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Sample records for 600h hybrid synergy

  1. Evaluation of the 2008 Lexus LS 600H Hybrid Synergy Drive System

    SciTech Connect

    Burress, T.A.; Coomer, C.L.; Campbell, S.L.; Wereszczak, A.A.; Cunningham, J.P.; Marlino, L.D.; Seiber, L.E.; Lin, H.T.

    2009-01-15

    Subsystems of the 2008 Lexus 600h hybrid electric vehicle (HEV) were studied and tested as part of an intensive benchmarking effort carried out to produce detailed information concerning the current state of nondomestic alternative vehicle technologies. Feedback provided by benchmarking efforts is particularly useful to partners of the Vehicle Technologies collaborative research program as it is essential in establishing reasonable yet challenging programmatic goals which facilitate development of competitive technologies. The competitive nature set forth by the Vehicle Technologies program not only promotes energy independence and economic stability, it also advocates the advancement of alternative vehicle technologies in an overall global perspective. These technologies greatly facilitate the potential to reduce dependency on depleting natural resources and mitigate harmful impacts of transportation upon the environment.

  2. Engineering Synergy: Energy and Mass Transport in Hybrid Nanomaterials.

    PubMed

    Cho, Eun Seon; Coates, Nelson E; Forster, Jason D; Ruminski, Anne M; Russ, Boris; Sahu, Ayaskanta; Su, Norman C; Yang, Fan; Urban, Jeffrey J

    2015-10-14

    An emerging class of materials that are hybrid in nature is propelling a technological revolution in energy, touching many fundamental aspects of energy-generation, storage, and conservation. Hybrid materials combine classical inorganic and organic components to yield materials that manifest new functionalities unattainable in traditional composites or other related multicomponent materials, which have additive function only. This Research News article highlights the exciting materials design innovations that hybrid materials enable, with an eye toward energy-relevant applications involving charge, heat, and mass transport. PMID:25754355

  3. A Muscle Synergy-Inspired Adaptive Control Scheme for a Hybrid Walking Neuroprosthesis

    PubMed Central

    Alibeji, Naji A.; Kirsch, Nicholas Andrew; Sharma, Nitin

    2015-01-01

    A hybrid neuroprosthesis that uses an electric motor-based wearable exoskeleton and functional electrical stimulation (FES) has a promising potential to restore walking in persons with paraplegia. A hybrid actuation structure introduces effector redundancy, making its automatic control a challenging task because multiple muscles and additional electric motor need to be coordinated. Inspired by the muscle synergy principle, we designed a low dimensional controller to control multiple effectors: FES of multiple muscles and electric motors. The resulting control system may be less complex and easier to control. To obtain the muscle synergy-inspired low dimensional control, a subject-specific gait model was optimized to compute optimal control signals for the multiple effectors. The optimal control signals were then dimensionally reduced by using principal component analysis to extract synergies. Then, an adaptive feedforward controller with an update law for the synergy activation was designed. In addition, feedback control was used to provide stability and robustness to the control design. The adaptive-feedforward and feedback control structure makes the low dimensional controller more robust to disturbances and variations in the model parameters and may help to compensate for other time-varying phenomena (e.g., muscle fatigue). This is proven by using a Lyapunov stability analysis, which yielded semi-global uniformly ultimately bounded tracking. Computer simulations were performed to test the new controller on a 4-degree of freedom gait model. PMID:26734606

  4. Quasilinear analysis of ion Bernstein and lower hybrid waves synergy

    SciTech Connect

    Paoletti, F.; Shoucri, M.; Shkarofsky, A.; Bernabei, S.; Ono, M.

    1996-02-01

    A quasilinear analysis of the absorption of Ion Bernstein Wave (IBW) by the electron population of the plasma is performed. It uses an analytical calculation of the amplitude of the electric field along the trajectory to obtain the quasilinear diffusion coefficient. A numerical integration of the Fokker-Planck equation is performed together with the dynamical evolution of the IBW and Lower Hybrid Wave (LHW) ray trajectories. The damping of IBW is calculated on the distorted distribution function generated by the previous application of Lower Hybrid Current Drive (LHCD) which has bridged the {ital n}{sub {parallel}}-gap. This calculation is particularly relevant because of the IBW/LHW experiments on the Princeton Beta Experiment-Modified (PBX-M). {copyright} {ital 1996 American Institute of Physics.}

  5. Evaluation of the 2007 Toyota Camry Hybrid Synergy Drive System

    SciTech Connect

    Burress, T A; Coomer, C L; Campbell, S L; Seiber, L E; Marlino, L D; Staunton, R H; Cunningham, J P

    2008-04-15

    The U.S. Department of Energy (DOE) and American automotive manufacturers General Motors, Ford, and DaimlerChrysler began a five-year, cost-shared partnership in 1993. Currently, hybrid electric vehicle (HEV) research and development is conducted by DOE through its FreedomCAR and Vehicle Technologies (FCVT) program. The mission of the FCVT program is to develop more energy efficient and environmentally friendly highway transportation technologies. Program activities include research, development, demonstration, testing, technology validation, and technology transfer. These activities are aimed at developing technologies that can be domestically produced in a clean and cost-competitive manner. Under the FCVT program, support is provided through a three-phase approach [1] which is intended to: • Identify overall propulsion and vehicle-related needs by analyzing programmatic goals and reviewing industry’s recommendations and requirements, then develop the appropriate technical targets for systems, subsystems, and component research and development activities; • Develop and validate individual subsystems and components, including electric motors, emission control devices, battery systems, power electronics, accessories, and devices to reduce parasitic losses; and • Determine how well the components and subassemblies work together in a vehicle environment or as a complete propulsion system and whether the efficiency and performance targets at the vehicle level have been achieved. The research performed in this area will help remove technical and cost barriers to enable technology for use in such advanced vehicles as hybrid electric, plug-in hybrid electric, electric, and fuel-cell-powered vehicles.

  6. Evaluation of the 2010 Toyota Prius Hybrid Synergy Drive System

    SciTech Connect

    Burress, Timothy A; Campbell, Steven L; Coomer, Chester; Ayers, Curtis William; Wereszczak, Andrew A; Cunningham, Joseph Philip; Marlino, Laura D; Seiber, Larry Eugene; Lin, Hua-Tay

    2011-03-01

    Subsystems of the 2010 Toyota Prius hybrid electric vehicle (HEV) were studied and tested as part of an intensive benchmarking effort carried out to produce detailed information concerning the current state of nondomestic alternative vehicle technologies. Feedback provided by benchmarking efforts is particularly useful to partners of the Vehicle Technologies collaborative research program as it is essential in establishing reasonable yet challenging programmatic goals which facilitate development of competitive technologies. The competitive nature set forth by the Vehicle Technologies Program (VTP) not only promotes energy independence and economic stability, it also advocates the advancement of alternative vehicle technologies in an overall global perspective. These technologies greatly facilitate the potential to reduce dependency on depleting natural resources and mitigate harmful impacts of transportation upon the environment.

  7. Optimized calculation of the synergy conditions between electron cyclotron current drive and lower hybrid current drive on EAST

    NASA Astrophysics Data System (ADS)

    Wei, Wei; Bo-Jiang, Ding; Y, Peysson; J, Decker; Miao-Hui, Li; Xin-Jun, Zhang; Xiao-Jie, Wang; Lei, Zhang

    2016-01-01

    The optimized synergy conditions between electron cyclotron current drive (ECCD) and lower hybrid current drive (LHCD) with normal parameters of the EAST tokamak are studied by using the C3PO/LUKE code based on the understanding of the synergy mechanisms so as to obtain a higher synergistic current and provide theoretical reference for the synergistic effect in the EAST experiment. The dependences of the synergistic effect on the parameters of two waves (lower hybrid wave (LHW) and electron cyclotron wave (ECW)), including the radial position of the power deposition, the power value of the LH and EC waves, and the parallel refractive indices of the LHW (N∥) are presented and discussed. Project supported by the National Magnetic Confinement Fusion Science Program of China (Grant Nos. 2011GB102000, 2012GB103000, and 2013GB106001), the National Natural Science Foundation of China (Grant Nos. 11175206 and 11305211), the JSPS-NRF-NSFC A3 Foresight Program in the Field of Plasma Physics (Grant No. 11261140328), and the Fundamental Research Funds for the Central Universities of China (Grant No. JZ2015HGBZ0472).

  8. Dependence of synergy current driven by lower hybrid wave and electron cyclotron wave on the frequency and parallel refractive index of electron cyclotron wave for Tokamaks

    SciTech Connect

    Huang, J.; Chen, S. Y. Tang, C. J.

    2014-01-15

    The physical mechanism of the synergy current driven by lower hybrid wave (LHW) and electron cyclotron wave (ECW) in tokamaks is investigated using theoretical analysis and simulation methods in the present paper. Research shows that the synergy relationship between the two waves in velocity space strongly depends on the frequency ω and parallel refractive index N{sub //} of ECW. For a given spectrum of LHW, the parameter range of ECW, in which the synergy current exists, can be predicted by theoretical analysis, and these results are consistent with the simulation results. It is shown that the synergy effect is mainly caused by the electrons accelerated by both ECW and LHW, and the acceleration of these electrons requires that there is overlap of the resonance regions of the two waves in velocity space.

  9. Investigation of Synergy Between Electrochemical Capacitors, Flywheels, and Batteries in Hybrid Energy Storage for PV Systems

    SciTech Connect

    Miller, John; Sibley, Lewis, B.; Wohlgemuth, John

    1999-06-01

    This report describes the results of a study that investigated the synergy between electrochemical capacitors (ECs) and flywheels, in combination with each other and with batteries, as energy storage subsystems in photovoltaic (PV) systems. EC and flywheel technologies are described and the potential advantages and disadvantages of each in PV energy storage subsystems are discussed. Seven applications for PV energy storage subsystems are described along with the potential market for each of these applications. A spreadsheet model, which used the net present value method, was used to analyze and compare the costs over time of various system configurations based on flywheel models. It appears that a synergistic relationship exists between ECS and flywheels. Further investigation is recommended to quantify the performance and economic tradeoffs of this synergy and its effect on overall system costs.

  10. Prehension Synergies

    PubMed Central

    Zatsiorsky, Vladimir M.; Latash, Mark L.

    2010-01-01

    The precision grip requires the control of the normal and tangential forces exerted by the fingers as well as the control of the rotational equilibrium of the grasped object. Prehension synergies involve the conjoint changes in finger forces and moments during multifinger gripping tasks. Some of these adjustments are dictated by mechanics, whereas others are the result of a choice by the performer. PMID:15064652

  11. A Nanostructured Bifunctional platform for Sensing of Glucose Biomarker in Artificial Saliva: Synergy in hybrid Pt/Au surfaces.

    PubMed

    Raymundo-Pereira, Paulo A; Shimizu, Flávio M; Coelho, Dyovani; Piazzeta, Maria H O; Gobbi, Angelo L; Machado, Sergio A S; Oliveira, Osvaldo N

    2016-12-15

    We report on a bimetallic, bifunctional electrode where a platinum (Pt) surface was patterned with nanostructured gold (Au) fingers with different film thicknesses, which was functionalized with glucose oxidase (GOx) to yield a highly sensitive glucose biosensor. This was achieved by using selective adsorption of a self-assembled monolayer (SAM) onto Au fingers, which allowed GOx immobilization only onto the Au-SAM surface. This modified electrode was termed bifunctional because it allowed to simultaneously immobilize the biomolecule (GOx) on gold to catalyze glucose, and detect hydrogen peroxide on Pt sites. Optimized electrocatalytic activity was reached for the architecture Pt/Au-SAM/GOx with 50nm thickness of Au, where synergy between Pt and Au allowed for detection of hydrogen peroxide (H2O2) at a low applied potential (0V vs. Ag/AgCl). Detection was performed for H2O2 in the range between 4.7 and 102.7 nmol L(-1), with detection limit of 3.4×10(-9) mol L(-1) (3.4 nmol L(-1)) and an apparent Michaelis-Menten rate constant of 3.2×10(-6)molL(-1), which is considerably smaller than similar devices with monometallic electrodes. The methodology was validated by measuring glucose in artificial saliva, including in the presence of interferents. The synergy between Pt and Au was confirmed in electrochemical impedance spectroscopy measurements with an increased electron transfer, compared to bare Pt and Au electrodes. The approach for fabricating the reproducible bimetallic Pt/Au electrodes is entirely generic and may be explored for other types of biosensors and biodevices where advantage can be taken of the combination of the two metals. PMID:27399934

  12. A Nanostructured Bifunctional platform for Sensing of Glucose Biomarker in Artificial Saliva: Synergy in hybrid Pt/Au surfaces.

    PubMed

    Raymundo-Pereira, Paulo A; Shimizu, Flávio M; Coelho, Dyovani; Piazzeta, Maria H O; Gobbi, Angelo L; Machado, Sergio A S; Oliveira, Osvaldo N

    2016-12-15

    We report on a bimetallic, bifunctional electrode where a platinum (Pt) surface was patterned with nanostructured gold (Au) fingers with different film thicknesses, which was functionalized with glucose oxidase (GOx) to yield a highly sensitive glucose biosensor. This was achieved by using selective adsorption of a self-assembled monolayer (SAM) onto Au fingers, which allowed GOx immobilization only onto the Au-SAM surface. This modified electrode was termed bifunctional because it allowed to simultaneously immobilize the biomolecule (GOx) on gold to catalyze glucose, and detect hydrogen peroxide on Pt sites. Optimized electrocatalytic activity was reached for the architecture Pt/Au-SAM/GOx with 50nm thickness of Au, where synergy between Pt and Au allowed for detection of hydrogen peroxide (H2O2) at a low applied potential (0V vs. Ag/AgCl). Detection was performed for H2O2 in the range between 4.7 and 102.7 nmol L(-1), with detection limit of 3.4×10(-9) mol L(-1) (3.4 nmol L(-1)) and an apparent Michaelis-Menten rate constant of 3.2×10(-6)molL(-1), which is considerably smaller than similar devices with monometallic electrodes. The methodology was validated by measuring glucose in artificial saliva, including in the presence of interferents. The synergy between Pt and Au was confirmed in electrochemical impedance spectroscopy measurements with an increased electron transfer, compared to bare Pt and Au electrodes. The approach for fabricating the reproducible bimetallic Pt/Au electrodes is entirely generic and may be explored for other types of biosensors and biodevices where advantage can be taken of the combination of the two metals.

  13. Experimental and Theoretical Investigation of Synergy between Ion Bernstein and Lower Hybrid Waves in PBX-M

    SciTech Connect

    A. Cardinali; A. Post-Zwicker; F. Paoletti; S. Bernabei; S. Von Goeler; W. Tighe

    1998-02-01

    The synergistic behavior of lower hybrid and ion Bernstein waves on the Princeton Beta Experiment-Modified tokamak [Phys. Fluids B 2, 1271 (1990)] is experimentally studied using a 2-D hard X-ray camera. The hard X-ray bremsstrahlung emission from suprathermal electrons, generated with lower hybrid current drive, is enhanced during ion Bernstein wave power injection. This enhancement is observed in limited regions of space suggesting the formation of localized current channels. The effects on plasma electrons during combined application of these two types of waves are theoretically investigated using a quasilinear model. The numerical code simultaneously solves the 3-D (R, Z, {Phi}) toroidal wave equation for the electric field (in the WKBJ approximation) and the Fokker-Planck equation for the distribution function in two dimensions (v{sub parallel}, v{sub perpendicular}) with an added quasilinear diffusion coefficient. The radial profile of the non-inductively generated current density, the transmitted power traces and the total power damping curve are calculated. The beneficial effects of a combined utilization of ion Bernstein and lower hybrid waves on the current drive are emphasized. The numerical results are compared with the experimental observations.

  14. Experimental and theoretical investigation of local synergy between ion Bernstein and lower hybrid waves in the Princeton Beta Experiment{emdash}Modified

    SciTech Connect

    Paoletti, F.; Cardinali, A.; Bernabei, S.; Post-Zwicker, A.; Tighe, W.; Von Goeler, S.

    1999-03-01

    The local synergistic behavior of lower hybrid and ion Bernstein waves on the Princeton Beta Experiment-Modified tokamak [Phys. Fluids B {bold 2}, 1271 (1990)] is experimentally studied using a two-dimensional hard x-ray camera. The hard x-ray bremsstrahlung emission from suprathermal electrons, generated with lower hybrid current drive, is enhanced during ion Bernstein wave power injection. This enhancement is observed in limited regions of space, suggesting the formation of localized current channels. The effects on plasma electrons during combined application of these two types of waves are theoretically investigated using a quasilinear model. The numerical code simultaneously solves the three-dimensional (R,Z,{Phi}) torbidal wave equation for the electric field, in the Wentzel{endash}Kramers{endash}Brillouin{endash}Jeffrey approximation, and the Fokker{endash}Planck equation for the distribution function in two dimensions (v{sub {parallel}},v{sub {perpendicular}}) with an added quasilinear diffusion coefficient. The radial profile of the noninductively generated current density, the transmitted power traces, and the total power damping curve are calculated. The beneficial effects of a combined utilization of ion Bernstein and lower hybrid waves on the current drive are emphasized. The numerical results are compared with the experimental observations. {copyright} {ital 1999 American Institute of Physics.}

  15. Compliant Synergies in Locomotion

    NASA Astrophysics Data System (ADS)

    Travers, Matthew; Choset, Howie; Goldman @ Georgia Tech. Physics Department Collaboration

    Biological systems appear to have natural mechanisms that allow them to readily compensate for unexpected environmental variations when compared to their mechanical (i.e., robotic) counterparts. We hypothesize that the basis for this discrepancy is almost innate: what biology appears to be born with, built-in mechanisms for coordinating their many degrees of freedom, we struggle to ``program.'' We therefore look toward biology for inspiration. In particular, we are interested in kinematic synergies, low-dimensional representations that explicitly encode the underlying structure of how systems coordinate their internal degrees of freedom to achieve high-level tasks. In this work, we derive parametric representations of kinematic synergies and present a new compliant locomotion control framework that enables the parameters to be directly controlled in response to external disturbances. We present results of this framework implemented on two separate platforms, a snake-like and hexapod robot. Our results show that, using synergies, the locomotion control of these very different systems can be reduced to simple, extremely capable, and common forms, thus offering new insights into both robotic as well as biological locomotion in complex terrains.

  16. Neural bases of hand synergies

    PubMed Central

    Santello, Marco; Baud-Bovy, Gabriel; Jörntell, Henrik

    2013-01-01

    The human hand has so many degrees of freedom that it may seem impossible to control. A potential solution to this problem is “synergy control” which combines dimensionality reduction with great flexibility. With applicability to a wide range of tasks, this has become a very popular concept. In this review, we describe the evolution of the modern concept using studies of kinematic and force synergies in human hand control, neurophysiology of cortical and spinal neurons, and electromyographic (EMG) activity of hand muscles. We go beyond the often purely descriptive usage of synergy by reviewing the organization of the underlying neuronal circuitry in order to propose mechanistic explanations for various observed synergy phenomena. Finally, we propose a theoretical framework to reconcile important and still debated concepts such as the definitions of “fixed” vs. “flexible” synergies and mechanisms underlying the combination of synergies for hand control. PMID:23579545

  17. On theory of motor synergies.

    PubMed

    Neilson, Peter D; Neilson, Megan D

    2010-10-01

    Recently Latash, Scholz, and Schöner (2007) proposed a new view of motor synergies which stresses the idea that the nervous system does not seek a unique solution to eliminate redundant degrees of freedom but rather uses redundant sets of elemental variables that each correct for errors in the other to achieve a performance goal. This is an attractive concept because the resulting flexibility in the synergy also provides for performance stability. But although Latash et al. construe this concept as the consequence of a "neural organization" they do not say what that may be, nor how it comes about. Adaptive model theory (AMT) is a computational theory developed in our laboratory to account for observed sensory-motor behavior. It gives a detailed account, in terms of biologically feasible neural adaptive filters, of the formation of motor synergies and control of synergistic movements. This account is amplified here to show specifically how the processes within the AMT computational framework lead directly to the flexibility/stability ratios of Latash et al. (2007). Accordingly, we show that quantitative analyses of experimental data, based on the uncontrolled manifold method, do not and indeed cannot refute the possibility that the nervous system tries to find a unique (optimal) solution to eliminate redundant degrees of freedom. We show that the desirable interplay between flexibility and stability demonstrated by uncontrolled manifold analysis can be equally well achieved by a system that forms and deploys optimized motor synergies, as in AMT.

  18. Systematic synergy modeling: understanding drug synergy from a systems biology perspective.

    PubMed

    Chen, Di; Liu, Xi; Yang, Yiping; Yang, Hongjun; Lu, Peng

    2015-09-16

    Owing to drug synergy effects, drug combinations have become a new trend in combating complex diseases like cancer, HIV and cardiovascular diseases. However, conventional synergy quantification methods often depend on experimental dose-response data which are quite resource-demanding. In addition, these methods are unable to interpret the explicit synergy mechanism. In this review, we give representative examples of how systems biology modeling offers strategies toward better understanding of drug synergy, including the protein-protein interaction (PPI) network-based methods, pathway dynamic simulations, synergy network motif recognitions, integrative drug feature calculations, and "omic"-supported analyses. Although partially successful in drug synergy exploration and interpretation, more efforts should be put on a holistic understanding of drug-disease interactions, considering integrative pharmacology and toxicology factors. With a comprehensive and deep insight into the mechanism of drug synergy, systems biology opens a novel avenue for rational design of effective drug combinations.

  19. Synergy, redundancy and unnormalized Granger causality.

    PubMed

    Stramaglia, S; Angelini, L; Cortes, J M; Marinazzo, D

    2015-08-01

    We analyze by means of Granger causality the effect of synergy and redundancy in the inference (from time series data) of the information flow between subsystems of a complex network. Whilst fully conditioned Granger causality is not affected by synergy, the pairwise analysis fails to put in evidence synergetic effects. We show that maximization of the total Granger causality to a given target, over all the possible partitions of the set of driving variables, puts in evidence redundant multiplets of variables influencing the target, provided that an unnormalized definition of Granger causality is adopted. Along the same lines we also introduce a pairwise index of synergy (w.r.t. to information flow to a third variable) which is zero when two independent sources additively influence a common target; thus, this definition differs from previous definitions of synergy.

  20. Sensory synergy as environmental input integration

    PubMed Central

    Alnajjar, Fady; Itkonen, Matti; Berenz, Vincent; Tournier, Maxime; Nagai, Chikara; Shimoda, Shingo

    2015-01-01

    The development of a method to feed proper environmental inputs back to the central nervous system (CNS) remains one of the challenges in achieving natural movement when part of the body is replaced with an artificial device. Muscle synergies are widely accepted as a biologically plausible interpretation of the neural dynamics between the CNS and the muscular system. Yet the sensorineural dynamics of environmental feedback to the CNS has not been investigated in detail. In this study, we address this issue by exploring the concept of sensory synergy. In contrast to muscle synergy, we hypothesize that sensory synergy plays an essential role in integrating the overall environmental inputs to provide low-dimensional information to the CNS. We assume that sensor synergy and muscle synergy communicate using these low-dimensional signals. To examine our hypothesis, we conducted posture control experiments involving lateral disturbance with nine healthy participants. Proprioceptive information represented by the changes on muscle lengths were estimated by using the musculoskeletal model analysis software SIMM. Changes on muscles lengths were then used to compute sensory synergies. The experimental results indicate that the environmental inputs were translated into the two dimensional signals and used to move the upper limb to the desired position immediately after the lateral disturbance. Participants who showed high skill in posture control were found to be likely to have a strong correlation between sensory and muscle signaling as well as high coordination between the utilized sensory synergies. These results suggest the importance of integrating environmental inputs into suitable low-dimensional signals before providing them to the CNS. This mechanism should be essential when designing the prosthesis' sensory system to make the controller simpler. PMID:25628523

  1. Are muscle synergies useful for neural control?

    PubMed

    de Rugy, Aymar; Loeb, Gerald E; Carroll, Timothy J

    2013-01-01

    The observation that the activity of multiple muscles can be well approximated by a few linear synergies is viewed by some as a sign that such low-dimensional modules constitute a key component of the neural control system. Here, we argue that the usefulness of muscle synergies as a control principle should be evaluated in terms of errors produced not only in muscle space, but also in task space. We used data from a force-aiming task in two dimensions at the wrist, using an electromyograms (EMG)-driven virtual biomechanics technique that overcomes typical errors in predicting force from recorded EMG, to illustrate through simulation how synergy decomposition inevitably introduces substantial task space errors. Then, we computed the optimal pattern of muscle activation that minimizes summed-squared muscle activities, and demonstrated that synergy decomposition produced similar results on real and simulated data. We further assessed the influence of synergy decomposition on aiming errors (AEs) in a more redundant system, using the optimal muscle pattern computed for the elbow-joint complex (i.e., 13 muscles acting in two dimensions). Because EMG records are typically not available from all contributing muscles, we also explored reconstructions from incomplete sets of muscles. The redundancy of a given set of muscles had opposite effects on the goodness of muscle reconstruction and on task achievement; higher redundancy is associated with better EMG approximation (lower residuals), but with higher AEs. Finally, we showed that the number of synergies required to approximate the optimal muscle pattern for an arbitrary biomechanical system increases with task-space dimensionality, which indicates that the capacity of synergy decomposition to explain behavior depends critically on the scope of the original database. These results have implications regarding the viability of muscle synergy as a putative neural control mechanism, and also as a control algorithm to restore

  2. Examining the Synergy of Practice

    PubMed Central

    2014-01-01

    Public health nurses in Ireland are charged with conducting a home visit to every postnatal mother within 48 hours of hospital discharge. This represents the beginning of a long-term relationship, not only with the mother and newborn child but also with the family. This article fundamentally demonstrates the essential work of the public health nurse in promoting the health of the baby within a family. In this article, the expertise the public health nurse uses in the first visit is examined in the context of 3 competencies: communication, partnerships with the family, and partnerships with individual family members. This expertise provides the foundation for a long-term therapeutic relationship with the family to the essential benefit of the baby’s early childhood growth and developmental milestones. Consequently, the first postnatal visit by public health nursing in Ireland represents a synergy of practice, which provides the foundation for enduring family relationships focused on potentializing both individual family members’ health and the family as a dynamic unit. PMID:27335911

  3. Greenhouses and their humanizing synergies

    NASA Astrophysics Data System (ADS)

    Haeuplik-Meusburger, Sandra; Paterson, Carrie; Schubert, Daniel; Zabel, Paul

    2014-03-01

    Greenhouses in space will require advanced technical systems of automatic watering, soil-less cultivation, artificial lighting, and computerized observation of plants. Functions discussed for plants in space habitats include physical/health requirements and human psychology, social cohesion, as well as the complex sensorial benefits of plants for humans. The authors consider the role of plants in long-term space missions historically since 1971 (Salyut 1) and propose a set of priorities to be considered within the design requirements for greenhouses and constructed environments given a range of benefits associated with plant-human relationships. They cite recent research into the use of greenhouses in extreme environments to reveal the relative importance of greenhouses for people living in isolated locations. Additionally, they put forward hypotheses about where greenhouses might factor into several strata of human health. In a recent design-in-use study of astronauts' experiences in space habitats discussed in Architecture for Astronauts (Springer Press 2011) it was found that besides the basic advantages for life support there are clearly additional "side benefits" for habitability and physical wellbeing, and thus long-term mission success. The authors have composed several key theses regarding the need to promote plant-human relationships in space, including areas where synergy and symbiosis occur. They cite new comprehensive research into the early US Space Program to reveal where programmatic requirements could be added to space architecture to increase the less quantifiable benefits to astronauts of art, recreation, and poetic engagement with their existential condition of estrangement from the planet. Specifically in terms of the technological requirements, the authors propose the integration of a new greenhouse subsystem component into space greenhouses—the Mobile Plant Cultivation Subsystem—a portable, personal greenhouse that can be integrated

  4. A modular neural model of motor synergies.

    PubMed

    Byadarhaly, Kiran V; Perdoor, Mithun C; Minai, Ali A

    2012-08-01

    Animals such as reptiles, amphibians and mammals (including humans) are mechanically extremely complex. It has been estimated that the human body has between 500 and 1400 degrees of freedom! And yet, these animals can generate an infinite variety of very precise, complicated and goal-directed movements in continuously changing and uncertain environments. Understanding how this is achieved is of great interest to both biologists and engineers. There are essentially two questions that must be addressed: (1) What type of control strategy is used to handle the large number of degrees of freedom involved? and (2) How is this strategy instantiated in the substrate of neural and musculoskeletal elements comprising the animal bodies? The first question has been studied intensively for several decades, providing strong indications that, rather than using standard feedback control based on continuous tracking of desired trajectories, animals' movements emerge from the controlled combination of pre-configured movement primitives or synergies. These synergies represent coordinated activity patterns over groups of muscles, and can be triggered as a whole with controlled amplitude and temporal offset. Complex movements can thus be constructed from the appropriate combination of a relatively small number of synergies, greatly simplifying the control problem. Although experimental studies on animal movements have confirmed the existence of motor synergies, and their utility has been demonstrated in the control of fairly complex robots, their neural basis remains poorly understood. In this paper, we introduce a simple but plausible and general neural model for motor synergies based on the principle that these functional modules reflect the structural modularity of the underlying physical system. Using this model, we show that a small set of synergies selected through a redundancy-reduction principle can generate a rich motor repertoire in a model two-jointed arm system. We

  5. Modelling natural and artificial hands with synergies

    PubMed Central

    Bicchi, Antonio; Gabiccini, Marco; Santello, Marco

    2011-01-01

    We report on recent work in modelling the process of grasping and active touch by natural and artificial hands. Starting from observations made in human hands about the correlation of degrees of freedom in patterns of more frequent use (postural synergies), we consider the implications of a geometrical model accounting for such data, which is applicable to the pre-grasping phase occurring when shaping the hand before actual contact with the grasped object. To extend applicability of the synergy model to study force distribution in the actual grasp, we introduce a modified model including the mechanical compliance of the hand's musculotendinous system. Numerical results obtained by this model indicate that the same principal synergies observed from pre-grasp postural data are also fundamental in achieving proper grasp force distribution. To illustrate the concept of synergies in the dual domain of haptic sensing, we provide a review of models of how the complexity and heterogeneity of sensory information from touch can be harnessed in simplified, tractable abstractions. These abstractions are amenable to fast processing to enable quick reflexes as well as elaboration of high-level percepts. Applications of the synergy model to the design and control of artificial hands and tactile sensors are illustrated. PMID:21969697

  6. Hierarchies of Synergies in Human Movements

    PubMed Central

    Latash, Mark L.; Gorniak, Stacey; Zatsiorsky, Vladimir M.

    2009-01-01

    This brief review addresses the problem of motor redundancy, which exists at many levels of the neuromotor hierarchies involved in the production of voluntary movements. An approach to this problem is described based on the principle of abundance. This approach offers an operational definition for motor synergies using the framework of the uncontrolled manifold hypothesis. It is shown that hierarchical systems have inherent trade-offs between synergies at different control levels. These trade-offs have been demonstrated in experimental studies of human multi-finger pressing and prehension. They are likely to be present in other hierarchical systems, for example those involved in the control of large groups of muscles. The framework of the equilibrium-point hypothesis offers a physiologically based mechanism, which may form the basis for hierarchies of synergies. PMID:20354578

  7. Bilateral synergies in foot force production tasks.

    PubMed

    Sarabon, Nejc; Markovic, Goran; Mikulic, Pavle; Latash, Mark L

    2013-05-01

    We analysed the effects of task symmetry during bilateral accurate force production tasks performed by the two feet. In particular, we tested a hypothesis that bilateral deficit would lead to higher indices of synergies defined as co-varied adjustments in the two forces across trials that reduced total force variability. The subjects produced steady-state force followed by a quick force pulse into the target. The two feet could be acting both into plantar flexion and into dorsiflexion (symmetrical tasks), or in opposite directions (asymmetrical task). We used the framework of the uncontrolled manifold hypothesis to quantify two variance components, one of which did not change total force (V UCM), while the other did (V ORT). Synergy indices during the asymmetrical task were higher than in either symmetrical task. The difference was due to higher V UCM (compared to the symmetrical plantar flexion task) or lower V ORT (compared to the symmetrical dorsiflexion task). The synergy index showed a drop (anticipatory synergy adjustment, ASA) starting 100-150 ms prior to the force pulse initiation. The ASA tended to be shorter and of a smaller magnitude for the asymmetrical task. This is the first demonstration of bilateral synergies during accurate force production by the legs. We conclude that bilateral deficit has no or weak effects on two-leg synergies. The results fit the earlier introduced scheme with two groups of neural variables defining average performance of a redundant system and patterns of co-variation among its elemental variables, respectively. PMID:23568657

  8. Team Synergies in Sport: Theory and Measures

    PubMed Central

    Araújo, Duarte; Davids, Keith

    2016-01-01

    Individual players act as a coherent unit during team sports performance, forming a team synergy. A synergy is a collective property of a task-specific organization of individuals, such that the degrees of freedom of each individual in the system are coupled, enabling the degrees of freedom of different individuals to co-regulate each other. Here, we present an explanation for the emergence of such collective behaviors, indicating how these can be assessed and understood through the measurement of key system properties that exist, considering the contribution of each individual and beyond These include: to (i) dimensional compression, a process resulting in independent degree of freedom being coupled so that the synergy has fewer degrees of freedom than the set of components from which it arises; (ii) reciprocal compensation, if one element do not produce its function, other elements should display changes in their contributions so that task goals are still attained; (iii) interpersonal linkages, the specific contribution of each element to a group task; and (iv), degeneracy, structurally different components performing a similar, but not necessarily identical, function with respect to context. A primary goal of our analysis is to highlight the principles and tools required to understand coherent and dynamic team behaviors, as well as the performance conditions that make such team synergies possible, through perceptual attunement to shared affordances in individual performers. A key conclusion is that teams can be trained to perceive how to use and share specific affordances, explaining how individual’s behaviors self-organize into a group synergy. Ecological dynamics explanations of team behaviors can transit beyond mere ratification of sport performance, providing a comprehensive conceptual framework to guide the implementation of diagnostic measures by sport scientists, sport psychologists and performance analysts. Complex adaptive systems, synergies, group

  9. Family Synergy, A Variant Family Organization

    ERIC Educational Resources Information Center

    LaFollette, Patrick

    1975-01-01

    This article describes "Family Synergy" which is a non-profit organization for people interested in or exploring nontraditional marriage and family forms. It acts as a clearinghouse for the exchange of ideas and also provides a supportive community for people actually exploring these new lifestyles. (Author)

  10. IT Portfolio Selection and IT Synergy

    ERIC Educational Resources Information Center

    Cho, Woo Je

    2010-01-01

    This dissertation consists of three chapters. The primary objectives of this dissertation are: (1) to provide a methodological framework of IT (Information Technology) portfolio management, and (2) to identify the effect of IT synergy on IT portfolio selection of a firm. The first chapter presents a methodological framework for IT project…

  11. Exploring Synergy between Classic Mutagens and Antibiotics To Examine Mechanisms of Synergy and Antibiotic Action

    PubMed Central

    Song, Lisa Yun; D'Souza, Sara; Lam, Karen; Kang, Tina Manzhu

    2015-01-01

    We used classical mutagens in Gram-negative Escherichia coli to study synergies with different classes of antibiotics, test models of antibiotic mechanisms of action, and examine the basis of synergy. We used 4-nitroquinoline 1-oxide (4NQO), zebularine (ZEB), 5-azacytidine (5AZ), 2-aminopurine (2AP), and 5-bromodeoxyuridine (5BrdU) as mutagens (with bactericidal potency of 4NQO > ZEB > 5AZ > 2AP > 5BrdU) and vancomycin (VAN), ciprofloxacin (CPR), trimethoprim (TMP), gentamicin (GEN), tetracycline (TET), erythromycin (ERY), and chloramphenicol (CHL) as antibiotics. We detected the strongest synergies with 4NQO, an agent that oxidizes guanines and ultimately results in double-strand breaks when paired with the bactericidal antibiotics VAN, TMP, CPR, and GEN, but no synergies with the bacteriostatic antibiotics TET, ERY, and CHL. Each of the other mutagens displays synergies with the bactericidal antibiotics to various degrees that reflect their potencies, as well as with some of the other mutagens. The results support recent models showing that bactericidal antibiotics kill bacteria principally by ultimately generating more double-strand breaks than can be repaired. We discuss the synergies seen here and elsewhere as representing dose effects of not the proximal target damage but rather the ultimate resulting double-strand breaks. We also used the results of pairwise tests to place the classic mutagens into functional antibacterial categories within a previously defined drug interaction network. PMID:26711761

  12. Combining activated carbon adsorption with heterogeneous photocatalytic oxidation: lack of synergy for biologically treated greywater and tetraethylene glycol dimethyl ether.

    PubMed

    Gulyas, Holger; Argáez, Angel Santiago Oria; Kong, Fanzhuo; Jorge, Carlos Liriano; Eggers, Susanne; Otterpohl, Ralf

    2013-01-01

    The aim of the study was to evaluate whether the addition of activated carbon in the photocatalytic oxidation of biologically pretreated greywater and of a polar aliphatic compound gives synergy, as previously demonstrated with phenol. Photocatalytic oxidation kinetics were recorded with fivefold concentrated biologically pretreated greywater and with aqueous tetraethylene glycol dimethyl ether solutions using a UV lamp and the photocatalyst TiO2 P25 in the presence and the absence of powdered activated carbon. The synergy factor, SF, was quantified as the ratio of photocatalytic oxidation rate constant in the presence of powdered activated carbon to the rate constant without activated carbon. No synergy was observed for the greywater concentrate (SF approximately 1). For the aliphatic compound, tetraethylene glycol dimethyl ether, addition of activated carbon actually had an inhibiting effect on photocatalysis (SF < 1), while synergy was confirmed in reference experiments using aqueous phenol solutions. The absence of synergy for the greywater concentrate can be explained by low adsorbability of its organic constituents by activated carbon. Inhibition of the photocatalytic oxidation of tetraethylene glycol dimethyl ether by addition of powdered activated carbon was attributed to shading of the photocatalyst by the activated carbon particles. It was assumed that synergy in the hybrid process was limited to aromatic organics. Regardless of the lack of synergy in the case of biologically pretreated greywater, the addition of powdered activated carbon is advantageous since, due to additional adsorptive removal of organics, photocatalytic oxidation resulted in a 60% lower organic concentration when activated carbon was present after the same UV irradiation time. PMID:24191472

  13. Combining activated carbon adsorption with heterogeneous photocatalytic oxidation: lack of synergy for biologically treated greywater and tetraethylene glycol dimethyl ether.

    PubMed

    Gulyas, Holger; Argáez, Angel Santiago Oria; Kong, Fanzhuo; Jorge, Carlos Liriano; Eggers, Susanne; Otterpohl, Ralf

    2013-01-01

    The aim of the study was to evaluate whether the addition of activated carbon in the photocatalytic oxidation of biologically pretreated greywater and of a polar aliphatic compound gives synergy, as previously demonstrated with phenol. Photocatalytic oxidation kinetics were recorded with fivefold concentrated biologically pretreated greywater and with aqueous tetraethylene glycol dimethyl ether solutions using a UV lamp and the photocatalyst TiO2 P25 in the presence and the absence of powdered activated carbon. The synergy factor, SF, was quantified as the ratio of photocatalytic oxidation rate constant in the presence of powdered activated carbon to the rate constant without activated carbon. No synergy was observed for the greywater concentrate (SF approximately 1). For the aliphatic compound, tetraethylene glycol dimethyl ether, addition of activated carbon actually had an inhibiting effect on photocatalysis (SF < 1), while synergy was confirmed in reference experiments using aqueous phenol solutions. The absence of synergy for the greywater concentrate can be explained by low adsorbability of its organic constituents by activated carbon. Inhibition of the photocatalytic oxidation of tetraethylene glycol dimethyl ether by addition of powdered activated carbon was attributed to shading of the photocatalyst by the activated carbon particles. It was assumed that synergy in the hybrid process was limited to aromatic organics. Regardless of the lack of synergy in the case of biologically pretreated greywater, the addition of powdered activated carbon is advantageous since, due to additional adsorptive removal of organics, photocatalytic oxidation resulted in a 60% lower organic concentration when activated carbon was present after the same UV irradiation time.

  14. Combining activated carbon adsorption with heterogeneous photocatalytic oxidation: Lack of synergy for biologically treated greywater and tetraethylene glycol dimethyl ether

    PubMed Central

    Gulyas, Holger; Argáez, Ángel Santiago Oria; Kong, Fanzhuo; Jorge, Carlos Liriano; Eggers, Susanne; Otterpohl, Ralf

    2013-01-01

    The aim of the study was to evaluate whether the addition of activated carbon in the photocatalytic oxidation of biologically pretreated greywater and of a polar aliphatic compound gives synergy, as previously demonstrated with phenol. Photocatalytic oxidation kinetics were recorded with fivefold concentrated biologically pretreated greywater and with aqueous tetraethylene glycol dimethyl ether solutions using a UV lamp and the photocatalyst TiO2 P25 in the presence and the absence of powdered activated carbon. The synergy factor, SF, was quantified as the ratio of photocatalytic oxidation rate constant in the presence of powdered activated carbon to the rate constant without activated carbon. No synergy was observed for the greywater concentrate (SF ≈ 1). For the aliphatic compound, tetraethylene glycol dimethyl ether, addition of activated carbon actually had an inhibiting effect on photocatalysis (SF < 1), while synergy was confirmed in reference experiments using aqueous phenol solutions. The absence of synergy for the greywater concentrate can be explained by low adsorbability of its organic constituents by activated carbon. Inhibition of the photocatalytic oxidation of tetraethylene glycol dimethyl ether by addition of powdered activated carbon was attributed to shading of the photocatalyst by the activated carbon particles. It was assumed that synergy in the hybrid process was limited to aromatic organics. Regardless of the lack of synergy in the case of biologically pretreated greywater, the addition of powdered activated carbon is advantageous since, due to additional adsorptive removal of organics, photocatalytic oxidation resulted in a 60% lower organic concentration when activated carbon was present after the same UV irradiation time. PMID:24191472

  15. Synergy and other interactions in phytomedicines.

    PubMed

    Williamson, E M

    2001-09-01

    Synergistic interactions are of vital importance in phytomedicines, to explain difficulties in always isolating a single active ingredient, and explain the efficacy of apparently low doses of active constituents in a herbal product. This concept, that a whole or partially purified extract of a plant offers advantages over a single isolated ingredient, also underpins the philosophy of herbal medicine. Evidence to support the occurrence of synergy in within phytomedicines is now accumulating and is reviewed here. Synergistic interactions are documented for constituents within a total extract of a single herb, as well as between different herbs in a formulation. Positive and negative aspects of interactions are discussed together with the methods used to identify and measure synergy. The evidence is divided into experimental, in vitro instances, as well as clinical examples where available. Herbs discussed include Ginkgo biloba, Piper methysticum (Kava-Kava), Glycyrrhiza glabra, Hypericum perforatum, Valeriana officinalis, Cannabis sativa, Salix alba and others.

  16. Leveraging synergy for multiple agent infotaxis

    SciTech Connect

    Gintautas, Vadas; Hagberg, Aric A; Bettencourt, Luis M A

    2008-01-01

    Social computation, whether in the form of a search performed by a swarm of agents or the predictions of markets, often supplies remarkably good solutions to complex problems, which often elude the best experts. There is an intuition, built upon many anecdotal examples, that pervading principles are at play that allow individuals trying to solve a problem locally to aggregate their information to arrive at an outcome superior than any available to isolated parties. Here we show that the general structure of this problem can be cast in terms of information theory and derive general mathematical conditions for information sharing and coordination that lead to optimal multi-agent searches. Specifically we illustrate the problem in terms of the construction of local search algorithms for autonomous agents looking for the spatial location of a stochastic source. We explore the types of search problems -defined in terms of the properties of the source and the nature of measurements at each sensor -for which coordination among multiple searchers yields an advantage beyond that gained by having the same number of independent searchers. We assert that effective coordination corresponds to synergy and that ineffective coordination corresponds to redundancy as defined using information theory. We classify explicit types of sources in terms of their potential for synergy. We show that sources that emit uncorrelated particles based on a Poisson process, provide no opportunity for synergetic coordination while others, particularly sources that emit correlated signals, do allow for strong synergy between searchers. These general considerations are crucial for designing optimal algorithms for particular search problems in real world settings.

  17. Tapping Geography's Potential for Synergy with Creative Instructional Approaches

    ERIC Educational Resources Information Center

    Conway-Gomez, Kristen; Williams, Nikki; Atkinson-Palombo, Carol; Ahlqvist, Ola; Kim, Eje; Morgan, Miranda

    2011-01-01

    We define synergy, explain its importance within the context of rapidly changing academia, and provide examples of how geographic educators have used creative instructional approaches to create synergies. Both the content of geography and some of the instructional approaches used by geographic educators support the discipline's ability to deliver…

  18. Bioinspired Hybrid White Light-Emitting Diodes.

    PubMed

    Weber, Michael D; Niklaus, Lukas; Pröschel, Marlene; Coto, Pedro B; Sonnewald, Uwe; Costa, Rubén D

    2015-10-01

    The first bioinspired hybrid white-light-emitting diodes (bio-HLEDs) featuring protein cascade coatings are presented. For easy fabrication a new strategy to stabilize proteins in rubber-like material was developed. The synergy between the excellent features of fluorescent proteins and the easily processed rubber produces bio-HLEDs with less than 10% loss in luminous efficiency over 100 hours.

  19. Muscle synergy analysis in children with cerebral palsy

    NASA Astrophysics Data System (ADS)

    Tang, Lu; Li, Fei; Cao, Shuai; Zhang, Xu; Wu, De; Chen, Xiang

    2015-08-01

    Objective. To explore the mechanism of lower extremity dysfunction of cerebral palsy (CP) children through muscle synergy analysis. Approach. Twelve CP children were involved in this study, ten adults (AD) and eight typically developed (TD) children were recruited as a control group. Surface electromyographic (sEMG) signals were collected bilaterally from eight lower limb muscles of the subjects during forward walking at a comfortable speed. A nonnegative matrix factorization algorithm was used to extract muscle synergies. In view of muscle synergy differences in number, structure and symmetry, a model named synergy comprehensive assessment (SCA) was proposed to quantify the abnormality of muscle synergies. Main results. There existed larger variations between the muscle synergies of the CP group and the AD group in contrast with the TD group. Fewer mature synergies were recruited in the CP group, and many abnormal synergies specific to the CP group appeared. Specifically, CP children were found to recruit muscle synergies with a larger difference in structure and symmetry between two legs of one subject and different subjects. The proposed SCA scale demonstrated its great potential to quantitatively assess the lower-limb motor dysfunction of CP children. SCA scores of the CP group (57.00 ± 16.78) were found to be significantly less (p < 0.01) than that of the control group (AD group: 95.74 ± 2.04; TD group: 84.19 ± 11.76). Significance. The innovative quantitative results of this study can help us to better understand muscle synergy abnormality in CP children, which is related to their motor dysfunction and even the physiological change in their nervous system.

  20. Hybrid spin-crossover nanostructures

    PubMed Central

    Quintero, Carlos M; Félix, Gautier; Suleimanov, Iurii; Sánchez Costa, José; Molnár, Gábor; Salmon, Lionel; Nicolazzi, William

    2014-01-01

    Summary This review reports on the recent progress in the synthesis, modelling and application of hybrid spin-crossover materials, including core–shell nanoparticles and multilayer thin films or nanopatterns. These systems combine, often in synergy, different physical properties (optical, magnetic, mechanical and electrical) of their constituents with the switching properties of spin-crossover complexes, providing access to materials with unprecedented capabilities. PMID:25551051

  1. Representation of Muscle Synergies in the Primate Brain

    PubMed Central

    d'Avella, Andrea; Roh, Jinsook; Carmena, Jose M.; Bizzi, Emilio

    2015-01-01

    Evidence suggests that the CNS uses motor primitives to simplify movement control, but whether it actually stores primitives instead of computing solutions on the fly to satisfy task demands is a controversial and still-unanswered possibility. Also in contention is whether these primitives take the form of time-invariant muscle coactivations (“spatial” synergies) or time-varying muscle commands (“spatiotemporal” synergies). Here, we examined forelimb muscle patterns and motor cortical spiking data in rhesus macaques (Macaca mulatta) handling objects of variable shape and size. From these data, we extracted both spatiotemporal and spatial synergies using non-negative decomposition. Each spatiotemporal synergy represents a sequence of muscular or neural activations that appeared to recur frequently during the animals' behavior. Key features of the spatiotemporal synergies (including their dimensionality, timing, and amplitude modulation) were independently observed in the muscular and neural data. In addition, both at the muscular and neural levels, these spatiotemporal synergies could be readily reconstructed as sequential activations of spatial synergies (a subset of those extracted independently from the task data), suggestive of a hierarchical relationship between the two levels of synergies. The possibility that motor cortex may execute even complex skill using spatiotemporal synergies has novel implications for the design of neuroprosthetic devices, which could gain computational efficiency by adopting the discrete and low-dimensional control that these primitives imply. SIGNIFICANCE STATEMENT We studied the motor cortical and forearm muscular activity of rhesus macaques (Macaca mulatta) as they reached, grasped, and carried objects of varied shape and size. We applied non-negative matrix factorization separately to the cortical and muscular data to reduce their dimensionality to a smaller set of time-varying “spatiotemporal” synergies. Each synergy

  2. Synergies among extinction drivers under global change.

    PubMed

    Brook, Barry W; Sodhi, Navjot S; Bradshaw, Corey J A

    2008-08-01

    If habitat destruction or overexploitation of populations is severe, species loss can occur directly and abruptly. Yet the final descent to extinction is often driven by synergistic processes (amplifying feedbacks) that can be disconnected from the original cause of decline. We review recent observational, experimental and meta-analytic work which together show that owing to interacting and self-reinforcing processes, estimates of extinction risk for most species are more severe than previously recognised. As such, conservation actions which only target single-threat drivers risk being inadequate because of the cascading effects caused by unmanaged synergies. Future work should focus on how climate change will interact with and accelerate ongoing threats to biodiversity, such as habitat degradation, overexploitation and invasive species.

  3. Space Propulsion Synergy Group ETO technology assessments

    NASA Astrophysics Data System (ADS)

    Bray, James

    The Space Propulsion Synergy Group (SPSG), which was chartered to support long-range strategic planning, has, using a broad industry/government team, evaluated and achieved consensus on the vehicles, propulsion systems, and propulsion technologies that have the best long-term potential for achieving desired system attributes. The breakthrough that enabled broad consensus was developing criteria that are measurable a priori. The SPSG invented a dual prioritization approach that balances long-term strategic thrusts with current programmatic constraints. This enables individual program managers to make decisions based on both individual project needs and long-term strategic needs. Results indicate that an SSTO using an integrated modular engine has the best long-term potential for a 20 Klb class vehicle, and that health monitoring and control technologies are among the highest dual priority liquid rocket technologies.

  4. Motor Synergies and the Equilibrium-Point Hypothesis

    PubMed Central

    Latash, Mark L.

    2010-01-01

    The article offers a way to unite three recent developments in the field of motor control and coordination: (1) The notion of synergies is introduced based on the principle of motor abundance; (2) The uncontrolled manifold hypothesis is described as offering a computational framework to identify and quantify synergies; and (3) The equilibrium-point hypothesis is described for a single muscle, single joint, and multi-joint systems. Merging these concepts into a single coherent scheme requires focusing on control variables rather than performance variables. The principle of minimal final action is formulated as the guiding principle within the referent configuration hypothesis. Motor actions are associated with setting two types of variables by a controller, those that ultimately define average performance patterns and those that define associated synergies. Predictions of the suggested scheme are reviewed, such as the phenomenon of anticipatory synergy adjustments, quick actions without changes in synergies, atypical synergies, and changes in synergies with practice. A few models are briefly reviewed. PMID:20702893

  5. Anticipatory synergy adjustments reflect individual performance of feedforward force control.

    PubMed

    Togo, Shunta; Imamizu, Hiroshi

    2016-10-01

    We grasp and dexterously manipulate an object through multi-digit synergy. In the framework of the uncontrolled manifold (UCM) hypothesis, multi-digit synergy is defined as the coordinated control mechanism of fingers to stabilize variable important for task success, e.g., total force. Previous studies reported anticipatory synergy adjustments (ASAs) that correspond to a drop of the synergy index before a quick change of the total force. The present study compared ASA's properties with individual performances of feedforward force control to investigate a relationship of those. Subjects performed a total finger force production task that consisted of a phase in which subjects tracked target line with visual information and a phase in which subjects produced total force pulse without visual information. We quantified their multi-digit synergy through UCM analysis and observed significant ASAs before producing total force pulse. The time of the ASA initiation and the magnitude of the drop of the synergy index were significantly correlated with the error of force pulse, but not with the tracking error. Almost all subjects showed a significant increase of the variance that affected the total force. Our study directly showed that ASA reflects the individual performance of feedforward force control independently of target-tracking performance and suggests that the multi-digit synergy was weakened to adjust the multi-digit movements based on a prediction error so as to reduce the future error.

  6. Hierarchical control of static prehension: II. Multi-digit synergies.

    PubMed

    Gorniak, Stacey L; Zatsiorsky, Vladimir M; Latash, Mark L

    2009-03-01

    The purpose of this study was to explore the ability of the central nervous system (CNS) to organize synergies at two levels of a hypothetical control hierarchy involved in two-hand multi-finger prehension tasks with one or more persons participating in the task together. At the higher level of the hierarchy, the total force and moment of force produced on an object are distributed between the thumb and the virtual finger (an imagined finger with mechanical output equal to the involved fingers of the hand), while at the lower level the virtual finger action is distributed among the four fingers. We tested a hypothesis that the CNS is able to organize synergies at only one level of the hierarchy. The subjects held vertically one of the two handles, a narrow one and a wide one. They used the four fingers of the right hand opposed by the right hand thumb, the left hand thumb, the left hand index finger, the thumb of an experimenter, the index finger of an experimenter, or an inanimate object. Forces and moments of force produced by each digit were recorded. Indices of synergies stabilizing the mechanical output variables at each of the two levels were computed. Contrary to the expectations, force and moment of force stabilizing synergies were found at one or both levels of the hierarchy across all tasks. Unimanual tasks exhibited higher synergy indices compared to all tasks, while intrapersonal synergy indices were higher than those of interpersonal synergies. The results suggest that both feed-forward and feedback mechanisms may be used to create force and moment of force stabilizing synergies. We invoke the notion of chain effects and generalize it for relations among variance components related to stabilization of different mechanical variables. The reference configuration hypothesis offers a fruitful framework for analysis of prehension synergies. PMID:19048236

  7. Functional muscle synergies constrain force production during postural tasks

    PubMed Central

    McKay, J. Lucas; Ting, Lena H.

    2015-01-01

    We recently demonstrated that a set of five functional muscle synergies were sufficient to characterize both hindlimb muscle activity and active forces during automatic postural responses in cats standing at multiple postural configurations. This characterization depended critically upon the assumption that the endpoint force vector (synergy force vector) produced by the activation of each muscle synergy rotated with the limb axis as the hindlimb posture varied in the sagittal plane. Here, we used a detailed, 3D static model of the hindlimb to confirm that this assumption is biomechanically plausible: as we varied the model posture, simulated synergy force vectors rotated monotonically with the limb axis in the parasagittal plane (r2 = 0.94 ± 0.08). We then tested whether a neural strategy of using these five functional muscle synergies provides the same force-generating capability as controlling each of the 31 muscles individually. We compared feasible force sets (FFS) from the model with and without a muscle synergy organization. FFS volumes were significantly reduced with the muscle synergy organization (F = 1556.01, p ≪ 0.01), and as posture varied, the synergy-limited FFSs changed in shape, consistent with changes in experimentally-measured active forces. In contrast, nominal FFS shapes were invariant with posture, reinforcing prior findings that postural forces cannot be predicted by hindlimb biomechanics alone. We propose that an internal model for postural force generation may coordinate functional muscle synergies that are invariant in intrinsic limb coordinates, and this reduced-dimension control scheme reduces the set of forces available for postural control. PMID:17980370

  8. Hierarchical control of static prehension: II. Multi-digit synergies

    PubMed Central

    Gorniak, Stacey L.; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2009-01-01

    The purpose of this study was to explore the ability of the central nervous system (CNS) to organize synergies at two levels of a hypothetical control hierarchy involved in two-hand multi-finger prehension tasks with one or more persons participating in the task together. At the higher level of the hierarchy, the total force and moment of force produced on an object are distributed between the thumb and the virtual finger (an imagined finger with mechanical output equal to the involved fingers of the hand), while at the lower level the virtual finger action is distributed among the four fingers. We tested a hypothesis that the CNS is able to organize synergies at only one level of the hierarchy. The subjects held vertically one of the two handles, a narrow one and a wide one. They used the four fingers of the right hand opposed by either the right hand thumb, the left hand thumb, the left hand index finger, the thumb of an experimenter, the index finger of an experimenter, or an inanimate object. Forces and moments of force produced by each digit were recorded. Indices of synergies stabilizing the mechanical output variables at each of the two levels were computed. Contrary to the expectations, force and moment of force stabilizing synergies were found at one or both levels of the hierarchy across all tasks. Unimanual tasks exhibited higher synergy indices compared to all tasks, while intrapersonal synergy indices were higher than those of interpersonal synergies. The results suggest that both feed-forward and feedback mechanisms may be used to create force and moment of force stabilizing synergies. We invoke the notion of chain effects and generalize it for relations among variance components related to stabilization of different mechanical variables. The reference configuration hypothesis offers a fruitful framework for analysis of prehension synergies. PMID:19048236

  9. Generational differences in work-family conflict and synergy.

    PubMed

    Beutell, Nicholas J

    2013-06-19

    This paper examines differences in work-family conflict and synergy among the four generational groups represented in the contemporary workforce: Generation Y Generation X, Baby Boomers, and Matures using data from the 2008 National Study of the Changing Workforce (n = 3,502). Significant generational differences were found for work-family conflict (work interfering with family and family interfering with work) but not for work-family synergy. Mental health and job pressure were the best predictors of work interfering with family conflict for each generational group. Work-family synergy presented a more complex picture. Work-family conflict and synergy were significantly related to job, marital, and life satisfaction. Implications and directions for future research are discussed.

  10. Generational Differences in Work-Family Conflict and Synergy

    PubMed Central

    Beutell, Nicholas J.

    2013-01-01

    This paper examines differences in work-family conflict and synergy among the four generational groups represented in the contemporary workforce: Generation Y Generation X, Baby Boomers, and Matures using data from the 2008 National Study of the Changing Workforce (n = 3,502). Significant generational differences were found for work-family conflict (work interfering with family and family interfering with work) but not for work-family synergy. Mental health and job pressure were the best predictors of work interfering with family conflict for each generational group. Work-family synergy presented a more complex picture. Work-family conflict and synergy were significantly related to job, marital, and life satisfaction. Implications and directions for future research are discussed. PMID:23783221

  11. Synergy optimization and operation management on syndicate complementary knowledge cooperation

    NASA Astrophysics Data System (ADS)

    Tu, Kai-Jan

    2014-10-01

    The number of multi enterprises knowledge cooperation has grown steadily, as a result of global innovation competitions. I have conducted research based on optimization and operation studies in this article, and gained the conclusion that synergy management is effective means to break through various management barriers and solve cooperation's chaotic systems. Enterprises must communicate system vision and access complementary knowledge. These are crucial considerations for enterprises to exert their optimization and operation knowledge cooperation synergy to meet global marketing challenges.

  12. Do muscle synergies reduce the dimensionality of behavior?

    PubMed Central

    Kuppuswamy, Naveen; Harris, Christopher M.

    2014-01-01

    The muscle synergy hypothesis is an archetype of the notion of Dimensionality Reduction (DR) occurring in the central nervous system due to modular organization. Toward validating this hypothesis, it is important to understand if muscle synergies can reduce the state-space dimensionality while maintaining task control. In this paper we present a scheme for investigating this reduction utilizing the temporal muscle synergy formulation. Our approach is based on the observation that constraining the control input to a weighted combination of temporal muscle synergies also constrains the dynamic behavior of a system in a trajectory-specific manner. We compute this constrained reformulation of system dynamics and then use the method of system balancing for quantifying the DR; we term this approach as Trajectory Specific Dimensionality Analysis (TSDA). We then investigate the consequence of minimization of the dimensionality for a given task. These methods are tested in simulations on a linear (tethered mass) and a non-linear (compliant kinematic chain) system. Dimensionality of various reaching trajectories is compared when using idealized temporal synergies. We show that as a consequence of this Minimum Dimensional Control (MDC) model, smooth straight-line Cartesian trajectories with bell-shaped velocity profiles emerged as the optima for the reaching task. We also investigated the effect on dimensionality due to adding via-points to a trajectory. The results indicate that a trajectory and synergy basis specific DR of behavior results from muscle synergy control. The implications of these results for the synergy hypothesis, optimal motor control, motor development, and robotics are discussed. PMID:25002844

  13. Global mental health and neuroscience: potential synergies.

    PubMed

    Stein, Dan J; He, Yanling; Phillips, Anthony; Sahakian, Barbara J; Williams, John; Patel, Vikram

    2015-02-01

    Global mental health has emerged as an important specialty. It has drawn attention to the burden of mental illness and to the relative gap in mental health research and services around the world. Global mental health has raised the question of whether this gap is a developmental issue, a health issue, a human rights issue, or a combination of these issues-and it has raised awareness of the need to develop new approaches for building capacity, mobilising resources, and closing the research and treatment gap. Translational neuroscience has also advanced. It comprises an important conceptual approach to understanding the neurocircuitry and molecular basis of mental disorders, to rethinking how best to undertake research on the aetiology, assessment, and treatment of these disorders, with the ultimate aim to develop entirely new approaches to prevention and intervention. Some apparent contrasts exist between these fields; global mental health emphasises knowledge translation, moving away from the bedside to a focus on health systems, whereas translational neuroscience emphasises molecular neuroscience, focusing on transitions between the bench and bedside. Meanwhile, important opportunities exist for synergy between the two paradigms, to ensure that present opportunities in mental health research and services are maximised. Here, we review the approaches of global mental health and clinical neuroscience to diagnosis, pathogenesis, and intervention, and make recommendations for facilitating an integration of these two perspectives. PMID:26359754

  14. Synergies with CTA and VHE Astrophysics

    NASA Astrophysics Data System (ADS)

    Hofmann, W.

    2016-06-01

    The Cherenkov Telescope Array (CTA) is a next-generation observatory for very high energy (VHE) gamma-ray astronomy. With one array of imaging atmospheric Cherenkov telescopes each in the northern and southern hemispheres, CTA will provide full-sky coverage, enhance flux sensitivity by one order of magnitude compared to current instruments, cover gamma-ray energies from 20 GeV to 300 TeV, and provide angular resolution of a few arc-minutes across a multi-degree field of view. In the context of its Key Science Projects (KSPs), CTA will conduct a census of particle acceleration in the universe, with quarter-sky extragalactic, full-plane Galactic and Large Magellanic Cloud surveys planned. Additional KSPs are focused on transients, acceleration up to PeV energies in our own galaxy, active galaxies, star-forming systems on a wide range of scales, and the Perseus cluster of galaxies. A major element of the programme is the search for dark matter, in particular the annihilation signature of WIMPs. Like for current-generation VHE instruments, CTA science will strongly rely upon multiwavelength observations of sources, with the X-ray domain playing a particularly crucial role. The presentation will briefly introduce CTA, summarize its science perspectives, and address the synergies with instruments in other wavebands.

  15. Synergy for a Strong Future FY 2008

    SciTech Connect

    Devore, L; Chrzanowski, P

    2008-11-06

    Lawrence Livermore National Security, LLC is committed to delivering the best combination of scientific research, technology development, business management, and safe, secure operations in support of Lawrence Livermore National Laboratory's critical national security mission. LLNS was formed specifically to manage LLNL for the Department of Energy's National Nuclear Security Administration. LLNS consists of a team of five organizations renowned for their expertise and accomplishments throughout the U.S. nuclear weapons complex and beyond - Bechtel National, University of California, Babcock & Wilcox, Washington Division of URS Corporation, and Battelle. Bechtel is the nation's largest engineering and construction firm and a leader in project management. The University of California is the world's largest public research institution. Babcock & Wilcox and the Washington Division of URS Corporation are top nuclear facilities contractors and between them manage four of DOE's five safest sites. Battelle is a global leader in science and technology development and commercialization. The LLNS Board of Governors provides oversight for the management of the Laboratory and holds the Director and LLNS President responsible for the Laboratory's performance. The Board has seven standing committees that assist in assessing Laboratory performance and monitoring risks and internal controls. Through the Board of Governors, the Laboratory can reach back to LLNS partner organizations to help ensure that it fulfills its national security mission with excellence in scientific research, technology development, business management, and safe, secure operations. LLNS assumed management of LLNL on October 1, 2007. This report highlights LLNS accomplishments in FY2008, its first year as the Laboratory's managing contractor. It is clear that LLNS and the Laboratory have exploited numerous synergies inherent in their relationship - for example, science and engineering, mission and operations

  16. Prehension synergies and control with referent hand configurations

    PubMed Central

    Friedman, Jason; Kim, Sun Wook; Feldman, Anatol G.; Zatsiorsky, Vladimir M.

    2010-01-01

    We used the framework of the equilibrium-point hypothesis (in its updated form based on the notion of referent configuration) to investigate the multi-digit synergies at two levels of a hypothetical hierarchy involved in prehensile actions. Synergies were analyzed at the thumb–virtual finger (VF) level (VF is an imaginary digit with the mechanical action equivalent to that of the four actual fingers) and at the individual finger level. The subjects performed very quick vertical movements of a handle into a target. A load could be attached off-center to provide a pronation or supination torque. In a few trials, the handle was unexpectedly fixed to the table and the digits slipped off the sensors. In such trials, the hand stopped at a higher vertical position and rotated into pronation or supination depending on the expected torque. The aperture showed non-monotonic changes with a large, fast decrease and further increase, ending up with a smaller distance between the thumb and the fingers as compared to unperturbed trials. Multi-digit synergies were quantified using indices of co-variation between digit forces and moments of force across unperturbed trials. Prior to the lifting action, high synergy indices were observed at the individual finger level while modest indices were observed at the thumb–VF level. During the lifting action, the synergies at the individual finger level disappeared while the synergy indices became higher at the thumb–VF level. The results support the basic premise that, within a given task, setting a referent configuration may be described with a few referent values of variables that influence the equilibrium state, to which the system is attracted. Moreover, the referent configuration hypothesis can help interpret the data related to the trade-off between synergies at different hierarchical levels. PMID:20033397

  17. Synergy of debris mitigation and removal

    NASA Astrophysics Data System (ADS)

    Lewis, Hugh G.; White, Adam E.; Crowther, Richard; Stokes, Hedley

    2012-12-01

    Since the end of the 20th Century there has been considerable effort made to devise mitigation measures to limit the growth of the debris population. This activity has led to the implementation of a "25-year rule" by a number of space-faring nations for the post-mission disposal of spacecraft and orbital stages intersecting the Low Earth Orbit (LEO) region. Through the use of projections made by computer models, it was anticipated that this 25-year rule, together with passivation and suppression of mission-related debris, would be sufficient to prevent the unconstrained growth of the LEO debris population. In the last decade both the LEO debris environment and the debris modelling capability have seen significant changes. In particular, recent population growth has been driven by a number of major break-ups, including the intentional destruction of the Fengyun-1C spacecraft and the collision between Iridium 33 and Cosmos 2251. State-of-the-art evolutionary models indicate that the LEO debris population will continue to grow in spite of good compliance with the commonly adopted mitigation measures and even in the absence of new launches. Consequently, this has led to considerable interest in the development of remediation measures and, especially, in debris removal. In this paper, we present a new and large study of debris mitigation and removal using the University of Southampton's evolutionary model, DAMAGE, together with the latest MASTER model population of objects ≥10 cm in LEO. Here, we have employed a concurrent approach to mitigation and remediation, whereby changes to the PMD rule and the inclusion of other mitigation measures have been considered together with multiple removal strategies. In this way, we have been able to demonstrate the synergy of these mitigation and remediation measures and to identify potential, aggregate solutions to the space debris problem. The results suggest that reducing the PMD rule offers benefits that include an increase in

  18. Resource synergy in stream periphyton communities

    SciTech Connect

    Hill, Walter; Fanta, S.E.; Roberts, Brian J; Francoeur, Steven N.

    2011-03-01

    1. Light and nutrients play pivotal roles in determining the growth of autotrophs, yet the potential for synergistic interactions between the two resources in algal communities is poorly understood, especially in stream ecosystems. In this study, light and phosphorus were manipulated in large experimental streams to examine resource colimitation and synergy in stream periphyton. 2. Whole-stream metabolism was simultaneously limited by light and phosphorus. Increasing the supply of either light or phosphorus resulted in significant increases in primary production and the transformation of the streams from heterotrophy to autotrophy. 3. Resource-driven changes in periphyton community structure occurred in concert with changes in production. Algal assemblages in highly shaded streams were composed primarily of small diatoms such as Achnanthidium minutissima, whereas larger diatoms such as Melosira varians predominated at higher irradiances. Phosphorus enrichment had relatively little effect on assemblage structure, but it did substantially diminish the abundance of Meridion circulare, a diatom whose mucilaginous colonies were conspicuously abundant in phosphorus-poor, high-light streams. Bacterial biomass declined relative to algal biomass with increases in primary productivity, regardless of whether the increases were caused by light or phosphorus. 4. Synergistic effects on primary production appeared to occur because the availability of one resource facilitated the utilization of the other. Light increased the abundance of large diatoms, which are known to convert high concentrations of nutrients into primary production more effectively than smaller taxa. Phosphorus enrichment led to the replacement of Meridion circulare by non-mucilaginous taxa in phosphorus-enriched streams, and we hypothesize that this change enabled more efficient use of light in photosynthesis. Higher ratios of chlorophyll a : biomass in phosphorus-enriched streams may have also led to more

  19. Space and Terrestrial Photovoltaics: Synergy and Diversity

    NASA Technical Reports Server (NTRS)

    Bailey, Sheila; Raffaelle, Ryne; Emery, Keith

    2002-01-01

    A historical view of the research and development in photovoltaics from the perspective of both the terrestrial and the space communities is presented from the early days through the '70s and '80s and the '90s and beyond. The synergy of both communities in the beginning and once again in the present and hopefully future are highlighted, with examples of the important features in each program. The space community which was impressed by the light-weight and reliability of photovoltaics drove much of the early development. Even up to today, nearly every satellites and other scientific space probe that has been launched has included some solar power. However, since the cost of these power systems were only a small fraction of the satellite and launch cost, the use of much of this technology for the terrestrial marketplace was not feasible. It was clear that the focus of the terrestrial community would be best served by reducing costs. This would include addressing a variety of manufacturing issues and raising the rate of production. Success in these programs and a resulting globalization of effort resulted in major strides in the reduction of PV module costs and increased production. Although, the space community derived benefit from some of these advancements, its focus was on pushing the envelope with regard to cell efficiency. The gap between theoretical efficiencies and experimental efficiencies for silicon, gallium arsenide and indium phosphide became almost non-existent. Recent work by both communities have focused on the development thin film cells of amorphous silicon, CuInSe2 and CdTe. These cells hold the promise of lower costs for the terrestrial community as well as possible flexible substrates, better radiation resistance, and higher specific power for the space community. It is predicted that future trends in both communities will be directed toward advances through the application of nanotechnology. A picture is emerging in which the space and

  20. Nuclear and Renewable Energy Synergies Workshop: Report of Proceedings

    SciTech Connect

    Ruth, M.; Antkowiak, M.; Gossett, S.

    2011-12-01

    Two of the major challenges the U.S. energy sector faces are greenhouse gas emissions and oil that is both imported and potentially reaching a peak (the point at which maximum extraction is reached). Interest in development of both renewable and nuclear energy has been strong because both have potential for overcoming these challenges. Research in both energy sources is ongoing, but relatively little research has focused on the potential benefits of combining nuclear and renewable energy. In September 2011, the Joint Institute for Strategic Energy Analysis (JISEA) convened the Nuclear and Renewable Energy Synergies Workshop at the U.S. Department of Energy's National Renewable Energy Laboratory (NREL) to identify potential synergies and strategic leveraging opportunities between nuclear energy and renewable energy. Industry, government, and academic thought leaders gathered to identify potential broad categories of synergies and brainstorm topic areas for additional analysis and research and development (R&D). This report records the proceedings and outcomes of the workshop.

  1. Understanding Human Motion Skill with Peak Timing Synergy

    NASA Astrophysics Data System (ADS)

    Ueno, Ken; Furukawa, Koichi

    The careful observation of motion phenomena is important in understanding the skillful human motion. However, this is a difficult task due to the complexities in timing when dealing with the skilful control of anatomical structures. To investigate the dexterity of human motion, we decided to concentrate on timing with respect to motion, and we have proposed a method to extract the peak timing synergy from multivariate motion data. The peak timing synergy is defined as a frequent ordered graph with time stamps, which has nodes consisting of turning points in motion waveforms. A proposed algorithm, PRESTO automatically extracts the peak timing synergy. PRESTO comprises the following 3 processes: (1) detecting peak sequences with polygonal approximation; (2) generating peak-event sequences; and (3) finding frequent peak-event sequences using a sequential pattern mining method, generalized sequential patterns (GSP). Here, we measured right arm motion during the task of cello bowing and prepared a data set of the right shoulder and arm motion. We successfully extracted the peak timing synergy on cello bowing data set using the PRESTO algorithm, which consisted of common skills among cellists and personal skill differences. To evaluate the sequential pattern mining algorithm GSP in PRESTO, we compared the peak timing synergy by using GSP algorithm and the one by using filtering by reciprocal voting (FRV) algorithm as a non time-series method. We found that the support is 95 - 100% in GSP, while 83 - 96% in FRV and that the results by GSP are better than the one by FRV in the reproducibility of human motion. Therefore we show that sequential pattern mining approach is more effective to extract the peak timing synergy than non-time series analysis approach.

