Dam example, and discusses ways to make the process work effectively in managing downstream natural resources and biodiversity.

  17. Reconceptualizing Family Adaptation to Developmental Delay.

    PubMed

    Pedersen, Anita L; Crnic, Keith A; Baker, Bruce L; Blacher, Jan

    2015-07-01

    This study explores accurate conceptualization of the adaptation construct in families of children with developmental delay aged 3 to 8 years. Parents' self-reported measures of adaptation and observed dyadic relationship variables were examined. Confirmatory factor analysis and longitudinal growth modeling were used to evaluate the nature of adaptational processes. Results indicate that adaptational processes vary across adaptation index, child developmental level, and parent gender. Adaptation indices did not load onto a single construct at any time point. Several adaptational processes remained stable across time, although others showed linear or quadratic change. The findings of the current study indicate that it is time for a change in how adaptation is conceived for families of children with developmental delay. PMID:26161471

  18. Promoting intestinal adaptation by nutrition and medication.

    PubMed

    Neelis, E G; Olieman, J F; Hulst, J M; de Koning, B A E; Wijnen, R M H; Rings, E H H M

    2016-04-01

    The ultimate goal in the treatment of short bowel syndrome is to wean patients off parenteral nutrition, by promoting intestinal adaptation. Intestinal adaptation is the natural compensatory process that occurs after small bowel resection. Stimulating the remaining bowel with enteral nutrition can enhance this process. Additionally, medication can be used to either reduce factors that complicate the adaptation process or to stimulate intestinal adaptation, such as antisecretory drugs and several growth factors. The aim of this review was to provide an overview of the best nutritional strategies and medication that best promote intestinal adaptation. PMID:27086889

  19. Adaptive SAR ATR problem set (AdaptSAPS)

    NASA Astrophysics Data System (ADS)

    Wise, Angela R.; Fitzgerald, Donna; Ross, Timothy D.

    2004-09-01

    A strong and growing interest in systems that adapt to changing circumstances was evident in panel discussions at the "Algorithms for SAR Imagery" Conference of the AeroSense Symposium in April 2003, with DARPA, Air Force, industry and academia participation. As a result, Conference Co-Chair Mr. Ed Zelnio suggested producing a dynamic model to create problem sets suitable for adaptive system research and development. Such a problem set provides a framework for the overall problem, including organization of operating conditions, performance measures and specific test cases. It is hoped that this AdaptSAPS framework will help provide the community with a more concrete base for discussing adaptation in SAR imagery exploitation. AdaptSAPS Version 1.0 was produced by the AFRL COMPASE and SDMS organizations and posted on 5 August 2003. AdaptSAPS consists of over a dozen MatLab programs that allow the user to create "missions" with SAR data of varying complexities and then present that test data one image at a time, first as unexploited imagery and then later with the exploitation results that an ATR could use for adaptation in an operational environment. AdaptSAPS keeps track of performance results and reports performance measures. This paper describes AdaptSAPS - its application process and possible improvements as a problem set.

  20. fMRI adaptation revisited.

    PubMed

    Larsson, Jonas; Solomon, Samuel G; Kohn, Adam

    2016-07-01

    Adaptation has been widely used in functional magnetic imaging (fMRI) studies to infer neuronal response properties in human cortex. fMRI adaptation has been criticized because of the complex relationship between fMRI adaptation effects and the multiple neuronal effects that could underlie them. Many of the longstanding concerns about fMRI adaptation have received empirical support from neurophysiological studies over the last decade. We review these studies here, and also consider neuroimaging studies that have investigated how fMRI adaptation effects are influenced by high-level perceptual processes. The results of these studies further emphasize the need to interpret fMRI adaptation results with caution, but they also provide helpful guidance for more accurate interpretation and better experimental design. In addition, we argue that rather than being used as a proxy for measurements of neuronal stimulus selectivity, fMRI adaptation may be most useful for studying population-level adaptation effects across cortical processing hierarchies. PMID:26703375

  1. Adaptive Algebraic Multigrid Methods

    SciTech Connect

    Brezina, M; Falgout, R; MacLachlan, S; Manteuffel, T; McCormick, S; Ruge, J

    2004-04-09

    Our ability to simulate physical processes numerically is constrained by our ability to solve the resulting linear systems, prompting substantial research into the development of multiscale iterative methods capable of solving these linear systems with an optimal amount of effort. Overcoming the limitations of geometric multigrid methods to simple geometries and differential equations, algebraic multigrid methods construct the multigrid hierarchy based only on the given matrix. While this allows for efficient black-box solution of the linear systems associated with discretizations of many elliptic differential equations, it also results in a lack of robustness due to assumptions made on the near-null spaces of these matrices. This paper introduces an extension to algebraic multigrid methods that removes the need to make such assumptions by utilizing an adaptive process. The principles which guide the adaptivity are highlighted, as well as their application to algebraic multigrid solution of certain symmetric positive-definite linear systems.

  2. [Combination of Genetic and Humanitarian (Cross-Cultural) Methods for the Identification of Human Genes Involved in the Process of Adaptation to Evolutionary New Environmental Factors].

    PubMed

    Borinskaya, S A; Yankovsky, N K

    2015-04-01

    Human settlement from the African ancestral home was accompanied by cultural and genetic adaptation to new habitat conditions (climate, infections, diet, etc.). We previously suggested for the first time an approach to the identification of human genes presumably involved in adaptation to evolutionary new environmental factors based on a combination of genetic and humanitarian methods of study. In order to search for the genes involved in adaptation and for environmental factors (to which this adaptation occurs), we attempted to find correlations between the population allele frequencies of the studied gene and formalized descriptions of peculiarities of the habitat of ethnic groups given in "Ethnographic Atlas" by G. P. Murdock. In the presented review, we summarized our own data on an experimental determination of the allele frequencies for lactase (LCT*), apolipoprotein E (APOE), and alcohol dehydrogenase (ADH1B) genes in populations of Russia. Based on these data and available materials of other investigators, we developed maps of worldwide allele frequency distribution for these genes. We detected a correlation of allele frequencies of these genes in populations with the presence of certain factors of the environment that these populations inhabit. It was also confirmed that the evolutionarily young LCT*-13910T allele, which determines lactase persistence and the possibility of milk consumption in adults, is distributed in populations for which dairy animal husbandry is typical. During the analysis of 68 populations, we for the first time demonstrated that the frequency of the APOE e4 allele (which is ancestral for humans and influences the lipid metabolism) is higher in groups with a high contribution of hunting and gathering. Our data are in favor of the hypothesis that it was exactly the e4 allele that was a subject for selection, while the e3 allele was less important for adaptation. We also for the first time demonstrated that the evolutionarily young ADH

  3. The challenge of adaptive structures

    NASA Astrophysics Data System (ADS)

    Breitbach, E. J.; Wimmel, R.

    Future lightweight design in space structure technology has to pay more attention to vibration suppression, to position control, or, more generally, to structure-inherent adaptability. These properties are often called "intelligent" or "smart", ignoring the fact that only creatures can have mental abilities. Having adaptation mechanisms for every dynamic process, living nature indeed teaches us that it is inexpedient if technical structural systems dispense with adaptability. Vibration and stability phenomena are making performance restrictions in space systems more and more evident. The DLR project ARES (Actively Reacting Flexible Structures) intends to overcome these limitations by developing a new class of technical systems. The ARES concept essentially consists of two new technologies: new kinds of integrated sensors and actuators working as components lying in the structural load path, and adaptive controllers consisting of digital filters which are adaptive in that they react against changing environmental influences as well as changes within the structure itself.

  4. Evolutionary genetics of plant adaptation

    PubMed Central

    Anderson, Jill T.; Willis, John H.; Mitchell-Olds, Thomas

    2011-01-01

    Plants provide unique opportunities to study the mechanistic basis and evolutionary processes of adaptation to diverse environmental conditions. Complementary laboratory and field experiments are important for testing hypothesis reflecting long term ecological and evolutionary history. For example, these approaches can infer whether local adaptation results from genetic tradeoffs (antagonistic pleiotropy), where native alleles are best adapted to local conditions, or if local adaptation is caused by conditional neutrality at many loci, where alleles show fitness differences in one environment, but not in the contrasting environment. Ecological genetics in natural populations of perennial or outcrossing plants also may differ substantially from model systems. In this review of the evolutionary genetics of plant adaptation, we emphasize the importance of field studies for understanding the evolutionary dynamics of model and non-model systems, highlight a key life history trait (flowering time), and discuss emerging conservation issues. PMID:21550682

  5. Smartphone adapters for digital photomicrography

    PubMed Central

    Roy, Somak; Pantanowitz, Liron; Amin, Milon; Seethala, Raja R.; Ishtiaque, Ahmed; Yousem, Samuel A.; Parwani, Anil V.; Cucoranu, Ioan; Hartman, Douglas J.

