bluuebunny/crossref_metadata_2025 huggingface dataset:
Research Progress with Atractylone as an Antitumor Agent
Authors: Yao Ying , Shen Guanghuan , Luo Jianghan , Wang Jinhong , Xu Zheng , Wang Hao , Cui Linlin
Published: November 2024

Atractylone is a sesquiterpenoid compound extracted from Rhizoma Atractylodis. As one of the main active components in the volatile oil of the Atractylodes genus, it has exhibited certain therapeutic effects, including anti-inflammatory, antiviral, antioxidant, antiallergic, antiangiogenic, and neuroprotective activities, among others. With further research on the chemical constituents and pharmacology of sesquiterpenes, research on the antitumor activity of Atractylone has also been further expanded. Much of the current literature pays particular attention to the antitumor activity of Atractylone, which was found to inhibit the apoptosis of tumor cells and prevent growth, invasion, and migration through different apoptosis pathways and signaling pathways. Due to its promising potential for cancer prevention, it may play a role in reducing the incidence of malignant tumors. In this paper, the antitumor activity and mechanism of Atractylone are reviewed, providing a reference to inform future research on the tumor treatment, clinical application, and further development and utilization of this plant genus.
Functional Olive Oil Production via Emulsions: Evaluation of Phenolic Encapsulation Efficiency, Storage Stability, and Bioavailability
Authors: Montoro-Alonso Sandra , Duque-Soto Carmen , Rueda-Robles Ascensión , Reina-Manuel José , Quirantes-Piné Rosa , Borrás-Linares Isabel , Lozano-Sánchez Jesús
Published: November 2024

Background/Objectives: Olive oil is valued for its health benefits, largely due to its bioactive compounds, including hydroxytyrosol (HTyr) and oleuropein (OLE), which have antioxidant, anti-inflammatory, and cardioprotective properties. However, many of these compounds are lost during the production process. This study developed a functional olive oil-derived product using water-in-oil emulsions (W/O) to incorporate commercial extracts rich in HTyr and OLE. Methods: HTyr and OLE were encapsulated in a W/O emulsion to preserve their bioactivity. The encapsulation efficiency (EE) was evaluated, and the performance of the emulsion was tested using an in vitro gastrointestinal digestion model. Bioaccessibility was measured by calculating the recovery percentage of HTyr and OLE during the digestion stages. Results: The results showed that OLE exhibited higher EE (88%) than HTyr (65%). During digestion, HTyr exhibited a gradual and controlled release, with bioaccessibility exceeding 80% in the gastric phase and a maintained stability throughout the intestinal phase. In contrast, OLE displayed high bioaccessibility in the gastric phase but experienced a notable decrease during the intestinal phase. Overall, the W/O emulsion provided superior protection and stability for both compounds, particularly for the secoiridoids, compared to the non-emulsified oil. Conclusions: The W/O emulsion improved the encapsulation and bioaccessibility of HTyr and OLE, constituting a promising method for enriching olive oil with bioactive phenolic compounds. Therefore, this method could enhance olive oil’s health benefits by increasing the availability of these bioactive compounds during digestion, offering the potential for the development of fortified foods.
Results from a Cross-Sectional Observational Study Examining Irritable Bowel Syndrome Patients Six Months After Finishing Their Participation in the ViIBS Trial
Authors: Sommermeyer Henning , Chmielowiec Krzysztof , Bernatek Malgorzata , Olszewski Pawel , Kopczynski Jaroslaw , Piątek Jacek
Published: November 2024

Background/Objectives. A recent clinical (ViIBS) trial investigating the effects of a balanced multi-strain synbiotic in irritable bowel syndrome (IBS) patients showed that twelve weeks of treatment resulted in significant improvements across all major IBS symptoms. The current observational study pursued three aims: investigate patients’ attitude towards the intake of pro- or synbiotics during the six months after finishing their trial participation, determine the severity of IBS symptoms, and assess IBS diagnosis scores. Methods. During a single six-month follow-up examination, patients were asked about the intake of probiotics or synbiotics. For the study, former placebo-group patients who abstained from taking probiotics were compared with synbiotic-group patients who continued taking the tested synbiotic. IBS symptom severity was assessed with the IBS—Severity of Symptoms Scale and the IBS diagnosis score with the IBS questionnaire of the World Gastroenterology Organisation. Results. The control group comprised 17 patients (out of 70 from the placebo group participating in the follow-up) and the treatment group 75 (out of 91 examined). IBS symptom severity was significantly lower in the treatment group (23.5 ± 33.1) than in the placebo group (232.6 ± 35.1). IBS diagnosis scores were 5.9 ± 2.5 and 21.2 ± 2.0 in the treatment and control group, respectively. Conclusions. Measurement values for the treatment group indicate the absence of IBS. The results indicate that the prolonged administration of the balanced multi-strain synbiotic can potentially reduce IBS symptom severity and IBS diagnosis scores to levels indicating the absence of IBS, an observation to be followed up in a controlled clinical trial.
Movement Behaviors and Bone Biomarkers in Young Pediatric Cancer Survivors: A Cross-Sectional Analysis of the iBoneFIT Project
Authors: Gil-Cosano Jose J. , Ubago-Guisado Esther , Llorente-Cantarero Francisco J. , Marmol-Perez Andres , Rodriguez-Solana Andrea , Pascual-Gazquez Juan F. , Mateos Maria E. , Molina-Hurtado Jose R. , Garcia-Fontana Beatriz , Narciso Pedro Henrique , Klentrou Panagiota , Gracia-Marco Luis
Published: November 2024