  2. Effects of fatigue on synergies in a hierarchical system

    PubMed Central

    Singh, Tarkeshwar; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2013-01-01

    We investigated the effect of fatigue produced by timed maximal voluntary contraction (MVC) of the index finger of one of the hands on performance in MVC and accurate cyclic force production tasks in right-handed subjects. Based on earlier studies, we hypothesized that fatigue would produce an increase in the indices of force-stabilizing synergies in both hands as well as between the hands in two-hand tasks. Synergies were defined as co-varied adjustments of commands to fingers (modes) across cycles that stabilized total force. Fatigue caused a significant reduction in the MVC of the exercised as well as the non-exercised hand. Indices of finger enslaving (lack of individuation) increased with fatigue in both hands, although the increase was significant in the exercised hand only. In contrast to the significant effects of fatigue on MVC forces performed by the non-exercised hand, there were no comparable transfer effects on the root mean square errors during accurate force production. During one-hand tasks, both hands showed high indices of force-stabilizing synergies. These indices were larger in the left hand. Fatigue led to a general increase in synergy indices. Exercise by the left hand had stronger effects on synergy indices seen in both hands. Exercise by the right hand showed ipsilateral effects only. Smaller effects of fatigue were observed on accuracy of performance of the force-down segments of the force cycles compared to the force-up segments. For the bimanual tasks, synergies were analyzed at two hierarchical levels, two-hand (four-finger) and within-a-hand (two-finger). An increase in the synergy index with fatigue was observed at the lower (two-finger) level of the hierarchy only. We interpret the lack of effects of fatigue at the upper (two-hand) level as a consequence of a trade-off between synergies at different levels of the hierarchy. The differences between the hands are discussed within the dynamic dominance hypothesis. PMID:23182434

  3. Effects of fatigue on synergies in a hierarchical system.

    PubMed

    Singh, Tarkeshwar; Zatsiorsky, Vladimir M; Latash, Mark L

    2012-12-01

    We investigated the effect of fatigue produced by timed maximal voluntary contraction (MVC) of the index finger of one of the hands on performance in MVC and accurate cyclic force production tasks in right-handed subjects. Based on earlier studies, we hypothesized that fatigue would produce an increase in the indices of force-stabilizing synergies in both hands as well as between the hands in two-hand tasks. Synergies were defined as co-varied adjustments of commands to fingers (modes) across cycles that stabilized total force. Fatigue caused a significant reduction in the MVC of the exercised as well as the non-exercised hand. Indices of finger enslaving (lack of individuation) increased with fatigue in both hands, although the increase was significant in the exercised hand only. In contrast to the significant effects of fatigue on MVC forces performed by the non-exercised hand, there were no comparable transfer effects on the root mean square errors during accurate force production. During one-hand tasks, both hands showed high indices of force-stabilizing synergies. These indices were larger in the left hand. Fatigue led to a general increase in synergy indices. Exercise by the left hand had stronger effects on synergy indices seen in both hands. Exercise by the right hand showed ipsilateral effects only. Smaller effects of fatigue were observed on accuracy of performance of the force-down segments of the force cycles compared to the force-up segments. For the bimanual tasks, synergies were analyzed at two hierarchical levels, two-hand (four-finger) and within-a-hand (two-finger). An increase in the synergy index with fatigue was observed at the lower (two-finger) level of the hierarchy only. We interpret the lack of effects of fatigue at the upper (two-hand) level as a consequence of a trade-off between synergies at different levels of the hierarchy. The differences between the hands are discussed within the dynamic dominance hypothesis. PMID:23182434

  4. Action Direction of Muscle Synergies in Three-Dimensional Force Space

    PubMed Central

    Hagio, Shota; Kouzaki, Motoki

    2015-01-01

    Redundancy in the musculoskeletal system was supposed to be simplified by muscle synergies, which modularly organize muscles. To clarify the underlying mechanisms of motor control using muscle synergies, it is important to examine the spatiotemporal contribution of muscle synergies in the task space. In this study, we quantified the mechanical contribution of muscle synergies as considering spatiotemporal correlation between the activation of muscle synergies and endpoint force fluctuations. Subjects performed isometric force generation in the three-dimensional force space. The muscle-weighting vectors of muscle synergies and their activation traces across different trials were extracted from electromyogram data using decomposing technique. We then estimated mechanical contribution of muscle synergies across each trial based on cross-correlation analysis. The contributing vectors were averaged for all trials, and the averaging was defined as action direction (AD) of muscle synergies. As a result, we extracted approximately five muscle synergies. The ADs of muscle synergies mainly depended on the anatomical functions of their weighting muscles. Furthermore, the AD of each muscle indicated the synchronous activation of muscles, which composed of the same muscle synergy. These results provide the spatiotemporal characteristics of muscle synergies as neural basis. PMID:26618156

  5. Unravelling novel synergies between organometallic and biological partners: a quantum mechanics/molecular mechanics study of an artificial metalloenzyme.

    PubMed

    Ortega-Carrasco, Elisabeth; Lledós, Agustí; Maréchal, Jean-Didier

    2014-07-01

    In recent years, the design of artificial metalloenzymes obtained by the insertion of homogeneous catalysts into biological macromolecules has become a major field of research. These hybrids, and the corresponding X-ray structures of several of them, are offering opportunities to better understand the synergy between organometallic and biological subsystems. In this work, we investigate the resting state and activation process of a hybrid inspired by an oxidative haemoenzyme but presenting an unexpected reactivity and structural features. An extensive series of quantum mechanics/molecular mechanics calculations show that the resting state and the activation processes of the novel enzyme differ from naturally occurring haemoenzymes in terms of the electronic state of the metal, participation of the first coordination sphere of the metal and the dynamic process. This study presents novel insights into the sensitivity of the association between organometallic and biological partners and illustrates the molecular challenge that represents the design of efficient enzymes based on this strategy.

  6. Unravelling novel synergies between organometallic and biological partners: a quantum mechanics/molecular mechanics study of an artificial metalloenzyme

    PubMed Central

    Ortega-Carrasco, Elisabeth; Lledós, Agustí; Maréchal, Jean-Didier

    2014-01-01

    In recent years, the design of artificial metalloenzymes obtained by the insertion of homogeneous catalysts into biological macromolecules has become a major field of research. These hybrids, and the corresponding X-ray structures of several of them, are offering opportunities to better understand the synergy between organometallic and biological subsystems. In this work, we investigate the resting state and activation process of a hybrid inspired by an oxidative haemoenzyme but presenting an unexpected reactivity and structural features. An extensive series of quantum mechanics/molecular mechanics calculations show that the resting state and the activation processes of the novel enzyme differ from naturally occurring haemoenzymes in terms of the electronic state of the metal, participation of the first coordination sphere of the metal and the dynamic process. This study presents novel insights into the sensitivity of the association between organometallic and biological partners and illustrates the molecular challenge that represents the design of efficient enzymes based on this strategy. PMID:24829279

  7. Authentic Tasks Online: A Synergy among Learner, Task, and Technology

    ERIC Educational Resources Information Center

    Herrington, Jan; Reeves, Thomas C.; Oliver, Ron

    2006-01-01

    Fostering synergies amongst "learner," "task," and "technology" to create innovative and immersive distance learning environments runs counter to the widespread practice of incorporating traditional classroom pedagogical strategies into Web-based delivery of courses. The most widely accepted model of online higher education appears to be one of…

  8. syNErgy: A Case Study in Workforce Curriculum Development

    ERIC Educational Resources Information Center

    Killingsworth, John; Grosskopf, Kevin R.

    2013-01-01

    With high unemployment and structural changes to industry, workforce development in the United States is a growing concern. Many semiskilled workers lack knowledge, skills, and abilities to be competitive for reemployment to green jobs. Nebraska's syNErgy research grant was introduced to address the training needs of unemployed and…

  9. Practice effects on intra-team synergies in football teams.

    PubMed

    Silva, Pedro; Chung, Dante; Carvalho, Thiago; Cardoso, Tiago; Davids, Keith; Araújo, Duarte; Garganta, Júlio

    2016-04-01

    Developing synchronised player movements for fluent competitive match play is a common goal for coaches of team games. An ecological dynamics approach advocates that intra-team synchronization is governed by locally created information, which specifies shared affordances responsible for synergy formation. To verify this claim we evaluated coordination tendencies in two newly-formed teams of recreational players during association football practice games, weekly, for fifteen weeks (thirteen matches). We investigated practice effects on two central features of synergies in sports teams - dimensional compression and reciprocal compensation here captured through near in-phase modes of coordination and time delays between coupled players during forward and backwards movements on field while attacking and defending. Results verified that synergies were formed and dissolved rapidly as a result of the dynamic creation of informational properties, perceived as shared affordances among performers. Practising once a week led to small improvements in the readjustment delays between co-positioning team members, enabling faster regulation of coordinated team actions. Mean values of the number of player and team synergies displayed only limited improvements, possibly due to the timescales of practice. No relationship between improvements in dimensional compression and reciprocal compensation were found for number of shots, amount of ball possession and number of ball recoveries made. Findings open up new perspectives for monitoring team coordination processes in sport.

  10. Peace Education, ESD and the Earth Charter: Interconnections and Synergies

    ERIC Educational Resources Information Center

    Toh, Swee-Hin; Cawagas, Virginia Floresca

    2010-01-01

    This article provides a review of how the values and principles of the Earth Charter initiative relate to two specific innovative movements of educational transformation, namely peace education and education for sustainable development (ESD). The interconnections and synergies between these movements and the Earth Charter are highlighted.…

  11. Learning Motor Synergies by Persons with Down Syndrome

    ERIC Educational Resources Information Center

    Latash, M. L.

    2007-01-01

    Persons with Down syndrome are frequently described as "clumsy". The recent progress in the development of quantitative approaches to motor synergies has allowed researchers to move towards an understanding of "clumsiness" at the level of underlying control mechanisms. This progress has also offered an opportunity to quantify changes in motor…

  12. A novel computational framework for deducing muscle synergies from experimental joint moments

    PubMed Central

    Gopalakrishnan, Anantharaman; Modenese, Luca; Phillips, Andrew T. M.

    2014-01-01

    Prior experimental studies have hypothesized the existence of a “muscle synergy” based control scheme for producing limb movements and locomotion in vertebrates. Such synergies have been suggested to consist of fixed muscle grouping schemes with the co-activation of all muscles in a synergy resulting in limb movement. Quantitative representations of these groupings (termed muscle weightings) and their control signals (termed synergy controls) have traditionally been derived by the factorization of experimentally measured EMG. This study presents a novel approach for deducing these weightings and controls from inverse dynamic joint moments that are computed from an alternative set of experimental measurements—movement kinematics and kinetics. This technique was applied to joint moments for healthy human walking at 0.7 and 1.7 m/s, and two sets of “simulated” synergies were computed based on two different criteria (1) synergies were required to minimize errors between experimental and simulated joint moments in a musculoskeletal model (pure-synergy solution) (2) along with minimizing joint moment errors, synergies also minimized muscle activation levels (optimal-synergy solution). On comparing the two solutions, it was observed that the introduction of optimality requirements (optimal-synergy) to a control strategy solely aimed at reproducing the joint moments (pure-synergy) did not necessitate major changes in the muscle grouping within synergies or the temporal profiles of synergy control signals. Synergies from both the simulated solutions exhibited many similarities to EMG derived synergies from a previously published study, thus implying that the analysis of the two different types of experimental data reveals similar, underlying synergy structures. PMID:25520645

  13. Muscle synergy organization is robust across a variety of postural perturbations.

    PubMed

    Torres-Oviedo, Gelsy; Macpherson, Jane M; Ting, Lena H

    2006-09-01

    We recently showed that four muscle synergies can reproduce multiple muscle activation patterns in cats during postural responses to support surface translations. We now test the robustness of functional muscle synergies, which specify muscle groupings and the active force vectors produced during postural responses under several biomechanically distinct conditions. We aimed to determine whether such synergies represent a generalized control strategy for postural control or if they are merely specific to each postural task. Postural responses to multidirectional translations at different fore-hind paw distances and to multidirectional rotations at the preferred stance distance were analyzed. Five synergies were required to adequately reconstruct responses to translation at the preferred stance distance-four were similar to our previous analysis of translation, whereas the fifth accounted for the newly added background activity during quiet stance. These five control synergies could account for > 80% total variability or r2 > 0.6 of the electromyographic and force tuning curves for all other experimental conditions. Forces were successfully reconstructed but only when they were referenced to a coordinate system that rotated with the limb axis as stance distance changed. Finally, most of the functional muscle synergies were similar across all of the six cats in terms of muscle synergy number, synergy activation patterns, and synergy force vectors. The robustness of synergy organization across perturbation types, postures, and animals suggests that muscle synergies controlling task-variables are a general construct used by the CNS for balance control.

  14. The flexion synergy, mother of all synergies and father of new models of gait

    PubMed Central

    Duysens, Jacques; De Groote, Friedl; Jonkers, Ilse

    2013-01-01

    Recently there has been a growing interest in the modular organization of leg movements, in particular those related to locomotion. One of the basic modules involves the flexion of the leg during swing and it was shown that this module is already present in neonates (Dominici et al., 2011). In this paper, we question how these finding build upon the original work by Sherrington, who proposed that the flexor reflex is the basic building block of flexion during swing phase. Similarly, the relation between the flexor reflex and the withdrawal reflex modules of Schouenborg and Weng (1994) will be discussed. It will be argued that there is large overlap between these notions on modules and the older concepts of reflexes. In addition, it will be shown that there is a great flexibility in the expression of some of these modules during gait, thereby allowing for a phase-dependent modulation of the appropriate responses. In particular, the end of the stance phase is a period when the flexor synergy is facilitated. It is proposed that this is linked to the activation of circuitry that is responsible for the generation of locomotor patterns (CPG, “central pattern generator”). More specifically, it is suggested that the responses in that period relate to the activation of a flexor burst generator. The latter structure forms the core of a new asymmetric model of the CPG. This activation is controlled by afferent input (facilitation by a broad range of afferents, suppression by load afferent input). Meanwhile, many of these physiologic features have found their way in the control of very flexible walking bipedal robots. PMID:23494365

  15. Evaluation of synergy in tire rubber-coal coprocessing

    SciTech Connect

    Mastral, A.M.; Mayoral, M.C.; Murillo, R.; Callen, M.; Garcia, T.; Tejero, M.P.; Torres, N.

    1998-09-01

    The tire rubber-coal synergy is evaluated through the different roles that rubber can have in coprocessing systems. For that, two different experimental designs were used: a swept fixed-bed reactor and tubing bomb minireactors. In this way, coal was coprocessed with rubber liquids from rubber pyrolysis and rubber hydrogenation, in a hydrogen atmosphere at 400 C. Coal was mixed as well with rubber in different proportions and hydrogenated at 375, 400, and 425 C, and oils obtained were characterized by thin-layer chromatography to obtain hydrocarbon type composition. Rubber behavior was compared to each of the main components of tires, and all the results indicated that the slight synergy found can be due to the small free radicals from vulcanized rubber decomposition, which are able to stabilize coal radicals to light products.

  16. Interpersonal synergies: static prehension tasks performed by two actors.

    PubMed

    Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun; Zatsiorsky, Vladimir M; Latash, Mark L

    2016-08-01

    We investigated multidigit synergies stabilizing components of the resultant force vector during joint performance of a static prehension task by two persons as compared to similar tasks performed by a single person using both hands. Subjects transferred the instrumented handle from the right hand to the left hand (one-person condition) or passed that handle to another person (two-person condition) while keeping the handle's position and orientation stationary. Only three digits were involved per hand, the thumb, the index finger, and the middle finger; the forces and moments produced by the digits were measured by six-component sensors. We estimated the performance-stabilizing synergies within the uncontrolled manifold framework by quantifying the intertrial variance structure of digit forces and moments. The analysis was performed at three levels: between hands, between virtual finger and virtual thumb (imagined digits producing the same mechanical variables as the corresponding actual digits combined) produced by the two hands (in both interpersonal and intrapersonal conditions), and between the thumb and virtual finger for one hand only. Additionally, we performed correlation and phase synchronization analyses of resultant tangential forces and internal normal forces. Overall, the one-person conditions were characterized by higher amount of intertrial variance that did not affect resultant normal force components, higher internal components of normal forces, and stronger synchronization of the normal forces generated by the hands. Our observations suggest that in two-person tasks, when participants try to achieve a common mechanical outcome, the performance-stabilizing synergies depend on non-visual information exchange, possibly via the haptic and proprioceptive systems. Therefore, synergies quantified in tasks using visual feedback only may not be generalizable to more natural tasks. PMID:27021074

  17. Synergy between Printex nano-carbons and silver nanoparticles for sensitive estimation of antioxidant activity.

    PubMed

    Raymundo-Pereira, Paulo A; Campos, Anderson M; Prado, Thiago M; Furini, Leonardo N; Boas, Naiza V; Calegaro, Marcelo L; Machado, Sergio A S

    2016-07-01

    We report on the synthesis, characterization and applications of a Printex L6 carbon-silver hybrid nanomaterial (PC-Ag), which was obtained using a polyol method. In addition, we also highlight the use of Printex L6 nano-carbon as a much cheaper alternative to the use of carbon nanotubes and graphene. The silver nanoparticles (AgNP) were prepared directly on the surface of the Printex 6L carbon "nanocarbon" material using ethylene glycol as the reducing agent. The hybrid nanomaterial was characterized by High-angle annular dark-field transmission electron microscopy (HAADF-TEM), energy-dispersive X-ray spectroscopy (EDX), selected area electron diffraction (SAED), Raman spectroscopy and cyclic voltammetry. Optimized electrocatalytic activity on glassy carbon electrode was reached for the architecture GC/PC-Ag, the silver nanoparticles with size ranging between 1 and 2 nm were well-distributed throughout the hybrid material. The synergy between PC nano-carbons and AgNPs was verified by detection of gallic acid (GA) at a low applied potential (0.091 V vs. Ag/AgCl). GA detection was performed in a concentration range between 5.0 × 10(-7) and 8.5 × 10(-6) mol L(-1), with a detection limit of 6.63 × 10(-8) mol L(-1) (66.3 nmol L(-1)), which is considerably lower than similar devices. The approach for fabricating the reproducible GC/PC-Ag electrodes is entirely generic and may be explored for other types of (bio)sensors and devices. PMID:27216397

  18. A synergy-driven approach to a myoelectric hand.

    PubMed

    Godfrey, S B; Ajoudani, A; Catalano, M; Grioli, G; Bicchi, A

    2013-06-01

    In this paper, we present the Pisa/IIT SoftHand with myoelectric control as a synergy-driven approach for a prosthetic hand. Commercially available myoelectric hands are more expensive, heavier, and less robust than their body-powered counterparts; however, they can offer greater freedom of motion and a more aesthetically pleasing appearance. The Pisa/IIT SoftHand is built on the motor control principle of synergies through which the immense complexity of the hand is simplified into distinct motor patterns. As the SoftHand grasps, it follows a synergistic path with built-in flexibility to allow grasping of a wide variety of objects with a single motor. Here we test, as a proof-of-concept, 4 myoelectric controllers: a standard controller in which the EMG signal is used only as a position reference, an impedance controller that determines both position and stiffness references from the EMG input, a standard controller with vibrotactile force feedback, and finally a combined vibrotactile-impedance (VI) controller. Four healthy subjects tested the control algorithms by grasping various objects. All controllers were sufficient for basic grasping, however the impedance and vibrotactile controllers reduced the physical and cognitive load on the user, while the combined VI mode was the easiest to use of the four. While these results need to be validated with amputees, they suggest a low-cost, robust hand employing hardware-based synergies is a viable alternative to traditional myoelectric prostheses. PMID:24187196

  19. Hybrid compounds: from simple combinations to nanomachines.

    PubMed

    Müller-Schiffmann, Andreas; Sticht, Heinrich; Korth, Carsten

    2012-02-01

    The combination of two different and independently acting compounds into one covalently linked hybrid compound can convey synergy from the effects of both independently acting moieties to the new composite compound, leading to a pharmacological potency greater than the sum of each individual moiety's potencies. Here, we review a variety of such hybrid compounds, which can consist of various functional parts, molecular recognition or subcellular targeting moieties, or combinations thereof, acting either simultaneously or sequentially. Such moieties within a hybrid compound can consist of a variety of substance classes, including small organic molecules, polypeptides or nucleic acids identified either via rational molecular design or selection from libraries. Precedent for hybrid compounds comes from naturally occurring proteins and small molecules, such as botulinum toxin and bleomycin, which are secreted by micro-organisms. We review the high degree of suitability of hybrid compounds for the treatment of multifactorial diseases by simultaneously hitting several targets along an identified disease pathway. Examples are hybrid compounds against Alzheimer's disease, against the cancer-relevant phosphoinisitide-3-kinase (PI3K)/AKT/mammalian target of rapamycin (mTOR) and epidermal growth factor signaling cascade, or in antimalarial therapy via simultaneous hitting of different mechanisms of hemozoin formation. Molecular recognition by peptides or aptamers (recognition-specific RNA or peptide sequences) can be combined with the transport of small molecule β-sheet breakers or toxins, or targeting to ubiquitin-dependent proteolysis. The vision of molecular nanomachines is currently realized in sequentially acting modular nanotransporters, consisting of four modules including a target, a membrane and nuclear translocation sequence, as well as a drug attachment domain. Through the rational combination of existing drugs and the synergy of their effects, a rapid

  20. Novel Methods to Enhance Precision and Reliability in Muscle Synergy Identification during Walking

    PubMed Central

    Kim, Yushin; Bulea, Thomas C.; Damiano, Diane L.

    2016-01-01

    Muscle synergies are hypothesized to reflect modular control of muscle groups via descending commands sent through multiple neural pathways. Recently, the number of synergies has been reported as a functionally relevant indicator of motor control complexity in individuals with neurological movement disorders. Yet the number of synergies extracted during a given activity, e.g., gait, varies within and across studies, even for unimpaired individuals. With no standardized methods for precise determination, this variability remains unexplained making comparisons across studies and cohorts difficult. Here, we utilize k-means clustering and intra-class and between-level correlation coefficients to precisely discriminate reliable from unreliable synergies. Electromyography (EMG) was recorded bilaterally from eight leg muscles during treadmill walking at self-selected speed. Muscle synergies were extracted from 20 consecutive gait cycles using non-negative matrix factorization. We demonstrate that the number of synergies is highly dependent on the threshold when using the variance accounted for by reconstructed EMG. Beyond use of threshold, our method utilized a quantitative metric to reliably identify four or five synergies underpinning walking in unimpaired adults and revealed synergies having poor reproducibility that should not be considered as true synergies. We show that robust and unreliable synergies emerge similarly, emphasizing the need for careful analysis in those with pathology. PMID:27695403

  1. Novel Methods to Enhance Precision and Reliability in Muscle Synergy Identification during Walking

    PubMed Central

    Kim, Yushin; Bulea, Thomas C.; Damiano, Diane L.

    2016-01-01

    Muscle synergies are hypothesized to reflect modular control of muscle groups via descending commands sent through multiple neural pathways. Recently, the number of synergies has been reported as a functionally relevant indicator of motor control complexity in individuals with neurological movement disorders. Yet the number of synergies extracted during a given activity, e.g., gait, varies within and across studies, even for unimpaired individuals. With no standardized methods for precise determination, this variability remains unexplained making comparisons across studies and cohorts difficult. Here, we utilize k-means clustering and intra-class and between-level correlation coefficients to precisely discriminate reliable from unreliable synergies. Electromyography (EMG) was recorded bilaterally from eight leg muscles during treadmill walking at self-selected speed. Muscle synergies were extracted from 20 consecutive gait cycles using non-negative matrix factorization. We demonstrate that the number of synergies is highly dependent on the threshold when using the variance accounted for by reconstructed EMG. Beyond use of threshold, our method utilized a quantitative metric to reliably identify four or five synergies underpinning walking in unimpaired adults and revealed synergies having poor reproducibility that should not be considered as true synergies. We show that robust and unreliable synergies emerge similarly, emphasizing the need for careful analysis in those with pathology.

  2. Consequences of biomechanically constrained tasks in the design and interpretation of synergy analyses

    PubMed Central

    Tresch, Matthew C.; Perreault, Eric J.

    2015-01-01

    Matrix factorization algorithms are commonly used to analyze muscle activity and provide insight into neuromuscular control. These algorithms identify low-dimensional subspaces, commonly referred to as synergies, which can describe variation in muscle activity during a task. Synergies are often interpreted as reflecting underlying neural control; however, it is unclear how these analyses are influenced by biomechanical and task constraints, which can also lead to low-dimensional patterns of muscle activation. The aim of this study was to evaluate whether commonly used algorithms and experimental methods can accurately identify synergy-based control strategies. This was accomplished by evaluating synergies from five common matrix factorization algorithms using muscle activations calculated from 1) a biomechanically constrained task using a musculoskeletal model and 2) without task constraints using random synergy activations. Algorithm performance was assessed by calculating the similarity between estimated synergies and those imposed during the simulations; similarities ranged from 0 (random chance) to 1 (perfect similarity). Although some of the algorithms could accurately estimate specified synergies without biomechanical or task constraints (similarity >0.7), with these constraints the similarity of estimated synergies decreased significantly (0.3–0.4). The ability of these algorithms to accurately identify synergies was negatively impacted by correlation of synergy activations, which are increased when substantial biomechanical or task constraints are present. Increased variability in synergy activations, which can be captured using robust experimental paradigms that include natural variability in motor activation patterns, improved identification accuracy but did not completely overcome effects of biomechanical and task constraints. These results demonstrate that a biomechanically constrained task can reduce the accuracy of estimated synergies and highlight

  3. Evidence for altered upper extremity muscle synergies in chronic stroke survivors with mild and moderate impairment

    PubMed Central

    Roh, Jinsook; Rymer, William Z.; Beer, Randall F.

    2015-01-01

    Previous studies indicate that motor coordination may be achieved by assembling task-dependent combinations of a few muscle synergies, defined here as fixed patterns of activation across a set of muscles. Our recent study of severely impaired chronic stroke survivors showed that some muscle synergies underlying isometric force generation at the hand are altered in the affected arm. However, whether similar alterations are evident in stroke survivors with lesser impairment remains unclear. Accordingly, we examined muscle synergies underlying spatial patterns of elbow and shoulder muscle activation recorded during an isometric force target matching protocol performed by 16 chronic stroke survivors, evenly divided across mild and moderate impairment levels. We applied non-negative matrix factorization to identify the muscle synergies and compared their structure across groups, including previously collected data from six age-matched control subjects and eight severely impaired stroke survivors. For all groups, EMG spatial patterns were well explained by task-dependent combinations of only a few (typically 4) muscle synergies. Broadly speaking, elbow-related synergies were conserved across stroke survivors, regardless of impairment level. In contrast, the shoulder-related synergies of some stroke survivors with mild and moderate impairment differed from controls, in a manner similar to severely impaired subjects. Cluster analysis of pooled synergies for the 30 subjects identified seven distinct clusters (synergies). Subsequent analysis confirmed that the incidences of three elbow-related synergies were independent of impairment level, while the incidences of four shoulder-related synergies were systematically correlated with impairment level. Overall, our results suggest that alterations in the shoulder muscle synergies underlying isometric force generation appear prominently in mild and moderate stroke, as in most cases of severe stroke, in an impairment level

  4. Classification of hand and wrist tasks of unknown force levels using muscle synergies.

    PubMed

    Atoufi, B; Kamavuako, E N; Hudgins, B; Englehart, K

    2015-08-01

    Muscle synergies have been proposed as a way for the central nervous system (CNS) to simplify the generation of motor commands and they have been shown to explain a large portion of the variation in the muscle patterns across a variety of conditions. However, whether human subjects are able to control prostheses proportionally with a small set of synergies has not been tested directly. Here we investigated if muscle synergies can be used to identify different wrist and hand motions. We recorded electromyographic (EMG) activity from eight arm muscles while the subjects exerted seven different intensity levels during the motions when performing seven classes of hand and wrist motion. From these data we extracted the muscle synergies and classified the tasks associated to each contraction intensity profile by linear discriminant analysis (LDA). We compared the performance obtained using muscle synergies with the performance of using the mean absolute values (MAV) as a feature. Also, the consistency of extracted muscle synergies was studied across intensity variations. While the synergies showed relative consistency particularly across closer intensity levels, average classification results generated with the synergies were less accurate than MAVs. These results indicate that although the performance of muscle synergies was very close to MAVs, they do not provide additional information for task identification across different exerted intensity levels. PMID:26736595

  5. Effects of unilateral stroke on multi-finger synergies and their feed-forward adjustments.

    PubMed

    Jo, H J; Maenza, C; Good, D C; Huang, X; Park, J; Sainburg, R L; Latash, M L

    2016-04-01

    We explored the changes in multi-finger synergies in patients after a single cortical stroke with mild motor impairments. We hypothesized that both synergy indices and anticipatory synergy adjustments prior to the initiation of a self-paced quick action would be diminished in the patients compared to age-matched controls. The patients with history of cortical stroke, and age-matched controls (n=12 in each group) performed one-finger and multi-finger accurate force production tasks involving both steady-state and quick force pulse production. Finger interdependence (enslaving) and multi-finger synergies stabilizing total force were quantified. The stroke patients showed lower maximal finger forces, in particular in the contralesional hand, which also showed increased enslaving indices. Multi-finger synergies during steady-state force production were, however, unchanged after stroke. In contrast, a drop in the synergy index prior to the force pulse generation was significantly delayed in the stroke patients. Our results show that mild cortical stroke leads to no significant changes in multifinger synergies, but there is impairment in feed-forward adjustments of the synergies prior to a quick action, a drop in the maximal force production, and an increase in enslaving. We conclude that studies of synergies reveal two aspects of synergic control differentially affected by cortical stroke. PMID:26828408

  6. Synergy effects of herb extracts: pharmacokinetics and pharmacodynamic basis.

    PubMed

    Yang, Yong; Zhang, Zaiqi; Li, Shuping; Ye, Xiaoli; Li, Xuegang; He, Kai

    2014-01-01

    Herbal medicine, especially traditional Chinese medicine and Ayurvedic medicine have played and still play an important role in fighting against various diseases. Emerging clinical studies regarding traditional Chinese medicine have provided convincing evidence for the first time to gain credibility and reputation outside China. Although synergistic therapeutic actions of herbal ingredients have been frequently reported, few reports have offered clear underlying mechanisms. This might be the main reason for the conflicting views with respect to the therapeutic efficacy of medicinal herbs. Therefore, this paper reviews the herb synergisms reported in the recent literature and discusses thoroughly the mechanisms underlying synergistic actions of herbal ingredients. The authors conducted an electronic literature search to detect articles published mainly in the last five years. Articles were included if they pertained to synergy research of ethnomedicines or the active compounds derived from them, included verification of synergy effects using modern analytical tools and molecular-biological methods. Results have revealed that the multi-component nature of medicinal herbs makes them particularly suitable for treating complex diseases and offers great potential for exhibiting synergistic actions. The mechanisms underlying synergistic therapeutic actions of herb medicines are (1): different agents may regulate either the same or different target in various pathways, and therefore cooperate in an agonistic, synergistic way; (2): regulate the enzymes and transporters that are involved in hepatic and intestinal metabolism to improve oral drug bioavailability; (3): overcome the drug resistance mechanisms of microbial and cancer cells; and (4): eliminate the adverse effects and enhance pharmacological potency of agents by "processing" or by drug-drug interaction. The exploration of synergistic mechanisms of herbal ingredients will not only help researchers to discover new

  7. Force-stabilizing synergies in motor tasks involving two actors

    PubMed Central

    Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2015-01-01

    We investigated the ability of two persons to produce force-stabilizing synergies in accurate multi-finger force production tasks under visual feedback on the total force only. The subjects produced a time profile of total force (the sum of two hand forces in one-person tasks and the sum of two subject forces in two-person tasks) consisting of a ramp-up, steady-state, and ramp-down segments; the steady-state segment was interrupted in the middle by a quick force pulse. Analyses of the structure of inter-trial finger force variance, motor equivalence, anticipatory synergy adjustments (ASAs), and the unintentional drift of the sharing pattern were performed. The two-person performance was characterized by a dramatically higher amount of inter-trial variance that did not affect total force, higher finger force deviations that did not affect total force (motor equivalent deviations), shorter ASAs, and larger drift of the sharing pattern. The rate of sharing pattern drift correlated with the initial disparity between the forces produced by the two persons (or two hands). The drift accelerated following the quick force pulse. Our observations show that sensory information on the task-specific performance variable is sufficient for the organization of performance-stabilizing synergies. They suggest, however, that two actors are less likely to follow a single optimization criterion as compared to a single performer. The presence of ASAs in the two-person condition might reflect fidgeting by one or both of the subjects. We discuss the characteristics of the drift in the sharing pattern as reflections of different characteristic times of motion within the sub-spaces that affect and do not affect salient performance variables. PMID:26105756

  8. Force-stabilizing synergies in motor tasks involving two actors.

    PubMed

    Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun; Zatsiorsky, Vladimir M; Latash, Mark L

    2015-10-01

    We investigated the ability of two persons to produce force-stabilizing synergies in accurate multi-finger force production tasks under visual feedback on the total force only. The subjects produced a time profile of total force (the sum of two hand forces in one-person tasks and the sum of two subject forces in two-person tasks) consisting of a ramp-up, steady-state, and ramp-down segments; the steady-state segment was interrupted in the middle by a quick force pulse. Analyses of the structure of inter-trial finger force variance, motor equivalence, anticipatory synergy adjustments (ASAs), and the unintentional drift of the sharing pattern were performed. The two-person performance was characterized by a dramatically higher amount of inter-trial variance that did not affect total force, higher finger force deviations that did not affect total force (motor equivalent deviations), shorter ASAs, and larger drift of the sharing pattern. The rate of sharing pattern drift correlated with the initial disparity between the forces produced by the two persons (or two hands). The drift accelerated following the quick force pulse. Our observations show that sensory information on the task-specific performance variable is sufficient for the organization of performance-stabilizing synergies. They suggest, however, that two actors are less likely to follow a single optimization criterion as compared to a single performer. The presence of ASAs in the two-person condition might reflect fidgeting by one or both of the subjects. We discuss the characteristics of the drift in the sharing pattern as reflections of different characteristic times of motion within the subspaces that affect and do not affect salient performance variables. PMID:26105756

  9. Interdisciplinary Evidence-based Practice: Moving from Silos to Synergy

    PubMed Central

    Newhouse, Robin P.; Spring, Bonnie

    2010-01-01

    Despite the assumption that health care providers work synergistically in practice, professions have tended to be more exclusive than inclusive when it comes to educating students in a collaborative approach to interdisciplinary evidence-based practice (EBP). This article explores the state of academic and clinical training regarding interdisciplinary EBP, describes efforts to foster interdisciplinary EBP, and suggests strategies to accelerate the translation of EBP across disciplines. Moving from silos to synergy in interdisciplinary EBP will require a paradigm shift. Changes can be leveraged professionally and politically using national initiatives currently in place on improving quality and health care reform. PMID:21074648

  10. Knowledge-analytics synergy in Clinical Decision Support.

    PubMed

    Slonim, Noam; Carmeli, Boaz; Goldsteen, Abigail; Keller, Oliver; Kent, Carmel; Rinott, Ruty

    2012-01-01

    Clinical Decision Support (CDS) systems hold tremendous potential for improving patient care. Most existing systems are knowledge-based tools that rely on relatively simple rules. More recent approaches rely on analytics techniques to automatically mine EHR data to reveal meaningful insights. Here, we propose the Knowledge-Analytics Synergy paradigm for CDS, in which we synergistically combine existing relevant knowledge with analytics applied to EHR data. We propose a framework for implementing such a paradigm and demonstrate its principles over real-world clinical and genomic data of hypertensive patients.

  11. Muscle synergies as a predictive framework for the EMG patterns of new hand postures

    NASA Astrophysics Data System (ADS)

    Ajiboye, A. B.; Weir, R. F.

    2009-06-01

    Synchronous muscle synergies have been suggested as a framework for dimensionality reduction in muscle coordination. Many studies have shown that synergies form a descriptive framework for a wide variety of tasks. We examined if a muscle synergy framework could accurately predict the EMG patterns associated with untrained static hand postures, in essence, if they formed a predictive framework. Hand and forearm muscle activities were recorded while subjects statically mimed 33 postures of the American Sign Language alphabet. Synergies were extracted from a subset of training postures using non-negative matrix factorization and used to predict the EMG patterns of the remaining postures. Across the subject population, as few as 11 postures could form an eight-dimensional synergy framework that allowed for at least 90% prediction of the EMG patterns of all 33 postures, including trial-to-trial variations. Synergies were quite robust despite using different postures in the training set, and also despite using a varied number of postures. Estimated synergies were categorized into those which were subject-specific and those which were general to the population. Population synergies were sparser than the subject-specific synergies, typically being dominated by a single muscle. Subject-specific synergies were more balanced in the coactivation of multiple muscles. We suggest as a result that global muscle coordination may be a combination of higher order control of robust subject-specific muscle synergies and lower order control of individuated muscles, and that this control paradigm may be useful in the control of EMG-based technologies, such as artificial limbs and functional electrical stimulation systems.

  12. Synergy between low and high energy radical femtochemistry

    NASA Astrophysics Data System (ADS)

    Gauduel, Y. A.

    2011-01-01

    The deleterious effects of ionizing radiation on integrated biological targets being dependent on the spatio-temporal distribution of short-lived radical processes, a thorough knowledge of these early events requires a real-time probing in the range 10-15 - 10-10 s. This manuscript review is focused on the synergy that exists between low (1-10 eV) and high (MeV) energy radiation femtochemistry (LERF, HERF respectively). The synergy remains crucial for the investigation of primary radical processes that take place within the prethermal regime of low energy secondary electrons. The quantum character of very-short lived electron in a prehydrated configuration provides a unique sub-nanometric probe to spatially explore some early radiation-induced biomolecular damage. This approach would foreshadow the development of innovative applications for spatio-temporal radiation biology such as, i) a highly-selective pro-drug activation using well-defined quantum states of short-lived radicals, ii) the real-time nanodosimetry in biologically relevant environments, and iii) the ultrashort irradiation of living cells.

  13. Discovering Pair-wise Synergies in Microarray Data

    PubMed Central

    Chen, Yuan; Cao, Dan; Gao, Jun; Yuan, Zheming

    2016-01-01

    Informative gene selection can have important implications for the improvement of cancer diagnosis and the identification of new drug targets. Individual-gene-ranking methods ignore interactions between genes. Furthermore, popular pair-wise gene evaluation methods, e.g. TSP and TSG, are helpless for discovering pair-wise interactions. Several efforts to discover pair-wise synergy have been made based on the information approach, such as EMBP and FeatKNN. However, the methods which are employed to estimate mutual information, e.g. binarization, histogram-based and KNN estimators, depend on known data or domain characteristics. Recently, Reshef et al. proposed a novel maximal information coefficient (MIC) measure to capture a wide range of associations between two variables that has the property of generality. An extension from MIC(X; Y) to MIC(X1; X2; Y) is therefore desired. We developed an approximation algorithm for estimating MIC(X1; X2; Y) where Y is a discrete variable. MIC(X1; X2; Y) is employed to detect pair-wise synergy in simulation and cancer microarray data. The results indicate that MIC(X1; X2; Y) also has the property of generality. It can discover synergic genes that are undetectable by reference feature selection methods such as MIC(X; Y) and TSG. Synergic genes can distinguish different phenotypes. Finally, the biological relevance of these synergic genes is validated with GO annotation and OUgene database. PMID:27470995

  14. Discovering Pair-wise Synergies in Microarray Data.

    PubMed

    Chen, Yuan; Cao, Dan; Gao, Jun; Yuan, Zheming

    2016-01-01

    Informative gene selection can have important implications for the improvement of cancer diagnosis and the identification of new drug targets. Individual-gene-ranking methods ignore interactions between genes. Furthermore, popular pair-wise gene evaluation methods, e.g. TSP and TSG, are helpless for discovering pair-wise interactions. Several efforts to discover pair-wise synergy have been made based on the information approach, such as EMBP and FeatKNN. However, the methods which are employed to estimate mutual information, e.g. binarization, histogram-based and KNN estimators, depend on known data or domain characteristics. Recently, Reshef et al. proposed a novel maximal information coefficient (MIC) measure to capture a wide range of associations between two variables that has the property of generality. An extension from MIC(X; Y) to MIC(X1; X2; Y) is therefore desired. We developed an approximation algorithm for estimating MIC(X1; X2; Y) where Y is a discrete variable. MIC(X1; X2; Y) is employed to detect pair-wise synergy in simulation and cancer microarray data. The results indicate that MIC(X1; X2; Y) also has the property of generality. It can discover synergic genes that are undetectable by reference feature selection methods such as MIC(X; Y) and TSG. Synergic genes can distinguish different phenotypes. Finally, the biological relevance of these synergic genes is validated with GO annotation and OUgene database. PMID:27470995

  15. Food synergy: the key to a healthy diet.

    PubMed

    Jacobs, David R; Tapsell, Linda C

    2013-05-01

    Food synergy is the concept that the non-random mixture of food constituents operates in concert for the life of the organism eaten and presumably for the life of the eater. Isolated nutrients have been extensively studied in well-designed, long-term, large randomised clinical trials, typically with null and sometimes with harmful effects. Therefore, although nutrient deficiency is a known phenomenon, serious for the sufferer, and curable by taking the isolated nutrient, the effect of isolated nutrients or other chemicals derived from food on chronic disease, when that chemical is not deficient, may not have the same beneficial effect. It appears that the focus on nutrients rather than foods is in many ways counterproductive. This observation is the basis for the argument that nutrition research should focus more strongly on foods and on dietary patterns. Unlike many dietary phenomena in nutritional epidemiology, diet pattern appears to be highly correlated over time within person. A consistent and robust conclusion is that certain types of beneficial diet patterns, notably described with words such as 'Mediterranean' and 'prudent', or adverse patterns, often described by the word 'Western', predict chronic disease. Food is much more complex than drugs, but essentially uninvestigated as food or pattern. The concept of food synergy leads to new thinking in nutrition science and can help to forge rational nutrition policy-making and to determine future nutrition research strategies.

  16. Supersite synergies improve volcanic SO2 flux monitoring

    NASA Astrophysics Data System (ADS)

    Burton, Michael; Di Muro, Andrea

    2014-05-01

    Both the Etna, Italy, volcano and Piton de la Fournaise (PdF), France, volcano Supersites are monitored with networks of scanning UV spectrometers. An ongoing collaboration between INGV and IPGP researchers has led to a dynamic technology transfer of novel new data analysis procedures to both networks. This new approach has been custom built to account for the particularities of both Supersites. For the Etna Supersite, the large, continuous gas emission, wide plumes and high plume height produce significant challenges for automatic networks of scanning UV spectrometers, due to the lack of a clear sky spectrum and light dilution effects. The novel approach presented here addresses both these issues. In the case of the PdF Supersite, negligible SO2 efflux is observed apart from immediately before, during and after volcanic eruptions. This necessitates a very sensitive and precise automatic analysis in order to detect the first whiffs of SO2 which act as a precursor to eruptive activity. Exactly such a solution has been developed and is demonstrated here. The technology transfer between these two Supersites promotes synergistic advantages, improving the monitoring capacity at both sites. However, until now such synergies have come about exclusively through local support from each site and the initiative of individual researchers. The full potential of such synergies can be greatly enhanced in the future if they are fully recognised and supported within the context of the Supersite initiative.

  17. Potent Synergy between Spirocyclic Pyrrolidinoindolinones and Fluconazole against Candida albicans.

    PubMed

    Premachandra, Ilandari Dewage Udara Anulal; Scott, Kevin A; Shen, Chengtian; Wang, Fuqiang; Lane, Shelley; Liu, Haoping; Van Vranken, David L

    2015-10-01

    A spiroindolinone, (1S,3R,3aR,6aS)-1-benzyl-6'-chloro-5-(4-fluorophenyl)-7'-methylspiro[1,2,3a,6a-tetrahydropyrrolo[3,4-c]pyrrole-3,3'-1H-indole]-2',4,6-trione, was previously reported to enhance the antifungal effect of fluconazole against Candida albicans. A diastereomer of this compound was synthesized, along with various analogues. Many of the compounds were shown to enhance the antifungal effect of fluconazole against C. albicans, some with exquisite potency. One spirocyclic piperazine derivative, which we have named synazo-1, was found to enhance the effect of fluconazole with an EC50 value of 300 pM against a susceptible strain of C. albicans and going as low as 2 nM against some resistant strains. Synazo-1 exhibits true synergy with fluconazole, with an FIC index below 0.5 in the strains tested. Synazo-1 exhibited low toxicity in mammalian cells relative to the concentrations required for antifungal synergy.

  18. Potent Synergy between Spirocyclic Pyrrolidinoindolinones and Fluconazole against Candida albicans

    PubMed Central

    Premachandra, Ilandari Dewage Udara Anulal; Scott, Kevin A.; Shen, Chengtian; Wang, Fuqiang; Lane, Shelley; Liu, Haoping

    2015-01-01

    A spiroindolinone (1S,3R,3aR,6aS)-1-benzyl-6′-chloro-5-(4-fluorophenyl)-7′-methylspiro[1,2,3a,6a-tetrahydropyrrolo[3,4-c]pyrrole-3,3′-1H-indole]-2′,4,6-trione was previously reported to enhance the antifungal effect of fluconazole against C. albicans. A diastereomer of that compound was synthesized, along with various analogues. Many of the compounds were shown to enhance the antifungal effect of fluconazole against C. albicans, some with exquisite potency. One spirocyclic piperazine derivative, which we have named synazo-1, enhanced the effect of fluconazole with EC50 of 300 pM against a susceptible strain of C. albicans and as low as 2 nM against some resistant strains. Synazo-1 exhibits true synergy with fluconazole with an FIC index below 0.5 in the strains tested. Synazo-1 exhibited low toxicity in mammalian cells relative to the concentrations required for the antifungal synergy. PMID:26263912

  19. Force feedback reinforces muscle synergies in insect legs.

    PubMed

    Zill, Sasha N; Chaudhry, Sumaiya; Büschges, Ansgar; Schmitz, Josef

    2015-11-01

    The nervous system solves complex biomechanical problems by activating muscles in modular, synergist groups. We have studied how force feedback in substrate grip is integrated with effects of sense organs that monitor support and propulsion in insects. Campaniform sensilla are mechanoreceptors that encode forces as cuticular strains. We tested the hypothesis that integration of force feedback from receptors of different leg segments during grip occurs through activation of specific muscle synergies. We characterized the effects of campaniform sensilla of the feet (tarsi) and proximal segments (trochanter and femur) on activities of leg muscles in stick insects and cockroaches. In both species, mechanical stimulation of tarsal sensilla activated the leg muscle that generates substrate grip (retractor unguis), as well as proximal leg muscles that produce inward pull (tibial flexor) and support/propulsion (trochanteral depressor). Stimulation of campaniform sensilla on proximal leg segments activated the same synergistic group of muscles. In stick insects, the effects of proximal receptors on distal leg muscles changed and were greatly enhanced when animals made active searching movements. In insects, the task-specific reinforcement of muscle synergies can ensure that substrate adhesion is rapidly established after substrate contact to provide a stable point for force generation. PMID:26193626

  20. Synergy 3000 CCS{trademark}: A new precision cleaning agent

    SciTech Connect

    Hand, T.; Bohnert, G.; Carter, R.; Flink, F.; Powers, M.

    1995-11-01

    Some of the semiaqueous cleaners in use employ terpenes as the cleaning agent, usually followed by a water rinse to remove the cleaner. Because terpenes are not miscible in water, these cleaners require the addition of surfactant to facilitate the water rinsing step, complicating recycling of the cleaner for reuse. A new critical cleaning solvent (CCS), named Synergy 3000 CCS{trademark} is a proprietary blend of terpene and heterocyclic alcohol solvents formulated to remove polar and nonpolar contaminants such as rosin fluxes, machining oils, greases, waxes, tape adhesive residue and handling soils from electrical and mechanical components and assemblies. It is a high purity, low odor solvent that does not require surfactants for water rinsing, and is derived from naturally and annually renewable resources. It demonstrates a high loading capacity for soils, grease, and contaminants and is compatible with a wide range of engineering materials commonly used in electronics applications. All of its components are biodegradable, are approved as food additives, and have no known human health effects. It has been formulated to have a higher flash point than citrus terpenes and flammable alcohols, and can be recycled via distillation. This paper presents some of the tests and evaluations that were performed during the development of Synergy 3000 CCS{trademark}, hereafter referred to as CCS, as well as current and potential applications for the solvent.

  1. Intra-Personal and Inter-Personal Kinetic Synergies During Jumping

    PubMed Central

    Slomka, Kajetan; Juras, Grzegorz; Sobota, Grzegorz; Furmanek, Mariusz; Rzepko, Marian; Latash, Mark L.

    2015-01-01

    We explored synergies between two legs and two subjects during preparation for a long jump into a target. Synergies were expected during one-person jumping. No such synergies were expected between two persons jumping in parallel without additional contact, while synergies were expected to emerge with haptic contact and become stronger with strong mechanical contact. Subjects performed jumps either alone (each foot standing on a separate force platform) or in dyads (parallel to each other, each person standing on a separate force platform) without any contact, with haptic contact, and with strong coupling. Strong negative correlations between pairs of force variables (strong synergies) were seen in the vertical force in one-person jumps and weaker synergies in two-person jumps with the strong contact. For other force variables, only weak synergies were present in one-person jumps and no negative correlations between pairs of force variable for two-person jumps. Pairs of moment variables from the two force platforms at steady state showed positive correlations, which were strong in one-person jumps and weaker, but still significant, in two-person jumps with the haptic and strong contact. Anticipatory synergy adjustments prior to action initiation were observed in one-person trials only. We interpret the different results for the force and moment variables at steady state as reflections of postural sway. PMID:26839608

  2. A model-based approach to predict muscle synergies using optimization: application to feedback control

    PubMed Central

    Sharif Razavian, Reza; Mehrabi, Naser; McPhee, John

    2015-01-01

    This paper presents a new model-based method to define muscle synergies. Unlike the conventional factorization approach, which extracts synergies from electromyographic data, the proposed method employs a biomechanical model and formally defines the synergies as the solution of an optimal control problem. As a result, the number of required synergies is directly related to the dimensions of the operational space. The estimated synergies are posture-dependent, which correlate well with the results of standard factorization methods. Two examples are used to showcase this method: a two-dimensional forearm model, and a three-dimensional driver arm model. It has been shown here that the synergies need to be task-specific (i.e., they are defined for the specific operational spaces: the elbow angle and the steering wheel angle in the two systems). This functional definition of synergies results in a low-dimensional control space, in which every force in the operational space is accurately created by a unique combination of synergies. As such, there is no need for extra criteria (e.g., minimizing effort) in the process of motion control. This approach is motivated by the need for fast and bio-plausible feedback control of musculoskeletal systems, and can have important implications in engineering, motor control, and biomechanics. PMID:26500530

  3. Intra-Personal and Inter-Personal Kinetic Synergies During Jumping.

    PubMed

    Slomka, Kajetan; Juras, Grzegorz; Sobota, Grzegorz; Furmanek, Mariusz; Rzepko, Marian; Latash, Mark L

    2015-12-22

    We explored synergies between two legs and two subjects during preparation for a long jump into a target. Synergies were expected during one-person jumping. No such synergies were expected between two persons jumping in parallel without additional contact, while synergies were expected to emerge with haptic contact and become stronger with strong mechanical contact. Subjects performed jumps either alone (each foot standing on a separate force platform) or in dyads (parallel to each other, each person standing on a separate force platform) without any contact, with haptic contact, and with strong coupling. Strong negative correlations between pairs of force variables (strong synergies) were seen in the vertical force in one-person jumps and weaker synergies in two-person jumps with the strong contact. For other force variables, only weak synergies were present in one-person jumps and no negative correlations between pairs of force variable for two-person jumps. Pairs of moment variables from the two force platforms at steady state showed positive correlations, which were strong in one-person jumps and weaker, but still significant, in two-person jumps with the haptic and strong contact. Anticipatory synergy adjustments prior to action initiation were observed in one-person trials only. We interpret the different results for the force and moment variables at steady state as reflections of postural sway. PMID:26839608

  4. Actinide incineration in fusion-fission hybrid-A model nuclear synergy

    NASA Astrophysics Data System (ADS)

    Taczanowski, Stefan

    2012-06-01

    The alliance of fusion with fission is a cause worthy of great efforts, as being able to ease (if not even to solve) serious problems that both these forms of nuclear energy are facing. Very high investment costs caused by tokamak enormous size, material consumption and difficult technology put in doubt whether alone the minute demand for fuel raw material (Li) and lack of danger of uncontrolled supercriticality prove sufficient for making it competitive. Preliminary evaluations demonstrated that a radical shift of energy production i.e. the energy gain from plasma to fission blanket is feasible [1]. A reduction in the fusion component to about 2% at given system power allows for a radical drop in plasma Q down to the values of ˜0.2-0.3 achievable in small systems [2] (e.g. mirrors) of sizes comparable to fission reactors. As a result in a Fusion-Driven Actinide Incinerator (FDI) both radiations from the plasma: corpuscular (i.e. neutrons and ions) and photons are drastically reduced. Thus are too, first of all - the neutron induced radiation damage: DPA and gas production, then plasma-wall interactions. The fundamental safety of the system has been proved by simulation of its collapse that has shown preservation its subcriticality. Summarizing, all the above problems may be solved with synergic union of fusion with fission embodied in the concept of FDI - small and less expensive.

  5. Hierarchical nanostructure and synergy of multimolecular signalling complexes

    PubMed Central

    Sherman, Eilon; Barr, Valarie A.; Merrill, Robert K.; Regan, Carole K.; Sommers, Connie L.; Samelson, Lawrence E.

    2016-01-01

    Signalling complexes are dynamic, multimolecular structures and sites for intracellular signal transduction. Although they play a crucial role in cellular activation, current research techniques fail to resolve their structure in intact cells. Here we present a multicolour, photoactivated localization microscopy approach for imaging multiple types of single molecules in fixed and live cells and statistical tools to determine the nanoscale organization, topology and synergy of molecular interactions in signalling complexes downstream of the T-cell antigen receptor. We observe that signalling complexes nucleated at the key adapter LAT show a hierarchical topology. The critical enzymes PLCγ1 and VAV1 localize to the centre of LAT-based complexes, and the adapter SLP-76 and actin molecules localize to the periphery. Conditional second-order statistics reveal a hierarchical network of synergic interactions between these molecules. Our results extend our understanding of the nanostructure of signalling complexes and are relevant to studying a wide range of multimolecular complexes. PMID:27396911

  6. Hierarchical nanostructure and synergy of multimolecular signalling complexes

    NASA Astrophysics Data System (ADS)

    Sherman, Eilon; Barr, Valarie A.; Merrill, Robert K.; Regan, Carole K.; Sommers, Connie L.; Samelson, Lawrence E.

    2016-07-01

    Signalling complexes are dynamic, multimolecular structures and sites for intracellular signal transduction. Although they play a crucial role in cellular activation, current research techniques fail to resolve their structure in intact cells. Here we present a multicolour, photoactivated localization microscopy approach for imaging multiple types of single molecules in fixed and live cells and statistical tools to determine the nanoscale organization, topology and synergy of molecular interactions in signalling complexes downstream of the T-cell antigen receptor. We observe that signalling complexes nucleated at the key adapter LAT show a hierarchical topology. The critical enzymes PLCγ1 and VAV1 localize to the centre of LAT-based complexes, and the adapter SLP-76 and actin molecules localize to the periphery. Conditional second-order statistics reveal a hierarchical network of synergic interactions between these molecules. Our results extend our understanding of the nanostructure of signalling complexes and are relevant to studying a wide range of multimolecular complexes.

  7. Emerging Synergy between Nanotechnology and Implantable Biosensors: A Review

    PubMed Central

    Vaddiraju, Santhisagar; Tomazos, Ioannis; Burgess, Diane J; Jain, Faquir C; Papadimitrakopoulos, Fotios

    2010-01-01

    The development of implantable biosensors for continuous monitoring of metabolites is an area of sustained scientific and technological interest. On the other hand, nanotechnology, a discipline which deals with the properties of materials at the nanoscale, is developing as a potent tool to enhance the performance of these biosensors. This article reviews the current state of implantable biosensors, highlighting the synergy between nanotechnology and sensor performance. Emphasis is placed on the electrochemical method of detection in light of its widespread usage and substantial nanotechnology-based improvements in various aspects of electrochemical biosensor performance. Finally, issues regarding toxicity and biocompatibility of nanomaterials, along with future prospects for the application of nanotechnology in implantable biosensors, are discussed. PMID:20042326

  8. Anomalies and synergy in the caloric effects of magnetoelectrics

    NASA Astrophysics Data System (ADS)

    Anand, Shashwat; Waghmare, Umesh V.

    2014-12-01

    We determine isothermal entropy changes (Δ S) associated with electrocaloric, magnetocaloric, and the corresponding multicaloric effects in a model type-I multiferroic system using Landau-Devonshire thermodynamic analysis. We show that (a) the magnetocaloric effect exhibits an unexpected anomaly at the ferroelectric transition occurring at a high temperature, even in the absence of magnetic ordering, and (b) the synergy between electro- and magnetocaloric effects leads to a significantly enhanced multicaloric effect (\\mid Δ {{S}MultiCE}\\mid \\gt \\mid Δ {{S}ECE}\\mid +\\mid Δ {{S}MCE}\\mid ) over a wide temperature range when the difference in temperatures of magnetic and ferroelectric ordering (\\mid Δ {{T}C}\\mid =\\mid TCE-TCM\\mid ) is small. This result originate from the coupled thermal fluctuations of magnetic and electric order parameters. While the former is useful in detecting multiferroic materials from the measurements covering higher temperature transition alone, the latter augurs well for caloric applications of multiferroics.

  9. Synergy between cellulases and pectinases in the hydrolysis of hemp.

    PubMed

    Zhang, Junhua; Pakarinen, Annukka; Viikari, Liisa

    2013-02-01

    The impact of pectinases in the hydrolysis of fresh, steam-exploded and ensiled hemp was investigated and the synergy between cellulases, pectinases and xylanase in the hydrolysis was evaluated. About half; 59.3% and 46.1% of pectin in the steam-exploded and ensiled hemp, respectively, could be removed by a low dosage of pectinases used. Pectinases were more efficient than xylanase in the hydrolysis of fresh and ensiled hemp whereas xylanase showed higher hydrolytic efficiency than the pectinase preparation used in the hydrolysis of steam-exploded hemp. Clear synergistic action between cellulases and xylanase could be observed in the hydrolysis of steam-exploded hemp. Supplementation of pectinase resulted in clear synergism with cellulases in the hydrolysis of all hemp substrates. Highest hydrolysis yield of steam-exploded hemp was obtained in the hydrolysis with cellulases and xylanase. In the hydrolysis of ensiled hemp, the synergistic action between cellulases and pectinases was more obvious for efficient hydrolysis.

  10. Synergies and trade-offs in achieving global biodiversity targets.

    PubMed

    Di Marco, Moreno; Butchart, Stuart H M; Visconti, Piero; Buchanan, Graeme M; Ficetola, Gentile F; Rondinini, Carlo

    2016-02-01

    After their failure to achieve a significant reduction in the global rate of biodiversity loss by 2010, world governments adopted 20 new ambitious Aichi biodiversity targets to be met by 2020. Efforts to achieve one particular target can contribute to achieving others, but different targets may sometimes require conflicting solutions. Consequently, lack of strategic thinking might result, once again, in a failure to achieve global commitments to biodiversity conservation. We illustrate this dilemma by focusing on Aichi Target 11. This target requires an expansion of terrestrial protected area coverage, which could also contribute to reducing the loss of natural habitats (Target 5), reducing human-induced species decline and extinction (Target 12), and maintaining global carbon stocks (Target 15). We considered the potential impact of expanding protected areas to mitigate global deforestation and the consequences for the distribution of suitable habitat for >10,000 species of forest vertebrates (amphibians, birds, and mammals). We first identified places where deforestation might have the highest impact on remaining forests and then identified places where deforestation might have the highest impact on forest vertebrates (considering aggregate suitable habitat for species). Expanding protected areas toward locations with the highest deforestation rates (Target 5) or the highest potential loss of aggregate species' suitable habitat (Target 12) resulted in partially different protected area network configurations (overlapping with each other by about 73%). Moreover, the latter approach contributed to safeguarding about 30% more global carbon stocks than the former. Further investigation of synergies and trade-offs between targets would shed light on these and other complex interactions, such as the interaction between reducing overexploitation of natural resources (Targets 6, 7), controlling invasive alien species (Target 9), and preventing extinctions of native

  11. GlobCurrent: Sentinel-3 Synergy in Action

    NASA Astrophysics Data System (ADS)

    Johannessen, J. A.; Chapron, B.; Collard, F.; Rio, M.-H.; Piolle, J.-F.; Quartly, G.; Shutler, J.; Escola, R.; Donlon, C.; Danielson, R.; Korosov, A.; Raj, R. P.; Kudryavtsev, V.; Roca, M.; Tournadre, J.; Larnicol, G.; Labroue, S.; Miller, P.; Nencioli, F.; Warren, M.; Hansen, M.

    2015-12-01

    The ESA Data User Element (DUE) funded GlobCurrent project (http://www.globcurrent.org) aims to: (i) advance the quantitative estimation of ocean surface currents from satellite sensor synergy; and (ii) demonstrate impact in user-led scientific, operational and commercial applications that, in turn, will improve and strengthen the uptake of satellite measurements. Today, a synergetic approach for quantitative analysis can build on high-resolution imaging radar and spectrometer data, infrared radiometer data and radar altimeter measurements. It will further integrate Sentinel-3 in combination with Sentinel-1 SAR data. From existing and past missions, it is often demonstrated that sharp gradients in the sea surface temperature (SST) field and the ocean surface chlorophyll-a distribution are spatially correlated with the sea surface roughness anomaly fields at small spatial scales, in the sub-mesocale (1-10 km) to the mesoscale (30-80 km). At the larger mesoscale range (>50 km), information derived from radar altimeters often depict the presence of coherent structures and eddies. The variability often appears largest in regions where the intense surface current regimes (>100 - 200 km) are found. These 2-dimensional structures manifested in the satellite observations represent evidence of the upper ocean (~100-200 m) dynamics. Whereas the quasi geostrophic assumption is valid for the upper ocean dynamics at the larger scale (>100 km), possible triggering mechanisms for the expressions at the mesoscale-to-sub-mesoscale may include spiraling tracers of inertial motion and the interaction of the wind-driven Ekman layer with the quasi-geostrophic current field. This latter, in turn, produces bands of downwelling (convergence) and upwelling (divergence) near fronts. A regular utilization of the sensor synergy approach with the combination of Sentinel-3 and Sentinel-1 will provide a highly valuable data set for further research and development to better relate the 2

  12. EFFECTS OF MUSCLE FATIGUE ON MULTI-MUSCLE SYNERGIES

    PubMed Central

    Singh, Tarkeshwar; Latash, Mark L.

    2011-01-01

    We studied the effects of fatigue of ankle dorsiflexors on multi-muscle synergies defined as co-varied adjustments of elemental variables (M-modes) that stabilize a task related performance variable (trajectory of the center of pressure, COP). M-modes were defined as muscle groups with parallel changes in activation levels. Healthy participants performed voluntary body sway in the anterior-posterior direction while trying to minimize sway in the medio-lateral direction at 0.25, 0.5 and 0.75 Hz. The trials were repeated before and during fatigue induced with a timed voluntary contraction against a constant load. Factor extraction using the principal component method was used to identify four M-modes within the space of integrated indices of muscle activity. Variance in the M-mode space at different phases across sway cycles was partitioned into two components, one that did not affect the average value of COP shift and the other that did. There were no significant effects of fatigue on variability of performance of the explicit task and on the amplitude of the COP shift. Variance of muscle activation indices and M-mode magnitudes increased during fatigue for muscles (and M-modes) both involved and not involved in the fatiguing exercise. Most of the M-mode variance increase was within the sub-space compatible with the unchanged COP trajectory resulting in an increase of the index of the multi-M-mode synergy. We conclude that one of the adaptive mechanisms to fatigue within a redundant multi-muscle system involves an increase in the variance of activation of non-fatigued muscles with a simultaneous increase in co-variation among muscle activations. The findings can be interpreted within the referent configuration hypothesis on the control of whole-body actions. PMID:21842189

  13. Effects of muscle fatigue on multi-muscle synergies.

    PubMed

    Singh, Tarkeshwar; Latash, Mark L

    2011-10-01

    We studied the effects of fatigue of ankle dorsiflexors on multi-muscle synergies defined as co-varied adjustments of elemental variables (M-modes) that stabilize a task-related performance variable (trajectory of the center of pressure, COP). M-modes were defined as muscle groups with parallel changes in activation levels. Healthy participants performed voluntary body sway in the anterior-posterior direction while trying to minimize sway in the medio-lateral direction at 0.25, 0.5, and 0.75 Hz. The trials were repeated before and during fatigue induced with a timed voluntary contraction against a constant load. Factor extraction using the principal component method was used to identify four M-modes within the space of integrated indices of muscle activity. Variance in the M-mode space at different phases across sway cycles was partitioned into two components, one that did not affect the average value of COP shift and the other that did. There were no significant effects of fatigue on variability of performance of the explicit task and on the amplitude of the COP shift. Variance of muscle activation indices and M-mode magnitudes increased during fatigue for muscles (and M-modes) both involved and not involved in the fatiguing exercise. Most of the M-mode variance increase was within the sub-space compatible with the unchanged COP trajectory resulting in an increase of the index of the multi-M-mode synergy. We conclude that one of the adaptive mechanisms to fatigue within a redundant multi-muscle system involves an increase in the variance of activation of non-fatigued muscles with a simultaneous increase in co-variation among muscle activations. The findings can be interpreted within the referent configuration hypothesis on the control of whole-body actions. PMID:21842189

  14. Marine parameters from synergy of optical and radar satellite data

    NASA Astrophysics Data System (ADS)

    Lehner, S.; Hoja, D.; Schulz-Stellenfleth, J.

    In 2001 the European Space Agency ESA will launch the earth observation satellite ENVISAT. It will carry several instruments that provide new opportunities to measure oceanographic variables. Together, they represent the main measurement techniques of satellite oceanography, and complement each other in an ideal manner. These instruments are to be used in synergy to: Improve the analysis of measured wind and ocean wave fields, and thereby improve weather forecasting at weather centers; Determine the extent and variables of sea ice and develop a five-day sea ice prediction model, to support maritime shipping and offshore activities; Monitor and map sediment and suspended matter transport in coastal regions, especially in areas with large river estuaries, which greatly affects shipping lanes, harbors, and dredging activities; Monitor hydrobiological and bio-geochemical variables related to water quality in coastal regions and large inland waters, which affects ecology, coastal development, aquaculture, drinking water supplies, and tourism. To prepare the oceanographic community to make best use of the ENVISAT sensors in the pre-launch phase, existing algorithms to derive marine parameters are used and validated using data from the ERS SAR, the ERS RA, SeaWiFS and IRS MOS sensors now in operation. Derived products are used to address problems that can best be tackled using the synergy of radar and optical data, such as the effect of surface slicks on radar wind measurements, of sea state on ocean color, of wind and waves on the resuspension of suspended matter, and of wind and waves on sea ice variables.

  15. Robustness of muscle synergies underlying three-dimensional force generation at the hand in healthy humans

    PubMed Central

    Rymer, William Z.; Beer, Randall F.

    2012-01-01

    Previous studies using advanced matrix factorization techniques have shown that the coordination of human voluntary limb movements may be accomplished using combinations of a small number of intermuscular coordination patterns, or muscle synergies. However, the potential use of muscle synergies for isometric force generation has been evaluated mostly using correlational methods. The results of such studies suggest that fixed relationships between the activations of pairs of muscles are relatively rare. There is also emerging evidence that the nervous system uses independent strategies to control movement and force generation, which suggests that one cannot conclude a priori that isometric force generation is accomplished by combining muscle synergies, as shown in movement control. In this study, we used non-negative matrix factorization to evaluate the ability of a few muscle synergies to reconstruct the activation patterns of human arm muscles underlying the generation of three-dimensional (3-D) isometric forces at the hand. Surface electromyographic (EMG) data were recorded from eight key elbow and shoulder muscles during 3-D force target-matching protocols performed across a range of load levels and hand positions. Four synergies were sufficient to explain, on average, 95% of the variance in EMG datasets. Furthermore, we found that muscle synergy composition was conserved across biomechanical task conditions, experimental protocols, and subjects. Our findings are consistent with the view that the nervous system can generate isometric forces by assembling a combination of a small number of muscle synergies, differentially weighted according to task constraints. PMID:22279190

  16. Are Movement Disorders and Sensorimotor Injuries Pathologic Synergies? When Normal Multi-Joint Movement Synergies Become Pathologic

    PubMed Central

    Santello, Marco; Lang, Catherine E.

    2015-01-01

    The intact nervous system has an exquisite ability to modulate the activity of multiple muscles acting at one or more joints to produce an enormous range of actions. Seemingly simple tasks, such as reaching for an object or walking, in fact rely on very complex spatial and temporal patterns of muscle activations. Neurological disorders such as stroke and focal dystonia affect the ability to coordinate multi-joint movements. This article reviews the state of the art of research of muscle synergies in the intact and damaged nervous system, their implications for recovery and rehabilitation, and proposes avenues for research aimed at restoring the nervous system’s ability to control movement. PMID:25610391

  17. Beyond synergies. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    Schwartz, Andrew B.

    2016-07-01

    The target paper by Santello et al. [1] uses the observation that hand shape during grasping can be described by a small set of basic postures, or "synergies," to describe the possible neural basis of motor control during this complex behavior. In the literature, the term "synergy" has been used with a number of different meanings and is still loosely defined, making it difficult to derive concrete analogs of corresponding neural structure. Here, I will define "synergy" broadly, as a set of parameters bound together by a pattern of correlation. With this definition, it can be argued that behavioral synergies are just one facet of the correlational structuring used by the brain to generate behavior. As pointed out in the target article, the structure found in synergies is driven by the physical constraints of our bodies and our surroundings, combined with the behavioral control imparted by our nervous system. This control itself is based on correlational structure which is likely to be a fundamental property of brain function.

  18. Discovering Anti-platelet Drug Combinations with an Integrated Model of Activator-Inhibitor Relationships, Activator-Activator Synergies and Inhibitor-Inhibitor Synergies

    PubMed Central

    Lombardi, Federica; Golla, Kalyan; Fitzpatrick, Darren J.; Casey, Fergal P.; Moran, Niamh; Shields, Denis C.

    2015-01-01

    Identifying effective therapeutic drug combinations that modulate complex signaling pathways in platelets is central to the advancement of effective anti-thrombotic therapies. However, there is no systems model of the platelet that predicts responses to different inhibitor combinations. We developed an approach which goes beyond current inhibitor-inhibitor combination screening to efficiently consider other signaling aspects that may give insights into the behaviour of the platelet as a system. We investigated combinations of platelet inhibitors and activators. We evaluated three distinct strands of information, namely: activator-inhibitor combination screens (testing a panel of inhibitors against a panel of activators); inhibitor-inhibitor synergy screens; and activator-activator synergy screens. We demonstrated how these analyses may be efficiently performed, both experimentally and computationally, to identify particular combinations of most interest. Robust tests of activator-activator synergy and of inhibitor-inhibitor synergy required combinations to show significant excesses over the double doses of each component. Modeling identified multiple effects of an inhibitor of the P2Y12 ADP receptor, and complementarity between inhibitor-inhibitor synergy effects and activator-inhibitor combination effects. This approach accelerates the mapping of combination effects of compounds to develop combinations that may be therapeutically beneficial. We integrated the three information sources into a unified model that predicted the benefits of a triple drug combination targeting ADP, thromboxane and thrombin signaling. PMID:25875950

  19. Flare Hybrids

    NASA Astrophysics Data System (ADS)

    Tomczak, M.; Dubieniecki, P.

    2015-12-01

    On the basis of the Solar Maximum Mission observations, Švestka ( Solar Phys. 121, 399, 1989) introduced a new class of flares, the so-called flare hybrids. When they start, they look like typical compact flares (phase 1), but later on, they look like flares with arcades of magnetic loops (phase 2). We summarize the characteristic features of flare hybrids in soft and hard X-rays as well as in the extreme ultraviolet; these features allow us to distinguish flare hybrids from other flares. In this article, additional energy release or long plasma cooling timescales are suggested as possible causes of phase 2. We estimate the frequency of flare hybrids, and study the magnetic configurations favorable for flare hybrid occurrence. Flare hybrids appear to be quite frequent, and the difference between the lengths of magnetic loops in the two interacting loop systems seem to be a crucial parameter for determining their characteristics.

  20. On the Synergy Between Gaia and Transit Surveys

    NASA Astrophysics Data System (ADS)

    Sozzetti, A.

    2012-09-01

    With a nominal launch date of September 2013, ESA's Gaia global astrometry mission will soon herald us into the era of micro-arcsecond-level (μas) precision positional astronomy. In its all-sky survey, Gaia will monitor astrometrically hundreds of thousands of main-sequence stars within ≈ 200 pc, looking for the presence of giant planetary companions within a few AUs from their host stars. Indeed, the wealth of information in the Gaia catalogue of exoplanets will constitute a fundamental contribution to several areas of exoplanet science (e.g., [1]), in particular when seen as a complement to other techniques for planet detection and characterization [2]. I will briefly address some of the relevant technical issues (choose your preferred algorithm, make sure your solution is robust, then double-check using a completely different approach!) associated with the precise and accurate determination of astrometric orbits of planetary systems using Gaia data (see e.g., [3], and references therein, for details). I will then highlight some of the important synergies between Gaia high-precision astrometry and other on-going and planned, indirect and direct planetfinding and (atmospheric) characterization programs, both from the ground (e.g., HARPS-N, APACHE, SPHERE) and in space (e.g., Kepler, TESS, ECho), and over a broad range of wavelengths, utilizing the connection between Gaia and space-borne and ground-based transit surveys as a proxy. I will particularly focus on the potential for improved understanding of planetary systems orbital architecture and physical properties when Kepler's exquisitely accurate photometry (supported by high-precision groundbased radial-velocity measurements where possible) will be combined with Gaia's superbly precise distance estimates (<1%) for all bright Kepler Objects of Interest (KOIs, V < 14.5) in the Kepler field and with the 5-yr time baseline of Gaia astrometry. For example, as a direct consequence of the use of Gaia parallaxes in

  1. Forest Biomass Mapping From Lidar and Radar Synergies

    NASA Technical Reports Server (NTRS)

    Sun, Guoqing; Ranson, K. Jon; Guo, Z.; Zhang, Z.; Montesano, P.; Kimes, D.

    2011-01-01

    The use of lidar and radar instruments to measure forest structure attributes such as height and biomass at global scales is being considered for a future Earth Observation satellite mission, DESDynI (Deformation, Ecosystem Structure, and Dynamics of Ice). Large footprint lidar makes a direct measurement of the heights of scatterers in the illuminated footprint and can yield accurate information about the vertical profile of the canopy within lidar footprint samples. Synthetic Aperture Radar (SAR) is known to sense the canopy volume, especially at longer wavelengths and provides image data. Methods for biomass mapping by a combination of lidar sampling and radar mapping need to be developed. In this study, several issues in this respect were investigated using aircraft borne lidar and SAR data in Howland, Maine, USA. The stepwise regression selected the height indices rh50 and rh75 of the Laser Vegetation Imaging Sensor (LVIS) data for predicting field measured biomass with a R(exp 2) of 0.71 and RMSE of 31.33 Mg/ha. The above-ground biomass map generated from this regression model was considered to represent the true biomass of the area and used as a reference map since no better biomass map exists for the area. Random samples were taken from the biomass map and the correlation between the sampled biomass and co-located SAR signature was studied. The best models were used to extend the biomass from lidar samples into all forested areas in the study area, which mimics a procedure that could be used for the future DESDYnI Mission. It was found that depending on the data types used (quad-pol or dual-pol) the SAR data can predict the lidar biomass samples with R2 of 0.63-0.71, RMSE of 32.0-28.2 Mg/ha up to biomass levels of 200-250 Mg/ha. The mean biomass of the study area calculated from the biomass maps generated by lidar- SAR synergy 63 was within 10% of the reference biomass map derived from LVIS data. The results from this study are preliminary, but do show the

  2. Exploring the molecular basis of antifungal synergies using genome-wide approaches

    Technology Transfer Automated Retrieval System (TEKTRAN)

    This is a review article summarizing genomic profiling strategies for determining the mechanism of action of antifungal synergies, and highlighting the potential applications of these technologies. Given the limitations of currently available antifungal agents and the development of drug resistance...

  3. Investigating Conversational Dynamics: Interactive Alignment, Interpersonal Synergy, and Collective Task Performance

    ERIC Educational Resources Information Center

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, "interactive alignment" and "interpersonal synergy", and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between interlocutors, the synergy…

  4. Motor primitives and synergies in spinal cord and after injury– the current state of play

    PubMed Central

    Giszter, Simon F.; Hart, Corey B.

