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This study introduces a fresh perspective on conventional notions of “shape” and “distribution” by utilizing the innovative framework of branch-length similarity (BLS) entropy. In our exploration of “shape,” we propose BLS entropy-based interpretations of circularity, elongation, and symmetry. We subject these novel concepts to quantitative evaluation against established benchmarks, highlighting their inherent advantages. The evaluation is conducted using a dataset of 1365 images from the MPEG-7 collection. Additionally, within the context of BLS entropy-driven “distributions,” we present an inventive approach involving the construction of networks that connect nodes through Delaunay triangles within a two-dimensional space. In this framework, we employ $\alpha $ and $\beta $ to quantify both local and global connectivity of individual nodes. To effectively demonstrate the utility of $\alpha $ and $\beta $ , we apply them to the analysis of intricate foraging dynamics exhibited by a school of fish. Through this application, we uncover shifts in both individual fish behavior and collective school dynamics, providing illuminating insights into their behavioral changes.

Subterranean termites construct a network of tunnels beneath the ground, comprising a main tunnel and branch tunnels. While termites do not construct tunnels that turn back in a “U” shape, the intersection of main and branch tunnels often forms closed curved structures (a loop). The loop structure can have either a positive or negative effect on the transport efficiency of termites in food transportation. However, little research has been conducted on the impact of loop tunnels on transport efficiency (E) due to the technical difficulties associated with direct observation. In this study, we used an individual-based model to simulate termite behavior during food transportation within a tunnel composed of a main tunnel and a loop tunnel. The model incorporates four control variables: the number of introduced simulated termites (k1), the probability of a simulated termite using a loop tunnel when walking towards a food or nest site (k2 or k3), and the length of the loop tunnel (k4). The simulation results reveal that the E value is high for (k2, k3) = (high, high), (low, low), (high, low), and (low, high) when the length of the loop tunnel is relatively short. However, when the length of the loop tunnel is relatively long, E is high only for (k2, k3) = (high, low) and (low, high). We found that these results are primarily influenced by the frequency of traffic jams. Therefore, termites would benefit from adopting strategies that reduce the occurrence of traffic jams during food transportation. In the Discussion section, we briefly touch on the strategy from an ecological perspective.

One-dimensional (1D) van der Waals (vdW) materials have garnered significant attention for their unique structures and properties, making them promising candidates for various applications in optoelectronics, catalysis, energy storage, and sensors. However, further advancements are required to fully exploit their potential as energy storage devices. This study presents an anode design paradigm utilizing 1D vdW-based V2PS10 crystals characterized by large vdW gaps, a small bandgap, and distinctive chemical compositions that favor lithium storage. To enhance their performance, we employ surface modification techniques to create V2PS10 @C composites, where conductive carbon is integrated with V2PS10 crystals. This modification significantly improves electron transport and Li-ion diffusion within the composite anodes. The resulting composite anodes exhibit exceptional electrochemical properties, including a high discharge capacity of 1154 mAh g−1 after the 50th cycle at 0.1 A g−1, superior rate performance with a current density of 561 mAh g−1 at 10 A g−1, and prolonged cycling stability, maintaining a capacity of 605 mAh g−1 for up to 800 cycles at 5 A g−1. These remarkable electrochemical performances underscore the immense potential of 1D vdW-based materials as next-generation anodes for lithium-ion batteries.

A binary time series can be transformed into a Branch Length Similarity (BLS) entropy profile by being mapped to a circumference called a time-circle. In this study, we explored how peaks and cliffs are formed and how they relate to time series. Peaks and cliffs are defined as spike shapes in their entropy profile and are called peaks (or cliffs) when their shape is symmetric (or asymmetric). We found that when signal bands with different signal densities are in the same time series, peaks or cliffs are formed on the side of the band with lower signal density. In addition, we found that when the signal density is moderately high, the distribution of peaks and cliffs appears as a global increase-decrease tendency of the entropy profile. The tendency appeared as a barrier in the entropy profile of the image. As an application of our findings, we successfully detected specific patterns in binary images using peaks, cliffs and the barriers.

The methods for investigation of DNA-binding proteins require site-selective chemical modifications to be introduced into oligonucleotides. Here, the authors report a chemo- and regioselective method for the modification of unpaired guanosines in single- and double-stranded oligonucleotides, based on Rh(I)-carbene catalysis.

