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Comprehensive Analysis of Model Errors in Blueberry Detection and Maturity Classification : Identifying Limitations and Proposing Future Improvements in Agricultural Monitoring
No full textPublisher Copyright: © 2023 by the authors.In blueberry farming, accurately assessing maturity is critical to efficient harvesting. Deep Learning solutions, which are increasingly popular in this area, often undergo evaluation through metrics like mean average precision (mAP). However, these metrics may only partially capture the actual performance of the models, especially in settings with limited resources like those in agricultural drones or robots. To address this, our study evaluates Deep Learning models, such as YOLOv7, RT-DETR, and Mask-RCNN, for detecting and classifying blueberries. We perform these evaluations on both powerful computers and embedded systems. Using Type-Influence Detector Error (TIDE) analysis, we closely examine the accuracy of these models. Our research reveals that partial occlusions commonly cause errors, and optimizing these models for embedded devices can increase their speed without losing precision. This work improves the understanding of object detection models for blueberry detection and maturity estimation
Release kinetics approach of stimuli-responsive mesoporous silica nanocarriers : pH-sensitive linker versus pH-sensitive framework
No full textPublisher Copyright: © 2023 Elsevier B.V.Silica-based stimuli-responsive nanomaterials have attracted significant attention in the field of drug delivery because they can achieve controlled release of anticancer drugs. For this, a gatekeeper is usually used, thus avoiding unwanted leakage at pH 7.4, while modulating the release under more acidic pH conditions in the tumor cell microenvironment. To optimize the efficiency of these nanostructures, it is crucial to study the release kinetics of anticancer drugs, predict their behavior, and modify the transport process mechanism. In the present study, we synthesized and characterized two types of pH-responsive mesoporous silica nanocarriers, which have transferrin conjugates on the surface serving as a gatekeeper. One nanocarrier was a conventional mesoporous silica nanoparticle (MSN) with transferrin attached through a pH-sensitive linker (MSN-Tf), while the other had a pH-sensitive diimine bridge in its framework, giving it degradable characteristic (dMSN-Tf). The use of conventional mathematical models and a three-parameter model that considers the drug-matrix interaction allowed the evaluation and elucidation of the different mechanisms involved in the kinetics of doxorubicin release from both materials at pH 7.4 and pH 5.0. The change in the kinetics of doxorubicin release from zero-order to first-order when it is in a degradable system such as dMSN-Tf, can be very useful for rapid drug delivery in acidic media such as inside cancer cells. Cell viability experiments in lung cancer cell lines A549 and H1299, showed enhanced anticancer activity by the nanomaterial with the pH-sensitive framework compared to the material that has a pH-sensitive linker. Overall, these findings provide important insights for optimizing the delivery of anticancer drugs
Can the Functional Physical Fitness of Older People with Overweight or Obesity Be Improved through a Multicomponent Physical Exercise Program? A Chilean Population Study
No full textPublisher Copyright: © 2024 by the authors.The aim of the present study was to understand the effect of a multicomponent physical exercise program on the functional physical fitness of older people with overweight or obesity in Chile, and whether these effects were similar in women and men. For this purpose, a quasi-experimental study was designed with a control group to evaluate the functional physical fitness through the Senior Fitness Test battery for older people [SFT; aerobic endurance (AE), lower body strength (LBS), upper body strength (UBS), upper body flexibility (UBF), lower body flexibility (LBF), dynamic balance (DB), and hand pressure strength right (HPSR) and left (HPSL)]. Seventy older people with overweight or obesity aged between 60 and 86 years participated (M = 73.15; SD = 5.94), and were randomized into a control group (CG, n = 35) and an experimental group (EG, n = 35). The results after the intervention between the CG and EG indicated that there were statistically significant differences in the AE (p = 0.036), in the LBS (p = 0.031), and in the LBF (p = 0.017), which did not exist before the intervention (p > 0.050), except in the HPSR (0.029). Regarding the results of the EG (pre vs. post-intervention), statistically significant differences were found in all of the variables studied: AE (p 0.05). Based on the results obtained, we can say that a multicomponent physical exercise program applied for 6 months in older people with overweight or obesity produces improvements in functional physical fitness regardless of sex, except in lower body flexibility and left-hand dynamometry
