Concept Of Synergy Research Articles

Design and Evaluation of a Novel Experimental Setup for Upper Limb Intermuscular Coordination Studies.

Motor disabilities limiting the mobility of limbs affect the quality of lives of people with neural injuries. Among various types of motor disabilities, abnormal intermuscular coordination is commonly observed from people with severe impairment. The concept of muscle synergy, defined as characteristic muscle co-activation patterns activated to produce complex motor behavior, has been applied to assess the alteration in intermuscular coordination in pathological populations. This study presents the development of a robotic system named KAIST upper limb synergy investigation system (KULSIS), for accurate measurement of intermuscular synergies while providing the convenient experimental setup. It provides full force/moment measurements for isometric force generation tasks at various upper limb postures and reaching tasks in a three-dimensional workspace. It is composed of: a three-degree-of-freedom gimbaled handle to adjust the orientation of the handle to accommodate potential hand-wrist deformity, a linear actuator that moves the handle for reaching tasks; a five-degree-of-freedom mechanism for positioning and adjusting the orientation of the linear actuator. The design was evaluated in terms of the workspace of the handle, mechanical stiffness and force/moment measurement accuracy. The position/force measurement is synchronized with electromyographic measurements. Muscle synergy patterns, activated during four isokinetic reaching motions, were also assessed as preliminary data using KULSIS from ten healthy subjects.

Evaluation of Finger Force Control Ability in terms of Multi-finger Synergy.

In this study, finger force control abilities are quantified by the concept of multi-finger synergy in conjunction with uncontrolled manifold (UCM) analysis. Two indices, named repeatability and flexibility, representing features of multi-finger synergy were proposed to overcome the limitation of previously introduced indices, such as floor effects and distortion problems. The proposed indices were applied to stroke patients and healthy adults through specifically designed experiments. The experimental results showed a clear difference between stroke patients and healthy adults. Also, interestingly, there was a difference in outcome between two stroke patient subgroups: stroke patients in whom the dominant hand was affected and non-dominant hand was affected groups.

Prophylaxis of Non-communicable Diseases: Why Fruits and Vegetables may be Better Chemopreventive Agents than Dietary Supplements Based on Isolated Phytochemicals?

The World Health Organization (WHO) report from 2014 documented that non-communicable socalled civilization diseases such as cardiovascular disease, chronic respiratory diseases, cancer or type 2 diabetes are responsible for over 50% of all premature deaths in the world. Research carried out over the past 20 years has provided data suggesting that diet is an essential factor influencing the risk of development of these diseases. The increasing knowledge on chemopreventive properties of certain food ingredients, in particular, those of plant origin, opened the discussion on the possibility to use edible plants or their active components in the prevention of these chronic diseases. Health-promoting properties of plant foods are associated with the presence of secondary metabolites that can affect many biological mechanisms of critical importance to the proper functioning of the human organism. Particularly, there have been numerous investigations indicating strong physiological effects of bioactive plant phenols belonging to the flavonoid family. These observations initiated mass production of dietary supplements containing flavonoids commercialized under the name antioxidants, even if their chemical properties did not justify such a term. However, epidemiological studies revealed that isolated bioactive phytochemicals are not as effective as fruits and vegetables containing these substances whereas they are of interest of the functional food industry. In this paper, the critical assessment of reasons for this turn of events has been attempted and the concept of food synergy has been suggested as a future strategy of dietary chemoprevention.

Characterizing Strategic Contributions of Physical Therapy to Natural Standing Motion in the Muscle Synergy Space.

Understanding the contributions of therapist skill during intervention is essential for improving existing rehabilitation methodologies. This study aims to characterize therapist intervention on an important activity of daily living, the sit-to-stand motion. Using the concept of muscle synergy, we quantify and compare naturally-occurring standing strategies with those induced by a physical therapist. In this paper, we show that natural standing strategies are not shared among healthy subjects. However, each subject retains their own set of strategies. Moreover, the results suggest that a therapist does not introduce new strategies during therapy, but rather modulates the existing strategies of the individuals. Using such a low-dimensional representation of standing behavior allows for development of low-cost tools for wider distribution.

Phytochemical composition and biological activities of differently pigmented cabbage (Brassica oleracea var. capitata) and cauliflower (Brassica oleracea var. botrytis) varieties.

