Search Results (107)

The direct current resistivity method holds advantages such as rapid, efficient, and automatic data acquisition. It is an important geophysical exploration technology for monitoring dynamic changes in subsurface geology. However, this method has such issues as volume effect and non-uniqueness in inversion. To meet the demand for high-resolution direct current resistivity inversion of dynamic geological models characterized by discontinuous changes, this study proposed a cross-gradient constrained time-lapse inversion method, thereby enhancing inversion imaging accuracy. A cross-gradient constraint term between models was incorporated into the objective function of time-lapse inversion to constrain the structural consistency and highlight local resistivity changes. This method avoided excessively smooth imaging as often caused by over-reliance on a reference model in time-lapse inversion, thereby significantly improving both the spatial resolution and quantitative accuracy of direct current resistivity monitoring inversion images. Numerical examples confirmed that the proposed method delivers higher inversion imaging accuracy in identifying dynamic resistivity changes, evidenced by a substantially lower normalized mean-square error (MSE). Furthermore, physical model experiments and a case study confirmed the stability of this method under actual monitoring conditions. The proposed method provides a more precise and effective inversion imaging technique for refined monitoring of dynamic changes in subsurface geologic bodies. Full article

Recent advances in generative artificial intelligence (AI) have enabled the creation of AI-generated characters modeled after historical figures, offering new opportunities for reflective and interactive engagement in both cultural heritage and education. This study explores the development and evaluation of a large language model representation of Joseph Lister (1827–1912), a pioneer of antiseptic surgery, within a retrieval-augmented generation framework. The purpose was to examine the model’s accuracy, authenticity, and reliability, highlighting challenges, best practices, and ethical considerations. Drawing on primary and secondary sources, including Lister’s writings, the model was constructed using OpenAI’s GPT-4o and refined through iterative validation. Prompts were categorized by cognitive complexity, and responses were evaluated against historical materials. The findings revealed a strong fidelity to Lister’s voice, with appropriate tone, diction, and temporal limits. Moreover, the model demonstrated behavioral control, reflective depth, and consistency across the different prompts. However, minor lapses in temporal framing and occasional embellishments were noted. The findings suggest that, when developed with care, AI-generated characters can support ethically grounded, historically sensitive learning experiences. At the same time, this approach warrants continued scrutiny and underscores the need for further interdisciplinary research and responsible implementation. Full article

Similarly to the short-lived messenger nitric oxide (NO), the more stable carbon monoxide (CO) molecule can also activate soluble guanylyl cyclase (sGC) to increase cGMP levels. However, CO-induced cGMP production is much less efficient. Using an accessible invertebrate model, we dissect a potential interaction between the canonical NO/sGC/cGMP and CO signalling pathways during development. The embryonic midgut of locusts is innervated by neurons that migrate in four discrete chains on its outer surface. Transcellular diffusing NO stimulates enteric neuron migration via cGMP signalling. The application of an NO donor results in virtually all enteric neurons being cGMP-immunoreactive while CO increases cGMP production only in approximately 33% of the migrating neurons. Cellular CO release appears to act as a slow down signal for motility. We quantify how CO specifically increases the interneuronal distance during chain migration. Moreover, time-lapse microscopy shows that CO reduces the directionality of the migrating neurons. These findings support the function of NO and CO as antagonistic signals for the coordination of collective cell migration during the development of the enteric nervous system. These experiments and the resulting insights into basic scientific questions prove once more that locust embryos are not only preparations for basic research, but also relevant models for screening of drugs targeting NO and CO signalling pathways as well as for isolating compounds affecting neuronal motility in general. Full article

