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18 pages, 4938 KiB  
Study Protocol
Optimization of Control Point Layout for Orthophoto Generation of Indoor Murals
by Dingfei Yan and Yongming Yang
Sensors 2025, 25(5), 1588; https://doi.org/10.3390/s25051588 - 5 Mar 2025
Viewed by 82
Abstract
This study focuses on the preservation of indoor murals, which can be supported by combining RTK and total station technology to explore the optimization of image geometric accuracy based on a control points layout. The study involves placing varying numbers of control points [...] Read more.
This study focuses on the preservation of indoor murals, which can be supported by combining RTK and total station technology to explore the optimization of image geometric accuracy based on a control points layout. The study involves placing varying numbers of control points on the mural surface and processing the collected data using a spatial coordinate transformation model to assess the impact of different layouts on image accuracy. Some control points are used to ensure the spatial positioning accuracy of the images, while others serve as check points to validate the geometric precision of the images. After data processing, high-precision digital orthophotos are generated using Agisoft PhotoScan2.0.1 software, with accuracy verified by the check points. The experimental results show that as the number of control points increases, image accuracy improves gradually. When the number of control points reaches 24, the geometric accuracy of the images stabilizes, and further increases in the number of control points have a limited effect on improving accuracy. Therefore, the study proposes an optimal layout scheme: 24 control points for every 16 square meters. This scheme not only meets millimeter-level precision requirements but also effectively optimizes resource allocation and reduces time costs. The research provides reliable data support for the high-precision preservation and restoration of murals and offers important references for similar cultural heritage preservation projects. Full article
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<p>Experimental workflow.</p>
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<p>Control point distribution map. Note: Black pentagons represent the check points, and red triangles represent the control points.</p>
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<p>Schematic diagram of control point layout schemes. Note: Black pentagons represent the check points, and red triangles represent the control points.</p>
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<p>Before Y-axis rotation.</p>
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<p>After Y-axis rotation.</p>
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<p>Digital orthophoto generated with 24 control points.</p>
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<p>Total root mean square error distribution.</p>
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32 pages, 10662 KiB  
Article
Characterization of Exhausted T Cell Signatures in Pan-Cancer Settings
by Rifat Tasnim Juthi, Saiful Arefeen Sazed, Manvita Mareboina, Apostolos Zaravinos and Ilias Georgakopoulos-Soares
Int. J. Mol. Sci. 2025, 26(5), 2311; https://doi.org/10.3390/ijms26052311 - 5 Mar 2025
Viewed by 181
Abstract
T cells play diverse roles in cancer immunology, acting as tumor suppressors, cytotoxic effectors, enhancers of cytotoxic T lymphocyte responses and immune suppressors; providing memory and surveillance; modulating the tumor microenvironment (TME); or activating innate immune cells. However, cancer cells can disrupt T [...] Read more.
T cells play diverse roles in cancer immunology, acting as tumor suppressors, cytotoxic effectors, enhancers of cytotoxic T lymphocyte responses and immune suppressors; providing memory and surveillance; modulating the tumor microenvironment (TME); or activating innate immune cells. However, cancer cells can disrupt T cell function, leading to T cell exhaustion and a weakened immune response against the tumor. The expression of exhausted T cell (Tex) markers plays a pivotal role in shaping the immune landscape of multiple cancers. Our aim was to systematically investigate the role of known T cell exhaustion (Tex) markers across multiple cancers while exploring their molecular interactions, mutation profiles, and potential implications for immunotherapy. The mRNA expression profile of six Tex markers, LAG-3, PDCD1, TIGIT, HAVCR2, CXCL13, and LAYN was investigated in pan-cancer. Utilizing data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO), The Cancer Proteome Atlas (TCPA), and other repositories, we characterized the differential expression of the Tex markers, their association with the patients’ survival outcome, and their mutation profile in multiple cancers. Additionally, we analyzed the effects on cancer-related pathways and immune infiltration within the TME, offering valuable insights into mechanisms of cancer immune evasion and progression. Finally, the correlation between their expression and sensitivity to multiple anti-cancer drugs was investigated extensively. Differential expression of all six markers was significantly associated with KIRC and poor prognosis in several cancers. They also played a potential activating role in apoptosis, EMT, and hormone ER pathways, as well as a potential inhibitory role in the DNA damage response and RTK oncogenic pathways. Infiltration of different immune cells was also found to be associated with the expression of the Tex-related genes in most cancer types. These findings underline that the reviving of exhausted T cells can be used to enhance the efficacy of immunotherapy in cancer patients. Full article
(This article belongs to the Special Issue Big Data in Multi-Omics)
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<p>(<b>A</b>) Bubble plot illustrating the fold change of six Tex marker genes across 14 cancer types. (<b>B</b>) Scattered boxplots showing differential expression of Tex mRNA expression in kidney tumors (KIRC) compared to normal kidney tissues. (<b>C</b>) The boxplots summarize the trend of the Tex mRNA expression from early to late stage KIRC. * <span class="html-italic">p</span> &lt; 0.05, **** <span class="html-italic">p</span> &lt; 0.0001, ns—not significant. (<b>D</b>) The bubble plots illustrate the difference between high and low mRNA expression of the Tex marker genes in different cancer types.</p>
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<p>(<b>A</b>) Bubble plot illustrating the fold change of six Tex marker genes across 14 cancer types. (<b>B</b>) Scattered boxplots showing differential expression of Tex mRNA expression in kidney tumors (KIRC) compared to normal kidney tissues. (<b>C</b>) The boxplots summarize the trend of the Tex mRNA expression from early to late stage KIRC. * <span class="html-italic">p</span> &lt; 0.05, **** <span class="html-italic">p</span> &lt; 0.0001, ns—not significant. (<b>D</b>) The bubble plots illustrate the difference between high and low mRNA expression of the Tex marker genes in different cancer types.</p>
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<p>(<b>A</b>) Survival outcome difference between the high and low expression group of the Tex marker genes. (<b>B</b>) Survival contribution (OS, DSS, and DFS) map of hazard ratio (HR) of the Tex marker genes in pan-cancer. Estimation was conducted using the Mantel–Cox test. Red block, higher risk; blue block, lower risk; darkened outline, significant prognosis. (<b>C</b>) Kaplan–Meier overall survival (OS) plots for high and low expression signatures of the Tex marker genes in uveal melanoma (UVM) and skin melanoma (SKCM). Red and blue dotted line represent 95% confidence interval (CI) for each group.</p>
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<p>(<b>A</b>) Survival outcome difference between the high and low expression group of the Tex marker genes. (<b>B</b>) Survival contribution (OS, DSS, and DFS) map of hazard ratio (HR) of the Tex marker genes in pan-cancer. Estimation was conducted using the Mantel–Cox test. Red block, higher risk; blue block, lower risk; darkened outline, significant prognosis. (<b>C</b>) Kaplan–Meier overall survival (OS) plots for high and low expression signatures of the Tex marker genes in uveal melanoma (UVM) and skin melanoma (SKCM). Red and blue dotted line represent 95% confidence interval (CI) for each group.</p>
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<p>(<b>A</b>) Cancers percentage in which the mRNA expression of the six Tex marker genes has a potential effect on the activity of 10 cancer-related pathways. Blue color depicts the shifting of the effect toward inhibition; red color depicts the shifting of the effect toward activation. Each cell contains a percentage (%) representing the proportion of cancer types in which each gene demonstrated a significant association (either inducing or inhibitory) with a specific pathway in pan-cancer. (<b>B</b>) PAS of high and low Tex genes’ mRNA expression in breast cancers (BRCA).</p>
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<p>(<b>A</b>) Heatmap representing mutation frequency of SNV across pan-cancer. (<b>B</b>) Oncoplot representing the frequency of mutation of Tex marker genes in 314 cases and their distribution across selected cancers. Percentage indicates the ratio of genetically altered tumor samples to the total no. of samples. (<b>C</b>) Percentage distribution of amplification and deletion of Tex marker genes. (<b>D</b>) Pie plot summarizing the CNV of Tex marker genes in the few cancer types. (<b>E</b>) Heterozygous CNV profile of Tex marker genes in pan-cancers. (<b>F</b>) Homozygous CNV profile of Tex marker genes in pan-cancers. (<b>G</b>) Methylation difference of Tex marker genes in selected cancers. (<b>H</b>) Methylation and mRNA expression correlation of Tex marker genes in pan-cancers.</p>
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<p>(<b>A</b>) Heatmap representing mutation frequency of SNV across pan-cancer. (<b>B</b>) Oncoplot representing the frequency of mutation of Tex marker genes in 314 cases and their distribution across selected cancers. Percentage indicates the ratio of genetically altered tumor samples to the total no. of samples. (<b>C</b>) Percentage distribution of amplification and deletion of Tex marker genes. (<b>D</b>) Pie plot summarizing the CNV of Tex marker genes in the few cancer types. (<b>E</b>) Heterozygous CNV profile of Tex marker genes in pan-cancers. (<b>F</b>) Homozygous CNV profile of Tex marker genes in pan-cancers. (<b>G</b>) Methylation difference of Tex marker genes in selected cancers. (<b>H</b>) Methylation and mRNA expression correlation of Tex marker genes in pan-cancers.</p>
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<p>(<b>A</b>) Heatmap representing mutation frequency of SNV across pan-cancer. (<b>B</b>) Oncoplot representing the frequency of mutation of Tex marker genes in 314 cases and their distribution across selected cancers. Percentage indicates the ratio of genetically altered tumor samples to the total no. of samples. (<b>C</b>) Percentage distribution of amplification and deletion of Tex marker genes. (<b>D</b>) Pie plot summarizing the CNV of Tex marker genes in the few cancer types. (<b>E</b>) Heterozygous CNV profile of Tex marker genes in pan-cancers. (<b>F</b>) Homozygous CNV profile of Tex marker genes in pan-cancers. (<b>G</b>) Methylation difference of Tex marker genes in selected cancers. (<b>H</b>) Methylation and mRNA expression correlation of Tex marker genes in pan-cancers.</p>