Brassica plants contain a wide spectrum of bioactive components that are responsible for their health-promoting potential such as vitamins, polyphenols and glucosinolates. This study attempted to relate the composition of bioactive phytochemicals and chosen biological activities (antioxidant, cytotoxic, anti-genotoxic, and influence on enzymatic activities) for extracts from differently pigmented cabbage (white and red) and cauliflower (white and purple) varieties. The assumption was that tested varieties of the same plant would exhibit similar chemical composition differing mostly in anthocyanin content and that the latter will be reflected in biological activity. Profiles of antioxidants obtained using post-column derivatization with ABTS radical confirmed, that the content and composition of anthocyanins is strongly correlated with the antioxidant capacity of tested plant extracts measured by spectrophotometric methods (ABTS, FC, DPPH, FRAP), and Cellular Antioxidant Activity (CAA) test. The results of determinations of other biological activities showed that opposite to purified bioactive phytochemicals, in the case of actual plant foods, there was no simple relationship between anthocyanin content and chemopreventive potential. Obtained results suggest that there must be some kind of interaction between different phytochemicals, which decides on the final health promoting activity of edible plants as suggested by for example the food synergy concept. © 2019 Society of Chemical Industry.

Evaluation of Finger Force Control Ability in Terms of Multi-Finger Synergy.

In this study, finger force control abilities are quantified by the concept of multi-finger synergy in conjunction with uncontrolled manifold (UCM) analysis. Two indices, namely, repeatability and flexibility, representing features of multi-finger synergy were proposed to overcome the limitation of previously introduced indices, such as floor effects and distortion problems. The proposed indices were applied to stroke patients and healthy adults through specifically designed experiments. The experimental results showed a clear difference between stroke patients and healthy adults. Also, interestingly, there was a difference in an outcome between two-stroke patient subgroups: stroke patients in whom the dominant hand was affected and non-dominant hand was affected groups.

Motor Control System for Adaptation of Healthy Individuals and Recovery of Poststroke Patients: A Case Study on Muscle Synergies.

Understanding the complex neuromuscular strategies underlying behavioral adaptation in healthy individuals and motor recovery after brain damage is essential for gaining fundamental knowledge on the motor control system. Relying on the concept of muscle synergy, which indicates the number of coordinated muscles needed to accomplish specific movements, we investigated behavioral adaptation in nine healthy participants who were introduced to a familiar environment and unfamiliar environment. We then compared the resulting computed muscle synergies with those observed in 10 moderate-stroke survivors throughout an 11-week motor recovery period. Our results revealed that computed muscle synergy characteristics changed after healthy participants were introduced to the unfamiliar environment, compared with those initially observed in the familiar environment, and exhibited an increased neural response to unpredictable inputs. The altered neural activities dramatically adjusted through behavior training to suit the unfamiliar environment requirements. Interestingly, we observed similar neuromuscular behaviors in patients with moderate stroke during the follow-up period of their motor recovery. This similarity suggests that the underlying neuromuscular strategies for adapting to an unfamiliar environment are comparable to those used for the recovery of motor function after stroke. Both mechanisms can be considered as a recall of neural pathways derived from preexisting muscle synergies, already encoded by the brain's internal model. Our results provide further insight on the fundamental principles of motor control and thus can guide the future development of poststroke therapies.

One Swallow Does Not Make a Summer: Siloes, Trade-Offs and Synergies in the Water-Energy-Food Nexus

Synergies are required to ensure coordination between UN agencies (on norms and indicators), Member States (on coherence of policy instruments) and consumers (on perceptions of safety and affordability of services) to advance the achievement of Sustainable Development Goal (SDG) target 6.3 which focusses on reuse of wastewater. In this paper we employ theoretical insights derived from an agent-based modeling approach to undertake a critical examination of the recent UN-WATER directive on SDG target 6.3 and advocate for an improved understanding of factors that determine whether and how effective wastewater reuse will be possible while accommodating for regional variation and institutional change. We demonstrate that by applying the Nexus approach it is feasible to overcome siloes by forging concepts of trade-offs and synergies to draw out coupled perspectives of bio-physical and institutional dimensions of water-energy-food interactions. By employing this proposition, the paper advocates for place-based observatories as a mechanism that can support valorization of data and methodological assumptions as a precursor to robust monitoring of the SDG's. The systematic use of literature reviews and expert opinion to develop and pilot-test composite indices via place-based observatories raises the prospect of a data light approach to monitoring SDGs; specifically, what are the merits of relying on extensive survey data compared to composite indices that while being amenable to supporting benchmarking and scenario analysis can provide the insight needed to inform decision-making and robust monitoring of global goals?

