Transposable elements are abundant in the human genome and have been increasingly recognized as sources of alternative promoters. Yet, the extent of their transcriptional activity in human tissues and the features that govern their regulatory potential remain unclear. Here, we integrated high-resolution RAMPAGE data from 115 human biosamples to construct a comprehensive atlas of 26,056 transcription start sites derived from transposable elements. These sites contribute to tissue-specific gene expression, with a notable fraction originating from primate- and hominid-specific elements. Transposable element-derived transcription start sites exhibit focused, narrow-peak architectures enriched for TATA boxes and depleted of CpG islands. Phylogenetic analyses reveal a continuous gradient in promoter strength and transcriptional precision across transposable element subfamilies, with evolutionarily younger elements retaining intrinsic promoter motifs that drive focused and robust transcription, whereas older, more divergent elements exhibit broader initiation patterns and lower intrinsic activity. Together, these findings advance our understanding of how the evolution and preservation of promoter features shape the capacity of transposable elements to be exapted as functional promoters, potentially contributing to lineage-specific regulatory innovation in primates.

Screening and construction of promoter-5'-untranslated region complex library of Sphingomonas paucimobilis for regulating the metabolic pathway of gellan biosynthesis.

Trees are increasingly at risk of maladaptation to their environment as climates change rapidly worldwide. Although adaptive evolution through natural selection is a key mechanism by which populations and species can persist in changing environments, we have limited information regarding the phenotypic traits under selection in warm and dry environments. We answer the following research questions: (1) What ecophysiological traits are under selection in warm, dry environments? (2) Does intrapopulation trait integration affect the response to selection in the warmer, drier site? (3) Is the plastic response of traits under selection adaptive? Using Picea mariana (black spruce) as a case study, we studied 425 trees representing seven provenances across three 50-year-old common garden trials established along a spatial climate gradient across eastern Canada. We measured height growth rate as a performance metric, and 10 traits that reflect water use, thermoregulation, structural support, and photosynthetic rate. All traits were under selection in at least one site, mostly in combination with other traits. For two trait combinations, the strength of selection gradients significantly increased from the colder, wetter site to the warmer, drier site: water use efficiency (WUE) with Huber value (HV), and carbon-to-nitrogen ratio (CN) with HV. In the warmer and drier site, trait-trait correlations among these three traits were largely absent, except for CN:HV in two provenances. Overall, reaction norms suggest that the plastic response was not aligned with selection for trait pairs in warm, dry climates. Results suggest that adaptive evolution in response to climate change in P. mariana may favor phenotypes with fewer needles that are conservative for water and resource use. In the seven study provenances, intrapopulation trait integration should minimally impede adaptive evolution, but plastic responses to warmer and drier conditions may constrain the expression of optimally adapted phenotypes.

The present study investigates the controlled electrokinetic motion of spherical colloids under the combined influence of an applied electric field and an electrolyte concentration gradient. The primary goal is to demonstrate how a concentration gradient impacts particle electrophoresis. When a concentration gradient exists in the bulk electrolyte─whether introduced intentionally or not─it drives particle motion through a synergistic effect involving both conventional electrophoresis and an additional mechanism known as diffusiophoresis. In this study, the concentration gradient is aligned to either reinforce or oppose the applied electric field. Besides, the particle is assumed to be charged and hydrophobic. We derived an analytical expression for the electrodiffusiophoretic mobility of such particles within the Debye-Hückel electrostatic limit. We further deduced numerical results for the electrodiffusiophoretic mobility considering the impact of the ion steric effect. The deduced numerical results are validated using both the derived analytical expression for electrodiffusiophoretic mobility under the low charge limit as well as existing experimental data for particle motion driven by either an electric field or an electrolyte concentration gradient. We observed that parameter R, which defines the ratio between the applied electric field strength and the concentration gradient strength, is crucial. It plays a vital role in determining both the magnitude and the propulsion direction of the particle's mobility. Furthermore, the propulsion direction of the particle can be precisely controlled by adjusting other key parameters, including the choice of electrolytes (and their bulk concentration), hydrodynamic slippage, and the surface charge density of the particle.

