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Sample records for adapted cluster-configuration interaction

  1. Symmetry adapted cluster-configuration interaction calculation of the photoelectron spectra of famous biological active steroids

    NASA Astrophysics Data System (ADS)

    Abyar, Fatemeh; Farrokhpour, Hossein

    2014-11-01

    The photoelectron spectra of some famous steroids, important in biology, were calculated in the gas phase. The selected steroids were 5α-androstane-3,11,17-trione, 4-androstane-3,11,17-trione, cortisol, cortisone, corticosterone, dexamethasone, estradiol and cholesterol. The calculations were performed employing symmetry-adapted cluster/configuration interaction (SAC-CI) method using the 6-311++G(2df,pd) basis set. The population ratios of conformers of each steroid were calculated and used for simulating the photoelectron spectrum of steroid. It was found that more than one conformer contribute to the photoelectron spectra of some steroids. To confirm the calculated photoelectron spectra, they compared with their corresponding experimental spectra. There were no experimental gas phase Hesbnd I photoelectron spectra for some of the steroids of this work in the literature and their calculated spectra can show a part of intrinsic characteristics of this molecules in the gas phase. The canonical molecular orbitals involved in the ionization of each steroid were calculated at the HF/6-311++g(d,p) level of theory. The spectral bands of each steroid were assigned by natural bonding orbital (NBO) calculations. Knowing the electronic structures of steroids helps us to understand their biological activities and find which sites of steroid become active when a modification is performing under a biological pathway.

  2. Dyson orbitals of N2O: electron momentum spectroscopy and symmetry adapted cluster-configuration interaction calculations.

    PubMed

    Miao, Y R; Ning, C G; Liu, K; Deng, J K

    2011-05-28

    Electron momentum spectroscopy and symmetry adapted cluster-configuration interaction (SAC-CI) theory were combined to study electron correlation effects in nitrous oxide molecule (N(2)O). The SAC-CI General-R method accurately reproduced the experimental ionization spectrum. This bench-marked method was also introduced for calculating the momentum distributions of N(2)O Dyson orbitals. Several calculated momentum distributions with different theoretical methods were compared with the high resolution experimental results. In the outer-valence region, Hartree-Fock (HF), density functional theory (DFT), and SAC-CI theory can well describe the experimental momentum distributions. SAC-CI presented a best performance among them. In the inner-valence region, HF and DFT cannot work well due to the severe breaking of the molecular orbital picture, while SAC-CI still produced an excellent description of experimental momentum profiles because it can accurately take into account electron correlations. Moreover, the thermally averaged calculation showed that the geometrical changes induced by the vibration at room temperature have no noticeable effects on momentum distribution of valence orbitals of N(2)O.

  3. Electronic spectra of azaindole and its excited state mixing: A symmetry-adapted cluster configuration interaction study

    NASA Astrophysics Data System (ADS)

    Arulmozhiraja, Sundaram; Coote, Michelle L.; Hasegawa, Jun-ya

    2015-11-01

    Electronic structures of azaindole were studied using symmetry-adapted cluster configuration interaction theory utilizing Dunning's cc-pVTZ basis set augmented with appropriate Rydberg spd functions on carbon and nitrogen atoms. The results obtained in the present study show good agreement with the available experimental values. Importantly, and contrary to previous theoretical studies, the excitation energy calculated for the important n-π∗ state agrees well with the experimental value. A recent study by Pratt and co-workers concluded that significant mixing of π-π∗ and n-π∗ states leads to major change in the magnitude and direction of the dipole moment of the upper state vibrational level in the 0,0 + 280 cm-1 band in the S1←S0 transition when compared to that of the zero-point level of the S1 state. The present study, however, shows that all the four lowest lying excited states, 1Lb π-π∗, 1La π-π∗, n-π∗, and π-σ∗, cross each other in one way or another, and hence, significant state mixing between them is likely. The upper state vibrational level in the 0,0 + 280 cm-1 band in the S1←S0 transition benefits from this four-state mixing and this can explain the change in magnitude and direction of the dipole moment of the S1 excited vibrational level. This multistate mixing, and especially the involvement of π-σ∗ state in mixing, could also provide a route for hydrogen atom detachment reactions. The electronic spectra of benzimidazole, a closely related system, were also investigated in the present study.

  4. Electronic spectra of azaindole and its excited state mixing: A symmetry-adapted cluster configuration interaction study

    SciTech Connect

    Arulmozhiraja, Sundaram Coote, Michelle L.; Hasegawa, Jun-ya

    2015-11-28

    Electronic structures of azaindole were studied using symmetry-adapted cluster configuration interaction theory utilizing Dunning’s cc-pVTZ basis set augmented with appropriate Rydberg spd functions on carbon and nitrogen atoms. The results obtained in the present study show good agreement with the available experimental values. Importantly, and contrary to previous theoretical studies, the excitation energy calculated for the important n–π{sup ∗} state agrees well with the experimental value. A recent study by Pratt and co-workers concluded that significant mixing of π-π{sup ∗} and n-π{sup ∗} states leads to major change in the magnitude and direction of the dipole moment of the upper state vibrational level in the 0,0 + 280 cm{sup −1} band in the S{sub 1}←S{sub 0} transition when compared to that of the zero-point level of the S{sub 1} state. The present study, however, shows that all the four lowest lying excited states, {sup 1}L{sub b} π-π{sup ∗}, {sup 1}L{sub a} π-π{sup ∗}, n-π{sup ∗}, and π-σ{sup ∗}, cross each other in one way or another, and hence, significant state mixing between them is likely. The upper state vibrational level in the 0,0 + 280 cm{sup −1} band in the S{sub 1}←S{sub 0} transition benefits from this four-state mixing and this can explain the change in magnitude and direction of the dipole moment of the S{sub 1} excited vibrational level. This multistate mixing, and especially the involvement of π-σ{sup ∗} state in mixing, could also provide a route for hydrogen atom detachment reactions. The electronic spectra of benzimidazole, a closely related system, were also investigated in the present study.

  5. Nonequilibrium solvation for vertical photoemission and photoabsorption processes using the symmetry-adapted cluster-configuration interaction method in the polarizable continuum model

    NASA Astrophysics Data System (ADS)

    Fukuda, Ryoichi; Ehara, Masahiro; Nakatsuji, Hiroshi; Cammi, Roberto

    2011-03-01

    In this paper, we present the theory and implementation of a nonequilibrium solvation model for the symmetry-adapted cluster (SAC) and symmetry-adapted cluster-configuration interaction (SAC-CI) method in the polarizable continuum model. For nonequilibrium solvation, we adopted the Pekar partition scheme in which solvent charges are divided into dynamical and inertial components. With this nonequilibrium solvation scheme, a vertical transition from an initial state to a final state may be described as follows: the initial state is described by equilibrium solvation, while in the final state, the inertial component remains in the solvation for the initial state; the dynamical component will be calculated self-consistently for the final state. The present method was applied to the vertical photoemission and absorption of s-trans acrolein and methylenecyclopropene. The effect of nonequilibrium solvation was significant for a polar solvent.

  6. Outer- and inner-valence satellites of carbon dioxide: electron momentum spectroscopy compared with symmetry-adapted-cluster configuration interaction general-R calculations.

    PubMed

    Tian, QiGuo; Yang, Jing; Shi, YuFeng; Shan, Xu; Chen, XiangJun

    2012-03-01

    The extensive study of outer- and inner-valence satellites of carbon dioxide by electron momentum spectroscopy is reported. The experiments have been performed using a high-sensitivity electron momentum spectrometer employing non-coplanar symmetric geometry at impact energy of about 1200 eV. Binding energy spectrum up to 50 eV, above the first double ionization threshold (~37.3 eV), is presented. Four main peaks and twelve satellites have been identified including four embedded in the double ionization continuum, among which the two beyond 42 eV are observed for the first time. High accuracy symmetry-adapted-cluster configuration interaction general-R calculation with aug-cc-pVTZ basis sets has also been performed and the result is in line with the experimental ionization spectrum except the relative intensities for some of the satellites in inner-valence region. The experimental momentum profiles for both the main ionization transitions and satellites have been obtained and compared with theoretical calculations by HF and B3LYP methods with 6-311++G∗ and aug-cc-pVTZ basis sets. Through comparison, the detailed assignments of the satellite bands have been achieved and the pole strengths for the relevant shake-up transitions are determined experimentally for the first time.

  7. Electronic excitation spectra of molecules in solution calculated using the symmetry-adapted cluster-configuration interaction method in the polarizable continuum model with perturbative approach.

    PubMed

    Fukuda, Ryoichi; Ehara, Masahiro; Cammi, Roberto

    2014-02-14

    A perturbative approximation of the state specific polarizable continuum model (PCM) symmetry-adapted cluster-configuration interaction (SAC-CI) method is proposed for efficient calculations of the electronic excitations and absorption spectra of molecules in solutions. This first-order PCM SAC-CI method considers the solvent effects on the energies of excited states up to the first-order with using the zeroth-order wavefunctions. This method can avoid the costly iterative procedure of the self-consistent reaction field calculations. The first-order PCM SAC-CI calculations well reproduce the results obtained by the iterative method for various types of excitations of molecules in polar and nonpolar solvents. The first-order contribution is significant for the excitation energies. The results obtained by the zeroth-order PCM SAC-CI, which considers the fixed ground-state reaction field for the excited-state calculations, are deviated from the results by the iterative method about 0.1 eV, and the zeroth-order PCM SAC-CI cannot predict even the direction of solvent shifts in n-hexane for many cases. The first-order PCM SAC-CI is applied to studying the solvatochromisms of (2,2(')-bipyridine)tetracarbonyltungsten [W(CO)4(bpy), bpy = 2,2(')-bipyridine] and bis(pentacarbonyltungsten)pyrazine [(OC)5W(pyz)W(CO)5, pyz = pyrazine]. The SAC-CI calculations reveal the detailed character of the excited states and the mechanisms of solvent shifts. The energies of metal to ligand charge transfer states are significantly sensitive to solvents. The first-order PCM SAC-CI well reproduces the observed absorption spectra of the tungsten carbonyl complexes in several solvents.

  8. Electronic excitation spectra of molecules in solution calculated using the symmetry-adapted cluster-configuration interaction method in the polarizable continuum model with perturbative approach

    NASA Astrophysics Data System (ADS)

    Fukuda, Ryoichi; Ehara, Masahiro; Cammi, Roberto

    2014-02-01

    A perturbative approximation of the state specific polarizable continuum model (PCM) symmetry-adapted cluster-configuration interaction (SAC-CI) method is proposed for efficient calculations of the electronic excitations and absorption spectra of molecules in solutions. This first-order PCM SAC-CI method considers the solvent effects on the energies of excited states up to the first-order with using the zeroth-order wavefunctions. This method can avoid the costly iterative procedure of the self-consistent reaction field calculations. The first-order PCM SAC-CI calculations well reproduce the results obtained by the iterative method for various types of excitations of molecules in polar and nonpolar solvents. The first-order contribution is significant for the excitation energies. The results obtained by the zeroth-order PCM SAC-CI, which considers the fixed ground-state reaction field for the excited-state calculations, are deviated from the results by the iterative method about 0.1 eV, and the zeroth-order PCM SAC-CI cannot predict even the direction of solvent shifts in n-hexane for many cases. The first-order PCM SAC-CI is applied to studying the solvatochromisms of (2,2'-bipyridine)tetracarbonyltungsten [W(CO)4(bpy), bpy = 2,2'-bipyridine] and bis(pentacarbonyltungsten)pyrazine [(OC)5W(pyz)W(CO)5, pyz = pyrazine]. The SAC-CI calculations reveal the detailed character of the excited states and the mechanisms of solvent shifts. The energies of metal to ligand charge transfer states are significantly sensitive to solvents. The first-order PCM SAC-CI well reproduces the observed absorption spectra of the tungsten carbonyl complexes in several solvents.

  9. Electronic excitation spectra of molecules in solution calculated using the symmetry-adapted cluster-configuration interaction method in the polarizable continuum model with perturbative approach

    SciTech Connect

    Fukuda, Ryoichi Ehara, Masahiro; Cammi, Roberto

    2014-02-14

    A perturbative approximation of the state specific polarizable continuum model (PCM) symmetry-adapted cluster-configuration interaction (SAC-CI) method is proposed for efficient calculations of the electronic excitations and absorption spectra of molecules in solutions. This first-order PCM SAC-CI method considers the solvent effects on the energies of excited states up to the first-order with using the zeroth-order wavefunctions. This method can avoid the costly iterative procedure of the self-consistent reaction field calculations. The first-order PCM SAC-CI calculations well reproduce the results obtained by the iterative method for various types of excitations of molecules in polar and nonpolar solvents. The first-order contribution is significant for the excitation energies. The results obtained by the zeroth-order PCM SAC-CI, which considers the fixed ground-state reaction field for the excited-state calculations, are deviated from the results by the iterative method about 0.1 eV, and the zeroth-order PCM SAC-CI cannot predict even the direction of solvent shifts in n-hexane for many cases. The first-order PCM SAC-CI is applied to studying the solvatochromisms of (2,2{sup ′}-bipyridine)tetracarbonyltungsten [W(CO){sub 4}(bpy), bpy = 2,2{sup ′}-bipyridine] and bis(pentacarbonyltungsten)pyrazine [(OC){sub 5}W(pyz)W(CO){sub 5}, pyz = pyrazine]. The SAC-CI calculations reveal the detailed character of the excited states and the mechanisms of solvent shifts. The energies of metal to ligand charge transfer states are significantly sensitive to solvents. The first-order PCM SAC-CI well reproduces the observed absorption spectra of the tungsten carbonyl complexes in several solvents.

  10. Symmetry-adapted-cluster configuration-interaction and equation-of-motion coupled-cluster studies of electronically excited states of copper tetrachloride and copper tetrabromide dianions

    NASA Astrophysics Data System (ADS)

    Ehara, Masahiro; Piecuch, Piotr; Lutz, Jesse J.; Gour, Jeffrey R.

    2012-05-01

    The valence excitation spectra of the copper tetrachloride and copper tetrabromide open-shell dianions, CuCl42- and CuBr42-, respectively, are investigated by a variety of symmetry-adapted-cluster configuration-interaction (SAC-CI) and equation-of-motion coupled-cluster (EOMCC) methods. The valence excited states of the CuCl42- and CuBr42- species that correspond to transitions from doubly occupied molecular orbitals (MOs) to a singly occupied MO (SOMO), for which experimental spectra are available, are examined with the ionized (IP) variants of the SAC-CI and EOMCC methods. The higher-energy excited states of CuCl42- and CuBr42- that correspond to transitions from SOMO to unoccupied MOs, which have not been characterized experimentally, are determined using the electron-attached (EA) SAC-CI and EOMCC approaches. An emphasis is placed on the scalar relativistic SAC-CI and EOMCC calculations based on the spin-free part of the second-order Douglass-Kroll-Hess Hamiltonian (DKH2) and on a comparison of the results of the IP and EA SAC-CI and EOMCC calculations with up to 2-hole-1-particle (2h-1p) and 2-particle-1-hole (2p-1h) excitations, referred to as the IP-SAC-CI SD-R and IP-EOMCCSD(2h-1p) methods in the IP case and EA-SAC-CI SD-R and EA-EOMCCSD(2p-1h) approaches in the EA case, with those obtained with the higher-level IP-EOMCC and EA-EOMCC theories with up to 3-hole-2-particle (3h-2p) and 3-particle-2-hole (3p-2h) excitations treated via active orbitals, abbreviated as IP-EOMCCSD(3h-2p) and EA-EOMCCSD(3p-2h), respectively, as well as with the available experimental data. It is demonstrated that all of the employed DKH2-based IP-SAC-CI and IP-EOMCC methods offer a reliable description of the valence excited states of the CuCl42- and CuBr42- complexes that correspond to transitions from doubly occupied MOs to SOMO, accurately reproducing the observed UV-vis absorption spectra in both peak positions and intensities, which enables a rigorous assignment of the

  11. Symmetry-adapted cluster and symmetry-adapted cluster-configuration interaction method in the polarizable continuum model: Theory of the solvent effect on the electronic excitation of molecules in solution

    NASA Astrophysics Data System (ADS)

    Cammi, Roberto; Fukuda, Ryoichi; Ehara, Masahiro; Nakatsuji, Hiroshi

    2010-07-01

    In this paper we present the theory and implementation of the symmetry-adapted cluster (SAC) and symmetry-adapted cluster-configuration interaction (SAC-CI) method, including the solvent effect, using the polarizable continuum model (PCM). The PCM and SAC/SAC-CI were consistently combined in terms of the energy functional formalism. The excitation energies were calculated by means of the state-specific approach, the advantage of which over the linear-response approach has been shown. The single-point energy calculation and its analytical energy derivatives are presented and implemented, where the free-energy and its derivatives are evaluated because of the presence of solute-solvent interactions. We have applied this method to s-trans-acrolein and metylenecyclopropene of their electronic excitation in solution. The molecular geometries in the ground and excited states were optimized in vacuum and in solution, and both the vertical and adiabatic excitations were studied. The PCM-SAC/SAC-CI reproduced the known trend of the solvent effect on the vertical excitation energies but the shift values were underestimated. The excited state geometry in planar and nonplanar conformations was investigated. The importance of using state-specific methods was shown for the solvent effect on the optimized geometry in the excited state. The mechanism of the solvent effect is discussed in terms of the Mulliken charges and electronic dipole moment.

  12. Valence ionized states of iron pentacarbonyl and eta5-cyclopentadienyl cobalt dicarbonyl studied by symmetry-adapted cluster-configuration interaction calculation and collision-energy resolved Penning ionization electron spectroscopy.

    PubMed

    Fukuda, Ryoichi; Ehara, Masahiro; Nakatsuji, Hiroshi; Kishimoto, Naoki; Ohno, Koichi

    2010-02-28

    Valence ionized states of iron pentacarbonyl Fe(CO)(5) and eta(5)-cyclopentadienyl cobalt dicarbonyl Co(eta(5)-C(5)H(5))(CO)(2) have been studied by ultraviolet photoelectron spectroscopy, two-dimensional Penning ionization electron spectroscopy (2D-PIES), and symmetry-adapted cluster-configuration interaction calculations. Theory provided reliable assignments for the complex ionization spectra of these molecules, which have metal-carbonyl bonds. Theoretical ionization energies agreed well with experimental observations and the calculated wave functions could explain the relative intensities of PIES spectra. The collision-energy dependence of partial ionization cross sections (CEDPICS) was obtained by 2D-PIES. To interpret these CEDPICS, the interaction potentials between the molecules and a Li atom were examined in several coordinates by calculations. The relation between the slope of the CEDPICS and the electronic structure of the ionized states, such as molecular symmetry and the spatial distribution of ionizing orbitals, was analyzed. In Fe(CO)(5), an attractive interaction was obtained for the equatorial CO, while the interaction for the axial CO direction was repulsive. For Co(eta(5)-C(5)H(5))(CO)(2), the interaction potential in the direction of both Co-C-O and Co-Cp ring was attractive. These anisotropic interactions and ionizing orbital distributions consistently explain the relative slopes of the CEDPICS.

  13. Calculation of Dyson orbitals using a symmetry-adapted-cluster configuration-interaction method for electron momentum spectroscopy: N{sub 2} and H{sub 2}O

    SciTech Connect

    Miao, Y. R.; Ning, C. G.; Deng, J. K.

    2011-06-15

    The symmetry-adapted-cluster (SAC) configuration-interaction (CI) theory was introduced to interpret the non-coplanar symmetric (e,2e) results. Dyson orbitals derived from the bench-marked SAC CI general-R method were utilized for computing the electron momentum distributions. The corresponding excitation energies and spectroscopic factors can be used to reproduce the ionization spectra. The implementation was demonstrated by examples of N{sub 2} and H{sub 2}O. The electron momentum distributions calculated using SAC CI method were compared with recent experimental results, as well as the Hartree-Fock and density-functional-theory calculations. The SAC CI method gave the best performance on the description of the experimental momentum distributions. It was found that the electron momentum distributions of Dyson orbitals related to the satellite lines can be notably different from those of their parent orbitals due to the electron correlation in the initial target states. Present work demonstrated that the SAC CI theory is a very useful and accurate tool for interpreting high-resolution electron momentum spectroscopy results.

  14. Convalescing Cluster Configuration Using a Superlative Framework

    PubMed Central

    Sabitha, R.; Karthik, S.

    2015-01-01

    Competent data mining methods are vital to discover knowledge from databases which are built as a result of enormous growth of data. Various techniques of data mining are applied to obtain knowledge from these databases. Data clustering is one such descriptive data mining technique which guides in partitioning data objects into disjoint segments. K-means algorithm is a versatile algorithm among the various approaches used in data clustering. The algorithm and its diverse adaptation methods suffer certain problems in their performance. To overcome these issues a superlative algorithm has been proposed in this paper to perform data clustering. The specific feature of the proposed algorithm is discretizing the dataset, thereby improving the accuracy of clustering, and also adopting the binary search initialization method to generate cluster centroids. The generated centroids are fed as input to K-means approach which iteratively segments the data objects into respective clusters. The clustered results are measured for accuracy and validity. Experiments conducted by testing the approach on datasets from the UC Irvine Machine Learning Repository evidently show that the accuracy and validity measure is higher than the other two approaches, namely, simple K-means and Binary Search method. Thus, the proposed approach proves that discretization process will improve the efficacy of descriptive data mining tasks. PMID:26543895

  15. 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.

  16. Interactive solution-adaptive grid generation procedure

    NASA Technical Reports Server (NTRS)

    Henderson, Todd L.; Choo, Yung K.; Lee, Ki D.

    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 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 encountered near outwardly concave boundaries in the control point technique. Therefore, all grid modifications are performed on the unit square in the parametric domain, and the new adapted grid is then mapped back to the physical domain. The grid adaption is achieved by adapting the control points to a numerical solution in the parametric domain using control sources obtained from the flow properties. Then a new modified grid is generated from the adapted control net. This process is efficient because the number of control points is much less than the number of grid points and the generation of the grid is an efficient algebraic process. TURBO-AD provides the user with both local and global controls.

  17. Biotic interactions govern genetic adaptation to toxicants.

    PubMed

    Becker, Jeremias Martin; Liess, Matthias

    2015-05-01

    The genetic recovery of resistant populations released from pesticide exposure is accelerated by the presence of environmental stressors. By contrast, the relevance of environmental stressors for the spread of resistance during pesticide exposure has not been studied. Moreover, the consequences of interactions between different stressors have not been considered. Here we show that stress through intraspecific competition accelerates microevolution, because it enhances fitness differences between adapted and non-adapted individuals. By contrast, stress through interspecific competition or predation reduces intraspecific competition and thereby delays microevolution. This was demonstrated in mosquito populations (Culex quinquefasciatus) that were exposed to the pesticide chlorpyrifos. Non-selective predation through harvesting and interspecific competition with Daphnia magna delayed the selection for individuals carrying the ace-1(R) resistance allele. Under non-toxic conditions, susceptible individuals without ace-1(R) prevailed. Likewise, predation delayed the reverse adaptation of the populations to a non-toxic environment, while the effect of interspecific competition was not significant. Applying a simulation model, we further identified how microevolution is generally determined by the type and degree of competition and predation. We infer that interactions with other species-especially strong in ecosystems with high biodiversity-can delay the development of pesticide resistance.

  18. Impedance adaptation for optimal robot-environment interaction

    NASA Astrophysics Data System (ADS)

    Ge, Shuzhi Sam; Li, Yanan; Wang, Chen

    2014-02-01

    In this paper, impedance adaptation is investigated for robots interacting with unknown environments. Impedance control is employed for the physical interaction between robots and environments, subject to unknown and uncertain environments dynamics. The unknown environments are described as linear systems with unknown dynamics, based on which the desired impedance model is obtained. A cost function that measures the tracking error and interaction force is defined, and the critical impedance parameters are found to minimise it. Without requiring the information of the environments dynamics, the proposed impedance adaptation is feasible in a large number of applications where robots physically interact with unknown environments. The validity of the proposed method is verified through simulation studies.

  19. Epistatically Interacting Substitutions Are Enriched during Adaptive Protein Evolution

    PubMed Central

    Gong, Lizhi Ian; Bloom, Jesse D.

    2014-01-01

    Most experimental studies of epistasis in evolution have focused on adaptive changes—but adaptation accounts for only a portion of total evolutionary change. Are the patterns of epistasis during adaptation representative of evolution more broadly? We address this question by examining a pair of protein homologs, of which only one is subject to a well-defined pressure for adaptive change. Specifically, we compare the nucleoproteins from human and swine influenza. Human influenza is under continual selection to evade recognition by acquired immune memory, while swine influenza experiences less such selection due to the fact that pigs are less likely to be infected with influenza repeatedly in a lifetime. Mutations in some types of immune epitopes are therefore much more strongly adaptive to human than swine influenza—here we focus on epitopes targeted by human cytotoxic T lymphocytes. The nucleoproteins of human and swine influenza possess nearly identical numbers of such epitopes. However, mutations in these epitopes are fixed significantly more frequently in human than in swine influenza, presumably because these epitope mutations are adaptive only to human influenza. Experimentally, we find that epistatically constrained mutations are fixed only in the adaptively evolving human influenza lineage, where they occur at sites that are enriched in epitopes. Overall, our results demonstrate that epistatically interacting substitutions are enriched during adaptation, suggesting that the prevalence of epistasis is dependent on the underlying evolutionary forces at play. PMID:24811236

  20. Multifaceted interactions between adaptive immunity and the central nervous system.

    PubMed

    Kipnis, Jonathan

    2016-08-19

    Neuroimmunologists seek to understand the interactions between the central nervous system (CNS) and the immune system, both under homeostatic conditions and in diseases. Unanswered questions include those relating to the diversity and specificity of the meningeal T cell repertoire; the routes taken by immune cells that patrol the meninges under healthy conditions and invade the parenchyma during pathology; the opposing effects (beneficial or detrimental) of these cells on CNS function; the role of immune cells after CNS injury; and the evolutionary link between the two systems, resulting in their tight interaction and interdependence. This Review summarizes the current standing of and challenging questions related to interactions between adaptive immunity and the CNS and considers the possible directions in which these aspects of neuroimmunology will be heading over the next decade. PMID:27540163

  1. Block-adaptive quantum mechanics: an adaptive divide-and-conquer approach to interactive quantum chemistry.

    PubMed

    Bosson, Maël; Grudinin, Sergei; Redon, Stephane

    2013-03-01

    We present a novel Block-Adaptive Quantum Mechanics (BAQM) approach to interactive quantum chemistry. Although quantum chemistry models are known to be computationally demanding, we achieve interactive rates by focusing computational resources on the most active parts of the system. BAQM is based on a divide-and-conquer technique and constrains some nucleus positions and some electronic degrees of freedom on the fly to simplify the simulation. As a result, each time step may be performed significantly faster, which in turn may accelerate attraction to the neighboring local minima. By applying our approach to the nonself-consistent Atom Superposition and Electron Delocalization Molecular Orbital theory, we demonstrate interactive rates and efficient virtual prototyping for systems containing more than a thousand of atoms on a standard desktop computer.

  2. Adaptivity and smart algorithms for fluid-structure interaction

    NASA Technical Reports Server (NTRS)

    Oden, J. Tinsley

    1990-01-01

    This paper reviews new approaches in CFD which have the potential for significantly increasing current capabilities of modeling complex flow phenomena and of treating difficult problems in fluid-structure interaction. These approaches are based on the notions of adaptive methods and smart algorithms, which use instantaneous measures of the quality and other features of the numerical flowfields as a basis for making changes in the structure of the computational grid and of algorithms designed to function on the grid. The application of these new techniques to several problem classes are addressed, including problems with moving boundaries, fluid-structure interaction in high-speed turbine flows, flow in domains with receding boundaries, and related problems.

  3. Controller-structure interaction compensation using adaptive residual mode filters

    NASA Technical Reports Server (NTRS)

    Davidson, Roger A.; Balas, Mark J.

    1990-01-01

    It is not feasible to construct controllers for large space structures or large scale systems (LSS's) which are of the same order as the structures. The complexity of the dynamics of these systems is such that full knowledge of its behavior cannot by processed by today's controller design methods. The controller for system performance of such a system is therefore based on a much smaller reduced-order model (ROM). Unfortunately, the interaction between the LSS and the ROM-based controller can produce instabilities in the closed-loop system due to the unmodeled dynamics of the LSS. Residual mode filters (RMF's) allow the systematic removal of these instabilities in a matter which does not require a redesign of the controller. In addition RMF's have a strong theoretical basis. As simple first- or second-order filters, the RMF CSI compensation technique is at once modular, simple and highly effective. RMF compensation requires knowledge of the dynamics of the system modes which resulted in the previous closed-loop instabilities (the residual modes), but this information is sometimes known imperfectly. An adaptive, self-tuning RMF design, which compensates for uncertainty in the frequency of the residual mode, has been simulated using continuous-time and discrete-time models of a flexible robot manipulator. Work has also been completed on the discrete-time experimental implementation on the Martin Marietta flexible robot manipulator experiment. This paper will present the results of that work on adaptive, self-tuning RMF's, and will clearly show the advantage of this adaptive compensation technique for controller-structure interaction (CSI) instabilities in actively-controlled LSS's.

  4. Adaptive information interactive mechanism for multi-UAV visual navigation

    NASA Astrophysics Data System (ADS)

    Liu, Hui; Dai, Qionghai

    2012-06-01

    Multi-unmanned aerial vehicle (UAV) cooperative communication for visual navigation has recently generated significant concern. It has large amounts of visual information to be transmitted and processed among UAVs with realtime requirements. And the UAV clusters have self-organized, time-varying and high dynamic characteristics. Considering the above conditions, we propose an adaptive information interactive mechanism (AIIM) for multi-UAV visual navigation. In the mechanism, the function modules for UAV inter-communication interface are designed, the mobility-based link lifetime is established and the information interactive protocol is presented. Thus we combine the mobility of UAVs with the corresponding communication requirements to make effective information interaction for UAVs. Task-oriented distributed control is adopted to improve the collaboration flexibility in the multi-UAV visual navigation system. In order to timely obtain the necessary visual information, each UAV can cooperate with other relevant UAVs which meet some certain terms such as situation, task or environmental conditions. Simulation results are presented to show the validity of the proposed mechanism in terms of end-to-end delay and links stability.

  5. Amygdala-prefrontal interactions in (mal)adaptive learning.

    PubMed

    Likhtik, Ekaterina; Paz, Rony

    2015-03-01

    The study of neurobiological mechanisms underlying anxiety disorders has been shaped by learning models that frame anxiety as maladaptive learning. Pavlovian conditioning and extinction are particularly influential in defining learning stages that can account for symptoms of anxiety disorders. Recently, dynamic and task related communication between the basolateral complex of the amygdala (BLA) and the medial prefrontal cortex (mPFC) has emerged as a crucial aspect of successful evaluation of threat and safety. Ongoing patterns of neural signaling within the mPFC-BLA circuit during encoding, expression and extinction of adaptive learning are reviewed. The mechanisms whereby deficient mPFC-BLA interactions can lead to generalized fear and anxiety are discussed in learned and innate anxiety. Findings with cross-species validity are emphasized.

  6. Adaptive multigrid domain decomposition solutions for viscous interacting flows

    NASA Technical Reports Server (NTRS)

    Rubin, Stanley G.; Srinivasan, Kumar

    1992-01-01

    Several viscous incompressible flows with strong pressure interaction and/or axial flow reversal are considered with an adaptive multigrid domain decomposition procedure. Specific examples include the triple deck structure surrounding the trailing edge of a flat plate, the flow recirculation in a trough geometry, and the flow in a rearward facing step channel. For the latter case, there are multiple recirculation zones, of different character, for laminar and turbulent flow conditions. A pressure-based form of flux-vector splitting is applied to the Navier-Stokes equations, which are represented by an implicit lowest-order reduced Navier-Stokes (RNS) system and a purely diffusive, higher-order, deferred-corrector. A trapezoidal or box-like form of discretization insures that all mass conservation properties are satisfied at interfacial and outflow boundaries, even for this primitive-variable, non-staggered grid computation.

  7. Adaptive emotional memory: the key hippocampal-amygdalar interaction.

    PubMed

    Desmedt, Aline; Marighetto, Aline; Richter-Levin, Gal; Calandreau, Ludovic

    2015-01-01

    For centuries philosophical and clinical studies have emphasized a fundamental dichotomy between emotion and cognition, as, for instance, between behavioral/emotional memory and explicit/representative memory. However, the last few decades cognitive neuroscience have highlighted data indicating that emotion and cognition, as well as their underlying neural networks, are in fact in close interaction. First, it turns out that emotion can serve cognition, as exemplified by its critical contribution to decision-making or to the enhancement of episodic memory. Second, it is also observed that reciprocally cognitive processes as reasoning, conscious appraisal or explicit representation of events can modulate emotional responses, like promoting or reducing fear. Third, neurobiological data indicate that reciprocal amygdalar-hippocampal influences underlie such mutual regulation of emotion and cognition. While supporting this view, the present review discusses experimental data, obtained in rodents, indicating that the hippocampal and amygdalar systems not only regulate each other and their functional outcomes, but also qualify specific emotional memory representations through specific activations and interactions. Specifically, we review consistent behavioral, electrophysiological, pharmacological, biochemical and imaging data unveiling a direct contribution of both the amygdala and hippocampal-septal system to the identification of the predictor of a threat in different situations of fear conditioning. Our suggestion is that these two brain systems and their interplay determine the selection of relevant emotional stimuli, thereby contributing to the adaptive value of emotional memory. Hence, beyond the mutual quantitative regulation of these two brain systems described so far, we develop the idea that different activations of the hippocampus and amygdala, leading to specific configurations of neural activity, qualitatively impact the formation of emotional memory

  8. Spatiotemporal Movement Planning and Rapid Adaptation for Manual Interaction

    PubMed Central

    Huber, Markus; Kupferberg, Aleksandra; Lenz, Claus; Knoll, Alois; Brandt, Thomas; Glasauer, Stefan

    2013-01-01

    Many everyday tasks require the ability of two or more individuals to coordinate their actions with others to increase efficiency. Such an increase in efficiency can often be observed even after only very few trials. Previous work suggests that such behavioral adaptation can be explained within a probabilistic framework that integrates sensory input and prior experience. Even though higher cognitive abilities such as intention recognition have been described as probabilistic estimation depending on an internal model of the other agent, it is not clear whether much simpler daily interaction is consistent with a probabilistic framework. Here, we investigate whether the mechanisms underlying efficient coordination during manual interactions can be understood as probabilistic optimization. For this purpose we studied in several experiments a simple manual handover task concentrating on the action of the receiver. We found that the duration until the receiver reacts to the handover decreases over trials, but strongly depends on the position of the handover. We then replaced the human deliverer by different types of robots to further investigate the influence of the delivering movement on the reaction of the receiver. Durations were found to depend on movement kinematics and the robot’s joint configuration. Modeling the task was based on the assumption that the receiver’s decision to act is based on the accumulated evidence for a specific handover position. The evidence for this handover position is collected from observing the hand movement of the deliverer over time and, if appropriate, by integrating this sensory likelihood with prior expectation that is updated over trials. The close match of model simulations and experimental results shows that the efficiency of handover coordination can be explained by an adaptive probabilistic fusion of a-priori expectation and online estimation. PMID:23724112

  9. An efficient computational scheme for electronic excitation spectra of molecules in solution using the symmetry-adapted cluster–configuration interaction method: The accuracy of excitation energies and intuitive charge-transfer indices

    SciTech Connect

    Fukuda, Ryoichi Ehara, Masahiro

    2014-10-21

    Solvent effects on electronic excitation spectra are considerable in many situations; therefore, we propose an efficient and reliable computational scheme that is based on the symmetry-adapted cluster-configuration interaction (SAC-CI) method and the polarizable continuum model (PCM) for describing electronic excitations in solution. The new scheme combines the recently proposed first-order PCM SAC-CI method with the PTE (perturbation theory at the energy level) PCM SAC scheme. This is essentially equivalent to the usual SAC and SAC-CI computations with using the PCM Hartree-Fock orbital and integrals, except for the additional correction terms that represent solute-solvent interactions. The test calculations demonstrate that the present method is a very good approximation of the more costly iterative PCM SAC-CI method for excitation energies of closed-shell molecules in their equilibrium geometry. This method provides very accurate values of electric dipole moments but is insufficient for describing the charge-transfer (CT) indices in polar solvent. The present method accurately reproduces the absorption spectra and their solvatochromism of push-pull type 2,2{sup ′}-bithiophene molecules. Significant solvent and substituent effects on these molecules are intuitively visualized using the CT indices. The present method is the simplest and theoretically consistent extension of SAC-CI method for including PCM environment, and therefore, it is useful for theoretical and computational spectroscopy.

  10. [Cyclic interactions in the processes of adaptation regulation].

    PubMed

    Vasilevskiĭ, N N; Aleksandrova, Zh G; Suvorov, N B

    1989-01-01

    Human adaptation is characterised by essential changes of functional systems biorhythms which appears in the changes of their components' sequence and in the dynamics of biorhythmological cycles. These objective laws, having been described for human EEG, allow to discern clearly the individual-typological peculiarities in man with different stages of adaptation, the same as the adaptive shifts during long-term influence of external factors. The cyclic course of adaptative processes is regarded as a measure of adaptability. With the help of biorhythmic multitude the memory is constantly satiated from the brain by discrete portions of adaptogenic information, which prevents the natural processes of the memory disintegration. PMID:2816008

  11. Communication Adaptability and Interaction Involvement as Predictors of Cross-Cultural Adjustment.

    ERIC Educational Resources Information Center

    Chen, Guo-Ming

    A study of 142 foreign college students staying in the United States examined the effects of communication adaptability and interaction involvement on cross-cultural adjustment. Further testing was conducted to investigate which of the components of communication adaptability and interaction involvement best predicted the dimensions of…

  12. Analyzing Katana referral hospital as a complex adaptive system: agents, interactions and adaptation to a changing environment.

    PubMed

    Karemere, Hermès; Ribesse, Nathalie; Marchal, Bruno; Macq, Jean

    2015-01-01

    This study deals with the adaptation of Katana referral hospital in Eastern Democratic Republic of Congo in a changing environment that is affected for more than a decade by intermittent armed conflicts. His objective is to generate theoretical proposals for addressing differently the analysis of hospitals governance in the aims to assess their performance and how to improve that performance. The methodology applied approach uses a case study using mixed methods ( qualitative and quantitative) for data collection. It uses (1) hospital data to measure the output of hospitals, (2) literature review to identify among others, events and interventions recorded in the history of hospital during the study period and (3) information from individual interviews to validate the interpretation of the results of the previous two sources of data and understand the responsiveness of management team referral hospital during times of change. The study brings four theoretical propositions: (1) Interaction between key agents is a positive force driving adaptation if the actors share a same vision, (2) The strength of the interaction between agents is largely based on the nature of institutional arrangements, which in turn are shaped by the actors themselves, (3) The owner and the management team play a decisive role in the implementation of effective institutional arrangements and establishment of positive interactions between agents, (4) The analysis of recipient population's perception of health services provided allow to better tailor and adapt the health services offer to the population's needs and expectations. Research shows that it isn't enough just to provide support (financial and technical), to manage a hospital for operate and adapt to a changing environment but must still animate, considering that it is a complex adaptive system and that this animation is nothing other than the induction of a positive interaction between agents.

  13. Effective Levels of Adaptation to Different Types of Users in Interactive Museum Systems.

    ERIC Educational Resources Information Center

    Paterno, F.; Mancini, C.

    2000-01-01

    Discusses user interaction with museum application interfaces and emphasizes the importance of adaptable and adaptive interfaces to meet differing user needs. Considers levels of support that can be given to different users during navigation of museum hypermedia information, using examples from the Web site for the Marble Museum (Italy).…

  14. Smart Swarms of Bacteria-Inspired Agents with Performance Adaptable Interactions

    PubMed Central

    Shklarsh, Adi; Ariel, Gil; Schneidman, Elad; Ben-Jacob, Eshel

    2011-01-01

    Collective navigation and swarming have been studied in animal groups, such as fish schools, bird flocks, bacteria, and slime molds. Computer modeling has shown that collective behavior of simple agents can result from simple interactions between the agents, which include short range repulsion, intermediate range alignment, and long range attraction. Here we study collective navigation of bacteria-inspired smart agents in complex terrains, with adaptive interactions that depend on performance. More specifically, each agent adjusts its interactions with the other agents according to its local environment – by decreasing the peers' influence while navigating in a beneficial direction, and increasing it otherwise. We show that inclusion of such performance dependent adaptable interactions significantly improves the collective swarming performance, leading to highly efficient navigation, especially in complex terrains. Notably, to afford such adaptable interactions, each modeled agent requires only simple computational capabilities with short-term memory, which can easily be implemented in simple swarming robots. PMID:21980274

  15. Long-range Acoustic Interactions in Insect Swarms: An Adaptive Gravity Model

    NASA Astrophysics Data System (ADS)

    Gorbonos, Dan; Ianconescu, Reuven; Puckett, James G.; Ni, Rui; Ouellette, Nicholas T.; Gov, Nir S.

    The collective motion of groups of animals emerges from the net effect of the interactions between individual members of the group. In many cases, such as birds, fish, or ungulates, these interactions are mediated by sensory stimuli that predominantly arise from nearby neighbors. But not all stimuli in animal groups are short range. Here, we consider mating swarms of midges, which interact primarily via long-range acoustic stimuli. We exploit the similarity in form between the decay of acoustic and gravitational sources to build a model for swarm behavior. By accounting for the adaptive nature of the midges' acoustic sensing, we show that our ``adaptive gravity'' model makes mean-field predictions that agree well with experimental observations of laboratory swarms. Our results highlight the role of sensory mechanisms and interaction range in collective animal behavior. The adaptive interactions that we present here open a new class of equations of motion, which may appear in other biological contexts.

  16. Adapting GOMS to Model Human-Robot Interaction

    SciTech Connect

    Drury, Jill; Scholtz, Jean; Kieras, David

    2007-03-09

    Human-robot interaction (HRI) has been maturing in tandem with robots’ commercial success. In the last few years HRI researchers have been adopting—and sometimes adapting—human-computer interaction (HCI) evaluation techniques to assess the efficiency and intuitiveness of HRI designs. For example, Adams (2005) used Goal Directed Task Analysis to determine the interaction needs of officers from the Nashville Metro Police Bomb Squad. Scholtz et al. (2004) used Endsley’s (1988) Situation Awareness Global Assessment Technique to determine robotic vehicle supervisors’ awareness of when vehicles were in trouble and thus required closer monitoring or intervention. Yanco and Drury (2004) employed usability testing to determine (among other things) how well a search-andrescue interface supported use by first responders. One set of HCI tools that has so far seen little exploration in the HRI domain, however, is the class of modeling and evaluation techniques known as formal methods.

  17. Adapting Parent-Child Interaction Therapy to Foster Care

    ERIC Educational Resources Information Center

    Mersky, Joshua P.; Topitzes, James; Grant-Savela, Stacey D.; Brondino, Michael J.; McNeil, Cheryl B.

    2016-01-01

    Objective: This study presents outcomes from a randomized trial of a novel Parent-Child Interaction Therapy (PCIT) model for foster families. Differential effects of two intervention doses on child externalizing and internalizing symptoms are examined. Method: A sample of 102 foster children was assigned to one of three conditions--brief PCIT,…

  18. Modelling interactions between mitigation, adaptation and sustainable development

    NASA Astrophysics Data System (ADS)

    Reusser, D. E.; Siabatto, F. A. P.; Garcia Cantu Ros, A.; Pape, C.; Lissner, T.; Kropp, J. P.

    2012-04-01

    Managing the interdependence of climate mitigation, adaptation and sustainable development requires a good understanding of the dominant socioecological processes that have determined the pathways in the past. Key variables include water and food availability which depend on climate and overall ecosystem services, as well as energy supply and social, political and economic conditions. We present our initial steps to build a system dynamic model of nations that represents a minimal set of relevant variables of the socio- ecological development. The ultimate goal of the modelling exercise is to derive possible future scenarios and test those for their compatibility with sustainability boundaries. Where dynamics go beyond sustainability boundaries intervention points in the dynamics can be searched.

  19. Adapted interactive writing instruction with kindergarten children who are deaf or hard of hearing.

    PubMed

    Williams, Cheri

    2011-01-01

    The study describes an adapted form of interactive writing (McCarrier, Pinnell, & Fountas, 2000) and examines its effectiveness as an approach to beginning writing instruction for young children who are deaf or hard of hearing. Systematic videotape analysis was used to document the content of 45 adapted interactive writing lessons across an academic year. Findings of the study suggest that interactive writing has the potential to support early writing development in young deaf and hard of hearing children, if supplemented by techniques that make the phonology of English visible.

  20. Promoting Positive Interactions in the Classroom: Adapting Parent-Child Interaction Therapy as a Universal Prevention Program

    ERIC Educational Resources Information Center

    Gershenson, Rachel A.; Lyon, Aaron R.; Budd, Karen S.

    2010-01-01

    The adaptation of Parent-Child Interaction Therapy (PCIT), an empirically-supported dyadic parent training intervention, to a preschool setting may provide an opportunity to enhance the well-being of both teachers and children by improving the teacher-child relationship and supplying teachers with effective tools for behavior management. The…

  1. Interactions between genetic drift, gene flow, and selection mosaics drive parasite local adaptation.

    PubMed

    Gandon, Sylvain; Nuismer, Scott L

    2009-02-01

    Interactions between gene flow, spatially variable selection, and genetic drift have long been a central focus of evolutionary research. In contrast, only recently has the potential importance of interactions between these factors for coevolutionary dynamics and the emergence of parasite local adaptation been realized. Here we study host-parasite coevolution in a metapopulation model when both the biotic and the abiotic components of the environment vary in space. We provide a general expression for parasite local adaptation that allows local adaptation to be partitioned into the contributions of spatial covariances between host and parasite genotype frequencies within and between habitats. This partitioning clarifies how relative rates of gene flow, spatially variable patterns of selection, and genetic drift interact to shape parasite local adaptation. Specifically, by using this expression in conjunction with coevolutionary models, we show that genetic drift can dramatically increase the level of parasite local adaptation under some models of specificity. We also show that the effect of migration on parasite local adaptation depends on the geographic mosaic of selection. We discuss how these predictions could be tested empirically or experimentally using microbial systems.

  2. Organizational Adaptative Behavior: The Complex Perspective of Individuals-Tasks Interaction

    NASA Astrophysics Data System (ADS)

    Wu, Jiang; Sun, Duoyong; Hu, Bin; Zhang, Yu

    Organizations with different organizational structures have different organizational behaviors when responding environmental changes. In this paper, we use a computational model to examine organizational adaptation on four dimensions: Agility, Robustness, Resilience, and Survivability. We analyze the dynamics of organizational adaptation by a simulation study from a complex perspective of the interaction between tasks and individuals in a sales enterprise. The simulation studies in different scenarios show that more flexible communication between employees and less hierarchy level with the suitable centralization can improve organizational adaptation.

  3. Through the interaction of neutral and adaptive mutations, evolutionary search finds a way.

    PubMed

    Yu, Tina; Miller, Julian Francis

    2006-01-01

    An evolutionary system that supports the interaction of neutral and adaptive mutations is investigated. Experimental results on a Boolean function and needle-in-haystack problems show that this system enables evolutionary search to find better solutions faster. Through a novel analysis based on the ratio of neutral to adaptive mutations, we identify this interaction as an engine that automatically adjusts the relative amounts of exploration and exploitation to achieve effective search (i.e., it is self-adaptive). Moreover, a hypothesis to describe the search process in this system is proposed and investigated. Our findings lead us to counter the arguments of those who dismiss the usefulness of neutrality. We argue that the benefits of neutrality are intimately related to its implementation, so that one must be cautious about making general claims about its merits or demerits.

  4. Tailoring and Adapting Parent-Child Interaction Therapy to New Populations

    ERIC Educational Resources Information Center

    Eyberg, Sheila M.

    2005-01-01

    This paper discusses the processes of tailoring and adapting empirically supported treatments (ESTs) for application to new populations, using examples from the five papers in this special issue on innovative approaches to parent-child interaction therapy (PCIT). The applications of PCIT in this issue represent a range of approaches to tailoring…

  5. Adaptation of Social Interaction Practices for the Preschool Years into Turkish: Validity and Reliability Study

    ERIC Educational Resources Information Center

    Samur, Ayse Ozturk; Soydan, Sema

    2013-01-01

    The aim of this study is to adapt SIPPY (social interaction practices for the preschool years) scale into Turkish. The SIPPY is a tool designed to assess teachers' judgments of the acceptability and feasibility, as well as their current use of literature-supported strategies for promoting the development of young children's social competence in…

  6. Adaptive Man-Machine Interaction in Information Retrieval; A Dissertation in Electrical Engineering.

    ERIC Educational Resources Information Center

    Edwards, John S.

    Three specific contributions to the field of information retrieval are presented. The first two describe the establishment of an adaptive, interactive man-machine dialogue that produces a form of unsolicited librarian-like assistance for the user in his selection of index terms to characterize an indexing function. The data set upon which the…

  7. The role of interactions in a world implementing adaptation and mitigation solutions to climate change.

    PubMed

    Warren, Rachel

    2011-01-13

    The papers in this volume discuss projections of climate change impacts upon humans and ecosystems under a global mean temperature rise of 4°C above preindustrial levels. Like most studies, they are mainly single-sector or single-region-based assessments. Even the multi-sector or multi-region approaches generally consider impacts in sectors and regions independently, ignoring interactions. Extreme weather and adaptation processes are often poorly represented and losses of ecosystem services induced by climate change or human adaptation are generally omitted. This paper addresses this gap by reviewing some potential interactions in a 4°C world, and also makes a comparison with a 2°C world. In a 4°C world, major shifts in agricultural land use and increased drought are projected, and an increased human population might increasingly be concentrated in areas remaining wet enough for economic prosperity. Ecosystem services that enable prosperity would be declining, with carbon cycle feedbacks and fire causing forest losses. There is an urgent need for integrated assessments considering the synergy of impacts and limits to adaptation in multiple sectors and regions in a 4°C world. By contrast, a 2°C world is projected to experience about one-half of the climate change impacts, with concomitantly smaller challenges for adaptation. Ecosystem services, including the carbon sink provided by the Earth's forests, would be expected to be largely preserved, with much less potential for interaction processes to increase challenges to adaptation. However, demands for land and water for biofuel cropping could reduce the availability of these resources for agricultural and natural systems. Hence, a whole system approach to mitigation and adaptation, considering interactions, potential human and species migration, allocation of land and water resources and ecosystem services, will be important in either a 2°C or a 4°C world.

  8. Long-range acoustic interactions in insect swarms: an adaptive gravity model

    NASA Astrophysics Data System (ADS)

    Gorbonos, Dan; Ianconescu, Reuven; Puckett, James G.; Ni, Rui; Ouellette, Nicholas T.; Gov, Nir S.

    2016-07-01

    The collective motion of groups of animals emerges from the net effect of the interactions between individual members of the group. In many cases, such as birds, fish, or ungulates, these interactions are mediated by sensory stimuli that predominantly arise from nearby neighbors. But not all stimuli in animal groups are short range. Here, we consider mating swarms of midges, which are thought to interact primarily via long-range acoustic stimuli. We exploit the similarity in form between the decay of acoustic and gravitational sources to build a model for swarm behavior. By accounting for the adaptive nature of the midges’ acoustic sensing, we show that our ‘adaptive gravity’ model makes mean-field predictions that agree well with experimental observations of laboratory swarms. Our results highlight the role of sensory mechanisms and interaction range in collective animal behavior. Additionally, the adaptive interactions that we present here open a new class of equations of motion, which may appear in other biological contexts.

  9. Identifying main effects and epistatic interactions from large-scale SNP data via adaptive group Lasso

    PubMed Central

    2010-01-01

    Background Single nucleotide polymorphism (SNP) based association studies aim at identifying SNPs associated with phenotypes, for example, complex diseases. The associated SNPs may influence the disease risk individually (main effects) or behave jointly (epistatic interactions). For the analysis of high throughput data, the main difficulty is that the number of SNPs far exceeds the number of samples. This difficulty is amplified when identifying interactions. Results In this paper, we propose an Adaptive Group Lasso (AGL) model for large-scale association studies. Our model enables us to analyze SNPs and their interactions simultaneously. We achieve this by introducing a sparsity constraint in our model based on the fact that only a small fraction of SNPs is disease-associated. In order to reduce the number of false positive findings, we develop an adaptive reweighting scheme to enhance sparsity. In addition, our method treats SNPs and their interactions as factors, and identifies them in a grouped manner. Thus, it is flexible to analyze various disease models, especially for interaction detection. However, due to the intensive computation when millions of interaction terms needs to be searched in the model fitting, our method needs to combined with some filtering methods when applied to genome-wide data for detecting interactions. Conclusion By using a wide range of simulated datasets and a real dataset from WTCCC, we demonstrate the advantages of our method. PMID:20122189

  10. Human-pet interaction and loneliness: a test of concepts from Roy's adaptation model.

    PubMed

    Calvert, M M

    1989-01-01

    This research used two key concepts from Roy's adaptation model of nursing to examine the relationship between human-pet interaction and loneliness in nursing home residents. These concepts included (a) environmental stimuli as factors influencing adaptation and (b) interdependence as a mode of response to the environment. The hypothesis of this study asserted that the residents of a nursing home who had greater levels of interaction with a pet program would experience less loneliness than those who had lower levels of interaction with a pet. The study used an ex post facto nonexperimental design with 65 subjects. The simplified version of the revised UCLA loneliness scale was used to measure loneliness. Reported level of human-pet interaction was measured according to a four-point scale (1 = no interaction, 4 = quite a lot of interaction). The hypothesis was supported at the p less than 0.03 level of significance. Implications for practice through organizing pet programs in situations where loneliness exists are discussed. Recommendations for future research include replicating the study using a larger sample and developing a comprehensive human-pet interaction tool. PMID:2594276

  11. A Modified Adaptive Lasso for Identifying Interactions in the Cox Model with the Heredity Constraint.

    PubMed

    Wang, Lu; Shen, Jincheng; Thall, Peter F

    2014-10-01

    In many biomedical studies, identifying effects of covariate interactions on survival is a major goal. Important examples are treatment-subgroup interactions in clinical trials, and gene-gene or gene-environment interactions in genomic studies. A common problem when implementing a variable selection algorithm in such settings is the requirement that the model must satisfy the strong heredity constraint, wherein an interaction may be included in the model only if the interaction's component variables are included as main effects. We propose a modified Lasso method for the Cox regression model that adaptively selects important single covariates and pairwise interactions while enforcing the strong heredity constraint. The proposed method is based on a modified log partial likelihood including two adaptively weighted penalties, one for main effects and one for interactions. A two-dimensional tuning parameter for the penalties is determined by generalized cross-validation. Asymptotic properties are established, including consistency and rate of convergence, and it is shown that the proposed selection procedure has oracle properties, given proper choice of regularization parameters. Simulations illustrate that the proposed method performs reliably across a range of different scenarios.

  12. Adaptive Landscape by Environment Interactions Dictate Evolutionary Dynamics in Models of Drug Resistance.

    PubMed

    Ogbunugafor, C Brandon; Wylie, C Scott; Diakite, Ibrahim; Weinreich, Daniel M; Hartl, Daniel L

    2016-01-01

    The adaptive landscape analogy has found practical use in recent years, as many have explored how their understanding can inform therapeutic strategies that subvert the evolution of drug resistance. A major barrier to applications of these concepts is a lack of detail concerning how the environment affects adaptive landscape topography, and consequently, the outcome of drug treatment. Here we combine empirical data, evolutionary theory, and computer simulations towards dissecting adaptive landscape by environment interactions for the evolution of drug resistance in two dimensions-drug concentration and drug type. We do so by studying the resistance mediated by Plasmodium falciparum dihydrofolate reductase (DHFR) to two related inhibitors-pyrimethamine and cycloguanil-across a breadth of drug concentrations. We first examine whether the adaptive landscapes for the two drugs are consistent with common definitions of cross-resistance. We then reconstruct all accessible pathways across the landscape, observing how their structure changes with drug environment. We offer a mechanism for non-linearity in the topography of accessible pathways by calculating of the interaction between mutation effects and drug environment, which reveals rampant patterns of epistasis. We then simulate evolution in several different drug environments to observe how these individual mutation effects (and patterns of epistasis) influence paths taken at evolutionary "forks in the road" that dictate adaptive dynamics in silico. In doing so, we reveal how classic metrics like the IC50 and minimal inhibitory concentration (MIC) are dubious proxies for understanding how evolution will occur across drug environments. We also consider how the findings reveal ambiguities in the cross-resistance concept, as subtle differences in adaptive landscape topography between otherwise equivalent drugs can drive drastically different evolutionary outcomes. Summarizing, we discuss the results with regards to their

  13. Adaptive Landscape by Environment Interactions Dictate Evolutionary Dynamics in Models of Drug Resistance

    PubMed Central

    Ogbunugafor, C. Brandon; Wylie, C. Scott; Diakite, Ibrahim; Weinreich, Daniel M.; Hartl, Daniel L.

    2016-01-01

    The adaptive landscape analogy has found practical use in recent years, as many have explored how their understanding can inform therapeutic strategies that subvert the evolution of drug resistance. A major barrier to applications of these concepts is a lack of detail concerning how the environment affects adaptive landscape topography, and consequently, the outcome of drug treatment. Here we combine empirical data, evolutionary theory, and computer simulations towards dissecting adaptive landscape by environment interactions for the evolution of drug resistance in two dimensions—drug concentration and drug type. We do so by studying the resistance mediated by Plasmodium falciparum dihydrofolate reductase (DHFR) to two related inhibitors—pyrimethamine and cycloguanil—across a breadth of drug concentrations. We first examine whether the adaptive landscapes for the two drugs are consistent with common definitions of cross-resistance. We then reconstruct all accessible pathways across the landscape, observing how their structure changes with drug environment. We offer a mechanism for non-linearity in the topography of accessible pathways by calculating of the interaction between mutation effects and drug environment, which reveals rampant patterns of epistasis. We then simulate evolution in several different drug environments to observe how these individual mutation effects (and patterns of epistasis) influence paths taken at evolutionary “forks in the road” that dictate adaptive dynamics in silico. In doing so, we reveal how classic metrics like the IC50 and minimal inhibitory concentration (MIC) are dubious proxies for understanding how evolution will occur across drug environments. We also consider how the findings reveal ambiguities in the cross-resistance concept, as subtle differences in adaptive landscape topography between otherwise equivalent drugs can drive drastically different evolutionary outcomes. Summarizing, we discuss the results with

  14. Complex ordering in spin networks: Critical role of adaptation rate for dynamically evolving interactions

    NASA Astrophysics Data System (ADS)

    Pathak, Anand; Sinha, Sitabhra

    2015-09-01

    Many complex systems can be represented as networks of dynamical elements whose states evolve in response to interactions with neighboring elements, noise and external stimuli. The collective behavior of such systems can exhibit remarkable ordering phenomena such as chimera order corresponding to coexistence of ordered and disordered regions. Often, the interactions in such systems can also evolve over time responding to changes in the dynamical states of the elements. Link adaptation inspired by Hebbian learning, the dominant paradigm for neuronal plasticity, has been earlier shown to result in structural balance by removing any initial frustration in a system that arises through conflicting interactions. Here we show that the rate of the adaptive dynamics for the interactions is crucial in deciding the emergence of different ordering behavior (including chimera) and frustration in networks of Ising spins. In particular, we observe that small changes in the link adaptation rate about a critical value result in the system exhibiting radically different energy landscapes, viz., smooth landscape corresponding to balanced systems seen for fast learning, and rugged landscapes corresponding to frustrated systems seen for slow learning.

  15. BOLD coherence reveals segregated functional neural interactions when adapting to distinct torque perturbations

    PubMed Central

    Tunik, Eugene; Schmitt, Paul J.; Grafton, Scott T.

    2007-01-01

    In the natural world, we experience and adapt to multiple extrinsic perturbations. This poses a challenge to neural circuits in discriminating between different context-appropriate responses. Using event-related fMRI, we characterized the neural dynamics involved in this process by randomly delivering a position- or velocity-dependent torque perturbation to subjects’ arms during a target capture task. Each perturbation was color-cued during movement preparation to provide contextual information. Though trajectories differed between perturbations, subjects significantly reduced error under both conditions. This was paralleled by reduced BOLD signal in the right dentate nucleus, the left sensorimotor cortex, and the left intraparietal sulcus. Trials included ‘NoGo’ conditions to dissociate activity related to preparation from execution and adaptation. Subsequent analysis identified perturbation-specific neural processes underlying preparation (‘NoGo’) and adaptation (‘Go’) early and late into learning. Between-perturbation comparisons of BOLD magnitude revealed negligible differences for both preparation and adaptation trials. However, a network-level analysis of BOLD coherence revealed that by late learning, response preparation (‘NoGo’) was attributed to a relative focusing of coherence within cortical and basal ganglia networks in both perturbation conditions, demonstrating a common network interaction for establishing arbitrary visuomotor associations. Conversely, late-learning adaptation (‘Go’) was attributed to a focusing of BOLD coherence between a cortical-basal ganglia network in the viscous condition and between a cortical-cerebellar network in the positional condition. Our findings demonstrate that trial-to-trial acquisition of two distinct adaptive responses is attributed not to anatomically segregated regions, but to differential functional interactions within common sensorimotor circuits. PMID:17202232

  16. 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

  17. Adaptive finite element program for automatic modeling of thermal processes during laser-tissue interaction

    NASA Astrophysics Data System (ADS)

    Yakunin, Alexander N.; Scherbakov, Yury N.

    1994-02-01

    The absence of satisfactory criteria for discrete model parameters choice during computer modeling of thermal processes of laser-biotissue interaction may be the premier sign for the accuracy of the numerical results obtained. The approach realizing the new concept of direct automatical adaptive grid construction is suggested. The intellectual program provides high calculation accuracy and is simple in practical usage so that a physician receives the ability to prescribe treatment without any assistance of a specialist in mathematical modeling.

  18. Spoken language interaction with model uncertainty: an adaptive human-robot interaction system

    NASA Astrophysics Data System (ADS)

    Doshi, Finale; Roy, Nicholas

    2008-12-01

    Spoken language is one of the most intuitive forms of interaction between humans and agents. Unfortunately, agents that interact with people using natural language often experience communication errors and do not correctly understand the user's intentions. Recent systems have successfully used probabilistic models of speech, language and user behaviour to generate robust dialogue performance in the presence of noisy speech recognition and ambiguous language choices, but decisions made using these probabilistic models are still prone to errors owing to the complexity of acquiring and maintaining a complete model of human language and behaviour. In this paper, a decision-theoretic model for human-robot interaction using natural language is described. The algorithm is based on the Partially Observable Markov Decision Process (POMDP), which allows agents to choose actions that are robust not only to uncertainty from noisy or ambiguous speech recognition but also unknown user models. Like most dialogue systems, a POMDP is defined by a large number of parameters that may be difficult to specify a priori from domain knowledge, and learning these parameters from the user may require an unacceptably long training period. An extension to the POMDP model is described that allows the agent to acquire a linguistic model of the user online, including new vocabulary and word choice preferences. The approach not only avoids a training period of constant questioning as the agent learns, but also allows the agent actively to query for additional information when its uncertainty suggests a high risk of mistakes. The approach is demonstrated both in simulation and on a natural language interaction system for a robotic wheelchair application.