    2014-01-01

    Background: Photomicrographs in Anatomic Pathology provide a means of quickly sharing information from a glass slide for consultation, education, documentation and publication. While static image acquisition historically involved the use of a permanently mounted camera unit on a microscope, such cameras may be expensive, need to be connected to a computer, and often require proprietary software to acquire and process images. Another novel approach for capturing digital microscopic images is to use smartphones coupled with the eyepiece of a microscope. Recently, several smartphone adapters have emerged that allow users to attach mobile phones to the microscope. The aim of this study was to test the utility of these various smartphone adapters. Materials and Methods: We surveyed the market for adapters to attach smartphones to the ocular lens of a conventional light microscope. Three adapters (Magnifi, Skylight and Snapzoom) were tested. We assessed the designs of these adapters and their effectiveness at acquiring static microscopic digital images. Results: All adapters facilitated the acquisition of digital microscopic images with a smartphone. The optimal adapter was dependent on the type of phone used. The Magnifi adapters for iPhone were incompatible when using a protective case. The Snapzoom adapter was easiest to use with iPhones and other smartphones even with protective cases. Conclusions: Smartphone adapters are inexpensive and easy to use for acquiring digital microscopic images. However, they require some adjustment by the user in order to optimize focus and obtain good quality images. Smartphone microscope adapters provide an economically feasible method of acquiring and sharing digital pathology photomicrographs. PMID:25191623

  6. Individual predictors of sensorimotor adaptability

    PubMed Central

    Seidler, Rachael D.; Mulavara, Ajitkumar P.; Bloomberg, Jacob J.; Peters, Brian T.

    2015-01-01

    There are large individual variations in strategies and rates of sensorimotor adaptation to spaceflight. This is seen in both the magnitude of performance disruptions when crewmembers are first exposed to microgravity, and in the rate of re-adaptation when they return to Earth’s gravitational environment. Understanding the sources of this variation can lead to a better understanding of the processes underlying adaptation, as well as provide insight into potential routes for facilitating performance of “slow adapters”. Here we review the literature on brain, behavioral, and genetic predictors of motor learning, recovery of motor function following neural insult, and sensorimotor adaptation. For example, recent studies have identified specific genetic polymorphisms that are associated with faster adaptation on manual joystick tasks and faster recovery of function following a stroke. Moreover, the extent of recruitment of specific brain regions during learning and adaptation has been shown to be predictive of the magnitude of subsequent learning. We close with suggestions for forward work aimed at identifying predictors of spaceflight adaptation success. Identification of “slow adapters” prior to spaceflight exposure would allow for more targeted preflight training and/or provision of booster training and adaptation adjuncts during spaceflight. PMID:26217197

  7. Circular SAR GMTI

    NASA Astrophysics Data System (ADS)

    Page, Douglas; Owirka, Gregory; Nichols, Howard; Scarborough, Steven

    2014-06-01

    We describe techniques for improving ground moving target indication (GMTI) performance in multi-channel synthetic aperture radar (SAR) systems. Our approach employs a combination of moving reference processing (MRP) to compensate for defocus of moving target SAR responses and space-time adaptive processing (STAP) to mitigate the effects of strong clutter interference. Using simulated moving target and clutter returns, we demonstrate focusing of the target return using MRP, and discuss the effect of MRP on the clutter response. We also describe formation of adaptive degrees of freedom (DOFs) for STAP filtering of MRP processed data. For the simulated moving target in clutter example, we demonstrate improvement in the signal to interference plus noise (SINR) loss compared to more standard algorithm configurations. In addition to MRP and STAP, the use of tracker feedback, false alarm mitigation, and parameter estimation techniques are also described. A change detection approach for reducing false alarms from clutter discretes is outlined, and processing of a measured data coherent processing interval (CPI) from a continuously orbiting platform is described. The results demonstrate detection and geolocation of a high-value target under track. The endoclutter target is not clearly visible in single-channel SAR chips centered on the GMTI track prediction. Detections are compared to truth data before and after geolocation using measured angle of arrival (AOA).

  8. Adaptive Dynamic Bayesian Networks

    SciTech Connect

    Ng, B M

    2007-10-26

    A discrete-time Markov process can be compactly modeled as a dynamic Bayesian network (DBN)--a graphical model with nodes representing random variables and directed edges indicating causality between variables. Each node has a probability distribution, conditional on the variables represented by the parent nodes. A DBN's graphical structure encodes fixed conditional dependencies between variables. But in real-world systems, conditional dependencies between variables may be unknown a priori or may vary over time. Model errors can result if the DBN fails to capture all possible interactions between variables. Thus, we explore the representational framework of adaptive DBNs, whose structure and parameters can change from one time step to the next: a distribution's parameters and its set of conditional variables are dynamic. This work builds on recent work in nonparametric Bayesian modeling, such as hierarchical Dirichlet processes, infinite-state hidden Markov networks and structured priors for Bayes net learning. In this paper, we will explain the motivation for our interest in adaptive DBNs, show how popular nonparametric methods are combined to formulate the foundations for adaptive DBNs, and present preliminary results.

  9. NEEDS - Information Adaptive System

    NASA Technical Reports Server (NTRS)

    Kelly, W. L.; Benz, H. F.; Meredith, B. D.

    1980-01-01

    The Information Adaptive System (IAS) is an element of the NASA End-to-End Data System (NEEDS) Phase II and is focused toward onboard image processing. The IAS is a data preprocessing system which is closely coupled to the sensor system. Some of the functions planned for the IAS include sensor response nonuniformity correction, geometric correction, data set selection, data formatting, packetization, and adaptive system control. The inclusion of these sensor data preprocessing functions onboard the spacecraft will significantly improve the extraction of information from the sensor data in a timely and cost effective manner, and provide the opportunity to design sensor systems which can be reconfigured in near real-time for optimum performance. The purpose of this paper is to present the preliminary design of the IAS and the plans for its development.

  10. Intestinal mucosal adaptation

    PubMed Central

    Drozdowski, Laurie; Thomson, Alan BR

    2006-01-01

    Intestinal failure is a condition characterized by malnutrition and/or dehydration as a result of the inadequate digestion and absorption of nutrients. The most common cause of intestinal failure is short bowel syndrome, which occurs when the functional gut mass is reduced below the level necessary for adequate nutrient and water absorption. This condition may be congenital, or may be acquired as a result of a massive resection of the small bowel. Following resection, the intestine is capable of adaptation in response to enteral nutrients as well as other trophic stimuli. Identifying factors that may enhance the process of intestinal adaptation is an exciting area of research with important potential clinical applications. PMID:16937429

  11. Adaptation of an evidence-based intervention targeting HIV-infected prisoners transitioning to the community: the process and outcome of formative research for the Positive Living Using Safety (PLUS) intervention.

    PubMed

    Copenhaver, Michael; Chowdhury, Sutopa; Altice, Frederick L

    2009-04-01

    No evidence-based interventions (EBIs) have been designed for implementation during the critical period when HIV-infected prisoners are being transitioned from prison to the community. We therefore conducted formative research aimed at systematically selecting and adapting an EBI that integrates HIV risk reduction and adherence to antiretroviral therapy to implement among HIV-infected prisoners transitioning back to the community. Our formative research involved a critical examination of established EBIs and associated published reports complemented by data elicited through structured interviews with key stakeholders in community and correctional settings and members of the target population. Between September 2006 and February 2007, structured one-on-one interviews were conducted with key stakeholders in the target organizations (n = 19) and with members of the target population (n = 26) in Hartford and New Haven, Connecticut. Based on the formative research, we abbreviated and adapted the Holistic Health Recovery Program targeting people living with HIV (HHRP+), an EBI, to consist of four 45-minute sessions that cover a range of prespecified topics so that participants may individually apply intervention content as needed to their own HIV risk profile and antiretroviral adherence issues. The EBI was adapted so that it could be provided in an individual or group format and delivered in either consecutive or weekly sessions and so that it could be provided within the prison system and delivered just prior to release, or in a community-based setting where it could be delivered immediately after release. This study provides a comprehensive exemplar of the process of selecting and adapting an EBI taking into account both empirical evidence and input from target organization stakeholders and target population members in real-world settings where high-risk populations are concentrated. PMID:19260773

  12. Adaptation of an Evidence-Based Intervention Targeting HIV-Infected Prisoners Transitioning to the Community: The Process and Outcome of Formative Research for the Positive Living Using Safety (PLUS) Intervention

    PubMed Central

    Chowdhury, Sutopa; Altice, Frederick L.