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<p>(<b>A</b>) Heatmap representing mutation frequency of SNV across pan-cancer. (<b>B</b>) Oncoplot representing the frequency of mutation of Tex marker genes in 314 cases and their distribution across selected cancers. Percentage indicates the ratio of genetically altered tumor samples to the total no. of samples. (<b>C</b>) Percentage distribution of amplification and deletion of Tex marker genes. (<b>D</b>) Pie plot summarizing the CNV of Tex marker genes in the few cancer types. (<b>E</b>) Heterozygous CNV profile of Tex marker genes in pan-cancers. (<b>F</b>) Homozygous CNV profile of Tex marker genes in pan-cancers. (<b>G</b>) Methylation difference of Tex marker genes in selected cancers. (<b>H</b>) Methylation and mRNA expression correlation of Tex marker genes in pan-cancers.</p>
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<p>(<b>A</b>) Association between Tex mRNA expression and immune infiltrates in OV and UCEC. (<b>B</b>) Correlation between the GSVA score and immune cell infiltration in pan-cancer. *: <span class="html-italic">p</span> value ≤ 0.05; #: FDR ≤ 0.05. (<b>C</b>) Difference of immune cell infiltration between Tex marker WT and mutants in UCEC. (<b>D</b>) Disparity of immune cell infiltration between gene set SNV groups in UCEC. (<b>E</b>) Correlation between Tex marker CNVs and immune infiltration in BRCA. (<b>F</b>) Difference of immune infiltration between gene set CNV groups in PAAD. (<b>G</b>) Correlation between methylated Tex markers and immune infiltration in the HNSC.</p>
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<p>(<b>A</b>) Association between Tex mRNA expression and immune infiltrates in OV and UCEC. (<b>B</b>) Correlation between the GSVA score and immune cell infiltration in pan-cancer. *: <span class="html-italic">p</span> value ≤ 0.05; #: FDR ≤ 0.05. (<b>C</b>) Difference of immune cell infiltration between Tex marker WT and mutants in UCEC. (<b>D</b>) Disparity of immune cell infiltration between gene set SNV groups in UCEC. (<b>E</b>) Correlation between Tex marker CNVs and immune infiltration in BRCA. (<b>F</b>) Difference of immune infiltration between gene set CNV groups in PAAD. (<b>G</b>) Correlation between methylated Tex markers and immune infiltration in the HNSC.</p>
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<p>(<b>A</b>) Association between Tex mRNA expression and immune infiltrates in OV and UCEC. (<b>B</b>) Correlation between the GSVA score and immune cell infiltration in pan-cancer. *: <span class="html-italic">p</span> value ≤ 0.05; #: FDR ≤ 0.05. (<b>C</b>) Difference of immune cell infiltration between Tex marker WT and mutants in UCEC. (<b>D</b>) Disparity of immune cell infiltration between gene set SNV groups in UCEC. (<b>E</b>) Correlation between Tex marker CNVs and immune infiltration in BRCA. (<b>F</b>) Difference of immune infiltration between gene set CNV groups in PAAD. (<b>G</b>) Correlation between methylated Tex markers and immune infiltration in the HNSC.</p>
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<p>(<b>A</b>) Correlation between Tex marker gene expression and IC50 across pan-cancer. (<b>B</b>) The ROC plot shows the relationship between Tex mRNA expression and sensitivity in chemotherapy in BRCA. (<b>C</b>) The ROC plot showing relationship between Tex mRNA expression and sensitivity in chemotherapy in OV. (<b>D</b>) The ROC plot shows the relationship between Tex mRNA expression and sensitivity in chemotherapy in GBM. (<b>E</b>) Drug sensitivity analysis of particular Tex marker genes. (<b>F</b>) The regulator prioritization clustering heatmap shows the association of Tex with immunosuppression indicators.</p>
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<p>(<b>A</b>) Correlation between Tex marker gene expression and IC50 across pan-cancer. (<b>B</b>) The ROC plot shows the relationship between Tex mRNA expression and sensitivity in chemotherapy in BRCA. (<b>C</b>) The ROC plot showing relationship between Tex mRNA expression and sensitivity in chemotherapy in OV. (<b>D</b>) The ROC plot shows the relationship between Tex mRNA expression and sensitivity in chemotherapy in GBM. (<b>E</b>) Drug sensitivity analysis of particular Tex marker genes. (<b>F</b>) The regulator prioritization clustering heatmap shows the association of Tex with immunosuppression indicators.</p>
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<p>(<b>A</b>) Correlation between Tex marker gene expression and IC50 across pan-cancer. (<b>B</b>) The ROC plot shows the relationship between Tex mRNA expression and sensitivity in chemotherapy in BRCA. (<b>C</b>) The ROC plot showing relationship between Tex mRNA expression and sensitivity in chemotherapy in OV. (<b>D</b>) The ROC plot shows the relationship between Tex mRNA expression and sensitivity in chemotherapy in GBM. (<b>E</b>) Drug sensitivity analysis of particular Tex marker genes. (<b>F</b>) The regulator prioritization clustering heatmap shows the association of Tex with immunosuppression indicators.</p>
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<p>(<b>A</b>) Correlation between Tex marker gene expression and IC50 across pan-cancer. (<b>B</b>) The ROC plot shows the relationship between Tex mRNA expression and sensitivity in chemotherapy in BRCA. (<b>C</b>) The ROC plot showing relationship between Tex mRNA expression and sensitivity in chemotherapy in OV. (<b>D</b>) The ROC plot shows the relationship between Tex mRNA expression and sensitivity in chemotherapy in GBM. (<b>E</b>) Drug sensitivity analysis of particular Tex marker genes. (<b>F</b>) The regulator prioritization clustering heatmap shows the association of Tex with immunosuppression indicators.</p>
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26 pages, 15590 KiB  
Article
Technical and Policy Analysis: Time Series of Land Subsidence for the Evaluation of the Jakarta Groundwater-Free Zone
by Joko Widodo, Edy Trihatmoko, Nugraheni Setyaningrum, Yuta Izumi, Rendi Handika, Mohammad Ardha, Rahmat Arief, Shinichi Sobue, Nurlinda Nurlinda, Pulung Arya Pranantya, Jovi Rauhillah Wiranu and Muhammad Rokhis Khomarudin
Urban Sci. 2025, 9(3), 67; https://doi.org/10.3390/urbansci9030067 - 4 Mar 2025
Viewed by 251
Abstract
Jakarta faces a critical challenge of extensive land subsidence, ranking prominently globally. This research employs a combined technical and policy evaluation approach to analyze the issue, incorporating sustainability considerations to assess the efficacy of Governor Regulation of Jakarta Number 93 of 2021, focusing [...] Read more.
Jakarta faces a critical challenge of extensive land subsidence, ranking prominently globally. This research employs a combined technical and policy evaluation approach to analyze the issue, incorporating sustainability considerations to assess the efficacy of Governor Regulation of Jakarta Number 93 of 2021, focusing on how the groundwater-free zone relates to land subsidence in the city. We processed 81 ALOS-2 PALSAR-2 synthetic aperture radar (SAR) data using persistent scatterer interferometric synthetic aperture radar (PS-InSAR) with HH polarization from 2017 to 2022 and ground truthing with 255 global positioning system (GPS) real-time kinematic (RTK) validation points. Our findings reveal a significant misalignment in the designated groundwater-free zone in the central part of Jakarta. At the same time, severe land subsidence primarily affects northern and northwestern Jakarta, with an average land subsidence rate of 5–6 cm/year. We strongly advocate for a thorough evaluation to rectify and redefine the boundaries of groundwater-free zones, improve regulatory frameworks, and effectively address land subsidence mitigation in the study area. The impact of domestic water needs on land subsidence highlights the urgency of action. Based on a combination of land subsidence velocity rates and domestic water demand, we have classified the cities in Jakarta into three levels of recommendations for groundwater-free zones. The cities are ranked in order of priority from highest to lowest: (1) West Jakarta, (2) North Jakarta, (3) South Jakarta, (4) East Jakarta, and (5) Central Jakarta, which holds the lowest priority. Full article
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<p>The study area of the research.</p>
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<p>Data statistics and normal baselines of ALOS-2 PALSAR-2 data used in this research (81 images).</p>
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<p>Data statistics and normal baselines of ALOS-2 PALSAR-2 data used in this research (81 images).</p>
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<p>Research flow.</p>
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<p>Interferogram of 81 ALOS 2 images and PS-InSAR result for Jakarta and surrounding area.</p>
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<p>Nash–Sutcliffe efficiency model results with a 0.8 (outstanding) value between PS-InSAR as a model and GNSS data as an observation (Obs).</p>
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<p>GNSS in conjunction with PS-InSAR data within a 100 m buffer.</p>
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<p>Jakarta land subsidence, 2017–2022.</p>
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<p>The average of the velocity subsidence rate (mm) in each city of Jakarta from 2017 to 2022. Interferogram of 81 ALOS 2 images.</p>
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<p>Time series land subsidence and DWNs (in liters) at the research location.</p>
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<p>Comparison of annual domestic water needs (DWNs) in the five administrative cities of Jakarta.</p>
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<p>Groundwater-free zone based on Governor Regulation Number 93 of 2021 with land subsidence rate/year (mm) in Jakarta with 81 scene baselines of ALOS PALSAR data and DWNs (in liters) during the acquisition period from 12 June 2017–06 June 2020.</p>
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<p>Zoning recommendation map for groundwater-free zones considering land subsidence and domestic water needs in Jakarta.</p>
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<p>The extent of recommended groundwater-free areas in Jakarta (Ha) based on land subsidence analysis and city-level water demand.</p>
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16 pages, 7077 KiB  
Article
A Variable-Threshold Segmentation Method for Rice Row Detection Considering Robot Travelling Prior Information
by Jing He, Wenhao Dong, Qingneng Tan, Jianing Li, Xianwen Song and Runmao Zhao
Agriculture 2025, 15(4), 413; https://doi.org/10.3390/agriculture15040413 - 15 Feb 2025
Viewed by 365
Abstract
Accurate rice row detection is critical for autonomous agricultural machinery navigation in complex paddy environments. Existing methods struggle with terrain unevenness, water reflections, and weed interference. This study aimed to develop a robust rice row detection method by integrating multi-sensor data and leveraging [...] Read more.