Architecting federations of systems: A framework for capturing synergy

AbstractThis paper defines Federations of Systems, introduces a tailored architecting framework, and demonstrates it in a satellite design case study. While certainly not being new concepts in the literature, federations are a class of Systems of Systems (SoS) that have not been extensively explored due to the scarcity of applied examples and still few practitioners facing their specific design challenges. This is expected to change with the advent of the Internet of Things, Machine to Machine applications, collaborative consumption, and Federated Satellite Systems. It has become henceforth necessary to develop approaches in design and architecting capable of addressing such interconnected sets of systems.Federations are SoS characterized by the absence of global goals and stakeholders, and cooperation enabled only on an opportunistic basis. Systems engage in federations when the perceived benefit exceeds the costs of the necessary interfaces. The proposed framework quantifies the upper limits to the net benefits of cooperation between systems through the concept of synergy. Using synergy as a heuristic to navigate federated design spaces, the framework predicts the appearance and evolution of federations.The demonstration of the framework in a six‐satellite federation shows that advantages of federating emerge with the collaboration between just two systems. Interface costs, architectural cost preferences, and network topology drive the achievable benefits. Specifically, when considering communication architectures under 80 MUSD for satellite systems, federating is advantageous when the interface lifecycle costs are below 15 MUSD. This demonstration case exemplifies how federating can assist systems in achieving design points that dominate the solutions of their local tradespace.

Response envelope analysis for quantitative evaluation of drug combinations.

The concept of synergy between two agents, over a century old, is important to the fields of biology, chemistry, pharmacology and medicine. A key step in drug combination analysis is the selection of an additivity model to identify combination effects including synergy, additivity and antagonism. Existing methods for identifying and interpreting those combination effects have limitations. We present here a computational framework, termed response envelope analysis (REA), that makes use of 3D response surfaces formed by generalized Loewe Additivity and Bliss Independence models of interaction to evaluate drug combination effects. Because the two models imply two extreme limits of drug interaction (mutually exclusive and mutually non-exclusive), a response envelope defined by them provides a quantitatively stringent additivity model for identifying combination effects without knowing the inhibition mechanism. As a demonstration, we apply REA to representative published data from large screens of anticancer and antibiotic combinations. We show that REA is more accurate than existing methods and provides more consistent results in the context of cross-experiment evaluation. The open-source software package associated with REA is available at: https://github.com/4dsoftware/rea. Supplementary data are available at Bioinformatics online.