  19. Adaptation of mammalian host-pathogen interactions in a changing arctic environment

    PubMed Central

    2011-01-01

    Many arctic mammals are adapted to live year-round in extreme environments with low winter temperatures and great seasonal variations in key variables (e.g. sunlight, food, temperature, moisture). The interaction between hosts and pathogens in high northern latitudes is not very well understood with respect to intra-annual cycles (seasons). The annual cycles of interacting pathogen and host biology is regulated in part by highly synchronized temperature and photoperiod changes during seasonal transitions (e.g., freezeup and breakup). With a warming climate, only one of these key biological cues will undergo drastic changes, while the other will remain fixed. This uncoupling can theoretically have drastic consequences on host-pathogen interactions. These poorly understood cues together with a changing climate by itself will challenge host populations that are adapted to pathogens under the historic and current climate regime. We will review adaptations of both host and pathogens to the extreme conditions at high latitudes and explore some potential consequences of rapid changes in the Arctic. PMID:21392401

  20. Cytonuclear interactions affect adaptive traits of the annual plant Arabidopsis thaliana in the field

    PubMed Central

    Roux, Fabrice; Mary-Huard, Tristan; Barillot, Elise; Wenes, Estelle; Botran, Lucy; Durand, Stéphanie; Villoutreix, Romain; Martin-Magniette, Marie-Laure; Camilleri, Christine; Budar, Françoise

    2016-01-01

    Although the contribution of cytonuclear interactions to plant fitness variation is relatively well documented at the interspecific level, the prevalence of cytonuclear interactions at the intraspecific level remains poorly investigated. In this study, we set up a field experiment to explore the range of effects that cytonuclear interactions have on fitness-related traits in Arabidopsis thaliana. To do so, we created a unique series of 56 cytolines resulting from cytoplasmic substitutions among eight natural accessions reflecting within-species genetic diversity. An assessment of these cytolines and their parental lines scored for 28 adaptive whole-organism phenotypes showed that a large proportion of phenotypic traits (23 of 28) were affected by cytonuclear interactions. The effects of these interactions varied from slight but frequent across cytolines to strong in some specific parental pairs. Two parental pairs accounted for half of the significant pairwise interactions. In one parental pair, Ct-1/Sha, we observed symmetrical phenotypic responses between the two nuclear backgrounds when combined with specific cytoplasms, suggesting nuclear differentiation at loci involved in cytonuclear epistasis. In contrast, asymmetrical phenotypic responses were observed in another parental pair, Cvi-0/Sha. In the Cvi-0 nuclear background, fecundity and phenology-related traits were strongly affected by the Sha cytoplasm, leading to a modified reproductive strategy without penalizing total seed production. These results indicate that natural variation in cytoplasmic and nuclear genomes interact to shape integrative traits that contribute to adaptation, thereby suggesting that cytonuclear interactions can play a major role in the evolutionary dynamics of A. thaliana. PMID:26979961

  1. Cytonuclear interactions affect adaptive traits of the annual plant Arabidopsis thaliana in the field.

    PubMed

    Roux, Fabrice; Mary-Huard, Tristan; Barillot, Elise; Wenes, Estelle; Botran, Lucy; Durand, Stéphanie; Villoutreix, Romain; Martin-Magniette, Marie-Laure; Camilleri, Christine; Budar, Françoise

    2016-03-29

    Although the contribution of cytonuclear interactions to plant fitness variation is relatively well documented at the interspecific level, the prevalence of cytonuclear interactions at the intraspecific level remains poorly investigated. In this study, we set up a field experiment to explore the range of effects that cytonuclear interactions have on fitness-related traits in Arabidopsis thaliana To do so, we created a unique series of 56 cytolines resulting from cytoplasmic substitutions among eight natural accessions reflecting within-species genetic diversity. An assessment of these cytolines and their parental lines scored for 28 adaptive whole-organism phenotypes showed that a large proportion of phenotypic traits (23 of 28) were affected by cytonuclear interactions. The effects of these interactions varied from slight but frequent across cytolines to strong in some specific parental pairs. Two parental pairs accounted for half of the significant pairwise interactions. In one parental pair, Ct-1/Sha, we observed symmetrical phenotypic responses between the two nuclear backgrounds when combined with specific cytoplasms, suggesting nuclear differentiation at loci involved in cytonuclear epistasis. In contrast, asymmetrical phenotypic responses were observed in another parental pair, Cvi-0/Sha. In the Cvi-0 nuclear background, fecundity and phenology-related traits were strongly affected by the Sha cytoplasm, leading to a modified reproductive strategy without penalizing total seed production. These results indicate that natural variation in cytoplasmic and nuclear genomes interact to shape integrative traits that contribute to adaptation, thereby suggesting that cytonuclear interactions can play a major role in the evolutionary dynamics ofA. thaliana. PMID:26979961

  2. Local genetic adaptation generates latitude-specific effects of warming on predator-prey interactions.

    PubMed

    De Block, Marjan; Pauwels, Kevin; Van Den Broeck, Maarten; De Meester, Luc; Stoks, Robby

    2013-03-01

    Temperature effects on predator-prey interactions are fundamental to better understand the effects of global warming. Previous studies never considered local adaptation of both predators and prey at different latitudes, and ignored the novel population combinations of the same predator-prey species system that may arise because of northward dispersal. We set up a common garden warming experiment to study predator-prey interactions between Ischnura elegans damselfly predators and Daphnia magna zooplankton prey from three source latitudes spanning >1500 km. Damselfly foraging rates showed thermal plasticity and strong latitudinal differences consistent with adaptation to local time constraints. Relative survival was higher at 24 °C than at 20 °C in southern Daphnia and higher at 20 °C than at 24 °C, in northern Daphnia indicating local thermal adaptation of the Daphnia prey. Yet, this thermal advantage disappeared when they were confronted with the damselfly predators of the same latitude, reflecting also a signal of local thermal adaptation in the damselfly predators. Our results further suggest the invasion success of northward moving predators as well as prey to be latitude-specific. We advocate the novel common garden experimental approach using predators and prey obtained from natural temperature gradients spanning the predicted temperature increase in the northern populations as a powerful approach to gain mechanistic insights into how community modules will be affected by global warming. It can be used as a space-for-time substitution to inform how predator-prey interaction may gradually evolve to long-term warming.

  3. Local genetic adaptation generates latitude-specific effects of warming on predator-prey interactions.

    PubMed

    De Block, Marjan; Pauwels, Kevin; Van Den Broeck, Maarten; De Meester, Luc; Stoks, Robby

    2013-03-01

    Temperature effects on predator-prey interactions are fundamental to better understand the effects of global warming. Previous studies never considered local adaptation of both predators and prey at different latitudes, and ignored the novel population combinations of the same predator-prey species system that may arise because of northward dispersal. We set up a common garden warming experiment to study predator-prey interactions between Ischnura elegans damselfly predators and Daphnia magna zooplankton prey from three source latitudes spanning >1500 km. Damselfly foraging rates showed thermal plasticity and strong latitudinal differences consistent with adaptation to local time constraints. Relative survival was higher at 24 °C than at 20 °C in southern Daphnia and higher at 20 °C than at 24 °C, in northern Daphnia indicating local thermal adaptation of the Daphnia prey. Yet, this thermal advantage disappeared when they were confronted with the damselfly predators of the same latitude, reflecting also a signal of local thermal adaptation in the damselfly predators. Our results further suggest the invasion success of northward moving predators as well as prey to be latitude-specific. We advocate the novel common garden experimental approach using predators and prey obtained from natural temperature gradients spanning the predicted temperature increase in the northern populations as a powerful approach to gain mechanistic insights into how community modules will be affected by global warming. It can be used as a space-for-time substitution to inform how predator-prey interaction may gradually evolve to long-term warming. PMID:23504827

  4. Peer Interaction and Group Education for Adaptation to Disease in Adolescents with Type 1 Diabetes Mellitus

    PubMed Central

    Altundag, Sebahat; Bayat, Meral

    2016-01-01

    Objective: To evaluate the effects of group interaction and training in the adaptation process to disease in adolescents with type 1 diabetes mellitus (T1DM). Methods: This experimental study with pre- and post-test control groups was conducted in the pediatric endocrine clinic at a university hospital. The data were collected through descriptive data form, social support assessment scale, self-esteem inventory and information form. The data collection forms were administered four times with 3-month intervals to the study and control groups. Training, peer interaction and social support attempts were provided to the study group. Results: After the training and peer interaction, it was determined that there was a decrease in HbA1c levels and an increase in self-esteem (p<0.001) and mean scores of social support (p<0.05), and significant increase in knowledge levels (p<0.001). As for the adolescents in the control group, it was determined that there was no change in their HbA1c levels (p>0.05), and that there was no difference in their self-esteem scores, mean knowledge levels (p>0.05) in comparison with their pre-test scores. Conclusion: The training and peer interaction in adolescents were found to be effective in the adaptation process to the disease. PMID:27648058

  5. Mirid (Hemiptera: Heteroptera) specialists of sticky plants: adaptations, interactions, and ecological implications.

    PubMed

    Wheeler, Alfred G; Krimmel, Billy A

    2015-01-01

    Sticky plants-those having glandular trichomes (hairs) that produce adhesive, viscous exudates-can impede the movement of, and entrap, generalist insects. Disparate arthropod groups have adapted to these widespread and taxonomically diverse plants, yet their interactions with glandular hosts rarely are incorporated into broad ecological theory. Ecologists and entomologists might be unaware of even well-documented examples of insects that are sticky-plant specialists. The hemipteran family Miridae (more specifically, the omnivorous Dicyphini: Dicyphina) is the best-known group of arthropods that specializes on sticky plants. In the first synthesis of relationships with glandular plants for any insect family, we review mirid interactions with sticky hosts, including their adaptations (behavioral, morphological, and physiological) and mutualisms with carnivorous plants, and the ecological and agricultural implications of mirid-sticky plant systems. We propose that mirid research applies generally to tritrophic interactions on trichome-defended plants, enhances an understanding of insect-plant interactions, and provides information useful in managing crop pests.

  6. Peer Interaction and Group Education for Adaptation to Disease in Adolescents with Type 1 Diabetes Mellitus

    PubMed Central

    Altundag, Sebahat; Bayat, Meral

    2016-01-01

    Objective: To evaluate the effects of group interaction and training in the adaptation process to disease in adolescents with type 1 diabetes mellitus (T1DM). Methods: This experimental study with pre- and post-test control groups was conducted in the pediatric endocrine clinic at a university hospital. The data were collected through descriptive data form, social support assessment scale, self-esteem inventory and information form. The data collection forms were administered four times with 3-month intervals to the study and control groups. Training, peer interaction and social support attempts were provided to the study group. Results: After the training and peer interaction, it was determined that there was a decrease in HbA1c levels and an increase in self-esteem (p<0.001) and mean scores of social support (p<0.05), and significant increase in knowledge levels (p<0.001). As for the adolescents in the control group, it was determined that there was no change in their HbA1c levels (p>0.05), and that there was no difference in their self-esteem scores, mean knowledge levels (p>0.05) in comparison with their pre-test scores. Conclusion: The training and peer interaction in adolescents were found to be effective in the adaptation process to the disease.

  7. Mirid (Hemiptera: Heteroptera) specialists of sticky plants: adaptations, interactions, and ecological implications.

    PubMed

    Wheeler, Alfred G; Krimmel, Billy A

    2015-01-01

    Sticky plants-those having glandular trichomes (hairs) that produce adhesive, viscous exudates-can impede the movement of, and entrap, generalist insects. Disparate arthropod groups have adapted to these widespread and taxonomically diverse plants, yet their interactions with glandular hosts rarely are incorporated into broad ecological theory. Ecologists and entomologists might be unaware of even well-documented examples of insects that are sticky-plant specialists. The hemipteran family Miridae (more specifically, the omnivorous Dicyphini: Dicyphina) is the best-known group of arthropods that specializes on sticky plants. In the first synthesis of relationships with glandular plants for any insect family, we review mirid interactions with sticky hosts, including their adaptations (behavioral, morphological, and physiological) and mutualisms with carnivorous plants, and the ecological and agricultural implications of mirid-sticky plant systems. We propose that mirid research applies generally to tritrophic interactions on trichome-defended plants, enhances an understanding of insect-plant interactions, and provides information useful in managing crop pests. PMID:25564742

  8. Cation-π interactions: accurate intermolecular potential from symmetry-adapted perturbation theory.

    PubMed

    Ansorg, Kay; Tafipolsky, Maxim; Engels, Bernd

    2013-09-01

    Symmetry-adapted perturbation theory (SAPT) is used to decompose the total intermolecular interaction energy between the ammonium cation and a benzene molecule into four physically motivated individual contributions: electrostatics, exchange, dispersion, and induction. Based on this rigorous decomposition, it is shown unambiguously that both the electrostatic and the induction energy components contribute almost equally to the attractive forces stabilizing the dimer with a nonnegligible contribution coming from the dispersion term. A polarizable potential model for the interaction of ammonium cation with benzene is parametrized by fitting these four energy components separately using the functional forms of the AMOEBA force field augmented with the missing charge penetration energy term calculated as a sum over pairwise electrostatic energies between spherical atoms. It is shown that the proposed model is able to produce accurate intermolecular interaction energies as compared to ab initio results, thus avoiding error compensation to a large extent.

  9. Responses to temperature and hypoxia as interacting stressors in fish: implications for adaptation to environmental change.

    PubMed

    McBryan, T L; Anttila, K; Healy, T M; Schulte, P M

    2013-10-01

    Anthropogenic environmental change is exposing animals to changes in a complex array of interacting stressors and is already having important effects on the distribution and abundance of species. However, despite extensive examination of the effects of stressors in isolation, knowledge of the effects of stressors in combination is limited. This lack of information makes predicting the responses of organisms to anthropogenic environmental change challenging. Here, we focus on the effects of temperature and hypoxia as interacting stressors in fishes. A review of the available evidence suggests that temperature and hypoxia act synergistically such that small shifts in one stressor could result in large effects on organismal performance when a fish is exposed to the 2 stressors in combination. Although these stressors pose substantial challenges for fish, there also is substantial intraspecific variation in tolerance to these stressors that could act as the raw material for the evolution of improved tolerance. However, the potential for adaptive change is, in part, dependent on the nature of the correlations among traits associated with tolerance. For example, negative genetic correlations (or trade-offs) between tolerances to temperature and hypoxia could limit the potential for adaptation to the combined stressors, while positive genetic correlations might be of benefit. The limited data currently available suggest that tolerances to hypoxia and to high-temperature may be positively correlated in some species of fish, suggesting the possibility for adaptive evolution in these traits in response to anthropogenic environmental change.

  10. Interactive prostate segmentation using atlas-guided semi-supervised learning and adaptive feature selection

    SciTech Connect

    Park, Sang Hyun; Gao, Yaozong; Shi, Yinghuan; Shen, Dinggang

    2014-11-01

    Purpose: Accurate prostate segmentation is necessary for maximizing the effectiveness of radiation therapy of prostate cancer. However, manual segmentation from 3D CT images is very time-consuming and often causes large intra- and interobserver variations across clinicians. Many segmentation methods have been proposed to automate this labor-intensive process, but tedious manual editing is still required due to the limited performance. In this paper, the authors propose a new interactive segmentation method that can (1) flexibly generate the editing result with a few scribbles or dots provided by a clinician, (2) fast deliver intermediate results to the clinician, and (3) sequentially correct the segmentations from any type of automatic or interactive segmentation methods. Methods: The authors formulate the editing problem as a semisupervised learning problem which can utilize a priori knowledge of training data and also the valuable information from user interactions. Specifically, from a region of interest near the given user interactions, the appropriate training labels, which are well matched with the user interactions, can be locally searched from a training set. With voting from the selected training labels, both confident prostate and background voxels, as well as unconfident voxels can be estimated. To reflect informative relationship between voxels, location-adaptive features are selected from the confident voxels by using regression forest and Fisher separation criterion. Then, the manifold configuration computed in the derived feature space is enforced into the semisupervised learning algorithm. The labels of unconfident voxels are then predicted by regularizing semisupervised learning algorithm. Results: The proposed interactive segmentation method was applied to correct automatic segmentation results of 30 challenging CT images. The correction was conducted three times with different user interactions performed at different time periods, in order to

  11. Adaptive GPU-accelerated force calculation for interactive rigid molecular docking using haptics.

    PubMed

    Iakovou, Georgios; Hayward, Steven; Laycock, Stephen D

    2015-09-01

    Molecular docking systems model and simulate in silico the interactions of intermolecular binding. Haptics-assisted docking enables the user to interact with the simulation via their sense of touch but a stringent time constraint on the computation of forces is imposed due to the sensitivity of the human haptic system. To simulate high fidelity smooth and stable feedback the haptic feedback loop should run at rates of 500Hz to 1kHz. We present an adaptive force calculation approach that can be executed in parallel on a wide range of Graphics Processing Units (GPUs) for interactive haptics-assisted docking with wider applicability to molecular simulations. Prior to the interactive session either a regular grid or an octree is selected according to the available GPU memory to determine the set of interatomic interactions within a cutoff distance. The total force is then calculated from this set. The approach can achieve force updates in less than 2ms for molecular structures comprising hundreds of thousands of atoms each, with performance improvements of up to 90 times the speed of current CPU-based force calculation approaches used in interactive docking. Furthermore, it overcomes several computational limitations of previous approaches such as pre-computed force grids, and could potentially be used to model receptor flexibility at haptic refresh rates.

  12. Adaptive GPU-accelerated force calculation for interactive rigid molecular docking using haptics.

    PubMed

    Iakovou, Georgios; Hayward, Steven; Laycock, Stephen D

    2015-09-01

    Molecular docking systems model and simulate in silico the interactions of intermolecular binding. Haptics-assisted docking enables the user to interact with the simulation via their sense of touch but a stringent time constraint on the computation of forces is imposed due to the sensitivity of the human haptic system. To simulate high fidelity smooth and stable feedback the haptic feedback loop should run at rates of 500Hz to 1kHz. We present an adaptive force calculation approach that can be executed in parallel on a wide range of Graphics Processing Units (GPUs) for interactive haptics-assisted docking with wider applicability to molecular simulations. Prior to the interactive session either a regular grid or an octree is selected according to the available GPU memory to determine the set of interatomic interactions within a cutoff distance. The total force is then calculated from this set. The approach can achieve force updates in less than 2ms for molecular structures comprising hundreds of thousands of atoms each, with performance improvements of up to 90 times the speed of current CPU-based force calculation approaches used in interactive docking. Furthermore, it overcomes several computational limitations of previous approaches such as pre-computed force grids, and could potentially be used to model receptor flexibility at haptic refresh rates. PMID:26186491

  13. Evidence of local adaptation in plant virus effects on host-vector interactions.

    PubMed

    Mauck, K E; De Moraes, C M; Mescher, M C

    2014-07-01

    host and apparently maladaptive with respect to virus transmission (e.g., host plant quality for aphids was significantly improved in this instance, and aphid dispersal was reduced). Taken together, these findings provide evidence of adaption by CMV to local hosts (including reduced infectivity and replication in novel versus native hosts) and further suggest that such adaptation may extend to effects on host-plant traits mediating interactions with aphid vectors. Thus, these results are consistent with the hypothesis that virus effects on host-vector interactions can be adaptive, and they suggest that multi-host pathogens may exhibit adaptation with respect to these and other effects on host phenotypes, perhaps especially in homogeneous monocultures.

  14. Adaptive finite-element approach for analysis of bone/prosthesis interaction.

    PubMed

    Hübsch, P F; Middleton, J; Meroi, E A; Natali, A N

    1995-01-01

    The study uses the finite-element method to analyse the stress field in a perfectly bonded hip prosthesis arising from loading through body weight. Special attention is paid to the accuracy of the numerical analysis, and adaptive mesh refinement is introduced to reduce the discretisation error. The finite-element procedure developed is especially well suited to analyse the behaviour of a bonded interface as it is capable of calculating accurately the stress at the nodal positions while satisfying the natural discontinuity in the stress field at this location. An orthotropic material model is used for the representation of the behaviour of the bone, and an axisymmetric geometry with non-symmetrical loading is adopted for the analysis. The results demonstrate the usefulness of adaptive mesh refinement and the significance of adopting anisotropic material modelling in the context of tissue/prosthesis interaction.

  15. Interactive effects of age and multi-gene profile on motor learning and sensorimotor adaptation.

    PubMed

    Noohi, Fatemeh; Boyden, Nate B; Kwak, Youngbin; Humfleet, Jennifer; Müller, Martijn L T M; Bohnen, Nicolaas I; Seidler, Rachael D

    2016-04-01

    The interactive association of age and dopaminergic polymorphisms on cognitive function has been studied extensively. However, there is limited research on whether age interacts with the association between genetic polymorphisms and motor learning. We examined a group of young and older adults' performance in three motor tasks: explicit sequence learning, visuomotor adaptation, and grooved pegboard. We assessed whether individuals' motor learning and performance were associated with their age and genotypes. We selected three genetic polymorphisms: Catechol-O-Methyl Transferase (COMT val158met) and Dopamine D2 Receptor (DRD2 G>T), which are involved with dopaminergic regulation, and Brain Derived Neurotrophic Factor (BDNF val66met) that modulates neuroplasticity and has been shown to interact with dopaminergic genes. Although the underlying mechanisms of the function of these three genotypes are different, the high performance alleles of each have been linked to better learning and performance. We created a composite polygene score based on the Number of High Performance Alleles (NHPA) that each individual carried. We found several associations between genetic profile, motor performance, and sensorimotor adaptation. More importantly, we found that this association varies with age, task type, and engagement of implicit versus explicit learning processes. PMID:26926580

  16. Evolutionary adaptive eye tracking for low-cost human computer interaction applications

    NASA Astrophysics Data System (ADS)

    Shen, Yan; Shin, Hak Chul; Sung, Won Jun; Khim, Sarang; Kim, Honglak; Rhee, Phill Kyu

    2013-01-01

    We present an evolutionary adaptive eye-tracking framework aiming for low-cost human computer interaction. The main focus is to guarantee eye-tracking performance without using high-cost devices and strongly controlled situations. The performance optimization of eye tracking is formulated into the dynamic control problem of deciding on an eye tracking algorithm structure and associated thresholds/parameters, where the dynamic control space is denoted by genotype and phenotype spaces. The evolutionary algorithm is responsible for exploring the genotype control space, and the reinforcement learning algorithm organizes the evolved genotype into a reactive phenotype. The evolutionary algorithm encodes an eye-tracking scheme as a genetic code based on image variation analysis. Then, the reinforcement learning algorithm defines internal states in a phenotype control space limited by the perceived genetic code and carries out interactive adaptations. The proposed method can achieve optimal performance by compromising the difficulty in the real-time performance of the evolutionary algorithm and the drawback of the huge search space of the reinforcement learning algorithm. Extensive experiments were carried out using webcam image sequences and yielded very encouraging results. The framework can be readily applied to other low-cost vision-based human computer interactions in solving their intrinsic brittleness in unstable operational environments.

  17. Interactive Genetic Algorithm - An Adaptive and Interactive Decision Support Framework for Design of Optimal Groundwater Monitoring Plans

    NASA Astrophysics Data System (ADS)

    Babbar-Sebens, M.; Minsker, B. S.

    2006-12-01

    that met the DM's preference criteria, therefore allowing the expert to select among several strong candidate designs depending on her/his LTM budget, c) two of the methodologies - Case-Based Micro Interactive Genetic Algorithm (CBMIGA) and Interactive Genetic Algorithm with Mixed Initiative Interaction (IGAMII) - were also able to assist in controlling human fatigue and adapt to the DM's learning process.

  18. Management, Drought, and Fire Interact to Pre-Adapt an Eastern Bolivian Forest to Disturbance

    NASA Astrophysics Data System (ADS)

    Shenkin, A.; Putz, F. "

    2012-12-01

    Logging, drought, and fire are considered to be among the largest threats facing Amazonian forests. While interactions between two of these three threats have been investigated, interactions between all three have yet to be reported. We hypothesized that logging pre-adapts forests to drought by selecting for drought-tolerant species in gaps and skid trails; that drought most severely affects trees with exposed crowns; that fires kill mostly small trees and those with thin bark; and, that the interaction of these three factors pushes forests towards a smaller-statured and lower basal-area forest that is drought- and fire-tolerant. To address these hypotheses, we complemented a 12-year biennially-censused silvicultural experimental plots that were partially burned in 2004 with a seedling drought-tolerance experiment, bark-thickness measurements, and measurements of seedling survival during the most severe drought in at least 50 years. We find that drought-tolerant seedlings have only slightly higher survival rates than drought-intolerants as climatological water deficit increases, but drought-tolerants survive substantially better than drought-intolerant seedlings in logging gaps and skid-trails, thereby pre-adapting the community of tree species to future droughts. We confirm previous findings that emergent and dominant adult trees suffer more than from drought than co-dominant and sub-canopy trees, and that fire kills mostly small and thin barked trees. Combined, drought and fire tend to reduce forest stature. Overall, we confirmed that logging, drought, and fire pushed this forest towards one that, while reduced in height and basal area, is better adapted to future disturbances.

  19. Spatial assignment of symmetry adapted perturbation theory interaction energy components: The atomic SAPT partition

    SciTech Connect

    Parrish, Robert M.; Sherrill, C. David

    2014-07-28

    We develop a physically-motivated assignment of symmetry adapted perturbation theory for intermolecular interactions (SAPT) into atom-pairwise contributions (the A-SAPT partition). The basic precept of A-SAPT is that the many-body interaction energy components are computed normally under the formalism of SAPT, following which a spatially-localized two-body quasiparticle interaction is extracted from the many-body interaction terms. For electrostatics and induction source terms, the relevant quasiparticles are atoms, which are obtained in this work through the iterative stockholder analysis (ISA) procedure. For the exchange, induction response, and dispersion terms, the relevant quasiparticles are local occupied orbitals, which are obtained in this work through the Pipek-Mezey procedure. The local orbital atomic charges obtained from ISA additionally allow the terms involving local orbitals to be assigned in an atom-pairwise manner. Further summation over the atoms of one or the other monomer allows for a chemically intuitive visualization of the contribution of each atom and interaction component to the overall noncovalent interaction strength. Herein, we present the intuitive development and mathematical form for A-SAPT applied in the SAPT0 approximation (the A-SAPT0 partition). We also provide an efficient series of algorithms for the computation of the A-SAPT0 partition with essentially the same computational cost as the corresponding SAPT0 decomposition. We probe the sensitivity of the A-SAPT0 partition to the ISA grid and convergence parameter, orbital localization metric, and induction coupling treatment, and recommend a set of practical choices which closes the definition of the A-SAPT0 partition. We demonstrate the utility and computational tractability of the A-SAPT0 partition in the context of side-on cation-π interactions and the intercalation of DNA by proflavine. A-SAPT0 clearly shows the key processes in these complicated noncovalent interactions, in

  20. Spatial assignment of symmetry adapted perturbation theory interaction energy components: The atomic SAPT partition.

    PubMed

    Parrish, Robert M; Sherrill, C David

    2014-07-28

    We develop a physically-motivated assignment of symmetry adapted perturbation theory for intermolecular interactions (SAPT) into atom-pairwise contributions (the A-SAPT partition). The basic precept of A-SAPT is that the many-body interaction energy components are computed normally under the formalism of SAPT, following which a spatially-localized two-body quasiparticle interaction is extracted from the many-body interaction terms. For electrostatics and induction source terms, the relevant quasiparticles are atoms, which are obtained in this work through the iterative stockholder analysis (ISA) procedure. For the exchange, induction response, and dispersion terms, the relevant quasiparticles are local occupied orbitals, which are obtained in this work through the Pipek-Mezey procedure. The local orbital atomic charges obtained from ISA additionally allow the terms involving local orbitals to be assigned in an atom-pairwise manner. Further summation over the atoms of one or the other monomer allows for a chemically intuitive visualization of the contribution of each atom and interaction component to the overall noncovalent interaction strength. Herein, we present the intuitive development and mathematical form for A-SAPT applied in the SAPT0 approximation (the A-SAPT0 partition). We also provide an efficient series of algorithms for the computation of the A-SAPT0 partition with essentially the same computational cost as the corresponding SAPT0 decomposition. We probe the sensitivity of the A-SAPT0 partition to the ISA grid and convergence parameter, orbital localization metric, and induction coupling treatment, and recommend a set of practical choices which closes the definition of the A-SAPT0 partition. We demonstrate the utility and computational tractability of the A-SAPT0 partition in the context of side-on cation-π interactions and the intercalation of DNA by proflavine. A-SAPT0 clearly shows the key processes in these complicated noncovalent interactions, in

  1. Artificial color tuning of firefly luminescence: Theoretical mutation by tuning electrostatic interactions between protein and luciferin

    NASA Astrophysics Data System (ADS)

    Nakatani, Naoki; Hasegawa, Jun-ya; Nakatsuji, Hiroshi

    2009-02-01

    Electrostatic interactions between firefly oxyluciferin and the surrounding proteins were analyzed, and the amino acids important for controlling emission energy were identified. We propose Arg223Ala, Glu344Ala, and Asp422Ala mutations in firefly oxyluciferase of Photinuspyralis, which artificially change the luminescence color by tuning the electrostatic effect from the luciferase proteins. In the theoretical mutation simulation, the emission energy of the triple mutant was estimated to be 2.05 eV (602 nm, reddish-orange), which is 0.18 eV lower than that of the wild type (2.23 eV, 557 nm, yellow-green). For calculating the emission energies, we used the symmetry-adapted cluster-configuration interaction (SAC-CI) method.

  2. Calculation of hyperfine coupling constant by symmetry adapted cluster expansion configuration interaction theory. II. Anisotropic constants

    NASA Astrophysics Data System (ADS)

    Momose, Takamasa; Yamaguchi, Makoto; Shida, Tadamasa

    1990-11-01

    Following the previous work on the isotropic hyperfine coupling constants (HFCCs) of polyatomic radicals the symmetry adapted cluster expansion-configuration interaction (SAC-CI) theory is applied to calculate anisotropic HFCCs also. The results are compared with available experimental data from diatomic to polyatomic radicals such as the vinoxy. For radicals consisting of only the first row atoms Dunning's double zeta (DZ) basis set is shown to be adequate, but for those containing the second row atoms inclusion of polarization functions is required. Compared with the isotropic HFCC the calculation of the anisotropic HFCC is less formidable. However, ignorance of electron correlation causes serious disagreements with experimental data.

  3. The interaction of sexually and naturally selected traits in the adaptive radiations of cichlid fishes.

    PubMed

    Salzburger, Walter

    2009-01-01

    The question of how genetic variation translates into organismal diversity has puzzled biologists for decades. Despite recent advances in evolutionary and developmental genetics, the mechanisms that underlie adaptation, diversification and evolutionary innovation remain largely unknown. The exceptionally diverse species flocks of cichlid fishes are textbook examples of adaptive radiation and explosive speciation and emerge as powerful model systems to study the genetic basis of animal diversification. East Africa's hundreds of endemic cichlid species are akin to a natural mutagenesis screen and differ greatly not only in ecologically relevant (hence naturally selected) characters such as mouth morphology and body shape, but also in sexually selected traits such as coloration. One of the most fascinating aspects of cichlid evolution is the frequent occurrence of evolutionary parallelisms, which has led to the question whether selection alone is sufficient to produce these parallel morphologies, or whether a developmental or genetic bias has influenced the direction of diversification. Here, I review fitness-relevant traits that could be responsible for the cichlids' evolutionary success and assess whether these were shaped by sexual or natural selection. I then focus on the interaction and the relative importance of sexual vs. natural selection in cichlid evolution. Finally, I discuss what is currently known about the genes underlying the morphogenesis of adaptively relevant traits and highlight the importance of the forthcoming cichlid genomes in the quest of the genetic basis of diversification in this group. PMID:18992003

  4. Disentangling interactions between adaptive divergence and gene flow when ecology drives diversification.

    PubMed

    Räsänen, Katja; Hendry, Andrew P

    2008-06-01

    Adaptive diversification is driven by selection in ecologically different environments. In absence of geographical barriers to dispersal, this adaptive divergence (AD) may be constrained by gene flow (GF). And yet the reverse may also be true, with AD constraining GF (i.e. 'ecological speciation'). Both of these causal effects have frequently been inferred from the presence of negative correlations between AD and GF in nature - yet the bi-directional causality warrants caution in such inferences. We discuss how the ability of correlative studies to infer causation might be improved through the simultaneous measurement of multiple ecological and evolutionary variables. On the one hand, inferences about the causal role of GF can be made by examining correlations between AD and the potential for dispersal. On the other hand, inferences about the causal role of AD can be made by examining correlations between GF and environmental differences. Experimental manipulations of dispersal and environmental differences are a particularly promising approach for inferring causation. At present, the best studies find strong evidence that GF constrains AD and some studies also find the reverse. Improvements in empirical approaches promise to eventually allow general inferences about the relative strength of different causal interactions during adaptive diversification.

  5. The interaction of sexually and naturally selected traits in the adaptive radiations of cichlid fishes.

    PubMed

    Salzburger, Walter

    2009-01-01

    The question of how genetic variation translates into organismal diversity has puzzled biologists for decades. Despite recent advances in evolutionary and developmental genetics, the mechanisms that underlie adaptation, diversification and evolutionary innovation remain largely unknown. The exceptionally diverse species flocks of cichlid fishes are textbook examples of adaptive radiation and explosive speciation and emerge as powerful model systems to study the genetic basis of animal diversification. East Africa's hundreds of endemic cichlid species are akin to a natural mutagenesis screen and differ greatly not only in ecologically relevant (hence naturally selected) characters such as mouth morphology and body shape, but also in sexually selected traits such as coloration. One of the most fascinating aspects of cichlid evolution is the frequent occurrence of evolutionary parallelisms, which has led to the question whether selection alone is sufficient to produce these parallel morphologies, or whether a developmental or genetic bias has influenced the direction of diversification. Here, I review fitness-relevant traits that could be responsible for the cichlids' evolutionary success and assess whether these were shaped by sexual or natural selection. I then focus on the interaction and the relative importance of sexual vs. natural selection in cichlid evolution. Finally, I discuss what is currently known about the genes underlying the morphogenesis of adaptively relevant traits and highlight the importance of the forthcoming cichlid genomes in the quest of the genetic basis of diversification in this group.

  6. A time-accurate adaptive grid method and the numerical simulation of a shock-vortex interaction

    NASA Technical Reports Server (NTRS)

    Bockelie, Michael J.; Eiseman, Peter R.

    1990-01-01

    A time accurate, general purpose, adaptive grid method is developed that is suitable for multidimensional steady and unsteady numerical simulations. The grid point movement is performed in a manner that generates smooth grids which resolve the severe solution gradients and the sharp transitions in the solution gradients. The temporal coupling of the adaptive grid and the PDE solver is performed with a grid prediction correction method that is simple to implement and ensures the time accuracy of the grid. Time accurate solutions of the 2-D Euler equations for an unsteady shock vortex interaction demonstrate the ability of the adaptive method to accurately adapt the grid to multiple solution features.

  7. Adaptive nonlinear polynomial neural networks for control of boundary layer/structural interaction

    NASA Technical Reports Server (NTRS)

    Parker, B. Eugene, Jr.; Cellucci, Richard L.; Abbott, Dean W.; Barron, Roger L.; Jordan, Paul R., III; Poor, H. Vincent

    1993-01-01

    The acoustic pressures developed in a boundary layer can interact with an aircraft panel to induce significant vibration in the panel. Such vibration is undesirable due to the aerodynamic drag and structure-borne cabin noises that result. The overall objective of this work is to develop effective and practical feedback control strategies for actively reducing this flow-induced structural vibration. This report describes the results of initial evaluations using polynomial, neural network-based, feedback control to reduce flow induced vibration in aircraft panels due to turbulent boundary layer/structural interaction. Computer simulations are used to develop and analyze feedback control strategies to reduce vibration in a beam as a first step. The key differences between this work and that going on elsewhere are as follows: that turbulent and transitional boundary layers represent broadband excitation and thus present a more complex stochastic control scenario than that of narrow band (e.g., laminar boundary layer) excitation; and secondly, that the proposed controller structures are adaptive nonlinear infinite impulse response (IIR) polynomial neural network, as opposed to the traditional adaptive linear finite impulse response (FIR) filters used in most studies to date. The controllers implemented in this study achieved vibration attenuation of 27 to 60 dB depending on the type of boundary layer established by laminar, turbulent, and intermittent laminar-to-turbulent transitional flows. Application of multi-input, multi-output, adaptive, nonlinear feedback control of vibration in aircraft panels based on polynomial neural networks appears to be feasible today. Plans are outlined for Phase 2 of this study, which will include extending the theoretical investigation conducted in Phase 2 and verifying the results in a series of laboratory experiments involving both bum and plate models.

  8. Adaptive nonlinear polynomial neural networks for control of boundary layer/structural interaction

    NASA Astrophysics Data System (ADS)

    Parker, B. Eugene, Jr.; Cellucci, Richard L.; Abbott, Dean W.; Barron, Roger L.; Jordan, Paul R., III; Poor, H. Vincent

    1993-12-01

    The acoustic pressures developed in a boundary layer can interact with an aircraft panel to induce significant vibration in the panel. Such vibration is undesirable due to the aerodynamic drag and structure-borne cabin noises that result. The overall objective of this work is to develop effective and practical feedback control strategies for actively reducing this flow-induced structural vibration. This report describes the results of initial evaluations using polynomial, neural network-based, feedback control to reduce flow induced vibration in aircraft panels due to turbulent boundary layer/structural interaction. Computer simulations are used to develop and analyze feedback control strategies to reduce vibration in a beam as a first step. The key differences between this work and that going on elsewhere are as follows: that turbulent and transitional boundary layers represent broadband excitation and thus present a more complex stochastic control scenario than that of narrow band (e.g., laminar boundary layer) excitation; and secondly, that the proposed controller structures are adaptive nonlinear infinite impulse response (IIR) polynomial neural network, as opposed to the traditional adaptive linear finite impulse response (FIR) filters used in most studies to date. The controllers implemented in this study achieved vibration attenuation of 27 to 60 dB depending on the type of boundary layer established by laminar, turbulent, and intermittent laminar-to-turbulent transitional flows. Application of multi-input, multi-output, adaptive, nonlinear feedback control of vibration in aircraft panels based on polynomial neural networks appears to be feasible today. Plans are outlined for Phase 2 of this study, which will include extending the theoretical investigation conducted in Phase 2 and verifying the results in a series of laboratory experiments involving both bum and plate models.

  9. Burkholderia cenocepacia Differential Gene Expression during Host–Pathogen Interactions and Adaptation to the Host Environment

    PubMed Central

    O’Grady, Eoin P.; Sokol, Pamela A.

    2011-01-01

    Members of the Burkholderia cepacia complex (Bcc) are important in medical, biotechnological, and agricultural disciplines. These bacteria naturally occur in soil and water environments and have adapted to survive in association with plants and animals including humans. All Bcc species are opportunistic pathogens including Burkholderia cenocepacia that causes infections in cystic fibrosis and chronic granulomatous disease patients. The adaptation of B. cenocepacia to the host environment was assessed in a rat chronic respiratory infection model and compared to that of high cell-density in vitro grown cultures using transcriptomics. The distribution of genes differentially expressed on chromosomes 1, 2, and 3 was relatively proportional to the size of each genomic element, whereas the proportion of plasmid-encoded genes differentially expressed was much higher relative to its size and most genes were induced in vivo. The majority of genes encoding known virulence factors, components of types II and III secretion systems and chromosome 2-encoded type IV secretion system were similarly expressed between in vitro and in vivo environments. Lower expression in vivo was detected for genes encoding N-acyl-homoserine lactone synthase CepI, orphan LuxR homolog CepR2, zinc metalloproteases ZmpA and ZmpB, LysR-type transcriptional regulator ShvR, nematocidal protein AidA, and genes associated with flagellar motility, Flp type pilus formation, and type VI secretion. Plasmid-encoded type IV secretion genes were markedly induced in vivo. Additional genes induced in vivo included genes predicted to be involved in osmotic stress adaptation or intracellular survival, metal ion, and nutrient transport, as well as those encoding outer membrane proteins. Genes identified in this study are potentially important for virulence during host–pathogen interactions and may be associated with survival and adaptation to the host environment during chronic lung infections. PMID:22919581

  10. The role of idiotypic interactions in the adaptive immune system: a belief-propagation approach

    NASA Astrophysics Data System (ADS)

    Bartolucci, Silvia; Mozeika, Alexander; Annibale, Alessia

    2016-08-01

    In this work we use belief-propagation techniques to study the equilibrium behaviour of a minimal model for the immune system comprising interacting T and B clones. We investigate the effect of the so-called idiotypic interactions among complementary B clones on the system’s activation. Our results show that B-B interactions increase the system’s resilience to noise, making clonal activation more stable, while increasing the cross-talk between different clones. We derive analytically the noise level at which a B clone gets activated, in the absence of cross-talk, and find that this increases with the strength of idiotypic interactions and with the number of T cells sending signals to the B clones. We also derive, analytically and numerically, via population dynamics, the critical line where clonal cross-talk arises. Our approach allows us to derive the B clone size distribution, which can be experimentally measured and gives important information about the adaptive immune system response to antigens and vaccination.

  11. The role of idiotypic interactions in the adaptive immune system: a belief-propagation approach

    NASA Astrophysics Data System (ADS)

    Bartolucci, Silvia; Mozeika, Alexander; Annibale, Alessia

    2016-08-01

    In this work we use belief-propagation techniques to study the equilibrium behaviour of a minimal model for the immune system comprising interacting T and B clones. We investigate the effect of the so-called idiotypic interactions among complementary B clones on the system’s activation. Our results show that B–B interactions increase the system’s resilience to noise, making clonal activation more stable, while increasing the cross-talk between different clones. We derive analytically the noise level at which a B clone gets activated, in the absence of cross-talk, and find that this increases with the strength of idiotypic interactions and with the number of T cells sending signals to the B clones. We also derive, analytically and numerically, via population dynamics, the critical line where clonal cross-talk arises. Our approach allows us to derive the B clone size distribution, which can be experimentally measured and gives important information about the adaptive immune system response to antigens and vaccination.

  12. Measuring the Impact of a Moving Target: Towards a Dynamic Framework for Evaluating Collaborative Adaptive Interactive Technologies

    PubMed Central

    Witteman, Holly; Bender, Jacqueline L; Urowitz, Sara; Wiljer, David; Jadad, Alejandro R

    2009-01-01

    Background Website evaluation is a key issue for researchers, organizations, and others responsible for designing, maintaining, endorsing, approving, and/or assessing the use and impact of interventions designed to influence health and health services. Traditionally, these evaluations have included elements such as content credibility, interface usability, and overall design aesthetics. With the emergence of collaborative, adaptive, and interactive ("Web 2.0") technologies such as wikis and other forms of social networking applications, these metrics may no longer be sufficient to adequately assess the quality, use or impact of a health website. Collaborative, adaptive, interactive applications support different ways for people to interact with health information on the Web, including the potential for increased user participation in the design, creation, and maintenance of such sites. Objective We propose a framework that addresses how to evaluate collaborative, adaptive, and interactive applications. Methods In this paper, we conducted a comprehensive review of a variety of databases using terminology related to this area. Results We present a review of evaluation frameworks and also propose a framework that incorporates collaborative, adaptive, and interactive technologies, grounded in evaluation theory. Conclusion This framework can be applied by researchers who wish to compare Web-based interventions, non-profit organizations, and clinical groups who aim to provide health information and support about a particular health concern via the Web, and decisions about funding grants by agencies interested in the role of social networks and collaborative, adaptive, and interactive technologies technologies to improve health and the health system. PMID:19632973

  13. Classification of short-lived objects using an interactive adaptable assistance system

    NASA Astrophysics Data System (ADS)

    El Bekri, Nadia; Angele, Susanne; Peinsipp-Byma, Elisabeth

    2015-05-01

    "Although we know that it is not a familiar object, after a while we can say what it resembles". The core task of an aerial image analyst is to recognize different object types based on certain clearly classified characteristics from aerial or satellite images. An interactive recognition assistance system compares selected features with a fixed set of reference objects (core data set). Therefore it is mainly designed to evaluate durable single objects like a specific type of ship or vehicle. Aerial image analysts on missions realized a changed warfare over the time. The task was not anymore to classify and thereby recognize a single durable object. The problem was that they had to classify strong variable objects and the reference set did not match anymore. In order to approach this new scope we introduce a concept to a further development of the interactive assistance system to be able to handle also short-lived, not clearly classifiable and strong variable objects like for example dhows. Dhows are the type of ships that are often used during pirate attacks at the coast of West Africa. Often these ships were build or extended by the pirates themselves. They follow no particular pattern as the standard construction of a merchant ship. In this work we differ between short-lived and durable objects. The interactive adaptable assistance system is supposed to assist image analysts with the classification of objects, which are new and not listed in the reference set of objects yet. The human interaction and perception is an important factor in order to realize this task and achieve the goal of recognition. Therefore we had to model the possibility to classify short-lived objects with appropriate procedures taking into consideration all aspects of short-lived objects. In this paper we will outline suitable measures and the possibilities to categorize short-lived objects via simple basic shapes as well as a temporary data storage concept for shortlived objects. The

  14. Levels of symmetry adapted perturbation theory (SAPT). I. Efficiency and performance for interaction energies.

    PubMed

    Parker, Trent M; Burns, Lori A; Parrish, Robert M; Ryno, Alden G; Sherrill, C David

    2014-03-01

    A systematic examination of the computational expense and accuracy of Symmetry-Adapted Perturbation Theory (SAPT) for the prediction of non-covalent interaction energies is provided with respect to both method [SAPT0, DFT-SAPT, SAPT2, SAPT2+, SAPT2+(3), and SAPT2+3; with and without CCD dispersion for the last three] and basis set [Dunning cc-pVDZ through aug-cc-pV5Z wherever computationally tractable, including truncations of diffuse basis functions]. To improve accuracy for hydrogen-bonded systems, we also include two corrections based on exchange-scaling (sSAPT0) and the supermolecular MP2 interaction energy (δMP2). When considering the best error performance relative to computational effort, we recommend as the gold, silver, and bronze standard of SAPT: SAPT2+(3)δMP2/aug-cc-pVTZ, SAPT2+/aug-cc-pVDZ, and sSAPT0/jun-cc-pVDZ. Their respective mean absolute errors in interaction energy across the S22, HBC6, NBC10, and HSG databases are 0.15 (62.9), 0.30 (4.4), and 0.49 kcal mol(-1) (0.03 h for adenine·thymine complex).

  15. Adaptive evolutionary paths from UV reception to sensing violet light by epistatic interactions

    PubMed Central

    Yokoyama, Shozo; Altun, Ahmet; Jia, Huiyong; Yang, Hui; Koyama, Takashi; Faggionato, Davide; Liu, Yang; Starmer, William T.

    2015-01-01

    Ultraviolet (UV) reception is useful for such basic behaviors as mate choice, foraging, predator avoidance, communication, and navigation, whereas violet reception improves visual resolution and subtle contrast detection. UV and violet reception are mediated by the short wavelength–sensitive (SWS1) pigments that absorb light maximally (λmax) at ~360 nm and ~395 to 440 nm, respectively. Because of strong nonadditive (epistatic) interactions among amino acid changes in the pigments, the adaptive evolutionary mechanisms of these phenotypes are not well understood. Evolution of the violet pigment of the African clawed frog (Xenopus laevis, λmax = 423 nm) from the UV pigment in the amphibian ancestor (λmax = 359 nm) can be fully explained by eight mutations in transmembrane (TM) I–III segments. We show that epistatic interactions involving the remaining TM IV–VII segments provided evolutionary potential for the frog pigment to gradually achieve its violet-light reception by tuning its color sensitivity in small steps. Mutants in these segments also impair pigments that would cause drastic spectral shifts and thus eliminate them from viable evolutionary pathways. The overall effects of epistatic interactions involving TM IV–VII segments have disappeared at the last evolutionary step and thus are not detectable by studying present-day pigments. Therefore, characterizing the genotype-phenotype relationship during each evolutionary step is the key to uncover the true nature of epistasis. PMID:26601250

  16. Nonlinear Effects of Nanoparticles: Biological Variability From Hormetic Doses, Small Particle Sizes, and Dynamic Adaptive Interactions

    PubMed Central

    Bell, Iris R.; Ives, John A.; Jonas, Wayne B.

    2014-01-01

    Researchers are increasingly focused on the nanoscale level of organization where biological processes take place in living systems. Nanoparticles (NPs, e.g., 1–100 nm diameter) are small forms of natural or manufactured source material whose properties differ markedly from those of the respective bulk forms of the “same” material. Certain NPs have diagnostic and therapeutic uses; some NPs exhibit low-dose toxicity; other NPs show ability to stimulate low-dose adaptive responses (hormesis). Beyond dose, size, shape, and surface charge variations of NPs evoke nonlinear responses in complex adaptive systems. NPs acquire unique size-dependent biological, chemical, thermal, optical, electromagnetic, and atom-like quantum properties. Nanoparticles exhibit high surface adsorptive capacity for other substances, enhanced bioavailability, and ability to cross otherwise impermeable cell membranes including the blood-brain barrier. With super-potent effects, nano-forms can evoke cellular stress responses or therapeutic effects not only at lower doses than their bulk forms, but also for longer periods of time. Interactions of initial effects and compensatory systemic responses can alter the impact of NPs over time. Taken together, the data suggest the need to downshift the dose-response curve of NPs from that for bulk forms in order to identify the necessarily decreased no-observed-adverse-effect-level and hormetic dose range for nanoparticles. PMID:24910581

  17. Multifluid adaptive-mesh simulation of the solar wind interaction with the local interstellar medium

    SciTech Connect

    Kryukov, I. A.; Borovikov, S. N.; Pogorelov, N. V.; Zank, G. P.

    2006-09-26

    DOE's SciDAC adaptive mesh refinement code Chombo has been modified for solution of compressible MHD flows with the application of high resolution, shock-capturing numerical schemes. The code developed is further extended to involve multiple fluids and applied to the problem of the solar wind interaction with the local interstellar medium. For this purpose, a set of MHD equations is solved together with a few sets of the Euler gas dynamics equations, depending on the number of neutral fluids included in the model. Our first results are presented that were obtained in the framework of an axially symmetric multifluid model which is applicable to magnetic-field-aligned flows. Details are shown of the generation and development of Rayleigh-Taylor and Kelvin-Helmholtz instabilities of the heliopause. A comparison is given of the results obtained with a two- and four-fluid models.

  18. Interactions of innate and adaptive immunity in brain development and function

    PubMed Central

    Filiano, Anthony J.; Gadani, Sachin P.; Kipnis, Jonathan

    2014-01-01

    It has been known for decades that the immune system has a tremendous impact on behavior. Most work has described the negative role of immune cells on the central nervous system. However, we and others have demonstrated over the last decade that a well-regulated immune system is needed for proper brain function. Here we discuss several neuro-immune interactions, using examples from brain homeostasis and disease states. We will highlight our understanding of the consequences of malfunctioning immunity on neurodevelopment and will discuss the roles of the innate and adaptive immune system in neurodevelopment and how T cells maintain a proper innate immune balance in the brain surroundings and within its parenchyma. Also, we describe how immune imbalance impairs higher order brain functioning, possibly leading to behavioral and cognitive impairment. Lastly, we propose our hypothesis that some behavioral deficits in neurodevelopmental disorders, such as in autism spectrum disorder, are the consequence of malfunctioning immunity. PMID:25110235

  19. Method and system for rendering and interacting with an adaptable computing environment

    DOEpatents

    Osbourn, Gordon Cecil; Bouchard, Ann Marie

    2012-06-12

    An adaptable computing environment is implemented with software entities termed "s-machines", which self-assemble into hierarchical data structures capable of rendering and interacting with the computing environment. A hierarchical data structure includes a first hierarchical s-machine bound to a second hierarchical s-machine. The first hierarchical s-machine is associated with a first layer of a rendering region on a display screen and the second hierarchical s-machine is associated with a second layer of the rendering region overlaying at least a portion of the first layer. A screen element s-machine is linked to the first hierarchical s-machine. The screen element s-machine manages data associated with a screen element rendered to the display screen within the rendering region at the first layer.

  20. Adaptation of the Mitochondrial Genome in Cephalopods: Enhancing Proton Translocation Channels and the Subunit Interactions

    PubMed Central

    Almeida, Daniela; Maldonado, Emanuel; Vasconcelos, Vitor; Antunes, Agostinho

    2015-01-01

    Mitochondrial protein-coding genes (mt genes) encode subunits forming complexes of crucial cellular pathways, including those involved in the vital process of oxidative phosphorylation (OXPHOS). Despite the vital role of the mitochondrial genome (mt genome) in the survival of organisms, little is known with respect to its adaptive implications within marine invertebrates. The molluscan Class Cephalopoda is represented by a marine group of species known to occupy contrasting environments ranging from the intertidal to the deep sea, having distinct metabolic requirements, varied body shapes and highly advanced visual and nervous systems that make them highly competitive and successful worldwide predators. Thus, cephalopods are valuable models for testing natural selection acting on their mitochondrial subunits (mt subunits). Here, we used concatenated mt genes from 17 fully sequenced mt genomes of diverse cephalopod species to generate a robust mitochondrial phylogeny for the Class Cephalopoda. We followed an integrative approach considering several branches of interest–covering cephalopods with distinct morphologies, metabolic rates and habitats–to identify sites under positive selection and localize them in the respective protein alignment and/or tridimensional structure of the mt subunits. Our results revealed significant adaptive variation in several mt subunits involved in the energy production pathway of cephalopods: ND5 and ND6 from Complex I, CYTB from Complex III, COX2 and COX3 from Complex IV, and in ATP8 from Complex V. Furthermore, we identified relevant sites involved in protein-interactions, lining proton translocation channels, as well as disease/deficiencies related sites in the aforementioned complexes. A particular case, revealed by this study, is the involvement of some positively selected sites, found in Octopoda lineage in lining proton translocation channels (site 74 from ND5) and in interactions between subunits (site 507 from ND5) of

  1. Adaptation of the Mitochondrial Genome in Cephalopods: Enhancing Proton Translocation Channels and the Subunit Interactions.

    PubMed

    Almeida, Daniela; Maldonado, Emanuel; Vasconcelos, Vitor; Antunes, Agostinho

    2015-01-01

    Mitochondrial protein-coding genes (mt genes) encode subunits forming complexes of crucial cellular pathways, including those involved in the vital process of oxidative phosphorylation (OXPHOS). Despite the vital role of the mitochondrial genome (mt genome) in the survival of organisms, little is known with respect to its adaptive implications within marine invertebrates. The molluscan Class Cephalopoda is represented by a marine group of species known to occupy contrasting environments ranging from the intertidal to the deep sea, having distinct metabolic requirements, varied body shapes and highly advanced visual and nervous systems that make them highly competitive and successful worldwide predators. Thus, cephalopods are valuable models for testing natural selection acting on their mitochondrial subunits (mt subunits). Here, we used concatenated mt genes from 17 fully sequenced mt genomes of diverse cephalopod species to generate a robust mitochondrial phylogeny for the Class Cephalopoda. We followed an integrative approach considering several branches of interest-covering cephalopods with distinct morphologies, metabolic rates and habitats-to identify sites under positive selection and localize them in the respective protein alignment and/or tridimensional structure of the mt subunits. Our results revealed significant adaptive variation in several mt subunits involved in the energy production pathway of cephalopods: ND5 and ND6 from Complex I, CYTB from Complex III, COX2 and COX3 from Complex IV, and in ATP8 from Complex V. Furthermore, we identified relevant sites involved in protein-interactions, lining proton translocation channels, as well as disease/deficiencies related sites in the aforementioned complexes. A particular case, revealed by this study, is the involvement of some positively selected sites, found in Octopoda lineage in lining proton translocation channels (site 74 from ND5) and in interactions between subunits (site 507 from ND5) of Complex I

  2. Adaptation of the Mitochondrial Genome in Cephalopods: Enhancing Proton Translocation Channels and the Subunit Interactions.

    PubMed

    Almeida, Daniela; Maldonado, Emanuel; Vasconcelos, Vitor; Antunes, Agostinho

    2015-01-01

    Mitochondrial protein-coding genes (mt genes) encode subunits forming complexes of crucial cellular pathways, including those involved in the vital process of oxidative phosphorylation (OXPHOS). Despite the vital role of the mitochondrial genome (mt genome) in the survival of organisms, little is known with respect to its adaptive implications within marine invertebrates. The molluscan Class Cephalopoda is represented by a marine group of species known to occupy contrasting environments ranging from the intertidal to the deep sea, having distinct metabolic requirements, varied body shapes and highly advanced visual and nervous systems that make them highly competitive and successful worldwide predators. Thus, cephalopods are valuable models for testing natural selection acting on their mitochondrial subunits (mt subunits). Here, we used concatenated mt genes from 17 fully sequenced mt genomes of diverse cephalopod species to generate a robust mitochondrial phylogeny for the Class Cephalopoda. We followed an integrative approach considering several branches of interest-covering cephalopods with distinct morphologies, metabolic rates and habitats-to identify sites under positive selection and localize them in the respective protein alignment and/or tridimensional structure of the mt subunits. Our results revealed significant adaptive variation in several mt subunits involved in the energy production pathway of cephalopods: ND5 and ND6 from Complex I, CYTB from Complex III, COX2 and COX3 from Complex IV, and in ATP8 from Complex V. Furthermore, we identified relevant sites involved in protein-interactions, lining proton translocation channels, as well as disease/deficiencies related sites in the aforementioned complexes. A particular case, revealed by this study, is the involvement of some positively selected sites, found in Octopoda lineage in lining proton translocation channels (site 74 from ND5) and in interactions between subunits (site 507 from ND5) of Complex I.

  3. Characterizing Microbe-Environment Interactions Through Experimental Evolution: The Autonomous Adaptive Directed Evolution Chamber

    NASA Astrophysics Data System (ADS)

    Ibanez, C. R.; Blaich, J.; Owyang, S.; Storrs, A.; Moffet, A.; Wong, N.; Zhou, J.; Gentry, D.

    2015-12-01

    We are developing a laboratory system for studying micro- to meso-scale interactions between microorganisms and their physicochemical environments. The Autonomous Adaptive Directed Evolution Chamber (AADEC) cultures microorganisms in controlled,small-scale geochemical environments. It observes corresponding microbial interactions to these environments and has the ability to adjust thermal, chemical, and other parameters in real time in response to these interactions. In addition to the sensed data, the system allows the generation of time-resolved ecological, genomic, etc. samples on the order of microbial generations. The AADEC currently houses cultures in liquid media and controls UVC radiation, heat exposure, and nutrient supply. In a proof-of-concept experimental evolution application, it can increase UVC radiation resistance of Escherichia coli cultures by iteratively exposing them to UVC and allowing the surviving cells to regrow. A baseline characterization generated a million fold resistance increase. This demonstration uses a single-well growth chamber prototype, but it was limited by scalability. We have expanded upon this system by implementing a microwell plate compatible fluidics system and sensor housing. This microwell plate system increases the diversity of microbial interactions seen in response to the geochemical environments generated by the system, allowing greater control over individual cultures' environments and detection of rarer events. The custom microfluidic card matches the footprint of a standard microwell plate. This card enables controllable fluid flow between wells and introduces multiple separate exposure and sensor chambers, increasing the variety of sensors compatible with the system. This gives the device control over scale and the interconnectedness of environments within the system. The increased controllability of the multiwell system provides a platform for implementing machine learning algorithms that will autonomously

  4. Context-dependent planktivory: interacting effects of turbidity and predation risk on adaptive foraging

    USGS Publications Warehouse

    Pangle, Kevin L.; Malinich, Timothy D.; Bunnell, David B.; DeVries, Dennis R.; Ludsin, Stuart A.

    2012-01-01

    By shaping species interactions, adaptive phenotypic plasticity can profoundly influence ecosystems. Predicting such outcomes has proven difficult, however, owing in part to the dependence of plasticity on the environmental context. Of particular relevance are environmental factors that affect sensory performance in organisms in ways that alter the tradeoffs associated with adaptive phenotypic responses. We explored the influence of turbidity, which simultaneously and differentially affects the sensory performance of consumers at multiple trophic levels, on the indirect effect of a top predator (piscivorous fish) on a basal prey resource (zooplankton) that is mediated through changes in the plastic foraging behavior of an intermediate consumer (zooplanktivorous fish). We first generated theoretical predictions of the adaptive foraging response of a zooplanktivore across wide gradients of turbidity and predation risk by a piscivore. Our model predicted that predation risk can change the negative relationship between intermediate consumer foraging and turbidity into a humped-shaped (unimodal) one in which foraging is low in both clear and highly turbid conditions due to foraging-related risk and visual constraints, respectively. Consequently, the positive trait-mediated indirect effect (TMIE) of the top predator on the basal resource is predicted to peak at low turbidity and decline thereafter until it reaches an asymptote of zero at intermediate turbidity levels (when foraging equals that which is predicted when the top predator is absent). We used field observations and a laboratory experiment to test our model predictions. In support, we found humped-shaped relationships between planktivory and turbidity for several zooplanktivorous fishes from diverse freshwater ecosystems with predation risk. Further, our experiment demonstrated that predation risk reduced zooplanktivory by yellow perch (Perca flavescens) at a low turbidity, but had no effect on consumption at

  5. Science Roles and Interactions in Adaptive Management of Large River Restoration Projects, Midwest United States

    NASA Astrophysics Data System (ADS)

    Jacobson, R. B.; Galat, D. L.; Smith, C. B.

    2010-12-01

    Most large-river restoration projects include formal or informal implementations of adaptive management strategies which acknowledge uncertainty and use scientific inquiry to learn and refine management options. Although the central role of science in reducing uncertainty is acknowledged in such projects, specific roles and interactions can vary widely, including how science relates to decision-making within the governance of these projects. Our objective is to present some structured generalizations about science roles and interactions as developed from the authors’ experiences in adaptive management of large river restoration in the Midwest United States. Scientific information may be introduced into decision making by scientists acting in any of the three roles common to adaptive management -- action agency representative, stakeholder, or science provider. We have observed that confusion and gridlock can arise when it is unclear if a scientist is acting as an advocate for a stakeholder or management position, or instead as an independent, “honest broker” of science. Although both advocacy and independence are proper and expected in public decision making, it is useful when scientists unambiguously identify their role. While complete scientific independence may be illusory, transparency and peer review can promote the ideal. Transparency comes from setting clear directions and objectives at the decision-making level and defining at the outset how learning will help assess progress and inform decisions. Independent peer reviews of proposals, study plans, and publications serve as a powerful tool to advance scientific independence, even if funding sources present a potential conflict of interest. Selection of experts for scientific advice and review often requires consideration of the balance between benefits of the “outside” expert (independent, knowledgeable but with little specific understanding of the river system), compared to those provided by the

  6. Antarctic archaea–virus interactions: metaproteome-led analysis of invasion, evasion and adaptation

    PubMed Central

    Tschitschko, Bernhard; Williams, Timothy J; Allen, Michelle A; Páez-Espino, David; Kyrpides, Nikos; Zhong, Ling; Raftery, Mark J; Cavicchioli, Ricardo

    2015-01-01

    Despite knowledge that viruses are abundant in natural ecosystems, there is limited understanding of which viruses infect which hosts, and how both hosts and viruses respond to those interactions—interactions that ultimately shape community structure and dynamics. In Deep Lake, Antarctica, intergenera gene exchange occurs rampantly within the low complexity, haloarchaea-dominated community, strongly balanced by distinctions in niche adaptation which maintain sympatric speciation. By performing metaproteomics for the first time on haloarchaea, genomic variation of S-layer, archaella and other cell surface proteins was linked to mechanisms of infection evasion. CRISPR defense systems were found to be active, with haloarchaea responding to at least eight distinct types of viruses, including those infecting between genera. The role of BREX systems in defending against viruses was also examined. Although evasion and defense were evident, both hosts and viruses also may benefit from viruses carrying and expressing host genes, thereby potentially enhancing genetic variation and phenotypic differences within populations. The data point to a complex inter-play leading to a dynamic optimization of host–virus interactions. This comprehensive overview was achieved only through the integration of results from metaproteomics, genomics and metagenomics. PMID:26125682

  7. A unified set-based test with adaptive filtering for gene-environment interaction analyses.

    PubMed

    Liu, Qianying; Chen, Lin S; Nicolae, Dan L; Pierce, Brandon L

    2016-06-01

    In genome-wide gene-environment interaction (GxE) studies, a common strategy to improve power is to first conduct a filtering test and retain only the SNPs that pass the filtering in the subsequent GxE analyses. Inspired by two-stage tests and gene-based tests in GxE analysis, we consider the general problem of jointly testing a set of parameters when only a few are truly from the alternative hypothesis and when filtering information is available. We propose a unified set-based test that simultaneously considers filtering on individual parameters and testing on the set. We derive the exact distribution and approximate the power function of the proposed unified statistic in simplified settings, and use them to adaptively calculate the optimal filtering threshold for each set. In the context of gene-based GxE analysis, we show that although the empirical power function may be affected by many factors, the optimal filtering threshold corresponding to the peak of the power curve primarily depends on the size of the gene. We further propose a resampling algorithm to calculate P-values for each gene given the estimated optimal filtering threshold. The performance of the method is evaluated in simulation studies and illustrated via a genome-wide gene-gender interaction analysis using pancreatic cancer genome-wide association data. PMID:26496228

  8. A unified set-based test with adaptive filtering for gene-environment interaction analyses

    PubMed Central

    Liu, Qianying; Chen, Lin S.; Nicolae, Dan L.; Pierce, Brandon L.