    2009-01-01

    Abstract No evidence-based interventions (EBIs) have been designed for implementation during the critical period when HIV-infected prisoners are being transitioned from prison to the community. We therefore conducted formative research aimed at systematically selecting and adapting an EBI that integrates HIV risk reduction and adherence to antiretroviral therapy to implement among HIV-infected prisoners transitioning back to the community. Our formative research involved a critical examination of established EBIs and associated published reports complemented by data elicited through structured interviews with key stakeholders in community and correctional settings and members of the target population. Between September 2006 and February 2007, structured one-on-one interviews were conducted with key stakeholders in the target organizations (n = 19) and with members of the target population (n = 26) in Hartford and New Haven, Connecticut. Based on the formative research, we abbreviated and adapted the Holistic Health Recovery Program targeting people living with HIV (HHRP+), an EBI, to consist of four 45-minute sessions that cover a range of prespecified topics so that participants may individually apply intervention content as needed to their own HIV risk profile and antiretroviral adherence issues. The EBI was adapted so that it could be provided in an individual or group format and delivered in either consecutive or weekly sessions and so that it could be provided within the prison system and delivered just prior to release, or in a community-based setting where it could be delivered immediately after release. This study provides a comprehensive exemplar of the process of selecting and adapting an EBI taking into account both empirical evidence and input from target organization stakeholders and target population members in real-world settings where high-risk populations are concentrated. PMID:19260773

  13. Information processing of genetically modified food messages under different motives: an adaptation of the multiple-motive heuristic-systematic model.

    PubMed

    Kim, Jooyoung; Paek, Hye-Jin

    2009-12-01

    Recent risk management research has noted the importance of understanding how the lay public processes and reacts to risk-related information. Guided by the multiple-motive heuristic-systematic model, this study examines (1) how individuals process messages in the context of genetically modified foods to change their attitudes and (2) how the persuasion process varies across types of motives. In the three treatment conditions of accuracy, defense, and impression motives, the respondents changed their attitudes through either the heuristic or the systematic mode, depending on their motives. The accuracy-motive group appeared to use the systematic processing mode, while the impression-motive group seemed to employ the heuristic processing mode. The empirical findings highlight the importance of incorporating motives to improve our understanding of the process of attitude change in risk management and communication contexts. PMID:19948001

  14. Adaptive independent component analysis to analyze electrocardiograms

    NASA Astrophysics Data System (ADS)

    Yim, Seong-Bin; Szu, Harold H.

    2001-03-01

    In this work, we apply adaptive version independent component analysis (ADAPTIVE ICA) to the nonlinear measurement of electro-cardio-graphic (ECG) signals for potential detection of abnormal conditions in the heart. In principle, unsupervised ADAPTIVE ICA neural networks can demix the components of measured ECG signals. However, the nonlinear pre-amplification and post measurement processing make the linear ADAPTIVE ICA model no longer valid. This is possible because of a proposed adaptive rectification pre-processing is used to linearize the preamplifier of ECG, and then linear ADAPTIVE ICA is used in iterative manner until the outputs having their own stable Kurtosis. We call such a new approach adaptive ADAPTIVE ICA. Each component may correspond to individual heart function, either normal or abnormal. Adaptive ADAPTIVE ICA neural networks have the potential to make abnormal components more apparent, even when they are masked by normal components in the original measured signals. This is particularly important for diagnosis well in advance of the actual onset of heart attack, in which abnormalities in the original measured ECG signals may be difficult to detect. This is the first known work that applies Adaptive ADAPTIVE ICA to ECG signals beyond noise extraction, to the detection of abnormal heart function.

  15. Range ambiguity clutter suppression for bistatic STAP radar

    NASA Astrophysics Data System (ADS)

    Xie, Wenchong; Zhang, Baihua; Wang, Yongliang; Zhu, Yong; Duan, Keqing; Li, Rongfeng

    2013-12-01

    Bistatic pulse-Doppler airborne radar has desirable properties such as the low probability of detection by other radars relative to its monostatic counterpart. However, the clutter characteristics of bistatic airborne radar are more complex than those of monostatic airborne radar. The clutter spectra not only vary severely with range, but also vary with bistatic configuration. In this article, the geometry model of bistatic airborne radar is given, and the approximate estimation expressions for clutter degrees of freedom (DOFs) are presented. Then a novel clutter suppression method for bistatic airborne radar with range ambiguity is presented. The method completes registration-based range ambiguity clutter compensation based on non-uniform sampling and the estimated clutter DOFs. The simulation results illustrate the performance improvement achieved for bistatic airborne radar.

  16. Process

    SciTech Connect

    Geenen, P.V.; Bennis, J.

    1989-04-04

    A process is described for minimizing the cracking tendency and uncontrolled dimensional change, and improving the strength of a rammed plastic refractory reactor liner comprising phosphate-bonded silicon carbide or phosphate-bonded alumina. It consists of heating the reactor liner placed or mounted in a reactor, prior to its first use, from ambient temperature up to a temperature of from about 490/sup 0/C to about 510/sup 0/C, the heating being carried out by heating the liner at a rate to produce a temperature increase of the liner not greater than about 6/sup 0/C per hour.

  17. ADAPTATION AND ADAPTABILITY, THE BELLEFAIRE FOLLOWUP STUDY.

    ERIC Educational Resources Information Center

    ALLERHAND, MELVIN E.; AND OTHERS

    A RESEARCH TEAM STUDIED INFLUENCES, ADAPTATION, AND ADAPTABILITY IN 50 POORLY ADAPTING BOYS AT BELLEFAIRE, A REGIONAL CHILD CARE CENTER FOR EMOTIONALLY DISTURBED CHILDREN. THE TEAM ATTEMPTED TO GAUGE THE SUCCESS OF THE RESIDENTIAL TREATMENT CENTER IN TERMS OF THE PSYCHOLOGICAL PATTERNS AND ROLE PERFORMANCES OF THE BOYS DURING INDIVIDUAL CASEWORK…

  18. Adaptive building skin structures

    NASA Astrophysics Data System (ADS)

    Del Grosso, A. E.; Basso, P.

    2010-12-01

    The concept of adaptive and morphing structures has gained considerable attention in the recent years in many fields of engineering. In civil engineering very few practical applications are reported to date however. Non-conventional structural concepts like deployable, inflatable and morphing structures may indeed provide innovative solutions to some of the problems that the construction industry is being called to face. To give some examples, searches for low-energy consumption or even energy-harvesting green buildings are amongst such problems. This paper first presents a review of the above problems and technologies, which shows how the solution to these problems requires a multidisciplinary approach, involving the integration of architectural and engineering disciplines. The discussion continues with the presentation of a possible application of two adaptive and dynamically morphing structures which are proposed for the realization of an acoustic envelope. The core of the two applications is the use of a novel optimization process which leads the search for optimal solutions by means of an evolutionary technique while the compatibility of the resulting configurations of the adaptive envelope is ensured by the virtual force density method.

  19. Adaptive Optical Scanning Holography

    PubMed Central

    Tsang, P. W. M.; Poon, Ting-Chung; Liu, J.-P.

    2016-01-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably. PMID:26916866

  20. Adaptive Optical Scanning Holography.

    PubMed

    Tsang, P W M; Poon, Ting-Chung; Liu, J-P

    2016-01-01

    Optical Scanning Holography (OSH) is a powerful technique that employs a single-pixel sensor and a row-by-row scanning mechanism to capture the hologram of a wide-view, three-dimensional object. However, the time required to acquire a hologram with OSH is rather lengthy. In this paper, we propose an enhanced framework, which is referred to as Adaptive OSH (AOSH), to shorten the holographic recording process. We have demonstrated that the AOSH method is capable of decreasing the acquisition time by up to an order of magnitude, while preserving the content of the hologram favorably. PMID:26916866

  1. Adaptive Image Denoising by Mixture Adaptation.

    PubMed

    Luo, Enming; Chan, Stanley H; Nguyen, Truong Q

    2016-10-01

    We propose an adaptive learning procedure to learn patch-based image priors for image denoising. The new algorithm, called the expectation-maximization (EM) adaptation, takes a generic prior learned from a generic external database and adapts it to the noisy image to generate a specific prior. Different from existing methods that combine internal and external statistics in ad hoc ways, the proposed algorithm is rigorously derived from a Bayesian hyper-prior perspective. There are two contributions of this paper. First, we provide full derivation of the EM adaptation algorithm and demonstrate methods to improve the computational complexity. Second, in the absence of the latent clean image, we show how EM adaptation can be modified based on pre-filtering. The experimental results show that the proposed adaptation algorithm yields consistently better denoising results than the one without adaptation and is superior to several state-of-the-art algorithms. PMID:27416593

  2. UV Tolerance of Spoilage Microorganisms and Acid-Shocked and Acid-Adapted Escherichia coli in Apple Juice Treated with a Commercial UV Juice-Processing Unit.

