Critical illness often causes prolonged weakness, possibly due to impaired skeletal muscle regeneration, but the timing and nature of satellite cell (SC) dysfunction remain unclear. We aimed to determine whether SC depletion and dysfunction are detectable early after intensive care unit admission and describe their pathophysiological nature. In this prospective single-centre observational cohort study, mechanically ventilated adults underwent paired vastus lateralis biopsies within 72 h of ICU admission and again after 7 and 180 days. Isolated satellite cells were studied for proliferation, differentiation and fusion, mitochondrial morphology, respiratory function, substrate oxidation, and selected signalling proteins. We enrolled 20 healthy control subjects and 33 ICU patients. Twenty three ICU patients survived to day 7 with a repeat biopsy. During 7 days in ICU, the patient developed profound weakness (MRC score 16 [0-32]) and insulin resistance (whole body glucose disposal 4.0 [3.5-5.1] versus 13.8 [8.8-16.1] mg/kg/min in controls). Satellite cell number per fibre was similar in controls and patients at admission (0.106 [0.085-0.129] vs. 0.098 [0.056-0.125]) and after 7 days (0.084 [0.066-0.117]; paired p = 0.784). SC proliferation was lower in older patients (ρ=-0.68 and - 0.49) and associated with lower muscle strength (ρ = 0.55 and 0.62). Myogenic differentiation was transiently impaired at day 0 (fusion index 68.9% [66.3-71.7] vs. 74.0% [70.3-77.1] in controls; p = 0.029). Satellite cell bioenergetics and substrate preferences were broadly preserved. In contrast, a more fragmented mitochondrial phenotype was associated with lower proliferation, lower respiratory performance, and worse muscle strength (ρ≈-0.6 to -0.8), whereas more interconnected morphology was associated with better function (ρ ≈ 0.6-0.7). Out of 10 ICU survivors at day 180, only 7 attended follow up. In those, impaired SF-36 physical score (62.5 [55.0 to 75.0]) and SC proliferation capacity (~50 %), contrasted with improved insulin sensitivity and SC number per fiber (~71 % and ~95% of control values, respectively). Critical illness was associated with disturbed satellite cell regenerative programming and altered mitochondrial remodelling rather than early depletion of the satellite cell pool or overt bioenergetic failure. Age was a stronger predictor of early satellite cell dysfunction than disease severity. ClinicalTrials.gov, NCT05671614. Registered 4 January 2023.
During meiosis, chromosomes must find, pair, and synapse with their homologous partners in the crowded milieu of the nucleus. Although homology detection generally relies on recombination, pairing can occur in its absence, suggesting alternative mechanisms. Here, we show that the barcode-like arrangement of non-coding satellite DNA repeats facilitates homologue pairing during meiosis. Using satellite DNA deletion, duplication, and translocation strains, we demonstrate that repeat mismatches perturb meiotic pairing, particularly at centromeres and pericentromeres. Notably, pairing defects are also observed in the progeny of D. melanogaster natural populations that have diverged in their satellite DNA content. In the absence of satellite DNA homology, pairing is antagonised by the HORMAD protein, Mad2, while a Pachytene checkpoint 2 (Pch2)-dependent meiotic delay restores pairing. In addition, compromised meiotic pairing is strongly correlated with mid-oogenesis cell death, a quality control mechanism that likely culls defective oocytes to prevent chromosome mis-segregation and aneuploidy. Taken together, our findings reveal an important role for satellite DNA repeats during meiotic homology detection. We propose that this repeat-based pairing mechanism exerts an underappreciated selective pressure, constraining the divergence of rapidly evolving satellite DNA within interbreeding natural populations.