    2015-01-01

    Summary In genome-wide gene-environment interaction (GxE) studies, a common strategy to improve power is to first conduct a filtering test and retain only the SNPs that pass the filtering in the subsequent GxE analyses. Inspired by two-stage tests and gene-based tests in GxE analysis, we consider the general problem of jointly testing a set of parameters when only a few are truly from the alternative hypothesis and when filtering information is available. We propose a unified set-based test that simultaneously considers filtering on individual parameters and testing on the set. We derive the exact distribution and approximate the power function of the proposed unified statistic in simplified settings, and use them to adaptively calculate the optimal filtering threshold for each set. In the context of gene-based GxE analysis, we show that although the empirical power function may be affected by many factors, the optimal filtering threshold corresponding to the peak of the power curve primarily depends on the size of the gene. We further propose a resampling algorithm to calculate p-values for each gene given the estimated optimal filtering threshold. The performance of the method is evaluated in simulation studies and illustrated via a genome-wide gene-gender interaction analysis using pancreatic cancer genome-wide association data. PMID:26496228

  9. Overcoming scepticism: Interacting influences of geographical location on perceived climate change adaptation measures to water resources in Spain

    NASA Astrophysics Data System (ADS)

    Iglesias, Ana; Garrote, Luis; Bardaji, Isabel; Iglesias, Pedro; Granados, Alfredo

    2016-04-01

    Though many climate adaptation efforts attempt to be defined with the participation of local communities, these strategies may be ineffective because among citizens affected equally, a local risk perception rather than scientific understanding largely drives adaptation choices. Further, the geographical location may polarize climate risk perceptions, making some adaptation efforts ineffective among sceptics. This study examines how the local degradation of the environment and water resources relates to adaption choices and in turn, climate change risk perception among a range of citizens in the Tagus basin, Spain (n = 300). We find respondents of less degraded areas have individualistic responses, and are significantly less likely to accept adaptation strategies than respondents in water stressed communities. The interaction between climate knowledge and adaptation choices is positively related to acceptance of adaptation choices in both groups, and had a stronger positive relationship among individualists. There is no statistical difference in acceptance of adaptation between individualists and communitarians at high levels of knowledge (top decile). Thus, education efforts specific to climate change may counteract divisions based geographical location and environmental stress.

  10. Babesia and its hosts: adaptation to long-lasting interactions as a way to achieve efficient transmission

    PubMed Central

    Chauvin, Alain; Moreau, Emmanuelle; Bonnet, Sarah; Plantard, Olivier; Malandrin, Laurence

    2009-01-01

    Babesia, the causal agent of babesiosis, are tick-borne apicomplexan protozoa. True babesiae (Babesia genus sensu stricto) are biologically characterized by direct development in erythrocytes and by transovarial transmission in the tick. A large number of true Babesia species have been described in various vertebrate and tick hosts. This review presents the genus then discusses specific adaptations of Babesia spp. to their hosts to achieve efficient transmission. The main adaptations lead to long-lasting interactions which result in the induction of two reservoirs: in the vertebrate host during low long-term parasitemia and throughout the life cycle of the tick host as a result of transovarial and transstadial transmission. The molecular bases of these adaptations in vertebrate hosts are partially known but few of the tick-host interaction mechanisms have been elucidated. PMID:19379662

  11. Launch Vehicle Manual Steering with Adaptive Augmenting Control In-flight Evaluations of Adverse Interactions Using a Piloted Aircraft

    NASA Technical Reports Server (NTRS)

    Hanson, Curt; Miller, Chris; Wall, John H.; Vanzwieten, Tannen S.; Gilligan, Eric; Orr, Jeb S.

    2015-01-01

    An adaptive augmenting control algorithm for the Space Launch System has been developed at the Marshall Space Flight Center as part of the launch vehicles baseline flight control system. A prototype version of the SLS flight control software was hosted on a piloted aircraft at the Armstrong Flight Research Center to demonstrate the adaptive controller on a full-scale realistic application in a relevant flight environment. Concerns regarding adverse interactions between the adaptive controller and a proposed manual steering mode were investigated by giving the pilot trajectory deviation cues and pitch rate command authority. Two NASA research pilots flew a total of twenty five constant pitch-rate trajectories using a prototype manual steering mode with and without adaptive control.

  12. Using a Multicomponent Adapted Power Card Strategy to Decrease Latency during Interactivity Transitions for Three Children with Developmental Disabilities

    ERIC Educational Resources Information Center

    Angell, Maureen E.; Nicholson, Joanna K.; Watts, Emily H.; Blum, Craig

    2011-01-01

    An adapted Power Card strategy was examined to determine effectiveness in decreasing latency in responding to teacher cues to initiate interactivity transitions in the classroom among three students, aged 10 to 11 years, with developmental disabilities (i.e., one with autism and two with intellectual disability). The Power Card strategy, a form of…

  13. Revision of FMM-Yukawa: An adaptive fast multipole method for screened Coulomb interactions

    NASA Astrophysics Data System (ADS)

    Zhang, Bo; Huang, Jingfang; Pitsianis, Nikos P.; Sun, Xiaobai

    2010-12-01

    FMM-YUKAWA is a mathematical software package primarily for rapid evaluation of the screened Coulomb interactions of N particles in three dimensional space. Since its release, we have revised and re-organized the data structure, software architecture, and user interface, for the purpose of enabling more flexible, broader and easier use of the package. The package and its documentation are available at http://www.fastmultipole.org/, along with a few other closely related mathematical software packages. New version program summaryProgram title: FMM-Yukawa Catalogue identifier: AEEQ_v2_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEQ_v2_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GNU GPL 2.0 No. of lines in distributed program, including test data, etc.: 78 704 No. of bytes in distributed program, including test data, etc.: 854 265 Distribution format: tar.gz Programming language: FORTRAN 77, FORTRAN 90, and C. Requires gcc and gfortran version 4.4.3 or later Computer: All Operating system: Any Classification: 4.8, 4.12 Catalogue identifier of previous version: AEEQ_v1_0 Journal reference of previous version: Comput. Phys. Comm. 180 (2009) 2331 Does the new version supersede the previous version?: Yes Nature of problem: To evaluate the screened Coulomb potential and force field of N charged particles, and to evaluate a convolution type integral where the Green's function is the fundamental solution of the modified Helmholtz equation. Solution method: The new version of fast multipole method (FMM) that diagonalizes the multipole-to-local translation operator is applied with the tree structure adaptive to sample particle locations. Reasons for new version: To handle much larger particle ensembles, to enable the iterative use of the subroutines in a solver, and to remove potential contention in assignments for parallelization. Summary of revisions: The software package FMM-Yukawa has been

  14. FMM-Yukawa: An adaptive fast multipole method for screened Coulomb interactions

    NASA Astrophysics Data System (ADS)

    Huang, Jingfang; Jia, Jun; Zhang, Bo

    2009-11-01

    A Fortran program package is introduced for the rapid evaluation of the screened Coulomb interactions of N particles in three dimensions. The method utilizes an adaptive oct-tree structure, and is based on the new version of fast multipole method in which the exponential expansions are used to diagonalize the multipole-to-local translations. The program and its full description, as well as several closely related packages are also available at http://www.fastmultipole.org/. This paper is a brief review of the program and its performance. Catalogue identifier: AEEQ_v1_0 Program summary URL:http://cpc.cs.qub.ac.uk/summaries/AEEQ_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: GPL 2.0 No. of lines in distributed program, including test data, etc.: 12 385 No. of bytes in distributed program, including test data, etc.: 79 222 Distribution format: tar.gz Programming language: Fortran77 and Fortran90 Computer: Any Operating system: Any RAM: Depends on the number of particles, their distribution, and the adaptive tree structure Classification: 4.8, 4.12 Nature of problem: To evaluate the screened Coulomb potential and force field of N charged particles, and to evaluate a convolution type integral where the Green's function is the fundamental solution of the modified Helmholtz equation. Solution method: An adaptive oct-tree is generated, and a new version of fast multipole method is applied in which the "multipole-to-local" translation operator is diagonalized. Restrictions: Only three and six significant digits accuracy options are provided in this version. Unusual features: Most of the codes are written in

  15. Human-Automation Interaction Design for Adaptive Cruise Control Systems of Ground Vehicles.

    PubMed

    Eom, Hwisoo; Lee, Sang Hun

    2015-01-01

    A majority of recently developed advanced vehicles have been equipped with various automated driver assistance systems, such as adaptive cruise control (ACC) and lane keeping assistance systems. ACC systems have several operational modes, and drivers can be unaware of the mode in which they are operating. Because mode confusion is a significant human error factor that contributes to traffic accidents, it is necessary to develop user interfaces for ACC systems that can reduce mode confusion. To meet this requirement, this paper presents a new human-automation interaction design methodology in which the compatibility of the machine and interface models is determined using the proposed criteria, and if the models are incompatible, one or both of the models is/are modified to make them compatible. To investigate the effectiveness of our methodology, we designed two new interfaces by separately modifying the machine model and the interface model and then performed driver-in-the-loop experiments. The results showed that modifying the machine model provides a more compact, acceptable, effective, and safe interface than modifying the interface model. PMID:26076406

  16. Human-Automation Interaction Design for Adaptive Cruise Control Systems of Ground Vehicles.

    PubMed

    Eom, Hwisoo; Lee, Sang Hun

    2015-01-01

    A majority of recently developed advanced vehicles have been equipped with various automated driver assistance systems, such as adaptive cruise control (ACC) and lane keeping assistance systems. ACC systems have several operational modes, and drivers can be unaware of the mode in which they are operating. Because mode confusion is a significant human error factor that contributes to traffic accidents, it is necessary to develop user interfaces for ACC systems that can reduce mode confusion. To meet this requirement, this paper presents a new human-automation interaction design methodology in which the compatibility of the machine and interface models is determined using the proposed criteria, and if the models are incompatible, one or both of the models is/are modified to make them compatible. To investigate the effectiveness of our methodology, we designed two new interfaces by separately modifying the machine model and the interface model and then performed driver-in-the-loop experiments. The results showed that modifying the machine model provides a more compact, acceptable, effective, and safe interface than modifying the interface model.

  17. 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.

  18. Human-Automation Interaction Design for Adaptive Cruise Control Systems of Ground Vehicles

    PubMed Central

    Eom, Hwisoo; Lee, Sang Hun

    2015-01-01

    A majority of recently developed advanced vehicles have been equipped with various automated driver assistance systems, such as adaptive cruise control (ACC) and lane keeping assistance systems. ACC systems have several operational modes, and drivers can be unaware of the mode in which they are operating. Because mode confusion is a significant human error factor that contributes to traffic accidents, it is necessary to develop user interfaces for ACC systems that can reduce mode confusion. To meet this requirement, this paper presents a new human-automation interaction design methodology in which the compatibility of the machine and interface models is determined using the proposed criteria, and if the models are incompatible, one or both of the models is/are modified to make them compatible. To investigate the effectiveness of our methodology, we designed two new interfaces by separately modifying the machine model and the interface model and then performed driver-in-the-loop experiments. The results showed that modifying the machine model provides a more compact, acceptable, effective, and safe interface than modifying the interface model. PMID:26076406

  19. Clinal resistance structure and pathogen local adaptation in a serpentine flax-flax rust interaction.

    PubMed

    Springer, Yuri P

    2007-08-01

    Because disease resistance is a hallmark signature of pathogen-mediated selection pressure on hosts, studies of resistance structure (the spatial distribution of disease resistance genes among conspecific host populations) can provide valuable insights into the influence of pathogens on host evolution and spatial variation in the magnitude of their effects. To date few studies of wild plant-pathogen interactions have characterized resistance structure by sampling across the host's biogeographic range, and only a handful have paired such investigations with studies of disease levels under natural conditions. I used a greenhouse cross-inoculation experiment to characterize genetic resistance of 16 populations of California dwarf flax (Hesperolinon californicum) to attack by multiple samples of the rust fungus Melampsora lini. I documented a latitudinal cline in resistance structure, manifest across the host's biogeographic range, which mirrored almost identically a cline in infection prevalence documented through field surveys of disease in study populations. These results provide empirical evidence for clinal patterns of antagonistic selection pressure, demonstrate that such patterns can be manifest across broad biogeographic scales, and suggest that rates of disease prevalence in wild plant populations may be tightly linked to the distribution of host resistance genes. Tests for local adaptation of the fungus revealed evidence of the phenomenon (significantly greater infection in sympatric plant-fungal pairings) as well as the potential for substantial bias to be introduced into statistical analyses by spatial patterns of host resistance structure.

  20. Adaptation of hybrid human-computer interaction systems using EEG error-related potentials.

    PubMed

    Chavarriaga, Ricardo; Biasiucci, Andrea; Forster, Killian; Roggen, Daniel; Troster, Gerhard; Millan, Jose Del R

    2010-01-01

    Performance improvement in both humans and artificial systems strongly relies in the ability of recognizing erroneous behavior or decisions. This paper, that builds upon previous studies on EEG error-related signals, presents a hybrid approach for human computer interaction that uses human gestures to send commands to a computer and exploits brain activity to provide implicit feedback about the recognition of such commands. Using a simple computer game as a case study, we show that EEG activity evoked by erroneous gesture recognition can be classified in single trials above random levels. Automatic artifact rejection techniques are used, taking into account that subjects are allowed to move during the experiment. Moreover, we present a simple adaptation mechanism that uses the EEG signal to label newly acquired samples and can be used to re-calibrate the gesture recognition system in a supervised manner. Offline analysis show that, although the achieved EEG decoding accuracy is far from being perfect, these signals convey sufficient information to significantly improve the overall system performance.

  1. An adapted Coffey model for studying susceptibility losses in interacting magnetic nanoparticles

    PubMed Central

    Osaci, Mihaela

    2015-01-01

    Summary Background: Nanoparticles can be used in biomedical applications, such as contrast agents for magnetic resonance imaging, in tumor therapy or against cardiovascular diseases. Single-domain nanoparticles dissipate heat through susceptibility losses in two modes: Néel relaxation and Brownian relaxation. Results: Since a consistent theory for the Néel relaxation time that is applicable to systems of interacting nanoparticles has not yet been developed, we adapted the Coffey theoretical model for the Néel relaxation time in external magnetic fields in order to consider local dipolar magnetic fields. Then, we obtained the effective relaxation time. The effective relaxation time is further used for obtaining values of specific loss power (SLP) through linear response theory (LRT). A comparative analysis between our model and the discrete orientation model, more often used in literature, and a comparison with experimental data from literature have been carried out, in order to choose the optimal magnetic parameters of a nanoparticle system. Conclusion: In this way, we can study effects of the nanoparticle concentration on SLP in an acceptable range of frequencies and amplitudes of external magnetic fields for biomedical applications, especially for tumor therapy by magnetic hyperthermia. PMID:26665090

  2. Predictive simulation of wind turbine wake interaction with an adaptive lattice Boltzmann method for moving boundaries

    NASA Astrophysics Data System (ADS)

    Deiterding, Ralf; Wood, Stephen L.

    2015-11-01

    Operating horizontal axis wind turbines create large-scale turbulent wake structures that affect the power output of downwind turbines considerably. The computational prediction of this phenomenon is challenging as efficient low dissipation schemes are necessary that represent the vorticity production by the moving structures accurately and are able to transport wakes without significant artificial decay over distances of several rotor diameters. We have developed the first version of a parallel adaptive lattice Boltzmann method for large eddy simulation of turbulent weakly compressible flows with embedded moving structures that considers these requirements rather naturally and enables first principle simulations of wake-turbine interaction phenomena at reasonable computational costs. The presentation will describe the employed algorithms and present relevant verification and validation computations. For instance, power and thrust coefficients of a Vestas V27 turbine are predicted within 5% of the manufacturer's specifications. Simulations of three Vestas V27-225kW turbines in triangular arrangement analyze the reduction in power production due to upstream wake generation for different inflow conditions.

  3. 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

  4. Recognition of human emotion using sensor agent robot for interactive and adaptive living spaces

    NASA Astrophysics Data System (ADS)

    Murata, Sozo; Mita, Akira

    2011-04-01

    Safer, more comfortable and energy-efficient living spaces are always demanded. However, most buildings are designed based on prescribed scenarios so that they do not act on abrupt changes of environments. We propose "Biofication of Living Spaces" that has functions of learning occupants' lifestyles and taking actions based on collected information. By doing so, we can incorporate the high adaptability to the building. Our goal is to make living spaces more "comfortable". However, human beings have emotion that implies the meaning of "comfortable" depends on each individual. Therefore our study focuses on recognition of human emotion. We suggest using robots as sensor agents. By using robots equipped with various sensors, they can interact with occupants and environment. We use a sensor agent robot called "e-bio". In this research, we construct a human tracking system and identified emotions of residents using their walking information. We focus on the influences of illuminance and sound. We classified emotions by calculating the distance of the mapped points in comfortable and uncomfortable spaces with parametric eigen space method, in which parameters are determined by a mapping of tracks in the space. As a method of pattern recognition, a weighted k-nearest neighbor is used. Experiments considering illuminance and sound environments, illustrates good correlation between emotion and environments.

  5. Aircraft Abnormal Conditions Detection, Identification, and Evaluation Using Innate and Adaptive Immune Systems Interaction

    NASA Astrophysics Data System (ADS)

    Al Azzawi, Dia

    Abnormal flight conditions play a major role in aircraft accidents frequently causing loss of control. To ensure aircraft operation safety in all situations, intelligent system monitoring and adaptation must rely on accurately detecting the presence of abnormal conditions as soon as they take place, identifying their root cause(s), estimating their nature and severity, and predicting their impact on the flight envelope. Due to the complexity and multidimensionality of the aircraft system under abnormal conditions, these requirements are extremely difficult to satisfy using existing analytical and/or statistical approaches. Moreover, current methodologies have addressed only isolated classes of abnormal conditions and a reduced number of aircraft dynamic parameters within a limited region of the flight envelope. This research effort aims at developing an integrated and comprehensive framework for the aircraft abnormal conditions detection, identification, and evaluation based on the artificial immune systems paradigm, which has the capability to address the complexity and multidimensionality issues related to aircraft systems. Within the proposed framework, a novel algorithm was developed for the abnormal conditions detection problem and extended to the abnormal conditions identification and evaluation. The algorithm and its extensions were inspired from the functionality of the biological dendritic cells (an important part of the innate immune system) and their interaction with the different components of the adaptive immune system. Immunity-based methodologies for re-assessing the flight envelope at post-failure and predicting the impact of the abnormal conditions on the performance and handling qualities are also proposed and investigated in this study. The generality of the approach makes it applicable to any system. Data for artificial immune system development were collected from flight tests of a supersonic research aircraft within a motion-based flight

  6. Climate sensitivity across marine domains of life: limits to evolutionary adaptation shape species interactions.

    PubMed

    Storch, Daniela; Menzel, Lena; Frickenhaus, Stephan; Pörtner, Hans-O

    2014-10-01

    Organisms in all domains, Archaea, Bacteria, and Eukarya will respond to climate change with differential vulnerabilities resulting in shifts in species distribution, coexistence, and interactions. The identification of unifying principles of organism functioning across all domains would facilitate a cause and effect understanding of such changes and their implications for ecosystem shifts. For example, the functional specialization of all organisms in limited temperature ranges leads us to ask for unifying functional reasons. Organisms also specialize in either anoxic or various oxygen ranges, with animals and plants depending on high oxygen levels. Here, we identify thermal ranges, heat limits of growth, and critically low (hypoxic) oxygen concentrations as proxies of tolerance in a meta-analysis of data available for marine organisms, with special reference to domain-specific limits. For an explanation of the patterns and differences observed, we define and quantify a proxy for organismic complexity across species from all domains. Rising complexity causes heat (and hypoxia) tolerances to decrease from Archaea to Bacteria to uni- and then multicellular Eukarya. Within and across domains, taxon-specific tolerance limits likely reflect ultimate evolutionary limits of its species to acclimatization and adaptation. We hypothesize that rising taxon-specific complexities in structure and function constrain organisms to narrower environmental ranges. Low complexity as in Archaea and some Bacteria provide life options in extreme environments. In the warmest oceans, temperature maxima reach and will surpass the permanent limits to the existence of multicellular animals, plants and unicellular phytoplankter. Smaller, less complex unicellular Eukarya, Bacteria, and Archaea will thus benefit and predominate even more in a future, warmer, and hypoxic ocean. PMID:24890266

  7. Climate sensitivity across marine domains of life: limits to evolutionary adaptation shape species interactions.

    PubMed

    Storch, Daniela; Menzel, Lena; Frickenhaus, Stephan; Pörtner, Hans-O

    2014-10-01

    Organisms in all domains, Archaea, Bacteria, and Eukarya will respond to climate change with differential vulnerabilities resulting in shifts in species distribution, coexistence, and interactions. The identification of unifying principles of organism functioning across all domains would facilitate a cause and effect understanding of such changes and their implications for ecosystem shifts. For example, the functional specialization of all organisms in limited temperature ranges leads us to ask for unifying functional reasons. Organisms also specialize in either anoxic or various oxygen ranges, with animals and plants depending on high oxygen levels. Here, we identify thermal ranges, heat limits of growth, and critically low (hypoxic) oxygen concentrations as proxies of tolerance in a meta-analysis of data available for marine organisms, with special reference to domain-specific limits. For an explanation of the patterns and differences observed, we define and quantify a proxy for organismic complexity across species from all domains. Rising complexity causes heat (and hypoxia) tolerances to decrease from Archaea to Bacteria to uni- and then multicellular Eukarya. Within and across domains, taxon-specific tolerance limits likely reflect ultimate evolutionary limits of its species to acclimatization and adaptation. We hypothesize that rising taxon-specific complexities in structure and function constrain organisms to narrower environmental ranges. Low complexity as in Archaea and some Bacteria provide life options in extreme environments. In the warmest oceans, temperature maxima reach and will surpass the permanent limits to the existence of multicellular animals, plants and unicellular phytoplankter. Smaller, less complex unicellular Eukarya, Bacteria, and Archaea will thus benefit and predominate even more in a future, warmer, and hypoxic ocean.

  8. ADAPTATION OF SUBJECTIVE RESPONSES TO ALCOHOL IS AFFECTED BY AN INTERACTION OF GABRA2 GENOTYPE AND RECENT DRINKING

    PubMed Central

    Kosobud, Ann E.K.; Wetherill, Leah; Plawecki, Martin H.; Kareken, David A.; Liang, Tiebing; Nurnberger, John L.; Windisch, Kyle; Xuei, Xiaoling; Edenberg, Howard J.; Foroud, Tatiana M.; O’Connor, Sean J.

    2015-01-01

    Background Subjective perceptions of alcohol intoxication are associated with altered risk for alcohol abuse and dependence. Acute adaptation of these perceptions may influence such risk, and may involve genes associated with pleasant perceptions or the relief of anxiety. This study assessed the effect of variation in the GABAA receptor genes GABRG1 and GABRA2 and recent drinking history on the acute adaptation of subjective responses to alcohol. Methods 132 non-dependent moderate to heavy drinkers, aged 21–27, participated in 2 single-blind, counterbalanced sessions, approximately one week apart. One session was an intravenous alcohol “clamp”, during which breath alcohol concentration was held steady at 60 mg/dL (60 mg%) for 3 hours, and the other an identical session using saline infusion. Subjective perceptions of intoxication, enjoyment, stimulation, relaxation, anxiety, tiredness and estimated number of drinks were acquired before (baseline), and during the first and final 45 minutes of the clamp. A placebo-adjusted index of the subject’s acute adaptation to alcohol was calculated for each of the 7 subjective measures, and used in a principal component analysis to create a single aggregate estimate for each subject’s adaptive response to alcohol. Analysis of covariance tested if GABRA2 and GABRG1 single nucleotide polymorphism (SNP) genotypes, gender, placebo session, family history of alcoholism, recent drinking history, and the genotype x recent drinking history interaction significantly predicted the adaptive response. Results Recent drinking history (p=0.01), and recent drinking history x genotype interaction (p=0.01) were significantly associated with acute adaptation of the subjective responses to alcohol for the GABRA2 SNP rs279858. Conclusion Higher recent drinking was found to be associated with reduced acute tolerance to positive, stimulating effects of alcohol in carriers of the rs279858 risk allele. We postulate that the GABRA2 effect on

  9. A low order flow/acoustics interaction method for the prediction of sound propagation using 3D adaptive hybrid grids

    SciTech Connect

    Kallinderis, Yannis; Vitsas, Panagiotis A.; Menounou, Penelope

    2012-07-15

    A low-order flow/acoustics interaction method for the prediction of sound propagation and diffraction in unsteady subsonic compressible flow using adaptive 3-D hybrid grids is investigated. The total field is decomposed into the flow field described by the Euler equations, and the acoustics part described by the Nonlinear Perturbation Equations. The method is shown capable of predicting monopole sound propagation, while employment of acoustics-guided adapted grid refinement improves the accuracy of capturing the acoustic field. Interaction of sound with solid boundaries is also examined in terms of reflection, and diffraction. Sound propagation through an unsteady flow field is examined using static and dynamic flow/acoustics coupling demonstrating the importance of the latter.

  10. Interactions between concentric form-from-structure and face perception revealed by visual masking but not adaptation

    PubMed Central

    Feczko, Eric; Shulman, Gordon L.; Petersen, Steven E.; Pruett, John R.

    2014-01-01

    Findings from diverse subfields of vision research suggest a potential link between high-level aspects of face perception and concentric form-from-structure perception. To explore this relationship, typical adults performed two adaptation experiments and two masking experiments to test whether concentric, but not nonconcentric, Glass patterns (a type of form-from-structure stimulus) utilize a processing mechanism shared by face perception. For the adaptation experiments, subjects were presented with an adaptor for 5 or 20 s, prior to discriminating a target. In the masking experiments, subjects saw a mask, then a target, and then a second mask. Measures of discriminability and bias were derived and repeated measures analysis of variance tested for pattern-specific masking and adaptation effects. Results from Experiment 1 show no Glass pattern-specific effect of adaptation to faces; results from Experiment 2 show concentric Glass pattern masking, but not adaptation, may impair upright/inverted face discrimination; results from Experiment 3 show concentric and radial Glass pattern masking impaired subsequent upright/inverted face discrimination more than translational Glass pattern masking; and results from Experiment 4 show concentric and radial Glass pattern masking impaired subsequent face gender discrimination more than translational Glass pattern masking. Taken together, these findings demonstrate interactions between concentric form-from-structure and face processing, suggesting a possible common processing pathway. PMID:24563526

  11. Crowding in extremophiles: linkage between solvation and weak protein-protein interactions, stability and dynamics, provides insight into molecular adaptation.

    PubMed

    Ebel, Christine; Zaccai, Giuseppe

    2004-01-01

    The study of the molecular adaptation of microorganisms to extreme environments (solvent, temperature, etc.) has provided tools to investigate the complex relationships between protein-solvent and protein-protein interactions, protein stability and protein dynamics, and how they are modulated by the crowded environment of the cell. We have evaluated protein-solvent and protein-protein interactions by solution experiments (analytical ultracentrifugation, small angle neutron and X-ray scattering, density) and crystallography, and protein dynamics by energy resolved neutron scattering. This review concerns work from our laboratory on (i) proteins from extreme halophilic Archaea, and (ii) psychrophile, mesophile, thermophile and hyperthermophile bacterial cells.

  12. Separating the role of biotic interactions and climate in determining adaptive response of plants to climate change.

    PubMed

    Tomiolo, Sara; Van der Putten, Wim H; Tielbörger, Katja

    2015-05-01

    Altered rainfall regimes will greatly affect the response of plant species to climate change. However, little is known about how direct effects of changing precipitation on plant performance may depend on other abiotic factors and biotic interactions. We used reciprocal transplants between climatically very different sites with simultaneous manipulation of soil, plant population origin, and neighbor conditions to evaluate local adaptation and possible adaptive response of four Eastern Mediterranean annual plant species to climate change. The effect of site on plant performance was negligible, but soil origin had a strong effect on fecundity, most likely due to differential water retaining ability. Competition by neighbors strongly reduced fitness. We separated the effects of the abiotic and biotic soil properties on plant performance by repeating the field experiment in a greenhouse under homogenous environmental conditions and including a soil biota manipulation treatment. As in the field, plant performance differed among soil origins and neighbor treatments. Moreover, we found plant species-specific responses to soil biota that may be best explained by the differential sensitivity to negative and positive soil biota effects. Overall, under the conditions of our experiment with two contrasting sites, biotic interactions had a strong effect on plant fitness that interacted with and eventually overrode climate. Because climate and biotic interactions covary, reciprocal transplants and climate gradient studies should consider soil biotic interactions and abiotic conditions when evaluating climate change effects on plant performance.

  13. Adapting the Structural Family Systems Rating to Assess the Patterns of Interaction in Families of Dementia Caregivers

    PubMed Central

    Mitrani, Victoria B.; Feaster, Daniel J.; McCabe, Brian E.; Czaja, Sara J.; Szapocznik, Jose

    2008-01-01

    Purpose: This study adapted the Structural Family Systems Ratings (SFSR), an observational measure of family interactions, for dementia caregivers. This article presents the development of the SFSR-Dementia Caregiver adaptation (SFSR-DC) and examines relationships between specific family-interaction patterns and caregiver distress. Design and Methods: The families of 177 Cuban American and White non-Hispanic American caregivers of dementia patients were assessed at baseline, 6, 12, and 18 months. Structural family theory and clinical experience were used to identify family interaction patterns believed to be related to caregiver emotional functioning. Factor analysis was used to refine subscales and develop a multiscale measure. Results: Six reliable subscales were related to caregiver distress and included in the SFSR-DC. There were two second-order factors. The SFSR-DC was provisionally cross-validated and showed invariance across the two ethnic groups. Implications: The SFSR-DC provides a method for examining specific and multiple interaction patterns in caregiver families and thus can advance knowledge regarding the role of the family in the stress processes of caregiving. These findings support the relevance of family interactions in caregiver distress and suggest that a treatment approach aimed at supporting family closeness and conflict resolution and reducing negativity might enhance caregiver well-being. PMID:16051907

  14. Metagenomic analysis of Atriplex microbiomes: Investigating Plant-microbe interactions that enhance adaptation to extreme habitats

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Cryptic symbiotic microbes influence host adaptation by improving nutrient uptake or stress tolerance. Current technologies for increasing plant productivity, whether for food and fuel production or for restoration and remediation, often utilize approaches that bypass, rather than leverage, microb...

  15. Genotype-by-environment interactions and adaptation to local temperature affect immunity and fecundity in Drosophila melanogaster.

    PubMed

    Lazzaro, Brian P; Flores, Heather A; Lorigan, James G; Yourth, Christopher P

    2008-03-01

    Natural populations of most organisms harbor substantial genetic variation for resistance to infection. The continued existence of such variation is unexpected under simple evolutionary models that either posit direct and continuous natural selection on the immune system or an evolved life history "balance" between immunity and other fitness traits in a constant environment. However, both local adaptation to heterogeneous environments and genotype-by-environment interactions can maintain genetic variation in a species. In this study, we test Drosophila melanogaster genotypes sampled from tropical Africa, temperate northeastern North America, and semi-tropical southeastern North America for resistance to bacterial infection and fecundity at three different environmental temperatures. Environmental temperature had absolute effects on all traits, but there were also marked genotype-by-environment interactions that may limit the global efficiency of natural selection on both traits. African flies performed more poorly than North American flies in both immunity and fecundity at the lowest temperature, but not at the higher temperatures, suggesting that the African population is maladapted to low temperature. In contrast, there was no evidence for clinal variation driven by thermal adaptation within North America for either trait. Resistance to infection and reproductive success were generally uncorrelated across genotypes, so this study finds no evidence for a fitness tradeoff between immunity and fecundity under the conditions tested. Both local adaptation to geographically heterogeneous environments and genotype-by-environment interactions may explain the persistence of genetic variation for resistance to infection in natural populations.

  16. Genotype-by-Environment Interactions and Adaptation to Local Temperature Affect Immunity and Fecundity in Drosophila melanogaster

    PubMed Central

    Lazzaro, Brian P.; Flores, Heather A.; Lorigan, James G.; Yourth, Christopher P.

    2008-01-01

    Natural populations of most organisms harbor substantial genetic variation for resistance to infection. The continued existence of such variation is unexpected under simple evolutionary models that either posit direct and continuous natural selection on the immune system or an evolved life history “balance” between immunity and other fitness traits in a constant environment. However, both local adaptation to heterogeneous environments and genotype-by-environment interactions can maintain genetic variation in a species. In this study, we test Drosophila melanogaster genotypes sampled from tropical Africa, temperate northeastern North America, and semi-tropical southeastern North America for resistance to bacterial infection and fecundity at three different environmental temperatures. Environmental temperature had absolute effects on all traits, but there were also marked genotype-by-environment interactions that may limit the global efficiency of natural selection on both traits. African flies performed more poorly than North American flies in both immunity and fecundity at the lowest temperature, but not at the higher temperatures, suggesting that the African population is maladapted to low temperature. In contrast, there was no evidence for clinal variation driven by thermal adaptation within North America for either trait. Resistance to infection and reproductive success were generally uncorrelated across genotypes, so this study finds no evidence for a fitness tradeoff between immunity and fecundity under the conditions tested. Both local adaptation to geographically heterogeneous environments and genotype-by-environment interactions may explain the persistence of genetic variation for resistance to infection in natural populations. PMID:18369474

  17. A Fast, Locally Adaptive, Interactive Retrieval Algorithm for the Analysis of DIAL Measurements

    NASA Astrophysics Data System (ADS)

    Samarov, D. V.; Rogers, R.; Hair, J. W.; Douglass, K. O.; Plusquellic, D.

    2010-12-01

    Differential absorption light detection and ranging (DIAL) is a laser-based tool which is used for remote, range-resolved measurement of particular gases in the atmosphere, such as carbon-dioxide and methane. In many instances it is of interest to study how these gases are distributed over a region such as a landfill, factory, or farm. While a single DIAL measurement only tells us about the distribution of a gas along a single path, a sequence of consecutive measurements provides us with information on how that gas is distributed over a region, making DIAL a natural choice for such studies. DIAL measurements present a number of interesting challenges; first, in order to convert the raw data to concentration it is necessary to estimate the derivative along the path of the measurement. Second, as the distribution of gases across a region can be highly heterogeneous it is important that the spatial nature of the measurements be taken into account. Finally, since it is common for the set of collected measurements to be quite large it is important for the method to be computationally efficient. Existing work based on Local Polynomial Regression (LPR) has been developed which addresses the first two issues, but the issue of computational speed remains an open problem. In addition to the latter, another desirable property is to allow user input into the algorithm. In this talk we present a novel method based on LPR which utilizes a variant of the RODEO algorithm to provide a fast, locally adaptive and interactive approach to the analysis of DIAL measurements. This methodology is motivated by and applied to several simulated examples and a study out of NASA Langley Research Center (LaRC) looking at the estimation of aerosol extinction in the atmosphere. A comparison study of our method against several other algorithms is also presented. References Chaudhuri, P., Marron, J.S., Scale-space view of curve estimation, Annals of Statistics 28 (2000) 408-428. Duong, T., Cowling

  18. Nucleo-olivary inhibition balances the interaction between the reactive and adaptive layers in motor control.

    PubMed

    Herreros, Ivan; Verschure, Paul F M J

    2013-11-01

    In the acquisition of adaptive motor reflexes to aversive stimuli, the cerebellar output fulfills a double purpose: it controls a motor response and it relays a sensory prediction. However, the question of how these two apparently incompatible goals might be achieved by the same cerebellar area remains open. Here we propose a solution where the inhibition of the Inferior Olive (IO) by the cerebellar Deep Nuclei (DN) translates the motor command signal into a sensory prediction allowing a single cerebellar area to simultaneously tackle both aspects of the problem: execution and prediction. We demonstrate that having a graded error signal, the gain of the Nucleo-Olivary Inhibition (NOI) balances the generation of the response between the cerebellar and the reflexive controllers or, in other words, between the adaptive and the reactive layers of behavior. Moreover, we show that the resulting system is fully autonomous and can either acquire or erase adaptive responses according to their utility.

  19. Numerical simulations of internal solitary waves interacting with uniform slopes using an adaptive model

    NASA Astrophysics Data System (ADS)

    Rickard, Graham; O'Callaghan, Joanne; Popinet, Stéphane

    Two-dimensional, non-linear, Boussinesq, non-hydrostatic simulations of internal solitary waves breaking and running up uniform slopes have been performed using an adaptive, finite volume fluid code "Gerris". It is demonstrated that the Gerris dynamical core performs well in this specific but important geophysical context. The "semi-structured" nature of Gerris is exploited to enhance model resolution along the slope where wave breaking and run-up occur. Comparison with laboratory experiments reveals that the generation of single and multiple turbulent surges ("boluses") as a function of slope angle is consistently reproduced by the model, comparable with observations and previous numerical simulations, suggesting aspects of the dynamical energy transfers are being represented by the model in two dimensions. Adaptivity is used to explore model convergence of the wave breaking dynamics, and it is shown that significant cpu memory and time savings are possible with adaptivity.

  20. Adapting to a Changing Environment: Modeling the Interaction of Directional Selection and Plasticity.

    PubMed

    Nunney, Leonard

    2016-01-01

    Human-induced habitat loss and fragmentation constrains the range of many species, making them unable to respond to climate change by moving. For such species to avoid extinction, they must respond with some combination of phenotypic plasticity and genetic adaptation. Haldane's "cost of natural selection" limits the rate of adaptation, but, although modeling has shown that in very large populations long-term adaptation can be maintained at rates substantially faster than Haldane's suggested limit, maintaining large populations is often an impossibility, so phenotypic plasticity may be crucial in enhancing the long-term survival of small populations. The potential importance of plasticity is in "buying time" for populations subject to directional environmental change: if genotypes can encompass a greater environmental range, then populations can maintain high fitness for a longer period of time. Alternatively, plasticity could be detrimental by lessening the effectiveness of natural selection in promoting genetic adaptation. Here, I modeled a directionally changing environment in which a genotype's adaptive phenotypic plasticity is centered around the environment where its fitness is highest. Plasticity broadens environmental tolerance and, provided it is not too costly, is favored by natural selection. However, a paradoxical result of the individually advantageous spread of plasticity is that, unless the adaptive trait is determined by very few loci, the long-term extinction risk of a population increases. This effect reflects a conflict between the short-term individual benefit of plasticity and a long-term detriment to population persistence, adding to the multiple threats facing small populations under conditions of climate change.

  1. Adaptive training algorithm for robot-assisted upper-arm rehabilitation, applicable to individualised and therapeutic human-robot interaction

    PubMed Central

    2013-01-01

    Background Rehabilitation robotics is progressing towards developing robots that can be used as advanced tools to augment the role of a therapist. These robots are capable of not only offering more frequent and more accessible therapies but also providing new insights into treatment effectiveness based on their ability to measure interaction parameters. A requirement for having more advanced therapies is to identify how robots can 'adapt’ to each individual’s needs at different stages of recovery. Hence, our research focused on developing an adaptive interface for the GENTLE/A rehabilitation system. The interface was based on a lead-lag performance model utilising the interaction between the human and the robot. The goal of the present study was to test the adaptability of the GENTLE/A system to the performance of the user. Methods Point-to-point movements were executed using the HapticMaster (HM) robotic arm, the main component of the GENTLE/A rehabilitation system. The points were displayed as balls on the screen and some of the points also had a real object, providing a test-bed for the human-robot interaction (HRI) experiment. The HM was operated in various modes to test the adaptability of the GENTLE/A system based on the leading/lagging performance of the user. Thirty-two healthy participants took part in the experiment comprising of a training phase followed by the actual-performance phase. Results The leading or lagging role of the participant could be used successfully to adjust the duration required by that participant to execute point-to-point movements, in various modes of robot operation and under various conditions. The adaptability of the GENTLE/A system was clearly evident from the durations recorded. The regression results showed that the participants required lower execution times with the help from a real object when compared to just a virtual object. The 'reaching away’ movements were longer to execute when compared to the 'returning

  2. Launch Vehicle Manual Steering with Adaptive Augmenting Control:In-Flight Evaluations of Adverse Interactions Using a Piloted Aircraft

    NASA Technical Reports Server (NTRS)

    Hanson, Curt; Miller, Chris; Wall, John H.; VanZwieten, Tannen S.; Gilligan, Eric T.; Orr, Jeb S.

    2015-01-01

    An Adaptive Augmenting Control (AAC) algorithm for the Space Launch System (SLS) has been developed at the Marshall Space Flight Center (MSFC) as part of the launch vehicle's baseline flight control system. A prototype version of the SLS flight control software was hosted on a piloted aircraft at the Armstrong Flight Research Center to demonstrate the adaptive controller on a full-scale realistic application in a relevant flight environment. Concerns regarding adverse interactions between the adaptive controller and a potential manual steering mode were also investigated by giving the pilot trajectory deviation cues and pitch rate command authority, which is the subject of this paper. Two NASA research pilots flew a total of 25 constant pitch rate trajectories using a prototype manual steering mode with and without adaptive control, evaluating six different nominal and off-nominal test case scenarios. Pilot comments and PIO ratings were given following each trajectory and correlated with aircraft state data and internal controller signals post-flight.

  3. Bilingual and Bicultural Adaptation. Educational and Psychological Interactions. Bulletin No. 66.

    ERIC Educational Resources Information Center

    Ekstrand, Lars Henric

    This report is a compilation of five research papers in second language acquisition and immigrant adaptability that are part of studies conducted in Sweden over the last twenty years. (1) "Language teaching and psycho-physics" discusses basic measurement problems in the assessment of second language proficiency, where testing of writing and…

  4. On Cooperative Behavior in Distributed Teams: The Influence of Organizational Design, Media Richness, Social Interaction, and Interaction Adaptation.

    PubMed

    Håkonsson, Dorthe D; Obel, Børge; Eskildsen, Jacob K; Burton, Richard M

    2016-01-01

    Self-interest vs. cooperation is a fundamental dilemma in animal behavior as well as in human and organizational behavior. In organizations, how to get people to cooperate despite or in conjunction with their self-interest is fundamental to the achievement of a common goal. While both organizational designs and social interactions have been found to further cooperation in organizations, some of the literature has received contradictory support, just as very little research, if any, has examined their joint effects in distributed organizations, where communication is usually achieved via different communication media. This paper reviews the extant literature and offers a set of hypotheses to integrate current theories and explanations. Further, it discusses how future research should examine the joint effects of media, incentives, and social interactions.

  5. On Cooperative Behavior in Distributed Teams: The Influence of Organizational Design, Media Richness, Social Interaction, and Interaction Adaptation.

    PubMed

    Håkonsson, Dorthe D; Obel, Børge; Eskildsen, Jacob K; Burton, Richard M

    2016-01-01

    Self-interest vs. cooperation is a fundamental dilemma in animal behavior as well as in human and organizational behavior. In organizations, how to get people to cooperate despite or in conjunction with their self-interest is fundamental to the achievement of a common goal. While both organizational designs and social interactions have been found to further cooperation in organizations, some of the literature has received contradictory support, just as very little research, if any, has examined their joint effects in distributed organizations, where communication is usually achieved via different communication media. This paper reviews the extant literature and offers a set of hypotheses to integrate current theories and explanations. Further, it discusses how future research should examine the joint effects of media, incentives, and social interactions. PMID:27242605

  6. On Cooperative Behavior in Distributed Teams: The Influence of Organizational Design, Media Richness, Social Interaction, and Interaction Adaptation

    PubMed Central

    Håkonsson, Dorthe D.; Obel, Børge; Eskildsen, Jacob K.; Burton, Richard M.

    2016-01-01

    Self-interest vs. cooperation is a fundamental dilemma in animal behavior as well as in human and organizational behavior. In organizations, how to get people to cooperate despite or in conjunction with their self-interest is fundamental to the achievement of a common goal. While both organizational designs and social interactions have been found to further cooperation in organizations, some of the literature has received contradictory support, just as very little research, if any, has examined their joint effects in distributed organizations, where communication is usually achieved via different communication media. This paper reviews the extant literature and offers a set of hypotheses to integrate current theories and explanations. Further, it discusses how future research should examine the joint effects of media, incentives, and social interactions. PMID:27242605

  7. Cyto•IQ: an adaptive cytometer for extracting the noisy dynamics of molecular interactions in live cells

    NASA Astrophysics Data System (ADS)

    Ball, David A.; Moody, Stephen E.; Peccoud, Jean

    2010-02-01

    We have developed a fundamentally new type of cytometer to track the statistics of dynamic molecular interactions in hundreds of individual live cells within a single experiment. This entirely new high-throughput experimental system, which we have named Cyto•IQ, reports statistical, rather than image-based data for a large cellular population. Like a flow cytometer, Cyto•IQ rapidly measures several fluorescent probes in a large population of cells to yield a reduced statistical model that is matched to the experimental goals set by the user. However, Cyto•IQ moves beyond flow cytometry by tracking multiple probes in individual cells over time. Using adaptive learning algorithms, we process data in real time to maximize the convergence of the statistical model parameter estimators. Software controlling Cyto•IQ integrates existing open source applications to interface hardware components, process images, and adapt the data acquisition strategy based on previously acquired data. These innovations allow the study of larger populations of cells, and molecular interactions with more complex dynamics, than is possible with traditional microscope-based approaches. Cyto•IQ supports research to characterize the noisy dynamics of molecular interactions controlling biological processes.

  8. Inquiry in Interaction: How Local Adaptations of Curricula Shape Classroom Communities

    ERIC Educational Resources Information Center

    Enyedy, Noel; Goldberg, Jennifer

    2004-01-01

    In this study, we seek a better understanding of how individuals and their daily interactions shape and reshape social structures that constitute a classroom community. Moreover, we provide insight into how discourse and classroom interactions shape the nature of a learning community, as well as which aspects of the classroom culture may be…

  9. Covert rapid action-memory simulation (CRAMS): A hypothesis of hippocampal-prefrontal interactions for adaptive behavior

    PubMed Central

    Wang, Jane X.; Cohen, Neal J.; Voss, Joel L.

    2014-01-01

    Effective choices generally require memory, yet little is known regarding the cognitive or neural mechanisms that allow memory to influence choices. We outline a new framework proposing that covert memory processing of hippocampus interacts with action-generation processing of prefrontal cortex in order to arrive at optimal, memory-guided choices. Covert, rapid action-memory simulation (CRAMS) is proposed here as a framework for understanding cognitive and/or behavioral choices, whereby prefrontal-hippocampal interactions quickly provide multiple simulations of potential outcomes used to evaluate the set of possible choices. We hypothesize that this CRAMS process is automatic, obligatory, and covert, meaning that many cycles of action-memory simulation occur in response to choice conflict without an individual’s necessary intention and generally without awareness of the simulations, leading to adaptive behavior with little perceived effort. CRAMS is thus distinct from influential proposals that adaptive memory-based behavior in humans requires consciously experienced memory-based construction of possible future scenarios and deliberate decisions among possible future constructions. CRAMS provides an account of why hippocampus has been shown to make critical contributions to the short-term control of behavior, and it motivates several new experimental approaches and hypotheses that could be used to better understand the ubiquitous role of prefrontal-hippocampal interactions in situations that require adaptively using memory to guide choices. Importantly, this framework provides a perspective that allows for testing decision-making mechanisms in a manner that translates well across human and nonhuman animal model systems. PMID:24752152

  10. Positive selection and compensatory adaptation interact to stabilize non-transmissible plasmids.

    PubMed

    San Millan, A; Peña-Miller, R; Toll-Riera, M; Halbert, Z V; McLean, A R; Cooper, B S; MacLean, R C

    2014-10-10

    Plasmids are important drivers of bacterial evolution, but it is challenging to understand how plasmids persist over the long term because plasmid carriage is costly. Classical models predict that horizontal transfer is necessary for plasmid persistence, but recent work shows that almost half of plasmids are non-transmissible. Here we use a combination of mathematical modelling and experimental evolution to investigate how a costly, non-transmissible plasmid, pNUK73, can be maintained in populations of Pseudomonas aeruginosa. Compensatory adaptation increases plasmid stability by eliminating the cost of plasmid carriage. However, positive selection for plasmid-encoded antibiotic resistance is required to maintain the plasmid by offsetting reductions in plasmid frequency due to segregational loss. Crucially, we show that compensatory adaptation and positive selection reinforce each other's effects. Our study provides a new understanding of how plasmids persist in bacterial populations, and it helps to explain why resistance can be maintained after antibiotic use is stopped.

  11. Positive selection and compensatory adaptation interact to stabilize non-transmissible plasmids

    PubMed Central

    Millan, A. San; Peña-Miller, R.; Toll-Riera, M.; Halbert, Z. V.; McLean, A. R.; Cooper, B. S.; MacLean, R. C.

    2014-01-01

    Plasmids are important drivers of bacterial evolution, but it is challenging to understand how plasmids persist over the long term because plasmid carriage is costly. Classical models predict that horizontal transfer is necessary for plasmid persistence, but recent work shows that almost half of plasmids are non-transmissible. Here we use a combination of mathematical modelling and experimental evolution to investigate how a costly, non-transmissible plasmid, pNUK73, can be maintained in populations of Pseudomonas aeruginosa. Compensatory adaptation increases plasmid stability by eliminating the cost of plasmid carriage. However, positive selection for plasmid-encoded antibiotic resistance is required to maintain the plasmid by offsetting reductions in plasmid frequency due to segregational loss. Crucially, we show that compensatory adaptation and positive selection reinforce each other’s effects. Our study provides a new understanding of how plasmids persist in bacterial populations, and it helps to explain why resistance can be maintained after antibiotic use is stopped. PMID:25302567

  12. Collaborative Education in Climate Change Sciences and Adaptation through Interactive Learning

    NASA Astrophysics Data System (ADS)

    Ozbay, G.; Sriharan, S.; Fan, C.

    2014-12-01

    As a result of several funded climate change education grants, collaboration between VSU, DSU, and MSU, was established to provide the innovative and cohesive education and research opportunities to underrepresented groups in the climate related sciences. Prior to offering climate change and adaptation related topics to the students, faculty members of the three collaborating institutions participated at a number of faculty training and preparation workshops for teaching climate change sciences (i.e. AMS Diversity Project Workshop, NCAR Faculty-Student Team on Climate Change, NASA-NICE Program). In order to enhance the teaching and student learning on various issues in the Environmental Sciences Programs, Climatology, Climate Change Sciences and Adaptation or related courses were developed at Delaware State University and its partner institutions (Virginia State University and Morgan State University). These courses were prepared to deliver information on physical basis for the earth's climate system and current climate change instruction modules by AMS and historic climate information (NOAA Climate Services, U.S. and World Weather Data, NCAR and NASA Climate Models). By using Global Seminar as a Model, faculty members worked in teams to engage students in videoconferencing on climate change through Contemporary Global Studies and climate courses including Climate Change and Adaptation Science, Sustainable Agriculture, Introduction to Environmental Sciences, Climatology, and Ecology and Adaptation courses. All climate change courses have extensive hands-on practices and research integrated into the student learning experiences. Some of these students have presented their classroom projects during Earth Day, Student Climate Change Symposium, Undergraduate Summer Symposium, and other national conferences.

  13. Inquiry in interaction: How local adaptations of curricula shape classroom communities

    NASA Astrophysics Data System (ADS)

    Enyedy, Noel; Goldberg, Jennifer

    2004-11-01

    In this study, we seek a better understanding of how individuals and their daily interactions shape and reshape social structures that constitute a classroom community. Moreover, we provide insight into how discourse and classroom interactions shape the nature of a learning community, as well as which aspects of the classroom culture may be consequential for learning. The participants in this study include two teachers who are implementing a new environmental science program, Global Learning through Observation to Benefit the Environment (GLOBE), and interacting with 54 children in an urban middle school. Both qualitative and quantitative data are analyzed and presented. To gain a better understanding of the inquiry teaching within classroom communities, we compare and contrast the discourse and interactions of the two teachers during three parallel environmental science lessons. The focus of our analysis includes (1) how the community identifies the object or goal of its activity; and (2) how the rights, rules, and roles for members are established and inhabited in interaction. Quantitative analyses of student pre- and posttests suggest greater learning for students in one classroom over the other, providing support for the influence of the classroom community and interactional choices of the teacher on student learning. Implications of the findings from this study are discussed in the context of curricular design, professional development, and educational reform. ? 2004 Wiley Periodicals, Inc. J Res Sci Teach 41: 905-935, 2004.

  14. Adaptive vibrational configuration interaction (A-VCI): A posteriori error estimation to efficiently compute anharmonic IR spectra

    NASA Astrophysics Data System (ADS)

    Garnier, Romain; Odunlami, Marc; Le Bris, Vincent; Bégué, Didier; Baraille, Isabelle; Coulaud, Olivier

    2016-05-01

    A new variational algorithm called adaptive vibrational configuration interaction (A-VCI) intended for the resolution of the vibrational Schrödinger equation was developed. The main advantage of this approach is to efficiently reduce the dimension of the active space generated into the configuration interaction (CI) process. Here, we assume that the Hamiltonian writes as a sum of products of operators. This adaptive algorithm was developed with the use of three correlated conditions, i.e., a suitable starting space, a criterion for convergence, and a procedure to expand the approximate space. The velocity of the algorithm was increased with the use of a posteriori error estimator (residue) to select the most relevant direction to increase the space. Two examples have been selected for benchmark. In the case of H2CO, we mainly study the performance of A-VCI algorithm: comparison with the variation-perturbation method, choice of the initial space, and residual contributions. For CH3CN, we compare the A-VCI results with a computed reference spectrum using the same potential energy surface and for an active space reduced by about 90%.

  15. Landscape genetics and hierarchical genetic structure in Atlantic salmon: the interaction of gene flow and local adaptation.

    PubMed

    Dionne, Mélanie; Caron, François; Dodson, Julian J; Bernatchez, Louis

    2008-05-01

    Disentangling evolutionary forces that may interact to determine the patterns of genetic differentiation within and among wild populations is a major challenge in evolutionary biology. The objective of this study was to assess the genetic structure and the potential influence of several ecological variables on the extent of genetic differentiation at multiple spatial scales in a widely distributed species, the Atlantic salmon, Salmo salar. A total of 2775 anadromous fish were sampled from 51 rivers along the North American Atlantic coast and were genotyped using 13 microsatellites. A Bayesian analysis clustered these populations into seven genetically and geographically distinct groups, characterized by different environmental and ecological factors, mainly temperature. These groups were also characterized by different extent of genetic differentiation among populations. Dispersal was relatively high and of the same magnitude within compared to among regional groups, which contrasted with the maintenance of a regional genetic structure. However, genetic differentiation was lower among populations exchanging similar rates of local as opposed to inter-regional migrants, over the same geographical scale. This raised the hypothesis that gene flow could be constrained by local adaptation at the regional scale. Both coastal distance and temperature regime were found to influence the observed genetic structure according to landscape genetic analyses. The influence of other factors such as latitude, river length and altitude, migration tactic, and stocking was not significant at any spatial scale. Overall, these results suggested that the interaction between gene flow and thermal regime adaptation mainly explained the hierarchical genetic structure observed among Atlantic salmon populations.

  16. Using the Chombo Adaptive Mesh Refinement Model in Shallow Water Mode to Simulate Interactions of Tropical Cyclone-like Vortices

    NASA Astrophysics Data System (ADS)

    Ferguson, J. O.; Jablonowski, C.; Johansen, H.; McCorquodale, P.; Ullrich, P. A.

    2015-12-01

    Complex multi-scale atmospheric phenomena such as tropical cyclones challenge the coarse uniform grids of convectional climate models. Adaptive mesh refinement (AMR) techniques seek to mitigate these problems by providing sufficiently high-resolution grid patches only over features of interests while limiting the computational burden of requiring such resolutions globally. One such model is the non-hydrostatic, finite-volume Chombo-AMR general circulation model (GCM), which implements refinement in both space and time on a cubed-sphere grid. The 2D shallow-water equations exhibit many of the complexities of 3D GCM dynamical cores and serve as an effective method for testing the dynamical core and the refinement strategies of adaptive atmospheric models. We implement a shallow-water test case consisting of a pair of interacting tropical cyclone-like vortices. Small changes in the initial conditions can lead to a variety of interactions that develop fine-scale spiral band structures and large-scale wave trains. We investigate the accuracy and efficiency of AMR's ability to capture and effectively follow the evolution of the vortices in time. These simulations serve to test the effectiveness of refinement for both static and dynamic grid configurations as well as the sensitivity of the model results to the refinement criteria.

  17. Utilizing Matrix-Filler Interactions in the Design of Stimuli-Responsive, Mechanically-Adaptive Electrospun Composites

    NASA Astrophysics Data System (ADS)

    Wanasekara, Nandula; Stone, David; Wnek, Gary; Korley, Lashanda

    2013-03-01

    A new class of all-organic, stimuli-responsive and mechanically-adaptive electrospun nanocomposites, which have the ability to alter their stiffness upon hydration, were developed. These materials were fabricated by incorporating an electrospun mat of poly(vinyl alcohol) (PVA) as the filler in a polymeric matrix consisting of either poly(vinyl acetate) (PVAc) or ethylene oxide-epicholorohydrin copolymer (EO-EPI). The incorporation of high stiffness, high aspect ratio PVA filler mat significantly enhanced the tensile storage modulus of EO-EPI based composites, while modulus enhancement was only noticed above the glass transition for PVAc-based composites. Composite materials based on a rubbery EO-EPI host polymer and PVA filler exhibit an irreversible reduction by a factor of 12 of the tensile modulus upon hydration. In contrast, composites comprised of PVAc show a reversible reduction of modulus by a factor of 280 upon water uptake. The mechanical morphing of the electrospun composites is the result of the filler crystallinity, and matrix-filler interactions facilitated by the surface hydroxyl groups of the PVA filler. The choice of polymer matrix and electrospun nanofiber fillers allow control of matrix-filler interactions in a new series of all-organic composites to achieve desired stimuli-responsiveness and mechanical-adaptability upon exposure to various stimuli.

  18. Adaptive vibrational configuration interaction (A-VCI): A posteriori error estimation to efficiently compute anharmonic IR spectra.

    PubMed

    Garnier, Romain; Odunlami, Marc; Le Bris, Vincent; Bégué, Didier; Baraille, Isabelle; Coulaud, Olivier

    2016-05-28

    A new variational algorithm called adaptive vibrational configuration interaction (A-VCI) intended for the resolution of the vibrational Schrödinger equation was developed. The main advantage of this approach is to efficiently reduce the dimension of the active space generated into the configuration interaction (CI) process. Here, we assume that the Hamiltonian writes as a sum of products of operators. This adaptive algorithm was developed with the use of three correlated conditions, i.e., a suitable starting space, a criterion for convergence, and a procedure to expand the approximate space. The velocity of the algorithm was increased with the use of a posteriori error estimator (residue) to select the most relevant direction to increase the space. Two examples have been selected for benchmark. In the case of H2CO, we mainly study the performance of A-VCI algorithm: comparison with the variation-perturbation method, choice of the initial space, and residual contributions. For CH3CN, we compare the A-VCI results with a computed reference spectrum using the same potential energy surface and for an active space reduced by about 90%. PMID:27250295

  19. Sex-related adaptive responses to interaction of drought and salinity in Populus yunnanensis.

    PubMed

    Chen, Lianghua; Zhang, Sheng; Zhao, Hongxia; Korpelainen, Helena; Li, Chunyang

    2010-10-01

    We used Populus yunnanensis Dode., a native dioecious species in southwestern China, as a model species to study morphological, physiological, biochemical and ultrastructural responses to drought, salinity and their combination. Females exhibited more growth inhibition, gas exchange rate depression and reactive oxygen species (ROS) accumulation; higher lipid peroxide levels, lower osmotic adjustment capacity and ascorbate-glutathione cycle enzyme activities; and more damage to cell organelles than did males under drought, salinity and especially under their combination. In addition, we found sex-specific responses in total chlorophyll content (TC), carotenoid concentration and carbon isotope composition under different osmotic stresses. Our results indicated that: (1) females are more sensitive and suffer from greater negative effects than do males under drought, salinity and especially under their combination; (2) sexual differences in adaptive responses to drought, salinity and their combination are context dependent; and (3) sex-specific reactions under a combination of stresses are distinct from single-stress responses. Thus, these results provide evidence for adaptive differentiation between sexes in responses to osmotic stresses and in the sensitivity to environmental change.

  20. An adaptive knowledge-driven medical image search engine for interactive diffuse parenchymal lung disease quantification

    NASA Astrophysics Data System (ADS)

    Tao, Yimo; Zhou, Xiang Sean; Bi, Jinbo; Jerebkoa, Anna; Wolf, Matthias; Salganicoff, Marcos; Krishnana, Arun

    2009-02-01

    Characterization and quantification of the severity of diffuse parenchymal lung diseases (DPLDs) using Computed Tomography (CT) is an important issue in clinical research. Recently, several classification-based computer-aided diagnosis (CAD) systems [1-3] for DPLD have been proposed. For some of those systems, a degradation of performance [2] was reported on unseen data because of considerable inter-patient variances of parenchymal tissue patterns. We believe that a CAD system of real clinical value should be robust to inter-patient variances and be able to classify unseen cases online more effectively. In this work, we have developed a novel adaptive knowledge-driven CT image search engine that combines offline learning aspects of classification-based CAD systems with online learning aspects of content-based image retrieval (CBIR) systems. Our system can seamlessly and adaptively fuse offline accumulated knowledge with online feedback, leading to an improved online performance in detecting DPLD in both accuracy and speed aspects. Our contribution lies in: (1) newly developed 3D texture-based and morphology-based features; (2) a multi-class offline feature selection method; and, (3) a novel image search engine framework for detecting DPLD. Very promising results have been obtained on a small test set.

