Flexible Orientation Research Articles

Integration of optic flow into the sky compass network in the brain of the desert locust.

Flexible orientation through any environment requires a sense of current relative heading that is updated based on self-motion. Global external cues originating from the sky or the earth's magnetic field and local cues provide a reference frame for the sense of direction. Locally, optic flow may inform about turning maneuvers, travel speed and covered distance. The central complex in the insect brain is associated with orientation behavior and largely acts as a navigation center. Visual information from global celestial cues and local landmarks are integrated in the central complex to form an internal representation of current heading. However, it is less clear how optic flow is integrated into the central-complex network. We recorded intracellularly from neurons in the locust central complex while presenting lateral grating patterns that simulated translational and rotational motion to identify these sites of integration. Certain types of central-complex neurons were sensitive to optic-flow stimulation independent of the type and direction of simulated motion. Columnar neurons innervating the noduli, paired central-complex substructures, were tuned to the direction of simulated horizontal turns. Modeling the connectivity of these neurons with a system of proposed compass neurons can account for rotation-direction specific shifts in the activity profile in the central complex corresponding to turn direction. Our model is similar but not identical to the mechanisms proposed for angular velocity integration in the navigation compass of the fly Drosophila.

Magnetic photonic crystals for biomedical applications.

Magnetic photonic crystals (PhCs), as a representative responsive structural color material, have attracted increasing research focus due to merits such as brilliant refraction colors, instant responsiveness, and excellent manipuility, thus having been widely applied for color displaying, three-dimensional printing, sensing, and so on. Featured with traits such as contactless manner, flexible orientations, and adjustable intensity of external magnetism, magnetic PhCs have shown great superiority especially in the field of biomedical applications such as bioimaging and auxiliary clinical diagnosis. In this review, we summarize the current advancements of magnetic PhCs. We first introduce the fundamental principles and typical characteristics of PhCs. Afterward, we present several typical self-assembly strategies with their frontiers in practical applications. Finally, we analyze the current situations of magnetic PhCs and put forward the prospective challenges and future development directions.

Cryo-ET reveals sarcomere structures at molecular resolution.

Muscles underpin movement and heart function. Individual muscle fibers can be very large syncytia of up to several centimeters in length and are comprised of the force-generating and load-bearing devices of muscles called sarcomeres. Contraction and relaxation of sarcomeres relies on the sliding between two types of filaments—the thin filament (comprising mainly F-actin, tropomyosin, and troponin) and the thick myosin filament. In addition, several other proteins are involved in the contraction mechanism and their mutational malfunction can lead to debilitating and even life-threatening diseases. In my presentation, I will explain how we managed to obtain high-resolution structures of native sarcomeres using cryo-electron tomography (cryo-ET). Our cryo-ET reconstructions reveal molecular details of the three-dimensional organization and interaction of actin and myosin in the A-band, I-band and Z-disc and demonstrate that α-actinin cross-links antiparallel actin filaments by forming doublets with 6 nm spacing. Structures of myosin, tropomyosin, actin, and nebulin at up to 4.5 Å further reveal two conformations of “double-headed” myosin, where the flexible orientation of the lever arm and light chains enable myosin not only to interact with the same actin filament, but also to split between two actin filaments. The structures provide high-resolution details of the interaction between nebulin and actin, demonstrating the stabilising role of nebulin. Unexpectedly, nebulin does not interact with myosin or tropomyosin, but with a troponin-T linker through two potential binding motifs on nebulin, explaining its regulatory role. Our results provide unexpected insights into the fundamental organization of vertebrate skeletal muscle and serve as a strong foundation for future investigations of muscle diseases.

Actions speak louder than words? The impact of subjective norms in the supply chain on green innovation

PurposeAdopting the theory of planned behavior, this study attempts to investigate how subjective norms in the supply chain influence a firm's green innovation and how such influences are contingent upon the firm's internal and external factors (i.e. flexibility orientation and environmental dynamism). Two types of subjective norms are examined, i.e. injunctive norms (what supply chain partners say) and descriptive norms (what supply chain partners do).Design/methodology/approachUsing survey data of 178 Chinese small and medium-sized manufacturers, we employ hierarchical linear regression to test the proposed hypotheses.FindingsOur results indicate that both injunctive and descriptive norms are instrumental in stimulating firms to take actions on green innovation. Moreover, the flexibility orientation of a firm can strengthen the effect of descriptive norms. It is also observed that environmental dynamism weakens the efficacy of injunctive norms but strengthens that of descriptive norms on green innovation.Originality/valueThis study is among the first to apply the theory of planned behavior to explain the microfoundations of focal firm's green innovation and distinguish two types of subjective norms in the supply chain. In addition, it extends the theory of planned behavior by revealing internal and external contingent factors (i.e. flexibility orientation and environmental dynamism) of the relationship between subjective norms and firm behaviors.