Accurate rice row detection is critical for autonomous agricultural machinery navigation in complex paddy environments. Existing methods struggle with terrain unevenness, water reflections, and weed interference. This study aimed to develop a robust rice row detection method by integrating multi-sensor data and leveraging robot travelling prior information. A 3D point cloud acquisition system combining 2D LiDAR, AHRS, and RTK-GNSS was designed. A variable-threshold segmentation method, dynamically adjusted based on real-time posture perception, was proposed to handle terrain variations. Additionally, a clustering algorithm incorporating rice row spacing and robot path constraints was developed to filter noise and classify seedlings. Experiments in dryland with simulated seedlings and real paddy fields demonstrated high accuracy: maximum absolute errors of 59.41 mm (dryland) and 69.36 mm (paddy), with standard deviations of 14.79 mm and 19.18 mm, respectively. The method achieved a 0.6489° mean angular error, outperforming existing algorithms. The fusion of posture-aware thresholding and path-based clustering effectively addresses the challenges in complex rice fields. This work enhances the automation of field management, offering a reliable solution for precision agriculture in unstructured environments. Its technical framework can be adapted to other row crop systems, promoting sustainable mechanization in global rice production. Full article
(This article belongs to the Section Digital Agriculture)
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<p>Schematic representation of acquisition process.</p>
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<p>Data pre-collection environment.</p>
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<p>Conversion from polar coordinates to Cartesian coordinates.</p>
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<p>Point cloud data pre-processing.</p>
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<p>Schematic diagram of automatic threshold setting. Note: red and blue solid lines indicate LiDAR scanning boundaries under different poses.</p>
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<p>Comparative analysis of the proposed variable-threshold method (the non-ground points are marked with red asterisks (*)).</p>
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<p>Comparative analysis of the proposed variable-threshold method on the weed-covered dataset.</p>
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<p>Center point extraction.</p>
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<p>Center point clustering.</p>
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<p>Experimental data collection platform and experimental environment.</p>
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<p>Seedling row detection experiments. Note: numbers 1–12 are indexes of RTK-GNSS measuring points.</p>
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<p>Seedling row detection experiments. Note: numbers 1–12 are indexes of RTK-GNSS measuring points.</p>
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21 pages, 4483 KiB  
Article
DEM Generation Incorporating River Channels in Data-Scarce Contexts: The “Fluvial Domain Method”
by Jairo R. Escobar Villanueva, Jhonny I. Pérez-Montiel and Andrea Gianni Cristoforo Nardini
Hydrology 2025, 12(2), 33; https://doi.org/10.3390/hydrology12020033 - 14 Feb 2025
Viewed by 741
Abstract
This paper presents a novel methodology to generate Digital Elevation Models (DEMs) in flat areas, incorporating river channels from relatively coarse initial data. The technique primarily utilizes filtered dense point clouds derived from SfM-MVS (Structure from Motion-Multi-View Stereo) photogrammetry of available crewed aerial [...] Read more.
This paper presents a novel methodology to generate Digital Elevation Models (DEMs) in flat areas, incorporating river channels from relatively coarse initial data. The technique primarily utilizes filtered dense point clouds derived from SfM-MVS (Structure from Motion-Multi-View Stereo) photogrammetry of available crewed aerial imagery datasets. The methodology operates under the assumption that the aerial survey was carried out during low-flow or drought conditions so that the dry (or almost dry) riverbed is detected, although in an imprecise way. Direct interpolation of the detected elevation points yields unacceptable river channel bottom profiles (often exhibiting unrealistic artifacts) and even distorts the floodplain. In our Fluvial Domain Method, channel bottoms are represented like “highways”, perhaps overlooking their (unknown) detailed morphology but gaining in general topographic consistency. For instance, we observed an 11.7% discrepancy in the river channel long profile (with respect to the measured cross-sections) and a 0.38 m RMSE in the floodplain (with respect to the GNSS-RTK measurements). Unlike conventional methods that utilize active sensors (satellite and airborne LiDAR) or classic topographic surveys—each with precision, cost, or labor limitations—the proposed approach offers a more accessible, cost-effective, and flexible solution that is particularly well suited to cases with scarce base information and financial resources. However, the method’s performance is inherently limited by the quality of input data and the simplification of complex channel morphologies; it is most suitable for cases where high-resolution geomorphological detail is not critical or where direct data acquisition is not feasible. The resulting DEM, incorporating a generalized channel representation, is well suited for flood hazard modeling. A case study of the Ranchería river delta in the Northern Colombian Caribbean demonstrates the methodology. Full article
(This article belongs to the Special Issue Hydrological Modeling and Sustainable Water Resources Management)
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<p>Study area: lower Ranchería River basin sector (green polygon), Riohacha (Colombia). The study reach focuses on the main channel from the “Aremasain” station to the branch named “Riito”.</p>
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<p>Dense vegetation context along the studied river reach.</p>
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<p>Deployment of GNSS-RTK points (gray dots) used for subsequent DEM adjustments from the photogrammetric process and validation (red triangles) of DSM/DEM products.</p>
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<p>Figure example shows a longitudinal channel profile (dashed red line) from the preliminary SfM-MVS DEM (without channel correction). Note the significant altimetric variability resulting from interpolation artifacts and the overestimation of the channel width due to the artificial lowering of the floodplain surface along the riverbanks. Flow direction is represented by the black arrow.</p>
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<p>General outline of the proposed method. The workflow starts with the input data at the bottom and culminates in the final product at the top, highlighting it as the process’s outcome: (1) Input data and preprocessing, (2) Elevation extraction from the preliminary DEM, (3) Bathymetric channel correction, and (4) Channel Integration with the preliminary DEM.</p>
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<p>Visualization of the error distribution and accuracy assessment of the digital models using histograms (<b>a</b>) and box plots (<b>b</b>). DSM as blue and DTM appears in yellow. Superimposed on the histogram are the expected normal distribution curves and white circles represents the outliers.</p>
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<p>Comparison between raw (blue) and smoothed elevation profiles of the channel obtained by SfM-MVS photogrammetry and the proposed method (red): (<b>a</b>) smoothed channel bottom, location of reference cross-sections and GNSS RTK observations (triangles); (<b>b</b>) refinement of the channel longitudinal profile using GNSS RTK adjustment in the last river reach (7 and 8). Purple boxes represent the cross-section location along the elevation profile.</p>
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<p>Comparison of the cross-sectional depth (h) geometry along the studied river (n = 8). Black lines represent depths estimated by the proposed method; purple lines represent reference (observed) depths.</p>
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<p>Comparison of maximum depths obtained from field measurements and estimated using the proposed method at eight reference cross-sections of the Ranchería River: (<b>a</b>) relative error and Mean Absolute Percentage Error (MAPE) analysis; (<b>b</b>) scatter plot showing the relationship between the observed and estimated depths. The solid black line represents the linear regression fit to the depths data (grey boxes), with the corresponding equation and R-squared value shown (dashed red line indicates perfect agreement).</p>
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18 pages, 4517 KiB  
Article
Running Parameter Analysis in 400 m Sprint Using Real-Time Kinematic Global Navigation Satellite Systems
by Keisuke Onodera, Naoto Miyamoto, Kiyoshi Hirose, Akiko Kondo, Wako Kajiwara, Hiroshi Nakano, Shunya Uda and Masaki Takeda
Sensors 2025, 25(4), 1073; https://doi.org/10.3390/s25041073 - 11 Feb 2025
Viewed by 529
Abstract
Accurate measurement of running parameters, including the step length (SL), step frequency (SF), and velocity, is essential for optimizing sprint performance. Traditional methods, such as 2D video analysis and inertial measurement units (IMUs), face limitations in precision and [...] Read more.
Accurate measurement of running parameters, including the step length (SL), step frequency (SF), and velocity, is essential for optimizing sprint performance. Traditional methods, such as 2D video analysis and inertial measurement units (IMUs), face limitations in precision and practicality. This study introduces and evaluates two methods for estimating running parameters using real-time kinematic global navigation satellite systems (RTK GNSS) with 100 Hz sampling. Method 1 identifies mid-stance phases via vertical position minima, while Method 2 aligns with the initial contact (IC) events through vertical velocity minima. Two collegiate sprinters completed a 400 m sprint under controlled conditions, with RTK GNSS measurements validated against 3D video analysis and IMU data. Both methods estimated the SF, SL, and velocity, but Method 2 demonstrated superior accuracy, achieving a lower RMSE (SF: 0.205 Hz versus 0.291 Hz; SL: 0.143 m versus 0.190 m) and higher correlation with the reference data. Method 2 also exhibited improved performance in curved sections and detected stride asymmetries with higher consistency than Method 1. These findings highlight RTK GNSS, particularly the velocity minima approach, as a robust, drift-free, single-sensor solution for detailed per-step sprint analysis in outdoor conditions. This approach offers a practical alternative to IMU-based methods and enables training optimization and performance evaluation. Full article
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<p>Experimental measurement system. (<b>A</b>) Athlete wearing the measurement system, including an RTK GNSS receiver, an antenna, and IMUs. (<b>B</b>) RTK GNSS receiver stored in a waist pack. (<b>C</b>) Head-mounted GNSS antenna set-up, with a triple-band helical antenna connected via an SMA cable. (<b>D</b>) IMUs attached above the ankles for <span class="html-italic">SF</span> validation, with an additional unit on the headgear for synchronization.</p>
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<p>GNSS-based step detection methods with IMU reference. A one-second snapshot of data from Subject A. The dashed vertical lines indicate camera-based IC. (<b>A</b>) Method 1 detected minima in vertical GNSS position (▽) near mid-stance. (<b>B</b>) Method 2 identified minima in vertical GNSS velocity (▼) aligned with IC. (<b>C</b>,<b>D</b>) Resultant accelerations from right and left foot IMUs, respectively, with asterisks (*) marking IC events. The grey line shows the raw data before applying the Butterworth filter.</p>
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<p>Comparison of GNSS-based methods (Method 1 and Method 2) versus camera-based measurements of <span class="html-italic">SF</span>, <span class="html-italic">SL</span>, and <span class="html-italic">running velocity</span>. (<b>A</b>–<b>C</b>) Scatter plots with the line of unity. (<b>D</b>–<b>F</b>) Bland–Altman plots showing <span class="html-italic">bias</span> and LOA. Data points are color-coded by subject: Subject A (blue circles) and Subject B (red squares). Overlapping data points appear darker due to transparency settings, visually indicating areas of higher data density.</p>
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<p>Comparison of GNSS-based methods (Method 1 and Method 2) versus IMU-derived <span class="html-italic">SF</span> in the 400 m sprint (left and right legs). (<b>A</b>,<b>B</b>) Scatter plots for Subject A (blue circles) and Subject B (red squares), with the <span class="html-italic">SF</span> for the left leg (<b>top</b>) and right leg (<b>bottom</b>) compared with the IMU-derived <span class="html-italic">SF</span>. (<b>C</b>,<b>D</b>) Corresponding Bland–Altman plots, indicating <span class="html-italic">bias</span> (solid line) and LOA (dashed lines). Overlapping data points appear darker due to transparency settings, visually indicating areas of higher data density.</p>
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<p>Comparison of GNSS-based methods (Method 1 and Method 2) with IMU-derived <span class="html-italic">SF</span> across curved and straight track sections. (<b>A</b>,<b>B</b>) Scatter plots for Subject A (blue circles) and Subject B (red squares), with data separated into curved (<b>top</b>) and straight (<b>bottom</b>) sections. (<b>C</b>,<b>D</b>) Bland–Altman plots indicating <span class="html-italic">bias</span> (solid line) and LOA (dashed lines). Overlapping data points appear darker due to transparency settings, visually indicating areas of higher data density.</p>
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<p>Step-by-step analysis of running parameters using RTK GNSS (Method 2) in a 400 m sprint. Panels show step-by-step changes in <span class="html-italic">running velocity</span>, <span class="html-italic">SF</span>, <span class="html-italic">SL</span>, and <span class="html-italic">elapsed time</span> for (<b>A</b>) Subject A (200 steps) and (<b>B</b>) Subject B (242 steps). The right steps are represented by filled circles (●), and the left steps are represented by open circles (○). Shaded areas for Subject A indicate periods in ‘Float’ solution, highlighting reduced GNSS accuracy.</p>
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22 pages, 13936 KiB  
Article
Multipath Effects Mitigation in Offshore Construction Platform GNSS-RTK Displacement Monitoring Using Parametric Temporal Convolution Network
by Yiyang Jiang, Cheng Guo, Jinfeng Wang and Rongqiao Xu
Remote Sens. 2025, 17(4), 601; https://doi.org/10.3390/rs17040601 - 10 Feb 2025
Viewed by 373
Abstract
The Global Navigation Satellite System (GNSS), renowned for its high precision and automation, has shone brightly in the deformation monitoring of offshore facilities and sea-crossing bridges. However, antennas placed in these locations are often subject to signal interference from various reflective surfaces, such [...] Read more.