  1. Adaptive hybrid brain-computer interaction: ask a trainer for assistance!

    PubMed

    Müller-Putz, Gernot R; Steyrl, David; Faller, Josef

    2014-01-01

    In applying mental imagery brain-computer interfaces (BCIs) to end users, training is a key part for novice users to get control. In general learning situations, it is an established concept that a trainer assists a trainee to improve his/her aptitude in certain skills. In this work, we want to evaluate whether we can apply this concept in the context of event-related desynchronization (ERD) based, adaptive, hybrid BCIs. Hence, in a first session we merged the features of a high aptitude BCI user, a trainer, and a novice user, the trainee, in a closed-loop BCI feedback task and automatically adapted the classifier over time. In a second session the trainees operated the system unassisted. Twelve healthy participants ran through this protocol. Along with the trainer, the trainees achieved a very high overall peak accuracy of 95.3 %. In the second session, where users operated the BCI unassisted, they still achieved a high overall peak accuracy of 83.6%. Ten of twelve first time BCI users successfully achieved significantly better than chance accuracy. Concluding, we can say that this trainer-trainee approach is very promising. Future research should investigate, whether this approach is superior to conventional training approaches. This trainer-trainee concept could have potential for future application of BCIs to end users.

  2. Language Learner/Native Speaker Interactions: Exploring Adaptability in Intercultural Encounters

    ERIC Educational Resources Information Center

    Chamberlin-Quinlisk, Carla

    2010-01-01

    Diversity and intercultural awareness initiatives are increasingly common at institutions of higher education in the USA. Although students recognize and appreciate the diversity of their surroundings, studies show that intercultural interactions at the social level are lacking. This study focuses on how English language learners, multilingual…

  3. Adapting to Conversation with Semantic Dementia: Using Enactment as a Compensatory Strategy in Everyday Social Interaction

    ERIC Educational Resources Information Center

    Kindell, Jacqueline; Sage, Karen; Keady, John; Wilkinson, Ray

    2013-01-01

    Background: Studies to date in semantic dementia have examined communication in clinical or experimental settings. There is a paucity of research describing the everyday interactional skills and difficulties seen in this condition. Aims: To examine the everyday conversation, at home, of an individual with semantic dementia. Methods &…

  4. Parallel adaptive fluid-structure interaction simulation of explosions impacting on building structures

    SciTech Connect

    Deiterding, Ralf; Wood, Stephen L

    2013-01-01

    We pursue a level set approach to couple an Eulerian shock-capturing fluid solver with space-time refinement to an explicit solid dynamics solver for large deformations and fracture. The coupling algorithms considering recursively finer fluid time steps as well as overlapping solver updates are discussed in detail. Our ideas are implemented in the AMROC adaptive fluid solver framework and are used for effective fluid-structure coupling to the general purpose solid dynamics code DYNA3D. Beside simulations verifying the coupled fluid-structure solver and assessing its parallel scalability, the detailed structural analysis of a reinforced concrete column under blast loading and the simulation of a prototypical blast explosion in a realistic multistory building are presented.

  5. Adaptive interactions between cytokines and the hypothalamic-pituitary-gonadal axis.

    PubMed

    Cannon, J G

    1998-09-29

    Circulating and tissue concentrations of pyrogenic cytokines, especially interleukin (IL)-1 beta, vary temporally through the menstrual cycle and pregnancy. The secretion of these cytokines in vitro by isolated human mononuclear cells is significantly influenced by exogenous gonadal steroids and gonadotropins. Reciprocally, cytokines influence gonadotropin secretion by the pituitary and steroidogenesis by the ovaries and testes. Several hypotheses have been advanced regarding the adaptive value of these interrelationships. Cytokine-induced synthesis of proteolytic enzymes and extracellular matrix proteins may be important for the tissue remodeling necessary for ovulation, implantation, and delivery. Tolerance of the fetal allograft may require downregulation of cytotoxic effector cells and reciprocal upregulation of humoral and nonspecific host defenses. The inhibitory influence of IL-1 beta on the luteinizing hormone surge may prevent inopportune conception, and the abortive influences of tumor necrosis factor-alpha and gamma interferon may terminate pregnancy during periods of infection.

  6. Three Connected Climate Education Interactives: Carbon Cycle, Earth System Energy Flows, and Climate Change Impacts/Adaptations

    NASA Astrophysics Data System (ADS)

    Sussman, A.

    2015-12-01

    The Pacific Islands Climate Education Partnership (PCEP) serves the U.S. Affiliated Pacific Island (USAPI) Region. The international entities served by PCEP are the state of Hawai'i (USA); three Freely Associated States (the Federated States of Micronesia, the Republic of the Marshall Islands, and the Republic of Palau), and three Territories (Guam, Commonwealth of Northern Mariana Islands, and American Samoa). Funded by NSF, the PCEP aims to educate the region's students and citizens in ways that exemplify modern science and indigenous environmental knowledge, address the urgency of climate change impacts, and focus on adaptation strategies that can increase resiliency with respect to climate change impacts. Unfortunately the vast majority of the science texts used in schools come from the US mainland and feature contexts that do not relate to the lives of Pacific island students. The curricular materials also tend to be older and to have very weak climate science content, especially with respect to tropical islands and climate change. In collaboration with public broadcast station WGBH, PCEP has developed three climate education interactives that sequentially provide an introduction to key climate change education concepts. The first in the series focuses on the global carbon cycle and connects increased atmospheric CO2 with rising global temperatures. The second analyzes Earth system energy flows to explain the key role of the increased greenhouse effect. The third focuses on four climate change impacts (higher temperatures, rising sea level, changes in precipitation, and ocean acidification), and adaptation strategies to increase resiliency of local ecosystems and human systems. While the interactives have a Pacific island visual and text perspective, they are broadly applicable for other education audiences. Learners can use the interactives to engage with the basic science concepts, and then apply the climate change impacts to their own contexts.

  7. Identification of interaction sites for dimerization and adapter recruitment in Toll/interleukin-1 receptor (TIR) domain of Toll-like receptor 4.

    PubMed

    Bovijn, Celia; Ulrichts, Peter; De Smet, Anne-Sophie; Catteeuw, Dominiek; Beyaert, Rudi; Tavernier, Jan; Peelman, Frank

    2012-02-01

    Toll-like receptor signaling requires interactions of the Toll/IL-1 receptor (TIR) domains of the receptor and adapter proteins. Using the mammalian protein-protein interaction trap strategy, homology modeling, and site-directed mutagenesis, we identify the interaction surfaces in the TLR4 TIR domain for the TLR4-TLR4, TLR4-MyD88 adapter-like (MAL), and TLR4-TRIF-related adapter molecule (TRAM) interaction. Two binding sites are equally important for TLR4 dimerization and adapter recruitment. In a model based on the crystal structure of the dimeric TLR10 TIR domain, the first binding site mediates TLR4-TLR4 TIR-TIR interaction. Upon dimerization, two identical second binding sites of the TLR4 TIR domain are juxtaposed and form an extended binding platform for both MAL and TRAM. In our mammalian protein-protein interaction trap assay, MAL and TRAM compete for binding to this platform. Our data suggest that adapter binding can stabilize the TLR4 TIR dimerization. PMID:22139835

  8. Identification of Interaction Sites for Dimerization and Adapter Recruitment in Toll/Interleukin-1 Receptor (TIR) Domain of Toll-like Receptor 4*

    PubMed Central

    Bovijn, Celia; Ulrichts, Peter; De Smet, Anne-Sophie; Catteeuw, Dominiek; Beyaert, Rudi; Tavernier, Jan; Peelman, Frank

    2012-01-01

    Toll-like receptor signaling requires interactions of the Toll/IL-1 receptor (TIR) domains of the receptor and adapter proteins. Using the mammalian protein-protein interaction trap strategy, homology modeling, and site-directed mutagenesis, we identify the interaction surfaces in the TLR4 TIR domain for the TLR4-TLR4, TLR4-MyD88 adapter-like (MAL), and TLR4-TRIF-related adapter molecule (TRAM) interaction. Two binding sites are equally important for TLR4 dimerization and adapter recruitment. In a model based on the crystal structure of the dimeric TLR10 TIR domain, the first binding site mediates TLR4-TLR4 TIR-TIR interaction. Upon dimerization, two identical second binding sites of the TLR4 TIR domain are juxtaposed and form an extended binding platform for both MAL and TRAM. In our mammalian protein-protein interaction trap assay, MAL and TRAM compete for binding to this platform. Our data suggest that adapter binding can stabilize the TLR4 TIR dimerization. PMID:22139835

  9. Adaptive hydrophobic and hydrophilic interactions of mussel foot proteins with organic thin films.

    PubMed

    Yu, Jing; Kan, Yajing; Rapp, Michael; Danner, Eric; Wei, Wei; Das, Saurabh; Miller, Dusty R; Chen, Yunfei; Waite, J Herbert; Israelachvili, Jacob N

    2013-09-24

    The adhesion of mussel foot proteins (Mfps) to a variety of specially engineered mineral and metal oxide surfaces has previously been investigated extensively, but the relevance of these studies to adhesion in biological environments remains unknown. Most solid surfaces exposed to seawater or physiological fluids become fouled by organic conditioning films and biofilms within minutes. Understanding the binding mechanisms of Mfps to organic films with known chemical and physical properties therefore is of considerable theoretical and practical interest. Using self-assembled monolayers (SAMs) on atomically smooth gold substrates and the surface forces apparatus, we explored the force-distance profiles and adhesion energies of three different Mfps, Mfp-1, Mfp-3, and Mfp-5, on (i) hydrophobic methyl (CH3)- and (ii) hydrophilic alcohol (OH)-terminated SAM surfaces between pH 3 and pH 7.5. At acidic pH, all three Mfps adhered strongly to the CH3-terminated SAM surfaces via hydrophobic interactions (range of adhesive interaction energy = -4 to -9 mJ/m(2)) but only weakly to the OH-terminated SAM surfaces through H- bonding (adhesive interaction energy ≤ -0.5 mJ/m(2)). 3, 4-Dihydroxyphenylalanine (Dopa) residues in Mfps mediate binding to both SAM surface types but do so through different interactions: typical bidentate H-bonding by Dopa is frustrated by the longer spacing of OH-SAMs; in contrast, on CH3-SAMs, Dopa in synergy with other nonpolar residues partitions to the hydrophobic surface. Asymmetry in the distribution of hydrophobic residues in intrinsically unstructured proteins, the distortion of bond geometry between H-bonding surfaces, and the manipulation of physisorbed binding lifetimes represent important concepts for the design of adhesive and nonfouling surfaces.

  10. Adaptive hydrophobic and hydrophilic interactions of mussel foot proteins with organic thin films

    PubMed Central

    Yu, Jing; Kan, Yajing; Rapp, Michael; Danner, Eric; Wei, Wei; Das, Saurabh; Miller, Dusty R.; Chen, Yunfei; Waite, J. Herbert; Israelachvili, Jacob N.

    2013-01-01

    The adhesion of mussel foot proteins (Mfps) to a variety of specially engineered mineral and metal oxide surfaces has previously been investigated extensively, but the relevance of these studies to adhesion in biological environments remains unknown. Most solid surfaces exposed to seawater or physiological fluids become fouled by organic conditioning films and biofilms within minutes. Understanding the binding mechanisms of Mfps to organic films with known chemical and physical properties therefore is of considerable theoretical and practical interest. Using self-assembled monolayers (SAMs) on atomically smooth gold substrates and the surface forces apparatus, we explored the force–distance profiles and adhesion energies of three different Mfps, Mfp-1, Mfp-3, and Mfp-5, on (i) hydrophobic methyl (CH3)- and (ii) hydrophilic alcohol (OH)-terminated SAM surfaces between pH 3 and pH 7.5. At acidic pH, all three Mfps adhered strongly to the CH3-terminated SAM surfaces via hydrophobic interactions (range of adhesive interaction energy = −4 to −9 mJ/m2) but only weakly to the OH-terminated SAM surfaces through H- bonding (adhesive interaction energy ≤ −0.5 mJ/m2). 3, 4-Dihydroxyphenylalanine (Dopa) residues in Mfps mediate binding to both SAM surface types but do so through different interactions: typical bidentate H-bonding by Dopa is frustrated by the longer spacing of OH-SAMs; in contrast, on CH3-SAMs, Dopa in synergy with other nonpolar residues partitions to the hydrophobic surface. Asymmetry in the distribution of hydrophobic residues in intrinsically unstructured proteins, the distortion of bond geometry between H-bonding surfaces, and the manipulation of physisorbed binding lifetimes represent important concepts for the design of adhesive and nonfouling surfaces. PMID:24014592

  11. An adaptive level set method for shock-driven fluid-structure interaction

    SciTech Connect

    Deiterding, Ralf

    2007-01-01

    The fluid-structure interaction simulation of shock- and detonation-loaded structures requires numerical methods that can cope with large deformations as well as local topology changes. A robust, level-set-based shock-capturing fluid solver is described that allows coupling to any solid mechanics solver. As computational example, the elastic response of a thin steel panel, modeled with both shell and beam theory, to a shock wave in air is considered.

  12. Emotion in languaging: languaging as affective, adaptive, and flexible behavior in social interaction

    PubMed Central

    Jensen, Thomas W.

    2014-01-01

    This article argues for a view on languaging as inherently affective. Informed by recent ecological tendencies within cognitive science and distributed language studies a distinction between first order languaging (language as whole-body sense making) and second order language (language as system like constraints) is put forward. Contrary to common assumptions within linguistics and communication studies separating language-as-a-system from language use (resulting in separations between language vs. body-language and verbal vs. non-verbal communication etc.) the first/second order distinction sees language as emanating from behavior making it possible to view emotion and affect as integral parts languaging behavior. Likewise, emotion and affect are studied, not as inner mental states, but as processes of organism-environment interactions. Based on video recordings of interaction between (1) children with special needs, and (2) couple in therapy and the therapist patterns of reciprocal influences between interactants are examined. Through analyzes of affective stance and patterns of inter-affectivity it is exemplified how language and emotion should not be seen as separate phenomena combined in language use, but rather as completely intertwined phenomena in languaging behavior constrained by second order patterns. PMID:25076921

  13. Emotion in languaging: languaging as affective, adaptive, and flexible behavior in social interaction.

    PubMed

    Jensen, Thomas W

    2014-01-01

    This article argues for a view on languaging as inherently affective. Informed by recent ecological tendencies within cognitive science and distributed language studies a distinction between first order languaging (language as whole-body sense making) and second order language (language as system like constraints) is put forward. Contrary to common assumptions within linguistics and communication studies separating language-as-a-system from language use (resulting in separations between language vs. body-language and verbal vs. non-verbal communication etc.) the first/second order distinction sees language as emanating from behavior making it possible to view emotion and affect as integral parts languaging behavior. Likewise, emotion and affect are studied, not as inner mental states, but as processes of organism-environment interactions. Based on video recordings of interaction between (1) children with special needs, and (2) couple in therapy and the therapist patterns of reciprocal influences between interactants are examined. Through analyzes of affective stance and patterns of inter-affectivity it is exemplified how language and emotion should not be seen as separate phenomena combined in language use, but rather as completely intertwined phenomena in languaging behavior constrained by second order patterns.

  14. Chemical Assignment of Symmetry-Adapted Perturbation Theory Interaction Energy Components: The Functional-Group SAPT Partition.

    PubMed

    Parrish, Robert M; Parker, Trent M; Sherrill, C David

    2014-10-14

    Recently, we introduced an effective atom-pairwise partition of the many-body symmetry-adapted perturbation theory (SAPT) interaction energy decomposition, producing a method known as atomic SAPT (A-SAPT) [Parrish, R. M.; Sherrill, C. D. J. Chem. Phys. 2014, 141, 044115]. A-SAPT provides ab initio atom-pair potentials for force field development and also automatic visualizations of the spatial contributions of noncovalent interactions, but often has difficulty producing chemically useful partitions of the electrostatic energy, due to the buildup of oscillating partial charges on adjacent functional groups. In this work, we substitute chemical functional groups in place of atoms as the relevant local quasiparticles in the partition, resulting in a functional-group-pairwise partition denoted as functional-group SAPT (F-SAPT). F-SAPT assigns integral sets of local occupied electronic orbitals and protons to chemical functional groups and linking σ bonds. Link-bond contributions can be further assigned to chemical functional groups to simplify the analysis. This approach yields a SAPT partition between pairs of functional groups with integral charge (usually neutral), preventing oscillations in the electrostatic partition. F-SAPT qualitatively matches chemical intuition and the cut-and-cap fragmentation technique but additionally yields the quantitative many-body SAPT interaction energy. The conceptual simplicity, chemical utility, and computational efficiency of F-SAPT is demonstrated in the context of phenol dimer, proflavine(+)-DNA intercalation, and a cucurbituril host-guest inclusion complex. PMID:26588139

  15. Aggregation of Infective Stages of Parasites as an Adaptation and Its Implications for the Study of Parasite-Host Interactions.

    PubMed

    Morrill, André; Forbes, Mark R

    2016-02-01

    The causes and consequences of aggregation among conspecifics have received much attention. For infecting macroparasites, causes include variation among hosts in susceptibility and whether infective stages are aggregated in the environment. Here, we link these two phenomena and explore whether aggregation of infective stages in the environment is adaptive to parasites encountering host condition-linked defenses and what effect such aggregations have for parasite-host interactions. Using simulation models, we show that parasite fitness is increased by aggregates attacking a host, particularly when investment into defenses is high. The fitness benefit of aggregation remains despite inclusion of factors that should curb the benefits of aggregation, namely, mortality of low-condition hosts (those hosts expected to be most susceptible to parasitism) and costs of high coinfection. For sample sizes common in studies, aggregation of infective stages reduces the likelihood of detecting host condition-parasitism relations, even when host condition is the only other factor in models affecting parasitism. Thus, it is not surprising that the expected inverse relations between host condition and parasitism, commonly a premise in studies of parasite-host interactions, are inconsistently found. An understanding of how parasites encounter hosts is thus needed for developing theory for parasite-host ecological and evolutionary interactions.

  16. Chemical Assignment of Symmetry-Adapted Perturbation Theory Interaction Energy Components: The Functional-Group SAPT Partition.

    PubMed

    Parrish, Robert M; Parker, Trent M; Sherrill, C David

    2014-10-14

    Recently, we introduced an effective atom-pairwise partition of the many-body symmetry-adapted perturbation theory (SAPT) interaction energy decomposition, producing a method known as atomic SAPT (A-SAPT) [Parrish, R. M.; Sherrill, C. D. J. Chem. Phys. 2014, 141, 044115]. A-SAPT provides ab initio atom-pair potentials for force field development and also automatic visualizations of the spatial contributions of noncovalent interactions, but often has difficulty producing chemically useful partitions of the electrostatic energy, due to the buildup of oscillating partial charges on adjacent functional groups. In this work, we substitute chemical functional groups in place of atoms as the relevant local quasiparticles in the partition, resulting in a functional-group-pairwise partition denoted as functional-group SAPT (F-SAPT). F-SAPT assigns integral sets of local occupied electronic orbitals and protons to chemical functional groups and linking σ bonds. Link-bond contributions can be further assigned to chemical functional groups to simplify the analysis. This approach yields a SAPT partition between pairs of functional groups with integral charge (usually neutral), preventing oscillations in the electrostatic partition. F-SAPT qualitatively matches chemical intuition and the cut-and-cap fragmentation technique but additionally yields the quantitative many-body SAPT interaction energy. The conceptual simplicity, chemical utility, and computational efficiency of F-SAPT is demonstrated in the context of phenol dimer, proflavine(+)-DNA intercalation, and a cucurbituril host-guest inclusion complex.

  17. Seniority number in spin-adapted spaces and compactness of configuration interaction wave functions.

    PubMed

    Alcoba, Diego R; Torre, Alicia; Lain, Luis; Massaccesi, Gustavo E; Oña, Ofelia B

    2013-08-28

    This work extends the concept of seniority number, which has been widely used for classifying N-electron Slater determinants, to wave functions of N electrons and spin S, as well as to N-electron spin-adapted Hilbert spaces. We propose a spin-free formulation of the seniority number operator and perform a study on the behavior of the expectation values of this operator under transformations of the molecular basis sets. This study leads to propose a quantitative evaluation for the convergence of the expansions of the wave functions in terms of Slater determinants. The non-invariant character of the seniority number operator expectation value of a wave function with respect to a unitary transformation of the molecular orbital basis set, allows us to search for a change of basis which minimizes that expectation value. The results found in the description of wave functions of selected atoms and molecules show that the expansions expressed in these bases exhibit a more rapid convergence than those formulated in the canonical molecular orbital bases and even in the natural orbital ones. PMID:24006970

  18. Ligand-apomyoglobin interactions. Configurational adaptability of the haem-binding site.

    PubMed Central

    Lind, K E; Moller, J V

    1976-01-01

    1. The interaction of the haem-binding region of apomyoglobin with different ligands was examined by ultrafiltration, equilibrium dialysis and spectrophotometry, to study unspecific features of protein-ligand interactions such as they occur in, for example, serum albumin binding. 2. Apomyoglobin, in contrast with metmyoglobin, binds at pH 7, with a high affinity, one molecule of Bromophenol Blue, bilirubin and protoporphyrin IX, two molecules of n-dodecanoate and n-decyl sulphate and four molecules of n-dodecyl sulphate and n-tetradecyl sulphate. 3. The number of high-affinity sites and/or association constants for the alkyl sulphates are enhanced by an increase of hydrocarbon length, indicating hydrophobic interactions with the protein. 4. Measurements of the temperature-dependence of the association constants of the high-affinity sites imply that the binding processes are largely entropy-driven. 5. Binding studies in the presence of two ligands show that bilirubin plus Bromophenol Blue and dodecanoate plus Bromophenol Blue can be simultaneously bound by apomyoglobin, but with decreased affinities. By contrast, the apomyoglobin-protoporphyrin IX complex does not react with Bromophenol Blue. 6. Optical-rotatory-dispersion measurements show that the laevorotation of apomyoglobin is increased towards that of metmyglobin in the presence of haemin and protoporphyrin IX. Small changes in the optical-rotatory-dispersion spectrum of apomyoglobin are observed in the presence of the other ligands. 7. It is concluded that the binding sites on apomyoglobin probably do not pre-exist but appear to be moulded from predominantly non-polar amino acid residues by reaction with hydrophobic ligands. 8. Comparison with data in the literature indicates that apomyoglobin on a weight basis has a larger hydrophobic area avaialble for binding of ligands than has human serum albumin. On the other hand, the association constants of serum for the ligands used in this study are generally

  19. On the reciprocal interaction between believing and feeling: an adaptive agent modelling perspective

    PubMed Central

    Memon, Zulfiqar A.

    2010-01-01

    An agent’s beliefs usually depend on informational or cognitive factors such as observation or received communication or reasoning, but also affective factors may play a role. In this paper, by adopting neurological theories on the role of emotions and feelings, an agent model is introduced incorporating the interaction between cognitive and affective factors in believing. The model describes how the strength of a belief may not only depend on information obtained, but also on the emotional responses on the belief. For feeling emotions a recursive body loop between preparations for emotional responses and feelings is assumed. The model introduces a second feedback loop for the interaction between feeling and belief. The strength of a belief and of the feeling both result from the converging dynamic pattern modelled by the combination of the two loops. For some specific cases it is described, for example, how for certain personal characteristics an optimistic world view is generated in the agent’s beliefs, or, for other characteristics, a pessimistic world view. Moreover, the paper shows how such affective effects on beliefs can emerge and become stronger over time due to experiences obtained. It is shown how based on Hebbian learning a connection from feeling to belief can develop. As these connections affect the strenghts of future beliefs, in this way an effect of judgment ‘by experience built up in the past’ or ‘by gut feeling’ can be obtained. Some example simulation results and a mathematical analysis of the equilibria are presented. PMID:21139709

  20. Spatially adaptive stochastic methods for fluid-structure interactions subject to thermal fluctuations in domains with complex geometries

    SciTech Connect

    Plunkett, Pat; Hu, Jonathan; Siefert, Christopher; Atzberger, Paul J.

    2014-08-07

    We develop stochastic mixed finite element methods for spatially adaptive simulations of fluid–structure interactions when subject to thermal fluctuations. To account for thermal fluctuations, we introduce a discrete fluctuation–dissipation balance condition to develop compatible stochastic driving fields for our discretization. We also perform analysis that shows our condition is sufficient to ensure results consistent with statistical mechanics. We show the Gibbs–Boltzmann distribution is invariant under the stochastic dynamics of the semi-discretization. To generate efficiently the required stochastic driving fields, we develop a Gibbs sampler based on iterative methods and multigrid to generate fields with O(N) computational complexity. Our stochastic methods provide an alternative to uniform discretizations on periodic domains that rely on Fast Fourier Transforms. To demonstrate in practice our stochastic computational methods, we investigate within channel geometries having internal obstacles and no-slip walls how the mobility/diffusivity of particles depends on location. Furthermore, our methods extend the applicability of fluctuating hydrodynamic approaches by allowing for spatially adaptive resolution of the mechanics and for domains that have complex geometries relevant in many applications.

  1. Spatially adaptive stochastic methods for fluid–structure interactions subject to thermal fluctuations in domains with complex geometries

    SciTech Connect

    Plunkett, Pat; Hu, Jonathan; Siefert, Christopher; Atzberger, Paul J.

    2014-11-15

    We develop stochastic mixed finite element methods for spatially adaptive simulations of fluid–structure interactions when subject to thermal fluctuations. To account for thermal fluctuations, we introduce a discrete fluctuation–dissipation balance condition to develop compatible stochastic driving fields for our discretization. We perform analysis that shows our condition is sufficient to ensure results consistent with statistical mechanics. We show the Gibbs–Boltzmann distribution is invariant under the stochastic dynamics of the semi-discretization. To generate efficiently the required stochastic driving fields, we develop a Gibbs sampler based on iterative methods and multigrid to generate fields with O(N) computational complexity. Our stochastic methods provide an alternative to uniform discretizations on periodic domains that rely on Fast Fourier Transforms. To demonstrate in practice our stochastic computational methods, we investigate within channel geometries having internal obstacles and no-slip walls how the mobility/diffusivity of particles depends on location. Our methods extend the applicability of fluctuating hydrodynamic approaches by allowing for spatially adaptive resolution of the mechanics and for domains that have complex geometries relevant in many applications.

  2. Genome and metagenome analyses reveal adaptive evolution of the host and interaction with the gut microbiota in the goose.

    PubMed

    Gao, Guangliang; Zhao, Xianzhi; Li, Qin; He, Chuan; Zhao, Wenjing; Liu, Shuyun; Ding, Jinmei; Ye, Weixing; Wang, Jun; Chen, Ye; Wang, Haiwei; Li, Jing; Luo, Yi; Su, Jian; Huang, Yong; Liu, Zuohua; Dai, Ronghua; Shi, Yixiang; Meng, He; Wang, Qigui

    2016-01-01

    The goose is an economically important waterfowl that exhibits unique characteristics and abilities, such as liver fat deposition and fibre digestion. Here, we report de novo whole-genome assemblies for the goose and swan goose and describe the evolutionary relationships among 7 bird species, including domestic and wild geese, which diverged approximately 3.4~6.3 million years ago (Mya). In contrast to chickens as a proximal species, the expanded and rapidly evolving genes found in the goose genome are mainly involved in metabolism, including energy, amino acid and carbohydrate metabolism. Further integrated analysis of the host genome and gut metagenome indicated that the most widely shared functional enrichment of genes occurs for functions such as glycolysis/gluconeogenesis, starch and sucrose metabolism, propanoate metabolism and the citrate cycle. We speculate that the unique physiological abilities of geese benefit from the adaptive evolution of the host genome and symbiotic interactions with gut microbes. PMID:27608918

  3. Genome and metagenome analyses reveal adaptive evolution of the host and interaction with the gut microbiota in the goose

    PubMed Central

    Gao, Guangliang; Zhao, Xianzhi; Li, Qin; He, Chuan; Zhao, Wenjing; Liu, Shuyun; Ding, Jinmei; Ye, Weixing; Wang, Jun; Chen, Ye; Wang, Haiwei; Li, Jing; Luo, Yi; Su, Jian; Huang, Yong; Liu, Zuohua; Dai, Ronghua; Shi, Yixiang; Meng, He; Wang, Qigui

    2016-01-01

    The goose is an economically important waterfowl that exhibits unique characteristics and abilities, such as liver fat deposition and fibre digestion. Here, we report de novo whole-genome assemblies for the goose and swan goose and describe the evolutionary relationships among 7 bird species, including domestic and wild geese, which diverged approximately 3.4~6.3 million years ago (Mya). In contrast to chickens as a proximal species, the expanded and rapidly evolving genes found in the goose genome are mainly involved in metabolism, including energy, amino acid and carbohydrate metabolism. Further integrated analysis of the host genome and gut metagenome indicated that the most widely shared functional enrichment of genes occurs for functions such as glycolysis/gluconeogenesis, starch and sucrose metabolism, propanoate metabolism and the citrate cycle. We speculate that the unique physiological abilities of geese benefit from the adaptive evolution of the host genome and symbiotic interactions with gut microbes. PMID:27608918

  4. Genome and metagenome analyses reveal adaptive evolution of the host and interaction with the gut microbiota in the goose.

    PubMed

    Gao, Guangliang; Zhao, Xianzhi; Li, Qin; He, Chuan; Zhao, Wenjing; Liu, Shuyun; Ding, Jinmei; Ye, Weixing; Wang, Jun; Chen, Ye; Wang, Haiwei; Li, Jing; Luo, Yi; Su, Jian; Huang, Yong; Liu, Zuohua; Dai, Ronghua; Shi, Yixiang; Meng, He; Wang, Qigui

    2016-01-01

    The goose is an economically important waterfowl that exhibits unique characteristics and abilities, such as liver fat deposition and fibre digestion. Here, we report de novo whole-genome assemblies for the goose and swan goose and describe the evolutionary relationships among 7 bird species, including domestic and wild geese, which diverged approximately 3.4~6.3 million years ago (Mya). In contrast to chickens as a proximal species, the expanded and rapidly evolving genes found in the goose genome are mainly involved in metabolism, including energy, amino acid and carbohydrate metabolism. Further integrated analysis of the host genome and gut metagenome indicated that the most widely shared functional enrichment of genes occurs for functions such as glycolysis/gluconeogenesis, starch and sucrose metabolism, propanoate metabolism and the citrate cycle. We speculate that the unique physiological abilities of geese benefit from the adaptive evolution of the host genome and symbiotic interactions with gut microbes.

  5. Reciprocity phase in various 2×2 games by agents equipped with two-memory length strategy encouraged by grouping for interaction and adaptation.

    PubMed

    Wakiyama, Motoya; Tanimoto, Jun

    2011-01-01

    This paper numerically investigates 2×2 games involving the Prisoner's Dilemma, Chicken, Hero, Leader, Stag Hunt, and Trivial Games in which agents have a strategy expressed by five-bit, two-memory length. Our motivation is to explore how grouping for game interaction and strategy adaptation influence ST reciprocity and R reciprocity (Tanimoto and Sagara, 2007a [Tanimoto, J., Sagara, H., 2007a. A study on emergence of coordinated alternating reciprocity in a 2×2 game with 2-memory length strategy. Biosystems 90(3), 728-737]. Enhanced R reciprocity is observed with the stronger grouping for game interaction when a relatively stronger grouping for strategy adaptation is assumed. On the other hand, enhanced ST reciprocity emerged with the stronger grouping for strategy adaptation when the relatively weaker grouping for game interaction is imposed. Our numerical experiment deals with those two groupings independently and dependently.

  6. Reciprocity phase in various 2×2 games by agents equipped with two-memory length strategy encouraged by grouping for interaction and adaptation.

    PubMed

    Wakiyama, Motoya; Tanimoto, Jun

    2011-01-01

    This paper numerically investigates 2×2 games involving the Prisoner's Dilemma, Chicken, Hero, Leader, Stag Hunt, and Trivial Games in which agents have a strategy expressed by five-bit, two-memory length. Our motivation is to explore how grouping for game interaction and strategy adaptation influence ST reciprocity and R reciprocity (Tanimoto and Sagara, 2007a [Tanimoto, J., Sagara, H., 2007a. A study on emergence of coordinated alternating reciprocity in a 2×2 game with 2-memory length strategy. Biosystems 90(3), 728-737]. Enhanced R reciprocity is observed with the stronger grouping for game interaction when a relatively stronger grouping for strategy adaptation is assumed. On the other hand, enhanced ST reciprocity emerged with the stronger grouping for strategy adaptation when the relatively weaker grouping for game interaction is imposed. Our numerical experiment deals with those two groupings independently and dependently. PMID:21035518

  7. Pseudomonas aeruginosa and Burkholderia cepacia in cystic fibrosis: genome evolution, interactions and adaptation.

    PubMed

    Eberl, Leo; Tümmler, Burkhard

    2004-09-01

    The Gram-negative bacteria Pseudomonas aeruginosa and Burkholderia cepacia are opportunistic human pathogens that are responsible for severe nosocomial infections in immunocompromised patients and are the major pathogens in cystic fibrosis (CF). The two bacteria not only inhabit the same environmental niches but can also form mixed biofilms in the lungs of CF patients. Hence, it appears very likely that the two organisms are capable of interacting with each other. Work of the past few years has shown that both bacteria utilize quorum-sensing systems, which rely on N-acyl-homoserine lactone signal molecules, to control the expression of virulence factors and biofilm development. Most importantly, evidence has been presented that these signal molecules also serve as a universal language for communication between the two organisms. Moreover, analyses of the diversity in P. aeruginosa revealed the presence of genome islands that contain genes that are highly homologous to genes identified in strains of Burkholderia sp. This finding suggests that there is a frequent exchange of genetic material between the two organisms.

  8. New Genomic Insights into "Entotheonella" Symbionts in Theonella swinhoei: Mixotrophy, Anaerobic Adaptation, Resilience, and Interaction.

    PubMed

    Liu, Fang; Li, Jinlong; Feng, Guofang; Li, Zhiyong

    2016-01-01

    "Entotheonella" (phylum "Tectomicrobia") is a filamentous symbiont that produces almost all known bioactive compounds derived from the Lithistida sponge Theonella swinhoei. In contrast to the comprehensive knowledge of its secondary metabolism, knowledge of its lifestyle, resilience, and interaction with the sponge host and other symbionts remains rudimentary. In this study, we obtained two "Entotheonella" genomes from T. swinhoei from the South China Sea through metagenome binning, and used a RASTtk pipeline to achieve better genome annotation. The high average nucleotide index values suggested they were the same phylotypes as the two "Entotheonella" phylotypes from T. swinhoei from the Japan Sea. Genomic features related to utilization of various carbon sources, peptidase secretion, CO2 fixation, sulfate reduction, anaerobic respiration, and denitrification indicated the mixotrophic nature of "Entotheonella." The endospore-forming potential along with metal- and antibiotic resistance indicated "Entotheonella" was highly resilient to harsh conditions. The potential for endospore formation also explained the widespread distribution of "Entotheonella" to some extent. The discovery of Type II (general secretion pathway proteins and the Widespread Colonization Island) and Type VI secretion systems in "Entotheonella" suggested it could secrete extracellular hydrolases, form tight adhesion, act against phagocytes, and kill other prokaryotes. Overall, the newly discovered genomic features suggest "Entotheonella" is a highly competitive member of the symbiotic community of T. swinhoei. PMID:27610106

  9. New Genomic Insights into "Entotheonella" Symbionts in Theonella swinhoei: Mixotrophy, Anaerobic Adaptation, Resilience, and Interaction.

    PubMed

    Liu, Fang; Li, Jinlong; Feng, Guofang; Li, Zhiyong

    2016-01-01

    "Entotheonella" (phylum "Tectomicrobia") is a filamentous symbiont that produces almost all known bioactive compounds derived from the Lithistida sponge Theonella swinhoei. In contrast to the comprehensive knowledge of its secondary metabolism, knowledge of its lifestyle, resilience, and interaction with the sponge host and other symbionts remains rudimentary. In this study, we obtained two "Entotheonella" genomes from T. swinhoei from the South China Sea through metagenome binning, and used a RASTtk pipeline to achieve better genome annotation. The high average nucleotide index values suggested they were the same phylotypes as the two "Entotheonella" phylotypes from T. swinhoei from the Japan Sea. Genomic features related to utilization of various carbon sources, peptidase secretion, CO2 fixation, sulfate reduction, anaerobic respiration, and denitrification indicated the mixotrophic nature of "Entotheonella." The endospore-forming potential along with metal- and antibiotic resistance indicated "Entotheonella" was highly resilient to harsh conditions. The potential for endospore formation also explained the widespread distribution of "Entotheonella" to some extent. The discovery of Type II (general secretion pathway proteins and the Widespread Colonization Island) and Type VI secretion systems in "Entotheonella" suggested it could secrete extracellular hydrolases, form tight adhesion, act against phagocytes, and kill other prokaryotes. Overall, the newly discovered genomic features suggest "Entotheonella" is a highly competitive member of the symbiotic community of T. swinhoei.

  10. Evolution of opercle shape in cichlid fishes from Lake Tanganyika - adaptive trait interactions in extant and extinct species flocks

    PubMed Central

    Wilson, Laura A. B.; Colombo, Marco; Sánchez-Villagra, Marcelo R.; Salzburger, Walter

    2015-01-01

    Phenotype-environment correlations and the evolution of trait interactions in adaptive radiations have been widely studied to gain insight into the dynamics underpinning rapid species diversification. In this study we explore the phenotype-environment correlation and evolution of operculum shape in cichlid fishes using an outline-based geometric morphometric approach combined with stable isotope indicators of macrohabitat and trophic niche. We then apply our method to a sample of extinct saurichthyid fishes, a highly diverse and near globally distributed group of actinopterygians occurring throughout the Triassic, to assess the utility of extant data to inform our understanding of ecomorphological evolution in extinct species flocks. A series of comparative methods were used to analyze shape data for 54 extant species of cichlids (N = 416), and 6 extinct species of saurichthyids (N = 44). Results provide evidence for a relationship between operculum shape and feeding ecology, a concentration in shape evolution towards present along with evidence for convergence in form, and significant correlation between the major axes of shape change and measures of gut length and body elongation. The operculum is one of few features that can be compared in extant and extinct groups, enabling reconstruction of phenotype-environment interactions and modes of evolutionary diversification in deep time. PMID:26584885

  11. Evolution of opercle shape in cichlid fishes from Lake Tanganyika - adaptive trait interactions in extant and extinct species flocks.

    PubMed

    Wilson, Laura A B; Colombo, Marco; Sánchez-Villagra, Marcelo R; Salzburger, Walter

    2015-11-20

    Phenotype-environment correlations and the evolution of trait interactions in adaptive radiations have been widely studied to gain insight into the dynamics underpinning rapid species diversification. In this study we explore the phenotype-environment correlation and evolution of operculum shape in cichlid fishes using an outline-based geometric morphometric approach combined with stable isotope indicators of macrohabitat and trophic niche. We then apply our method to a sample of extinct saurichthyid fishes, a highly diverse and near globally distributed group of actinopterygians occurring throughout the Triassic, to assess the utility of extant data to inform our understanding of ecomorphological evolution in extinct species flocks. A series of comparative methods were used to analyze shape data for 54 extant species of cichlids (N = 416), and 6 extinct species of saurichthyids (N = 44). Results provide evidence for a relationship between operculum shape and feeding ecology, a concentration in shape evolution towards present along with evidence for convergence in form, and significant correlation between the major axes of shape change and measures of gut length and body elongation. The operculum is one of few features that can be compared in extant and extinct groups, enabling reconstruction of phenotype-environment interactions and modes of evolutionary diversification in deep time.

  12. Analysis of helicopter blade-vortex interaction noise with application to adaptive-passive and active alleviation methods

    NASA Astrophysics Data System (ADS)

    Tauszig, Lionel Christian

    This study focuses on detection and analysis methods of helicopter blade-vortex interactions (BVI) and applies these methods to two different BVI noise alleviation schemes---an adaptive-passive and an active scheme. A standard free-wake analysis based on relaxation methods is extended in this study to compute high-resolution blade loading, to account for blade-to-blade dissimilarities, and dual vortices when there is negative loading at the blade tips. The free-wake geometry is still calculated on a coarse azimuthal grid and then interpolated to a high-resolution grid to calculate the BVI induced impulsive loading. Blade-to-blade dissimilarities are accounted by allowing the different blades to release their own vortices. A number of BVI detection criteria, including the spherical method (a geometric criterion developed in this thesis) are critically examined. It was determined that high-resolution azimuthal discretization is required in virtually all detection methods except the spherical method which detected the occurrence of parallel BVI even while using a low-resolution azimuthal mesh. Detection methods based on inflow and blade loads were, in addition, found to be sensitive to vortex core size. While most BVI studies use the high-resolution airloads to compute BVI noise, the total noise can often be due to multiple dominant interactions on the advancing and retreating sides. A methodology is developed to evaluate the contribution of an individual interaction to the total BVI noise, based on using the loading due to an individual vortex as an input to the acoustic code WOPWOP. The adaptive-passive BVI alleviation method considered in this study comprises of reducing the length of one set of opposite blades (of a 4-bladed rotor) in low-speed descent. Results showed that differential coning resulting from the blade dissimilarity increases the blade-vortex miss-distances and reduces the BVI noise by 4 dB. The Higher Harmonic Control Aeroacoustic Rotor Test (HART

  13. A Systems Biology Approach to the Coordination of Defensive and Offensive Molecular Mechanisms in the Innate and Adaptive Host-Pathogen Interaction Networks.

    PubMed

    Wu, Chia-Chou; Chen, Bor-Sen

    2016-01-01

    Infected zebrafish coordinates defensive and offensive molecular mechanisms in response to Candida albicans infections, and invasive C. albicans coordinates corresponding molecular mechanisms to interact with the host. However, knowledge of the ensuing infection-activated signaling networks in both host and pathogen and their interspecific crosstalk during the innate and adaptive phases of the infection processes remains incomplete. In the present study, dynamic network modeling, protein interaction databases, and dual transcriptome data from zebrafish and C. albicans during infection were used to infer infection-activated host-pathogen dynamic interaction networks. The consideration of host-pathogen dynamic interaction systems as innate and adaptive loops and subsequent comparisons of inferred innate and adaptive networks indicated previously unrecognized crosstalk between known pathways and suggested roles of immunological memory in the coordination of host defensive and offensive molecular mechanisms to achieve specific and powerful defense against pathogens. Moreover, pathogens enhance intraspecific crosstalk and abrogate host apoptosis to accommodate enhanced host defense mechanisms during the adaptive phase. Accordingly, links between physiological phenomena and changes in the coordination of defensive and offensive molecular mechanisms highlight the importance of host-pathogen molecular interaction networks, and consequent inferences of the host-pathogen relationship could be translated into biomedical applications.

  14. Evaluating an Adaptive and Interactive mHealth Smoking Cessation and Medication Adherence Program: A Randomized Pilot Feasibility Study

    PubMed Central

    Anderson, Melissa L; Bradley, Katharine; An, Lawrence C; Catz, Sheryl L

    2016-01-01

    Background Mobile health (mHealth) interventions hold great promise for helping smokers quit since these programs can have wide reach and facilitate access to comprehensive, interactive, and adaptive treatment content. However, the feasibility, acceptability, and effectiveness of these programs remain largely untested. Objective To assess feasibility and acceptability of the My Mobile Advice Program (MyMAP) smoking cessation program and estimate its effects on smoking cessation and medication adherence to inform future research planning. Methods Sixty-six smokers ready to quit were recruited from a large regional health care system and randomized to one of two mHealth programs: (1) standard self-help including psychoeducational materials and guidance how to quit smoking or (2) an adaptive and interactive program consisting of the same standard mHealth self-help content as controls received plus a) real-time, adaptively tailored advice for managing nicotine withdrawal symptoms and medication side-effects and b) asynchronous secure messaging with a cessation counselor. Participants in both arms were also prescribed a 12-week course of varenicline. Follow-up assessments were conducted at 2 weeks post-target quit date (TQD), 3 months post-TQD, and 5 months post-TQD. Indices of program feasibility and acceptability included acceptability ratings, utilization metrics including use of each MyMAP program component (self-help content, secure messaging, and adaptively tailored advice), and open-ended feedback from participants. Smoking abstinence and medication adherence were also assessed to estimate effects on these treatment outcomes. Results Utilization data indicated the MyMAP program was actively used, with higher mean program log-ins by experimental than control participants (10.6 vs 2.7, P<.001). The majority of experimental respondents thought the MyMAP program could help other people quit smoking (22/24, 92%) and consistently take their stop-smoking medication (17

  15. Bromo volcano area as human-environment system: interaction of volcanic eruption, local knowledge, risk perception and adaptation strategy

    NASA Astrophysics Data System (ADS)

    Bachri, Syamsul; Stötter, Johann; Sartohadi, Junun

    2013-04-01

    People in the Bromo area (located within Tengger Caldera) have learn to live with the threat of volcanic hazard since this volcano is categorized as an active volcano in Indonesia. During 2010, the eruption intensity increased yielding heavy ash fall and glowing rock fragments. A significant risk is also presented by mass movement which reaches areas up to 25 km from the crater. As a result of the 2010 eruption, 12 houses were destroyed, 25 houses collapsed and there were severe also effects on agriculture and the livestock sector. This paper focuses on understanding the interaction of Bromo volcanic eruption processes and their social responses. The specific aims are to 1) identify the 2010 eruption of Bromo 2) examine the human-volcano relationship within Bromo area in general, and 3) investigate the local knowledge related to hazard, risk perception and their adaptation strategies in specific. In-depth interviews with 33 informants from four districts nearest to the crater included local people and authorities were carried out. The survey focused on farmers, key persons (dukun), students and teachers in order to understand how people respond to Bromo eruption. The results show that the eruption in 2010 was unusual as it took continued for nine months, the longest period in Bromo history. The type of eruption was phreatomagmatic producing material dominated by ash to fine sand. This kind of sediment typically belongs to Tengger mountain eruptions which had produced vast explosions in the past. Furthermore, two years after the eruption, the interviewed people explained that local knowledge and their experiences with volcanic activity do not influence their risk perception. Dealing with this eruption, people in the Bromo area applied 'lumbung desa' (traditional saving systems) and mutual aid activity for surviving the volcanic eruption. Keywords: Human-environment system, local knowledge, risk perception, adaptation strategies, Bromo Volcano Indonesia

  16. Searching for Pedagogical Adaptations by Exploring Teacher's Tacit Knowledge and Interactional Co-Regulation in the Education of Pupils with Autism

    ERIC Educational Resources Information Center

    Rama, Irene; Kontu, Elina

    2012-01-01

    The purpose of this article is to introduce a research design, which aims to find useful pedagogical adaptations for teaching pupils with autism. Autism is a behavioural syndrome characterised by disabilities and dysfunctions in interaction and communication, which is why it is interesting to explore educational processes particularly from an…

  17. The Role of Interactions between Student and Classroom Context in Developing Adaptive Self-Efficacy in One Sixth-Grade Mathematics Classroom

    ERIC Educational Resources Information Center

    Yetkin Ozdemir, I. Elif; Pape, Stephen J.

    2013-01-01

    Research and theory suggest several instructional practices that could enhance student self-efficacy. However, little is known about the ways these instructional practices interact with individual students to create opportunities or challenges for developing adaptive self-efficacy. In this study, we focused on two sources of efficacy, mastery…

  18. Potential for adaptive evolution at species range margins: contrasting interactions between red coral populations and their environment in a changing ocean

    PubMed Central

    Ledoux, Jean-Baptiste; Aurelle, Didier; Bensoussan, Nathaniel; Marschal, Christian; Féral, Jean-Pierre; Garrabou, Joaquim

    2015-01-01

    Studying population-by-environment interactions (PEIs) at species range margins offers the opportunity to characterize the responses of populations facing an extreme regime of selection, as expected due to global change. Nevertheless, the importance of these marginal populations as putative reservoirs of adaptive genetic variation has scarcely been considered in conservation biology. This is particularly true in marine ecosystems for which the deep refugia hypothesis proposes that disturbed shallow and marginal populations of a given species can be replenished by mesophotic ones. This hypothesis therefore assumes that identical PEIs exist between populations, neglecting the potential for adaptation at species range margins. Here, we combine reciprocal transplant and common garden experiments with population genetics analyses to decipher the PEIs in the red coral, Corallium rubrum. Our analyses reveal partially contrasting PEIs between shallow and mesophotic populations separated by approximately one hundred meters, suggesting that red coral populations may potentially be locally adapted to their environment. Based on the effective population size and connectivity analyses, we posit that genetic drift may be more important than gene flow in the adaptation of the red coral. We further investigate how adaptive divergence could impact population viability in the context of warming and demonstrate differential phenotypic buffering capacities against thermal stress. Our study questions the relevance of the deep refugia hypothesis and highlights the conservation value of marginal populations as a putative reservoir of adaptive genetic polymorphism. PMID:25859324

  19. Odor-Specific Habituation Arises from Interaction of Afferent Synaptic Adaptation and Intrinsic Synaptic Potentiation in Olfactory Cortex

    ERIC Educational Resources Information Center

    Linster, Christiane; Menon, Alka V.; Singh, Christopher Y.; Wilson, Donald A.

    2009-01-01

    Segmentation of target odorants from background odorants is a fundamental computational requirement for the olfactory system and is thought to be behaviorally mediated by olfactory habituation memory. Data from our laboratory have shown that odor-specific adaptation in piriform neurons, mediated at least partially by synaptic adaptation between…

  20. White noise analysis of pace-maker-response interactions and non-linearities in slowly adapting crayfish stretch receptor.

    PubMed Central

    Buño, W; Bustamante, J; Fuentes, J

    1984-01-01

    Input-output relations were investigated in the slowly adapting stretch receptor organ of crayfish using a Gaussian white noise length input with a 0.03-12.5 Hz band width and the resulting action potential output. The noise input was presented to the de-efferented receptor in situ, at three mean elongations and at four different amplitudes. The three mean elongations were set within the normal range in vivo, two at the extremes close to the minimum and maximum physiological lengths and the other in the mid-range. With white noise inputs there is a finite probability that the system will be tested in all possible conditions within the chosen band width because white noise has the advantage that it contains, with a finite probability, all possible stimulus wave forms at random. The analysis indicated similarities between the effects of the input variables, namely white noise amplitude and mean elongation. With low input variables the activity was periodic. With larger inputs, impulse rates were higher and irregular. The average length trajectories leading to a spike (i.e. the average stimulus) were either biphasic with high inputs or multiphasic and periodic with lower input variables. The frequency of periodicity increased with mean elongation. Although for a given length and noise amplitude a variety of individual length trajectories preceded spikes, the final biphasic shortening-lengthening average stimulus sequence before a spike was similar in all cases irrespective of the input variables. The number of possible trajectories decreased with increments in the input variables. The standard deviation of length values for each average stimulus was computed and displayed as a function of time relative to the spike. It was first constant, and decreased gradually to a minimum value at the spike reference. Standard deviation values were lower for higher white noise amplitudes and mean elongation. Simple, short-lasting stimulus wave forms in the white noise were isolated

  1. INTERACTIONS BETWEEN UNSUPERVISED LEARNING AND THE DEGREE OF SPECTRAL MISMATCH ON SHORT-TERM PERCEPTUAL ADAPTATION TO SPECTRALLY-SHIFTED SPEECH

    PubMed Central

    Li, Tianhao; Galvin, John J.; Fu, Qian-Jie

    2009-01-01

    Objectives Cochlear implant listeners are able to at least partially adapt to the spectral mismatch associated with the implant device and speech processor via daily exposure and/or explicit training. The overall goal of this study was to investigate interactions between short-term unsupervised learning (i.e., passive adaptation) and the degree of spectral mismatch in normal-hearing listeners’ adaptation to spectrally-shifted vowels. Methods Normal-hearing subjects were tested while listening to acoustic cochlear implant simulations. Unsupervised learning was measured by testing vowel recognition repeatedly over a five-day period; no feedback or explicit training was provided. In Experiment 1, subjects listened to 8-channel, sine-wave vocoded speech. The spectral envelope was compressed to simulate a 16 mm cochlear implant electrode array. The analysis bands were fixed and the compressed spectral envelope was linearly shifted toward the base by 3.6, 6 or 8.3 mm to simulate different insertion depths of the electrode array, resulting in a slight, moderate, or severe spectral shift. In Experiment 2, half the subjects were exclusively exposed to a severe shift with 8 or 16 channels (“exclusive groups”), and half the subjects were exposed to 8-channel severely-shifted speech, 16-channel severely-shifted speech and 8-channel moderately-shifted speech, alternately presented within each test session (“mixed group”). The region of stimulation in the cochlea was fixed (16 mm in extent, 15 mm from the apex) and the analysis bands were manipulated to create the spectral shift conditions. To determine whether increased spectral resolution would improve adaptation, subjects were exposed to 8- or 16-channel severely-shifted speech. Results In Experiment 1, at the end of the adaptation period, there was no significant difference between 8-channel speech that was spectrally-matched or shifted by 3.6 mm. There was a significant, but less-complete adaptation to the 6 mm

  2. Large-scale symmetry-adapted perturbation theory computations via density fitting and Laplace transformation techniques: investigating the fundamental forces of DNA-intercalator interactions.

    PubMed

    Hohenstein, Edward G; Parrish, Robert M; Sherrill, C David; Turney, Justin M; Schaefer, Henry F

    2011-11-01

    Symmetry-adapted perturbation theory (SAPT) provides a means of probing the fundamental nature of intermolecular interactions. Low-orders of SAPT (here, SAPT0) are especially attractive since they provide qualitative (sometimes quantitative) results while remaining tractable for large systems. The application of density fitting and Laplace transformation techniques to SAPT0 can significantly reduce the expense associated with these computations and make even larger systems accessible. We present new factorizations of the SAPT0 equations with density-fitted two-electron integrals and the first application of Laplace transformations of energy denominators to SAPT. The improved scalability of the DF-SAPT0 implementation allows it to be applied to systems with more than 200 atoms and 2800 basis functions. The Laplace-transformed energy denominators are compared to analogous partial Cholesky decompositions of the energy denominator tensor. Application of our new DF-SAPT0 program to the intercalation of DNA by proflavine has allowed us to determine the nature of the proflavine-DNA interaction. Overall, the proflavine-DNA interaction contains important contributions from both electrostatics and dispersion. The energetics of the intercalator interaction are are dominated by the stacking interactions (two-thirds of the total), but contain important contributions from the intercalator-backbone interactions. It is hypothesized that the geometry of the complex will be determined by the interactions of the intercalator with the backbone, because by shifting toward one side of the backbone, the intercalator can form two long hydrogen-bonding type interactions. The long-range interactions between the intercalator and the next-nearest base pairs appear to be negligible, justifying the use of truncated DNA models in computational studies of intercalation interaction energies.

  3. Cell culture adaptation mutations in foot-and-mouth disease virus serotype A capsid proteins: implications for receptor interactions

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In this study we describe the adaptive changes fixed on the capsid of several foot-and-mouth disease virus serotype A strains during propagation in cell monolayers. Viruses passaged extensively in three cell lines (BHK-21, LFBK and IB-RS-2), consistently gained several positively charged amino acids...

  4. Adaptation of the TH Epsilon Mu formalism for the analysis of the equivalence principle in the presence of the weak and electroweak interaction

    NASA Technical Reports Server (NTRS)

    Fennelly, A. J.

    1981-01-01

    The TH epsilon mu formalism, used in analyzing equivalence principle experiments of metric and nonmetric gravity theories, is adapted to the description of the electroweak interaction using the Weinberg-Salam unified SU(2) x U(1) model. The use of the TH epsilon mu formalism is thereby extended to the weak interactions, showing how the gravitational field affects W sub mu (+ or -1) and Z sub mu (0) boson propagation and the rates of interactions mediated by them. The possibility of a similar extension to the strong interactions via SU(5) grand unified theories is briefly discussed. Also, using the effects of the potentials on the baryon and lepton wave functions, the effects of gravity on transition mediated in high-A atoms which are electromagnetically forbidden. Three possible experiments to test the equivalence principle in the presence of the weak interactions, which are technologically feasible, are then briefly outline: (1) K-capture by the FE nucleus (counting the emitted X-ray); (2) forbidden absorption transitions in high-A atoms' vapor; and (3) counting the relative Beta-decay rates in a suitable alpha-beta decay chain, assuming the strong interactions obey the equivalence principle.

  5. Designing Smart Artifacts for Adaptive Mediation of Social Viscosity: Triadic Actor-Network Enactments as a Basis for Interaction Design

    ERIC Educational Resources Information Center

    Salamanca, Juan

    2012-01-01

    With the advent of ubiquitous computing, interaction design has broadened its object of inquiry into how smart computational artifacts inconspicuously act in people's everyday lives. Although user-centered design approaches remains useful for exploring how people cope with interactive systems, they cannot explain how this new breed of…

  6. Adaptation of Tri-molecular fluorescence complementation allows assaying of regulatory Csr RNA-protein interactions in bacteria.

    PubMed

    Gelderman, Grant; Sivakumar, Anusha; Lipp, Sarah; Contreras, Lydia

    2015-02-01

    sRNAs play a significant role in controlling and regulating cellular metabolism. One of the more interesting aspects of certain sRNAs is their ability to make global changes in the cell by interacting with regulatory proteins. In this work, we demonstrate the use of an in vivo Tri-molecular Fluorescence Complementation assay to detect and visualize the central regulatory sRNA-protein interaction of the Carbon Storage Regulatory system in E. coli. The Carbon Storage Regulator consists primarily of an RNA binding protein, CsrA, that alters the activity of mRNA targets and of an sRNA, CsrB, that modulates the activity of CsrA. We describe the construction of a fluorescence complementation system that detects the interactions between CsrB and CsrA. Additionally, we demonstrate that the intensity of the fluorescence of this system is able to detect changes in the affinity of the CsrB-CsrA interaction, as caused by mutations in the protein sequence of CsrA. While previous methods have adopted this technique to study mRNA or RNA localization, this is the first attempt to use this technique to study the sRNA-protein interaction directly in bacteria. This method presents a potentially powerful tool to study complex bacterial RNA protein interactions in vivo.

  7. LandCaRe DSS--an interactive decision support system for climate change impact assessment and the analysis of potential agricultural land use adaptation strategies.

    PubMed

    Wenkel, Karl-Otto; Berg, Michael; Mirschel, Wilfried; Wieland, Ralf; Nendel, Claas; Köstner, Barbara

    2013-09-01

    Decision support to develop viable climate change adaptation strategies for agriculture and regional land use management encompasses a wide range of options and issues. Up to now, only a few suitable tools and methods have existed for farmers and regional stakeholders that support the process of decision-making in this field. The interactive model-based spatial information and decision support system LandCaRe DSS attempts to close the existing methodical gap. This system supports interactive spatial scenario simulations, multi-ensemble and multi-model simulations at the regional scale, as well as the complex impact assessment of potential land use adaptation strategies at the local scale. The system is connected to a local geo-database and via the internet to a climate data server. LandCaRe DSS uses a multitude of scale-specific ecological impact models, which are linked in various ways. At the local scale (farm scale), biophysical models are directly coupled with a farm economy calculator. New or alternative simulation models can easily be added, thanks to the innovative architecture and design of the DSS. Scenario simulations can be conducted with a reasonable amount of effort. The interactive LandCaRe DSS prototype also offers a variety of data analysis and visualisation tools, a help system for users and a farmer information system for climate adaptation in agriculture. This paper presents the theoretical background, the conceptual framework, and the structure and methodology behind LandCaRe DSS. Scenario studies at the regional and local scale for the two Eastern German regions of Uckermark (dry lowlands, 2600 km(2)) and Weißeritz (humid mountain area, 400 km(2)) were conducted in close cooperation with stakeholders to test the functionality of the DSS prototype. The system is gradually being transformed into a web version (http://www.landcare-dss.de) to ensure the broadest possible distribution of LandCaRe DSS to the public. The system will be continuously

  8. Identification of Molecular Fingerprints in Human Heat Pain Thresholds by Use of an Interactive Mixture Model R Toolbox (AdaptGauss).

    PubMed

    Ultsch, Alfred; Thrun, Michael C; Hansen-Goos, Onno; Lötsch, Jörn

    2015-10-28

    Biomedical data obtained during cell experiments, laboratory animal research, or human studies often display a complex distribution. Statistical identification of subgroups in research data poses an analytical challenge. Here were introduce an interactive R-based bioinformatics tool, called "AdaptGauss". It enables a valid identification of a biologically-meaningful multimodal structure in the data by fitting a Gaussian mixture model (GMM) to the data. The interface allows a supervised selection of the number of subgroups. This enables the expectation maximization (EM) algorithm to adapt more complex GMM than usually observed with a noninteractive approach. Interactively fitting a GMM to heat pain threshold data acquired from human volunteers revealed a distribution pattern with four Gaussian modes located at temperatures of 32.3, 37.2, 41.4, and 45.4 °C. Noninteractive fitting was unable to identify a meaningful data structure. Obtained results are compatible with known activity temperatures of different TRP ion channels suggesting the mechanistic contribution of different heat sensors to the perception of thermal pain. Thus, sophisticated analysis of the modal structure of biomedical data provides a basis for the mechanistic interpretation of the observations. As it may reflect the involvement of different TRP thermosensory ion channels, the analysis provides a starting point for hypothesis-driven laboratory experiments.

  9. Mapping the Dynamic Network Interactions Underpinning Cognition: A cTBS-fMRI Study of the Flexible Adaptive Neural System for Semantics

    PubMed Central

    Jung, JeYoung; Lambon Ralph, Matthew A.

    2016-01-01

    Higher cognitive function reflects the interaction of a network of multiple brain regions. Previous investigations have plotted out these networks using functional or structural connectivity approaches. While these map the topography of the regions involved, they do not explore the key aspect of this neuroscience principle—namely that the regions interact in a dynamic fashion. Here, we achieved this aim with respect to semantic memory. Although converging evidence implicates the anterior temporal lobes (ATLs), bilaterally, as a crucial component in semantic representation, the underlying neural interplay between the ATLs remains unclear. By combining continuous theta-burst stimulation (cTBS) with functional magnetic resonance imaging (fMRI), we perturbed the left ventrolateral ATL (vATL) and investigated acute changes in neural activity and effective connectivity of the semantic system. cTBS resulted in decreased activity at the target region and compensatory, increased activity at the contralateral vATL. In addition, there were task-specific increases in effective connectivity between the vATLs, reflecting an increased facilitatory intrinsic connectivity from the right to left vATL. Our results suggest that semantic representation is founded on a flexible, adaptive bilateral neural system and reveals an adaptive plasticity-based mechanism that might support functional recovery after unilateral damage in neurological patients. PMID:27242027

  10. Adaptive interactions between HLA and HIV-1: Highly divergent selection imposed by HLA class I molecules with common supertype motifs1

    PubMed Central

    John, Mina; Heckerman, David; James, Ian; Park, Lawrence P.; Carlson, Jonathan M.; Chopra, Abha; Gaudieri, Silvana; Nolan, David; Haas, David W.; Riddler, Sharon A.; Haubrich, Richard; Mallal, Simon

    2010-01-01

    Currently 1.1 million individuals in the United States of America are living with HIV-1 infection. While this is a relatively small proportion of the global pandemic, the remarkable mix of ancestries in the U.S.A, drawn together over the past two centuries of continuous population migrations, provides an important and unique perspective on adaptive interactions between HIV-1 and human genetic diversity. HIV-1 is a rapidly adaptable organism and mutates within or near immune epitopes which are determined by the human leukocyte antigen (HLA) class I genotype of the infected host. We characterized HLA-associated polymorphisms across the full HIV-1 proteome in a large, ethnically diverse, national U.S cohort of HIV-1 infected individuals. We found a striking divergence in the immunoselection patterns associated with HLA variants which have very similar or identical peptide binding specificities but are differentially distributed among racial/ethnic groups. Though their similarity in peptide binding functionally clusters these HLA variants into supertypes, their differences at sites within the peptide binding groove contributes to ‘race-specific’ selection effects on circulating HIV-1 viruses. This suggests that the interactions between the HLA/HIV peptide complex and the T cell receptor (TCR) varies significantly within HLA supertype groups, which in turn, influences HIV-1 evolution. PMID:20231689

  11. Freshwater prokaryote and virus communities can adapt to a controlled increase in salinity through changes in their structure and interactions

    NASA Astrophysics Data System (ADS)

    Marine, Combe; Thierry, Bouvier; Olivier, Pringault; Emma, Rochelle-Newall; Corinne, Bouvier; Martin, Agis; The Thu, Pham; Jean-Pascal, Torreton; Van Thuoc, Chu; Bettarel, Yvan

    2013-11-01

    Little information exists on the ecological adaptive responses of riverine microorganisms to the salinity changes that typically occur in transitional waters. This study examined the precise effects of a gradual increase in salinity (+3 units per day for 12 days) on freshwater virus and prokaryote communities collected in the Red River Delta (northern Vietnam). The abundance, activity, morphology and diversity of both communities were examined along this simulated salinity gradient (0-36). Three main successive ecological stages were observed: (1) a continuous decline in prokaryotic and viral abundance from the start of the salinization process up to salinity 12-15 together with a strong decrease in the proportion of active cells, (2) a shift in both community compositions (salinity 9-15) and (3) a marked prevalence of lysogenic over lytic cycles up to salinity 21 followed by a collapse of both types of viral infection. Finally, after salinity 21, and up to seawater salinities (i.e. 36) the prokaryotic community showed multiple signs of recovery with their abundance and function even reaching initial levels. These results suggest that most of the physiological and phylogenetic changes that occurred within the salinity range 10-20 seemed to favor the installation of osmotically adapted prokaryotes accompanied by a specific cortege of viral parasites which might both be able to survive and even proliferate in saltwater conditions.

