Publicaciones Científicas

Abstract A recent experimental study has reported significant changes in the behaviour of the fish Galaxias maculatus due to the presence of the parasite trematode Tylodelphys sp. in its cranial cavity. The underlying mechanisms of these behavioural changes remain unknown. This study aims to elucidate potential histological alterations caused by the trematode Tylodelphys sp. in G. maculatus hosts.Specifically, cranial tissues from parasitized and non-parasitized fish were compared to assess possible structural changes or lesions associated with the presence of the parasites.It was found that Tylodelphys sp. does not induce visible changes in the brain, meningeal tissue, or cranial bones of the fish. Tylodelphys sp. primary resides in the posterior region ofthe cranial cavity, within the cerebrospinal fluid surrounding the brain near the hypothalamus, basal nuclei, and other structures related to vision and locomotion. Therefore, Tylodelphys sp. appears to influence the behaviour of its fish host without causing direct damage to the brain tissue, possibly through increased cerebrospinal fluid pressure or chemical interactions with the host’s brain, mechanisms that should be further investigated in future studies.

Background: Boxing performance heavily relies on lower-limb strength and power. Velocity-based resistance training (VBT), which adjusts load and repetition volume using real-time velocity feedback, may provide a more individualized and effective approach compared to traditional percentage-based training (PBT). However, its long-term effect on boxing-specific performance outcomes remains underexplored. Methods: Twenty-eight male collegiate boxers were randomly assigned to a VBT group (n = 14) or a PBT group (n = 14) for an 8-week training program. Both groups performed four sets of each exercise (back squat, Bulgarian split-squat, and deadlift) at 70% of their one-repetition maximum (1RM). The VBT group performed a flexible number of repetitions until their velocity dropped below a 10% threshold, whereas the PBT group consistently performed sets of 5 repetition. Pre- and post-intervention assessments included 1RM strength, countermovement jump (CMJ) height, standing long jump (SLJ) distance, and 30 m sprint run time. Results: All dependent variables demonstrated significant main effects of “time” (p < 0.001; averaged Hedges’ g = 0.44 for VBT group and 0.23 for PBT group). Notably, significant “time” × “group” interactions were observed for the CMJ, SLJ, and 30 m sprint run (p ≤ 0.038), whereas no significant interactions were found for 1RM strength measures across exercises (p ≥ 0.163). Furthermore, when comparing the magnitude of changes between groups, the VBT group exhibited small effect size improvements in CMJ height (Hedges’ g = 0.41), SLJ distance (Hedges’ g = 0.56), and 30 m sprint time (Hedges’ g = 0.51). In contrast, all other variables only showed trivial (Hedges’ g < 0.20) differences between groups. Conclusion: Both training programs led to comparable improvements in maximal strength (1RM) across exercises. However, VBT was more effective than PBT in enhancing performance in high-velocity tasks such as vertical and horizontal jumps and sprinting. These findings support the use of VBT to optimize neuromuscular adaptations relevant to explosive actions in male collegiate boxers.

Dumping Syndrome (DS) is a significant complication following bariatric surgery, particularly Roux-en-Y gastric bypass (RYGB). This condition is characterised by gastrointestinal and vasomotor symptoms resulting from altered anatomy and hormonal dysregulation, notably accelerated gastric emptying and an exaggerated release of gut peptides. Based on the timing of symptom onset after food ingestion, DS is classified as early (EDS) or late (LDS). The critical roles of peptides such as GLP-1, GIP, insulin, and YY peptide are highlighted, along with the involvement of neuroendocrine pathways in symptom manifestation. Diagnosis relies on a combination of clinical evaluation and dynamic testing, with the oral glucose tolerance test (OGTT) often considered a key reference standard for diagnosis. Initial management involves dietary modifications, emphasising the glycaemic index of foods and meal distribution. In cases where nutritional interventions are insufficient, pharmacotherapy with agents such as acarbose, somatostatin analogues (octreotide and pasireotide), GLP-1 receptor agonists (liraglutide), calcium channel blockers (verapamil), and emerging therapies, including herbal medicine, may be considered. For refractory cases, surgical options like bypass reversal or partial pancreatectomy are reserved, although their efficacy can be variable. Despite advancements in understanding and treating DS, further large-scale, randomised controlled trials are essential to validate novel strategies and optimise long-term management. This review provides an updated and comprehensive overview of the aetiology, pathophysiological mechanisms, diagnostic approaches, and current management strategies for DS.