Urban heat island circulation (UHIC) determines the wind and thermal environments in urban areas. For Loess Tableland valley towns, the evolution characteristics of the UHIC over this negative terrain are not well understood, and therefore, it is important to investigate the evolution characteristics. A city-scale computational fluid dynamics (CSCFD) model is used, and simulation results are validated by the water tank experiment. The evolution process over such negative terrain can be divided into transient and quasi-steady stages, and in the transient stage, the airflow pattern evolves from thermal convection to city-scale closed circulation, while that in the quasi-steady stage is only city-scale closed circulation. In order to further reveal the characteristics of city-scale closed circulation, the sensitivities of different factors influencing the start time, outflow time, mixing height and heat island intensity are analyzed, and the most significant factors influencing these four parameters are urban heat flux, slope height, slope height, and potential temperature lapse rate, respectively. Finally, the dimensionless mixing height and heat island intensity for the valley town increase by 56.80% and 128.68%, respectively, compared to those for the flat city. This study provides guidance for the location and layout of built-up areas in the valley towns. Full article

In non-ribosomal peptide synthesis of cyanobacteria, promiscuous adenylation domains allow the incorporation of clickable non-natural amino acids into peptide products—namely into microcystins (MCs) or into anabaenopeptins (APs): 4-azidophenylalanine (Phe-Az), N-propargyloxy-carbonyl-L-lysine (Prop-Lys), or O-propargyl-L-tyrosine (Prop-Tyr). Subsequently, chemo-selective labeling is used to visualize the clickable cyanopeptides using Alexa Fluor 488 (A488). In this study, the time-lapse build up or decline of azide- or alkyne-modified MCs or APs was visualized during maximum growth, specifically MC biosynthesis in Microcystis aeruginosa and AP biosynthesis in Planktothrix agardhii. Throughout the time-lapse build up or decline, the A488 signal occurred with heterogeneous intracellular distribution. There was a fast increase or decrease in the A488 signal for either Prop-Tyr or Prop-Lys, while a delayed or unobservable A488 signal for Phe-Az was related to increased cell size as well as a reduction in growth and autofluorescence. The proportion of clickable MC/AP in peptide extracts as recorded by a chemical–analytical technique correlated positively with A488 labeling intensity quantified via laser-scanning confocal microscopy for individual cells or via flow cytometry at the population level. It is concluded that chemical modification of MC/AP can be used to track intracellular dynamics in biosynthesis using both analytical chemistry and high-resolution imaging. Full article

Constructing stable and flexible neuronal networks with multi-neurite wiring is essential for the in vitro modeling of brain function, connectivity, and neuroplasticity. However, most existing neuroengineering platforms rely on static microfabrication techniques, which limit the ability to dynamically control circuit architecture during cultivation. In this study, we developed a modifiable agarose gel-based platform that enables real-time microstructure fabrication using an infrared (IR) laser system under live-cell conditions. This approach allows for the stepwise construction of directional neurite paths, including sequential microchannel formation, cell chamber fabrication, and controlled neurite–neurite crossings. To support long-term neuronal health and network integrity in agarose microstructures, we incorporated direct glial co-culture into the system. A comparative analysis showed that co-culture significantly enhanced neuronal adhesion, neurite outgrowth, and survival over several weeks. The feeder layer configuration provided localized trophic support while maintaining a clear separation between glial and neuronal populations. Dynamic wiring experiments further confirmed the platform’s precision and compatibility. Neurites extended through newly fabricated channels and crossed pre-existing neurites without morphological damage, even when laser fabrication occurred after initial outgrowth. Time-lapse imaging showed a temporary growth cone stalling at crossing points, followed by successful elongation in all tested samples. Furthermore, the direct laser irradiation of extending neurites during microstructure modification did not visibly impair neurite elongation, suggesting minimal morphological damage under the applied conditions. However, potential effects on molecular signaling and electrophysiological function remain to be evaluated in future studies. Together, these findings establish a powerful, flexible system for constructive neuroengineering. The platform supports long-term culture, real-time modification, and multidirectional wiring, offering new opportunities for studying neural development, synaptic integration, and regeneration in vitro. Full article