    PubMed

    Usaga, Jessie; Padilla-Zakour, Olga I; Worobo, Randy W

    2016-02-01

    The enhanced thermal tolerance and survival responses of Escherichia coli O157:H7 in acid and acidified foods is a major safety concern for the production of low-pH products, including beverages. Little is known about this phenomenon when using UV light treatments. This study was conducted to evaluate the effects of strain (E. coli O157:H7 strains C7927, ATCC 35150, ATCC 43895, and ATCC 43889 and E. coli ATCC 25922) and physiological state (control-unadapted, acid adapted, and acid shocked) on the UV tolerance of E. coli in apple juice treated under conditions stipulated in current U.S. Food and Drug Administration regulations. A greater than 5-log reduction of E. coli was obtained under all tested conditions. A significant effect of strain (P < 0.05) was observed, but the physiological state did not influence pathogen inactivation (P ≥ 0.05). The UV sensitivity of three spoilage microorganisms (Aspergillus niger, Penicillium commune, and Alicyclobacillus acidoterrestris) was also determined at UV doses of 0 to 98 mJ/cm(2). Alicyclobacillus was the most UV sensitive, followed by Penicillium and Aspergillus. Because of the nonsignificant differences in UV sensitivity of E. coli in different physiological states, the use of an unadapted inoculum would be adequate to conduct challenge studies with the commercial UV unit used in this study at a UV dose of 14 mJ/cm(2). The high UV tolerance of spoilage microorganisms supports the need to use a hurdle approach (e.g., coupling of refrigeration, preservatives, and/or other technologies) to extend the shelf life of UV-treated beverages. PMID:26818991

  3. Visual adaptation dominates bimodal visual-motor action adaptation.

    PubMed

    de la Rosa, Stephan; Ferstl, Ylva; Bülthoff, Heinrich H

    2016-01-01

    A long standing debate revolves around the question whether visual action recognition primarily relies on visual or motor action information. Previous studies mainly examined the contribution of either visual or motor information to action recognition. Yet, the interaction of visual and motor action information is particularly important for understanding action recognition in social interactions, where humans often observe and execute actions at the same time. Here, we behaviourally examined the interaction of visual and motor action recognition processes when participants simultaneously observe and execute actions. We took advantage of behavioural action adaptation effects to investigate behavioural correlates of neural action recognition mechanisms. In line with previous results, we find that prolonged visual exposure (visual adaptation) and prolonged execution of the same action with closed eyes (non-visual motor adaptation) influence action recognition. However, when participants simultaneously adapted visually and motorically - akin to simultaneous execution and observation of actions in social interactions - adaptation effects were only modulated by visual but not motor adaptation. Action recognition, therefore, relies primarily on vision-based action recognition mechanisms in situations that require simultaneous action observation and execution, such as social interactions. The results suggest caution when associating social behaviour in social interactions with motor based information. PMID:27029781

  4. Visual adaptation dominates bimodal visual-motor action adaptation

    PubMed Central

    de la Rosa, Stephan; Ferstl, Ylva; Bülthoff, Heinrich H.

    2016-01-01

    A long standing debate revolves around the question whether visual action recognition primarily relies on visual or motor action information. Previous studies mainly examined the contribution of either visual or motor information to action recognition. Yet, the interaction of visual and motor action information is particularly important for understanding action recognition in social interactions, where humans often observe and execute actions at the same time. Here, we behaviourally examined the interaction of visual and motor action recognition processes when participants simultaneously observe and execute actions. We took advantage of behavioural action adaptation effects to investigate behavioural correlates of neural action recognition mechanisms. In line with previous results, we find that prolonged visual exposure (visual adaptation) and prolonged execution of the same action with closed eyes (non-visual motor adaptation) influence action recognition. However, when participants simultaneously adapted visually and motorically – akin to simultaneous execution and observation of actions in social interactions - adaptation effects were only modulated by visual but not motor adaptation. Action recognition, therefore, relies primarily on vision-based action recognition mechanisms in situations that require simultaneous action observation and execution, such as social interactions. The results suggest caution when associating social behaviour in social interactions with motor based information. PMID:27029781

  5. Processing of Visual Imagery by an Adaptive Model of the Visual System: Its Performance and its Significance. Final Report, June 1969-March 1970.

    ERIC Educational Resources Information Center

    Tallman, Oliver H.

    A digital simulation of a model for the processing of visual images is derived from known aspects of the human visual system. The fundamental principle of computation suggested by a biological model is a transformation that distributes information contained in an input stimulus everywhere in a transform domain. Each sensory input contributes under…

  6. Teaching About Adaptation: Why Evolutionary History Matters

    NASA Astrophysics Data System (ADS)

    Kampourakis, Kostas

    2013-02-01

    Adaptation is one of the central concepts in evolutionary theory, which nonetheless has been given different definitions. Some scholars support a historical definition of adaptation, considering it as a trait that is the outcome of natural selection, whereas others support an ahistorical definition, considering it as a trait that contributes to the survival and reproduction of its possessors. Finally, adaptation has been defined as a process, as well. Consequently, two questions arise: the first is a philosophical one and focuses on what adaptation actually is; the second is a pedagogical one and focuses on what science teachers and educators should teach about it. In this article, the various definitions of adaptation are discussed and their uses in some textbooks are presented. It is suggested that, given elementary students' intuitions about purpose and design in nature and secondary students' teleological explanations for the origin of adaptations, any definition of adaptation as a trait should include some information about its evolutionary history.

  7. Climate adaptation planning in practice: an evaluation of adaptation plans from three developed nations

    SciTech Connect

    Preston, Benjamin L; Westaway, Richard M.; Yuen, Emma J.

    2011-04-01

    Formal planning for climate change adaptation is emerging rapidly at a range of geo-political scales. This first generation of adaptation plans provides useful information regarding how institutions are framing the issue of adaptation and the range of processes that are recognized as being part of an adaptation response. To better understand adaptation planning among developed nations, a set of 57 adaptation plans from Australia, the United Kingdom and the United States was evaluated against a suite of 19 planning processes identified from existing guidance instruments for adaptation planning. Total scores among evaluated plans ranged from 16% of the maximum possible score to 61%, with an average of 37%. These results suggest adaptation plans are largely under-developed. Critical weaknesses in adaptation planning are related to limited consideration for non-climatic factors as well as neglect for issues of adaptive capacity including entitlements to various forms of capital needed for effective adaptation. Such gaps in planning suggest there are opportunities for institutions to make better use of existing guidance for adaptation planning and the need to consider the broader governance context in which adaptation will occur. In addition, the adaptation options prescribed by adaptation plans reflect a preferential bias toward low-risk capacity-building (72% of identified options) over the delivery of specific actions to reduce vulnerability. To the extent these findings are representative of the state of developed nation adaptation planning, there appear to be significant deficiencies in climate change preparedness, even among those nations often assumed to have the greatest adaptive capacity.

  8. Transcription Adaptation during In Vitro Adipogenesis and Osteogenesis of Porcine Mesenchymal Stem Cells: Dynamics of Pathways, Biological Processes, Up-Stream Regulators, and Gene Networks

    PubMed Central

    Bionaz, Massimo; Monaco, Elisa; Wheeler, Matthew B.

    2015-01-01

    The importance of mesenchymal stem cells (MSC) for bone regeneration is growing. Among MSC the bone marrow-derived stem cells (BMSC) are considered the gold standard in tissue engineering and regenerative medicine; however, the adipose-derived stem cells (ASC) have very similar properties and some advantages to be considered a good alternative to BMSC. The molecular mechanisms driving adipogenesis are relatively well-known but mechanisms driving osteogenesis are poorly known, particularly in pig. In the present study we have used transcriptome analysis to unravel pathways and biological functions driving in vitro adipogenesis and osteogenesis in BMSC and ASC. The analysis was performed using the novel Dynamic Impact Approach and functional enrichment analysis. In addition, a k-mean cluster analysis in association with enrichment analysis, networks reconstruction, and transcription factors overlapping analysis were performed in order to uncover the coordination of biological functions underlining differentiations. Analysis indicated a larger and more coordinated transcriptomic adaptation during adipogenesis compared to osteogenesis, with a larger induction of metabolism, particularly lipid synthesis (mostly triglycerides), and a larger use of amino acids for synthesis of feed-forward adipogenic compounds, larger cell signaling, lower cell-to-cell interactions, particularly for the cytoskeleton organization and cell junctions, and lower cell proliferation. The coordination of adipogenesis was mostly driven by Peroxisome Proliferator-activated Receptors together with other known adipogenic transcription factors. Only a few pathways and functions were more induced during osteogenesis compared to adipogenesis and some were more inhibited during osteogenesis, such as cholesterol and protein synthesis. Up-stream transcription factor analysis indicated activation of several lipid-related transcription regulators (e.g., PPARs and CEBPα) during adipogenesis but osteogenesis

  9. Memory distortion: an adaptive perspective

    PubMed Central

    Schacter, Daniel L.; Guerin, Scott A.; St. Jacques, Peggy L.