    2013-01-01

    Modular pattern generator elements, also known as burst synergies or motor primitives, have become a useful and important way of describing motor behavior, albeit controversial. It is suggested that these synergy elements may comprise part of the pattern shaping layers of a McCrea/Rybak two layer pattern generator, as well as being used in other ways in spinal cord. The data supporting modular synergies ranges across species including man and encompasses motor pattern analyses and neural recordings. Recently, synergy persistence and changes following clinical trauma have been presented. These new data underscore the importance of understanding the modular structure of motor behaviors and the underlying circuitry in order to best provide principled therapies and to understand phenomena reported in the clinic. We discuss the evidence and different viewpoints on modularity, the neural underpinnings identified thus far, and possible critical issues for the future of this area. PMID:23531009

  5. Simulating Serial-Target Antibacterial Drug Synergies Using Flux Balance Analysis

    PubMed Central

    Dantas, Gautam; Church, George M.; Galagan, James; Lehár, Joseph; Sommer, Morten O. A.

    2016-01-01

    Flux balance analysis (FBA) is an increasingly useful approach for modeling the behavior of metabolic systems. However, standard FBA modeling of genetic knockouts cannot predict drug combination synergies observed between serial metabolic targets, even though such synergies give rise to some of the most widely used antibiotic treatments. Here we extend FBA modeling to simulate responses to chemical inhibitors at varying concentrations, by diverting enzymatic flux to a waste reaction. This flux diversion yields very similar qualitative predictions to prior methods for single target activity. However, we find very different predictions for combinations, where flux diversion, which mimics the kinetics of competitive metabolic inhibitors, can explain serial target synergies between metabolic enzyme inhibitors that we confirmed in Escherichia coli cultures. FBA flux diversion opens the possibility for more accurate genome-scale predictions of drug synergies, which can be used to suggest treatments for infections and other diseases. PMID:26821252

  6. Using the Synergy Model to guide the practice of rapid response teams.

    PubMed

    Arashin, Kelly A

    2010-01-01

    The goals of Rapid Response Teams are to provide interventional care upon recognizing a clinical change in a patient's condition and to prevent further progression of declining health. There are many clinical situations in which the critical care nurse or advanced practice nurse can apply the Synergy Model to patient care. Understanding how the Synergy Model can guide the Rapid Response Team interventions and practice by identifying and matching patient and nurse characteristics can possibly achieve improved patient outcomes.

  7. Muscle Synergies Heavily Influence the Neural Control of Arm Endpoint Stiffness and Energy Consumption.

    PubMed

    Inouye, Joshua M; Valero-Cuevas, Francisco J

    2016-02-01

    Much debate has arisen from research on muscle synergies with respect to both limb impedance control and energy consumption. Studies of limb impedance control in the context of reaching movements and postural tasks have produced divergent findings, and this study explores whether the use of synergies by the central nervous system (CNS) can resolve these findings and also provide insights on mechanisms of energy consumption. In this study, we phrase these debates at the conceptual level of interactions between neural degrees of freedom and tasks constraints. This allows us to examine the ability of experimentally-observed synergies--correlated muscle activations--to control both energy consumption and the stiffness component of limb endpoint impedance. In our nominal 6-muscle planar arm model, muscle synergies and the desired size, shape, and orientation of endpoint stiffness ellipses, are expressed as linear constraints that define the set of feasible muscle activation patterns. Quadratic programming allows us to predict whether and how energy consumption can be minimized throughout the workspace of the limb given those linear constraints. We show that the presence of synergies drastically decreases the ability of the CNS to vary the properties of the endpoint stiffness and can even preclude the ability to minimize energy. Furthermore, the capacity to minimize energy consumption--when available--can be greatly affected by arm posture. Our computational approach helps reconcile divergent findings and conclusions about task-specific regulation of endpoint stiffness and energy consumption in the context of synergies. But more generally, these results provide further evidence that the benefits and disadvantages of muscle synergies go hand-in-hand with the structure of feasible muscle activation patterns afforded by the mechanics of the limb and task constraints. These insights will help design experiments to elucidate the interplay between synergies and the mechanisms

  8. Transdisciplinary breastfeeding support: Creating program and policy synergy across the reproductive continuum

    PubMed Central

    Labbok, Miriam H

    2008-01-01

    This paper was presented at the symposium on Breastfeeding and Feminism: A Focus on Reproductive Health, Rights and Justice. It underscores the power and potential of synergy between and among organizations and individuals supporting breastfeeding, the mother-child dyad, and reproductive health to increase sustainable breastfeeding support. These concepts were brought together to lay the groundwork for working group discussions of synergy in program and policy actions. PMID:18680583

  9. Quantifying Synergy: A Systematic Review of Mixture Toxicity Studies within Environmental Toxicology

    PubMed Central

    Cedergreen, Nina

    2014-01-01

    Cocktail effects and synergistic interactions of chemicals in mixtures are an area of great concern to both the public and regulatory authorities. The main concern is whether some chemicals can enhance the effect of other chemicals, so that they jointly exert a larger effect than predicted. This phenomenon is called synergy. Here we present a review of the scientific literature on three main groups of environmentally relevant chemical toxicants: pesticides, metal ions and antifouling compounds. The aim of the review is to determine 1) the frequency of synergy, 2) the extent of synergy, 3) whether any particular groups or classes of chemicals tend to induce synergy, and 4) which physiological mechanisms might be responsible for this synergy. Synergy is here defined as mixtures with minimum two-fold difference between observed and predicted effect concentrations using Concentration Addition (CA) as a reference model and including both lethal and sub-lethal endpoints. The results showed that synergy occurred in 7%, 3% and 26% of the 194, 21 and 136 binary pesticide, metal and antifoulants mixtures included in the data compilation on frequency. The difference between observed and predicted effect concentrations was rarely more than 10-fold. For pesticides, synergistic mixtures included cholinesterase inhibitors or azole fungicides in 95% of 69 described cases. Both groups of pesticides are known to interfere with metabolic degradation of other xenobiotics. For the four synergistic metal and 47 synergistic antifoulant mixtures the pattern in terms of chemical groups inducing synergy was less clear. Hypotheses in terms of mechanisms governing these interactions are discussed. It was concluded that true synergistic interactions between chemicals are rare and often occur at high concentrations. Addressing the cumulative rather than synergistic effect of co-occurring chemicals, using standard models as CA, is therefore regarded as the most important step in the risk

  10. The Einstein-Brazil Fogarty: A decade of synergy.

    PubMed

    Nosanchuk, Joshua D; Nosanchuk, Murphy D; Rodrigues, Marcio L; Nimrichter, Leonardo; Carvalho, Antonio C Campos de; Weiss, Louis M; Spray, David C; Tanowitz, Herbert B

    2015-01-01

    A rich, collaborative program funded by the US NIH Fogarty program in 2004 has provided for a decade of remarkable opportunities for scientific advancement through the training of Brazilian undergraduate, graduate and postdoctoral students from the Federal University and Oswaldo Cruz Foundation systems at Albert Einstein College of Medicine. The focus of the program has been on the development of trainees in the broad field of Infectious Diseases, with a particular focus on diseases of importance to the Brazilian population. Talented trainees from various regions in Brazil came to Einstein to learn techniques and study fungal, parasitic and bacterial pathogens. In total, 43 trainees enthusiastically participated in the program. In addition to laboratory work, these students took a variety of courses at Einstein, presented their results at local, national and international meetings, and productively published their findings. This program has led to a remarkable synergy of scientific discovery for the participants during a time of rapid acceleration of the scientific growth in Brazil. This collaboration between Brazilian and US scientists has benefitted both countries and serves as a model for future training programs between these countries.

  11. Locus equations are an acoustic expression of articulator synergy

    PubMed Central

    Iskarous, Khalil; Fowler, Carol A.; Whalen, D. H.

    2010-01-01

    The study investigated the articulatory basis of locus equations, regression lines relating F2 at the start of a Consonant-Vowel (CV) transition to F2 at the middle of the vowel, with C fixed and V varying. Several studies have shown that consonants of different places of articulation have locus equation slopes that descend from labial to velar to alveolar, and intercept magnitudes that increase in the opposite order. Using formulas from the theory of bivariate regression that express regression slopes and intercepts in terms of standard deviations and averages of the variables, it is shown that the slope directly encodes a well-established measure of coarticulation resistance. It is also shown that intercepts are directly related to the degree to which the tongue body assists the formation of the constriction for the consonant. Moreover, it is shown that the linearity of locus equations and the linear relation between locus equation slopes and intercepts originates in linearity in articulation between the horizontal position of the tongue dorsum in the consonant and to that in the vowel. It is concluded that slopes and intercepts of acoustic locus equations are measures of articulator synergy. PMID:20968373

  12. Facilitating Inter-Domain Synergies in Ambient Assisted Living Environments.

    PubMed

    Schwartze, Jonas; Schrom, Harald; Wolf, Klaus-Hendrik; Marschollek, Michael

    2016-01-01

    Current Ambient Assisted Living (AAL) environments lack integration of sensors and actuators of other sub-domains. Creating technical and organizational integration is addressed by the BASIS project (Build Automation by a Scalable and Intelligent System), which aims to build a cross-domain home bus system. The main objective of this paper is to present an overview of design, architecture and state of realization of BASIS by describing the requirements development process, underlying hardware design and software architecture. We built a distributed system of one independent building manager with several redundantly meshed segment controllers, each controlling a bus segment with any number of bus nodes. The software system layer is divided into logical partitions representing each sub-domain. Structured data storage is possible with a special FHIR based home centered data warehouse. The system has been implemented in six apartments running under daily living conditions. BASIS integrates a broad range of sub-domains, which poses challenges to all project partners in terms of a common terminology, and project management methods, but enables development of inter-domain synergies like using the same sensor and actuator hardware for a broad range of services and use cases. PMID:27577428

  13. Decline of North Atlantic eels: a fatal synergy?

    PubMed

    Wirth, Thierry; Bernatchez, Louis

    2003-04-01

    Panmictic species pose particular problems for conservation because their welfare can be addressed effectively only on a global scale. We recently documented by means of microsatellite analysis that the European eel (Anguilla anguilla) is not panmictic but instead shows genetic isolation by distance. In this study, we extended the analysis to the American eel (A. rostrata) by applying identical analytical procedures and statistical power. Results obtained for the American eel were in sharp contrast with those obtained for the European eel: the null hypothesis of panmixia could not be rejected, and no isolation by distance was detected. This implies that the species must be managed as a single population. Using Bayesian statistics, we also found that the effective population sizes for both species were surprisingly low and that the populations had undergone severe contractions, most probably during the Wisconsinan glaciation. The apparent sensitivity of eels to climatic changes affecting the strength and position of the Gulf Stream 20,000 years ago is particularly worrying, given the effects of the ongoing global warming on the North Atlantic climate. Moreover, additional short-term stresses such as surging glass eel prizes, overfishing and lethal parasitic infections negatively affect eel population size. The fascinating transatlantic migration and life cycle of Atlantic eels is also their Achilles' heel as these negative short- and long-term effects will probably culminate in a fatal synergy if drastic conservation measures are not implemented to protect these international biological resources.

  14. Techno-ecological synergy: a framework for sustainable engineering.

    PubMed

    Bakshi, Bhavik R; Ziv, Guy; Lepech, Michael D

    2015-02-01

    Even though the importance of ecosystems in sustaining all human activities is well-known, methods for sustainable engineering fail to fully account for this role of nature. Most methods account for the demand for ecosystem services, but almost none account for the supply. Incomplete accounting of the very foundation of human well-being can result in perverse outcomes from decisions meant to enhance sustainability and lost opportunities for benefiting from the ability of nature to satisfy human needs in an economically and environmentally superior manner. This paper develops a framework for understanding and designing synergies between technological and ecological systems to encourage greater harmony between human activities and nature. This framework considers technological systems ranging from individual processes to supply chains and life cycles, along with corresponding ecological systems at multiple spatial scales ranging from local to global. The demand for specific ecosystem services is determined from information about emissions and resource use, while the supply is obtained from information about the capacity of relevant ecosystems. Metrics calculate the sustainability of individual ecosystem services at multiple spatial scales and help define necessary but not sufficient conditions for local and global sustainability. Efforts to reduce ecological overshoot encourage enhancement of life cycle efficiency, development of industrial symbiosis, innovative designs and policies, and ecological restoration, thus combining the best features of many existing methods. Opportunities for theoretical and applied research to make this framework practical are also discussed.

  15. Synergy with new radio facilities: from LOFAR to SKA

    NASA Astrophysics Data System (ADS)

    Morganti, R.

    2016-06-01

    A number of new radio telescopes are coming on-line paving the way to the Square Kilometre Array. Their new capabilities, e.g. large field of view, broad instantaneous band and fast response, offer new possibilities for the science. I will briefly give an overview of the facilities that are becoming available. Many of them have open time and some are planning large surveys that will be made available to the entire astronomical community, providing an important legacy. I will then focus on some of the results obtained with the Low Frequency Array (LOFAR) on topics where a strong synergy with XMM is (or should be) present. In particular, I will focus on pulsars (e.g. fast switching mode pulsars) and accreting systems among the galactic objects. For the extragalactic objects, the combination radio/X-ray is key for understanding the energetics and, therefore, the impact that radio AGN have on their surroundings. I will in particular focus on results from observations of radio galaxies and clusters. Fast response to transient objects in the radio sky is also receiving a lot of attention with LOFAR (and other radio telescopes).

  16. Integrating parasitology and marine ecology: Seven challenges towards greater synergy

    NASA Astrophysics Data System (ADS)

    Poulin, Robert; Blasco-Costa, Isabel; Randhawa, Haseeb S.

    2016-07-01

    Despite their very different historical origins as scientific disciplines, parasitology and marine ecology have already combined successfully to make important contributions to our understanding of the functioning of natural ecosystems. For example, robust assessments of the contribution of parasites to ecosystem biomass and energetics, and of their impact on community-wide biodiversity and food web structure, have all been made for the first time in marine systems. Nevertheless, for the marriage between parasitology and marine ecology to remain fruitful, several challenges must first be overcome. We discuss seven such challenges on the road to a greater synergy between these disciplines: (1) Raising awareness of parasitism as an ecological force by increasing the proportion of articles about parasites and diseases in marine ecology journals; (2) Making greater use of theory and conceptual frameworks from marine ecology to guide parasitological research; (3) Speeding up or at least maintaining the current rate at which marine parasites are found and described; (4) Elucidating a greater proportion of life cycles in all major groups of marine parasites; (5) Increasing the number of host-parasite model systems on which our knowledge is based; (6) Extending parasitological research offshore and into ocean depths; and (7) Developing, as needed, new epidemiological theory and transmission models for the marine environment. None of these challenges is insurmountable, and addressing just a few of them should guarantee that parasitology and marine ecology will continue to join forces and make further substantial contributions.

  17. ESD and Education for All: synergies and potential conflicts

    NASA Astrophysics Data System (ADS)

    Gadotti, Moacir

    2010-06-01

    This paper analyses how Education for Sustainable Development (ESD) can assist in increasing access to quality education and discusses how it can contribute to the content and learning methods on the Education for All (EFA) agenda. It explores both the tensions and the common ground between ESD and EFA, and identifies the potential synergies between them. ESD implies a transformation of every aspect of school life at all levels: pre-school, primary and secondary. At the policy level, governments are in a position to establish links between ESD and EFA, recognising that the purpose of education is not just to support present economic development, but also to help individuals and societies to develop their potential without damaging the environment. At the grassroots level, in schools, much can—and must—be done by school leaders, teachers and students to integrate sustainability into all aspects of school life and the curriculum, thereby establishing connections between social, environmental, cultural and economic problems and achievements.

  18. Pathways to social evolution: reciprocity, relatedness, and synergy.

    PubMed

    Van Cleve, Jeremy; Akçay, Erol

    2014-08-01

    Many organisms live in populations structured by space and by class, exhibit plastic responses to their social partners, and are subject to nonadditive ecological and fitness effects. Social evolution theory has long recognized that all of these factors can lead to different selection pressures but has only recently attempted to synthesize how these factors interact. Using models for both discrete and continuous phenotypes, we show that analyzing these factors in a consistent framework reveals that they interact with one another in ways previously overlooked. Specifically, behavioral responses (reciprocity), genetic relatedness, and synergy interact in nontrivial ways that cannot be easily captured by simple summary indices of assortment. We demonstrate the importance of these interactions by showing how they have been neglected in previous synthetic models of social behavior both within and between species. These interactions also affect the level of behavioral responses that can evolve in the long run; proximate biological mechanisms are evolutionarily stable when they generate enough responsiveness relative to the level of responsiveness that exactly balances the ecological costs and benefits. Given the richness of social behavior across taxa, these interactions should be a boon for empirical research as they are likely crucial for describing the complex relationship linking ecology, demography, and social behavior.

  19. Comparison of Vehicle Efficiency Technology Attributes and Synergy Estimates

    SciTech Connect

    Duleep, G.

    2011-02-01

    Analyzing the future fuel economy of light-duty vehicles (LDVs) requires detailed knowledge of the vehicle technologies available to improve LDV fuel economy. The National Highway Transportation Safety Administration (NHTSA) has been relying on technology data from a 2001 National Academy of Sciences (NAS) study (NAS 2001) on corporate average fuel economy (CAFE) standards, but the technology parameters were updated in the new proposed rulemaking (EPA and NHTSA 2009) to set CAFE and greenhouse gas standards for the 2011 to 2016 period. The update is based largely on an Environmental Protection Agency (EPA) analysis of technology attributes augmented by NHTSA data and contractor staff assessments. These technology cost and performance data were documented in the Draft Joint Technical Support Document (TSD) issued by EPA and NHTSA in September 2009 (EPA/NHTSA 2009). For these tasks, the Energy and Environmental Analysis (EEA) division of ICF International (ICF) examined each technology and technology package in the Draft TSD and assessed their costs and performance potential based on U.S. Department of Energy (DOE) program assessments. ICF also assessed the technologies? other relevant attributes based on data from actual production vehicles and from recently published technical articles in engineering journals. ICF examined technology synergy issues through an ICF in-house model that uses a discrete parameter approach.

  20. Comparison of Vehicle Efficiency Technology Attributes and Synergy Estimates

    SciTech Connect

    Duleep, G.

    2011-02-01

    Analyzing the future fuel economy of light-duty vehicles (LDVs) requires detailed knowledge of the vehicle technologies available to improve LDV fuel economy. The National Highway Transportation Safety Administration (NHTSA) has been relying on technology data from a 2001 National Academy of Sciences (NAS) study (NAS 2001) on corporate average fuel economy (CAFE) standards, but the technology parameters were updated in the new proposed rulemaking (EPA and NHTSA 2009) to set CAFE and greenhouse gas standards for the 2011 to 2016 period. The update is based largely on an Environmental Protection Agency (EPA) analysis of technology attributes augmented by NHTSA data and contractor staff assessments. These technology cost and performance data were documented in the Draft Joint Technical Support Document (TSD) issued by EPA and NHTSA in September 2009 (EPA/NHTSA 2009). For these tasks, the Energy and Environmental Analysis (EEA) division of ICF International (ICF) examined each technology and technology package in the Draft TSD and assessed their costs and performance potential based on U.S. Department of Energy (DOE) program assessments. ICF also assessed the technologies, other relevant attributes based on data from actual production vehicles, and recently published technical articles in engineering journals. ICF examined technology synergy issues through an ICF in-house model that uses a discrete parameter approach.

  1. Facilitating Inter-Domain Synergies in Ambient Assisted Living Environments.

    PubMed

    Schwartze, Jonas; Schrom, Harald; Wolf, Klaus-Hendrik; Marschollek, Michael

    2016-01-01

    Current Ambient Assisted Living (AAL) environments lack integration of sensors and actuators of other sub-domains. Creating technical and organizational integration is addressed by the BASIS project (Build Automation by a Scalable and Intelligent System), which aims to build a cross-domain home bus system. The main objective of this paper is to present an overview of design, architecture and state of realization of BASIS by describing the requirements development process, underlying hardware design and software architecture. We built a distributed system of one independent building manager with several redundantly meshed segment controllers, each controlling a bus segment with any number of bus nodes. The software system layer is divided into logical partitions representing each sub-domain. Structured data storage is possible with a special FHIR based home centered data warehouse. The system has been implemented in six apartments running under daily living conditions. BASIS integrates a broad range of sub-domains, which poses challenges to all project partners in terms of a common terminology, and project management methods, but enables development of inter-domain synergies like using the same sensor and actuator hardware for a broad range of services and use cases.

  2. Energy mitigation, adaptation and biodiversity: Synergies and antagonisms

    NASA Astrophysics Data System (ADS)

    Berry, P. M.; Paterson, J. S.

    2009-11-01

    In this paper we review the current impacts of different energy producers (and energy conservation) on biodiversity and investigate the potential for achieving positive biodiversity effects along with mitigation and adaptation objectives. Very few energy producers achieve all three aims - although it may be possible with careful choice of location and management. In some instances, energy conservation can provide mitigation, adaptation and biodiversity benefits. There is still a gap in knowledge regarding the effects of newer energy technologies on biodiversity. There is an additional concern that many supposedly 'green' renewable energy projects may actually harm biodiversity to such a degree that their overall human benefits are negated. The increasing understanding that ecosystem services are vital for human well-being though means that attempting positive mitigation, adaptation and biodiversity conservation in the energy sector should be an imperative goal for international policy. Whilst research into synergies between mitigation and adaptation is established, there has been very little that has examined the impacts on biodiversity as well. Further work is required to identify and provide evidence of the best ways of optimising mitigation, adaptation and biodiversity in the energy sector.

  3. 10+ more years of Chandra-XMM-Newton Synergy

    NASA Astrophysics Data System (ADS)

    Wilkes, B.

    2016-06-01

    In this current golden age of X-ray astronomy, the frontiers of the X-ray Universe are continually expanding in multiple, often unexpected, directions, due to the extraordinary success and longevity of both ESA's XMM-Newton and NASA's Chandra X-ray Observatory. These two ground-breaking, major observatories are supported by a number of smaller, more focused missions which feed into and expand the discovery space of X-ray astronomy even further. With the prospect of another decade of observing, now is an excellent time to take stock of how far we have come, and to look forward to the future with a view to maximizing the scientific legacy of both XMM-Newton and Chandra. This not only involves optimizing the contents of the archives and the impact of the science results, but also laying the ground-work for the next generation of X-ray telescopes, led by ESA's Athena mission in the late 2020s. I will summarize the synergy between XMM-Newton and Chandra, including complementary capabilities which facilitate coordinated observations and science programs, and overlapping capabilities which often provide the necessary confirmation (or not) of new, marginal and/or controversial results.

  4. Ocean Surface reconstruction from the synergy of Sentinel-3 sensors

    NASA Astrophysics Data System (ADS)

    Gonzalez-Haro, C.; Autret, E.; Isern-Fontanet, J.; Tandeo, P.; Le Goff, C.; Garello, R.; Fablet, R.

    2015-12-01

    Along-track altimetric measurements of Sea Surface Heights (SSH) are very well suited to quantify across-track currents. However, the spatial resolution of derived 2D velocities is restricted to scales above 100-150 km and the limited number of altimeters can lead to errors in the location of currents. On the contrary, infrared measurements of Sea Surface Temperature (SST) are well suited to locate flow patterns but it is difficult to extract quantitative estimations of ocean currents. During the last years, some works began to exploit the synergy of SST and altimetry measurements in order to retrieve ocean currents. Nevertheless, all this previous works employed measurements which were near in time but not simultaneous. In that sense, Sentinel-3 is a multi-instrument mission that will circumvent this temporal limitation, providing simultaneous measurements of SST and altimetry with high-end accuracy and reliability. Our approach, based on the spectral properties of simultaneous SST and SSH observations, is tested using ENVISAT (RA, AATSR) data, since its geometry is similar to that of Sentinel-3 (SRAL, SLSTR).

  5. Global phosphorus scarcity: identifying synergies for a sustainable future.

    PubMed

    Neset, Tina-Simone S; Cordell, Dana

    2012-01-15

    Global food production is dependent on constant inputs of phosphorus. In the current system this phosphorus is not predominantly derived from organic recycled waste, but to a large degree from phosphate-rock based mineral fertilisers. However, phosphate rock is a finite resource that cannot be manufactured. Our dependency therefore needs to be addressed from a sustainability perspective in order to ensure global food supplies for a growing global population. The situation is made more urgent by predictions that, for example, the consumption of resource intensive foods and the demand for biomass energy will increase. The scientific and societal debate has so far been focussed on the exact timing of peak phosphorus and on when the total depletion of the global reserves will occur. Even though the timing of these events is important, all dimensions of phosphorus scarcity need to be addressed in a manner which acknowledges linkages to other sustainable development challenges and which takes into consideration the synergies between different sustainability measures. Many sustainable phosphorus measures have positive impacts on other challenges; for example, shifting global diets to more plant-based foods would not only reduce global phosphorus consumption, but also reduce greenhouse gas emissions, reduce nitrogen fertiliser demand and reduce water consumption.

  6. Techno-ecological synergy: a framework for sustainable engineering.

    PubMed

    Bakshi, Bhavik R; Ziv, Guy; Lepech, Michael D

    2015-02-01

    Even though the importance of ecosystems in sustaining all human activities is well-known, methods for sustainable engineering fail to fully account for this role of nature. Most methods account for the demand for ecosystem services, but almost none account for the supply. Incomplete accounting of the very foundation of human well-being can result in perverse outcomes from decisions meant to enhance sustainability and lost opportunities for benefiting from the ability of nature to satisfy human needs in an economically and environmentally superior manner. This paper develops a framework for understanding and designing synergies between technological and ecological systems to encourage greater harmony between human activities and nature. This framework considers technological systems ranging from individual processes to supply chains and life cycles, along with corresponding ecological systems at multiple spatial scales ranging from local to global. The demand for specific ecosystem services is determined from information about emissions and resource use, while the supply is obtained from information about the capacity of relevant ecosystems. Metrics calculate the sustainability of individual ecosystem services at multiple spatial scales and help define necessary but not sufficient conditions for local and global sustainability. Efforts to reduce ecological overshoot encourage enhancement of life cycle efficiency, development of industrial symbiosis, innovative designs and policies, and ecological restoration, thus combining the best features of many existing methods. Opportunities for theoretical and applied research to make this framework practical are also discussed. PMID:25560912

  7. Synergy between intention recognition and commitments in cooperation dilemmas.

    PubMed

    Han, The Anh; Santos, Francisco C; Lenaerts, Tom; Pereira, Luís Moniz

    2015-01-01

    Commitments have been shown to promote cooperation if, on the one hand, they can be sufficiently enforced, and on the other hand, the cost of arranging them is justified with respect to the benefits of cooperation. When either of these constraints is not met it leads to the prevalence of commitment free-riders, such as those who commit only when someone else pays to arrange the commitments. Here, we show how intention recognition may circumvent such weakness of costly commitments. We describe an evolutionary model, in the context of the one-shot Prisoner's Dilemma, showing that if players first predict the intentions of their co-player and propose a commitment only when they are not confident enough about their prediction, the chances of reaching mutual cooperation are largely enhanced. We find that an advantageous synergy between intention recognition and costly commitments depends strongly on the confidence and accuracy of intention recognition. In general, we observe an intermediate level of confidence threshold leading to the highest evolutionary advantage, showing that neither unconditional use of commitment nor intention recognition can perform optimally. Rather, our results show that arranging commitments is not always desirable, but that they may be also unavoidable depending on the strength of the dilemma. PMID:25791431

  8. The Einstein-Brazil Fogarty: A decade of synergy

    PubMed Central

    Nosanchuk, Joshua D.; Nosanchuk, Murphy D.; Rodrigues, Marcio L.; Nimrichter, Leonardo; de Carvalho, Antonio C. Campos; Weiss, Louis M.; Spray, David C.; Tanowitz, Herbert B.

    2015-01-01

    Abstract A rich, collaborative program funded by the US NIH Fogarty program in 2004 has provided for a decade of remarkable opportunities for scientific advancement through the training of Brazilian undergraduate, graduate and postdoctoral students from the Federal University and Oswaldo Cruz Foundation systems at Albert Einstein College of Medicine. The focus of the program has been on the development of trainees in the broad field of Infectious Diseases, with a particular focus on diseases of importance to the Brazilian population. Talented trainees from various regions in Brazil came to Einstein to learn techniques and study fungal, parasitic and bacterial pathogens. In total, 43 trainees enthusiastically participated in the program. In addition to laboratory work, these students took a variety of courses at Einstein, presented their results at local, national and international meetings, and productively published their findings. This program has led to a remarkable synergy of scientific discovery for the participants during a time of rapid acceleration of the scientific growth in Brazil. This collaboration between Brazilian and US scientists has benefitted both countries and serves as a model for future training programs between these countries. PMID:26691452

  9. Decomposition of spontaneous movements of infants as combinations of limb synergies.

    PubMed

    Kato, Moe; Hirashima, Masaya; Oohashi, Hiroki; Watanabe, Hama; Taga, Gentaro

    2014-09-01

    We hypothesized that a variety of limb movements in infants, including spontaneous movements and movements during interactions with the environment, can be represented as combinations of limb synergies, which are building blocks for generating coordinated movements of multiple limbs. A decomposition algorithm based on a nonnegative matrix factorization was applied to the discrete data segments taken from continuous data of limb movements in 298 infants (age, 3-4 months). The data were linearly decomposed into bases, which were referred to as synergies. The results showed that approximately 70% of the variance in the velocity profiles of the data segments of the four limbs can be explained by a set of five simple synergies that represent single-limb movements and the synchronous movement of all limbs. The present method showed that the complex properties of limb movements can be represented as combinations of synergies. Furthermore, comparisons of movement patterns across different age groups showed that in older infants, the contribution ratios of each synergy were different between spontaneous movements and movements during playing with a toy, whereas in younger infants, there were no differences in the contribution ratios between the different movement conditions. These results demonstrate that decomposition into limb synergies is useful for determining the spatiotemporal properties of interlimb coordination during spontaneous movements and task-constrained movements in infants. PMID:24825825

  10. Target-Independent Prediction of Drug Synergies Using Only Drug Lipophilicity

    PubMed Central

    2015-01-01

    Physicochemical properties of compounds have been instrumental in selecting lead compounds with increased drug-likeness. However, the relationship between physicochemical properties of constituent drugs and the tendency to exhibit drug interaction has not been systematically studied. We assembled physicochemical descriptors for a set of antifungal compounds (“drugs”) previously examined for interaction. Analyzing the relationship between molecular weight, lipophilicity, H-bond donor, and H-bond acceptor values for drugs and their propensity to show pairwise antifungal drug synergy, we found that combinations of two lipophilic drugs had a greater tendency to show drug synergy. We developed a more refined decision tree model that successfully predicted drug synergy in stringent cross-validation tests based on only lipophilicity of drugs. Our predictions achieved a precision of 63% and allowed successful prediction for 58% of synergistic drug pairs, suggesting that this phenomenon can extend our understanding for a substantial fraction of synergistic drug interactions. We also generated and analyzed a large-scale synergistic human toxicity network, in which we observed that combinations of lipophilic compounds show a tendency for increased toxicity. Thus, lipophilicity, a simple and easily determined molecular descriptor, is a powerful predictor of drug synergy. It is well established that lipophilic compounds (i) are promiscuous, having many targets in the cell, and (ii) often penetrate into the cell via the cellular membrane by passive diffusion. We discuss the positive relationship between drug lipophilicity and drug synergy in the context of potential drug synergy mechanisms. PMID:25026390

  11. Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands.

    PubMed

    Santello, Marco; Bianchi, Matteo; Gabiccini, Marco; Ricciardi, Emiliano; Salvietti, Gionata; Prattichizzo, Domenico; Ernst, Marc; Moscatelli, Alessandro; Jörntell, Henrik; Kappers, Astrid M L; Kyriakopoulos, Kostas; Albu-Schäffer, Alin; Castellini, Claudio; Bicchi, Antonio

    2016-07-01

    The term 'synergy' - from the Greek synergia - means 'working together'. The concept of multiple elements working together towards a common goal has been extensively used in neuroscience to develop theoretical frameworks, experimental approaches, and analytical techniques to understand neural control of movement, and for applications for neuro-rehabilitation. In the past decade, roboticists have successfully applied the framework of synergies to create novel design and control concepts for artificial hands, i.e., robotic hands and prostheses. At the same time, robotic research on the sensorimotor integration underlying the control and sensing of artificial hands has inspired new research approaches in neuroscience, and has provided useful instruments for novel experiments. The ambitious goal of integrating expertise and research approaches in robotics and neuroscience to study the properties and applications of the concept of synergies is generating a number of multidisciplinary cooperative projects, among which the recently finished 4-year European project "The Hand Embodied" (THE). This paper reviews the main insights provided by this framework. Specifically, we provide an overview of neuroscientific bases of hand synergies and introduce how robotics has leveraged the insights from neuroscience for innovative design in hardware and controllers for biomedical engineering applications, including myoelectric hand prostheses, devices for haptics research, and wearable sensing of human hand kinematics. The review also emphasizes how this multidisciplinary collaboration has generated new ways to conceptualize a synergy-based approach for robotics, and provides guidelines and principles for analyzing human behavior and synthesizing artificial robotic systems based on a theory of synergies. PMID:26923030

  12. Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands

    NASA Astrophysics Data System (ADS)

    Santello, Marco; Bianchi, Matteo; Gabiccini, Marco; Ricciardi, Emiliano; Salvietti, Gionata; Prattichizzo, Domenico; Ernst, Marc; Moscatelli, Alessandro; Jörntell, Henrik; Kappers, Astrid M. L.; Kyriakopoulos, Kostas; Albu-Schäffer, Alin; Castellini, Claudio; Bicchi, Antonio

    2016-07-01

    The term 'synergy' - from the Greek synergia - means 'working together'. The concept of multiple elements working together towards a common goal has been extensively used in neuroscience to develop theoretical frameworks, experimental approaches, and analytical techniques to understand neural control of movement, and for applications for neuro-rehabilitation. In the past decade, roboticists have successfully applied the framework of synergies to create novel design and control concepts for artificial hands, i.e., robotic hands and prostheses. At the same time, robotic research on the sensorimotor integration underlying the control and sensing of artificial hands has inspired new research approaches in neuroscience, and has provided useful instruments for novel experiments. The ambitious goal of integrating expertise and research approaches in robotics and neuroscience to study the properties and applications of the concept of synergies is generating a number of multidisciplinary cooperative projects, among which the recently finished 4-year European project "The Hand Embodied" (THE). This paper reviews the main insights provided by this framework. Specifically, we provide an overview of neuroscientific bases of hand synergies and introduce how robotics has leveraged the insights from neuroscience for innovative design in hardware and controllers for biomedical engineering applications, including myoelectric hand prostheses, devices for haptics research, and wearable sensing of human hand kinematics. The review also emphasizes how this multidisciplinary collaboration has generated new ways to conceptualize a synergy-based approach for robotics, and provides guidelines and principles for analyzing human behavior and synthesizing artificial robotic systems based on a theory of synergies.

  13. Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands.

    PubMed

    Santello, Marco; Bianchi, Matteo; Gabiccini, Marco; Ricciardi, Emiliano; Salvietti, Gionata; Prattichizzo, Domenico; Ernst, Marc; Moscatelli, Alessandro; Jörntell, Henrik; Kappers, Astrid M L; Kyriakopoulos, Kostas; Albu-Schäffer, Alin; Castellini, Claudio; Bicchi, Antonio

    2016-07-01

    The term 'synergy' - from the Greek synergia - means 'working together'. The concept of multiple elements working together towards a common goal has been extensively used in neuroscience to develop theoretical frameworks, experimental approaches, and analytical techniques to understand neural control of movement, and for applications for neuro-rehabilitation. In the past decade, roboticists have successfully applied the framework of synergies to create novel design and control concepts for artificial hands, i.e., robotic hands and prostheses. At the same time, robotic research on the sensorimotor integration underlying the control and sensing of artificial hands has inspired new research approaches in neuroscience, and has provided useful instruments for novel experiments. The ambitious goal of integrating expertise and research approaches in robotics and neuroscience to study the properties and applications of the concept of synergies is generating a number of multidisciplinary cooperative projects, among which the recently finished 4-year European project "The Hand Embodied" (THE). This paper reviews the main insights provided by this framework. Specifically, we provide an overview of neuroscientific bases of hand synergies and introduce how robotics has leveraged the insights from neuroscience for innovative design in hardware and controllers for biomedical engineering applications, including myoelectric hand prostheses, devices for haptics research, and wearable sensing of human hand kinematics. The review also emphasizes how this multidisciplinary collaboration has generated new ways to conceptualize a synergy-based approach for robotics, and provides guidelines and principles for analyzing human behavior and synthesizing artificial robotic systems based on a theory of synergies.

  14. Prehension synergies and hand function in early-stage Parkinson's disease.

    PubMed

    Jo, Hang Jin; Park, Jaebum; Lewis, Mechelle M; Huang, Xuemei; Latash, Mark L

    2015-02-01

    We explored the multi-digit synergies and hand performance in object manipulations and pressing tasks in patients with early-stage Parkinson's disease (PD) and healthy controls. Synergies were defined as inter-trials co-variation patterns among forces/moments produced by individual digits that stabilized a resultant mechanical variable. The subjects performed three main tasks: pressing (steady-state force production followed by a force pulse into the target), prehension (manipulation of a handheld instrumented handle imitating the action of taking a sip from a glass), and functional object manipulation (moving a glass with water as quickly and accurately as possible along a chain of targets). The PD patients were slower compared to controls in all three tasks. Patients showed smaller synergy indices in the pressing and prehension tasks. In the prehension tasks, patients showed elevated grip force at steady states with smaller grip force modulation during the handle motion. PD patients showed smaller feed-forward synergy adjustments in preparation to the quick action in the pressing and (to a smaller degree) prehension tasks. Synergy indices correlated with the time index of performance in the functional glass-with-water task, whereas none of the indices correlated with the Unified PD Rating Scale part III-motor scores. We interpret the results as pointing at an important role of subcortical structures in motor synergies and their feed-forward adjustments to action. PMID:25370346

  15. The role of partnership functioning and synergy in achieving sustainability of innovative programmes in community care.

    PubMed

    Cramm, Jane M; Phaff, Sanne; Nieboer, Anna P

    2013-03-01

    This cross-sectional study (conducted in April-May 2011) explored associations between partnership functioning synergy and sustainability of innovative programmes in community care. The study sample consisted of 106 professionals (of 244 individuals contacted) participating in 21 partnerships that implemented different innovative community care programmes in Rotterdam, The Netherlands. Partnership functioning was evaluated by assessing leadership, resources administration and efficiency. Synergy was considered the proximal outcome of partnership functioning, which, in turn, influenced the achievement of programme sustainability. On a 5-point scale of increasing sustainability, mean sustainability scores ranged from 1.9 to 4.9. The results of the regression analysis demonstrated that sustainability was positively influenced by leadership (standardised regression coefficient β = 0.32; P < 0.001) and non-financial resources (β = 0.25; P = 0.008). No significant relationship was found between administration or efficiency and programme sustainability. Partnership synergy acted as a mediator for partnership functioning and significantly affected sustainability (β = 0.39; P < 0.001). These findings suggest that the sustainability of innovative programmes in community care is achieved more readily when synergy is created between partners. Synergy was more likely to emerge with boundary-spanning leaders, who understood and appreciated partners' different perspectives, and could bridge their diverse cultures and were comfortable sharing ideas, resources and power. In addition, the acknowledgement of and ability to use members' resources were found to be valuable in engaging partners' involvement and achieving synergy in community care partnerships.

  16. Collaborative Research. Atmospheric Pressure Microplasma Chemistry-Photon Synergies

    SciTech Connect

    Park, Sung-Jin; Eden, James Gary

    2015-12-01

    Combining the effects of low temperature, atmospheric pressure microplasmas and microplasma photon sources offers the promise of greatly expanding the range of applications for each of them. The plasma sources create active chemical species and these can be activated further by the addition of photons and the associated photochemistry. There are many ways to combine the effects of plasma chemistry and photochemistry, especially if there are multiple phases present. This project combined the construction of appropriate test experimental systems, various spectroscopic diagnostics and mathematical modeling. Through a continuous discussion and co-design process with the UC-Berkeley Team, we have successfully completed the fabrication and testing of all components for a microplasma array-assisted system designed for photon-activated plasma chemistry research. Microcavity plasma lamps capable of generating more than 20 mW/cm2 at 172 nm (Xe dimer) were fabricated with a custom form factor to mate to the plasma chemistry setup, and a lamp was current being installed by the Berkeley team so as to investigate plasma chemistry-photon synergies at a higher photon energy (~7.2 eV) as compared to the UVA treatment that is afforded by UV LEDs operating at 365 nm. In particular, motivated by the promising results from the Berkeley team with UVA treatment, we also produced the first generation of lamps that can generate photons in the 300-370 nm wavelength range. Another set of experiments, conducted under the auspices of this grant, involved the use of plasma microjet arrays. The combination of the photons and excited radicals produced by the plasma column resulted in broad area deactivation of bacteria.

  17. AIDS Vaccines and Preexposure Prophylaxis: Is Synergy Possible?

    PubMed Central

    Excler, Jean-Louis; Rida, Wasima; Priddy, Frances; Gilmour, Jill; McDermott, Adrian B.; Kamali, Anatoli; Anzala, Omu; Mutua, Gaudensia; Sanders, Eduard J.; Koff, Wayne; Berkley, Seth

    2011-01-01

    Abstract While the long-term goal is to develop highly effective AIDS vaccines, first generation vaccines may be only partially effective. Other HIV prevention modalities such as preexposure prophylaxis with antiretrovirals (PrEP) may have limited efficacy as well. The combined administration of vaccine and PrEP (VAXPREP), however, may have a synergistic effect leading to an overall benefit that is greater than the sum of the individual effects. We propose two test-of-concept trial designs for an AIDS vaccine plus oral or topical ARV. In one design, evidence that PrEP reduces the risk of HIV acquisition is assumed to justify offering it to all participants. A two-arm study comparing PrEP alone to VAXPREP is proposed in which 30 to 60 incident infections are observed to assess the additional benefit of vaccination on risk of infection and setpoint viral load. The demonstrated superiority of VAXPREP does not imply vaccine alone is efficacious. Similarly, the lack of superiority does not imply vaccine alone is ineffective, as antagonism could exist between vaccine and PrEP. In the other design, PrEP is assumed not to be in general use. A 2 × 2 factorial design is proposed in which high-risk individuals are randomized to one of four arms: placebo vaccine given with placebo PrEP, placebo vaccine given with PrEP, vaccine given with placebo PrEP, or VAXPREP. Between 60 and 210 infections are required to detect a benefit of vaccination with or without PrEP on risk of HIV acquisition or setpoint viral load, with fewer infections needed when synergy is present. PMID:21043994

  18. Exploring and exploiting the synergy of non-covalent interactions on the surface of gold nanoparticles for fluorescent turn-on sensing of bacterial lipopolysaccharide.

    PubMed

    Gao, Jinhong; Lai, Yangwei; Wu, Chuanliu; Zhao, Yibing

    2013-09-01

    The sensing of lipopolysaccharide (LPS) relies on the synergy of multiple electrostatic and hydrophobic interactions between LPS and the sensor. However, how non-covalent interactions are coordinated to impel the recognition process still remains elusive, and the exploration of which would promote the development of LPS sensors with higher specificity and sensitivity. In this work, we hypothesize that Au NPs would provide a straightforward and flexible platform for studying the synergy of non-covalent interactions. The detailed mechanism of interactions between the designed fluorescent probes and Au NPs with two distinct surface properties was systematically explored. We demonstrated that only when the electrostatic attraction and hydrophobic stacking are both present, the binding of fluorescent probes onto Au NPs can be not only highly efficient, but also positively cooperative. After that, hybrid systems that consist of Au NPs and surface-assembled fluorescent probes were exploited for fluorescent turn-on sensing of LPS. The results show that the sensitivity and selectivity to LPS relies strongly on the binding affinity between fluorescent probes and Au NPs. Fluorescent probes assembled Au NPs thus provide an attractive platform for further optimization of the sensitivity/selectivity of LPS sensing.

  19. A hybrid air conditioner driven by a hybrid solar collector

    NASA Astrophysics Data System (ADS)

    Al-Alili, Ali

    The objective of this thesis is to search for an efficient way of utilizing solar energy in air conditioning applications. The current solar Air Conditioners (A/C)s suffer from low Coefficient of Performance (COP) and performance degradation in hot and humid climates. By investigating the possible ways of utilizing solar energy in air conditioning applications, the bottlenecks in these approaches were identified. That resulted in proposing a novel system whose subsystem synergy led to a COP higher than unity. The proposed system was found to maintain indoor comfort at a higher COP compared to the most common solar A/Cs, especially under very hot and humid climate conditions. The novelty of the proposed A/C is to use a concentrating photovoltaic/thermal collector, which outputs thermal and electrical energy simultaneously, to drive a hybrid A/C. The performance of the hybrid A/C, which consists of a desiccant wheel, an enthalpy wheel, and a vapor compression cycle (VCC), was investigated experimentally. This work also explored the use of a new type of desiccant material, which can be regenerated with a low temperature heat source. The experimental results showed that the hybrid A/C is more effective than the standalone VCC in maintaining the indoor conditions within the comfort zone. Using the experimental data, the COP of the hybrid A/C driven by a hybrid solar collector was found to be at least double that of the current solar A/Cs. The innovative integration of its subsystems allows each subsystem to do what it can do best. That leads to lower energy consumption which helps reduce the peak electrical loads on electric utilities and reduces the consumer operating cost since less energy is purchased during the on peak periods and less solar collector area is needed. In order for the proposed A/C to become a real alternative to conventional systems, its performance and total cost were optimized using the experimentally validated model. The results showed that for an

  20. Muscle Synergies Heavily Influence the Neural Control of Arm Endpoint Stiffness and Energy Consumption

    PubMed Central

    Inouye, Joshua M.; Valero-Cuevas, Francisco J.

    2016-01-01

    Much debate has arisen from research on muscle synergies with respect to both limb impedance control and energy consumption. Studies of limb impedance control in the context of reaching movements and postural tasks have produced divergent findings, and this study explores whether the use of synergies by the central nervous system (CNS) can resolve these findings and also provide insights on mechanisms of energy consumption. In this study, we phrase these debates at the conceptual level of interactions between neural degrees of freedom and tasks constraints. This allows us to examine the ability of experimentally-observed synergies—correlated muscle activations—to control both energy consumption and the stiffness component of limb endpoint impedance. In our nominal 6-muscle planar arm model, muscle synergies and the desired size, shape, and orientation of endpoint stiffness ellipses, are expressed as linear constraints that define the set of feasible muscle activation patterns. Quadratic programming allows us to predict whether and how energy consumption can be minimized throughout the workspace of the limb given those linear constraints. We show that the presence of synergies drastically decreases the ability of the CNS to vary the properties of the endpoint stiffness and can even preclude the ability to minimize energy. Furthermore, the capacity to minimize energy consumption—when available—can be greatly affected by arm posture. Our computational approach helps reconcile divergent findings and conclusions about task-specific regulation of endpoint stiffness and energy consumption in the context of synergies. But more generally, these results provide further evidence that the benefits and disadvantages of muscle synergies go hand-in-hand with the structure of feasible muscle activation patterns afforded by the mechanics of the limb and task constraints. These insights will help design experiments to elucidate the interplay between synergies and the

  1. Muscle Synergies of Untrained Subjects during 6 min Maximal Rowing on Slides and Fixed Ergometer.

    PubMed

    Shaharudin, Shazlin; Zanotto, Damiano; Agrawal, Sunil

    2014-12-01

    The slides ergometer (SE) was an improvisation from fixed ergometer (FE) to bridge the gap of mechanics between ergometer rowing and on-water rowing. The specific mechanical constraints of these two types of ergometers may affect the pattern of muscle recruitment, coordination and adaptation. The main purpose of this study was to evaluate the muscle synergy during 6 minutes maximal rowing on slides (SE) and fixed ergometers (FE). The laterality of muscle synergy was also examined. Surface electromyography activity, power output, heart rate, stroke length and stroke rate were analyzed from nine physically active subjects to assess the rowing performance. Physically active subjects, who were not specifically trained in rowing, were chosen to exclude the training effect on muscle synergy. Principal component analysis (PCA) with varimax rotation was applied to extract muscle synergy. Three muscle synergies were sufficient to explain the majority of variance in SE (94.4 ± 2.2 %) and FE (92.8 ± 1.7 %). Subjects covered more rowing distance, exerted greater power output and attained higher maximal heart rate during rowing on SE than on FE. The results proved the flexibility of muscle synergy to adapt to the mechanical constraints. Rowing on SE emphasized on bi-articular muscles contrary to rowing on FE which relied on cumulative effect of trunk and upper limb muscles during propulsive phase. Key pointsThree muscle synergies were extracted during maximal rowing on both fixed and slides ergometerUntrained subjects emphasized leg muscles while rowing on SEUntrained subjects focused on back muscles during FE rowing. PMID:25435771

  2. Systematic Review and Meta-Analysis of In Vitro Synergy of Polymyxins and Carbapenems

    PubMed Central

    Avni, Tomer; Leibovici, Leonard; Adler, Amos; Friberg, Lena; Stergiopoulou, Theodouli; Carmeli, Yehuda; Paul, Mical

    2013-01-01

    Our objective was to examine the evidence of in vitro synergy of polymyxin-carbapenem combination therapy against Gram-negative bacteria (GNB). A systematic review and meta-analysis were performed. All studies examining in vitro interactions of antibiotic combinations consisting of any carbapenem with colistin or polymyxin B against any GNB were used. A broad search was conducted with no language, date, or publication status restrictions. Synergy rates, defined as a fractional inhibitory concentration index of ≤0.5 or a >2-log reduction in CFU, were pooled separately for time-kill, checkerboard, and Etest methods in a mixed-effect meta-analysis of rates. We examined whether the synergy rate depended on the testing method, type of antibiotic, bacteria, and resistance to carbapenems. Pooled rates with 95% confidence intervals (CI) are shown. Thirty-nine published studies and 15 conference proceeding were included, reporting on 246 different tests on 1,054 bacterial isolates. In time-kill studies, combination therapy showed synergy rates of 77% (95% CI, 64 to 87%) for Acinetobacter baumannii, 44% (95% CI, 30 to 59%) for Klebsiella pneumoniae, and 50% (95% CI, 30 to 69%) for Pseudomonas aeruginosa, with low antagonism rates for all. Doripenem showed high synergy rates for all three bacteria. For A. baumannii, meropenem was more synergistic than imipenem, whereas for P. aeruginosa the opposite was true. Checkerboard and Etest studies generally reported lower synergy rates than time-kill studies. The use of combination therapy led to less resistance development in vitro. The combination of a carbapenem with a polymyxin against GNB, especially A. baumannii, is supported in vitro by high synergy rates, with low antagonism and less resistance development. These findings should be examined in clinical studies. PMID:23917322

  3. Synergy Between Theory and Experiment in Physical Chemistry: Studies on Thermochemistry, Sites of Ionization and Reaction Mechanisms

    NASA Astrophysics Data System (ADS)

    Notario, Rafael

    2008-03-01

    The word "synergy" means "working together". Synergy refers to the interaction of two or more agents or forces so that their combined effect is greater than the sum of their individual effects. Several examples are presented on the synergy between theory and experiment in physical chemistry taken from studies on the thermochemistry of oxygen- and sulfur-containing six-membered heterocycles, the site of ionization in bifunctional species, and the mechanism of thermolysis reactions.

  4. Hybrid mesons

    NASA Astrophysics Data System (ADS)

    Meyer, C. A.; Swanson, E. S.

    2015-05-01

    A review of the theoretical and experimental status of hybrid hadrons is presented. The states π1(1400) , π1(1600) , and π1(2015) are thoroughly reviewed, along with experimental results from GAMS, VES, Obelix, COMPASS, KEK, CLEO, Crystal Barrel, CLAS, and BNL. Theoretical lattice results on the gluelump spectrum, adiabatic potentials, heavy and light hybrids, and transition matrix elements are discussed. These are compared with bag, string, flux tube, and constituent gluon models. Strong and electromagnetic decay models are described and compared to lattice gauge theory results. We conclude that while good evidence for the existence of a light isovector exotic meson exists, its confirmation as a hybrid meson awaits discovery of its iso-partners. We also conclude that lattice gauge theory rules out a number of hybrid models and provides a reference to judge the success of others.

  5. Extracting motor synergies from random movements for low-dimensional task-space control of musculoskeletal robots.

    PubMed

    Fu, Kin Chung Denny; Dalla Libera, Fabio; Ishiguro, Hiroshi

    2015-10-08

    In the field of human motor control, the motor synergy hypothesis explains how humans simplify body control dimensionality by coordinating groups of muscles, called motor synergies, instead of controlling muscles independently. In most applications of motor synergies to low-dimensional control in robotics, motor synergies are extracted from given optimal control signals. In this paper, we address the problems of how to extract motor synergies without optimal data given, and how to apply motor synergies to achieve low-dimensional task-space tracking control of a human-like robotic arm actuated by redundant muscles, without prior knowledge of the robot. We propose to extract motor synergies from a subset of randomly generated reaching-like movement data. The essence is to first approximate the corresponding optimal control signals, using estimations of the robot's forward dynamics, and to extract the motor synergies subsequently. In order to avoid modeling difficulties, a learning-based control approach is adopted such that control is accomplished via estimations of the robot's inverse dynamics. We present a kernel-based regression formulation to estimate the forward and the inverse dynamics, and a sliding controller in order to cope with estimation error. Numerical evaluations show that the proposed method enables extraction of motor synergies for low-dimensional task-space control.

  6. Extracting motor synergies from random movements for low-dimensional task-space control of musculoskeletal robots.

    PubMed

    Fu, Kin Chung Denny; Dalla Libera, Fabio; Ishiguro, Hiroshi

    2015-10-01

    In the field of human motor control, the motor synergy hypothesis explains how humans simplify body control dimensionality by coordinating groups of muscles, called motor synergies, instead of controlling muscles independently. In most applications of motor synergies to low-dimensional control in robotics, motor synergies are extracted from given optimal control signals. In this paper, we address the problems of how to extract motor synergies without optimal data given, and how to apply motor synergies to achieve low-dimensional task-space tracking control of a human-like robotic arm actuated by redundant muscles, without prior knowledge of the robot. We propose to extract motor synergies from a subset of randomly generated reaching-like movement data. The essence is to first approximate the corresponding optimal control signals, using estimations of the robot's forward dynamics, and to extract the motor synergies subsequently. In order to avoid modeling difficulties, a learning-based control approach is adopted such that control is accomplished via estimations of the robot's inverse dynamics. We present a kernel-based regression formulation to estimate the forward and the inverse dynamics, and a sliding controller in order to cope with estimation error. Numerical evaluations show that the proposed method enables extraction of motor synergies for low-dimensional task-space control. PMID:26448530

  7. Hybrid SCR

    SciTech Connect

    Jantzen, T.; Zammit, K.

    1996-01-01

    Hybrid selective catalytic reduction (SCR) systems consist of either a combination of SCR techniques (i.e. in-dust SCR combined with air heater SCR) or selective noncatalytic reduction (SNCR) in combination with SCR. These Hybrid SCR systems can offer substantial benefits in reduced cost and enhanced performance; however, their applicability is very unit specific. This paper presents the results of a study to document the current experience and develop a tool by which utilities can determine the applicability of Hybrid SCR to meet their NO{sub x} reduction goals, a guideline for selecting the best configuration, and a reference for developing the design parameters necessary to implement the technology. Hybrid SCR systems have been installed and demonstrated on utility boilers. The systems have included in-duct SCR combined with air heater SCR and SNCR combined with SCR as includes a review of the results of these demonstrations as well as comments on the applicability of those results for other utility systems. Finally this document provides a reference for the development of design parameters for the implementation of Hybrid SCR. There are a number of technical and commercial considerations which must be resolved prior to designing or procuring a Hybrid SCR system. The boiler operating, temperature and emissions data necessary for the final design are presented along with the process design variables which must be specified. Procurement suggestions are included to assist the user in addressing some of the more pertinent commercial issues.

  8. Electromyogram synergy control of a dexterous artificial hand to unscrew and screw objects

    PubMed Central

    2014-01-01

    Background Due to their limited dexterity, it is currently not possible to use a commercially available prosthetic hand to unscrew or screw objects without using elbow and shoulder movements. For these tasks, prosthetic hands function like a wrench, which is unnatural and limits their use in tight working environments. Results from timed rotational tasks with human subjects demonstrate the clinical need for increased dexterity of prosthetic hands, and a clinically viable solution to this problem is presented for an anthropomorphic artificial hand. Methods Initially, a human hand motion analysis was performed during a rotational task. From these data, human hand synergies were derived and mapped to an anthropomorphic artificial hand. The synergy for the artificial hand is controlled using conventional dual site electromyogram (EMG) signals. These EMG signals were mapped to the developed synergy to control four joints of the dexterous artificial hand simultaneously. Five limb absent and ten able-bodied test subjects participated in a comparison study to complete a timed rotational task as quickly as possible with their natural hands (except for one subject with a bilateral hand absence), eight commercially available prosthetic hands, and the proposed synergy controller. Each test subject used two to four different artificial hands. Results With the able-bodied subjects, the developed synergy controller reduced task completion time by 177% on average. The limb absent subjects completed the task faster on average than with their own prostheses by 46%. There was a statistically significant improvement in task completion time with the synergy controller for three of the four limb absent participants with integrated prostheses, and was not statistically different for the fourth. Conclusions The proposed synergy controller reduced average task completion time compared to commercially available prostheses. Additionally, the synergy controller is able to function in a small

  9. Climate change mitigation and adaptation in the land use sector: from complementarity to synergy.

    PubMed

    Duguma, Lalisa A; Minang, Peter A; van Noordwijk, Meine

    2014-09-01

    Currently, mitigation and adaptation measures are handled separately, due to differences in priorities for the measures and segregated planning and implementation policies at international and national levels. There is a growing argument that synergistic approaches to adaptation and mitigation could bring substantial benefits at multiple scales in the land use sector. Nonetheless, efforts to implement synergies between adaptation and mitigation measures are rare due to the weak conceptual framing of the approach and constraining policy issues. In this paper, we explore the attributes of synergy and the necessary enabling conditions and discuss, as an example, experience with the Ngitili system in Tanzania that serves both adaptation and mitigation functions. An in-depth look into the current practices suggests that more emphasis is laid on complementarity-i.e., mitigation projects providing adaptation co-benefits and vice versa rather than on synergy. Unlike complementarity, synergy should emphasize functionally sustainable landscape systems in which adaptation and mitigation are optimized as part of multiple functions. We argue that the current practice of seeking co-benefits (complementarity) is a necessary but insufficient step toward addressing synergy. Moving forward from complementarity will require a paradigm shift from current compartmentalization between mitigation and adaptation to systems thinking at landscape scale. However, enabling policy, institutional, and investment conditions need to be developed at global, national, and local levels to achieve synergistic goals.

  10. Climate Change Mitigation and Adaptation in the Land Use Sector: From Complementarity to Synergy

    NASA Astrophysics Data System (ADS)

    Duguma, Lalisa A.; Minang, Peter A.; van Noordwijk, Meine

    2014-09-01

    Currently, mitigation and adaptation measures are handled separately, due to differences in priorities for the measures and segregated planning and implementation policies at international and national levels. There is a growing argument that synergistic approaches to adaptation and mitigation could bring substantial benefits at multiple scales in the land use sector. Nonetheless, efforts to implement synergies between adaptation and mitigation measures are rare due to the weak conceptual framing of the approach and constraining policy issues. In this paper, we explore the attributes of synergy and the necessary enabling conditions and discuss, as an example, experience with the Ngitili system in Tanzania that serves both adaptation and mitigation functions. An in-depth look into the current practices suggests that more emphasis is laid on complementarity—i.e., mitigation projects providing adaptation co-benefits and vice versa rather than on synergy. Unlike complementarity, synergy should emphasize functionally sustainable landscape systems in which adaptation and mitigation are optimized as part of multiple functions. We argue that the current practice of seeking co-benefits (complementarity) is a necessary but insufficient step toward addressing synergy. Moving forward from complementarity will require a paradigm shift from current compartmentalization between mitigation and adaptation to systems thinking at landscape scale. However, enabling policy, institutional, and investment conditions need to be developed at global, national, and local levels to achieve synergistic goals.

  11. Reorganization of muscle synergies during multidirectional reaching in the horizontal plane with experimental muscle pain

    PubMed Central

    Muceli, Silvia; Falla, Deborah

    2014-01-01

    Muscle pain induces a complex reorganization of the motor strategy which cannot be fully explained by current theories. We tested the hypothesis that the neural control of muscles during reaching in the presence of nociceptive input is determined by a reorganization of muscle synergies with respect to control conditions. Muscle pain was induced by injection of hypertonic saline into the anterior deltoid muscle of eight men. Electromyographic (EMG) signals were recorded from 12 upper limb muscles as subjects performed a reaching task before (baseline) and after the injection of hypertonic (pain) saline, and after the pain sensation vanished. The EMG envelopes were factorized in muscle synergies, and activation signals extracted for each condition. Nociceptive stimulation resulted in a complex muscle reorganization without changes in the kinematic output. The anterior deltoid muscle activity decreased in all subjects while the changes in other muscles were subject specific. Three synergies sufficed to describe the EMG patterns in each condition, suggesting that reaching movements remain modular in the presence of experimental pain. Muscle reorganization in all subjects was accompanied by a change in the activation signals compatible with a change in the central drive to muscles. One, two or three synergies were shared between the baseline and painful conditions, depending on the subject. These results indicate that nociceptive stimulation may induce a reorganization of modular control in reaching. We speculate that such reorganization may be due to the recruitment of synergies specific to the painful condition. PMID:24453279

  12. Pilot Screening to Determine Antimicrobial Synergies in a Multidrug-Resistant Bacterial Strain Library

    PubMed Central

    Kim, Si-Hyun; Park, Chulmin; Chun, Hye-Sun; Choi, Jae-Ki; Lee, Hyo-Jin; Cho, Sung-Yeon; Park, Sun Hee; Choi, Su-Mi; Choi, Jung-Hyun; Yoo, Jin-Hong

    2016-01-01

    With the rise in multidrug-resistant (MDR) bacterial infections, there has been increasing interest in combinations of ≥2 antimicrobial agents with synergistic effects. We established an MDR bacterial strain library to screen for in vitro antimicrobial synergy by using a broth microdilution checkerboard method and high-throughput luciferase-based bacterial cell viability assay. In total, 39 MDR bacterial strains, including 23 carbapenem-resistant gram-negative bacteria, 9 vancomycin-intermediate Staphylococcus aureus, and 7 vancomycin-resistant Enterococcus faecalis, were used to screen for potential antimicrobial synergies. Synergies were more frequently identified with combinations of imipenem plus trimethoprim–sulfamethoxazole for carbapenem-resistant Acinetobacter baumannii in the library. To verify this finding, we tested 34 A. baumannii clinical isolates resistant to both imipenem and trimethoprim–sulfamethoxazole by the checkerboard method. The imipenem plus trimethoprim–sulfamethoxazole combination showed synergy in the treatment of 21 (62%) of the clinical isolates. The results indicate that pilot screening for antimicrobial synergy in the MDR bacterial strain library could be valuable in the selection of combination therapeutic regimens to treat MDR bacterial infections. Further studies are warranted to determine whether this screening system can be useful to screen for the combined effects of conventional antimicrobials and new-generation antimicrobials or nonantimicrobials. PMID:26974861

  13. Synergy: a web resource for exploring gene regulation in Synechocystis sp. PCC6803.

    PubMed

    Mähler, Niklas; Cheregi, Otilia; Funk, Christiane; Netotea, Sergiu; Hvidsten, Torgeir R

    2014-01-01

    Despite being a highly studied model organism, most genes of the cyanobacterium Synechocystis sp. PCC 6803 encode proteins with completely unknown function. To facilitate studies of gene regulation in Synechocystis, we have developed Synergy (http://synergy.plantgenie.org), a web application integrating co-expression networks and regulatory motif analysis. Co-expression networks were inferred from publicly available microarray experiments, while regulatory motifs were identified using a phylogenetic footprinting approach. Automatically discovered motifs were shown to be enriched in the network neighborhoods of regulatory proteins much more often than in the neighborhoods of non-regulatory genes, showing that the data provide a sound starting point for studying gene regulation in Synechocystis. Concordantly, we provide several case studies demonstrating that Synergy can be used to find biologically relevant regulatory mechanisms in Synechocystis. Synergy can be used to interactively perform analyses such as gene/motif search, network visualization and motif/function enrichment. Considering the importance of Synechocystis for photosynthesis and biofuel research, we believe that Synergy will become a valuable resource to the research community.

  14. Hybrid Vehicle Technologies and their potential for reducing oil use

    NASA Astrophysics Data System (ADS)

    German, John

    2006-04-01

    Vehicles with hybrid gasoline-electric powertrains are starting to gain market share. Current hybrid vehicles add an electric motor, battery pack, and power electronics to the conventional powertrain. A variety of engine/motor configurations are possible, each with advantages and disadvantages. In general, efficiency is improved due to engine shut-off at idle, capture of energy during deceleration that is normally lost as heat in the brakes, downsizing of the conventional engine, and, in some cases, propulsion on the electric motor alone. Ongoing increases in hybrid market share are dependent on cost reduction, especially the battery pack, efficiency synergies with other vehicle technologies, use of the high electric power to provide features desired by customers, and future fuel price and availability. Potential barriers include historically low fuel prices, high discounting of the fuel savings by new vehicle purchasers, competing technologies, and tradeoffs with other factors desired by customers, such as performance, utility, safety, and luxury features.

  15. Nonadiabatic molecular dynamics simulations: synergies between theory and experiments.

    PubMed

    Tavernelli, Ivano

    2015-03-17

    Recent developments in nonadiabatic dynamics enabled ab inito simulations of complex ultrafast processes in the condensed phase. These advances have opened new avenues in the study of many photophysical and photochemical reactions triggered by the absorption of electromagnetic radiation. In particular, theoretical investigations can be combined with the most sophisticated femtosecond experimental techniques to guide the interpretation of measured time-resolved observables. At the same time, the availability of experimental data at high (spatial and time) resolution offers a unique opportunity for the benchmarking and the improvement of those theoretical models used to describe complex molecular systems in their natural environment. The established synergy between theory and experiments can produce a better understanding of new ultrafast physical and chemical processes at atomistic scale resolution. Furthermore, reliable ab inito molecular dynamics simulations can already be successfully employed as predictive tools to guide new experiments as well as the design of novel and better performing materials. In this paper, I will give a concise account on the state of the art of molecular dynamics simulations of complex molecular systems in their excited states. The principal aim of this approach is the description of a given system of interest under the most realistic ambient conditions including all environmental effects that influence experiments, for instance, the interaction with the solvent and with external time-dependent electric fields, temperature, and pressure. To this end, time-dependent density functional theory (TDDFT) is among the most efficient and accurate methods for the representation of the electronic dynamics, while trajectory surface hopping gives a valuable representation of the nuclear quantum dynamics in the excited states (including nonadiabatic effects). Concerning the environment and its effects on the dynamics, the quantum mechanics

  16. The MESSENGER Venus Flybys: Opportunities for Synergy with Venus Express

    NASA Astrophysics Data System (ADS)

    Solomon, S. C.; McNutt, R. L.; Domingue, D. L.; Gold, R. E.; Svedhem, H.; Titov, D.; Helbert, J.

    2006-12-01

    provide measurements of the interplanetary magnetic field (IMF), bow shock signatures, and pickup ion waves as a reference for EPPS and Venus Express observations. The encounter will enable two-point measurements of IMF penetration into the Venus ionosphere, primary plasma boundaries, and the near-tail region. During the MESSENGER flyby the instruments on Venus Express will be operated to maximize the synergy between the two spacecraft for this unique opportunity.

  17. Nonadiabatic molecular dynamics simulations: synergies between theory and experiments.

    PubMed

    Tavernelli, Ivano

    2015-03-17

    Recent developments in nonadiabatic dynamics enabled ab inito simulations of complex ultrafast processes in the condensed phase. These advances have opened new avenues in the study of many photophysical and photochemical reactions triggered by the absorption of electromagnetic radiation. In particular, theoretical investigations can be combined with the most sophisticated femtosecond experimental techniques to guide the interpretation of measured time-resolved observables. At the same time, the availability of experimental data at high (spatial and time) resolution offers a unique opportunity for the benchmarking and the improvement of those theoretical models used to describe complex molecular systems in their natural environment. The established synergy between theory and experiments can produce a better understanding of new ultrafast physical and chemical processes at atomistic scale resolution. Furthermore, reliable ab inito molecular dynamics simulations can already be successfully employed as predictive tools to guide new experiments as well as the design of novel and better performing materials. In this paper, I will give a concise account on the state of the art of molecular dynamics simulations of complex molecular systems in their excited states. The principal aim of this approach is the description of a given system of interest under the most realistic ambient conditions including all environmental effects that influence experiments, for instance, the interaction with the solvent and with external time-dependent electric fields, temperature, and pressure. To this end, time-dependent density functional theory (TDDFT) is among the most efficient and accurate methods for the representation of the electronic dynamics, while trajectory surface hopping gives a valuable representation of the nuclear quantum dynamics in the excited states (including nonadiabatic effects). Concerning the environment and its effects on the dynamics, the quantum mechanics

  18. Synergy and pinning effects in a monatomic liquid film in confined conditions.

    PubMed

    Wu, Weikang; Zhang, Leining; Ren, Hongru; Zhang, Kun; Li, Hui; He, Yezeng

    2015-05-28

    The freezing behavior of a monatomic liquid film in confined conditions during rapid cooling was studied by molecular dynamics simulations. We illustrated the synergy and pinning effects of the local icosahedral order during freezing. Our results show that the icosahedron contributes to nucleation through the synergy with other short-range ordered structures and participates in crystal growth via assimilation, but the pinning effect should be overcome when crystals grow. Furthermore, a semi-ordered morphology with maze-like nano-patterns emerged due to the cooperation between the synergy effect and the pinning effect. Our findings shed light on the correlation between the local icosahedral order and the crystalline medium-range order, providing a better understanding of the rapid solidification.

  19. Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury.

    PubMed

    Wenger, Nikolaus; Moraud, Eduardo Martin; Gandar, Jerome; Musienko, Pavel; Capogrosso, Marco; Baud, Laetitia; Le Goff, Camille G; Barraud, Quentin; Pavlova, Natalia; Dominici, Nadia; Minev, Ivan R; Asboth, Leonie; Hirsch, Arthur; Duis, Simone; Kreider, Julie; Mortera, Andrea; Haverbeck, Oliver; Kraus, Silvio; Schmitz, Felix; DiGiovanna, Jack; van den Brand, Rubia; Bloch, Jocelyne; Detemple, Peter; Lacour, Stéphanie P; Bézard, Erwan; Micera, Silvestro; Courtine, Grégoire

    2016-02-01

    Electrical neuromodulation of lumbar segments improves motor control after spinal cord injury in animal models and humans. However, the physiological principles underlying the effect of this intervention remain poorly understood, which has limited the therapeutic approach to continuous stimulation applied to restricted spinal cord locations. Here we developed stimulation protocols that reproduce the natural dynamics of motoneuron activation during locomotion. For this, we computed the spatiotemporal activation pattern of muscle synergies during locomotion in healthy rats. Computer simulations identified optimal electrode locations to target each synergy through the recruitment of proprioceptive feedback circuits. This framework steered the design of spatially selective spinal implants and real-time control software that modulate extensor and flexor synergies with precise temporal resolution. Spatiotemporal neuromodulation therapies improved gait quality, weight-bearing capacity, endurance and skilled locomotion in several rodent models of spinal cord injury. These new concepts are directly translatable to strategies to improve motor control in humans. PMID:26779815

  20. Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury.

    PubMed

    Wenger, Nikolaus; Moraud, Eduardo Martin; Gandar, Jerome; Musienko, Pavel; Capogrosso, Marco; Baud, Laetitia; Le Goff, Camille G; Barraud, Quentin; Pavlova, Natalia; Dominici, Nadia; Minev, Ivan R; Asboth, Leonie; Hirsch, Arthur; Duis, Simone; Kreider, Julie; Mortera, Andrea; Haverbeck, Oliver; Kraus, Silvio; Schmitz, Felix; DiGiovanna, Jack; van den Brand, Rubia; Bloch, Jocelyne; Detemple, Peter; Lacour, Stéphanie P; Bézard, Erwan; Micera, Silvestro; Courtine, Grégoire

    2016-02-01

    Electrical neuromodulation of lumbar segments improves motor control after spinal cord injury in animal models and humans. However, the physiological principles underlying the effect of this intervention remain poorly understood, which has limited the therapeutic approach to continuous stimulation applied to restricted spinal cord locations. Here we developed stimulation protocols that reproduce the natural dynamics of motoneuron activation during locomotion. For this, we computed the spatiotemporal activation pattern of muscle synergies during locomotion in healthy rats. Computer simulations identified optimal electrode locations to target each synergy through the recruitment of proprioceptive feedback circuits. This framework steered the design of spatially selective spinal implants and real-time control software that modulate extensor and flexor synergies with precise temporal resolution. Spatiotemporal neuromodulation therapies improved gait quality, weight-bearing capacity, endurance and skilled locomotion in several rodent models of spinal cord injury. These new concepts are directly translatable to strategies to improve motor control in humans.