Sustained attention is a critical cognitive function, especially in contexts such as driving safety, where performance deterioration due to fatigue or drowsiness can have serious consequences. Although individual differences in sustained attention have been recognized and are known to decline with age, quantitative analyses considering sex and circadian timing are limited. In this study, we analyzed psychomotor vigilance task (PVT) data from 356 participants to investigate the effects of age, sex, and time of day on attention performance. Participants completed a 5-min PVT, and metrics including the reaction time (RT), minor lapses (MNLs, ≥5 ms), major lapses (MJLs, ≥8 ms), and false starts (FSs) were calculated. A general linear model was applied with sex and testing time (8:00–12:00, 13:00–16:00, 16:00–18:00) as fixed factors and age as a covariate. Stepwise multiple regression was also used to assess how well age, sex, and time of day explain performance. The RT showed significant differences by time and age (p < 0.001), with higher numbers of MNLs during morning sessions. Both sexes demonstrated significantly better performance in the afternoon compared to the morning. These results highlight the importance of controlling for the testing time in PVT-based experiments and underscore the measurable individual differences in sustained attention. Full article

To preserve flood control infrastructure, it is essential to quickly detect and accurately identify concealed leakage hazards within embankment projects. In this paper, we propose a novel embankment monitoring method based on the time-lapse transient electromagnetic method and complemented by a theoretical framework for analyzing time-lapse data through the lens of resistivity change rates. A time-lapse model that scrutinizes dynamic response patterns associated with leakage anomalies is constructed, while the efficacy of this methodology is verified through rigorous field experiments. Our research findings reveal a well-defined negative correlation between the resistivity variation rate and the development stage of anomalies. Our proposed method demonstrates enhanced sensitivity in the detection of dynamic evolutionary patterns in latent seepage defects, particularly in low-resistivity environments. Moreover, it successfully delineates both the spatial expansions and electrical property alterations of anomalies, providing a novel technical approach for latent seepage defect monitoring and risk management in embankments. Full article

Thyroid hormone receptor alpha (THRα) is a nuclear hormone receptor that binds triiodothyronine (T3) and acts as an important transcription factor in development, metabolism, and reproduction. The coding gene, THRA, has two major splicing isoforms in mammals, THRA1 and THRA2, which encode THRα1 and THRα1, respectively. The better characterized isoform, THRα1, is a transcriptional stimulator of genes involved in cell metabolism and growth. The less well-characterized isoform, THRα2, lacks the ligand-binding domain (LBD) and may act as an inhibitor of THRα1 activity. Thus, the ratio of THRα1 to THRα2 isoforms is critical for transcriptional regulation in various tissues and during development and may be abnormal in a number of thyroid hormone resistance syndromes. However, the complete characterization of the THRα isoform expression pattern in healthy human tissues, and especially the study of changes in the ratio of THRα1 to THRα2 in cultured patient cells, has been hampered by the lack of suitable tools to detect the isoform-specific expression patterns. Therefore, we developed a plasmid pCMV-THRA-RFP-EGFP splicing detector that allows the visualization and quantification of the differential expression of THRA1 and THRA2 splicing isoforms in living single cells during time-lapse and perturbation experiments. This tool enables experiments to further characterize the role of THRα2 and to perform high-throughput drug screening. Molecules that modify THRA splicing may be developed into drugs for the treatment of thyroid hormone resistance syndromes. Full article

Recently, the use of click chemistry for localization of chemically modified cyanopeptides has been introduced, i.e., taking advantage of promiscuous adenylation (A) domains in non-ribosomal peptide synthesis (NRPS), allowing for the incorporation of clickable non-natural amino acids (non-AAs) into their peptide products. In this study, time-lapse experiments have been performed using pulsed feeding of three different non-AAs in order to observe the synthesis or decline of azide- or alkyne-modified microcystins (MCs) or anabaenopeptins (APs). The cyanobacteria Microcystis aeruginosa and Planktothrix agardhii were grown under maximum growth rate conditions (r = 0.35–0.6 and 0.2–0.4 (day⁻¹), respectively) in the presence of non-AAs for 12–168 h. The decline of the azide- or alkyne-modified MC or AP was observed via pulse-feeding. In general, the increase in clickable MC/AP in peptide content reached a plateau after 24–48 h and was related to growth rate, i.e., faster-growing cells also produced more clickable MC/AP. Overall, the proportion of clickable MC/AP in the intracellular fraction correlated with the proportion observed in the dissolved fraction. Conversely, the overall linear decrease in clickable MC/AP points to a rather constant decline via dilution by growth instead of a regulated or induced release in the course of the synthesis process. Full article