Abstract Cavities may form above the tail of torpedo anchors after installation and can significantly influence their subsequent vertical pullout behavior. However, there is still a lack of deep understanding of the effect of a fully open cavity on the vertical pullout capacity of torpedo anchors. This study investigates the vertical pullout capacity of torpedo anchors with a fully open cavity using the coupled Eulerian–Lagrangian (CEL) method implemented in abaqus. A comprehensive parametric analysis was conducted considering the impacts of anchor aspect ratio, fin aspect ratio, embedment depth, and soil strength profile. The results indicate that cavities reduce markedly both the end bearing and shaft friction resistance by altering the soil flow near the anchor tail, and thus affecting the anchor vertical bearing capacity. A capacity reduction coefficient β, defined for quantifying the loss in capacity due to the cavity, is found depending primarily on the shaft and fin aspect ratios. Specifically, β increases logarithmically with the shaft aspect ratio and decreases exponentially with the fin aspect ratio, while it is insensitive to embedment depth and soil strength gradient. Based on these findings, a simplified design procedure is proposed to predict the vertical pullout capacity considering cavity effect for engineering design in practice. This work improves the understanding of soil flow behavior influenced by cavities and provides a practical method to enhance the reliability of torpedo anchor design under vertical loading.

ABSTRACT Aim To determine how species richness gradients—commonly considered universal—vary across the phylogenetic hierarchy of birds and mammals, and to uncover how clade age and size predetermine the gradients. Location Global. Time Period Last 120 million years. Taxa Studied Birds and mammals (~15,000 species). Methods We used large‐scale phylogenies of birds and mammals and captured the species richness gradient for each of their monophyletic clades. Gradient strength was quantified with respect to latitude, environmental productivity and temperature using multiple measures (raw slopes, log transformation, log–log transformation, and correlations). To distinguish statistical from biological effects, we compared the observed gradients to those generated by null models that randomly reassigned species to clades while preserving the phylogeny and species distributions. Results Species richness gradients show considerable variation. Small and young clades exhibited inconsistent gradients—including reverse or flat gradients—while older and larger clades converged on steep, consistent gradients. Even moderately large clades (~500 species) commonly displayed reverse gradients. Null models replicated this trend but only partially, implying that biological effects also drive gradient variation. These phylogenetic trends were sensitive to the choice of gradient measure: raw slopes frequently inflated the strength of this trend and the apparent differences among clades, while log and log–log transformations revealed only moderate trends. Main Conclusions Species richness gradients are not universal, nor are they phylogenetic scale‐invariant. Instead, they follow systematic trends across the phylogenetic hierarchy. Young, small clades often bear signatures of their region of origin and historical dispersal, whereas older, larger clades converge on similar gradients. Recognising the variation and the phylogenetic trends within it elucidates the formation of biodiversity patterns. We offer guidelines for choosing gradient measures, arguing that multiple metrics, combined with careful use of null models, are necessary for a nuanced understanding of how, and why, global biodiversity patterns diverge from the presumed universal gradients.

The study of mechanical response and crack propagation behavior of layered composite rock mass is helpful for the efficient extraction of geological energy and the safety and stability of underground space structures. The shale is a heterogeneous rock, which is often mixed with mudstone and sandstone. Studying the propagation law of cracks in layered composite rock mass can better serve underground engineering. In this paper, three different strength rock materials (coarse sandstone, red sandstone, and gray sandstone) were spliced together to make three-point bending specimens with prefabricated cracks in the middle, and three-point bending experiments under different loading rates were carried out. The digital image correlation method was used to visualize the strain distribution in the three-point bending experiment, and the difference in crack propagation in different layered composite rock masses was studied. The numerical simulation is established by the cohesive element, and the correctness of the simulation is verified by the displacement-load data. Then the crack propagation speed under different conditions is studied. The results show that there are differences and similarities in the crack propagation process in different strength gradient composite rock masses. When the crack propagates from strong to weak, the crack tip receives more complex tensile shear force, which facilitates the crack crossing the interface. As the loading speed increases, the earlier the prefabricated crack initiates, the shorter the time it stays at the joint surface. When the crack propagates from strong to weak, the crack propagation is more penetrating.