Long-term, individual-level studies can provide valuable insights into the effects of climate and landscape change on the ecology and population dynamics of wild animals. However, many such studies lack environmental data collected at the spatial and temporal resolutions needed to determine how populations respond to changing conditions. In these cases, the retrospective use of satellite-derived data can provide a way to recover past environmental information. Using a 27-year dataset of an Australian insectivorous passerine, the superb fairy-wren Malurus cyaneus, we assessed how climate variation influences vegetation productivity and, indirectly, superb fairy-wren life history traits through potential changes in trophic interactions. Specifically, we combined long-term, individual-level monitoring of superb fairy-wrens and local weather records with Landsat satellite imagery, from which we derived measures of vegetation productivity using the Normalised Difference Vegetation Index (NDVI) as a proxy for food availability through arthropod abundance. We found a complex set of associations between NDVI and different components of weather, when considering both concurrent and lagged effects. Our analyses of the causes of seasonal variation in superb fairy-wren life history traits demonstrated that NDVI was associated with: (i) temporal variation in breeding success, with years with high spring and summer NDVI values having relatively high average breeding success; and (ii) spatial variation in adult mortality in autumn and winter, with superb fairy-wren territories with low autumn-winter NDVI values having higher average mortality rates. Notably, autumn-winter NDVI values were found to have remained relatively consistent over time, indicating that vegetation productivity cannot explain recently observed increases in adult autumn-winter mortality. Our study illustrates the potential of using long-term Landsat satellite imagery to investigate whether associations between animal life history traits and climate are mediated by vegetation productivity and to what extent temporal trends are influenced by climate change.
Fine particulate matter (PM₂.₅) poses severe public health and environmental risks in Nepal's Tarai and Dun Valley regions, where ground-based air quality monitoring is spatially sparse and temporally inconsistent. This study integrates ground-based observations, satellite-derived Aerosol Optical Depth (AOD) from MODIS MCD19A2, TROPOMI trace gases (CO, NO₂, SO₂), and ERA5 meteorological reanalysis (temperature, relative humidity, wind components) to characterize the spatiotemporal variability of PM₂.₅ and to reconstruct long-term trends from 2000 to 2023. Daily PM₂.₅ measurements from six monitoring stations across southern Nepal were analyzed alongside collocated satellite and reanalysis data. Correlation analysis revealed strong positive associations between PM₂.₅ and both AOD (r = 0.59) and CO (r = 0.62), while temperature (r = -0.38) and relative humidity (r = -0.46) showed moderate negative correlations. A Random Forest model incorporating AOD, CO, temperature, relative humidity, and wind components achieved robust predictive performance (R2 = 0.65, RMSE = 22.6 µg/m3), substantially outperforming multiple linear regression (R2 = 0.54). The strong contribution of CO performance dropped to R2 = 0.62 when excluded, highlights the dominance of combustion sources (biomass burning, vehicular emissions, forest fires) in driving PM₂.₅ pollution. Long-term reconstruction using AOD and meteorological variables (excluding CO due to limited historical data) revealed a distinct east-west gradient. Eastern stations (Jhumka, Bharatpur, Hetauda) show statistically significant increasing trends (up to + 0.41 µg/m3/year, p < 0.01), while western stations (Dhangadhi, Bhimdatta, Dang) exhibit stable or slightly declining trends. Seasonal analysis showed the highest concentrations during winter and pre-monsoon (January-April, > 60 µg/m3) and substantial reductions during monsoon months due to rainfall-driven washout. The results underscore the importance of integrating satellite and ground-based data with machine learning to assess historical air quality, identify pollution hotspots, and inform evidence-based mitigation strategies in data-sparse regions. This framework provides a robust basis for air quality management and public health planning in southern Nepal and across the Indo-Gangetic Plain, where transboundary cooperation is essential to reverse worsening pollution trends.
Excessive tryptamine in food poses a significant risk to human health, emphasizing the demand for efficient, sensitive, and rapid detection technologies. Surface-enhanced Raman Spectroscopy (SERS) aptasensors are presently attracting a lot of attention due to their ability to detect targets at low concentrations. However, their inherent instability and poor anti-interference ability hinder their widespread use. Herein, a two-layer core-satellite magnetic SERS aptasensor was constructed to achieve the sensitive detection of tryptamine. The SERS aptasensor consisted of magnetic SERS recognition probes (magnetite nanoparticles coated with gold nanoparticles and aptamer: Fe3O4@Au-apt) and SERS signal probes (gold nanoparticles of two different sizes functionalized with the Raman reporter molecule 4-mercaptobenzonitrile and complimentary deoxyribonucleic acid strands). In the absence of tryptamine, the SERS signal probes attached to the aptamer on the SERS recognition probes to form a two-layer core-satellite structure with an intense SERS signal at 2226 cm- 1 in the "biological-silent" region due to the 4-Mercaptobenzonitrile. In the presence of tryptamine, tryptamine bonded to aptamer on the SERS recognition probe leading to detachment of the SERS signal probes, weakening the SERS signal at 2226 cm- 1. The aptasensor exhibited a favorable linear range from 0.001 to 100 mg L- 1, with a detection limit of 0.39 × 10- 3 mg L- 1 toward tryptamine. The fabricated sensor was practically applied to the detection of tryptamine in liquor, white wine and vinegar samples, with results highly consistent with high performance liquid chromatography data, demonstrating the broad prospects of the developed analytical method in food threat detection.