4′‐SCF3‐Labeling Constitutes a Sensitive 19F NMR Probe for Characterization of Interactions in the Minor Groove of DNA

AbstractFluorinated nucleotides are invaluable for 19F NMR studies of nucleic acid structure and function. Here, we synthesized 4′‐SCF3‐thymidine (T ) and incorporated it into DNA by means of solid‐phase DNA synthesis. NMR studies showed that the 4′‐SCF3 group exhibited a flexible orientation in the minor groove of DNA duplexes and was well accommodated by various higher order DNA structures. The three magnetically equivalent fluorine atoms in 4′‐SCF3‐DNA constitute an isolated spin system, offering high 19F NMR sensitivity and excellent resolution of the positioning of T within various secondary and tertiary DNA structures. The high structural adaptability and high sensitivity of T make it a valuable 19F NMR probe for quantitatively distinguishing diverse DNA structures with single‐nucleotide resolution and for monitoring the dynamics of interactions in the minor groove of double‐stranded DNA.

4'-SCF3 -Labeling Constitutes a Sensitive 19 F NMR Probe for Characterization of Interactions in the Minor Groove of DNA.

Fluorinated nucleotides are invaluable for 19 F NMR studies of nucleic acid structure and function. Here, we synthesized 4'-SCF3 -thymidine (T ) and incorporated it into DNA by means of solid-phase DNA synthesis. NMR studies showed that the 4'-SCF3 group exhibited a flexible orientation in the minor groove of DNA duplexes and was well accommodated by various higher order DNA structures. The three magnetically equivalent fluorine atoms in 4'-SCF3 -DNA constitute an isolated spin system, offering high 19 F NMR sensitivity and excellent resolution of the positioning of T within various secondary and tertiary DNA structures. The high structural adaptability and high sensitivity of T make it a valuable 19 F NMR probe for quantitatively distinguishing diverse DNA structures with single-nucleotide resolution and for monitoring the dynamics of interactions in the minor groove of double-stranded DNA.

Examining the influence of big data analytics and additive manufacturing on supply chain risk control and resilience: An empirical study

Drawing upon the contingent resource‐based perspective of supply chain resilience, this study tests whether fourth industrial revolution (4IR) technologies such as big data analytics (BDA) and additive manufacturing (AM) control risks and develop supply chain (SC) resilience under flexible orientation and control orientation. Primary data was collected from 190 samples in India and the PLS-SEM technique was then used to perform data analysis. The findings indicate that big data analytics and additive manufacturing can aid in risk control and in turn improve the SC resilience of a firm and further minimize the propagation of the supply chain ripple effect in case of disruption. This study sheds light on firms’ 4IR resources (BDA and AM) that can be useful in developing risk control capabilities to deal with disruptions in supply chains. BDA, in particular, impacts risk intelligence, whereas AM impacts both preparedness and intelligence risk control. Distinguishing between BDA and AM is therefore important when firms are considering which technology to adopt. Therefore, for the sample analyzed, BDA has a prominent role in building risk control and resilience capabilities. These findings are an important contribution to SC risk management theory and this study also creates new research opportunities. Firms need to adopt collaborative planning, forecasting, smart manufacturing, and replenishments initiatives for vulnerable supply chain activities to reduce the SC ripple effect. Lastly, flexible, real-time production helps reduce the SC ripple effect.

Optimal design of loading device based on a redundantly actuated parallel manipulator

Reliability of machine tools has attracted much attention both in academia and industry. The loading device is very important for the reliability study of CNC machine tools as it can apply multi-axis dynamic forces to the spindle to replace cutting tests. A loading device based on the redundantly actuated parallel manipulator (R5LD) with strong loading capability is proposed in this paper. Firstly, to evaluate the loading capability, this paper proposes new transmission indices for redundantly actuated parallel manipulators (PMs). Besides, the prescribed flexible orientation workspace and regular workspace are defined for the loading device. Then, the corresponding performance atlases are represented graphically in the design space. The structure parameters of the R5LD are achieved in the optimum region of performance atlases. Finally, the R5LD with the optimum parameters is compared with the loading device based on the corresponding non-redundant PM. The R5LD has a larger regular workspace and better transmission performance. The additional UPS chain of the R5LD makes the configuration more symmetrical, balances forces distribution among chains, and strengthens the loading capability of the loading device.