Estudio de prefactibilidad técnica económica para la instalación de una empresa de servicios y soluciones eléctricas, en la Región Metropolitana
Get PDFLa investigación se orienta a evaluar la viabilidad técnica y económica de la instalación de una empresa de servicios y soluciones eléctricas en la Región Metropolitana de Chile. A través de la identificación del mercado de servicios y soluciones eléctricas en la Región Metropolitana de Chile, la determinación de los recursos técnicos, humanos y legales necesarios para la operación de la empresa, el diseño del modelo de negocio y finalmente la elaboración de un estudio económico-financiero que proyecte la inversión inicial, los costos operativos, los ingresos potenciales y los indicadores de rentabilidad, para evaluar la viabilidad financiera del proyecto y su sostenibilidad a largo plazo. El análisis PESTEL revela un entorno dinámico con factores que impulsan la demanda de servicios y soluciones eléctricas en la Región Metropolitana. La transición energética hacia fuentes renovables, el crecimiento económico moderado, la conciencia ambiental y la digitalización del sector generan oportunidades para empresas que ofrezcan soluciones innovadoras y sostenibles. Sin embargo, la competitividad del mercado y las regulaciones del sector exigen una estrategia sólida y un profundo conocimiento del entorno. El análisis de las cinco fuerzas de Porter evidencia un mercado competitivo con barreras de entrada moderadas, un poder de negociación variable de proveedores y compradores, y una creciente amenaza de sustitutos provenientes de las energías renovables y la eficiencia energética. En este contexto, la empresa deberá diferenciarse a través de la especialización, la innovación y la calidad de sus servicios para lograr una posición competitiva sostenible. El proyecto presenta un Valor Actual Neto (VAN) positivo en todos los escenarios analizados, lo que indica que generará ingresos superiores a los costos asociados. Un VAN positivo es un fuerte indicador de la rentabilidad del proyecto, sugiriendo que es una inversión viable a largo plazo. La TIR es significativamente alta (47% en el escenario puro, 56% con financiamiento del 50% y 78% con financiamiento del 75%). Esto sugiere que el proyecto no solo supera el costo de capital, sino que también ofrece un retorno atractivo para los inversionistas, por lo que resulta positivamente factible.The research is oriented to evaluate the technical and economic feasibility of the installation of an electrical services and solutions company in the Metropolitan Region of Chile. Through the identification of the market for electrical services and solutions in the Metropolitan Region of Chile, the determination of the technical, human and legal resources necessary for the operation of the company, the design of the business model and finally the elaboration of an economicfinancial study that projects the initial investment, operating costs, potential income and profitability indicators, to evaluate the financial viability of the project and its long-term sustainability. The PESTEL analysis reveals a dynamic environment with factors driving the demand for electrical services and solutions in the Metropolitan Region. The energy transition to renewable sources, moderate economic growth, environmental awareness and digitalization of the sector create opportunities for companies offering innovative and sustainable solutions. However, market competitiveness and industry regulations require a sound strategy and a deep understanding of the environment. Porter's five forces analysis evidences a competitive market with moderate barriers to entry, variable bargaining power of suppliers and buyers, and a growing threat of substitutes from renewable energy and energy efficiency. In this context, the company will have to differentiate itself through specialization, innovation and the quality of its services in order to achieve a sustainable competitive position. The project has a positive Net Present Value (NPV) in all scenarios analyzed, indicating that it will generate revenues in excess of the associated costs. A positive NPV is a strong indicator of the project's profitability, suggesting that it is a viable long-term investment. The IRR is significantly high (47% in the pure scenario, 56% with 50% financing and 78% with 75% financing). This suggests that the project not only exceeds the cost of capital, but also offers an attractive return for investors, making it positively feasible
Habitar el tiempo. Breves consideraciones sobre el cuidado de la casa común.