Background/Objectives: This study aims to investigate the association of movement behaviors with irisin, sclerostin, and bone turnover markers in young pediatric cancer survivors. Methods: A total of 116 young pediatric cancer survivors (12.1 ± 3.3 years; 42% female) were recruited. Time spent in movement behaviors over at least seven consecutive 24 h periods was measured by accelerometers (wGT3x-BT accelerometer, ActiGraph). Blood samples were collected at rest and serum was analyzed for irisin, sclerostin, cross-linked telopeptide of type I collagen (CTX), procollagen type I amino-terminal propeptide (P1NP), total osteocalcin (OC), alkaline phosphatase (ALP), 25-hydroxyvitamin D, parathyroid hormone (PTH), calcium, phosphorous, and magnesium. Results: Irisin and sclerostin were not significantly correlated with bone turnover markers. Sedentary time was negatively correlated with the P1NP (r = −0.411, p = 0.027) and total OC (r = −0.479, p = 0.015) Z-scores, whereas moderate-to-vigorous physical activity was positively correlated with the P1NP (r = 0.418, p = 0.024) and total OC (r = 0.478, p = 0.016) Z-scores. Moreover, total physical activity was positively correlated with the total OC Z-score (r = 0.448, p = 0.025). Finally, the uncoupling index [CTX/P1NP] was positively correlated with sedentary time (r = 0.424, p = 0.012) and negatively correlated with light physical activity (r = −0.352, 0.041). Conclusions: Reducing sedentary time and increasing physical activity may favor bone formation over resorption in young pediatric cancer survivors.
Nicotinamide Riboside Ameliorates Fructose-Induced Lipid Metabolism Disorders in Mice by Activating Browning of WAT, and May Be Also Related to the Regulation of Gut Microbiota
Authors: Zhang Huaqi , Zhao Xuenuo , Zhang Li , Sun Dan , Ma Yanzhen , Bai Yixian , Bai Xue , Liang Xi , Liang Hui
Published: November 2024

Objectives: This study aims to observe the preventive effect of nicotinamide riboside (NR) on fructose-induced lipid metabolism disorders and explore its mechanism. Methods: Male C57BL/6J mice were fed a 20% fructose solution and given 400 mg/kg NR daily by gavage for 10 weeks. Results: The results indicated that NR supplementation significantly reduced the body weight, liver weight, white adipose tissue (WAT) weight, serum, and hepatic lipid levels. NR upregulated the protein expression levels of sirtuin-1 (SIRT1), AMP-activated protein kinase (AMPK), PR domain containing 16 (PRDM16), uncoupling protein 1 (UCP1), peroxisome proliferator-activated receptor-gamma coactiva-tor-1-alpha (PGC-1α), nuclear respiratory factor 1-encoding gene (NRF1), mitochondrial transcription factor A (TFAM), cluster of differentiation 137 (CD137), transmembrane protein 26 (TMEM26), and T-box 1 (TBX1). Moreover, NR enhanced the Actinobacteria and Enterorhabdus abundance. Spearman’s correlation analysis revealed that significant correlations exist between Firmicutes, Bacteroidetes, and Erysipelotrichaceae with browning-related indicators. Conclusions: In conclusion, NR could alleviate lipid metabolic abnormalities induced by fructose through activating SIRT1/AMPK-mediated browning of WAT. The mechanism by which NR improves fructose-induced lipid metabolism disorders may also be associated with the modulation of intestinal flora.
Switching Mediterranean Consumers to Mediterranean Sustainable Healthy Dietary Patterns (SWITCHtoHEALTHY): Study Protocol of a Multicentric and Multi-Cultural Family-Based Nutritional Intervention Study
Authors: Calderón-Pérez Lorena , Domingo Alícia , Bas Josep , Gutiérrez Biotza , Crescenti Anna , Rahmani Djamel , Sarroca Amèlia , Gil José , Goumeida Kenza , Zhang Jin Tianyu , Güldaş Metin , Demir Çağla , Hamdouchi Asmaa , Gymnopoulos Lazaros , Dimitropoulos Kosmas , Degli Innocenti Perla , Rosi Alice , Scazzina Francesca , Petri Eva , Urtasun Leyre , Salvio Giuseppe , Feld Marco , Boqué Noemi
Published: November 2024