Duchenne muscular dystrophy (DMD) is a debilitating and fatal X-linked disease affecting 1/5,000 males worldwide that currently has no cure [D. Duan, N. Goemans, S. Takeda, E. Mercuri, A. Aartsma-Rus, Nat. Rev. Dis. Primers 7, 1-19 (2021), 10.1038/s41572-021-00248-3]. Vast amounts of research have been conducted on DMD, and one of the most common animal models for DMD studies is the mouse muscular dystrophy (mdx) model [J. W. McGreevy, C. H. Hakim, M. A. McIntosh, D. Duan, DMM Dis. Model. Mech. 8, 195-213 (2015), 10.1242/DMM.018424/-/DC1]. Unfortunately, despite its shared genetic etiology, the mdx mouse shows a relatively mild dystrophic phenotype compared to affected humans, limiting its overall utility as a research model (G. Donen, N. Milad, P. Bernatchez, J. Neuromuscul. Dis. 10, 1003 (2023), 10.3233/JND-230126]. Notably, mdx mice have a mutation preventing the production of full-length dystrophin but are still able to produce numerous short isoforms of dystrophin. Here, we provide a comprehensive functional characterization of DMD-Null mice, which lack all dystrophin isoforms. Our studies demonstrate that DMD-Null mice show a more severe skeletal muscle phenotype than mdx mice, characterized by profound weakness, decreased exercise tolerance, and impaired muscle regeneration, while utrophin upregulation was similarly observed in DMD-Null and mdx mice. We identify a marked deficit in satellite cell proliferation and myogenic differentiation, accompanied by downregulation of regenerative gene programs. These findings suggest potential contributions of short dystrophin isoforms to muscle stem cell function, and establish DMD-Null mice as a unique model for investigating the pathogenesis of DMD and testing therapeutic interventions targeting satellite cell health and regeneration.
High-capacity inter-satellite laser communication links are essential for global coverage, remote sensing, and deep space missions, but face challenges from path loss, pointing errors, and limited aperture sizes that degrade performance at extended ranges and high data rates. This work reports simulative evaluation of an Inter-Satellite Laser Communication Transmission (Is-LCT) system with 160 Gb/s data rate. Orthogonal Frequency Division Multiplexing (OFDM), Polarization Division Multiplexing (PDM), and 32-level Quadrature Amplitude Modulation (32-QAM) techniques have been used to enhance the system baud rate, bandwidth efficiency and transmission rate of the system. Advanced signal processing techniques have been used to improve the performance of the proposed system. The proposed Is-LCT system is investigated for enhancing range, optical efficiency, aperture diameter, laser power, and pointing error using Error Vector Magnitude (EVM), Bit Error Rate (BER), and constellation as the metrics for performance evaluation. The obtained results demonstrate reliable 160 Gb/s data transmission at 7000 km Is-LCT range with BER[Formula: see text]3.8[Formula: see text], EVM[Formula: see text] 12%, and clear constellation of the received optical signal.
Satellite greening has become a key tool for monitoring alpine vegetation change, but a positive vegetation-index trend is not an ecological observation in itself. This perspective shows that interpreting alpine greening requires addressing two sequential challenges: methodological complexity, which can bias trends during image processing, and phenomenological complexity, because different ecological processes can produce similar spectral signals. Progress now depends less on producing more greening maps than on linking robust satellite trends to ground-based ecological processes.