The Global Navigation Satellite System (GNSS), renowned for its high precision and automation, has shone brightly in the deformation monitoring of offshore facilities and sea-crossing bridges. However, antennas placed in these locations are often subject to signal interference from various reflective surfaces, such as rivers and oceans, which significantly compromises observation accuracy and reliability. Synthesizing previous research, we first propose a method for multipath dataset construction, which involves GNSS observation linear combinations, detailed mapping of the near-field reflector, and employed static solution residuals as reference. Subsequently, we construct and train a corresponding para-TCN (parametric Temporal Convolution Network) to enable real-time prediction of multipath prediction. Through time domain and frequency domain analysis, it has been demonstrated that the trained network can capture the main features of multipath models and suppress those components in both the data distribution and frequency band, effectively mitigating the interference of multipath errors in observations. Full article
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<p>Geometry of an off-shore based GNSS antenna infected by possible multipath signals.</p>
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<p>Phase diagram of a multipath infected signal.</p>
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<p>The flowchart illustrating how trained network support the positioning process. GNSS observation would experience regular RTK resolution once to obtain current residuals to feed into networks, then those predicted multipath would serve as the correction to help mitigate multipath in current carrier phase residuals.</p>
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<p>Diagram of dataset construction, data processing and network training. Noted that the para-TCN sets are bunch of network identity in structure yet differed by the input dataset which utilized in network training. Here P.R. is short for pseudorange, Res. for residual, and C.P. for carrier phase. Geometric (near-field environment) segmentation is optional as marked with asterisk, and specific details can be found in <a href="#sec4-remotesensing-17-00601" class="html-sec">Section 4</a>.</p>
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<p>On the left displays a statistical representation the properties of collected data, with each horizontal axis representing a sequence and the vertical axis indicating its length, providing further insight into the concentration of GEO and IGSO satellite data. The right figure illustrates the comparison of total data volume for the corresponding categories.</p>
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<p>Detailed characterization of the offshore construction platform (multipath data acquisition site) and near-field environments of the GNSS base and rover stations. The platform’s pile foundation is anchored into bedrock, ensuring structural rigidity. The rover antenna is situated in a tidal zone where sea level fluctuations induce dynamic sea surface reflections. A functional relationship between satellite elevation and azimuth angles within sea surface reflection regions can be derived based on geometric constraints.</p>
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<p>The CWT diagram of the code multipath effect, wherein <math display="inline"><semantics> <mrow> <mi>h</mi> <mo>=</mo> <mn>10</mn> </mrow> </semantics></math> m and a constant reflection coefficient <math display="inline"><semantics> <mrow> <mi>α</mi> <mo>=</mo> <mn>0.01</mn> </mrow> </semantics></math>. The fundamental frequency of the multipath effect initiates at 0.029 Hz and decreases with an increasing elevation angle. Concurrently, the third harmonic component vanishes at medium elevation angles, while the second harmonic component disappears at high elevation angles.</p>
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<p>Network framework using parametric TCNs, where the input consists of observations and code multipath, while the output is a real-time prediction sequence for multipath signals. The detail of colored blocks could be referring to the right corner.</p>
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<p>The network’s suppression effect of sequence distribution of (<b>a</b>) a calculation example of local St.D. of carrier residual before and after mitigation (<b>b</b>) GPS MEO cases (<b>c</b>) Beidou MEO cases (<b>d</b>) Beidou IGSO case. The order of each sequence within the entire test set is indicated in the upper-left corner of the subplots, and the rate of distribution change is recorded above each plot.</p>
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<p>The network’s suppression effect of sequence distribution of (<b>a</b>) a calculation example of local St.D. of carrier residual before and after mitigation (<b>b</b>) GPS MEO cases (<b>c</b>) Beidou MEO cases (<b>d</b>) Beidou IGSO case. The order of each sequence within the entire test set is indicated in the upper-left corner of the subplots, and the rate of distribution change is recorded above each plot.</p>
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<p>The St.D. of the residual sequences before and after mitigation: All dataset. Each point in the graph represents St.D. of a case before (y-axis) and after (x-axis) mitigation, while the dashed line represents their linear fit. Therefore, the line slope indicates the percentage expectation of data correction achieved by the network.</p>
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<p>Power spectral density (PSD) of residual sequences before and after mitigation for (<b>a</b>) GPS MEO (<b>b</b>) Beidou MEO (<b>c</b>) Beidou IGSO satellites, while Pow. and Freq. are short for Power and Frequency, respectively. Data presents in the figure are identity with those of <a href="#remotesensing-17-00601-f009" class="html-fig">Figure 9</a>. As illustrated on the topside, each PSD has been locally enlarged for better visualization. Additionally, owing to variations in data distribution, the coordinate scales differ across the figures.</p>
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<p>A comparison of the average signal power across all datasets before and after mitigation, presented in a format consistent with <a href="#remotesensing-17-00601-f010" class="html-fig">Figure 10</a>. As a statistical representation of <a href="#remotesensing-17-00601-f011" class="html-fig">Figure 11</a>, the network demonstrates a significant ability to suppress the frequency bands affected by multipath (in quadratic form, the dominant frequencies become more pronounced).</p>
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<p>The number of observed epochs for all satellites recorded on 1 April 2023, and the proportion of these epochs that were corrected by the network.</p>
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<p>The ENU (East-North-Up) three-dimensional displacement for part of the data before and after network processing. The network’s suppression effect on data distribution is partially reflected in the mitigation of periodic component peaks.</p>
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<p>Skymap of the GNSS rover antenna. Area within the light blue shadowed area is the region affected by sea reflection, as shown in lower-left corner of <a href="#remotesensing-17-00601-f006" class="html-fig">Figure 6</a>.</p>
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<p>Diagram of the TCN-backbone architecture, using simplified parameters to represent the original sequence nodes utilized in computing the value of a single node in the output layer. Three input layers below contain identical input data, with color variations used to distinguish between different dilation rates.</p>
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29 pages, 4682 KiB  
Article
LSAF-LSTM-Based Self-Adaptive Multi-Sensor Fusion for Robust UAV State Estimation in Challenging Environments
by Mahammad Irfan, Sagar Dalai, Petar Trslic, James Riordan and Gerard Dooly
Machines 2025, 13(2), 130; https://doi.org/10.3390/machines13020130 - 9 Feb 2025
Viewed by 598
Abstract
Unmanned aerial vehicle (UAV) state estimation is fundamental across applications like robot navigation, autonomous driving, virtual reality (VR), and augmented reality (AR). This research highlights the critical role of robust state estimation in ensuring safe and efficient autonomous UAV navigation, particularly in challenging [...] Read more.
Unmanned aerial vehicle (UAV) state estimation is fundamental across applications like robot navigation, autonomous driving, virtual reality (VR), and augmented reality (AR). This research highlights the critical role of robust state estimation in ensuring safe and efficient autonomous UAV navigation, particularly in challenging environments. We propose a deep learning-based adaptive sensor fusion framework for UAV state estimation, integrating multi-sensor data from stereo cameras, an IMU, two 3D LiDAR’s, and GPS. The framework dynamically adjusts fusion weights in real time using a long short-term memory (LSTM) model, enhancing robustness under diverse conditions such as illumination changes, structureless environments, degraded GPS signals, or complete signal loss where traditional single-sensor SLAM methods often fail. Validated on an in-house integrated UAV platform and evaluated against high-precision RTK ground truth, the algorithm incorporates deep learning-predicted fusion weights into an optimization-based odometry pipeline. The system delivers robust, consistent, and accurate state estimation, outperforming state-of-the-art techniques. Experimental results demonstrate its adaptability and effectiveness across challenging scenarios, showcasing significant advancements in UAV autonomy and reliability through the synergistic integration of deep learning and sensor fusion. Full article
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<p>Proposed architecture for LSTM-based self-adaptive multi-sensor fusion (LSAF).</p>
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<p>An illustration of the proposed LSAF framework. The global estimator combines local estimations from various global sensors to achieve precise local accuracy and globally drift free pose estimation, which builds upon our previous work [<a href="#B28-machines-13-00130" class="html-bibr">28</a>].</p>
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<p>Proposed LSTM-based multi-sensor fusion architecture for UAV state estimation.</p>
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<p>LSTM cell architecture for adaptive multi-sensor fusion.</p>
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<p>Training and validation loss of the proposed LSTM-based self-adaptive multi-sensor fusion (LSAF) framework over 1000 epochs.</p>
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<p>Training and validation MAE of the proposed LSTM-based self-adaptive multi-sensor fusion (LSAF) framework over 1000 epochs.</p>
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<p>Proposed block diagram for LSTM-based self-adaptive multi-sensor fusion (LSAF).</p>
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<p>The experimental environment in different scenarios during the data collection. Panel (<b>a</b>,<b>b</b>) represent the UAV hardware along with sensor integration and panel (<b>c</b>,<b>d</b>) are the open-field dataset environment view from stereo and LiDAR sensors, respectively, which build upon our previous work [<a href="#B28-machines-13-00130" class="html-bibr">28</a>].</p>
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<p>Trajectory plots of the proposed LSAF method and comparison with FASTLIO2 and VINS-Fusion.</p>
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<p>Box plots showing the overall APE of each strategy.</p>
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<p>Absolute estimated position of x, y, and z axes showing plots of various methods on the UAV car parking dataset.</p>
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<p>Absolute position error of roll, yaw, and pitch showing the plots of various methods on the UAV car parking dataset.</p>
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<p>Trajectory plots of the proposed LSAF method and comparison with FASTLIO2 and VINS-Fusion on the UL outdoor handheld dataset.</p>
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<p>Box plots showing the overall APE of each strategy.</p>
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<p>Absolute estimated position of x, y, and z axes showing the plots of various methods on the UL outdoor handheld dataset.</p>
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<p>Absolute position error of roll, yaw, and pitch showing the plots of various methods on the UL outdoor handheld dataset.</p>
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<p>Trajectory plots of the proposed LSAF method and comparison with FASTLIO2 and VINS-Fusion.</p>
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<p>Absolute estimated position of the x, y, and z axes showing the plots of various methods on the UAV car bridge dataset.</p>
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<p>Absolute position error of roll, yaw, and pitch showing plots of various methods on the UAV car bridge dataset.</p>
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<p>Box plots showing the overall APE of each strategy.</p>
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15 pages, 2163 KiB  
Article
Electroporation Induces Unexpected Alterations in Gene Expression: A Tip for Selection of Optimal Transfection Method
by Taiji Hamada, Seiya Yokoyama, Toshiaki Akahane, Kei Matsuo, Ikumi Kitazono, Tatsuhiko Furukawa and Akihide Tanimoto
Curr. Issues Mol. Biol. 2025, 47(2), 91; https://doi.org/10.3390/cimb47020091 - 31 Jan 2025
Viewed by 584
Abstract
Electroporation is an efficient method for nucleotide and protein transfer, and is used for clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9)-mediated genome editing. In this study, we investigated the effects of electroporation on platelet-derived growth factor receptor alpha (PDGFRA [...] Read more.