  1. A synergy-based hand control is encoded in human motor cortical areas.

    PubMed

    Leo, Andrea; Handjaras, Giacomo; Bianchi, Matteo; Marino, Hamal; Gabiccini, Marco; Guidi, Andrea; Scilingo, Enzo Pasquale; Pietrini, Pietro; Bicchi, Antonio; Santello, Marco; Ricciardi, Emiliano

    2016-01-01

    How the human brain controls hand movements to carry out different tasks is still debated. The concept of synergy has been proposed to indicate functional modules that may simplify the control of hand postures by simultaneously recruiting sets of muscles and joints. However, whether and to what extent synergic hand postures are encoded as such at a cortical level remains unknown. Here, we combined kinematic, electromyography, and brain activity measures obtained by functional magnetic resonance imaging while subjects performed a variety of movements towards virtual objects. Hand postural information, encoded through kinematic synergies, were represented in cortical areas devoted to hand motor control and successfully discriminated individual grasping movements, significantly outperforming alternative somatotopic or muscle-based models. Importantly, hand postural synergies were predicted by neural activation patterns within primary motor cortex. These findings support a novel cortical organization for hand movement control and open potential applications for brain-computer interfaces and neuroprostheses. PMID:26880543

  2. Spatiotemporal neuromodulation therapies engaging muscle synergies improve motor control after spinal cord injury

    PubMed Central

    Wenger, Nikolaus; Moraud, Eduardo Martin; Gandar, Jerome; Musienko, Pavel; Capogrosso, Marco; Baud, Laetitia; Le Goff, Camille G.; Barraud, Quentin; Pavlova, Natalia; Dominici, Nadia; Minev, Ivan R.; Asboth, Leonie; Hirsch, Arthur; Duis, Simone; Kreider, Julie; Mortera, Andrea; Haverbeck, Oliver; Kraus, Silvio; Schmitz, Felix; DiGiovanna, Jack; van den Brand, Rubia; Bloch, Jocelyne; Detemple, Peter; Lacour, Stéphanie P.; Bézard, Erwan; Micera, Silvestro; Courtine, Grégoire

    2016-01-01

    Electrical neuromodulation of lumbar segments improves motor control after spinal cord injury in animal models and humans. However, the physiological principles underlying the effect of this intervention remain poorly understood, which has limited this therapeutic approach to continuous stimulation applied to restricted spinal cord locations. Here, we developed novel stimulation protocols that reproduce the natural dynamics of motoneuron activation during locomotion. For this, we computed the spatiotemporal activation pattern of muscle synergies during locomotion in healthy rats. Computer simulations identified optimal electrode locations to target each synergy through the recruitment of proprioceptive feedback circuits. This framework steered the design of spatially selective spinal implants and real–time control software that modulate extensor versus flexor synergies with precise temporal resolution. Spatiotemporal neuromodulation therapies improved gait quality, weight–bearing capacities, endurance and skilled locomotion in multiple rodent models of spinal cord injury. These new concepts are directly translatable to strategies to improve motor control in humans. PMID:26779815

  3. Pharmacological synergy: the next frontier on therapeutic advancement for migraine.

    PubMed

    Blumenfeld, Andrew; Gennings, Chris; Cady, Roger

    2012-04-01

    mechanisms are involved in terminating acute episodes of migraine. Clinicians now capitalize on this observation and use migraine medication in combination with another to improve patient outcomes, for example, using an antiemetic with an opioid or a triptan and NSAIDs. More recently, the Food and Drug Adminstration has approved a combination product containing 85mg of sumatriptan plus 500mg of naproxen sodium for acute treatment of migraine. Clinical trials conducted prior to approval demonstrated that the combination of sumatriptan and naproxen was more effective as a migraine abortive than either of its components but that each component and the combination were more effective than placebo. Exactly how sumatriptan and naproxen interact to create therapeutic synergism is unknown though its mere occurrence suggests that models assisting medical understanding and prediction of pharmacological synergism may improve clinical outcome over products acting through a single receptor mechanism. Migraine is a syndrome, meaning it is defined by observed symptoms rather than known pathophysiology. Multiple pathogenic mechanisms are likely involved in generating this diverse array of symptoms understood as the migraine symptom complex. Sumatriptan and naproxen have independent mechanisms of action and target distinct aspects of the vascular and inflammatory processes hypothesized to underlie migraine. Sumatriptan acts on the 5-HT(1B) and 5-HT(1D) receptors, whereas naproxen inhibits the COX-1 and COX-2 enzymes. Sumatriptan has vasoconstricting effects as well as effects on neurogenic inflammation by decreasing the release of substance P and calcitonin gene-related peptide. In contrast, naproxen affects prostaglandins and other inflammatory mediators. Because sumatriptan and naproxen both relieve migraine yet interact with different cellular targets within the migraine pathway, it is reasonable to assume there is a unique synergy between these medications that improves treatment

  4. Stability of the multi-finger prehension synergy studied with transcranial magnetic stimulation

    PubMed Central

    Niu, Xun; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2008-01-01

    We used transcranial magnetic stimulation (TMS) to explore the stability of the three constituents of the multi-finger prehension synergy. Patterns of co-variation between mechanical variables produced by individual digits were used as indices of the prehension synergy. We tested hypotheses that TMS would violate these patterns and that different components of the prehension synergy would take different times to restore. Subjects held an instrumented handle with one of the three external load and one of the seven external torques statically in the air. Single-pulse TMS was applied unexpectedly over the hand projection in the contralateral hemisphere. The normal forces showed a quick TMS-induced increase that was proportional to the background force magnitude. This was also true for the tangential forces produced by the thumb, middle and ring fingers but not by the index and little fingers. The total moment of force changed proportionally to its background value with predominance of supination responses. During the quick force response to TMS, patterns of digit force co-variation stabilizing the total tangential force and total moment of force were violated. Two stages of synergy restoration were identified taking approximately 0.3 s and 1.5 s. These times differed among the three synergy components. The results support the idea of a prehension synergy as a neural mechanism that facilitates conjoint changes in forces produced by individual digits with the purpose to stabilize the hand action on the hand-held object. The data also support applicability of the principle of superposition to the human hand action. PMID:18592229

  5. Tumor microenvironment and metabolic synergy in breast cancers: critical importance of mitochondrial fuels and function.

    PubMed

    Martinez-Outschoorn, Ubaldo; Sotgia, Federica; Lisanti, Michael P

    2014-04-01

    Metabolic synergy or metabolic coupling between glycolytic stromal cells (Warburg effect) and oxidative cancer cells occurs in human breast cancers and promotes tumor growth. The Warburg effect or aerobic glycolysis is the catabolism of glucose to lactate to obtain adenosine triphosphate (ATP). This review summarizes the main findings on this stromal metabolic phenotype, and the associated signaling pathways, as well as the critical role of oxidative stress and autophagy, all of which promote carcinoma cell mitochondrial metabolism and tumor growth. Loss of Caveolin 1 (Cav-1) and the upregulation of monocarboxylate transporter 4 (MCT4) in stromal cells are novel markers of the Warburg effect and metabolic synergy between stromal and carcinoma cells. MCT4 and Cav-1 are also breast cancer prognostic biomarkers. Reactive oxygen species (ROS) are key mediators of the stromal Warburg effect. High ROS also favors cancer cell mitochondrial metabolism and tumorigenesis, and anti-oxidants can reverse this altered stromal and carcinoma metabolism. A pseudo-hypoxic state with glycolysis and low mitochondrial metabolism in the absence of hypoxia is a common feature in breast cancer. High ROS induces loss of Cav-1 in stromal cells and is sufficient to generate a pseudo-hypoxic state. Loss of Cav-1 in the stroma drives glycolysis and lactate extrusion via HIF-1α stabilization and the upregulation of MCT4. Stromal cells with loss of Cav-1 and/or high expression of MCT4 also show a catabolic phenotype, with enhanced macroautophagy. This catabolic state in stromal cells is driven by hypoxia-inducible factor (HIF)-1α, nuclear factor κB (NFκB), and JNK activation and high ROS generation. A feed-forward loop in stromal cells regulates pseudo-hypoxia and metabolic synergy, with Cav-1, MCT4, HIF-1α, NFκB, and ROS as its key elements. Metabolic synergy also may occur between cancer cells and cells in distant organs from the tumor. Cancer cachexia, which is due to severe organismal

  6. Health, supervisory support, and workplace culture in relation to work-family conflict and synergy.

    PubMed

    Beutell, Nicholas J

    2010-08-01

    This research examined health, supervisory support, and workplace culture as predictors of work interfering with family, family interfering with work, and work-family synergy. The analysis of data from 2,796 respondents from the 2002 National Study of the Changing Workforce yielded significant relations among measures of mental health, self-rated health, supervisory support, and work-family culture with a focus on career concerns. Support was found for a measure of work-family synergy. Implications and directions for research are discussed.

  7. Anticipatory synergy adjustments: preparing a quick action in an unknown direction.

    PubMed

    Zhou, Tao; Wu, Yen-Hsun; Bartsch, Angelo; Cuadra, Cristian; Zatsiorsky, Vladimir M; Latash, Mark L

    2013-05-01

    We studied a mechanism of feed-forward control of a multi-finger action, namely anticipatory synergy adjustments (ASAs), prior to a quick force correction in response to a change in the gain of the visual feedback. Synergies were defined as co-varied across trials adjustments of commands to fingers that stabilized (decreased variance of) the total force. We hypothesized that ASAs would be highly sensitive to prior information about the timing of the action but not to information on its direction, i.e., on whether the gain would go up or down. The subjects produced accurate constant total force by pressing with four fingers on individual force sensors. The feedback signal could change from veridical (the sum of finger forces) to modified, with the middle finger force multiplied by 0.2 or by 1.8. The timing of the gain change and its direction could be known or unknown to the subject in advance. When the timing of the gain change was known, ASA was seen as a drop in the synergy index starting about 250-300 ms prior to the first visible correction of the total force. When the gain change timing was unknown, ASAs started much later, less than 100 ms prior to the total force correction. The magnitude of synergy index changes was significantly larger under the "time known" conditions. Information on the direction of the visual gain change had no effect on the ASA timing, while the ASA magnitude was somewhat larger when this information was not available to the subject. After the total force correction, the synergy index was significantly larger for the force signal computed using the modified gain values as compared to the synergy index value for the actual total force. We conclude that ASAs represent an important feed-forward motor control mechanism that allows preparing for a quick action even when the direction of the action is not known in advance. The results emphasize the subtle control of multi-finger synergies that are specific to the exact contributions of

  8. Anticipatory synergy adjustments: Preparing a quick action in an unknown direction

    PubMed Central

    Zhou, Tao; Wu, Yen-Hsun; Bartsch, Angelo; Cuadra, Cristian; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2013-01-01

    We studied a mechanism of feed-forward control of a multi-finger action, namely anticipatory synergy adjustments (ASAs) prior to a quick force correction in response to a change in the gain of the visual feedback. Synergies were defined as co-varied across trials adjustments of commands to fingers that stabilized (decreased variance of) the total force. We hypothesized that ASAs would be highly sensitive to prior information about the timing of the action but not to information on its direction, i.e., on whether the gain would go up or down. The subjects produced accurate constant total force by pressing with four fingers on individual force sensors. The feedback signal could change from veridical (the sum of finger forces) to modified, with the middle finger force multiplied by 0.2 or by 1.8. The timing of the gain change and its direction could be known or unknown to the subject in advance. When the timing of the gain change was known, ASA was seen as a drop in the synergy index starting about 250–300 ms prior to the first visible correction of the total force. When the gain change timing was unknown, ASAs started much later, less than 100 ms prior to the total force correction. The magnitude of synergy index changes was significantly larger under the “time known” conditions. Information on the direction of the visual gain change had no effect on the ASA timing, while the ASA magnitude was somewhat larger when this information was not available to the subject. After the total force correction, the synergy index was significantly larger for the force signal computed using the modified gain values as compared to the synergy index value for the actual total force. We conclude that ASAs represent an important feed-forward motor control mechanism that allows preparing for a quick action even when the direction of the action is not known in advance. The results emphasize the subtle control of multi-finger synergies that are specific to the exact contributions of

  9. Muscle synergies may improve optimization prediction of knee contact forces during walking.

    PubMed

    Walter, Jonathan P; Kinney, Allison L; Banks, Scott A; D'Lima, Darryl D; Besier, Thor F; Lloyd, David G; Fregly, Benjamin J

    2014-02-01

    The ability to predict patient-specific joint contact and muscle forces accurately could improve the treatment of walking-related disorders. Muscle synergy analysis, which decomposes a large number of muscle electromyographic (EMG) signals into a small number of synergy control signals, could reduce the dimensionality and thus redundancy of the muscle and contact force prediction process. This study investigated whether use of subject-specific synergy controls can improve optimization prediction of knee contact forces during walking. To generate the predictions, we performed mixed dynamic muscle force optimizations (i.e., inverse skeletal dynamics with forward muscle activation and contraction dynamics) using data collected from a subject implanted with a force-measuring knee replacement. Twelve optimization problems (three cases with four subcases each) that minimized the sum of squares of muscle excitations were formulated to investigate how synergy controls affect knee contact force predictions. The three cases were: (1) Calibrate+Match where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously matched, (2) Precalibrate+Predict where experimental knee contact forces were predicted using precalibrated muscle model parameters values from the first case, and (3) Calibrate+Predict where muscle model parameter values were calibrated and experimental knee contact forces were simultaneously predicted, all while matching inverse dynamic loads at the hip, knee, and ankle. The four subcases used either 44 independent controls or five synergy controls with and without EMG shape tracking. For the Calibrate+Match case, all four subcases closely reproduced the measured medial and lateral knee contact forces (R2 ≥ 0.94, root-mean-square (RMS) error < 66 N), indicating sufficient model fidelity for contact force prediction. For the Precalibrate+Predict and Calibrate+Predict cases, synergy controls yielded better contact force

  10. Determination of in vitro synergy for dual antimicrobial therapy against resistant Neisseria gonorrhoeae using Etest and agar dilution.

    PubMed

    Wind, Carolien M; de Vries, Henry J C; van Dam, Alje P

    2015-03-01

    In response to antimicrobial resistance of Neisseria gonorrhoeae to last-resort extended-spectrum cephalosporins, combination therapy of azithromycin+ceftriaxone is now recommended. Dual therapy can be effective to treat monoresistant strains as well as multidrug-resistant strains, preferably employing the effect of in vitro synergy. As reports on in vitro synergy of azithromycin+ceftriaxone in N. gonorrhoeae are conflicting, in this study an evaluation of this combination was performed using a cross-wise Etest method and agar dilution. Synergy was defined as a fractional inhibitory concentration index (FICI) of ≤0.5. To identify other dual treatment options for gonorrhoea, in vitro synergy was evaluated for 65 dual antimicrobial combinations using Etest. Azithromycin, cefixime, ceftriaxone, colistin, ertapenem, fosfomycin, gentamicin, minocycline, moxifloxacin, rifampicin, spectinomycin and tigecycline were screened for synergy in all possible combinations. No synergy or antagonism was found for any of the 65 combinations. The geometric mean FICI ranged from 0.82 to 2.00. The mean FICI of azithromycin+ceftriaxone was 1.18 (Etest) and 0.55 (agar dilution). The difference between both methods did not result in a difference in interpretation of synergy. Ceftriaxone-resistant strain F89 was tested in all combinations and no synergy was found for any of them. Most importantly, the ceftriaxone minimum inhibitory concentration of F89 was not decreased below the breakpoint with any concentration of azithromycin.

  11. School District and University Co-Teaching: Toward Instructional Synergy in an Induction/M.Ed. Program

    ERIC Educational Resources Information Center

    Buczynski, Sandy; Sisserson, Kendra

    2008-01-01

    What happens when a district teacher assumes the role of university student? What happens when two instructors from two different institutions are at the helm of a single graduate-level university course? The duality of these situations is recognized in the notion of what the authors termed "instructional synergy", drawing upon synergy as both…

  12. The effect of parameters of equilibrium-based 3-D biomechanical models on extracted muscle synergies during isometric lumbar exertion.

    PubMed

    Eskandari, A H; Sedaghat-Nejad, E; Rashedi, E; Sedighi, A; Arjmand, N; Parnianpour, M

    2016-04-11

    A hallmark of more advanced models is their higher details of trunk muscles represented by a larger number of muscles. The question is if in reality we control these muscles individually as independent agents or we control groups of them called "synergy". To address this, we employed a 3-D biomechanical model of the spine with 18 trunk muscles that satisfied equilibrium conditions at L4/5, with different cost functions. The solutions of several 2-D and 3-D tasks were arranged in a data matrix and the synergies were computed by using non-negative matrix factorization (NMF) algorithms. Variance accounted for (VAF) was used to evaluate the number of synergies that emerged by the analysis, which were used to reconstruct the original muscle activations. It was showed that four and six muscle synergies were adequate to reconstruct the input data of 2-D and 3-D torque space analysis. The synergies were different by choosing alternative cost functions as expected. The constraints affected the extracted muscle synergies, particularly muscles that participated in more than one functional tasks were influenced substantially. The compositions of extracted muscle synergies were in agreement with experimental studies on healthy participants. The following computational methods show that the synergies can reduce the complexity of load distributions and allow reduced dimensional space to be used in clinical settings.

  13. Sensors and OBIA synergy for operational monitoring of surface water

    NASA Astrophysics Data System (ADS)

    Masson, Eric; Thenard, Lucas

    2010-05-01

    , frequent drought period and now with foreseen climate change impacts. This third case will demonstrate the efficiency of SPOT 5 programming in synergy with OBIA methodology to assess the evolution of dam surface water within a complete water cycle (i.e. 2008-09). In all those three cases image segmentation and classification algorithms developed with e-Cognition 8 software allow an easy to use implementation of simple to highly sophisticate OBIA rulsets fully operational in batch processes. Finally this contribution foresees the new opportunity of integration of Worldview 2 multispectral imagery (i.e. 8 bands) including its "coastal" band that will also find an application in continental surface water bathymetry. Worldview 2 is a recently launch satellite (e.g. October 2009) that starts to collect earth observation data since January 2010. It is therefore a promising new remote sensing tool to develop operational hydrology in combination high resolution SAR imagery and OBIA methodology. This contribution will conclude on the strong potential for operationalisation in hydrology and water resources management that recent and future sensors and image analysis methodologies are offering to water management and decision makers.

  14. Prehension Synergies during Smooth Changes of the External Torque

    PubMed Central

    Sun, Yao; Park, Jaebum; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2011-01-01

    We studied characteristics of digit action and their co-variation patterns across trials (prehension synergies) during static holding of an object while the external torque could change slowly and smoothly. The subjects held in the air an instrumented handle with an attachment that allowed a smooth change in the external torque over about 12 s; the load was always kept constant. Series of trials were performed under three conditions: The torque could be zero throughout the trial or it could change slowly requiring a smooth change of the effort from a non-zero pronation value to zero (PR-0) or from a non-zero supination value to zero (SU-0). The handle was kept vertical at all times. Indices of variance and co-variation of elemental variables (forces and moments of force produced by individual digits) stabilizing such performance variables as total normal force, total tangential force, and total moment of force were computed at two levels of an assumed control hierarchy. At the upper level, the task is shared between the thumb and virtual finger (an imagined digit with the mechanical action equal to that of the four fingers), while at the lower level, action of the virtual finger is shared among the actual four fingers. We analyzed the total moment of force as the sum of the moments of force produced by the thumb and virtual finger and also as the sum of the moments of force produced by the normal forces and tangential forces. The results showed that the adjustments in the total moment of force were produced primarily with changes in the moment produced by the virtual finger and by changes in the moment produced by the normal forces. The normal force of the thumb at the final state (which was the same across conditions) was larger in the two conditions with changes in the external torque. The safety margin was significantly higher in the PR-0 condition, and it dropped with the decrease in the external torque. A co-contraction index was computed to reflect moment of

  15. Prehension synergies during smooth changes of the external torque.

    PubMed

    Sun, Yao; Park, Jaebum; Zatsiorsky, Vladimir M; Latash, Mark L

    2011-09-01

    We studied characteristics of digit action and their co-variation patterns across trials (prehension synergies) during static holding of an object while the external torque could change slowly and smoothly. The subjects held in the air an instrumented handle with an attachment that allowed a smooth change in the external torque over about 12 s; the load was always kept constant. Series of trials were performed under three conditions: The torque could be zero throughout the trial, or it could change slowly requiring a smooth change of the effort from a non-zero pronation value to zero (PR-0) or from a non-zero supination value to zero (SU-0). The handle was kept vertical at all times. Indices of variance and co-variation of elemental variables (forces and moments of force produced by individual digits) stabilizing such performance variables as total normal force, total tangential force, and total moment of force were computed at two levels of an assumed control hierarchy. At the upper level, the task is shared between the thumb and virtual finger (an imagined digit with the mechanical action equal to that of the four fingers), while at the lower level, the action of the virtual finger is shared among the actual four fingers. We analyzed the total moment of force as the sum of the moments of force produced by the thumb and virtual finger and also as the sum of the moments of force produced by the normal forces and tangential forces. The results showed that the adjustments in the total moment of force were produced primarily with changes in the moment produced by the virtual finger and by changes in the moment produced by the normal forces. The normal force of the thumb at the final state (which was the same across conditions) was larger in the two conditions with changes in the external torque. The safety margin was significantly higher in the PR-0 condition, and it dropped with the decrease in the external torque. A co-contraction index was computed to reflect the

  16. Hybrid opto-electric techniques for molecular diagnostics

    SciTech Connect

    Haque, Aeraj Ul

    2012-01-01

    Hybrid optoelectric techniques reflect a new paradigm in microfluidics. In essence, these are microfluidic techniques that employ a synergistic combination of optical and electrical forces to enable noninvasive manipulation of fluids and/or particle-type entities at the micro/nano-scale [1]. Synergy between optical and electrical forces bestows these techniques with several unique features that are promising to bring new opportunities in molecular diagnostics. Within the scope of molecular diagnostics, several aspects of optoelectric techniques promise to play a relevant role. These include, but are not limited to, sample preparation, sorting, purification, amplification and detection.

  17. Effect of fuel origin on synergy during co-gasification of biomass and coal in CO2.

    PubMed

    Zhang, Yan; Zheng, Yan; Yang, Mingjun; Song, Yongchen

    2016-01-01

    The effect of fuel origin on synergy in coal/biomass blends during co-gasification has been assessed using a congruent-mass thermogravimetry analysis (TGA) method. Results revealed that synergy occurs when ash residuals are formed, followed by an almost complete gasification of biomass. Potassium species in biomass ash play a catalytic role in promoting gasification reactivity of coal char, which is a direct consequence of synergy during co-gasification. The SEM-EDS spectra provided conclusive evidence that the transfer of potassium from biomass to the surface of coal char occurs during co-pyrolysis/gasification. Biomass ash rich in silica eliminated synergy in coal/biomass blends but not to the extent of inhibiting the reaction rate of the blended chars to make it slower than that of separated ones. The best result in terms of synergy was concluded to be the combination of low-ash coal and K-rich biomass.

  18. Effect of fuel origin on synergy during co-gasification of biomass and coal in CO2.

    PubMed

    Zhang, Yan; Zheng, Yan; Yang, Mingjun; Song, Yongchen

    2016-01-01

    The effect of fuel origin on synergy in coal/biomass blends during co-gasification has been assessed using a congruent-mass thermogravimetry analysis (TGA) method. Results revealed that synergy occurs when ash residuals are formed, followed by an almost complete gasification of biomass. Potassium species in biomass ash play a catalytic role in promoting gasification reactivity of coal char, which is a direct consequence of synergy during co-gasification. The SEM-EDS spectra provided conclusive evidence that the transfer of potassium from biomass to the surface of coal char occurs during co-pyrolysis/gasification. Biomass ash rich in silica eliminated synergy in coal/biomass blends but not to the extent of inhibiting the reaction rate of the blended chars to make it slower than that of separated ones. The best result in terms of synergy was concluded to be the combination of low-ash coal and K-rich biomass. PMID:26580896

  19. Simplified and effective motor control based on muscle synergies to exploit musculoskeletal dynamics

    PubMed Central

    Berniker, Max; Jarc, Anthony; Bizzi, Emilio; Tresch, Matthew C.

    2009-01-01

    The basic hypothesis of producing a range of behaviors using a small set of motor commands has been proposed in various forms to explain motor behaviors ranging from basic reflexes to complex voluntary movements. Yet many fundamental questions regarding this long-standing hypothesis remain unanswered. Indeed, given the prominent nonlinearities and high dimensionality inherent in the control of biological limbs, the basic feasibility of a low-dimensional controller and an underlying principle for its creation has remained elusive. We propose a principle for the design of such a controller, that it endeavors to control the natural dynamics of the limb, taking into account the nature of the task being performed. Using this principle, we obtained a low-dimensional model of the hindlimb and a set of muscle synergies to command it. We demonstrate that this set of synergies was capable of producing effective control, establishing the viability of this muscle synergy hypothesis. Finally, by combining the low-dimensional model and the muscle synergies we were able to build a relatively simple controller whose overall performance was close to that of the system's full-dimensional nonlinear controller. Taken together, the results of this study establish that a low-dimensional controller is capable of simplifying control without degrading performance. PMID:19380738

  20. A novel ECMO circuit using a SYNERGY circulite pump in a swine model.

    PubMed

    Biscotti, Mauer; Singh, Gopal; Downey, Peter; Bacchetta, Matthew

    2014-01-01

    Extracorporeal membrane oxygenation (ECMO) is used in the management of refractory cardiopulmonary failure. With improvements in technology, patients can be transferred between hospitals, ambulated, and supported for extended periods of time while on ECMO. The SYNERGY CircuLite micropump is a blood pump that has been used as a ventricular assist device for partial support. In this study, we assessed the blood biocompatibility of the SYNERGY blood pump in conjunction with a Quadrox D oxygenator for use in a novel ECMO circuit in a swine model. This clinical design was used to demonstrate early feasibility of this pump system. Four pigs were placed on venovenous ECMO circuit, which consisted of a SYNERGY pump, Quadrox D oxygenator, and Cobe E Pack 3/8 inch tubing. All animals survived the 6 hour ECMO run without catastrophic biocompatibility issues. There was no statistically discernible change from baseline in hematologic parameters, including hemoglobin, plasma-free hemoglobin, total bilirubin, lactate dehydrogenase, D-dimer, fibrinogen, platelets, and P-selectin. We believe that this study serves as a proof of concept and basis for further studies using the SYNERGY pump as a component of ECMO systems.

  1. Synergy in Urban Relationships--Public School Adult Education, Community Colleges, and Community Education.

    ERIC Educational Resources Information Center

    Griffith, William S.

    The presentation reviews selected developments in inter-organizational cooperation and coordination at the local, State, and national levels in order to provide a basis for identifying major questions and issues faced by the National Council of Urban Administrators of Adult Education (NCUAAE) as they strive for synergy in adult education. Trends…

  2. Inverse estimation of multiple muscle activations from joint moment with muscle synergy extraction.

    PubMed

    Li, Zhan; Guiraud, David; Hayashibe, Mitsuhiro

    2015-01-01

    Human movement is produced resulting from synergetic combinations of multiple muscle contractions. The resultant joint movement can be estimated through the related multiple-muscle activities, which is formulated as the forward problem. Neuroprosthetic applications may benefit from cocontraction of agonist and antagonist muscle pairs to achieve more stable and robust joint movements. It is necessary to estimate the activation of each individual muscle from desired joint torque(s), which is the inverse problem. A synergy-based solution is presented for the inverse estimation of multiple muscle activations from joint movement, focusing on one degree-of-freedom tasks. The approach comprises muscle synergy extraction via the nonnegative matrix factorization algorithm. Cross validation is performed to evaluate the method for prediction accuracy based on experimental data from ten able-bodied subjects. The results demonstrate that the approach succeeds to inversely estimate the multiple muscle activities from the given joint torque sequence. In addition, the other one's averaged synergy ratio was applied for muscle activation estimation with leave-one-out cross-validation manner, which resulted in 9.3% estimation error over all the subjects. The obtained results support the common muscle synergy-based neuroprosthetics control concept.

  3. Air surface microdischarge-photon synergy in antibacterial plasma-activated water

    NASA Astrophysics Data System (ADS)

    Graves, David; Pavlovich, Mathew; Chang, Hung-Wen; Sakiyama, Yuki; Clark, Douglas

    2013-09-01

    We show that the antibacterial effects of air plasma on water can be amplified by synergy with ultraviolet (UV) photons. We use the surface microdischarge configuration (SMD) in atmospheric air adjacent to bacteria-laden water coupled with UVA (360 nm) photons from a light emitting diode (LED) to demonstrate this synergy. Air SMD, especially if operated in a confined space, can operate in different modes: low power mode (<0.1 W/cm2) generates primarily O3 whereas higher powers generate mainly nitrogen oxides; we focus here on the latter. The nitrogen oxide mode creates a powerful antibacterial mixture in water, including NO2-, NO3- and H2O2. Although these species alone can be strongly antibacterial, especially at low pH, we show that addition of UVA photons greatly amplifies the antibacterial effect. We first measured log reductions with only photons and then only plasma. Only when UVA exposes water after plasma does the synergy appear. Synergy appears to be due to UVA photolysis of plasma-generated NO2- to form NO and OH. We conclude that combining plasma-generated chemical species with activating photons can amplify and strengthen plasma effectiveness in many biological and other applications. Supported by Department of Energy, Office of Fusion Science Plasma Science Center.

  4. "I've Known Rivers": A Reflection on the Synergy of Multigenre, Multimodal Texts

    ERIC Educational Resources Information Center

    Richter, Elizabeth

    2016-01-01

    In this article an elementary literacy specialist reflects on the use of multigenre, multimodal texts to support the teaching of poetry. She explores the synergy between poetry and related informational, visual, and auditory texts to afford deeper insights into the poem and the poet, in this instance, the poem, "The Negro Speaks of…

  5. Effect of handedness on muscle synergies during upper limb planar movements.

    PubMed

    Duthilleul, N; Pirondini, E; Coscia, M; Micera, S

    2015-08-01

    Handedness is a prominent but poorly understood aspect of human motor performances. Despite it is generally accepted that it results from differences in the neural control of the arm, the mechanisms at the origin of the side-difference in motor performances are still unknown. In this work, we propose to deepen this aspect by investigating muscle synergies organization. We obtained muscle synergies through the factorization of the superficial electromyographical (EMG) activity related to fifteen upper limb muscles in the dominant and non-dominant side of 5 healthy young right and left dominant subjects, while executing planar wide and tight circular trajectories. Our preliminary results showed that right and left handed subjects performed the circular trajectories with a different muscle organization. Moreover, a task-related side-difference in muscle synergies was observed. Further investigations in a larger cohort of individuals are necessary to determine the neural mechanisms generating the differences in number and organization of muscle synergies between left and right handed individuals. PMID:26737035

  6. Synergy, Holistic Education and R. Buckminster Fuller: Education for a World in Transformation.

    ERIC Educational Resources Information Center

    Gerber, Alex

    This pamphlet relates this quotation by R. Buckminster Fuller to the educational process: "To be optimally effective, undertake at outset the most comprehensive task in the most comprehensive and incisively detailed manner." The principle of synergy can be used to determine when something is "optimally effective." One example of how teachers can…

  7. Media Credibility Reconsidered: Synergy between On-Air and Online News.

    ERIC Educational Resources Information Center

    Bucy, Erik P.

    2003-01-01

    Examines the combined effects of on-air and online network news exposure, placing student and adult news consumers in broadcast news, online news, and telewebbing conditions. Indicates that perceptions of network news credibility are affected by channel used. Offers evidence for the existence of a synergy effect between on-air and online news. (PM)

  8. Extended inclusive fitness theory: synergy and assortment drives the evolutionary dynamics in biology and economics.

    PubMed

    Jaffe, Klaus

    2016-01-01

    W.D. Hamilton's Inclusive Fitness Theory explains the conditions that favor the emergence and maintenance of social cooperation. Today we know that these include direct and indirect benefits an agent obtains by its actions, and through interactions with kin and with genetically unrelated individuals. That is, in addition to kin-selection, assortation or homophily, and social synergies drive the evolution of cooperation. An Extended Inclusive Fitness Theory (EIFT) synthesizes the natural selection forces acting on biological evolution and on human economic interactions by assuming that natural selection driven by inclusive fitness produces agents with utility functions that exploit assortation and synergistic opportunities. This formulation allows to estimate sustainable cost/benefit threshold ratios of cooperation among organisms and/or economic agents, using existent analytical tools, illuminating our understanding of the dynamic nature of society, the evolution of cooperation among kin and non-kin, inter-specific cooperation, co-evolution, symbioses, division of labor and social synergies. EIFT helps to promote an interdisciplinary cross fertilization of the understanding of synergy by, for example, allowing to describe the role for division of labor in the emergence of social synergies, providing an integrated framework for the study of both, biological evolution of social behavior and economic market dynamics. Another example is a bio-economic understanding of the motivations of terrorists, which identifies different forms of terrorism.

  9. Heat transfer enhancement with mixing vane spacers using the field synergy principle

    NASA Astrophysics Data System (ADS)

    Yang, Lixin; Zhou, Mengjun; Tian, Zihao

    2016-08-01

    The single-phase heat transfer characteristics in a PWR fuel assembly are important. Many investigations attempt to obtain the heat transfer characteristics by studying the flow features in a 5´5 rod bundle with a spacer grid. The field synergy principle is used to discuss the mechanism of heat transfer enhancement using mixing vanes according to computational fluid dynamics results, including a spacer grid without mixing vanes, one with a split mixing vane, and one with a separate mixing vane. The results show that the field synergy principle is feasible to explain the mechanism of heat transfer enhancement in a fuel assembly. The enhancement in subchannels is more effective than on the rod's surface. If the pressure loss is ignored, the performance of the split mixing vane is superior to the separate mixing vane based on the enhanced heat transfer. Increasing the blending angle of the split mixing vane improves heat transfer enhancement, the maximum of which is 7.1%. Increasing the blending angle of the separate mixing vane did not significantly enhance heat transfer in the rod bundle, and even prevented heat transfer at a blending angle of 50°. This finding testifies to the feasibility of predicting heat transfer in a rod bundle with a spacer grid by field synergy, and upon comparison with analyzed flow features only, the field synergy method may provide more accurate guidance for optimizing the use of mixing vanes.

  10. A New Web-based Tool for Aerosol Data Analysis: the AERONET Data Synergy Tool

    NASA Astrophysics Data System (ADS)

    Giles, D. M.; Holben, B. N.; Slutsker, I.; Welton, E. J.; Chin, M.; Schmaltz, J.; Kucsera, T.; Diehl, T.

    2006-12-01

    The Aerosol Robotic Network (AERONET) provides important aerosol microphysical and optical properties via an extensive distribution of continental sites and sparsely-distributed coastal and oceanic sites among the major oceans and inland seas. These data provide only spatial point measurements while supplemental data are needed for a complete aerosol analysis. Ancillary data sets (e.g., MODIS true color imagery and back trajectory analyses) are available by navigating to several web data sources. In an effort to streamline aerosol data discovery and analysis, a new web data tool called the "AERONET Data Synergy Tool" was launched from the AERONET web site. This tool provides access to ground-based (AERONET and MPLNET), satellite (MODIS, SeaWiFS, TOMS, and OMI) and model (GOCART and back trajectory analyses) databases via one web portal. The Data Synergy Tool user can access these data sources to obtain properties such as the optical depth, composition, absorption, size, spatial and vertical distribution, and source region of aerosols. AERONET Ascension Island and COVE platform site data will be presented to highlight the Data Synergy Tool capabilities in analyzing urban haze, smoke, and dust aerosol events over the ocean. Future development of the AERONET Data Synergy Tool will include the expansion of current data sets as well as the implementation of other Earth Science data sets pertinent to advancing aerosol research.

  11. Forging Our Own Path: Building Synergy from Opposing Forces: Response to Pomerenke and Rogers.

    ERIC Educational Resources Information Center

    Thomas, Gail Fann

    2001-01-01

    Suggests that educators view teaching and research, ivory tower and "the trenches," positivism and interpretive studies, English and business, theory and practice as two sides of the same coin; that coin is business communication. Addresses three integrative themes: (1) the synergy of scholarships; (2) the dilemma of disciplinary biases; and (3) a…

  12. Stability and Composition of Functional Synergies for Speech Movements in Children with Developmental Speech Disorders

    ERIC Educational Resources Information Center

    Terband, H.; Maassen, B.; van Lieshout, P.; Nijland, L.

    2011-01-01

    The aim of this study was to investigate the consistency and composition of functional synergies for speech movements in children with developmental speech disorders. Kinematic data were collected on the reiterated productions of syllables spa(/spa[image omitted]/) and paas(/pa[image omitted]s/) by 10 6- to 9-year-olds with developmental speech…

  13. Mechanical Analysis and Hierarchies of Multi-digit Synergies during Accurate Object Rotation

    PubMed Central

    Zhang, Wei; Olafsdottir, Halla B.; Zatsiorsky, Vladimir M.; Latash, Mark L.

    2009-01-01

    We studied the mechanical variables (the grip force and the total moment of force) and multi-digit synergies at two levels (the virtual finger-thumb level, VF-TH, and the individual finger level, IMRL) of a hypothetical control hierarchy during accurate rotation of a hand-held instrumented handle. Synergies were defined as co-varied changes in elemental variables (forces and moments of force) that stabilize the output at a particular level. Indices of multi-digit synergies showed higher values at the hierarchically higher level (VF-TH) for both normal and tangential forces. The moment of force was stabilized at both hierarchical levels during the steady-state phases but not during the movement. The results support the principles of superposition and of mechanical advantage. They also support an earlier hypothesis on an inherent trade-off between synergies at the two hierarchical levels, although the controller showed more subtle and versatile synergic control than the one hypothesized earlier. PMID:19799165

  14. Synergy Access: A Global Newsletter on Futuristic Communications, Media & Networking. Number 1.

    ERIC Educational Resources Information Center

    Thomas, Wes, Ed.

    A global newsletter on futuristic communications, media and networking is dedicated to creating open, humanistic environments for better interpersonal communication and to exploring the phenomenon of synergy, the coming together of people, ideas and environments for creation of something greater than the sum of the parts. Editorials, poetry, and…

  15. Neoliberalism, New Public Management and the Sustainable Development Agenda of Higher Education: History, Contradictions and Synergies

    ERIC Educational Resources Information Center

    Bessant, Sophie E. F.; Robinson, Zoe P.; Ormerod, R. Mark

    2015-01-01

    This paper explores the ideological and the practical relationship between neoliberalism and New Public Management (NPM) and the sustainable development agenda of western higher education. Using the United Kingdom and specifically English universities as an example, it investigates the contradictions and the synergies between neoliberal and NPM…

  16. The "Synergies" Research-Practice Partnership Project: A "2020 Vision" Case Study

    ERIC Educational Resources Information Center

    Falk, John H.; Dierking, Lynn D.; Staus, Nancy L.; Wyld, Jennifer N.; Bailey, Deborah L.; Penuel, William R.

    2016-01-01

    This paper, describes "Synergies," an on-going longitudinal study and design effort, being conducted in a diverse, under-resourced community in Portland, Oregon, with the goal of measurably improving STEM learning, interest and participation by early adolescents, both in school and out of school. Authors examine how the work of this…

  17. Educational Opportunities Based on the University-Industry Synergies in an Open Innovation Framework

    ERIC Educational Resources Information Center

    Lucia, Oscar; Burdio, Jose M.; Acero, Jesus; Barragan, Luis A.; Garcia, Jose R.

    2012-01-01

    Collaboration between Industry and University is becoming more important in order to improve the competitiveness of the research and development activities. Moreover, establishing synergies to bridge the gap between the academic and industrial spheres has demonstrated to be advantageous for both of them. Nowadays, Industry is moving towards an…

  18. Inquiry and Irony: Promise and Paradox in Paul Jablon's "The Synergy of Inquiry"

    ERIC Educational Resources Information Center

    Nurenberg, David

    2016-01-01

    Paul Jablon's "The Synergy of Inquiry" (2014) is well-timed. The 2014 deadline set by No Child Left Behind (NCLB, 2002) for universal student proficiency has come and gone, and according to the National Assessment of Educational Progress, "proficiency rates last year were below 50 percent for nearly every racial and ethnic group, in…

  19. Perceptions of Research Scientists and Science Educators Regarding Science Education: Call for Synergy.

    ERIC Educational Resources Information Center

    Melear, Claudia T.

    Improvement in science teacher education has been called for by several scientists and science education organizations. The concept of synergy is suggested as a model for enhanced improvements in the overall preparation of science teachers due to positive interactions between groups responsible for science teacher education, scientists, and…

  20. Extended inclusive fitness theory: synergy and assortment drives the evolutionary dynamics in biology and economics.

    PubMed

    Jaffe, Klaus

    2016-01-01

    W.D. Hamilton's Inclusive Fitness Theory explains the conditions that favor the emergence and maintenance of social cooperation. Today we know that these include direct and indirect benefits an agent obtains by its actions, and through interactions with kin and with genetically unrelated individuals. That is, in addition to kin-selection, assortation or homophily, and social synergies drive the evolution of cooperation. An Extended Inclusive Fitness Theory (EIFT) synthesizes the natural selection forces acting on biological evolution and on human economic interactions by assuming that natural selection driven by inclusive fitness produces agents with utility functions that exploit assortation and synergistic opportunities. This formulation allows to estimate sustainable cost/benefit threshold ratios of cooperation among organisms and/or economic agents, using existent analytical tools, illuminating our understanding of the dynamic nature of society, the evolution of cooperation among kin and non-kin, inter-specific cooperation, co-evolution, symbioses, division of labor and social synergies. EIFT helps to promote an interdisciplinary cross fertilization of the understanding of synergy by, for example, allowing to describe the role for division of labor in the emergence of social synergies, providing an integrated framework for the study of both, biological evolution of social behavior and economic market dynamics. Another example is a bio-economic understanding of the motivations of terrorists, which identifies different forms of terrorism. PMID:27468393

  1. Suboptimal Muscle Synergy Activation Patterns Generalize their Motor Function across Postures

    PubMed Central

    Sohn, M. Hongchul; Ting, Lena H.

    2016-01-01

    We used a musculoskeletal model to investigate the possible biomechanical and neural bases of using consistent muscle synergy patterns to produce functional motor outputs across different biomechanical conditions, which we define as generalizability. Experimental studies in cats demonstrate that the same muscle synergies are used during reactive postural responses at widely varying configurations, producing similarly-oriented endpoint force vectors with respect to the limb axis. However, whether generalizability across postures arises due to similar biomechanical properties or to neural selection of a particular muscle activation pattern has not been explicitly tested. Here, we used a detailed cat hindlimb model to explore the set of feasible muscle activation patterns that produce experimental synergy force vectors at a target posture, and tested their generalizability by applying them to different test postures. We used three methods to select candidate muscle activation patterns: (1) randomly-selected feasible muscle activation patterns, (2) optimal muscle activation patterns minimizing muscle effort at a given posture, and (3) generalizable muscle activation patterns that explicitly minimized deviations from experimentally-identified synergy force vectors across all postures. Generalizability was measured by the deviation between the simulated force direction of the candidate muscle activation pattern and the experimental synergy force vectors at the test postures. Force angle deviations were the greatest for the randomly selected feasible muscle activation patterns (e.g., >100°), intermediate for effort-wise optimal muscle activation patterns (e.g., ~20°), and smallest for generalizable muscle activation patterns (e.g., <5°). Generalizable muscle activation patterns were suboptimal in terms of effort, often exceeding 50% of the maximum possible effort (cf. ~5% in minimum-effort muscle activation patterns). The feasible muscle activation ranges of individual

  2. Muscle Synergies Facilitate Computational Prediction of Subject-Specific Walking Motions

    PubMed Central

    Meyer, Andrew J.; Eskinazi, Ilan; Jackson, Jennifer N.; Rao, Anil V.; Patten, Carolynn; Fregly, Benjamin J.

    2016-01-01

    Researchers have explored a variety of neurorehabilitation approaches to restore normal walking function following a stroke. However, there is currently no objective means for prescribing and implementing treatments that are likely to maximize recovery of walking function for any particular patient. As a first step toward optimizing neurorehabilitation effectiveness, this study develops and evaluates a patient-specific synergy-controlled neuromusculoskeletal simulation framework that can predict walking motions for an individual post-stroke. The main question we addressed was whether driving a subject-specific neuromusculoskeletal model with muscle synergy controls (5 per leg) facilitates generation of accurate walking predictions compared to a model driven by muscle activation controls (35 per leg) or joint torque controls (5 per leg). To explore this question, we developed a subject-specific neuromusculoskeletal model of a single high-functioning hemiparetic subject using instrumented treadmill walking data collected at the subject’s self-selected speed of 0.5 m/s. The model included subject-specific representations of lower-body kinematic structure, foot–ground contact behavior, electromyography-driven muscle force generation, and neural control limitations and remaining capabilities. Using direct collocation optimal control and the subject-specific model, we evaluated the ability of the three control approaches to predict the subject’s walking kinematics and kinetics at two speeds (0.5 and 0.8 m/s) for which experimental data were available from the subject. We also evaluated whether synergy controls could predict a physically realistic gait period at one speed (1.1 m/s) for which no experimental data were available. All three control approaches predicted the subject’s walking kinematics and kinetics (including ground reaction forces) well for the model calibration speed of 0.5 m/s. However, only activation and synergy controls could predict the

  3. Improving activity of minicellulosomes by integration of intra- and intermolecular synergies

    PubMed Central

    2013-01-01

    Background Complete hydrolysis of cellulose to glucose requires the synergistic action of three general types of glycoside hydrolases; endoglucanases, exoglucanases, and cellobiases. Cellulases that are found in Nature vary considerably in their modular diversity and architecture. They include: non-complexed enzymes with single catalytic domains, independent single peptide chains incorporating multiple catalytic modules, and complexed, scaffolded structures, such as the cellulosome. The discovery of the latter two enzyme architectures has led to a generally held hypothesis that these systems take advantage of intramolecular and intermolecular proximity synergies, respectively, to enhance cellulose degradation. We use domain engineering to exploit both of these concepts to improve cellulase activity relative to the activity of mixtures of the separate catalytic domains. Results We show that engineered minicellulosomes can achieve high levels of cellulose conversion on crystalline cellulose by taking advantage of three types of synergism; (1) a complementary synergy produced by interaction of endo- and exo-cellulases, (2) an intramolecular synergy of multiple catalytic modules in a single gene product (this type of synergism being introduced for the first time to minicellulosomes targeting crystalline cellulose), and (3) an intermolecular proximity synergy from the assembly of these cellulases into larger multi-molecular structures called minicellulosomes. The binary minicellulosome constructed in this study consists of an artificial multicatalytic cellulase (CBM4-Ig-GH9-X11-X12-GH8-Doc) and one cellulase with a single catalytic domain (a modified Cel48S with the structure CBM4-Ig-GH48-Doc), connected by a non-catalytic scaffoldin protein. The high level endo-exo synergy and intramolecular synergies within the artificial multifunctional cellulase have been combined with an additional proximity-dependent synergy produced by incorporation into a minicellulosome

  4. Multi-digit coordination during lifting a horizontally oriented object: synergies control with referent configurations

    PubMed Central

    Wu, Yen-Hsun; Zatsiorsky, Vladimir M.

    2012-01-01

    We explored digit coordination during the acceleration phase of a quick lifting movement of a hand-held horizontal object. We tested three hypotheses related to: (1) the scaling of mechanical variables produced by the hand with changes in the external load, torque, and moment of inertia; (2) changes in the safety margin for the thumb with both the loading conditions and acceleration; and (3) changes in the indices of synergies. The subjects held a horizontal handle with a prismatic grasp (the thumb acted on top of the handle) and performed series of “very quick” lifting movements to a visual target. Multi-digit synergies were quantified as co-variation indices among elemental variables (forces and moments produced by individual digits). The resultant force scaled with the external load but not torque, while the grip force scaled with the external torque but not load. The safety margin dropped with an increase in acceleration; it also showed changes with the external torque and moment of inertia. Total moment of force was primarily produced by the tangential forces (over 80 %) across all movement phases and loading conditions. The index and little fingers produced close to zero moment with their normal forces, while the middle and ring fingers produced consistent moments due to the reproducible shifts of their centers of pressure. Synergy indices at the upper level of the assumed hierarchy (the task is shared between the thumb and virtual finger—an imagined digit with the action equal to that of the four fingers combined) did not drop with acceleration for the three force vector components and one of the moment vector components. They did drop with acceleration at the lower level (virtual finger action is shared among the four fingers). There was a trade-off between synergy indices computed at the two levels for the three force vector components, but not for the moment of force components. We confirmed specialization of different fingers with respect to

  5. Multi-digit coordination during lifting a horizontally oriented object: synergies control with referent configurations.

    PubMed

    Wu, Yen-Hsun; Zatsiorsky, Vladimir M; Latash, Mark L

    2012-10-01

    We explored digit coordination during the acceleration phase of a quick lifting movement of a hand-held horizontal object. We tested three hypotheses related to: (1) the scaling of mechanical variables produced by the hand with changes in the external load, torque, and moment of inertia; (2) changes in the safety margin for the thumb with both the loading conditions and acceleration; and (3) changes in the indices of synergies. The subjects held a horizontal handle with a prismatic grasp (the thumb acted on top of the handle) and performed series of "very quick" lifting movements to a visual target. Multi-digit synergies were quantified as co-variation indices among elemental variables (forces and moments produced by individual digits). The resultant force scaled with the external load but not torque, while the grip force scaled with the external torque but not load. The safety margin dropped with an increase in acceleration; it also showed changes with the external torque and moment of inertia. Total moment of force was primarily produced by the tangential forces (over 80 %) across all movement phases and loading conditions. The index and little fingers produced close to zero moment with their normal forces, while the middle and ring fingers produced consistent moments due to the reproducible shifts of their centers of pressure. Synergy indices at the upper level of the assumed hierarchy (the task is shared between the thumb and virtual finger--an imagined digit with the action equal to that of the four fingers combined) did not drop with acceleration for the three force vector components and one of the moment vector components. They did drop with acceleration at the lower level (virtual finger action is shared among the four fingers). There was a trade-off between synergy indices computed at the two levels for the three force vector components, but not for the moment of force components. We confirmed specialization of different fingers with respect to different

  6. Inference and representations of hand actions through grasping synergies. Comment on "Grasping synergies: A motor-control approach to the mirror neuron mechanism" by D'Ausilio, Bartoli, and Maffongelli

    NASA Astrophysics Data System (ADS)

    Santello, Marco

    2015-03-01

    The concept of synergy, denoting the coordination of multiple elements working together toward a common goal, has been extensively studied to understand how the central nervous system (CNS) controls movement (for review see [5,9]). Although this definition is appealing in its simplicity, 'multiple elements', 'working together', and 'common goal' each take different meanings depending on the scale at which a given sensorimotor system is studied, whether the 'working together' is defined in spatial and/or temporal domains, and the hypothesized synergy's 'common goal'. For example, the elements involved in a synergy can be defined as single motor units, muscles, or joints. Similarly, the goal of a synergy may be defined as a means available to the CNS to 'simplify' the control of multiple elements, or to minimize a given cost function or movement feature - all of which may differ across tasks and tasks conditions. These considerations underscore the fact that a universally accepted definition of synergies and their functional role remains to be established (for review see [6]). Thus, the nature and functional role(s) of synergies is still debated in the literature. Nevertheless, it is generally agreed that the reduction in the number of independent degrees of freedom that is manifested through synergies emerges from the interaction of biomechanical and neural factors constraining the spatial and temporal coordination of multiple muscles.

  7. Are we ready to move beyond the reductionist approach of classical synergy control?. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    Lacquaniti, Francesco; Ivanenko, Yuri P.; Zago, Myrka

    2016-07-01

    Starting from the classical concepts introduced by Sherrington [1] and considerably elaborated by Bernstein [2], much has been learned about motor synergies in the last several years. The contributions of the group funded by the European project "The Hand Embodied" are remarkable in the field of biological and robotic control of the hand based on synergies, and they are reflected in this enjoyable review [3]. There, Santello et al. adopt Bernstein's definition of motor synergies as multiple elements working together towards a common goal, with the result that multiple degrees of freedom are controlled within a lower-dimensional space than the available number of dimensions.

  8. Hybrid microelectronic technology

    NASA Astrophysics Data System (ADS)

    Moran, P.

    Various areas of hybrid microelectronic technology are discussed. The topics addressed include: basic thick film processing, thick film pastes and substrates, add-on components and attachment methods, thin film processing, and design of thick film hybrid circuits. Also considered are: packaging hybrid circuits, automating the production of hybrid circuits, application of hybrid techniques, customer's view of hybrid technology, and quality control and assurance in hybrid circuit production.

  9. On the Origin of Muscle Synergies: Invariant Balance in the Co-activation of Agonist and Antagonist Muscle Pairs

    PubMed Central

    Hirai, Hiroaki; Miyazaki, Fumio; Naritomi, Hiroaki; Koba, Keitaro; Oku, Takanori; Uno, Kanna; Uemura, Mitsunori; Nishi, Tomoki; Kageyama, Masayuki; Krebs, Hermano Igo

    2015-01-01

    Investigation of neural representation of movement planning has attracted the attention of neuroscientists, as it may reveal the sensorimotor transformation essential to motor control. The analysis of muscle synergies based on the activity of agonist–antagonist (AA) muscle pairs may provide insight into such transformations, especially for a reference frame in the muscle space. In this study, we examined the AA concept using the following explanatory variables: the AA ratio, which is related to the equilibrium-joint angle, and the AA sum, which is associated with joint stiffness. We formulated muscle synergies as a function of AA sums, positing that muscle synergies are composite units of mechanical impedance. The AA concept can be regarded as another form of the equilibrium-point (EP) hypothesis, and it can be extended to the concept of EP-based synergies. We introduce, here, a novel tool for analyzing the neurological and motor functions underlying human movements and review some initial insights from our results about the relationships between muscle synergies, endpoint stiffness, and virtual trajectories (time series of EP). Our results suggest that (1) muscle synergies reflect an invariant balance in the co-activation of AA muscle pairs; (2) each synergy represents the basis for the radial, tangential, and null movements of the virtual trajectory in the polar coordinates centered on the specific joint at the base of the body; and (3) the alteration of muscle synergies (for example, due to spasticity or rigidity following neurological injury) results in significant distortion of endpoint stiffness and concomitant virtual trajectories. These results indicate that muscle synergies (i.e., the balance of muscle mechanical impedance) are essential for motor control. PMID:26636079

  10. Inter-joint coupling and joint angle synergies of human catching movements.

    PubMed

    Bockemühl, Till; Troje, Nikolaus F; Dürr, Volker

    2010-02-01

    A central question in motor control is how the central nervous system (CNS) deals with redundant degrees of freedom (DoFs) inherent in the musculoskeletal system. One way to simplify control of a redundant system is to combine several DoFs into synergies. In reaching movements of the human arm, redundancy occurs at the kinematic level because there is an unlimited number of arm postures for each position of the hand. Redundancy also occurs at the level of muscle forces because each arm posture can be maintained by a set of muscle activation patterns. Both postural and force-related motor synergies may contribute to simplify the control problem. The present study analyzes the kinematic complexity of natural, unrestrained human arm movements, and detects the amount of kinematic synergy in a vast variety of arm postures. We have measured inter-joint coupling of the human arm and shoulder girdle during fast, unrestrained, and untrained catching movements. Participants were asked to catch a ball launched towards them on 16 different trajectories. These had to be reached from two different initial positions. Movement of the right arm was recorded using optical motion capture and was transformed into 10 joint angle time courses, corresponding to 3 DoFs of the shoulder girdle and 7 of the arm. The resulting time series of the arm postures were analyzed by principal components analysis (PCA). We found that the first three principal components (PCs) always captured more than 97% of the variance. Furthermore, subspaces spanned by PC sets associated with different catching positions varied smoothly across the arm's workspace. When we pooled complete sets of movements, three PCs, the theoretical minimum for reaching in 3D space, were sufficient to explain 80% of the data's variance. We assumed that the linearly correlated DoFs of each significant PC represent cardinal joint angle synergies, and showed that catching movements towards a multitude of targets in the arm's workspace

  11. Hybrid supramolecular and colloidal hydrogels that bridge multiple length scales.

    PubMed

    Janeček, Emma-Rose; McKee, Jason R; Tan, Cindy S Y; Nykänen, Antti; Kettunen, Marjo; Laine, Janne; Ikkala, Olli; Scherman, Oren A

    2015-04-27

    Hybrid nanocomposites were constructed based on colloidal nanofibrillar hydrogels with interpenetrating supramolecular hydrogels, displaying enhanced rheological yield strain and a synergistic improvement in storage modulus. The supramolecular hydrogel consists of naphthyl-functionalized hydroxyethyl cellulose and a cationic polystyrene derivative decorated with methylviologen moieties, physically cross-linked with cucurbit[8]uril macrocyclic hosts. Fast exchange kinetics within the supramolecular system are enabled by reversible cross-linking through the binding of the naphthyl and viologen guests. The colloidal hydrogel consists of nanofibrillated cellulose that combines a mechanically strong nanofiber skeleton with a lateral fibrillar diameter of a few nanometers. The two networks interact through hydroxyethyl cellulose adsorption to the nanofibrillated cellulose surfaces. This work shows methods to bridge the length scales of molecular and colloidal hybrid hydrogels, resulting in synergy between reinforcement and dynamics.

  12. Hybrid Supramolecular and Colloidal Hydrogels that Bridge Multiple Length Scales**

    PubMed Central

    Janeček, Emma-Rose; McKee, Jason R; Tan, Cindy S Y; Nykänen, Antti; Kettunen, Marjo; Laine, Janne; Ikkala, Olli; Scherman, Oren A

    2015-01-01

    Hybrid nanocomposites were constructed based on colloidal nanofibrillar hydrogels with interpenetrating supramolecular hydrogels, displaying enhanced rheological yield strain and a synergistic improvement in storage modulus. The supramolecular hydrogel consists of naphthyl-functionalized hydroxyethyl cellulose and a cationic polystyrene derivative decorated with methylviologen moieties, physically cross-linked with cucurbit[8]uril macrocyclic hosts. Fast exchange kinetics within the supramolecular system are enabled by reversible cross-linking through the binding of the naphthyl and viologen guests. The colloidal hydrogel consists of nanofibrillated cellulose that combines a mechanically strong nanofiber skeleton with a lateral fibrillar diameter of a few nanometers. The two networks interact through hydroxyethyl cellulose adsorption to the nanofibrillated cellulose surfaces. This work shows methods to bridge the length scales of molecular and colloidal hybrid hydrogels, resulting in synergy between reinforcement and dynamics. PMID:25772264

  13. Hybrid Supramolecular and Colloidal Hydrogels that Bridge Multiple Length Scales†

    PubMed Central

    Janeček, Emma‐Rose; McKee, Jason R.; Tan, Cindy S. Y.; Nykänen, Antti; Kettunen, Marjo; Laine, Janne

    2015-01-01

    Abstract Hybrid nanocomposites were constructed based on colloidal nanofibrillar hydrogels with interpenetrating supramolecular hydrogels, displaying enhanced rheological yield strain and a synergistic improvement in storage modulus. The supramolecular hydrogel consists of naphthyl‐functionalized hydroxyethyl cellulose and a cationic polystyrene derivative decorated with methylviologen moieties, physically cross‐linked with cucurbit[8]uril macrocyclic hosts. Fast exchange kinetics within the supramolecular system are enabled by reversible cross‐linking through the binding of the naphthyl and viologen guests. The colloidal hydrogel consists of nanofibrillated cellulose that combines a mechanically strong nanofiber skeleton with a lateral fibrillar diameter of a few nanometers. The two networks interact through hydroxyethyl cellulose adsorption to the nanofibrillated cellulose surfaces. This work shows methods to bridge the length scales of molecular and colloidal hybrid hydrogels, resulting in synergy between reinforcement and dynamics. PMID:27478263

  14. Hybrid Gear

    NASA Technical Reports Server (NTRS)

    Handschuh, Robert F. (Inventor); Roberts, Gary D. (Inventor)

    2016-01-01

    A hybrid gear consisting of metallic outer rim with gear teeth and metallic hub in combination with a composite lay up between the shaft interface (hub) and gear tooth rim is described. The composite lay-up lightens the gear member while having similar torque carrying capability and it attenuates the impact loading driven noise/vibration that is typical in gear systems. The gear has the same operational capability with respect to shaft speed, torque, and temperature as an all-metallic gear as used in aerospace gear design.

  15. Hybrid Simulator

    2005-10-15

    HybSim (short for Hybrid Simulator) is a flexible, easy to use screening tool that allows the user to quanti the technical and economic benefits of installing a village hybrid generating system and simulates systems with any combination of —Diesel generator sets —Photovoltaic arrays -Wind Turbines and -Battery energy storage systems Most village systems (or small population sites such as villages, remote military bases, small communities, independent or isolated buildings or centers) depend on diesel generationmore » systems for their source of energy. HybSim allows the user to determine other "sources" of energy that can greatly reduce the dollar to kilo-watt hour ratio. Supported by the DOE, Energy Storage Program, HybSim was initially developed to help analyze the benefits of energy storage systems in Alaskan villages. Soon after its development, other sources of energy were added providing the user with a greater range of analysis opportunities and providing the village with potentially added savings. In addition to village systems, HybSim has generated interest for use from military institutions in energy provisions and USAID for international village analysis.« less

  16. Investigating Conversational Dynamics: Interactive Alignment, Interpersonal Synergy, and Collective Task Performance.

    PubMed

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, interactive alignment and interpersonal synergy, and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between interlocutors, the synergy approach points to structural organization at the level of the interaction-such as complementary patterns straddling speech turns and interlocutors. We develop a general, quantitative method to assess lexical, prosodic, and speech/pause patterns related to the two approaches and their impact on collective performance in a corpus of task-oriented conversations. The results show statistical presence of patterns relevant for both approaches. However, synergetic aspects of dialog provide the best statistical predictors of collective performance and adding aspects of the alignment approach does not improve the model. This suggests that structural organization at the level of the interaction plays a crucial role in task-oriented conversations, possibly constraining and integrating processes related to alignment.

  17. Investigating Conversational Dynamics: Interactive Alignment, Interpersonal Synergy, and Collective Task Performance.

    PubMed

    Fusaroli, Riccardo; Tylén, Kristian

    2016-01-01

    This study investigates interpersonal processes underlying dialog by comparing two approaches, interactive alignment and interpersonal synergy, and assesses how they predict collective performance in a joint task. While the interactive alignment approach highlights imitative patterns between interlocutors, the synergy approach points to structural organization at the level of the interaction-such as complementary patterns straddling speech turns and interlocutors. We develop a general, quantitative method to assess lexical, prosodic, and speech/pause patterns related to the two approaches and their impact on collective performance in a corpus of task-oriented conversations. The results show statistical presence of patterns relevant for both approaches. However, synergetic aspects of dialog provide the best statistical predictors of collective performance and adding aspects of the alignment approach does not improve the model. This suggests that structural organization at the level of the interaction plays a crucial role in task-oriented conversations, possibly constraining and integrating processes related to alignment. PMID:25988263

  18. The Successful Synergy of Swift and Fermi/GBM in Magnetars

    NASA Technical Reports Server (NTRS)

    Kouveliotou, Chryssa

    2011-01-01

    The magnetar rate of discovery has increased dramatically in the last decade. Five sources were discovered in the last three years alone as a result of the very efficient synergy among three X- and .gamma-ray instruments on NASA satellites: the Swift/Burst Alert Telescope (BAT), the Fermi/Gamma ray Burst Monitor (GBM), and the Rossi X-Ray Timing Explorer; RXTE/Proportional Counter Array (PCA). To date, there are approx. 25 magnetar candidates, of which two are (one each) in the Large and Small Magellanic Cloud and the rest reside on the Galactic plane of our Milky Way. I will discuss here the main properties of the Magnetar Population and the common projects that can be achieved with the synergy of Swift and GBM.

  19. EBW-Bootstrap Current Synergy in the National Spherical Torus Experiment (NSTX)

    SciTech Connect

    R.W. Harvey; G. Taylor

    2005-02-02

    Current driven by electron Bernstein waves (EBW) and by the electron bootstrap effect are calculated separately and concurrently with a kinetic code, to determine the degree of synergy between them. A target {beta} = 40% NSTX plasma is examined. A simple bootstrap model in the CQL3D Fokker-Planck code is used in these studies: the transiting electron distributions are connected in velocity-space at the trapped-passing boundary to trapped-electron distributions which are displaced radially by a half-banana width outwards/inwards for the co-/counter-passing regions. This model agrees well with standard bootstrap current calculations, over the outer 60% of the plasma radius. Relatively small synergy net bootstrap current is obtained for EBW power up to 4 MW. Locally, bootstrap current density increases in proportion to increased plasma pressure, and this effect can significantly affect the radial profile of driven current.

  20. Bihemispheric Transcranial Direct Current Stimulation Enhances Effector-Independent Representations of Motor Synergy and Sequence Learning

    PubMed Central

    Husain, Masud; Wiestler, Tobias; Diedrichsen, Jörn

    2014-01-01

    Complex manual tasks—everything from buttoning up a shirt to playing the piano—fundamentally involve two components: (1) generating specific patterns of muscle activity (here, termed “synergies”); and (2) stringing these into purposeful sequences. Although transcranial direct current stimulation (tDCS) of the primary motor cortex (M1) has been found to increase the learning of motor sequences, it is unknown whether it can similarly facilitate motor synergy learning. Here, we determined the effects of tDCS on the learning of motor synergies using a novel hand configuration task that required the production of difficult muscular activation patterns. Bihemispheric tDCS was applied to M1 of healthy, right-handed human participants during 4 d of repetitive left-hand configuration training in a double-blind design. tDCS augmented synergy learning, leading subsequently to faster and more synchronized execution. This effect persisted for at least 4 weeks after training. Qualitatively similar tDCS-associated improvements occurred during training of finger sequences in a separate subject cohort. We additionally determined whether tDCS only improved the acquisition of motor memories for specific synergies/sequences or whether it also facilitated more general parts of the motor representations, which could be transferred to novel movements. Critically, we observed that tDCS effects generalized to untrained hand configurations and untrained finger sequences (i.e., were nonspecific), as well as to the untrained hand (i.e., were effector-independent). Hence, bihemispheric tDCS may be a promising adjunct to neurorehabilitative training regimes, in which broad transfer to everyday tasks is highly desirable. PMID:24431461

  1. Synergy characterization for Enterococcus faecalis strains displaying moderately high-level gentamicin and streptomycin resistance.

    PubMed Central

    Bantar, C E; Micucci, M; Fernandez Canigia, L; Smayevsky, J; Bianchini, H M

    1993-01-01

    Synergy of 14 Enterococcus faecalis strains displaying moderately high-level aminoglycoside resistance (MICs, 500 and 256 to 1,000 micrograms/ml for gentamicin and streptomycin, respectively) was characterized by time-kill studies. All strains proved resistant to penicillin plus the respective aminoglycoside. Strains with moderately high-level aminoglycoside resistance should be considered to exhibit high-level resistance in severe infections. PMID:8349776

  2. Synergy characterization for Enterococcus faecalis strains displaying moderately high-level gentamicin and streptomycin resistance.

    PubMed

    Bantar, C E; Micucci, M; Fernandez Canigia, L; Smayevsky, J; Bianchini, H M

    1993-07-01

    Synergy of 14 Enterococcus faecalis strains displaying moderately high-level aminoglycoside resistance (MICs, 500 and 256 to 1,000 micrograms/ml for gentamicin and streptomycin, respectively) was characterized by time-kill studies. All strains proved resistant to penicillin plus the respective aminoglycoside. Strains with moderately high-level aminoglycoside resistance should be considered to exhibit high-level resistance in severe infections.

  3. Learned parametrized dynamic movement primitives with shared synergies for controlling robotic and musculoskeletal systems

    PubMed Central

    Rückert, Elmar; d'Avella, Andrea

    2013-01-01

    A salient feature of human motor skill learning is the ability to exploit similarities across related tasks. In biological motor control, it has been hypothesized that muscle synergies, coherent activations of groups of muscles, allow for exploiting shared knowledge. Recent studies have shown that a rich set of complex motor skills can be generated by a combination of a small number of muscle synergies. In robotics, dynamic movement primitives are commonly used for motor skill learning. This machine learning approach implements a stable attractor system that facilitates learning and it can be used in high-dimensional continuous spaces. However, it does not allow for reusing shared knowledge, i.e., for each task an individual set of parameters has to be learned. We propose a novel movement primitive representation that employs parametrized basis functions, which combines the benefits of muscle synergies and dynamic movement primitives. For each task a superposition of synergies modulates a stable attractor system. This approach leads to a compact representation of multiple motor skills and at the same time enables efficient learning in high-dimensional continuous systems. The movement representation supports discrete and rhythmic movements and in particular includes the dynamic movement primitive approach as a special case. We demonstrate the feasibility of the movement representation in three multi-task learning simulated scenarios. First, the characteristics of the proposed representation are illustrated in a point-mass task. Second, in complex humanoid walking experiments, multiple walking patterns with different step heights are learned robustly and efficiently. Finally, in a multi-directional reaching task simulated with a musculoskeletal model of the human arm, we show how the proposed movement primitives can be used to learn appropriate muscle excitation patterns and to generalize effectively to new reaching skills. PMID:24146647

  4. Opportunities for Synergy Between Natural Gas and Renewable Energy in the Electric Power and Transportation Sectors

    SciTech Connect

    Lee, A.; Zinaman, O.; Logan, J.

    2012-12-01

    Use of both natural gas and renewable energy has grown significantly in recent years. Both forms of energy have been touted as key elements of a transition to a cleaner and more secure energy future, but much of the current discourse considers each in isolation or concentrates on the competitive impacts of one on the other. This paper attempts, instead, to explore potential synergies of natural gas and renewable energy in the U.S. electric power and transportation sectors.

  5. Evaluation and modeling of synergy to pheromone and plant kairomone in American palm weevil

    PubMed Central

    2011-01-01

    Background Many behavioral responses to odors are synergistic, particularly in insects. In beetles, synergy often involves a pheromone and a plant odor, and pest management relies on them for the use of combined lures. To investigate olfactory synergy mechanisms, we need to distinguish synergistic effects from additive ones, when all components of the mixture are active. Results As versatile tools and procedures were not available, we developed a bioassay, and a mathematical model to evaluate synergy between aggregation pheromone (P) and host plant odors (kairomone: K) in the American palm weevil, a pest insect showing enhanced responses to P+K mixtures. Responses to synthetic P and natural K were obtained using a 4-arm olfactometer coupled to a controlled volatile delivery system. We showed that: (1) Response thresholds were ca. 10 and 100 pg/s respectively for P and K. (2) Both stimuli induced similar maximum response. (3) Increasing the dose decreased the response for P to the point of repellence and maintained a maximum response for K. (4) P and K were synergistic over a 100-fold range of doses with experimental responses to P+K mixtures greater than the ones predicted assuming additive effects. Responses close to maximum were associated with the mixture amounts below the response threshold for both P and K. Conclusion These results confirm the role of olfactory synergy in optimizing active host-plant localization by phytophagous insects. Our evaluation procedure can be generalized to test synergistic or inhibitory integrated responses of various odor mixtures for various insects. PMID:21463509

  6. Two aspects of feedforward postural control: anticipatory postural adjustments and anticipatory synergy adjustments

    PubMed Central

    Klous, Miriam; Mikulic, Pavle

    2011-01-01

    We used the framework of the uncontrolled manifold hypothesis to explore the relations between anticipatory synergy adjustments (ASAs) and anticipatory postural adjustments (APAs) during feedforward control of vertical posture. ASAs represent a drop in the index of a multimuscle-mode synergy stabilizing the coordinate of the center of pressure in preparation to an action. ASAs reflect early changes of an index of covariation among variables reflecting muscle activation, whereas APAs reflect early changes in muscle activation levels averaged across trials. The assumed purpose of ASAs is to modify stability of performance variables, whereas the purpose of APAs is to change magnitudes of those variables. We hypothesized that ASAs would be seen before APAs and that this finding would be consistent with regard to the muscle-mode composition defined on the basis of different tasks and phases of action. Subjects performed a voluntary body sway task and a quick, bilateral shoulder flexion task under self-paced and reaction time conditions. Surface muscle activity of 12 leg and trunk muscles was analyzed to identify sets of 4 muscle modes for each task and for different phases within the shoulder flexion task. Variance components in the muscle-mode space and indexes of multimuscle-mode synergy stabilizing shift of the center of pressure were computed. ASAs were seen ∼100–150 ms prior to the task initiation, before APAs. The results were consistent with respect to different sets of muscle modes defined over the two tasks and different shoulder flexion phases. We conclude that the preparation for a self-triggered postural perturbation is associated with two types of anticipatory adjustments, ASAs and APAs. They reflect different feedforward processes within the hypothetical hierarchical control scheme, resulting in changes in patterns of covariation of elemental variables and in their patterns averaged across trials, respectively. The results show that synergies

  7. Multi-muscle synergies in a dual postural task: evidence for the principle of superposition

    PubMed Central

    Klous, Miriam; Danna-dos-Santos, Alessander

    2010-01-01

    We used the framework of the uncontrolled manifold hypothesis to quantify multi-muscle synergies stabilizing the moment of force about the frontal axis (MY) and the shear force in the anterior–posterior direction (FX) during voluntary body sway performed by standing subjects. We tested a hypothesis whether the controller could stabilize both MY and FX at the same time when the task and the visual feedback was provided only on one of the variables (MY). Healthy young subjects performed voluntary body sway in the anterior–posterior direction while different loads were attached at the ankle level producing horizontal forces acting forward or backwards. Principal component analysis was used to identify three M-modes within the space of integrated indices of muscle activation. Variance in the M-mode space across sway cycles was partitioned into two components, one that did not affect a selected performance variable (MY or FX) and the other that did. Under all loading conditions and for each performance variable, a higher value for the former variance component was found. We interpret these results as reflections of two multi-M-mode synergies stabilizing both FX and MY. The indices of synergies were modulated within the sway cycle; both performance variables were better stabilized when the body moved forward than when it moved backward. The results show that the controller can use a set of three elemental variables (M-modes) to stabilize two performance variables at the same time. No negative interference was seen between the synergy indices computed for the two performance variables supporting the principle of superposition with respect to multi-muscle postural control. PMID:20047089

  8. Quantifying subpopulation synergy for antibiotic combinations via mechanism-based modeling and a sequential dosing design.

    PubMed

    Landersdorfer, Cornelia B; Ly, Neang S; Xu, Hongmei; Tsuji, Brian T; Bulitta, Jürgen B

    2013-05-01

    Quantitative modeling of combination therapy can describe the effects of each antibiotic against multiple bacterial populations. Our aim was to develop an efficient experimental and modeling strategy that evaluates different synergy mechanisms using a rapidly killing peptide antibiotic (nisin) combined with amikacin or linezolid as probe drugs. Serial viable counts over 48 h were obtained in time-kill experiments with all three antibiotics in monotherapy against a methicillin-resistant Staphylococcus aureus USA300 strain (inoculum, 10(8) CFU/ml). A sequential design (initial dosing of 8 or 32 mg/liter nisin, switched to amikacin or linezolid at 1.5 h) assessed the rate of killing by amikacin and linezolid against nisin-intermediate and nisin-resistant populations. Simultaneous combinations were additionally studied and all viable count profiles comodeled in S-ADAPT and NONMEM. A mechanism-based model with six populations (three for nisin times two for amikacin) yielded unbiased and precise (r = 0.99, slope = 1.00; S-ADAPT) individual fits. The second-order killing rate constants for nisin against the three populations were 5.67, 0.0664, and 0.00691 liter/(mg · h). For amikacin, the maximum killing rate constants were 10.1 h(-1) against its susceptible and 0.771 h(-1) against its less-susceptible populations, with 14.7 mg/liter amikacin causing half-maximal killing. After incorporating the effects of nisin and amikacin against each population, no additional synergy function was needed. Linezolid inhibited successful bacterial replication but did not efficiently kill populations less susceptible to nisin. Nisin plus amikacin achieved subpopulation synergy. The proposed sequential and simultaneous dosing design offers an efficient approach to quantitatively characterize antibiotic synergy over time and prospectively evaluate antibiotic combination dosing strategies. PMID:23478962

  9. Motoneuronal and muscle synergies involved in cat hindlimb control during fictive and real locomotion: a comparison study.

    PubMed

    Markin, Sergey N; Lemay, Michel A; Prilutsky, Boris I; Rybak, Ilya A

    2012-04-01

    We compared the activity profiles and synergies of spinal motoneurons recorded during fictive locomotion evoked in immobilized decerebrate cat preparations by midbrain stimulation to the activity profiles and synergies of the corresponding hindlimb muscles obtained during forward level walking in cats. The fictive locomotion data were collected in the Spinal Cord Research Centre, University of Manitoba, and provided by Dr. David McCrea; the real locomotion data were obtained in the laboratories of M. A. Lemay and B. I. Prilutsky. Scatterplot representation and minimum spanning tree clustering algorithm were used to identify the possible motoneuronal and muscle synergies operating during both fictive and real locomotion. We found a close similarity between the activity profiles and synergies of motoneurons innervating one-joint muscles during fictive locomotion and the profiles and synergies of the corresponding muscles during real locomotion. However, the activity patterns of proximal nerves controlling two-joint muscles, such as posterior biceps and semitendinosus (PBSt) and rectus femoris (RF), were not uniform in fictive locomotion preparations and differed from the activity profiles of the corresponding two-joint muscles recorded during forward level walking. Moreover, the activity profiles of these nerves and the corresponding muscles were unique and could not be included in the synergies identified in fictive and real locomotion. We suggest that afferent feedback is involved in the regulation of locomotion via motoneuronal synergies controlled by the spinal central pattern generator (CPG) but may also directly affect the activity of motoneuronal pools serving two-joint muscles (e.g., PBSt and RF). These findings provide important insights into the organization of the spinal CPG in mammals, the motoneuronal and muscle synergies engaged during locomotion, and their afferent control.