This study presents a comprehensive examination of coastal dune morphology, migration, and internal structures in Nitzanim, Israel. Our approach integrated Ground Penetrating Radar (GPR) and satellite analysis to understand their evolution and internal architecture. The methodology involved multi-frequency GPR (500 MHz, 250 MHz, and 100 MHz) for subsurface imaging and multi-temporal Landsat, Sentinel-2, and aerial/UAV imagery, with NDVI (Normalized Difference Vegetation Index) analysis for long-term vegetation cover and dune migration monitoring. Results demonstrate a clear trend of decreasing vegetation cover across the study area from 1995 to 2025, which coincides with increased dune mobility and shifts in dune position, with peak migration rates occurring after a localized anthropogenic change: the construction of an artificial lake in 2005. For example, the northern dune's brink line shifted approximately 71 m eastward from its 1995 position, with its southern segment becoming completely exposed by 2015 due to vegetation loss. Concurrently, processed GPR profiles revealed a coherent sequence of quasi-linear internal reflectors within the dune body, with shallow reflections near the crest exhibiting a distinct eastward inclination, suggesting the prevailing direction of past sediment transport. The consistency of these structural elements across different GPR frequencies highlighted the robustness of the multi-frequency GPR methodology employed. Furthermore, the study revealed a relationship between vegetation dynamics and the internal stratification visible in GPR data. While high NDVI values in 1995 correlated with sand accumulation and a visible accumulation line, a reduction in vegetation cover between 2010 and 2025 coincided with an apparent decrease in vertically accreted stratification in GPR profiles, suggesting a relative increase in lateral dune migration during the most recent phase. The combined multidisciplinary approach offers crucial insights into the complex history of dune stabilization, reactivation, and migration in the Nitzanim coastal dunes. It contributes to process understanding in aeolian geomorphology, informing environmental management and conservation strategies in dynamic desert landscapes.
Age-related sarcopenia is a degenerative condition characterized by loss of muscle mass and strength. Satellite cells (SCs), the stem cells of skeletal muscle, decline in number and function with age, contributing to sarcopenia. Enhancing SC function represents a promising therapeutic strategy. Neuromuscular electrical stimulation (NMES) induces passive muscle contraction and improves SC activity, partly through calcium-dependent mechanisms. Calcium signaling is essential not only for excitation-contraction coupling but also for SC proliferation and differentiation. This review summarizes age-related changes in SCs, current sarcopenia treatments, and the therapeutic potential of NMES. We propose a novel combined strategy integrating NMES with calcium signaling modulation to synergistically enhance SC function. This approach offers a promising avenue for treating age-related sarcopenia and warrants further investigation.
Cattle ranching is a sustainability challenge worldwide, and in the Amazon, the planet's largest tropical forest, it remains the main driver of deforestation. Yet, cattle numbers have typically been estimated from coarse census data or indirect proxies, limiting our ability to monitor land-use change at finer scales. Here, we introduce a novel approach that applies deep learning-based density estimation to very high-resolution satellite imagery to detect individual animals across the Brazilian Amazon. Our cattle data set covers over 12,000 km² in four states and is integrated with pasture maps to analyze property-level stocking rates. We find patterns of extensive land use, deriving conservative stocking rate estimates of 0.73 head per hectare in 2018-2019, with lower cattle stocking rates on properties with higher recent deforestation and properties further away from slaughterhouses. While the use of VHR imagery presents challenges of coverage and detection, our framework establishes a foundation for advancing livestock monitoring and supports strategies to address deforestation and promote sustainable resource management.
Exosomes carry diverse biologically active substances that can be transferred between cells, thereby influencing physiological and pathological states of the organism. Abnormal exosome levels are closely associated with cancer. Consequently, the precise detection of exosomes holds considerable importance for noninvasive cancer diagnosis and monitoring. Nevertheless, achieving highly sensitive and consistently reproducible detection of exosomes continues to pose a significant challenge in clinical diagnostics. In this research, we developed a reusable magnetic aptamer-based surface-enhanced Raman scattering (SERS) sensor with built-in calibration for the accurate quantification of exosomes derived from oral cancer. The sensor was synthesized through a layer-by-layer assembly strategy to form an internal standard encoded core-satellite structure (NiFe2O4@PB@Ag), which was subsequently conjugated with SH-modified complementary DNA (cDNA) to form NiFe2O4@PB@Ag-cDNA. This was then hybridized with ROX-labeled aptamers (ROX: 6-carboxy-X-rhodamine) to construct the final NiFe2O4@PB@Ag-dsDNA SERS aptasensor. Magnetic-induced assembly of the sensor, combined with the surface plasmon effect, significantly improved the SERS performance, enabling dual amplification of both internal standard and target signals. This resulted in a 1.9-fold increase in signal intensity compared to the condition lacking magnetic-induced assembly. Furthermore, this SERS sensor exhibited a wide linear range for exosome detection, spanning from 5.0 × 103 to 5.0 × 1011 particles/mL, with a limit of detection (LOD) as low as 1.15 × 103 particles/mL. Finally, in clinical testing of plasma samples, the sensor reliably differentiated exosome concentrations between individuals with oral cancer and healthy controls, providing a robust and reliable platform for exosome-based liquid biopsy in clinical applications.