Background/Objectives: Populations in Mediterranean countries are abandoning the traditional Mediterranean diet (MD) and lifestyle, shifting towards unhealthier habits due to profound cultural and socioeconomic changes. The SWITCHtoHEALTHY project aims to demonstrate the effectiveness of a multi-component nutritional intervention to improve the adherence of families to the MD in three Mediterranean countries, thus prompting a dietary behavior change. Methods: A parallel, randomized, single-blinded, and controlled multicentric nutritional intervention study will be conducted over 3 months in 480 families with children and adolescents aged 3–17 years from Spain, Morocco, and Turkey. The multi-component intervention will combine digital interactive tools, hands-on educational materials, and easy-to-eat healthy snacks developed for this study. Through the developed SWITCHtoHEALTHY app, families will receive personalized weekly meal plans, which also consider what children eat at school. The engagement of all family members will be prompted by using a life simulation game. In addition, a set of activities and educational materials for adolescents based on a learning-through-playing approach will be codesigned. Innovative and sustainable plant-based snacks will be developed and introduced into the children’s dietary plan as healthy alternatives for between meals. By using a full-factorial design, families will be randomized into eight groups (one control and seven interventions) to test the independent and combined effects of each component (application and/or educational materials and/or snacks). The impact of the intervention on diet quality, economy, and the environment, as well as on classical anthropometric parameters and vital signs, will be assessed in three different visits. The COM-B behavioral model will be used to assess essential factors driving the behavior change. The main outcome will be adherence to the MD assessed through MEDAS in adults and KIDMED in children and adolescents. Conclusions: SWITCHtoHEALTHY will provide new insights into the use of sustained models for inducing dietary and lifestyle behavior changes in the family setting. It will facilitate generating, boosting, and maintaining the switch to a healthier MD dietary pattern across the Mediterranean area. Registered Trial, National Institutes of Health, ClinicalTrials.gov (NCT06057324).
Contributions of Fat and Fatty Acids Intake to the Latin American Diet: Results of ELANS Study
Authors: Cortés Sanabria Lilia Yadira , Herrera-Cuenca Marianella , Yépez García Martha Cecilia , Hernández Pablo , Ramírez Guillermo , Vásquez Maura , Sifontes Yaritza , Liria-Domínguez María Reyna , Rigotti Attilio , Fisberg Mauro , Previdelli Agatha Nogueira , Kovalskys Irina , Landaeta-Jiménez Maritza , Gómez Georgina
Published: November 2024

Background/Objectives: Fats, although essential for the proper functioning of the body, have been linked to an increased risk of developing chronic diseases, especially cardiovascular disease. The aim of this study was to evaluate the intake of total fat and its components (saturated, monounsaturated, polyunsaturated, and trans fats) in men and women aged 15 to 65 years of the urban population in eight Latin American countries. Methods: Survey data were collected from the Latin American Study of Nutrition and Health (ELANS, by its acronym in Spanish), an epidemiological study, including 9218 subjects from Argentina, Brazil, Chile, Colombia, Costa Rica, Ecuador, Peru, and Venezuela. Results: In general, 76.2% of the subjects consumed fat within normal ranges (20–35% of the total caloric value (TCV)). When analyzing its components, a majority of the subjects consumed saturated and polyunsaturated fats within the recommended ranges. However, 94.5% of the population does not comply with the recommended maximum intake of monounsaturated fatty acids (MUFA) (10–20%), and only 57.5% comply with the intake recommendation for trans fatty acids (TRANS) (0–2%). Likewise, on average, women had a significantly higher intake of all types of fat compared to men. Finally, the average fat intake by age indicates that regardless of the age range, the consumption of all fats except MUFA and TRANS are within the recommended ranges, with MUFA being slightly below and TRANS above. Conclusions: Even though the fat intake of the population falls within the recommended range, it is necessary to improve the quality by favoring the consumption of MUFA-rich foods regionally accepted, such as avocados, and reducing the consumption of TRANS.
Ultra-Processed Food Consumption and Cardiometabolic Risk Factors in Children Living in Northeastern Brazil
Authors: Silva-Luis Cristiane Cosmo , Lopes Mariana Souza , Gomes Sávio Marcelino , Cantalice Matias Palloma Karlla , Brandini Fernando Paiva , Costa Paulo César Trindade , de Moraes Rúbia Cartaxo Squizato , Baccin Martins Vinícius José , de Brito Alves José Luiz
Published: November 2024

Objective: To analyze the association between ultra-processed food (UPF) consumption and cardiometabolic, biochemical, and inflammatory risk factors in children in a metropolis in Northeast Brazil. Methods: A cross-sectional study using baseline data from a community-based controlled trial was carried out with 151 children from public schools in João Pessoa, Paraíba, Brazil aged 7 to 10 years. Dietary consumption was assessed using 24 h food recall, and UPF consumption was estimated using the NOVA classification system. Anthropometry (BMI for age), blood pressure, biochemical parameters (ALT, AST, GGT, cholesterol, LDL-c, HDL-c, triglycerides, fasting glucose, HbA1c, HOMA-IR, creatinine, urea, hs-CRP), and cytokines (IL-2, IL-4, IL-6, IL-10, IL-17a, IFN-γ, and TNF-α) were also assessed. Results: Children in the third tertile (highest UPF consumption) had higher serum concentrations of LDL-c (p-value = 0.04) and ALT (p-value = 0.01), with a trend towards higher AST (p-value = 0.06). Total energy (p-value = 0.01), trans fatty acid (p-value = 0.02), and sodium (p-value = 0.04) intakes were higher in the highest tertile, whereas protein (p-value < 0.01) and fiber (p-value < 0.01) intakes were lower. Concentrations of IL-17A (p-value = 0.01) and IL-10 (p-value = 0.04) were significantly higher in the second tertile. Multiple linear regression showed that UPF consumption was significantly associated with increased LDL-c, ALT, and AST concentrations. Conclusions: High intake of UPFs was associated with dyslipidemia, elevated liver enzymes, and inflammatory changes in children. Dietary interventions are needed to reduce UPF consumption and prevent cardiometabolic and liver disease in childhood.
Evaluation of the Potential of Novel Co-Processed Excipients to Enable Direct Compression and Modified Release of Ibuprofen
Authors: Aleksić Ivana , Glišić Teodora , Ćirin-Varađan Slobodanka , Djuris Mihal , Djuris Jelena , Parojčić Jelena
Published: November 2024