This study addresses a real-world logistics problem in forestry operations: the distribution of plants from cultivation centers to planting sites under strict delivery time windows and limited depot resources. We introduce the Coordinated Truck Loading and Routing Problem (CTLRP), an extension of the classical Vehicle Routing Problem with Time Windows (VRPTW) that integrates routing decisions with truck loading schedules at a single depot with constrained capacity. To solve this NP-hard problem, we develop a metaheuristic algorithm based on Ant Colony Optimization (ACO), enhanced with a global memory system and a novel stochastic return rule that allows trucks to return to the depot when additional deliveries are suboptimal. Parameter calibration experiments are conducted to determine optimal values for the return probability and ant population size. The algorithm is tested on a real forestry dispatch scenario over six working days. The results show that an Ant Colony System (ACS–CTLRP) algorithm reduces total distance traveled by 23%, travel time by 22%, and the number of trucks used by 13 units, while increasing fleet utilization from 54% to 83%. These findings demonstrate that the proposed method significantly outperforms current company planning and offers a transferable framework for depot-constrained routing problems in time-sensitive distribution environments.

The use of generative chat in education has become widespread over the last four years, raising many questions about its use and the effects of AI on learning. The aim of the current systematic review is to analyze the main effects of feedback through the use of generative chat on the production of academic texts by university students. This research is defined as a systematic review of the literature according to the guidelines of the PRISMA statement. The search was conducted in three international important databases (Scopus, Eric, and WoS), from which 12 articles were selected. The results highlighted that there are positive effects on university students’ writing when generative chat is used as a means of providing feedback. Among the main results, it was observed that feedback via chat helps to improve aspects mainly associated with the structure and organization of texts, allows for the proper use of grammatical conventions, and improves the fluency and cohesion of sentences, as well as the precision of ideas and vocabulary. In addition, other benefits were observed in the review, such as improved self-efficacy, self-regulation, proactivity, motivation, and reflection on writing, which promotes critical thinking about the text but also about AI, reducing anxiety and stress.

Schizophrenia poses a significant burden on global health systems and societies. Atypical antipsychotics like clozapine and quetiapine have been shown to be effective in schizophrenia treatment. The most recent head-to-head systematic review comparing clozapine and quetiapine was conducted over a decade ago, and its findings remained inconclusive due to the limited number of high-quality, adequately powered trials. An updated synthesis is therefore warranted. A systematic search was carried out in the Cochrane Schizophrenia Group's Study-Based Register of Trials to identify all double-blind, randomized controlled trials comparing clozapine with quetiapine in schizophrenia and related disorders in terms of efficacy and safety. Risk ratios were calculated and mean differences for binary and continuous outcomes respectively, were assessed using the random effects model. Risk of bias was assessed for included studies and a Summary of findings table created using the GRADE approach. One short-term study involving 63 adults with first-episode schizophrenia fulfill the inclusion criteria, where the overall risk of bias was unclear due to missing reports. No significant differences were observed in global state, relapse, metabolic effects, and general mental state. Clozapine was associated with more somnolence, hypersalivation, and constipation. Other adverse effects and early discontinuation did not significantly differ. Clozapine and quetiapine appear to have similar efficacy in schizophrenia treatment with distinct adverse effect profiles. More high-quality RCTs are needed to confirm efficacy equivalence and clarify safety differences between clozapine and quetiapine, providing the robust evidence required to support safer and more appropriate prescribing practices.