Repetitive DNA sequences comprise a significant proportion of eukaryotic genomes and play an important role in genome structure, function, and evolution. The genome of the beetle Tenebrio molitor is particularly rich in satellite DNAs (satDNAs), which represent a prominent component of its repetitive DNA fraction. While dominantly found in long arrays confined to heterochromatin, satDNAs can also be found in short arrays in extra-heterochromatic regions. However, their cytogenetic detectability and spatial distribution can be influenced by chromatin condensation and epigenetic context. In this brief report, we investigated chromatin condensation dynamics during male germline development in T. molitor and examined how these dynamics affect the detection and localization of high- and low-copy satDNAs. DNA staining, immunodetection of the H3K9me3 epigenetic mark of constitutive heterochromatin, and fluorescence in situ hybridization (FISH) of satDNA sequences were used to examine the relationship between chromatin organization, the functional state of heterochromatin, and satDNAs positioning and detectability. Our results revealed that a large, central, and highly condensed chromosomal core is enriched in H3K9me3 and corresponds to constitutive heterochromatin. Major satDNA forms the bulk of this compartment and remains readily detectable regardless of chromatin condensation level. In contrast, the detectability of low-copy satDNAs decreased with increasing chromatin condensation. Additionally, numerous weak, punctate signals belonging to low-copy satDNAs were observed outside the DAPI-bright chromosomal mass, located in very loosely condensed chromatin, largely excluded from the heterochromatic chromosomal core. These findings demonstrate that chromatin condensation and constitutive heterochromatin organization strongly influence satDNA detectability and spatial distribution in T. molitor.
This article presents a spatially explicit persistent cropland mask for the Canadian prairies covering Alberta, Saskatchewan, Manitoba. Data was generated using 64-band embedding data from AlphaEarth with Agri-Food Canada (AAFC) Annual Crop Inventory used for label generation. Stratified-random points from across the prairies were used with a Random Forest classifier to determine cropland and noncropland areas. The trained models were applied across the prairies from 2017 to 2024 in an annual wall-to-wall classification framework at 10 m resolution for each year. Annual classifications were then combined to create a multi-year frequency layer where pixels with more than two years of continuous cropping were labelled as cropland, creating a stable mask layer. The dataset contains a 10 m resolution binary raster mask layer in GeoTIFF format to support a wide range of applications including cropland mapping, land-use change assessment, agricultural monitoring, yield modelling, soil and climate studies, and machine-learning-based geospatial applications. • Annual Prairie-wide cropland mask cloud-optimized GeoTIFFs generated using AlphaEarth data embeddings and Random Forest models trained on stratified random reference samples. • Multi-year cropland frequency and stable cropland mask layers derived from aggregated annual predictions, enabling consistent identification of persistent cropland across the Canadian Prairies.
