Coordination Patterns Research Articles

Computationally aided design of single‐ion‐conducting block copolymer electrolytes to boost lithium‐ion conductivity

AbstractIn this work, we implement a combinatory approach that integrates molecular dynamics (MD) simulation and a Gaussian process regression (GPR) algorithm to explore optimal design strategies for a generic single‐ion‐conducting block copolymer electrolyte (SIC‐BCPE) model system that covers a rich design parameter space inspired by recently established poly(ethylene oxide)‐based block copolymer electrolytes. The GPR algorithm is employed to efficiently reveal the relationships between the desired lithium‐ion conductivity and four design parameters reflecting both chain architectural control and specific tuning of molecular chemistry. Guided by the GPR results, an optimal combination of four parameter values is inferred, and MD simulation confirms that the corresponding SIC‐BCPE system produces relatively higher lithium‐ion conductivity. To further understand the influence of each molecular parameter on the trends of lithium‐ion conductivity, we analyse the proportion variation of different types of lithium‐ion coordination and identify a strong correlation between the ion coordination pattern and ionic conductivity. Due to its generality, we expect that the MD‐GPR combinatory approach reported in this work is applicable to a broad range of other polymer‐based ion transport systems. © 2024 Society of Chemical Industry.

Can a human sing with an unseen artificial partner? Coordination dynamics when singing with an unseen human or artificial partner

This study investigated whether a singer’s coordination patterns differ when singing with an unseen human partner versus an unseen artificial partner (VOCALOID 6 voice synthesis software). We used cross-correlation analysis to compare the correlation of the amplitude envelope time series between the partner’s and the participant’s singing voices. We also conducted a Granger causality test to determine whether the past amplitude envelope of the partner helps predict the future amplitude envelope of the participants, or if the reverse is true. We found more pronounced characteristics of anticipatory synchronization and increased similarity in the unfolding dynamics of the amplitude envelopes in the human-partner condition compared to the artificial-partner condition, despite the tempo fluctuations in the human-partner condition. The results suggested that subtle qualities of the human singing voice, possibly stemming from intrinsic dynamics of the human body, may contain information that enables human agents to align their singing behavior dynamics with a human partner.

Simulation Study of the Upper-limb Isometric Wrench Feasible Set with Glenohumeral Joint Constraints.

The aim of this work is to improve musculoskeletal-based models of the upper-limb Wrench Feasible Set i.e. the set of achievable maximal wrenches at the hand for applications in collaborative robotics and computer aided ergonomics. In particular, a recent method performing wrench capacity evaluation called the Iterative Convex Hull Method is upgraded in order to integrate non dislocation and compression limitation constraints at the glenohumeral joint not taken into account in the available models. Their effects on the amplitude of the force capacities at the hand, glenohumeral joint reaction forces and upper-limb muscles coordination in comparison to the original iterative convex hull method are investigated in silico. The results highlight the glenohumeral potential dislocation for the majority of elements of the wrench feasible set with the original Iterative Convex Hull method and the fact that the modifications satisfy correctly stability constraints at the glenohumeral joint. Also, the induced muscles coordination pattern favors the action of stabilizing muscles, in particular the rotator-cuff muscles, and lowers that of known potential destabilizing ones according to the literature.

Decentralization and diaspora capture: transnationalism, autocracy, and hybrid power in federal Ethiopia

ABSTRACT This article analyzes how transnational actors navigate the tensions between federal policy, more localized power structures, and informal forms of authority in Ethiopia’s Somali Regional State (SRS). The concept of ‘diaspora capture’ foregrounds the efforts of state officials and transnational elites to take control of processes through which diaspora identities and patterns of coordination are formed and negotiated within webs of kinship and economic relations. Somali social structure has often been described as essentially ‘stateless’ or democratic to the point of anarchy, and Somali transnationalism is marked by webs of kinship-based reciprocity and informal economic practice. Nevertheless, we show that in eastern Ethiopia, post-conflict diaspora engagement since 2010 is characterized by persistent efforts of government elites and diaspora actors to gain influence over each other, reshaping the transnational terrain. We argue for more attention in transnational studies to how the conflicts and tensions between national or federal policy environments and subnational authority structures can create new fields of transnational interaction and unexpected collaborations between local governments (including autocratic ones) and diaspora constituents.