Hill's considerations are not causal criteria.

Natural gas hydrate deposition poses a significant threat to pipeline transportation safety. Due to the high-pressure, sealed environment in which hydrates form, it is challenging to analyze the microdamage characteristics of hydrate layers under dynamic conditions using conventional equipment. This limitation hinders our understanding of the damage evolution patterns and mechanisms within deposited layers under stress loading. This study combines experimental and numerical simulation methods to clarify the mechanical evolution of hydrate deposits. A predictive model was established for consolidation forces as a function of the consolidation time and subcooling degree. For the first time, a discrete element simulation was used to model deposits with structural strength gradients, analyzing damage mechanisms and evolution patterns under stress loading. The consolidation strength of the hydrate deposit layer exhibits a trend of initially increasing significantly with the consolidation time before gradually stabilizing. Under stress loading, tensile damage dominates the failure mechanism. Consolidation time has little effect on the crack ratio; however, as stress loading intensifies, the ratio of tensile cracks to shear cracks decreases from 7:1 to 4:1. Furthermore, the codirectional nature of gravitational and contact forces results in a greater tendency for damage along the deposit layer's longitudinal direction. The failure patterns of these deposits are influenced by stress concentration paths and the direction of aging consolidation gradients, which lead to differences in the degree of destruction. This study establishes the first research framework for examining damage evolution in deep-water pipeline hydrate deposits, providing a theoretical foundation for the study of hydrate deposit stability.

Localized 1H magnetic resonance spectroscopy (MRS) is a powerful tool in pre-clinical and clinical neurological research, offering non-invasive insight into neurochemical composition in localized brain regions. Zebrafish (Danio rerio) are increasingly being utilized as models in neurological disorder research, providing valuable insights into disease mechanisms. However, the small size of the zebrafish brain and limited MRS sensitivity at low magnetic fields hinder comprehensive neurochemical analysis of localized brain regions. Here, we investigate the potential of ultra-high-field (UHF) MR systems, particularly 28.2 T, for this purpose. This present study pioneers the application of localized 1H spectroscopy in zebrafish brain at 28.2 T. Point resolved spectroscopy (PRESS) sequence parameters were optimized to reduce the impact of chemical shift displacement error and to enable molecular level information from distinct brain regions. Optimized parameters included gradient strength, excitation frequency, echo time, and voxel volume specifically targeting the 0–4.5 ppm chemical shift regions. Exceptionally high-resolution cerebral metabolite spectra were successfully acquired from localized regions of the zebrafish brain in voxels as small as 125 nL, allowing for the identification and quantification of major brain metabolites with remarkable spectral clarity, including lactate, myo-inositol, creatine, alanine, glutamate, glutamine, choline (phosphocholine + glycerol-phospho-choline), taurine, aspartate, N-acetylaspartyl-glutamate (NAAG), N-acetylaspartate (NAA), and γ-aminobutyric acid (GABA). The unprecedented spatial resolution achieved in a small model organism enabled detailed comparisons of the neurochemical composition across distinct zebrafish brain regions, including the forebrain, midbrain, and hindbrain. This level of precision opens exciting new opportunities to investigate how specific diseases in zebrafish models influence the neurochemical composition of specific brain areas.