In this study, the branch-length similarity entropy profile is estimated by mapping the time-series signal to the circumference of the time circle, and the self-similarity is defined based on the profile. To explore the self-similarity property, the effect of the distance between two signals, “0” and “1”, on the entropy value for signal “1” is investigated. Furthermore, two application problems are addressed: quantification of the mixing state of fragments and clusters, and characterization of the behavioral trajectory of an organism. The results indicate that use of the self-similarity property solves both the problems. Additionally, the problems that must be addressed to broaden the applicability of self-similarity are discussed.

[2 + 2] cycloaddition of alkynes with alkenes would normally require UV light irradiation. Here, the authors report an alkyne–alkene [2 + 2] cycloaddition based on visible light energy transfer photocatalysis, both inter- and intramolecularly, to afford cyclobutenes and 1,3-dienes.

Neuronal sphingosine kinase 1 (SphK1) acetylates COX2 which is needed for microglial phagocytosis activity, and release of pro-resolving mediators (SPMs) from neurons. Here the authors examine how SphK1-mediates COX2 acetylation, and how this leads to increased secretion of SPMs from neurons in the context of Alzheimer’s disease models.

Multivariate quadratic (MQ) equations-based cryptography is one of the most promising alternatives for currently used public-key cryptographic algorithms in the post-quantum era. It is important to design practical public-key signature schemes on embedded processors and resource-constrained devices for emerging applications in Internet of Things. The MQ-signature schemes are suitable for low-cost constrained devices since they require only modest computational resources. In this paper, we propose an efficient MQ-signature scheme, SOV, using sparse polynomials with a shorter secret key and give its security analysis against known algebraic attacks. Compared to Rainbow, the secret key of SOV has reduced by a factor of 90% without increasing the public key size. In particular, SOV requires signatures of 52 bytes, while ECDSA-256 requires signatures of 64 bytes.

The most common screening techniques to diagnose a patient’s illness are blood collection and intravenous procedures. To find a collection or injection site, conventional blood collection support tools, such as latex tubing and buckle-type tourniquets, are generally used to compress the patient’s blood vessels. This conventional passive method has significant problems such as latex allergy, vulnerability to site contamination and potential bloodstream infection, and physical damage due to improper use. To overcome the disadvantages of conventional blood collection support tools, an automatic tourniquet with a high-elasticity biocompatible strap was constructed. The automatic tourniquet is designed to automatically adjust the strap length using a motor to control the pressure according to the body dimensions of patients. In order to evaluate the performance of the automatic tourniquet, blood flow characteristics were analyzed using an ultrasound measurement system. The results demonstrated that the automatic tourniquet showed better performance compared with those of other blood collection support tools.

Branch length similarity (BLS) entropy is defined in a network consisting of a single node and branches. In this study, we mapped the binary time-series signal to the circumference of the time circle so that the BLS entropy can be calculated for the binary time-series. We obtained the BLS entropy values for “1” signals on the time circle. The set of values are the BLS entropy profile. We selected the local maximum (minimum) point, slope, and inflection point of the entropy profile as the characteristic features of the binary time-series and investigated and explored their significance. The local maximum (minimum) point indicates the time at which the rate of change in the signal density becomes zero. The slope and inflection points correspond to the degree of change in the signal density and the time at which the signal density changes occur, respectively. Moreover, we show that the characteristic features can be widely used in binary time-series analysis by characterizing the movement trajectory of Caenorhabditis elegans. We also mention the problems that need to be explored mathematically in relation to the features and propose candidates for additional features based on the BLS entropy profile.

We propose a new measure (Γ) to quantify the degree of self-similarity of a shape using branch length similarity (BLS) entropy which is defined on a simple network consisting of a single node and its branches. To investigate the properties of this measure, we computed the Γ values for 70 object groups (20 shapes in each group) in the MPEG-7 shape database and performed grouping on the values. With relatively high Γ values, identical groups had visually similar shapes. On the other hand, the identical groups with low Γ values had visually different shapes. However, the aspect of topological similarity of the shapes also warrants consideration. The shapes of statistically different groups exhibited significant visual difference from each other. Also, in order to show that the Γ can have a wide variety of applicability when properly used with other variables, we showed that the finger gestures in the (Γ, Z) space are successfully classified. Here, the Z means a correlation coefficient value between entropy profiles for gesture shapes. As shown in the applications, Γ has a strong advantage over conventional geometric measures in that it captures the geometrical and topological properties of a shape together. If we could define the BLS entropy for color, Γ could be used to characterize images expressed in RGB. We briefly discussed the problems to be solved before the applicability of Γ can be expanded to various fields.