  10. Construction of synergy networks from gene expression data related to disease.

    PubMed

    Chatterjee, Prantik; Pal, Nikhil Ranjan

    2016-09-30

    A few methods have been developed to determine whether genes collaborate with each other in relation to a particular disease using an information theoretic measure of synergy. Here, we propose an alternative definition of synergy and justify that our definition improves upon the existing measures of synergy in the context of gene interactions. We use this definition on a prostate cancer data set consisting of gene expression levels in both cancerous and non-cancerous samples and identify pairs of genes which are unable to discriminate between cancerous and non-cancerous samples individually but can do so jointly when we take their synergistic property into account. We also propose a very simple yet effective technique for computation of conditional entropy at a very low cost. The worst case complexity of our method is O(n) while the best case complexity of a state-of-the-art method is O(n(2)). Furthermore, our method can also be extended to find synergistic relation among triplets or even among a larger number of genes. Finally, we validate our results by demonstrating that these findings cannot be due to pure chance and provide the relevance of the synergistic pairs in cancer biology.

  11. A synergy-based hand control is encoded in human motor cortical areas

    PubMed Central

    Leo, Andrea; Handjaras, Giacomo; Bianchi, Matteo; Marino, Hamal; Gabiccini, Marco; Guidi, Andrea; Scilingo, Enzo Pasquale; Pietrini, Pietro; Bicchi, Antonio; Santello, Marco; Ricciardi, Emiliano

    2016-01-01

    How the human brain controls hand movements to carry out different tasks is still debated. The concept of synergy has been proposed to indicate functional modules that may simplify the control of hand postures by simultaneously recruiting sets of muscles and joints. However, whether and to what extent synergic hand postures are encoded as such at a cortical level remains unknown. Here, we combined kinematic, electromyography, and brain activity measures obtained by functional magnetic resonance imaging while subjects performed a variety of movements towards virtual objects. Hand postural information, encoded through kinematic synergies, were represented in cortical areas devoted to hand motor control and successfully discriminated individual grasping movements, significantly outperforming alternative somatotopic or muscle-based models. Importantly, hand postural synergies were predicted by neural activation patterns within primary motor cortex. These findings support a novel cortical organization for hand movement control and open potential applications for brain-computer interfaces and neuroprostheses. DOI: http://dx.doi.org/10.7554/eLife.13420.001 PMID:26880543

  12. Study on reactivity characteristics and synergy behaviours of rice straw and bituminous coal co-gasification.

    PubMed

    Wei, Juntao; Guo, Qinghua; Chen, Handing; Chen, Xueli; Yu, Guangsuo

    2016-11-01

    Co-gasification of rice straw (RS) and Shenfu bituminous coal (SF) was conducted in a thermogravimetric analyzer (TGA) to explore the effects of gasification temperature and blend ratio on reactivity characteristics and synergy behaviours of co-gasification. Moreover, the relationship between the synergy and the K/Ca transformation in co-gasification was studied using flame atomic absorption spectrum (FAAS) and in-situ heating stage microscope. The results showed that the whole reactivities increased with increasing RS proportion and gasification temperature. The transformation of water-soluble and ion-exchanged (ws-ie) calcium was enhanced in whole co-gasification and the ws-ie potassium transformation was obviously inhibited in mid-late reaction. Hence, synergy behaviours were synthetically determined by the enhancement of Ca deactivation and the strengthening of K catalysis. The inhibiting effect was occurred in initial co-gasification and was converted to the synergistic effect at a characteristic conversion, which decreased with increasing RS proportion and decreasing gasification temperature. PMID:27611034

  13. Striking multiple synergies created by combining reduced graphene oxides and carbon nanotubes for polymer nanocomposites

    NASA Astrophysics Data System (ADS)

    Song, Ping'an; Liu, Lina; Fu, Shenyuan; Yu, Youming; Jin, Chunde; Wu, Qiang; Zhang, Yan; Li, Qian

    2013-03-01

    The extraordinary properties of carbon nanotubes (CNTs) and graphene stimulate the development of advanced composites. Recently, several studies have reported significant synergies in the mechanical, electrical and thermal conductivity properties of polymer nanocomposites by incorporating their nanohybrids. In this work, we created polypropylene nanocomposites with homogeneous dispersion of CNTs and reduced graphene oxides via a facile polymer-latex-coating plus melt-mixing strategy, and investigated their synergistic effects in their viscoelastic, gas barrier, and flammability properties. Interestingly, the results show remarkable synergies, enhancing their melt modulus and viscosity, O2 barrier, and flame retardancy properties and respectively exhibiting a synergy percentage of 15.9%, 45.3%, and 20.3%. As previously reported, we also observed remarkable synergistic effects in their tensile strength (14.3%) and Young’s modulus (27.1%), electrical conductivity (32.3%) and thermal conductivity (34.6%). These impressive results clearly point towards a new strategy to create advanced materials by adding binary combinations of different types of nanofillers.

  14. Striking multiple synergies created by combining reduced graphene oxides and carbon nanotubes for polymer nanocomposites.

    PubMed

    Song, Ping'an; Liu, Lina; Fu, Shenyuan; Yu, Youming; Jin, Chunde; Wu, Qiang; Zhang, Yan; Li, Qian

    2013-03-29

    The extraordinary properties of carbon nanotubes (CNTs) and graphene stimulate the development of advanced composites. Recently, several studies have reported significant synergies in the mechanical, electrical and thermal conductivity properties of polymer nanocomposites by incorporating their nanohybrids. In this work, we created polypropylene nanocomposites with homogeneous dispersion of CNTs and reduced graphene oxides via a facile polymer-latex-coating plus melt-mixing strategy, and investigated their synergistic effects in their viscoelastic, gas barrier, and flammability properties. Interestingly, the results show remarkable synergies, enhancing their melt modulus and viscosity, O2 barrier, and flame retardancy properties and respectively exhibiting a synergy percentage of 15.9%, 45.3%, and 20.3%. As previously reported, we also observed remarkable synergistic effects in their tensile strength (14.3%) and Young's modulus (27.1%), electrical conductivity (32.3%) and thermal conductivity (34.6%). These impressive results clearly point towards a new strategy to create advanced materials by adding binary combinations of different types of nanofillers.

  15. Construction of synergy networks from gene expression data related to disease.

    PubMed

    Chatterjee, Prantik; Pal, Nikhil Ranjan

    2016-09-30

    A few methods have been developed to determine whether genes collaborate with each other in relation to a particular disease using an information theoretic measure of synergy. Here, we propose an alternative definition of synergy and justify that our definition improves upon the existing measures of synergy in the context of gene interactions. We use this definition on a prostate cancer data set consisting of gene expression levels in both cancerous and non-cancerous samples and identify pairs of genes which are unable to discriminate between cancerous and non-cancerous samples individually but can do so jointly when we take their synergistic property into account. We also propose a very simple yet effective technique for computation of conditional entropy at a very low cost. The worst case complexity of our method is O(n) while the best case complexity of a state-of-the-art method is O(n(2)). Furthermore, our method can also be extended to find synergistic relation among triplets or even among a larger number of genes. Finally, we validate our results by demonstrating that these findings cannot be due to pure chance and provide the relevance of the synergistic pairs in cancer biology. PMID:27222483

  16. Molecular Signatures of Nicotinoid-Pathogen Synergy in the Termite Gut

    PubMed Central

    Sen, Ruchira; Raychoudhury, Rhitoban; Cai, Yunpeng; Sun, Yijun; Lietze, Verena-Ulrike; Peterson, Brittany F.; Scharf, Michael E.; Boucias, Drion G.

    2015-01-01

    Previous studies in lower termites revealed unexpected synergies between nicotinoid insecticides and fungal entomopathogens. The present study investigated molecular mechanisms of nicotinoid-pathogen synergy in the lower termite Reticulitermes flavipes, using the nicotinoid, imidacloprid, in combination with fungal and bacterial entomopathogens. Particular focus was placed on metatranscriptome composition and microbial dynamics in the symbiont-rich termite gut, which houses diverse mixes of protists and bacteria. cDNA microarrays containing a mix of host and protist symbiont oligonucleotides were used to simultaneously assess termite and protist gene expression. Five treatments were compared that included single challenges with sublethal doses of fungi (Metharizium anisopliae), bacteria (Serratia marcescens) or imidacloprid, and dual challenges with fungi + imidacloprid or bacteria + imidacloprid. Our findings point towards protist dysbiosis and compromised social behavior, rather than suppression of stereotypical immune defense mechanisms, as the dominant factors underlying nicotinoid-pathogen synergy in termites. Also, greater impacts observed for the fungal pathogen than for the bacterial pathogen suggest that the rich bacterial symbiont community in the R. flavipes gut (>5000 species-level phylotypes) exists in an ecological balance that effectively excludes exogenous bacterial pathogens. These findings significantly advance our understanding of antimicrobial defenses in this important eusocial insect group, as well as provide novel insights into how nicotinoids can exert deleterious effects on social insect colonies. PMID:25837376

  17. Evaluating synergy between marbofloxacin and gentamicin in Pseudomonas aeruginosa strains isolated from dogs with otitis externa.

    PubMed

    Jerzsele, Ákos; Pásztiné-Gere, Erzsébet

    2015-03-01

    The aim of this study was to determine antimicrobial susceptibility of Pseudomonas aeruginosa strains to marbofloxacin and gentamicin, and investigate the possible synergistic, additive, indifferent or antagonistic effects between the two agents. P. aeruginosa strains can develop resistance quickly against certain antibiotics if used alone, thus the need emerges to find synergistic combinations. A total of 68 P. aeruginosa strains isolated from dogs were examined. In order to describe interactions between marbofloxacin and gentamicin the checkerboard microdilution method was utilized. The MICs (minimum inhibitory concentrations) for marbofloxacin and gentamicin were in the range 0.25-64 mg/L and 0.25-32 mg/L, respectively. The combination of marbofloxacin and gentamicin was more effective with a MIC range of 0.031-8 mg/L and a MIC90 of 1 mg/L, compared to 16 mg/L for marbofloxacin alone and 8 mg/L for gentamicin alone. The FIC (fractional inhibitory concentration) indices ranged from 0.0945 (pronounced synergy) to 1.0625 (indifference). Synergy between marbofloxacin and gentamicin was found in 33 isolates. The mean FIC index is 0.546, which represents a partial synergistic/additive effect close to the full synergy threshold. In vitro results indicate that marbofloxacin and gentamicin as partially synergistic agents may prove clinically useful in combination therapy against P. aeruginosa infections. Although marbofloxacin is not used in the human practice, the interactions between fluoroquinolones and aminoglycosides may have importance outside the veterinary field.

  18. Stages in Learning Motor Synergies: A View Based on the Equilibrium-Point Hypothesis

    PubMed Central

    Latash, Mark L.

    2009-01-01

    This review describes a novel view on stages in motor learning based on recent developments of the notion of synergies, the uncontrolled manifold hypothesis, and the equilibrium-point hypothesis (referent configuration) that allow to merge these notions into a single scheme of motor control. The principle of abundance and the principle of minimal final action form the foundation for analyses of natural motor actions performed by redundant sets of elements. Two main stages of motor learning are introduced corresponding to (1) discovery and strengthening of motor synergies stabilizing salient performance variable(s), and (2) their weakening when other aspects of motor performance are optimized. The first stage may be viewed as consisting of two steps, the elaboration of an adequate referent configuration trajectory and the elaboration of multi-joint (multi-muscle) synergies stabilizing the referent configuration trajectory. Both steps are expected to lead to more variance in the space of elemental variables that is compatible with a desired time profile of the salient performance variable (“good variability”). Adjusting control to other aspects of performance during the second stage (for example, esthetics, energy expenditure, time, fatigue, etc.) may lead to a drop in the “good variability”. Experimental support for the suggested scheme is reviewed. PMID:20060610

  19. Molecular signatures of nicotinoid-pathogen synergy in the termite gut.

    PubMed

    Sen, Ruchira; Raychoudhury, Rhitoban; Cai, Yunpeng; Sun, Yijun; Lietze, Verena-Ulrike; Peterson, Brittany F; Scharf, Michael E; Boucias, Drion G

    2015-01-01

    Previous studies in lower termites revealed unexpected synergies between nicotinoid insecticides and fungal entomopathogens. The present study investigated molecular mechanisms of nicotinoid-pathogen synergy in the lower termite Reticulitermes flavipes, using the nicotinoid, imidacloprid, in combination with fungal and bacterial entomopathogens. Particular focus was placed on metatranscriptome composition and microbial dynamics in the symbiont-rich termite gut, which houses diverse mixes of protists and bacteria. cDNA microarrays containing a mix of host and protist symbiont oligonucleotides were used to simultaneously assess termite and protist gene expression. Five treatments were compared that included single challenges with sublethal doses of fungi (Metharizium anisopliae), bacteria (Serratia marcescens) or imidacloprid, and dual challenges with fungi + imidacloprid or bacteria + imidacloprid. Our findings point towards protist dysbiosis and compromised social behavior, rather than suppression of stereotypical immune defense mechanisms, as the dominant factors underlying nicotinoid-pathogen synergy in termites. Also, greater impacts observed for the fungal pathogen than for the bacterial pathogen suggest that the rich bacterial symbiont community in the R. flavipes gut (>5000 species-level phylotypes) exists in an ecological balance that effectively excludes exogenous bacterial pathogens. These findings significantly advance our understanding of antimicrobial defenses in this important eusocial insect group, as well as provide novel insights into how nicotinoids can exert deleterious effects on social insect colonies.

  20. The Influence of Dopaminergic Striatal Innervation on Upper Limb Locomotor Synergies

    PubMed Central

    Isaias, Ioannis U.; Volkmann, Jens; Marzegan, Alberto; Marotta, Giorgio; Cavallari, Paolo; Pezzoli, Gianni

    2012-01-01

    To determine the role of striatal dopaminergic innervation on upper limb synergies during walking, we measured arm kinematics in 13 subjects with Parkinson disease. Patients were recruited according to several inclusion criteria to represent the best possible in vivo model of dopaminergic denervation. Of relevance, we included only subjects with normal spatio-temporal parameters of the stride and gait speed to avoid an impairment of upper limbs locomotor synergies as a consequence of gait impairment per se. Dopaminergic innervation of the striatum was measured by FP-CIT and SPECT. All patients showed a reduction of gait-associated arms movement. No linear correlation was found between arm ROM reduction and contralateral dopaminergic putaminal innervation loss. Still, a partition analysis revealed a 80% chance of reduced arm ROM when putaminal dopamine content loss was >47%. A significant correlation was described between the asymmetry indices of the swinging of the two arms and dopaminergic striatal innervation. When arm ROM was reduced, we found a positive correlation between upper-lower limb phase shift modulation (at different gait velocities) and striatal dopaminergic innervation. These findings are preliminary evidence that dopaminergic striatal tone plays a modulatory role in upper-limb locomotor synergies and upper-lower limb coupling while walking at different velocities. PMID:23236504

  1. Antibacterial synergy of curcumin with antibiotics against biofilm producing clinical bacterial isolates

    PubMed Central

    Kali, Arunava; Bhuvaneshwar, Devaraj; Charles, Pravin M. V.; Seetha, Kunigal Srinivasaiah

    2016-01-01

    Introduction: The role of natural bioactive substances in treating infections has been rediscovered as bacterial resistance become common to most of the antibiotics. Curcumin is a bioactive substance from turmeric. Owing to antimicrobial properties, its prospect as an antibacterial agent is currently under focus. Materials and Methods: We have evaluated the in vitro synergy of curcumin with antibiotics against sixty biofilm producing bacterial isolates. Congo red agar method was used to identify the biofilm producing isolates. Curcumin minimum inhibitory concentration (MIC) was determined by agar dilution method. Its antibiotic synergy was identified by the increase in disc diffusion zone size on Mueller-Hinton agar with 32 mg/L curcumin. Results: The mean MICs of curcumin against Gram-positive and Gram-negative isolates were 126.9 mg/L and 117.4 mg/L, respectively. Maximum synergy was observed with ciprofloxacin among Gram-positive and amikacin, gentamicin, and cefepime among Gram-negative isolates. Conclusions: Curcumin per se as well as in combination with other antibiotics has a demonstrable antibacterial action against biofilm producing bacterial isolates. It may have a beneficial role in supplementing antibiotic therapy. PMID:27330262

  2. Study on reactivity characteristics and synergy behaviours of rice straw and bituminous coal co-gasification.

    PubMed

    Wei, Juntao; Guo, Qinghua; Chen, Handing; Chen, Xueli; Yu, Guangsuo

    2016-11-01

    Co-gasification of rice straw (RS) and Shenfu bituminous coal (SF) was conducted in a thermogravimetric analyzer (TGA) to explore the effects of gasification temperature and blend ratio on reactivity characteristics and synergy behaviours of co-gasification. Moreover, the relationship between the synergy and the K/Ca transformation in co-gasification was studied using flame atomic absorption spectrum (FAAS) and in-situ heating stage microscope. The results showed that the whole reactivities increased with increasing RS proportion and gasification temperature. The transformation of water-soluble and ion-exchanged (ws-ie) calcium was enhanced in whole co-gasification and the ws-ie potassium transformation was obviously inhibited in mid-late reaction. Hence, synergy behaviours were synthetically determined by the enhancement of Ca deactivation and the strengthening of K catalysis. The inhibiting effect was occurred in initial co-gasification and was converted to the synergistic effect at a characteristic conversion, which decreased with increasing RS proportion and decreasing gasification temperature.

  3. Sensorimotor feedback based on task-relevant error robustly predicts temporal recruitment and multidirectional tuning of muscle synergies

    PubMed Central

    Safavynia, Seyed A.

    2013-01-01

    We hypothesized that motor outputs are hierarchically organized such that descending temporal commands based on desired task-level goals flexibly recruit muscle synergies that specify the spatial patterns of muscle coordination that allow the task to be achieved. According to this hypothesis, it should be possible to predict the patterns of muscle synergy recruitment based on task-level goals. We demonstrated that the temporal recruitment of muscle synergies during standing balance control was robustly predicted across multiple perturbation directions based on delayed sensorimotor feedback of center of mass (CoM) kinematics (displacement, velocity, and acceleration). The modulation of a muscle synergy's recruitment amplitude across perturbation directions was predicted by the projection of CoM kinematic variables along the preferred tuning direction(s), generating cosine tuning functions. Moreover, these findings were robust in biphasic perturbations that initially imposed a perturbation in the sagittal plane and then, before sagittal balance was recovered, perturbed the body in multiple directions. Therefore, biphasic perturbations caused the initial state of the CoM to differ from the desired state, and muscle synergy recruitment was predicted based on the error between the actual and desired upright state of the CoM. These results demonstrate that that temporal motor commands to muscle synergies reflect task-relevant error as opposed to sensory inflow. The proposed hierarchical framework may represent a common principle of motor control across motor tasks and levels of the nervous system, allowing motor intentions to be transformed into motor actions. PMID:23100133

  4. KINEMATIC SYNERGIES DURING SACCADES INVOLVING WHOLE-BODY ROTATION: A STUDY BASED ON THE UNCONTROLLED MANIFOLD HYPOTHESIS

    PubMed Central

    Degani, Adriana M.; Danna-Dos-Santos, Alessander; Robert, Thomas; Latash, Mark L.

    2010-01-01

    We used the framework of the uncontrolled manifold hypothesis to study the coordination of body segments and eye movements in standing persons during the task of shifting the gaze to a target positioned behind the body. The task was performed at a comfortable speed and fast. Multi-segment and head-eye synergies were quantified as co-varied changes in elemental variables (body segment rotations and eye rotation) that stabilized (reduced the across trials variability) of head rotation in space and gaze trajectory. Head position in space was stabilized by co-varied rotations of body segments prior to the action, during its later stages, and after its completion. The synergy index showed a drop that started prior to the action initiation (anticipatory synergy adjustment) and continued during the phase of quick head rotation. Gaze direction was stabilized only at the movement completion and immediately after the saccade at movement initiation under the “fast” instruction. The study documents for the first time anticipatory synergy adjustments during whole-body actions. It shows multi-joint synergies stabilizing head trajectory in space. In contrast, there was no synergy between head and eye rotations during saccades that would achieve a relatively invariant gaze trajectory. PMID:20346529

  5. Hybridized tetraquarks

    NASA Astrophysics Data System (ADS)

    Esposito, A.; Pilloni, A.; Polosa, A. D.

    2016-07-01

    We propose a new interpretation of the neutral and charged X , Z exotic hadron resonances. Hybridized-tetraquarks are neither purely compact tetraquark states nor bound or loosely bound molecules but rather a manifestation of the interplay between the two. While meson molecules need a negative or zero binding energy, its counterpart for h-tetraquarks is required to be positive. The formation mechanism of this new class of hadrons is inspired by that of Feshbach metastable states in atomic physics. The recent claim of an exotic resonance in the Bs0 π± channel by the D0 Collaboration and the negative result presented subsequently by the LHCb Collaboration are understood in this scheme, together with a considerable portion of available data on X , Z particles. Considerations on a state with the same quantum numbers as the X (5568) are also made.

  6. A meta-analysis of in vitro antibiotic synergy against Acinetobacter baumannii.

    PubMed

    March, Gabriel A; Bratos, Miguel A

    2015-12-01

    The aim of the work was to describe the different in vitro models for testing synergism of antibiotics and gather the results of antibiotic synergy against multidrug-resistant Acinetobacter baumannii (MDR-Ab). The different original articles were obtained from different web sites. In order to compare the results obtained by the different methods for synergy testing, the Pearson chi-square and the Fischer tests were used. Moreover, non-parametric chi-square test was used in order to compare the frequency distribution in each analysed manuscript. In the current meta-analysis 24 manuscripts, which encompassed 2016 tests of in vitro synergism of different antimicrobials against MDR-Ab, were revised. Checkerboard synergy testing was used in 11 studies, which encompasses 1086 tests (53.9%); time-kill assays were applied in 12 studies, which encompass 359 tests (17.8%); gradient diffusion methods were used in seven studies, encompassing 293 tests (14.5%). And, finally, time-kill plus checkerboard were applied in two studies, encompassing 278 tests (13.8%). By comparing these data, checkerboard and time-kill methods were significantly more used than gradient diffusion methods (p<0.005). Regarding synergy rates obtained on the basis of the applied method, checkerboard provided 227 tests (20.9%) with a synergistic effect; time-kill assays yielded 222 tests (61.8%) with a synergistic effect; gradient diffusion methods only provided 29 tests (9.9%) with a synergistic effect; and, finally, time-kill plus checkerboard yielded just 15 tests (5.4%) with a synergistic effect. When comparing these percentages, synergy rates reported by time-kill methods were significantly higher than that obtained by checkerboard and gradient diffusion methods (p<0.005). On the basis of the revised data, the combinations of a bactericidal antibiotic plus Tigecycline, Vancomycin or Teicoplanin are not recommended. The best combinations of antibiotics are those which include bactericidal antibiotics

  7. Postural Control during Upper Body Locomotor-Like Movements: Similar Synergies Based on Dissimilar Muscle Modes

    PubMed Central

    Danna-Dos-Santos, Alessander; Shapkova, Elena Yu.; Shapkova, Alexandra L.; Degani, Adriana M.; Latash, Mark L.

    2009-01-01

    We studied the organization of leg and trunk muscles into groups (M-modes) and co-variation of M-mode involvement (M-mode synergies) during whole-body tasks associated with large variations of the moment of force about the vertical body axis. Our major questions were: (1) Can muscle activation patterns during such tasks be described with a few M-modes common across tasks and subjects? (2) Do these modes form the basis for synergies stabilizing MZ time pattern? (3) Will this organization differ between an explicit body rotation task and a task associated with locomotor-like alternating arm movements? Healthy subjects stood barefoot on the force platform and performed two motor tasks while paced by the metronome at 0.7, 1.0, and 1.4 Hz: Cyclic rotation of the upper body about the vertical body axis (body rotation task), and alternating rhythmic arm movements imitating those during running or quick walking (arm movement task). Principal component analysis was used to identify three M-modes within the space of integrated indices of muscle activity. The M-mode vectors showed clustering neither across subjects nor across frequencies. Variance in the M-mode space across sway cycles was partitioned into two components, one that did not affect the average value of MZ shift ("good variance") and the other that did. An index was computed reflecting the relative amount of the "good variance"; positive values of this index have been interpreted as reflecting a multi-M-mode synergy stabilizing the MZ trajectory. On average, the index was positive for both tasks and across all frequencies studied. However, the magnitude of the index was smaller for the intermediate frequency (1 Hz). The results show that the organization of muscles into groups during relatively complex whole-body tasks can differ significantly across both task variations and subjects. Nevertheless, the central nervous system seems to be able to build MZ stabilizing synergies based on different sets of M

  8. Making hybrids of two-hybrid systems.

    PubMed

    Dagher, M C; Filhol-Cochet, O

    1997-05-01

    Two-hybrid systems are powerful tools to find new partners for a protein of interest. However, exchange of material between two-hybrid users has been handicapped by the various versions of two-hybrid systems available and by the widely accepted idea that they are not compatible. In the present paper we show that, contrary to the dogma, the most often used two-hybrid systems may be combined by either transformation or mating assays. The protocol to be followed in each case is provided. This will greatly increase the prospects of the growing network of interacting proteins, by reconciling the "two-hybrid systems" and the "interaction trap".

  9. Synergy of β-Lactams with Vancomycin against Methicillin-Resistant Staphylococcus aureus: Correlation of Disk Diffusion and Checkerboard Methods.

    PubMed

    Sy, Cheng Len; Huang, Tsi-Shu; Chen, Chii Shiang; Chen, Yao-Shen; Tsai, Hung-Chin; Wann, Shue-Renn; Wu, Kuan-Sheng; Chen, Jui-Kuang; Lee, Susan Shin-Jung; Liu, Yung-Ching

    2016-03-01

    Modified disk diffusion (MDD) and checkerboard tests were employed to assess the synergy of combinations of vancomycin and β-lactam antibiotics for 59 clinical isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Mu50 (ATCC 700699). Bacterial inocula equivalent to 0.5 and 2.0 McFarland standard were inoculated on agar plates containing 0, 0.5, 1, and 2 μg/ml of vancomycin. Oxacillin-, cefazolin-, and cefoxitin-impregnated disks were applied to the surface, and the zones of inhibition were measured at 24 h. The CLSI-recommended checkerboard method was used as a reference to detect synergy. The MICs for vancomycin were determined using the Etest method, broth microdilution, and the Vitek 2 automated system. Synergy was observed with the checkerboard method in 51% to 60% of the isolates when vancomycin was combined with any β-lactam. The fractional inhibitory concentration indices were significantly lower in MRSA isolates with higher vancomycin MIC combinations (P < 0.05). The overall agreement between the MDD and checkerboard methods to detect synergy in MRSA isolates with bacterial inocula equivalent to McFarland standard 0.5 were 33.0% and 62.5% for oxacillin, 45.1% and 52.4% for cefazolin, and 43.1% and 52.4% for cefoxitin when combined with 0.5 and 2 μg/ml of vancomycin, respectively. Based on our study, the simple MDD method is not recommended as a replacement for the checkerboard method to detect synergy. However, it may serve as an initial screening method for the detection of potential synergy when it is not feasible to perform other labor-intensive synergy tests. PMID:26677253

  10. Integration of robotics and neuroscience beyond the hand: What kind of synergies?. Comment on "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    d'Avella, Andrea

    2016-07-01

    Santello et al. [1] review an impressive amount of work on the control of biological and artificial hands that demonstrates how the concept of synergies can lead to a successful integration of robotics and neuroscience. Is it possible to generalize the same approach to the control of biological and artificial limbs and bodies beyond the hand? The human hand synergies that appear most relevant for robotic hands are those defined at the kinematic level, i.e. postural synergies [2]. Postural synergies capture the geometric relations among the many joints of the hand and allow for a low dimensional characterization and synthesis of the static hand postures involved in grasping and manipulating a large set of objects. However, many other complex motor skills such as walking, reaching, throwing, and catching require controlling multi-articular time-varying trajectories rather than static postures. Dynamic control of biological and artificial limbs and bodies, especially when geometric and inertial parameters are uncertain and the joints are compliant, poses great challenges. What kind of synergies might simplify the dynamic control of motor skills involving upper and lower limbs as well as the whole body?

  11. Hybrid mimics and hybrid vigor in Arabidopsis

    PubMed Central

    Wang, Li; Greaves, Ian K.; Groszmann, Michael; Wu, Li Min; Dennis, Elizabeth S.; Peacock, W. James

    2015-01-01

    F1 hybrids can outperform their parents in yield and vegetative biomass, features of hybrid vigor that form the basis of the hybrid seed industry. The yield advantage of the F1 is lost in the F2 and subsequent generations. In Arabidopsis, from F2 plants that have a F1-like phenotype, we have by recurrent selection produced pure breeding F5/F6 lines, hybrid mimics, in which the characteristics of the F1 hybrid are stabilized. These hybrid mimic lines, like the F1 hybrid, have larger leaves than the parent plant, and the leaves have increased photosynthetic cell numbers, and in some lines, increased size of cells, suggesting an increased supply of photosynthate. A comparison of the differentially expressed genes in the F1 hybrid with those of eight hybrid mimic lines identified metabolic pathways altered in both; these pathways include down-regulation of defense response pathways and altered abiotic response pathways. F6 hybrid mimic lines are mostly homozygous at each locus in the genome and yet retain the large F1-like phenotype. Many alleles in the F6 plants, when they are homozygous, have expression levels different to the level in the parent. We consider this altered expression to be a consequence of transregulation of genes from one parent by genes from the other parent. Transregulation could also arise from epigenetic modifications in the F1. The pure breeding hybrid mimics have been valuable in probing the mechanisms of hybrid vigor and may also prove to be useful hybrid vigor equivalents in agriculture. PMID:26283378

  12. Hybrid supercapacitor-battery materials for fast electrochemical charge storage.

    PubMed

    Vlad, A; Singh, N; Rolland, J; Melinte, S; Ajayan, P M; Gohy, J-F

    2014-01-01

    High energy and high power electrochemical energy storage devices rely on different fundamental working principles--bulk vs. surface ion diffusion and electron conduction. Meeting both characteristics within a single or a pair of materials has been under intense investigations yet, severely hindered by intrinsic materials limitations. Here, we provide a solution to this issue and present an approach to design high energy and high power battery electrodes by hybridizing a nitroxide-polymer redox supercapacitor (PTMA) with a Li-ion battery material (LiFePO4). The PTMA constituent dominates the hybrid battery charge process and postpones the LiFePO4 voltage rise by virtue of its ultra-fast electrochemical response and higher working potential. We detail on a unique sequential charging mechanism in the hybrid electrode: PTMA undergoes oxidation to form high-potential redox species, which subsequently relax and charge the LiFePO4 by an internal charge transfer process. A rate capability equivalent to full battery recharge in less than 5 minutes is demonstrated. As a result of hybrid's components synergy, enhanced power and energy density as well as superior cycling stability are obtained, otherwise difficult to achieve from separate constituents.

  13. Hybrid supercapacitor-battery materials for fast electrochemical charge storage

    PubMed Central

    Vlad, A.; Singh, N.; Rolland, J.; Melinte, S.; Ajayan, P. M.; Gohy, J.-F.

    2014-01-01

    High energy and high power electrochemical energy storage devices rely on different fundamental working principles - bulk vs. surface ion diffusion and electron conduction. Meeting both characteristics within a single or a pair of materials has been under intense investigations yet, severely hindered by intrinsic materials limitations. Here, we provide a solution to this issue and present an approach to design high energy and high power battery electrodes by hybridizing a nitroxide-polymer redox supercapacitor (PTMA) with a Li-ion battery material (LiFePO4). The PTMA constituent dominates the hybrid battery charge process and postpones the LiFePO4 voltage rise by virtue of its ultra-fast electrochemical response and higher working potential. We detail on a unique sequential charging mechanism in the hybrid electrode: PTMA undergoes oxidation to form high-potential redox species, which subsequently relax and charge the LiFePO4 by an internal charge transfer process. A rate capability equivalent to full battery recharge in less than 5 minutes is demonstrated. As a result of hybrid's components synergy, enhanced power and energy density as well as superior cycling stability are obtained, otherwise difficult to achieve from separate constituents. PMID:24603843

  14. Synergy and antagonism between iron chelators and antifungal drugs in Cryptococcus.

    PubMed

    Lai, Yu-Wen; Campbell, Leona T; Wilkins, Marc R; Pang, Chi Nam Ignatius; Chen, Sharon; Carter, Dee A

    2016-10-01

    Fungal infections remain very difficult to treat, and developing new antifungal drugs is difficult and expensive. Recent approaches therefore seek to augment existing antifungals with synergistic agents that can lower the therapeutic dose, increase efficacy and prevent resistance from developing. Iron limitation can inhibit microbial growth, and iron chelators have been employed to treat fungal infections. In this study, chequerboard testing was used to explore combinations of iron chelators with antifungal agents against pathogenic Cryptococcus spp. with the aim of determining how disruption to iron homeostasis affects antifungal susceptibility. The iron chelators ethylenediaminetetraacetic acid (EDTA), deferoxamine (DFO), deferiprone (DFP), deferasirox (DSX), ciclopirox olamine and lactoferrin (LF) were paired with the antifungal agents amphotericin B (AmB), fluconazole, itraconazole, voriconazole and caspofungin. All chelators except for DFO increased the efficacy of AmB, and significant synergy was seen between AmB and LF for all Cryptococcus strains. Addition of exogenous iron rescued cells from the antifungal effect of LF alone but could not prevent inhibition by AmB + LF, indicating that synergy was not due primarily to iron chelation but to other properties of LF that were potentiated in the presence of AmB. Significant synergy was not seen consistently for other antifungal-chelator combinations, and EDTA, DSX and DFP antagonised the activity of azole drugs in strains of Cryptococcus neoformans var. grubii. This study highlights the range of interactions that can be induced by chelators and indicates that most antifungal drugs are not enhanced by iron limitation in Cryptococcus. PMID:27474467

  15. Analysis of Hand and Wrist Postural Synergies in Tolerance Grasping of Various Objects

    PubMed Central

    Liu, Yuan; Jiang, Li; Yang, Dapeng; Liu, Hong

    2016-01-01

    Human can successfully grasp various objects in different acceptable relative positions between human hand and objects. This grasp functionality can be described as the grasp tolerance of human hand, which is a significant functionality of human grasp. To understand the motor control of human hand completely, an analysis of hand and wrist postural synergies in tolerance grasping of various objects is needed. Ten healthy right-handed subjects were asked to perform the tolerance grasping with right hand using 6 objects of different shapes, sizes and relative positions between human hand and objects. Subjects were wearing CyberGlove attaching motion tracker on right hand, allowing a measurement of the hand and wrist postures. Correlation analysis of joints and inter-joint/inter-finger modules were carried on to explore the coordination between joints or modules. As the correlation between hand and wrist module is not obvious in tolerance grasping, individual analysis of wrist synergies would be more practical. In this case, postural synergies of hand and wrist were then presented separately through principal component analysis (PCA), expressed through the principal component (PC) information transmitted ratio, PC elements distribution and reconstructed angle error of joints. Results on correlation comparison of different module movements can be well explained by the influence factors of the joint movement correlation. Moreover, correlation analysis of joints and modules showed the wrist module had the lowest correlation among all inter-finger and inter-joint modules. Hand and wrist postures were both sufficient to be described by a few principal components. In terms of the PC elements distribution of hand postures, compared with previous investigations, there was a greater proportion of movement in the thumb joints especially the interphalangeal (IP) and opposition rotation (ROT) joint. The research could serve to a complete understanding of hand grasp, and the design

  16. Synergy of Penicillin-Netilmicin Combinations Against Enterococci Including Strains Highly Resistant to Streptomycin or Kanamycin

    PubMed Central

    Sanders, Christine C.

    1977-01-01

    The in vitro activity of combinations of penicillin and netilimicin was determined against 20 clinical isolates of enterococci and compared with that obtained in simultaneous tests with penicillin/sisomicin, penicillin/streptomycin, and penicillin/kanamycin. Synergy between the two drugs in each combination was determined by the use of quantitative kill curves and was defined as a killing by the combination at least 100-fold greater than that produced by the most effective drug alone. Penicillin/netilmicin and penicillin/sisomicin combinations were found to be synergistic against the majority of isolates tested, including strains resistant to penicillin/streptomycin or penicillin/kanamycin combinations. This synergy with penicillin could be demonstrated at a concentration of ≤7 μg/ml for either netilmicin or sisomicin. Studies on the kinetics of killing produced by these combinations showed the rate and extent of killing to be directly dependent upon the organism's relative susceptibility to the aminoglycoside alone and the aminoglycoside concentration in the combination. Results also indicated that the interaction between penicillin and netilmicin was true synergy; i.e., rapid and complete killing was produced by combinations containing each drug at concentrations insufficient to produce any killing alone, and the killing observed could not be produced by either drug alone at a concentration equivalent to the total drug concentration in the combination. The potential clinical application of this synergistic interaction should be investigated further, especially in view of recent reports showing netilmicin to be considerably less toxic than gentamicin in experimental animals. PMID:242509

  17. Analysis of Hand and Wrist Postural Synergies in Tolerance Grasping of Various Objects.

    PubMed

    Liu, Yuan; Jiang, Li; Yang, Dapeng; Liu, Hong

    2016-01-01

    Human can successfully grasp various objects in different acceptable relative positions between human hand and objects. This grasp functionality can be described as the grasp tolerance of human hand, which is a significant functionality of human grasp. To understand the motor control of human hand completely, an analysis of hand and wrist postural synergies in tolerance grasping of various objects is needed. Ten healthy right-handed subjects were asked to perform the tolerance grasping with right hand using 6 objects of different shapes, sizes and relative positions between human hand and objects. Subjects were wearing CyberGlove attaching motion tracker on right hand, allowing a measurement of the hand and wrist postures. Correlation analysis of joints and inter-joint/inter-finger modules were carried on to explore the coordination between joints or modules. As the correlation between hand and wrist module is not obvious in tolerance grasping, individual analysis of wrist synergies would be more practical. In this case, postural synergies of hand and wrist were then presented separately through principal component analysis (PCA), expressed through the principal component (PC) information transmitted ratio, PC elements distribution and reconstructed angle error of joints. Results on correlation comparison of different module movements can be well explained by the influence factors of the joint movement correlation. Moreover, correlation analysis of joints and modules showed the wrist module had the lowest correlation among all inter-finger and inter-joint modules. Hand and wrist postures were both sufficient to be described by a few principal components. In terms of the PC elements distribution of hand postures, compared with previous investigations, there was a greater proportion of movement in the thumb joints especially the interphalangeal (IP) and opposition rotation (ROT) joint. The research could serve to a complete understanding of hand grasp, and the design

  18. Trade-Off and Synergy among Ecosystem Services in the Guanzhong-Tianshui Economic Region of China.

    PubMed

    Qin, Keyu; Li, Jing; Yang, Xiaonan

    2015-11-01

    Natural ecosystems provide society with important goods and services. With rapidly increasing populations and excessive utilization of natural resources, humans have been enhancing the production of some services at the expense of others. Although the need for certain trade-offs between conservation and development is urgent, having only a small number of efficient methods to assess such trade-offs has impeded progress. This study focuses on the evaluation of ecosystem services under different land use schemes. It reveals the spatial and temporal distributions of and changes in ecosystem services. Based on a correlation rate model and distribution mapping, the trade-offs and synergies of these ecosystem services can be found. Here, we also describe a new simple approach to quantify the relationships of every trade-off and synergy. The results show that all ecosystem services possess trade-offs and synergies in the study area. The trend of improving carbon sequestration and water interception indicate that these key ecosystem services have the strongest synergy. And the decrease in regional agricultural production and other services, except water yield, may be considered as trade-offs. The synergy between water yield and agricultural production was the most significant, while the trade-off between water interception and carbon sequestration was the most apparent, according to our interaction quantification model. The results of this study have implications for planning and monitoring the future management of natural capital and ecosystem services, and can be integrated into land use decision-making. PMID:26540068

  19. Trade-Off and Synergy among Ecosystem Services in the Guanzhong-Tianshui Economic Region of China.

    PubMed

    Qin, Keyu; Li, Jing; Yang, Xiaonan

    2015-11-03

    Natural ecosystems provide society with important goods and services. With rapidly increasing populations and excessive utilization of natural resources, humans have been enhancing the production of some services at the expense of others. Although the need for certain trade-offs between conservation and development is urgent, having only a small number of efficient methods to assess such trade-offs has impeded progress. This study focuses on the evaluation of ecosystem services under different land use schemes. It reveals the spatial and temporal distributions of and changes in ecosystem services. Based on a correlation rate model and distribution mapping, the trade-offs and synergies of these ecosystem services can be found. Here, we also describe a new simple approach to quantify the relationships of every trade-off and synergy. The results show that all ecosystem services possess trade-offs and synergies in the study area. The trend of improving carbon sequestration and water interception indicate that these key ecosystem services have the strongest synergy. And the decrease in regional agricultural production and other services, except water yield, may be considered as trade-offs. The synergy between water yield and agricultural production was the most significant, while the trade-off between water interception and carbon sequestration was the most apparent, according to our interaction quantification model. The results of this study have implications for planning and monitoring the future management of natural capital and ecosystem services, and can be integrated into land use decision-making.

  20. Trade-Off and Synergy among Ecosystem Services in the Guanzhong-Tianshui Economic Region of China

    PubMed Central

    Qin, Keyu; Li, Jing; Yang, Xiaonan

    2015-01-01

    Natural ecosystems provide society with important goods and services. With rapidly increasing populations and excessive utilization of natural resources, humans have been enhancing the production of some services at the expense of others. Although the need for certain trade-offs between conservation and development is urgent, having only a small number of efficient methods to assess such trade-offs has impeded progress. This study focuses on the evaluation of ecosystem services under different land use schemes. It reveals the spatial and temporal distributions of and changes in ecosystem services. Based on a correlation rate model and distribution mapping, the trade-offs and synergies of these ecosystem services can be found. Here, we also describe a new simple approach to quantify the relationships of every trade-off and synergy. The results show that all ecosystem services possess trade-offs and synergies in the study area. The trend of improving carbon sequestration and water interception indicate that these key ecosystem services have the strongest synergy. And the decrease in regional agricultural production and other services, except water yield, may be considered as trade-offs. The synergy between water yield and agricultural production was the most significant, while the trade-off between water interception and carbon sequestration was the most apparent, according to our interaction quantification model. The results of this study have implications for planning and monitoring the future management of natural capital and ecosystem services, and can be integrated into land use decision-making. PMID:26540068

  1. Synergy of inelastic and elastic energy loss. Temperature effects and electronic stopping power dependence

    SciTech Connect

    Zarkadoula, Eva; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2015-06-16

    A combination of an inelastic thermal spike model suitable for insulators and molecular dynamics simulations is used to study the effects of temperature and electronic energy loss on ion track formation, size and morphology in SrTiO3 systems with pre-existing disorder. We find temperature dependence of the ion track size. In addition, we find a threshold in the electronic energy loss for a given pre-existing defect concentration, which indicates a threshold in the synergy between the inelastic and elastic energy loss.

  2. Synergy of inelastic and elastic energy loss. Temperature effects and electronic stopping power dependence

    DOE PAGESBeta

    Zarkadoula, Eva; Xue, Haizhou; Zhang, Yanwen; Weber, William J.

    2015-06-16

    A combination of an inelastic thermal spike model suitable for insulators and molecular dynamics simulations is used to study the effects of temperature and electronic energy loss on ion track formation, size and morphology in SrTiO3 systems with pre-existing disorder. We find temperature dependence of the ion track size. In addition, we find a threshold in the electronic energy loss for a given pre-existing defect concentration, which indicates a threshold in the synergy between the inelastic and elastic energy loss.

  3. Impaired grip-lift synergy in children with unilateral brain lesions.

    PubMed

    Forssberg, H; Eliasson, A C; Redon-Zouitenn, C; Mercuri, E; Dubowitz, L

    1999-06-01

    Children with spastic hemiplegia have impaired dexterity in the affected extremity. The purpose of the present study was to investigate whether the force co-ordination pattern during precision grip in 13 children between 4 and 10 years of age with predominant unilateral brain lesions is related to manual dexterity and to the location and size of the brain lesion. The force co-ordination pattern was investigated by means of a specially designed object that monitored the isometric fingertip forces applied to the contact surfaces during precision grip. Hand function was measured by means of neurological examination, functional hand-grips and dexterity. Brain lesions were identified by series of ultrasound and MRI scans. Normally, the fingertip forces are applied to the object in the initial phase of the lift in an invariant force co-ordination pattern (i.e. grip-lift synergy), in which the grip and load forces are initiated simultaneously and increase in parallel with unimodal force rate trajectories. A majority of children with unilateral brain lesions had not developed the force co-ordination pattern typical for their age, but produced an immature or a pathological pattern. The developmental level of the grip-lift synergy was determined and quantified according to criteria derived from earlier studies on normally developed children. There was a clear relationship between the developmental level of the grip-lift synergy and impaired dexterity, indicating that proper development of the force co-ordination pattern is important for skilled hand function. The grip-lift synergy correlated with the total extent of lesions in the contralateral cortex and white matter and with lesions in the thalamus/basal ganglia, while no correlation was found for isolated cortical lesions. The results suggest that the neural circuits involved in the control of the precision grip are organized in a parallel and distributed system in the hemispheres, and that the basal ganglia are important

  4. Drivers and synergies in the management of inland fisheries: Searching for sustainable solutions

    USGS Publications Warehouse

    Lynch, Abigail; Beard, Douglas

    2015-01-01

    At the 2015 Global Conference on Inland Fisheries, we convened a Drivers and Synergies panel and working group to discuss competing sectors (e.g., hydropower, transportation, agriculture, mining and oil and gas extraction, forestry, tourism and recreation, and aquaculture) and large-scale drivers which exist predominately outside of the water sectors (e.g., economic growth, diversifying economies, population growth, urbanization, and climate change).  Drivers will influence these sectors and tradeoffs will be made.  Management of sustainable inland water systems requires making informed choices emphasizing those services that will provide sustainable benefits for humans while maintaining well-functioning ecological systems.  

  5. Proton Beam Fast Ignition Fusion: Synergy of Weibel and Rayleigh-Taylor Instabilities

    NASA Astrophysics Data System (ADS)

    Stefan, V. Alexander

    2011-04-01

    The proton beam generation and focusing in fast ignition inertial confinement fusion is studied. The spatial and energy spread of the proton beam generated in a laser-solid interaction is increased due to the synergy of Weibel and Rayleigh-Taylor instabilities. The focal spot radius can reach 100 μm, which is nearly an order of magnitude larger than the optimal value. The energy spread decreases the beam deposition energy in the focal spot. Under these conditions, ignition of a precompressed DT fuel is achieved with the beam powers much higher than the values presently in consideration. Work supported in part by NIKOLA TESLA Laboratories (Stefan University), La Jolla, CA.

  6. Administrative Synergy

    ERIC Educational Resources Information Center

    Hewitt, Kimberly Kappler; Weckstein, Daniel K.

    2012-01-01

    One of the biggest obstacles to overcome in creating and sustaining an administrative professional learning community (PLC) is time. Administrators are constantly deluged by the tyranny of the urgent. It is a Herculean task to carve out time for PLCs, but it is imperative to do so. In this article, the authors describe how an administrative PLC…

  7. Towards a synergy framework across neuroscience and robotics: Lessons learned and open questions. Reply to comments on: "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands"

    NASA Astrophysics Data System (ADS)

    Santello, Marco; Bianchi, Matteo; Gabiccini, Marco; Ricciardi, Emiliano; Salvietti, Gionata; Prattichizzo, Domenico; Ernst, Marc; Moscatelli, Alessandro; Jorntell, Henrik; Kappers, Astrid M. L.; Kyriakopoulos, Kostas; Schaeffer, Alin Abu; Castellini, Claudio; Bicchi, Antonio

    2016-07-01

    We would like to thank all commentators for their insightful commentaries. Thanks to their diverse and complementary expertise in neuroscience and robotics, the commentators have provided us with the opportunity to further discuss state-of-the-art and gaps in the integration of neuroscience and robotics reviewed in our article. We organized our reply in two sections that capture the main points of all commentaries [1-9]: (1) Advantages and limitations of the synergy approach in neuroscience and robotics, and (2) Learning and role of sensory feedback in biological and robotics synergies.

  8. Working hard to make a simple definition of synergies. Comment on: "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" by Marco Santello et al.

    NASA Astrophysics Data System (ADS)

    Alessandro, Cristiano; Oliveira Barroso, Filipe; Tresch, Matthew

    2016-07-01

    The paper "Hand synergies: Integration of robotics and neuroscience for understanding the control of biological and artificial hands" [1] presents a comprehensive review of the work carried out as part of the EU funded project "The Hand Embodied". The work uses the concept of "synergy" to study the neuromuscular control of the human hand and to design novel robotics systems. The project has been very productive and has made important contributions. We are therefore confident that it will lead to further advancements and experiments in the future.

  9. Partnerships in Health Disparities Research and the Roles of Pastors of Black Churches: Potential Conflict, Synergy, and Expectations

    PubMed Central

    Corbie-Smith, Giselle; Goldmon, Moses; Isler, Malika Roman; Washington, Chanetta; Ammerman, Alice; Green, Melissa; Bunton, Audrina

    2011-01-01

    Background The black church is a promising site to engage in health disparities research; however, little is understood about the pastors' perspectives. We used role theory to explore their expectations, potential conflicts, and synergy with research. Methods Four focus groups (n = 30) were conducted with pastors and analyzed using principles of grounded theory and content analysis. Results Pastors identified a variety of potential roles in research. They noted potential conflicts due to perceptions of research, the process, and pace of research. Areas of synergy included perceptions of health disparities research as consistent with the healthy mind, body, and spirit ideology, and clear benefits to congregations and communities. Pastors' research expectations included long-term commitments, honest and clear communication, investigator visibility, respect for church traditions/practices, and support in forming collaborations. Conclusions Understanding pastors' roles, potential areas of synergy and conflict, and collaboration expectations offers insight in support of successful church-academic partnerships. PMID:20922927

  10. A central back-coupling hypothesis on the organization of motor synergies: a physical metaphor and a neural model

    PubMed Central

    Latash, Mark L.; Shim, Jae Kun; Smilga, Andrei V.; Zatsiorsky, Vladimir M.

    2010-01-01

    We offer a hypothesis on the organization of multi-effector motor synergies and illustrate it with the task of force production with a set of fingers. A physical metaphor, a leaking bucket, is analyzed to demonstrate that an inanimate structure can show apparent error compensation among its elements. A neural model is developed using tunable back-coupling loops as means of assuring error compensation in a task-specific way. The model demonstrates non-trivial features of multi-finger interaction such as delayed emergence of force stabilizing synergies and simultaneous stabilization of the total force and total moment produced by the fingers. The hypothesis suggests that neurophysiological structures involving short-latency feedback may play a central role in the formation of motor synergies. PMID:15739110

  11. Farnesol decreases biofilms of Staphylococcus epidermidis and exhibits synergy with nafcillin and vancomycin.

    PubMed

    Pammi, Mohan; Liang, Rong; Hicks, John M; Barrish, Jim; Versalovic, James

    2011-12-01

    Biofilm infections are frequently caused by Staphylococcus epidermidis, are resistant to antimicrobial agents, and adversely affect patient outcomes. We evaluated farnesol (FSL), the Candida quorum-sensing molecule, on S. epidermidis biofilms, in vitro and in vivo. We evaluated ED50, ED75, and ED90 (drug concentrations causing 50%, 75%, and 90% inhibition, respectively) of FSL and evaluated synergy with nafcillin and vancomycin. FSL's effects on morphology of S. epidermidis biofilms were analyzed using confocal microscopy and real-time changes using a bioluminescent strain of S. epidermidis, Xen 43. In mice, effects of FSL treatment on s.c. catheter biofilms; cultures of blood, kidney, and catheter and pericatheter tissues; and bioluminescence in strain Xen 43 were evaluated. FSL inhibited biofilms (ED50 ranged from 0.625 to 2.5 mM) and was synergistic with nafcillin and vancomycin at most combination ratios. FSL significantly decreased biovolume, substratum coverage, and mean thickness of S. epidermidis biofilms. In mice, FSL significantly decreased viable colony counts of S. epidermidis from blood, kidney, and catheter and pericatheter tissues and decreased Xen 43 bioluminescence. We confirmed the antibiofilm effects of FSL both in vitro and in vivo, in a bioluminescent strain and its synergy with antibiotics. FSL may be effective against clinical S. epidermidis biofilm infections. PMID:21857375

  12. Antibacterial activity and synergy, in vitro and in vivo, of a combination of amoxycillin and flucloxacillin.

    PubMed

    Comber, K R; Merrikin, D J; Sutherland, R

    1979-01-01

    The antibacterial activity of a combination of equal parts of amoxycillin and flucloxacillin was compared in vitro and in vivo with that of amoxycillin and flucloxacillin against a range of gram-positive and gram-negative bacteria. The combination generally showed additive effects against bacteria sensitive to the individual penicillins and there was no evidence of antagonism, but synergistic effects were observed between amoxycillin and flucloxacillin against certain amoxycillin-resistant gram-negative bacilli. The extent of synergism varied according to the particular bacterial species under test and synergy was observed only against bacteria with chromosomally-mediated beta-lactamases and not against bacteria with R-factor-mediated beta-lactamases. In general, amoxycillin + flucloxacillin demonstrated activity against experimental mouse infections in good agreement with demonstrated activity against experimental mouse infections in good agreement with its in vitro activity, and synergy was produced against a range of gram-negative bacilli in vivo. The data suggest that clinical trial with amoxycillin + flucloxacillin in the treatment of selected infections including those due to some amoxycillin-resistant bacteria may well be justified.

  13. Confirmation of Maslow's Hypothesis of Synergy: Developing an Acceptance of Selfishness at the Workplace Scale.

    PubMed

    Takaki, Jiro; Taniguchi, Toshiyo; Fujii, Yasuhito

    2016-04-30

    This study aimed to develop a new Acceptance of Selfishness at the Workplace Scale (ASWS) and to confirm Maslow's hypothesis of synergy: if both a sense of contribution and acceptance of selfishness at the workplace are high, workers are psychologically healthy. In a cross-sectional study with employees of three Japanese companies, 656 workers answered a self-administered questionnaire on paper completely (response rate = 66.8%). Each questionnaire was submitted to us in a sealed envelope and analyzed. The ASWS indicated high internal consistency (Cronbach's alpha = 0.86). Significant (p < 0.001) positive moderate correlations between ASWS scores and job control scores support the ASWS's convergent and discriminant validity. Significant (p < 0.001) associations of ASWS scores with psychological distress and work engagement supported the ASWS's criterion validity. In short, ASWS was a psychometrically satisfactory measure. Significant (p < 0.05) interactions between a sense of contribution and acceptance of selfishness at the workplace in linear regression models showed that when those two factors are low, psychological distress becomes high. However, when a sense of contribution and acceptance of selfishness are high, work engagement also becomes high. Thus, Maslow's hypothesis of synergy was confirmed.

  14. Farnesol decreases biofilms of Staphylococcus epidermidis and exhibits synergy with nafcillin and vancomycin.

    PubMed

    Pammi, Mohan; Liang, Rong; Hicks, John M; Barrish, Jim; Versalovic, James

    2011-12-01

    Biofilm infections are frequently caused by Staphylococcus epidermidis, are resistant to antimicrobial agents, and adversely affect patient outcomes. We evaluated farnesol (FSL), the Candida quorum-sensing molecule, on S. epidermidis biofilms, in vitro and in vivo. We evaluated ED50, ED75, and ED90 (drug concentrations causing 50%, 75%, and 90% inhibition, respectively) of FSL and evaluated synergy with nafcillin and vancomycin. FSL's effects on morphology of S. epidermidis biofilms were analyzed using confocal microscopy and real-time changes using a bioluminescent strain of S. epidermidis, Xen 43. In mice, effects of FSL treatment on s.c. catheter biofilms; cultures of blood, kidney, and catheter and pericatheter tissues; and bioluminescence in strain Xen 43 were evaluated. FSL inhibited biofilms (ED50 ranged from 0.625 to 2.5 mM) and was synergistic with nafcillin and vancomycin at most combination ratios. FSL significantly decreased biovolume, substratum coverage, and mean thickness of S. epidermidis biofilms. In mice, FSL significantly decreased viable colony counts of S. epidermidis from blood, kidney, and catheter and pericatheter tissues and decreased Xen 43 bioluminescence. We confirmed the antibiofilm effects of FSL both in vitro and in vivo, in a bioluminescent strain and its synergy with antibiotics. FSL may be effective against clinical S. epidermidis biofilm infections.

  15. High prevalence of biofilm synergy among bacterial soil isolates in cocultures indicates bacterial interspecific cooperation

    PubMed Central

    Ren, Dawei; Madsen, Jonas S; Sørensen, Søren J; Burmølle, Mette

    2015-01-01

    Biofilms that form on roots, litter and soil particles typically contain multiple bacterial species. Currently, little is known about multispecies biofilm interactions and few studies have been based on environmental isolates. Here, the prevalence of synergistic effects in biofilm formation among seven different soil isolates, cocultured in combinations of four species, was investigated. We observed greater biofilm biomass production in 63% of the four-species culture combinations tested than in biofilm formed by single-species cultures, demonstrating a high prevalence of synergism in multispecies biofilm formation. One four-species consortium, composed of Stenotrophomonas rhizophila, Xanthomonas retroflexus, Microbacterium oxydans and Paenibacillus amylolyticus, exhibited strong synergy in biofilm formation and was selected for further study. Of the four strains, X. retroflexus was the only one capable of forming abundant biofilm in isolation, under the in vitro conditions investigated. In accordance, strain-specific quantitative PCR revealed that X. retroflexus was predominant within the four-species consortium (>97% of total biofilm cell number). Despite low relative abundance of all the remaining strains, all were indispensable for the strong synergistic effect to occur within the four-species biofilm. Moreover, absolute individual strain cell numbers were significantly enhanced when compared with those of single-species biofilms, indicating that all the individual strains benefit from inclusion in the multispecies community. Our results show a high prevalence of synergy in biofilm formation in multispecies consortia isolated from a natural bacterial habitat and suggest that interspecific cooperation occurs. PMID:24936766

  16. Techno-ecological synergy as a path toward sustainability of a North American residential system.

    PubMed

    Urban, Robert A; Bakshi, Bhavik R

    2013-02-19

    For any human-designed system to be sustainable, ecosystem services that support it must be readily available. This work explicitly accounts for this dependence by designing synergies between technological and ecological systems. The resulting techno-ecological network mimics nature at the systems level, can stay within ecological constraints, and can identify novel designs that are economically and environmentally attractive that may not be found by the traditional design focus on technological options. This approach is showcased by designing synergies for a typical American suburban home at local and life cycle scales. The objectives considered are carbon emissions, water withdrawal, and cost savings. Systems included in the design optimization include typical ecosystems in suburban yards: lawn, trees, water reservoirs, and a vegetable garden; technological systems: heating, air conditioning, faucets, solar panels, etc.; and behavioral variables: heating and cooling set points. The ecological and behavioral design variables are found to have a significant effect on the three objectives, in some cases rivaling and exceeding the effect of traditional technological options. These results indicate the importance and benefits of explicitly including ecosystems in the design of sustainable systems, something that is rarely done in existing methods.

  17. The metaphor-gestalt synergy underlying the self-organisation of perception as a semiotic process.

    PubMed

    Rail, David

    2013-04-01

    Recently the basis of concept and language formation has been redefined by the proposal that they both stem from perception and embodiment. The experiential revolution has lead to a far more integrated and dynamic understanding of perception as a semiotic system. The emergence of meaning in the perceptual process stems from the interaction between two key mechanisms. These are first, the generation of schemata through recurrent sensorimotor activity (SM) that underlies category and language formation (L). The second is the interaction between metaphor (M) and gestalt mechanisms (G) that generate invariant mappings beyond the SM domain that both conserve and diversify our understanding and meaning potential. We propose an important advance in our understanding of perception as a semiotic system through exploring the affect of self-organising to criticality where hierarchical behaviour becomes widely integrated through 1/f process and isomorphisms. Our proposal leads to several important implications. First, that SM and L form a functional isomorphism depicted as SM <=> L. We contend that SM <=> L is emergent, corresponding to the phenomenal self. Second, meaning structures the isomorphism SM <=>L through the synergy between M and G (M-G). M-G synergy is based on a combination of structuring and imagination. We contend that the interaction between M-G and SM <=> L functions as a macro-micro comutation that governs perception as semiosis. We discuss how our model relates to current research in fractal time and verb formation.

  18. Probing Corticospinal Recruitment Patterns and Functional Synergies with Transcranial Magnetic Stimulation

    PubMed Central

    Mathew, James; Kübler, Angelika; Bauer, Robert; Gharabaghi, Alireza

    2016-01-01

    Background: On the one hand, stimulating the motor cortex at different spots may activate the same muscle and result in a muscle-specific cortical map. Maps of different muscles, which are functionally coupled, may present with a large overlap but may also show a relevant variability. On the other hand, stimulation of the motor cortex at one spot with different stimulation intensities results in a characteristic input–output (IO) curve for one specific muscle but may simultaneously also activate different, functionally coupled muscles. A comparison of the cortical map overlap of synergistic muscles and their IO curves has not yet been carried out. Objective: The aim of this study was to probe functional synergies of forearm muscles with transcranial magnetic stimulation by harnessing the convergence and divergence of the corticospinal output. Methods: We acquired bihemispheric cortical maps and IO curves of the extensor carpi ulnaris, extensor carpi radialis, and extensor digitorum communis muscles by subjecting 11 healthy subjects to both monophasic and biphasic pulse waveforms. Results: The degree of synergy between pairs of forearm muscles was captured by the overlap of the cortical motor maps and the respective IO curves which were influenced by the pulse waveform. Monophasic and biphasic stimulation were particularly suitable for disentangling synergistic muscles in the right and left hemisphere, respectively. Conclusion: Combining IO curves and different pulse waveforms may provide complementary information on neural circuit dynamics and corticospinal recruitment patterns of synergistic muscles and their neuroplastic modulation. PMID:27458344

  19. Grasping synergies: a motor-control approach to the mirror neuron mechanism.

    PubMed

    D'Ausilio, Alessandro; Bartoli, Eleonora; Maffongelli, Laura

    2015-03-01

    The discovery of mirror neurons revived interest in motor theories of perception, fostering a number of new studies as well as controversies. In particular, the degree of motor specificity with which others' actions are simulated is highly debated. Human corticospinal excitability studies support the conjecture that a mirror mechanism encodes object-directed goals or low-level kinematic features of others' reaching and grasping actions. These interpretations lead to different experimental predictions and implications for the functional role of the simulation of others' actions. We propose that the representational granularity of the mirror mechanism cannot be any different from that of the motor system during action execution. Hence, drawing from motor control models, we propose that the building blocks of the mirror mechanism are the relatively few motor synergies explaining the variety of hand functions. The recognition of these synergies, from action observation, can be potentially very robust to visual noise and thus demonstrate a clear advantage of using motor knowledge for classifying others' action.

  20. Grasping synergies: A motor-control approach to the mirror neuron mechanism

    NASA Astrophysics Data System (ADS)

    D'Ausilio, Alessandro; Bartoli, Eleonora; Maffongelli, Laura

    2015-03-01

    The discovery of mirror neurons revived interest in motor theories of perception, fostering a number of new studies as well as controversies. In particular, the degree of motor specificity with which others' actions are simulated is highly debated. Human corticospinal excitability studies support the conjecture that a mirror mechanism encodes object-directed goals or low-level kinematic features of others' reaching and grasping actions. These interpretations lead to different experimental predictions and implications for the functional role of the simulation of others' actions. We propose that the representational granularity of the mirror mechanism cannot be any different from that of the motor system during action execution. Hence, drawing from motor control models, we propose that the building blocks of the mirror mechanism are the relatively few motor synergies explaining the variety of hand functions. The recognition of these synergies, from action observation, can be potentially very robust to visual noise and thus demonstrate a clear advantage of using motor knowledge for classifying others' action.

  1. Synergy Potential of Indole Alkaloids and Its Derivative against Drug-resistant Escherichia coli.

    PubMed

    Dwivedi, Gaurav Raj; Gupta, Shikha; Maurya, Anupam; Tripathi, Shubhandra; Sharma, Ashok; Darokar, Mahendra P; Srivastava, Santosh K

    2015-12-01

    Antibacterial and synergy potential of naturally occurring indole alkaloids (IA): 10-methoxy tetrahydroalstonine (1), isoreserpiline (2), 10 and 11 demethoxyreserpiline (3), reserpiline (4), serpentine (5), ajmaline (6), ajmalicine (7), yohimbine (8), and α-yohimbine (9) was evaluated using microbroth dilution assay. Further, α-yohimbine (9) was chemically transformed into six semisynthetic derivatives (9A-9F), and their antibacterial and synergy potential in combination with nalidixic acid (NAL) against E. coli strains CA8000 and DH5α were also evaluated. The IA 1, 2, 4, 5, 9 and the derivative 9F showed eightfold reduction in the MIC of NAL against the DH5α and four- to eightfold reduction against CA8000. These alkaloids also reduced MIC of another antibiotic, tetracycline up to 8folds, against the MDREC-KG4, a multidrug-resistant clinical isolate of E. coli. Mode of action study of these alkaloids showed efflux pumps inhibitory potential, which was supported by their in silico binding affinity and downregulation of efflux pump genes. These results may be of great help in the development of cost-effective antibacterial combinations for treating patients infected with multidrug-resistant Gram-negative infections.

  2. Carbapenems and Rifampin Exhibit Synergy against Mycobacterium tuberculosis and Mycobacterium abscessus

    PubMed Central

    Kaushik, Amit; Makkar, Nayani; Pandey, Pooja; Parrish, Nicole; Singh, Urvashi

    2015-01-01

    An effective regimen for treatment of tuberculosis (TB) is comprised of multiple drugs that inhibit a range of essential cellular activities in Mycobacterium tuberculosis. The effectiveness of a regimen is further enhanced if constituent drugs act with synergy. Here, we report that faropenem (a penem) or biapenem, doripenem, or meropenem (carbapenems), which belong to the β-lactam class of antibiotics, and rifampin, one of the drugs that forms the backbone of TB treatment, act with synergy when combined. One of the reasons (carba)penems are seldom used for treatment of TB is the high dosage levels required, often at the therapeutic limits. The synergistic combination of rifampin and these (carba)penems indicates that (carba)penems can be administered at dosages that are therapeutically relevant. The combination of faropenem and rifampin also limits the frequency of resistant mutants, as we were unable to obtain spontaneous mutants in the presence of these two drugs. The combinations of rifampin and (carba)penems were effective not only against drug-sensitive Mycobacterium tuberculosis but also against drug-resistant clinical isolates that are otherwise resistant to rifampin. A combination of doripenem or biapenem and rifampin also exhibited synergistic activity against Mycobacterium abscessus. Although the MICs of these three drugs alone against M. abscessus are too high to be of clinical relevance, their concentrations in combinations are therapeutically relevant; therefore, they warrant further evaluation for clinical utility to treat Mycobacterium abscessus infection, especially in cystic fibrosis patients. PMID:26259792

  3. Carbapenems and Rifampin Exhibit Synergy against Mycobacterium tuberculosis and Mycobacterium abscessus.

    PubMed

    Kaushik, Amit; Makkar, Nayani; Pandey, Pooja; Parrish, Nicole; Singh, Urvashi; Lamichhane, Gyanu

    2015-10-01

    An effective regimen for treatment of tuberculosis (TB) is comprised of multiple drugs that inhibit a range of essential cellular activities in Mycobacterium tuberculosis. The effectiveness of a regimen is further enhanced if constituent drugs act with synergy. Here, we report that faropenem (a penem) or biapenem, doripenem, or meropenem (carbapenems), which belong to the β-lactam class of antibiotics, and rifampin, one of the drugs that forms the backbone of TB treatment, act with synergy when combined. One of the reasons (carba)penems are seldom used for treatment of TB is the high dosage levels required, often at the therapeutic limits. The synergistic combination of rifampin and these (carba)penems indicates that (carba)penems can be administered at dosages that are therapeutically relevant. The combination of faropenem and rifampin also limits the frequency of resistant mutants, as we were unable to obtain spontaneous mutants in the presence of these two drugs. The combinations of rifampin and (carba)penems were effective not only against drug-sensitive Mycobacterium tuberculosis but also against drug-resistant clinical isolates that are otherwise resistant to rifampin. A combination of doripenem or biapenem and rifampin also exhibited synergistic activity against Mycobacterium abscessus. Although the MICs of these three drugs alone against M. abscessus are too high to be of clinical relevance, their concentrations in combinations are therapeutically relevant; therefore, they warrant further evaluation for clinical utility to treat Mycobacterium abscessus infection, especially in cystic fibrosis patients. PMID:26259792

  4. Nonlinear Synergies and Multiscale Structural Dynamics in Complex Systems: Theoretical Advances and Applications to Hydroclimate Dynamics

    NASA Astrophysics Data System (ADS)

    Perdigão, R. A. P.

    2015-12-01

    The dynamical evolution of complex coevolving systems is assessed in a novel nonlinear statistical-dynamical framework formally linking nonlinear statistical measures of codependence and emergence with fundamental dynamical interaction laws. The methodological developments are then used to shed light onto fundamental interactions underlying complex behaviour in hydroclimate dynamics. For that purpose, a dynamical model is presented predicting evolving hydroclimatic quantities and their distributions under nonlinearly coevolving geophysical processes. The functional model is based on first principles regulating the dynamics of each system constituent and their synergies, therefore its applicability is general and data-independent, not requiring local calibrations. Moreover, it enables the dynamical estimation of hydroclimatic variations in space and time from the given knowledge at different spatiotemporal conditions. This paves the way for a robust physically based prediction of hydroclimatic changes in unmonitored areas. Validation is achieved by producing, with the dynamical model, a comprehensive spatiotemporal legacy consistent with the observed distributions along with their dynamical and statistical properties and relations. The similarity between simulated and observed distributions is further assessed with robust information-theoretic diagnostics. This study ultimately brings to light emerging signatures of structural change in hydroclimate dynamics arising from nonlinear synergies across spatiotemporal scales, and contributes to a better dynamical understanding and prediction of spatiotemporal regimes, transitions and extremes. The study further sheds light onto a diversity of emerging properties from harmonic to hyper-chaotic dynamics in hydroclimatic systems.

  5. Confirmation of Maslow's Hypothesis of Synergy: Developing an Acceptance of Selfishness at the Workplace Scale.

    PubMed

    Takaki, Jiro; Taniguchi, Toshiyo; Fujii, Yasuhito

    2016-01-01

    This study aimed to develop a new Acceptance of Selfishness at the Workplace Scale (ASWS) and to confirm Maslow's hypothesis of synergy: if both a sense of contribution and acceptance of selfishness at the workplace are high, workers are psychologically healthy. In a cross-sectional study with employees of three Japanese companies, 656 workers answered a self-administered questionnaire on paper completely (response rate = 66.8%). Each questionnaire was submitted to us in a sealed envelope and analyzed. The ASWS indicated high internal consistency (Cronbach's alpha = 0.86). Significant (p < 0.001) positive moderate correlations between ASWS scores and job control scores support the ASWS's convergent and discriminant validity. Significant (p < 0.001) associations of ASWS scores with psychological distress and work engagement supported the ASWS's criterion validity. In short, ASWS was a psychometrically satisfactory measure. Significant (p < 0.05) interactions between a sense of contribution and acceptance of selfishness at the workplace in linear regression models showed that when those two factors are low, psychological distress becomes high. However, when a sense of contribution and acceptance of selfishness are high, work engagement also becomes high. Thus, Maslow's hypothesis of synergy was confirmed. PMID:27144575

  6. Techno-ecological synergy as a path toward sustainability of a North American residential system.

    PubMed

    Urban, Robert A; Bakshi, Bhavik R

    2013-02-19

    For any human-designed system to be sustainable, ecosystem services that support it must be readily available. This work explicitly accounts for this dependence by designing synergies between technological and ecological systems. The resulting techno-ecological network mimics nature at the systems level, can stay within ecological constraints, and can identify novel designs that are economically and environmentally attractive that may not be found by the traditional design focus on technological options. This approach is showcased by designing synergies for a typical American suburban home at local and life cycle scales. The objectives considered are carbon emissions, water withdrawal, and cost savings. Systems included in the design optimization include typical ecosystems in suburban yards: lawn, trees, water reservoirs, and a vegetable garden; technological systems: heating, air conditioning, faucets, solar panels, etc.; and behavioral variables: heating and cooling set points. The ecological and behavioral design variables are found to have a significant effect on the three objectives, in some cases rivaling and exceeding the effect of traditional technological options. These results indicate the importance and benefits of explicitly including ecosystems in the design of sustainable systems, something that is rarely done in existing methods. PMID:23294016

  7. Plasmas meet nanoparticles—where synergies can advance the frontier of medicine

    NASA Astrophysics Data System (ADS)

    Kong, M. G.; Keidar, M.; Ostrikov, K.

    2011-05-01

    Nanoparticles and low-temperature plasmas have been developed, independently and often along different routes, to tackle the same set of challenges in biomedicine. There are intriguing similarities and contrasts in their interactions with cells and living tissues, and these are reflected directly in the characteristics and scope of their intended therapeutic solutions, in particular their chemical reactivity, selectivity against pathogens and cancer cells, safety to healthy cells and tissues and targeted delivery to diseased tissues. Time has come to ask the inevitable question of possible plasma-nanoparticle synergy and the related benefits to the development of effective, selective and safe therapies for modern medicine. This perspective paper offers a detailed review of the strengths and weakenesses of nanomedicine and plasma medicine as a stand-alone technology, and then provides a critical analysis of some of the major opportunities enabled by synergizing nanotechnology and plasma technology. It is shown that the plasma-nanoparticle synergy is best captured through plasma nanotechnology and its benefits for medicine are highly promising.