ABSTRACTThe hippocampus, a brain region critical for memory, undergoes significant age‐related changes at both the macroscopic and microstructural levels. This study investigates these changes using high‐gradient diffusion MRI (dMRI) data analyzed in an unfolded hippocampal space. We applied the Soma and Neurite Density Imaging (SANDI) model to quantify microstructural alterations in 72 cognitively healthy participants aged 19–85 years, scanned on a 3 T Connectome MRI scanner with a maximum gradient strength of 300 mT/m. By combining SANDI with a super‐resolution algorithm and the HippUnfold toolbox, we achieved high spatial fidelity in our analysis. We observed significant age‐related reductions in soma fraction and soma radius, particularly in the subiculum and dentate gyrus, alongside increases in extracellular diffusivity and extracellular fraction, indicating a decline in cellular density and structural integrity. These microstructural changes occur alongside macroscopic alterations such as reduced hippocampal volume and cortical thickness, decreased gyrification, and increased curvature in specific subfields. The spatial correlations between microstructural and macroscopic metrics across the unfolded hippocampal space are weak, both in their mean values and in how they change with age. Our findings suggest that SANDI metrics provide sensitive and complementary information to traditional structural measures, offering new insights into the microstructural underpinnings of hippocampal aging. This study highlights the potential of advanced dMRI techniques to detect subtle age‐related changes in hippocampal microstructure, which may contribute to our understanding of aging and its impact on memory and cognition.

The relevance of the work lies in the need for reliable and non-invasive tools to assess the functional state of athletes and to correct the training process. The goal is to develop a methodology for assessing the characteristics of the locomotor system in speed rock climbers during training using an experimental sample of a contact LED track (CLT). Methods and participants of the study included kinematic analysis of jumping exercises using the CLT; with speed rock climbers participating, including men (n = 9), with master of sport (6 people) and candidate master of sport (3 people). Results of the study showed correlations between the height of the seated jump (r = -0.85), counter-movement jump with arm swing (r = -0.87), index of reactive strength (r = -0.75), specific height of jump (r = -0.76), and competition time during the passage of a standard route for speed rock climbers. Conclusions. The results obtained suggest that in speed climbing, athletes with high maximum strength and the ability to achieve peak power faster than their opponents have an advantage. The speed-climbing work of athletes is characterized by a pronounced strength-speed nature. Athletes with a high strength gradient, able to significantly increase power at a fast pace and create the necessary conditions for taking off and performing effective jumps, may have an advantage in long-distance climbing. The method developed for assessing the characteristics the locomotor system characteristics using CLT is a mobile, objective, and informative method for promptly monitoring and optimizing of the speed-strength potential of athletes.

Temperature gradient and shear strength in nanosecond laser welding of silicon carbide and copper

Continuous time crystals (CTCs) are a phase of matter characterized by spontaneous breaking of continuous time-translation symmetry. Recently, CTCs have garnered interest due to breakthroughs in experimental implementation. Here we report the experimental observation of CTCs in noble-gas nuclear spins and uncover previously unexplored dynamical phenomena. We observe that the CTCs manifest as persistent limit cycle oscillations of nuclear spins, with coherence times exceeding hours. Notably, these oscillations are robust against noise perturbations and exhibit random time phases upon repetitive realization, epitomizing continuous time-translation symmetry-breaking intrinsic to CTCs. Additionally, we observe a dynamical phase featuring quasi-periodic oscillations and random time phases, indicating the emergence of the continuous time quasi-crystals proposed by recent theories. By varying the feedback strength and magnetic gradient, we observe complex dynamical phase transitions between time crystal phases and chaotic regimes. This work broadens the catalog of phases of spin gases and unlocks opportunities in precision measurements.