Electroporation is an efficient method for nucleotide and protein transfer, and is used for clustered regularly interspaced short palindromic repeat (CRISPR)-associated protein 9 (Cas9)-mediated genome editing. In this study, we investigated the effects of electroporation on platelet-derived growth factor receptor alpha (PDGFRA) and receptor tyrosine kinase (RTK) expression in U-251 and U-87 MG cells. PDGFRA mRNA and protein expression decreased 2 days after electroporation in both cell lines, with recovery observed after 13 days in U-87 MG cells. However, in U-251 MG cells, PDGFRα expression remained suppressed, despite mRNA recovery after 13 days. Similar expression profiles were observed for lipofection in the U-251 MG cells. Comprehensive RNA sequencing confirmed electroporation-induced up- and down-regulation of RTK mRNA in U-251 MG cells 2 days post-electroporation. In contrast, recombinant adeno-associated virus (rAAV) transfected with mNeonGreen fluorescent protein or Cas9 did not affect PDGFRA, RTKs, or inflammatory cytokine expression, suggesting fewer adverse effects of rAAV on U-251 MG cells. These findings emphasize the need for adequate recovery periods following electroporation or the adoption of alternative methods, such as rAAV transfection, to ensure the accurate assessment of CRISPR-mediated gene editing outcomes. Full article
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<p>Effects of electroporation on <span class="html-italic">PDGFRA</span> mRNA and PDGFRα expression. (<b>A</b>) Effect of electroporation on <span class="html-italic">PDGFRA</span> mRNA expression in U-251 MG cells. (<b>B</b>) Upper panels: Representative images of the fluorescence in situ hybridization analysis of U-87 MG and HAP1 cells. A probe mix for <span class="html-italic">PDGFRA</span> (red arrows, BAC clone RP11-231C18) and CEP4 (green arrows) was used. Scale bar: 5 μm. Lower panel: <span class="html-italic">PDGFRA</span> and CEP4 signals were calculated by counting the number of signals from 30 cells. The CEP4 signal was used to determine chromosome copy number (ploidy status). The <span class="html-italic">PDGFRA</span>/CEP4 signal ratio was calculated using the following formula: signal ratio = (<span class="html-italic">PDGFRA</span> signal)/(CEP4 signal). (<b>C</b>,<b>D</b>) Effects of electroporation on <span class="html-italic">PDGFRA</span> mRNA (<b>C</b>) and PDGFRα (<b>D</b>) expression in U-251 MG, U-87 MG, and HAP1 cells. (<b>E</b>) Densitometric quantification of the Western blot results in <a href="#cimb-47-00091-f001" class="html-fig">Figure 1</a>D. (<b>F</b>,<b>G</b>) Effects of electroporation on <span class="html-italic">PDGFRA</span> mRNA (<b>F</b>) and PDGFRα (<b>G</b>) expression in U-251 MG cells. (<b>H</b>) Densitometric quantification of the Western blot results in <a href="#cimb-47-00091-f001" class="html-fig">Figure 1</a>G. (<b>I</b>) Cell proliferation was monitored after electroporation in U-251 MG cells using WST-8 assay. Values are presented as fold-increases over those on the day following seeding (n = 6). The day of electroporation was designated as Day 0. Quantitative data are represented as mean ± standard error. *, <span class="html-italic">p</span> &lt; 0.05; **, <span class="html-italic">p</span> &lt; 0.01; ***, <span class="html-italic">p</span> &lt; 0.001; n.s., not significant. <span class="html-italic">PDGFRA</span>, platelet-derived growth factor receptor alpha; EP, electroporation; CEP4, chromosome enumeration probe for chromosome 4.</p>
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<p>RNA-seq analysis of U-251 MG cells after electroporation. (<b>A</b>–<b>D</b>) Principal component analysis (<b>A</b>), k-means clustering analysis (<b>B</b>), and DEG analyses, (<b>C</b>,<b>D</b>) transcript counts derived from U-251 MG cells treated with or without electroporation using the iDEP application [<a href="#B17-cimb-47-00091" class="html-bibr">17</a>]. (<b>E</b>,<b>F</b>) Effects of electroporation on <span class="html-italic">RTK</span> mRNA (<b>E</b>) and protein (<b>F</b>) expression in U-251 MG cells. (<b>G</b>) Densitometric quantification of the Western blot results in (<b>F</b>). The day of electroporation was designated as Day 0. Quantitative data represented as mean ± standard error. *, <span class="html-italic">p</span> &lt; 0.05; **, <span class="html-italic">p</span> &lt; 0.01; ***, <span class="html-italic">p</span> &lt; 0.001; n.s., not significant. Rep1, Rep2, and Rep3 represent the three replicates. EP, electroporation.</p>
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<p>(<b>A</b>–<b>D</b>) Variation in <span class="html-italic">PDGFRA</span> mRNA expression after electroporation under various conditions (<b>A</b>) and lipofection (<b>C</b>) on Day 2 after transfection in U-251 MG cells. Editing activity (modification rate) after electroporation using modified conditions (<b>B</b>) and lipofection (<b>D</b>) on Day 2 after transfection in U-251 MG cells. The modification rate was calculated as the number of reads with modifications (insertion, deletion, and substitution) divided by the number of total reads measured via NGS. (<b>E</b>,<b>F</b>) Effects of lipofection on <span class="html-italic">PDGFRA</span> mRNA (<b>E</b>) and PDGFRα (<b>F</b>) expression in U-251 MG cells. (<b>G</b>) Densitometric quantification of the Western blot results in (<b>F</b>); (<b>H</b>) Effects of lipofection on <span class="html-italic">RTK</span> mRNA expression 2 days after transfection in U-251 MG cells. The day of transfer (electroporation and lipofection) was designated as Day 0. Quantitative data are presented as mean ± standard error. *, <span class="html-italic">p</span> &lt; 0.05; **, <span class="html-italic">p</span> &lt; 0.01; ***, <span class="html-italic">p</span> &lt; 0.001; n.s., not significant.</p>
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<p>(<b>A</b>) <span class="html-italic">PDGFRA</span> mRNA expression on Day 2 after rAAV transfection in U-251 MG cells. (<b>B</b>) Editing activity (modification rate) on Day 2 in U-251 MG cells. The modification rate is calculated as the number of reads with modifications (insertion, deletion, and substitution)/number of total reads measured by NGS. (<b>C</b>) Effects of rAAV infection on <span class="html-italic">RTK</span> mRNA expression in U-251 MG cells. (<b>D</b>,<b>E</b>) Effects of infection with mNeonGreen (mNG) fluorescent protein-expressing rAAV on <span class="html-italic">PDGFRA</span> and <span class="html-italic">RTK</span> mRNA expression in U-251 MG cells. The day of rAAV infection was designated as Day 0. Quantitative data are represented as mean ± standard error. ***, <span class="html-italic">p</span> &lt; 0.001; n.s., not significant.</p>
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<p>RNA-seq analysis after rAAV transduction in U-251 MG cells. (<b>A</b>–<b>D</b>) Principal component (<b>A</b>), k-means clustering (<b>B</b>), and DEG analyses (<b>C</b>,<b>D</b>) for transcript counts derived from U-251 MG cells treated with or without rAAV infection using iDEP [<a href="#B17-cimb-47-00091" class="html-bibr">17</a>]. (<b>E</b>) Effects of rAAV infection on mRNA expression of immune-related genes in U-251 MG cells. The day of rAAV infection was designated as Day 0. Quantitative data are presented as mean ± standard error. **, <span class="html-italic">p</span> &lt; 0.01; n.s., not significant. Rep1, Rep2, and Rep3 represent the three replicates.</p>
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29 pages, 15780 KiB  
Article
Assessing Lightweight Folding UAV Reliability Through a Photogrammetric Case Study: Extracting Urban Village’s Buildings Using Object-Based Image Analysis (OBIA) Method
by Junyu Kuang, Yingbiao Chen, Zhenxiang Ling, Xianxin Meng, Wentao Chen and Zihao Zheng
Drones 2025, 9(2), 101; https://doi.org/10.3390/drones9020101 - 29 Jan 2025
Viewed by 583
Abstract
With the rapid advancement of drone technology, modern drones have achieved high levels of functional integration, alongside structural improvements that include lightweight, compact designs with foldable features, greatly enhancing their flexibility and applicability in photogrammetric applications. Nevertheless, limited research currently explores data collected [...] Read more.