  8. The neuroendocrine response to stress under the effect of drugs: Negative synergy between amphetamine and stressors.

    PubMed

    Gómez-Román, Almudena; Ortega-Sánchez, Juan A; Rotllant, David; Gagliano, Humberto; Belda, Xavier; Delgado-Morales, Raúl; Marín-Blasco, Ignacio; Nadal, Roser; Armario, Antonio

    2016-01-01

    There have been numerous studies into the interaction between stress and addictive drugs, yet few have specifically addressed how the organism responds to stress when under the influence of psychostimulants. Thus, we studied the effects of different acute stressors (immobilization, interleukin-1β and forced swimming) in young adult male rats simultaneously exposed to amphetamine (AMPH, 4 mg/kg SC), evaluating classic biological markers. AMPH administration itself augmented the plasma hypothalamic-pituitary-adrenal (HPA) hormones, adrenocorticotropin (ACTH) and corticosterone, without affecting plasma glucose levels. By contrast, this drug dampened the peripheral HPA axis, as well as the response of glucose to the three stressors. We also found that AMPH administration completely blocked the forced swim-induced expression of the corticotropin-releasing hormone (hnCRH) and it partially reduced c-fos expression in the paraventricular nucleus of the hypothalamus (PVN). Indeed, this negative synergy in the forced swim test could even be observed with a lower dose of AMPH (1mg/kg, SC), a dose that is usually received in self-administration experiments. In conclusion, when rats that receive AMPH are subjected to stress, a negative synergy occurs that dampens the prototypic peripheral physiological response to stress and activation of the PVN. PMID:26433325

  9. Prehension synergies during fatigue of a single digit: adaptations in control with referent configurations.

    PubMed

    Singh, Tarkeshwar; Zatsiorsky, Vladimir M; Latash, Mark L

    2014-07-01

    The effects of muscle fatigue on the stability of precision grasps are not well known. The purpose of the current study was to investigate the effects of exercise-induced fatigue of a digit on prehension synergies in a static precision grasp. One group of participants performed the fatiguing exercise using the thumb (group-thumb) and the second group performed the exercise using the index finger (group-index). Grasp force and load-resisting force-stabilizing synergies were weaker during fatigue for group-thumb and showed no significant change for group-index. These results indicate that fatiguing the thumb compromises the stability of the precision grasp more than when the index finger is fatigued. Our results support the idea of hierarchical organization of prehension control. We proffer an explanation of our results based on two control constructs: a) Principle of superposition. This principle states that prehension can be viewed as a superposition of two independent processes controlling the slip and the tilt of the object respectively; and b) The referent configuration hypothesis. According to this hypothesis, the neural control of actions is associated with defining a set of referent values for task-related coordinates (given an external force field) defined as the referent configuration. PMID:24457335

  10. Synergy between bio-based industry and the feed industry through biorefinery.

    PubMed

    Teekens, Amanda M; Bruins, Marieke E; van Kasteren, Johannes Mn; Hendriks, Wouter H; Sanders, Johan Pm

    2016-06-01

    Processing biomass into multi-functional components can contribute to the increasing demand for raw materials for feed and bio-based non-food products. This contribution aims to demonstrate synergy between the bio-based industry and the feed industry through biorefinery of currently used feed ingredients. Illustrating the biorefinery concept, rapeseed was selected as a low priced feed ingredient based on market prices versus crude protein, crude fat and apparent ileal digestible lysine content. In addition it is already used as an alternative protein source in diets and can be cultivated in European climate zones. Furthermore, inclusion level of rapeseed meal in pig diet is limited because of its nutritionally active factors. A conceptual process was developed to improve rapeseeds nutritional value and producing other bio-based building blocks simultaneously. Based on the correlation between market prices of feed ingredients and its protein and fat content, the value of refined products was estimated. Finally, a sensitivity analysis, under two profit scenario, shows that the process is economically feasible. This study demonstrates that using biorefinery processes on feed ingredients can improve feed quality. In conjunction, it produces building blocks for a bio-based industry and creates synergy between bio-based and feed industry for more efficient use of biomass. © 2015 Society of Chemical Industry.

  11. Electron Bernstein wave-bootstrap current synergy in the National Spherical Torus Experiment

    SciTech Connect

    Harvey, R.W.; Taylor, G.

    2005-05-15

    Current driven by electron Bernstein waves (EBW) and by the electron bootstrap effect are calculated separately and concurrently with a kinetic code to determine the degree of synergy between them. A target {beta}=40% NSTX [M. Ono, S. Kaye, M. Peng et al., Proceedings of the 17th IAEA Fusion Energy Conference, edited by M. Spak (IAEA, Vienna, Austria, 1999), Vol. 3, p. 1135] plasma is examined. A simple bootstrap model in the collisional-quasilinear CQL3D Fokker-Planck code (National Technical Information Service document No. DE93002962) is used in these studies: the transiting electron distributions are connected in velocity space at the trapped-passing boundary to trapped-electron distributions that are displaced radially by a half-banana-width outwards/inwards for the co-passing/counter-passing regions. This model agrees well with standard bootstrap current calculations over the outer 60% of the plasma radius. Relatively small synergy net bootstrap current is obtained for EBW power up to 4 MW. Locally, bootstrap current density increases in proportion to increased plasma pressure, and this effect can significantly affect the radial profile of driven current.

  12. The role of muscle synergies in myoelectric control: trends and challenges for simultaneous multifunction control

    NASA Astrophysics Data System (ADS)

    Ison, Mark; Artemiadis, Panagiotis

    2014-10-01

    Myoelectric control is filled with potential to significantly change human-robot interaction due to the ability to non-invasively measure human motion intent. However, current control schemes have struggled to achieve the robust performance that is necessary for use in commercial applications. As demands in myoelectric control trend toward simultaneous multifunctional control, multi-muscle coordinations, or synergies, play larger roles in the success of the control scheme. Detecting and refining patterns in muscle activations robust to the high variance and transient changes associated with surface electromyography is essential for efficient, user-friendly control. This article reviews the role of muscle synergies in myoelectric control schemes by dissecting each component of the scheme with respect to associated challenges for achieving robust simultaneous control of myoelectric interfaces. Electromyography recording details, signal feature extraction, pattern recognition and motor learning based control schemes are considered, and future directions are proposed as steps toward fulfilling the potential of myoelectric control in clinically and commercially viable applications.

  13. Method of Drawing Up a Road Map that Considers the Synergy Effect for IT Investment

    NASA Astrophysics Data System (ADS)

    Nakagawa, Tadasuke; Tani, Shigeyuki; Akatsu, Masaharu; Komoda, Norihisa

    IT governance lacks a comprehensive vision of the investment in two or more projects. It is necessary to decide the priority level that maximizes the effect under the constraint conditions. The problem is complex because while sometimes a greater effect can be obtained by introducing two or more measures at the same time, other times the effect of two measures introduced at the same time might not be significant. Although there is thus a synergy effect when two or more measures are introduced, no method for drawing up an investment-decision road map considered that effect. We therefore developed one. What a decision-maker thinks about when considering the introduction of two or more measures can be visualized by drawing up a comprehensive road map that satisfies constraint conditions such as effectiveness of measure, budget, time, staff size, order of introduction, the synergy effect. Road map users can easily reach a consensus because the map, by taking into account the constraint conditions and the investment decision-making process, helps them logically explain the order in which the measures should be introduced.

  14. The metaphor-gestalt synergy underlying the self-organisation of perception as a semiotic process.

    PubMed

    Rail, David

    2013-04-01

    Recently the basis of concept and language formation has been redefined by the proposal that they both stem from perception and embodiment. The experiential revolution has lead to a far more integrated and dynamic understanding of perception as a semiotic system. The emergence of meaning in the perceptual process stems from the interaction between two key mechanisms. These are first, the generation of schemata through recurrent sensorimotor activity (SM) that underlies category and language formation (L). The second is the interaction between metaphor (M) and gestalt mechanisms (G) that generate invariant mappings beyond the SM domain that both conserve and diversify our understanding and meaning potential. We propose an important advance in our understanding of perception as a semiotic system through exploring the affect of self-organising to criticality where hierarchical behaviour becomes widely integrated through 1/f process and isomorphisms. Our proposal leads to several important implications. First, that SM and L form a functional isomorphism depicted as SM <=> L. We contend that SM <=> L is emergent, corresponding to the phenomenal self. Second, meaning structures the isomorphism SM <=>L through the synergy between M and G (M-G). M-G synergy is based on a combination of structuring and imagination. We contend that the interaction between M-G and SM <=> L functions as a macro-micro comutation that governs perception as semiosis. We discuss how our model relates to current research in fractal time and verb formation. PMID:23517606

  15. The synergy professional practice model and its patient characteristics tool: a staff empowerment strategy.

    PubMed

    MacPhee, Maura; Wardrop, Andrea; Campbell, Cheryl; Wejr, Patricia

    2011-10-01

    Nurse leaders can positively influence practice environments through a number of empowerment strategies, among them professional practice models. These models encompass the philosophy, structures and processes that support nurses' control over their practice and their voice within healthcare organizations. Nurse-driven professional practice models can serve as a framework for collaborative decision-making among nursing and other staff. This paper describes a provincewide pilot project in which eight nurse-led project teams in four healthcare sectors worked with the synergy professional practice model and its patient characteristics tool. The teams learned how the model and tool can be used to classify patients' acuity levels and make staffing assignments based on a "best fit" between patient needs and staff competencies. The patient characteristics tool scores patients' acuities on eight characteristics such as stability, vulnerability and resource availability. This tool can be used to make real-time patient assessments. Other potential applications for the model and tool are presented, such as care planning, team-building and determining appropriate staffing levels. Our pilot project evidence suggests that the synergy model and its patient characteristics tool may be an empowerment strategy that nursing leaders can use to enhance their practice environments.

  16. Hybridization and hybrid speciation under global change.

    PubMed

    Vallejo-Marín, Mario; Hiscock, Simon J

    2016-09-01

    Contents 1170 I. 1170 II. 1172 III. 1175 IV. 1180 V. 1183 1184 References 1184 SUMMARY: An unintended consequence of global change is an increase in opportunities for hybridization among previously isolated lineages. Here we illustrate how global change can facilitate the breakdown of reproductive barriers and the formation of hybrids, drawing on the flora of the British Isles for insight. Although global change may ameliorate some of the barriers preventing hybrid establishment, for example by providing new ecological niches for hybrids, it will have limited effects on environment-independent post-zygotic barriers. For example, genic incompatibilities and differences in chromosome numbers and structure within hybrid genomes are unlikely to be affected by global change. We thus speculate that global change will have a larger effect on eroding pre-zygotic barriers (eco-geographical isolation and phenology) than post-zygotic barriers, shifting the relative importance of these two classes of reproductive barriers from what is usually seen in naturally produced hybrids where pre-zygotic barriers are the largest contributors to reproductive isolation. Although the long-term fate of neo-hybrids is still to be determined, the massive impact of global change on the dynamics and distribution of biodiversity generates an unprecedented opportunity to study large numbers of unpredicted, and often replicated, hybridization 'experiments', allowing us to peer into the birth and death of evolutionary lineages. PMID:27214560

  17. From hybrid swarms to swarms of hybrids

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The introgression of modern humans (Homo sapiens) with Neanderthals 40,000 YBP after a half-million years of separation, may have led to the best example of a hybrid swarm on earth. Modern trade and transportation in support of the human hybrids has continued to introduce additional species, genotyp...

  18. Muscle Synergies in Cycling after Incomplete Spinal Cord Injury: Correlation with Clinical Measures of Motor Function and Spasticity

    PubMed Central

    Barroso, Filipe O.; Torricelli, Diego; Bravo-Esteban, Elisabeth; Taylor, Julian; Gómez-Soriano, Julio; Santos, Cristina; Moreno, Juan C.; Pons, José L.

    2016-01-01

    Background: After incomplete spinal cord injury (iSCI), patients suffer important sensorimotor impairments, such as abnormal locomotion patterns and spasticity. Complementary to current clinical diagnostic procedures, the analysis of muscle synergies has emerged as a promising tool to study muscle coordination, which plays a major role in the control of multi-limb functional movements. Objective: Based on recent findings suggesting that walking and cycling share similar synergistic control, the analysis of muscle synergies during cycling might be explored as an early descriptor of gait-related impaired control. This idea was split into the following two hypotheses: (a) iSCI patients present a synergistic control of muscles during cycling; (b) muscle synergies outcomes extracted during cycling correlate with clinical measurements of gait performance and/or spasticity. Methods: Electromyographic (EMG) activity of 13 unilateral lower limb muscles was recorded in a group of 10 healthy individuals and 10 iSCI subjects during cycling at four different cadences. A non-negative matrix factorization (NNMF) algorithm was applied to identify synergistic components (i.e., activation coefficients and muscle synergy vectors). Reconstruction goodness scores (VAF and r2) were used to evaluate the ability of a given number of synergies to reconstruct the EMG signals. A set of metrics based on the similarity between pathologic and healthy synergies were correlated with clinical scales of gait performance and spasticity. Results: iSCI patients preserved a synergistic control of muscles during cycling. The similarity with the healthy reference was consistent with the degree of the impairment, i.e., less impaired patients showed higher similarities with the healthy reference. There was a strong correlation between reconstruction goodness scores at 42 rpm and motor performance scales (TUG, 10-m test and WISCI II). On the other hand, the similarity between the healthy and affected

  19. Mesoscale hybrid calibration artifact

    DOEpatents

    Tran, Hy D.; Claudet, Andre A.; Oliver, Andrew D.

    2010-09-07

    A mesoscale calibration artifact, also called a hybrid artifact, suitable for hybrid dimensional measurement and the method for make the artifact. The hybrid artifact has structural characteristics that make it suitable for dimensional measurement in both vision-based systems and touch-probe-based systems. The hybrid artifact employs the intersection of bulk-micromachined planes to fabricate edges that are sharp to the nanometer level and intersecting planes with crystal-lattice-defined angles.

  20. Deconstructing the Methods and Synergies in Problem-Based Learning, Community-Based Project-Organized Education: Perspectives at the University of Venda, South Africa

    ERIC Educational Resources Information Center

    Netshandama, V. O.; Farrell, Sarah P.

    2006-01-01

    This case study discusses the deconstructions and synergies of problem-based learning (PBL) and community-based project-organized education. The growing literature on these methods lacks in coverage of their synergies and their applicability to meaningful projects with communities as partners. Community-based learning is inherently problem based…

  1. Hybrid quantum information processing

    SciTech Connect

    Furusawa, Akira

    2014-12-04

    I will briefly explain the definition and advantage of hybrid quantum information processing, which is hybridization of qubit and continuous-variable technologies. The final goal would be realization of universal gate sets both for qubit and continuous-variable quantum information processing with the hybrid technologies. For that purpose, qubit teleportation with a continuousvariable teleporter is one of the most important ingredients.

  2. Hybrid armature projectile

    DOEpatents

    Hawke, R.S.; Asay, J.R.; Hall, C.A.; Konrad, C.H.; Sauve, G.L.; Shahinpoor, M.; Susoeff, A.R.

    1993-03-02

    A projectile for a railgun that uses a hybrid armature and provides a seed block around part of the outer surface of the projectile to seed the hybrid plasma brush. In addition, the hybrid armature is continuously vaporized to replenish plasma in a plasma armature to provide a tandem armature and provides a unique ridge and groove to reduce plasma blowby.

  3. Hybrid armature projectile

    DOEpatents

    Hawke, Ronald S.; Asay, James R.; Hall, Clint A.; Konrad, Carl H.; Sauve, Gerald L.; Shahinpoor, Mohsen; Susoeff, Allan R.

    1993-01-01

    A projectile for a railgun that uses a hybrid armature and provides a seed block around part of the outer surface of the projectile to seed the hybrid plasma brush. In addition, the hybrid armature is continuously vaporized to replenish plasma in a plasma armature to provide a tandem armature and provides a unique ridge and groove to reduce plasama blowby.

  4. Hybrid quantum information processing

    NASA Astrophysics Data System (ADS)

    Furusawa, Akira

    2014-12-01

    I will briefly explain the definition and advantage of hybrid quantum information processing, which is hybridization of qubit and continuous-variable technologies. The final goal would be realization of universal gate sets both for qubit and continuous-variable quantum information processing with the hybrid technologies. For that purpose, qubit teleportation with a continuousvariable teleporter is one of the most important ingredients.

  5. Homoploid hybrid expectations

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Homoploid hybrid speciation occurs when a stable, fertile, and reproductively isolated lineage results from hybridization between two distinct species without a change in ploidy level. Reproductive isolation between a homoploid hybrid species and its parents is generally attained via chromosomal re...

  6. The role of synergies within generative models of action execution and recognition: A computational perspective. Comment on "Grasping synergies: A motor-control approach to the mirror neuron mechanism" by A. D'Ausilio et al.

    NASA Astrophysics Data System (ADS)

    Pezzulo, Giovanni; Donnarumma, Francesco; Iodice, Pierpaolo; Prevete, Roberto; Dindo, Haris

    2015-03-01

    Controlling the body - given its huge number of degrees of freedom - poses severe computational challenges. Mounting evidence suggests that the brain alleviates this problem by exploiting "synergies", or patterns of muscle activities (and/or movement dynamics and kinematics) that can be combined to control action, rather than controlling individual muscles of joints [1-10].

  7. The hydrogen hybrid option

    SciTech Connect

    Smith, J.R.

    1993-10-15

    The energy efficiency of various piston engine options for series hybrid automobiles are compared with conventional, battery powered electric, and proton exchange membrane (PEM) fuel cell hybrid automobiles. Gasoline, compressed natural gas (CNG), and hydrogen are considered for these hybrids. The engine and fuel comparisons are done on a basis of equal vehicle weight, drag, and rolling resistance. The relative emissions of these various fueled vehicle options are also presented. It is concluded that a highly optimized, hydrogen fueled, piston engine, series electric hybrid automobile will have efficiency comparable to a similar fuel cell hybrid automobile and will have fewer total emissions than the battery powered vehicle, even without a catalyst.

  8. Flexible Muscle Modes and Synergies in Challenging Whole-Body Tasks

    PubMed Central

    Danna-dos-Santos, Alessander; Degani, Adriana M.; Latash, Mark L.

    2008-01-01

    We used the idea of hierarchical control to study multi-muscle synergies during a whole-body sway task performed by a standing person. Within this view, at the lower level of the hierarchy, muscles are united into groups (M-modes). At the higher level, gains at the M-modes are co-varied by the controller in a task specific way to ensure low variability of important physical variables. In particular, we hypothesized that (1) the composition of M-modes could adjust and (2) an index of M-mode co-variation would become weaker in more challenging conditions. Subjects were required to perform a whole-body sway at 0.5 Hz paced by a metronome. They performed the task with eyes open and closed, while standing on both feet or on one foot only, with and without vibration applied to the Achilles tendons. Integrated indices of muscle activation were subjected to principal component analysis to identify M-modes. An increase in the task complexity led to an increase in the number of principal components that contained significantly loaded indices of muscle activation from 3 to 5. Hence, in more challenging tasks, the controller manipulated a larger number of variables. Multiple regression analysis was used to define the Jacobian of the system mapping small changes in M-mode gains onto shifts of the center of pressure (COP) in the anterior-posterior direction. Further, the variance in the M-mode space across sway cycles was partitioned into two components, one that did not affect an average across cycles COP coordinate and the other that did (good and bad variance, respectively). Under all conditions, the subjects showed substantially more good variance than bad variance interpreted as a multi-M-mode synergy stabilizing the COP trajectory. An index of the strength of the synergy was comparable across all conditions, and there was no modulation of this index over the sway cycle. Hence, our first hypothesis that the composition of M-modes could adjust under challenging conditions

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

    NASA Astrophysics Data System (ADS)

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

    2015-11-01

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

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

    NASA Astrophysics Data System (ADS)

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

    2016-05-01

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

  11. Hybridization and extinction.

    PubMed

    Todesco, Marco; Pascual, Mariana A; Owens, Gregory L; Ostevik, Katherine L; Moyers, Brook T; Hübner, Sariel; Heredia, Sylvia M; Hahn, Min A; Caseys, Celine; Bock, Dan G; Rieseberg, Loren H

    2016-08-01

    Hybridization may drive rare taxa to extinction through genetic swamping, where the rare form is replaced by hybrids, or by demographic swamping, where population growth rates are reduced due to the wasteful production of maladaptive hybrids. Conversely, hybridization may rescue the viability of small, inbred populations. Understanding the factors that contribute to destructive versus constructive outcomes of hybridization is key to managing conservation concerns. Here, we survey the literature for studies of hybridization and extinction to identify the ecological, evolutionary, and genetic factors that critically affect extinction risk through hybridization. We find that while extinction risk is highly situation dependent, genetic swamping is much more frequent than demographic swamping. In addition, human involvement is associated with increased risk and high reproductive isolation with reduced risk. Although climate change is predicted to increase the risk of hybridization-induced extinction, we find little empirical support for this prediction. Similarly, theoretical and experimental studies imply that genetic rescue through hybridization may be equally or more probable than demographic swamping, but our literature survey failed to support this claim. We conclude that halting the introduction of hybridization-prone exotics and restoring mature and diverse habitats that are resistant to hybrid establishment should be management priorities. PMID:27468307

  12. Synergy dynamics of vortices and solitons in an atomic Bose-Einstein condensate excited by an oscillating potential

    SciTech Connect

    Fujimoto, Kazuya; Tsubota, Makoto

    2010-10-15

    The hydrodynamics of quantized vortices and solitons in an atomic Bose-Einstein condensate excited by an oscillating potential are studied by numerically solving the two-dimensional Gross-Pitaevskii equation. The oscillating potential keeps nucleating vortex dipoles, whose impulses alternately change their direction synchronously with the oscillation of the potential. This leads to synergy dynamics of vortices and solitons in quantum fluids.

  13. How to Achieve Synergy between Medical Education and Cognitive Neuroscience? An Exercise on Prior Knowledge in Understanding

    ERIC Educational Resources Information Center

    Ruiter, Dirk J.; van Kesteren, Marlieke T. R.; Fernandez, Guillen

    2012-01-01

    A major challenge in contemporary research is how to connect medical education and cognitive neuroscience and achieve synergy between these domains. Based on this starting point we discuss how this may result in a common language about learning, more educationally focused scientific inquiry, and multidisciplinary research projects. As the topic of…

  14. Research Synergy: The Graduate School of Public Health, the SDSU Research Foundation, and San Diego State University

    ERIC Educational Resources Information Center

    Williams, Stephen J.

    2014-01-01

    The evolution of a research university can take many paths. Described here is a case study of the synergy between the establishment and growth of a primarily graduate school and the commitment to developing a research university, all with the assistance of a separately incorporated non-profit research administration entity. The result has been a…

  15. A Personalized Multi-Channel FES Controller Based on Muscle Synergies to Support Gait Rehabilitation after Stroke

    PubMed Central

    Ferrante, Simona; Chia Bejarano, Noelia; Ambrosini, Emilia; Nardone, Antonio; Turcato, Anna M.; Monticone, Marco; Ferrigno, Giancarlo; Pedrocchi, Alessandra

    2016-01-01

    It has been largely suggested in neuroscience literature that to generate a vast variety of movements, the Central Nervous System (CNS) recruits a reduced set of coordinated patterns of muscle activities, defined as muscle synergies. Recent neurophysiological studies have recommended the analysis of muscle synergies to finely assess the patient's impairment, to design personalized interventions based on the specific nature of the impairment, and to evaluate the treatment outcomes. In this scope, the aim of this study was to design a personalized multi-channel functional electrical stimulation (FES) controller for gait training, integrating three novel aspects: (1) the FES strategy was based on healthy muscle synergies in order to mimic the neural solutions adopted by the CNS to generate locomotion; (2) the FES strategy was personalized according to an initial locomotion assessment of the patient and was designed to specifically activate the impaired biomechanical functions; (3) the FES strategy was mapped accurately on the altered gait kinematics providing a maximal synchronization between patient's volitional gait and stimulation patterns. The novel intervention was tested on two chronic stroke patients. They underwent a 4-week intervention consisting of 30-min sessions of FES-supported treadmill walking three times per week. The two patients were characterized by a mild gait disability (walking speed > 0.8 m/s) at baseline. However, before treatment both patients presented only three independent muscle synergies during locomotion, resembling two different gait abnormalities. After treatment, the number of extracted synergies became four and they increased their resemblance with the physiological muscle synergies, which indicated a general improvement in muscle coordination. The originally merged synergies seemed to regain their distinct role in locomotion control. The treatment benefits were more evident for one patient, who achieved a clinically important change

  16. A Personalized Multi-Channel FES Controller Based on Muscle Synergies to Support Gait Rehabilitation after Stroke

    PubMed Central

    Ferrante, Simona; Chia Bejarano, Noelia; Ambrosini, Emilia; Nardone, Antonio; Turcato, Anna M.; Monticone, Marco; Ferrigno, Giancarlo; Pedrocchi, Alessandra

    2016-01-01

    It has been largely suggested in neuroscience literature that to generate a vast variety of movements, the Central Nervous System (CNS) recruits a reduced set of coordinated patterns of muscle activities, defined as muscle synergies. Recent neurophysiological studies have recommended the analysis of muscle synergies to finely assess the patient's impairment, to design personalized interventions based on the specific nature of the impairment, and to evaluate the treatment outcomes. In this scope, the aim of this study was to design a personalized multi-channel functional electrical stimulation (FES) controller for gait training, integrating three novel aspects: (1) the FES strategy was based on healthy muscle synergies in order to mimic the neural solutions adopted by the CNS to generate locomotion; (2) the FES strategy was personalized according to an initial locomotion assessment of the patient and was designed to specifically activate the impaired biomechanical functions; (3) the FES strategy was mapped accurately on the altered gait kinematics providing a maximal synchronization between patient's volitional gait and stimulation patterns. The novel intervention was tested on two chronic stroke patients. They underwent a 4-week intervention consisting of 30-min sessions of FES-supported treadmill walking three times per week. The two patients were characterized by a mild gait disability (walking speed > 0.8 m/s) at baseline. However, before treatment both patients presented only three independent muscle synergies during locomotion, resembling two different gait abnormalities. After treatment, the number of extracted synergies became four and they increased their resemblance with the physiological muscle synergies, which indicated a general improvement in muscle coordination. The originally merged synergies seemed to regain their distinct role in locomotion control. The treatment benefits were more evident for one patient, who achieved a clinically important change

  17. 3D Online Visualization and Synergy of NASA A-Train Data Using Google Earth

    NASA Technical Reports Server (NTRS)

    Chen, Aijun; Kempler, Steven; Leptoukh, Gregory; Smith, Peter

    2010-01-01

    This poster presentation reviews the use of Google Earth to assist in three dimensional online visualization of NASA Earth science and geospatial data. The NASA A-Train satellite constellation is a succession of seven sun-synchronous orbit satellites: (1) OCO-2 (Orbiting Carbon Observatory) (will launch in Feb. 2013), (2) GCOM-W1 (Global Change Observation Mission), (3) Aqua, (4) CloudSat, (5) CALIPSO (Cloud-Aerosol Lidar & Infrared Pathfinder Satellite Observations), (6) Glory, (7) Aura. The A-Train makes possible synergy of information from multiple resources, so more information about earth condition is obtained from the combined observations than would be possible from the sum of the observations taken independently

  18. Scientific community and civil protection synergy during the Stromboli 2002-2003 Eruption

    NASA Astrophysics Data System (ADS)

    Bertolaso, G.; Bonaccorso, A.; Boschi, E.

    The eruption of Stromboli 2002-2003, thanks to its complex scenario (flank instability, tsunami, necessity to rapidly upgrade monitoring networks), has provided an important opportunity to verify the response of the national system of civil protection to volcanic emergencies. In particular, it has tested and validated the model of collaboration, in use by Italian law, between the Department of Civil Protection and the National Institute of Geophysics and Volcanology. This synergy has enabled a better understanding and ability to tackle the eruptive crisis from its first stages, as well as implement monitoring systems both dependably and swiftly. In this work, the numerous first monitoring tasks carried out during the critical initial stages of the eruption are described, and the activities and planned action are reported over the course of the eruption that has made Stromboli one of the best monitored volcanoes not only in Italy but throughout the world.

  19. The sweet taste of true synergy: positive allosteric modulation of the human sweet taste receptor.

    PubMed

    Servant, Guy; Tachdjian, Catherine; Li, Xiaodong; Karanewsky, Donald S

    2011-11-01

    A diet low in carbohydrates helps to reduce the amount of ingested calories and to maintain a healthy weight. With this in mind, food and beverage companies have reformulated a large number of their products, replacing sugar or high fructose corn syrup with several different types of zero-calorie sweeteners to decrease or even totally eliminate their caloric content. A challenge remains, however, with the level of acceptance of some of these products in the market-place. Many consumers believe that zero-calorie sweeteners simply do not taste like sugar. A recent breakthrough reveals that positive allosteric modulators of the human sweet taste receptor, small molecules that enhance the receptor activity and sweetness perception, could be more effective than other reported taste enhancers at reducing calories in consumer products without compromising on the true taste of sugar. A unique mechanism of action at the receptor level could explain the robust synergy achieved with these new modulators.

  20. Benefits from synergies and advanced technologies for an advanced-technology space station

    NASA Technical Reports Server (NTRS)

    Garrett, L. Bernard; Ferebee, Melvin J., Jr.; Queijo, Manuel J.; Butterfield, Ansel J.

    1991-01-01

    A configuration for a second-generation advanced technology space station has been defined in a series of NASA-sponsored studies. Definitions of subsystems specifically addressed opportunities for beneficial synergistic interactions and those potential synergies and their benefits are identified. One of the more significant synergistic benefits involves the multi-function utilization of water within a large system that generates artificial gravity by rotation. In such a system, water not only provides the necessary crew life support, but also serves as counterrotator mass, as moveable ballast, and as a source for propellant gases. Additionally, the synergistic effects between advanced technology materials, operation at reduced artificial gravity, and lower cabin atmospheric pressure levels show beneficial interactions that can be quantified in terms of reduced mass to orbit.

  1. Unexpected redwood mortality from synergies between wildfire and an emerging infectious disease.

    PubMed

    Metz, Margaret R; Varner, J Morgan; Frangioso, Kerri M; Meentemeyer, Ross K; Rizzo, David M

    2013-10-01

    An under-examined component of global change is the alteration of disturbance regimes due to warming climates, continued species invasions, and accelerated land-use change. These drivers of global change are themselves novel ecosystem disturbances that may interact with historically occurring disturbances in complex ways. Here we use the natural experiment presented by wildfires in redwood forests impacted by an emerging infectious disease to demonstrate unexpected synergies of novel disturbance interactions. The dominant tree, coast redwood (fire resistant without negative disease impacts), experienced unexpected synergistic increases in mortality when fire and disease co-occurred. The increased mortality risk, more than fourfold at the peak of the effect, was not predictable from impacts of either disturbance alone. Changes in fire behavior associated with changes to forest fuels that occurred through disease progression overwhelmed redwood's usual resilience to wildfire. Our results demonstrate the potential for interacting disturbances to initiate novel successional trajectories and compromise ecosystem resilience.

  2. A Tool for Balance Control Training Using Muscle Synergies and Multimodal Interfaces

    PubMed Central

    Galeano, D.; Brunetti, F.; Torricelli, D.; Piazza, S.; Pons, J. L.

    2014-01-01

    Balance control plays a key role in neuromotor rehabilitation after stroke or spinal cord injuries. Computerized dynamic posturography (CDP) is a classic technological tool to assess the status of balance control and to identify potential disorders. Despite the more accurate diagnosis generated by these tools, the current strategies to promote rehabilitation are still limited and do not take full advantage of the technologies available. This paper presents a novel balance training platform which combines a CDP device made from low-cost interfaces, such as the Nintendo Wii Balance Board and the Microsoft Kinect. In addition, it integrates a custom electrical stimulator that uses the concept of muscle synergies to promote natural interaction. The aim of the platform is to support the exploration of innovative multimodal therapies. Results include the technical validation of the platform using mediolateral and anteroposterior sways as basic balance training therapies. PMID:24982896

  3. Synergy of combining sonolysis and photocatalysis in the degradation and mineralization of chlorinated aromatic compounds.

    PubMed

    Peller, Julie; Wiest, Olaf; Kamat, Prashant V

    2003-05-01

    Merits of using advanced oxidation processes such as sonolysis and photocatalysis as well as a combination of the two have been explored using model herbicides such as 2,4-dichlorophenoxy acetic acid and 2,4-dichlorophenoxypropionic acid and the chlorinated phenols 2,4-dichlorophenol and 2,4,6-trichlorophenol. Whereas sonolysis is quite effective in the initial degradation of chlorinated aromatic molecules, complete mineralization is difficult to achieve. Photocatalysis is selective toward the degradation of polar compounds but causes the build up of undesirable chemical intermediates. In contrast to sonolytic degradation, photocatalysis is very effective toward achieving complete mineralization. By simultaneously carrying out high-frequency sonolysis and photocatalysis we have succeeded in achieving faster and complete mineralization with no build up of toxic intermediates even at very low catalyst loadings. The synergy of combining the two advanced oxidation processes is discussed.

  4. Effect of muscular fatigue on fractal upper limb coordination dynamics and muscle synergies.

    PubMed

    Bueno, Diana R; Lizano, J M; Montano, L

    2015-08-01

    Rehabilitation exercises cause fatigue because tasks are repetitive. Therefore, inevitable human motion performance changes occur during the therapy. Although traditionally fatigue is considered an event that occurs in the musculoskeletal level, this paper studies whether fatigue can be regarded as context that influences lower-dimensional motor control organization and coordination at neural level. Non Negative Factorization Matrix (NNFM) and Detrended Fluctuations Analysis (DFA) are the tools used to analyze the changes in the coordination of motor function when someone is affected by fatigue. The study establishes that synergies remain fairly stable with the onset of fatigue, but the fatigue affects the dynamical coordination understood as a cognitive process. These results have been validated with 9 healthy subjects for three representative exercises for upper limb: biceps, triceps and deltoid. PMID:26737679

  5. BIOLOGICAL ADHESIVES. Adaptive synergy between catechol and lysine promotes wet adhesion by surface salt displacement.

    PubMed

    Maier, Greg P; Rapp, Michael V; Waite, J Herbert; Israelachvili, Jacob N; Butler, Alison

    2015-08-01

    In physiological fluids and seawater, adhesion of synthetic polymers to solid surfaces is severely limited by high salt, pH, and hydration, yet these conditions have not deterred the evolution of effective adhesion by mussels. Mussel foot proteins provide insights about adhesive adaptations: Notably, the abundance and proximity of catecholic Dopa (3,4-dihydroxyphenylalanine) and lysine residues hint at a synergistic interplay in adhesion. Certain siderophores—bacterial iron chelators—consist of paired catechol and lysine functionalities, thereby providing a convenient experimental platform to explore molecular synergies in bioadhesion. These siderophores and synthetic analogs exhibit robust adhesion energies (E(ad) ≥-15 millijoules per square meter) to mica in saline pH 3.5 to 7.5 and resist oxidation. The adjacent catechol-lysine placement provides a "one-two punch," whereby lysine evicts hydrated cations from the mineral surface, allowing catechol binding to underlying oxides. PMID:26250681

  6. Synergy between baicalein and penicillins against penicillinase-producing Staphylococcus aureus.

    PubMed

    Qian, Minyi; Tang, Shusheng; Wu, Congming; Wang, Yang; He, Tao; Chen, Tingting; Xiao, Xilong

    2015-09-01

    The combination of baicalein (the active constituent of Scutellaria baicalensis) with penicillin G/amoxicillin showed potent synergy against 20 clinical penicillinase-producing Staphylococcus aureus strains including 10 isolates that were additionally methicillin-resistant (MRSA). The fractional inhibitory concentration (FIC) indices of penicillins+baiclein ranged from 0.14 to 0.38. Baicalein protected penicillins (penicillin G and amoxicillin) from penicillinase and increased the susceptibility of penicillinase-supplemented S. aureus ATCC 29213 in a dose-dependent manner. The inhibition of penicillinase activity by baicalein should be responsible for the synergism and protective effect. These findings offer us good evidence that the penicillins combined with baicalein showed potent synergistic activity against penicillinase-producing S. aureus and penicillinase-producing MRSA in vitro and might provide promising implications for clinical treatment of these bacterial infections.

  7. Culture shock and synergy. Academic/managed care/corporate alliances in outcomes management.

    PubMed

    Berman, W H; Darling, H; Hurt, S W; Hunkeler, E M

    1994-01-01

    The Behavioral Health Outcomes Study is a partnership in conducting outcomes measurement involving a corporate healthcare purchaser, five managed behavioral healthcare organizations and academic researchers. The goals of this study are to: evaluate the feasibility of incorporating patient self-reported data in outcomes research; identify factors that may be predictors of outcome; and evaluate the effectiveness of an employee-sponsored aftercare program. The differing perspectives and needs of the three partners have created a number of challenges in the areas of goals, confidentiality, proprietary vs. open access issues and methodology. However, after the study's first year, it is clear not only that outcomes research can be conducted under such a partnership, but that the partnership generates a kind of synergy in problem-solving.

  8. An essential role of acetylcholine-glutamate synergy at habenular synapses in nicotine dependence.

    PubMed

    Frahm, Silke; Antolin-Fontes, Beatriz; Görlich, Andreas; Zander, Johannes-Friedrich; Ahnert-Hilger, Gudrun; Ibañez-Tallon, Ines

    2015-12-01

    A great deal of interest has been focused recently on the habenula and its critical role in aversion, negative-reward and drug dependence. Using a conditional mouse model of the ACh-synthesizing enzyme choline acetyltransferase (Chat), we report that local elimination of acetylcholine (ACh) in medial habenula (MHb) neurons alters glutamate corelease and presynaptic facilitation. Electron microscopy and immuno-isolation analyses revealed colocalization of ACh and glutamate vesicular transporters in synaptic vesicles (SVs) in the central IPN. Glutamate reuptake in SVs prepared from the IPN was increased by ACh, indicating vesicular synergy. Mice lacking CHAT in habenular neurons were insensitive to nicotine-conditioned reward and withdrawal. These data demonstrate that ACh controls the quantal size and release frequency of glutamate at habenular synapses, and suggest that the synergistic functions of ACh and glutamate may be generally important for modulation of cholinergic circuit function and behavior.

  9. Agricultural and food chemistry: 50 years of synergy between AGFD and JAFC.

    PubMed

    Seiber, James N; Kleinschmidt, Loreen A

    2009-09-23

    The Division of Agricultural and Food Chemistry (AGFD) and the American Chemical Society had the foresight to launch the Journal of Agricultural and Food Chemistry in 1953. JAFC, still closely connected with the Division, has grown to be the premier international journal in the field, providing an outlet for publishing original research articles, reviews, perspectives, and editorials, for agricultural and food chemists from many nations. JAFC has expanded coverage of current areas of intense interest, such as bioactive constituents of foods, biotechnology, and biobased products and biofuels, as well as continuing strong coverage of such mainstream categories as food chemistry/biochemistry, analytical methods, safety and toxicology, and agrochemistry. In 2008 alone, JAFC published over 1650 peer-reviewed manuscripts, several symposia (largely from AGFD symposia at ACS National Meetings), and a number of reviews. The synergy between AGFD and JAFC offers many benefits and exciting opportunities for advancing the science of agricultural and food chemistry for the future. PMID:19719123

  10. Uncovering Tensions and Capitalizing on Synergies in HIV/AIDS and Antiviolence Programs

    PubMed Central

    Dunbar, Megan S.; Krishnan, Suneeta; Hatcher, Abigail M.; Sawires, Sharif

    2011-01-01

    Research frequently points to the need to empower women to effectively combat the twin epidemics of HIV/AIDS and gender-based violence. Simultaneously, there has been increased attention given to working with men in gender equality efforts. The latter approach intervenes on masculinities as part of the fight against HIV/AIDS and violence. No research has considered these 2 lines of work side by side to address several important questions: What are the points of overlap, and the tensions and contradictions between these 2 approaches? What are the limitations and unintended consequences of each? We analyzed these 2 parallel research trends and made suggestions for how to capitalize on the synergies that come from bolstering each position with the strengths of the other. PMID:21164091

  11. A Desirable Engineer Providing Manifold Prospects Enhanced by Synergy Effect of Science and Liberal Arts

    NASA Astrophysics Data System (ADS)

    Harada, Shoji

    Quick globalization makes prediction of future human activity on production and economy more difficult. This is mainly because of increase in factors affecting relationship among different people with different way of life, culture, tradition and so on. To survive in such complicated world each engineer is desired to provide the knowledge of liberal arts as well as highly specialized knowledge. A synergy power generated by collaborative work of science-and liberal arts-minded way of thinking is a promising tool to unveil difficult world. This paper first describes degradation of liberal arts education during past two decades. Then, several movements for stopping that degradation are introduced in conjunction with the author‧s overseas experiences. Finally, a necessity of bringing up well competitive desirable engineer through collaborative work by university and company is proposed.

  12. Emergence of motor synergy in vertical reaching task via tacit learning.

    PubMed

    Hayashibe, Mitsuhiro; Shimoda, Shingo

    2013-01-01

    The dynamics of multijoint limbs often causes complex dynamic interaction torques which are the inertial effect of other joints motion. It is known that Cerebellum takes important role in a motor learning by developing the internal model. In this paper, we propose a novel computational control paradigm in vertical reaching task which involves the management of interaction torques and gravitational effect. The obtained results demonstrate that the proposed method is valid for acquiring motor synergy in the system with actuation redundancy and resulted in the energy efficient solutions. It is highlighted that the tacit learning in vertical reaching task can bring computational adaptability and optimality with model-free and cost-function-free approach differently from previous studies.

  13. Synergy between experimental and theoretical methods in the exploration of homogeneous transition metal catalysis.

    PubMed

    Lupp, D; Christensen, N J; Fristrup, P

    2014-08-01

    In this Perspective, we will focus on the use of both experimental and theoretical methods in the exploration of reaction mechanisms in homogeneous transition metal catalysis. We briefly introduce the use of Hammett studies and kinetic isotope effects (KIE). Both of these techniques can be complemented by computational chemistry - in particular in cases where interpretation of the experimental results is not straightforward. The good correspondence between experiment and theory is only possible due to recent advances within the applied theoretical framework. We therefore also highlight the innovations made in the last decades with emphasis on dispersion-corrected DFT and solvation models. The current state-of-the-art is highlighted using examples from the literature with particular focus on the synergy between experiment and theory.

  14. A tool for balance control training using muscle synergies and multimodal interfaces.

    PubMed

    Galeano, D; Brunetti, F; Torricelli, D; Piazza, S; Pons, J L

    2014-01-01

    Balance control plays a key role in neuromotor rehabilitation after stroke or spinal cord injuries. Computerized dynamic posturography (CDP) is a classic technological tool to assess the status of balance control and to identify potential disorders. Despite the more accurate diagnosis generated by these tools, the current strategies to promote rehabilitation are still limited and do not take full advantage of the technologies available. This paper presents a novel balance training platform which combines a CDP device made from low-cost interfaces, such as the Nintendo Wii Balance Board and the Microsoft Kinect. In addition, it integrates a custom electrical stimulator that uses the concept of muscle synergies to promote natural interaction. The aim of the platform is to support the exploration of innovative multimodal therapies. Results include the technical validation of the platform using mediolateral and anteroposterior sways as basic balance training therapies. PMID:24982896

  15. Synergy between Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the Bioleaching Process of Copper

    PubMed Central

    Zheng, Xuecheng; Li, Dongwei

    2016-01-01

    This study investigates the synergy of Rhizobium phaseoli and Acidithiobacillus ferrooxidans in the bioleaching process of copper. The results showed that additional R. phaseoli could increase leaching rate and cell number of A. ferrooxidans. When the initial cell number ratio between A. ferrooxidans and R. phaseoli was 2 : 1, A. ferrooxidans attained the highest final cell number of approximately 2 × 108 cells/mL and the highest copper leaching rate of 29%, which is 7% higher than that in the group with A. ferrooxidans only. R. phaseoli may use metabolized polysaccharides from A. ferrooxidans, and organic acids could chelate or precipitate harmful heavy metals to reduce their damage on A. ferrooxidans and promote its growth. Organic acids could also damage the mineral lattice to increase the leaching effect. PMID:26942203

  16. Sildenafil and furosemide associated ototoxicity: consideration of drug-drug interactions, synergy, and broader clinical relevance.

    PubMed

    Skeith, Leslie; Yamashita, Cory; Mehta, Sanjay; Farquhar, Donald; Kim, Richard B

    2013-01-01

    Drug-induced ototoxicity, particularly those involving phosphodiesterase type 5 (PDE-5) inhibitors, is considered to be rare and to our knowledge such an adverse effect has not been reported in Canada. Here we present a case of a 77-year old man initiated on a sildenfil regimen for the treatment of pulmonary hypertension, who developed sudden bilateral hearing loss after taking sildenafil, in the setting of high dose furosemide and diltiazem. We outline the likely interplay of patient characteristics, drug synergy and drug-drug interactions in the development of his ototoxicity. Importantly, given the extent and popularity of PDE-5 inhibitors for erectile dysfunction as well as a newer therapeutic option for pulmonary hypertension, clinicians should be aware of the risk for drug-induced ototoxicity, particularly in the setting of concomitant loop diuretics and CYP3A4 inhibiting medications. PMID:23756362

  17. BIOLOGICAL ADHESIVES. Adaptive synergy between catechol and lysine promotes wet adhesion by surface salt displacement.

    PubMed

    Maier, Greg P; Rapp, Michael V; Waite, J Herbert; Israelachvili, Jacob N; Butler, Alison

    2015-08-01

    In physiological fluids and seawater, adhesion of synthetic polymers to solid surfaces is severely limited by high salt, pH, and hydration, yet these conditions have not deterred the evolution of effective adhesion by mussels. Mussel foot proteins provide insights about adhesive adaptations: Notably, the abundance and proximity of catecholic Dopa (3,4-dihydroxyphenylalanine) and lysine residues hint at a synergistic interplay in adhesion. Certain siderophores—bacterial iron chelators—consist of paired catechol and lysine functionalities, thereby providing a convenient experimental platform to explore molecular synergies in bioadhesion. These siderophores and synthetic analogs exhibit robust adhesion energies (E(ad) ≥-15 millijoules per square meter) to mica in saline pH 3.5 to 7.5 and resist oxidation. The adjacent catechol-lysine placement provides a "one-two punch," whereby lysine evicts hydrated cations from the mineral surface, allowing catechol binding to underlying oxides.

  18. Agricultural and food chemistry: 50 years of synergy between AGFD and JAFC.

    PubMed

    Seiber, James N; Kleinschmidt, Loreen A

    2009-09-23

    The Division of Agricultural and Food Chemistry (AGFD) and the American Chemical Society had the foresight to launch the Journal of Agricultural and Food Chemistry in 1953. JAFC, still closely connected with the Division, has grown to be the premier international journal in the field, providing an outlet for publishing original research articles, reviews, perspectives, and editorials, for agricultural and food chemists from many nations. JAFC has expanded coverage of current areas of intense interest, such as bioactive constituents of foods, biotechnology, and biobased products and biofuels, as well as continuing strong coverage of such mainstream categories as food chemistry/biochemistry, analytical methods, safety and toxicology, and agrochemistry. In 2008 alone, JAFC published over 1650 peer-reviewed manuscripts, several symposia (largely from AGFD symposia at ACS National Meetings), and a number of reviews. The synergy between AGFD and JAFC offers many benefits and exciting opportunities for advancing the science of agricultural and food chemistry for the future.

  19. Synergy among transition element, nitrogen, and carbon for oxygen reduction reaction in alkaline medium

    NASA Astrophysics Data System (ADS)

    Li, Zhou Peng; Liu, Zi Xuan; Zhu, Kun Ning; Li, Zhuo; Liu, Bin Hong

    2012-12-01

    A series of M-doped polypyrrole (PPy)-modified BP2000 catalysts (M = Mn, Fe, Co, Ni, and Cu) are synthesized using the hydrothermal method. The synergy among a transition element, nitrogen, and carbon for oxygen reduction reaction (ORR) in alkaline medium is discussed based on the physical characterization and electrochemical analyses of the Co-doped PPy-modified BP2000. PPy is found to adhere carbon black particles together to form a porous 3D network during the PPy modification on BP2000. PPy reconfiguration occurs during the hydrothermal treatment process. The individual interactions between BP and PPy, BP and Co, and Co and PPy exhibit insignificant effects on the enhancement of ORR. The cooperative interaction among Co, N, and C plays a very important role in the enhancement of ORR. The doping effect of transition-metal salt on ORR enhancement depends on the nature of the transition element and the corresponding anion.

  20. A tool for balance control training using muscle synergies and multimodal interfaces.

    PubMed

    Galeano, D; Brunetti, F; Torricelli, D; Piazza, S; Pons, J L

    2014-01-01

    Balance control plays a key role in neuromotor rehabilitation after stroke or spinal cord injuries. Computerized dynamic posturography (CDP) is a classic technological tool to assess the status of balance control and to identify potential disorders. Despite the more accurate diagnosis generated by these tools, the current strategies to promote rehabilitation are still limited and do not take full advantage of the technologies available. This paper presents a novel balance training platform which combines a CDP device made from low-cost interfaces, such as the Nintendo Wii Balance Board and the Microsoft Kinect. In addition, it integrates a custom electrical stimulator that uses the concept of muscle synergies to promote natural interaction. The aim of the platform is to support the exploration of innovative multimodal therapies. Results include the technical validation of the platform using mediolateral and anteroposterior sways as basic balance training therapies.

  1. Linking salmon aquaculture synergies and trade-offs on ecosystem services to human wellbeing constituents.

    PubMed

    Outeiro, Luis; Villasante, Sebastian

    2013-12-01

    Salmon aquaculture has emerged as a successful economic industry generating high economic revenues to invest in the development of Chiloe region, Southern Chile. However, salmon aquaculture also consumes a substantial amount of ecosystem services, and the direct and indirect impacts on human wellbeing are still unknown and unexplored. This paper identifies the synergies and trade-offs caused by the salmon industry on a range of ecosystem services. The results show that large economic benefits due to the increase of provisioning ecosystem services are also causing a reduction on regulating and cultural services. Despite the improvement on average income and poverty levels experienced in communities closely associated with the sector, this progress is not large enough and social welfare did not improve substantially over the last decade. The rest of human wellbeing constituents in Chiloe region have not changed significantly compared to the development in the rest of the country.

  2. Synergy between acid and endotoxin in an experimental model of aspiration-related lung injury progression.

    PubMed

    Tetenev, Konstantin; Cloutier, Mary E; von Reyn, Jessica A; Ather, Jennifer L; Candon, James; Allen, Gilman B

    2015-11-15

    Aspiration is a common cause of lung injury, but it is unclear why some cases are self-limited while others progress to acute respiratory distress syndrome (ARDS). Sporadic exposure to more than one insult could account for this variable progression. We investigated whether synergy between airway acid and endotoxin (LPS) amplifies injury severity in mice and whether LPS levels in human patients could corroborate our experimental findings. C57BL/6 mice aspirated acid (pH 1.3) or normal saline (NS), followed by LPS aerosol or nothing. Bronchoalveolar lavage fluid (BALF) was obtained 2 to 49 h later. Mice were injected with FITC-dextran 25 h after aspiration and connected to a ventilator, and lung elastance (H) measured periodically following deep inflation (DI). Endotracheal and gastric aspirates were also collected from patients in the intensive care unit and assayed for pH and LPS. Lung instability (ΔH following DI) and pressure-volume hysteresis in acid- or LPS-exposed mice was greater than in controls but markedly greater in the combined acid/LPS group. BALF neutrophils, cytokines, protein, and FITC-dextran in the acid/LPS mice were geometrically higher than all other groups. BALF from acid-only mice markedly amplified LPS-induced TNF-α production in cultured macrophages. Human subjects had variable endotracheal LPS levels with the highest burden in those at higher risk of aspiration. Acid aspiration amplifies LPS signaling in mice to disrupt barrier function and lung mechanics in synergy. High variation in airway LPS and greater airway LPS burden in patients at higher risk of aspiration could help explain the sporadic progression of aspiration to ARDS. PMID:26408552

  3. Antileptospiral activity of xanthones from Garcinia mangostana and synergy of gamma-mangostin with penicillin G

    PubMed Central

    2013-01-01

    Background Leptospirosis, one of the most widespread zoonotic infectious diseases worldwide, is caused by spirochetes bacteria of the genus Leptospira. The present study examined inhibitory activity of purified xanthones and crude extracts from Garcinia mangostana against both non-pathogenic and pathogenic leptospira. Synergy between γ-mangostin and penicillin G against leptospires was also determined. Methods Minimal inhibitory concentrations (MIC) of crude extracts and purified xanthones from G. mangostana and penicillin G for a non-pathogenic (L. biflexa serovar Patoc) and pathogenic (L. interrogans serovar Bataviae, Autumnalis, Javanica and Saigon) leptospires were determined by using broth microdilution method and alamar blue. The synergy was evaluated by calculating the fractional inhibitory concentration (FIC) index. Results The results of broth microdilution test demonstrated that the crude extract and purified xanthones from mangosteen possessed antileptospiral activities. The crude extracts were active against all five serovars of test leptospira with MICs ranging from 200 to ≥ 800 μg/ml. Among the crude extracts and purified xanthones, garcinone C was the most active compound against both of pathogenic (MIC =100 μg/ml) and non-pathogenic leptospira (MIC = 200 μg/ml). However, these MIC values were higher than those of traditional antibiotics. Combinations of γ-mangostin with penicillin G generated synergistic effect against L. interrogans serovars Bataviae, Autumnalis and Javanica (FIC = 0.52, 0.50, and 0.04, respectively) and no interaction against L. biflexa serovar Patoc (FIC =0.75). However, antagonistic activity (FIC = 4.03) was observed in L. interrogans serovar Saigon. Conclusions Crude extracts and purified xanthones from fruit pericarp of G. mangostana with significant antibacterial activity may be used to control leptospirosis. The combination of xanthone with antibiotic enhances the antileptospiral efficacy. PMID

  4. Atomic-structural synergy for catalytic CO oxidation over palladium-nickel nanoalloys.

    PubMed

    Shan, Shiyao; Petkov, Valeri; Yang, Lefu; Luo, Jin; Joseph, Pharrah; Mayzel, Dina; Prasai, Binay; Wang, Lingyan; Engelhard, Mark; Zhong, Chuan-Jian

    2014-05-14

    Alloying palladium (Pd) with other transition metals at the nanoscale has become an important pathway for preparation of low-cost, highly active and stable catalysts. However, the lack of understanding of how the alloying phase state, chemical composition and atomic-scale structure of the alloys at the nanoscale influence their catalytic activity impedes the rational design of Pd-nanoalloy catalysts. This work addresses this challenge by a novel approach to investigating the catalytic oxidation of carbon monoxide (CO) over palladium-nickel (PdNi) nanoalloys with well-defined bimetallic composition, which reveals a remarkable maximal catalytic activity at Pd:Ni ratio of ~50:50. Key to understanding the structural-catalytic synergy is the use of high-energy synchrotron X-ray diffraction coupled to atomic pair distribution function (HE-XRD/PDF) analysis to probe the atomic structure of PdNi nanoalloys under controlled thermochemical treatments and CO reaction conditions. Three-dimensional (3D) models of the atomic structure of the nanoalloy particles were generated by reverse Monte Carlo simulations (RMC) guided by the experimental HE-XRD/PDF data. Structural details of the PdNi nanoalloys were extracted from the respective 3D models and compared with the measured catalytic properties. The comparison revealed a strong correlation between the phase state, chemical composition and atomic-scale structure of PdNi nanoalloys and their catalytic activity for CO oxidation. This correlation is further substantiated by analyzing the first atomic neighbor distances and coordination numbers inside the nanoalloy particles and at their surfaces. These findings have provided new insights into the structural synergy of nanoalloy catalysts by controlling the phase state, composition and atomic structure, complementing findings of traditional density functional theory studies.

  5. Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys

    SciTech Connect

    Shan, Shiyao; Petkov, Valeri; Yang, Lefu; Luo, Jin; Joseph, Pharrah; Mayzel, Dina; Prasai, Binay; Wang, Lingyan; Engelhard, Mark H.; Zhong, Chuan-Jian

    2014-05-05

    Alloying palladium (Pd) with other transition metals at the nanoscale has become an important pathway for preparation of low-cost, highly-active and stable catalysts. However the lack of understanding of how the alloying phase state, chemical composition and atomic-scale structure of the alloys at the nanoscale influence their catalytic activity impedes the rational design of Pd-nanoalloy catalysts. This work addresses this challenge by a novel approach to investigating the catalytic oxidation of carbon monoxide (CO) over palladium-nickel (PdNi) nanoalloys with well-defined bimetallic composition, which reveals a remarkable a maximal catalytic activity at Pd:Ni ratio of ~50:50. Key to understanding the structural-catalytic synergy is the use of high-energy synchrotron X-ray diffraction coupled to atomic pair distribution function (HE-XRD/PDF) analysis to probe the atomic structure of PdNi nanoalloys under controlled thermochemical treatments and CO reaction conditions. Three-dimensional (3D) models of the atomic structure of the nanoalloy particles were generated by reverse Monte Carlo simulations (RMC) guided by the experimental HE-XRD/PDF data. Structural details of the PdNi nanoalloys were extracted from the respective 3D models and compared with the measured catalytic properties. The comparison revealed a strong correlation between the phase state, chemical composition and atomic-scale structure of PdNi nanoalloys and their catalytic activity for CO oxidation. This correlation is further substantiated by analyzing the first atomic neighbor distances and coordination numbers inside the nanoalloy particles and at their surfaces. These findings have provided new insights into the structural synergy of nanoalloy catalysts by controlling the phase state, composition and atomic structure, complementing findings of traditional density functional theory studies.

  6. Atomic-Structural Synergy for Catalytic CO Oxidation over Palladium-Nickel Nanoalloys

    SciTech Connect

    Shan, Shiyao; Petkov, Valeri; Yang, Lefu; Luo, Jin; Joseph, Pharrah; Mayzel, Dina; Prasai, Binay; Wang, Lingyan; Engelhard, Mark; Zhong, Chuan-Jian

    2014-05-05

    Alloying palladium (Pd) with other transition metals at the nanoscale has become an important pathway for preparation of low-cost, highly active and stable catalysts. However, the lack of understanding of how the alloying phase state, chemical composition and atomic-scale structure of the alloys at the nanoscale influence their catalytic activity impedes the rational design of Pd-nanoalloy catalysts. This work addresses this challenge by a novel approach to investigating the catalytic oxidation of carbon monoxide (CO) over palladium–nickel (PdNi) nanoalloys with well-defined bimetallic composition, which reveals a remarkable maximal catalytic activity at Pd:Ni ratio of ~50:50. Key to understanding the structural-catalytic synergy is the use of high-energy synchrotron X-ray diffraction coupled to atomic pair distribution function (HE-XRD/PDF) analysis to probe the atomic structure of PdNi nanoalloys under controlled thermochemical treatments and CO reaction conditions. Three-dimensional (3D) models of the atomic structure of the nanoalloy particles were generated by reverse Monte Carlo simulations (RMC) guided by the experimental HE-XRD/PDF data. Structural details of the PdNi nanoalloys were extracted from the respective 3D models and compared with the measured catalytic properties. The comparison revealed a strong correlation between the phase state, chemical composition and atomic-scale structure of PdNi nanoalloys and their catalytic activity for CO oxidation. This correlation is further substantiated by analyzing the first atomic neighbor distances and coordination numbers inside the nanoalloy particles and at their surfaces. These findings have provided new insights into the structural synergy of nanoalloy catalysts by controlling the phase state, composition and atomic structure, complementing findings of traditional density functional theory studies.

  7. Synergy Between Experiments and Simulations in Laser and Beam-Driven Plasma Acceleration and Light Sources

    NASA Astrophysics Data System (ADS)

    Mori, Warren B.

    2015-11-01

    Computer simulations have been an integral part of plasma physics research since the early 1960s. Initially, they provided the ability to confirm and test linear and nonlinear theories in one-dimension. As simulation capabilities and computational power improved, then simulations were also used to test new ideas and applications of plasmas in multi-dimensions. As progress continued, simulations were also used to model experiments. Today computer simulations of plasmas are ubiquitously used to test new theories, understand complicated nonlinear phenomenon, model the full temporal and spatial scale of experiments, simulate parameters beyond the reach of current experiments, and test the performance of new devices before large capital expenditures are made to build them. In this talk I review the progress in simulations in a particular area of plasma physics: plasma based acceleration (PBA). In PBA a short laser pulse or particle beam propagates through long regions of plasma creating plasma wave wakefields on which electrons or positrons surf to high energies. In some cases the wakefields are highly nonlinear, involve three-dimensional effects, and the trajectories of plasma particles cross making it essential that fully kinetic and three-dimensional models are used. I will show how particle-in-cell (PIC) simulations were initially used to propose the basic idea of PBA in one dimension. I will review some of the dramatic progress in the experimental demonstration of PBA and show how this progress was dramatically helped by a synergy between experiments and full-scale multi-dimensional PIC simulations. This will include a review of how the capability of PIC simulation tools has improved. I will also touch on some recent progress on improvements to PIC simulations of PBA and discuss how these improvements may push the synergy further towards real time steering of experiments and start to end modeling of key components of a future linear collider or XFEL based on PBA

  8. Cellulase-Xylanase Synergy in Designer Cellulosomes for Enhanced Degradation of a Complex Cellulosic Substrate

    PubMed Central

    Moraïs, Sarah; Barak, Yoav; Caspi, Jonathan; Hadar, Yitzhak; Lamed, Raphael; Shoham, Yuval; Wilson, David B.; Bayer, Edward A.

    2010-01-01

    Designer cellulosomes are precision-engineered multienzyme complexes in which the molecular architecture and enzyme content are exquisitely controlled. This system was used to examine enzyme cooperation for improved synergy among Thermobifida fusca glycoside hydrolases. Two T. fusca cellulases, Cel48A exoglucanase and Cel5A endoglucanase, and two T. fusca xylanases, endoxylanases Xyn10B and Xyn11A, were selected as enzymatic components of a mixed cellulase/xylanase-containing designer cellulosome. The resultant mixed multienzyme complex was fabricated on a single scaffoldin subunit bearing all four enzymes. Conversion of T. fusca enzymes to the cellulosomal mode followed by their subsequent incorporation into a tetravalent cellulosome led to assemblies with enhanced activity (~2.4-fold) on wheat straw as a complex cellulosic substrate. The enhanced synergy was caused by the proximity of the enzymes on the complex compared to the free-enzyme systems. The hydrolytic properties of the tetravalent designer cellulosome were compared with the combined action of two separate divalent cellulase- and xylanase-containing cellulosomes. Significantly, the tetravalent designer cellulosome system exhibited an ~2-fold enhancement in enzymatic activity compared to the activity of the mixture of two distinct divalent scaffoldin-borne enzymes. These results provide additional evidence that close proximity between cellulases and xylanases is key to the observed concerted degradation of the complex cellulosic substrate in which the integrated enzymes complement each other by promoting access to the relevant polysaccharide components of the substrate. The data demonstrate that cooperation among xylanases and cellulases can be augmented by their integration into a single designer cellulosome. PMID:21157512

  9. Synergy between rhinacanthins from Rhinacanthus nasutus in inhibition against mosquito cytochrome P450 enzymes.

    PubMed

    Kotewong, Rattanawadee; Pouyfung, Phisit; Duangkaew, Panida; Prasopthum, Aruna; Rongnoparut, Pornpimol

    2015-07-01

    The cytochrome P450 monooxygenases play a major role in insecticide detoxification and become a target for development of insecticide synergists. In this study, a collection of rhinacanthins (rhinacanthin-D, -E, -G, -N, -Q, and -H/I) purified from Rhinacanthus nasutus, in addition to previously purified rhinacanthin-B and -C, were isolated. These compounds displayed various degrees of inhibition against benzyloxyresorufin-O-debenzylation mediated by CYP6AA3 and CYP6P7 which were implicated in pyrethroid resistance in Anopheles minimus malaria vector. Inhibition modes and kinetics were determined for each of rhinacanthins. Cell-based inhibition assays by rhinacanthins employing 3-(4, 5-dimethylthiazol-2-y-l)-2, 5-diphenyltetrazolium bromide (MTT) cytotoxicity test were explored their synergistic effects with cypermethrin toxicity on CYP6AA3- and CYP6P7-expressing Spodoptera frugiperda (Sf9) cells. Rhinacanthin-B, -D, -E, -G, and -N exhibited mechanism-based inhibition against CYP6AA3, an indication of irreversible inhibition, while rhinacanthin-B, -D, -G, and -N were mechanism-based inhibitors of CYP6P7. There was structure-function relationship of these rhinacanthins in inhibition effects against both enzymes. In vitro enzymatic inhibition assays revealed that there were synergistic interactions among rhinacanthins, except rhinacanthin-B and -Q, in inhibition against both enzymes. These rhinacanthins exerted synergism with cypermethrin toxicity on Sf9 cells expressing each of the two P450 enzymes via P450 inhibition and in addition could interact in synergy to further increase cypermethrin toxicity. The inhibition potentials, synergy among rhinacanthins in inhibition against the P450 detoxification enzymes, and synergism with cypermethrin toxicity of the R. nasutus constituents of reported herein could be beneficial to implement effective resistance management of mosquito vector control.

  10. Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects.

    PubMed

    Russo, Ethan B

    2011-08-01

    Tetrahydrocannabinol (THC) has been the primary focus of cannabis research since 1964, when Raphael Mechoulam isolated and synthesized it. More recently, the synergistic contributions of cannabidiol to cannabis pharmacology and analgesia have been scientifically demonstrated. Other phytocannabinoids, including tetrahydrocannabivarin, cannabigerol and cannabichromene, exert additional effects of therapeutic interest. Innovative conventional plant breeding has yielded cannabis chemotypes expressing high titres of each component for future study. This review will explore another echelon of phytotherapeutic agents, the cannabis terpenoids: limonene, myrcene, α-pinene, linalool, β-caryophyllene, caryophyllene oxide, nerolidol and phytol. Terpenoids share a precursor with phytocannabinoids, and are all flavour and fragrance components common to human diets that have been designated Generally Recognized as Safe by the US Food and Drug Administration and other regulatory agencies. Terpenoids are quite potent, and affect animal and even human behaviour when inhaled from ambient air at serum levels in the single digits ng·mL(-1) . They display unique therapeutic effects that may contribute meaningfully to the entourage effects of cannabis-based medicinal extracts. Particular focus will be placed on phytocannabinoid-terpenoid interactions that could produce synergy with respect to treatment of pain, inflammation, depression, anxiety, addiction, epilepsy, cancer, fungal and bacterial infections (including methicillin-resistant Staphylococcus aureus). Scientific evidence is presented for non-cannabinoid plant components as putative antidotes to intoxicating effects of THC that could increase its therapeutic index. Methods for investigating entourage effects in future experiments will be proposed. Phytocannabinoid-terpenoid synergy, if proven, increases the likelihood that an extensive pipeline of new therapeutic products is possible from this venerable plant. http

  11. Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects

    PubMed Central

    Russo, Ethan B

    2011-01-01

    Tetrahydrocannabinol (THC) has been the primary focus of cannabis research since 1964, when Raphael Mechoulam isolated and synthesized it. More recently, the synergistic contributions of cannabidiol to cannabis pharmacology and analgesia have been scientifically demonstrated. Other phytocannabinoids, including tetrahydrocannabivarin, cannabigerol and cannabichromene, exert additional effects of therapeutic interest. Innovative conventional plant breeding has yielded cannabis chemotypes expressing high titres of each component for future study. This review will explore another echelon of phytotherapeutic agents, the cannabis terpenoids: limonene, myrcene, α-pinene, linalool, β-caryophyllene, caryophyllene oxide, nerolidol and phytol. Terpenoids share a precursor with phytocannabinoids, and are all flavour and fragrance components common to human diets that have been designated Generally Recognized as Safe by the US Food and Drug Administration and other regulatory agencies. Terpenoids are quite potent, and affect animal and even human behaviour when inhaled from ambient air at serum levels in the single digits ng·mL−1. They display unique therapeutic effects that may contribute meaningfully to the entourage effects of cannabis-based medicinal extracts. Particular focus will be placed on phytocannabinoid-terpenoid interactions that could produce synergy with respect to treatment of pain, inflammation, depression, anxiety, addiction, epilepsy, cancer, fungal and bacterial infections (including methicillin-resistant Staphylococcus aureus). Scientific evidence is presented for non-cannabinoid plant components as putative antidotes to intoxicating effects of THC that could increase its therapeutic index. Methods for investigating entourage effects in future experiments will be proposed. Phytocannabinoid-terpenoid synergy, if proven, increases the likelihood that an extensive pipeline of new therapeutic products is possible from this venerable plant. LINKED ARTICLES

  12. Is there a reliable and invariant set of muscle synergy during isometric biaxial trunk exertion in the sagittal and transverse planes by healthy subjects?

    PubMed

    Sedaghat-Nejad, Ehsan; Mousavi, Seyed Javad; Hadizadeh, Maliheh; Narimani, Roya; Khalaf, Kinda; Campbell-Kyureghyan, Naira; Parnianpour, Mohamad

    2015-09-18

    It has been suggested that the central nervous system simplifies muscle control through basic units, called synergies. In this study, we have developed a novel target-matching protocol and used non-negative matrix factorization (NMF) technique to extract trunk muscle synergies and corresponding torque synergies. Isometric torque data at the L5/S1 level and electromyographic patterns of twelve abdominal and back muscles from twelve healthy participants (five females) were simultaneously recorded. Each participant performed a total number of 24 isometric target-matching tasks using 12 different angular directions and 2 levels of uniaxial and biaxial exertions. Within- and between-subject similarities were assessed by considering both the data of different pairs of participants, where the activation coefficients of one participant were used in the NMF analysis of another participant, and the Pearson's correlation coefficients (R) between muscle synergy vectors. The results showed that, for a healthy person, a set of four muscles (overall variance accounted for (VAF) of 97.9 ± 0.53%) and four corresponding torque synergies (overall VAF of 92.2 ± 3.03%) could efficiently decompose the sagittal and transverse torque planes into their main directions. Furthermore, the correlation coefficients were 0.77 ± 0.12, 0.86 ± 0.08, 0.78 ± 0.12, and 0.93 ± 0.04, for all synergies, reflecting the consistency of muscle synergies across participants. Overall, our results suggest that by taking advantage of muscle synergies we could potentially overcome the redundancy inherent to control strategies of the trunk neuromuscular system. In future studies, the synergies identified in patients with low back pain could be compared with those extracted from healthy participants towards various clinical and rehabilitation applications.

  13. Hybrid radiator cooling system

    DOEpatents

    France, David M.; Smith, David S.; Yu, Wenhua; Routbort, Jules L.

    2016-03-15

    A method and hybrid radiator-cooling apparatus for implementing enhanced radiator-cooling are provided. The hybrid radiator-cooling apparatus includes an air-side finned surface for air cooling; an elongated vertically extending surface extending outwardly from the air-side finned surface on a downstream air-side of the hybrid radiator; and a water supply for selectively providing evaporative cooling with water flow by gravity on the elongated vertically extending surface.

  14. Managing hybrid marketing systems.

    PubMed

    Moriarty, R T; Moran, U

    1990-01-01

    As competition increases and costs become critical, companies that once went to market only one way are adding new channels and using new methods - creating hybrid marketing systems. These hybrid marketing systems hold the promise of greater coverage and reduced costs. But they are also hard to manage; they inevitably raise questions of conflict and control: conflict because marketing units compete for customers; control because new indirect channels are less subject to management authority. Hard as they are to manage, however, hybrid marketing systems promise to become the dominant design, replacing the "purebred" channel strategy in all kinds of businesses. The trick to managing the hybrid is to analyze tasks and channels within and across a marketing system. A map - the hybrid grid - can help managers make sense of their hybrid system. What the chart reveals is that channels are not the basic building blocks of a marketing system; marketing tasks are. The hybrid grid forces managers to consider various combinations of channels and tasks that will optimize both cost and coverage. Managing conflict is also an important element of a successful hybrid system. Managers should first acknowledge the inevitability of conflict. Then they should move to bound it by creating guidelines that spell out which customers to serve through which methods. Finally, a marketing and sales productivity (MSP) system, consisting of a central marketing database, can act as the central nervous system of a hybrid marketing system, helping managers create customized channels and service for specific customer segments.

  15. Hybridization facilitates evolutionary rescue

    PubMed Central

    Stelkens, Rike B; Brockhurst, Michael A; Hurst, Gregory D D; Greig, Duncan

    2014-01-01

    The resilience of populations to rapid environmental degradation is a major concern for biodiversity conservation. When environments deteriorate to lethal levels, species must evolve to adapt to the new conditions to avoid extinction. Here, we test the hypothesis that evolutionary rescue may be enabled by hybridization, because hybridization increases genetic variability. Using experimental evolution, we show that interspecific hybrid populations of Saccharomyces yeast adapt to grow in more highly degraded environments than intraspecific and parental crosses, resulting in survival rates far exceeding those of their ancestors. We conclude that hybridization can increase evolutionary responsiveness and that taxa able to exchange genes with distant relatives may better survive rapid environmental change. PMID:25558281

  16. From hybrid swarms to swarms of hybrids

    USGS Publications Warehouse

    Stohlgren, Thomas J.; Szalanski, Allen L; Gaskin, John F.; Young, Nicholas E.; West, Amanda; Jarnevich, Catherine S.; Tripodi, Amber

    2015-01-01

    Science has shown that the introgression or hybridization of modern humans (Homo sapiens) with Neanderthals up to 40,000 YBP may have led to the swarm of modern humans on earth. However, there is little doubt that modern trade and transportation in support of the humans has continued to introduce additional species, genotypes, and hybrids to every country on the globe. We assessed the utility of species distributions modeling of genotypes to assess the risk of current and future invaders. We evaluated 93 locations of the genus Tamarix for which genetic data were available. Maxent models of habitat suitability showed that the hybrid, T. ramosissima x T. chinensis, was slightly greater than the parent taxa (AUCs > 0.83). General linear models of Africanized honey bees, a hybrid cross of Tanzanian Apis mellifera scutellata and a variety of European honey bee including A. m. ligustica, showed that the Africanized bees (AUC = 0.81) may be displacing European honey bees (AUC > 0.76) over large areas of the southwestern U.S. More important, Maxent modeling of sub-populations (A1 and A26 mitotypes based on mDNA) could be accurately modeled (AUC > 0.9), and they responded differently to environmental drivers. This suggests that rapid evolutionary change may be underway in the Africanized bees, allowing the bees to spread into new areas and extending their total range. Protecting native species and ecosystems may benefit from risk maps of harmful invasive species, hybrids, and genotypes.

  17. Explorations into the Synergy Between Faith, Health, and Health-Care Among Black Baptists

    PubMed Central

    Maclin, Sandy D.

    2013-01-01

    Background U.S. health disparities are documented by race/ethnic, socioeconomic, gender, and geographic demographics. Since federal health record keeping began, regardless of other demographic factors, Black people continue to record statistical significant disparities. The complementary and alternative medicine (CAM) domain of mind-body medicine provides a method and language to assess the metaphysical constructs of faith, spirituality and religion and their influence on health and healthcare practices. Explorations into the synergy between faith, health and healthcare among a convenient sample of Black Baptist conventioneers provides an opportunity to better understand if and how faith can be used to enhance the health and wellbeing of Black people. Methodology In 2005 a convenience sample of 2,500 Black persons among 10,000 Joint Baptist conventioneers participated in the study; 1,827 completed and returned an 80 item questionnaire. 500 surveys were lost due to computer malfunctions. Survey results covered: demographic, health/safety, health care, and faith/religion/health. Results 58.6% of respondents were women; 61% were married. Most (66.2%) reported good health and few were told by their physician they had a chronic disease. 33.5% never talk to their pastor about health problems or (42.7%) physician visits. Mental health responses: (98.7%) get along well with others; (93.6%) were satisfied with life; (92.8%) feel good about themselves; and (97.6%) were in good spirits most times. Many were in social organizations (40.6%). 96.1% felt religion was very important in their life; 91% thought religion affects physical/mental health; and 89.1% believed faith affects mental/physical health. 95.7% believe faith can change a health crisis. Most described religion and faith differently. Discussion The Black Church has history in social justice connected to community health. Responses to religion/faith affirm the interconnectedness of the synergy between faith

  18. Hybrid baryons [alpha].

    SciTech Connect

    Page, P. R.

