Search Results (47)

Background/Objectives: mRNA vaccines introduced during the COVID-19 pandemic were a significant step forward in the rapid development and deployment of vaccines in a global pandemic context. These vaccines showed good protective efficacy, but—due to limited breadth of the immune response—they required frequent boosters with manufactured spike sequences that often lagged behind the circulating strains. In order to enhance the breadth, durability, and magnitude of immune responses, we studied the effect of combining priming with an RNA vaccine technology with boosting with protein/adjuvant using a TLR4-agonist based adjuvant. Methods: Specifically, four proprietary adjuvants (EmT4^TM, LiT4Q^TM, MiT4^TM, and AlT4^TM) were investigated in combination with multiple modes of SARS-CoV-2 vaccination (protein, peptide, RNA) for their effectiveness in boosting antibody responses to SARS-CoV-2 spike protein in murine models. Results: Results showed significant improvement in immune response strength and breadth—especially against more distant SARS-CoV-2 variants such as Omicron—when adjuvants were used in combination with boosters following an RNA vaccine prime. Conclusions: The use of novel TLR4 adjuvants in combination with protein or RNA vaccinations presents a promising strategy for improving the efficacy of vaccines in the event of future pandemics, by leveraging rapid response using an RNA vaccine prime and following up with protein/adjuvant-based vaccines to enhance the breadth of immunity. Full article

Airspace sectorization is an effective approach to balance increasing air traffic demand and limited airspace resources. It directly impacts the efficiency and safety of airspace operations. Traditional airspace sectorization methods are often based on fixed spatial scales, failing to fully consider the complexity and interrelationships of airspace partitioning across different spatial scales. This makes it challenging to balance large-scale airspace management with local dynamic demands. To address this issue, a multi-scale airspace sectorization framework is proposed, which integrates a multi-resolution grid system and a hierarchical deep reinforcement learning algorithm. First, an airspace grid model is constructed using Quaternary Triangular Mesh (QTM), along with an efficient workload calculation model based on grid encoding. Then, a sector optimization model is developed using hierarchical deep Q-network (HDQN), where the top-level and bottom-level policies coordinate to perform global airspace control area partitioning and local sectorization. The use of multi-resolution grids enhances the interaction efficiency between the reinforcement learning model and the environment. Prior knowledge is also incorporated to enhance training efficiency and effectiveness. Experimental results demonstrate that the proposed framework outperforms traditional models in both computational efficiency and workload balancing performance. Full article

We present a comprehensive theoretical investigation about the operational regions of quantum systems, specifically examining their roles as working media functioning between two thermal reservoirs in quantum thermal machines (QTMs). This study provides relevant and novel insights, including a complete spectrum of QTMs within the operational region of these quantum systems, and introduces new QTM designs never before described in the literature. Additionally, this work introduces a standardized and cohesive classification scheme for QTMs, ensuring robustness in nomenclature and operational distinctions, which enhances both theoretical understanding and practical application. Notably, one of these designs directly addresses the need for a more appropriate explanation of the operation of a laser (or maser) as a QTM. Initial calculations were performed to achieve results applicable to any quantum system subjected to rules analogous to those used in classical thermal machine studies. These results were then used to analyze two-level quantum systems as the working medium of QTMs in the Otto cycle. In particular, we analyzed two specific quantum systems: the laser and a spinless electron in a one-dimensional quantum ring, yielding consistent and innovative results. Overall, this study offers valuable insights into the operation and classification of QTMs, establishing a clear and unified framework for their nomenclature while opening new avenues for the design and enhancement of these devices. Full article

An Earth system spatial grid (ESSG) is an extension of a discrete global grid system (DGGS) in the radial direction. It is an important tool for organizing, representing, simulating, analyzing, sharing, and visualizing spatial data. The existing ESSGs suffer from complex spatial relationships and significant geometric distortion. To mitigate these problems, a spherical geodesic degenerate octree grid (SGDOG) and its encoding and decoding schemes are proposed in this paper. The SGDOG extends the great circle arc QTM in the radial direction and adopts different levels of the great circle arc QTM at different radial depths. The subdivision of SGDOG is simple and clear, and has multi-level characteristics. The experimental results demonstrate that the SGDOG has advantages of simple spatial relationships, convergent volume distortion, and real-time encoding and decoding. The SGDOG has the potential to organize and manage global spatial data and perform large-scale visual analysis of the Earth system. Full article