The speculation of coastal land for tourism and housing has led to the rapid urbanization of Chilean coastal settlements and to the reduction of critical ecosystems that contribute to resilience against tsunami hazards. This study analyzes the mitigative and adaptive capacities of these settlements based on their natural resources, focusing on differences across settlements with varying degrees of urbanization. Mitigative capacity refers to the ability to minimize the impact of a tsunami through bioshields like coastal forests, wetlands, and dunes in the Coastal Plane. Adaptive capacity encompasses longer-term resources that support recovery, such as food, water, and refuge provided by forests, prairies and agricultural land among others in the Coastal Range. Using spatial and multivariate analyses, 53 coastal settlements were evaluated, leading to three settlement clusters with distinct degree of urbanization, type of settlement (village or city), and differences in their latitudinal distribution and in the number of prairies and agricultural land in the Coastal Range. Results show no significant differences between settlement clusters and mitigative capacity. On the other hand, the study finds that cities' type of settlements, with greater prairie and agricultural land in the Coastal Range, particularly in central and northern Chile, show a higher capacity for adaptation, based on transportation and refuge available after the tsunami. This research highlights the crucial role of natural resources in both immediate disaster mitigation and long-term adaptation. Understanding the differences in resource availability among settlements can inform urban planning strategies to develop tsunami-resilient communities along Chile's southern Pacific coast.

The projected increase in coastal risk requires a reevaluation of coastal risk reduction strategies. A multi-model approach is proposed to examine the variability of coastal storms influenced by climate change and El Niño Southern Oscillation (ENSO). To this end, the historic coastal storm of August 8 2015, resulting from a local extratropical cyclone (ETC) off the central Chilean coast, was analyzed through the coupling of the WRF atmospheric model, Delft3D FM (D-FLOW and D-WAVE modules), and EOT20 astronomical tide model. The results show that the characteristics of local ETCs are susceptible to regional temperature gradients associated with climate change and ENSO. The coastal storm of August 8 2015, presented a decrease in wave height and counterclockwise rotation of wave direction along the Chilean coast under the climate change scenario. Meanwhile, the ENSO scenarios under cold conditions generated a ETC track’s displacement toward the north, causing both an increase in wave height along the coast of the Antofagasta and Atacama regions and a decrease in wave height in the Valparaíso, O’Higgins, and Maule regions. Findings from this study emphasize the importance of considering dynamic design for coastal structures rather than traditional methods to adapt to changing storm patterns.

This paper investigates solitary wave-induced scour around square structures, a critical factor affecting the integrity of coastal infrastructure. The phenomenon is studied numerically and validated through original experiments conducted in our laboratories. Specifically, a solitary wave interacting with a square structure on a beach with bathymetry representative of Chilean coasts is analyzed. Additional validation is performed using an experiment from the literature involving dam-break-induced scour behind coastal dikes. The numerical modeling is carried out using DualSPHysics, an open-source simulation tool based on the Smoothed Particle Hydrodynamics (SPH) method, which has shown effective results for wave modeling and scour studies. This study demonstrates the model’s effectiveness in addressing wave-induced scour problems. The interaction between a tsunami-representative solitary wave and the sediment is modeled using the Herschel-Bulkley-Papanastasiou (HBP) model for granular materials. The results show that the numerical model, combined with the rheological model, accurately predicts the maximum scour depths in both configurations. Furthermore, the simulations closely align with experimental observations and previous studies, confirming that scour depth correlates with flow depth, with deeper scour occurring at the corners of structures compared to the central faces. These findings improve predictive capabilities for tsunami impacts on coastal structures, highlighting the need for future research to incorporate more realistic wave characteristics to enhance prediction accuracy.

Landslide-induced tsunamis pose a significant yet underrecognized hazard in lake-rich, tectonically active regions such as south-central Chile. This study reconstructs and numerically models two contrasting tsunamigenic landslide scenarios in Lake Rupanco: (i) a multi-source subaerial landslide triggered by the 1960 Valdivia earthquake (Mw 9.5), and (ii) a large, deep-seated paleo-landslide inferred from geomorphological and bathymetric evidence. Field surveys, historical imagery, and a high-resolution topo-bathymetric dataset were used to define landslide geometries and initial conditions. Simulations were performed using the Landslide-HySEA model, calibrated through a global sensitivity analysis to constrain key rheological parameters. The 1960 scenario generated peak wave amplitudes of up to 33.3 m, while the paleo-landslide produced waves reaching 22.0 m. Both events resulted in run-up heights exceeding 10 m and inundation distances over 200 m along the lake’s eastern and southern shores. The results demonstrate that landslide dynamics—not just volume—are critical in tsunami generation, and highlight the importance of integrating both historical and paleo-events into hazard assessments for confined water bodies in seismically active settings.