    2002-01-01

    The authors review the status of hybrid baryons. The only known way to study hybrids rigorously is via excited adiabatic potentials. Hybrids can be modeled by both the bag and flux tube models. The low lying hybrid baryon is N 1/2{sup +} with a mass of 1.5 - 1.8 GeV. Hybrid baryons can be produced in the glue rich processes of diffractive {gamma}N and {pi}N production, {Psi} decays and p{bar p} annihilation. We review the current status of research on three quarks with a gluonic excitation, called a hybrid baryon. The excitation is not an orbital or radial excitation between the quarks. Hybrid baryons have also been reviewed elsewhere. The Mercedes-Benz logl in Figure 1 indicates two possible views of the confining interaction of three quarks, an essential issue in the study of hybrid baryons. In the logo the three points where the Y shape meets the boundary circle should be identified with the three quarks. There are two possibilities fo rthe interaction of the quarks: (1) a pairwise interaction of the quarks represented by the circle, or (2) a Y shaped interaction between the quarks, represented by the Y-shape in the logo.

  19. Hybrid Courses Are Best.

    ERIC Educational Resources Information Center

    Brown, David G.

    2001-01-01

    Describes research that has investigated and compared students in face-to-face classes, Web-based classes, and hybrid courses which combine both methods. Presents a chart that shows comparative advantages of face to face versus virtual classes, and discusses results that show hybrid courses have the highest success rate. (LRW)

  20. Muscle synergies involved in shifting the center of pressure while making a first step.

    PubMed

    Wang, Yun; Zatsiorsky, Vladimir M; Latash, Mark L

    2005-11-01

    We used the framework of the uncontrolled manifold (UCM) hypothesis to analyze multi-muscle synergies involved in making a step by a standing person. We hypothesized that leg and trunk muscles are organized into stable groups (muscle modes, M-modes) related to shifts of the center of pressure (COP) in the anterior-posterior and medio-lateral directions. Another hypothesis was that the magnitudes of the modes co-vary across repetitive trials to stabilize a certain magnitude of the COP shift in both directions. M-modes were defined using principal component analysis applied to indices of changes in the electromyographic (EMG) activity prior to releasing variable loads that were held by the subject using a pulley system. For the task of releasing the load behind the body three M-modes associated with a backward COP shift were defined. Four M-modes were defined for the task of releasing the load at the body side associated with a lateral COP shift. Multiple regression analysis was used to relate changes in the M-mode magnitudes to COP shifts. EMG changes prior to making a step were quantified over five 100 ms time windows before the lift-off of the stepping leg. Two components of the variance in the M-mode space computed across repetitions of a stepping task were quantified-a component that did not affect the average COP shift in a particular direction (variance within the UCM, V (UCM)), and a component that affected the COP shift (variance orthogonal to the UCM, V (ORT)). V (UCM) was significantly higher than V (ORT) for both directions of the COP shifts. This relation was observed for the M-modes in the stepping leg as well as in the support leg. The stepping leg showed a different time evolution of the ratio V (UCM)/V (ORT) such that the difference between the two variance components disappeared closer to the time of the lift-off. The findings corroborate both main hypotheses. The study supports a view that control of whole-body actions involves grouping the muscles

  1. Drug Synergy of Tenofovir and Nanoparticle-Based Antiretrovirals for HIV Prophylaxis

    PubMed Central

    Chaowanachan, Thanyanan; Krogstad, Emily; Ball, Cameron; Woodrow, Kim A.

    2013-01-01

    Background The use of drug combinations has revolutionized the treatment of HIV but there is no equivalent combination product that exists for prevention, particularly for topical HIV prevention. Strategies to combine chemically incompatible agents may facilitate the discovery of unique drug-drug activities, particularly unexplored combination drug synergy. We fabricated two types of nanoparticles, each loaded with a single antiretroviral (ARV) that acts on a specific step of the viral replication cycle. Here we show unique combination drug activities mediated by our polymeric delivery systems when combined with free tenofovir (TFV). Methodology/Principal Findings Biodegradable poly(lactide-co-glycolide) nanoparticles loaded with efavirenz (NP-EFV) or saquinavir (NP-SQV) were individually prepared by emulsion or nanoprecipitation techniques. Nanoparticles had reproducible size (d ∼200 nm) and zeta potential (-25 mV). The drug loading of the nanoparticles was approximately 7% (w/w). NP-EFV and NP-SQV were nontoxic to TZM-bl cells and ectocervical explants. Both NP-EFV and NP-SQV exhibited potent protection against HIV-1 BaL infection in vitro. The HIV inhibitory effect of nanoparticle formulated ARVs showed up to a 50-fold reduction in the 50% inhibitory concentration (IC50) compared to free drug. To quantify the activity arising from delivery of drug combinations, we calculated combination indices (CI) according to the median-effect principle. NP-EFV combined with free TFV demonstrated strong synergistic effects (CI50 = 0.07) at a 1∶50 ratio of IC50 values and additive effects (CI50 = 1.05) at a 1∶1 ratio of IC50 values. TFV combined with NP-SQV at a 1∶1 ratio of IC50 values also showed strong synergy (CI50 = 0.07). Conclusions ARVs with different physicochemical properties can be encapsulated individually into nanoparticles to potently inhibit HIV. Our findings demonstrate for the first time that combining TFV with either NP-EFV or NP

  2. Ground-based lidar and microwave radiometry synergy for high vertical resolution absolute humidity profiling

    NASA Astrophysics Data System (ADS)

    Barrera-Verdejo, María; Crewell, Susanne; Löhnert, Ulrich; Orlandi, Emiliano; Di Girolamo, Paolo

    2016-08-01

    Continuous monitoring of atmospheric humidity profiles is important for many applications, e.g., assessment of atmospheric stability and cloud formation. Nowadays there are a wide variety of ground-based sensors for atmospheric humidity profiling. Unfortunately there is no single instrument able to provide a measurement with complete vertical coverage, high vertical and temporal resolution and good performance under all weather conditions, simultaneously. For example, Raman lidar (RL) measurements can provide water vapor with a high vertical resolution, albeit with limited vertical coverage, due to sunlight contamination and the presence of clouds. Microwave radiometers (MWRs) receive water vapor information throughout the troposphere, though their vertical resolution is poor. In this work, we present an MWR and RL system synergy, which aims to overcome the specific sensor limitations. The retrieval algorithm combining these two instruments is an optimal estimation method (OEM), which allows for an uncertainty analysis of the retrieved profiles. The OEM combines measurements and a priori information, taking the uncertainty of both into account. The measurement vector consists of a set of MWR brightness temperatures and RL water vapor profiles. The method is applied to a 2-month field campaign around Jülich (Germany), focusing on clear sky periods. Different experiments are performed to analyze the improvements achieved via the synergy compared to the individual retrievals. When applying the combined retrieval, on average the theoretically determined absolute humidity uncertainty is reduced above the last usable lidar range by a factor of ˜ 2 with respect to the case where only RL measurements are used. The analysis in terms of degrees of freedom per signal reveal that most information is gained above the usable lidar range, especially important during daytime when the lidar vertical coverage is limited. The retrieved profiles are further evaluated using

  3. Hybrid reactors. [Fuel cycle

    SciTech Connect

    Moir, R.W.

    1980-09-09

    The rationale for hybrid fusion-fission reactors is the production of fissile fuel for fission reactors. A new class of reactor, the fission-suppressed hybrid promises unusually good safety features as well as the ability to support 25 light-water reactors of the same nuclear power rating, or even more high-conversion-ratio reactors such as the heavy-water type. One 4000-MW nuclear hybrid can produce 7200 kg of /sup 233/U per year. To obtain good economics, injector efficiency times plasma gain (eta/sub i/Q) should be greater than 2, the wall load should be greater than 1 MW.m/sup -2/, and the hybrid should cost less than 6 times the cost of a light-water reactor. Introduction rates for the fission-suppressed hybrid are usually rapid.

  4. Hybrid baryons in QCD

    SciTech Connect

    Dudek, Jozef J.; Edwards, Robert G.

    2012-03-21

    In this study, we present the first comprehensive study of hybrid baryons using lattice QCD methods. Using a large basis of composite QCD interpolating fields we extract an extensive spectrum of baryon states and isolate those of hybrid character using their relatively large overlap onto operators which sample gluonic excitations. We consider the spectrum of Nucleon and Delta states at several quark masses finding a set of positive parity hybrid baryons with quantum numbers $N_{1/2^+},\\,N_{1/2^+},\\,N_{3/2^+},\\, N_{3/2^+},\\,N_{5/2^+},\\,$ and $\\Delta_{1/2^+},\\, \\Delta_{3/2^+}$ at an energy scale above the first band of `conventional' excited positive parity baryons. This pattern of states is compatible with a color octet gluonic excitation having $J^{P}=1^{+}$ as previously reported in the hybrid meson sector and with a comparable energy scale for the excitation, suggesting a common bound-state construction for hybrid mesons and baryons.

  5. Hybrid propulsion technology program

    NASA Technical Reports Server (NTRS)

    1990-01-01

    Technology was identified which will enable application of hybrid propulsion to manned and unmanned space launch vehicles. Two design concepts are proposed. The first is a hybrid propulsion system using the classical method of regression (classical hybrid) resulting from the flow of oxidizer across a fuel grain surface. The second system uses a self-sustaining gas generator (gas generator hybrid) to produce a fuel rich exhaust that was mixed with oxidizer in a separate combustor. Both systems offer cost and reliability improvement over the existing solid rocket booster and proposed liquid boosters. The designs were evaluated using life cycle cost and reliability. The program consisted of: (1) identification and evaluation of candidate oxidizers and fuels; (2) preliminary evaluation of booster design concepts; (3) preparation of a detailed point design including life cycle costs and reliability analyses; (4) identification of those hybrid specific technologies needing improvement; and (5) preperation of a technology acquisition plan and large scale demonstration plan.

  6. Hybrid rocket performance

    NASA Technical Reports Server (NTRS)

    Frederick, Robert A., Jr.

    1992-01-01

    A hybrid rocket is a system consisting of a solid fuel grain and a gaseous or liquid oxidizer. Figure 1 shows three popular hybrid propulsion cycles that are under current consideration. NASA MSFC has teamed with industry to test two hybrid propulsion systems that will allow scaling to motors of potential interest for Titan and Atlas systems, as well as encompassing the range of interest for SEI lunar ascent stages and National Launch System Cargo Transfer Vehicle (NLS CTV) and NLS deorbit systems. Hybrid systems also offer advantages as moderate-cost, environmentally acceptable propulsion system. The objective of this work was to recommend a performance prediction methodology for hybrid rocket motors. The scope included completion of: a literature review, a general methodology, and a simplified performance model.

  7. Challenging gait leads to stronger lower-limb kinematic synergies: The effects of walking within a more narrow pathway.

    PubMed

    Rosenblatt, N J; Latash, M L; Hurt, C P; Grabiner, M D

    2015-07-23

    Previous studies using the uncontrolled manifold (UCM) analysis demonstrated that during the swing phase of gait, multi-joint kinematic synergies act to stabilize, i.e., minimize the variance of, the mediolateral trajectory of the swinging limb. Importantly, these synergies are strongest during midswing, suggesting that during gait, individuals may employ strategies to avoid collisions between the limbs at this instance. The purpose of the current study was to test this hypothesis by quantifying whether the synergy index (ΔV) during the middle period of the swing phase of treadmill walking was affected when the width of the treadmill belt was narrowed, a task expected to increase the risk of limb collisions. Eleven healthy young adults walked on a dual-belt treadmill under two conditions: (1) dual-belt - both belts of the treadmill moved at 1.2 m/s (total width: 62.5 cm) and the subject walked with one foot on each of the moving belts and (2) single-belt - one treadmill belt moved at 1.2m/s while the other belt remained stationary and the subject walked with both feet on the moving belt (total width: 30.5 cm). During both conditions, motion capture recorded the positions of 22 passive reflective markers from which UCM analysis was used to quantify ΔV in the joint configuration space. Results indicate that ΔV during the middle-third of swing phase significantly increased by 20% during single-belt walking (p<.01). We interpret this as evidence that the stronger synergies at midswing are needed to stabilize the limb trajectory in order to reduce the risk of between-limb collisions during a period when the lower limbs are nearest each other in the frontal plane. PMID:26003449

  8. Towards multifunctional agricultural landscapes in Europe: Assessing and governing synergies between food production, biodiversity, and ecosystem services - TALE

    NASA Astrophysics Data System (ADS)

    Volk, Martin; Cord, Anna; Demiguel, Ángel; Holzkämper, Annelie; Kaim, Andrea; Kirchner, Mathias; Lienhoop, Nele; Nieto Romero, Marta; Nitsch, Heike; Rutz, Cordula; Saa, Antonio; Schmid, Erwin; Schönhart, Martin; Schramek, Jörg; Strauch, Michael; Tarquis Alfonso, Ana Maria; van der Zanden, Emma H.; Verburg, Peter; Willaarts, Bárbara; Zarrineh, Nina; Rivas, David; Hagemann, Nina

    2016-04-01

    There is a need to improve our understanding of the synergies between biodiversity, food and energy production and other regulating or cultural ecosystem services (ESS) and the development of technical and policy measures to support these synergies. Procedures to quantify synergies and trade-offs between ESS and biodiversity are considered as promising solutions to close this gap. The BiodivERsA project TALE aims at developing such methodologies in a set of representative European agricultural landscapes in Germany, Switzerland, Austria, The Netherlands and Spain. This will be done by using i) a framework that links process-based, integrated, and statistical models with optimization algorithms, and ii) a set of land use scenarios and land use policies, iii) a systematic stakeholder integration process that allows the incorporation of expert knowledge in all phases of the research project to safeguard that research results are of practical relevance. Moreover, the project not only addresses experts but provides an innovative online learning environment that is accessible also for students and the general public.

  9. Adapting portfolio theory for the evaluation of multiple investments in health with a multiplicative extension for treatment synergies.

    PubMed

    Bridges, J F P; Stewart, M; King, M T; van Gool, K

    2002-01-01

    Portfolio theory is central to the analysis of risk in many areas of economics but is seldom used appropriately in health economics. This contribution examines the use of portfolio theory in the context of cost-effectiveness analysis (CEA). A number of modifications are needed to apply portfolio analysis to the economic evaluation of health care interventions. First, the method of reporting the results of a CEA, and consequently some of the underlying assumptions, needs to be modified. Second, portfolio theory needs to be expressed in terms of effects on individuals aggregated to a population. Finally, one needs to allow for the possibility of synergy between the various health interventions. This paper derives a general formula for a portfolio of health care interventions that allows for synergies between interventions where the population effects are aggregated from individual effects. A number of special cases are also derived to highlight the nature of the formulation of the modified portfolio theory. We conclude that, while modified portfolio theory adds a theoretical foundation to health care evaluations, it may not be operational until estimates of the correlation between interventions are available, and the question of uncertainty is resolved in health care evaluation. Also, while a synergy may be present at the individual level, when aggregated over a large population it may not be significant given the standard assumption of constant returns to scale.

  10. Reaching control of a full-torso, modelled musculoskeletal robot using muscle synergies emergent under reinforcement learning.

    PubMed

    Diamond, A; Holland, O E

    2014-03-01

    'Anthropomimetic' robots mimic both human morphology and internal structure-skeleton, muscles, compliance and high redundancy--thus presenting a formidable challenge to conventional control. Here we derive a novel controller for this class of robot which learns effective reaching actions through the sustained activation of weighted muscle synergies, an approach which draws upon compelling, recent evidence from animal and human studies, but is almost unexplored to date in the musculoskeletal robot literature. Since the effective synergy patterns for a given robot will be unknown, we derive a reinforcement-learning approach intended to allow their emergence, in particular those patterns aiding linearization of control. Using an extensive physics-based model of the anthropomimetic ECCERobot, we find that effective reaching actions can be learned comprising only two sequential motor co-activation patterns, each controlled by just a single common driving signal. Factor analysis shows the emergent muscle co-activations can be largely reconstructed using weighted combinations of only 13 common fragments. Testing these 'candidate' synergies as drivable units, the same controller now learns the reaching task both faster and better.

  11. A Synergy-Based Optimally Designed Sensing Glove for Functional Grasp Recognition.

    PubMed

    Ciotti, Simone; Battaglia, Edoardo; Carbonaro, Nicola; Bicchi, Antonio; Tognetti, Alessandro; Bianchi, Matteo

    2016-01-01

    Achieving accurate and reliable kinematic hand pose reconstructions represents a challenging task. The main reason for this is the complexity of hand biomechanics, where several degrees of freedom are distributed along a continuous deformable structure. Wearable sensing can represent a viable solution to tackle this issue, since it enables a more natural kinematic monitoring. However, the intrinsic accuracy (as well as the number of sensing elements) of wearable hand pose reconstruction (HPR) systems can be severely limited by ergonomics and cost considerations. In this paper, we combined the theoretical foundations of the optimal design of HPR devices based on hand synergy information, i.e., the inter-joint covariation patterns, with textile goniometers based on knitted piezoresistive fabrics (KPF) technology, to develop, for the first time, an optimally-designed under-sensed glove for measuring hand kinematics. We used only five sensors optimally placed on the hand and completed hand pose reconstruction (described according to a kinematic model with 19 degrees of freedom) leveraging upon synergistic information. The reconstructions we obtained from five different subjects were used to implement an unsupervised method for the recognition of eight functional grasps, showing a high degree of accuracy and robustness. PMID:27271621

  12. A Riemannian geometry theory of human movement: The geodesic synergy hypothesis.

    PubMed

    Neilson, Peter D; Neilson, Megan D; Bye, Robin T

    2015-12-01

    Mass-inertia loads on muscles change with posture and with changing mechanical interactions between the body and the environment. The nervous system must anticipate changing mass-inertia loads, especially during fast multi-joint coordinated movements. Riemannian geometry provides a mathematical framework for movement planning that takes these inertial interactions into account. To demonstrate this we introduce the controlled (vs. biomechanical) degrees of freedom of the body as the coordinate system for a configuration space with movements represented as trajectories. This space is not Euclidean. It is endowed at each point with a metric equal to the mass-inertia matrix of the body in that configuration. This warps the space to become Riemannian with curvature at each point determined by the differentials of the mass-inertia at that point. This curvature takes nonlinear mass-inertia interactions into account with lengths, velocities, accelerations and directions of movement trajectories all differing from those in Euclidean space. For newcomers to Riemannian geometry we develop the intuitive groundwork for a Riemannian field theory of human movement encompassing the entire body moving in gravity and in mechanical interaction with the environment. In particular we present a geodesic synergy hypothesis concerning planning of multi-joint coordinated movements to achieve goals with minimal muscular effort. PMID:26302481

  13. A synergy of values. Catholic healthcare leaders must implement their organization's mission and model its values.

    PubMed

    Clifton, R M; McEnroe, J J

    1994-06-01

    Catholic organizations need to select, develop, and retain healthcare leaders who dedicate themselves to carrying on the Church's healing ministry and the work begun by those who have preceded them. Persons entrusted to carry on Jesus' healing mission perform their duties out of a sense of commitment to the ministry and a love for the persons with whom they work and whom they serve. They recognize a synergy between their own values and the values of the healthcare organizations they lead. Dedication to leadership in Catholic healthcare can be viewed from three perspectives: the Bible and selected documents of the Catholic Church; the transfer of responsibility for Catholic healthcare from religious congregations to evolving forms of sponsorship; and the implications for the selection, development, and retention of healthcare leaders, both lay and religious. Servant-leadership is an integral part of the religious tradition that underlies Catholic healthcare. As cooperation increases between healthcare providers, third-party payers, employers, and other healthcare agents. Catholic healthcare organizations are challenged to reassert a mission and values that will enable healthcare in the United States to be delivered both compassionately and competently.

  14. Nanoparticle synergies in modifying thermal conductivity for heat exchanger in condensing boilers

    NASA Astrophysics Data System (ADS)

    Yang, Kai; He, Shan; Butcher, Thomas; Trojanowski, Rebecca; Sun, Ning; Gersappe, Dilip; Rafailovich, Miriam

    2013-03-01

    The heat exchanger we are using for condensing boilers is mainly made from aluminum alloys and stainless steel. However, the metal is relatively expensive and corrosion together with maintenance is also a big problem. Therefore, we have developed a new design and material which contain carbon black, carbon nanotube, aluminum oxide and graphene as additives in polypropylene. When multiple types of particles can be melt blended simultaneously and synergies can be achieved, imparting particles to the nanocomposite, achieved much higher thermal conductivity rather than single additive. Here we show the flame retardant nanocomposite which can pass the UL-94-V0 vertical burning test, perform nice in Cone Calorimetry Test and has relatively good mechanical properties. SEM images of the blend show that the Carbon nanobute and other additives well dispersed within the polymer matrix which match our computational calculation for getting the percolation to achieve thermal conductivity around 1.5W/m .K rather than 0.23W/m .K as pure polypropylene. Haydale/Cheap Tubes

  15. Pore Structure and Synergy in Antimicrobial Peptides of the Magainin Family

    PubMed Central

    Pino-Angeles, Almudena; Leveritt, John M.; Lazaridis, Themis

    2016-01-01

    Magainin 2 and PGLa are among the best-studied cationic antimicrobial peptides. They bind preferentially to negatively charged membranes and apparently cause their disruption by the formation of transmembrane pores, whose detailed structure is still unclear. Here we report the results of 5–9 μs all-atom molecular dynamics simulations starting from tetrameric transmembrane helical bundles of these two peptides, as well as their stoichiometric mixture, and the analog MG-H2 in DMPC or 3:1 DMPC/DMPG membranes. The simulations produce pore structures that appear converged, although some effect of the starting peptide arrangement (parallel vs. antiparallel) is still observed on this timescale. The peptides remain mostly helical and adopt tilted orientations. The calculated tilt angles for PGLa are in excellent agreement with recent solid state NMR experiments. The antiparallel dimer structure in the magainin 2 simulations resembles previously determined NMR and crystal structures. More transmembrane orientations and a larger and more ordered pore are seen in the 1:1 heterotetramer with an antiparallel helix arrangement. Insights into the mechanism of synergy between these two peptides are obtained via implicit solvent modeling of homo- and heterodimers and analysis of interactions in the atomistic simulations. This analysis suggests stronger pairwise interactions in the heterodimer than in the two homodimers. PMID:26727376

  16. Discovery of Drug Synergies in Gastric Cancer Cells Predicted by Logical Modeling.

    PubMed

    Flobak, Åsmund; Baudot, Anaïs; Remy, Elisabeth; Thommesen, Liv; Thieffry, Denis; Kuiper, Martin; Lægreid, Astrid

    2015-08-01

    Discovery of efficient anti-cancer drug combinations is a major challenge, since experimental testing of all possible combinations is clearly impossible. Recent efforts to computationally predict drug combination responses retain this experimental search space, as model definitions typically rely on extensive drug perturbation data. We developed a dynamical model representing a cell fate decision network in the AGS gastric cancer cell line, relying on background knowledge extracted from literature and databases. We defined a set of logical equations recapitulating AGS data observed in cells in their baseline proliferative state. Using the modeling software GINsim, model reduction and simulation compression techniques were applied to cope with the vast state space of large logical models and enable simulations of pairwise applications of specific signaling inhibitory chemical substances. Our simulations predicted synergistic growth inhibitory action of five combinations from a total of 21 possible pairs. Four of the predicted synergies were confirmed in AGS cell growth real-time assays, including known effects of combined MEK-AKT or MEK-PI3K inhibitions, along with novel synergistic effects of combined TAK1-AKT or TAK1-PI3K inhibitions. Our strategy reduces the dependence on a priori drug perturbation experimentation for well-characterized signaling networks, by demonstrating that a model predictive of combinatorial drug effects can be inferred from background knowledge on unperturbed and proliferating cancer cells. Our modeling approach can thus contribute to preclinical discovery of efficient anticancer drug combinations, and thereby to development of strategies to tailor treatment to individual cancer patients.

  17. Occurrence of Lipophilic Marine Toxins in Shellfish from Galicia (NW of Spain) and Synergies among Them

    PubMed Central

    Rodríguez, Laura P.; González, Virginia; Martínez, Aníbal; Paz, Beatriz; Lago, Jorge; Cordeiro, Victoria; Blanco, Lucía; Vieites, Juan Manuel; Cabado, Ana G.

    2015-01-01

    Lipophilic marine toxins pose a serious threat for consumers and an enormous economic problem for shellfish producers. Synergistic interaction among toxins may play an important role in the toxicity of shellfish and consequently in human intoxications. In order to study the toxic profile of molluscs, sampled during toxic episodes occurring in different locations in Galicia in 2014, shellfish were analyzed by liquid chromatography tandem mass spectrometry (LC–MS/MS), the official method for the detection of lipophilic toxins. The performance of this procedure was demonstrated to be fit for purpose and was validated in house following European guidelines. The vast majority of toxins present in shellfish belonged to the okadaic acid (OA) group and some samples from a particular area contained yessotoxin (YTX). Since these toxins occur very often with other lipophilic toxins, we evaluated the potential interactions among them. A human neuroblastoma cell line was used to study the possible synergies of OA with other lipophilic toxins. Results show that combination of OA with dinophysistoxin 2 (DTX2) or YTX enhances the toxicity triggered by OA, decreasing cell viability and cell proliferation, depending on the toxin concentration and incubation time. The effects of other lipophilic toxins as 13-desmethyl Spirolide C were also evaluated in vitro. PMID:25815891

  18. Landfills as critical infrastructures: synergy between non-invasive monitoring technologies

    NASA Astrophysics Data System (ADS)

    Scozzari, Andrea; Raco, Brunella; Battaglini, Raffaele

    2014-05-01

    This work deals with a methodology for estimating the behaviour of a landfill system by means of the integration between two different non-invasive technologies. In fact, there is a widespread agreement on the fact that these infrastructures produce about 23% of the total anthropogenic methane released to the atmosphere. Despite that, there's still no internationally accepted protocol to quantify the leakage of biogas from a landfill with a common standard approach. This work proposes an assessment of the performance of a landfill system in terms of biogas release to the atmosphere. Such evaluation is performed by means of a direct measurement of gas flux with the accumulation chamber method, combined with the detection of thermal anomalies by infrared radiometry. In order to derive flux maps from a set of punctual measurements and calculate an overall quantity of emitted gas, a geostatistical technique is necessarily applied and briefly illustrated. A case study regarding an infrastructure located in Tuscany (Italy) is shown, where a discussion about the evolution of the landfill site through successive campaigns is also suggested. The role played by infrared thermography and its synergy with direct flux measurements is clearly perceivable in this context. The main benefit of the presented approach is a significant increase of the energy recovered from the landfill sites by optimising the collection of biogas, which implies a reduction of the total anthropogenic methane originated from the disposal of wastes released to the atmosphere.

  19. Cognitive synergy in groups and group-to-individual transfer of decision-making competencies.

    PubMed

    Curşeu, Petru L; Meslec, Nicoleta; Pluut, Helen; Lucas, Gerardus J M

    2015-01-01

    In a field study (148 participants organized in 38 groups) we tested the effect of group synergy and one's position in relation to the collaborative zone of proximal development (CZPD) on the change of individual decision-making competencies. We used two parallel sets of decision tasks reported in previous research to test rationality and we evaluated individual decision-making competencies in the pre-group and post-group conditions as well as group rationality (as an emergent group level phenomenon). We used multilevel modeling to analyze the data and the results showed that members of synergetic groups had a higher cognitive gain as compared to members of non-synergetic groups, while highly rational members (members above the CZPD) had lower cognitive gains compared to less rational group members (members situated below the CZPD). These insights extend the literature on group-to-individual transfer of learning and have important practical implications as they show that group dynamics influence the development of individual decision-making competencies.

  20. Synergy and destructive interferences between local magnetic anisotropies in binuclear complexes

    NASA Astrophysics Data System (ADS)

    Guihéry, Nathalie; Ruamps, Renaud; Maurice, Rémi; de Graaf, Coen

    2015-12-01

    Magnetic anisotropy is responsible for the single molecule magnet behavior of transition metal complexes. This behavior is characterized by a slow relaxation of the magnetization for low enough temperatures, and thus for a possible blocking of the magnetization. This bistable behavior can lead to possible technological applications in the domain of data storage or quantum computing. Therefore, the understanding of the microscopic origin of magnetic anisotropy has received a considerable interest during the last two decades. The presentation focuses on the determination of the anisotropy parameters of both mono-nuclear and bi-nuclear types of complexes and on the control and optimization of the anisotropic properties. The validity of the model Hamiltonians commonly used to characterize such complexes has been questioned and it is shown that neither the standard multispin Hamiltonian nor the giant spin Hamiltonian are appropriate for weakly coupled ions. Alternative models have been proposed and used to properly extract the relevant parameters. Rationalizations of the magnitude and nature of both local anisotropies of single ions and the molecular anisotropy of polynuclear complexes are provided. The synergy and interference effects between local magnetic anisotropies are studied in a series of binuclear complexes.

  1. Uncovering compounds by synergy of cluster expansion and high-throughput methods.

    PubMed

    Levy, Ohad; Hart, Gus L W; Curtarolo, Stefano

    2010-04-01

    Predicting from first-principles calculations whether mixed metallic elements phase-separate or form ordered structures is a major challenge of current materials research. It can be partially addressed in cases where experiments suggest the underlying lattice is conserved, using cluster expansion (CE) and a variety of exhaustive evaluation or genetic search algorithms. Evolutionary algorithms have been recently introduced to search for stable off-lattice structures at fixed mixture compositions. The general off-lattice problem is still unsolved. We present an integrated approach of CE and high-throughput ab initio calculations (HT) applicable to the full range of compositions in binary systems where the constituent elements or the intermediate ordered structures have different lattice types. The HT method replaces the search algorithms by direct calculation of a moderate number of naturally occurring prototypes representing all crystal systems and guides CE calculations of derivative structures. This synergy achieves the precision of the CE and the guiding strengths of the HT. Its application to poorly characterized binary Hf systems, believed to be phase-separating, defines three classes of alloys where CE and HT complement each other to uncover new ordered structures.

  2. Maximum performance synergy: A new approach to recording studio control room design

    NASA Astrophysics Data System (ADS)

    Szymanski, Jeff D.

    2003-10-01

    Popular recording studio control room designs include LEDE(tm), RFZ(tm), and nonenvironment rooms. The common goal of all of these is to create an accurate acoustical environment that does not distort or otherwise color audio reproduction. Also common to these designs is the frequent need to have multiple ancillary recording rooms, often adjacent to the main control room, where group members perform. This approach, where group members are physically separated from one another, can lead to lack of ensemble in the finished recordings. New twists on old acoustical treatment techniques have been implemented at a studio in Nashville, Tennessee, which minimize the need for multiple ancillary recording rooms, thus creating an environment where talent, producer and recording professionals can all occupy the same space for maximum performance synergy. Semi-separated performance areas are designed around a central, critical listening area. The techniques and equipment required to achieve this separation are reviewed, as are advantages and disadvantages to this new control room design approach.

  3. Food recognition by Chaetopterus variopedatus (Renier): synergy of mechanical and chemical stimulation

    SciTech Connect

    Sumida, B.H.; Case, J.F.

    1983-01-01

    Food recognition and related behavior was studied in specimens of Chaetopterus variopedatus (Renier) housed in glass tubes in flowing seawater. Particulates and amino acids were added to the flow, mimicking food stimuli and water currents produced by the worm's fanning and were recorded with a Doppler flow meter. Fanning duration was negatively correlated with feeding. Of amino acids tested, glycine and taurine significantly reduced fanning duration. Cellulose chromatography beads, a non-chemically enriched particulate food mimic, also significantly reduced fanning duration. However, neither particulate nor chemical stimuli were equal to plankton (Gonyaulax polyedra) in reducing fanning duration. When an ineffectively low concentration of glycine was presented simultaneously with chromatography beads, at one-hundredth the particle concentration of plankton, fanning duration shortened to periods characteristic of responses to plankton. These results suggest that both particulate (tactile) and chemical stimuli are important in the recognition of food. Synergy between the two senses appears necessary to effect a maximum feeding response. Long-term (24 hour) exposure to low-concentration water-soluble petroleum fractions (WSF) caused desensitization of chemoreception in adult C. variopedatus. Short-term exposure to WSF had no effect on fanning duration. Dilute acetic acid solution evoked simultaneous bioluminescence and rejection responses. 39 references, 7 figures, 7 tables.

  4. Functional synergy between the Munc13 C-terminal C1 and C2 domains

    PubMed Central

    Liu, Xiaoxia; Seven, Alpay Burak; Camacho, Marcial; Esser, Victoria; Xu, Junjie; Trimbuch, Thorsten; Quade, Bradley; Su, Lijing; Ma, Cong; Rosenmund, Christian; Rizo, Josep

    2016-01-01

    Neurotransmitter release requires SNARE complexes to bring membranes together, NSF-SNAPs to recycle the SNAREs, Munc18-1 and Munc13s to orchestrate SNARE complex assembly, and Synaptotagmin-1 to trigger fast Ca2+-dependent membrane fusion. However, it is unclear whether Munc13s function upstream and/or downstream of SNARE complex assembly, and how the actions of their multiple domains are integrated. Reconstitution, liposome-clustering and electrophysiological experiments now reveal a functional synergy between the C1, C2B and C2C domains of Munc13-1, indicating that these domains help bridging the vesicle and plasma membranes to facilitate stimulation of SNARE complex assembly by the Munc13-1 MUN domain. Our reconstitution data also suggest that Munc18-1, Munc13-1, NSF, αSNAP and the SNAREs are critical to form a ‘primed’ state that does not fuse but is ready for fast fusion upon Ca2+ influx. Overall, our results support a model whereby the multiple domains of Munc13s cooperate to coordinate synaptic vesicle docking, priming and fusion. DOI: http://dx.doi.org/10.7554/eLife.13696.001 PMID:27213521

  5. Scaling and optimal synergy: Two principles determining microbial growth in complex media

    NASA Astrophysics Data System (ADS)

    Massucci, Francesco Alessandro; Guimerà, Roger; Nunes Amaral, Luís A.; Sales-Pardo, Marta

    2015-06-01

    High-throughput experimental techniques and bioinformatics tools make it possible to obtain reconstructions of the metabolism of microbial species. Combined with mathematical frameworks such as flux balance analysis, which assumes that nutrients are used so as to maximize growth, these reconstructions enable us to predict microbial growth. Although such predictions are generally accurate, these approaches do not give insights on how different nutrients are used to produce growth, and thus are difficult to generalize to new media or to different organisms. Here, we propose a systems-level phenomenological model of metabolism inspired by the virial expansion. Our model predicts biomass production given the nutrient uptakes and a reduced set of parameters, which can be easily determined experimentally. To validate our model, we test it against in silico simulations and experimental measurements of growth, and find good agreement. From a biological point of view, our model uncovers the impact that individual nutrients and the synergistic interaction between nutrient pairs have on growth, and suggests that we can understand the growth maximization principle as the optimization of nutrient synergies.

  6. Developmental synergy between thalamic structure and interhemispheric connectivity in the visual system of preterm infants

    PubMed Central

    Ceschin, Rafael; Wisnowski, Jessica L.; Paquette, Lisa B.; Nelson, Marvin D.; Blüml, Stefan; Panigrahy, Ashok

    2015-01-01

    Thalamic structural co-variation with cortical regions has been demonstrated in preterm infants, but its relationship to cortical function and severity of non-cystic white matter injury (non-cystic WMI) is unclear. The relationship between thalamic morphology and both cortical network synchronization and cortical structural connectivity has not been established. We tested the hypothesis that in preterm neonates, thalamic volume would correlate with primary cortical visual function and microstructural integrity of cortico-cortical visual association pathways. A total of 80 term-equivalent preterm and 44 term-born infants underwent high-resolution structural imaging coupled with visual functional magnetic resonance imaging or diffusion tensor imaging. There was a strong correlation between thalamic volume and primary visual cortical activation in preterms with non-cystic WMI (r = 0.81, p-value = 0.001). Thalamic volume also correlated strongly with interhemispheric cortico-cortical connectivity (splenium) in preterm neonates with a relatively higher severity of non-cystic WMI (p-value < 0.001). In contrast, there was lower correlation between thalamic volume and intrahemispheric cortico-cortical connectivity, including the inferior longitudinal fasciculus and inferior frontal orbital fasciculus. This study shows distinct temporal overlap in the disruption of thalamo-cortical and interhemispheric cortico-cortical connectivity in preterm infants suggesting developmental synergy between thalamic morphology and the emergence of cortical networks in the last trimester. PMID:26106571

  7. Effects of Design Variants in Lower-Limb Prostheses on Gait Synergy

    PubMed Central

    Pitkin, Mark R.

    2016-01-01

    A lower-limb prosthesis is the mechanical device with which an amputee’s residual limb interacts with the walking surface. The pressure and shear forces that affect the residuum due to prosthesis use are the sources of pain, residual-limb skin problems and gait deviations. Direct approaches to reducing these problems include improving fit, alignment technique and socket design as well as increasing cushioning with socket liners. A summary of typical malalignments and their consequences is presented. The malalignments are considered sources of excessive moments applied to the residuum, which simplifies the analysis of a patient’s gait. A better design of prosthetic joints could improve prosthetic gait. This article addresses the key mechanical parameter of prosthetic joints, namely the dependence “moment of resistance/angle of deflection.” A mathematical model has been developed that links stresses on the residuum in transtibial amputees with the moment of resistance in the prosthetic ankle at the critical gait phases. Analysis of the model yields a substantial decrease in stresses on the residuum during the most demanding, load-bearing phase of stance if the moment of resistance in the ankle is similar to that seen in the biological ankle joint. Gait study shows use of the experimental rolling-joint prosthetic foot more closely simulates normal gait synergy than the SACH foot. PMID:27087763

  8. The Synergies research-practice partnership project: a 2020 Vision case study

    NASA Astrophysics Data System (ADS)

    Falk, John H.; Dierking, Lynn D.; Staus, Nancy L.; Wyld, Jennifer N.; Bailey, Deborah L.; Penuel, William R.

    2016-03-01

    This paper, describes Synergies, an on-going longitudinal study and design effort, being conducted in a diverse, under-resourced community in Portland, Oregon, with the goal of measurably improving STEM learning, interest and participation by early adolescents, both in school and out of school. Authors examine how the work of this particular research-practice partnership is attempting to accommodate the six principles outlined in this issue: (1) to more accurately reflect learning as a lifelong process occurring across settings, situations and time frames; (2) to consider what STEM content is worth learning; (3) to examine learning as a cultural process, involving varied repertoires of practice across learners' everyday lives; (4) to directly involve practitioners (and learners) in the research process; (5) to document how existing and emerging technologies and new media are, and will continue, to shape and redefine the content and practice of STEM learning research; and, (6) to take into account the broader socio-cultural-political contexts of the needs and concerns of the larger global society.

  9. The Synergy Between Total Scattering and Advanced Simulation Techniques: Quantifying Geopolymer Gel Evolution

    SciTech Connect

    White, Claire; Bloomer, Breaunnah E.; Provis, John L.; Henson, Neil J.; Page, Katharine L.

    2012-05-16

    With the ever increasing demands for technologically advanced structural materials, together with emerging environmental consciousness due to climate change, geopolymer cement is fast becoming a viable alternative to traditional cements due to proven mechanical engineering characteristics and the reduction in CO2 emitted (approximately 80% less CO2 emitted compared to ordinary Portland cement). Nevertheless, much remains unknown regarding the kinetics of the molecular changes responsible for nanostructural evolution during the geopolymerization process. Here, in-situ total scattering measurements in the form of X-ray pair distribution function (PDF) analysis are used to quantify the extent of reaction of metakaolin/slag alkali-activated geopolymer binders, including the effects of various activators (alkali hydroxide/silicate) on the kinetics of the geopolymerization reaction. Restricting quantification of the kinetics to the initial ten hours of reaction does not enable elucidation of the true extent of the reaction, but using X-ray PDF data obtained after 128 days of reaction enables more accurate determination of the initial extent of reaction. The synergies between the in-situ X-ray PDF data and simulations conducted by multiscale density functional theory-based coarse-grained Monte Carlo analysis are outlined, particularly with regard to the potential for the X-ray data to provide a time scale for kinetic analysis of the extent of reaction obtained from the multiscale simulation methodology.

  10. Functional synergy between the Munc13 C-terminal C1 and C2 domains.

    PubMed

    Liu, Xiaoxia; Seven, Alpay Burak; Camacho, Marcial; Esser, Victoria; Xu, Junjie; Trimbuch, Thorsten; Quade, Bradley; Su, Lijing; Ma, Cong; Rosenmund, Christian; Rizo, Josep

    2016-05-23

    Neurotransmitter release requires SNARE complexes to bring membranes together, NSF-SNAPs to recycle the SNAREs, Munc18-1 and Munc13s to orchestrate SNARE complex assembly, and Synaptotagmin-1 to trigger fast Ca(2+)-dependent membrane fusion. However, it is unclear whether Munc13s function upstream and/or downstream of SNARE complex assembly, and how the actions of their multiple domains are integrated. Reconstitution, liposome-clustering and electrophysiological experiments now reveal a functional synergy between the C1, C2B and C2C domains of Munc13-1, indicating that these domains help bridging the vesicle and plasma membranes to facilitate stimulation of SNARE complex assembly by the Munc13-1 MUN domain. Our reconstitution data also suggest that Munc18-1, Munc13-1, NSF, αSNAP and the SNAREs are critical to form a 'primed' state that does not fuse but is ready for fast fusion upon Ca(2+) influx. Overall, our results support a model whereby the multiple domains of Munc13s cooperate to coordinate synaptic vesicle docking, priming and fusion.

  11. Synergy and destructive interferences between local magnetic anisotropies in binuclear complexes

    SciTech Connect

    Guihéry, Nathalie; Ruamps, Renaud; Maurice, Rémi

    2015-12-31

    Magnetic anisotropy is responsible for the single molecule magnet behavior of transition metal complexes. This behavior is characterized by a slow relaxation of the magnetization for low enough temperatures, and thus for a possible blocking of the magnetization. This bistable behavior can lead to possible technological applications in the domain of data storage or quantum computing. Therefore, the understanding of the microscopic origin of magnetic anisotropy has received a considerable interest during the last two decades. The presentation focuses on the determination of the anisotropy parameters of both mono-nuclear and bi-nuclear types of complexes and on the control and optimization of the anisotropic properties. The validity of the model Hamiltonians commonly used to characterize such complexes has been questioned and it is shown that neither the standard multispin Hamiltonian nor the giant spin Hamiltonian are appropriate for weakly coupled ions. Alternative models have been proposed and used to properly extract the relevant parameters. Rationalizations of the magnitude and nature of both local anisotropies of single ions and the molecular anisotropy of polynuclear complexes are provided. The synergy and interference effects between local magnetic anisotropies are studied in a series of binuclear complexes.

  12. IBEX: The Evolving Global View and Synergies with In Situ Voyager Observations

    NASA Astrophysics Data System (ADS)

    McComas, D. J.

    2015-12-01

    The Interstellar Boundary Explorer (IBEX) has now returned nearly seven years of observations, which comprise 14 full sets of energy resolved all-sky maps and provide the global view of our Sun's interaction with very local part of the galaxy. With such a long baseline of observations, we are able to examine time variations in the outer heliosphere as it responds to both 11-year solar cycle variations and longer term secular evolution of the three dimensional solar wind. Now that we have collected over half a solar cycle of observations, IBEX is beginning to show us how the heliosphere - our home in the galaxy - varies in time as well as space. In this talk we present the most recent observations and review some other recent discoveries from IBEX. We also examine the synergy between the global view provided by IBEX and the in situ observations form the Voyager 1 and 2 spacecraft. Finally, we discuss the incredible improvement in interstellar observations - and our understanding of the local interstellar medium - that the Interstellar Mapping and Acceleration Probe (IMAP) will provide.

  13. Nuclear microprobe - synchrotron synergy: towards integrated quantitative real-time elemental imaging using PIXE and SCRF.

    SciTech Connect

    Ryan, C. G.; Etschmann, B. E.; Vogt, S.; Maser, J.; Harland, C. L.; van Achterbergh, E.; Legnini, D.; Experimental Facilities Division; CSIRO Exploration and Mining; Australian Synchrotron Research Program, ANSTO

    2005-01-01

    The Dynamic Analysis (DA) method, for the projection of quantitative elemental images using Proton Induced X-ray Emission (PIXE), has been extended for use with energy-dispersive Synchrotron X-ray Fluorescence (SXRF) data collected with the X-ray microprobe by making use of similarities and synergy with nuclear microscopy. The broad element sensitivity of PIXE is complemented by the selective nature of SXRF, where the beam energy can be tuned to optimize the sensitivity in a portion of the periodic table. PIXE combined with Proton Induced {gamma}-ray Emission (PIGE) in this study provided images of geological samples of 25 elements, including characteristic X-rays up to the energy of the Nd K lines (37 keV). Maximum sensitivity was achieved for elements around Z {approx} 33 with detection limits of {approx}250 ppb (in 5 h). SXRF using a 16.1 keV photon microbeam provided images of 16 elements, with optimum sensitivity around Z {approx} 35 with detection limits of {approx}70 ppb (in 11 h), an improvement of {approx}2.4 times when corrected for acquisition time.

  14. Cognitive synergy in groups and group-to-individual transfer of decision-making competencies

    PubMed Central

    Curşeu, Petru L.; Meslec, Nicoleta; Pluut, Helen; Lucas, Gerardus J. M.

    2015-01-01

    In a field study (148 participants organized in 38 groups) we tested the effect of group synergy and one's position in relation to the collaborative zone of proximal development (CZPD) on the change of individual decision-making competencies. We used two parallel sets of decision tasks reported in previous research to test rationality and we evaluated individual decision-making competencies in the pre-group and post-group conditions as well as group rationality (as an emergent group level phenomenon). We used multilevel modeling to analyze the data and the results showed that members of synergetic groups had a higher cognitive gain as compared to members of non-synergetic groups, while highly rational members (members above the CZPD) had lower cognitive gains compared to less rational group members (members situated below the CZPD). These insights extend the literature on group-to-individual transfer of learning and have important practical implications as they show that group dynamics influence the development of individual decision-making competencies. PMID:26441750

  15. Synergy and Mode of Action of Ceftazidime plus Quercetin or Luteolin on Streptococcus pyogenes

    PubMed Central

    Siriwong, Supatcharee; Thumanu, Kanjana; Hengpratom, Tanaporn; Eumkeb, Griangsak

    2015-01-01

    Streptococcus pyogenes causes streptococcal toxic shock syndrome. The recommended therapy has been often failure through the interfering of beta-lactamase-producing bacteria (BLPB). The present study was to investigate antibacterial activity, synergy, and modes of action of luteolin and quercetin using alone and plus ceftazidime against S. pyogenes. The MICs of ceftazidime, luteolin, and quercetin against all S. pyogenes were 0.50, 128, and 128 µg mL−1, respectively. A synergistic effect was exhibited on luteolin and quercetin plus ceftazidime against these strains at fractional inhibitory concentration indices 0.37 and 0.27, respectively, and was confirmed by the viable count. These combinations increased cytoplasmic membrane (CM) permeability, caused irregular cell shape, peptidoglycan, and CM damage, and decreased nucleic acid but increased proteins in bacterial cells. Enzyme assay demonstrated that these flavonoids had an inhibitory activity against β-lactamase. In summary, this study provides evidence that the inhibitory mode of action of luteolin and quercetin may be mediated via three mechanisms: (1) inhibiting of peptidoglycan synthesis, (2) increasing CM permeability, and (3) decreasing nucleic acid but increasing the protein contents of bacterial cells. So, luteolin and quercetin propose the high potential to develop adjunct to ceftazidime for the treatment of coexistence of the BLPB and S. pyogenes infections. PMID:26576195

  16. Educational opportunities based on the university-industry synergies in an open innovation framework

    NASA Astrophysics Data System (ADS)

    Lucia, Óscar; Burdio, José M.; Acero, Jesús; Barragán, Luis A.; Garcia, José R.

    2012-03-01

    Collaboration between Industry and University is becoming more important in order to improve the competitiveness of the research and development activities. Moreover, establishing synergies to bridge the gap between the academic and industrial spheres has demonstrated to be advantageous for both of them. Nowadays, Industry is moving towards an open innovation structure, in which external agents as universities play a key role. Besides, University is also seeking a more active learning methodology to improve the education of students for the real world. Considering this framework, a special effort should be done to take advantage of the collaborative work between Industry and University. The aim of this paper is to present the collaborative framework and the benefits obtained of the educational activities as a consequence of the long-term collaboration established between the University of Zaragoza and the Bosh and Siemens Home Appliances Group. The key stones of the collaboration are presented, and the positive outcomes for the students are highlighted. The strengths, weaknesses, opportunities, and threats of the proposed program are also discussed.

  17. Tradeoffs and synergies between biofuel production and large-scale solar infrastructure in deserts

    NASA Astrophysics Data System (ADS)

    Ravi, S.; Lobell, D. B.; Field, C. B.

    2012-12-01

    Solar energy installations in deserts are on the rise, fueled by technological advances and policy changes. Deserts, with a combination of high solar radiation and availability of large areas unusable for crop production are ideal locations for large scale solar installations. For efficient power generation, solar infrastructures require large amounts of water for operation (mostly for cleaning panels and dust suppression), leading to significant moisture additions to desert soil. A pertinent question is how to use the moisture inputs for sustainable agriculture/biofuel production. We investigated the water requirements for large solar infrastructures in North American deserts and explored the possibilities for integrating biofuel production with solar infrastructure. In co-located systems the possible decline in yields due to shading by solar panels may be offsetted by the benefits of periodic water addition to biofuel crops, simpler dust management and more efficient power generation in solar installations, and decreased impacts on natural habitats and scarce resources in deserts. In particular, we evaluated the potential to integrate solar infrastructure with biomass feedstocks that grow in arid and semi-arid lands (Agave Spp), which are found to produce high yields with minimal water inputs. To this end, we conducted detailed life cycle analysis for these coupled agave biofuel - solar energy systems to explore the tradeoffs and synergies, in the context of energy input-output, water use and carbon emissions.

  18. Synergies in the space of control variables within the equilibrium-point hypothesis.

    PubMed

    Ambike, S; Mattos, D; Zatsiorsky, V M; Latash, M L

    2016-02-19

    We use an approach rooted in the recent theory of synergies to analyze possible co-variation between two hypothetical control variables involved in finger force production based on the equilibrium-point (EP) hypothesis. These control variables are the referent coordinate (R) and apparent stiffness (C) of the finger. We tested a hypothesis that inter-trial co-variation in the {R; C} space during repeated, accurate force production trials stabilizes the fingertip force. This was expected to correspond to a relatively low amount of inter-trial variability affecting force and a high amount of variability keeping the force unchanged. We used the "inverse piano" apparatus to apply small and smooth positional perturbations to fingers during force production tasks. Across trials, R and C showed strong co-variation with the data points lying close to a hyperbolic curve. Hyperbolic regressions accounted for over 99% of the variance in the {R; C} space. Another analysis was conducted by randomizing the original {R; C} data sets and creating surrogate data sets that were then used to compute predicted force values. The surrogate sets always showed much higher force variance compared to the actual data, thus reinforcing the conclusion that finger force control was organized in the {R; C} space, as predicted by the EP hypothesis, and involved co-variation in that space stabilizing total force. PMID:26701299

  19. Synergy, compatibility, and innovation: merging Lewis acids with stereoselective enamine catalysis.

    PubMed

    Gualandi, Andrea; Mengozzi, Luca; Wilson, Claire M; Cozzi, Pier Giorgio

    2014-04-01

    In recent years there has been an accelerated rate of development in the field of organocatalysis, with asymmetric organocatalysis now reaching full maturity. The invention of new organocatalytic reactions and the exploration of new concepts now appear in tandem with the application of organocatalytic techniques in the synthesis of natural products and active pharmaceutical ingredients (APIs). After a "golden rush" in organocatalysis, researchers are now starting to combine different methods, thereby taking advantage of the significant benefits of synergy. Metals are used in combination with organocatalytic processes, thus reaching complexity that is found in nature, where enzymes take advantage of the presence of certain metals to increase the arsenal of organic transformations available. In this Focus review, we illustrate the possibility of a "happy marriage" between Lewis acids and organocatalytic stereoselective processes. Questions have been raised about the combination of Lewis acids and organocatalysis owing to the presence of water and/or strong bases in these processes. Some Lewis acids have been shown to be compatible with organocatalysis and concepts relating to their use will be illustrated herein. To summarize the fruitful use of Lewis acids in stereoselective organocatalytic processes, we will draw attention to the advantages and selectivity achieved using this method.

  20. Synergy in Two-Frequency Fast Wave Cyclotron Harmonic Absorption in DIII-D

    SciTech Connect

    Pinsker, R. I.; Choi, M.; Heidbrink, W. W.; Zhu, Y.; Porkolab, M.; Baity, F. W.; Hosea, J. C.

    2009-11-26

    Fast waves (FWs) at 60 MHz and at 90 MHz are coupled to DIII-D discharges for central heating and current drive at net FW power up to 3.5 MW. The primary absorption mechanism is intended to be direct electron damping in the plasma core. In discharges at B = 2 T with fast deuteron populations from neutral beam injection, 4th and 6th deuterium cyclotron harmonic absorption on the fast ions competes with direct electron damping. Previous experiments have shown that the 6{omega}{sub D} absorption of the 90 MHz FWs is weaker than the 4{omega}{sub D} absorption of 60 MHz FWs, in agreement with a model that includes unspecified edge losses. Recent experiments have shown that if the fast deuterons are accelerated by absorption of 60 MHz (4{omega}{sub D}) FWs, adding 90 MHz power (6{omega}{sub D}) can increase the fusion neutron rate by a larger increment than is obtained with 90 MHz power alone. Details of this synergy between 4{omega}{sub D} and 6{omega}{sub D} absorption are presented.

  1. The role of nanoparticle synergies in modifying the thermal properties of biodegradable polymer blends

    NASA Astrophysics Data System (ADS)

    Yang, Kai; He, Shan; Davis, Rachel; Rafailovich, Miriam; Kashiwagi, Takashi

    2012-02-01

    Most of thermoplastic polymers are brittle, when sufficient amounts are added to get flame retardant properties.Furthermore, melt-blending starch with other biodegradable polymers is difficult since very few polymers are compatible with starches.We have developed a new nanoparticles where resorcinol diphenyl phosphates (RDP) is used to modify the surface energy, allowing the particles to be dispersed within polymer.When multiple types of particles share the same coating,they can be melt blended simultaneously and synergies can be achieved, imparting properties to the nanocomposite, which cannot be achieved by any single additive. Here we show that RDP modified starch, can be extruded together with the biodegradable polymers,Ecoflex and polylactic acid,to produce flame retardant nanocomposites which can pass the UL-94-V0 test.TEM images of the blend show that the RDP-coated starch particles were well dispersed within the polymer matrix providing the flame retardant properties,while the RDP clays are reducing the interfacial tension and contributing to compatibilization. Nanomechanical measurements of the chars remaining after cone calorimetric measurements indicate that maintaining flexibility of the chars may be an additional factor in achieving good flame retardant properties.

  2. Response of Aphidius colemani to aphid sex pheromone varies depending on plant synergy and prior experience.

    PubMed

    Fernández-Grandon, G M; Poppy, G M

    2015-08-01

    A critical stage in the success of a parasitoid is the ability to locate a host within its habitat. It is hypothesized that a series of olfactory cues may be involved in altering the parasitoid's movement patterns at this stage of foraging. This paper focuses specifically on host habitat location and host location and the olfactory stimuli necessary to mediate the transition between these stages. Firstly, we confirm the ability of the parasitoid Aphidius colemani to detect the aphid sex pheromone at an electrophysiological level. Following this we investigate the effect of the sex pheromone component (4aS,7S,7aR)-nepetalactone on the movement patterns of A. colemani and its retention within an area. The key findings of this work are that A. colemani is able to detect the sex pheromone components, that parasitoid retention is increased by a synergy of nepetalactone and other host-associated cues and that foraging patterns are augmented by the presence of nepetalactone or experience associated with nepetalactone. PMID:25991073

  3. Synergy Between Polyvinylpyrrolidone-Coated Silver Nanoparticles and Azole Antifungal Against Drug-Resistant Candida albicans.

    PubMed

    Sun, Lingmei; Liao, Kai; Li, Yiping; Zhao, Lei; Liang, Sai; Guo, Dan; Hu, Jun; Wang, Dayong

    2016-03-01

    In the clinical practice, resistance of Candida albicans to antifungal agents has frequently emerged. Silver-nanoparticles (Ag-NPs) have been demonstrated to have the antifungal property. We investigated the potential for synergy between polyvinylpyrrolidone (PVP)-coated Ag-NPs and azole antifungal, such as fluconazole or voriconazole, against drug-resistant C. albicans strain CA10. When antifungal agent was examined alone, fluconazole and voriconazole did not kill drug-resistant C. albicans, and PVP-coated Ag-NPs had only the moderate killing ability. In contrast, the combinational treatment of PVP-coated Ag-NPs with fluconazole or voriconazole was effective in being against the drug-resistant C. albicans. After the combinational treatment, we detected the disruption of cell membrane integrity, the tendency of PVP-coated Ag-NPs to adhere to cell membrane, and the inhibition of budding process. Moreover, after the combinational treatment, the defects in ergosterol signaling and efflux pump functions were detected. Our results suggest that the combinational use of engineered nanomaterials (ENMs), such as PVP-coated Ag-NPs, with the conventional antifungal may be a viable strategy to combat drug-resistant fungal infection.

  4. A Synergy-Based Optimally Designed Sensing Glove for Functional Grasp Recognition

    PubMed Central

    Ciotti, Simone; Battaglia, Edoardo; Carbonaro, Nicola; Bicchi, Antonio; Tognetti, Alessandro; Bianchi, Matteo

    2016-01-01

    Achieving accurate and reliable kinematic hand pose reconstructions represents a challenging task. The main reason for this is the complexity of hand biomechanics, where several degrees of freedom are distributed along a continuous deformable structure. Wearable sensing can represent a viable solution to tackle this issue, since it enables a more natural kinematic monitoring. However, the intrinsic accuracy (as well as the number of sensing elements) of wearable hand pose reconstruction (HPR) systems can be severely limited by ergonomics and cost considerations. In this paper, we combined the theoretical foundations of the optimal design of HPR devices based on hand synergy information, i.e., the inter-joint covariation patterns, with textile goniometers based on knitted piezoresistive fabrics (KPF) technology, to develop, for the first time, an optimally-designed under-sensed glove for measuring hand kinematics. We used only five sensors optimally placed on the hand and completed hand pose reconstruction (described according to a kinematic model with 19 degrees of freedom) leveraging upon synergistic information. The reconstructions we obtained from five different subjects were used to implement an unsupervised method for the recognition of eight functional grasps, showing a high degree of accuracy and robustness. PMID:27271621

  5. An essential role of acetylcholine-glutamate synergy at habenular synapses in nicotine dependence

    PubMed Central

    Frahm, Silke; Antolin-Fontes, Beatriz; Görlich, Andreas; Zander, Johannes-Friedrich; Ahnert-Hilger, Gudrun; Ibañez-Tallon, Ines

    2015-01-01

    A great deal of interest has been focused recently on the habenula and its critical role in aversion, negative-reward and drug dependence. Using a conditional mouse model of the ACh-synthesizing enzyme choline acetyltransferase (Chat), we report that local elimination of acetylcholine (ACh) in medial habenula (MHb) neurons alters glutamate corelease and presynaptic facilitation. Electron microscopy and immuno-isolation analyses revealed colocalization of ACh and glutamate vesicular transporters in synaptic vesicles (SVs) in the central IPN. Glutamate reuptake in SVs prepared from the IPN was increased by ACh, indicating vesicular synergy. Mice lacking CHAT in habenular neurons were insensitive to nicotine-conditioned reward and withdrawal. These data demonstrate that ACh controls the quantal size and release frequency of glutamate at habenular synapses, and suggest that the synergistic functions of ACh and glutamate may be generally important for modulation of cholinergic circuit function and behavior. DOI: http://dx.doi.org/10.7554/eLife.11396.001 PMID:26623516

  6. Composition- and Structure-Tunable Gold-Cobalt Nanoparticles and Electrocatalytic Synergy for Oxygen Evolution Reaction.

    PubMed

    Lu, Aolin; Peng, Dong-Liang; Chang, Fangfang; Skeete, Zakiya; Shan, Shiyao; Sharma, Anju; Luo, Jin; Zhong, Chuan-Jian

    2016-08-10

    The increasing energy crisis constitutes an inspiring drive seeking alternative energies such as hydrogen from water splitting which is clean and abundant, but a key challenge for water splitting is the need of highly efficient catalysts for oxygen evolution reaction (OER). This report describes findings of an investigation of the synthesis of gold-cobalt (AuCo) nanoparticles by a facile one-pot and injection method and their use as highly efficient catalysts for OER. While particle size depends on the synthesis method, the composition of the nanoparticles is controlled by feeding ratio of Au and Co precursors in the synthesis. Depending on Co content, the nanoparticles exhibit largely phase-segregated domains with a core (Au)-shell (Co) type of structure at a high level of Co. Upon the thermochemical treatment of carbon-supported AuCo nanoparticles, the redox activity of Co species in the nanoparticles with cycle number is shown to decrease which changes the surface oxidation state of Co species without changing the composition significantly. The electrocatalytic activity for OER in alkaline electrolytes is shown to depend on the bimetallic composition, displaying a maximum activity for an Au:Co ratio of ∼2:3. This dependence is also shown to correlate with the surface oxidation state and redox activities, providing an insight into the electrocatalytic activity. Mechanistic aspects of the electrocataltytic properties are discussed in terms of the bifunctional synergy of Co and Au in the nanoparticle catalysts. PMID:27479685

  7. A Riemannian geometry theory of human movement: The geodesic synergy hypothesis.

    PubMed

    Neilson, Peter D; Neilson, Megan D; Bye, Robin T

    2015-12-01

    Mass-inertia loads on muscles change with posture and with changing mechanical interactions between the body and the environment. The nervous system must anticipate changing mass-inertia loads, especially during fast multi-joint coordinated movements. Riemannian geometry provides a mathematical framework for movement planning that takes these inertial interactions into account. To demonstrate this we introduce the controlled (vs. biomechanical) degrees of freedom of the body as the coordinate system for a configuration space with movements represented as trajectories. This space is not Euclidean. It is endowed at each point with a metric equal to the mass-inertia matrix of the body in that configuration. This warps the space to become Riemannian with curvature at each point determined by the differentials of the mass-inertia at that point. This curvature takes nonlinear mass-inertia interactions into account with lengths, velocities, accelerations and directions of movement trajectories all differing from those in Euclidean space. For newcomers to Riemannian geometry we develop the intuitive groundwork for a Riemannian field theory of human movement encompassing the entire body moving in gravity and in mechanical interaction with the environment. In particular we present a geodesic synergy hypothesis concerning planning of multi-joint coordinated movements to achieve goals with minimal muscular effort.

  8. Synergies in the space of control variables within the equilibrium-point hypothesis.

    PubMed

    Ambike, S; Mattos, D; Zatsiorsky, V M; Latash, M L

    2016-02-19

    We use an approach rooted in the recent theory of synergies to analyze possible co-variation between two hypothetical control variables involved in finger force production based on the equilibrium-point (EP) hypothesis. These control variables are the referent coordinate (R) and apparent stiffness (C) of the finger. We tested a hypothesis that inter-trial co-variation in the {R; C} space during repeated, accurate force production trials stabilizes the fingertip force. This was expected to correspond to a relatively low amount of inter-trial variability affecting force and a high amount of variability keeping the force unchanged. We used the "inverse piano" apparatus to apply small and smooth positional perturbations to fingers during force production tasks. Across trials, R and C showed strong co-variation with the data points lying close to a hyperbolic curve. Hyperbolic regressions accounted for over 99% of the variance in the {R; C} space. Another analysis was conducted by randomizing the original {R; C} data sets and creating surrogate data sets that were then used to compute predicted force values. The surrogate sets always showed much higher force variance compared to the actual data, thus reinforcing the conclusion that finger force control was organized in the {R; C} space, as predicted by the EP hypothesis, and involved co-variation in that space stabilizing total force.

  9. Synergy Between Polyvinylpyrrolidone-Coated Silver Nanoparticles and Azole Antifungal Against Drug-Resistant Candida albicans.

    PubMed

    Sun, Lingmei; Liao, Kai; Li, Yiping; Zhao, Lei; Liang, Sai; Guo, Dan; Hu, Jun; Wang, Dayong

    2016-03-01

    In the clinical practice, resistance of Candida albicans to antifungal agents has frequently emerged. Silver-nanoparticles (Ag-NPs) have been demonstrated to have the antifungal property. We investigated the potential for synergy between polyvinylpyrrolidone (PVP)-coated Ag-NPs and azole antifungal, such as fluconazole or voriconazole, against drug-resistant C. albicans strain CA10. When antifungal agent was examined alone, fluconazole and voriconazole did not kill drug-resistant C. albicans, and PVP-coated Ag-NPs had only the moderate killing ability. In contrast, the combinational treatment of PVP-coated Ag-NPs with fluconazole or voriconazole was effective in being against the drug-resistant C. albicans. After the combinational treatment, we detected the disruption of cell membrane integrity, the tendency of PVP-coated Ag-NPs to adhere to cell membrane, and the inhibition of budding process. Moreover, after the combinational treatment, the defects in ergosterol signaling and efflux pump functions were detected. Our results suggest that the combinational use of engineered nanomaterials (ENMs), such as PVP-coated Ag-NPs, with the conventional antifungal may be a viable strategy to combat drug-resistant fungal infection. PMID:27455637

  10. Hybridization and speciation.

    PubMed

    Abbott, R; Albach, D; Ansell, S; Arntzen, J W; Baird, S J E; Bierne, N; Boughman, J; Brelsford, A; Buerkle, C A; Buggs, R; Butlin, R K; Dieckmann, U; Eroukhmanoff, F; Grill, A; Cahan, S H; Hermansen, J S; Hewitt, G; Hudson, A G; Jiggins, C; Jones, J; Keller, B; Marczewski, T; Mallet, J; Martinez-Rodriguez, P; Möst, M; Mullen, S; Nichols, R; Nolte, A W; Parisod, C; Pfennig, K; Rice, A M; Ritchie, M G; Seifert, B; Smadja, C M; Stelkens, R; Szymura, J M; Väinölä, R; Wolf, J B W; Zinner, D

    2013-02-01

    Hybridization has many and varied impacts on the process of speciation. Hybridization may slow or reverse differentiation by allowing gene flow and recombination. It may accelerate speciation via adaptive introgression or cause near-instantaneous speciation by allopolyploidization. It may have multiple effects at different stages and in different spatial contexts within a single speciation event. We offer a perspective on the context and evolutionary significance of hybridization during speciation, highlighting issues of current interest and debate. In secondary contact zones, it is uncertain if barriers to gene flow will be strengthened or broken down due to recombination and gene flow. Theory and empirical evidence suggest the latter is more likely, except within and around strongly selected genomic regions. Hybridization may contribute to speciation through the formation of new hybrid taxa, whereas introgression of a few loci may promote adaptive divergence and so facilitate speciation. Gene regulatory networks, epigenetic effects and the evolution of selfish genetic material in the genome suggest that the Dobzhansky-Muller model of hybrid incompatibilities requires a broader interpretation. Finally, although the incidence of reinforcement remains uncertain, this and other interactions in areas of sympatry may have knock-on effects on speciation both within and outside regions of hybridization.

  11. Hybrid electric vehicles TOPTEC

    SciTech Connect

    1994-06-21

    This one-day TOPTEC session began with an overview of hybrid electric vehicle technology. Updates were given on alternative types of energy storage, APU control for low emissions, simulation programs, and industry and government activities. The keynote speech was about battery technology, a key element to the success of hybrids. The TOPEC concluded with a panel discussion on the mission of hybrid electric vehicles, with a perspective from industry and government experts from United States and Canada on their view of the role of this technology.

  12. Artificial mismatch hybridization

    DOEpatents

    Guo, Zhen; Smith, Lloyd M.

    1998-01-01

    An improved nucleic acid hybridization process is provided which employs a modified oligonucleotide and improves the ability to discriminate a control nucleic acid target from a variant nucleic acid target containing a sequence variation. The modified probe contains at least one artificial mismatch relative to the control nucleic acid target in addition to any mismatch(es) arising from the sequence variation. The invention has direct and advantageous application to numerous existing hybridization methods, including, applications that employ, for example, the Polymerase Chain Reaction, allele-specific nucleic acid sequencing methods, and diagnostic hybridization methods.

  13. Towers of hybrid mesons

    SciTech Connect

    Semay, Claude; Buisseret, Fabien; Silvestre-Brac, Bernard

    2009-05-01

    A hybrid meson is a quark-antiquark pair in which, contrary to ordinary mesons, the gluon field is in an excited state. In the framework of constituent models, the interaction potential is assumed to be the energy of an excited string. An approximate, but accurate, analytical solution of the Schroedinger equation with such a potential is presented. When applied to hybrid charmonia and bottomonia, towers of states are predicted in which the masses are a linear function of a harmonic oscillator band number for the quark-antiquark pair. Such a formula could be a reliable guide for the experimental detection of heavy hybrid mesons.

  14. Hybrid matrix fiber composites

    DOEpatents

    Deteresa, Steven J.; Lyon, Richard E.; Groves, Scott E.

    2003-07-15

    Hybrid matrix fiber composites having enhanced compressive performance as well as enhanced stiffness, toughness and durability suitable for compression-critical applications. The methods for producing the fiber composites using matrix hybridization. The hybrid matrix fiber composites include two chemically or physically bonded matrix materials, whereas the first matrix materials are used to impregnate multi-filament fibers formed into ribbons and the second matrix material is placed around and between the fiber ribbons that are impregnated with the first matrix material and both matrix materials are cured and solidified.

  15. Mind the gap in SEA: An institutional perspective on why assessment of synergies amongst climate change mitigation, adaptation and other policy areas are missing

    SciTech Connect

    Vammen Larsen, Sanne; Kornov, Lone; Wejs, Anja

    2012-02-15

    This article takes its point of departure in two approaches to integrating climate change into Strategic Environmental Assessment (SEA): Mitigation and adaptation, and in the fact that these, as well as the synergies between them and other policy areas, are needed as part of an integrated assessment and policy response. First, the article makes a review of how positive and negative synergies between a) climate change mitigation and adaptation and b) climate change and other environmental concerns are integrated into Danish SEA practice. Then, the article discusses the implications of not addressing synergies. Finally, the article explores institutional explanations as to why synergies are not addressed in SEA practice. A document analysis of 149 Danish SEA reports shows that only one report comprises the assessment of synergies between mitigation and adaptation, whilst 9,4% of the reports assess the synergies between climate change and other environmental concerns. The consequences of separation are both the risk of trade-offs and missed opportunities for enhancing positive synergies. In order to propose explanations for the lacking integration, the institutional background is analysed and discussed, mainly based on Scott's theory of institutions. The institutional analysis highlights a regulatory element, since the assessment of climate change synergies is underpinned by legislation, but not by guidance. This means that great focus is on normative elements such as the local interpretation of legislation and of climate change mitigation and adaptation. The analysis also focuses on how the fragmentation of the organisation in which climate change and SEA are embedded has bearings on both normative and cultural-cognitive elements. This makes the assessment of synergies challenging. The evidence gathered and presented in the article points to a need for developing the SEA process and methodology in Denmark with the aim to include climate change in the assessments in a

  16. Hybrid rocket combustion study

    NASA Technical Reports Server (NTRS)

    Strand, L. D.; Ray, R. L.; Cohen, N. S.

    1993-01-01

    The objectives of this study of 'pure' or 'classic' hybrids are to (1) extend our understanding of the boundary layer combustion process and the critical engineering parameters that define this process, (2) develop an up-to-date hybrid fuel combustion model, and (3) apply the model to correlate the regression rate and scaling properties of potential fuel candidates. Tests were carried out with a hybrid slab window motor, using several diagnostic techniques, over a range of motor pressure and oxidizer mass flux conditions. The results basically confirmed turbulent boundary layer heat and mass transfer as the rate limiting process for hybrid fuel decomposition and combustion. The measured fuel regression rates showed good agreement with the analytical model predictions. The results of model scaling calculations to Shuttle SRM size conditions are presented.

  17. Hybrid adsorptive membrane reactor

    NASA Technical Reports Server (NTRS)

    Tsotsis, Theodore T. (Inventor); Sahimi, Muhammad (Inventor); Fayyaz-Najafi, Babak (Inventor); Harale, Aadesh (Inventor); Park, Byoung-Gi (Inventor); Liu, Paul K. T. (Inventor)

    2011-01-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  18. Diesel hybridization and emissions.

    SciTech Connect

    Pasquier, M.; Monnet, G.

    2004-04-21

    The CTR Vehicle Systems and Fuels team a diesel hybrid powertrain. The goal of this experiment was to investigate and demonstrate the potential of diesel engines for hybrid electric vehicles (HEVs) in a fuel economy and emissions. The test set-up consisted of a diesel engine coupled to an electric motor driving a Continuously Variable Transmission (CVT). This hybrid drive is connected to a dynamometer and a DC electrical power source creating a vehicle context by combining advanced computer models and emulation techniques. The experiment focuses on the impact of the hybrid control strategy on fuel economy and emissions-in particular, nitrogen oxides (NO{sub x}) and particulate matter (PM). The same hardware and test procedure were used throughout the entire experiment to assess the impact of different control approaches.

  19. Hybrid plasmachemical reactor

    SciTech Connect

    Lelevkin, V. M. Smirnova, Yu. G.; Tokarev, A. V.

    2015-04-15

    A hybrid plasmachemical reactor on the basis of a dielectric barrier discharge in a transformer is developed. The characteristics of the reactor as functions of the dielectric barrier discharge parameters are determined.

  20. Hybrid adsorptive membrane reactor

    DOEpatents

    Tsotsis, Theodore T.; Sahimi, Muhammad; Fayyaz-Najafi, Babak; Harale, Aadesh; Park, Byoung-Gi; Liu, Paul K. T.

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  1. Systems for hybrid cars

    NASA Astrophysics Data System (ADS)

    Bitsche, Otmar; Gutmann, Guenter

    Not only sharp competition but also legislation are pushing development of hybrid drive trains. Based on conventional internal combustion engine (ICE) vehicles, these drive trains offer a wide range of benefits from reduced fuel consumption and emission to multifaceted performance improvements. Hybrid electric drive trains may also facilitate the introduction of fuel cells (FC). The battery is the key component for all hybrid drive trains, as it dominates cost and performance issues. The selection of the right battery technology for the specific automotive application is an important task with an impact on costs of development and use. Safety, power, and high cycle life are a must for all hybrid applications. The greatest pressure to reduce cost is in soft hybrids, where lead-acid embedded in a considerate management presents the cheapest solution, with a considerable improvement in performance needed. From mild to full hybridization, an improvement in specific power makes higher costs more acceptable, provided that the battery's service life is equivalent to the vehicle's lifetime. Today, this is proven for the nickel-metal hydride system. Lithium ion batteries, which make use of a multiple safety concept, and with some development anticipated, provide even better prospects in terms of performance and costs. Also, their scalability permits their application in battery electric vehicles—the basis for better performance and enhanced user acceptance. Development targets for the batteries are discussed with a focus on system aspects such as electrical and thermal management and safety.

  2. Human hybrid hybridoma

    SciTech Connect

    Tiebout, R.F.; van Boxtel-Oosterhof, F.; Stricker, E.A.M.; Zeijlemaker, W.P.