Biomechanical Analysis of Limb Coordination in Front-Crawl Among Elite S10 and S12 Para Swimmers: Implications for Performance Optimization

Para swimmers categorized as S10 and S12 are of particular interest due to their disability grading being closest to that of able-bodied swimmers, making them an ideal group for investigating disparities in limb coordination patterns. This study aimed to investigate whether S10 and S12 para swimmers, whose disability grading for movement and visual ability, respectively, were the closest to that of able-bodied swimmers, would differ in terms of the biomechanics of limb coordination. This study recruited twenty para swimmers (ten with minor limb absence (S10) in the hand and ten with minor visual impairment (S12)). Using panoramic video, the phase duration, stroke length, stroke rate, index of coordination, synchronization, and inter-limb coordination were digitized and compared in the context of a front-crawl sprinting test. The results showed a significantly different duration of the recovery phase for S10 para swimmers at the affected side, where a more random coordination pattern between arm and leg at the pull and push phases was statistically seen. The variation of the inter-limb coordination gradually increased for S10 para swimmers from hand entry to the end of push, but gradually reduced for S12 para swimmers. These results suggest that the same pace was achieved by different hand–leg coordination patterns according to their physical constraints. Consequently, the unique coordination patterns of different para swimmers from this study offer an opportunity to explore the adaptive strategies and biomechanical adjustments that enable optimal performance for para swimmers.

Adding multiple electrons to helicenes: how they respond?

Helicenes of increasing dimensions and complexity have recently burst into the scene due to their unique structures coupled with interesting chiral, optical, and conducting properties. The helicene-related research has quickly progressed from fundamental curiosity to a diverse range of applications in organic catalysis, optoelectronic devices, chiroptical switches, sensors, and energy storage. The in-depth understanding of electron accepting properties of helicenes should further advance their materials chemistry applications, however, previous reports only relied on spectrocopic and electrochemical studies, while their structural changes weren't extensively discussed. Therefore, we initiated a broad investigation of chemical reduction behaviour of helicenes ranging in size and properties coupled with X-ray diffraction characterization of the reduced products. The responses of helicenes with different structures to the stepwise electron addition were investigated using a combination of X-ray crystallography, spectroscopic methods, and calculations. This study revealed topology- and charge-dependent consequences of chemical reduction ranging from reversible geometry perturbation to irreversible core transformation and site-specific reactivity of helicenes in addition to original alkali metal coordination patterns. This overview is focused on the crystallographically confirmed examples stemming from chemical reduction reactions of different helicenes with alkali metals. The opened discussion should stimulate further exploration of reactivity and complexation of novel π-expanded and heteroatom-doped helicenes based on the revealed structure-property correlations, thus advancing their applications as intriguing new materials.

Kinematic coordination in the rearfoot, midfoot, and forefoot differs depending on subgroups based on foot stiffness and kinetic parameters during walking

This study aimed to classify subgroups of healthy young adults based on foot stiffness and related kinetic parameters during gait, as well as to analyze intra-foot sagittal kinematics within each subgroup. Data were collected from 25 males and 24 females using a 3D motion capture system, which measured the rearfoot, midfoot, and forefoot segments. Cluster analysis identified three subgroups based on the following variables: the truss coefficient, windlass coefficient, forward component of ground reaction force (F-GRF), and ankle plantar flexion power. Group 1 demonstrated the highest foot stiffness, as indicated by the largest truss coefficient, while Groups 2 and 3 exhibited lower stiffness, characterized by greater dorsiflexion of the midfoot and forefoot relative to the rearfoot during the stance phase. Additionally, the kinematic coordination patterns between the rearfoot-midfoot and midfoot-forefoot of Groups 2 and 3 during the early and late stance phases showed significant variation. Group 3, in particular, exhibited lower F-GRF and ankle plantar flexion power than Groups 1 and 2. These results suggest that midfoot movement during the late stance phase is critical in generating foot stiffness, with a midfoot-dominant kinematic pattern potentially serving as a key contributor. The study underscores the importance of understanding intersegmental coordination for managing foot stiffness, which could have implications for improving gait mechanics and preventing injuries. Further research is needed to explore how these findings can be applied to individuals with various foot conditions or pathologies.