The reaction of nitronyl nitroxide biradical NITPhMeImbis(5-(2-methylimidazole)-1,3-bis(1′-oxyl-3′-oxido-4′,4′,5′,5′-tetramethyl-4,5-hydro-1H-imidazol-2-yl)-benzene) with Dy(hfac)₃ and La(hfac)₃ (hfac = hexafluoroacetylacetonate) afforded a heterolanthanide complex [Dy_0.56La_1.44(hfac)₇(NITPhMeImbisH)] (1). In this complex, the biradical NITPhMeImbis ligand chelates one Ln(III) ion via its two neighboring NO units and simultaneously binds the La(III) ion through another NO group to form a dinuclear structure. Direct current (dc) magnetic measurement shows the dominant ferromagnetic couplings in Complex 1. Spin dynamics studies exhibit visible frequency-dependent peaks of χ″ signals under a dc field evidenced by field-induced magnetic relaxation behavior, which is a combination of Orbach and QTM processes, giving the U_eff, τ₀ and τ_QTM values of 15.14 K, 3.04 × 10⁻⁷ s and 3.61 × 10⁻⁴ s, respectively. Full article

Anguilliform locomotion, an efficient aquatic locomotion mode where the whole body is engaged in fluid–body interaction, contains sophisticated physics. We hypothesized that data-driven modeling techniques may extract models or patterns of the swimmers’ dynamics without implicitly measuring the hydrodynamic variables. This work proposes empirical kinematic control and data-driven modeling of a soft swimming robot. The robot comprises six serially connected segments that can individually bend with the segmental pneumatic artificial muscles. Kinematic equations and relations are proposed to measure the desired actuation to mimic anguilliform locomotion kinematics. The robot was tested experimentally and the position and velocities of spatially digitized points were collected using QualiSys^® Tracking Manager (QTM) 1.6.0.1. The collected data were analyzed offline, proposing a new complex variable delay-embedding dynamic mode decomposition (CDE DMD) algorithm that combines complex state filtering and time embedding to extract a linear approximate model. While the experimental results exhibited exotic curves in phase plane and time series, the analysis results showed that the proposed algorithm extracts linear and chaotic modes contributing to the data. It is concluded that the robot dynamics can be described by the linearized model interrupted by chaotic modes. The technique successfully extracts coherent modes from limited measurements and linearizes the system dynamics. Full article

A theoretical study, based on ab initio electronic structure calculation, is performed in a group of 16 pentacoordinate Dy-SIMs. Theoretical results provide a reasonable explanation of the observed SMM performance based on a concise criterion, i.e., the co-existence of long τ_QTM and high U_eff. To have the desired electronic structure favoring good SMM performance, the contribution from the equatorial coordinating atoms might be even more important than that from the axial coordinating atoms. Widening the axial ∠O–Dy–O might be a probable way to improve the SMM performance of pentacoordinated Dy-SIMs. Starting from existing systems, a rigid-scan type exploration indicates the possibility of U_eff higher than 1600 K. Full article

We report here the synthesis of a series of nine coordinated mononuclear Ln^III complexes [LnL₁Cl₂(DMF)]Cl·2.5DMF and [LnL¹(L₂)₂]Cl·4CH₃OH (Ln^III = Gd^III, Dy^III, Er^III and Yb^III, HL₂ = 9-anthracenecarboxylic acid), where L1 is a hexadentate N₄O₂ Schiff base ligand prepared from the condensation of 1,10-phenanthroline-2,9-dicarbaldehyde and semicarbazone. The X-ray crystal structures of these complexes show the Ln^III ions to possess LnN₄O₂Cl₂ and LnN₄O₄ coordination spheres, which can be considered to be derived from a hexagonal bipyramidal geometry, with the ligand in the equatorial plane and the anions (chloride or 9-antracenecarboxylate) in axial positions, which undergo distortion after coordination of either a molecule of DMF or a bidentate coordination of the 9-anthracenecarboxxylate ligand. All these compounds exhibit field-induced slow magnetization relaxation (SMR). The absence of SMR at zero field due to QTM, as well as the processes involved in the magnetic relaxation under a field of 0.1 T, have been justified on the basis of theoretical calculations and the distortion of the respective coordination spheres. The severe discrepancy between the calculated and experimental thermal energy barriers for the Dy^III complexes seems to indicate that the relaxation occurs with the contribution of spin–vibrational coupling, which is favored by the flexibility of the ligand. Full article