Large-scale evaluation efforts and their implications for the field.

The BUILD initiative is part of the Diversity Program Consortium, which the National Institutes of Health funded to increase diversity in biomedical research. This chapter aims to identify implications for the field from the multisite evaluation of BUILD initiative programs by reviewing the work undertaken by the authors of the other chapters in this issue. Given the complexities involved in multisite evaluations, innovative approaches and methods were used to balance the needs of each site with the overall objectives of the broader initiative. These approaches included a flexible orientation to the evaluation, mixed-methods designs that prioritized understanding the context before measuring it, and innovative analytic techniques (e.g., meta-analysis) to recognize the uniqueness of each site while providing insights about their cumulative impact. The BUILD initiative evaluation also offered many other valuable lessons about engaging stakeholders, focusing on use, and responding to changing priorities over time.

Modeling learning traits and team performance with knowledge application: Training and education for engineering work teams

Drawing upon the trait activation theory, this paper explains team performance from a mediating perspective of knowledge application, which represents a teamwork process of knowledge management. The empirical results of this study reveal that knowledge application mediates the negative relationship between power distance and team performance and the positive relationship between flexibility orientation and team performance. Teamwork engagement moderates the relationship between learning goal orientation and knowledge application and the relationship between flexibility orientation and knowledge application. Finally, team familiarity moderates the relationship between flexibility orientation and knowledge application. Research implications and limitations are also discussed herein.

Cryo-EM Structure Reveals Polymorphic Ligand-bound States of IGF1R

Type 1 insulin-like growth factor receptor (IGF1R) plays an important role in regulating cellular metabolism and cell growth and has been identified as an anticancer drug target. Although previous studies have revealed some structures of IGF1R with different ligands, the continuous dynamic conformation change remains unclear. Here, we report 10 distinct structures (7.9–3.6 Å) of IGF1R bound to IGF1 or insulin to reveal the polymorphic conformations of ligand-bound IGF1R. These results showed that the α-CT2, disulfide bond (C670-C670′), and FnIII-2 domains had the most flexible orientations for the conformational change that occurs when ligands bind to the receptor. In addition, we found one special conformation (tentatively named the diverter-switch state) in both complexes, which may be one of the apo-IGF1R forms under ligand-treatment conditions. Hence, these results illustrated the mechanism of how different ligands could bind to human IGF1R and provided a rational template for drug design.

Conformational Dynamics of the Soluble and Membrane-Bound Forms of Interleukin-1 Receptor Type-1: Insights into Linker Flexibility and Domain Orientation.

Interleukin-1 receptor type 1 (IL-1R1) is a key player in inflammation and immune responses. This receptor regulates IL-1 activity in two forms: as a membrane-bound form and as a soluble ectodomain. The details and differences between the conformational dynamics of the membrane-bound and the soluble IL-1R1 ectodomains (ECDs) remain largely elusive. Here, we study and compare the structural dynamics of the soluble and membrane-bound IL-1R1-ECDs using molecular dynamics (MD) simulations, focusing on the flexible interdomain linker of the ECD, as well as the spatial rearrangements between the Ig-like domains of the ECD. To explore the membrane-bound conformations, a full-length IL-1R1 structural model was developed and subjected to classical equilibrium MD. Comparative analysis of multiple MD trajectories of the soluble and the membrane-bound IL-1R1-ECDs reveals that (i) as somewhat expected, the extent of the visited “open-to-closed” transitional states differs significantly between the soluble and membrane-bound forms; (ii) the soluble form presents open-closed transitions, sampling a wider rotational motion between the Ig-like domains of the ECD, visiting closed and “twisted” conformations in higher extent, whereas the membrane-bound form is characterized by more conformationally restricted states; (iii) interestingly, the backbone dihedral angles of residues Glu202, Glu203 and Asn204, located in the flexible linker, display the highest variations during the transition between discrete conformational states detected in IL-1R1, thus appearing to work as the “central wheel of a clock’s movement”. The simulations and analyses presented in this contribution offer a deeper insight into the structure and dynamics of IL-1R1, which may be explored in a drug discovery setting.