    1987-11-15

    Hybrid hybridomas are obtained by fusion of two cells, each producing its own antibody. Several authors have reported the construction of murine hybrid hybridomas with the aim to obtain bispecific monoclonal antibodies. The authors have investigated, in a model system, the feasibility of constructing a human hybrid hybridoma. They fused two monoclonal cell lines: an ouabain-sensitive and azaserine/hypoxanthine-resistant Epstein-Barr virus-transformed human cell line that produces an IgG1kappa antibody directed against tetanus toxiod and an azaserine/hypoxanthine-sensitive and ouabain-resistant human-mouse xenohybrid cell line that produces a human IgG1lambda antibody directed against hepatitis-B surface antigen. Hybrid hybridoma cells were selected in culture medium containing azaserine/hypoxanthine and ouabain. The hybrid nature of the secreted antibodies was analyzed by means of two antigen-specific immunoassay. The results show that it is possible, with the combined use of transformation and xenohybridization techniques, to construct human hybrid hybridomas that produce bispecific antibodies. Bispecific antibodies activity was measured by means of two radioimmunoassays.

  3. Role of synergy between wear and corrosion in degradation of materials

    NASA Astrophysics Data System (ADS)

    Azzi, Marwan

    Tribocorrosion is a term used to describe the material degradation due to the combination of electrochemical and tribological processes. Due to a synergetic effect, the material loss can be larger than the sum of the losses due to wear and corrosion acting separately. In this thesis, the synergy of wear and corrosion was investigated for different types of material, namely the Ti-6Al-4V alloy, the SS316L stainless steel coated with a thin film of Diamond Like Carbon (DLC), and the SS301 stainless steel coated with a thin film of chromium silicon nitride (CrSiN). A tribocorrosion apparatus was designed and constructed to conduct wear experiments in corrosive media. Sliding ball-on-plate configuration was used in this design, where the contact between the ball and the specimen is totally immersed in the test electrolyte. The specimen was connected to a potentiostat to control its electrochemical parameters, namely the potential and the current. Electrochemical techniques were used to control the kinetics of corrosion reactions, and therefore it was possible to assess separately the role of corrosion and wear in the total degradation of material, and to evaluate the synergy between them. For Ti-6Al-4V, it was found that the corrosion and tribocorrosion depend strongly on the structure of the material. The alpha-equiaxed microstructure with fine dispersed beta-phase exhibited the best corrosion resistance. The corrosion resistance was found to decrease when the basal plane was preferentially aligned parallel to the surface, which is attributed to a low resistance to charge transfer in the oxide films formed on this plane. On the other hand, when wear and corrosion were involved simultaneously, the oxide layer protecting the substrate against dissolution was mechanically destroyed leading to a high corrosion rate. It was found that the hardness was the most important factor determining the tribocorrosion behavior of the Ti-6Al-4V alloy; samples with high hardness

  4. Investigating synergies of data fusion and image segmentation in earth observation based rapid mapping workflows

    NASA Astrophysics Data System (ADS)

    Witharana, C.

    2013-12-01

    In humanitarian emergencies, the timeliness of data provision and the short time-window available for dispatching value-added information pose major challenges to the mapping community. We have been engaged with a continuous research effort to explore novel ways to catalyze the EO-based humanitarian crisis information retrieval chain. This paper is an exploratory study, which aimed to discover the synergies of data fusion and image segmentation in the context of EO-based rapid mapping workflows. Our approach pillared on the geographic object-based image analysis (GEOBIA) focusing on multiscale, internally-displaced persons' (IDP) camp information extraction from very high spatial resolution (VHSR) images. We applied twelve pansharpening algorithms to two subsets of a GeoEye-1 image scene that was taken over a former war-induced ephemeral settlement in Sri Lanka. A multidimensional assessment was employed to benchmark pansharpening algorithms with respect to their spectral and spatial fidelity. The multiresolution segmentation (MRS) algorithm of the eCognition Developer software served as the key algorithm in the segmentation process. The first study site was used for comparing segmentation results produced from the twelve fused products at a series of scale, shape, and compactness settings of the MRS algorithm. The segmentation quality and optimum parameter settings of the MRS algorithm were estimated by using empirical discrepancy measures. Non-parametric statistical tests were used to compare the quality of image object candidates, which were derived from the twelve pansharpened products. A wall-to-wall classification was performed based on a support vector machine (SVM) classifier to classify image objects candidates of the fused images. The second site simulated a more realistic crisis information extraction scenario where the domain expertise is crucial in segmentation and classification. We compared segmentation and classification results of the original

  5. Community health workers for universal health-care coverage: from fragmentation to synergy.

    PubMed

    Tulenko, Kate; Møgedal, Sigrun; Afzal, Muhammad Mahmood; Frymus, Diana; Oshin, Adetokunbo; Pate, Muhammad; Quain, Estelle; Pinel, Arletty; Wynd, Shona; Zodpey, Sanjay

    2013-11-01

    To achieve universal health coverage, health systems will have to reach into every community, including the poorest and hardest to access. Since Alma-Ata, inconsistent support of community health workers (CHWs) and failure to integrate them into the health system have impeded full realization of their potential contribution in the context of primary health care. Scaling up and maintaining CHW programmes is fraught with a host of challenges: poor planning; multiple competing actors with little coordination; fragmented, disease-specific training; donor-driven management and funding; tenuous linkage with the health system; poor coordination, supervision and support, and under-recognition of CHWs' contribution. The current drive towards universal health coverage (UHC) presents an opportunity to enhance people's access to health services and their trust, demand and use of such services through CHWs. For their potential to be fully realized, however, CHWs will need to be better integrated into national health-care systems in terms of employment, supervision, support and career development. Partners at the global, national and district levels will have to harmonize and synchronize their engagement in CHW support while maintaining enough flexibility for programmes to innovate and respond to local needs. Strong leadership from the public sector will be needed to facilitate alignment with national policy frameworks and country-led coordination and to achieve synergies and accountability, universal coverage and sustainability. In moving towards UHC, much can be gained by investing in building CHWs' skills and supporting them as valued members of the health team. Stand-alone investments in CHWs are no shortcut to progress.

  6. The neurobiology of borderline personality disorder: the synergy of "nature and nurture".

    PubMed

    Pally, Regina

    2002-05-01

    The author reviews the current state of our knowledge concerning the neurobiology of borderline personality disorder (BPD). A converging body of scientific evidence indicates that patients with BPD suffer from impairments in the brain systems that regulate impulsivity, aggression, and affect. This article reviews data on the neurobiology of the symptoms of BPD, including emotional and behavioral dysregulation, identity disturbance, cognitive impairments, and interpersonal difficulties. The author first considers the evolutionary context in which BPD can develop to put the neurobiological findings in perspective, and then discusses the roles of both genetic inheritance and the environment in the development of BPD. The role of neurotransmitter systems in the development of impulsive-aggression and affective instability is reviewed. Possible neurobiological contributors to the identity disturbance seen in BPD are also described. The author then considers environmental contributions to BPD and discusses the synergy of nature and nurture in the development of BPD symptoms. Findings concerning the types of neurobiological impairments that can arise as a result of childhood neglect and abuse and other types of chronic severe stress and trauma are discussed. Finally, the author reviews studies of animal attachment models that suggest that types of maternal care can produce lifelong behavioral and physiological differences in offspring and that this effect is mediated through the regulation of gene expression. The author suggests that the large body of neuroscience research reviewed in this article suggests that, while patients with BPD may be born with innate genetic tendencies for impaired brain systems for regulating impulses and affect, the environment they find themselves born into may be critical in determining whether or not they develop the full blown syndrome of BPD. PMID:15985870

  7. Discovery of Drug Synergies in Gastric Cancer Cells Predicted by Logical Modeling

    PubMed Central

    Flobak, Åsmund; Baudot, Anaïs; Remy, Elisabeth; Thommesen, Liv; Thieffry, Denis; Kuiper, Martin; Lægreid, Astrid

    2015-01-01

    Discovery of efficient anti-cancer drug combinations is a major challenge, since experimental testing of all possible combinations is clearly impossible. Recent efforts to computationally predict drug combination responses retain this experimental search space, as model definitions typically rely on extensive drug perturbation data. We developed a dynamical model representing a cell fate decision network in the AGS gastric cancer cell line, relying on background knowledge extracted from literature and databases. We defined a set of logical equations recapitulating AGS data observed in cells in their baseline proliferative state. Using the modeling software GINsim, model reduction and simulation compression techniques were applied to cope with the vast state space of large logical models and enable simulations of pairwise applications of specific signaling inhibitory chemical substances. Our simulations predicted synergistic growth inhibitory action of five combinations from a total of 21 possible pairs. Four of the predicted synergies were confirmed in AGS cell growth real-time assays, including known effects of combined MEK-AKT or MEK-PI3K inhibitions, along with novel synergistic effects of combined TAK1-AKT or TAK1-PI3K inhibitions. Our strategy reduces the dependence on a priori drug perturbation experimentation for well-characterized signaling networks, by demonstrating that a model predictive of combinatorial drug effects can be inferred from background knowledge on unperturbed and proliferating cancer cells. Our modeling approach can thus contribute to preclinical discovery of efficient anticancer drug combinations, and thereby to development of strategies to tailor treatment to individual cancer patients. PMID:26317215

  8. Augmented reality and photogrammetry: A synergy to visualize physical and virtual city environments

    NASA Astrophysics Data System (ADS)

    Portalés, Cristina; Lerma, José Luis; Navarro, Santiago

    2010-01-01

    Close-range photogrammetry is based on the acquisition of imagery to make accurate measurements and, eventually, three-dimensional (3D) photo-realistic models. These models are a photogrammetric product per se. They are usually integrated into virtual reality scenarios where additional data such as sound, text or video can be introduced, leading to multimedia virtual environments. These environments allow users both to navigate and interact on different platforms such as desktop PCs, laptops and small hand-held devices (mobile phones or PDAs). In very recent years, a new technology derived from virtual reality has emerged: Augmented Reality (AR), which is based on mixing real and virtual environments to boost human interactions and real-life navigations. The synergy of AR and photogrammetry opens up new possibilities in the field of 3D data visualization, navigation and interaction far beyond the traditional static navigation and interaction in front of a computer screen. In this paper we introduce a low-cost outdoor mobile AR application to integrate buildings of different urban spaces. High-accuracy 3D photo-models derived from close-range photogrammetry are integrated in real (physical) urban worlds. The augmented environment that is presented herein requires for visualization a see-through video head mounted display (HMD), whereas user's movement navigation is achieved in the real world with the help of an inertial navigation sensor. After introducing the basics of AR technology, the paper will deal with real-time orientation and tracking in combined physical and virtual city environments, merging close-range photogrammetry and AR. There are, however, some software and complex issues, which are discussed in the paper.

  9. Achieving synergy between chemical oxidation and stabilization in a contaminated soil.

    PubMed

    Srivastava, Vipul J; Hudson, Jeffrey Michael; Cassidy, Daniel P

    2016-07-01

    Eight in situ solidification/stabilization (ISS) amendments were tested to promote in situ chemical oxidation (ISCO) with activated persulfate (PS) in a contaminated soil. A 3% (by weight) dose of all ISS amendments selected for this study completely activated a 1.5% dose of PS within 3 h by raising temperatures above 30 °C (heat activation) and/or increasing pH above 10.5 (alkaline activation). Heat is released by the reaction of CaO with water, and pH increases because this reaction produces Ca(OH)2. Heat activation is preferred because it generates 2 mol of oxidizing radicals per mole of PS, whereas alkaline activation releases only 1. The relative contribution of heat vs. alkaline activation increased with CaO content of the ISS amendment, which was reflected by enhanced contaminant oxidation with increasing CaO content, and was confirmed by comparing to controls promoting purely heat or alkaline (NaOH) activation. The test soil was contaminated with benzene, toluene, ethylbenzene, and xylenes (BTEX) and polycyclic aromatic hydrocarbons (PAH), particularly naphthalene (NAP). ISS-activated PS oxidized between 47% and 84% of the BTEX & NAP, and between 13% and 33% of the higher molecular weight PAH. ISS-activated PS reduced the leachability of BTEX & NAP by 76%-91% and of the 17 PAH by 83%-96%. Combined ISCO/ISS reduced contaminant leachability far than ISCO or ISS treatments alone, demonstrating the synergy that is possible with combined remedies. PMID:27088536

  10. Soil moisture estimation using synergy of optical, SAR, and topographic data with Gaussian Process Regression

    NASA Astrophysics Data System (ADS)

    Stamenkovic, J.; Notarnicola, C.; Spindler, N.; Cuozzo, G.; Bertoldi, G.; Della Chiesa, S.; Niedrist, G.; Greifeneder, F.; Tuia, D.; Borgeaud, M.; Thiran, J.-Ph.

    2014-10-01

    In this work we address the synergy of optical, SAR (Synthetic Aperture Radar) and topographic data in soil moisture retrieval over an Alpine area. As estimation technique, we consider Gaussian Process Regression (GPR). The test area is located in South Tyrol, Italy where the main land types are meadows and pastures. Time series of ASAR Wide Swath - SAR, optical, topographic and ancillary data (meteorological information and snow cover maps) acquired repetitively in 2010 were examined. Regarding optical data, we used both, daily MODIS reflectances, and daily NDVI, interpolated from the 16-day MODIS composite. Slope, elevation and aspect were extracted from a 2.5 m DEM (Digital Elevation Model) and resampled to 10 m. Daily soil moisture measurements were collected in the three fixed stations (two located in meadows and one located in pasture). The snow maps were used to mask the points covered by snow. The best performance was obtained by adding MODIS band 6 at 1640 nm to SAR and DEM features. The corresponding coefficient of determination, R2, was equal to 0.848, and the root mean square error, RMSE, to 5.4 % Vol. Compared to the case when no optical data were considered, there was an increase of ca. 0.05 in R2 and a decrease in RMSE of ca. 0.7 % Vol. This work showed that the joint use of NDVI or water absorption reflectance with SAR and topographic data can improve the estimation of soil moisture in specific Alpine area and that GPR is an effective method for estimation.

  11. Molecular mechanisms of corticosteroid synergy with thyroid hormone during tadpole metamorphosis.

    PubMed

    Bonett, Ronald M; Hoopfer, Eric D; Denver, Robert J

    2010-09-01

    Corticosteroids (CS) act synergistically with thyroid hormone (TH) to accelerate amphibian metamorphosis. Earlier studies showed that CS increase nuclear 3,5,3'-triiodothyronine (T(3)) binding capacity in tadpole tail, and 5' deiodinase activity in tadpole tissues, increasing the generation of T(3) from thyroxine (T(4)). In the present study we investigated CS synergy with TH by analyzing expression of key genes involved in TH and CS signaling using tadpole tail explant cultures, prometamorphic tadpoles, and frog tissue culture cells (XTC-2 and XLT-15). Treatment of tail explants with T(3) at 100 nM, but not at 10 nM caused tail regression. Corticosterone (CORT) at three doses (100, 500 and 3400 nM) had no effect or increased tail size. T(3) at 10 nM plus CORT caused tails to regress similar to 100 nM T(3). Thyroid hormone receptor beta (TRbeta) mRNA was synergistically upregulated by T(3) plus CORT in tail explants, tail and brain in vivo, and tissue culture cells. The activating 5' deiodinase type 2 (D2) mRNA was induced by T(3) and CORT in tail explants and tail in vivo. Thyroid hormone increased expression of glucocorticoid (GR) and mineralocorticoid receptor (MR) mRNAs. Our findings support that the synergistic actions of TH and CS in metamorphosis occur at the level of expression of genes for TRbeta and D2, enhancing tissue sensitivity to TH. Concurrently, TH enhances tissue sensitivity to CS by upregulating GR and MR. Environmental stressors can modulate the timing of tadpole metamorphosis in part by CS enhancing the response of tadpole tissues to the actions of TH.

  12. Measuring galaxy environment with the synergy of future photometric and spectroscopic surveys

    NASA Astrophysics Data System (ADS)

    Cucciati, O.; Marulli, F.; Cimatti, A.; Merson, A. I.; Norberg, P.; Pozzetti, L.; Baugh, C. M.; Branchini, E.

    2016-10-01

    We exploit the synergy between low-resolution spectroscopy and photometric redshifts to study environmental effects on galaxy evolution in slitless spectroscopic surveys from space. As a test case, we consider the future Euclid Deep survey (˜40 deg2), which combines a slitless spectroscopic survey limited at Hα flux ≥5 × 10-17 erg cm-2 s-1 and a photometric survey limited in H band (H ≤ 26). We use Euclid-like galaxy mock catalogues, in which we anchor the photometric redshifts to the 3D galaxy distribution of the available spectroscopic redshifts. We then estimate the local density contrast by counting objects in cylindrical cells with radius from 1 to 10 h-1Mpc, over the redshift range 0.9 < z < 1.8. We compare this density field with the one computed in a mock catalogue with the same depth as the Euclid Deep survey (H = 26) but without redshift measurement errors. We find that our method successfully separates high- from low-density environments (the last from the first quintile of the density distribution), with higher efficiency at low redshift and large cells: the fraction of low-density regions mistaken by high-density peaks is <1 per cent for all scales and redshifts explored, but for scales of 1 h-1Mpc for which is a few per cent. These results show that we can efficiently study environment in photometric samples if spectroscopic information is available for a smaller sample of objects that sparsely samples the same volume. We demonstrate that these studies are possible in the Euclid Deep survey, i.e. in a redshift range in which environmental effects are different from those observed in the local Universe, hence providing new constraints for galaxy evolution models.

  13. Whole plant extracts versus single compounds for the treatment of malaria: synergy and positive interactions

    PubMed Central

    2011-01-01

    Background In traditional medicine whole plants or mixtures of plants are used rather than isolated compounds. There is evidence that crude plant extracts often have greater in vitro or/and in vivo antiplasmodial activity than isolated constituents at an equivalent dose. The aim of this paper is to review positive interactions between components of whole plant extracts, which may explain this. Methods Narrative review. Results There is evidence for several different types of positive interactions between different components of medicinal plants used in the treatment of malaria. Pharmacodynamic synergy has been demonstrated between the Cinchona alkaloids and between various plant extracts traditionally combined. Pharmacokinetic interactions occur, for example between constituents of Artemisia annua tea so that its artemisinin is more rapidly absorbed than the pure drug. Some plant extracts may have an immunomodulatory effect as well as a direct antiplasmodial effect. Several extracts contain multidrug resistance inhibitors, although none of these has been tested clinically in malaria. Some plant constituents are added mainly to attenuate the side-effects of others, for example ginger to prevent nausea. Conclusions More clinical research is needed on all types of interaction between plant constituents. This could include clinical trials of combinations of pure compounds (such as artemisinin + curcumin + piperine) and of combinations of herbal remedies (such as Artemisia annua leaves + Curcuma longa root + Piper nigum seeds). The former may enhance the activity of existing pharmaceutical preparations, and the latter may improve the effectiveness of existing herbal remedies for use in remote areas where modern drugs are unavailable. PMID:21411015

  14. Neural representations of ethologically relevant hand/mouth synergies in the human precentral gyrus.

    PubMed

    Desmurget, Michel; Richard, Nathalie; Harquel, Sylvain; Baraduc, Pierre; Szathmari, Alexandru; Mottolese, Carmine; Sirigu, Angela

    2014-04-15

    Complex motor responses are often thought to result from the combination of elemental movements represented at different neural sites. However, in monkeys, evidence indicates that some behaviors with critical ethological value, such as self-feeding, are represented as motor primitives in the precentral gyrus (PrG). In humans, such primitives have not yet been described. This could reflect well-known interspecies differences in the organization of sensorimotor regions (including PrG) or the difficulty of identifying complex neural representations in peroperative settings. To settle this alternative, we focused on the neural bases of hand/mouth synergies, a prominent example of human behavior with high ethological value. By recording motor- and somatosensory-evoked potentials in the PrG of patients undergoing brain surgery (2-60 y), we show that two complex nested neural representations can mediate hand/mouth actions within this structure: (i) a motor representation, resembling self-feeding, where electrical stimulation causes the closing hand to approach the opening mouth, and (ii) a motor-sensory representation, likely associated with perioral exploration, where cross-signal integration is accomplished at a cortical site that generates hand/arm actions while receiving mouth sensory inputs. The first finding extends to humans' previous observations in monkeys. The second provides evidence that complex neural representations also exist for perioral exploration, a finely tuned skill requiring the combination of motor and sensory signals within a common control loop. These representations likely underlie the ability of human children and newborns to accurately produce coordinated hand/mouth movements, in an otherwise general context of motor immaturity.

  15. Hard Disk/Solid State Drive Synergy in Support of Data-Intensive Computing

    SciTech Connect

    Liu,Ke; Jiang, Song; Davis, Kei

    2012-07-19

    Data-intensive applications are becoming increasingly common in high-performance computing. Examples include combustion simulation, human genome analysis, and satellite image processing. Efficient access of data sets is critical to the performance of these applications. Because of the size of the data today's economically feasible approach is to store the data files on an array of hard disks or data servers equipped with hard disks and managed by a parallel file system such as PVFS or Lustre wherein the data is striped over a (large) number of disks for high aggregate I/O throughout. With file striping, a request for a segment of logically contiguous file space is decomposed into multiple sub-requests, each to a different server. While the data unit for this striping is usually reasonably large to benefit disk efficiency, the first and/or last sub-requests can be much smaller than the striping unit if the request does not align with the striping pattern, severely compromising hard disk efficiency and thus application performance. We propose to exploit solid state drives (SSD), whose efficiency is much less sensitive to small random accesses, to enable the alignment of requests to disk with the data striping pattern. In this scheme hard disks mainly serve large, aligned, sequential requests, with SSDs serving small or unaligned requests, thus respecting the relative cost, performance, and durability characteristics of the two media, and thereby achieving synergy in performance/cost. We will describe the design of the proposed scheme, its implementation on CCS-7's Darwin cluster, and performance results.

  16. Searching for Drug Synergy in Complex Dose-Response Landscapes Using an Interaction Potency Model.

    PubMed

    Yadav, Bhagwan; Wennerberg, Krister; Aittokallio, Tero; Tang, Jing

    2015-01-01

    Rational design of multi-targeted drug combinations is a promising strategy to tackle the drug resistance problem for many complex disorders. A drug combination is usually classified as synergistic or antagonistic, depending on the deviation of the observed combination response from the expected effect calculated based on a reference model of non-interaction. The existing reference models were proposed originally for low-throughput drug combination experiments, which make the model assumptions often incompatible with the complex drug interaction patterns across various dose pairs that are typically observed in large-scale dose-response matrix experiments. To address these limitations, we proposed a novel reference model, named zero interaction potency (ZIP), which captures the drug interaction relationships by comparing the change in the potency of the dose-response curves between individual drugs and their combinations. We utilized a delta score to quantify the deviation from the expectation of zero interaction, and proved that a delta score value of zero implies both probabilistic independence and dose additivity. Using data from a large-scale anticancer drug combination experiment, we demonstrated empirically how the ZIP scoring approach captures the experimentally confirmed drug synergy while keeping the false positive rate at a low level. Further, rather than relying on a single parameter to assess drug interaction, we proposed the use of an interaction landscape over the full dose-response matrix to identify and quantify synergistic and antagonistic dose regions. The interaction landscape offers an increased power to differentiate between various classes of drug combinations, and may therefore provide an improved means for understanding their mechanisms of action toward clinical translation.

  17. Essential Oils in Food Preservation: Mode of Action, Synergies, and Interactions with Food Matrix Components

    PubMed Central

    Hyldgaard, Morten; Mygind, Tina; Meyer, Rikke Louise

    2012-01-01

    Essential oils are aromatic and volatile liquids extracted from plants. The chemicals in essential oils are secondary metabolites, which play an important role in plant defense as they often possess antimicrobial properties. The interest in essential oils and their application in food preservation has been amplified in recent years by an increasingly negative consumer perception of synthetic preservatives. Furthermore, food-borne diseases are a growing public health problem worldwide, calling for more effective preservation strategies. The antibacterial properties of essential oils and their constituents have been documented extensively. Pioneering work has also elucidated the mode of action of a few essential oil constituents, but detailed knowledge about most of the compounds’ mode of action is still lacking. This knowledge is particularly important to predict their effect on different microorganisms, how they interact with food matrix components, and how they work in combination with other antimicrobial compounds. The main obstacle for using essential oil constituents as food preservatives is that they are most often not potent enough as single components, and they cause negative organoleptic effects when added in sufficient amounts to provide an antimicrobial effect. Exploiting synergies between several compounds has been suggested as a solution to this problem. However, little is known about which interactions lead to synergistic, additive, or antagonistic effects. Such knowledge could contribute to design of new and more potent antimicrobial blends, and to understand the interplay between the constituents of crude essential oils. The purpose of this review is to provide an overview of current knowledge about the antibacterial properties and antibacterial mode of action of essential oils and their constituents, and to identify research avenues that can facilitate implementation of essential oils as natural preservatives in foods. PMID:22291693

  18. AZD5363 Inhibits Inflammatory Synergy between Interleukin-17 and Insulin/Insulin-Like Growth Factor 1

    PubMed Central

    Chen, Chong; Zhang, Qiuyang; Liu, Sen; Lambrechts, Mark; Qu, Yine; You, Zongbing

    2014-01-01

    In the United States, one-third of population is affected by obesity and almost 29 million people are suffering from type 2 diabetes. Obese people have elevated serum levels of insulin, insulin-like growth factor 1 (IGF1), and interleukin-17 (IL-17). Insulin and IGF1 are known to enhance IL-17-induced expression of inflammatory cytokines and chemokines, which may contribute to the chronic inflammatory status observed in obese people. We have previously demonstrated that insulin/IGF1 signaling pathway crosstalks with IL-17-activated nuclear factor-κB pathway through inhibiting glycogen synthase kinase 3β (GSK3β) activity. However, it is unclear whether GSK3α also plays a role and whether this crosstalk can be manipulated by AZD5363, a novel pan-Akt inhibitor that has been shown to increase glycogen synthase kinase 3 activity through reducing phosphorylation of GSK3α and GSK3β. In this study, we investigated IL-17-induced expression of C-X-C motif ligand 1 (Cxcl1), C-C motif ligand 20 (Ccl20), and interleukin-6 (Il-6) in wild-type, GSK3α−/−, and GSK3β−/− mouse embryonic fibroblast cells as well as in mouse prostate tissues by real-time quantitative PCR. We examined the proteins involved in the signaling pathways by Western blot analysis. We found that insulin and IGF1 enhanced IL-17-induced expression of Cxcl1, Ccl20, and Il-6, which was associated with increased phosphorylation of GSK3α and GSK3β in the presence of insulin and IGF1. AZD5363 inhibited the synergy between IL-17 and insulin/IGF1 through reducing phosphorylation of GSK3α and GSK3β by inhibiting Akt function. These findings imply that the cooperative crosstalk of IL-17 and insulin/IGF1 in initiating inflammatory responses may be alleviated by AZD5363. PMID:25520943

  19. Inspiring future scientists in middle-schools through synergy between classroom learning and water cycle research

    NASA Astrophysics Data System (ADS)

    Noone, D. C.; Kellagher, E.; Berkelhammer, M. B.; Raudzens Bailey, A.; Kaushik, A.

    2012-12-01

    Water is at the core of many issues in environmental change from local to global scales, and learning about the water cycle offers students an opportunity to explore core scientific concepts and their local environment. In climate research, there are significant uncertainties in the role water plays in the climate system. Water also acts as a central theme that provides opportunities for experiential science education at all levels. The "Water Spotters" program underway at University of Colorado exploits the synergy between needs for enrichment of middle-school science education and the needs for water sample collection to provide primary data for climate research. The program takes advantage of the prominent agricultural landscape of the region in eastern Colorado, which is a poignant example of how society influences the climate through irrigation, evaporation/transpiration and run-off and whose productivity is influenced by the climate system. Both natural grasslands and alpine ecosystems in the surrounding regions serve as examples of the native landscape. In coordination with the St. Vrain Valley School District MESA (Math Engineering Science Achievement) program, middle-school students collect rain water samples that are analyzed and used as a core component of the research goals. In concert, new lessons have been developed in coordination with science teachers that emphasize both core scientific standards and application learning about the water cycle. We present the new curriculum modules developed for the program and that are distributed to middle-school teachers. The modules include original lessons and lessons with expanded original material to teach about water and water isotopes. Curriculum packages that include media resources are increasingly important to teachers. The Water Spotters program uses video to teach collection protocols and give background on the project. Weather station data from schools are disseminated online alongside the rainwater

  20. Synergy between broccoli sprout extract and selenium in the upregulation of thioredoxin reductase in human hepatocytes.

    PubMed

    Li, Dan; Wu, Kun; Howie, A Forbes; Beckett, Geoffrey J; Wang, Wei; Bao, Yongping

    2008-09-01

    Dietary isothiocyanates and selenium (Se) can up-regulate thioredoxin reductase 1 (TR1) in cultured human HepG2 and MCF-7 cells [Zhang et al. (2003). Synergy between sulforaphane and selenium in the induction of thioredoxin reductase 1 requires both transcriptional and translational modulation. Carcinogenesis, 24, 497-503; Wang et al. (2005). Sulforaphane, erucin and iberin up-regulate thioredoxin reductase expression in human MCF-7 cells. Journal of Agricultural and Food Chemistry, 53, 1417-1421] at both the protein and mRNA levels. In this study, broccoli sprout extract (a rich source of the isothiocyanates sulforaphane and iberin) and Se interacted synergistically to induce TR1 in immortalised human hepatocytes. Broccoli sprout extracts containing 1.6, 4 and 8μM isothiocyanates were tested for their ability to induce TR1 at the protein and mRNA level. Although induction of TR1 mRNA by broccoli sprout extract (1.6-8μM) was only 1.7-2.2-fold, co-treatment with Se (0.2-1μM) enhanced the expression of TR1 mRNA (3.0-3.3-fold). Moreover, broccoli sprout extract induced the cellular concentration of TR1 and TR enzymatic activity, an induction that was augmented by Se addition. Thus, broccoli sprout extract (8μM) and Se induced cellular TR1 concentration and enzymatic activity 3.7- and 5-fold respectively, whereas, Se or broccoli sprout extract alone produced an induction of only approximately 2-fold. These data suggest that dietary isothiocyanates from broccoli sprouts and Se are important agents in the regulation of redox status in human liver cells. The synergistic effect between isothiocyanates and Se at physiologically-relevant concentrations on the induction of TR1 may play an important role in protection against oxidative stress.

  1. Development of ATLID-MSI synergy for retrieving the vertical profiles of aerosol components

    NASA Astrophysics Data System (ADS)

    Kudo, R.; Nishizawa, T.; Higurashi, A.; Sugimoto, N.; Oikawa, E.

    2014-12-01

    EarthCARE is an earth observation satellite and will be launched in 2016. Using its two sensors, ATLID (High spectral resolution lidar) and MSI (Multi-spectral imager), we are developing the synergy algorithm to retrieve the vertical profiles of extinction coefficients at 355 nm of four aerosol components (Water-soluble, black carbon, dust, and sea-salt particles), and the column mean of mode radii of water-soluble and dust particles. The ATLID data are extinction coefficient, backscatter coefficient, and depolarization ratio for total aerosols at 355 nm. The MSI data are radiances at 670 and 865 nm. The dry volume concentrations of four aerosol components at each altitude and the mode radii of water-soluble and dust particles in the column are simultaneously optimized to ATLID and MSI data by the gauss newton method. After the optimization, the vertical profiles of the extinction coefficient at 355 nm of four aerosol components are obtained. The size distributions of four aerosol components are assumed to be a lognormal distribution. The refractive indices of four aerosol components are given from previously observational studies. The humidity growth is considered for water-soluble and sea-salt particles. The volume concentration and the mode radius of the sea-salt particle are parameterized using the surface wind speed on the ocean. We assumed that the shape of the water-soluble, black carbon, and sea-salt particles are spherical, and the shape of the dust particle is spheroidal. We tested the algorithm using the ATLID and MSI data simulated using clean, dust-transported, and smoke-transported aerosols. The extinction coefficients of each component at 355 nm are retrieved well. The mode radius of water-soluble and dust particles were somehow overestimated.

  2. Community health workers for universal health-care coverage: from fragmentation to synergy.

    PubMed

    Tulenko, Kate; Møgedal, Sigrun; Afzal, Muhammad Mahmood; Frymus, Diana; Oshin, Adetokunbo; Pate, Muhammad; Quain, Estelle; Pinel, Arletty; Wynd, Shona; Zodpey, Sanjay

    2013-11-01

    To achieve universal health coverage, health systems will have to reach into every community, including the poorest and hardest to access. Since Alma-Ata, inconsistent support of community health workers (CHWs) and failure to integrate them into the health system have impeded full realization of their potential contribution in the context of primary health care. Scaling up and maintaining CHW programmes is fraught with a host of challenges: poor planning; multiple competing actors with little coordination; fragmented, disease-specific training; donor-driven management and funding; tenuous linkage with the health system; poor coordination, supervision and support, and under-recognition of CHWs' contribution. The current drive towards universal health coverage (UHC) presents an opportunity to enhance people's access to health services and their trust, demand and use of such services through CHWs. For their potential to be fully realized, however, CHWs will need to be better integrated into national health-care systems in terms of employment, supervision, support and career development. Partners at the global, national and district levels will have to harmonize and synchronize their engagement in CHW support while maintaining enough flexibility for programmes to innovate and respond to local needs. Strong leadership from the public sector will be needed to facilitate alignment with national policy frameworks and country-led coordination and to achieve synergies and accountability, universal coverage and sustainability. In moving towards UHC, much can be gained by investing in building CHWs' skills and supporting them as valued members of the health team. Stand-alone investments in CHWs are no shortcut to progress. PMID:24347709

  3. Spatiotemporal structure of REM sleep twitching reveals developmental origins of motor synergies

    PubMed Central

    Blumberg, Mark S.; Coleman, Cassandra M.; Gerth, Ashlynn I.; McMurray, Bob

    2013-01-01

    Summary Background During active (or REM) sleep, infant rats and other mammals exhibit myoclonic twitches of skeletal muscles throughout the body, resulting in jerky, discrete movements of the distal limbs. Hundreds of thousands of limb twitches are produced each day and sensory feedback from these movements is a substantial driver of infant brain activity, suggesting that these movements contribute to motor learning and sensorimotor integration. However, it is not known whether the production of twitches is random or spatiotemporally structured, or whether the patterning of twitching changes with age. Such information is critical if we are to understand how twitches contribute to development. Results We used high-speed videography and 3-D motion tracking to assess the spatiotemporal structure of twitching at forelimb joints in 2- and 8-day-old rats. At both ages, twitches exhibited highly structured spatiotemporal properties at multiple timescales, including synergistic and multi-joint movements within and across forelimbs. Hierarchical cluster analysis and latent class analysis revealed developmental changes in the quantity and patterning of twitching. Critically, we found evidence for a selectionist process whereby movement patterns at the early age compete for retention and expression over development. Conclusions These findings indicate that twitches are not produced randomly, but rather are highly structured at multiple timescales. This structure has important implications for our understanding of the brain and spinal mechanisms that produce twitching and the role that sensory feedback from twitching plays in the development of sensorimotor systems. We suggest that twitches represent a heretofore overlooked form of motor exploration that helps animals probe the biomechanics of their limbs, build motor synergies, and lay a foundation for complex, automatic, and goal-directed wake movements. PMID:24139739

  4. Measure and exploitation of multisensor and multiwavelength synergy for remote sensing: 2. Application to the retrieval of atmospheric temperature and water vapor from MetOp

    NASA Astrophysics Data System (ADS)

    Aires, Filipe; Paul, Maxime; Prigent, Catherine; Rommen, BjöRn; Bouvet, Marc

    2011-01-01

    In the companion paper, classical information content (IC) analysis was used to measure the potential synergy between the microwave (MW) and infrared (IR) observations from Atmospheric Microwave Sounding Unit-A, Microwave Humidity Sounder, and Improved Atmospheric Sounding in the Infrared instruments, used to retrieve the atmospheric profiles of temperature and water vapor over ocean, under clear-sky conditions. Some limitations of IC were pointed out that questioned the reliability of this technique for synergy characterization. The goal of this second paper is to develop a methodology to measure realistic potential synergies and to construct retrieval methods able to exploit them. Three retrieval methods are considered: the k nearest neighbors, the linear regression, and the neural networks (NN). These statistical retrieval schemes are tested on an application involving IR and MW synergy. Only clear-sky, near-nadir radiances over ocean are considered. The IR/MW synergy is expected to be stronger in cloudy cases, but it will be shown that it can also be observed in clear situations. The inversion algorithms are calibrated and tested with simulated observations, without any loss of generality, using similar theoretical assumption (same radiative transfer model, observational noise, and a priori information) in order to truly compare the IC and the direct statistical retrieval approaches. Multivariate and nonlinear methods such as the NN approach show that there is a strong potential for synergy. Synergy measurement tools such as the method proposed in this study should be considered in the future for the definition of new missions: The instrument characteristics should be determined not independently, sensor by sensor, but taking into account all the instruments together as a whole observing system.

  5. Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO)

    PubMed Central

    Sim, Victor S.T.; She, Qianhong; Chong, Tzyy Haur; Tang, Chuyang Y.; Fane, Anthony G.; Krantz, William B.

    2013-01-01

    This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%–20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination. PMID:24956940

  6. Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO).

    PubMed

    Sim, Victor S T; She, Qianhong; Chong, Tzyy Haur; Tang, Chuyang Y; Fane, Anthony G; Krantz, William B

    2013-01-01

    This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%-20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination. PMID:24956940

  7. Strategic Co-Location in a Hybrid Process Involving Desalination and Pressure Retarded Osmosis (PRO).

    PubMed

    Sim, Victor S T; She, Qianhong; Chong, Tzyy Haur; Tang, Chuyang Y; Fane, Anthony G; Krantz, William B

    2013-07-04

    This paper focuses on a Hybrid Process that uses feed salinity dilution and osmotic power recovery from Pressure Retarded Osmosis (PRO) to achieve higher overall water recovery. This reduces the energy consumption and capital costs of conventional seawater desalination and water reuse processes. The Hybrid Process increases the amount of water recovered from the current 66.7% for conventional seawater desalination and water reuse processes to a potential 80% through the use of reclaimed water brine as an impaired water source. A reduction of up to 23% in energy consumption is projected via the Hybrid Process. The attractiveness is amplified by potential capital cost savings ranging from 8.7%-20% compared to conventional designs of seawater desalination plants. A decision matrix in the form of a customizable scorecard is introduced for evaluating a Hybrid Process based on the importance of land space, capital costs, energy consumption and membrane fouling. This study provides a new perspective, looking at processes not as individual systems but as a whole utilizing strategic co-location to unlock the synergies available in the water-energy nexus for more sustainable desalination.

  8. Hybrid Propulsion Demonstration Program 250K Hybrid Motor

    NASA Technical Reports Server (NTRS)

    Story, George; Zoladz, Tom; Arves, Joe; Kearney, Darren; Abel, Terry; Park, O.

    2003-01-01

    The Hybrid Propulsion Demonstration Program (HPDP) program was formed to mature hybrid propulsion technology to a readiness level sufficient to enable commercialization for various space launch applications. The goal of the HPDP was to develop and test a 250,000 pound vacuum thrust hybrid booster in order to demonstrate hybrid propulsion technology and enable manufacturing of large hybrid boosters for current and future space launch vehicles. The HPDP has successfully conducted four tests of the 250,000 pound thrust hybrid rocket motor at NASA's Stennis Space Center. This paper documents the test series.

  9. Effectiveness of a grant program's efforts to promote synergy within its funded initiatives: perceptions of participants of the Southern Rural Access Program

    PubMed Central

    Pathman, Donald E; Chuang, Emmeline; Weiner, Bryan J

    2008-01-01

    Background Foundations and public agencies commonly fund focused initiatives for individual grantees. These discrete, stand-alone initiatives can risk failure by being carried out in isolation. Fostering synergy among grantees' initiatives is one strategy proposed for promoting the success and impact of grant programs. We evaluate an explicit strategy to build synergy within the Robert Wood Johnson Foundation's Southern Rural Access Program (SRAP), which awarded grants to collaboratives within eight southeastern U.S. states to strengthen basic health care services in targeted rural counties. Methods We interviewed 39 key participants of the SRAP, including the program director within each state and the principal subcontractors heading the program's funded initiatives that supported heath professionals' recruitment, retention and training, made loans to health care providers, and built networks among providers. Interews were recorded and transcribed. Two investigators independently coded the transcripts and a third investigator distilled the main points. Results Participants generally perceived that the SRAP yielded more synergies than other grant programs in which they had participated and that these synergies added to the program's impact. The synergies most often noted were achieved through relationship building among grantees and with outside agencies, sharing information and know-how, sharing resources, combining efforts to yield greater capacity, joining voices to advocate for common goals, and spotting gaps in services offered and then filling these gaps. The SRAP's strategies that participants felt fostered synergy included targeting funding to culturally and geographically similar states, supporting complementary types of initiatives, promoting opportunities to network through semi-annual meetings and regular conference calls, and the advocacy efforts of the program's leadership. Participants noted that synergies were sometimes hindered by turf issues and

  10. Dual dimensionality reduction reveals independent encoding of motor features in a muscle synergy for insect flight control.

    PubMed

    Sponberg, Simon; Daniel, Thomas L; Fairhall, Adrienne L

    2015-04-01

    What are the features of movement encoded by changing motor commands? Do motor commands encode movement independently or can they be represented in a reduced set of signals (i.e. synergies)? Motor encoding poses a computational and practical challenge because many muscles typically drive movement, and simultaneous electrophysiology recordings of all motor commands are typically not available. Moreover, during a single locomotor period (a stride or wingstroke) the variation in movement may have high dimensionality, even if only a few discrete signals activate the muscles. Here, we apply the method of partial least squares (PLS) to extract the encoded features of movement based on the cross-covariance of motor signals and movement. PLS simultaneously decomposes both datasets and identifies only the variation in movement that relates to the specific muscles of interest. We use this approach to explore how the main downstroke flight muscles of an insect, the hawkmoth Manduca sexta, encode torque during yaw turns. We simultaneously record muscle activity and turning torque in tethered flying moths experiencing wide-field visual stimuli. We ask whether this pair of muscles acts as a muscle synergy (a single linear combination of activity) consistent with their hypothesized function of producing a left-right power differential. Alternatively, each muscle might individually encode variation in movement. We show that PLS feature analysis produces an efficient reduction of dimensionality in torque variation within a wingstroke. At first, the two muscles appear to behave as a synergy when we consider only their wingstroke-averaged torque. However, when we consider the PLS features, the muscles reveal independent encoding of torque. Using these features we can predictably reconstruct the variation in torque corresponding to changes in muscle activation. PLS-based feature analysis provides a general two-sided dimensionality reduction that reveals encoding in high dimensional

  11. Dual Dimensionality Reduction Reveals Independent Encoding of Motor Features in a Muscle Synergy for Insect Flight Control

    PubMed Central

    Sponberg, Simon; Daniel, Thomas L.; Fairhall, Adrienne L.

    2015-01-01

    What are the features of movement encoded by changing motor commands? Do motor commands encode movement independently or can they be represented in a reduced set of signals (i.e. synergies)? Motor encoding poses a computational and practical challenge because many muscles typically drive movement, and simultaneous electrophysiology recordings of all motor commands are typically not available. Moreover, during a single locomotor period (a stride or wingstroke) the variation in movement may have high dimensionality, even if only a few discrete signals activate the muscles. Here, we apply the method of partial least squares (PLS) to extract the encoded features of movement based on the cross-covariance of motor signals and movement. PLS simultaneously decomposes both datasets and identifies only the variation in movement that relates to the specific muscles of interest. We use this approach to explore how the main downstroke flight muscles of an insect, the hawkmoth Manduca sexta, encode torque during yaw turns. We simultaneously record muscle activity and turning torque in tethered flying moths experiencing wide-field visual stimuli. We ask whether this pair of muscles acts as a muscle synergy (a single linear combination of activity) consistent with their hypothesized function of producing a left-right power differential. Alternatively, each muscle might individually encode variation in movement. We show that PLS feature analysis produces an efficient reduction of dimensionality in torque variation within a wingstroke. At first, the two muscles appear to behave as a synergy when we consider only their wingstroke-averaged torque. However, when we consider the PLS features, the muscles reveal independent encoding of torque. Using these features we can predictably reconstruct the variation in torque corresponding to changes in muscle activation. PLS-based feature analysis provides a general two-sided dimensionality reduction that reveals encoding in high dimensional

  12. Inhibition of cholesterol metabolism underlies synergy between mTOR pathway inhibition and chloroquine in bladder cancer cells

    PubMed Central

    King, M A; Ganley, I G; Flemington, V

    2016-01-01

    Mutations to fibroblast growth factor receptor 3 (FGFR3) and phosphatase and tensin homologue (PTEN) signalling pathway components (for example, PTEN loss, PIK3CA, AKT1, TSC1/2) are common in bladder cancer, yet small-molecule inhibitors of these nodes (FGFR/PTENi) show only modest activity in preclinical models. As activation of autophagy is proposed to promote survival under FGFR/PTENi, we have investigated this relationship in a panel of 18 genetically diverse bladder cell lines. We found that autophagy inhibition does not sensitise bladder cell lines to FGFR/PTENi, but newly identify an autophagy-independent cell death synergy in FGFR3-mutant cell lines between mTOR (mammalian target of rapamycin) pathway inhibitors and chloroquine (CQ)—an anti-malarial drug used as a cancer therapy adjuvant in over 30 clinical trials. The mechanism of synergy is consistent with lysosomal cell death (LCD), including cathepsin-driven caspase activation, and correlates with suppression of cSREBP1 and cholesterol biosynthesis in sensitive cell lines. Remarkably, loss of viability can be rescued by saturating cellular membranes with cholesterol or recapitulated by statin-mediated inhibition, or small interfering RNA knockdown, of enzymes regulating cholesterol metabolism. Modulation of CQ-induced cell death by atorvastatin and cholesterol is reproduced across numerous cell lines, confirming a novel and fundamental role for cholesterol biosynthesis in regulating LCD. Thus, we have catalogued the molecular events underlying cell death induced by CQ in combination with an anticancer therapeutic. Moreover, by revealing a hitherto unknown aspect of lysosomal biology under stress, we propose that suppression of cholesterol metabolism in cancer cells should elicit synergy with CQ and define a novel approach to future cancer treatments. PMID:26853465

  13. Inhibition of cholesterol metabolism underlies synergy between mTOR pathway inhibition and chloroquine in bladder cancer cells.

    PubMed

    King, M A; Ganley, I G; Flemington, V

    2016-08-25

    Mutations to fibroblast growth factor receptor 3 (FGFR3) and phosphatase and tensin homologue (PTEN) signalling pathway components (for example, PTEN loss, PIK3CA, AKT1, TSC1/2) are common in bladder cancer, yet small-molecule inhibitors of these nodes (FGFR/PTENi) show only modest activity in preclinical models. As activation of autophagy is proposed to promote survival under FGFR/PTENi, we have investigated this relationship in a panel of 18 genetically diverse bladder cell lines. We found that autophagy inhibition does not sensitise bladder cell lines to FGFR/PTENi, but newly identify an autophagy-independent cell death synergy in FGFR3-mutant cell lines between mTOR (mammalian target of rapamycin) pathway inhibitors and chloroquine (CQ)-an anti-malarial drug used as a cancer therapy adjuvant in over 30 clinical trials. The mechanism of synergy is consistent with lysosomal cell death (LCD), including cathepsin-driven caspase activation, and correlates with suppression of cSREBP1 and cholesterol biosynthesis in sensitive cell lines. Remarkably, loss of viability can be rescued by saturating cellular membranes with cholesterol or recapitulated by statin-mediated inhibition, or small interfering RNA knockdown, of enzymes regulating cholesterol metabolism. Modulation of CQ-induced cell death by atorvastatin and cholesterol is reproduced across numerous cell lines, confirming a novel and fundamental role for cholesterol biosynthesis in regulating LCD. Thus, we have catalogued the molecular events underlying cell death induced by CQ in combination with an anticancer therapeutic. Moreover, by revealing a hitherto unknown aspect of lysosomal biology under stress, we propose that suppression of cholesterol metabolism in cancer cells should elicit synergy with CQ and define a novel approach to future cancer treatments. PMID:26853465

  14. Hybrid baryons in QCD

    DOE PAGESBeta

    Dudek, Jozef J.; Edwards, Robert G.

    2012-03-21

    In this study, we present the first comprehensive study of hybrid baryons using lattice QCD methods. Using a large basis of composite QCD interpolating fields we extract an extensive spectrum of baryon states and isolate those of hybrid character using their relatively large overlap onto operators which sample gluonic excitations. We consider the spectrum of Nucleon and Delta states at several quark masses finding a set of positive parity hybrid baryons with quantum numbersmore » $$N_{1/2^+},\\,N_{1/2^+},\\,N_{3/2^+},\\, N_{3/2^+},\\,N_{5/2^+},\\,$$ and $$\\Delta_{1/2^+},\\, \\Delta_{3/2^+}$$ at an energy scale above the first band of `conventional' excited positive parity baryons. This pattern of states is compatible with a color octet gluonic excitation having $$J^{P}=1^{+}$$ as previously reported in the hybrid meson sector and with a comparable energy scale for the excitation, suggesting a common bound-state construction for hybrid mesons and baryons.« less

  15. Research on Hybrid Vehicle Drivetrain

    NASA Astrophysics Data System (ADS)

    Xie, Zhongzhi

    Hybrid cars as a solution to energy saving, emission reduction measures, have received widespread attention. Motor drive system as an important part of the hybrid vehicles as an important object of study. Based on the hybrid electric vehicle powertrain control system for permanent magnet synchronous motor as the object of study. Can be applied to hybrid car compares the characteristics of traction motors, chose permanent magnet synchronous Motors as drive motors for hybrid vehicles. Building applications in hybrid cars in MATLAB/Simulink simulation model of permanent-magnet synchronous motor speed control system and analysis of simulation results.

  16. [Synergy retween D.P.R. 1124/65 and D.Lgs 81/2008: current events and perspectives].

    PubMed

    Savino, E; Miccio, A; Ossicini, A

    2010-01-01

    Already by the enactment of D.P.R. 1124/65 Legislator has, de iure e de facto, carried out an interaction between INAIL and the Competent Doctor (once Factory Doctor). By the enactment of the new Consolidated Act about Safety, the synergy between D.P.R. 1124/65 and D.Lgs. 81/2008 and, consequently, between INAIL doctor and Competent Doctor has further been enhanced, laying the essential requirements, according to the AA.s for a greater and greater collaboration between the two professional figures, with the objective of a more and more caring guardianship of the worker's health in the occupational field.

  17. A Synergy Effect of Trisodium Phosphate and Ethanol on Inactivation of Murine Norovirus 1 on Lettuce and Bell Pepper.

    PubMed

    Kim, Eun-Jin; Lee, Young-Duck; Kim, Kwang-Yup; Park, Jong-Hyun

    2015-12-28

    The synergy effect of trisodium phosphate (TSP) and ethanol against murine norovirus 1 (MNV-1), as a surrogate for human noroviruses, on fresh produces was evaluated. More than 2% (w/v) of TSP effectively inactivated MNV-1. The single treatment of 1% TSP or 30% ethanol for 30 min was not effective on MNV-1; however, cotreatment showed inactivation of MNV-1 on stainless steel and the produces of lettuce and bell pepper under 15 min. The results suggest that cotreatment of TSP and ethanol at a low concentration and a short time of exposure might be useful for the reduction of norovirus in some produce.

  18. A Synergy Effect of Trisodium Phosphate and Ethanol on Inactivation of Murine Norovirus 1 on Lettuce and Bell Pepper.

    PubMed

    Kim, Eun-Jin; Lee, Young-Duck; Kim, Kwang-Yup; Park, Jong-Hyun

    2015-12-28

    The synergy effect of trisodium phosphate (TSP) and ethanol against murine norovirus 1 (MNV-1), as a surrogate for human noroviruses, on fresh produces was evaluated. More than 2% (w/v) of TSP effectively inactivated MNV-1. The single treatment of 1% TSP or 30% ethanol for 30 min was not effective on MNV-1; however, cotreatment showed inactivation of MNV-1 on stainless steel and the produces of lettuce and bell pepper under 15 min. The results suggest that cotreatment of TSP and ethanol at a low concentration and a short time of exposure might be useful for the reduction of norovirus in some produce. PMID:26323270

  19. A Synergy Method to Improve Ensemble Weather Predictions and Differential SAR Interferograms

    NASA Astrophysics Data System (ADS)

    Ulmer, Franz-Georg; Adam, Nico

    2015-11-01

    A compensation of atmospheric effects is essential for mm-sensitivity in differential interferometric synthetic aperture radar (DInSAR) techniques. Numerical weather predictions are used to compensate these disturbances allowing a reduction in the number of required radar scenes. Practically, predictions are solutions of partial differential equations which never can be precise due to model or initialisation uncertainties. In order to deal with the chaotic nature of the solutions, ensembles of predictions are computed. From a stochastic point of view, the ensemble mean is the expected prediction, if all ensemble members are equally likely. This corresponds to the typical assumption that all ensemble members are physically correct solutions of the set of partial differential equations. DInSAR allows adding to this knowledge. Observations of refractivity can now be utilised to check the likelihood of a solution and to weight the respective ensemble member to estimate a better expected prediction. The objective of the paper is to show the synergy between ensemble weather predictions and differential interferometric atmospheric correction. We demonstrate a new method first to compensate better for the atmospheric effect in DInSAR and second to estimate an improved numerical weather prediction (NWP) ensemble mean. Practically, a least squares fit of predicted atmospheric effects with respect to a differential interferogram is computed. The coefficients of this fit are interpreted as likelihoods and used as weights for the weighted ensemble mean. Finally, the derived weighted prediction has minimal expected quadratic errors which is a better solution compared to the straightforward best-fitting ensemble member. Furthermore, we propose an extension of the algorithm which avoids the systematic bias caused by deformations. It makes this technique suitable for time series analysis, e.g. persistent scatterer interferometry (PSI). We validate the algorithm using the well known

  20. Rheology and synergy of κ-carrageenan/locust bean gum/konjac glucomannan gels.

    PubMed

    Brenner, Tom; Wang, Zheng; Achayuthakan, Piyada; Nakajima, Tetsuya; Nishinari, Katsuyoshi

    2013-10-15

    The rheology and melting of mixed polysaccharide gels containing konjac glucomannan (KGM), locust bean gum (LBG) and κ-carrageenan (KC) were studied. Synergy-type peaks in the Young's modulus at optimal mixing ratios were found for both KC/LBG and KC/KGM binary gels at a fixed total polysaccharide content (1:5.5 for LBG:KC and 1:7 for KGM:KC). The Young's modulus peak for KC/KGM was higher than for KC/LBG gels. The same stoichiometric mixing ratios were found when either LBG or KGM was added to KC at a fixed KC concentration, where the Young's modulus increased up to additions at the stoichiometric ratio, but leveled off at higher LBG or KGM additions. Addition of KGM or LBG to the 2-component gels beyond the stoichiometric (optimal) mixing ratio at a fixed total polysaccharide content led to a decrease in the Young's modulus and an increase in the rupture strain and stress in extension, and both trends were stronger for KGM than for LBG. Differential scanning calorimetry of the gels revealed the development of a second melting peak for the KC/KGM gels that increased with KGM addition up to higher KGM contents than the stoichiometric ratio. For the KC/LBG gels, only a slight broadening and shift to a higher temperature were observed. When the three polysaccharides were mixed, the DSC endotherms reflected only the main features of the interaction between KC and KGM, and the same was true for the fracture in extension. The different trends led to higher Young's moduli at intermediate KC concentrations when a 1:1 addition of LBG:KGM was used than when either only KGM or LBG was added at a fixed total polysaccharide concentration. This suggests that no special interactions arise when the three polysaccharides are mixed and the binding mechanisms are simply a sum of the bindings observed for KC/KGM and KC/LBG two-component gels.

  1. Toward biophysical synergy: Investigating advection along the Polar Front to identify factors influencing Alaska sablefish recruitment

    NASA Astrophysics Data System (ADS)

    Shotwell, S. Kalei; Hanselman, Dana H.; Belkin, Igor M.

    2014-09-01

    index in the sablefish model provided moderate reduction in unexplained recruitment variability and increased future projections of spawning biomass in the medium term. Based on this result, we developed a conceptual model of three mechanisms that in combination form an ocean domain dynamic synergy (ODDS) which influences sablefish survival through the pelagic early life history stage. Successfully incorporating environmental time series into the sablefish assessment could establish a foundation for future ecosystem-based management and allow for more informed and efficient resource allocation to stakeholders.

  2. Human Monoclonal Antibody Combination against SARS Coronavirus: Synergy and Coverage of Escape Mutants

    PubMed Central

    Poon, Leo L. M; Marissen, Wilfred E; Leung, Cynthia S. W; Cox, Freek; Cheung, Chung Y; Bakker, Arjen Q; Bogaards, Johannes A; van Deventer, Els; Preiser, Wolfgang; Doerr, Hans Wilhelm; Chow, Vincent T; de Kruif, John; Peiris, Joseph S. M; Goudsmit, Jaap

    2006-01-01

    , synergy between CR3014 and CR3022 may allow for a lower total antibody dose to be administered for passive immune prophylaxis of SARS-CoV infection. PMID:16796401

  3. INK128 Exhibits Synergy with Azoles against Exophiala spp. and Fusarium spp.

    PubMed Central

    Gao, Lujuan; Sun, Yi; He, Chengyan; Li, Ming; Zeng, Tongxiang; Lu, Qiaoyun

    2016-01-01

    Infections of Exophiala spp. and Fusarium spp. are often chronic and recalcitrant. Systemic disseminations, which mostly occur in immunocompromised patients, are often refractory to available antifungal therapies. The conserved target of rapamycin (TOR) orchestrates cell growth and proliferation in response to nutrients and growth factors, which are important for pathogenicity and virulence. INK128 is a second-generation ATP-competitive TOR inhibitor, which binds the TOR catalytic domain and selectively inhibits TOR. In the present study, we investigated the in vitro activities of INK128 alone and the interactions of INK128 with conventional antifungal drugs including itraconazole, voriconazole, posaconazole, and amphotericin B against 18 strains of Exophiala spp. and 10 strains of Fusarium spp. via broth microdilution checkerboard technique system adapted from Clinical and Laboratory Standards Institute broth microdilution method M38-A2. INK128 alone was inactive against all isolates tested. However, favorable synergistic effects between INK128 and voriconazole were observed in 61% Exophiala strains and 60% Fusarium strains, despite Fusarium strains exhibited high MIC values (4–8 μg/ml) against voriconazole. In addition, synergistic effects of INK128/itraconazole were shown in 33% Exophiala strains and 30% Fusarium strains, while synergy of INK128/posaconazole were observed in 28% Exophiala strains and 30% Fusarium strains. The effective working ranges of INK128 were 0.125–2 μg/ml and 1–4 μg/ml against Exophiala isolates and Fusarium isolates, respectively. No synergistic effect was observed when INK128 was combined with amphotericin B. No antagonism was observed in all combinations. In conclusion, INK128 could enhance the in vitro antifungal activity of voriconazole, itraconazole and posaconazole against Exophiala spp. and Fusarium spp., suggesting that azoles, especially voriconazole, combined with TOR kinase inhibitor might provide a potential strategy

  4. Synergy in microcosms with environmentally realistic concentrations of prochloraz and esfenvalerate.

    PubMed

    Bjergager, Maj-Britt A; Hanson, Mark L; Lissemore, Linda; Henriquez, Nikki; Solomon, Keith R; Cedergreen, Nina

    2011-01-25

    pesticide treatments, indications of stabilisation or the beginning of recovery occurred between day 7 and day 14 and full recovery was observed in some of the less affected populations of cladocerans, copepods, and chironomids after 28 days. The occurrence of the synergistic interactions between prochloraz and esfenvalerate in the microcosms and at environmentally realistic concentrations implies that the synergistic interactions may also take place in invertebrate communities in natural ponds and ditches being exposed to azoles and pyrethroids via for example runoff or drift. The question of how to deal with synergy between chemicals in the environment from a regulatory perspective is briefly discussed. PMID:21216352

  5. Ames Hybrid Combustion Facility

    NASA Technical Reports Server (NTRS)

    Zilliac, Greg; Karabeyoglu, Mustafa A.; Cantwell, Brian; Hunt, Rusty; DeZilwa, Shane; Shoffstall, Mike; Soderman, Paul T.; Bencze, Daniel P. (Technical Monitor)

    2003-01-01

    The report summarizes the design, fabrication, safety features, environmental impact, and operation of the Ames Hybrid-Fuel Combustion Facility (HCF). The facility is used in conducting research into the scalability and combustion processes of advanced paraffin-based hybrid fuels for the purpose of assessing their applicability to practical rocket systems. The facility was designed to deliver gaseous oxygen at rates between 0.5 and 16.0 kg/sec to a combustion chamber operating at pressures ranging from 300 to 900. The required run times were of the order of 10 to 20 sec. The facility proved to be robust and reliable and has been used to generate a database of regression-rate measurements of paraffin at oxygen mass flux levels comparable to those of moderate-sized hybrid rocket motors.

  6. Photoproduction of hybrid mesons

    SciTech Connect

    Barnes, T. |

    1998-11-01

    In this contribution the author discusses prospects for photoproducing hybrid mesons at CEBAF, based on recent model results and experimental indications of possible hybrids. One excellent opportunity appears to be a search for I = 1, J{sup PC} = 2{sup +{minus}} ``b{sub 2}{sup o}`` hybrids in (a{sub 2}{pi}){sup o} through diffraction photoproduction. Other notable possibilities accessible through {pi}{sup +}; {pi}{sub J}{sup +}(1770) in f{sub 2}{pi}{sup +} and (b{sub 1}{pi}){sup +}; {pi}{sup +}(1800) in f{sub 0}{pi}{sup +}, f{sub 2}{pi}{sup =}, {rho}{sup +}{omega} and ({rho}{pi}){sup +}; a{sub 1} in f{sub 1}{pi}{sup +} and f{sub 2}{pi}{sup +}; and {omega} in ({rho}{pi}){sup o}, {omega}{eta} and K{sub 1}K.

  7. Hybridization in geese: a review.

    PubMed

    Ottenburghs, Jente; van Hooft, Pim; van Wieren, Sipke E; Ydenberg, Ronald C; Prins, Herbert H T

    2016-01-01

    The high incidence of hybridization in waterfowl (ducks, geese and swans) makes this bird group an excellent study system to answer questions related to the evolution and maintenance of species boundaries. However, knowledge on waterfowl hybridization is biased towards ducks, with a large knowledge gap in geese. In this review, we assemble the available information on hybrid geese by focusing on three main themes: (1) incidence and frequency, (2) behavioural mechanisms leading to hybridization, and (3) hybrid fertility. Hybridization in geese is common on a species-level, but rare on a per-individual level. An overview of the different behavioural mechanisms indicates that forced extra-pair copulations and interspecific nest parasisitm can both lead to hybridization. Other sources of hybrids include hybridization in captivity and vagrant geese, which may both lead to a scarcity of conspecifics. The different mechanisms are not mutually exclusive and it is currently not possible to discriminate between the different mechanisms without quantitative data. Most hybrid geese are fertile; only in crosses between distantly related species do female hybrids become sterile. This fertility pattern, which is in line with Haldane's Rule, may facilitate interspecific gene flow between closely related species. The knowledge on hybrid geese should be used, in combination with the information available on hybridization in ducks, to study the process of avian speciation. PMID:27182276

  8. Smart hybrid rotary damper

    NASA Astrophysics Data System (ADS)

    Yang, C. S. Walter; DesRoches, Reginald

    2014-03-01

    This paper develops a smart hybrid rotary damper using a re-centering smart shape memory alloy (SMA) material as well as conventional energy-dissipating metallic plates that are easy to be replaced. The ends of the SMA and steel plates are inserted in the hinge. When the damper rotates, all the plates bend, providing energy dissipating and recentering characteristics. Such smart hybrid rotary dampers can be installed in structures to mitigate structural responses and to re-center automatically. The damaged energy-dissipating plates can be easily replaced promptly after an external excitation, reducing repair time and costs. An OpenSEES model of a smart hybrid rotary was established and calibrated to reproduce the realistic behavior measured from a full-scale experimental test. Furthermore, the seismic performance of a 3-story moment resisting model building with smart hybrid rotary dampers designed for downtown Los Angeles was also evaluated in the OpenSEES structural analysis software. Such a smart moment resisting frame exhibits perfect residual roof displacement, 0.006", extremely smaller than 18.04" for the conventional moment resisting frame subjected to a 2500 year return period ground motion for the downtown LA area (an amplified factor of 1.15 on Kobe earthquake). The smart hybrid rotary dampers are also applied into an eccentric braced steel frame, which combines a moment frame system and a bracing system. The results illustrate that adding smart hybrid rotaries in this braced system not only completely restores the building after an external excitation, but also significantly reduces peak interstory drifts.

  9. Hybridization of natural systems with advanced treatment processes for organic micropollutant removals: new concepts in multi-barrier treatment.

    PubMed

    Sudhakaran, Sairam; Maeng, Sung Kyu; Amy, Gary

    2013-07-01

    Organic micropollutants (OMPs) represent a major constraint in drinking water supply. In the past, emphasis has been on individual treatment processes comprising conventional treatment (coagulation, sedimentation, and filtration) followed by advanced treatment processes (adsorption, ion-exchange, oxidation, and membrane separation). With the depletion of water resources and high demand for power and chemical usage, efforts need to be made to judiciously use advanced treatment processes. There is a new interest in multiple barriers with synergies in which two coupled processes can function as a hybrid process. Within the context of this paper, the hybrid processes include a natural treatment process coupled with an advanced process. Pilot/full-scale studies have shown efficient removal of OMPs by these hybrid processes. With this hybridization, the usage of resources such as power and chemicals can be reduced. In this study, coupling/hybridization of aquifer recharge and recovery (ARR) with oxidation (O3), advanced oxidation process which involves OH radicals (AOP), nanofiltration (NF), reverse osmosis (RO) and granular activated carbon (GAC) adsorption for OMP removal was studied. O3 or AOP as a pre-treatment and GAC, NF, RO, or UV/chlorination as a post-treatment to ARR was studied. NF can be replaced by RO for removal of OMPs since studies have shown similar performance of NF to RO for removal of many OMPs, thereby reducing costs and providing a more sustainable approach. PMID:23664475

  10. Hybridization of natural systems with advanced treatment processes for organic micropollutant removals: new concepts in multi-barrier treatment.

    PubMed

    Sudhakaran, Sairam; Maeng, Sung Kyu; Amy, Gary

    2013-07-01

    Organic micropollutants (OMPs) represent a major constraint in drinking water supply. In the past, emphasis has been on individual treatment processes comprising conventional treatment (coagulation, sedimentation, and filtration) followed by advanced treatment processes (adsorption, ion-exchange, oxidation, and membrane separation). With the depletion of water resources and high demand for power and chemical usage, efforts need to be made to judiciously use advanced treatment processes. There is a new interest in multiple barriers with synergies in which two coupled processes can function as a hybrid process. Within the context of this paper, the hybrid processes include a natural treatment process coupled with an advanced process. Pilot/full-scale studies have shown efficient removal of OMPs by these hybrid processes. With this hybridization, the usage of resources such as power and chemicals can be reduced. In this study, coupling/hybridization of aquifer recharge and recovery (ARR) with oxidation (O3), advanced oxidation process which involves OH radicals (AOP), nanofiltration (NF), reverse osmosis (RO) and granular activated carbon (GAC) adsorption for OMP removal was studied. O3 or AOP as a pre-treatment and GAC, NF, RO, or UV/chlorination as a post-treatment to ARR was studied. NF can be replaced by RO for removal of OMPs since studies have shown similar performance of NF to RO for removal of many OMPs, thereby reducing costs and providing a more sustainable approach.

  11. Hybrid Weyl semimetal

    NASA Astrophysics Data System (ADS)

    Li, Fei-Ye; Luo, Xi; Dai, Xi; Yu, Yue; Zhang, Fan; Chen, Gang

    2016-09-01

    We construct a tight-binding model realizing one pair of Weyl nodes and three distinct Weyl semimetals. In the type-I (type-II) Weyl semimetal, both nodes belong to type-I (type-II) Weyl nodes. In addition, there exists a third type, previously undiscovered and dubbed "hybrid Weyl semimetal", in which one Weyl node is of type I while the other is of type II. For the hybrid Weyl semimetal, we further demonstrate the bulk Fermi surfaces and the topologically protected surface states, analyze the unique Landau-level structure and quantum oscillation, and discuss the conditions for possible material realization.

  12. Hybrid polarity SAR architecture

    NASA Astrophysics Data System (ADS)

    Raney, R. Keith

    2009-05-01

    A space-based synthetic aperture radar (SAR) designed to provide quantitative information on a global scale implies severe requirements to maximize coverage and to sustain reliable operational calibration. These requirements are best served by the hybrid-polarity architecture, in which the radar transmits in circular polarization, and receives on two orthogonal linear polarizations, coherently, retaining their relative phase. This paper summarizes key attributes of hybrid-polarity dual- and quadrature-polarized SARs, reviews the associated advantages, formalizes conditions under which the signal-to-noise ratio is conserved, and describes the evolution of this architecture from first principles.

  13. Subwavelength hybrid terahertz waveguides.

    PubMed

    Nam, Sung Hyun; Taylor, Antoinette J; Efimov, Anatoly

    2009-12-01

    We introduce and present general properties of hybrid terahertz waveguides. Weakly confined Zenneck waves on a metal-dielectric interface at terahertz frequencies can be transformed to a strongly confined yet low-loss subwavelength mode through coupling with a photonic mode of a nearby high-index dielectric strip. We analyze confinement, attenuation, and dispersion properties of this mode. The proposed design is suitable for planar integration and allows easy fabrication on chip scale. The superior waveguiding properties at terahertz frequencies could enable the hybrid terahertz waveguides as building blocks for terahertz integrated circuits.

  14. Hybrid network intrusion detection

    NASA Astrophysics Data System (ADS)

    Tahmoush, David

    2014-05-01

    We report on a machine learning classifier that can be used to discover the patterns hidden within large networking data flows. It utilizes an existing intrusion detection system (IDS) as an oracle to learn a faster, less resource intensive normalcy classifier as a front-end to a hybrid network IDS. This system has the capability to recognize new attacks that are similar to known attack signatures. It is also more highly scalable and distributable than the signature-based IDS. The new hybrid design also allows distributed updates and retraining of the normalcy classifier to stay up-to-date with current threats.

  15. Hybridized polymer matrix composite

    NASA Technical Reports Server (NTRS)

    Stern, B. A.; Visser, T.

    1981-01-01

    Under certain conditions of combined fire and impact, graphite fibers are released to the atmosphere by graphite fiber composites. The retention of graphite fibers in these situations is investigated. Hybrid combinations of graphite tape and cloth, glass cloth, and resin additives are studied with resin systems. Polyimide resins form the most resistant composites and resins based on simple novolac epoxies the least resistant of those tested. Great improvement in the containment of the fibers is obtained in using graphite/glass hybrids, and nearly complete prevention of individual fiber release is made possible by the use of resin additives.

  16. Diagnostics for hybrid reactors

    SciTech Connect

    Orsitto, Francesco Paolo

    2012-06-19

    The Hybrid Reactor(HR) can be considered an attractive actinide-burner or a fusion assisted transmutation for destruction of transuranic(TRU) nuclear waste. The hybrid reactor has two important subsystems: the tokamak neutron source and the blanket which includes a fuel zone where the TRU are placed and a tritium breeding zone. The diagnostic system for a HR must be as simple and robust as possible to monitor and control the plasma scenario, guarantee the protection of the machine and monitor the transmutation.

  17. A Mathematical Approach to Hybridization

    ERIC Educational Resources Information Center

    Matthews, P. S. C.; Thompson, J. J.

    1975-01-01

    Presents an approach to hybridization which exploits the similarities between the algebra of wave functions and vectors. This method will account satisfactorily for the number of orbitals formed when applied to hybrids involving the s and p orbitals. (GS)

  18. Inference on treatment effects from a randomized clinical trial in the presence of premature treatment discontinuation: the SYNERGY trial.

    PubMed

    Zhang, Min; Tsiatis, Anastasios A; Davidian, Marie; Pieper, Karen S; Mahaffey, Kenneth W

    2011-04-01

    The Superior Yield of the New Strategy of Enoxaparin, Revascularization, and GlYcoprotein IIb/IIIa inhibitors (SYNERGY) was a randomized, open-label, multicenter clinical trial comparing 2 anticoagulant drugs on the basis of time-to-event endpoints. In contrast to other studies of these agents, the primary, intent-to-treat analysis did not find evidence of a difference, leading to speculation that premature discontinuation of the study agents by some subjects may have attenuated the apparent treatment effect and thus to interest in inference on the difference in survival distributions were all subjects in the population to follow the assigned regimens, with no discontinuation. Such inference is often attempted via ad hoc analyses that are not based on a formal definition of this treatment effect. We use SYNERGY as a context in which to describe how this effect may be conceptualized and to present a statistical framework in which it may be precisely identified, which leads naturally to inferential methods based on inverse probability weighting. PMID:20797983

  19. Improve Synergy Between Health Information Exchange and Electronic Health Records to Increase Rates of Continuously Insured Patients

    PubMed Central

    Gold, Rachel; Burdick, Tim; Angier, Heather; Wallace, Lorraine; Nelson, Christine; Likumahuwa-Ackman, Sonja; Sumic, Aleksandra; DeVoe, Jennifer E.

    2015-01-01

    Introduction: The Affordable Care Act increases health insurance options, yet many Americans may struggle to consistently maintain coverage. While health care providers have traditionally not been involved in providing insurance enrollment support to their patients, the ability for them to do so now exists. We propose that providers could capitalize on the expansion of electronic health records (EHRs) and the advances in health information exchanges (HIEs) to improve their patients’ insurance coverage rates and continuity. Evidence for Argument: We describe a project in which we are building strategies for linking, and thus improving synergy between, payer and EHR data. Through this effort, care teams will have access to new automated tools and increased EHR functionality designed to help them assist their patients in obtaining and maintaining health insurance coverage. Suggestion for the Future: The convergence of increasing EHR adoption, improving HIE functionality, and expanding insurance coverage options, creates new opportunities for clinics to help their patients obtain public health insurance. Harnessing this nascent ability to exchange information between payers and providers may improve synergies between HIE and EHRs, and thus support clinic-based efforts to keep patients continuously insured. PMID:26355818

  20. Flexibility and pragmatism in promoting health: an experience of synergy between health and religion in the Islamic Republic of Iran.

    PubMed

    Adams, C; Manenti, A

    2012-08-01

    In the Islamic Republic of Iran, religion has traditionally played a central role in the lives of the people. Following the Islamic Revolution in 1979, it has also become integral to the country's governance. Since the Revolution, an exceptional synergy has arisen between the domain of religion and the health sector in the development of family planning policies, which have resulted in dramatic changes in population growth and fertility: the population growth rate decreased from 3.9% (1986) to 1.2% (2000) and total fertility from 6.8 (1984) to 2.1 (2000). The extraordinary aspect of this experience is that the position of religious authorities changed from one of opposition to one of active promotion of family planning. This paper describes the establishment and course of family planning programmes in Iran and makes use of interviews with two main protagonists of this experience (Dr Alireza Marandi--Minister of Health 1984-1989, 1993-1997; Dr Hossein Malekafzali--former Deputy Minister of Health). It is hoped that dissemination of this experience outside of the Islamic Republic of Iran will encourage the development of similar dialogue and synergy between religion and health in other countries.