Objective.This study aims to propose and validate a novel electrically controlled field-free line (FFL) magnetic particle imaging (MPI) system to address several aspects of existing electronically rotated FFL-MPI designs, including limitations in gradient enhancement, structural complexity of the drive system, and coil coupling effects.Methods. We employ a dynamic ring-shaped magnetic-field-converging gradient array, consisting of multiple pairs of electromagnets symmetrically arranged along the radial and axial directions. This configuration ensures that the magnetic field direction of the generated FFL remains consistently perpendicular to both the gradient direction and the imaging plane. Tomographic imaging uses only one set of drive coils arranged orthogonally to the gradient coils. Three-dimensional FFL scanning is realized by dynamically modulating the current phase of the radial coil pairs in conjunction with differential current control of the axial coil pairs. In addition, we conduct electromagnetic and image reconstruction simulations to evaluate the FFL generation characteristics and reconstruction performance under magnetic configurations with different numbers of pole pairs.Results. Simulation results demonstrate that the proposed system can achieve efficient and stable FFL rotation and axial translation, supporting rapid 3D tomographic scanning. In addition, we systematically analyzed how different pole-pair configurations affect the quality of the generated FFL and the resulting image resolution. These findings offer concrete guidance on how pole-pair scaling influences gradient strength, field uniformity, and system complexity.Significance. The proposed MagRing-MPI system enhances magnetic field gradients and imaging quality, simplifies the drive-coil configuration to reduce system complexity, and minimizes electromagnetic coupling and feedthrough effects. These improvements provide a promising foundation for the development of scalable and high-performance MPI systems.

Objective.Electromagnetic (EM) modeling is an effective method for evaluating the gradient safety of magnetic resonance imaging (MRI) for patients with active implantable medical devices (AIMDs). However, the combined effects of multiple factors-including gradient coil design constraints, implanted lead path, gradient strength, and scan configuration-on gradient-induced voltage (GIV) risk has not been systematically investigated. In particular, the magnetic field distribution outside the region of linearity (ROL) of gradient coils cannot be uniquely determined from their nominal gradient profile, and its impact on AIMD gradient safety assessment remains poorly understood.Approach.This study presents a multifactorial analysis of MRI gradient safety by integrating gradient coil modeling with anatomical lead path tracing using a reference human body shell. We examine how variations in coil design constraints affect magnetic field distributions and how these, in turn, influence GIV for three representative AIMDs' pathways: deep brain stimulators (DBSs), cardiac pacemakers (PMs), and sacral nerve stimulators (SNMs). Multiple gradient strengths, coil excitation modes, and scanning positions are assessed.Results.Magnetic field distributions vary significantly between coil designs, particularly in the concomitantBxandBycomponents, with differences reaching up to 53%. These variations result in GIV difference that increases with gradient strength. The maximum GIV differences for DBS, SNM, and PM reach 1.08 V, 0.52 V, and 0.93 V, respectively, underY-axis excitation. The concomitant field plays a significant role in these differences. Simultaneous excitation of all axes does not always produce the highest GIV due to cancellation effects. Cross-AIMD analysis shows high-risk zones are concentrated in and around the ROL.Significance.This work fills a gap by systematically evaluating how coil design, implant characteristics, gradient strength, and scan configurations influence GIV risk, providing a foundation for more comprehensive, individualized MRI gradient safety assessments.

Hypothesis:This study aimed to evaluate the interactions of multiple active hearing implants in the 7T magnetic resonance (MR) environment by assessing interactions occurring between the implantable device and the MR environment. One cochlear implant and 2 bone conduction implant models were used in the study.Background:The use of MR techniques in patients with active hearing implants has become a daily practice at 1.5 and 3T. Scanners using field strengths of 7T are becoming more widely available and are likely to be associated with even greater patient risk.Methods:Six potential interactions were investigated: magnetically induced force and torque, retaining magnet magnetization, device functionality, device heating, and image artifacts.Results:Device functionality was verified after 10 exposures. When no magnet was present, the force ratio, defined as the magnetically induced force divided by the force induced by gravity, remained below 0.3 for all devices. With the magnet in place, the force ratio increased to 11. Average magnetization changes measured were similar to the population spread at baseline. For all devices, heating did not exceed 0.35 °C compared with background heating after 15 minutes of consecutive scanning at 3.2 W/kg or with a gradient field strength of 41.8T/s.Conclusions:The findings show no adverse effects or performance degradation of the implant within the predefined test conditions. Preliminary outcomes of this feasibility study are positive, yet do not imply implant safety in the 7T MR environment. Formal verification will be required to label a device safe at this field strength.