    2011-01-01

    Memory is prone to distortions that can have serious consequences in everyday life. Here we integrate emerging evidence that several types of memory distortions – imagination inflation, gist-based and associative memory errors, and post-event misinformation – reflect adaptive cognitive processes that contribute to the efficient functioning of memory, but produce distortions as a consequence of doing so. We consider recent cognitive and neuroimaging studies that link these distortions with adaptive processes, including simulation of future events, semantic and contextual encoding, creativity, and memory updating. We also discuss new evidence concerning factors that can influence the occurrence of memory distortions, such as sleep and retrieval conditions, as well as conceptual issues related to the development of an adaptive perspective. PMID:21908231

  10. Adaptive capture of expert knowledge

    SciTech Connect

    Barrett, C.L.; Jones, R.D.; Hand, Un Kyong |

    1995-05-01

    A method is introduced that can directly acquire knowledge-engineered, rule-based logic in an adaptive network. This adaptive representation of the rule system can then replace the rule system in simulated intelligent agents and thereby permit further performance-based adaptation of the rule system. The approach described provides both weight-fitting network adaptation and potentially powerful rule mutation and selection mechanisms. Nonlinear terms are generated implicitly in the mutation process through the emergent interaction of multiple linear terms. By this method it is possible to acquire nonlinear relations that exist in the training data without addition of hidden layers or imposition of explicit nonlinear terms in the network. We smoothed and captured a set of expert rules with an adaptive network. The motivation for this was to (1) realize a speed advantage over traditional rule-based simulations; (2) have variability in the intelligent objects not possible by rule-based systems but provided by adaptive systems: and (3) maintain the understandability of rule-based simulations. A set of binary rules was smoothed and converted into a simple set of arithmetic statements, where continuous, non-binary rules are permitted. A neural network, called the expert network, was developed to capture this rule set, which it was able to do with zero error. The expert network is also capable of learning a nonmonotonic term without a hidden layer. The trained network in feedforward operation is fast running, compact, and traceable to the rule base.

  11. Habituation of visual adaptation

    PubMed Central

    Dong, Xue; Gao, Yi; Lv, Lili; Bao, Min

    2016-01-01

    Our sensory system adjusts its function driven by both shorter-term (e.g. adaptation) and longer-term (e.g. learning) experiences. Most past adaptation literature focuses on short-term adaptation. Only recently researchers have begun to investigate how adaptation changes over a span of days. This question is important, since in real life many environmental changes stretch over multiple days or longer. However, the answer to the question remains largely unclear. Here we addressed this issue by tracking perceptual bias (also known as aftereffect) induced by motion or contrast adaptation across multiple daily adaptation sessions. Aftereffects were measured every day after adaptation, which corresponded to the degree of adaptation on each day. For passively viewed adapters, repeated adaptation attenuated aftereffects. Once adapters were presented with an attentional task, aftereffects could either reduce for easy tasks, or initially show an increase followed by a later decrease for demanding tasks. Quantitative analysis of the decay rates in contrast adaptation showed that repeated exposure of the adapter appeared to be equivalent to adaptation to a weaker stimulus. These results suggest that both attention and a non-attentional habituation-like mechanism jointly determine how adaptation develops across multiple daily sessions. PMID:26739917

  12. Habituation of visual adaptation.

    PubMed

    Dong, Xue; Gao, Yi; Lv, Lili; Bao, Min

    2016-01-01

    Our sensory system adjusts its function driven by both shorter-term (e.g. adaptation) and longer-term (e.g. learning) experiences. Most past adaptation literature focuses on short-term adaptation. Only recently researchers have begun to investigate how adaptation changes over a span of days. This question is important, since in real life many environmental changes stretch over multiple days or longer. However, the answer to the question remains largely unclear. Here we addressed this issue by tracking perceptual bias (also known as aftereffect) induced by motion or contrast adaptation across multiple daily adaptation sessions. Aftereffects were measured every day after adaptation, which corresponded to the degree of adaptation on each day. For passively viewed adapters, repeated adaptation attenuated aftereffects. Once adapters were presented with an attentional task, aftereffects could either reduce for easy tasks, or initially show an increase followed by a later decrease for demanding tasks. Quantitative analysis of the decay rates in contrast adaptation showed that repeated exposure of the adapter appeared to be equivalent to adaptation to a weaker stimulus. These results suggest that both attention and a non-attentional habituation-like mechanism jointly determine how adaptation develops across multiple daily sessions. PMID:26739917

  13. Adaptive oxide electronics: A review

    NASA Astrophysics Data System (ADS)

    Ha, Sieu D.; Ramanathan, Shriram

    2011-10-01

    Novel information processing techniques are being actively explored to overcome fundamental limitations associated with CMOS scaling. A new paradigm of adaptive electronic devices is emerging that may reshape the frontiers of electronics and enable new modalities. Creating systems that can learn and adapt to various inputs has generally been a complex algorithm problem in information science, albeit with wide-ranging and powerful applications from medical diagnosis to control systems. Recent work in oxide electronics suggests that it may be plausible to implement such systems at the device level, thereby drastically increasing computational density and power efficiency and expanding the potential for electronics beyond Boolean computation. Intriguing possibilities of adaptive electronics include fabrication of devices that mimic human brain functionality: the strengthening and weakening of synapses emulated by electrically, magnetically, thermally, or optically tunable properties of materials.In this review, we detail materials and device physics studies on functional metal oxides that may be utilized for adaptive electronics. It has been shown that properties, such as resistivity, polarization, and magnetization, of many oxides can be modified electrically in a non-volatile manner, suggesting that these materials respond to electrical stimulus similarly as a neural synapse. We discuss what device characteristics will likely be relevant for integration into adaptive platforms and then survey a variety of oxides with respect to these properties, such as, but not limited to, TaOx, SrTiO3, and Bi4-xLaxTi3O12. The physical mechanisms in each case are detailed and analyzed within the framework of adaptive electronics. We then review theoretically formulated and current experimentally realized adaptive devices with functional oxides, such as self-programmable logic and neuromorphic circuits. Finally, we speculate on what advances in materials physics and engineering may

  14. Cognitive performance during a simulated climb of Mount Everest: implications for brain function and central adaptive processes under chronic hypoxic stress.

    PubMed

    Abraini, J H; Bouquet, C; Joulia, F; Nicolas, M; Kriem, B

    1998-07-01

    High altitude is characterized by hypoxic environmental conditions and is well known to induce both physiological and psychological disturbances. In the present study, called ”Everest-Comex 97”, the authors investigated the effects of high altitude on the psychosensorimotor and reasoning processes of eight climbers participating in a simulated climb from sea level to 8,848 m over a 31-day period of confinement in a decompression chamber. Tests of visual reaction time, psychomotor ability, and number ordination were used. The climbers’ data were compared with data from a similar laboratory study at sea level in control subjects. Continued testing of the control subjects at sea level clearly led to learning effects and improvement of performance in psychomotor ability and number ordination. In the climbers, similar learning effects occurred up to an altitude of 5,500–6,500 m. With further increases in altitude, the climbers’ psychomotor performance and mental efficiency deteriorated progressively, leading to significant differences in psychomotor ability and mental efficiency between control subjects and climbers (9 and 13% respectively at 8,000 m and 17.5 and 16.5% respectively at 8,848 m). Three days (72 h) after the climbers had returned to sea level, their mental and psychomotor performances were still significantly lower than those of control subjects (by approximately 10%). In contrast, visual reaction time showed no significant changes in either climbers or control subjects. It is suggested that chronic hypoxic stress could alter selectively mental learning processes, i.e. explicit, rather than implicit (stimulus-response learning processes) memory and cortico-limbic rather than basal ganglia-sensorimotor system function. PMID:9683728

  15. Visual adaptation and face perception

    PubMed Central

    Webster, Michael A.; MacLeod, Donald I. A.

    2011-01-01

    The appearance of faces can be strongly affected by the characteristics of faces viewed previously. These perceptual after-effects reflect processes of sensory adaptation that are found throughout the visual system, but which have been considered only relatively recently in the context of higher level perceptual judgements. In this review, we explore the consequences of adaptation for human face perception, and the implications of adaptation for understanding the neural-coding schemes underlying the visual representation of faces. The properties of face after-effects suggest that they, in part, reflect response changes at high and possibly face-specific levels of visual processing. Yet, the form of the after-effects and the norm-based codes that they point to show many parallels with the adaptations and functional organization that are thought to underlie the encoding of perceptual attributes like colour. The nature and basis for human colour vision have been studied extensively, and we draw on ideas and principles that have been developed to account for norms and normalization in colour vision to consider potential similarities and differences in the representation and adaptation of faces. PMID:21536555

  16. Hydropower, adaptive management, and biodiversity

    SciTech Connect

    Wieringa, M.J.; Morton, A.G.