Time-lapse ground-penetrating radar (GPR) surveys, combined with automated infiltration experiments, provide a non-invasive approach for investigating the distribution of infiltrated water within the soil medium and creating three-dimensional images of the wetting bulb. This study developed and validated an experimental protocol aimed at quantifying and visualizing water distribution fluxes in layered soils under both unsaturated and saturated conditions. The 3D images of the wetting bulb significantly enhanced the interpretation of infiltration data, enabling a detailed analysis of water movement through the layered system. We used the infiltrometer data and the Beerkan Estimation of Soil Transfer parameters (BEST) method to determine soil capacitive indicators and evaluate the physical quality of the upper soil layer. The field survey involved conducting time-lapse GPR surveys alongside infiltration experiments between GPR repetitions. These experiments included both tension and ponding tests, designed to sequentially activate the soil matrix and the full pore network. The results showed that the soil under study exhibited significant soil aeration and macroporosity (represented by AC and p_MAC), while indicators related to microporosity (such as PAWC and RFC) were notably low. The RFC value of 0.55 m³ m⁻³ indicated the soil’s limited capacity to retain water relative to its total pore volume. The PAWC value of 0.10 m³ m⁻³ indicated a scarcity of micropores ranging from 0.2 to 30 μm in diameter, which typically hold water accessible to plant roots within the total porosity. The saturated soil hydraulic conductivity, K_s, values ranged from 192.2 to 1031.0 mm h⁻¹, with a mean of 424.4 mm h⁻¹, which was 7.9 times higher than the corresponding unsaturated hydraulic conductivity measured at a pressure head of h = −30 mm (K₋₃₀). The results indicated that the upper soil layer supports root proliferation and effectively drains excess water to the underlying limestone layer. However, this layer has limited capacity to store and supply water to plant roots and acts as a restrictive barrier, promoting non-uniform downward water movement, as revealed by the 3D GPR images. The observed difference in hydraulic conductivity between the two layers suggests that surface ponding and overland flow are generated through a saturation excess mechanism. Water percolating through the soil can accumulate above the limestone layer, creating a shallow perched water table. During extreme rainfall events, this water table may rise, leading to the complete saturation of the soil profile. Full article

Continuous measurements of soil moisture in the deeper parts of the unsaturated zone remain an important challenge. This study examines the development of an integrated system for the continuous and 3-D monitoring of the vadose zone processes in a cost- and energy-efficient way. This system comprises TDR, ERT and GPR geophysical techniques. Their capacities to adequately image subsurface moisture changes with continuous and time-lapse measurements are assessed during an artificial infiltration experiment conducted in a characteristic urban site with anthropogenic fills and much compaction. A 3-D array was designed for each method to expand the information of a single TDR probe and obtain a broader image of the subsurface. Custom spatial TDR probes installed in boreholes made with a percussion drilling instrument were used for soil moisture measurements. Moisture profiles along the probes were estimated with a numerical one-dimensional inversion model and a standard calibration equation. High conductivity water used during all infiltration tests led to the detection of the flow by all techniques. Preferential flow was present throughout the experiment and imaged sufficiently by all methods. Overall, the integrated approach conceals each method’s weaknesses and provides a reliable 3-D view of the subsurface. The results suggest that this approach can be used to monitor the unsaturated zone at even greater depths. Full article