Sustainable development goals – an analysis of outcomes

PurposeThe concept of sustainability evokes a multiplicity of meanings, depending on the field. Some authors have criticized the concept for its vagueness. Notwithstanding this criticism, worldwide efforts to meet the sustainable development goals (SDGs) are in progress and are expected to yield results by 2030. This paper aims to addresses two issues and make two primary contributions. First, the concept of sustainability is revisited to develop its integrative understanding. This concept is built on systems thinking – specifically, on the concepts of synergy, emergence, recursion and self-organization. Second, an approach is developed to help determine whether the efforts being made towards the SDGs can be expected to be effective (i.e., whether the world can hope to soon be a system that self-organizes towards sustainability).Design/methodology/approachBased on the assumption that the SDGs and their respective targets are systemically interrelated, the data on the progress towards the SDGs are correlated and the outcome is analysed.FindingsThe emerging pattern of correlations reflected the systemic coherence of the efforts as an indication of self-organization towards sustainability. This pattern also revealed that the efforts are still spotty and that the systemic synergy has not yet taken place. This correlation approach to Brazil is then applied. The data about Brazil’s progress towards the SDGs from the World Bank’s Word Development Indicators (WDI) database are gathered. The outcomes indicated that Brazil as a whole cannot yet be seen as self-organizing system that is evolving towards sustainability.Research limitations/implicationsTo enable the calculation of the correlation matrix, the data series were not allowed to have missing values. Some of the WDI data series had many missing values and had to be eliminated. This unfortunately reduced the variability of the original data. In addition, the missing values in the remaining data series had to be calculated by means of interpolation or extrapolation. There are alternative algorithms to perform such functions. The impact of the interpolation and extrapolation of the missing values on the study, as well as the pros and cons of different algorithms, required investigation. It is important to remark that the WDI series was the only global and open data set that aligned with the SDGs.Social implicationsIn Brazil, it is important to maintain the public policies that affect SDG 1-6, but it is necessary to develop policies geared towards SDG 12. Environmental goals also need more public policies (SDGs 14 and 15). To achieve this 2030 Agenda, much effort will be required for SDG 17, which is related to greater synergy through partnerships.Originality/valueThree qualitatively distinct levels of efforts to sustainability are identified: individual, organizational and world activities. At the individual level, progress regarding sustainability depends on personal attitudes, including the willingness to abandon a self-centred lifestyle in favour of a more cooperative way of living and making decisions, and to embrace a new approach to ethics, which replaces self-interest by self-denial and self-sacrifice (de Raadt & de Raadt, 2014). At the organizational level, a paradox of the need to internalize environmental and social costs into generic strategies and the sustainability strategy that involves core businesses are challenges for systems working towards sustainability. When it comes to global level, in this paper, the authors tried to make a contribution to push forward the frontier of knowledge by proposing an approach to understand whether the progress made towards the SDGs in the past 25 years indicates that the world is, after all, organizing for sustainability (Schwaninger, 2015).

Effect of Kinetic Degrees of Freedom on Multi-Finger Synergies and Task Performance during Force Production and Release Tasks

Complex structures present in a human body has relatively large degrees-of-freedom (DOFs) as compared to the requirement of a particular task. This phenomenon called motor redundancy initially deemed as a computational problem rather can be understood as having the flexibility to perform the certain task successfully. Hence, the purpose of our study was to examine the positive impact of extra DOFs (redundant DOFs) during force production tasks. For this purpose, an experimental setup was designed to simulate archery-like shooting, and purposeful organization of a redundant set of finger forces determined the stability of important performance variables as well as accurate and precise performance. DOFs were adjusted by changing the number of fingers explicitly involved in the task. The concept of motor synergy and computational framework of uncontrolled manifold (UCM) approach was used to quantify stability indices during finger force production. As a result, accuracy and precision of the task improved with an increase in DOFs. Also, the stability indices of net finger forces and moment increased with active DOFs of fingers. We concluded that the controller actively utilizes extra DOFs to increase the stability of the performance, which is associated with the improved accuracy and precision of the task.

Quality Enhancement through Hybrid Skill Management Concept for Multi-Type Aircraft Fleet

Scarcity of resources is becoming a universal challenge for the world community. Conservation of resources could only be possible if the quality concept of waste reduction is introduced and implemented in utilization of existing resources. Out of the countless dimensions of resource conservation, this research focuses on formulation of maintenance model through human resource conservation and its optimum utilization in aviation industry. The research work remained converged to the basic managerial aspect of skill management for Multi-type rating certification. The paper introduces a new concept with enhanced managerial quality for the first line operations of Multi-type aircraft fleet. The concept has introduced synergy concept for human resource utilization to reduce the requirement of per aircraft technicians and engineers. The research has identified that quality enhancement in three major areas namely hiring process, skill development process and maintenance practices have major role to play for optimum utilization of human resource assets. The results finally achieved show remarkable reduction in overall cost effect even though with enhanced quality.

Including nature in the food-energy-water nexus can improve sustainability across multiple ecosystem services

Activities in the food-energy-water nexus require ecosystem services to maintain productivity and prevent ecological degradation. This work applies techno-ecological synergy concepts in an optimization formulation to design a system for co-producing food and energy under constraints on ecological sustainability. The system includes land use activities and biomass conversion processes for the production of energy carriers, as well as supporting ecosystems that increase the supply of key ecosystem services. The co-production system was linearized and reduced to a mixed-integer linear program, which was optimized for single objectives under a variety of production and sustainability constraints. Results indicate that for the system considered to achieve high food and energy co-production, land use options should be balanced between food-producing crops and electricity-producing wind turbines and solar panels. Results also show that ecological sustainability can be achieved for this system with relatively small changes in land use patterns. The inclusion of nature in the design enables the system as a whole to achieve ecological sustainability for multiple ecosystem services with moderate sacrifices of food and energy productivity.