Bio-inspired robots with elongated anatomy, like eels, are studied to discover anguilliform swimming principles and improve the robots’ locomotion accordingly. Soft continuum robots replicate animal–environment physics better than noncompliant, rigid, multi-body eel robots. In this study, a slender soft robot was designed and tested in an actual swimming experiment in a still-water tank. The robot employs soft pneumatic muscles laterally connected to a flexible backbone and activated with a rhythmic input. The position of seven markers mounted on the robot’s backbone was recorded using QualiSys^® Tracking Manager (QTM) 1.6.0.1. The system was modeled as a fully coupled fluid–solid interaction (FSI) system using COMSOL Multiphysics^® 6.1. Further data postprocessing and analysis were conducted, proposing a new mode decomposition algorithm using simulation data. Experiments show the success of swimming with a velocity of 28 mm/s and at a frequency of 0.9 Hz. The mode analysis allowed the modeling and explanation of the fluctuation. Results disclose the presence of traveling waves related to anguilliform waves obtained by the superposition of two main modes. The similarities of the results with natural anguilliform locomotion are discussed. It is concluded that soft robot undulation is ruled by dynamic modes induced by robot–environment interaction. Full article

Gastrodia elata, commonly known as Tian Ma, is a perennial mycoheterotrophic orchid. Qianyang Tian Ma (QTM), a geographical indication agricultural product from Hongjiang City, Hunan Province, China, is primarily characterized by the red variety, G. elata f. elata. A severe outbreak of tuber brown rot disease was documented in QTM during the harvesting season in Hunan. The fungal pathogen associated with the disease was isolated on potato saccharose agar (PSA) and identified through morphological and phylogenetic analyses. Pathogenicity tests were performed on healthy tubers of G. elata f. elata. The results showed that the representative isolate, named TMB, produced white hyphal colonies with a ring structure, broom-like phialides, partially curved ellipsoidal conidia, and orange–yellow spherical ascocarps on PSA. Phylogenetic analysis of the ITS, LSU, rpb2 and tub2 sequences using Bayesian and maximum-likelihood methods identified the isolate TMB as Clonostachys rosea, based on morphological and phylogenetic data. Pathogenicity tests revealed typical disease symptoms on healthy G. elata tubers 15 days post-inoculation with the isolate TMB. C. rosea is known to cause diseases in economically important crops, but there are no reports of its occurrence on G. elata f. elata in China. This study provides valuable insights into the occurrence, prevention, and control of brown rot disease in G. elata f. elata. Full article

The COVID-19 pandemic, the Russia–Ukraine and the Israel–Hamas conflicts, and the resulting global economic shocks will affect the world economy for several years. This paper analyzes and discusses monetary finance (MF) using the Quantity Theory of Money (QTM) to understand economic dynamics. To achieve this goal, we utilize a Structural Vector Autoregressive (SVAR) identification scheme with sign restrictions on datasets from advanced economies. The findings indicate that monetary growth plays a role in short-term inflationary dynamics, while its effects are less significant in the medium to long term. The aim of the paper is to contribute to ongoing debate surrounding the potential strategies for addressing the economic downturn through the reintroduction of monetary finance (MF). Full article

Based on Cognitive Load Theory (CLT), learning by studying worked examples, that is, step-by-step solutions, has been shown to reduce cognitive load and enhance learning outcomes more than learning by solving conventional problems. Two types of worked examples that have been predominantly used in well-structured learning domains include product-oriented worked examples (ProductWEs) which provide strategic information and process-oriented worked examples (ProcessWEs) which provide strategic information and principled knowledge. However, less research has been conducted on worked examples’ effectiveness in ill-structured learning domains. In a study with 85 university students enrolled in teaching programs, we investigated whether ProcessWEs or ProductWEs better support identifying and applying knowledge regarding the quality teaching component of substantive communication. Participants completed tasks under three instructional conditions: ProcessWE, ProductWE, and conventional problem-solving. Results showed that ProcessWEs outperformed ProductWEs, ProductWEs outperformed conventional problem-solving, and conventional problem-solving had higher perceived task difficulty than the other two conditions. This study theoretically contributes to CLT research as it found that the use of ProcessWEs and ProductWEs is effective in an ill-structured learning domain and makes a practical contribution by showing what a ProductWE or ProcessWE in an ill-structured learning domain ‘looks like’. Full article