Background/Objectives: Improving the production rates of modern tablet presses places ever greater demands on the performance of excipients. Although co-processing has emerged as a promising solution, there is still a lack of directly compressible excipients for modified-release formulations. The aim of the present study was to address this issue by investigating the potential of novel co-processed excipients for the manufacture of modified-release tablets containing ibuprofen. Methods: The excipients were prepared by melt granulation of lactose monohydrate with glyceryl palmitostearate as a binder. The influence of glyceryl palmitostearate particle size, ibuprofen content, compression pressure, and compression speed on the compaction behavior of the tablet blends was analyzed. Results: Novel co-processed excipients ensured good flowability and acceptable mechanical properties of the tablets containing up to 70% ibuprofen. Furthermore, lipid-based co-processed excipients proved to be very promising for directly compressible formulations with high-dose, highly adhesive active pharmaceutical ingredients such as ibuprofen, as they do not require additional lubricants. The influence of compression speed on the tensile strength of the tablets prepared was not pronounced, indicating the robustness of these directly compressible excipients. The investigated lipid-based excipients enabled a prolonged release of ibuprofen over 10 h. Conclusions: The novel lipid-based co-processed excipients have shown great potential for directly compressible formulations with modified release of high-dose, challenging active pharmaceutical ingredients.
Assessing the Host Range of Ophraella communa for the Biological Control of Ambrosia artemisiifolia in France
Authors: Rousset Zoé , Zamprogna Alberto , Jaworski Coline C. , Desneux Nicolas , Lesieur Vincent
Published: November 2024

Ambrosia artemisiifolia is a well-known invasive species in Europe, causing health issues with its extremely allergenic pollen and yield loss through competition in agriculture. One potential biological control agent is Ophraella communa, accidentally introduced in Europe in 2013. This species was discovered in France in 2023, but before planning further mass releases for biological control, it is necessary to assess its safety for agricultural crops and local plant biodiversity. Prior to its first detection in France, we conducted a host-range study of the beetle in a confined laboratory with no-choice and choice tests for 16 plant species, selected based on the centrifugal phylogenetic method. Results showed a restricted host range to the Heliantheae tribe and minimal risk to indigenous European plant species, with no larval survival and barely any eggs laid on these plants. Choice tests also showed a strong preference of O. communa for A. artemisiifolia. Our results combined with previous studies and observations in the field in other countries suggest a low risk to sunflower, Helianthus annuus, which is an important crop in France. This confirms that O. communa could be a low-risk biological control agent that can be used in classical biological control programs against A. artemisiifolia in France.
Deep Learning Model Size Performance Evaluation for Lightning Whistler Detection on Arase Satellite Dataset
Authors: Suarjaya I Made Agus Dwi , Putri Desy Purnami Singgih , Tanaka Yuji , Purnama Fajar , Bayupati I Putu Agung , Linawati  , Kasahara Yoshiya , Matsuda Shoya , Miyoshi Yoshizumi , Shinohara Iku
Published: November 2024

The plasmasphere within Earth’s magnetosphere plays a crucial role in space physics, with its electron density distribution being pivotal and strongly influenced by solar activity. Very Low Frequency (VLF) waves, including whistlers, provide valuable insights into this distribution, making the study of their propagation through the plasmasphere essential for predicting space weather impacts on various technologies. In this study, we evaluate the performance of different deep learning model sizes for lightning whistler detection using the YOLO (You Only Look Once) architecture. To achieve this, we transformed the entirety of raw data from the Arase (ERG) Satellite for August 2017 into 2736 images, which were then used to train the models. Our approach involves exposing the models to spectrogram diagrams—visual representations of the frequency content of signals—derived from the Arase Satellite’s WFC (WaveForm Capture) subsystem, with a focus on analyzing whistler-mode plasma waves. We experimented with various model sizes, adjusting epochs, and conducted performance analysis using a partial set of labeled data. The testing phase confirmed the effectiveness of the models, with YOLOv5n emerging as the optimal choice due to its compact size (3.7 MB) and impressive detection speed, making it suitable for resource-constrained applications. Despite challenges such as image quality and the detection of smaller whistlers, YOLOv5n demonstrated commendable accuracy in identifying scenarios with simple shapes, thereby contributing to a deeper understanding of whistlers’ impact on Earth’s magnetosphere and fulfilling the core objectives of this study.
Damage Detection and Segmentation in Disaster Environments Using Combined YOLO and Deeplab
Authors: Jo So-Hyeon , Woo Joo , Kang Chang Ho , Kim Sun Young
Published: November 2024