Reactivity of a Sterical Flexible Pentabenzylcyclopentadienyl Samarocene

Reactivity studies of the classical divalent lanthanide compound [CpBz52Sm] (CpBz5 = pentabenzylcyclopentadienyl-anion) towards diphenyl dichalcogenides and d-element carbonyl complexes led to remarkable results. In the compounds obtained, a different number of Sm-C(phenyl) interactions and differently oriented benzyl groups were observed, suggesting—despite the preference of these interactions in [CpBz52Sm] described in previous studies—a flexible orientation of the benzyl groups and thus a variable steric shielding of the metal center by the ligand. The obtained compounds are either present as monometallic complexes (reduction of the dichalcogenides) or tetrametallic bridged compounds in the case of the d/f-element carbonyl complexes.

Finite Assembly of Three‐Dimensional DNA Hierarchical Nanoarchitectures through Orthogonal and Directional Bonding

AbstractReliable orthogonal bonding with precise and flexible orientation control would be ideal for building finite complex nanostructures via self‐assembly. Employing a three‐dimensional (3D) DNA origami, hexagonal prism DNA origami (HDO), as building block, we demonstrate it is practical to construct finite hierarchical nanoarchitectures with complicated conformations through orthogonal and directional bonding. The as‐designed HDO building block has twelve prescribed directional valences in 3D space and each of them supports two opposite orientations, yielding the capability to generate abundant directional bonding. Meanwhile, we minimize the thorny non‐specific interactions among HDOs and enable the orthogonal bonding between any two valences based on self‐similar designing. Consequently, various hierarchical nanostructures are prepared at will simply by the combination of HDOs with appropriate valences. We believe this route towards hierarchically assembly is inspiring and hope it will facilitate the fabrication of functional superstructures.

Finite Assembly of Three‐Dimensional DNA Hierarchical Nanoarchitectures through Orthogonal and Directional Bonding

AbstractReliable orthogonal bonding with precise and flexible orientation control would be ideal for building finite complex nanostructures via self‐assembly. Employing a three‐dimensional (3D) DNA origami, hexagonal prism DNA origami (HDO), as building block, we demonstrate it is practical to construct finite hierarchical nanoarchitectures with complicated conformations through orthogonal and directional bonding. The as‐designed HDO building block has twelve prescribed directional valences in 3D space and each of them supports two opposite orientations, yielding the capability to generate abundant directional bonding. Meanwhile, we minimize the thorny non‐specific interactions among HDOs and enable the orthogonal bonding between any two valences based on self‐similar designing. Consequently, various hierarchical nanostructures are prepared at will simply by the combination of HDOs with appropriate valences. We believe this route towards hierarchically assembly is inspiring and hope it will facilitate the fabrication of functional superstructures.

FAR-Net: Fast Anchor Refining for Arbitrary-Oriented Object Detection

Compared with natural images, targets in remote-sensing images are often distributed with more flexible orientation, aspect ratio, and scale. Thus, anchor-based algorithms often employ plenty of preset anchors to encode the above-mentioned attributes in object detection tasks. However, they often suffer from the following issues: 1) significant computational burden caused by dense-sampling anchors; 2) serious background interference since many anchors only cover small parts of the actual target; and 3) feature misalignment between the targets with the preset anchors due to the absence of the most discriminant features for target extraction. Therefore, in this letter, a fast anchor refining network (FAR-Net) is advocated to address the remaining issues for arbitrary-oriented object detection in the remote-sensing field. To be specific, a rotation alignment module (RAM) and balanced regression loss function (BR-loss) are carefully designed in the FAR-Net. The RAM is capable of generating high-quality anchors based on a refinement convolution and adaptively aligning the convolutional features by complying with the anchor boxes to reduce redundant calculation. The BR-loss is designed by employing a balanced loss function to prevent misaligned anchors from causing major gradient descents, thereby achieving a more stable network training procedure. Extensive experiments on public remote-sensing datasets (HRSC2016 and UCAS-AOD) demonstrate the excellent detection performance of our algorithm in comparison with numerous existing detectors.

IS YOUR SUPPLY CHAIN READY FOR THE NEXT DISRUPTION? BUILDING RESILIENT CHAINS

ABSTRACT The ability to recover from disruptions is important for organizations and supply chains. Empirical data were used to investigate factors that affect supply chain recovery from disruptions, including collaboration, visibility, flexibility, analytical orientation, and supply chain risk management. A literature review was conducted to build an online questionnaire that was applied to manufacturing firms in Brazil. This work’s statistical method includes confirmatory factor analysis and structural equation modeling. Our results indicate that a package of resilience capabilities - collaboration, flexibility, visibility, and analytical orientation - positively affect supply chain resilience. Improving such capabilities, therefore, will allow supply chains to recover better from disruptions. It was also discovered, however, that supply chains do not recover from disruptions by way of supply chain risk management alone. Mutual impacts also exist between the group of resilience capabilities and supply chain risk management.