  12. Increasing Integrated Workplace Social Interactions: The Effects of Job Modification, Natural Supports, Adaptive Communication Instruction, and Job Coach Training.

    ERIC Educational Resources Information Center

    Mautz, Denise; Storey, Keith; Certo, Nick

    2001-01-01

    A study involving an adult with severe mental retardation and other disabilities found that the addition of a communication device, job coach social facilitation training, and eliciting co-worker support for social integration increased the social interactions of the employee in a supported employment setting. (Contains references.) (CR)

  13. [Significance of electron interactions of fatty acids of phospholipid molecules in the organism adaptation to habitation temperature].

    PubMed

    Zabelinskiĭ, S A; Chebotareva, M A; Arakelova, E S; Shukoliukova, E P; Furaev, V V; Kalandarov, A M; Feĭzulaev, B A; Krivchenko, A I

    2009-01-01

    Data in the fatty acid composition of muscle tissue phospholipids of some representatives of gastropod molluscs (Gastropoda) have been presented for the first time. In the lake phytophagues Lymnaea stagnalis and Lymnaea ovata the long-chained C22-acid was not detected, whereas in the predator common whelk Buccinum undatum, C22:6omega3 was present. Comparison of absorption spectra (240-720 nm) of lipid extracts of the studied invertebrates and of rat has been performed. The obtained data are discussed from the point of view of participation of pi-electrons of phospholipid fatty acid molecules in adaptation of membranes to the habitation temperature, which arises owing to interelectron attraction and to the process of formation of Cooper's pairs.

  14. Adaptive responses and disruptive effects: how major wildfire influences kinship-based social interactions in a forest marsupial.

    PubMed

    Banks, Sam C; Blyton, Michaela D J; Blair, David; McBurney, Lachlan; Lindenmayer, David B

    2012-02-01

    Environmental disturbance is predicted to play a key role in the evolution of animal social behaviour. This is because disturbance affects key factors underlying social systems, such as demography, resource availability and genetic structure. However, because natural disturbances are unpredictable there is little information on their effects on social behaviour in wild populations. Here, we investigated how a major wildfire affected cooperation (sharing of hollow trees) by a hollow-dependent marsupial. We based two alternative social predictions on the impacts of fire on population density, genetic structure and resources. We predicted an adaptive social response from previous work showing that kin selection in den-sharing develops as competition for den resources increases. Thus, kin selection should occur in burnt areas because the fire caused loss of the majority of hollow-bearing trees, but no detectable mortality. Alternatively, fire may have a disruptive social effect, whereby postfire home range-shifts 'neutralize' fine-scale genetic structure, thereby removing opportunities for kin selection between neighbours. Both predictions occurred: the disruptive social effect in burnt habitat and the adaptive social response in adjacent unburnt habitat. The latter followed a massive demographic influx to unburnt 'refuge' habitat that increased competition for dens, leading to a density-related kin selection response. Our results show remarkable short-term plasticity of animal social behaviour and demonstrate how the social effects of disturbance extend into undisturbed habitat owing to landscape-scale demographic shifts. We predicted long-term changes in kinship-based cooperative behaviour resulting from the genetic and resource impacts of forecast changes to fire regimes in these forests.

  15. Toxicity of cobalt ferrite (CoFe2O4) nanobeads in Chlorella vulgaris: interaction, adaptation and oxidative stress.

    PubMed

    Ahmad, Farooq; Yao, Hongzhou; Zhou, Ying; Liu, Xiaoyi

    2015-11-01

    The potential toxicity of CoFe2O4 nanobeads (NBs) in Chlorella vulgaris was observed up to 72h. Algal cell morphology, membrane integrity and viability were severely compromised due to adsorption and aggregation of NBs on algal surfaces, release of Fe(3+) and Co(2+) ions and possible mechanical damage by NBs. Interactions with NBs and effective decrease in ions released by aggregation and exudation of algal cells as a self defense mechanism were observed by Fourier transform infrared attenuated total reflectance (FTIR-ATR) and inductively coupled plasma mass spectrometry (ICP-MS). The results corroborated CoFe2O4 NBs induced ROS triggered oxidative stress, leading to a reduction in catalase activity, activation of the mutagenic glutathione s-transferase (mu-GST) and acid phosphatase (AP) antioxidant enzymes, and an increase in genetic aberrations, metabolic and cellular signal transduction dysfunction. Circular dichroism (CD) spectra indicated the weak interactions of NBs with BSA, with slight changes in the α-helix structure of BSA confirming conformational changes in structure, hence the potential for functional interactions with biomolecules. Possible interferences of CoFe2O4 NBs with assay techniques and components indicated CoFe2O4 NBs at lower concentration do not show any significant interference with ROS, catalase, mu-GST and no interference with CD measurements. This study showed ROS production is one of the pathways of toxicity initiated by CoFe2O4 NBs and illustrates the complex processes that may occur between organisms and NBs in natural complex ecosystem.

  16. Functional interaction of medial mediodorsal thalamic nucleus but not nucleus accumbens with amygdala and orbital prefrontal cortex is essential for adaptive response selection after reinforcer devaluation.

    PubMed

    Izquierdo, Alicia; Murray, Elisabeth A

    2010-01-13

    In nonhuman primates, reward-based decision making may be assessed through choices of objects overlying two different foods, one of which has been devalued by selective satiation. The most adaptive object choices yield the food of higher value. A large body of data identifies the amygdala and orbital prefrontal cortex (PFo) as neural mediators of adaptive responses to reinforcer devaluation. More recent work in nonhuman primates reveals the critical role of the medial, magnocellular portion of the mediodorsal nucleus of the thalamus (MDm) as well. Because both the nucleus accumbens (NA) and the MDm are anatomically related to the amygdala and PFo, and because both regions are implicated in reward processing, we tested whether either region necessarily interacts with the amygdala and PFo to mediate reinforcer devaluation effects. We used a crossed-disconnection design in which monkeys received amygdala and PFo lesions in one hemisphere combined with either NA or MDm lesions in the contralateral hemisphere. Monkeys that sustained NA disconnection, like controls, showed robust shifts in object choices in response to reinforcer devaluation. In contrast, monkeys that sustained MDm disconnection failed to adjust their object choices. Thus, MDm, but not NA, works together with the amygdala and PFo to support reward-based decision making.

  17. A variable-number-of-tandem-repeats polymorphism in the dopamine D4 receptor gene affects social adaptation of alcohol use: investigation of a gene-environment interaction.

    PubMed

    Larsen, Helle; van der Zwaluw, Carmen S; Overbeek, Geertjan; Granic, Isabela; Franke, Barbara; Engels, Rutger C M E

    2010-08-01

    Research suggests that people adapt their own drinking behavior to that of other people. According to a genetic-differences approach, some individuals may be more inclined than others to adapt their alcohol consumption level to that of other people. Using a 3 (drinking condition) x 2 (genotype) experimental design (N = 113), we tested whether susceptibility to alcohol-related cues (i.e., seeing someone drink) was related to the variable number of tandem repeats in exon 3 of the D4 dopamine receptor gene. A strong gene-environment interaction showed that participants carrying at least one copy of the 7-repeat allele consumed substantially more alcohol in the presence of a heavy-drinking individual than did participants without this allele. This study highlights that individual variability in sensitivity to other people's drinking behavior may be attributable to genetic differences. Carrying the 7-repeat allele may increase the risk for heavy alcohol use or abuse in the company of heavy-drinking peers.

  18. Electronic excitation of molecules in solution calculated using the symmetry-adapted cluster–configuration interaction method in the polarizable continuum model

    SciTech Connect

    Fukuda, Ryoichi Ehara, Masahiro

    2015-12-31

    The effects from solvent environment are specific to the electronic states; therefore, a computational scheme for solvent effects consistent with the electronic states is necessary to discuss electronic excitation of molecules in solution. The PCM (polarizable continuum model) SAC (symmetry-adapted cluster) and SAC-CI (configuration interaction) methods are developed for such purposes. The PCM SAC-CI adopts the state-specific (SS) solvation scheme where solvent effects are self-consistently considered for every ground and excited states. For efficient computations of many excited states, we develop a perturbative approximation for the PCM SAC-CI method, which is called corrected linear response (cLR) scheme. Our test calculations show that the cLR PCM SAC-CI is a very good approximation of the SS PCM SAC-CI method for polar and nonpolar solvents.

  19. Rhizobium leguminosarum bv. trifolii rosR is required for interaction with clover, biofilm formation and adaptation to the environment

    PubMed Central

    2010-01-01

    Background Rhizobium leguminosarum bv. trifolii is a symbiotic nitrogen-fixing bacterium that elicits nodules on roots of host plants Trifolium spp. Bacterial surface polysaccharides are crucial for establishment of a successful symbiosis with legumes that form indeterminate-type nodules, such as Trifolium, Pisum, Vicia, and Medicago spp. and aid the bacterium in withstanding osmotic and other environmental stresses. Recently, the R. leguminosarum bv. trifolii RosR regulatory protein which controls exopolysaccharide production has been identified and characterized. Results In this work, we extend our earlier studies to the characterization of rosR mutants which exhibit pleiotropic phenotypes. The mutants produce three times less exopolysaccharide than the wild type, and the low-molecular-weight fraction in that polymer is greatly reduced. Mutation in rosR also results in quantitative alterations in the polysaccharide constituent of lipopolysaccharide. The rosR mutants are more sensitive to surface-active detergents, antibiotics of the beta-lactam group and some osmolytes, indicating changes in the bacterial membranes. In addition, the rosR mutants exhibit significant decrease in motility and form a biofilm on plastic surfaces, which differs significantly in depth, architecture, and bacterial viability from that of the wild type. The most striking effect of rosR mutation is the considerably decreased attachment and colonization of root hairs, indicating that the mutation affects the first stage of the invasion process. Infection threads initiate at a drastically reduced rate and frequently abort before they reach the base of root hairs. Although these mutants form nodules on clover, they are unable to fix nitrogen and are outcompeted by the wild type in mixed inoculations, demonstrating that functional rosR is important for competitive nodulation. Conclusions This report demonstrates the significant role RosR regulatory protein plays in bacterial stress adaptation

  20. Multi-Allelic Major Effect Genes Interact with Minor Effect QTLs to Control Adaptive Color Pattern Variation in Heliconius erato

    PubMed Central

    Papa, Riccardo; Kapan, Durrell D.; Counterman, Brian A.; Maldonado, Karla; Lindstrom, Daniel P.; Reed, Robert D.; Nijhout, H. Frederik; Hrbek, Tomas; McMillan, W. Owen

    2013-01-01

    Recent studies indicate that relatively few genomic regions are repeatedly involved in the evolution of Heliconius butterfly wing patterns. Although this work demonstrates a number of cases where homologous loci underlie both convergent and divergent wing pattern change among different Heliconius species, it is still unclear exactly how many loci underlie pattern variation across the genus. To address this question for Heliconius erato, we created fifteen independent crosses utilizing the four most distinct color pattern races and analyzed color pattern segregation across a total of 1271 F2 and backcross offspring. Additionally, we used the most variable brood, an F2 cross between H. himera and the east Ecuadorian H. erato notabilis, to perform a quantitative genetic analysis of color pattern variation and produce a detailed map of the loci likely involved in the H. erato color pattern radiation. Using AFLP and gene based markers, we show that fewer major genes than previously envisioned control the color pattern variation in H. erato. We describe for the first time the genetic architecture of H. erato wing color pattern by assessing quantitative variation in addition to traditional linkage mapping. In particular, our data suggest three genomic intervals modulate the bulk of the observed variation in color. Furthermore, we also identify several modifier loci of moderate effect size that contribute to the quantitative wing pattern variation. Our results are consistent with the two-step model for the evolution of mimetic wing patterns in Heliconius and support a growing body of empirical data demonstrating the importance of major effect loci in adaptive change. PMID:23533571

  1. Multi-allelic major effect genes interact with minor effect QTLs to control adaptive color pattern variation in Heliconius erato.

    PubMed

    Papa, Riccardo; Kapan, Durrell D; Counterman, Brian A; Maldonado, Karla; Lindstrom, Daniel P; Reed, Robert D; Nijhout, H Frederik; Hrbek, Tomas; McMillan, W Owen

    2013-01-01

    Recent studies indicate that relatively few genomic regions are repeatedly involved in the evolution of Heliconius butterfly wing patterns. Although this work demonstrates a number of cases where homologous loci underlie both convergent and divergent wing pattern change among different Heliconius species, it is still unclear exactly how many loci underlie pattern variation across the genus. To address this question for Heliconius erato, we created fifteen independent crosses utilizing the four most distinct color pattern races and analyzed color pattern segregation across a total of 1271 F2 and backcross offspring. Additionally, we used the most variable brood, an F2 cross between H. himera and the east Ecuadorian H. erato notabilis, to perform a quantitative genetic analysis of color pattern variation and produce a detailed map of the loci likely involved in the H. erato color pattern radiation. Using AFLP and gene based markers, we show that fewer major genes than previously envisioned control the color pattern variation in H. erato. We describe for the first time the genetic architecture of H. erato wing color pattern by assessing quantitative variation in addition to traditional linkage mapping. In particular, our data suggest three genomic intervals modulate the bulk of the observed variation in color. Furthermore, we also identify several modifier loci of moderate effect size that contribute to the quantitative wing pattern variation. Our results are consistent with the two-step model for the evolution of mimetic wing patterns in Heliconius and support a growing body of empirical data demonstrating the importance of major effect loci in adaptive change. PMID:23533571

  2. Interactions Between Snow-Adapted Organisms, Minerals and Snow in a Mars-Analog Environment, and Implications for the Possible Formation of Mineral Biosignatures

    NASA Astrophysics Data System (ADS)

    Hausrath, E.; Bartlett, C. L.; Garcia, A. H.; Tschauner, O. D.; Murray, A. E.; Raymond, J. A.

    2015-12-01

    Increasing evidence suggests that icy environments on bodies such as Mars, Europa, and Enceladus may be important potential habitats in our solar system. Life in icy environments faces many challenges, including water limitation, temperature extremes, and nutrient limitation. Understanding how life has adapted to withstand these challenges on Earth may help understand potential life on other icy worlds, and understanding the interactions of such life with minerals may help shed light on the detection of possible mineral biosignatures. Snow environments, being particularly nutrient limited, may require specific adaptations by the microbiota living there. Previous observations have suggested that associated minerals and microorganisms play an important role in snow algae micronutrient acquisition. Here, in order to interpret micronutrient uptake by snow algae, and potential formation of mineral biosignatures, we present observations of interactions between snow algae and associated microorganisms and minerals in both natural, Mars-analog environments, and laboratory experiments. Samples of snow, dust, snow algae, and microorganisms were collected from Mount Anderson Ridge, CA. Some samples were DAPI-stained and analyzed by epifluorescent microscopy, and others were freeze-dried and examined by scanning electron microscopy, synchrotron X-ray diffraction (XRD) and synchrotron X-ray fluorescence (XRF). Xenic cultures of the snow alga Chloromonas brevispina were also grown under Fe-limiting conditions with and without the Fe-containing mineral nontronite to determine impacts of the mineral on algal growth. Observations from epifluorescent microscopy show bacteria closely associated with the snow algae, consistent with a potential role in micronutrient acquisition. Particles are also present on the algal cell walls, and synchrotron-XRD and XRF observations indicate that they are Fe-rich, and may therefore be a micronutrient source. Laboratory experiments indicated

  3. Playful and mindful interactions in the recursive adaptations of the zone of proximal development: a critical complexity science approach

    NASA Astrophysics Data System (ADS)

    Raia, Federica; Deng, Mario C.

    2011-12-01

    We discuss Konstantinos Alexakos, Jayson Jones and Victor Rodriguez's hermeneutic study of formation and function of kinship-like relationships among inner city male students of color in a college physics classroom. From our Critical Complexity Science framework we first discuss the reading erlebnisse of students laughing at and with each other as something that immediately captured our attention in being transformative of the classroom. We continue by exploring their classroom and research experience as an emergent structure modifying their collective as well as their individual experiences. As we analyze both the classroom and the research space as a complex system, we reflect on the instructor/students interactions characterized by an asymmetrical "power" relationship. From our analysis we propose to consider the zone of proximal development as the constantly emerging and transforming person experience ( erlebnisse and erfahrung).

  4. Flowfield-Dependent Variation (FDV) method for compressible, incompressible, viscous, and inviscid flow interactions with FDV adaptive mesh refinements and parallel processing

    NASA Astrophysics Data System (ADS)

    Heard, Gary Wayne

    A new approach to solution-adaptive grid refinement using the finite element method and Flowfield-Dependent Variation (FDV) theory applied to the Navier-Stokes system of equations is discussed. Flowfield-Dependent Variation (FDV) parameters are introduced into a modified Taylor series expansion of the conservation variables, with the Navier-Stokes system of equations substituted into the Taylor series. The FDV parameters are calculated from the current Fowfield conditions, and automatically adjust the resulting equations from elliptic to parabolic to hyperbolic in type to assure solution accuracy in evolving fluid flowfields that may consist of interactions between regions of compressible and incompressible flow, viscous and inviscid flow, and turbulent and laminar flow. The system of equations is solved using an element-by-element iterative GMRES solver with the elements grouped together to allow the element operations to be performed in parallel. The FDV parameters play many roles in the numerical scheme. One of these roles is to control formations of shock wave discontinuities in high speeds and pressure oscillations in low speeds. To demonstrate these abilities, various example problems are shown, including supersonic flows over a flat plate and a compression corner, and flows involving triple shock waves generated on fin geometries for high speed compressible flows. Furthermore, analysis of low speed incompressible flows is presented in the form of flow in a lid-driven cavity at various Reynolds numbers. Another role of the FDV parameters is their use as error indicators for a solution-adaptive mesh. The finite element grid is refined as dictated by the magnitude of the FDV parameters. Examples of adaptive grids generated using the FDV parameters as error indicators are presented for supersonic flow over flat plate/compression ramp combinations in both two and three dimensions. Grids refined using the FDV parameters as error indicators are comparable to ones

  5. [Biventricular-pulmonary interaction as the prime mechanism in the adaptation of the human heart to orthostatic posture].

    PubMed

    Guazzi, M; Maltagliati, A; Tamborini, G

    1997-01-01

    (interdependence) and pericardial constraint; facilitation and predominance of blood drainage for the lungs during ventricular diastole. Thus, the basic adaptation to erect positioning in man seems to be a mechanical one, mainly consisting of an interplay between heart and lungs. Increase in heart rate and vasoconstriction appear to be supportive mechanisms at more vertical postures.

  6. The Interaction of Trunk-Load and Trunk-Position Adaptations on Knee Anterior Shear and Hamstrings Muscle Forces During Landing

    PubMed Central

    Kulas, Anthony S.; Hortobágyi, Tibor; DeVita, Paul

    2010-01-01

    Abstract Context: Because anterior cruciate ligament (ACL) injuries can occur during deceleration maneuvers, biomechanics research has been focused on the lower extremity kinetic chain. Trunk mass and changes in trunk position affect lower extremity joint torques and work during gait and landing, but how the trunk affects knee joint and muscle forces is not well understood. Objective: To evaluate the effects of added trunk load and adaptations to trunk position on knee anterior shear and knee muscle forces in landing. Design: Crossover study. Setting: Controlled laboratory environment. Patients or Other Participants: Twenty-one participants (10 men: age  =  20.3 ± 1.15 years, height  =  1.82 ± 0.04 m, mass  =  78.2 ± 7.3 kg; 11 women: age  =  20.0 ± 1.10 years, height  =  1.72 ± 0.06 m, mass  =  62.3 ± 6.4 kg). Intervention(s): Participants performed 2 sets of 8 double-leg landings under 2 conditions: no load and trunk load (10% body mass). Participants were categorized into one of 2 groups based on the kinematic trunk adaptation to the load: trunk flexor or trunk extensor. Main Outcome Measure(s): We estimated peak and average knee anterior shear, quadriceps, hamstrings, and gastrocnemius forces with a biomechanical model. Results: We found condition-by-group interactions showing that adding a trunk load increased peak (17%) and average (35%) knee anterior shear forces in the trunk-extensor group but did not increase them in the trunk-flexor group (peak: F1,19  =  10.56, P  =  .004; average: F1,19  =  9.56, P  =  .006). We also found a main effect for condition for quadriceps and gastrocnemius forces. When trunk load was added, peak (6%; F1,19  =  5.52, P  =  .030) and average (8%; F1,19  =  8.83, P  =  .008) quadriceps forces increased and average (4%; F1,19  =  4.94, P  =  .039) gastrocnemius forces increased, regardless of group. We found a condition-by-group interaction for peak (F1,19

  7. Search for exotic cluster configurations in 14C nucleus

    NASA Astrophysics Data System (ADS)

    Korotkova, L. Yu; Chernyshev, B. A.; Gurov, Yu B.; Karpuhin, V. S.; Lapushkin, S. V.; Pritula, R. V.; Schurenkova, T. D.

    2016-02-01

    The analysis of 2-dimentional Dalitz’ diagram, measured in 14C(π-, pd)X reaction, allowed to distinguish the pion absorption by p intranuclear cluster and to obtain an indication on the existence of 3p + 11Li configuration in 14C nucleus. Highly excited states of 12,13Be isotopes were found with the energy of Ex ≈ 30 MeV for the first time. It was shown that these states decay as follows 12Be*→p + 11Li and 13Be*→d + 11Li.

  8. New Genomic Insights into “Entotheonella” Symbionts in Theonella swinhoei: Mixotrophy, Anaerobic Adaptation, Resilience, and Interaction

    PubMed Central

    Liu, Fang; Li, Jinlong; Feng, Guofang; Li, Zhiyong

    2016-01-01

    “Entotheonella” (phylum “Tectomicrobia”) is a filamentous symbiont that produces almost all known bioactive compounds derived from the Lithistida sponge Theonella swinhoei. In contrast to the comprehensive knowledge of its secondary metabolism, knowledge of its lifestyle, resilience, and interaction with the sponge host and other symbionts remains rudimentary. In this study, we obtained two “Entotheonella” genomes from T. swinhoei from the South China Sea through metagenome binning, and used a RASTtk pipeline to achieve better genome annotation. The high average nucleotide index values suggested they were the same phylotypes as the two “Entotheonella” phylotypes from T. swinhoei from the Japan Sea. Genomic features related to utilization of various carbon sources, peptidase secretion, CO2 fixation, sulfate reduction, anaerobic respiration, and denitrification indicated the mixotrophic nature of “Entotheonella.” The endospore-forming potential along with metal- and antibiotic resistance indicated “Entotheonella” was highly resilient to harsh conditions. The potential for endospore formation also explained the widespread distribution of “Entotheonella” to some extent. The discovery of Type II (general secretion pathway proteins and the Widespread Colonization Island) and Type VI secretion systems in “Entotheonella” suggested it could secrete extracellular hydrolases, form tight adhesion, act against phagocytes, and kill other prokaryotes. Overall, the newly discovered genomic features suggest “Entotheonella” is a highly competitive member of the symbiotic community of T. swinhoei. PMID:27610106

  9. Adaptation, Clonal Interference, and Frequency-Dependent Interactions in a Long-Term Evolution Experiment with Escherichia coli

    PubMed Central

    Maddamsetti, Rohan; Lenski, Richard E.; Barrick, Jeffrey E.

    2015-01-01

    Twelve replicate populations of Escherichia coli have been evolving in the laboratory for >25 years and 60,000 generations. We analyzed bacteria from whole-population samples frozen every 500 generations through 20,000 generations for one well-studied population, called Ara−1. By tracking 42 known mutations in these samples, we reconstructed the history of this population’s genotypic evolution over this period. The evolutionary dynamics of Ara−1 show strong evidence of selective sweeps as well as clonal interference between competing lineages bearing different beneficial mutations. In some cases, sets of several mutations approached fixation simultaneously, often conveying no information about their order of origination; we present several possible explanations for the existence of these mutational cohorts. Against a backdrop of rapid selective sweeps both earlier and later, two genetically diverged clades coexisted for >6000 generations before one went extinct. In that time, many additional mutations arose in the clade that eventually prevailed. We show that the clades evolved a frequency-dependent interaction, which prevented the immediate competitive exclusion of either clade, but which collapsed as beneficial mutations accumulated in the clade that prevailed. Clonal interference and frequency dependence can occur even in the simplest microbial populations. Furthermore, frequency dependence may generate dynamics that extend the period of coexistence that would otherwise be sustained by clonal interference alone. PMID:25911659

  10. New Genomic Insights into “Entotheonella” Symbionts in Theonella swinhoei: Mixotrophy, Anaerobic Adaptation, Resilience, and Interaction

    PubMed Central

    Liu, Fang; Li, Jinlong; Feng, Guofang; Li, Zhiyong

    2016-01-01

    “Entotheonella” (phylum “Tectomicrobia”) is a filamentous symbiont that produces almost all known bioactive compounds derived from the Lithistida sponge Theonella swinhoei. In contrast to the comprehensive knowledge of its secondary metabolism, knowledge of its lifestyle, resilience, and interaction with the sponge host and other symbionts remains rudimentary. In this study, we obtained two “Entotheonella” genomes from T. swinhoei from the South China Sea through metagenome binning, and used a RASTtk pipeline to achieve better genome annotation. The high average nucleotide index values suggested they were the same phylotypes as the two “Entotheonella” phylotypes from T. swinhoei from the Japan Sea. Genomic features related to utilization of various carbon sources, peptidase secretion, CO2 fixation, sulfate reduction, anaerobic respiration, and denitrification indicated the mixotrophic nature of “Entotheonella.” The endospore-forming potential along with metal- and antibiotic resistance indicated “Entotheonella” was highly resilient to harsh conditions. The potential for endospore formation also explained the widespread distribution of “Entotheonella” to some extent. The discovery of Type II (general secretion pathway proteins and the Widespread Colonization Island) and Type VI secretion systems in “Entotheonella” suggested it could secrete extracellular hydrolases, form tight adhesion, act against phagocytes, and kill other prokaryotes. Overall, the newly discovered genomic features suggest “Entotheonella” is a highly competitive member of the symbiotic community of T. swinhoei.

  11. Adaptation, Clonal Interference, and Frequency-Dependent Interactions in a Long-Term Evolution Experiment with Escherichia coli.

    PubMed

    Maddamsetti, Rohan; Lenski, Richard E; Barrick, Jeffrey E

    2015-06-01

    Twelve replicate populations of Escherichia coli have been evolving in the laboratory for >25 years and 60,000 generations. We analyzed bacteria from whole-population samples frozen every 500 generations through 20,000 generations for one well-studied population, called Ara-1. By tracking 42 known mutations in these samples, we reconstructed the history of this population's genotypic evolution over this period. The evolutionary dynamics of Ara-1 show strong evidence of selective sweeps as well as clonal interference between competing lineages bearing different beneficial mutations. In some cases, sets of several mutations approached fixation simultaneously, often conveying no information about their order of origination; we present several possible explanations for the existence of these mutational cohorts. Against a backdrop of rapid selective sweeps both earlier and later, two genetically diverged clades coexisted for >6000 generations before one went extinct. In that time, many additional mutations arose in the clade that eventually prevailed. We show that the clades evolved a frequency-dependent interaction, which prevented the immediate competitive exclusion of either clade, but which collapsed as beneficial mutations accumulated in the clade that prevailed. Clonal interference and frequency dependence can occur even in the simplest microbial populations. Furthermore, frequency dependence may generate dynamics that extend the period of coexistence that would otherwise be sustained by clonal interference alone.

  12. The parity-adapted basis set in the formulation of the photofragment angular momentum polarization problem: The role of the Coriolis interaction

    SciTech Connect

    Shternin, Peter S.; Vasyutinskii, Oleg S.

    2008-05-21

    We present a theoretical framework for calculating the recoil-angle dependence of the photofragment angular momentum polarization taking into account both radial and Coriolis nonadiabatic interactions in the diatomic/linear photodissociating molecules. The parity-adapted representation of the total molecular wave function has been used throughout the paper. The obtained full quantum-mechanical expressions for the photofragment state multipoles have been simplified by using the semiclassical approximation in the high-J limit and then analyzed for the cases of direct photodissociation and slow predissociation in terms of the anisotropy parameters. In both cases, each anisotropy parameter can be presented as a linear combination of the generalized dynamical functions f{sub K}(q,q{sup '},q-tilde,q-tilde{sup '}) of the rank K representing contribution from different dissociation mechanisms including possible radial and Coriolis nonadiabatic transitions, coherent effects, and the rotation of the recoil axis. In the absence of the Coriolis interactions, the obtained results are equivalent to the earlier published ones. The angle-recoil dependence of the photofragment state multipoles for an arbitrary photolysis reaction is derived. As shown, the polarization of the photofragments in the photolysis of a diatomic or a polyatomic molecule can be described in terms of the anisotropy parameters irrespective of the photodissociation mechanism.

  13. A host-factor interaction and localization map for a plant-adapted rhabdovirus implicates cytoplasm-tethered transcription activators in cell-to-cell movement.

    PubMed

    Min, Byoung-Eun; Martin, Kathleen; Wang, Renyuan; Tafelmeyer, Petra; Bridges, Max; Goodin, Michael

    2010-11-01

    To identify host factors that play critical roles in processes, including cell-to-cell movement of plant-adapted rhabdoviruses, we constructed and validated a high-resolution Nicotiana benthamiana yeast two-hybrid library. The library was screened with the putative movement protein (sc4), nucleocapsid (N), and matrix (M) proteins of Sonchus yellow net virus (SYNV). This resulted in identification of 31 potential host factors. Steady-state localization studies using autofluorescent protein fusions to full-length clones of interactors were conducted in transgenic N. benthamiana marker lines. Bimolecular fluorescence complementation assays were used to validate two-hybrid interactions. The sc4 interactor, sc4i21, localized to microtubules. The N interactor, Ni67, localized to punctuate loci on the endoplasmic reticulum. These two proteins are 84% identical homologues of the Arabidopsis phloem-associated transcription activator AtVOZ1, and contain functional nuclear localization signals. Sc4i17 is a microtubule-associated motor protein. The M interactor, Mi7, is a nuclear-localized transcription factor. Combined with a binary interaction map for SYNV proteins, our data support a model in which the SYNV nucleocapsids are exported from the nucleus and moved cell-to-cell by transcription activators tethered in the cytoplasm.

  14. The parity-adapted basis set in the formulation of the photofragment angular momentum polarization problem: the role of the Coriolis interaction.

    PubMed

    Shternin, Peter S; Vasyutinskii, Oleg S

    2008-05-21

    We present a theoretical framework for calculating the recoil-angle dependence of the photofragment angular momentum polarization taking into account both radial and Coriolis nonadiabatic interactions in the diatomic/linear photodissociating molecules. The parity-adapted representation of the total molecular wave function has been used throughout the paper. The obtained full quantum-mechanical expressions for the photofragment state multipoles have been simplified by using the semiclassical approximation in the high-J limit and then analyzed for the cases of direct photodissociation and slow predissociation in terms of the anisotropy parameters. In both cases, each anisotropy parameter can be presented as a linear combination of the generalized dynamical functions fK(q,q',q,q') of the rank K representing contribution from different dissociation mechanisms including possible radial and Coriolis nonadiabatic transitions, coherent effects, and the rotation of the recoil axis. In the absence of the Coriolis interactions, the obtained results are equivalent to the earlier published ones. The angle-recoil dependence of the photofragment state multipoles for an arbitrary photolysis reaction is derived. As shown, the polarization of the photofragments in the photolysis of a diatomic or a polyatomic molecule can be described in terms of the anisotropy parameters irrespective of the photodissociation mechanism.

  15. Adaptive switching of interaction potentials in the time domain: an extended Lagrangian approach tailored to transmute force field to QM/MM simulations and back.

    PubMed

    Böckmann, Marcus; Doltsinis, Nikos L; Marx, Dominik

    2015-06-01

    An extended Lagrangian formalism that allows for a smooth transition between two different descriptions of interactions during a molecular dynamics simulation is presented. This time-adaptive method is particularly useful in the context of multiscale simulation as it provides a sound recipe to switch on demand between different hierarchical levels of theory, for instance between ab initio ("QM") and force field ("MM") descriptions of a given (sub)system in the course of a molecular dynamics simulation. The equations of motion can be integrated straightforwardly using the usual propagators, such as the Verlet algorithm. First test cases include a bath of harmonic oscillators, of which a subset is switched to a different force constant and/or equilibrium position, as well as an all-MM to QM/MM transition in a hydrogen-bonded water dimer. The method is then applied to a smectic 8AB8 liquid crystal and is shown to be able to switch dynamically a preselected 8AB8 molecule from an all-MM to a QM/MM description which involves partition boundaries through covalent bonds. These examples show that the extended Lagrangian approach is not only easy to implement into existing code but that it is also efficient and robust. The technique moreover provides easy access to a conserved energy quantity, also in cases when Nosé-Hoover chain thermostatting is used throughout dynamical switching. A simple quadratic driving potential proves to be sufficient to guarantee a smooth transition whose time scale can be easily tuned by varying the fictitious mass parameter associated with the auxiliary variable used to extend the Lagrangian. The method is general and can be applied to time-adaptive switching on demand between two different levels of theory within the framework of hybrid scale-bridging simulations. PMID:26575543

  16. Genetic and physiological data suggest demographic and adaptive responses in complex interactions between populations of figs (Ficus pumila) and their pollinating wasps (Wiebesia pumilae).

    PubMed

    Wang, Hurng-Yi; Hsieh, Chia-Hung; Huang, Chin-Gi; Kong, Siu-Wah; Chang, Hsiao-Chi; Lee, Ho-Huei; Wang, Wei-Kuang; Chen, Shih-Lun; Tzeng, Hsy-Yu; Wu, Wen-Jer

    2013-07-01

    To study interactions between host figs and their pollinating wasps and the influence of climatic change on their genetic structures, we sequenced cytoplasmic and nuclear genes and genotyped nuclear microsatellite loci from two varieties of Ficus pumila, the widespread creeping fig and endemic jelly fig, and from their pollinating wasps, Wiebesia pumilae, found in Taiwan and on nearby offshore islands. Great divergence in the mitochondrial cytochrome c oxidase subunit I (mtCOI) with no genetic admixture in nuclear markers indicated that creeping- and jelly-fig wasps are genetically distinct. Compared with creeping-fig wasps, jelly-fig wasps also showed better resistance under cold (20 °C) than warm (25 and 30 °C) conditions in a survival test, indicating their adaptation to a cold environment, which may have facilitated population expansion during the ice age as shown by a nuclear intron and 10 microsatellite loci. An excess of amino acid divergence and a pattern of too many rare mtCOI variants of jelly-fig wasps as revealed by computer simulations and neutrality tests implied the effect of positive selection, which we hypothesize was associated with the cold-adaptation process. Chloroplast DNA of the two fig plants was completely segregated, with signs of genetic admixture in nuclear markers. As creeping- and jelly-fig wasps can pollinate creeping figs, occasional gene flow between the two figs is thus possible. Therefore, it is suggested that pollinating wasps may be playing an active role in driving introgression between different types of host fig.

  17. Heat shock partially dissociates the overlapping modules of the yeast protein-protein interaction network: a systems level model of adaptation.

    PubMed

    Mihalik, Ágoston; Csermely, Peter

    2011-10-01

    Network analysis became a powerful tool giving new insights to the understanding of cellular behavior. Heat shock, the archetype of stress responses, is a well-characterized and simple model of cellular dynamics. S. cerevisiae is an appropriate model organism, since both its protein-protein interaction network (interactome) and stress response at the gene expression level have been well characterized. However, the analysis of the reorganization of the yeast interactome during stress has not been investigated yet. We calculated the changes of the interaction-weights of the yeast interactome from the changes of mRNA expression levels upon heat shock. The major finding of our study is that heat shock induced a significant decrease in both the overlaps and connections of yeast interactome modules. In agreement with this the weighted diameter of the yeast interactome had a 4.9-fold increase in heat shock. Several key proteins of the heat shock response became centers of heat shock-induced local communities, as well as bridges providing a residual connection of modules after heat shock. The observed changes resemble to a 'stratus-cumulus' type transition of the interactome structure, since the unstressed yeast interactome had a globally connected organization, similar to that of stratus clouds, whereas the heat shocked interactome had a multifocal organization, similar to that of cumulus clouds. Our results showed that heat shock induces a partial disintegration of the global organization of the yeast interactome. This change may be rather general occurring in many types of stresses. Moreover, other complex systems, such as single proteins, social networks and ecosystems may also decrease their inter-modular links, thus develop more compact modules, and display a partial disintegration of their global structure in the initial phase of crisis. Thus, our work may provide a model of a general, system-level adaptation mechanism to environmental changes. PMID:22022244

  18. Heat shock partially dissociates the overlapping modules of the yeast protein-protein interaction network: a systems level model of adaptation.

    PubMed

    Mihalik, Ágoston; Csermely, Peter

    2011-10-01

    Network analysis became a powerful tool giving new insights to the understanding of cellular behavior. Heat shock, the archetype of stress responses, is a well-characterized and simple model of cellular dynamics. S. cerevisiae is an appropriate model organism, since both its protein-protein interaction network (interactome) and stress response at the gene expression level have been well characterized. However, the analysis of the reorganization of the yeast interactome during stress has not been investigated yet. We calculated the changes of the interaction-weights of the yeast interactome from the changes of mRNA expression levels upon heat shock. The major finding of our study is that heat shock induced a significant decrease in both the overlaps and connections of yeast interactome modules. In agreement with this the weighted diameter of the yeast interactome had a 4.9-fold increase in heat shock. Several key proteins of the heat shock response became centers of heat shock-induced local communities, as well as bridges providing a residual connection of modules after heat shock. The observed changes resemble to a 'stratus-cumulus' type transition of the interactome structure, since the unstressed yeast interactome had a globally connected organization, similar to that of stratus clouds, whereas the heat shocked interactome had a multifocal organization, similar to that of cumulus clouds. Our results showed that heat shock induces a partial disintegration of the global organization of the yeast interactome. This change may be rather general occurring in many types of stresses. Moreover, other complex systems, such as single proteins, social networks and ecosystems may also decrease their inter-modular links, thus develop more compact modules, and display a partial disintegration of their global structure in the initial phase of crisis. Thus, our work may provide a model of a general, system-level adaptation mechanism to environmental changes.

  19. Interactive effects of dietary adaptation period length and titration diet type on apparent ileal phosphorus digestibility and phosphorus retention in growing broilers.

    PubMed

    Perryman, K R; Cattley, R C; Masey O'Neill, H V; Bedford, M R; Dozier, W A

    2016-10-01

    Two experiments were conducted to examine the effects of different corn titration diets and dietary adaptation period length (DAPL) on intestinal histology, apparent ileal P digestibility (AIPD), and apparent P retention (APR) in Ross × Ross 708 male broilers from 20 to 24 d of age. It was hypothesized that purified ingredients in nutrient-deficient titration diets may affect P availability with varying DAPL. In experiment 1, 1,152 broilers were utilized in a 3 × 3 factorial treatment structure with 3 diets (control, 25% corn titration diet [25CTD], or 75% corn titration diet [75CTD]) and 3 DAPL (0, 24, or 72 h). Experiment 2 was conducted with 576 broilers as a 4 × 3 factorial arrangement with 4 diets (control, 25CTD, 75CTD, or nitrogen-free diet [NFD]) and 3 DAPL (24, 48, or 72 h). All diets contained purified ingredients except for the control diet, which had the same formulation as the common starter and served as a control for DAPL. The NFD diet was fed as a highly purified protein-free diet. Broilers were fed a common diet until 19 d of age and then transferred to experimental diets at 20 d of age. In experiment 1, diet type did not affect (P > 0.05) intestinal histology. However, diet type and DAPL each influenced (P.≤.0.001) diet AIPD. Higher (P.≤.0.001) AIPD was measured for the control diet compared with the 75CDT, and the 25CTD had the lowest AIPD. Following a 24 h DAPL, AIPD was higher (P.≤.0.001) than after a DAPL of 0 or 72 h. In experiment 2, diet type × DAPL interactions (P.≤.0.001) were observed for APR of the control diet, 75CTD, and NFD, but not the 25CTD. Because APR of the control diet was affected by varying DAPL, factors other than differences in diet type may have been responsible for inconsistencies in the measure of P availability. Furthermore, no clear evidence was observed that broilers were able to adapt to P-deficient diets by increasing APR or AIPD. In conclusion, a standard DAPL should be established as a means to

  20. 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...

  1. Fireplace adapters

    SciTech Connect

    Hunt, R.L.

    1983-12-27

    An adapter is disclosed for use with a fireplace. The stove pipe of a stove standing in a room to be heated may be connected to the flue of the chimney so that products of combustion from the stove may be safely exhausted through the flue and outwardly of the chimney. The adapter may be easily installed within the fireplace by removing the damper plate and fitting the adapter to the damper frame. Each of a pair of bolts has a portion which hooks over a portion of the damper frame and a threaded end depending from the hook portion and extending through a hole in the adapter. Nuts are threaded on the bolts and are adapted to force the adapter into a tight fit with the adapter frame.

  2. Genetic interactions between diverged alleles of Early heading date 1 (Ehd1) and Heading date 3a (Hd3a)/ RICE FLOWERING LOCUS T1 (RFT1) control differential heading and contribute to regional adaptation in rice (Oryza sativa).

    PubMed

    Zhao, Jing; Chen, Hongyi; Ren, Ding; Tang, Huiwu; Qiu, Rong; Feng, Jinglei; Long, Yunming; Niu, Baixiao; Chen, Danping; Zhong, Tianyu; Liu, Yao-Guang; Guo, Jingxin

    2015-11-01

    Initiation of flowering, also called heading, in rice (Oryza sativa) is determined by the florigens encoded by Heading date 3a (Hd3a) and RICE FLOWERING LOCUS T1 (RFT1). Early heading date 1 (Ehd1) regulates Hd3a and RFT1. However, different rice varieties have diverged alleles of Ehd1 and Hd3a/RFT1 and their genetic interactions remain largely unclear. Here we generated three segregating populations for different combinations of diverged Ehd1 and Hd3a/RFT1 alleles, and analyzed their genetic interactions between these alleles. We demonstrated that, in an ehd1 mutant background, Hd3a was silenced, but RFT1 was expressed (although at lower levels than in plants with a functional Ehd1) under short-day (SD) and long-day (LD) conditions. We identified a nonfunctional RFT1 allele (rft1); the lines carrying homozygous ehd1 and Hd3a/rft1 failed to induce the floral transition under SD and LD conditions. Like Hd3a, RFT1 also interacted with 14-3-3 proteins, the florigen receptors, but a nonfunctional RFT1 with a crucial E105K mutation failed to interact with 14-3-3 proteins. Furthermore, analyses of sequence variation and geographic distribution suggested that functional RFT1 alleles were selected during rice adaptation to high-latitude regions. Our results demonstrate the important roles of RFT1 in rice flowering and regional adaptation.

  3. 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

  4. Adaptive Computing.

    ERIC Educational Resources Information Center

    Harrell, William

    1999-01-01

    Provides information on various adaptive technology resources available to people with disabilities. (Contains 19 references, an annotated list of 129 websites, and 12 additional print resources.) (JOW)

  5. Contour adaptation.

    PubMed

    Anstis, Stuart

    2013-01-01

    It is known that adaptation to a disk that flickers between black and white at 3-8 Hz on a gray surround renders invisible a congruent gray test disk viewed afterwards. This is contrast adaptation. We now report that adapting simply to the flickering circular outline of the disk can have the same effect. We call this "contour adaptation." This adaptation does not transfer interocularly, and apparently applies only to luminance, not color. One can adapt selectively to only some of the contours in a display, making only these contours temporarily invisible. For instance, a plaid comprises a vertical grating superimposed on a horizontal grating. If one first adapts to appropriate flickering vertical lines, the vertical components of the plaid disappears and it looks like a horizontal grating. Also, we simulated a Cornsweet (1970) edge, and we selectively adapted out the subjective and objective contours of a Kanisza (1976) subjective square. By temporarily removing edges, contour adaptation offers a new technique to study the role of visual edges, and it demonstrates how brightness information is concentrated in edges and propagates from them as it fills in surfaces.

  6. Prism Adaptation in Schizophrenia

    ERIC Educational Resources Information Center

    Bigelow, Nirav O.; Turner, Beth M.; Andreasen, Nancy C.; Paulsen, Jane S.; O'Leary, Daniel S.; Ho, Beng-Choon

    2006-01-01

    The prism adaptation test examines procedural learning (PL) in which performance facilitation occurs with practice on tasks without the need for conscious awareness. Dynamic interactions between frontostriatal cortices, basal ganglia, and the cerebellum have been shown to play key roles in PL. Disruptions within these neural networks have also…

  7. Climate adaptation

    NASA Astrophysics Data System (ADS)

    Kinzig, Ann P.

    2015-03-01

    This paper is intended as a brief introduction to climate adaptation in a conference devoted otherwise to the physics of sustainable energy. Whereas mitigation involves measures to reduce the probability of a potential event, such as climate change, adaptation refers to actions that lessen the impact of climate change. Mitigation and adaptation differ in other ways as well. Adaptation does not necessarily have to be implemented immediately to be effective; it only needs to be in place before the threat arrives. Also, adaptation does not necessarily require global, coordinated action; many effective adaptation actions can be local. Some urban communities, because of land-use change and the urban heat-island effect, currently face changes similar to some expected under climate change, such as changes in water availability, heat-related morbidity, or changes in disease patterns. Concern over those impacts might motivate the implementation of measures that would also help in climate adaptation, despite skepticism among some policy makers about anthropogenic global warming. Studies of ancient civilizations in the southwestern US lends some insight into factors that may or may not be important to successful adaptation.

  8. Adaptive Controller Effects on Pilot Behavior

    NASA Technical Reports Server (NTRS)

    Trujillo, Anna C.; Gregory, Irene M.; Hempley, Lucas E.

    2014-01-01

    Adaptive control provides robustness and resilience for highly uncertain, and potentially unpredictable, flight dynamics characteristic. Some of the recent flight experiences of pilot-in-the-loop with an adaptive controller have exhibited unpredicted interactions. In retrospect, this is not surprising once it is realized that there are now two adaptive controllers interacting, the software adaptive control system and the pilot. An experiment was conducted to categorize these interactions on the pilot with an adaptive controller during control surface failures. One of the objectives of this experiment was to determine how the adaptation time of the controller affects pilots. The pitch and roll errors, and stick input increased for increasing adaptation time and during the segment when the adaptive controller was adapting. Not surprisingly, altitude, cross track and angle deviations, and vertical velocity also increase during the failure and then slowly return to pre-failure levels. Subjects may change their behavior even as an adaptive controller is adapting with additional stick inputs. Therefore, the adaptive controller should adapt as fast as possible to minimize flight track errors. This will minimize undesirable interactions between the pilot and the adaptive controller and maintain maneuvering precision.

  9. 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

  10. Toothbrush Adaptations.

    ERIC Educational Resources Information Center

    Exceptional Parent, 1987

    1987-01-01

    Suggestions are presented for helping disabled individuals learn to use or adapt toothbrushes for proper dental care. A directory lists dental health instructional materials available from various organizations. (CB)

  11. A systematic approach for the accurate non-invasive estimation of blood glucose utilizing a novel light-tissue interaction adaptive modelling scheme

    NASA Astrophysics Data System (ADS)

    Rybynok, V. O.; Kyriacou, P. A.

    2007-10-01

    Diabetes is one of the biggest health challenges of the 21st century. The obesity epidemic, sedentary lifestyles and an ageing population mean prevalence of the condition is currently doubling every generation. Diabetes is associated with serious chronic ill health, disability and premature mortality. Long-term complications including heart disease, stroke, blindness, kidney disease and amputations, make the greatest contribution to the costs of diabetes care. Many of these long-term effects could be avoided with earlier, more effective monitoring and treatment. Currently, blood glucose can only be monitored through the use of invasive techniques. To date there is no widely accepted and readily available non-invasive monitoring technique to measure blood glucose despite the many attempts. This paper challenges one of the most difficult non-invasive monitoring techniques, that of blood glucose, and proposes a new novel approach that will enable the accurate, and calibration free estimation of glucose concentration in blood. This approach is based on spectroscopic techniques and a new adaptive modelling scheme. The theoretical implementation and the effectiveness of the adaptive modelling scheme for this application has been described and a detailed mathematical evaluation has been employed to prove that such a scheme has the capability of extracting accurately the concentration of glucose from a complex biological media.

  12. Co-evolution in a landrace meta-population: two closely related pathogens interacting with the same host can lead to different adaptive outcomes

    PubMed Central

    Rau, Domenico; Rodriguez, Monica; Leonarda Murgia, Maria; Balmas, Virgilio; Bitocchi, Elena; Bellucci, Elisa; Nanni, Laura; Attene, Giovanna; Papa, Roberto

    2015-01-01

    We examined the local adaptation patterns in a system comprising several interconnected heterogeneous plant populations from which populations of two phylogenetically closely related pathogens were also sampled. The host is Hordeum vulgare (cultivated barley); the pathogens are Pyrenophora teres f. teres (net form) and Pyrenophora teres f. maculata (spot form), the causal agents of barley net blotch. We integrated two approaches, the comparison between the population structures of the host and the pathogens, and a cross-inoculation test. We demonstrated that two closely related pathogens with very similar niche specialisation and life-styles can give rise to different co-evolutionary outcomes on the same host. Indeed, we detected local adaptation for the net form of the pathogen but not for the spot form. We also provided evidence that an a-priori well-known resistance quantitative-trait-locus on barley chromosome 6H is involved in the co-evolutionary ‘arms race’ between the plant and the net-form pathogen. Moreover, data suggested latitudinal clines of host resistance and that different ecological conditions can result in differential selective pressures at different sites. Our data are of interest for on-farm conservation of plant genetic resources, as also in establishing efficient breeding programs and strategies for deployment of resistance genes of P. teres. PMID:26248796

  13. ReliefSeq: a gene-wise adaptive-K nearest-neighbor feature selection tool for finding gene-gene interactions and main effects in mRNA-Seq gene expression data.

    PubMed

    McKinney, Brett A; White, Bill C; Grill, Diane E; Li, Peter W; Kennedy, Richard B; Poland, Gregory A; Oberg, Ann L

    2013-01-01

    Relief-F is a nonparametric, nearest-neighbor machine learning method that has been successfully used to identify relevant variables that may interact in complex multivariate models to explain phenotypic variation. While several tools have been developed for assessing differential expression in sequence-based transcriptomics, the detection of statistical interactions between transcripts has received less attention in the area of RNA-seq analysis. We describe a new extension and assessment of Relief-F for feature selection in RNA-seq data. The ReliefSeq implementation adapts the number of nearest neighbors (k) for each gene to optimize the Relief-F test statistics (importance scores) for finding both main effects and interactions. We compare this gene-wise adaptive-k (gwak) Relief-F method with standard RNA-seq feature selection tools, such as DESeq and edgeR, and with the popular machine learning method Random Forests. We demonstrate performance on a panel of simulated data that have a range of distributional properties reflected in real mRNA-seq data including multiple transcripts with varying sizes of main effects and interaction effects. For simulated main effects, gwak-Relief-F feature selection performs comparably to standard tools DESeq and edgeR for ranking relevant transcripts. For gene-gene interactions, gwak-Relief-F outperforms all comparison methods at ranking relevant genes in all but the highest fold change/highest signal situations where it performs similarly. The gwak-Relief-F algorithm outperforms Random Forests for detecting relevant genes in all simulation experiments. In addition, Relief-F is comparable to the other methods based on computational time. We also apply ReliefSeq to an RNA-Seq study of smallpox vaccine to identify gene expression changes between vaccinia virus-stimulated and unstimulated samples. ReliefSeq is an attractive tool for inclusion in the suite of tools used for analysis of mRNA-Seq data; it has power to detect both main

  14. ReliefSeq: A Gene-Wise Adaptive-K Nearest-Neighbor Feature Selection Tool for Finding Gene-Gene Interactions and Main Effects in mRNA-Seq Gene Expression Data

    PubMed Central

    McKinney, Brett A.; White, Bill C.; Grill, Diane E.; Li, Peter W.; Kennedy, Richard B.; Poland, Gregory A.; Oberg, Ann L.

    2013-01-01

    Relief-F is a nonparametric, nearest-neighbor machine learning method that has been successfully used to identify relevant variables that may interact in complex multivariate models to explain phenotypic variation. While several tools have been developed for assessing differential expression in sequence-based transcriptomics, the detection of statistical interactions between transcripts has received less attention in the area of RNA-seq analysis. We describe a new extension and assessment of Relief-F for feature selection in RNA-seq data. The ReliefSeq implementation adapts the number of nearest neighbors (k) for each gene to optimize the Relief-F test statistics (importance scores) for finding both main effects and interactions. We compare this gene-wise adaptive-k (gwak) Relief-F method with standard RNA-seq feature selection tools, such as DESeq and edgeR, and with the popular machine learning method Random Forests. We demonstrate performance on a panel of simulated data that have a range of distributional properties reflected in real mRNA-seq data including multiple transcripts with varying sizes of main effects and interaction effects. For simulated main effects, gwak-Relief-F feature selection performs comparably to standard tools DESeq and edgeR for ranking relevant transcripts. For gene-gene interactions, gwak-Relief-F outperforms all comparison methods at ranking relevant genes in all but the highest fold change/highest signal situations where it performs similarly. The gwak-Relief-F algorithm outperforms Random Forests for detecting relevant genes in all simulation experiments. In addition, Relief-F is comparable to the other methods based on computational time. We also apply ReliefSeq to an RNA-Seq study of smallpox vaccine to identify gene expression changes between vaccinia virus-stimulated and unstimulated samples. ReliefSeq is an attractive tool for inclusion in the suite of tools used for analysis of mRNA-Seq data; it has power to detect both main

  15. ReliefSeq: a gene-wise adaptive-K nearest-neighbor feature selection tool for finding gene-gene interactions and main effects in mRNA-Seq gene expression data.

    PubMed

    McKinney, Brett A; White, Bill C; Grill, Diane E; Li, Peter W; Kennedy, Richard B; Poland, Gregory A; Oberg, Ann L

    2013-01-01

    Relief-F is a nonparametric, nearest-neighbor machine learning method that has been successfully used to identify relevant variables that may interact in complex multivariate models to explain phenotypic variation. While several tools have been developed for assessing differential expression in sequence-based transcriptomics, the detection of statistical interactions between transcripts has received less attention in the area of RNA-seq analysis. We describe a new extension and assessment of Relief-F for feature selection in RNA-seq data. The ReliefSeq implementation adapts the number of nearest neighbors (k) for each gene to optimize the Relief-F test statistics (importance scores) for finding both main effects and interactions. We compare this gene-wise adaptive-k (gwak) Relief-F method with standard RNA-seq feature selection tools, such as DESeq and edgeR, and with the popular machine learning method Random Forests. We demonstrate performance on a panel of simulated data that have a range of distributional properties reflected in real mRNA-seq data including multiple transcripts with varying sizes of main effects and interaction effects. For simulated main effects, gwak-Relief-F feature selection performs comparably to standard tools DESeq and edgeR for ranking relevant transcripts. For gene-gene interactions, gwak-Relief-F outperforms all comparison methods at ranking relevant genes in all but the highest fold change/highest signal situations where it performs similarly. The gwak-Relief-F algorithm outperforms Random Forests for detecting relevant genes in all simulation experiments. In addition, Relief-F is comparable to the other methods based on computational time. We also apply ReliefSeq to an RNA-Seq study of smallpox vaccine to identify gene expression changes between vaccinia virus-stimulated and unstimulated samples. ReliefSeq is an attractive tool for inclusion in the suite of tools used for analysis of mRNA-Seq data; it has power to detect both main

  16. 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).

  17. Interactive Presentation of Content

    ERIC Educational Resources Information Center

    Magdin, Martin; Turcáni, Milan; Vrábel, Marek

    2009-01-01

    In the paper we discus about design of universal environment for solution of creating effective multimedia applications with accent on the implementation of interactive elements with the possibility of using the adaptive systems (AS). We also discuss about possibilities of offline presentation of this interactive multimedia adaptive animations…

  18. Adaptive management

    USGS Publications Warehouse

    Allen, Craig R.; Garmestani, Ahjond S.

    2015-01-01

    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 management has explicit structure, including a careful elucidation of goals, identification of alternative management objectives and hypotheses of causation, and procedures for the collection of data followed by evaluation and reiteration. The process is iterative, and serves to reduce uncertainty, build knowledge and improve management over time in a goal-oriented and structured process.

  19. 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.

  20. Salinity regulation of the interaction of halovirus SNJ1 with its host and alteration of the halovirus replication strategy to adapt to the variable ecosystem.

    PubMed

    Mei, Yunjun; He, Congcong; Huang, Yongchi; Liu, Ying; Zhang, Ziqian; Chen, Xiangdong; Shen, Ping

    2015-01-01

    Halovirus is a major force that affects the evolution of extreme halophiles and the biogeochemistry of hypersaline environments. However, until now, the systematic studies on the halovirus ecology and the effects of salt concentration on virus-host systems are lacking. To provide more valuable information for understanding ecological strategies of a virus-host system in the hypersaline ecosystem, we studied the interaction between halovirus SNJ1 and its host Natrinema sp.J7-2 under various NaCl concentrations. We found that the adsorption rate and lytic rate increased with salt concentration, demonstrating that a higher salt concentration promoted viral adsorption and proliferation. Contrary to the lytic rate, the lysogenic rate decreased as the salt concentration increased. Our results also demonstrated that cells incubated at a high salt concentration prior to infection increased the ability of the virus to adsorb and lyse its host cells; therefore, the physiological status of host cells also affected the virus-host interaction. In conclusion, SNJ1 acted as a predator, lysing host cells and releasing progeny viruses in hypersaline environments; in low salt environments, viruses lysogenized host cells to escape the damage from low salinity. PMID:25853566

  1. Salinity Regulation of the Interaction of Halovirus SNJ1 with Its Host and Alteration of the Halovirus Replication Strategy to Adapt to the Variable Ecosystem

    PubMed Central

    Mei, Yunjun; He, Congcong; Huang, Yongchi; Liu, Ying; Zhang, Ziqian; Chen, Xiangdong; Shen, Ping

    2015-01-01

    Halovirus is a major force that affects the evolution of extreme halophiles and the biogeochemistry of hypersaline environments. However, until now, the systematic studies on the halovirus ecology and the effects of salt concentration on virus-host systems are lacking. To provide more valuable information for understanding ecological strategies of a virus-host system in the hypersaline ecosystem, we studied the interaction between halovirus SNJ1 and its host Natrinema sp.J7-2 under various NaCl concentrations. We found that the adsorption rate and lytic rate increased with salt concentration, demonstrating that a higher salt concentration promoted viral adsorption and proliferation. Contrary to the lytic rate, the lysogenic rate decreased as the salt concentration increased. Our results also demonstrated that cells incubated at a high salt concentration prior to infection increased the ability of the virus to adsorb and lyse its host cells; therefore, the physiological status of host cells also affected the virus-host interaction. In conclusion, SNJ1 acted as a predator, lysing host cells and releasing progeny viruses in hypersaline environments; in low salt environments, viruses lysogenized host cells to escape the damage from low salinity. PMID:25853566

  2. How to build an adapted and bioactive cell microenvironment? A chemical interaction study of the structure of Ca-alginate matrices and their repercussion on confined cells.

    PubMed

    Bienaimé, Christophe; Barbotin, Jean-Noël; Nava-Saucedo, José-Edmundo

    2003-11-01

    Alginates are increasingly being used as medical materials (matrices for tissue regeneration, surgical sponges, hemostatic bandages, microbial and cell encapsulation, artificial bacterial biofilms, etc.). The constitution of alginate gel networks is a complex phenomenon. A great number of different kinds of polysaccharidic frameworks can come to existence depending on the conditions used for their attainment. For instance, the degree of heterogeneity and porosity of Ca-alginate beads rely on this molecular organization. The formation of structural irregularities (superficial crust, cavities, shafts, dense or light gel frameworks, ordered or chaotic domains, etc.) within the alginate gel beads are inherent to this skeletal design. Several specific staining molecules (e.g. calcon carboxylic acid, murexide, methylene blue) that are negatively or positively charged interact with the gel network. These molecules allowed us to reveal a great variety of chemical interactions shown by the pattern coloration of the internal structure of the gel. The results observed are very different for the several matrices analyzed, which could explain to a great extent the singular behavior that cells confined in these kind of matrices exhibit.

  3. Peptide–polymer ligands for a tandem WW-domain, an adaptive multivalent protein–protein interaction: lessons on the thermodynamic fitness of flexible ligands

    PubMed Central

    Koschek, Katharina; Durmaz, Vedat; Krylova, Oxana; Wieczorek, Marek; Gupta, Shilpi; Richter, Martin; Bujotzek, Alexander; Fischer, Christina; Haag, Rainer; Freund, Christian; Weber, Marcus

    2015-01-01

    Summary Three polymers, poly(N-(2-hydroxypropyl)methacrylamide) (pHPMA), hyperbranched polyglycerol (hPG), and dextran were investigated as carriers for multivalent ligands targeting the adaptive tandem WW-domain of formin-binding protein (FBP21). Polymer carriers were conjugated with 3–9 copies of the proline-rich decapeptide GPPPRGPPPR-NH2 (P1). Binding of the obtained peptide–polymer conjugates to the tandem WW-domain was investigated employing isothermal titration calorimetry (ITC) to determine the binding affinity, the enthalpic and entropic contributions to free binding energy, and the stoichiometry of binding for all peptide–polymer conjugates. Binding affinities of all multivalent ligands were in the µM range, strongly amplified compared to the monovalent ligand P1 with a K D > 1 mM. In addition, concise differences were observed, pHPMA and hPG carriers showed moderate affinity and bound 2.3–2.8 peptides per protein binding site resulting in the formation of aggregates. Dextran-based conjugates displayed affinities down to 1.2 µM, forming complexes with low stoichiometry, and no precipitation. Experimental results were compared with parameters obtained from molecular dynamics simulations in order to understand the observed differences between the three carrier materials. In summary, the more rigid and condensed peptide–polymer conjugates based on the dextran scaffold seem to be superior to induce multivalent binding and to increase affinity, while the more flexible and dendritic polymers, pHPMA and hPG are suitable to induce crosslinking upon binding. PMID:26124884

  4. Changes in induced hues at low luminance and following dark adaptation suggest rod-cone interactions may differ for luminance increments and decrements.