The Alignment of Internal and External Audit Agencies in Administering Public Sector Audits in Indonesia

The management of public finance to achieve national prosperity requires the effective, efficient, and integrated work of the existing audit boards. Therefore, continuous evaluation of the alignment of internal and external audit agencies is essential to ensure reliable public financial management and prevent corruption. This study describes the performance and coordination patterns between internal and external audit agencies by detailing their synchronization patterns in administering financial audits in the Indonesian public sector. Using a normative legal research method, the study incorporates legislative and conceptual approaches. The findings reveal that the performance of both internal and external audit agencies in safeguarding public finance from fraud shows varied degrees of effectiveness. However, a comprehensive regulatory framework governing the alignment of these agencies remains absent. Furthermore, synchronization in public finance audits is pursued through a unified regulatory framework, horizontal alignment among agencies, and the establishment of clear boundaries of authority and coordination mechanisms between the internal and external audit agencies. Further research should consider the potential for consolidating various regulations of public sector audits through an omnibus law approach.

Multi-channel EMG manifestations of upper-extremity muscle coordination imbalance among community-dwelling sarcopenic seniors

BackgroundSarcopenia is an age-related, insidious, crippling but curable degenerative disease if diagnosed and treated early. However, no accessible and accurate early screening method is available for community settings that does not require specialized personnel. One of the hallmarks of sarcopenia is the pathological changes of muscle fiber type composition and motor unit firing patterns. Surface electromyography (sEMG) may serve as an effective tool for detecting differences between healthy and sarcopenic individuals due to its superior wearability and accessibility compared to other screening methods such as medical imaging and bioimpedance measurements, making it ideal for community-based sarcopenic screening. Our study aims to explore sEMG biomarkers that can be used for screening or diagnosis of sarcopenia.ResultsWe collected multi-channel sEMG signals from six forearm muscles of 98 healthy and 55 sarcopenic community-dwelling older adults. Participants performed grasp tasks at 20% and 50% of maximum voluntary contraction (MVC). Hexagons created by various EMG features, normalized with respect to respective MVC, and symmetry analyses were performed to estimate multi-muscle coordination patterns. An innovative index, namely incenter–circumcenter distance of muscle coordination (ICDMC), is proposed to discriminate between the healthy and sarcopenic groups. We utilized non-parametric tests to compare the ICDMC between the two groups, considering a p-value less than 0.05 statistically significant. The results showed that at 20% MVC, ICDMCs from root mean square (RMS), mean absolute value (MAV), slope sign changes (SSC) and wavelength (WL) showed statistically significant differences. More insights of this sEMG manifestation of sarcopenia were revealed by gender- and age-stratifications analyses.ConclusionsOur results demonstrated that there are clear sEMG manifestations of altered muscle coordination in sarcopenic patients. More consistent force generation patterns were observed in the sarcopenic group, especially at lower contraction intensities. The novel ICDMC can quantify differences between sarcopenic and healthy muscle. These results warrant further research to further develop more accessible sarcopenia screening strategies in community settings based on electrophysiological measurements such as sEMG.

Altered inter-segmental coordination in athletes with a history of concussion

ABSTRACT Concussion-recovered athletes have a higher risk of injury following return to sport. This study investigated the effect of history of concussion on the pattern and variability of inter-segmental coordination in athletes during squat jumps and timed squat and hinge tasks. A human pose estimation algorithm was applied to videos of 111 athletes (72 with no history of concussion (NOHX), 9 within 1 year of concussion (CONC1), 30 more than one-year post-concussion (CONC2) performing a series of movement tasks. Continuous relative phase metrics, calculated from phase angles of two contiguous segments, were used to evaluate inter-segmental coordination. Linear models were used to evaluate the causal effect of concussion group on hip, knee, and ankle coordination and repetition duration for each task. CONC1 affected repetition duration and knee and hip coordination and variability, while CONC2 influenced knee coordination. The findings suggest that concussion may have long-term persisting effects on lower-limb inter-segmental coordination in athletes.