This work presents the results of an advanced geophysical characterization of a contaminated site, where a correct understanding of the dynamics in the unsaturated zone is fundamental to evaluate the effective management of the remediation strategies. Large-scale surface electrical resistivity tomography (ERT) was used to perform a preliminary assessment of the structure in a thick unsaturated zone and to detect the presence of a thin layer of clay supporting an overlying thin perched aquifer. Discontinuities in this clay layer have an enormous impact on the infiltration processes of both water and solutes, including contaminants. In the case here presented, the technical strategy is to interrupt the continuity of the clay layer upstream of the investigated site in order to prevent most of the subsurface water flow from reaching the contaminated area. Therefore, a deep trench was dug upstream of the site and, in order to evaluate the effectiveness of this approach in facilitating water infiltration into the underlying aquifer, a forced infiltration experiment was carried out and monitored using ERT and ground-penetrating radar (GPR) measurements in a cross-hole time-lapse configuration. The results of the forced infiltration experiment are presented here, with a particular emphasis on the contribution of hydro-geophysical methods to the general understanding of the subsurface water dynamics at this complex site. Full article

Changes in the masses of icebergs due to deterioration processes affect the drift of icebergs and should be taken into account when assessing iceberg risks in the areas of offshore development. In 2022 and 2023, eight laboratory experiments were carried out in the wave tank of the University Centre in Svalbard to study the melting of icebergs in sea water under calm and rough conditions. In the experiments, the water temperatures varied from $0 ℃$ to $2.2 ℃$. Cylindrical iceberg models were made from columnar ice cores with a diameter of 24 cm. In one experiment, the iceberg model was protected on the sides with plastic fencing to investigate the iceberg’s protection from melting when towed to deliver fresh water. The iceberg masses, water temperatures, and ice temperatures were measured in the experiments. The water velocity near the iceberg models was measured with an acoustic Doppler velocimeter. During the experiments, time-lapse cameras were used to describe the shapes and measure the vertical dimensions of the icebergs. Using experimental data, we calculated the horizontal dimensions of icebergs, latent heat fluxes, conductive heat fluxes inside the iceberg models, and turbulent heat fluxes in water as a function of time. We discovered the influence of surface waves and water mixing on the melt rates and found a significant reduction in the melt rates due to the lateral protection of the iceberg model using a plastic barrier. Based on the experimental data obtained, the ratio of the rates of lateral and bottom melting of the icebergs and lateral melting of the icebergs under wave conditions was parametrized depending on the wave frequency. Full article

Ground-penetrating radar (GPR) is a rapid and non-destructive geophysical technique widely employed to detect and quantify subsurface structures and characteristics. Its capability for time lapse (TL) detection provides essential insights into subsurface hydrological dynamics, including lateral flow and soil water distribution. However, during TL-GPR surveys, field conditions often create discrepancies in surface geometry, which introduces mismatches across sequential TL-GPR images. These discrepancies may generate spurious signal variations that impede the accurate interpretation of TL-GPR data when assessing subsurface hydrological processes. In responding to this issue, this study introduces a TL-GPR image alignment method by employing the dynamic time warping (DTW) algorithm. The purpose of the proposed method, namely TLIAM–DTW, is to correct for geometric mismatch in TL-GPR images collected from the identical survey line in the field. We validated the efficacy of the TLIAM–DTW method using both synthetic data from gprMax V3.0 simulations and actual field data collected from a hilly, forested area post-infiltration experiment. Analyses of the aligned TL-GPR images revealed that the TLIAM–DTW method effectively eliminates the influence of geometric mismatch while preserving the integrity of signal variations due to actual subsurface hydrological processes. Quantitative assessments of the proposed methods, measured by mean absolute error (MAE) and root mean square error (RMSE), showed significant improvements. After performing the TLIAM–DTW method, the MAE and RMSE between processed TL-GPR images and background images were reduced by 96% and 78%, respectively, in simple simulation scenarios; in more complex simulations, MAE declined by 27–31% and RMSE by 17–43%. Field data yielded reductions in MAE and RMSE of >82% and 69%, respectively. With these substantial improvements, the processed TL-GPR images successfully depict the spatial and temporal transitions associated with subsurface lateral flows, thereby enhancing the accuracy of monitoring subsurface hydrological processes under field conditions. Full article