    PubMed

    Shepherd, A J; Wyatt, G

    2008-01-01

    Color contrast describes the influence of one color on the perception of colors in neighboring areas. This study addressed two issues: (1) the accurate representation of the color changes; (ii) the underlying visual mechanisms. Observers matched the hue that was induced in a neutral square when it was set in one of four standard colored surrounds: "red" (+L(-M) relative to neutral), "green" (-L(+M)), "purple" (+S), and "yellow" (-S). The standard and matching displays were viewed haploscopically. The standard neutral square was either a luminance increment, or decrement, both of which appeared the complementary color to the surrounds in which they were inset. In Experiment 1, the surround luminance in each eye's display was either equal, at 18 cd x m(-2), or the match surround luminance was reduced to 2.5 cd x m(-2). The matches with equal surround luminances could be represented as vector shifts in a logarithmic MacLeod-Boynton (r, b) chromaticity diagram, as described previously (Shepherd, 1997, 1999). The low luminance matches were, however, displaced further from neutral, as if larger chromatic differences were needed. The precise direction of the displacements differed for luminance increments and decrements: the red, green and yellow decrement matches were also displaced vertically downwards in the MacLeod-Boynton diagram. In Experiment 2, dark-adapting before setting repeat color matches displaced the decrement matches vertically, but did not affect the increment matches. Thus, rod intrusion in S-cone pathways may have boosted the S-cone signal for the lowest luminance decrement matches in Experiment 1 and account for the vertical shift in MacLeod-Boynton co-ordinates. The distinct pattern of displacements for low luminance increments and decrements may be explained if the match is set at a cone-opponent, rather than a cone contrast, site and if rod signals have an input only to S-cone decrement, perhaps S-OFF, pathways.

  5. 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.

  6. Adaptive VFH

    NASA Astrophysics Data System (ADS)

    Odriozola, Iñigo; Lazkano, Elena; Sierra, Basi

    2011-10-01

    This paper investigates the improvement of the Vector Field Histogram (VFH) local planning algorithm for mobile robot systems. The Adaptive Vector Field Histogram (AVFH) algorithm has been developed to improve the effectiveness of the traditional VFH path planning algorithm overcoming the side effects of using static parameters. This new algorithm permits the adaptation of planning parameters for the different type of areas in an environment. Genetic Algorithms are used to fit the best VFH parameters to each type of sector and, afterwards, every section in the map is labelled with the sector-type which best represents it. The Player/Stage simulation platform has been chosen for making all sort of tests and to prove the new algorithm's adequateness. Even though there is still much work to be carried out, the developed algorithm showed good navigation properties and turned out to be softer and more effective than the traditional VFH algorithm.

  7. 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.

  8. 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.

  9. 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.

  10. Residues Essential for Panton-Valentine Leukocidin S Component Binding to Its Cell Receptor Suggest Both Plasticity and Adaptability in Its Interaction Surface

    PubMed Central

    Laventie, Benoit-Joseph; Guérin, Frédéric; Mourey, Lionel; Tawk, Mira Y.; Jover, Emmanuel; Maveyraud, Laurent; Prévost, Gilles

    2014-01-01

    Panton-Valentine leukocidin (PVL), a bicomponent staphylococcal leukotoxin, is involved in the poor prognosis of necrotizing pneumonia. The present study aimed to elucidate the binding mechanism of PVL and in particular its cell-binding domain. The class S component of PVL, LukS-PV, is known to ensure cell targeting and exhibits the highest affinity for the neutrophil membrane (Kd∼10−10 M) compared to the class F component of PVL, LukF-PV (Kd∼10−9 M). Alanine scanning mutagenesis was used to identify the residues involved in LukS-PV binding to the neutrophil surface. Nineteen single alanine mutations were performed in the rim domain previously described as implicated in cell membrane interactions. Positions were chosen in order to replace polar or exposed charged residues and according to conservation between leukotoxin class S components. Characterization studies enabled to identify a cluster of residues essential for LukS-PV binding, localized on two loops of the rim domain. The mutations R73A, Y184A, T244A, H245A and Y250A led to dramatically reduced binding affinities for both human leukocytes and undifferentiated U937 cells expressing the C5a receptor. The three-dimensional structure of five of the mutants was determined using X-ray crystallography. Structure analysis identified residues Y184 and Y250 as crucial in providing structural flexibility in the receptor-binding domain of LukS-PV. PMID:24643034

  11. Gut microbial adaptation to dietary consumption of fructose, artificial sweeteners and sugar alcohols: implications for host-microbe interactions contributing to obesity.

    PubMed

    Payne, A N; Chassard, C; Lacroix, C

    2012-09-01

    The Western diet, comprised of highly refined carbohydrates and fat but reduced complex plant polysaccharides, has been attributed to the prevalence of obesity. A concomitant rise in the consumption of fructose and sugar substitutes such as sugar alcohols, artificial sweeteners, even rare sugars, has mirrored this trend, as both probable contributor and solution to the epidemic. Acknowledgement of the gut microbiota as a factor involved in obesity has sparked much controversy as to the cause and consequence of this relationship. Dietary intakes are a known modulator of gut microbial phylogeny and metabolic activity, frequently exploited to stimulate beneficial bacteria, promoting health benefits. Comparably little research exists on the impact of 'unconscious' dietary modulation on the resident commensal community mediated by increased fructose and sugar substitute consumption. This review highlights mechanisms of potential host and gut microbial fructose and sugar substitute metabolism. Evidence is presented suggesting these sugar compounds, particularly fructose, condition the microbiota, resulting in acquisition of a westernized microbiome with altered metabolic capacity. Disturbances in host-microbe interactions resulting from fructose consumption are also explored.

  12. Interaction of estradiol and high density lipoproteins on proliferation of the human breast cancer cell line MCF-7 adapted to grow in serum free conditions

    SciTech Connect

    Jozan, S.; Faye, J.C.; Tournier, J.F.; Tauber, J.P.; David, J.F.; Bayard, F.

    1985-11-27

    The responsiveness of the human mammary carcinoma cell line MCF-7 to estradiol and tamoxifen treatment has been studied in different culture conditions. Cells from exponentially growing cultures were compared with cells in their initial cycles after replating from confluent cultures (''confluent-log'' cells). It has been observed that estradiol stimulation of tritiated thymidine incorporation decreases with cell density and that ''confluent-log'' cells are estrogen unresponsive for a period of four cell cycles in serum-free medium conditions. On the other hand, growth of cells replated from exponentially growing, as well as from confluent cultures, can be inhibited by tamoxifen or a combined treatment with tamoxifen and the progestin levonorgestrel. This growth inhibitory effect can be rescued by estradiol when cells are replated from exponentially growing cultures. The growth inhibitory effect cannot be rescued by estradiol alone (10(-10) to 10(-8) M) when cells are replated from confluent cultures. In this condition, the addition of steroid depleted serum is necessary to reverse the state of estradiol unresponsiveness. Serum can be replaced by high density lipoproteins but not by low density lipoproteins or lipoprotein deficient serum. The present data show that estradiol and HDL interact in the control of MCF-7 cell proliferation.

  13. Coupled adaptive complex networks.

    PubMed

    Shai, S; Dobson, S

    2013-04-01

    Adaptive networks, which combine topological evolution of the network with dynamics on the network, are ubiquitous across disciplines. Examples include technical distribution networks such as road networks and the internet, natural and biological networks, and social science networks. These networks often interact with or depend upon other networks, resulting in coupled adaptive networks. In this paper we study susceptible-infected-susceptible (SIS) epidemic dynamics on coupled adaptive networks, where susceptible nodes are able to avoid contact with infected nodes by rewiring their intranetwork connections. However, infected nodes can pass the disease through internetwork connections, which do not change with time: The dependencies between the coupled networks remain constant. We develop an analytical formalism for these systems and validate it using extensive numerical simulation. We find that stability is increased by increasing the number of internetwork links, in the sense that the range of parameters over which both endemic and healthy states coexist (both states are reachable depending on the initial conditions) becomes smaller. Finally, we find a new stable state that does not appear in the case of a single adaptive network but only in the case of weakly coupled networks, in which the infection is endemic in one network but neither becomes endemic nor dies out in the other. Instead, it persists only at the nodes that are coupled to nodes in the other network through internetwork links. We speculate on the implications of these findings. PMID:23679478

  14. Coupled adaptive complex networks

    NASA Astrophysics Data System (ADS)

    Shai, S.; Dobson, S.

    2013-04-01

    Adaptive networks, which combine topological evolution of the network with dynamics on the network, are ubiquitous across disciplines. Examples include technical distribution networks such as road networks and the internet, natural and biological networks, and social science networks. These networks often interact with or depend upon other networks, resulting in coupled adaptive networks. In this paper we study susceptible-infected-susceptible (SIS) epidemic dynamics on coupled adaptive networks, where susceptible nodes are able to avoid contact with infected nodes by rewiring their intranetwork connections. However, infected nodes can pass the disease through internetwork connections, which do not change with time: The dependencies between the coupled networks remain constant. We develop an analytical formalism for these systems and validate it using extensive numerical simulation. We find that stability is increased by increasing the number of internetwork links, in the sense that the range of parameters over which both endemic and healthy states coexist (both states are reachable depending on the initial conditions) becomes smaller. Finally, we find a new stable state that does not appear in the case of a single adaptive network but only in the case of weakly coupled networks, in which the infection is endemic in one network but neither becomes endemic nor dies out in the other. Instead, it persists only at the nodes that are coupled to nodes in the other network through internetwork links. We speculate on the implications of these findings.

  15. Prism adaptation by mental practice.

    PubMed

    Michel, Carine; Gaveau, Jérémie; Pozzo, Thierry; Papaxanthis, Charalambos

    2013-09-01

    The prediction of our actions and their interaction with the external environment is critical for sensorimotor adaptation. For instance, during prism exposure, which deviates laterally our visual field, we progressively correct movement errors by combining sensory feedback with forward model sensory predictions. However, very often we project our actions to the external environment without physically interacting with it (e.g., mental actions). An intriguing question is whether adaptation will occur if we imagine, instead of executing, an arm movement while wearing prisms. Here, we investigated prism adaptation during mental actions. In the first experiment, participants (n = 54) performed arm pointing movements before and after exposure to the optical device. They were equally divided into six groups according to prism exposure: Prisms-Active, Prisms-Imagery, Prisms-Stationary, Prisms-Stationary-Attention, No Conflict-Prisms-Imagery, No Prisms-Imagery. Adaptation, measured by the difference in pointing errors between pre-test and post-test, occurred only in Prisms-Active and Prisms-Imagery conditions. The second experiment confirmed the results of the first experiment and further showed that sensorimotor adaptation was mainly due to proprioceptive realignment in both Prisms-Active (n = 10) and Prisms-Imagery (n = 10) groups. In both experiments adaptation was greater following actual than imagined pointing movements. The present results are the first demonstration of prism adaptation by mental practice under prism exposure and they are discussed in terms of internal forward models and sensorimotor plasticity.

  16. Effects of two amino acid substitutions in the capsid proteins on the interaction of two cell-adapted PanAsia-1 strains of foot-and-mouth disease virus serotype O with heparan sulfate receptor

    PubMed Central

    2014-01-01

    Background Some cell-adapted strains of foot-and-mouth disease virus (FMDV) can utilize heparan sulfate (HS) as a receptor to facilitate viral infection in cultured cells. A number of independent sites on the capsid that might be involved in FMDV-HS interaction have been studied. However, the previously reported residues do not adequately explain HS-dependent infection of two cell-adapted PanAsia-1 strains (O/Tibet/CHA/6/99tc and O/Fujian/CHA/9/99tc) of FMDV serotype O. To identify the molecular determinant(s) for the interaction of O/Tibet/CHA/6/99tc and O/Fujian/CHA/9/99tc with HS receptor, several chimeric viruses and site-directed mutants were generated by using an infectious cDNA of a non-HS-utilizing rescued virus (Cathay topotype) as the genomic backbone. Phenotypic properties of these viruses were determined by plaque assays and virus adsorption and penetration assays in cultured cells. Results Only two of the rescued viruses encoding VP0 of O/Tibet/CHA/6/99tc or VP1 of O/Fujian/CHA/9/99tc formed plaques on wild-type Chinese hamster ovary (WT-CHO; HS+) cells, but not on HS-negative pgsD-677 cells. The formation of plaques by these two chimeric viruses on WT-CHO cells could be abolished by the introduction of single amino acid mutations Gln-2080 → Leu in VP2 of O/Tibet/CHA/6/99tc and Lys-1083 → Glu in VP1 of O/Fujian/CHA/9/99tc, respectively. Nonetheless, the introduced mutation Leu-2080 → Gln in VP2 of O/Fujian/CHA/9/99tc for the construction of expectant recombinant plasmid led to non-infectious progeny virus in baby hamster kidney 21 (BHK-21) cells, and the site-directed mutant encoding Glu-1083 → Lys in VP1 of O/Tibet/CHA/6/99tc did not acquire the ability to produce plaques on WT-CHO cells. Significant differences in the inhibition of the infectivity of four HS-utilizing viruses by heparin and RGD-containing peptide were observed in BHK-21 cells. Interestingly, the chimeric virus encoding VP0 of O/Fujian/CHA/9/99tc, and the site

  17. Adaptive vehicle motion estimation and prediction

    NASA Astrophysics Data System (ADS)

    Zhao, Liang; Thorpe, Chuck E.

    1999-01-01

    Accurate motion estimation and reliable maneuver prediction enable an automated car to react quickly and correctly to the rapid maneuvers of the other vehicles, and so allow safe and efficient navigation. In this paper, we present a car tracking system which provides motion estimation, maneuver prediction and detection of the tracked car. The three strategies employed - adaptive motion modeling, adaptive data sampling, and adaptive model switching probabilities - result in an adaptive interacting multiple model algorithm (AIMM). The experimental results on simulated and real data demonstrate that our tracking system is reliable, flexible, and robust. The adaptive tracking makes the system intelligent and useful in various autonomous driving tasks.

  18. Stability of an adaptive hybrid community

    PubMed Central

    Mougi, A.

    2016-01-01

    Contrary to stable natural ecosystems, the classical ecological theory predicts that complex ecological communities are fragile. The adaptive switching of interaction partners was proposed as a key factor to resolve the complexity–stability problem. However, this theory is based on the food webs that comprise predator–prey interactions alone; thus, the manner in which adaptive behavior affects the dynamics of hybrid communities with multiple interaction types remains unclear. Here, using a bipartite community network model with antagonistic and mutualistic interactions, I show that adaptive partner shifts by both antagonists and mutualists are crucial to the persistence of communities. The results show that adaptive behavior destabilizes the dynamics of communities with a single interaction type; however, the hybridity of multiple interaction types within a community greatly improves the stability. Moreover, adaptive behavior does not create a positive complexity–stability relationship in communities with a single interaction type but it does in the hybrid community. The diversity of interaction types is predicted to play a crucial role in community maintenance in an adaptive world. PMID:27323666

  19. Adapting Books: Ready, Set, Read!: EAT: Equipment, Adaptations, and Technology

    ERIC Educational Resources Information Center

    Schoonover, Judith; Norton-Darr, Sally

    2016-01-01

    Developing multimodal materials to introduce or extend literacy experiences sets the stage for literacy success. Alternative ways to organize, display and arrange, interact and respond to information produces greater understanding of concepts. Adaptations include making books easier to use (turning pages or holding), and text easier to read…

  20. Adaptive colouration in amphibians.

    PubMed

    Rudh, Andreas; Qvarnström, Anna

    2013-01-01

    Amphibians, i.e. salamanders, frogs and caecilians show a wide range of bright colours in combination with contrasting patterns. There is variation among species, populations and also within species and populations. Furthermore, individuals often change colours during developmental stages or in response to environmental factors. This extraordinary variation means that there are excellent opportunities to test hypotheses of the adaptive significance of colours using amphibian species as models. We review the present view of functions of colouration in amphibians with the main focus on relatively unexplored topics. Variation in colouration has been found to play a role in thermoregulation, UV protection, predator avoidance and sexual signalling. However, many proposed cases of adaptive functions of colouration in amphibians remain virtually scientifically unexplored and surprisingly few genes influencing pigmentation or patterning have been detected. We would like to especially encourage more studies that take advantage of recent developments in measurement of visual properties of several possible signalling receivers (e.g. predators, competitors or mates). Future investigations on interactions between behaviour, ecology and vision have the potential to challenge our current view of the adaptive function of colouration in amphibians.

  1. 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.

  2. Adaptive colouration in amphibians.

    PubMed

    Rudh, Andreas; Qvarnström, Anna

    2013-01-01

    Amphibians, i.e. salamanders, frogs and caecilians show a wide range of bright colours in combination with contrasting patterns. There is variation among species, populations and also within species and populations. Furthermore, individuals often change colours during developmental stages or in response to environmental factors. This extraordinary variation means that there are excellent opportunities to test hypotheses of the adaptive significance of colours using amphibian species as models. We review the present view of functions of colouration in amphibians with the main focus on relatively unexplored topics. Variation in colouration has been found to play a role in thermoregulation, UV protection, predator avoidance and sexual signalling. However, many proposed cases of adaptive functions of colouration in amphibians remain virtually scientifically unexplored and surprisingly few genes influencing pigmentation or patterning have been detected. We would like to especially encourage more studies that take advantage of recent developments in measurement of visual properties of several possible signalling receivers (e.g. predators, competitors or mates). Future investigations on interactions between behaviour, ecology and vision have the potential to challenge our current view of the adaptive function of colouration in amphibians. PMID:23664831

  3. Adaptive Signal Processing Testbed

    NASA Astrophysics Data System (ADS)

    Parliament, Hugh A.

    1991-09-01

    The design and implementation of a system for the acquisition, processing, and analysis of signal data is described. The initial application for the system is the development and analysis of algorithms for excision of interfering tones from direct sequence spread spectrum communication systems. The system is called the Adaptive Signal Processing Testbed (ASPT) and is an integrated hardware and software system built around the TMS320C30 chip. The hardware consists of a radio frequency data source, digital receiver, and an adaptive signal processor implemented on a Sun workstation. The software components of the ASPT consists of a number of packages including the Sun driver package; UNIX programs that support software development on the TMS320C30 boards; UNIX programs that provide the control, user interaction, and display capabilities for the data acquisition, processing, and analysis components of the ASPT; and programs that perform the ASPT functions including data acquisition, despreading, and adaptive filtering. The performance of the ASPT system is evaluated by comparing actual data rates against their desired values. A number of system limitations are identified and recommendations are made for improvements.

  4. Developing More Adaptive, Innovative, and Interactive Organizations.

    ERIC Educational Resources Information Center

    Doerfel, Marya L.; Ruben, Brent D.

    2002-01-01

    Presents a comprehensive view of benchmarking, including best-practice approaches to organizational assessment and improvement in higher education (the Malcolm Baldrige and "balanced scorecard" frameworks) and lessons that can be gleaned from the benchmarking process. (EV)

  5. Acquiring case adaptation knowledge: A hybrid approach

    SciTech Connect

    Leake, D.B.; Kinley, A.; Wilson, D.

    1996-12-31

    The ability of case-based reasoning (CBR) systems to apply cases to novel situations depends on their case adaptation knowledge. However, endowing CBR systems with adequate adaptation knowledge has proven to be a very difficult task. This paper describes a hybrid method for performing case adaptation, using a combination of rule-based and case-based reasoning. It shows how this approach provides a framework for acquiring flexible adaptation knowledge from experiences with autonomous adaptation and suggests its potential as a basis for acquisition of adaptation knowledge from interactive user guidance. It also presents initial experimental results examining the benefits of the approach and comparing the relative contributions of case learning and adaptation learning to reasoning performance.

  6. Adaptive soft molecular self-assemblies.

    PubMed

    Wang, Andong; Shi, Wenyue; Huang, Jianbin; Yan, Yun

    2016-01-14

    Adaptive molecular self-assemblies provide possibility of constructing smart and functional materials in a non-covalent bottom-up manner. Exploiting the intrinsic properties of responsiveness of non-covalent interactions, a great number of fancy self-assemblies have been achieved. In this review, we try to highlight the recent advances in this field. The following contents are focused: (1) environmental adaptiveness, including smart self-assemblies adaptive to pH, temperature, pressure, and moisture; (2) special chemical adaptiveness, including nanostructures adaptive to important chemicals, such as enzymes, CO2, metal ions, redox agents, explosives, biomolecules; (3) field adaptiveness, including self-assembled materials that are capable of adapting to external fields such as magnetic field, electric field, light irradiation, and shear forces. PMID:26509717

  7. Free-energy landscapes of granular clusters grown by magnetic interaction.

    PubMed

    González-Gutiérrez, Jorge; Carrillo-Estrada, J L; Carvente, O; Ruiz-Suárez, J C

    2014-05-01

    We experimentally study the aggregation of small clusters made of non-Brownian dipolar beads in a vibro-fluidized system. The particles are paramagnetic spheres that add around a fixed magnetic seed inside a granular gas of glass beads. We observe that under appropriate physical conditions symmetric and asymmetric cluster configurations are created and, as the number of particles increases, the aggregation time obeys a power law. We use an ensemble statistics to evaluate the free-energies and entropies landscapes of the granular clusters. The correspondence between such landscapes shows that, even if the system is of macroscopic scale and not in strict equilibrium, our approach to understand the relationship between the cluster structures and the interactions that create them is reliable.

  8. Adaptation, Bacteria and Maxwell's Demons

    NASA Astrophysics Data System (ADS)

    Galajda, Peter; Keymer, Juan E.; Austin, Robert H.

    2007-03-01

    We propose a method to study the adaptation of bacterial populations with an asymmetric wall of Maxwell Demon openings. A Maxwell Demon opening is a funnel which is easier to enter than to leave. The interaction of swimming cells with such a Maxwell Demon Wall results in a population density separation, in apparent (but not real) violation of the Second Law of Thermodynamics, as we will show. Bacteria can be exposed to spatial challenges in order to move to e. g. higher food levels. The question we address in these experiments is: do the bacteria adapt and overcome the Maxwell Demon Wall?

  9. 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…

  10. Perceptual adaptation helps us identify faces.

    PubMed

    Rhodes, Gillian; Watson, Tamara L; Jeffery, Linda; Clifford, Colin W G

    2010-05-12

    Adaptation is a fundamental property of perceptual processing. In low-level vision, it can calibrate perception to current inputs, increasing coding efficiency and enhancing discrimination around the adapted level. Adaptation also occurs in high-level vision, as illustrated by face aftereffects. However, the functional consequences of face adaptation remain uncertain. Here we investigated whether adaptation can enhance identification performance for faces from an adapted, relative to an unadapted, population. Five minutes of adaptation to an average Asian or Caucasian face reduced identification thresholds for faces from the adapted relative to the unadapted race. We replicated this interaction in two studies, using different participants, faces and adapting procedures. These results suggest that adaptation has a functional role in high-level, as well as low-level, visual processing. We suggest that adaptation to the average of a population may reduce responses to common properties shared by all members of the population, effectively orthogonalizing identity vectors in a multi-dimensional face space and freeing neural resources to code distinctive properties, which are useful for identification.

  11. Adaptive Image Denoising by Mixture Adaptation

    NASA Astrophysics Data System (ADS)

    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. 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.

  12. Adaptation Challenges and Emerging Efforts in Adaptation Planning in California

    NASA Astrophysics Data System (ADS)

    Moser, S. C.

    2008-12-01

    Following Governor Schwarzenegger's Executive Order (S-03-05) of 2005, numerous researchers have been engaged in an ongoing assessment effort to support the state's mitigation and adaptation efforts. Under the sponsorship and coordination of the California Energy Commission's Public Interest Energy Research (PIER) Program, a wide range of climate change impacts and adaptation studies are being conducted and summarized on a biannual basis to assess the latest climate change science, potential impacts on critical sectors, and the state's efforts to manage its climate change risks. In the past, adaptation needs assessments in the state have primarily used a hazards-based (i.e., climate scenario-driven, top-down) approach, while vulnerability-based, bottom-up studies are only now emerging. They are increasingly viewed as complementary and necessary to adequately inform adaptation strategies. This paper briefly highlights this assessment history and then focuses on the planning efforts currently underway to prepare California's first state-wide adaptation plan. As the science and policy/management evolve in tandem, this paper will suggest future policy- or use-inspired research areas, and offer recommendations on how to improve interaction between researchers and practitioners at the science-policy interface, in order to build the state's decision support capacity in the face of a rapidly changing climate.

  13. Assessing Adaptive Instructional Design Tools and Methods in ADAPT[IT].

    ERIC Educational Resources Information Center

    Eseryel, Deniz; Spector, J. Michael

    ADAPT[IT] (Advanced Design Approach for Personalized Training - Interactive Tools) is a European project within the Information Society Technologies program that is providing design methods and tools to guide a training designer according to the latest cognitive science and standardization principles. ADAPT[IT] addresses users in two significantly…

  14. Performance monitoring for new phase dynamic optimization of instruction dispatch cluster configuration

    DOEpatents

    Balasubramonian, Rajeev; Dwarkadas, Sandhya; Albonesi, David

    2012-01-24

    In a processor having multiple clusters which operate in parallel, the number of clusters in use can be varied dynamically. At the start of each program phase, the configuration option for an interval is run to determine the optimal configuration, which is used until the next phase change is detected. The optimum instruction interval is determined by starting with a minimum interval and doubling it until a low stability factor is reached.

  15. Protein adaptations in archaeal extremophiles.

    PubMed

    Reed, Christopher J; Lewis, Hunter; Trejo, Eric; Winston, Vern; Evilia, Caryn

    2013-01-01

    Extremophiles, especially those in Archaea, have a myriad of adaptations that keep their cellular proteins stable and active under the extreme conditions in which they live. Rather than having one basic set of adaptations that works for all environments, Archaea have evolved separate protein features that are customized for each environment. We categorized the Archaea into three general groups to describe what is known about their protein adaptations: thermophilic, psychrophilic, and halophilic. Thermophilic proteins tend to have a prominent hydrophobic core and increased electrostatic interactions to maintain activity at high temperatures. Psychrophilic proteins have a reduced hydrophobic core and a less charged protein surface to maintain flexibility and activity under cold temperatures. Halophilic proteins are characterized by increased negative surface charge due to increased acidic amino acid content and peptide insertions, which compensates for the extreme ionic conditions. While acidophiles, alkaliphiles, and piezophiles are their own class of Archaea, their protein adaptations toward pH and pressure are less discernible. By understanding the protein adaptations used by archaeal extremophiles, we hope to be able to engineer and utilize proteins for industrial, environmental, and biotechnological applications where function in extreme conditions is required for activity.

  16. 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.

  17. Adaptive interface for spoken dialog

    NASA Astrophysics Data System (ADS)

    Dusan, Sorin; Flanagan, James

    2002-05-01

    Speech has become increasingly important in human-computer interaction. Spoken dialog interfaces rely on automatic speech recognition, speech synthesis, language understanding, and dialog management. A main issue in dialog systems is that they typically are limited to pre-programmed vocabularies and sets of sentences. The research reported here focuses on developing an adaptive spoken dialog interface capable of acquiring new linguistic units and their corresponding semantics during the human-computer interaction. The adaptive interface identifies unknown words and phrases in the users utterances and asks the user for the corresponding semantics. The user can provide the meaning or the semantic representation of the new linguistic units through multiple modalities, including speaking, typing, pointing, touching, or showing. The interface then stores the new linguistic units in a semantic grammar and creates new objects defining the corresponding semantic representation. This process takes place during natural interaction between user and computer and, thus, the interface does not have to be rewritten and compiled to incorporate the newly acquired language. Users can personalize the adaptive spoken interface for different domain applications, or according to their personal preferences. [Work supported by NSF.

  18. Ethnic Visibility and Adaptive Strategies: Samoans in the Seattle Area

    ERIC Educational Resources Information Center

    Kotchek, Lydia

    1977-01-01

    Describes the ways and means of adaptation and interaction used by a purportedly invisible ethnic minority, the Samoan population of Seattle, Washington, and discusses both how these ways and means of adaptation and interaction relate to each other and how they are facilitated or blocked by the relative invisibility of the group. (Author/JM)

  19. 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…

  20. Dual-arm manipulators with adaptive control

    NASA Technical Reports Server (NTRS)

    Seraji, Homayoun (Inventor)

    1991-01-01

    The described and improved multi-arm invention of this application presents three strategies for adaptive control of cooperative multi-arm robots which coordinate control over a common load. In the position-position control strategy, the adaptive controllers ensure that the end-effector positions of both arms track desired trajectories in Cartesian space despite unknown time-varying interaction forces exerted through a load. In the position-hybrid control strategy, the adaptive controller of one arm controls end-effector motions in the free directions and applied forces in the constraint directions; while the adaptive controller of the other arm ensures that the end-effector tracks desired position trajectories. In the hybrid-hybrid control strategy, the adaptive controllers ensure that both end-effectors track reference position trajectories while simultaneously applying desired forces on the load. In all three control strategies, the cross-coupling effects between the arms are treated as disturbances which are compensated for by the adaptive controllers while following desired commands in a common frame of reference. The adaptive controllers do not require the complex mathematical model of the arm dynamics or any knowledge of the arm dynamic parameters or the load parameters such as mass and stiffness. Circuits in the adaptive feedback and feedforward controllers are varied by novel adaptation laws.

  1. Combination of Adaptive Feedback Cancellation and Binaural Adaptive Filtering in Hearing Aids

    NASA Astrophysics Data System (ADS)

    Lombard, Anthony; Reindl, Klaus; Kellermann, Walter

    2009-12-01

    We study a system combining adaptive feedback cancellation and adaptive filtering connecting inputs from both ears for signal enhancement in hearing aids. For the first time, such a binaural system is analyzed in terms of system stability, convergence of the algorithms, and possible interaction effects. As major outcomes of this study, a new stability condition adapted to the considered binaural scenario is presented, some already existing and commonly used feedback cancellation performance measures for the unilateral case are adapted to the binaural case, and possible interaction effects between the algorithms are identified. For illustration purposes, a blind source separation algorithm has been chosen as an example for adaptive binaural spatial filtering. Experimental results for binaural hearing aids confirm the theoretical findings and the validity of the new measures.

  2. Deleterious Passengers in Adapting Populations

    PubMed Central

    Good, Benjamin H.; Desai, Michael M.

    2014-01-01

    Most new mutations are deleterious and are eventually eliminated by natural selection. But in an adapting population, the rapid amplification of beneficial mutations can hinder the removal of deleterious variants in nearby regions of the genome, altering the patterns of sequence evolution. Here, we analyze the interactions between beneficial “driver” mutations and linked deleterious “passengers” during the course of adaptation. We derive analytical expressions for the substitution rate of a deleterious mutation as a function of its fitness cost, as well as the reduction in the beneficial substitution rate due to the genetic load of the passengers. We find that the fate of each deleterious mutation varies dramatically with the rate and spectrum of beneficial mutations and the deleterious substitution rate depends nonmonotonically on the population size and the rate of adaptation. By quantifying this dependence, our results allow us to estimate which deleterious mutations will be likely to fix and how many of these mutations must arise before the progress of adaptation is significantly reduced. PMID:25194161

  3. Contrast adaptation in the Limulus lateral eye.

    PubMed

    Valtcheva, Tchoudomira M; Passaglia, Christopher L

    2015-12-01

    Luminance and contrast adaptation are neuronal mechanisms employed by the visual system to adjust our sensitivity to light. They are mediated by an assortment of cellular and network processes distributed across the retina and visual cortex. Both have been demonstrated in the eyes of many vertebrates, but only luminance adaptation has been shown in invertebrate eyes to date. Since the computational benefits of contrast adaptation should apply to all visual systems, we investigated whether this mechanism operates in horseshoe crab eyes, one of the best-understood neural networks in the animal kingdom. The spike trains of optic nerve fibers were recorded in response to light stimuli modulated randomly in time and delivered to single ommatidia or the whole eye. We found that the retina adapts to both the mean luminance and contrast of a white-noise stimulus, that luminance- and contrast-adaptive processes are largely independent, and that they originate within an ommatidium. Network interactions are not involved. A published computer model that simulates existing knowledge of the horseshoe crab eye did not show contrast adaptation, suggesting that a heretofore unknown mechanism may underlie the phenomenon. This mechanism does not appear to reside in photoreceptors because white-noise analysis of electroretinogram recordings did not show contrast adaptation. The likely site of origin is therefore the spike discharge mechanism of optic nerve fibers. The finding of contrast adaption in a retinal network as simple as the horseshoe crab eye underscores the broader importance of this image processing strategy to vision. PMID:26445869

  4. Contrast adaptation in the Limulus lateral eye.

    PubMed

    Valtcheva, Tchoudomira M; Passaglia, Christopher L

    2015-12-01

    Luminance and contrast adaptation are neuronal mechanisms employed by the visual system to adjust our sensitivity to light. They are mediated by an assortment of cellular and network processes distributed across the retina and visual cortex. Both have been demonstrated in the eyes of many vertebrates, but only luminance adaptation has been shown in invertebrate eyes to date. Since the computational benefits of contrast adaptation should apply to all visual systems, we investigated whether this mechanism operates in horseshoe crab eyes, one of the best-understood neural networks in the animal kingdom. The spike trains of optic nerve fibers were recorded in response to light stimuli modulated randomly in time and delivered to single ommatidia or the whole eye. We found that the retina adapts to both the mean luminance and contrast of a white-noise stimulus, that luminance- and contrast-adaptive processes are largely independent, and that they originate within an ommatidium. Network interactions are not involved. A published computer model that simulates existing knowledge of the horseshoe crab eye did not show contrast adaptation, suggesting that a heretofore unknown mechanism may underlie the phenomenon. This mechanism does not appear to reside in photoreceptors because white-noise analysis of electroretinogram recordings did not show contrast adaptation. The likely site of origin is therefore the spike discharge mechanism of optic nerve fibers. The finding of contrast adaption in a retinal network as simple as the horseshoe crab eye underscores the broader importance of this image processing strategy to vision.

  5. Organizational Adaptation and Higher Education.

    ERIC Educational Resources Information Center

    Cameron, Kim S.

    1984-01-01

    Organizational adaptation and types of adaptation needed in academe in the future are reviewed and major conceptual approaches to organizational adaptation are presented. The probable environment that institutions will face in the future that will require adaptation is discussed. (MLW)

  6. Human heat adaptation.

    PubMed

    Taylor, Nigel A S

    2014-01-01

    In this overview, human morphological and functional adaptations during naturally and artificially induced heat adaptation are explored. Through discussions of adaptation theory and practice, a theoretical basis is constructed for evaluating heat adaptation. It will be argued that some adaptations are specific to the treatment used, while others are generalized. Regarding ethnic differences in heat tolerance, the case is put that reported differences in heat tolerance are not due to natural selection, but can be explained on the basis of variations in adaptation opportunity. These concepts are expanded to illustrate how traditional heat adaptation and acclimatization represent forms of habituation, and thermal clamping (controlled hyperthermia) is proposed as a superior model for mechanistic research. Indeed, this technique has led to questioning the perceived wisdom of body-fluid changes, such as the expansion and subsequent decay of plasma volume, and sudomotor function, including sweat habituation and redistribution. Throughout, this contribution was aimed at taking another step toward understanding the phenomenon of heat adaptation and stimulating future research. In this regard, research questions are posed concerning the influence that variations in morphological configuration may exert upon adaptation, the determinants of postexercise plasma volume recovery, and the physiological mechanisms that modify the cholinergic sensitivity of sweat glands, and changes in basal metabolic rate and body core temperature following adaptation.

  7. Connectionist Interaction Information Retrieval.

    ERIC Educational Resources Information Center

    Dominich, Sandor

    2003-01-01

    Discussion of connectionist views for adaptive clustering in information retrieval focuses on a connectionist clustering technique and activation spreading-based information retrieval model using the interaction information retrieval method. Presents theoretical as well as simulation results as regards computational complexity and includes…

  8. Human adaptation and readaptation for Mars mission

    NASA Technical Reports Server (NTRS)

    Schmitt, Harrison H.

    1986-01-01

    Human adaptation and readaptation in space appears to involve complex physiological and psychological interactions and adjustments. There is no comprehensive clinical characterization of the symptoms of these interactions, much less a comprehensive examination and testing of appropriate measures to counteract the near and long term adverse consequences. The variety of credible potential countermeasures is great; however, a systematic clinical research program for Shuttle and space station must be implemented as an early part of a Mars Mission strategy.

  9. 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.

  10. 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.

  11. Adaptation and visual coding

    PubMed Central

    Webster, Michael A.

    2011-01-01

    Visual coding is a highly dynamic process and continuously adapting to the current viewing context. The perceptual changes that result from adaptation to recently viewed stimuli remain a powerful and popular tool for analyzing sensory mechanisms and plasticity. Over the last decade, the footprints of this adaptation have been tracked to both higher and lower levels of the visual pathway and over a wider range of timescales, revealing that visual processing is much more adaptable than previously thought. This work has also revealed that the pattern of aftereffects is similar across many stimulus dimensions, pointing to common coding principles in which adaptation plays a central role. However, why visual coding adapts has yet to be fully answered. PMID:21602298

  12. Parallel Anisotropic Tetrahedral Adaptation

    NASA Technical Reports Server (NTRS)

    Park, Michael A.; Darmofal, David L.

    2008-01-01

    An adaptive method that robustly produces high aspect ratio tetrahedra to a general 3D metric specification without introducing hybrid semi-structured regions is presented. The elemental operators and higher-level logic is described with their respective domain-decomposed parallelizations. An anisotropic tetrahedral grid adaptation scheme is demonstrated for 1000-1 stretching for a simple cube geometry. This form of adaptation is applicable to more complex domain boundaries via a cut-cell approach as demonstrated by a parallel 3D supersonic simulation of a complex fighter aircraft. To avoid the assumptions and approximations required to form a metric to specify adaptation, an approach is introduced that directly evaluates interpolation error. The grid is adapted to reduce and equidistribute this interpolation error calculation without the use of an intervening anisotropic metric. Direct interpolation error adaptation is illustrated for 1D and 3D domains.

  13. 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

  14. Gravitational adaptation of animals

    NASA Technical Reports Server (NTRS)

    Smith, A. H.; Burton, R. R.

    1982-01-01

    The effect of gravitational adaptation is studied in a group of five Leghorn cocks which had become physiologically adapted to 2 G after 162 days of centrifugation. After this period of adaptation, they are periodically exposed to a 2 G field, accompanied by five previously unexposed hatch-mates, and the degree of retained acceleration adaptation is estimated from the decrease in lymphocyte frequency after 24 hr at 2 G. Results show that the previously adapted birds exhibit an 84% greater lymphopenia than the unexposed birds, and that the lymphocyte frequency does not decrease to a level below that found at the end of 162 days at 2 G. In addition, the capacity for adaptation to chronic acceleration is found to be highly heritable. An acceleration tolerant strain of birds shows lesser mortality during chronic acceleration, particularly in intermediate fields, although the result of acceleration selection is largely quantitative (a greater number of survivors) rather than qualitative (behavioral or physiological changes).

  15. Experimental adaptive Bayesian tomography

    NASA Astrophysics Data System (ADS)

    Kravtsov, K. S.; Straupe, S. S.; Radchenko, I. V.; Houlsby, N. M. T.; Huszár, F.; Kulik, S. P.

    2013-06-01

    We report an experimental realization of an adaptive quantum state tomography protocol. Our method takes advantage of a Bayesian approach to statistical inference and is naturally tailored for adaptive strategies. For pure states, we observe close to N-1 scaling of infidelity with overall number of registered events, while the best nonadaptive protocols allow for N-1/2 scaling only. Experiments are performed for polarization qubits, but the approach is readily adapted to any dimension.

  16. Adaptive Pairing Reversible Watermarking.

    PubMed

    Dragoi, Ioan-Catalin; Coltuc, Dinu

    2016-05-01

    This letter revisits the pairwise reversible watermarking scheme of Ou et al., 2013. An adaptive pixel pairing that considers only pixels with similar prediction errors is introduced. This adaptive approach provides an increased number of pixel pairs where both pixels are embedded and decreases the number of shifted pixels. The adaptive pairwise reversible watermarking outperforms the state-of-the-art low embedding bit-rate schemes proposed so far.

  17. Adaptation as organism design

    PubMed Central

    Gardner, Andy

    2009-01-01

    The problem of adaptation is to explain the apparent design of organisms. Darwin solved this problem with the theory of natural selection. However, population geneticists, whose responsibility it is to formalize evolutionary theory, have long neglected the link between natural selection and organismal design. Here, I review the major historical developments in theory of organismal adaptation, clarifying what adaptation is and what it is not, and I point out future avenues for research. PMID:19793739

  18. Digital adaptive sampling.

    NASA Technical Reports Server (NTRS)

    Breazeale, G. J.; Jones, L. E.

    1971-01-01

    Discussion of digital adaptive sampling, which is consistently better than fixed sampling in noise-free cases. Adaptive sampling is shown to be feasible and, it is considered, should be studied further. It should be noted that adaptive sampling is a class of variable rate sampling in which the variability depends on system signals. Digital rather than analog laws should be studied, because cases can arise in which the analog signals are not even available. An extremely important problem is implementation.

  19. Quantifying the Adaptive Cycle.

    PubMed

    Angeler, David G; Allen, Craig R; Garmestani, Ahjond S; Gunderson, Lance H; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994-2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems. PMID:26716453

  20. Quantifying the adaptive cycle

    USGS Publications Warehouse

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems.

  1. Human adaptation to smog

    SciTech Connect

    Evans, G.W. Jacobs, S.V.; Frager, N.B.

    1982-10-01

    This study examined the health effects of human adaptation to photochemical smog. A group of recent arrivals to the Los Angeles air basin were compared to long-term residents of the basin. Evidence for adaptation included greater irritation and respiratory problems among the recent arrivals and desensitization among the long-term residents in their judgments of the severity of the smog problem to their health. There was no evidence for biochemical adaptation as measured by hemoglobin response to oxidant challenge. The results were discussed in terms of psychological adaption to chronic environmental stressors.

  2. 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.

  3. Quantifying the Adaptive Cycle

    PubMed Central

    Angeler, David G.; Allen, Craig R.; Garmestani, Ahjond S.; Gunderson, Lance H.; Hjerne, Olle; Winder, Monika

    2015-01-01

    The adaptive cycle was proposed as a conceptual model to portray patterns of change in complex systems. Despite the model having potential for elucidating change across systems, it has been used mainly as a metaphor, describing system dynamics qualitatively. We use a quantitative approach for testing premises (reorganisation, conservatism, adaptation) in the adaptive cycle, using Baltic Sea phytoplankton communities as an example of such complex system dynamics. Phytoplankton organizes in recurring spring and summer blooms, a well-established paradigm in planktology and succession theory, with characteristic temporal trajectories during blooms that may be consistent with adaptive cycle phases. We used long-term (1994–2011) data and multivariate analysis of community structure to assess key components of the adaptive cycle. Specifically, we tested predictions about: reorganisation: spring and summer blooms comprise distinct community states; conservatism: community trajectories during individual adaptive cycles are conservative; and adaptation: phytoplankton species during blooms change in the long term. All predictions were supported by our analyses. Results suggest that traditional ecological paradigms such as phytoplankton successional models have potential for moving the adaptive cycle from a metaphor to a framework that can improve our understanding how complex systems organize and reorganize following collapse. Quantifying reorganization, conservatism and adaptation provides opportunities to cope with the intricacies and uncertainties associated with fast ecological change, driven by shifting system controls. Ultimately, combining traditional ecological paradigms with heuristics of complex system dynamics using quantitative approaches may help refine ecological theory and improve our understanding of the resilience of ecosystems. PMID:26716453

  4. Decentralized adaptive control

    NASA Technical Reports Server (NTRS)

    Oh, B. J.; Jamshidi, M.; Seraji, H.

    1988-01-01

    A decentralized adaptive control is proposed to stabilize and track the nonlinear, interconnected subsystems with unknown parameters. The adaptation of the controller gain is derived by using model reference adaptive control theory based on Lyapunov's direct method. The adaptive gains consist of sigma, proportional, and integral combination of the measured and reference values of the corresponding subsystem. The proposed control is applied to the joint control of a two-link robot manipulator, and the performance in computer simulation corresponds with what is expected in theoretical development.

  5. Thermal adaptation of net ecosystem exchange

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Thermal adaptation of gross primary production and ecosystem respiration has been well documented over broad thermal gradients. However, no study has examined their interaction as a function of temperature, i.e. the thermal responses of net ecosystem exchange of carbon (NEE). In this study, we const...

  6. Adaptive Dialogue Systems for Assistive Living Environments

    ERIC Educational Resources Information Center

    Papangelis, Alexandros

    2013-01-01

    Adaptive Dialogue Systems (ADS) are intelligent systems, able to interact with users via multiple modalities, such as speech, gestures, facial expressions and others. Such systems are able to make conversation with their users, usually on a specific, narrow topic. Assistive Living Environments are environments where the users are by definition not…

  7. Adaptive control of dual-arm robots

    NASA Technical Reports Server (NTRS)

    Seraji, H.

    1987-01-01

    Three strategies for adaptive control of cooperative dual-arm robots are described. In the position-position control strategy, the adaptive controllers ensure that the end-effector positions of both arms track desired trajectories in Cartesian space despite unknown time-varying interaction forces exerted through the load. In the position-hybrid control strategy, the adaptive controller of one arm controls end-effector motions in the free directions and applied forces in the constraint directions, while the adaptive controller of the other arm ensures that the end-effector tracks desired position trajectories. In the hybrid-hybrid control strategy, the adaptive controllers ensure that both end-effectors track reference position trajectories while simultaneously applying desired forces on the load. In all three control strategies, the cross-coupling effects between the arms are treated as disturbances which are rejected by the adaptive controllers while following desired commands in a common frame of reference. The adaptive controllers do not require the complex mathematical model of the arm dynamics or any knowledge of the arm dynamic parameters or the load parameters such as mass and stiffness. The controllers have simple structures and are computationally fast for on-line implementation with high sampling rates.

  8. Genomic evidence for adaptation by gene duplication.

    PubMed

    Qian, Wenfeng; Zhang, Jianzhi

    2014-08-01

    Gene duplication is widely believed to facilitate adaptation, but unambiguous evidence for this hypothesis has been found in only a small number of cases. Although gene duplication may increase the fitness of the involved organisms by doubling gene dosage or neofunctionalization, it may also result in a simple division of ancestral functions into daughter genes, which need not promote adaptation. Hence, the general validity of the adaptation by gene duplication hypothesis remains uncertain. Indeed, a genome-scale experiment found similar fitness effects of deleting pairs of duplicate genes and deleting individual singleton genes from the yeast genome, leading to the conclusion that duplication rarely results in adaptation. Here we contend that the above comparison is unfair because of a known duplication bias among genes with different fitness contributions. To rectify this problem, we compare homologous genes from the budding yeast Saccharomyces cerevisiae and the fission yeast Schizosaccharomyces pombe. We discover that simultaneously deleting a duplicate gene pair in S. cerevisiae reduces fitness significantly more than deleting their singleton counterpart in S. pombe, revealing post-duplication adaptation. The duplicates-singleton difference in fitness effect is not attributable to a potential increase in gene dose after duplication, suggesting that the adaptation is owing to neofunctionalization, which we find to be explicable by acquisitions of binary protein-protein interactions rather than gene expression changes. These results provide genomic evidence for the role of gene duplication in organismal adaptation and are important for understanding the genetic mechanisms of evolutionary innovation. PMID:24904045

  9. The sensory ecology of adaptive landscapes

    PubMed Central

    Jordan, Lyndon A.; Ryan, Michael J.

    2015-01-01

    In complex environments, behavioural plasticity depends on the ability of an animal to integrate numerous sensory stimuli. The multidimensionality of factors interacting to shape plastic behaviour means it is difficult for both organisms and researchers to predict what constitutes an adaptive response to a given set of conditions. Although researchers may be able to map the fitness pay-offs of different behavioural strategies in changing environments, there is no guarantee that the study species will be able to perceive these pay-offs. We thus risk a disconnect between our own predictions about adaptive behaviour and what is behaviourally achievable given the umwelt of the animal being studied. This may lead to erroneous conclusions about maladaptive behaviour in circumstances when the behaviour exhibited is the most adaptive possible given sensory limitations. With advances in the computational resources available to behavioural ecologists, we can now measure vast numbers of interactions among behaviours and environments to create adaptive behavioural surfaces. These surfaces have massive heuristic, predictive and analytical potential in understanding adaptive animal behaviour, but researchers using them are destined to fail if they ignore the sensory ecology of the species they study. Here, we advocate the continued use of these approaches while directly linking them to perceptual space to ensure that the topology of the generated adaptive landscape matches the perceptual reality of the animal it intends to study. Doing so will allow predictive models of animal behaviour to reflect the reality faced by the agents on adaptive surfaces, vastly improving our ability to determine what constitutes an adaptive response for the animal in question. PMID:26018831

  10. Parallel Adaptive Mesh Refinement

    SciTech Connect

    Diachin, L; Hornung, R; Plassmann, P; WIssink, A

    2005-03-04

    As large-scale, parallel computers have become more widely available and numerical models and algorithms have advanced, the range of physical phenomena that can be simulated has expanded dramatically. Many important science and engineering problems exhibit solutions with localized behavior where highly-detailed salient features or large gradients appear in certain regions which are separated by much larger regions where the solution is smooth. Examples include chemically-reacting flows with radiative heat transfer, high Reynolds number flows interacting with solid objects, and combustion problems where the flame front is essentially a two-dimensional sheet occupying a small part of a three-dimensional domain. Modeling such problems numerically requires approximating the governing partial differential equations on a discrete domain, or grid. Grid spacing is an important factor in determining the accuracy and cost of a computation. A fine grid may be needed to resolve key local features while a much coarser grid may suffice elsewhere. Employing a fine grid everywhere may be inefficient at best and, at worst, may make an adequately resolved simulation impractical. Moreover, the location and resolution of fine grid required for an accurate solution is a dynamic property of a problem's transient features and may not be known a priori. Adaptive mesh refinement (AMR) is a technique that can be used with both structured and unstructured meshes to adjust local grid spacing dynamically to capture solution features with an appropriate degree of resolution. Thus, computational resources can be focused where and when they are needed most to efficiently achieve an accurate solution without incurring the cost of a globally-fine grid. Figure 1.1 shows two example computations using AMR; on the left is a structured mesh calculation of a impulsively-sheared contact surface and on the right is the fuselage and volume discretization of an RAH-66 Comanche helicopter [35]. Note the

  11. Adaptive multiconfigurational wave functions

    SciTech Connect

    Evangelista, Francesco A.

    2014-03-28

    A method is suggested to build simple multiconfigurational wave functions specified uniquely by an energy cutoff Λ. These are constructed from a model space containing determinants with energy relative to that of the most stable determinant no greater than Λ. The resulting Λ-CI wave function is adaptive, being able to represent both single-reference and multireference electronic states. We also consider a more compact wave function parameterization (Λ+SD-CI), which is based on a small Λ-CI reference and adds a selection of all the singly and doubly excited determinants generated from it. We report two heuristic algorithms to build Λ-CI wave functions. The first is based on an approximate prescreening of the full configuration interaction space, while the second performs a breadth-first search coupled with pruning. The Λ-CI and Λ+SD-CI approaches are used to compute the dissociation curve of N{sub 2} and the potential energy curves for the first three singlet states of C{sub 2}. Special attention is paid to the issue of energy discontinuities caused by changes in the size of the Λ-CI wave function along the potential energy curve. This problem is shown to be solvable by smoothing the matrix elements of the Hamiltonian. Our last example, involving the Cu{sub 2}O{sub 2}{sup 2+} core, illustrates an alternative use of the Λ-CI method: as a tool to both estimate the multireference character of a wave function and to create a compact model space to be used in subsequent high-level multireference coupled cluster computations.

  12. Physiologic adaptation to space - Space adaptation syndrome

    NASA Technical Reports Server (NTRS)

    Vanderploeg, J. M.

    1985-01-01

    The adaptive changes of the neurovestibular system to microgravity, which result in space motion sickness (SMS), are studied. A list of symptoms, which range from vomiting to drowsiness, is provided. The two patterns of symptom development, rapid and gradual, and the duration of the symptoms are described. The concept of sensory conflict and rearrangements to explain SMS is being investigated.

  13. Adaptive multi-resolution 3D Hartree-Fock-Bogoliubov solver for nuclear structure

    NASA Astrophysics Data System (ADS)

    Pei, J. C.; Fann, G. I.; Harrison, R. J.; Nazarewicz, W.; Shi, Yue; Thornton, S.

    2014-08-01

    Background: Complex many-body systems, such as triaxial and reflection-asymmetric nuclei, weakly bound halo states, cluster configurations, nuclear fragments produced in heavy-ion fusion reactions, cold Fermi gases, and pasta phases in neutron star crust, are all characterized by large sizes and complex topologies in which many geometrical symmetries characteristic of ground-state configurations are broken. A tool of choice to study such complex forms of matter is an adaptive multi-resolution wavelet analysis. This method has generated much excitement since it provides a common framework linking many diversified methodologies across different fields, including signal processing, data compression, harmonic analysis and operator theory, fractals, and quantum field theory. Purpose: To describe complex superfluid many-fermion systems, we introduce an adaptive pseudospectral method for solving self-consistent equations of nuclear density functional theory in three dimensions, without symmetry restrictions. Methods: The numerical method is based on the multi-resolution and computational harmonic analysis techniques with a multi-wavelet basis. The application of state-of-the-art parallel programming techniques include sophisticated object-oriented templates which parse the high-level code into distributed parallel tasks with a multi-thread task queue scheduler for each multi-core node. The internode communications are asynchronous. The algorithm is variational and is capable of solving coupled complex-geometric systems of equations adaptively, with functional and boundary constraints, in a finite spatial domain of very large size, limited by existing parallel computer memory. For smooth functions, user-defined finite precision is guaranteed. Results: The new adaptive multi-resolution Hartree-Fock-Bogoliubov (HFB) solver madness-hfb is benchmarked against a two-dimensional coordinate-space solver hfb-ax that is based on the B-spline technique and a three-dimensional solver

  14. A roadmap for climate change adaptation in Sweden's forests: addressing wicked problems using adaptive management

    NASA Astrophysics Data System (ADS)

    Rist, L.; Felton, A.; Samuelsson, L.; Marald, E.; Karlsson, B.; Johansson, U.; Rosvall, O.

    2013-12-01

    Climate change is expected to have significant direct and indirect effects on forest ecosystems. Forests will have to adapt not only to changes in mean climate variables but also to increased climatic variability and altered disturbance regimes. Rates of change will likely exceed many forests capabilities to naturally adapt and many of today's trees will be exposed to the climates of 2090. In Sweden the effects are already being seen and more severe impacts are expected in the future. Exacerbating the challenge posed by climate change, a large proportion of Sweden's forests are, as a consequence of dominant production goals, greatly simplified and thus potentially more vulnerable to the uncertainties and risks associated with climate change. This simplification also confers reduced adaptive capacity to respond to potential impacts. Furthermore, many adaptation measures themselves carry uncertainties and risks. Future changes and effects are thus uncertain, yet forest managers, policymakers, scientists and other stakeholders must act. Strategies that build social and ecological resilience in the face of multiple interacting unknowns and surprises are needed. Adaptive management aims to collect and integrate knowledge about how a managed system is likely to respond to alternative management schemes and changing environmental conditions within a continuous decision process. There have been suggestions that adaptive management is not well suited to the large complex uncertainties associated with climate change and associated adaptation measures. However, more recently it has been suggested that adaptive management can handle such wicked problems, given adequate resources and a suitable breakdown of the targeted uncertainties. Here we test this hypothesis by evaluating how an adaptive management process could be used to manage the uncertainties and risks associated with securing resilient, biodiverse and productive forests in Sweden in the face of climate change. We

  15. Coherent optical adaptive techniques.

    PubMed

    Bridges, W B; Brunner, P T; Lazzara, S P; Nussmeier, T A; O'Meara, T R; Sanguinet, J A; Brown, W P

    1974-02-01

    The theory of multidither adaptive optical radar phased arrays is briefly reviewed as an introduction to the experimental results obtained with seven-element linear and three-element triangular array systems operating at 0.6328 microm. Atmospheric turbulence compensation and adaptive tracking capabilities are demonstrated.

  16. Research, Adaptation, & Change.

    ERIC Educational Resources Information Center

    Morris, Lee A., Ed.; And Others

    Research adaptation is an endeavor that implies solid collaboration among school practitioners and university and college researchers. This volume addresses the broad issues of research as an educational endeavor, adaptation as a necessary function associated with applying research findings to school situations, and change as an inevitable…

  17. 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).

  18. [Postvagotomy adaptation syndrome].

    PubMed

    Shapovalov, V A

    1998-01-01

    It was established in experiment, that the changes of the natural resistance of organism indexes and of the peritoneal cavity cytology has compensatory-adaptational character while the denervation-adaptational syndrome occurrence and progress, which may be assessed as eustress. Vagotomy and operative trauma cause qualitatively different reactions of an organism.

  19. Adaptive Sampling Proxy Application

    2012-10-22

    ASPA is an implementation of an adaptive sampling algorithm [1-3], which is used to reduce the computational expense of computer simulations that couple disparate physical scales. The purpose of ASPA is to encapsulate the algorithms required for adaptive sampling independently from any specific application, so that alternative algorithms and programming models for exascale computers can be investigated more easily.

  20. Water Resource Adaptation Program

    EPA Science Inventory

    The Water Resource Adaptation Program (WRAP) contributes to the U.S. Environmental Protection Agency’s (U.S. EPA) efforts to provide water resource managers and decision makers with the tools needed to adapt water resources to demographic and economic development, and future clim...

  1. Retinal Imaging: Adaptive Optics

    NASA Astrophysics Data System (ADS)

    Goncharov, A. S.; Iroshnikov, N. G.; Larichev, Andrey V.

    This chapter describes several factors influencing the performance of ophthalmic diagnostic systems with adaptive optics compensation of human eye aberration. Particular attention is paid to speckle modulation, temporal behavior of aberrations, and anisoplanatic effects. The implementation of a fundus camera with adaptive optics is considered.

  2. Emergent Fields through Adaptation and Identity: Overcoming Social Distance

    ERIC Educational Resources Information Center

    DeGennaro, Donna; Brown, Tiffany

    2009-01-01

    We examine the inseparability of one's environment with the elements of adaptation and identity. Specifically, we revisit the Project H.O.M.E. learning environment as we suggest that the entities of adaption and environment are not only binding, but also naturally in constant flux as they interact with each other. Contrary to nature, however, the…

  3. Adaptive Intelligent Support to Improve Peer Tutoring in Algebra

    ERIC Educational Resources Information Center

    Walker, Erin; Rummel, Nikol; Koedinger, Kenneth R.

    2014-01-01

    Adaptive collaborative learning support (ACLS) involves collaborative learning environments that adapt their characteristics, and sometimes provide intelligent hints and feedback, to improve individual students' collaborative interactions. ACLS often involves a system that can automatically assess student dialogue, model effective and…

  4. Complex Adaptive Schools: Educational Leadership and School Change

    ERIC Educational Resources Information Center

    Kershner, Brad; McQuillan, Patrick

    2016-01-01

    This paper utilizes the theoretical framework of complexity theory to compare and contrast leadership and educational change in two urban schools. Drawing on the notion of a complex adaptive system--an interdependent network of interacting elements that learns and evolves in adapting to an ever-shifting context--our case studies seek to reveal the…

  5. Exploring Adaptability through Learning Layers and Learning Loops

    ERIC Educational Resources Information Center

    Lof, Annette

    2010-01-01

    Adaptability in social-ecological systems results from individual and collective action, and multi-level interactions. It can be understood in a dual sense as a system's ability to adapt to disturbance and change, and to navigate system transformation. Inherent in this conception, as found in resilience thinking, are the concepts of learning and…

  6. Parallel Adaptive Multi-Mechanics Simulations using Diablo

    SciTech Connect

    Parsons, D; Solberg, J

    2004-12-03

    Coupled multi-mechanics simulations (such as thermal-stress and fluidstructure interaction problems) are of substantial interest to engineering analysts. In addition, adaptive mesh refinement techniques present an attractive alternative to current mesh generation procedures and provide quantitative error bounds that can be used for model verification. This paper discusses spatially adaptive multi-mechanics implicit simulations using the Diablo computer code. (U)

  7. An adaptive lidar

    NASA Astrophysics Data System (ADS)

    Oshlakov, V. G.; Andreev, M. I.; Malykh, D. D.

    2009-09-01

    Using the polarization characteristics of a target and its underlying surface one can change the target contrast range. As the target one can use the compact and discrete structures with different characteristics to reflect electromagnetic waves. An important problem, solved by the adaptive polarization lidar, is to determine the availability and identification of different targets based on their polarization characteristics against the background of underlying surface, which polarization characteristics are unknown. Another important problem of the adaptive polarization lidar is a search for the objects, which polarization characteristics are unknown, against the background of underlying surface, which polarization characteristics are known. The adaptive polarization lidar makes it possible to determine the presence of impurities in sea water. The characteristics of the adaptive polarization lidar undergo variations, i.e., polarization characteristics of a sensing signal and polarization characteristics of the receiver are varied depending on the problem to be solved. One of the versions of construction of the adaptive polarization lidar is considered. The increase of the contrast in the adaptive lidar has been demonstrated by the numerical experiment when sensing hydrosols on the background of the Rayleigh scattering, caused by clear water. The numerical experiment has also demonstrated the increase of the contrast in the adaptive lidar when sensing at two wavelengths of dry haze and dense haze on the background of the Rayleigh scattering, caused by the clear atmosphere. The most effective wavelength was chosen.

  8. [Adaptive optics for ophthalmology].

    PubMed

    Saleh, M

    2016-04-01

    Adaptive optics is a technology enhancing the visual performance of an optical system by correcting its optical aberrations. Adaptive optics have already enabled several breakthroughs in the field of visual sciences, such as improvement of visual acuity in normal and diseased eyes beyond physiologic limits, and the correction of presbyopia. Adaptive optics technology also provides high-resolution, in vivo imaging of the retina that may eventually help to detect the onset of retinal conditions at an early stage and provide better assessment of treatment efficacy.

  9. Adaptive network countermeasures.

    SciTech Connect

    McClelland-Bane, Randy; Van Randwyk, Jamie A.; Carathimas, Anthony G.; Thomas, Eric D.

    2003-10-01

    This report describes the results of a two-year LDRD funded by the Differentiating Technologies investment area. The project investigated the use of countermeasures in protecting computer networks as well as how current countermeasures could be changed in order to adapt with both evolving networks and evolving attackers. The work involved collaboration between Sandia employees and students in the Sandia - California Center for Cyber Defenders (CCD) program. We include an explanation of the need for adaptive countermeasures, a description of the architecture we designed to provide adaptive countermeasures, and evaluations of the system.

