Gran Telescopio Canarias (Spain)

BackgroundJuvenile loggerhead sea turtles represent a crucial but understudied stage of the species life cycle. Most studies have been conducted at regional scales and there remains a need for a broader scale synthesis. In the North Atlantic, loggerheads encounter numerous threats such as fishing during their transoceanic journey, so it is important to get a broad view of their distribution, movement and habitat preferences.MethodsFor this study, we gathered tracking data from 124 juvenile loggerheads tagged along the Azores, Canary Islands, Madeira and in the western North Atlantic to develop a habitat model for the entire basin. We used a SSM to interpolate tracks to daily positions, simulated pseudo-absences with a correlated random walk for background data, and explored 17 environmental variables using boosted regression trees to select the best model in terms of biological realism and predictive power. The best model obtained (AUC = 0.988) was then used to predict habitat suitability for the North Atlantic for the period 1998–2022. Stranding records of loggerheads in France, UK and Ireland were used to discuss the predictions.ResultsAfter filtering, tracks of 105 individuals, covering most of the basin, were used in the model. Our predictions of habitat suitability show the importance of the Gulf Stream and the Azorean Current. Habitat suitability is predicted to be higher in the area between 30° and 45°N all year round, while open waters below 30°N, including Cape Verde, are not predicted to be a suitable habitat. In northern and eastern areas, like the Bay of Biscay and UK and Irish waters, habitat suitability varied seasonally, with colder seasons showing lower values. Accordingly, strandings in those areas occurred mostly during winter (December-February; 45.1%) and spring (March-May; 34.1%).ConclusionsThe model offers a first basin-scale prediction of the seasonal distribution of juvenile loggerheads in the North-Atlantic, which shows consistency with stranding and bycatch data in the basin. This study represents a first step towards a broader scale understanding of juveniles’ habitat preferences that can be used to quantify the magnitude and extent of the threats that they face.Supplementary InformationThe online version contains supplementary material available at 10.1186/s40462-026-00640-2.

As unshaven hair transplantation grows in popularity, terminology has become inconsistent across publications and advertising. This creates confusion for patients and clinicians and undermines informed consent. To map usage, identify confusion sources, and propose definitions for the spectrum of "Unshaven" follicular unit excision (FUE) approaches. The authors performed a structured review of scientific literature, Google Trends for public-facing terms, searches of clinic and media webpages, and standardized prompts to artificial intelligence chatbots. Findings were synthesized into operational definitions and classification. For the FUE procedure, the authors observed overlap, misuse, and conflation of techniques labeled "Unshaven," particularly between partially shaven methods and truly unshaven approaches. Synthesis yielded five categories with explicit procedural boundaries: Shaven FUE, Partially Shaven FUE, Unshaven FUE with pretrimming, Unshaven FUE without pretrimming, and Long-Hair FUE. For each, the authors outline defining steps, patient-visible outcomes, indications, and recommend patient-facing descriptors. The authors propose that 'Shaven' versus 'Unshaven' FUE terminology should be defined exclusively by the donor harvesting technique, irrespective of whether the recipient area is shaved. The proposed standardized nomenclature clarifies FUE categories, improves counseling and expectation-setting, and supports transparent reporting, ethical advertising, and comparability across studies. The authors encourage adoption by clinicians, training programs, and journals.

Abstract The tourism industry increasingly requires adaptive recommendation systems capable of understanding traveler preferences and learning from user behavior. Traditional conversational agents and retrieval-based systems remain limited by static knowledge and lack continuous personalization. This study presents an integrated framework combining Large Language Models, Retrieval-Augmented Generation, and Reinforcement Learning via Multi-Armed Bandit algorithms to develop an adaptive conversational assistant for dynamic travel itinerary recommendations. Orchestrated with LangGraph for stateful dialogue management and deployed on AWS, the system continuously updates its recommendation policies from user interactions. Case studies demonstrate its ability to balance exploration and exploitation. The conversational design emulates human travel advisors through guided questioning and preference elicitation. This architecture bridges the gap between static retrieval and adaptive learning, enabling a closed-loop conversational AI that evolves from user feedback. The research validates the feasibility of production-ready, reinforcement learning–driven personalization in tourism and provides a scalable foundation for adaptive recommendation systems beyond tourism.

• Determination of avocado maturity in pre-harvest state is crucial in agriculture. • This work correlates dry matter content in avocados with multimodal sensing scheme. • Multimodal scheme is composed of remote data and on-site data from the fruit. • Machine learning techniques have been evaluated for all combinations of datasets. • The developed models have potential to revolutionize avocado harvesting strategies. In recent years, avocado has gained significant global importance due to its nutritional benefits, and rising consumer demand, becoming a staple in health-conscious diets. This growing interest has also raised concerns about environmental sustainability, and as a result, efforts are being made to promote more sustainable farming practices while meeting the rising demand. In this study, we present a tool designed to enhance the efficiency of the pre-harvest process and improve avocado quality. We propose a multimodal sensing scheme integrating three different data sources: a portable multispectral system for in situ measurements, satellite imagery and, onsite environmental sensors to estimate the fruit ripening stage. This combined remote and onsite yielded a high correlation with dry matter content, considered here as the reference indicator of avocado ripening, across three consecutive harvest seasons. The performance of various machine learning techniques was evaluated using different combinations of these datasets. Notably, the artificial neural network (ANN) model achieved the highest accuracy (0.74) and recall (0.96) for predicting the overripe avocado class. Therefore, ANN model was extended to regression models, where all of them have demonstrated high predictive accuracy, with R 2 coefficient ranges from 0.81 to 0.91. The online data achieved the highest coefficient (0.91), providing a slightly better performance compared to the offline model. Nonetheless, predictions based solely on multispectral data remain valuable, particularly when online data are unavailable.