    1996-11-01

    Adaptive management is a policy framework within which an iterative process of decision making is allowed based on the observed responses to and effectiveness of previous decisions. The use of adaptive management allows science-based research and monitoring of natural resource and ecological community responses, in conjunction with societal values and goals, to guide decisions concerning man`s activities. The adaptive management process has been proposed for application to hydropower operations at Glen Canyon Dam on the Colorado River, a situation that requires complex balancing of natural resources requirements and competing human uses. This example is representative of the general increase in public interest in the operation of hydropower facilities and possible effects on downstream natural resources and of the growing conflicts between uses and users of river-based resources. This paper describes the adaptive management process, using the Glen Canyon Dam example, and discusses ways to make the process work effectively in managing downstream natural resources and biodiversity. 10 refs., 2 figs.

  17. Adapting Data Processing To Compare Model and Experiment Accurately: A Discrete Element Model and Magnetic Resonance Measurements of a 3D Cylindrical Fluidized Bed.

    PubMed

    Boyce, Christopher M; Holland, Daniel J; Scott, Stuart A; Dennis, John S

    2013-12-18

    Discrete element modeling is being used increasingly to simulate flow in fluidized beds. These models require complex measurement techniques to provide validation for the approximations inherent in the model. This paper introduces the idea of modeling the experiment to ensure that the validation is accurate. Specifically, a 3D, cylindrical gas-fluidized bed was simulated using a discrete element model (DEM) for particle motion coupled with computational fluid dynamics (CFD) to describe the flow of gas. The results for time-averaged, axial velocity during bubbling fluidization were compared with those from magnetic resonance (MR) experiments made on the bed. The DEM-CFD data were postprocessed with various methods to produce time-averaged velocity maps for comparison with the MR results, including a method which closely matched the pulse sequence and data processing procedure used in the MR experiments. The DEM-CFD results processed with the MR-type time-averaging closely matched experimental MR results, validating the DEM-CFD model. Analysis of different averaging procedures confirmed that MR time-averages of dynamic systems correspond to particle-weighted averaging, rather than frame-weighted averaging, and also demonstrated that the use of Gaussian slices in MR imaging of dynamic systems is valid. PMID:24478537

  18. Adapting Data Processing To Compare Model and Experiment Accurately: A Discrete Element Model and Magnetic Resonance Measurements of a 3D Cylindrical Fluidized Bed

    PubMed Central

    2013-01-01

    Discrete element modeling is being used increasingly to simulate flow in fluidized beds. These models require complex measurement techniques to provide validation for the approximations inherent in the model. This paper introduces the idea of modeling the experiment to ensure that the validation is accurate. Specifically, a 3D, cylindrical gas-fluidized bed was simulated using a discrete element model (DEM) for particle motion coupled with computational fluid dynamics (CFD) to describe the flow of gas. The results for time-averaged, axial velocity during bubbling fluidization were compared with those from magnetic resonance (MR) experiments made on the bed. The DEM-CFD data were postprocessed with various methods to produce time-averaged velocity maps for comparison with the MR results, including a method which closely matched the pulse sequence and data processing procedure used in the MR experiments. The DEM-CFD results processed with the MR-type time-averaging closely matched experimental MR results, validating the DEM-CFD model. Analysis of different averaging procedures confirmed that MR time-averages of dynamic systems correspond to particle-weighted averaging, rather than frame-weighted averaging, and also demonstrated that the use of Gaussian slices in MR imaging of dynamic systems is valid. PMID:24478537

  19. Analyzing Hedges in Verbal Communication: An Adaptation-Based Approach

    ERIC Educational Resources Information Center

    Wang, Yuling

    2010-01-01

    Based on Adaptation Theory, the article analyzes the production process of hedges. The procedure consists of the continuous making of choices in linguistic forms and communicative strategies. These choices are made just for adaptation to the contextual correlates. Besides, the adaptation process is dynamic, intentional and bidirectional.

  20. Dilemmatic group memberships of hard-of-hearing employees during the process of acquiring and adapting to the use of hearing aids.

    PubMed

    Koskela, Inka; Ruusuvuori, Johanna; Juvonen-Posti, Pirjo; Nevala, Nina; Husman, Päivi; Aaltonen, Tarja; Lonka, Eila; Laakso, Minna

    2016-09-01

    We describe how hard-of-hearing (HOH) employees renegotiate both their existing and new group memberships when they acquire and begin to use hearing aids (HAs). Our research setting was longitudinal and we carried out a theory-informed qualitative analysis of multiple qualitative data. When an individual discovers that they have a hearing problem and acquire a HA, their group memberships undergo change. First, HOH employees need to start negotiating their relationship with the HOH group. Second, they need to consider whether they see themselves as members of the disabled or the nondisabled employee group. This negotiation tends to be context-bound, situational, and nonlinear as a process, involving a back-and-forth movement in the way in which HOH employees value different group memberships. The dilemmatic negotiation of new group memberships and the other social aspects involved in HA rehabilitation tend to remain invisible to rehabilitation professionals, occupational healthcare, and employers. PMID:27128825

  1. Adaptation in CRISPR-Cas Systems.

    PubMed

    Sternberg, Samuel H; Richter, Hagen; Charpentier, Emmanuelle; Qimron, Udi

    2016-03-17

    Clustered regularly interspaced short palindromic repeats (CRISPR) and CRISPR-associated (Cas) proteins constitute an adaptive immune system in prokaryotes. The system preserves memories of prior infections by integrating short segments of foreign DNA, termed spacers, into the CRISPR array in a process termed adaptation. During the past 3 years, significant progress has been made on the genetic requirements and molecular mechanisms of adaptation. Here we review these recent advances, with a focus on the experimental approaches that have been developed, the insights they generated, and a proposed mechanism for self- versus non-self-discrimination during the process of spacer selection. We further describe the regulation of adaptation and the protein players involved in this fascinating process that allows bacteria and archaea to harbor adaptive immunity. PMID:26949040

  2. Expressing Adaptation Strategies Using Adaptation Patterns

    ERIC Educational Resources Information Center

    Zemirline, N.; Bourda, Y.; Reynaud, C.

    2012-01-01

    Today, there is a real challenge to enable personalized access to information. Several systems have been proposed to address this challenge including Adaptive Hypermedia Systems (AHSs). However, the specification of adaptation strategies remains a difficult task for creators of such systems. In this paper, we consider the problem of the definition…

  3. [Peculiarities of adaptation of servicemen service].

    PubMed

    Shelepov, A M; Smagulov, N K; Mukhametzhanov, A M

    2012-09-01

    Review of issues about the adaptation of servicemen in the process of military service is presented. Characteristics of military service, conditions and levels of official-military activity, peculiarities of adaptation, factors providing progression of psychosomatic diseases and dysaptation, concept "occupational health" are considered. PMID:23156112

  4. Developing Adaptive Teaching Competency through Coaching

    ERIC Educational Resources Information Center

    Vogt, Franziska; Rogalla, Marion

    2009-01-01

    The research project Adaptive Teaching Competency seeks to conceptualise the processes of tuning teaching to individual students' learning needs and to empirically test, within the field of science teaching, to what extent Adaptive Teaching Competency can be fostered through teacher education. 32 primary and secondary teachers took part in an…

  5. Russian Loanword Adaptation in Persian; Optimal Approach

    ERIC Educational Resources Information Center

    Kambuziya, Aliye Kord Zafaranlu; Hashemi, Eftekhar Sadat

    2011-01-01

    In this paper we analyzed some of the phonological rules of Russian loanword adaptation in Persian, on the view of Optimal Theory (OT) (Prince & Smolensky, 1993/2004). It is the first study of phonological process on Russian loanwords adaptation in Persian. By gathering about 50 current Russian loanwords, we selected some of them to analyze. We…

  6. Behavior of adaptive digital erosions

    NASA Astrophysics Data System (ADS)

    Cuciurean-Zapan, Clara; Dougherty, Edward R.; Chen, Yidong

    1996-10-01

    Design of statistically optimal erosion-based filters is problematic due to the complexity of the search process. Specialized search techniques and constraints on optimality are used to mitigate the full search. Adaptation of structuring elements has also ben employed. The present paper looks at the behavior of an adaptive filter relative to the actual optimal filter for a single erosion in two models, signal-union-noise and dilation. It does so in the context of state transitions, where filter states are stacks that determine the structuring element upon thresholding.