Feasibility of Synergy-Based Exoskeleton Robot Control in Hemiplegia.

Here, we present a study on exoskeleton robot control based on inter-limb locomotor synergies using a robot control method developed to target hemiparesis. The robot control is based on inter-limb locomotor synergies and kinesiological information from the non-paretic leg and a walking aid cane to generate motion patterns for the assisted leg. The developed synergy-based system was tested against an autonomous robot control system in five patients with hemiparesis and varying locomotor abilities. Three of the participants were able to walk using the robot. Results from these participants showed an improved spatial symmetry ratio and more consistent step length with the synergy-based method compared with that for the autonomous method, while the increase in the range of motion for the assisted joints was larger with the autonomous system. The kinematic synergy distribution of the participants walking without the robot suggests a relationship between each participant's synergy distribution and his/her ability to control the robot: participants with two independent synergies accounting for approximately 80% of the data variability were able to walk with the robot. This observation was not consistently apparent with conventional clinical measures such as the Brunnstrom stages. This paper contributes to the field of robot-assisted locomotion therapy by introducing the concept of inter-limb synergies, demonstrating performance differences between synergy-based and autonomous robot control, and investigating the range of disability in which the system is usable.

DEFENSE DIPLOMACY IMPLEMENTATION: THE SYNERGY OF INDONESIA AND AUSTRALIA IN DEALING WITH ILLEGAL IMMIGRANTS IN THE SEA BORDER

<strong>Abstract</strong> - Illegal Immigrant is a common problem between Indonesia and Australia. However, in handling the problem in sea border, Indonesia take a humanitarian approach while Australia take security approach through Operation Sovereign Border that had resulted to diplomatic confrontation. Therefore, this study focus on analyzing synergy of the two countries in dealing with illegal immigrant in sea border area. This study uses national security, migration as security issue to analyze national interest. Cooperative security, defense diplomacy, synergy concept and naval diplomacy theory to analyze defense diplomacy implementation as a whole. The approach of this study is qualitative method through data collection processed by software NVivo which are beneficial for coding, triangulation, and finding relations among interviewees while Soft System Methodology used as data analysis technique consist of seven steps that are very comprehensive in explaining the whole study. The results of this study showed the two countries have not synergized yet. Indonesia and Australia have common non-traditional security interests and different traditional security interests because Indonesia has a territorial importance base opposed to Australian immigration interests. Indonesia and Australia have been doing bilateral defense diplomacy through 2 + 2 Dialogue, Defense Ministers Meeting and Navy to Navy Talk but have not produced a concrete solution, therefore sharing responsibility and Confidence Building Measures have not been achieved. Thus, naval diplomacy is required to support defense diplomacy through coordinated patrols that Standard Operating Procedure and Standard Exercise Procedure must be formulated in order to achieve interests of both countries.<br /><strong>Keywords</strong>: Illegal Immigrants, National Security, Defense Diplomacy, Synergy, Soft System Methodology

Evaluation of matrix factorisation approaches for muscle synergy extraction

The muscle synergy concept provides a widely-accepted paradigm to break down the complexity of motor control. In order to identify the synergies, different matrix factorisation techniques have been used in a repertoire of fields such as prosthesis control and biomechanical and clinical studies. However, the relevance of these matrix factorisation techniques is still open for discussion since there is no ground truth for the underlying synergies. Here, we evaluate factorisation techniques and investigate the factors that affect the quality of estimated synergies. We compared commonly used matrix factorisation methods: Principal component analysis (PCA), Independent component analysis (ICA), Non-negative matrix factorization (NMF) and second-order blind identification (SOBI). Publicly available real data were used to assess the synergies extracted by each factorisation method in the classification of wrist movements. Synthetic datasets were utilised to explore the effect of muscle synergy sparsity, level of noise and number of channels on the extracted synergies. Results suggest that the sparse synergy model and a higher number of channels would result in better estimated synergies. Without dimensionality reduction, SOBI showed better results than other factorisation methods. This suggests that SOBI would be an alternative when a limited number of electrodes is available but its performance was still poor in that case. Otherwise, NMF had the best performance when the number of channels was higher than the number of synergies. Therefore, NMF would be the best method for muscle synergy extraction.