Building damage due to various causes occurs frequently and has risk factors that can cause additional collapses. However, it is difficult to accurately identify objects in complex structural sites because of inaccessible situations and image noise. In conventional approaches, close-up images have been used to detect and segment damage images such as cracks. In this study, the method of using a deep learning model is proposed for the rapid determination and analysis of multiple damage types, such as cracks and concrete rubble, in disaster sites. Through the proposed method, it is possible to perform analysis by receiving image information from a robot explorer instead of a human, and it is possible to detect and segment damage information even when the damaged point is photographed at a distance. To accomplish this goal, damage information is detected and segmented using YOLOv7 and Deeplabv2. Damage information is quickly detected through YOLOv7, and semantic segmentation is performed using Deeplabv2 based on the bounding box information obtained through YOLOv7. By using images with various resolutions and senses of distance for training, damage information can be effectively detected not only at short distances but also at long distances. When comparing the results, depending on how YOLOv7 and Deeplabv2 were used, they returned better scores than the comparison model, with a Recall of 0.731, Precision of 0.843, F1 of 0.770, and mIoU of 0.638, and had the lowest standard deviation.
Multiscale Spatiotemporal Variation Analysis of Regional Water Use Efficiency Based on Multifractals
Authors: Zhao Tong , Wang Yanan , Zhang Yulu , Wang Qingyun , Wu Penghai , Yang Hui , He Zongyi , Li Junli
Published: November 2024

Understanding the complex variations in water use efficiency (WUE) is critical for optimizing agricultural productivity and resource management. Traditional analytical methods often fail to capture the nonlinear and multiscale variations inherent in WUE, where multifractal theory offers distinct advantages. Given its limited application in WUE studies, this paper analyzes the spatiotemporal characteristics and influencing factors of the WUE in Anhui Province from 2001 to 2022 using a multifractal, multiscale approach. The results indicated that the WUE exhibited significant interannual variation, peaking in summer, especially in August (2.4552 gC·mm−1·m−2), with the monthly average showing an inverted “V” shape. Across different spatial and temporal scales, the WUE displayed clear multifractal characteristics. Temporally, the variation in fractal features between years was not prominent, while inter-seasonal variation was most complex in August during summer. Spatially, the most distinct multifractal patterns were observed in hilly and mountainous areas, particularly in regions with brown soil distribution. Rainfall was identified as the primary natural driver influencing regional WUE changes. This study aims to promote the sustainable use of water resources while ensuring the stability of agricultural production within protected farmlands.
EDWNet: A Novel Encoder–Decoder Architecture Network for Water Body Extraction from Optical Images
Authors: Zhang Tianyi , Ji Wenbo , Li Weibin , Qin Chenhao , Wang Tianhao , Ren Yi , Fang Yuan , Han Zhixiong , Jiao Licheng
Published: November 2024

Automated water body (WB) extraction is one of the hot research topics in the field of remote sensing image processing. To address the challenges of over-extraction and incomplete extraction in complex water scenes, we propose an encoder–decoder architecture semantic segmentation network for high-precision extraction of WBs called EDWNet. We integrate the Cross-layer Feature Fusion (CFF) module to solve difficulties in segmentation of WB edges, utilizing the Global Attention Mechanism (GAM) module to reduce information diffusion, and combining with the Deep Attention Module (DAM) module to enhance the model’s global perception ability and refine WB features. Additionally, an auxiliary head is incorporated to optimize the model’s learning process. In addition, we analyze the feature importance of bands 2 to 7 in Landsat 8 OLI images, constructing a band combination (RGB 763) suitable for algorithm’s WB extraction. When we compare EDWNet with various other semantic segmentation networks, the results on the test dataset show that EDWNet has the highest accuracy. EDWNet is applied to accurately extract WBs in the Weihe River basin from 2013 to 2021, and we quantitatively analyzed the area changes of the WBs during this period and their causes. The results show that EDWNet is suitable for WB extraction in complex scenes and demonstrates great potential in long time-series and large-scale WB extraction.
Full-Aperture Reflective Remote Fourier Ptychography with Sample Matching
Authors: Wang Dayong , Meng Jiahao , Zhao Jie , Wang Renyuan , Wang Yunxin , Rong Lu , Lin Shufeng , Li Ling
Published: November 2024

Fourier ptychography (FP) can break through the limitations of existing optical systems with a single aperture and realize large field-of-view (FOV) and high-resolution (HR) imaging simultaneously by aperture synthesis in the frequency domain. The method has potential applications for remote sensing and space-based imaging. However, the aperture stop of the imaging system was generally set to be much smaller than the system with an adjustable diaphragm, so it failed to make full use of the imaging capability of the system. In this paper, a reflective remote FP with full aperture is proposed, and the optical aperture of the camera is set to be the maximum according to the sample-matching condition, which can further improve the imaging resolution by exploring the whole capability of the system. Firstly, the physical model of the remote FP is established using oblique illumination of a convergent spherical wave. Then, the sampling characteristics of the low-resolution (LR) intensity image are analyzed. Assuming diffraction-limited imaging, the size of the aperture of the optical system needs to match the sampling of the detector. An experimental setup with an imaging distance of 2.4 m is built, and a series of LR images is collected by moving the camera for the diffused samples, including the USAF resolution test target and the banknote, where the diameter of the single aperture is set to the maximum to match the size of the CCD pixel under the practical minimum F# of the camera of 2.8. The high-resolution image is reconstructed by applying the iterative phase retrieval algorithm. The experimental results show that the reconstructed resolution is improved to 2.5×. This verifies that remote FP with full aperture can effectively improve the imaging resolution using only the present single-aperture optical system.
Polarisation Synthesis Applied to 3D Polarimetric Imaging for Enhanced Buried Object Detection and Identification
Authors: Forster Samuel J. I. , Peyton Anthony J. , Podd Frank J. W. , Davidson Nigel
Published: November 2024