Water quality monitoring is integral to preserving the health of freshwater ecosystems, and satellite remote sensing has emerged as one monitoring method. Sentinel-2, in particular, has been valuable for water quality monitoring due to its 5-day global temporal revisit time and spatial resolution that ranges from 10 to 60 metres. Sentinel-2 can be used to measure and monitor chlorophyll-a, which historically has been used as an indicator of water quality, eutrophication and harmful algal blooms. Our goal was to review aquatic chlorophyll-a Sentinel-2 research to assess the types of validation evidence reported. Validation evidence is defined here as the set of information key to assessing algorithm performance, and include the spatial and temporal scales of satellite validation, reported in situ sampling method context information, demonstration of validation results through plots, and appropriate algorithm performance metrics. We highlight how the body of literature collectively contributes to advancing a national scale chlorophyll-a product that could support future resource management applications. Our review of 122 published studies indicated that much of the validation evidence corresponded to early stages, as defined by the NASA data maturity framework, due to a limited focus on individual lakes and limited detail on methodology for reproducibility. Prioritizing data accessibility for both in situ data and satellite workflows used in published studies; reporting methods with transparency and consistency; and using standard algorithm performance metrics could provide a consistent framework to support and enhance the utility of satellite inland water quality research. These three quality assurance mechanisms can promote effective evaluation of approaches for remote sensing of chlorophyll-a. Adopting these quality criteria could enable the integration of validation evidence from multiple studies, supporting more spatially and temporally representative products that would advance these approaches towards maturation for broader application.
Bardet-Biedl syndrome is a pleiotropic ciliopathy marked by retinal degeneration, obesity, polydactyly, renal and reproductive anomalies, and cognitive impairment. BBS1, the most frequently mutated gene in Bardet-Biedl syndrome, encodes a key component of the BBSome complex, which is essential for ciliary membrane trafficking. Although BBS1 is known to be essential for proper BBSome function, the effects of disease-associated BBS1 variants on its activity remain incompletely understood. In this study, we examined how patient-derived BBS1 mutations affect BBSome integrity and its role in cargo transport within primary cilia. Our results show that particular BBS1 mutations interfere with distinct stages of BBSome assembly and trafficking. While M390R disrupts initial pre-BBSome assembly at pericentriolar satellites, E224K impairs both the maturation of the pre-BBSome into the BBSome and its movement from pericentriolar satellites to the cilium. In contrast, the R160Q variant preserves BBSome assembly and permits its localization to cilia. It specifically weakens the BBSome-GPCR interaction mediated by TOM1L2, resulting in defective GPR161 export and increased ciliary IFT turnover. Overall, our study establishes a mechanistic framework linking specific BBS1 mutations to distinct defects in BBSome assembly and function. This framework defines functional classes of BBS1 variants and provides deeper insight into the molecular mechanism and severity of Bardet-Biedl syndrome.
Senescence is broadly considered an age-related phenomenon; however, it also been implicated in normal tissue repair and wound healing. Skeletal muscle repair is a complex process that requires the coordination of several different cell populations but the role of senescence in skeletal muscle repair has yet to be fully elucidated. We hypothesize that senescence serves as a control mechanism throughout the regenerative process and the removal of senescent cells through senolytics will negatively impact the repair process in young mice. Briefly, young mice were exposed to either (a) vehicle (VEH), receiving only a cardiotoxin (CTx) injection in one hindlimb or (b) 7 days of senolytic treatment (SEN) pre-CTx and 3x/week for 4 weeks post-CTx. Dasatinib + Quercetin (D+Q) was used to selectively eliminate senescent cells. There were no significant differences between groups in functional measures such as hindlimb grip strength and cross-sectional area. eMHC+ fibers remained elevated at D28 in the SEN group. Macrophage infiltration was twice as high in the SEN group compared to VEH at D7. Satellite cell quantity and fibrotic area were significantly increased at D14 in the SEN group compared to VEH. We conclude that reducing senescent cells during muscle repair in young mice significantly altered the kinetics of muscle repair. Therefore, senescent cells may act as a regulatory mechanism in skeletal muscle to orchestrate the activity of the different cell populations involved in repair and regeneration such as immune cells, satellite cells, and fibrotic cells.