With the rapid advancement of drone technology, modern drones have achieved high levels of functional integration, alongside structural improvements that include lightweight, compact designs with foldable features, greatly enhancing their flexibility and applicability in photogrammetric applications. Nevertheless, limited research currently explores data collected by such compact UAVs, and whether they can balance a small form factor with high data quality remains uncertain. To address this challenge, this study acquired the remote sensing data of a peri-urban area using the DJI Mavic 3 Enterprise and applied Object-Based Image Analysis (OBIA) to extract high-density buildings. It was found that this drone offers high portability, a low operational threshold, and minimal regulatory constraints in practical applications, while its captured imagery provides rich textural details that clearly depict the complex surface features in urban villages. To assess the accuracy of the extraction results, the visual comparison between the segmentation outputs and airborne LiDAR point clouds captured by the DJI M300 RTK was performed, and classification performance was evaluated based on confusion matrix metrics. The results indicate that the boundaries of the segmented objects align well with the building edges in the LiDAR point cloud. The classification accuracy of the three selected algorithms exceeded 80%, with the KNN classifier achieving an accuracy of 91% and a Kappa coefficient of 0.87, which robustly demonstrate the reliability of the UAV data and validate the feasibility of the proposed approach in complex cases. As a practical case reference, this study is expected to promote the wider application of lightweight UAVs across various fields. Full article
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<p>Framework of This Study.</p>
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<p>Overview of the Study Area: (<b>a</b>) Location of Guangzhou Higher Education Mega Center within Guangzhou City; (<b>b</b>) DOM of Guangzhou Higher Education Mega Center; (<b>c</b>) DOM of Beiting Village. Images (<b>b</b>) and (<b>c</b>) were sourced from remote sensing imagery collected by the research team using a fixed-wing UAV, with a resolution of 0.2 m.</p>
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<p>Mavic 3 Enterprise with RTK Module stored in portable case, including six batteries, charging components, and spare parts.</p>
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<p>DJI M300 RTK Equipped with GreenValley LiAir X3-H LiDAR System.</p>
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<p>Flight path planning on DJI Pilot 2.</p>
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<p>MRS Workflow Diagram.</p>
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<p>Overall DOM and Local Detail of the Study Area.</p>
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<p>Overall DSM and Local Comparison of the Study Area.</p>
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<p>Overall VDVI and Local Comparison of the Study Area.</p>
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<p>Overall LAS and Local Detail of the Study Area.</p>
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<p>Determination of Shape and Compactness Using the Control Variable Method: (<b>a</b>) Shape Set to 0.7; (<b>b</b>) Compactness Set to 0.8.</p>
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<p>ESP2 Results.</p>
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<p>Scale Set to 320.</p>
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<p>Comparison of MRS results with hybrid visualization of LAS, (<b>a</b>–<b>d</b>) illustrate the comparison results of four different high-density building areas.</p>
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<p>Results of Building Extraction Using K-Nearest Neighbor (KNN) Method.</p>
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<p>Ground-based LiDAR Equipment and Point Cloud Data: (<b>a</b>) GreenValley LiGirp H120 handheld LiDAR scanning device; (<b>b</b>) Overlay of airborne and handheld point cloud data, with the highlighted point cloud in the yellow box representing the range of data captured by the ground-based LiDAR.</p>
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<p>Cross-sectional Views of a Same Location: (<b>a</b>) Airborne point cloud data slope map; (<b>b</b>) Handheld LiDAR point cloud data slope map, with the red box highlighting the narrow alley where data acquisition is challenging.</p>
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17 pages, 6296 KiB  
Article
Tracking Long-Distance Systematic Trajectories of Different Robot Mower Patterns with Enhanced Custom-Built Software
by Sofia Matilde Luglio, Christian Frasconi, Lorenzo Gagliardi, Michele Raffaelli, Andrea Peruzzi, Stefano Pieri, Marco Volterrani, Simone Magni and Marco Fontanelli
AgriEngineering 2025, 7(2), 30; https://doi.org/10.3390/agriengineering7020030 - 28 Jan 2025
Viewed by 547
Abstract
Sustainable turfgrass management is essential for maintaining healthy and visually appealing green spaces. Autonomous mowers have emerged as an innovative solution, but the efficiency and quality of mowing operations depend on several factors. This study investigates the impact of mowing patterns and cutting [...] Read more.
Sustainable turfgrass management is essential for maintaining healthy and visually appealing green spaces. Autonomous mowers have emerged as an innovative solution, but the efficiency and quality of mowing operations depend on several factors. This study investigates the impact of mowing patterns and cutting heights on the performance of an autonomous mower through updated custom-built software. Three different mowing patterns (vertical, diagonal, and horizontal) and two cutting heights (3 cm and 6 cm) were analyzed to analyze mowing efficiency, coverage, and cutting uniformity. The vertical pattern emerged as the most effective, maximizing speed (0.52 m/s) and efficiency (0.77), while minimizing overlap (4.27 cm) and uncut areas (0.014 m2). In contrast, the horizontal and diagonal patterns showed lower efficiency (0.71 and 0.76) and less coverage percentage (97.05% and 96.71%) compared to the vertical pattern (98.57%). Cutting height influenced performance, with higher heights sometimes requiring adjustments to prevent inefficiencies. The interaction between the mowing pattern and cutting height was critical for optimizing both operational efficiency and cutting quality. These findings highlight the importance of selecting an appropriate mowing pattern and cutting height tailored to the specific operational goals. Full article
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<p>(<b>a</b>) The rover fixed on the robot mower while it is cutting one of the areas; (<b>b</b>) the base station collocated outside the working area.</p>
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<p>New software functionality: gap between points, gap between passages, automatic analysis of cutting activity. The red dot indicates that the real time function is not active, when this function is active the dot becomes green. The green dots indicate the rover waypoints as recorded by the RTK system.</p>
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<p>Real-time window where it possible to visualize the robot position and working trajectories. In the figure it is possible to observe the progress of the robot mower trajectories (horizontal trajectories) coverage in real time. The red areas represent the trajectories of the robot mower as time passes.</p>
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<p>(<b>a</b>) Effect of pattern on the turfgrass height. (<b>b</b>) Effect of the interaction between cutting height (indicated in the figure as “height”) and pattern on turfgrass height. Means denoted by different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.05 (LSD test), these letters are located above the upper confidence limit. LCL (Lower Confidence Limit) and UCL (Upper Confidence Limit) are reported. p1: vertical pattern with the lowest cutting height; p2: vertical pattern with the highest cutting height; p3: horizontal pattern with the lowest cutting height; p4: horizontal pattern with the highest cutting height; p5: diagonal pattern with the lowest cutting height; p6: diagonal pattern with the highest cutting height. D: diagonal pattern; H: horizontal pattern; V: vertical pattern.</p>
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<p>(<b>a</b>) Effect of pattern on the percentage of area covered. (<b>b</b>) Effect of the interaction between cutting height (indicated in the figure as “height”) and pattern on percentage of area covered. Means denoted by different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.05 (LSD test), these letters are located above the upper confidence limit. LCL (Lower Confidence Limit) and UCL (Upper Confidence Limit) are reported. p1: vertical pattern with the lowest cutting height; p2: vertical pattern with the highest cutting height; p3: horizontal pattern with the lowest cutting height; p4: horizontal pattern with the highest cutting height; p5: diagonal pattern with the lowest cutting height; p6: diagonal pattern with the highest cutting height. D: diagonal pattern; H: horizontal pattern; V: vertical pattern.</p>
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<p>Colorimetric maps showing the number of passages and the trajectories of the autonomous mower different patterns with the lowest cutting height: (<b>a</b>) vertical, (<b>b</b>) horizontal, (<b>c</b>) diagonal. Darker areas mean higher trampling. Green areas within the cutting areas, are the zones did not trample by the autonomous mower.</p>
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<p>Colorimetric maps showing the number of passages and the trajectories of the autonomous mower different patterns with the highest cutting height: (<b>a</b>) vertical, (<b>b</b>) horizontal, (<b>c</b>) diagonal. Darker areas mean higher trampling. Green areas within the cutting areas, are the zones did not trample by the autonomous mower.</p>
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<p>Local magnification of areas characterized by (<b>a</b>) a higher trampling level zone and no cut turning area (horizontal pattern with the highest cutting height), (<b>b</b>) no cut turning area (diagonal pattern with the highest cutting height), (<b>c</b>) no cut area in the linear trajectory of diagonal pattern (diagonal pattern with the highest cutting height), (<b>d</b>) area characterized by higher trampling level and overlapping (diagonal pattern with the lowest cutting height). Details of each type of area (<b>a</b>–<b>d</b>) are highlighted by yellow rectangles. On the right, the colorimetric scale of the colorimetric map is shown, the color near to the max value means a high level of trampling activity and the correlated number of passages.</p>
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<p>(<b>a</b>) Effect of pattern on the distance travelled. (<b>b</b>) Effect of the interaction between cutting height (indicated in the figure as “height”) and pattern on distance travelled. Means denoted by different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.05 (LSD test), these letters are located above the upper confidence limit. LCL (Lower Confidence Limit) and UCL (Upper Confidence Limit) are reported. p1: vertical pattern with the lowest cutting height; p2: vertical pattern with the highest cutting height; p3: horizontal pattern with the lowest cutting height; p4: horizontal pattern with the highest cutting height; p5: diagonal pattern with the lowest cutting height; p6: diagonal pattern with the highest cutting height. D: diagonal pattern; H: horizontal pattern; V: vertical pattern.</p>
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<p>(<b>a</b>) Effect of pattern on efficiency. (<b>b</b>) Effect of the interaction between cutting height (indicated in the figure as “height”) and pattern on efficiency. Means denoted by different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.05 (LSD test), these letters are located above the upper confidence limit. LCL (Lower Confidence Limit) and UCL (Upper Confidence Limit) are reported. p1: vertical pattern with the lowest cutting height; p2: vertical pattern with the highest cutting height; p3: horizontal pattern with the lowest cutting height; p4: horizontal pattern with the highest cutting height; p5: diagonal pattern with the lowest cutting height; p6: diagonal pattern with the highest cutting height. D: diagonal pattern; H: horizontal pattern; V: vertical pattern.</p>
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<p>(<b>a</b>) Effect of pattern on speed. (<b>b</b>) Effect of the pattern on speed. Means denoted by different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.05 (LSD test), these letters are located above the upper confidence limit. LCL (Lower Confidence Limit) and UCL (Upper Confidence Limit) are reported. D: diagonal pattern; H: horizontal pattern; V: vertical pattern.</p>
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<p>(<b>a</b>) Effect of pattern on overlapping. (<b>b</b>) Effect of the interaction between cutting height (indicated in the figure as “height”) and pattern on overlapping. Means denoted by different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.05 (LSD test) these letters are located above the upper confidence limit. LCL (Lower Confidence Limit) and UCL (Upper Confidence Limit) are reported. p1: vertical pattern with the lowest cutting height; p2: vertical pattern with the highest cutting height; p3: horizontal pattern with the lowest cutting height; p4: horizontal pattern with the highest cutting height; p5: diagonal pattern with the lowest cutting height; p6: diagonal pattern with the highest cutting height. D: diagonal pattern; H: horizontal pattern; V: vertical pattern.</p>
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<p>Effect of the interaction between cutting height (indicated in the figure as “height”) and pattern on no cut area at the end of each row. Means denoted by different letters indicate statistically significant differences at <span class="html-italic">p</span> &lt; 0.05 (LSD test), these letters are located above the upper confidence limit. LCL (Lower Confidence Limit) and UCL (Upper Confidence Limit) are reported. p1: vertical pattern with the lowest cutting height; p2: vertical pattern with the highest cutting height; p3: horizontal pattern with the lowest cutting height; p4: horizontal pattern with the highest cutting height; p5: diagonal pattern with the lowest cutting height; p6: diagonal pattern with the highest cutting height.</p>
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25 pages, 6632 KiB  
Article
Estimating Winter Wheat Canopy Chlorophyll Content Through the Integration of Unmanned Aerial Vehicle Spectral and Textural Insights
by Huiling Miao, Rui Zhang, Zhenghua Song and Qingrui Chang
Remote Sens. 2025, 17(3), 406; https://doi.org/10.3390/rs17030406 - 24 Jan 2025
Viewed by 602
Abstract
Chlorophyll content is an essential parameter for evaluating the growth condition of winter wheat, and its accurate monitoring through remote sensing is of great significance for early warnings about winter wheat growth. In order to investigate unmanned aerial vehicle (UAV) multispectral technology’s capability [...] Read more.