Formation of Radical-like NH Ligand from NH3 at Ambient Conditions Mediated by Dialkyl Rare-Earth Complexes.

Although intensive work on ammonia activation has been carried out in recent decades, generating nitrogen-centered radicals from NH3 under ambient conditions remains quite challenging. In the presented research, the conversion of NH3 to radical-like NH ligand has been achieved by the reactions of a series of dialkyl rare-earth (RE) complexes (1-RE, RE = Tb, Dy, Y, Ho, Er, Yb, and Lu) supported by β-diketiminate ligands with NH3 in n-hexane at room temperature, resulting in the formations of the radical-like μ3-NH ligands containing trinuclear RE complexes (2-RE). The radical-like feature of the μ3-NH ligand was revealed by electron paramagnetic resonance and magnetic measurements, radical trapping experiments, and computational spin density analysis. In addition, H2 was detected to form during the reaction of 1-RE with NH3, indicating that the radical-like μ3-NH ligand was likely to be generated via N-H bond homolysis. Moreover, the solvents and coordination pattern of β-diketiminate ligands are crucial for the formation of the radical-like μ3-NH ligand from NH3. When toluene instead of n-hexane was used in the reaction of 1-RE with NH3, an array of octaamido tetranuclear RE complexes (3-RE) was obtained. The reaction of the dialkyl yttrium complex (4-Y) bearing a modified β-diketiminate ligand, in which the two mesityl substituents are replaced by a 2,6-diisopropylphenyl group and a 2-(dimethylamino)ethyl group, with NH3 in both n-hexane and toluene only yielded a tetranuclear yttrium complex carrying the dianionic closed-shell μ3-NH ligands (5-Y).

Flight power muscles have a coordinated, causal role in hawkmoth pitch turns.

Flying insects solve a daunting control problem of generating a patterned and precise motor program to stay airborne and generate agile maneuvers. In this motor program, each muscle encodes information about movement in precise spike timing down to the millisecond scale. Whereas individual muscles share information about movement, we do not know if they have separable effects on an animal's motion, or if muscles functionally interact such that the effects of any muscle's timing depend heavily on the state of the entire musculature. To answer these questions, we performed spike-resolution electromyography and electrical stimulation in the hawkmoth Manduca sexta during tethered flapping. We specifically explored how flight power muscles contribute to pitch control. Combining correlational study of visually-induced turns with causal manipulation of spike timing, we discovered likely coordination patterns for pitch turns, and investigated if these patterns can drive pitch control. We observed significant timing change of the main downstroke muscles, the dorsolongitudinal muscles (DLMs), associated with pitch turns. Causally inducing this timing change in the DLMs with electrical stimulation produced a consistent, mechanically relevant feature in pitch torque, establishing that power muscles in Manduca have a control role in pitch. Because changes were evoked in only the DLMs, however, these pitch torque features left large unexplained variation. We find this unexplained variation indicates significant functional overlap in pitch control such that precise timing of one power muscle does not produce a precise turn, demonstrating the importance of coordination across the entire motor program for flight.

Intralimb Coordination Pattern of the Lower Limbs in Male Athletes With Allograft and Autograft Anterior Cruciate Ligament Reconstruction During Landing

Background and Objectives: Two common choices exist for anterior cruciate ligament (ACL) reconstruction, autograft and allograft. Hamstring tendon autografts and soft-tissue allografts are commonly used for ACL reconstruction. The outcomes between these two grafts are controversial. This research aims to quantify and compare lower limb joint coordination between two ACL reconstruction graft options and healthy individuals. Methods: Sixty-one athletes were enrolled after ACL reconstruction surgery (allograft, n=22; autograft, n=18). Furthermore, twenty-one healthy athletes were considered in the control group. The inclusion criteria included unilateral anterior cruciate ligament reconstruction surgery with allograft and autograft methods, male athletes with a minimum of 9 months and a maximum of two years since their surgery, successfully passing a series of quadriceps and hamstring strength tests and distance jumping before entering sports-specific activities under the supervision of a sports physiotherapist, and returning to pre-injury sports activities. Results: Autograft was not statistically different from matched healthy limbs in terms of joint coordination variability and magnitude (P>0.05). However, the magnitude of joint coordination was superior to the allograft group compared to the autograft reconstructed ACL (P<0.05). Conclusion: Although our result reported no significant difference between groups in joint coordination variability, having an insight into coordinative function after ACL reconstruction will help develop postoperative rehabilitation programs as well as minimize the re-injury risk among patients. We also suggest that scholars should conduct more robust trials with valid research designs to control the results of ACL reconstruction comparison with autograft and allograft.