In offshore drilling and geological exploration, the stability of jack-up rigs is predominantly determined by the bearing capacities of spudcan foundations during seabed penetration. The penetration depth of spudcans is relatively shallow in hard clay. The formation of a cavity on the top surface of a spudcan often complicates accurate estimation of its capacity. This study employs the finite element method, in conjunction with the Swipe and Probe loading techniques, to examine the failure surfaces of soils of varying strengths. Numerical simulations that consider different gradients of undrained shear strength and cavity depths demonstrate that cavity depth significantly influences the failure envelope. The findings indicate that higher soil strength increases the bearing capacity and reduces the area of soil displacement at failure. Moreover, an enhanced theoretical equation for predicting the vertical-horizontal-moment (V-H-M) failure envelope in hard clay strata is proposed. The equation’s accuracy has been verified against numerical simulation results, revealing an error margin of 3–10% under high vertical loads. This model serves as a practical and valuable tool for assessing the stability of jack-up rigs in hard clay, providing critical insights for engineering design safety and risk assessment.

Ultra-high gradient strength is crucial for achieving high spatial resolution in advanced magnetic resonance imaging (MRI) applications. However, it is challenging to design gradient coils to generate ultra-high gradient strengths with superior coil operational efficiency in a limited space. In this work, we propose an innovative hybrid gradient coil design approach that synergistically integrates the discrete wire scheme with the current density technique. The primary coils are configured using a discrete wire technique that achieves a compact and high-density winding structure, generating exceptional gradient field intensity. Concurrently, the shielding layer utilizes the current density method and stream function to effectively constrain stray magnetic fields and eddy current effects. Comparative analysis with conventional gradient coils demonstrates that the hybrid design approach achieves a doubling of gradient strength (e.g., 2450 vs 1000 mT/m) and a quadrupling of efficiency (e.g., 49 vs 12 mT/m/A). Furthermore, the mechanical design is also analyzed to ensure structural integrity and manufacturability. This novel design method provides new insights into overcoming the trade-offs among gradient performance metrics, establishing a promising approach for developing new-generation high-resolution MRI systems.

Abstract Linear magnetic holes (LMHs) are pressure-balanced structures characterized by reduced magnetic pressure and compensatory thermal pressure enhancements, driven by proton temperature and/or density variations. Here we systematically investigate the relative contributions of the proton temperature and density to the thermal pressure by examining LMH characteristics separately in high-speed and low-speed solar wind streams. Using Solar Orbiter data (2020–2024), we analyze 348 LMHs (∼4.5–5.0 day–1; 256 in low-speed and 92 in high-speed streams) identified via a combined partial variance of increments and minimum variance analysis method. Based on their thermal pressure contributions, the selected LMHs are classified into four types: temperature-dominant (T-LMHs), density-dominant (N-LMHs), temperature-and-density-enhanced (TN-LMHs), and background-like (BG-LMHs). We find that in low-speed streams, BG-LMHs are the most common (39%), followed by T-LMHs (25%). In high-speed streams, TN-LMHs are the most frequent (32%). For the first time, we introduce magnetic variance rate (MVR, the normalized temporal gradient of magnetic strength) to quantify phase steepness and a thermal dominance coefficient (TDC, the difference between normalized temperature and density perturbations) to assess the temperature contribution. The results reveal a statistically significant correlation between MVR and TDC exclusively in T-LMHs within low-speed streams (Spearman’s r = 0.4056, P = 0.0009), while other types and high-speed streams show no correlation (r < 0.23, P > 0.14). This selective correlation supports the role of ponderomotive forces—generated by steepening of nonlinear Alfvén waves—in heating T-LMHs, particularly in compressible low-speed wind environments. These results provide the first observational evidence linking phase-steepening dynamics to thermal enhancements in LMHs.