Detecting sub-surface objects poses significant challenges, partly due to attenuation of the ground medium and cluttered environments. The acquisition polarisation and antenna orientation can also yield significant variation of detection performance. These challenges can be mitigated by developing more versatile systems and algorithms to enhance detection and identification. In this study, a novel application of a 3D SAR inverse algorithm and polarisation synthesis was applied to ultra-wideband polarimetric data of buried objects. The principle of polarisation synthesis facilitates an adaptable technique which can be used to match the target’s polarisation characteristics, and the application of this revealed hidden structures, enhanced detection, and increased received power when compared to single polarisation results. This study emphasises the significance of polarimetry in ground-penetrating radar (GPR), particularly for target discrimination in high-lift-off applications. The findings offer valuable insights that could drive future research and enhance the performance of these sensing systems.
Influence of Land Use and Land Cover Changes and Precipitation Patterns on Groundwater Storage in the Mississippi River Watershed: Insights from GRACE Satellite Data
Authors: Dash Padmanava , Shekhar Sushant , Paul Varun , Feng Gary
Published: November 2024

Growing human demands are placing significant pressure on groundwater resources, causing declines in many regions. Identifying areas where groundwater levels are declining due to human activities is essential for effective resource management. This study investigates the influence of land use and land cover, crop types, and precipitation patterns on groundwater level trends across the Mississippi River Watershed (MRW), USA. Groundwater storage changes from 2003 to 2015 were estimated using data from the Gravity Recovery and Climate Experiment (GRACE) satellite mission. A spatiotemporal analysis was conducted at four scales: the entire MRW, groundwater regimes based on groundwater level change rates, 31 states within the MRW, and six USGS hydrologic unit code (HUC)-2 watersheds. The results indicate that the Lower Mississippi region experienced the fastest groundwater decline, with a Sen’s slope of −0.07 cm/year for the mean equivalent water thickness, which was attributed to intensive groundwater-based soybean farming. By comparing groundwater levels with changes in land use, crop types, and precipitation, trends driven by human activities were identified. This work underscores the ongoing relevance of GRACE data and the GRACE Follow-On mission, launched in 2018, which continues to provide vital data for monitoring groundwater storage. These insights are critical for managing groundwater resources and mitigating human impacts on the environment.
Dynamic Expansion and Merging of the Equatorial Ionization Anomaly During the 10–11 May 2024 Super Geomagnetic Storm
Authors: Aa Ercha , Chen Yanhong , Luo Bingxian
Published: November 2024

This study investigates the responses of the equatorial and low-latitude ionosphere in the American–Atlantic longitude sector during the super geomagnetic storm that occurred on 10–11 May 2024. The investigation utilizes multi-instrument datasets, including ground-based observations (GNSS TEC, ionosonde, and Fabry–Perot interferometer) as well as space-borne satellite measurements (GOLD, Swarm, DMSP, and TIMED). Our findings reveal significant day-to-day variations in the storm-time equatorial ionization anomaly (EIA), summarized as follows: (1) During the main phase of the storm, the low- and mid-latitude ionosphere experienced a positive storm, with TEC drastically enhanced by 50–100% within a few hours. The EIA crests exhibited a substantial poleward expansion, reaching as high as ±35° MLAT. This expansion was caused by the enhanced fountain effect driven by penetration electric fields, along with increased ambipolar diffusion due to transient meridional wind surges. (2) During the recovery phase of the storm, the global ionosphere was characterized by a substantial negative storm with a 50–80% depletion in TEC. The EIA crests were notably suppressed and merged into a single equatorial band, which can be attributed to the composition change effect and the influence of disturbance dynamo electric fields. These results illustrate the complex processes of magnetosphere–ionosphere–thermosphere coupling during a superstorm, highlighting the significant impacts of space weather on the global ionosphere.
A Spaceborne Passive Localization Algorithm Based on MSD-HOUGH for Multiple Signal Sources
Authors: Zhang Liting , Huan Hao , Ran Tao , Zhang Shangyu , Zhang Yushu , Ding Hao
Published: November 2024

Recently, the passive synthetic aperture (PSA) technique has been used in passive localization to improve the position accuracy of single source by estimating the Doppler parameter of the received signal. However, in the presence of multiple sources, time-frequency aliasing will lead to serious cross-term interference during Doppler signal extraction, resulting in low localization performance. To solve this problem, a spaceborne passive synthetic aperture localization algorithm based on the multiple-stay detector HOUGH transform (MSD-HOUGH) is proposed in this paper. Firstly, an improved convolutional neural network based on the adaptive histogram equalization method (AHE-CNN) is proposed to achieve source number estimation. Then, the PSA Doppler equations are established in the HOUGH domain, which can suppress the cross-term interference of the multiple emitters. Meanwhile, a multiple-stay detector (MSD) is designed to reduce the pseudo-peaks in HOUGH domain. The estimated source number determines when the MSD will be terminated. Finally, a PSA cost function is established based on the estimated Doppler parameter to achieve signal source localization. Experimental results show that compared with other localization methods, the proposed algorithm has a significant improvement for multiple signal source localization.
Machine Learning Enhances Soil Aggregate Stability Mapping for Effective Land Management in a Semi-Arid Region
Authors: Khosravani Pegah , Moosavi Ali Akbar , Baghernejad Majid , Kebonye Ndiye M. , Mousavi Seyed Roohollah , Scholten Thomas
Published: November 2024