Integrating carbon reduction and ecological resilience strategies in the silk road economic corridor

The Silk Road Economic Belt has become a pivotal region for China's sustainable development, focusing on the balance between carbon emissions and ecological resilience. Understanding the coordination between these factors is crucial for advancing China's westward economic shift and optimizing urban and demographic structures. This study investigates the coupling and coordination dynamics between carbon emissions and ecological resilience across 15 key cities in the Silk Road Economic Belt, using data from 2008 to 2018. By applying a "pressure-state-response" framework, the ecological resilience of the region is quantitatively assessed. Spatial disparities and the dynamic evolution of coupling coordination are analyzed through the Gini coefficient and kernel density estimation. The findings reveal significant regional variations in ecological resilience and a decline in coupling coordination over time. Shifts in the patterns of coordination indicate opportunities for enhancing resource utilization and environmental management. This research provides theoretical insights for policymakers to improve green development strategies, optimize industrial structures, and plan urban green spaces more effectively within the Silk Road Economic Belt.

Neuromuscular synergy characteristics of Tai Chi leg stirrup movements: optimal coordination patterns throughout various phases.

To investigate the neuromuscular activity characteristics of Tai Chi athletes and identify optimal muscle synergy patterns. Data were collected from 12 elite Tai Chi athletes using a Vicon motion capture system, a Kistler 3D force plate, and a Noraxon surface electromyography system. Muscle synergy patterns were extracted using Non-negative Matrix Factorization. Four muscle synergy patterns were identified in each of the three phases of the leg stirrup movement, with the optimal synergy pattern for each phase determined as follows: knee lift phase: rectus femoris and vastus lateralis of the right leg; extension phase: rectus femoris, vastus lateralis, biceps femoris, and medial gastrocnemius of the right leg; recovery phase: rectus femoris, vastus lateralis, and medial gastrocnemius of the right leg. These patterns explain the muscle coordination activities for each phase. This study identified the optimal muscle synergy patterns for each phase, supporting the fluidity and force generation of the leg stirrup movement. This provides Tai Chi athletes with a more efficient way to exert strength and maintain balance.

Synthesis, Structures, and Properties for PIII-Doped Hetero-Buckybowls and Their Phosphonium Salts.

Doping polycyclic aromatic hydrocarbons with heteroatoms enables manipulation of their electronic structures. Herein, the structures and properties of phosphorus (P) doped heterosumanenes (HSEs) are regulated by varying the valence states of P-dopant. The phosphine sulfide (PV) and chalcogens (S, Se, Te) co-doped HSEs (1-3) are reduced to trivalent phosphorus (PIII) doped analogues 4-6. Then, the PIII-dopants on 4-6 are converted to phosphonium salts (R4P+), giving 7-9. The valence states of P-dopant show great influence on molecular geometries and electronic structures. Taking P and S co-doped HSEs as example, bowl-depths increase in the order of 1 (PV)<7 (R4P+)<4 (PIII), and the HOMO energy levels and HOMO-LUMO gaps increase to be 7<1<4. Consistent with the theoretical calculation, the first oxidation potentials decrease and the absorption/emission bands show blue shift from 7 to 1 to 4. The transformation of PV to PIII leads to large variations on the coordination with Ag+, owing to the alteration of coordination site from P=S to PIII. The phosphonium salts show ring-opening of phosphole rings under electrochemical reduction. It is found that chalcogen atoms play pivotal roles on coordination patterns of coordination complexes and the conversion rates of ring-opening reactions.

Volumetric voltage imaging of neuronal populations in the mouse brain by confocal light-field microscopy.