The Voronoi diagram on the Earth’s surface is a significant data model, characterized by natural proximity and dynamic stability, which has emerged as one of the most promising solutions for global spatial dynamic management and analysis. However, traditional algorithms for generating spherical raster Voronoi diagrams find it challenging to dynamically adjust the Voronoi diagram while maintaining precision and efficiency. The efficient and accurate construction of the spherical Voronoi diagram has become one of the bottleneck issues limiting its further large-scale application. To this end, this paper proposes a dynamic construction scheme for the spherical Voronoi diagram based on the QTM (Quaternary Triangular Mesh) system, with the aim of enabling efficient generation, local updates, and multi-scale visualization of the spherical Voronoi diagrams. In this paper, canonical ordering is introduced. Tailored for the properties of the spherical triangular grid, it constructs a unified and standardized sorting strategy for the dilation of the spherical grids. The construction and updating of the spherical Voronoi diagram are achieved through the ordered dilation of sites. Furthermore, the multi-scale visualization of the spherical Voronoi diagram is realized through the hierarchical structure of the QTM. The paper presents our algorithm intuitively through pseudocode, conducts comparative experiments on the feasibility and efficiency, and designs an experiment for the dynamic navigation and management of ocean-going vessels based on the global multi-resolution Voronoi diagram. The experimental results demonstrate that our algorithm effectively controls the error of the generation of the raster Voronoi diagram and has a significant efficiency advantage when processing dynamic environments. Full article

In order to improve the adhesive and passing performance of agricultural tracked vehicles under a non-structural environment, a theoretical design method of the structure of a bionic track pattern is proposed in this article. The Saanen goat is taken as the experimental subject, and the hoof tips and hoof spheres are taken as the characteristic functional parts, whose pressure is measured by thin film pressure sensors. The Qualisys Track Manager (QTM) gait analysis system was used to obtain the gait sequence of goats under multi-slope. The changes in vertical ground reaction force (GRF) and vertical impulse (VI) of the hoof tips and spheres and adhesion coefficient under multi-slope were analyzed. The results show that with the increase in slope, the GRF is transferred from the left hind hoof to the right front hoof, and the right front hoof has the most significant effect. Under the 10-degree slope, the peak vertical GRF and VI of the inner tip of the right front hoof are the largest; peak vertical GRF is 146.20 N, and VI is 127.67 N·s. The adhesion coefficient is the largest; the right front and left hind hoof are in the diagonal two-phase supported state, and μ is 0.3455. Therefore, the inner tip of the right front hoof is used as a bionic prototype to design the track pattern architecture. It provides a theoretical basis for the design and optimization of bionic patterns applied to agricultural tracked vehicles. Full article

Shoulder rehabilitation is a process that requires physical therapy sessions to recover the mobility of the affected limbs. However, these sessions are often limited by the availability and cost of specialized technicians, as well as the patient’s travel to the session locations. This paper presents a novel smartphone-based approach using a pose estimation algorithm to evaluate the quality of the movements and provide feedback, allowing patients to perform autonomous recovery sessions. This paper reviews the state of the art in wearable devices and camera-based systems for human body detection and rehabilitation support and describes the system developed, which uses MediaPipe to extract the coordinates of 33 key points on the patient’s body and compares them with reference videos made by professional physiotherapists using cosine similarity and dynamic time warping. This paper also presents a clinical study that uses QTM, an optoelectronic system for motion capture, to validate the methods used by the smartphone application. The results show that there are statistically significant differences between the three methods for different exercises, highlighting the importance of selecting an appropriate method for specific exercises. This paper discusses the implications and limitations of the findings and suggests directions for future research. Full article