IS YOUR SUPPLY CHAIN READY FOR THE NEXT DISRUPTION? BUILDING RESILIENT CHAINS

ABSTRACT The ability to recover from disruptions is important for organizations and supply chains. Empirical data were used to investigate factors that affect supply chain recovery from disruptions, including collaboration, visibility, flexibility, analytical orientation, and supply chain risk management. A literature review was conducted to build an online questionnaire that was applied to manufacturing firms in Brazil. This work’s statistical method includes confirmatory factor analysis and structural equation modeling. Our results indicate that a package of resilience capabilities - collaboration, flexibility, visibility, and analytical orientation - positively affect supply chain resilience. Improving such capabilities, therefore, will allow supply chains to recover better from disruptions. It was also discovered, however, that supply chains do not recover from disruptions by way of supply chain risk management alone. Mutual impacts also exist between the group of resilience capabilities and supply chain risk management.

Increasing Central Serotonin with 5-hydroxytryptophan Disrupts the Inhibition of Social Gaze in Nonhuman Primates.

To competently navigate the world, individuals must flexibly balance distinct aspects of social gaze, orienting toward others and inhibiting orienting responses, depending on the context. These behaviors are often disrupted amongst patient populations treated with serotonergic drugs. However, those in the field lack a clear understanding of how the serotonergic system mediates social orienting and inhibiting behaviors. Here, we tested how increasing central concentrations of serotonin with the direct precursor 5-hydroxytryptophan (5-HTP) would modulate the ability of rhesus macaques (both sexes) to use eye movements to flexibly orient to, or inhibit orienting to, faces. Systemic administrations of 5-HTP effectively increased central serotonin levels and impaired flexible orientation and inhibition. Critically, 5-HTP selectively impaired the ability of monkeys to inhibit orienting to face images, whereas it similarly impaired orienting to face and control images. 5-HTP also caused monkeys to perseverate on their gaze responses, making them worse at flexibly switching between orienting and inhibiting behaviors. Furthermore, the effects of 5-HTP on performance correlated with a constriction of the pupil, an increased time to initiate trials, and an increased reaction time, suggesting that the disruptive effects of 5-HTP on social gaze behaviors are likely driven by a downregulation of arousal and motivational states. Together, these findings provide causal evidence for a modulatory relationship between 5-HTP and social gaze behaviors in nonhuman primates and offer translational insights for the role of the serotonergic system in social gaze.SIGNIFICANCE STATEMENT Behavioral changes arising from pharmacological agents that target serotonergic functions are complex and difficult to predict. Here, we examined the causal impacts of administering the direct precursor of serotonin, 5-HTP, on orienting and inhibiting social gaze in nonhuman primates. 5-HTP increased central concentrations of serotonin and selectively impaired the ability of monkeys to inhibit orienting to faces while similarly impairing the ability of monkeys to orient to face and control images. These behavioral gaze impairments were systematically associated with a downregulation of arousal and motivational states, indexed by pupil constriction, increased time to initiate trials, and increased reaction time. These findings provide a causal link between 5-HTP and social gaze behaviors in nonhuman primates and provide translational insights about serotonergic interventions.

Prescribed flexible orientation workspace and performance comparison of non-redundant 3-DOF planar parallel mechanisms

The functionality of a workspace is one of the most important considerations in planar parallel manipulators (PPMs) design. Dexterous workspace (DW) is the subset of the reachable workspace (RW) and it means that full rotational dexterity is preserved in every translational position in space. However, DW is impractical as PPMs cannot rotate a full 360° because of interference. This paper proposes a workspace called prescribed flexible orientation workspace (PFOW) that characterizes the orientation capability of PPMs. To optimize and compare 3 degree-of-freedom (3-DOF) PPMs, a normalized and unified performance characteristic index is built based on indices including PFOW, condition number, velocity, payload, stiffness, and transmission indices which plays a guiding role in the optimization process. The best configuration is obtained through graphical performance comparison. In general, this work presents the analysis of rotational dexterity of PPMs and provides a guidance for optimization and selection.