  10. Viruses are a dominant driver of protein adaptation in mammals

    PubMed Central

    Enard, David; Cai, Le; Gwennap, Carina; Petrov, Dmitri A

    2016-01-01

    Viruses interact with hundreds to thousands of proteins in mammals, yet adaptation against viruses has only been studied in a few proteins specialized in antiviral defense. Whether adaptation to viruses typically involves only specialized antiviral proteins or affects a broad array of virus-interacting proteins is unknown. Here, we analyze adaptation in ~1300 virus-interacting proteins manually curated from a set of 9900 proteins conserved in all sequenced mammalian genomes. We show that viruses (i) use the more evolutionarily constrained proteins within the cellular functions they interact with and that (ii) despite this high constraint, virus-interacting proteins account for a high proportion of all protein adaptation in humans and other mammals. Adaptation is elevated in virus-interacting proteins across all functional categories, including both immune and non-immune functions. We conservatively estimate that viruses have driven close to 30% of all adaptive amino acid changes in the part of the human proteome conserved within mammals. Our results suggest that viruses are one of the most dominant drivers of evolutionary change across mammalian and human proteomes. DOI: http://dx.doi.org/10.7554/eLife.12469.001 PMID:27187613

  11. Adaptive interface for personalizing information seeking.

    PubMed

    Narayanan, S; Koppaka, Lavanya; Edala, Narasimha; Loritz, Don; Daley, Raymond

    2004-12-01

    An adaptive interface autonomously adjusts its display and available actions to current goals and abilities of the user by assessing user status, system task, and the context. Knowledge content adaptability is needed for knowledge acquisition and refinement tasks. In the case of knowledge content adaptability, the requirements of interface design focus on the elicitation of information from the user and the refinement of information based on patterns of interaction. In such cases, the emphasis on adaptability is on facilitating information search and knowledge discovery. In this article, we present research on adaptive interfaces that facilitates personalized information seeking from a large data warehouse. The resulting proof-of-concept system, called source recommendation system (SRS), assists users in locating and navigating data sources in the repository. Based on the initial user query and an analysis of the content of the search results, the SRS system generates a profile of the user tailored to the individual's context during information seeking. The user profiles are refined successively and are used in progressively guiding the user to the appropriate set of sources within the knowledge base. The SRS system is implemented as an Internet browser plug-in to provide a seamless and unobtrusive, personalized experience to the users during the information search process. The rationale behind our approach, system design, empirical evaluation, and implications for research on adaptive interfaces are described in this paper.

  12. Adaptive Heat Engine.

    PubMed

    Allahverdyan, A E; Babajanyan, S G; Martirosyan, N H; Melkikh, A V

    2016-07-15

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where-due to feedback from the functional part-the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment.

  13. Adaptive Heat Engine.

    PubMed

    Allahverdyan, A E; Babajanyan, S G; Martirosyan, N H; Melkikh, A V

    2016-07-15

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where-due to feedback from the functional part-the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment. PMID:27472104

  14. 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

  15. Rocketing into Adaptive Inquiry.

    ERIC Educational Resources Information Center

    Farenga, Stephen J.; Joyce, Beverly A.; Dowling, Thomas W.

    2002-01-01

    Defines adaptive inquiry and argues for employing this method which allows lessons to be shaped in response to student needs. Illustrates this idea by detailing an activity in which teams of students build rockets. (DDR)

  16. Adaptive Management of Ecosystems

    EPA Science Inventory

    Adaptive management is an approach to natural resource management that emphasizes learning through management. As such, management may be treated as experiment, with replication, or management may be conducted in an iterative manner. Although the concept has resonated with many...

  17. 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.

  18. Adaptive Heat Engine

    NASA Astrophysics Data System (ADS)

    Allahverdyan, A. E.; Babajanyan, S. G.; Martirosyan, N. H.; Melkikh, A. V.

    2016-07-01

    A major limitation of many heat engines is that their functioning demands on-line control and/or an external fitting between the environmental parameters (e.g., temperatures of thermal baths) and internal parameters of the engine. We study a model for an adaptive heat engine, where—due to feedback from the functional part—the engine's structure adapts to given thermal baths. Hence, no on-line control and no external fitting are needed. The engine can employ unknown resources; it can also adapt to results of its own functioning that make the bath temperatures closer. We determine resources of adaptation and relate them to the prior information available about the environment.

  19. Islands, resettlement and adaptation

    NASA Astrophysics Data System (ADS)

    Barnett, Jon; O'Neill, Saffron J.

    2012-01-01

    Resettlement of people living on islands in anticipation of climate impacts risks maladaptation, but some forms of population movement carry fewer risks and larger rewards in terms of adapting to climate change.

  20. Dissociation as complex adaptation.

    PubMed

    Sel, R

    1997-03-01

    In this article the general theory of complex adaptive systems, substantiated by non-linear dynamics, will be used to put the dissociative disorders into a theoretical framework and clarify their genesis and presentation. When a system is far out of equilibrium, dissipative structures may be formed ('order out of chaos', as Prigogine (1) has put it). These structures provide the starting point for further evolution and co-evolution of competing groups of functional schemata divided on a bifurcation surface. Complex adaptation is almost inevitable in a complicated system (such as the brain) driven by non-linear dynamics. Dissociation is thus regarded as a consequence of adaptation to a chaotic environment rich in contrasts. In a sufficiently complex environment a person with dissociative identity disorder is more adapted and thus more likely to occur than a 'normal' monopersonality individual.

  1. Adaptable DC offset correction

    NASA Technical Reports Server (NTRS)

    Golusky, John M. (Inventor); Muldoon, Kelly P. (Inventor)

    2009-01-01

    Methods and systems for adaptable DC offset correction are provided. An exemplary adaptable DC offset correction system evaluates an incoming baseband signal to determine an appropriate DC offset removal scheme; removes a DC offset from the incoming baseband signal based on the appropriate DC offset scheme in response to the evaluated incoming baseband signal; and outputs a reduced DC baseband signal in response to the DC offset removed from the incoming baseband signal.

  2. Leak test adapter for containers

    DOEpatents

    Hallett, Brian H.; Hartley, Michael S.

    1996-01-01

    An adapter is provided for facilitating the charging of containers and leak testing penetration areas. The adapter comprises an adapter body and stem which are secured to the container's penetration areas. The container is then pressurized with a tracer gas. Manipulating the adapter stem installs a penetration plug allowing the adapter to be removed and the penetration to be leak tested with a mass spectrometer. Additionally, a method is provided for using the adapter.

  3. 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.

  4. Adaptation through proportion

    NASA Astrophysics Data System (ADS)

    Xiong, Liyang; Shi, Wenjia; Tang, Chao

    2016-08-01

    Adaptation is a ubiquitous feature in biological sensory and signaling networks. It has been suggested that adaptive systems may follow certain simple design principles across diverse organisms, cells and pathways. One class of networks that can achieve adaptation utilizes an incoherent feedforward control, in which two parallel signaling branches exert opposite but proportional effects on the output at steady state. In this paper, we generalize this adaptation mechanism by establishing a steady-state proportionality relationship among a subset of nodes in a network. Adaptation can be achieved by using any two nodes in the sub-network to respectively regulate the output node positively and negatively. We focus on enzyme networks and first identify basic regulation motifs consisting of two and three nodes that can be used to build small networks with proportional relationships. Larger proportional networks can then be constructed modularly similar to LEGOs. Our method provides a general framework to construct and analyze a class of proportional and/or adaptation networks with arbitrary size, flexibility and versatile functional features.

  5. The Climate Adaptation Frontier

    SciTech Connect

    Preston, Benjamin L

    2013-01-01

    Climate adaptation has emerged as a mainstream risk management strategy for assisting in maintaining socio-ecological systems within the boundaries of a safe operating space. Yet, there are limits to the ability of systems to adapt. Here, we introduce the concept of an adaptation frontier , which is defined as a socio-ecological system s transitional adaptive operating space between safe and unsafe domains. A number of driving forces are responsible for determining the sustainability of systems on the frontier. These include path dependence, adaptation/development deficits, values conflicts and discounting of future loss and damage. The cumulative implications of these driving forces are highly uncertain. Nevertheless, the fact that a broad range of systems already persist at the edge of their frontiers suggests a high likelihood that some limits will eventually be exceeded. The resulting system transformation is likely to manifest as anticipatory modification of management objectives or loss and damage. These outcomes vary significantly with respect to their ethical implications. Successful navigation of the adaptation frontier will necessitate new paradigms of risk governance to elicit knowledge that encourages reflexive reevaluation of societal values that enable or constrain sustainability.

  6. Adaptive-network models of collective dynamics

    NASA Astrophysics Data System (ADS)

    Zschaler, G.

    2012-09-01

    Complex systems can often be modelled as networks, in which their basic units are represented by abstract nodes and the interactions among them by abstract links. This network of interactions is the key to understanding emergent collective phenomena in such systems. In most cases, it is an adaptive network, which is defined by a feedback loop between the local dynamics of the individual units and the dynamical changes of the network structure itself. This feedback loop gives rise to many novel phenomena. Adaptive networks are a promising concept for the investigation of collective phenomena in different systems. However, they also present a challenge to existing modelling approaches and analytical descriptions due to the tight coupling between local and topological degrees of freedom. In this work, which is essentially my PhD thesis, I present a simple rule-based framework for the investigation of adaptive networks, using which a wide range of collective phenomena can be modelled and analysed from a common perspective. In this framework, a microscopic model is defined by the local interaction rules of small network motifs, which can be implemented in stochastic simulations straightforwardly. Moreover, an approximate emergent-level description in terms of macroscopic variables can be derived from the microscopic rules, which we use to analyse the system's collective and long-term behaviour by applying tools from dynamical systems theory. We discuss three adaptive-network models for different collective phenomena within our common framework. First, we propose a novel approach to collective motion in insect swarms, in which we consider the insects' adaptive interaction network instead of explicitly tracking their positions and velocities. We capture the experimentally observed onset of collective motion qualitatively in terms of a bifurcation in this non-spatial model. We find that three-body interactions are an essential ingredient for collective motion to emerge

  7. Pervasive Adaptation in Car Crowds

    NASA Astrophysics Data System (ADS)

    Ferscha, Alois; Riener, Andreas

    Advances in the miniaturization and embedding of electronics for microcomputing, communication and sensor/actuator systems, have fertilized the pervasion of technology into literally everything. Pervasive computing technology is particularly flourishing in the automotive domain, exceling the “smart car”, embodying intelligent control mechanics, intelligent driver assistance, safety and comfort systems, navigation, tolling, fleet management and car-to-car interaction systems, as one of the outstanding success stories of pervasive computing. This paper raises the issue of the socio-technical phenomena emerging from the reciprocal interrelationship between drivers and smart cars, particularly in car crowds. A driver-vehicle co-model (DVC-model) is proposed, expressing the complex interactions between the human driver and the in-car and on-car technologies. Both explicit (steering, shifting, overtaking), as well as implicit (body posture, respiration) interactions are considered, and related to the drivers vital state (attentive, fatigue, distracted, aggressive). DVC-models are considered as building blocks in large scale simulation experiments, aiming to analyze and understand adaptation phenomena rooted in the feed-back loops among individual driver behavior and car crowds.

  8. Constrained Adaptive Sensing

    NASA Astrophysics Data System (ADS)

    Davenport, Mark A.; Massimino, Andrew K.; Needell, Deanna; Woolf, Tina

    2016-10-01

    Suppose that we wish to estimate a vector $\\mathbf{x} \\in \\mathbb{C}^n$ from a small number of noisy linear measurements of the form $\\mathbf{y} = \\mathbf{A x} + \\mathbf{z}$, where $\\mathbf{z}$ represents measurement noise. When the vector $\\mathbf{x}$ is sparse, meaning that it has only $s$ nonzeros with $s \\ll n$, one can obtain a significantly more accurate estimate of $\\mathbf{x}$ by adaptively selecting the rows of $\\mathbf{A}$ based on the previous measurements provided that the signal-to-noise ratio (SNR) is sufficiently large. In this paper we consider the case where we wish to realize the potential of adaptivity but where the rows of $\\mathbf{A}$ are subject to physical constraints. In particular, we examine the case where the rows of $\\mathbf{A}$ are constrained to belong to a finite set of allowable measurement vectors. We demonstrate both the limitations and advantages of adaptive sensing in this constrained setting. We prove that for certain measurement ensembles, the benefits offered by adaptive designs fall far short of the improvements that are possible in the unconstrained adaptive setting. On the other hand, we also provide both theoretical and empirical evidence that in some scenarios adaptivity does still result in substantial improvements even in the constrained setting. To illustrate these potential gains, we propose practical algorithms for constrained adaptive sensing by exploiting connections to the theory of optimal experimental design and show that these algorithms exhibit promising performance in some representative applications.

  9. Electricity Market Complex Adaptive System

    2004-10-14

    EMCAS is a model developed for the simulation and analysis of electricity markets. As power markets are relatively new and still continue to evolve, there is a growing need for advanced modeling approaches that simulate the behavior of electricity markets over time and how market participants may act and react to the changing economic, financial, and regulatory environments in which they operate. A new and rather promising approach applied in the EMCAS software is tomore » model the electricity market as a complex adaptive system using an agent-based modeling and simulation scheme. With its unique combination of various novel approaches, the Agent Based Modeling System (ABMS) provides the ability to capture and investigate the complex interactions between the physical infrastructures (generation, transmission, and distribution) and the economic behavior of market participants that are a trademark of the newly emerging markets.« less

  10. Adaptive Behavior vs Adaptive Skills: Dimensions in Coping Development.

    ERIC Educational Resources Information Center

    Leland, Henry

    This paper views the adaptive behavior of individuals with mental retardation as a coping response to the biological and social demands of the environment. Adaptive skills are contrasted with adaptive behaviors, with skills being based primarily on developing new learning and habituating specific responses. Adaptive behavior represents a more…

  11. Turbulent Output-Based Anisotropic Adaptation

    NASA Technical Reports Server (NTRS)

    Park, Michael A.; Carlson, Jan-Renee

    2010-01-01

    Controlling discretization error is a remaining challenge for computational fluid dynamics simulation. Grid adaptation is applied to reduce estimated discretization error in drag or pressure integral output functions. To enable application to high O(10(exp 7)) Reynolds number turbulent flows, a hybrid approach is utilized that freezes the near-wall boundary layer grids and adapts the grid away from the no slip boundaries. The hybrid approach is not applicable to problems with under resolved initial boundary layer grids, but is a powerful technique for problems with important off-body anisotropic features. Supersonic nozzle plume, turbulent flat plate, and shock-boundary layer interaction examples are presented with comparisons to experimental measurements of pressure and velocity. Adapted grids are produced that resolve off-body features in locations that are not known a priori.

  12. [Cellular adaptation and cancerogenesis].

    PubMed

    La Torre, F; Silpigni, A; Tomasello, R; Picone, G S; La Torre, I; Aragona, M

    1998-06-01

    The paper describes the main adaptive mechanisms involved in the carcinogenic process. As a result of the action of carcinogenic agents (physical, chemical, biological), and in relation to the functional status of the affected cells, a number of systems are triggered off: detoxification and conjugation systems, the metabolisation of the said agents, DNA repairing enzymes, increased shock proteins (HSP), the induction of clonal proliferation. All these systems are valuable to the survival of the body and the species and culminate in the apoptosis of damaged cells as the last attempt at adaptation of a social kind for the good of the body. When these compensation mechanisms prove ineffective, imprecise or are exceeded by cell adaptive capacity, the resulting structural and functional alterations trigger off (induction) a very long process which often lasts between one and two thirds of the body's life, in various stages, multistep and multifactorial: this neoplastic transformation leads to a purposeless, egoistic, anarchic proliferation of cells which wish to survive at all costs, even to the detriment of the body of which they form part. Following the exhaustion of cell adaptive defences, there is an accumulation of additional genetic alterations (promotion and progression), the cells become manifestly neoplastic and continue their egoistic adaptation, according to the laws of natural selection: the cells which survive are those which adapt best to the hostile environment of the host's body, which are unaffected by proliferation control mechanisms (contact inhibition, differentiation factors, apoptosis, etc.), which make the best of the growth factors present in their microenvironment, which accomplish the so-called decathlon of the metastatization process, namely acquiring new capacities which can overcome the basal membrane, invade tissues to which they are attracted and continue to proliferate. Manifestly neoplastic cells become not self at a later stage

  13. Emotional facial expressions reduce neural adaptation to face identity.

    PubMed

    Gerlicher, Anna M V; van Loon, Anouk M; Scholte, H Steven; Lamme, Victor A F; van der Leij, Andries R

    2014-05-01

    In human social interactions, facial emotional expressions are a crucial source of information. Repeatedly presented information typically leads to an adaptation of neural responses. However, processing seems sustained with emotional facial expressions. Therefore, we tested whether sustained processing of emotional expressions, especially threat-related expressions, would attenuate neural adaptation. Neutral and emotional expressions (happy, mixed and fearful) of same and different identity were presented at 3 Hz. We used electroencephalography to record the evoked steady-state visual potentials (ssVEP) and tested to what extent the ssVEP amplitude adapts to the same when compared with different face identities. We found adaptation to the identity of a neutral face. However, for emotional faces, adaptation was reduced, decreasing linearly with negative valence, with the least adaptation to fearful expressions. This short and straightforward method may prove to be a valuable new tool in the study of emotional processing.

  14. Genome-environment associations in sorghum landraces predict adaptive traits

    PubMed Central

    Lasky, Jesse R.; Upadhyaya, Hari D.; Ramu, Punna; Deshpande, Santosh; Hash, C. Tom; Bonnette, Jason; Juenger, Thomas E.; Hyma, Katie; Acharya, Charlotte; Mitchell, Sharon E.; Buckler, Edward S.; Brenton, Zachary; Kresovich, Stephen; Morris, Geoffrey P.

    2015-01-01

    Improving environmental adaptation in crops is essential for food security under global change, but phenotyping adaptive traits remains a major bottleneck. If associations between single-nucleotide polymorphism (SNP) alleles and environment of origin in crop landraces reflect adaptation, then these could be used to predict phenotypic variation for adaptive traits. We tested this proposition in the global food crop Sorghum bicolor, characterizing 1943 georeferenced landraces at 404,627 SNPs and quantifying allelic associations with bioclimatic and soil gradients. Environment explained a substantial portion of SNP variation, independent of geographical distance, and genic SNPs were enriched for environmental associations. Further, environment-associated SNPs predicted genotype-by-environment interactions under experimental drought stress and aluminum toxicity. Our results suggest that genomic signatures of environmental adaptation may be useful for crop improvement, enhancing germplasm identification and marker-assisted selection. Together, genome-environment associations and phenotypic analyses may reveal the basis of environmental adaptation. PMID:26601206

  15. Genome-environment associations in sorghum landraces predict adaptive traits.

    PubMed

    Lasky, Jesse R; Upadhyaya, Hari D; Ramu, Punna; Deshpande, Santosh; Hash, C Tom; Bonnette, Jason; Juenger, Thomas E; Hyma, Katie; Acharya, Charlotte; Mitchell, Sharon E; Buckler, Edward S; Brenton, Zachary; Kresovich, Stephen; Morris, Geoffrey P

    2015-07-01

    Improving environmental adaptation in crops is essential for food security under global change, but phenotyping adaptive traits remains a major bottleneck. If associations between single-nucleotide polymorphism (SNP) alleles and environment of origin in crop landraces reflect adaptation, then these could be used to predict phenotypic variation for adaptive traits. We tested this proposition in the global food crop Sorghum bicolor, characterizing 1943 georeferenced landraces at 404,627 SNPs and quantifying allelic associations with bioclimatic and soil gradients. Environment explained a substantial portion of SNP variation, independent of geographical distance, and genic SNPs were enriched for environmental associations. Further, environment-associated SNPs predicted genotype-by-environment interactions under experimental drought stress and aluminum toxicity. Our results suggest that genomic signatures of environmental adaptation may be useful for crop improvement, enhancing germplasm identification and marker-assisted selection. Together, genome-environment associations and phenotypic analyses may reveal the basis of environmental adaptation. PMID:26601206

  16. AMGET, an R-Based Postprocessing Tool for ADAPT 5

    PubMed Central

    Guiastrennec, B; Wollenberg, L; Forrest, A; Ait-Oudhia, S

    2013-01-01

    ADAPT 5 is a powerful modeling software for population pharmacokinetic and pharmacodynamic systems analysis, but provides limited built-in functionality for creating pre- and post-analysis diagnostic plots. ADAPT 5 Model Evaluation Graphical Toolkit (AMGET), an external package written in the open source R programming language, was developed specifically to support efficient postprocessing of ADAPT 5 runs, as well as NONMEM and S-ADAPT runs. Using interactive navigational menus, users of AMGET are able to rapidly create informative diagnostic plots enriched by the display of numerical and graphical elements with a high degree of customization using a simple settings spreadsheet. This article describes each feature of the AMGET package and illustrates how it allows users to utilize the powerful numerical routines of the ADAPT 5 package in a more efficient manner through the use of a simulated dataset and a simple pharmacokinetic model optimized using the maximum likelihood expectation maximization (MLEM) algorithm of ADAPT 5. PMID:23903464

  17. Emotional facial expressions reduce neural adaptation to face identity.

    PubMed

    Gerlicher, Anna M V; van Loon, Anouk M; Scholte, H Steven; Lamme, Victor A F; van der Leij, Andries R

    2014-05-01

    In human social interactions, facial emotional expressions are a crucial source of information. Repeatedly presented information typically leads to an adaptation of neural responses. However, processing seems sustained with emotional facial expressions. Therefore, we tested whether sustained processing of emotional expressions, especially threat-related expressions, would attenuate neural adaptation. Neutral and emotional expressions (happy, mixed and fearful) of same and different identity were presented at 3 Hz. We used electroencephalography to record the evoked steady-state visual potentials (ssVEP) and tested to what extent the ssVEP amplitude adapts to the same when compared with different face identities. We found adaptation to the identity of a neutral face. However, for emotional faces, adaptation was reduced, decreasing linearly with negative valence, with the least adaptation to fearful expressions. This short and straightforward method may prove to be a valuable new tool in the study of emotional processing. PMID:23512931

  18. Neural nets for adaptive filtering and adaptive pattern recognition

    SciTech Connect

    Widrow, B.; Winter, R.

    1988-03-01

    The fields of adaptive signal processing and adaptive neural networks have been developing independently but have that adaptive linear combiner (ALC) in common. With its inputs connected to a tapped delay line, the ALC becomes a key component of an adaptive filter. With its output connected to a quantizer, the ALC becomes an adaptive threshold element of adaptive neuron. Adaptive threshold elements, on the other hand, are the building blocks of neural networks. Today neural nets are the focus of widespread research interest. Areas of investigation include pattern recognition and trainable logic. Neural network systems have not yet had the commercial impact of adaptive filtering. The commonality of the ALC to adaptive signal processing and adaptive neural networks suggests the two fields have much to share with each other. This article describes practical applications of the ALC in signal processing and pattern recognition.

  19. Solar tomography adaptive optics.

    PubMed

    Ren, Deqing; Zhu, Yongtian; Zhang, Xi; Dou, Jiangpei; Zhao, Gang

    2014-03-10

    Conventional solar adaptive optics uses one deformable mirror (DM) and one guide star for wave-front sensing, which seriously limits high-resolution imaging over a large field of view (FOV). Recent progress toward multiconjugate adaptive optics indicates that atmosphere turbulence induced wave-front distortion at different altitudes can be reconstructed by using multiple guide stars. To maximize the performance over a large FOV, we propose a solar tomography adaptive optics (TAO) system that uses tomographic wave-front information and uses one DM. We show that by fully taking advantage of the knowledge of three-dimensional wave-front distribution, a classical solar adaptive optics with one DM can provide an extra performance gain for high-resolution imaging over a large FOV in the near infrared. The TAO will allow existing one-deformable-mirror solar adaptive optics to deliver better performance over a large FOV for high-resolution magnetic field investigation, where solar activities occur in a two-dimensional field up to 60'', and where the near infrared is superior to the visible in terms of magnetic field sensitivity.

  20. Adaptation and risk management

    SciTech Connect

    Preston, Benjamin L

    2011-01-01

    Adaptation assessment methods are compatible with the international risk management standard ISO:31000. Risk management approaches are increasingly being recommended for adaptation assessments at both national and local levels. Two orientations to assessments can commonly be identified: top-down and bottom-up, and prescriptive and diagnostic. Combinations of these orientations favor different types of assessments. The choice of orientation can be related to uncertainties in prediction and taking action, in the type of adaptation and in the degree of system stress. Adopting multiple viewpoints is to be encouraged, especially in complex situations. The bulk of current guidance material is consistent with top-down and predictive approaches, thus is most suitable for risk scoping and identification. Abroad range ofmaterial fromwithin and beyond the climate change literature can be used to select methods to be used in assessing and implementing adaptation. The framing of risk, correct formulation of the questions being investigated and assessment methodology are critical aspects of the scoping phase. Only when these issues have been addressed should be issue of specific methods and tools be addressed. The reorientation of adaptation from an assessment focused solely on anthropogenic climate change to broader issues of vulnerability/resilience, sustainable development and disaster risk, especially through a risk management framework, can draw from existing policy and management understanding in communities, professions and agencies, incorporating existing agendas, knowledge, risks, and issues they already face.

  1. Neuromuscular adaptation to actual and simulated weightlessness

    NASA Technical Reports Server (NTRS)

    Edgerton, V. R.; Roy, R. R.

    1994-01-01

    The chronic "unloading" of the neuromuscular system during spaceflight has detrimental functional and morphological effects. Changes in the metabolic and mechanical properties of the musculature can be attributed largely to the loss of muscle protein and the alteration in the relative proportion of the proteins in skeletal muscle, particularly in the muscles that have an antigravity function under normal loading conditions. These adaptations could result in decrements in the performance of routine or specialized motor tasks, both of which may be critical for survival in an altered gravitational field, i.e., during spaceflight and during return to 1 G. For example, the loss in extensor muscle mass requires a higher percentage of recruitment of the motor pools for any specific motor task. Thus, a faster rate of fatigue will occur in the activated muscles. These consequences emphasize the importance of developing techniques for minimizing muscle loss during spaceflight, at least in preparation for the return to 1 G after spaceflight. New insights into the complexity and the interactive elements that contribute to the neuromuscular adaptations to space have been gained from studies of the role of exercise and/or growth factors as countermeasures of atrophy. The present chapter illustrates the inevitable interactive effects of neural and muscular systems in adapting to space. It also describes the considerable progress that has been made toward the goal of minimizing the functional impact of the stimuli that induce the neuromuscular adaptations to space.

  2. Automated adaptive inference of phenomenological dynamical models

    PubMed Central

    Daniels, Bryan C.; Nemenman, Ilya

    2015-01-01

    Dynamics of complex systems is often driven by large and intricate networks of microscopic interactions, whose sheer size obfuscates understanding. With limited experimental data, many parameters of such dynamics are unknown, and thus detailed, mechanistic models risk overfitting and making faulty predictions. At the other extreme, simple ad hoc models often miss defining features of the underlying systems. Here we develop an approach that instead constructs phenomenological, coarse-grained models of network dynamics that automatically adapt their complexity to the available data. Such adaptive models produce accurate predictions even when microscopic details are unknown. The approach is computationally tractable, even for a relatively large number of dynamical variables. Using simulated data, it correctly infers the phase space structure for planetary motion, avoids overfitting in a biological signalling system and produces accurate predictions for yeast glycolysis with tens of data points and over half of the interacting species unobserved. PMID:26293508

  3. 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.

  4. Cardiovascular adaptation to spaceflight

    NASA Technical Reports Server (NTRS)

    Hargens, A. R.; Watenpaugh, D. E.

    1996-01-01

    This article reviews recent flight and ground-based studies of cardiovascular adaptation to spaceflight. Prominent features of microgravity exposure include loss of gravitational pressures, relatively low venous pressures, headward fluid shifts, plasma volume loss, and postflight orthostatic intolerance and reduced exercise capacity. Many of these short-term responses to microgravity extend themselves during long-duration microgravity exposure and may be explained by altered pressures (blood and tissue) and fluid balance in local tissues nourished by the cardiovascular system. In this regard, it is particularly noteworthy that tissues of the lower body (e.g., foot) are well adapted to local hypertension on Earth, whereas tissues of the upper body (e.g., head) are not as well adapted to increase in local blood pressure. For these and other reasons, countermeasures for long-duration flight should include reestablishment of higher, Earth-like blood pressures in the lower body.

  5. Cardiovascular adaptation to spaceflight

    NASA Technical Reports Server (NTRS)

    Charles, John B.; Lathers, Claire M.

    1991-01-01

    Data are presented on the rate of adaptation of the human cardiovascular system to conditions of spaceflight, with particular attention given to data obtained during spaceflight in the U.S. Space Shuttle Program. It is pointed out that many of the cardiovascular changes that occurred during spaceflights that lasted from 2 to 11 days can be traced directly to changes in the body fluid volume. The beneficial effects of a fluid loading countermeasure (oral rehydration) and of the supine body position on the heart rate during the spaceflight are demonstrated. It is noted that, after hours or a few days of spaceflight, a state of adaptation is reached, in which the subject is well adapted and appropriately hydrated for the weightless environment. However, the return to the normal gravity of the earth leaves the individual especially sensitive to orthostatic stress.

  6. Adaptation without Plasticity.

    PubMed

    Del Mar Quiroga, Maria; Morris, Adam P; Krekelberg, Bart

    2016-09-27

    Sensory adaptation is a phenomenon in which neurons are affected not only by their immediate input but also by the sequence of preceding inputs. In visual cortex, for example, neurons shift their preferred orientation after exposure to an oriented stimulus. This adaptation is traditionally attributed to plasticity. We show that a recurrent network generates tuning curve shifts observed in cat and macaque visual cortex, even when all synaptic weights and intrinsic properties in the model are fixed. This demonstrates that, in a recurrent network, adaptation on timescales of hundreds of milliseconds does not require plasticity. Given the ubiquity of recurrent connections, this phenomenon likely contributes to responses observed across cortex and shows that plasticity cannot be inferred solely from changes in tuning on these timescales. More broadly, our findings show that recurrent connections can endow a network with a powerful mechanism to store and integrate recent contextual information. PMID:27681421

  7. Adaptive cancellation techniques

    NASA Astrophysics Data System (ADS)

    1983-11-01

    An adaptive signal canceller has been evaluated for the enhancement of pulse signal reception during the transmission of a high power ECM jamming signal. The canceller design is based on the use of DRFM(Digital RF Memory) technology as part of an adaptive multiple tapped delay line. The study includes analysis of relationship of tap spacing and waveform bandwidth, survey of related documents in areas of sidelobe cancellers, transversal equalizers, and adaptive filters, and derivation of control equations and corresponding control processes. The simulation of overall processes included geometric analysis of the multibeam transmitting antenna, multiple reflection sources and the receiving antenna; waveforms, tap spacings and bandwidths; and alternate control algorithms. Conclusions are provided regarding practical system control algorithms, design characteristics and limitations.

  8. Adaptive structures. [for space applications

    NASA Technical Reports Server (NTRS)

    Wada, B. K.; Fanson, J. L.; Crawley, E. F.

    1990-01-01

    Current research in the field of advanced adaptive structures for space applications is reviewed. A classification of adaptive structures is proposed whereby such structures are subdivided into adaptive, sensory, controlled, active, and intelligent structures. The definition and properties of each type of adaptive structures are presented, and methods of structure control are discussed.

  9. Adaptive response modelling

    NASA Astrophysics Data System (ADS)

    Campa, Alessandro; Esposito, Giuseppe; Belli, Mauro

    Cellular response to radiation is often modified by a previous delivery of a small "priming" dose: a smaller amount of damage, defined by the end point being investigated, is observed, and for this reason the effect is called adaptive response. An improved understanding of this effect is essential (as much as for the case of the bystander effect) for a reliable radiation risk assessment when low dose irradiations are involved. Experiments on adaptive response have shown that there are a number of factors that strongly influence the occurrence (and the level) of the adaptation. In particular, priming doses and dose rates have to fall in defined ranges; the same is true for the time interval between the delivery of the small priming dose and the irradiation with the main, larger, dose (called in this case challenging dose). Different hypotheses can be formulated on the main mechanism(s) determining the adaptive response: an increased efficiency of DNA repair, an increased level of antioxidant enzymes, an alteration of cell cycle progression, a chromatin conformation change. An experimental clearcut evidence going definitely in the direction of one of these explanations is not yet available. Modelling can be done at different levels. Simple models, relating the amount of damage, through elementary differential equations, to the dose and dose rate experienced by the cell, are relatively easy to handle, and they can be modified to account for the priming irradiation. However, this can hardly be of decisive help in the explanation of the mechanisms, since each parameter of these models often incorporates in an effective way several cellular processes related to the response to radiation. In this presentation we show our attempts to describe adaptive response with models that explicitly contain, as a dynamical variable, the inducible adaptive agent. At a price of a more difficult treatment, this approach is probably more prone to give support to the experimental studies

  10. Adaptive Cruise Control (ACC)

    NASA Astrophysics Data System (ADS)

    Reif, Konrad

    Die adaptive Fahrgeschwindigkeitsregelung (ACC, Adaptive Cruise Control) ist eine Weiterentwicklung der konventionellen Fahrgeschwindigkeitsregelung, die eine konstante Fahrgeschwindigkeit einstellt. ACC überwacht mittels eines Radarsensors den Bereich vor dem Fahrzeug und passt die Geschwindigkeit den Gegebenheiten an. ACC reagiert auf langsamer vorausfahrende oder einscherende Fahrzeuge mit einer Reduzierung der Geschwindigkeit, sodass der vorgeschriebene Mindestabstand zum vorausfahrenden Fahrzeug nicht unterschritten wird. Hierzu greift ACC in Antrieb und Bremse ein. Sobald das vorausfahrende Fahrzeug beschleunigt oder die Spur verlässt, regelt ACC die Geschwindigkeit wieder auf die vorgegebene Sollgeschwindigkeit ein (Bild 1). ACC steht somit für eine Geschwindigkeitsregelung, die sich dem vorausfahrenden Verkehr anpasst.

  11. Adaptive management: Chapter 1

    USGS Publications Warehouse

    Allen, Craig R.; Garmestani, Ahjond S.; Allen, Craig R.; Garmestani, Ahjond S.

    2015-01-01

    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 management has explicit structure, including a careful elucidation of goals, identification of alternative management objectives and hypotheses of causation, and procedures for the collection of data followed by evaluation and reiteration. The process is iterative, and serves to reduce uncertainty, build knowledge and improve management over time in a goal-oriented and structured process.

  12. Learning and Domain Adaptation

    NASA Astrophysics Data System (ADS)

    Mansour, Yishay

    Domain adaptation is a fundamental learning problem where one wishes to use labeled data from one or several source domains to learn a hypothesis performing well on a different, yet related, domain for which no labeled data is available. This generalization across domains is a very significant challenge for many machine learning applications and arises in a variety of natural settings, including NLP tasks (document classification, sentiment analysis, etc.), speech recognition (speakers and noise or environment adaptation) and face recognition (different lighting conditions, different population composition).

  13. 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.

  14. Verification of Adaptive Systems

    SciTech Connect

    Pullum, Laura L; Cui, Xiaohui; Vassev, Emil; Hinchey, Mike; Rouff, Christopher; Buskens, Richard

    2012-01-01

    Adaptive systems are critical for future space and other unmanned and intelligent systems. Verification of these systems is also critical for their use in systems with potential harm to human life or with large financial investments. Due to their nondeterministic nature and extremely large state space, current methods for verification of software systems are not adequate to provide a high level of assurance for them. The combination of stabilization science, high performance computing simulations, compositional verification and traditional verification techniques, plus operational monitors, provides a complete approach to verification and deployment of adaptive systems that has not been used before. This paper gives an overview of this approach.

  15. Saccade adaptation in autism and Asperger's disorder.

    PubMed

    Johnson, B P; Rinehart, N J; White, O; Millist, L; Fielding, J

    2013-07-23

    Autism and Asperger's disorder (AD) are neurodevelopmental disorders primarily characterized by deficits in social interaction and communication, however motor coordination deficits are increasingly recognized as a prevalent feature of these conditions. Although it has been proposed that children with autism and AD may have difficulty utilizing visual feedback during motor learning tasks, this has not been directly examined. Significantly, changes within the cerebellum, which is implicated in motor learning, are known to be more pronounced in autism compared to AD. We used the classic double-step saccade adaptation paradigm, known to depend on cerebellar integrity, to investigate differences in motor learning and the use of visual feedback in children aged 9-14 years with high-functioning autism (HFA; IQ>80; n=10) and AD (n=13). Performance was compared to age and IQ matched typically developing children (n=12). Both HFA and AD groups successfully adapted the gain of their saccades in response to perceived visual error, however the time course for adaptation was prolonged in the HFA group. While a shift in saccade dynamics typically occurs during adaptation, we revealed aberrant changes in both HFA and AD groups. This study contributes to a growing body of evidence centrally implicating the cerebellum in ocular motor dysfunction in autism. Specifically, these findings collectively imply functional impairment of the cerebellar network and its inflow and outflow tracts that underpin saccade adaptation, with greater disturbance in HFA compared to AD.

  16. Complex adaptive behavior and dexterous action

    PubMed Central

    Harrison, Steven J.; Stergiou, Nicholas

    2016-01-01

    Dexterous action, as conceptualized by Bernstein in his influential ecological analysis of human behavior, is revealed in the ability to flexibly generate behaviors that are adaptively tailored to the demands of the context in which they are embedded. Conceived as complex adaptive behavior, dexterity depends upon the qualities of robustness and degeneracy, and is supported by the functional complexity of the agent-environment system. Using Bernstein’s and Gibson’s ecological analyses of behavior situated in natural environments as conceptual touchstones, we consider the hypothesis that complex adaptive behavior capitalizes upon general principles of self-organization. Here, we outline a perspective in which the complex interactivity of nervous-system, body, and environment is revealed as an essential resource for adaptive behavior. From this perspective, we consider the implications for interpreting the functionality and dysfunctionality of human behavior. This paper demonstrates that, optimal variability, the topic of this special issue, is a logical consequence of interpreting the functionality of human behavior as complex adaptive behavior. PMID:26375932

  17. Physiological Self-Regulation and Adaptive Automation

    NASA Technical Reports Server (NTRS)

    Prinzell, Lawrence J.; Pope, Alan T.; Freeman, Frederick G.

    2007-01-01

    Adaptive automation has been proposed as a solution to current problems of human-automation interaction. Past research has shown the potential of this advanced form of automation to enhance pilot engagement and lower cognitive workload. However, there have been concerns voiced regarding issues, such as automation surprises, associated with the use of adaptive automation. This study examined the use of psychophysiological self-regulation training with adaptive automation that may help pilots deal with these problems through the enhancement of cognitive resource management skills. Eighteen participants were assigned to 3 groups (self-regulation training, false feedback, and control) and performed resource management, monitoring, and tracking tasks from the Multiple Attribute Task Battery. The tracking task was cycled between 3 levels of task difficulty (automatic, adaptive aiding, manual) on the basis of the electroencephalogram-derived engagement index. The other two tasks remained in automatic mode that had a single automation failure. Those participants who had received self-regulation training performed significantly better and reported lower National Aeronautics and Space Administration Task Load Index scores than participants in the false feedback and control groups. The theoretical and practical implications of these results for adaptive automation are discussed.

  18. Adaptive Holographic Fiber-Optic Interferometer

    NASA Astrophysics Data System (ADS)

    Kozhevnikov, Nikolai M.; Lipovskaya, Margarita J.

    1990-04-01

    Interaction of phase-modulated light beams in photorefractive local inertial responce media was analysed. Interaction of this type allows to registrate phase-modulated signals adaptively under low frequency phase disturbtion. The experiments on multimode fiber-optic interferometer with demodulation element based on photorefractive bacteriorhodopsin-doped polimer film are described. As the writing of dynamic phase hologram is an inertial process the signal fluctuations with the frequencies up to 100 Hz can be canceled. The hologram efficiencies are enough to registrate high frequency phase shifts ~10-4 radn.

  19. Robust Optimal Adaptive Control Method with Large Adaptive Gain

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan T.

    2009-01-01

    In the presence of large uncertainties, a control system needs to be able to adapt rapidly to regain performance. Fast adaptation is referred to the implementation of adaptive control with a large adaptive gain to reduce the tracking error rapidly. However, a large adaptive gain can lead to high-frequency oscillations which can adversely affect robustness of an adaptive control law. A new adaptive control modification is presented that can achieve robust adaptation with a large adaptive gain without incurring high-frequency oscillations as with the standard model-reference adaptive control. The modification is based on the minimization of the Y2 norm of the tracking error, which is formulated as an optimal control problem. The optimality condition is used to derive the modification using the gradient method. The optimal control modification results in a stable adaptation and allows a large adaptive gain to be used for better tracking while providing sufficient stability robustness. Simulations were conducted for a damaged generic transport aircraft with both standard adaptive control and the adaptive optimal control modification technique. The results demonstrate the effectiveness of the proposed modification in tracking a reference model while maintaining a sufficient time delay margin.

  20. Hybrid Adaptive Flight Control with Model Inversion Adaptation

    NASA Technical Reports Server (NTRS)

    Nguyen, Nhan

    2011-01-01

    This study investigates a hybrid adaptive flight control method as a design possibility for a flight control system that can enable an effective adaptation strategy to deal with off-nominal flight conditions. The hybrid adaptive control blends both direct and indirect adaptive control in a model inversion flight control architecture. The blending of both direct and indirect adaptive control provides a much more flexible and effective adaptive flight control architecture than that with either direct or indirect adaptive control alone. The indirect adaptive control is used to update the model inversion controller by an on-line parameter estimation of uncertain plant dynamics based on two methods. The first parameter estimation method is an indirect adaptive law based on the Lyapunov theory, and the second method is a recursive least-squares indirect adaptive law. The model inversion controller is therefore made to adapt to changes in the plant dynamics due to uncertainty. As a result, the modeling error is reduced that directly leads to a decrease in the tracking error. In conjunction with the indirect adaptive control that updates the model inversion controller, a direct adaptive control is implemented as an augmented command to further reduce any residual tracking error that is not entirely eliminated by the indirect adaptive control.

  1. Reflections on the Adaptive Designs Accelerating Promising Trials Into Treatments (ADAPT-IT) Process—Findings from a Qualitative Study

    PubMed Central

    Guetterman, Timothy C.; Fetters, Michael D.; Legocki, Laurie J.; Mawocha, Samkeliso; Barsan, William G.; Lewis, Roger J.; Berry, Donald A.; Meurer, William J.

    2015-01-01

    Context The context for this study was the Adaptive Designs Advancing Promising Treatments Into Trials (ADAPT-IT) project, which aimed to incorporate flexible adaptive designs into pivotal clinical trials and to conduct an assessment of the trial development process. Little research provides guidance to academic institutions in planning adaptive trials. Objectives The purpose of this qualitative study was to explore the perspectives and experiences of stakeholders as they reflected back about the interactive ADAPT-IT adaptive design development process, and to understand their perspectives regarding lessons learned about the design of the trials and trial development. Materials and methods We conducted semi-structured interviews with ten key stakeholders and observations of the process. We employed qualitative thematic text data analysis to reduce the data into themes about the ADAPT-IT project and adaptive clinical trials. Results The qualitative analysis revealed four themes: education of the project participants, how the process evolved with participant feedback, procedures that could enhance the development of other trials, and education of the broader research community. Discussion and conclusions While participants became more likely to consider flexible adaptive designs, additional education is needed to both understand the adaptive methodology and articulate it when planning trials. PMID:26622163

  2. Telepresence, time delay, and adaptation

    NASA Technical Reports Server (NTRS)

    Held, Richard; Durlach, Nathaniel

    1989-01-01

    Displays are now being used extensively throughout the society. More and more time is spent watching television, movies, computer screens, etc. Furthermore, in an increasing number of cases, the observer interacts with the display and plays the role of operator as well as observer. To a large extent, the normal behavior in the normal environment can also be thought of in these same terms. Taking liberties with Shakespeare, it might be said, all the world's a display and all the individuals in it are operators in and on the display. Within this general context of interactive display systems, a discussion is began with a conceptual overview of a particular class of such systems, namely, teleoperator systems. The notion is considered of telepresence and the factors that limit telepresence, including decorrelation between the: (1) motor output of the teleoperator as sensed directly via the kinesthetic/tactual system, and (2) the motor output of the teleoperator as sensed indirectly via feedback from the slave robot, i.e., via a visual display of the motor actions of the slave robot. Finally, the deleterious effect of time delay (a particular decorrelation) on sensory-motor adaptation (an important phenomenon related to telepresence) is examined.

  3. Multimodel inference and adaptive management

    USGS Publications Warehouse

    Rehme, S.E.; Powell, L.A.; Allen, C.R.

    2011-01-01

    Ecology is an inherently complex science coping with correlated variables, nonlinear interactions and multiple scales of pattern and process, making it difficult for experiments to result in clear, strong inference. Natural resource managers, policy makers, and stakeholders rely on science to provide timely and accurate management recommendations. However, the time necessary to untangle the complexities of interactions within ecosystems is often far greater than the time available to make management decisions. One method of coping with this problem is multimodel inference. Multimodel inference assesses uncertainty by calculating likelihoods among multiple competing hypotheses, but multimodel inference results are often equivocal. Despite this, there may be pressure for ecologists to provide management recommendations regardless of the strength of their study’s inference. We reviewed papers in the Journal of Wildlife Management (JWM) and the journal Conservation Biology (CB) to quantify the prevalence of multimodel inference approaches, the resulting inference (weak versus strong), and how authors dealt with the uncertainty. Thirty-eight percent and 14%, respectively, of articles in the JWM and CB used multimodel inference approaches. Strong inference was rarely observed, with only 7% of JWM and 20% of CB articles resulting in strong inference. We found the majority of weak inference papers in both journals (59%) gave specific management recommendations. Model selection uncertainty was ignored in most recommendations for management. We suggest that adaptive management is an ideal method to resolve uncertainty when research results in weak inference.

  4. Narrative, Adaptation, and Change

    ERIC Educational Resources Information Center

    Bateson, Mary Catherine

    2007-01-01

    This paper explores how individuals and communities orient themselves to the future by the way they story the past. There is a persistent tendency to think of such narratives as factual and therefore stable. The mutability of such narratives is actually a key adaptive characteristic, ranging from complete repression of individual traumas to public…

  5. Adaptive Sampling Designs.

    ERIC Educational Resources Information Center

    Flournoy, Nancy

    Designs for sequential sampling procedures that adapt to cumulative information are discussed. A familiar illustration is the play-the-winner rule in which there are two treatments; after a random start, the same treatment is continued as long as each successive subject registers a success. When a failure occurs, the other treatment is used until…

  6. Adaptive Behavior Guidelines.

    ERIC Educational Resources Information Center

    Ohio Association of Supervisors and Work-Study Coordinators.

    These guidelines were prepared to provide direction toward implementing a functional instruction curriculum that leads to independence and occupational skills for Ohio's developmentally handicapped and multihandicapped students. The curriculum uses a three-part definition of adaptive behavior, involving independent functioning, personal…

  7. Adapting to the Environment.

    ERIC Educational Resources Information Center

    Kovach, Amy L.

    2003-01-01

    Presents an activity on natural selection and how the peppered moth's adaptive values for their colors changed during the Industrial Revolution in Manchester, England, influencing their survival and ultimately affecting the survival of their offspring. Includes activity objectives. (Author/KHR)

  8. Telescope Adaptive Optics Code

    2005-07-28

    The Telescope AO Code has general adaptive optics capabilities plus specialized models for three telescopes with either adaptive optics or active optics systems. It has the capability to generate either single-layer or distributed Kolmogorov turbulence phase screens using the FFT. Missing low order spatial frequencies are added using the Karhunen-Loeve expansion. The phase structure curve is extremely dose to the theoreUcal. Secondly, it has the capability to simulate an adaptive optics control systems. The defaultmore » parameters are those of the Keck II adaptive optics system. Thirdly, it has a general wave optics capability to model the science camera halo due to scintillation from atmospheric turbulence and the telescope optics. Although this capability was implemented for the Gemini telescopes, the only default parameter specific to the Gemini telescopes is the primary mirror diameter. Finally, it has a model for the LSST active optics alignment strategy. This last model is highly specific to the LSST« less

  9. Adaptive sequential controller

    DOEpatents

    El-Sharkawi, Mohamed A.; Xing, Jian; Butler, Nicholas G.; Rodriguez, Alonso

    1994-01-01

    An adaptive sequential controller (50/50') for controlling a circuit breaker (52) or other switching device to substantially eliminate transients on a distribution line caused by closing and opening the circuit breaker. The device adaptively compensates for changes in the response time of the circuit breaker due to aging and environmental effects. A potential transformer (70) provides a reference signal corresponding to the zero crossing of the voltage waveform, and a phase shift comparator circuit (96) compares the reference signal to the time at which any transient was produced when the circuit breaker closed, producing a signal indicative of the adaptive adjustment that should be made. Similarly, in controlling the opening of the circuit breaker, a current transformer (88) provides a reference signal that is compared against the time at which any transient is detected when the circuit breaker last opened. An adaptive adjustment circuit (102) produces a compensation time that is appropriately modified to account for changes in the circuit breaker response, including the effect of ambient conditions and aging. When next opened or closed, the circuit breaker is activated at an appropriately compensated time, so that it closes when the voltage crosses zero and opens when the current crosses zero, minimizing any transients on the distribution line. Phase angle can be used to control the opening of the circuit breaker relative to the reference signal provided by the potential transformer.

  10. Adaptive Recreational Equipment.

    ERIC Educational Resources Information Center

    Schilling, Mary Lou, Ed.

    1983-01-01

    Designed for teachers interested in therapeutic recreation, the document lists sources of adaptive recreational equipment and their homemade counterparts. Brief descriptions for ordering or constructing recreational equipment for the visually impaired, poorly coordinated, physically impaired, and mentally retarded are given. Specific adaptations…

  11. Adapting Bulls to Florida

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The adaptation of bulls used for natural breeding purposes to the Gulf Coast region of the United States including all of Florida is an important topic. Nearly 40% of the U.S. cow/calf population resides in the Gulf Coast and Southeast. Thus, as A.I. is relatively rare, the number of bulls used for ...

  12. 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…

  13. Adaptive Physical Education.

    ERIC Educational Resources Information Center

    Muller, Robert M.

    GRADES OR AGES: Elementary grades. SUBJECT MATTER: Adaptive physical education. ORGANIZATION AND PHYSICAL APPEARANCE: The aims and objectives of the program and the screening procedure are described. Common postural deviations are identified and a number of congenital and other defects described. Details of the modified program are given. There is…

  14. Are Tibetans better adapted?

    PubMed

    Moore, L G; Curran-Everett, L; Droma, T S; Groves, B M; McCullough, R E; McCullough, R G; Sun, S F; Sutton, J R; Zamudio, S; Zhuang, J G

    1992-10-01

    Evidence is reviewed from our recent (1987-1991) investigations which demonstrate better high-altitude adaptation among Tibetans than in acclimatized newcomers or other lifelong high-altitude residents. Characteristics of oxygen transport contributing to the Tibetans' remarkable exercise performance are described.

  15. Adaptive Computerized Instruction.

    ERIC Educational Resources Information Center

    Ray, Roger D.; And Others

    1995-01-01

    Describes an artificially intelligent multimedia computerized instruction system capable of developing a conceptual image of what a student is learning while the student is learning it. It focuses on principles of learning and adaptive behavioral control systems theory upon which the system is designed and demonstrates multiple user modes.…

  16. Adaptation to abiotic conditions drives local adaptation in bacteria and viruses coevolving in heterogeneous environments.

    PubMed

    Gorter, Florien A; Scanlan, Pauline D; Buckling, Angus

    2016-02-01

    Parasite local adaptation, the greater performance of parasites on their local compared with foreign hosts, has important consequences for the maintenance of diversity and epidemiology. While the abiotic environment may significantly affect local adaptation, most studies to date have failed either to incorporate the effects of the abiotic environment, or to separate them from those of the biotic environment. Here, we tease apart biotic and abiotic components of local adaptation using the bacterium Pseudomonas fluorescens and its viral parasite bacteriophage Φ2. We coevolved replicate populations of bacteria and phages at three different temperatures, and determined their performance against coevolutionary partners from the same and different temperatures. Crucially, we measured performance at different assay temperatures, which allowed us to disentangle adaptation to biotic and abiotic habitat components. Our results show that bacteria and phages are more resistant and infectious, respectively, at the temperature at which they previously coevolved, confirming that local adaptation to abiotic conditions can play a crucial role in determining parasite infectivity and host resistance. Our work underlines the need to assess host-parasite interactions across multiple relevant abiotic environments, and suggests that microbial adaption to local temperatures can create ecological barriers to dispersal across temperature gradients.

  17. Transformational adaptation when incremental adaptations to climate change are insufficient

    PubMed Central

    Kates, Robert W.; Travis, William R.; Wilbanks, Thomas J.

    2012-01-01

    All human–environment systems adapt to climate and its natural variation. Adaptation to human-induced change in climate has largely been envisioned as increments of these adaptations intended to avoid disruptions of systems at their current locations. In some places, for some systems, however, vulnerabilities and risks may be so sizeable that they require transformational rather than incremental adaptations. Three classes of transformational adaptations are those that are adopted at a much larger scale, that are truly new to a particular region or resource system, and that transform places and shift locations. We illustrate these with examples drawn from Africa, Europe, and North America. Two conditions set the stage for transformational adaptation to climate change: large vulnerability in certain regions, populations, or resource systems; and severe climate change that overwhelms even robust human use systems. However, anticipatory transformational adaptation may be difficult to implement because of uncertainties about climate change risks and adaptation benefits, the high costs of transformational actions, and institutional and behavioral actions that tend to maintain existing resource systems and policies. Implementing transformational adaptation requires effort to initiate it and then to sustain the effort over time. In initiating transformational adaptation focusing events and multiple stresses are important, combined with local leadership. In sustaining transformational adaptation, it seems likely that supportive social contexts and the availability of acceptable options and resources for actions are key enabling factors. Early steps would include incorporating transformation adaptation into risk management and initiating research to expand the menu of innovative transformational adaptations. PMID:22509036

  18. Transformational adaptation when incremental adaptations to climate change are insufficient.

    PubMed

    Kates, Robert W; Travis, William R; Wilbanks, Thomas J

    2012-05-01

    All human-environment systems adapt to climate and its natural variation. Adaptation to human-induced change in climate has largely been envisioned as increments of these adaptations intended to avoid disruptions of systems at their current locations. In some places, for some systems, however, vulnerabilities and risks may be so sizeable that they require transformational rather than incremental adaptations. Three classes of transformational adaptations are those that are adopted at a much larger scale, that are truly new to a particular region or resource system, and that transform places and shift locations. We illustrate these with examples drawn from Africa, Europe, and North America. Two conditions set the stage for transformational adaptation to climate change: large vulnerability in certain regions, populations, or resource systems; and severe climate change that overwhelms even robust human use systems. However, anticipatory transformational adaptation may be difficult to implement because of uncertainties about climate change risks and adaptation benefits, the high costs of transformational actions, and institutional and behavioral actions that tend to maintain existing resource systems and policies. Implementing transformational adaptation requires effort to initiate it and then to sustain the effort over time. In initiating transformational adaptation focusing events and multiple stresses are important, combined with local leadership. In sustaining transformational adaptation, it seems likely that supportive social contexts and the availability of acceptable options and resources for actions are key enabling factors. Early steps would include incorporating transformation adaptation into risk management and initiating research to expand the menu of innovative transformational adaptations.

  19. Adaptation to Climate change Impacts on the Mediterranean islands' Agriculture (ADAPT2CLIMA)

    NASA Astrophysics Data System (ADS)

    Giannakopoulos, Christos; Karali, Anna; Lemesios, Giannis; Loizidou, Maria; Papadaskalopoulou, Christina; Moustakas, Konstantinos; Papadopoulou, Maria; Moriondo, Marco; Markou, Marinos; Hatziyanni, Eleni; Pasotti, Luigi

    2016-04-01

    Agriculture is one of the economic sectors that will likely be hit hardest by climate change, since it directly depends on climatic factors such as temperature, sunlight, and precipitation. The EU LIFE ADAPT2CLIMA (http://adapt2clima.eu/en/) project aims to facilitate the development of adaptation strategies for agriculture by deploying and demonstrating an innovative decision support tool. The ADAPT2CLIMA tool will make it possible to simulate the impacts of climate change on crop production and the effectiveness of selected adaptation options in decreasing vulnerability to climate change in three Mediterranean islands, namely Crete (Greece), Sicily (Italy), and Cyprus. The islands were selected for two reasons: firstly, they figure among the most important cultivation areas at national level. Secondly, they exhibit similarities in terms of location (climate), size, climate change threats faced (coastal agriculture, own water resources), agricultural practices, and policy relevance. In particular, the tool will provide: i) climate change projections; ii) hydrological conditions related to agriculture: iii) a vulnerability assessment of selected crops; iv) an evaluation of the adaptation options identified. The project is expected to contribute significantly to increasing climate resilience of agriculture areas in Sicily, Cyprus and Crete as well as at EU and international level by: • Developing, implementing and demonstrating an innovative and interactive decision support tool (ADAPT2CLIMA tool) for adaptation planning in agriculture that estimates future climate change impacts on local water resources, as well as the climate change vulnerability of the agricultural crop production in the project areas; • Evaluating the technical and economic viability of the implementation of the ADAPT2CLIMA tool; • Developing climate change adaptation strategies for agriculture (including a monitoring plan) for the three project areas and presenting them to the competent

  20. Functional connectivity patterns reflect individual differences in conflict adaptation.

    PubMed

    Wang, Xiangpeng; Wang, Ting; Chen, Zhencai; Hitchman, Glenn; Liu, Yijun; Chen, Antao

    2015-04-01

    Individuals differ in the ability to utilize previous conflict information to optimize current conflict resolution, which is termed the conflict adaptation effect. Previous studies have linked individual differences in conflict adaptation to distinct brain regions. However, the network-based neural mechanisms subserving the individual differences of the conflict adaptation effect have not been studied. The present study employed a psychophysiological interaction (PPI) analysis with a color-naming Stroop task to examine this issue. The main results were as follows: (1) the anterior cingulate cortex (ACC)-seeded PPI revealed the involvement of the salience network (SN) in conflict adaptation, while the posterior parietal cortex (PPC)-seeded PPI revealed the engagement of the central executive network (CEN). (2) Participants with high conflict adaptation effect showed higher intra-CEN connectivity and lower intra-SN connectivity; while those with low conflict adaptation effect showed higher intra-SN connectivity and lower intra-CEN connectivity. (3) The PPC-centered intra-CEN connectivity positively predicted the conflict adaptation effect; while the ACC-centered intra-SN connectivity had a negative correlation with this effect. In conclusion, our data demonstrated that conflict adaptation is likely supported by the CEN and the SN, providing a new perspective on studying individual differences in conflict adaptation on the basis of large-scale networks. PMID:25721566

  1. Adaptive passive fathometer processing.

    PubMed

    Siderius, Martin; Song, Heechun; Gerstoft, Peter; Hodgkiss, William S; Hursky, Paul; Harrison, Chris

    2010-04-01

    Recently, a technique has been developed to image seabed layers using the ocean ambient noise field as the sound source. This so called passive fathometer technique exploits the naturally occurring acoustic sounds generated on the sea-surface, primarily from breaking waves. The method is based on the cross-correlation of noise from the ocean surface with its echo from the seabed, which recovers travel times to significant seabed reflectors. To limit averaging time and make this practical, beamforming is used with a vertical array of hydrophones to reduce interference from horizontally propagating noise. The initial development used conventional beamforming, but significant improvements have been realized using adaptive techniques. In this paper, adaptive methods for this process are described and applied to several data sets to demonstrate improvements possible as compared to conventional processing.

  2. Bacterial surface adaptation

    NASA Astrophysics Data System (ADS)

    Utada, Andrew

    2014-03-01

    Biofilms are structured multi-cellular communities that are fundamental to the biology and ecology of bacteria. Parasitic bacterial biofilms can cause lethal infections and biofouling, but commensal bacterial biofilms, such as those found in the gut, can break down otherwise indigestible plant polysaccharides and allow us to enjoy vegetables. The first step in biofilm formation, adaptation to life on a surface, requires a working knowledge of low Reynolds number fluid physics, and the coordination of biochemical signaling, polysaccharide production, and molecular motility motors. These crucial early stages of biofilm formation are at present poorly understood. By adapting methods from soft matter physics, we dissect bacterial social behavior at the single cell level for several prototypical bacterial species, including Pseudomonas aeruginosa and Vibrio cholerae.

  3. 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.

  4. Unconsciously triggered conflict adaptation.

    PubMed

    van Gaal, Simon; Lamme, Victor A F; Ridderinkhof, K Richard

    2010-01-01

    In conflict tasks such as the Stroop, the Eriksen flanker or the Simon task, it is generally observed that the detection of conflict in the current trial reduces the impact of conflicting information in the subsequent trial; a phenomenon termed conflict adaptation. This higher-order cognitive control function has been assumed to be restricted to cases where conflict is experienced consciously. In the present experiment we manipulated the awareness of conflict-inducing stimuli in a metacontrast masking paradigm to directly test this assumption. Conflicting response tendencies were elicited either consciously (through primes that were weakly masked) or unconsciously (strongly masked primes). We demonstrate trial-by-trial conflict adaptation effects after conscious as well as unconscious conflict, which could not be explained by direct stimulus/response repetitions. These findings show that unconscious information can have a longer-lasting influence on our behavior than previously thought and further stretch the functional boundaries of unconscious cognition. PMID:20634898

  5. Adaptive control for accelerators

    DOEpatents

    Eaton, Lawrie E.; Jachim, Stephen P.; Natter, Eckard F.

    1991-01-01

    An adaptive feedforward control loop is provided to stabilize accelerator beam loading of the radio frequency field in an accelerator cavity during successive pulses of the beam into the cavity. A digital signal processor enables an adaptive algorithm to generate a feedforward error correcting signal functionally determined by the feedback error obtained by a beam pulse loading the cavity after the previous correcting signal was applied to the cavity. Each cavity feedforward correcting signal is successively stored in the digital processor and modified by the feedback error resulting from its application to generate the next feedforward error correcting signal. A feedforward error correcting signal is generated by the digital processor in advance of the beam pulse to enable a composite correcting signal and the beam pulse to arrive concurrently at the cavity.

  6. 75 FR 57859 - Specially Adapted Housing and Special Home Adaptation

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-09-23

    ..., 2009, (74 FR 67145), VA proposed to amend its regulations pertaining to eligibility for specially... AFFAIRS 38 CFR Part 3 RIN 2900-AN21 Specially Adapted Housing and Special Home Adaptation AGENCY... housing and special home adaptation grants. This final rule incorporates certain provisions from...

  7. 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…

  8. Adaptive continuous twisting algorithm

    NASA Astrophysics Data System (ADS)

    Moreno, Jaime A.; Negrete, Daniel Y.; Torres-González, Victor; Fridman, Leonid

    2016-09-01

    In this paper, an adaptive continuous twisting algorithm (ACTA) is presented. For double integrator, ACTA produces a continuous control signal ensuring finite time convergence of the states to zero. Moreover, the control signal generated by ACTA compensates the Lipschitz perturbation in finite time, i.e. its value converges to the opposite value of the perturbation. ACTA also keeps its convergence properties, even in the case that the upper bound of the derivative of the perturbation exists, but it is unknown.

  9. Intelligent adaptive structures

    NASA Technical Reports Server (NTRS)

    Wada, Ben K.