Chlorophyll content is an essential parameter for evaluating the growth condition of winter wheat, and its accurate monitoring through remote sensing is of great significance for early warnings about winter wheat growth. In order to investigate unmanned aerial vehicle (UAV) multispectral technology’s capability to estimate the chlorophyll content of winter wheat, this study proposes a method for estimating the relative canopy chlorophyll content (RCCC) of winter wheat based on UAV multispectral images. Concretely, an M350RTK UAV with an MS600 Pro multispectral camera was utilized to collect data, immediately followed by ground chlorophyll measurements with a Dualex handheld instrument. Then, the band information and texture features were extracted by image preprocessing to calculate the vegetation indices (VIs) and the texture indices (TIs). Univariate and multivariate regression models were constructed using random forest (RF), backpropagation neural network (BPNN), kernel extremum learning machine (KELM), and convolutional neural network (CNN), respectively. Finally, the optimal model was utilized for spatial mapping. The results provided the following indications: (1) Red-edge vegetation indices (RIs) and TIs were key to estimating RCCC. Univariate regression models were tolerable during the flowering and filling stages, while the superior multivariate models, incorporating multiple features, revealed more complex relationships, improving R² by 0.35% to 69.55% over the optimal univariate models. (2) The RF model showed notable performance in both univariate and multivariate regressions, with the RF model incorporating RIS and TIS during the flowering stage achieving the best results (R²_train = 0.93, RMSE_train = 1.36, RPD_train = 3.74, R²_test = 0.79, RMSE_test = 3.01, RPD_test = 2.20). With more variables, BPNN, KELM, and CNN models effectively leveraged neural network advantages, improving training performance. (3) Compared to using single-feature indices for RCCC estimation, the combination of vegetation indices and texture indices increased from 0.16% to 40.70% in the R² values of some models. Integrating UAV multispectral spectral and texture data allows effective RCCC estimation for winter wheat, aiding wheatland management, though further work is needed to extend the applicability of the developed estimation models. Full article
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<p>An overview of the experimental area: (<b>a</b>) the geographic location of the study area; (<b>b</b>) the UAV image and sampling points; (<b>c</b>) the planting varieties and fertilization conditions in the experimental field. Note: In (<b>a</b>), the gray area represents Xianyang City, the blue area represents Qian County, and the red points indicate the study area. In (<b>b</b>), yellow points represent sampling locations. In (<b>c</b>), the blue area represents the ‘Xinmai 40’ variety, the green area represents the ‘Xinong 889’ variety, and the yellow area represents the ‘Xiaoyan 22’ variety. N0, N1, N2, N3, N4, and N5 represent six nitrogen fertilization gradients: 0, 60, 90, 120, 160, and 240 kg/ha, respectively.</p>
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<p>The correlation heatmap of the texture features constituting TIs at the heading stage. Note: (<b>a</b>–<b>c</b>), respectively, represent the correlation heatmaps between the texture features that constitute the DTI, RTI, and NDTI. In each image, mean, var, hom, con, dis, ent, sm, and corr represent the following texture features: mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment, and correlation, respectively. The numbers 1, 2, 3, 4, 5, and 6 represent the blue band (centered at 450 nm), green band (centered at 555 nm), red band (centered at 660 nm), red-edge band (centered at 720 nm), red-edge band (centered at 750 nm), and near-infrared band (centered at 840 nm), respectively.</p>
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<p>The univariate regression models of RCCC. (<b>a</b>) The univariate regression models for RCCC at the heading stage; (<b>b</b>) the univariate regression models for RCCC at the flowering stage; (<b>c</b>) the univariate regression models for RCCC at the filling stage. Note: In each figure, the green bars represent the R² values for the training set, the brown bars represent the R² values for the testing set, the solid yellow pentagrams represent the RPD values for the training set, the hollow yellow pentagrams represent the RPD values for the testing set, the solid red squares represent the RMSE values for the training set, and the hollow red squares represent the RMSE values for the testing set. Numbers 1 to 18 successively represent the input parameters: NPCI, VDVI, NDVI, GNDVI, GCI, SR, MSR, RESR<sub>720</sub>, RESR<sub>750</sub>, LCI<sub>720</sub>, LCI<sub>750</sub>, NDRE<sub>720</sub>, NDRE<sub>750</sub>, RECI<sub>720</sub>, RECI<sub>750</sub>, DTI, RTI, and NDTI.</p>
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<p>The multivariate regression models of RCCC based on VIs, RIs, and TIs. (<b>a</b>) The multivariate regression models for RCCC at the heading stage; (<b>b</b>) the multivariate regression models for RCCC at the flowering stage; (<b>c</b>) the multivariate regression models for RCCC at the filling stage. Note: In each figure, the green bars represent the R² values for the training set, the brown bars represent the R² values for the testing set, the solid yellow pentagrams represent the RPD values for the training set, the hollow yellow pentagrams represent the RPD values for the testing set, the solid red squares represent the RMSE values for the training set, and the hollow red squares represent the RMSE values for the testing set. Numbers 1 to 18 successively represent the input parameters: NPCI, VDVI, NDVI, GNDVI, GCI, SR, MSR, RESR<sub>720</sub>, RESR<sub>750</sub>, LCI<sub>720</sub>, LCI<sub>750</sub>, NDRE<sub>720</sub>, NDRE<sub>750</sub>, RECI<sub>720</sub>, RECI<sub>750</sub>, DTI, RTI, and NDTI.</p>
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<p>The multivariate regression models of RCCC based on VIs+TIs and RIs+TIs. (<b>a</b>) The multivariate regression models for RCCC at the heading stage; (<b>b</b>) the multivariate regression models for RCCC at the flowering stage; (<b>c</b>) the multivariate regression models for RCCC at the filling stage. Note: In each figure, the green bars represent the R² values for the training set, the brown bars represent the R² values for the testing set, the solid yellow pentagrams represent the RPD values for the training set, the hollow yellow pentagrams represent the RPD values for the testing set, the solid red squares represent the RMSE values for the training set, and the hollow red squares represent the RMSE values for the testing set. Numbers 1 to 18 successively represent the input parameters: NPCI, VDVI, NDVI, GNDVI, GCI, SR, MSR, RESR<sub>720</sub>, RESR<sub>750</sub>, LCI<sub>720</sub>, LCI<sub>750</sub>, NDRE<sub>720</sub>, NDRE<sub>750</sub>, RECI<sub>720</sub>, RECI<sub>750</sub>, DTI, RTI, and NDTI.</p>
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<p>The spatial distribution maps of RCCC during heading, flowering, and filling stages. (<b>a</b>) The spatial distribution map of RCCC at the heading stage; (<b>b</b>) the spatial distribution map of RCCC at the flowering stage; (<b>c</b>) the spatial distribution map of RCCC at the filling stage.</p>
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<p>The correlation heatmaps of the texture features constituting TIs at the flowering stage. Note: (<b>a</b>–<b>c</b>), respectively, represent the correlation heatmaps between the texture features that constitute the DTI, RTI, and NDTI. In each image, mean, var, hom, con, dis, ent, sm, and corr represent the following texture features: mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment, and correlation, respectively. The numbers 1, 2, 3, 4, 5, and 6 represent the blue band (centered at 450 nm), green band (centered at 555 nm), red band (centered at 660 nm), red-edge band (centered at 720 nm), red-edge band (centered at 750 nm), and near-infrared band (centered at 840 nm), respectively.</p>
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<p>The correlation heatmaps of the texture features constituting TIs at the filling stage. Note: (<b>a</b>–<b>c</b>), respectively, represent the correlation heatmaps between the texture features that constitute the DTI, RTI, and NDTI. In each image, mean, var, hom, con, dis, ent, sm, and corr represent the following texture features: mean, variance, homogeneity, contrast, dissimilarity, entropy, second moment, and correlation, respectively. The numbers 1, 2, 3, 4, 5, and 6 represent the blue band (centered at 450 nm), green band (centered at 555 nm), red band (centered at 660 nm), red-edge band (centered at 720 nm), red-edge band (centered at 750 nm), and near-infrared band (centered at 840 nm), respectively.</p>
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15 pages, 6022 KiB  
Review
A Bibliometric Analysis of Geological Hazards Monitoring Technologies
by Zhengyao Liu, Jing Huang, Yonghong Li, Xiaokang Liu, Fei Qiang and Yiping He
Sustainability 2025, 17(3), 962; https://doi.org/10.3390/su17030962 - 24 Jan 2025
Viewed by 540
Abstract
This study systematically analyzed research trends and hot issues in the field of geological hazard prediction using bibliometric analysis methods. A total of 12,123 related articles published from 1976 to 2023 were retrieved from the Web of Science (WOS) and China National Knowledge [...] Read more.