  7. A fast and efficient adaptive parallel ray tracing based model for thermally coupled surface radiation in casting and heat treatment processes

    NASA Astrophysics Data System (ADS)

    Fainberg, J.; Schaefer, W.

    2015-06-01

    A new algorithm for heat exchange between thermally coupled diffusely radiating interfaces is presented, which can be applied for closed and half open transparent radiating cavities. Interfaces between opaque and transparent materials are automatically detected and subdivided into elementary radiation surfaces named tiles. Contrary to the classical view factor method, the fixed unit sphere area subdivision oriented along the normal tile direction is projected onto the surrounding radiation mesh and not vice versa. Then, the total incident radiating flux of the receiver is approximated as a direct sum of radiation intensities of representative “senders” with the same weight factor. A hierarchical scheme for the space angle subdivision is selected in order to minimize the total memory and the computational demands during thermal calculations. Direct visibility is tested by means of a voxel-based ray tracing method accelerated by means of the anisotropic Chebyshev distance method, which reuses the computational grid as a Chebyshev one. The ray tracing algorithm is fully parallelized using MPI and takes advantage of the balanced distribution of all available tiles among all CPU's. This approach allows tracing of each particular ray without any communication. The algorithm has been implemented in a commercial casting process simulation software. The accuracy and computational performance of the new radiation model for heat treatment, investment and ingot casting applications is illustrated using industrial examples.

  8. Modification of energy-transfer processes in the cyanobacterium, Arthrospira platensis, to adapt to light conditions, probed by time-resolved fluorescence spectroscopy.

    PubMed

    Akimoto, Seiji; Yokono, Makio; Aikawa, Shimpei; Kondo, Akihiko

    2013-11-01

    In cyanobacteria, the interactions among pigment-protein complexes are modified in response to changes in light conditions. In the present study, we analyzed excitation energy transfer from the phycobilisome and photosystem II to photosystem I in the cyanobacterium Arthrospira (Spirulina) platensis. The cells were grown under lights with different spectral profiles and under different light intensities, and the energy-transfer characteristics were evaluated using steady-state absorption, steady-state fluorescence, and picosecond time-resolved fluorescence spectroscopy techniques. The fluorescence rise and decay curves were analyzed by global analysis to obtain fluorescence decay-associated spectra. The direct energy transfer from the phycobilisome to photosystem I and energy transfer from photosystem II to photosystem I were modified depending on the light quality, light quantity, and cultivation period. However, the total amount of energy transferred to photosystem I remained constant under the different growth conditions. We discuss the differences in energy-transfer processes under different cultivation and light conditions. PMID:23605291

  9. Physiological response of Pichia pastoris GS115 to methanol-induced high level production of the Hepatitis B surface antigen: catabolic adaptation, stress responses, and autophagic processes

    PubMed Central

    2012-01-01

    Background Pichia pastoris is an established eukaryotic host for the production of recombinant proteins. Most often, protein production is under the control of the strong methanol-inducible aox1 promoter. However, detailed information about the physiological alterations in P. pastoris accompanying the shift from growth on glycerol to methanol-induced protein production under industrial relevant conditions is missing. Here, we provide an analysis of the physiological response of P. pastoris GS115 to methanol-induced high-level production of the Hepatitis B virus surface antigen (HBsAg). High product titers and the retention of the protein in the endoplasmic reticulum (ER) are supposedly of major impact on the host physiology. For a more detailed understanding of the cellular response to methanol-induced HBsAg production, the time-dependent changes in the yeast proteome and ultrastructural cell morphology were analyzed during the production process. Results The shift from growth on glycerol to growth and HBsAg production on methanol was accompanied by a drastic change in the yeast proteome. In particular, enzymes from the methanol dissimilation pathway started to dominate the proteome while enzymes from the methanol assimilation pathway, e.g. the transketolase DAS1, increased only moderately. The majority of methanol was metabolized via the energy generating dissimilatory pathway leading to a corresponding increase in mitochondrial size and numbers. The methanol-metabolism related generation of reactive oxygen species induced a pronounced oxidative stress response (e.g. strong increase of the peroxiredoxin PMP20). Moreover, the accumulation of HBsAg in the ER resulted in the induction of the unfolded protein response (e.g. strong increase of the ER-resident disulfide isomerase, PDI) and the ER associated degradation (ERAD) pathway (e.g. increase of two cytosolic chaperones and members of the AAA ATPase superfamily) indicating that potential degradation of HBsAg could

  10. [Criteria for determining the adaptation of children to studying loads].

    PubMed

    Potupchik, T V; Makarova, M V; Prakhin, E I; Evert, L S; Baksheeva, S S

    2011-01-01

    Three hundred and two Krasnoyarsk gymnasium students were examined to define criteria for determining the adaptation to high schooling loads. The values of the emotional status and adaptive processes were studied in children with varying resistance and varying mastering capacities; the impact of cardiovascular parameters on their adaptive process was defined The criteria for estimating the adaptation to high schooling loads were the presence or absence of acute chills and neurotic reactions, cardiovascular performance, and psychoemotional status. PMID:22250390

  11. Biochemical adaptation to ocean acidification.

    PubMed

    Stillman, Jonathon H; Paganini, Adam W

    2015-06-01

    The change in oceanic carbonate chemistry due to increased atmospheric PCO2  has caused pH to decline in marine surface waters, a phenomenon known as ocean acidification (OA). The effects of OA on organisms have been shown to be widespread among diverse taxa from a wide range of habitats. The majority of studies of organismal response to OA are in short-term exposures to future levels of PCO2 . From such studies, much information has been gathered on plastic responses organisms may make in the future that are beneficial or harmful to fitness. Relatively few studies have examined whether organisms can adapt to negative-fitness consequences of plastic responses to OA. We outline major approaches that have been used to study the adaptive potential for organisms to OA, which include comparative studies and experimental evolution. Organisms that inhabit a range of pH environments (e.g. pH gradients at volcanic CO2 seeps or in upwelling zones) have great potential for studies that identify adaptive shifts that have occurred through evolution. Comparative studies have advanced our understanding of adaptation to OA by linking whole-organism responses with cellular mechanisms. Such optimization of function provides a link between genetic variation and adaptive evolution in tuning optimal function of rate-limiting cellular processes in different pH conditions. For example, in experimental evolution studies of organisms with short generation times (e.g. phytoplankton), hundreds of generations of growth under future conditions has resulted in fixed differences in gene expression related to acid-base regulation. However, biochemical mechanisms for adaptive responses to OA have yet to be fully characterized, and are likely to be more complex than simply changes in gene expression or protein modification. Finally, we present a hypothesis regarding an unexplored area for biochemical adaptation to ocean acidification. In this hypothesis, proteins and membranes exposed to the

  12. Imaging an Adapted Dentoalveolar Complex

    PubMed Central

    Herber, Ralf-Peter; Fong, Justine; Lucas, Seth A.; Ho, Sunita P.

    2012-01-01

    Adaptation of a rat dentoalveolar complex was illustrated using various imaging modalities. Micro-X-ray computed tomography for 3D modeling, combined with complementary techniques, including image processing, scanning electron microscopy, fluorochrome labeling, conventional histology (H&E, TRAP), and immunohistochemistry (RANKL, OPN) elucidated the dynamic nature of bone, the periodontal ligament-space, and cementum in the rat periodontium. Tomography and electron microscopy illustrated structural adaptation of calcified tissues at a higher resolution. Ongoing biomineralization was analyzed using fluorochrome labeling, and by evaluating attenuation profiles using virtual sections from 3D tomographies. Osteoclastic distribution as a function of anatomical location was illustrated by combining histology, immunohistochemistry, and tomography. While tomography and SEM provided past resorption-related events, future adaptive changes were deduced by identifying matrix biomolecules using immunohistochemistry. Thus, a dynamic picture of the dentoalveolar complex in rats was illustrated. PMID:22567314

  13. Adaptive sampling for noisy problems

    SciTech Connect

    Cantu-Paz, E

    2004-03-26

    The usual approach to deal with noise present in many real-world optimization problems is to take an arbitrary number of samples of the objective function and use the sample average as an estimate of the true objective value. The number of samples is typically chosen arbitrarily and remains constant for the entire optimization process. This paper studies an adaptive sampling technique that varies the number of samples based on the uncertainty of deciding between two individuals. Experiments demonstrate the effect of adaptive sampling on the final solution quality reached by a genetic algorithm and the computational cost required to find the solution. The results suggest that the adaptive technique can effectively eliminate the need to set the sample size a priori, but in many cases it requires high computational costs.