Soil aggregate stability (SAS) is needed to evaluate the soil’s resistance to degradation and erosion, especially in semi-arid regions. Traditional laboratory methods for assessing SAS are labor-intensive and costly, limiting timely and cost-effective monitoring. Thus, we developed cost-efficient wall-to-wall spatial prediction maps for two fundamental SAS proxies [mean weight diameter (MWD) and geometric mean diameter (GMD)], across a 5000-hectare area in Southwest Iran. Machine learning algorithms coupled with environmental and soil covariates were used. Our results showed that topographic covariates were the most influential covariates in predicting these SAS proxies. Overall, our SAS maps are valuable tools for sustainable soil and natural resource management, enabling decision-making for addressing potential soil degradation and promoting sustainable land use in semi-arid regions.
Remote Sensing Fine Estimation Model of PM2.5 Concentration Based on Improved Long Short-Term Memory Network: A Case Study on Beijing–Tianjin–Hebei Urban Agglomeration in China
Authors: Ji Yiye , Wang Yanjun , Wang Cheng , Tang Xuchao , Song Mengru
Published: November 2024

The accurate prediction of PM2.5 concentration across extensive temporal and spatial scales is essential for air pollution control and safeguarding public health. To address the challenges of the uneven coverage and limited number of traditional PM2.5 ground monitoring networks, the low inversion accuracy of PM2.5 concentration, and the incomplete understanding of its spatiotemporal dynamics, this study proposes a refined PM2.5 concentration estimation model, Bi-LSTM-SA, integrating multi-source remote sensing data. First, utilizing multi-source remote sensing data, such as MODIS aerosol optical depth (AOD) products, meteorological data, and PM2.5 monitoring sites, AERONET AOD was used to validate the accuracy of the MODIS AOD data. Variables including temperature (TEMP), relative humidity (RH), surface pressure (SP), wind speed (WS), and total precipitation (PRE) were selected, followed by the application of the variance inflation factor (VIF) and Pearson’s correlation coefficient (R) for variable screening. Second, to effectively capture temporal dependencies and emphasize key features, an improved Long Short-Term Memory Network (LSTM) model, Bi-LSTM-SA, was constructed by combining a bidirectional LSTM (Bi-LSTM) model with a self-adaptive attention mechanism (SA). This model was evaluated through ablation and comparative experiments using three cross-validation methods: sample-based, temporal, and spatial. The effectiveness of this method was demonstrated on Beijing–Tianjin–Hebei urban agglomeration, achieving a coefficient of determination (R2) of 0.89, root mean squared error (RMSE) of 12.76 μg/m3, and mean absolute error (MAE) of 8.27 μg/m3. Finally, this model was applied to predict PM2.5 concentration on Beijing–Tianjin–Hebei urban agglomeration in 2023, revealing the characteristics of its spatiotemporal evolution. Additionally, the results indicated that this model performs exceptionally well in hourly PM2.5 concentration forecasting and can be used for PM2.5 concentration hourly prediction tasks. This study provides technical support for the large-scale, accurate remote sensing inversion of PM2.5 concentration and offers fundamental insights for regional atmospheric environmental protection.
Vertical Distribution, Diurnal Evolution, and Source Region of Formaldehyde During the Warm Season Under Ozone-Polluted and Non-Polluted Conditions in Nanjing, China
Authors: Cheng Keqiang , Xie Mingjie , Wang Yuhang , Lu Yahan
Published: November 2024

Formaldehyde (HCHO), a key volatile organic compound (VOC) in the atmosphere, plays a crucial role in driving photochemical processes. Satellite-based observations of column concentrations of HCHO and other gaseous pollutants (e.g., NO2) have generally been used in previous studies to elucidate the mechanisms behind secondary organic aerosol (SOA) and ozone (O3) formation. This study aimed to investigate the characteristics of HCHO by retrieving its vertical profile over Nanjing during the warm season (May–June 2022) and analyzing the diurnal variation in vertical distribution and potential source regions on non-polluted (MDA8 O3 < 160 μg m−3, NO3P) and O3-polluted (MDA8 O3 ≥ 160 μg m−3, O3P) days. Under both conditions, HCHO was primarily concentrated below 1.5 km altitude, with average vertical profiles displaying similar Boltzmann-like distributions. However, HCHO concentrations on O3P days were 1.2–1.6 times higher than those on non-polluted days at the same altitude below 1.5 km. Maximum HCHO concentrations occurred in the afternoon, while the peak value in the 0.1–0.4 km layers was reached around noon (~11:00 a.m.). The variation rates (VR) of HCHO in the 0.3–1.2 km altitudes had a maximum on O3P days (approximately 0.33 ppbv h−1), and were significantly higher (p < 0.01) than the VR observed on NO3P days (0.14–0.20 ppbv h−1). The analysis of footprints showed that HCHO concentrations were jointly influenced by the upstream region and the surroundings of the study site. The study results improve the understanding of the vertical distribution and potential source regions of HCHO.
Temporal Associations Between Polarimetric Updraft Proxies and Signatures of Inflow and Hail in Supercells
Authors: Van Den Broeke Matthew S. , Green Erik R.
Published: November 2024