This study systematically analyzed research trends and hot issues in the field of geological hazard prediction using bibliometric analysis methods. A total of 12,123 related articles published from 1976 to 2023 were retrieved from the Web of Science (WOS) and China National Knowledge Infrastructure (CNKI) databases. Co-occurrence analysis and burst detection were conducted on the literature using the VOSviewer and CiteSpace tools to identify the research trends in geological hazard monitoring technologies. The results reveal that “data fusion”, “landslide identification”, “deep learning”, and “risk early warning” are currently the main research hot spots. Additionally, the combined application of Global Navigation Satellite System (GNSS) and Real-Time Kinematic (RTK) technologies, as well as GNSS and Long Short-Term Memory (LSTM) models, were identified as important directions for future research. The bibliometric perspective offers a systematic theoretical framework and technical guidance for future research, thereby facilitating the sustainable advancement of safety, security, and disaster management. Full article
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<p>Distribution of publications and citations in the field of geological hazards detection research from 1976 to 2023.</p>
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<p>The top 10 research institutions by publication volume.</p>
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<p>Burst occurrence analysis of related publishing institutions.</p>
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<p>Relationship chart of AI and AAI publication volume for the top 10 provinces from 2010 to 2023. (<b>a</b>) Beijing and Sichuan; (<b>b</b>) Hebei and Shaanxi; (<b>c</b>) Hunan and Gansu (<b>d</b>) Chongqing and Zhejiang; (<b>e</b>) first quadrant point count chart.</p>
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<p>Systematic map of keywords.</p>
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<p>Keyword burst map of geological hazards prediction field.</p>
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<p>Components of a database-based multi-source data-driven intelligent geological hazards warning system.</p>
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<p>Correlation analysis of intelligent geological hazards warning based on multi-source data-driven components.</p>
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<p>Co-occurrence analysis centered on GNSS.</p>
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<p>Co-occurrence analysis of geological hazards based on literature database.</p>
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19 pages, 7788 KiB  
Article
Research on Outdoor Navigation of Intelligent Wheelchair Based on a Novel Layered Cost Map
by Jianwei Cui, Siji Yu, Yucheng Shang, Yuxiang Dai and Wenyi Zhang
Actuators 2025, 14(2), 46; https://doi.org/10.3390/act14020046 - 22 Jan 2025
Viewed by 535
Abstract
With the aging of the population and the increase in the number of people with disabilities, intelligent wheelchairs are essential in improving travel autonomy and quality of life. In this paper, we propose an autonomous outdoor navigation framework for intelligent wheelchairs based on [...] Read more.
With the aging of the population and the increase in the number of people with disabilities, intelligent wheelchairs are essential in improving travel autonomy and quality of life. In this paper, we propose an autonomous outdoor navigation framework for intelligent wheelchairs based on hierarchical cost maps to address the challenges of wheelchair navigation in complex and dynamic outdoor environments. First, the framework integrates multi-sensors such as RTK high-precision GPS, IMU, and 3D LIDAR; fuses RTK, IMU, and odometer data to realize high-precision positioning; and performs path planning and obstacle avoidance through dynamic hierarchical cost maps. Secondly, the drivable area layer is integrated into the traditional hierarchical cost map, in which the drivable area detection algorithm utilizes local plane fitting and elevation difference analysis to achieve efficient ground point cloud segmentation and real-time updating, which ensures the real-time safety of navigation. The experiments are validated in real outdoor scenes and simulation environments, and the results show that the speed of drivable region detection is about 30 ms, the positioning accuracy of wheelchair outdoor navigation is less than 10 cm, and the distance of active obstacle avoidance is 1 m. This study provides an effective solution for the autonomous navigation of the intelligent wheelchair in a complex outdoor environment, and it has a high robustness and application potential. Full article
(This article belongs to the Topic Advances in Mobile Robotics Navigation, 2nd Volume)
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<p>Intelligent wheelchair system architecture design. The multimode perception layer integrates a variety of sensor data and is responsible for environment perception and obstacle detection, providing the necessary real-time environmental information for autonomous navigation; the autonomous navigation layer is accountable for path planning and decision-making based on the environment perception information and scheduling the execution of the motion control layer; the communication transmission layer is accountable for realizing data exchange between different components according to the agreed communication protocol; the physical layer is the foundation layer of the whole system, which mainly includes Hardware components of the wheelchair.</p>
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<p>Intelligent wheelchair and sensor installation position.</p>
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<p>Intelligent wheelchair outdoor navigation software architecture, where the red arrows represent the transfer of data, the black arrows represent the role of the function packages, and the blue arrows represent the interaction between the hardware and the data.</p>
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<p>RTK localization architecture diagram.</p>
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<p>Schematic of LiDAR spherical coordinate system. This is a 16-line LiDAR with a horizontal field of view of 360°, a vertical field of view of 30°, a horizontal angular resolution of 1°, and a vertical angular resolution of 2°.</p>
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<p>Schematic of ground point screening based on PCA local ground fitting.</p>
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<p>The red box shows the processing of the point cloud. Firstly, the environmental point cloud data are collected by LiDAR. The point cloud is ground segmented, elevated points are extracted, and a raster of the drivable area is calculated, which is then imported into the hierarchical cost map. The green box shows the updating process of each layer of the hierarchical cost map, and the updating order is from bottom to top. Firstly, the static map is imported to initialize the cost map as shown in (<b>a</b>); the blue grid appears on the static map layer, indicating the static obstacles on the map; then, the LiDAR detects the environmental obstacles, and the obstacle layer is updated as shown in (<b>b</b>). The blue grid appears on the obstacle layer, indicating the static obstacles and the dynamic obstacles detected by the LiDAR. Then, the drivable area is updated based on the imported drivable area raster layer shown in (<b>c</b>). The orange grid indicates the calculated drivable area grid and the blue grid indicates the drivable area boundary and its rear area; finally, the expansion layer is updated according to the detected obstacles by expanding the map, as shown in (<b>d</b>). The gray grid indicates the expansion layer, which enables the wheelchair to stay away from obstacles during path planning; up to this point, the cost map has been completely updated, and the layers are merged into a complete total cost map. (<b>e</b>) The map is updated in real time, and the right blue grid changes position to indicate dynamic obstacle movement.</p>
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<p>Schematic diagram of the target point and wheelchair path planning movement.</p>
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<p>Intelligent wheelchair drivable area detection results.</p>
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<p>Drivable area layered cost map experiment: (<b>a</b>) an accurate picture, (<b>b</b>) the actual point cloud data collected, and (<b>c</b>) cost map, where the white part of the raster has a surrogate value of 0, and the black part represents the non-drivable area which is the layer of the drivable area, the light blue part is the obstacle layer, and the red part is the expansion layer.</p>
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<p>Outdoor path planning experiment. (<b>a</b>) Schematic diagram of the path planning of the Gaode map, and (<b>b</b>) path planning after ROS receives the first target point, the red points are laser points processed by the ground point cloud segmentation algorithm.</p>
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<p>Outdoor path planning experiment. (<b>a</b>) Illustration of obstacles in the actual scene, and (<b>b</b>) cost map and path planning in the presence of obstacles.</p>
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22 pages, 1785 KiB  
Review
MET Activation in Lung Cancer and Response to Targeted Therapies
by Sarah Anna Okun, Daniel Lu, Katherine Sew, Asha Subramaniam and William W. Lockwood
Cancers 2025, 17(2), 281; https://doi.org/10.3390/cancers17020281 - 16 Jan 2025
Viewed by 1303
Abstract
The hepatocyte growth factor receptor (MET) is a receptor tyrosine kinase (RTK) that mediates the activity of a variety of downstream pathways upon its activation. These pathways regulate various physiological processes within the cell, including growth, survival, proliferation, and motility. Under normal physiological [...] Read more.
The hepatocyte growth factor receptor (MET) is a receptor tyrosine kinase (RTK) that mediates the activity of a variety of downstream pathways upon its activation. These pathways regulate various physiological processes within the cell, including growth, survival, proliferation, and motility. Under normal physiological conditions, this allows MET to regulate various development and regenerative processes; however, mutations resulting in aberrant MET activity and the consequent dysregulation of downstream signaling can contribute to cellular pathophysiology. Mutations within MET have been identified in a variety of cancers and have been shown to mediate tumorigenesis by increasing RTK activity and downstream signaling. In lung cancer specifically, a number of patients have been identified as possessing MET alterations, commonly receptor amplification (METamp) or splice site mutations resulting in loss of exon 14 (METex14). Due to MET’s role in mediating oncogenesis, it has become an attractive clinical target and has led to the development of various targeted therapies, including MET tyrosine kinase inhibitors (TKIs). Unfortunately, these TKIs have demonstrated limited clinical efficacy, as patients often present with either primary or acquired resistance to these therapies. Mechanisms of resistance vary but often occur through off-target or bypass mechanisms that render downstream signaling pathways insensitive to MET inhibition. This review provides an overview of the therapeutic landscape for MET-positive cancers and explores the various mechanisms that contribute to therapeutic resistance in these cases. Full article
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<p>Structural organization of MET. The extracellular region is made up of the semaphorin (SEMA) domain, the plexin-semaphorin-integrin (PSI) domain, and four immunoglobulin-plexin-transcription (IPT) domains, which facilitate ligand binding and receptor dimerization. The intracellular region contains the juxtamembrane domain, the kinase domain, and the C-terminal docking site; these regions are involved in the regulation of MET activity and the activation of downstream signaling cascades. Receptor activation occurs upon the binding of hepatocyte growth factor (HGF), resulting in receptor dimerization and a series of transphosphorylation events.</p>
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<p>Frequency of MET alterations in solid cancer types. Alterations include mutations, copy number alterations, and structural variants (including fusions). Data from MSK-CHORD (MSK, Nature 2024) [<a href="#B25-cancers-17-00281" class="html-bibr">25</a>].</p>
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<p>MET alterations observed in cancer. (<b>A</b>) SEMA domain mutations (e.g., N375S) decrease MET’s ligand affinity and increase HER2 heterodimerization. (<b>B</b>) MET fusions result in the loss of ligand binding and regulatory domains, resulting in increased signaling activity. (<b>C</b>) Kinase domain mutations (e.g., M1268T and Y1248H) lead to constitutive kinase activity. (<b>D</b>) Skipping of exon 14 impairs MET degradation, leading to increased half-life and signaling activity. (<b>E</b>) Amplification results in elevated MET levels and activity within the cell.</p>
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<p>MET signaling facilitates various processes that contribute to pathogenesis. Activated MET leads to the activation of the PI3K and MAPK pathways, which promote cell proliferation and survival. MET is also able to activate FAK and CRK, resulting in greater cell motility and invasion.</p>
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