    1990-01-01

    'Intelligent Adaptive Structures' (IAS) refers to structural systems whose geometric and intrinsic structural characteristics can be automatically changed to meet mission requirements with changing operational scenarios. An IAS is composed of actuators, sensors, and a control logic; these are integrated in a distributed fashion within the elements of the structure. The IAS concepts thus far developed for space antennas and other precision structures should be applicable to civil, marine, automotive, and aeronautical structural systems.

  10. 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.

  11. Adaptive optics ophthalmoscopy

    PubMed Central

    Roorda, Austin; Duncan, Jacque L.

    2016-01-01

    This review starts with a brief history and description of adaptive optics (AO) technology, followed by a showcase of the latest capabilities of AO systems for imaging the human retina and an extensive review of the literature on where AO is being used clinically. The review concludes with a discussion on future directions and guidance on usage and interpretation of images from AO systems for the eye. PMID:26973867

  12. Vestibulospinal adaptation to microgravity

    NASA Technical Reports Server (NTRS)

    Paloski, W. H.

    1998-01-01

    Human balance control is known to be transiently disrupted after spaceflight; however, the mechanisms responsible for postflight postural ataxia are still under investigation. In this report, we propose a conceptual model of vestibulospinal adaptation based on theoretical adaptive control concepts and supported by the results from a comprehensive study of balance control recovery after spaceflight. The conceptual model predicts that immediately after spaceflight the balance control system of a returning astronaut does not expect to receive gravity-induced afferent inputs and that descending vestibulospinal control of balance is disrupted until the central nervous system is able to cope with the newly available vestibular otolith information. Predictions of the model are tested using data from a study of the neurosensory control of balance in astronauts immediately after landing. In that study, the mechanisms of sensorimotor balance control were assessed under normal, reduced, and/or altered (sway-referenced) visual and somatosensory input conditions. We conclude that the adaptive control model accurately describes the neurobehavioral responses to spaceflight and that similar models of altered sensory, motor, or environmental constraints are needed clinically to predict responses that patients with sensorimotor pathologies may have to various visual-vestibular or changing stimulus environments.

  13. Scale adaptive compressive tracking.

    PubMed

    Zhao, Pengpeng; Cui, Shaohui; Gao, Min; Fang, Dan

    2016-01-01

    Recently, the compressive tracking (CT) method (Zhang et al. in Proceedings of European conference on computer vision, pp 864-877, 2012) has attracted much attention due to its high efficiency, but it cannot well deal with the scale changing objects due to its constant tracking box. To address this issue, in this paper we propose a scale adaptive CT approach, which adaptively adjusts the scale of tracking box with the size variation of the objects. Our method significantly improves CT in three aspects: Firstly, the scale of tracking box is adaptively adjusted according to the size of the objects. Secondly, in the CT method, all the compressive features are supposed independent and equal contribution to the classifier. Actually, different compressive features have different confidence coefficients. In our proposed method, the confidence coefficients of features are computed and used to achieve different contribution to the classifier. Finally, in the CT method, the learning parameter λ is constant, which will result in large tracking drift on the occasion of object occlusion or large scale appearance variation. In our proposed method, a variable learning parameter λ is adopted, which can be adjusted according to the object appearance variation rate. Extensive experiments on the CVPR2013 tracking benchmark demonstrate the superior performance of the proposed method compared to state-of-the-art tracking algorithms. PMID:27386298

  14. Multidimensional Adaptation in MAS Organizations.

    PubMed

    Alberola, Juan M; Julian, Vicente; Garcia-Fornes, Ana

    2013-04-01

    Organization adaptation requires determining the consequences of applying changes not only in terms of the benefits provided but also measuring the adaptation costs as well as the impact that these changes have on all of the components of the organization. In this paper, we provide an approach for adaptation in multiagent systems based on a multidimensional transition deliberation mechanism (MTDM). This approach considers transitions in multiple dimensions and is aimed at obtaining the adaptation with the highest potential for improvement in utility based on the costs of adaptation. The approach provides an accurate measurement of the impact of the adaptation since it determines the organization that is to be transitioned to as well as the changes required to carry out this transition. We show an example of adaptation in a service provider network environment in order to demonstrate that the measurement of the adaptation consequences taken by the MTDM improves the organization performance more than the other approaches.

  15. Risk-adaptive radiotherapy

    NASA Astrophysics Data System (ADS)

    Kim, Yusung

    Currently, there is great interest in integrating biological information into intensity-modulated radiotherapy (IMRT) treatment planning with the aim of boosting high-risk tumor subvolumes. Selective boosting of tumor subvolumes can be accomplished without violating normal tissue complication constraints using information from functional imaging. In this work we have developed a risk-adaptive optimization-framework that utilizes a nonlinear biological objective function. Employing risk-adaptive radiotherapy for prostate cancer, it is possible to increase the equivalent uniform dose (EUD) by up to 35.4 Gy in tumor subvolumes having the highest risk classification without increasing normal tissue complications. Subsequently, we have studied the impact of functional imaging accuracy, and found on the one hand that loss in sensitivity had a large impact on expected local tumor control, which was maximal when a low-risk classification for the remaining low risk PTV was chosen. While on the other hand loss in specificity appeared to have a minimal impact on normal tissue sparing. Therefore, it appears that in order to improve the therapeutic ratio a functional imaging technique with a high sensitivity, rather than specificity, is needed. Last but not least a comparison study between selective boosting IMRT strategies and uniform-boosting IMRT strategies yielding the same EUD to the overall PTV was carried out, and found that selective boosting IMRT considerably improves expected TCP compared to uniform-boosting IMRT, especially when lack of control of the high-risk tumor subvolumes is the cause of expected therapy failure. Furthermore, while selective boosting IMRT, using physical dose-volume objectives, did yield similar rectal and bladder sparing when compared its equivalent uniform-boosting IMRT plan, risk-adaptive radiotherapy, utilizing biological objective functions, did yield a 5.3% reduction in NTCP for the rectum. Hence, in risk-adaptive radiotherapy the

  16. Advanced Adaptive Optics Technology Development

    SciTech Connect

    Olivier, S

    2001-09-18

    The NSF Center for Adaptive Optics (CfAO) is supporting research on advanced adaptive optics technologies. CfAO research activities include development and characterization of micro-electro-mechanical systems (MEMS) deformable mirror (DM) technology, as well as development and characterization of high-resolution adaptive optics systems using liquid crystal (LC) spatial light modulator (SLM) technology. This paper presents an overview of the CfAO advanced adaptive optics technology development activities including current status and future plans.

  17. Smart Rehabilitation Devices: Part II – Adaptive Motion Control

    PubMed Central

    Dong, Shufang; Lu, Ke-Qian; Sun, J. Q.; Rudolph, Katherine

    2008-01-01

    This article presents a study of adaptive motion control of smart versatile rehabilitation devices using MR fluids. The device provides both isometric and isokinetic strength training and is reconfigurable for several human joints. Adaptive controls are developed to regulate resistance force based on the prescription of the therapist. Special consideration has been given to the human–machine interaction in the adaptive control that can modify the behavior of the device to account for strength gains or muscle fatigue of the human subject. PMID:18548131

  18. Bridging the Gap: Adaptive Games and Student-Centered VLEs

    NASA Astrophysics Data System (ADS)

    Del Blanco, Ángel; Torrente, Javier; Moreno-Ger, Pablo; Fernández-Manjón, Baltasar

    The widely used e-learning technology is facing new challenges such as how to produce student-centered systems that can be adapted to the needs of each student. Those objectives should be met in a standard compliant way to simplify general adoption. In this context, educational videogames are proposed as an ideal medium to facilitate adaptation and tracking of the students’ performance for assessment purposes. However, there are still barriers between the gaming and e-learning worlds preventing their mutual interaction. In this paper we propose a middleware to bridge this gap, integrating adaptive educational videogames in e-learning environments with a special focus on the ongoing standardization efforts.

  19. Emergent fields through adaptation and identity: overcoming social distance

    NASA Astrophysics Data System (ADS)

    Degennaro, Donna; Brown, Tiffany

    2009-03-01

    We examine the inseparability of one's environment with the elements of adaptation and identity. Specifically, we revisit the Project H.O.M.E. learning environment as we suggest that the entities of adaption and environment are not only binding, but also naturally in constant flux as they interact with each other. Contrary to nature, however, the social distance between the instructors and learners is the result of a human construct that often hinders adaptation and identity development. We address the factors that afforded participants overcoming social distance and ultimately cultivating a shift in the learning structure of Project H.O.M.E.

  20. A Genetic Incompatibility Accelerates Adaptation in Yeast.

    PubMed

    Bui, Duyen T; Dine, Elliot; Anderson, James B; Aquadro, Charles F; Alani, Eric E

    2015-07-01

    During mismatch repair (MMR) MSH proteins bind to mismatches that form as the result of DNA replication errors and recruit MLH factors such as Mlh1-Pms1 to initiate excision and repair steps. Previously, we identified a negative epistatic interaction involving naturally occurring polymorphisms in the MLH1 and PMS1 genes of baker's yeast. Here we hypothesize that a mutagenic state resulting from this negative epistatic interaction increases the likelihood of obtaining beneficial mutations that can promote adaptation to stress conditions. We tested this by stressing yeast strains bearing mutagenic (incompatible) and non-mutagenic (compatible) mismatch repair genotypes. Our data show that incompatible populations adapted more rapidly and without an apparent fitness cost to high salt stress. The fitness advantage of incompatible populations was rapid but disappeared over time. The fitness gains in both compatible and incompatible strains were due primarily to mutations in PMR1 that appeared earlier in incompatible evolving populations. These data demonstrate a rapid and reversible role (by mating) for genetic incompatibilities in accelerating adaptation in eukaryotes. They also provide an approach to link experimental studies to observational population genomics. PMID:26230253

  1. Mutation rates as adaptations.

    PubMed

    Maley, C

    1997-06-01

    In order to better understand life, it is helpful to look beyond the envelop of life as we know it. A simple model of coevolution was implemented with the addition of a gene for the mutation rate of the individual. This allowed the mutation rate itself to evolve in a lineage. The model shows that when the individuals interact in a sort of zero-sum game, the lineages maintain relatively high mutation rates. However, when individuals engage in interactions that have greater consequences for one individual in the interaction than the other, lineages tend to evolve relatively low mutation rates. This model suggests that one possible cause for differential mutation rates across genes may be the coevolutionary pressure of the various forms of interactions with other genes. PMID:9219670

  2. Adaptive evolution of animal toxin multigene families.

    PubMed

    Kordis, D; Gubensek, F

    2000-12-30

    Animal toxins comprise a diverse array of proteins that have a variety of biochemical and pharmacological functions. A large number of animal toxins are encoded by multigene families. From studies of several toxin multigene families at the gene level the picture is emerging that most have been functionally diversified by gene duplication and adaptive evolution. The number of pharmacological activities in most toxin multigene families results from their adaptive evolution. The molecular evolution of animal toxins has been analysed in some multigene families, at both the intraspecies and interspecies levels. In most toxin multigene families, the rate of non-synonymous to synonymous substitutions (dN/dS) is higher than one. Thus natural selection has acted to diversify coding sequences and consequently the toxin functions. The selection pressure for the rapid adaptive evolution of animal toxins is the need for quick immobilization of the prey in classical predator and prey interactions. Currently available evidence for adaptive evolution in animal toxin multigene families will be considered in this review.

  3. Food-chain length and adaptive foraging.

    PubMed

    Kondoh, Michio; Ninomiya, Kunihiko

    2009-09-01

    Food-chain length, the number of feeding links from the basal species to the top predator, is a key characteristic of biological communities. However, the determinants of food-chain length still remain controversial. While classical theory predicts that food-chain length should increase with increasing resource availability, empirical supports of this prediction are limited to those from simple, artificial microcosms. A positive resource availability-chain length relationship has seldom been observed in natural ecosystems. Here, using a theoretical model, we show that those correlations, or no relationships, may be explained by considering the dynamic food-web reconstruction induced by predator's adaptive foraging. More specifically, with foraging adaptation, the food-chain length becomes relatively invariant, or even decreases with increasing resource availability, in contrast to a non-adaptive counterpart where chain length increases with increasing resource availability; and that maximum chain length more sharply decreases with resource availability either when species richness is higher or potential link number is larger. The interactive effects of resource availability, adaptability and community complexity may explain the contradictory effects of resource availability in simple microcosms and larger ecosystems. The model also explains the recently reported positive effect of habitat size on food-chain length as a result of increased species richness and/or decreased connectance owing to interspecific spatial segregation.

  4. Rethinking adaptation for a 4°C world.

    PubMed

    Stafford Smith, Mark; Horrocks, Lisa; Harvey, Alex; Hamilton, Clive

    2011-01-13

    With weakening prospects of prompt mitigation, it is increasingly likely that the world will experience 4°C and more of global warming. In such a world, adaptation decisions that have long lead times or that have implications playing out over many decades become more uncertain and complex. Adapting to global warming of 4°C cannot be seen as a mere extrapolation of adaptation to 2°C; it will be a more substantial, continuous and transformative process. However, a variety of psychological, social and institutional barriers to adaptation are exacerbated by uncertainty and long timeframes, with the danger of immobilizing decision-makers. In this paper, we show how complexity and uncertainty can be reduced by a systematic approach to categorizing the interactions between decision lifetime, the type of uncertainty in the relevant drivers of change and the nature of adaptation response options. We synthesize a number of issues previously raised in the literature to link the categories of interactions to a variety of risk-management strategies and tactics. Such application could help to break down some barriers to adaptation and both simplify and better target adaptation decision-making. The approach needs to be tested and adopted rapidly. PMID:21115520

  5. Stochastic analysis of epidemics on adaptive time varying networks

    NASA Astrophysics Data System (ADS)

    Kotnis, Bhushan; Kuri, Joy

    2013-06-01

    Many studies investigating the effect of human social connectivity structures (networks) and human behavioral adaptations on the spread of infectious diseases have assumed either a static connectivity structure or a network which adapts itself in response to the epidemic (adaptive networks). However, human social connections are inherently dynamic or time varying. Furthermore, the spread of many infectious diseases occur on a time scale comparable to the time scale of the evolving network structure. Here we aim to quantify the effect of human behavioral adaptations on the spread of asymptomatic infectious diseases on time varying networks. We perform a full stochastic analysis using a continuous time Markov chain approach for calculating the outbreak probability, mean epidemic duration, epidemic reemergence probability, etc. Additionally, we use mean-field theory for calculating epidemic thresholds. Theoretical predictions are verified using extensive simulations. Our studies have uncovered the existence of an “adaptive threshold,” i.e., when the ratio of susceptibility (or infectivity) rate to recovery rate is below the threshold value, adaptive behavior can prevent the epidemic. However, if it is above the threshold, no amount of behavioral adaptations can prevent the epidemic. Our analyses suggest that the interaction patterns of the infected population play a major role in sustaining the epidemic. Our results have implications on epidemic containment policies, as awareness campaigns and human behavioral responses can be effective only if the interaction levels of the infected populace are kept in check.

  6. Attention modulates visual size adaptation.

    PubMed

    Kreutzer, Sylvia; Fink, Gereon R; Weidner, Ralph

    2015-01-01

    The current study determined in healthy subjects (n = 16) whether size adaptation occurs at early, i.e., preattentive, levels of processing or whether higher cognitive processes such as attention can modulate the illusion. To investigate this issue, bottom-up stimulation was kept constant across conditions by using a single adaptation display containing both small and large adapter stimuli. Subjects' attention was directed to either the large or small adapter stimulus by means of a luminance detection task. When attention was directed toward the small as compared to the large adapter, the perceived size of the subsequent target was significantly increased. Data suggest that different size adaptation effects can be induced by one and the same stimulus depending on the current allocation of attention. This indicates that size adaptation is subject to attentional modulation. These findings are in line with previous research showing that transient as well as sustained attention modulates visual features, such as contrast sensitivity and spatial frequency, and influences adaptation in other contexts, such as motion adaptation (Alais & Blake, 1999; Lankheet & Verstraten, 1995). Based on a recently suggested model (Pooresmaeili, Arrighi, Biagi, & Morrone, 2013), according to which perceptual adaptation is based on local excitation and inhibition in V1, we conclude that guiding attention can boost these local processes in one or the other direction by increasing the weight of the attended adapter. In sum, perceptual adaptation, although reflected in changes of neural activity at early levels (as shown in the aforementioned study), is nevertheless subject to higher-order modulation.

  7. Adaptive nonlinear flight control

    NASA Astrophysics Data System (ADS)

    Rysdyk, Rolf Theoduor

    1998-08-01

    Research under supervision of Dr. Calise and Dr. Prasad at the Georgia Institute of Technology, School of Aerospace Engineering. has demonstrated the applicability of an adaptive controller architecture. The architecture successfully combines model inversion control with adaptive neural network (NN) compensation to cancel the inversion error. The tiltrotor aircraft provides a specifically interesting control design challenge. The tiltrotor aircraft is capable of converting from stable responsive fixed wing flight to unstable sluggish hover in helicopter configuration. It is desirable to provide the pilot with consistency in handling qualities through a conversion from fixed wing flight to hover. The linear model inversion architecture was adapted by providing frequency separation in the command filter and the error-dynamics, while not exiting the actuator modes. This design of the architecture provides for a model following setup with guaranteed performance. This in turn allowed for convenient implementation of guaranteed handling qualities. A rigorous proof of boundedness is presented making use of compact sets and the LaSalle-Yoshizawa theorem. The analysis allows for the addition of the e-modification which guarantees boundedness of the NN weights in the absence of persistent excitation. The controller is demonstrated on the Generic Tiltrotor Simulator of Bell-Textron and NASA Ames R.C. The model inversion implementation is robustified with respect to unmodeled input dynamics, by adding dynamic nonlinear damping. A proof of boundedness of signals in the system is included. The effectiveness of the robustification is also demonstrated on the XV-15 tiltrotor. The SHL Perceptron NN provides a more powerful application, based on the universal approximation property of this type of NN. The SHL NN based architecture is also robustified with the dynamic nonlinear damping. A proof of boundedness extends the SHL NN augmentation with robustness to unmodeled actuator

  8. A Framework for Context-Aware Adaptation in Public Displays

    NASA Astrophysics Data System (ADS)

    Cardoso, Jorge C. S.; José, Rui

    Several approaches for context-aware public display systems exist but none has been able to bridge the gap between the myriad of possible interactive features of a display and adaptation rules for its content. In this paper, we propose a framework of digital footprints generated by the interaction with public displays that can be used as a means to dynamically characterise a place. We describe these footprints, how they can be generated and how they can be used by context-aware display systems to adapt to the social environment of a place.

  9. An Adaptive TVD Limiter

    NASA Astrophysics Data System (ADS)

    Jeng, Yih Nen; Payne, Uon Jan

    1995-05-01

    An adaptive TVD limiter, based on a limiter approximating the upper boundary of the TVD range and that of the third-order upwind TVD scheme, is developed in this work. The limiter switches to the comprressive limiter near a discontinuity, to the third-order TVD scheme's limiter in the smooth region, and to a weighted averaged scheme in the transition region between smooth and high gradient solutions. Numerical experiments show that the proposed scheme works very well for one-dimensional scalar equation problems but becomes less effective in one- and two-dimensional Euler equation problems. Further study is required for the two-dimensional scalar equation problems.

  10. Renal adaptation during hibernation.

    PubMed

    Jani, Alkesh; Martin, Sandra L; Jain, Swati; Keys, Daniel; Edelstein, Charles L

    2013-12-01

    Hibernators periodically undergo profound physiological changes including dramatic reductions in metabolic, heart, and respiratory rates and core body temperature. This review discusses the effect of hypoperfusion and hypothermia observed during hibernation on glomerular filtration and renal plasma flow, as well as specific adaptations in renal architecture, vasculature, the renin-angiotensin system, and upregulation of possible protective mechanisms during the extreme conditions endured by hibernating mammals. Understanding the mechanisms of protection against organ injury during hibernation may provide insights into potential therapies for organ injury during cold storage and reimplantation during transplantation.

  11. Adaptive Transfer Function Networks

    SciTech Connect

    Goulding, J.R. |

    1993-06-01

    Real-time pattern classification and time-series forecasting applications continue to drive artificial neural network (ANN) technology. As ANNs increase in complexity, the throughput of digital computer simulations decreases. A novel ANN, the Adaptive Transfer Function Network (ATF-Net), directly addresses the issue of throughput. ATF-Nets are global mapping equations generated by the superposition of ensembles of neurodes having arbitrary continuous functions receiving encoded input data. ATF-Nets may be implemented on parallel digital computers. An example is presented which illustrates a four-fold increase in computational throughput.

  12. Adaptive Transfer Function Networks

    SciTech Connect

    Goulding, J.R. Portland State Univ., OR . Dept. of Electrical Engineering)

    1993-01-01

    Real-time pattern classification and time-series forecasting applications continue to drive artificial neural network (ANN) technology. As ANNs increase in complexity, the throughput of digital computer simulations decreases. A novel ANN, the Adaptive Transfer Function Network (ATF-Net), directly addresses the issue of throughput. ATF-Nets are global mapping equations generated by the superposition of ensembles of neurodes having arbitrary continuous functions receiving encoded input data. ATF-Nets may be implemented on parallel digital computers. An example is presented which illustrates a four-fold increase in computational throughput.

  13. 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

  14. Reentry vehicle adaptive telemetry

    SciTech Connect

    Kidner, R.E.

    1993-09-01

    In RF telemetry (TM) the allowable RF bandwidth limits the amount of data in the telemetered data set. Typically the data set is less than ideal to accommodate all aspects of a test. In the case of diagnostic data, the compromise often leaves insufficient diagnostic data when problems occur. As a solution, intelligence was designed into a TM, allowing it to adapt to changing data requirements. To minimize the computational requirements for an intelligent TM, a fuzzy logic inference engine was developed. This reference engine was simulated on a PC and then loaded into a TM hardware package for final testing.

  15. Reentry vehicle adaptive telemetry

    NASA Astrophysics Data System (ADS)

    Kidner, R. E.

    1993-09-01

    In RF telemetry (TM) the allowable RF bandwidth limits the amount of data in the telemetered data set. Typically the data set is less than ideal to accommodate all aspects of a test. In the case of diagnostic data, the compromise often leaves insufficient diagnostic data when problems occur. As a solution, intelligence was designed into a TM allowing it to adapt to changing data requirements. To minimize the computational requirements for an intelligent TM, a fuzzy logic inference engine was developed. This reference engine was simulated on a PC and then loaded into a TM hardware package for final testing.

  16. Laser adaptive holographic hydrophone

    NASA Astrophysics Data System (ADS)

    Romashko, R. V.; Kulchin, Yu N.; Bezruk, M. N.; Ermolaev, S. A.

    2016-03-01

    A new type of a laser hydrophone based on dynamic holograms, formed in a photorefractive crystal, is proposed and studied. It is shown that the use of dynamic holograms makes it unnecessary to use complex optical schemes and systems for electronic stabilisation of the interferometer operating point. This essentially simplifies the scheme of the laser hydrophone preserving its high sensitivity, which offers the possibility to use it under a strong variation of the environment parameters. The laser adaptive holographic hydrophone implemented at present possesses the sensitivity at a level of 3.3 mV Pa-1 in the frequency range from 1 to 30 kHz.

  17. Visualization of adaptive mesh refinement data

    NASA Astrophysics Data System (ADS)

    Weber, Gunther H.; Hagen, Hans; Hamann, Bernd; Joy, Kenneth I.; Ligocki, Terry J.; Ma, Kwan-Liu; Shalf, John M.

    2001-05-01

    The complexity of physical phenomena often varies substantially over space and time. There can be regions where a physical phenomenon/quantity varies very little over a large extent. At the same time, there can be small regions where the same quantity exhibits highly complex variations. Adaptive mesh refinement (AMR) is a technique used in computational fluid dynamics to simulate phenomena with drastically varying scales concerning the complexity of the simulated variables. Using multiple nested grids of different resolutions, AMR combines the topological simplicity of structured-rectilinear grids, permitting efficient computational and storage, with the possibility to adapt grid resolutions in regions of complex behavior. We present methods for direct volume rendering of AMR data. Our methods utilize AMR grids directly for efficiency of the visualization process. We apply a hardware-accelerated rendering method to AMR data supporting interactive manipulation of color-transfer functions and viewing parameters. We also present a cell-projection-based rendering technique for AMR data.

  18. Host Sexual Dimorphism and Parasite Adaptation

    PubMed Central

    Duneau, David; Ebert, Dieter

    2012-01-01

    In species with separate sexes, parasite prevalence and disease expression is often different between males and females. This effect has mainly been attributed to sex differences in host traits, such as immune response. Here, we make the case for how properties of the parasites themselves can also matter. Specifically, we suggest that differences between host sexes in many different traits, such as morphology and hormone levels, can impose selection on parasites. This selection can eventually lead to parasite adaptations specific to the host sex more commonly encountered, or to differential expression of parasite traits depending on which host sex they find themselves in. Parasites adapted to the sex of the host in this way can contribute to differences between males and females in disease prevalence and expression. Considering those possibilities can help shed light on host–parasite interactions, and impact epidemiological and medical science. PMID:22389630

  19. Grid adaptation using chimera composite overlapping meshes

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Liou, Meng-Sing; Chow, Chuen-Yen

    1994-01-01

    The objective of this paper is to perform grid adaptation using composite overlapping meshes in regions of large gradient to accurately capture the salient features during computation. The chimera grid scheme, a multiple overset mesh technique, is used in combination with a Navier-Stokes solver. The numerical solution is first converged to a steady state based on an initial coarse mesh. Solution-adaptive enhancement is then performed by using a secondary fine grid system which oversets on top of the base grid in the high-gradient region, but without requiring the mesh boundaries to join in any special way. Communications through boundary interfaces between those separated grids are carried out using trilinear interpolation. Application to the Euler equations for shock reflections and to shock wave/boundary layer interaction problem are tested. With the present method, the salient features are well-resolved.

  20. Grid adaptation using Chimera composite overlapping meshes

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Liou, Meng-Sing; Chow, Chuen-Yen

    1993-01-01

    The objective of this paper is to perform grid adaptation using composite over-lapping meshes in regions of large gradient to capture the salient features accurately during computation. The Chimera grid scheme, a multiple overset mesh technique, is used in combination with a Navier-Stokes solver. The numerical solution is first converged to a steady state based on an initial coarse mesh. Solution-adaptive enhancement is then performed by using a secondary fine grid system which oversets on top of the base grid in the high-gradient region, but without requiring the mesh boundaries to join in any special way. Communications through boundary interfaces between those separated grids are carried out using tri-linear interpolation. Applications to the Euler equations for shock reflections and to a shock wave/boundary layer interaction problem are tested. With the present method, the salient features are well resolved.

  1. Grid adaption using Chimera composite overlapping meshes

    NASA Technical Reports Server (NTRS)

    Kao, Kai-Hsiung; Liou, Meng-Sing; Chow, Chuen-Yen

    1993-01-01

    The objective of this paper is to perform grid adaptation using composite over-lapping meshes in regions of large gradient to capture the salient features accurately during computation. The Chimera grid scheme, a multiple overset mesh technique, is used in combination with a Navier-Stokes solver. The numerical solution is first converged to a steady state based on an initial coarse mesh. Solution-adaptive enhancement is then performed by using a secondary fine grid system which oversets on top of the base grid in the high-gradient region, but without requiring the mesh boundaries to join in any special way. Communications through boundary interfaces between those separated grids are carried out using tri-linear interpolation. Applications to the Euler equations for shock reflections and to a shock wave/boundary layer interaction problem are tested. With the present method, the salient features are well resolved.

  2. Adaptive functional systems: Learning with chaos

    NASA Astrophysics Data System (ADS)

    Komarov, M. A.; Osipov, G. V.; Burtsev, M. S.

    2010-12-01

    We propose a new model of adaptive behavior that combines a winnerless competition principle and chaos to learn new functional systems. The model consists of a complex network of nonlinear dynamical elements producing sequences of goal-directed actions. Each element describes dynamics and activity of the functional system which is supposed to be a distributed set of interacting physiological elements such as nerve or muscle that cooperates to obtain certain goal at the level of the whole organism. During "normal" behavior, the dynamics of the system follows heteroclinic channels, but in the novel situation chaotic search is activated and a new channel leading to the target state is gradually created simulating the process of learning. The model was tested in single and multigoal environments and had demonstrated a good potential for generation of new adaptations.

  3. Adaptation in Collaborative Governance Regimes

    NASA Astrophysics Data System (ADS)

    Emerson, Kirk; Gerlak, Andrea K.

    2014-10-01

    Adaptation and the adaptive capacity of human and environmental systems have been of central concern to natural and social science scholars, many of whom characterize and promote the need for collaborative cross-boundary systems that are seen as flexible and adaptive by definition. Researchers who study collaborative governance systems in the public administration, planning and policy literature have paid less attention to adaptive capacity specifically and institutional adaptation in general. This paper bridges the two literatures and finds four common dimensions of capacity, including structural arrangements, leadership, knowledge and learning, and resources. In this paper, we focus on institutional adaptation in the context of collaborative governance regimes and try to clarify and distinguish collaborative capacity from adaptive capacity and their contributions to adaptive action. We posit further that collaborative capacities generate associated adaptive capacities thereby enabling institutional adaptation within collaborative governance regimes. We develop these distinctions and linkages between collaborative and adaptive capacities with the help of an illustrative case study in watershed management within the National Estuary Program.

  4. Adaptation in collaborative governance regimes.

    PubMed

    Emerson, Kirk; Gerlak, Andrea K

    2014-10-01

    Adaptation and the adaptive capacity of human and environmental systems have been of central concern to natural and social science scholars, many of whom characterize and promote the need for collaborative cross-boundary systems that are seen as flexible and adaptive by definition. Researchers who study collaborative governance systems in the public administration, planning and policy literature have paid less attention to adaptive capacity specifically and institutional adaptation in general. This paper bridges the two literatures and finds four common dimensions of capacity, including structural arrangements, leadership, knowledge and learning, and resources. In this paper, we focus on institutional adaptation in the context of collaborative governance regimes and try to clarify and distinguish collaborative capacity from adaptive capacity and their contributions to adaptive action. We posit further that collaborative capacities generate associated adaptive capacities thereby enabling institutional adaptation within collaborative governance regimes. We develop these distinctions and linkages between collaborative and adaptive capacities with the help of an illustrative case study in watershed management within the National Estuary Program.

  5. Web Delivery of Adaptive and Interactive Language Tutoring: Revisited

    ERIC Educational Resources Information Center

    Heift, Trude

    2016-01-01

    This commentary reconsiders the description and assessment of the design and implementation of "German Tutor," an Intelligent Language Tutoring System (ILTS) for learners of German as a foreign language, published in 2001. Based on our experience over the past 15 years with the design and real classroom use of an ILTS, we address a…

  6. Epistatic adaptive evolution of human color vision.

    PubMed

    Yokoyama, Shozo; Xing, Jinyi; Liu, Yang; Faggionato, Davide; Altun, Ahmet; Starmer, William T

    2014-12-01

    Establishing genotype-phenotype relationship is the key to understand the molecular mechanism of phenotypic adaptation. This initial step may be untangled by analyzing appropriate ancestral molecules, but it is a daunting task to recapitulate the evolution of non-additive (epistatic) interactions of amino acids and function of a protein separately. To adapt to the ultraviolet (UV)-free retinal environment, the short wavelength-sensitive (SWS1) visual pigment in human (human S1) switched from detecting UV to absorbing blue light during the last 90 million years. Mutagenesis experiments of the UV-sensitive pigment in the Boreoeutherian ancestor show that the blue-sensitivity was achieved by seven mutations. The experimental and quantum chemical analyses show that 4,008 of all 5,040 possible evolutionary trajectories are terminated prematurely by containing a dehydrated nonfunctional pigment. Phylogenetic analysis further suggests that human ancestors achieved the blue-sensitivity gradually and almost exclusively by epistasis. When the final stage of spectral tuning of human S1 was underway 45-30 million years ago, the middle and long wavelength-sensitive (MWS/LWS) pigments appeared and so-called trichromatic color vision was established by interprotein epistasis. The adaptive evolution of human S1 differs dramatically from orthologous pigments with a major mutational effect used in achieving blue-sensitivity in a fish and several mammalian species and in regaining UV vision in birds. These observations imply that the mechanisms of epistatic interactions must be understood by studying various orthologues in different species that have adapted to various ecological and physiological environments. PMID:25522367

  7. Epistatic Adaptive Evolution of Human Color Vision

    PubMed Central

    Yokoyama, Shozo; Xing, Jinyi; Liu, Yang; Faggionato, Davide; Altun, Ahmet; Starmer, William T.

    2014-01-01

    Establishing genotype-phenotype relationship is the key to understand the molecular mechanism of phenotypic adaptation. This initial step may be untangled by analyzing appropriate ancestral molecules, but it is a daunting task to recapitulate the evolution of non-additive (epistatic) interactions of amino acids and function of a protein separately. To adapt to the ultraviolet (UV)-free retinal environment, the short wavelength-sensitive (SWS1) visual pigment in human (human S1) switched from detecting UV to absorbing blue light during the last 90 million years. Mutagenesis experiments of the UV-sensitive pigment in the Boreoeutherian ancestor show that the blue-sensitivity was achieved by seven mutations. The experimental and quantum chemical analyses show that 4,008 of all 5,040 possible evolutionary trajectories are terminated prematurely by containing a dehydrated nonfunctional pigment. Phylogenetic analysis further suggests that human ancestors achieved the blue-sensitivity gradually and almost exclusively by epistasis. When the final stage of spectral tuning of human S1 was underway 45–30 million years ago, the middle and long wavelength-sensitive (MWS/LWS) pigments appeared and so-called trichromatic color vision was established by interprotein epistasis. The adaptive evolution of human S1 differs dramatically from orthologous pigments with a major mutational effect used in achieving blue-sensitivity in a fish and several mammalian species and in regaining UV vision in birds. These observations imply that the mechanisms of epistatic interactions must be understood by studying various orthologues in different species that have adapted to various ecological and physiological environments. PMID:25522367

  8. Epistatic adaptive evolution of human color vision.

    PubMed

    Yokoyama, Shozo; Xing, Jinyi; Liu, Yang; Faggionato, Davide; Altun, Ahmet; Starmer, William T

    2014-12-01

    Establishing genotype-phenotype relationship is the key to understand the molecular mechanism of phenotypic adaptation. This initial step may be untangled by analyzing appropriate ancestral molecules, but it is a daunting task to recapitulate the evolution of non-additive (epistatic) interactions of amino acids and function of a protein separately. To adapt to the ultraviolet (UV)-free retinal environment, the short wavelength-sensitive (SWS1) visual pigment in human (human S1) switched from detecting UV to absorbing blue light during the last 90 million years. Mutagenesis experiments of the UV-sensitive pigment in the Boreoeutherian ancestor show that the blue-sensitivity was achieved by seven mutations. The experimental and quantum chemical analyses show that 4,008 of all 5,040 possible evolutionary trajectories are terminated prematurely by containing a dehydrated nonfunctional pigment. Phylogenetic analysis further suggests that human ancestors achieved the blue-sensitivity gradually and almost exclusively by epistasis. When the final stage of spectral tuning of human S1 was underway 45-30 million years ago, the middle and long wavelength-sensitive (MWS/LWS) pigments appeared and so-called trichromatic color vision was established by interprotein epistasis. The adaptive evolution of human S1 differs dramatically from orthologous pigments with a major mutational effect used in achieving blue-sensitivity in a fish and several mammalian species and in regaining UV vision in birds. These observations imply that the mechanisms of epistatic interactions must be understood by studying various orthologues in different species that have adapted to various ecological and physiological environments.

  9. Classifying climate change adaptation frameworks

    NASA Astrophysics Data System (ADS)

    Armstrong, Jennifer

    2014-05-01

    Complex socio-ecological demographics are factors that must be considered when addressing adaptation to the potential effects of climate change. As such, a suite of deployable climate change adaptation frameworks is necessary. Multiple frameworks that are required to communicate the risks of climate change and facilitate adaptation. Three principal adaptation frameworks have emerged from the literature; Scenario - Led (SL), Vulnerability - Led (VL) and Decision - Centric (DC). This study aims to identify to what extent these adaptation frameworks; either, planned or deployed are used in a neighbourhood vulnerable to climate change. This work presents a criterion that may be used as a tool for identifying the hallmarks of adaptation frameworks and thus enabling categorisation of projects. The study focussed on the coastal zone surrounding the Sizewell nuclear power plant in Suffolk in the UK. An online survey was conducted identifying climate change adaptation projects operating in the study area. This inventory was analysed to identify the hallmarks of each adaptation project; Levels of dependency on climate model information, Metrics/units of analysis utilised, Level of demographic knowledge, Level of stakeholder engagement, Adaptation implementation strategies and Scale of adaptation implementation. The study found that climate change adaptation projects could be categorised, based on the hallmarks identified, in accordance with the published literature. As such, the criterion may be used to establish the matrix of adaptation frameworks present in a given area. A comprehensive summary of the nature of adaptation frameworks in operation in a locality provides a platform for further comparative analysis. Such analysis, enabled by the criterion, may aid the selection of appropriate frameworks enhancing the efficacy of climate change adaptation.

  10. Visuo-Vestibular Interactions

    NASA Technical Reports Server (NTRS)

    1997-01-01

    Session TA3 includes short reports covering: (1) Vestibulo-Oculomotor Interaction in Long-Term Microgravity; (2) Effects of Weightlessness on the Spatial Orientation of Visually Induced Eye Movements; (3) Adaptive Modification of the Three-Dimensional Vestibulo-Ocular Reflex during Prolonged Microgravity; (4) The Dynamic Change of Brain Potential Related to Selective Attention to Visual Signals from Left and Right Visual Fields; (5) Locomotor Errors Caused by Vestibular Suppression; and (6) A Novel, Image-Based Technique for Three-Dimensional Eye Measurement.

  11. Adaptive RED algorithm based on minority game

    NASA Astrophysics Data System (ADS)

    Wei, Jiaolong; Lei, Ling; Qian, Jingjing

    2007-11-01

    With more and more applications appearing and the technology developing in the Internet, only relying on terminal system can not satisfy the complicated demand of QoS network. Router mechanisms must be participated into protecting responsive flows from the non-responsive. Routers mainly use active queue management mechanism (AQM) to avoid congestion. In the point of interaction between the routers, the paper applies minority game to describe the interaction of the users and observes the affection on the length of average queue. The parameters α, β of ARED being hard to confirm, adaptive RED based on minority game can depict the interactions of main body and amend the parameter α, β of ARED to the best. Adaptive RED based on minority game optimizes ARED and realizes the smoothness of average queue length. At the same time, this paper extends the network simulator plat - NS by adding new elements. Simulation has been implemented and the results show that new algorithm can reach the anticipative objects.

  12. Axioms of adaptivity

    PubMed Central

    Carstensen, C.; Feischl, M.; Page, M.; Praetorius, D.

    2014-01-01

    This paper aims first at a simultaneous axiomatic presentation of the proof of optimal convergence rates for adaptive finite element methods and second at some refinements of particular questions like the avoidance of (discrete) lower bounds, inexact solvers, inhomogeneous boundary data, or the use of equivalent error estimators. Solely four axioms guarantee the optimality in terms of the error estimators. Compared to the state of the art in the temporary literature, the improvements of this article can be summarized as follows: First, a general framework is presented which covers the existing literature on optimality of adaptive schemes. The abstract analysis covers linear as well as nonlinear problems and is independent of the underlying finite element or boundary element method. Second, efficiency of the error estimator is neither needed to prove convergence nor quasi-optimal convergence behavior of the error estimator. In this paper, efficiency exclusively characterizes the approximation classes involved in terms of the best-approximation error and data resolution and so the upper bound on the optimal marking parameters does not depend on the efficiency constant. Third, some general quasi-Galerkin orthogonality is not only sufficient, but also necessary for the R-linear convergence of the error estimator, which is a fundamental ingredient in the current quasi-optimality analysis due to Stevenson 2007. Finally, the general analysis allows for equivalent error estimators and inexact solvers as well as different non-homogeneous and mixed boundary conditions. PMID:25983390

  13. Insect--plant adaptations.

    PubMed

    Southwood, T R

    1984-01-01

    The adaptation of insects to plants probably commenced in the early Permian period, though most current associations will be more recent. A major burst of adaptation must have followed the rise of the Angiosperms in the Cretaceous period, though some particular associations are as recent as this century. Living plants form a large proportion of the potential food in most habitats, though insects have had to overcome certain general hurdles to live and feed on them. Insects affect the reproduction and survival of plants, and thus the diversity of plant secondary chemicals may have evolved as a response. Where an insect species has a significant effect on a plant species that is its only host, coevolution may be envisaged. A spectacular example is provided by Heliconius butterflies and passion flower vines, studied by L.E. Gilbert and others. But such cases may be likened to 'vortices in the evolutionary stream': most plant species are influenced by a range of phytophagous insects so that selection will be for general defences--a situation termed diffuse coevolution. Evidence is presented on recent host-plant shifts to illustrate both the restrictions and the flexibility in current insect-plant associations.

  14. Insect--plant adaptations.

    PubMed

    Southwood, T R

    1984-01-01

    The adaptation of insects to plants probably commenced in the early Permian period, though most current associations will be more recent. A major burst of adaptation must have followed the rise of the Angiosperms in the Cretaceous period, though some particular associations are as recent as this century. Living plants form a large proportion of the potential food in most habitats, though insects have had to overcome certain general hurdles to live and feed on them. Insects affect the reproduction and survival of plants, and thus the diversity of plant secondary chemicals may have evolved as a response. Where an insect species has a significant effect on a plant species that is its only host, coevolution may be envisaged. A spectacular example is provided by Heliconius butterflies and passion flower vines, studied by L.E. Gilbert and others. But such cases may be likened to 'vortices in the evolutionary stream': most plant species are influenced by a range of phytophagous insects so that selection will be for general defences--a situation termed diffuse coevolution. Evidence is presented on recent host-plant shifts to illustrate both the restrictions and the flexibility in current insect-plant associations. PMID:6559112

  15. The neuromechanical adaptations to Achilles tendinosis

    PubMed Central

    Chang, Yu-Jen; Kulig, Kornelia

    2015-01-01

    Human movement is initiated, controlled and executed in a hierarchical system including the nervous system, muscle and tendon. If a component in the loop loses its integrity, the entire system has to adapt to that deficiency. Achilles tendon, when degenerated, exhibits lower stiffness. This local mechanical deficit may be compensated for by an alteration of motor commands from the CNS. These modulations in motor commands from the CNS may lead to altered activation of the agonist, synergist and antagonist muscles. The present study aimed to investigate the effect of tendon degeneration on its mechanical properties, the neuromechanical behaviour of the surrounding musculature and the existence of the CNS modulation accompanying tendinosis. We hypothesize that the degenerated tendon will lead to diminished tissue mechanical properties and protective muscle activation patterns, as well as an up-regulated descending drive from the CNS. Strong evidence, as reported in the present study, indicates that tendinotic tendons are more compliant compared to healthy tendons. This unilateral involvement affected the neuromuscular control on the involved side but not the non-involved side. The muscle–tendon unit on the tendinotic side exhibits a lowered temporal efficiency, which leads to altered CNS control. The altered CNS control is then expressed as an adapted muscle activation pattern in the lower leg. Taken together, the findings of the present study illustrate the co-ordinated multi-level adaptations to a mechanical lesion in a tendon caused by pathology. Key points Achilles tendinosis is a localized degenerative musculoskeletal disorder that develops over a long period of time and leads to a compliant human Achilles tendon. We demonstrate that the compliant Achilles tendon elicited a series of adaptations from different levels of the human movement control system, such as the muscle–tendon interaction, CNS control and other muscles in the lower leg. These results

  16. Genetic structure and local adaptation of European wheat yellow rust populations: the role of temperature-specific adaptation

    PubMed Central

    Mboup, Mamadou; Bahri, Bochra; Leconte, Marc; De Vallavieille-Pope, Claude; Kaltz, Oliver; Enjalbert, Jérôme

    2012-01-01

    Environmental heterogeneity influences coevolution and local adaptation in host–parasite systems. This also concerns applied issues, because the geographic range of parasites may depend on their capacity to adapt to abiotic conditions. We studied temperature-specific adaptation in the wheat yellow/stripe rust pathogen, Puccinia striiformis f.sp. tritici (PST). Using laboratory experiments, PST isolates from northern and southern France were studied for their ability to germinate and to infect bread and durum wheat cultivars over a temperature gradient. Pathogen origin × temperature interactions for infectivity and germination rate suggest local adaptation to high- versus low-temperature regimes in south and north. Competition experiments in southern and northern field sites showed a general competitive advantage of southern over northern isolates. This advantage was particularly pronounced in the southern ‘home’ site, consistent with a model integrating laboratory infectivity and field temperature variation. The stable PST population structure in France likely reflects adaptation to ecological and genetic factors: persistence of southern PST may be due to adaptation to the warmer Mediterranean climate; and persistence of northern PST can be explained by adaptation to commonly used cultivars, for which southern isolates are lacking the relevant virulence genes. Thus, understanding the role of temperature-specific adaptations may help to improve forecast models or breeding programmes. PMID:25568055

  17. Adaptive EAGLE dynamic solution adaptation and grid quality enhancement

    NASA Technical Reports Server (NTRS)

    Luong, Phu Vinh; Thompson, J. F.; Gatlin, B.; Mastin, C. W.; Kim, H. J.

    1992-01-01

    In the effort described here, the elliptic grid generation procedure in the EAGLE grid code was separated from the main code into a subroutine, and a new subroutine which evaluates several grid quality measures at each grid point was added. The elliptic grid routine can now be called, either by a computational fluid dynamics (CFD) code to generate a new adaptive grid based on flow variables and quality measures through multiple adaptation, or by the EAGLE main code to generate a grid based on quality measure variables through static adaptation. Arrays of flow variables can be read into the EAGLE grid code for use in static adaptation as well. These major changes in the EAGLE adaptive grid system make it easier to convert any CFD code that operates on a block-structured grid (or single-block grid) into a multiple adaptive code.

  18. Adaptive differential pulse-code modulation with adaptive bit allocation

    NASA Astrophysics Data System (ADS)

    Frangoulis, E. D.; Yoshida, K.; Turner, L. F.

    1984-08-01

    Studies have been conducted regarding the possibility to obtain good quality speech at data rates in the range from 16 kbit/s to 32 kbit/s. The techniques considered are related to adaptive predictive coding (APC) and adaptive differential pulse-code modulation (ADPCM). At 16 kbit/s adaptive transform coding (ATC) has also been used. The present investigation is concerned with a new method of speech coding. The described method employs adaptive bit allocation, similar to that used in adaptive transform coding, together with adaptive differential pulse-code modulation, employing first-order prediction. The new method has the objective to improve the quality of the speech over that which can be obtained with conventional ADPCM employing a fourth-order predictor. Attention is given to the ADPCM-AB system, the design of a subjective test, and the application of switched preemphasis to ADPCM.

  19. Saccade Adaptation and Visual Uncertainty

    PubMed Central

    Souto, David; Gegenfurtner, Karl R.; Schütz, Alexander C.

    2016-01-01

    Visual uncertainty may affect saccade adaptation in two complementary ways. First, an ideal adaptor should take into account the reliability of visual information for determining the amount of correction, predicting that increasing visual uncertainty should decrease adaptation rates. We tested this by comparing observers' direction discrimination and adaptation rates in an intra-saccadic-step paradigm. Second, clearly visible target steps may generate a slower adaptation rate since the error can be attributed to an external cause, instead of an internal change in the visuo-motor mapping that needs to be compensated. We tested this prediction by measuring saccade adaptation to different step sizes. Most remarkably, we found little correlation between estimates of visual uncertainty and adaptation rates and no slower adaptation rates with more visible step sizes. Additionally, we show that for low contrast targets backward steps are perceived as stationary after the saccade, but that adaptation rates are independent of contrast. We suggest that the saccadic system uses different position signals for adapting dysmetric saccades and for generating a trans-saccadic stable visual percept, explaining that saccade adaptation is found to be independent of visual uncertainty. PMID:27252635

  20. Saccade Adaptation and Visual Uncertainty.

    PubMed

    Souto, David; Gegenfurtner, Karl R; Schütz, Alexander C

    2016-01-01

    Visual uncertainty may affect saccade adaptation in two complementary ways. First, an ideal adaptor should take into account the reliability of visual information for determining the amount of correction, predicting that increasing visual uncertainty should decrease adaptation rates. We tested this by comparing observers' direction discrimination and adaptation rates in an intra-saccadic-step paradigm. Second, clearly visible target steps may generate a slower adaptation rate since the error can be attributed to an external cause, instead of an internal change in the visuo-motor mapping that needs to be compensated. We tested this prediction by measuring saccade adaptation to different step sizes. Most remarkably, we found little correlation between estimates of visual uncertainty and adaptation rates and no slower adaptation rates with more visible step sizes. Additionally, we show that for low contrast targets backward steps are perceived as stationary after the saccade, but that adaptation rates are independent of contrast. We suggest that the saccadic system uses different position signals for adapting dysmetric saccades and for generating a trans-saccadic stable visual percept, explaining that saccade adaptation is found to be independent of visual uncertainty.

  1. Effects of incomplete adaptation and disturbance in adaptive control.

    NASA Technical Reports Server (NTRS)

    Lindorff, D. P.

    1972-01-01

    In this paper consideration is given to the effects of disturbance and incomplete parameter adaptation on the performance of adaptive control systems in which Liapunov theory is used in deriving the control law. A design equation for the bounded error is derived. It is further shown that parameters in the adaptive controller may not converge in the presence of disturbance unless the input signal has a rich enough frequency constant. Design examples are presented.

  2. Parallel computations and control of adaptive structures

    NASA Technical Reports Server (NTRS)

    Park, K. C.; Alvin, Kenneth F.; Belvin, W. Keith; Chong, K. P. (Editor); Liu, S. C. (Editor); Li, J. C. (Editor)

    1991-01-01

    The equations of motion for structures with adaptive elements for vibration control are presented for parallel computations to be used as a software package for real-time control of flexible space structures. A brief introduction of the state-of-the-art parallel computational capability is also presented. Time marching strategies are developed for an effective use of massive parallel mapping, partitioning, and the necessary arithmetic operations. An example is offered for the simulation of control-structure interaction on a parallel computer and the impact of the approach presented for applications in other disciplines than aerospace industry is assessed.

  3. Adaptive control of a robotic manipulator

    NASA Technical Reports Server (NTRS)

    Lewis, R. A.

    1977-01-01

    A control hierarchy for a robotic manipulator is described. The hierarchy includes perception and robot/environment interaction, the latter consisting of planning, path control, and terminal guidance loops. Environment-sensitive features include the provision of control governed by proximity, tactile, and visual sensors as well as the usual kinematic sensors. The manipulator is considered as part of an overall robot system. 'Adaptive control' in the present context refers to both the hierarchical nature of the control system and to its environment-responsive nature.

  4. Adaptive immunity to fungi.

    PubMed

    Verma, Akash; Wüthrich, Marcel; Deepe, George; Klein, Bruce

    2014-11-06

    Life-threatening fungal infections have risen sharply in recent years, owing to the advances and intensity of medical care that may blunt immunity in patients. This emerging crisis has created the growing need to clarify immune defense mechanisms against fungi with the ultimate goal of therapeutic intervention. We describe recent insights in understanding the mammalian immune defenses that are deployed against pathogenic fungi. We focus on adaptive immunity to the major medically important fungi and emphasize three elements that coordinate the response: (1) dendritic cells and subsets that are mobilized against fungi in various anatomical compartments; (2) fungal molecular patterns and their corresponding receptors that signal responses and shape the differentiation of T-cell subsets and B cells; and, ultimately (3) the effector and regulatory mechanisms that eliminate these invaders while constraining collateral damage to vital tissue. These insights create a foundation for the development of new, immune-based strategies for prevention or enhanced clearance of systemic fungal diseases.

  5. Adaptive immunity to fungi.

    PubMed

    Wüthrich, Marcel; Deepe, George S; Klein, Bruce

    2012-01-01

    Only a handful of the more than 100,000 fungal species on our planet cause disease in humans, yet the number of life-threatening fungal infections in patients has recently skyrocketed as a result of advances in medical care that often suppress immunity intensely. This emerging crisis has created pressing needs to clarify immune defense mechanisms against fungi, with the ultimate goal of therapeutic applications. Herein, we describe recent insights in understanding the mammalian immune defenses deployed against pathogenic fungi. The review focuses on adaptive immune responses to the major medically important fungi and emphasizes how dendritic cells and subsets in various anatomic compartments respond to fungi, recognize their molecular patterns, and signal responses that nurture and shape the differentiation of T cell subsets and B cells. Also emphasized is how the latter deploy effector and regulatory mechanisms that eliminate these nasty invaders while also constraining collateral damage to vital tissue.

  6. Adapting to complexity

    SciTech Connect

    Ruthen, R.

    1993-01-01

    Researchers at Santa Fe and elsewhere are just beginning to think about ways in which this framework and other new insights into complex adaptive systems can be proved. But Kauffman is confident that more robust models and further experiments will support a view of evolution that bridges living and nonliving systems. [open quotes]Every attempt to find something that is being maximized in evolution has always met with failure,[close quotes] Kauffman observes. [open quotes]Yet I have this feeling that there is something very general going on about how far from equilibrium systems have organized themselves. I don't know what that something is yet. But I can taste it.[close quotes

  7. Adaptive structures in space

    NASA Technical Reports Server (NTRS)

    Wada, B. K.; Fanson, J. L.; Chen, G. S.; Kuo, C.-P.

    1990-01-01

    Future NASA missions will need large (20 to 100m) structural systems with precision position (few microns to submicron) requirements. Data are presented which indicate the technology deficiencies of previous programs and analyses in current state-of-the-art structural design approaches, analytical prediction capabilities, control of structure capabilities, and ground test technologies to meet the performance requirements of future large precision structural systems. Test results on laboratory truss structures that demonstrate static displacement control, active damping, and on-orbit system identification are described. It is shown that for large precision structures, adaptive structures provide not only a means to achieve the precision and characteristics required in space, but can also significantly alleviate the ground test requirements for flight-validating the hardware.

  8. Adapting populations in space: clonal interference and genetic diversity

    NASA Astrophysics Data System (ADS)

    Weissman, Daniel; Barton, Nick

    Most species inhabit ranges much larger than the scales over which individuals interact. How does this spatial structure interact with adaptive evolution? We consider a simple model of a spatially-extended, adapting population and show that, while clonal interference severely limits the adaptation of purely asexual populations, even rare recombination is enough to allow adaptation at rates approaching those of well-mixed populations. We also find that the genetic hitchhiking produced by the adaptive alleles sweeping through the population has strange effects on the patterns of genetic diversity. In large spatial ranges, even low rates of adaptation cause all individuals in the population to rapidly trace their ancestry back to individuals living in a small region in the center of the range. The probability of fixation of an allele is thus strongly dependent on the allele's spatial location, with alleles from the center favored. Surprisingly, these effects are seen genome-wide (instead of being localized to the regions of the genome undergoing the sweeps). The spatial concentration of ancestry produces a power-law dependence of relatedness on distance, so that even individuals sampled far apart are likely to be fairly closely related, masking the underlying spatial structure.

  9. Team-Centered Perspective for Adaptive Automation Design

    NASA Technical Reports Server (NTRS)

    Prinzel, Lawrence J., III

    2003-01-01

    Automation represents a very active area of human factors research. The journal, Human Factors, published a special issue on automation in 1985. Since then, hundreds of scientific studies have been published examining the nature of automation and its interaction with human performance. However, despite a dramatic increase in research investigating human factors issues in aviation automation, there remain areas that need further exploration. This NASA Technical Memorandum describes a new area of automation design and research, called adaptive automation. It discusses the concepts and outlines the human factors issues associated with the new method of adaptive function allocation. The primary focus is on human-centered design, and specifically on ensuring that adaptive automation is from a team-centered perspective. The document shows that adaptive automation has many human factors issues common to traditional automation design. Much like the introduction of other new technologies and paradigm shifts, adaptive automation presents an opportunity to remediate current problems but poses new ones for human-automation interaction in aerospace operations. The review here is intended to communicate the philosophical perspective and direction of adaptive automation research conducted under the Aerospace Operations Systems (AOS), Physiological and Psychological Stressors and Factors (PPSF) project.

  10. Local plant adaptation across a subarctic elevational gradient.

    PubMed

    Kardol, Paul; De Long, Jonathan R; Wardle, David A

    2014-11-01

    Predicting how plants will respond to global warming necessitates understanding of local plant adaptation to temperature. Temperature may exert selective effects on plants directly, and also indirectly through environmental factors that covary with temperature, notably soil properties. However, studies on the interactive effects of temperature and soil properties on plant adaptation are rare, and the role of abiotic versus biotic soil properties in plant adaptation to temperature remains untested. We performed two growth chamber experiments using soils and Bistorta vivipara bulbil ecotypes from a subarctic elevational gradient (temperature range: ±3(°)C) in northern Sweden to disentangle effects of local ecotype, temperature, and biotic and abiotic properties of soil origin on plant growth. We found partial evidence for local adaption to temperature. Although soil origin affected plant growth, we did not find support for local adaptation to either abiotic or biotic soil properties, and there were no interactive effects of soil origin with ecotype or temperature. Our results indicate that ecotypic variation can be an important driver of plant responses to the direct effects of increasing temperature, while responses to covariation in soil properties are of a phenotypic, rather than adaptive, nature. PMID:26064553

  11. Language control in bilinguals: The adaptive control hypothesis

    PubMed Central

    Abutalebi, Jubin

    2013-01-01

    Speech comprehension and production are governed by control processes. We explore their nature and dynamics in bilingual speakers with a focus on speech production. Prior research indicates that individuals increase cognitive control in order to achieve a desired goal. In the adaptive control hypothesis we propose a stronger hypothesis: Language control processes themselves adapt to the recurrent demands placed on them by the interactional context. Adapting a control process means changing a parameter or parameters about the way it works (its neural capacity or efficiency) or the way it works in concert, or in cascade, with other control processes (e.g., its connectedness). We distinguish eight control processes (goal maintenance, conflict monitoring, interference suppression, salient cue detection, selective response inhibition, task disengagement, task engagement, opportunistic planning). We consider the demands on these processes imposed by three interactional contexts (single language, dual language, and dense code-switching). We predict adaptive changes in the neural regions and circuits associated with specific control processes. A dual-language context, for example, is predicted to lead to the adaptation of a circuit mediating a cascade of control processes that circumvents a control dilemma. Effective test of the adaptive control hypothesis requires behavioural and neuroimaging work that assesses language control in a range of tasks within the same individual. PMID:25077013

  12. 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).

  13. Adaptivity in Agent-Based Routing for Data Networks

    NASA Technical Reports Server (NTRS)

    Wolpert, David H.; Kirshner, Sergey; Merz, Chris J.; Turner, Kagan

    2000-01-01

    Adaptivity, both of the individual agents and of the interaction structure among the agents, seems indispensable for scaling up multi-agent systems (MAS s) in noisy environments. One important consideration in designing adaptive agents is choosing their action spaces to be as amenable as possible to machine learning techniques, especially to reinforcement learning (RL) techniques. One important way to have the interaction structure connecting agents itself be adaptive is to have the intentions and/or actions of the agents be in the input spaces of the other agents, much as in Stackelberg games. We consider both kinds of adaptivity in the design of a MAS to control network packet routing. We demonstrate on the OPNET event-driven network simulator the perhaps surprising fact that simply changing the action space of the agents to be better suited to RL can result in very large improvements in their potential performance: at their best settings, our learning-amenable router agents achieve throughputs up to three and one half times better than that of the standard Bellman-Ford routing algorithm, even when the Bellman-Ford protocol traffic is maintained. We then demonstrate that much of that potential improvement can be realized by having the agents learn their settings when the agent interaction structure is itself adaptive.

  14. [Individual adaptation strategy under extreme environmental conditions in humans].

    PubMed

    Soroko, S I; Aldasheva, A A

    2012-01-01

    Starting from the researches of I.M. Sechenov, I.P. Pavlov, A.A. Uchtomskii, the Russian psychophysiological school considers adaptation in connection with the biological and social origin of a man as the integrated, coordinated and self-controlled human organism's reaction to maintain the vital functions in the constantly changing environmental conditions. On the base of well-known systemic-dynamic methodology and scrutinizing the issue of man and environment interaction V.I. Medvedev added to the theory of man's adaptation the activity paradigm that enable to uncover the distinctive features of professional activities in various environment conditions. The theoretical and practical investigations based on the activity methodology gave the opportunity to find out the new principles of interaction between man and environment and on the strategy of adaptive behavior. From this investigations one could see that the main characteristic of interaction "man-environment" is that man represents proactive side, man simulate different adaptation strategies using both genetically-fixed and acquired mechanisms of adaptive behavior. PMID:23393785

  15. 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.

  16. Toward reflexive climate adaptation research

    DOE PAGES

    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

  17. Drug Interactions

    PubMed Central

    Tong Logan, Angela; Silverman, Andrew

    2012-01-01

    One of the most clinically significant complications related to the use of pharmacotherapy is the potential for drug-drug or drug-disease interactions. The gastrointestinal system plays a large role in the pharmacokinetic profile of most medications, and many medications utilized in gastroenterology have clinically significant drug interactions. This review will discuss the impact of alterations of intestinal pH, interactions mediated by phase I hepatic metabolism enzymes and P-glycoprotein, the impact of liver disease on drug metabolism, and interactions seen with commonly utilized gastrointestinal medications. PMID:22933873

  18. Pattern specificity of contrast adaptation

    PubMed Central

    Anstis, Stuart

    2014-01-01

    Contrast adaptation is specific to precisely localised edges, so that adapting to a flickering photograph makes one less sensitive to that same photograph, but not to similar photographs. When two low-contrast photos, A and B, are transparently superimposed, then adapting to a flickering high-contrast B leaves no net afterimage, but it makes B disappear from the A+B picture, which now simply looks like A. PMID:25165518

  19. Adaptive Mesh Refinement in CTH

    SciTech Connect

    Crawford, David

    1999-05-04

    This paper reports progress on implementing a new capability of adaptive mesh refinement into the Eulerian multimaterial shock- physics code CTH. The adaptivity is block-based with refinement and unrefinement occurring in an isotropic 2:1 manner. The code is designed to run on serial, multiprocessor and massive parallel platforms. An approximate factor of three in memory and performance improvements over comparable resolution non-adaptive calculations has-been demonstrated for a number of problems.

  20. Face Adaptation Effects Show Strong and Long-Lasting Transfer from Lab to More Ecological Contexts

    PubMed Central

    Carbon, Claus-Christian; Ditye, Thomas

    2012-01-01

    A review on recent experiments on figural face aftereffects reveals that adaptation effects in famous faces can last for hours up to days. Such adaptations seem to be highly reliable regarding test–retest designs as well as regarding the generalizability of adaptation across different adaptation routines and adaptations toward different kinds of facial properties. However, in the studies conducted so far, adaptation and the subsequent test phase were carried out in typical laboratory environments. Under these circumstances, it cannot be ruled out that the observed effects are, in fact, episodic learn–test compatibility effects. To test for ecological validity in adaptation effects we used an adaptation paradigm including environmental and social properties that differed between adaptation and test phase. With matched samples (n1 = n2 = 54) we found no main effects of experimental setting compatibility resulting from varying where the tests where conducted (environmental condition) nor any interaction with effects of stimulus compatibility resulting from varying stimulus similarity between adaptation and test phase using the same picture, different pictures of the same person, or different persons (transfer). This indicates that these adaptation effects are not artificial or merely lab-biased effects. Adaptation to face stimuli may document representational adaptations and tuning mechanisms that integrate new visual input in a very fast, reliable, and sustainable way. PMID:22291676