Recurring polarimetric radar signatures in supercells include deep and persistent differential reflectivity (ZDR) columns, hail inferred in low-level scans, and the ZDR arc signature. Prior investigations of supercell polarimetric signatures reveal positive correlations between the ZDR column depth and cross-sectional area and quantitative characteristics of the radar reflectivity field. This study expands upon prior work by examining temporal associations between supercell polarimetric radar signatures, incorporating a dataset of relatively discrete, right-moving supercells from the continental United States observed by the Weather Surveillance Radar 1988-Doppler (WSR-88D) network. Cross-correlation coefficients were calculated between the ZDR column area and depth and the base-scan hail area, ZDR arc area, and mean ZDR arc value. These correlation values were computed with a positive and negative lag time of up to 45 min. Results of the lag correlation analysis are consistent with prior observations indicative of storm cycling, including temporal associations between ZDR columns and inferred hail signatures/ZDR arcs in both tornadic and nontornadic supercells, but were most pronounced in tornadic storms.
Impact of Latency and Continuity of GNSS Products on Filter-Based Real-Time LEO Satellite Clock Determination
Authors: Wu Meifang , Wang Kan , Wang Jinqian , Xie Wei , Liu Jiawei , Chen Beixi , Ge Yulong , El-Mowafy Ahmed , Yang Xuhai
Published: November 2024

High-precision Low Earth Orbit (LEO) satellite clocks are essential for LEO-augmented Positioning, Navigation, and Timing (PNT) services. Nowadays, high-precision LEO satellite clocks can be determined in real-time using a Kalman filter either onboard or on the ground, as long as the GNSS observations collected onboard LEO satellites can be transmitted to the ground in real-time. While various real-time and high-precision GNSS products are available nowadays in the latter case, their continuity and latencies in engineering reality are not as perfect as expected and will lead to unignorable impacts on the precision of the real-time LEO satellite clocks. In this study, based on real observations of Sentinel-3B, the impacts of different latencies and continuity of the real-time GNSS products on LEO real-time clocks are determined and discussed for two scenarios, namely the “epoch estimation” and “arc estimation” scenarios. The former case refers to the traditional filter-based processing epoch-by-epoch, and the latter case connects LEO satellite clocks from different rounds of filter-based processing under a certain arc length. The two scenarios lead to the “end-loss” and “mid-gap” situations. Latencies of the real-time GNSS products are discussed for the cases of orbit-only latency, clock-only latency, and combined forms, and different handling methods for the missing GNSS satellite clocks are discussed and compared. Results show that the real-time LEO satellite clock precision is very sensitive to the precision of real-time GNSS satellite clocks, and prediction of the latter becomes essential in case of their latencies. For the “end-loss” situation, with a latency of 30 to 120 s for the GNSS real-time clocks, the LEO satellite clock precision is reduced from about 0.2 to 0.28–0.57 ns. Waiting for the GNSS products in case of their short latencies and predicting the LEO satellite clocks instead could be a better option. For “arc-estimation”, when the gap of GNSS real-time products increases from 5 to 60 min, the real-time LEO clock precision decreases from 0.26 to 0.32 ns.
Coastal Reclamation Embankment Deformation: Dynamic Monitoring and Future Trend Prediction Using Multi-Temporal InSAR Technology in Funing Bay, China
Authors: Huang Jinhua , Wang Baohang , Cai Xiaohe , Yan Bojie , Li Guangrong , Li Wenhong , Zhao Chaoying , Yang Liye , Zheng Shouzhu , Cui Linjie
Published: November 2024

Reclamation is an effective strategy for alleviating land scarcity in coastal areas, thereby providing additional arable land and opportunities for marine ranching. Monitoring the safety of artificial reclamation embankments is crucial for protecting these reclaimed areas. This study employed synthetic aperture radar interferometry (InSAR) using 224 Sentinel-1A data, spanning from 9 January 2016 to 8 April 2024, to investigate the deformation characteristics of the coastal reclamation embankment in Funing Bay, China. We optimized the phase-unwrapping network by employing ambiguity-detection and redundant-observation methods to facilitate the multitemporal InSAR phase-unwrapping process. The deformation results indicated that the maximum observed land subsidence rate exceeded 50 mm per year. The Funing Bay embankment exhibited a higher level of internal deformation than areas closer to the sea. Time-series analysis revealed a gradual deceleration in the deformation rate. Furthermore, a geotechnical model was utilized to predict future deformation trends. Understanding the spatial dynamics of deformation characteristics in the Funing Bay reclamation embankment will be beneficial for ensuring the safe operation of future coastal reclamation projects.
Accuracy and Precision of Shallow-Water Photogrammetry from the Sea Surface
Authors: Casella Elisa , Scicchitano Giovanni , Rovere Alessio
Published: November 2024

Mapping shallow-water bathymetry and morphology represents a technical challenge. In fact, acoustic surveys are limited by water depths reachable by boat, and airborne surveys have high costs. Photogrammetric approaches (either via drone or from the sea surface) have opened up the possibility to perform shallow-water surveys easily and at accessible costs. This work presents a simple, low-cost, and highly portable platform that allows gathering sequential photos and echosounder depth values of shallow-water sites (up to 5 m depth). The photos are then analysed in conjunction with photogrammetric techniques to obtain digital bathymetric models and orthomosaics of the seafloor. The workflow was tested on four repeated surveys of the same area in the Western Mediterranean and allowed obtaining digital bathymetric models with centimetric average accuracy and precision and root mean square errors within a few decimetres. The platform presented in this work can be employed to obtain first-order bathymetric products, enabling the contextual establishment of the depth accuracy of the final products.