Understanding the physical characteristics of small Solar System bodies is important not only for refining formation and evolution models but also for space mission operations. Although several kilometre-sized asteroids have been visited by spacecraft, asteroid 1998 KY26—the final target of Hayabusa2#, the extended mission of the Japan Aerospace Exploration Agency’s Hayabusa2 spacecraft—will be the first decametre-scale asteroid to be explored in situ. Its small size and rapid spin place it above the upper limit on the rotation rate, indicating it may differ from previously studied bodies. In this work, we conducted a photometric campaign during 1998 KY26’s close approach to Earth in 2024, revealing a high optical albedo and Xe-type colours. We determine its spin period to be (5.3516 ± 0.0001) minutes—half the period of earlier estimates. Lightcurve inversion produces retrograde pole solutions in both convex and non-convex shape models. Combined with 1998 Goldstone radar data, these results give a diameter of (11 ± 2) m, three times smaller than previously derived values. The derived cohesive strength levels necessary to keep the structure intact, which is less than 20 Pa, suggest a possibility of the asteroid’s rubble pile structure, though this finding does not rule out its monolithic structure. These results can be validated with future James Webb Space Telescope observations. Our comprehensive characterisation can inform the planning of the Hayabusa2# rendezvous in 2031 and helps pave the way for future studies of dark comets.

Abstract We report a candidate repeating tidal disruption event (TDE), AT2022sxl, found from large-field optical survey data. Two flares with a separation time of ∼7.2 yr between the two optical peaks are observed. Related mid-infrared (MIR) flares, with delay times of ∼200 days are also seen. We analyze two optical spectra of the TDE source, one near the optical peak of the second flare from the Transient Name Server and one at the quiescent flux level after the second flare. The latter was taken by us with the 10.4 m Gran Telescopio Canarias. Comparing the features of the two spectra, we identify that the host is likely a composite galaxy at redshift 0.23, and the TDE event, probably an H+He type, mainly powered broad components in the emission lines of H α , H β , and He I λ 5876. More interestingly, we find that two Bronze-type neutrino events, detected by the IceCube neutrino observatory, match the TDE in position and the second flare, especially the delayed MIR flare, in time. We discuss the MIR luminosity properties of the currently reported (candidate) neutrino-emitting TDEs and suggest that luminous MIR emission is a prerequisite for neutrino production in TDEs.

Abstract Mesophotic coral ecosystems (MCEs), occurring between 30 and 150 m depth, are increasingly recognized for their ecological importance, yet they remain underexplored, particularly in the southwestern Indian Ocean. During benthic surveys conducted at depths ranging from 15 to 75 m off northwestern Reunion Island, we documented a dense and extensive marine animal forest (MAF) dominated by large arborescent octocorals Subergorgia cf. suberosa. This monospecific community formed a complex three‐dimensional habitat spanning a substantial area at mesophotic depths over the northwestern abrupt slopes of Reunion Island. Colonies reached over 1.5 m in height, providing structural habitat for diverse fish and macroinvertebrate assemblages. A total of 53 fish species from 22 families were recorded in association with this MAF, alongside numerous epibionts and understory anthozoans. Despite its ecological value, this habitat faces significant anthropogenic pressures, particularly from fishing activities. Nearly 25% of photographed S. cf. suberosa colonies were entangled in fishing lines, with visible damage including tissue necrosis and polyp loss affecting up to 47% of colonies. These impacts, along with sedimentation from runoff, raise concerns for the long‐term persistence of this mesophotic habitat‐forming community, as long‐lived, slow‐growing organisms like gorgonians may be more impacted by these types of disturbances and take longer to recover than fast‐growing organisms. Our findings represent the first quantitative assessment of Subergorgia dominance and associated biodiversity in this region and highlight its role as a potential refuge for shallow reef taxa. The ecological significance, spatial extent, and fragility of this MAF underscore the urgent need for spatially replicated surveys, targeted conservation strategies, and regulation of damaging activities such as fishing. We advocate for increased research efforts focused on mesophotic habitats, with particular attention to the population dynamics and ecological functions of large gorgonians, to better understand the role of MCEs in reef resilience under accelerating environmental changes.

Abstract Understanding the physical characteristics of small bodies in the Solar System is crucial for refining models of their formation and evolution. Although several kilometre-sized asteroids have already been visited by spacecraft, 1998 KY26 will be the first asteroid in the decametre range to be explored in situ. Its diameter and spin period place it above the spin barrier, suggesting that its formation and properties may differ from those of previously visited bodies. However, the key physical characteristics of 1998 KY26 remain poorly understood. We conducted a photometric observing campaign during 1998 KY26’s close approach to Earth in 2024. Our observations revealed that 1998 KY26 has a high optical albedo and colours consistent with an E-type taxonomy. We also determined its spin period to be (5.3516 ± 0.0001) minutes—twice as fast as previously reported. Using lightcurve inversion methods, we derived a retrograde pole solution and constructed convex and non-convex shape models. By integrating these models with Goldstone radar data from 1998, we estimated 1998 KY26’s diameter to be (11 ± 2) m. The most likely structure for 1998 KY26 is monolithic, yet a fine grained rubble-pile structure is theoretically possible given its required small strength level. We found that it will be possible to validate these results with future JWST observations. Our comprehensive characterisation of 1998 KY26 can inform the planning of the Hayabusa2# spacecraft’s rendezvous encounter, scheduled for July 2031. Additionally, it provides valuable insights into the non-gravitational forces acting on small Solar System bodies, enhancing our understanding of their orbital evolution which could shed light on the nature of dark comets.