Electromyogram refinement using muscle synergy based regulation of uncertain information

Electromyogram signal (EMG) measurement frequently experiences uncertainty attributed to issues caused by technical constraints such as cross talk and maximum voluntary contraction. Due to these problems, individual EMGs exhibit uncertainty in representing their corresponding muscle activations. To regulate this uncertainty, we proposed an EMG refinement, which refines EMGs with regulating the contribution redundancy of the signals from EMGs to approximating torques through EMG-driven torque estimation (EDTE) using the muscular skeletal forward dynamic model. To regulate this redundancy, we must consider the synergistic contribution redundancy of muscles, including “unmeasured” muscles, to approximating torques, which primarily causes redundancy of EDTE. To suppress this redundancy, we used the concept of muscle synergy, which is a key concept of analyzing the neurophysiological regulation of contribution redundancy of muscles to exerting torques. Based on this concept, we designed a muscle-synergy-based EDTE as a framework for EMG refinement, which regulates the abovementioned uncertainty of individual EMGs in consideration of unmeasured muscles. In achieving the proposed EMG refinement, the most considerable point is to suppress a large change such as overestimation attributed to enhancement of the contribution of particular muscles to estimating torques. Therefore it is reasonable to refine EMGs by minimizing the change in EMGs. To evaluate this model, we used a Bland-Altman plot, which quantitatively evaluates the proportional bias of refined signals to EMGs. Through this evaluation, we showed that the proposed EDTE minimizes the bias while approximating torques. Therefore this minimization optimally regulates the uncertainty of EMGs and thereby leads to optimal EMG refinement.

Neuromuscular synergies in motor control in normal and poststroke individuals

Muscle synergies are proposed to function as motor primitives that are modulated by frontal brain areas to construct a large repertoire of movement. This paper reviews the history of the development of our current theoretical understanding of nervous system-based motor control mechanisms and more specifically the concept of muscle synergies. Computational models of muscle synergies, especially the nonnegative matrix factorization algorithm, are discussed with specific reference to the changes in synergy control post-central nervous system (CNS) lesions. An alternative approach for motor control is suggested, exploiting a combination of synergies control or flexible muscle control used for gross motor skills and for individualized finger movements. Rehabilitation approaches, either supporting or inhibiting the use of basic movement patterns, are discussed in the context of muscle synergies. Applications are discussed for the use of advanced technologies that can promote the recovery and functioning of the human CNS after stroke.

Muscle Synergy-Driven Robust Motion Control.

Humans are able to robustly maintain desired motion and posture under dynamically changing circumstances, including novel conditions. To accomplish this, the brain needs to optimize the synergistic control between muscles against external dynamic factors. However, previous related studies have usually simplified the control of multiple muscles using two opposing muscles, which are minimum actuators to simulate linear feedback control. As a result, they have been unable to analyze how muscle synergy contributes to motion control robustness in a biological system. To address this issue, we considered a new muscle synergy concept used to optimize the synergy between muscle units against external dynamic conditions, including novel conditions. We propose that two main muscle control policies synergistically control muscle units to maintain the desired motion against external dynamic conditions. Our assumption is based on biological evidence regarding the control of multiple muscles via the corticospinal tract. One of the policies is the group control policy (GCP), which is used to control muscle group units classified based on functional similarities in joint control. This policy is used to effectively resist external dynamic circumstances, such as disturbances. The individual control policy (ICP) assists the GCP in precisely controlling motion by controlling individual muscle units. To validate this hypothesis, we simulated the reinforcement of the synergistic actions of the two control policies during the reinforcement learning of feedback motion control. Using this learning paradigm, the two control policies were synergistically combined to result in robust feedback control under novel transient and sustained disturbances that did not involve learning. Further, by comparing our data to experimental data generated by human subjects under the same conditions as those of the simulation, we showed that the proposed synergy concept may be used to analyze muscle synergy-driven motion control robustness in humans.