  14. Three timescales in prism adaptation.

    PubMed

    Inoue, Masato; Uchimura, Motoaki; Karibe, Ayaka; O'Shea, Jacinta; Rossetti, Yves; Kitazawa, Shigeru

    2015-01-01

    It has been proposed that motor adaptation depends on at least two learning systems, one that learns fast but with poor retention and another that learns slowly but with better retention (Smith MA, Ghazizadeh A, Shadmehr R. PLoS Biol 4: e179, 2006). This two-state model has been shown to account for a range of behavior in the force field adaptation task. In the present study, we examined whether such a two-state model could also account for behavior arising from adaptation to a prismatic displacement of the visual field. We first confirmed that an "adaptation rebound," a critical prediction of the two-state model, occurred when visual feedback was deprived after an adaptation-extinction episode. We then examined the speed of decay of the prism aftereffect (without any visual feedback) after repetitions of 30, 150, and 500 trials of prism exposure. The speed of decay decreased with the number of exposure trials, a phenomenon that was best explained by assuming an "ultraslow" system, in addition to the fast and slow systems. Finally, we compared retention of aftereffects 24 h after 150 or 500 trials of exposure: retention was significantly greater after 500 than 150 trials. This difference in retention could not be explained by the two-state model but was well explained by the three-state model as arising from the difference in the amount of adaptation of the "ultraslow process." These results suggest that there are not only fast and slow systems but also an ultraslow learning system in prism adaptation that is activated by prolonged prism exposure of 150-500 trials. PMID:25298383

  15. Sleep facilitates long-term face adaptation.

    PubMed

    Ditye, Thomas; Javadi, Amir Homayoun; Carbon, Claus-Christian; Walsh, Vincent

    2013-10-22

    Adaptation is an automatic neural mechanism supporting the optimization of visual processing on the basis of previous experiences. While the short-term effects of adaptation on behaviour and physiology have been studied extensively, perceptual long-term changes associated with adaptation are still poorly understood. Here, we show that the integration of adaptation-dependent long-term shifts in neural function is facilitated by sleep. Perceptual shifts induced by adaptation to a distorted image of a famous person were larger in a group of participants who had slept (experiment 1) or merely napped for 90 min (experiment 2) during the interval between adaptation and test compared with controls who stayed awake. Participants' individual rapid eye movement sleep duration predicted the size of post-sleep behavioural adaptation effects. Our data suggest that sleep prevented decay of adaptation in a way that is qualitatively different from the effects of reduced visual interference known as 'storage'. In the light of the well-established link between sleep and memory consolidation, our findings link the perceptual mechanisms of sensory adaptation--which are usually not considered to play a relevant role in mnemonic processes--with learning and memory, and at the same time reveal a new function of sleep in cognition. PMID:23986109

  16. Interactive solution-adaptive grid generation

    NASA Technical Reports Server (NTRS)

    Choo, Yung K.; Henderson, Todd L.

    1992-01-01

    TURBO-AD is an interactive solution-adaptive grid generation program under development. The program combines an interactive algebraic grid generation technique and a solution-adaptive grid generation technique into a single interactive solution-adaptive grid generation package. The control point form uses a sparse collection of control points to algebraically generate a field grid. This technique provides local grid control capability and is well suited to interactive work due to its speed and efficiency. A mapping from the physical domain to a parametric domain was used to improve difficulties that had been encountered near outwardly concave boundaries in the control point technique. Therefore, all grid modifications are performed on a unit square in the parametric domain, and the new adapted grid in the parametric domain is then mapped back to the physical domain. The grid adaptation is achieved by first adapting the control points to a numerical solution in the parametric domain using control sources obtained from flow properties. Then a new modified grid is generated from the adapted control net. This solution-adaptive grid generation process is efficient because the number of control points is much less than the number of grid points and the generation of a new grid from the adapted control net is an efficient algebraic process. TURBO-AD provides the user with both local and global grid controls.

  17. A holistic strategy for adaptive land management

    USGS Publications Warehouse

    Herrick, Jeffrey E.; Duniway, Michael C.; Pyke, David A.; Bestelmeyer, Brandon T.; Wills, Skye A.; Brown, Joel R.; Karl, Jason W.; Havstad, Kris M.

    2012-01-01

    Adaptive management is widely applied to natural resources management (Holling 1973; Walters and Holling 1990). Adaptive management can be generally defined as an iterative decision-making process that incorporates formulation of management objectives, actions designed to address these objectives, monitoring of results, and repeated adaptation of management until desired results are achieved (Brown and MacLeod 1996; Savory and Butterfield 1999). However, adaptive management is often criticized because very few projects ever complete more than one cycle, resulting in little adaptation and little knowledge gain (Lee 1999; Walters 2007). One significant criticism is that adaptive management is often used as a justification for undertaking actions with uncertain outcomes or as a surrogate for the development of specific, measurable indicators and monitoring programs (Lee 1999; Ruhl 2007).

  18. Auto adaptative laser welding

    SciTech Connect

    Coste, F.; Fabbro, R.; Douay, D.; Sabatier, L.; Lacote, D.

    1996-12-31

    The weld preparation in a laboratory environment for laser welding concerning edge misalignments, edge or gap preparation is no longer valid for industrial configurations where these different parameters are not accurately controlled. Therefore in that case, the achievement of consistent qualities of processing, requires the use of sensors for seam tracking and gap recognition. The authors discuss here preliminary experiments involving the use of these elements in order to pilot a scanning head in view of strongly reducing the precision requirements for gap preparation. This set-up is the first step in the development of an auto-adaptative device for laser welding which will be composed of seam tracking and recognition sensors, scanning laser head and a filler wire device.

  19. Adaptive compressive sensing camera

    NASA Astrophysics Data System (ADS)

    Hsu, Charles; Hsu, Ming K.; Cha, Jae; Iwamura, Tomo; Landa, Joseph; Nguyen, Charles; Szu, Harold

    2013-05-01

    We have embedded Adaptive Compressive Sensing (ACS) algorithm on Charge-Coupled-Device (CCD) camera based on the simplest concept that each pixel is a charge bucket, and the charges comes from Einstein photoelectric conversion effect. Applying the manufactory design principle, we only allow altering each working component at a minimum one step. We then simulated what would be such a camera can do for real world persistent surveillance taking into account of diurnal, all weather, and seasonal variations. The data storage has saved immensely, and the order of magnitude of saving is inversely proportional to target angular speed. We did design two new components of CCD camera. Due to the matured CMOS (Complementary metal-oxide-semiconductor) technology, the on-chip Sample and Hold (SAH) circuitry can be designed for a dual Photon Detector (PD) analog circuitry for changedetection that predicts skipping or going forward at a sufficient sampling frame rate. For an admitted frame, there is a purely random sparse matrix [Φ] which is implemented at each bucket pixel level the charge transport bias voltage toward its neighborhood buckets or not, and if not, it goes to the ground drainage. Since the snapshot image is not a video, we could not apply the usual MPEG video compression and Hoffman entropy codec as well as powerful WaveNet Wrapper on sensor level. We shall compare (i) Pre-Processing FFT and a threshold of significant Fourier mode components and inverse FFT to check PSNR; (ii) Post-Processing image recovery will be selectively done by CDT&D adaptive version of linear programming at L1 minimization and L2 similarity. For (ii) we need to determine in new frames selection by SAH circuitry (i) the degree of information (d.o.i) K(t) dictates the purely random linear sparse combination of measurement data a la [Φ]M,N M(t) = K(t) Log N(t).

  20. Adaptive evolution of molecular phenotypes

    NASA Astrophysics Data System (ADS)

    Held, Torsten; Nourmohammad, Armita; Lässig, Michael

    2014-09-01

    Molecular phenotypes link genomic information with organismic functions, fitness, and evolution. Quantitative traits are complex phenotypes that depend on multiple genomic loci. In this paper, we study the adaptive evolution of a quantitative trait under time-dependent selection, which arises from environmental changes or through fitness interactions with other co-evolving phenotypes. We analyze a model of trait evolution under mutations and genetic drift in a single-peak fitness seascape. The fitness peak performs a constrained random walk in the trait amplitude, which determines the time-dependent trait optimum in a given population. We derive analytical expressions for the distribution of the time-dependent trait divergence between populations and of the trait diversity within populations. Based on this solution, we develop a method to infer adaptive evolution of quantitative traits. Specifically, we show that the ratio of the average trait divergence and the diversity is a universal function of evolutionary time, which predicts the stabilizing strength and the driving rate of the fitness seascape. From an information-theoretic point of view, this function measures the macro-evolutionary entropy in a population ensemble, which determines the predictability of the evolutionary process. Our solution also quantifies two key characteristics of adapting populations: the cumulative fitness flux, which measures the total amount of adaptation, and the adaptive load, which is the fitness cost due to a population's lag behind the fitness peak.