Voltage imaging measures neuronal activity directly and holds promise for understanding information processing within individual neurons and across populations. However, imaging voltage over large neuronal populations has been challenging owing to the simultaneous requirements of high imaging speed and signal-to-noise ratio, large volume coverage and low photobleaching rate. Here, to overcome this challenge, we developed a confocal light-field microscope that surpassed the traditional limits in speed and noise performance by incorporating a speed-enhanced camera, a fast and robust scanning mechanism, laser-speckle-noise elimination and optimized light efficiency. With this method, we achieved simultaneous recording from more than 300 spiking neurons within an 800-µm-diameter and 180-µm-thick volume in the mouse cortex, for more than 20 min. By integrating the spatial and voltage activity profiles, we have mapped three-dimensional neural coordination patterns in awake mouse brains. Our method is robust for routine application in volumetric voltage imaging.

Chiral Self-Assembly of Twisted Prisms, Cuboids, and Polyhedral Capped Cages with Tartrate Ligands.

Homochiral triangular prisms, cuboid cages, and capped polyhedral cages are successfully synthesized via coordination-driven self-assembly. Typical tartrate ligands demonstrated notable torsional flexibility and variable coordination numbers, allowing for diverse coordination patterns, including saturated chelation and terminal mono-coordination with half-sandwich rhodium and iridium fragments. The ligand lengths, molar ratios, and metal vertices are meticulously designed and fine-tuned to yield chiral cages with entirely distinct architectures. Tartrate ligand exhibits abundant hydrogen bonding interactions and chiral induction capabilities, these supramolecular assemblies are characterized by single-crystal X-ray diffraction, nuclear magnetic resonance, and circular dichroism spectroscopy. An efficient method is developed for constructing chiral structurally versatile cage-like entities, facilitating self-assembly in complicated multi-component systems.

Four novel coordination polymers with beautiful three-dimensional frameworks as potential Fe3+/Cr2O72− sensors

Protecting water resources is the innate obligation of human beings, and detecting pollutants in water is an important work to protect water resources. In this work, we have prepared four novel coordination polymers, named {[Zn3(L)2(H2O)4]‧5H2O}n (1), {[Zn6(L)4(4,4′-bpy)(H2O)6]‧3H2O}n (2), [Cd(HL)(H2O)]n (3) and [Cd3(L)2(pyz)(H2O)3]n (4) (H3L = 1-(3-carboxybenzyl)-1H-pyrazole-3,5-dicarboxylic acid, 4,4′-bpy = 4,4′-bipyridine and pyz = pyrazine). The organic ligands exhibit various coordination patterns, making the beautiful structures of the four compounds quite different. Compounds 1, 2, and 4 all show three core clusters and form the final three-dimensional frameworks by interconnecting metal clusters and organic ligands. Meanwhile, compound 3 displays the infinite metal chain and forms the final three-dimensional framework. These four compounds were also used to detect cations/anions in the water, showing that they can selectively detect Fe3+ and Cr2O72−. The excellent anti-interference ability, limit of detection, and reproducibility suggest that these four compounds are all potential sensing materials for Fe3+ and Cr2O72−.

Comparative analysis of tardigrade locomotion across life stage, species, and disulfiram treatment.

Animal locomotion requires coordination between the central and peripheral nervous systems, between sensory inputs and motor outputs, and between nerves and muscles. Analysis of locomotion thus provides a comprehensive and sensitive readout of nervous system function and dysfunction. Tardigrades, the smallest known walking animals, coordinate movement of their eight legs with a relatively simple nervous system, and are a promising model for neuronal control of limb-driven locomotion. Here, we developed open-source tools for automated tracking of tardigrade locomotion in an unconstrained two-dimensional environment, for measuring multiple parameters of individual leg movements, and for quantifying interleg coordination. We used these tools to analyze >13,000 complete strides in >100 tardigrades, and identified preferred walking speeds and distinct step coordination patterns associated with those speeds. In addition, the rear legs of tardigrades, although they have distinct anatomy and step kinematics, were nonetheless incorporated into overall patterns of interleg coordination. Finally, comparisons of tardigrade locomotion across lifespan, between species, and upon disulfiram treatment suggested that neuronal regulation of high-level aspects of walking (e.g. speed, turns, walking bout initiation) operate independently from circuits controlling individual leg movements and interleg coordination.