Tracking small-bodied animals in estuarine environments entails significant technological and analytical challenges. Diamond-backed terrapins are small (max 1.4 kg) turtles that inhabit salt marshes of the eastern U.S. and the Gulf of Mexico. Terrapin movements have been studied with VHF radio telemetry, acoustic telemetry, and mark and recapture methods, which have indicated maximum straight-line movement distances < 10 km and mean home ranges < 1 km2. We deployed 21 Argos satellite tags on adult female terrapins at two sites on Long Island, New York to better understand the spatial ecology of this imperiled species, and to test newly available tracking technology. We processed the location data three ways: (1) we used a location data filter to remove unlikely terrestrial and oceanic locations and applied a state-space model to account for Argos location errors, (2) we applied the state-space model to unfiltered data to determine the effects of not removing unlikely locations, and (3) we used only the highest quality location class 3 (LC 3) locations. We used the data resulting from each of these approaches to calculate four different movement metrics: summer home range size (95% minimum convex polygons (MCPs) and kernel density estimates (50% and 95% KDE, with both reference [href] and least squares cross validation [LSCV] bandwidths)), the total distance traveled from June to August, maximum distance traveled in one day, and daily movement rates. Home ranges estimated from the three processing techniques were similar in size and covered the same spatial areas. Estimates for total distance traveled, daily movement rates, and maximum distance traveled were similar between the state-space modeling techniques, but LC 3 estimated distances were twice as long. Movement metrics and home ranges were similar between the two study sites, despite differences in urbanization and bay size. These results suggest that most movement metrics and home range estimates are fairly insensitive to these different analytical techniques, even at relatively smaller spatial scales. Additionally, our study indicates substantially larger home ranges and longer straight-line movements than VHF telemetry or sonic tag studies, highlighting the utility of satellite tags to improve our understanding of terrapin ecology and conservation.
Biologging and telemetry have transformed our understanding of marine megafauna movement ecology. Yet, methodological constraints continue to limit data quality and deployment duration. Devices recording whale shark (Rhincodon typus) behaviours and movements have been used for decades, but they remain challenging to deploy and vary in success. Recently, spring-loaded clamp-based systems have emerged as one of the most widely used approaches to attach electronic tags to the fins of this globally endangered species. Currently, however, no consensus guidelines exist as to how to optimise this approach, potentially leading to continued underperforming deployments limiting analysis potential. Here, we synthesise experiences with clamp-based tagging worldwide through a targeted survey of whale shark researchers. We explore performance and challenges with a view to propose current best practices in the field. Whale shark researcher responses to the survey highlighted clamp-based systems as a practical and more widely applicable approach than drill-based methods, which are often used to secure tags to other large sharks. They also noted that clamps have greater retention potential and are suitable for a wider range of tags compared to dart-based methods, but are still constrained by design, placement, and deployment conditions. Researchers used a variety of materials and designs to build their own clamps, often facilitated by direct collaboration with each other or key manufacturers. Clamps produced highly variable outcomes, ranging from successful long-term satellite transmissions over 200 days and short-term biologging for 48 h at 20 Hz, to premature detachment and cases of fin damage. For long-term clamps, changes in position on the fin allowed for more stable satellite transmissions over time. Some clamp designs achieved data quantity and quality close to that of drilled deployments, demonstrating their potential to rival traditional methods while offering a less invasive approach. Results emphasised the ongoing need for technological refinement and rigorous evaluation of clamp performance and associated impacts. Based on collective insights, we present a unified approach to clamp design and positioning, and identify key priorities for advancing this attachment technology, such as aiming for positions b-2 and c-2 on the fin and ensuring the clamp bridge distance (always between 30 and 50 mm) and tension are matched to shark size. Optimising clamp systems could substantially improve our ability to generate high-quality, long-duration movement data while minimising tagging impacts on the animal where possible. This could enhance ecological and conservation research outcomes for endangered whale sharks, with broader implications for tagging other large-bodied marine megafauna. The online version contains supplementary material available at 10.1186/s40317-026-00462-4.
This data article presents a multi-source dataset of satellite-based auxiliary data designed for forest modelling and monitoring. The dataset integrates annual medoid composites derived from Sentinel-1, Sentinel-2, and Landsat imagery, together with spectral indices, Landsat-based 3I3D change metrics, forest mask and forest type layers, and terrain variables derived from the Copernicus GLO-30 DEM, offering comprehensive information on forest cover, spectral behavior, and change metrics. It provides harmonized predictors across seven European countries, ensuring consistency, scalability, and ease of use for researchers developing or validating models to understand forest dynamics and estimate forest-related variables such as biomass or canopy recovery. A curated subset of the dataset is distributed via Zenodo, along with direct public access links to the complete multi-terabyte archive. The data support applications in forest biodiversity conservation, carbon monitoring, biomass modelling, and climate-change impact assessment.