No full textEn la encíclica Laudato si´ (2015) se realiza un diagnóstico sobre los principales problemas ecológicos a los cuales nos enfrentamos hoy en día, haciendo un llamado a cuidar nuestra casa común. ¿Pero cómo debemos cuidarla? En el presente artículo, mostraremos la importancia de habitar el tiempo a la hora de querer enfrentarnos a la crisis ecológica. Específicamente reflexionaremos sobre cómo al hacernos conscientes de la influencia del tiempo en nuestro día a día podemos adoptar una vida más acorde con el mundo que nos rodea, y sobre todo con Dios. De este modo, si bien, la relación entre el tiempo y Dios está muy presente en la historia del pensamiento occidental, por ejemplo, en San Agustín, Santo Tomás de Aquino, Newton, Leibniz, Levinas, por mencionar sólo algunos, su relación con el medio ambiente no es tan evidente, ni tampoco una línea de argumentación común. Por este motivo, en el presente artículo intentaremos mostrar la importancia que tiene comprender la naturaleza del tiempo a la hora de querer establecer soluciones a la cuestión ecológica
Convergences and divergences in the professional trajectories of Secondary Technical-Vocational Education teachers who study pedagogy
Get PDFPublisher Copyright: © 2024 PEL, CC BY-NC,This study examines the career trajectories of three secondary technical-vocational education teachers in Chile who decided to study pedagogy while working in technical high schools. Unlike the traditional teacher training path, these professionals entered the workforce before formalizing their pedagogical education, offering a unique perspective on their professional development. The analysis focuses on identifying points of convergence and divergence in their trajectories, using biographical narratives to uncover key moments, motivations, and vocational shifts. The results revealed positive previous educational experiences and an early attraction to teaching as common points, while differences were found in the paths taken before entering teaching. Unlike conventionally trained teachers, these professionals approach pedagogy with a clear understanding of their formative process, underscoring the importance of tailoring teacher training programs to their specific needs. Thus, this study offers an insightful perspective on the professional development of technical-vocational education teachers, suggesting ways to enrich training processes in this educational field.Este estudio examina las trayectorias profesionales de tres docentes de Educación Media Técnico-Profesional (EMTP) en Chile que decidieron estudiar pedagogía mientras ejercían la docencia en liceos técnicos. A diferencia de la ruta tradicional de formación docente, estos profesionales primero ingresaron al campo laboral antes de formalizar su educación pedagógica, ofreciendo una perspectiva única sobre su desarrollo profesional. El análisis se centra en identificar puntos de convergencia y divergencia en sus trayecto- rias, utilizando relatos biográficos para desentrañar momentos clave, motivaciones y giros vocacionales. Los resultados revelaron experiencias educativas previas positivas y una atracción temprana hacia la docencia como puntos comunes, mientras que las diferencias radicaron en los recorridos previos a su ingreso a la enseñanza. A diferencia de los docentes formados convencionalmente, estos profesionales abordan la pedagogía con una comprensión clara de su proceso formativo, subrayando la importancia de adaptar los programas de formación docente a sus necesidades específicas. Así, este estudio ofrece una perspectiva reveladora sobre el desarrollo profesional de los docentes de EMTP, sugiriendo vías para enriquecer los procesos de formación en este ámbito educativo
Brain clocks capture diversity and disparities in aging and dementia across geographically diverse populations
No full textPublisher Copyright: © The Author(s) 2024.Brain clocks, which quantify discrepancies between brain age and chronological age, hold promise for understanding brain health and disease. However, the impact of diversity (including geographical, socioeconomic, sociodemographic, sex and neurodegeneration) on the brain-age gap is unknown. We analyzed datasets from 5,306 participants across 15 countries (7 Latin American and Caribbean countries (LAC) and 8 non-LAC countries). Based on higher-order interactions, we developed a brain-age gap deep learning architecture for functional magnetic resonance imaging (2,953) and electroencephalography (2,353). The datasets comprised healthy controls and individuals with mild cognitive impairment, Alzheimer disease and behavioral variant frontotemporal dementia. LAC models evidenced older brain ages (functional magnetic resonance imaging: mean directional error = 5.60, root mean square error (r.m.s.e.) = 11.91; electroencephalography: mean directional error = 5.34, r.m.s.e. = 9.82) associated with frontoposterior networks compared with non-LAC models. Structural socioeconomic inequality, pollution and health disparities were influential predictors of increased brain-age gaps, especially in LAC (R² = 0.37, F² = 0.59, r.m.s.e. = 6.9). An ascending brain-age gap from healthy controls to mild cognitive impairment to Alzheimer disease was found. In LAC, we observed larger brain-age gaps in females in control and Alzheimer disease groups compared with the respective males. The results were not explained by variations in signal quality, demographics or acquisition methods. These findings provide a quantitative framework capturing the diversity of accelerated brain aging
Resilience and mental health in practicing chilean teachers during the pandemic
No full textPublisher Copyright: © 2023 Elsevier LtdThe connection between resilience and psychological well-being, as well as the associations between various resilience profiles and well-being, remain unclear. This study investigated the resilience profiles of teachers and their links to psychological well-being and mental health symptoms. The data were gathered from 602 Chilean teachers who completed questionnaires assessing resilience, well-being, and mental health symptoms. The primary findings revealed a significant relationship between resilience and mental health, especially among experienced teachers who perceived their working conditions as better. This study provides compelling evidence supporting the notion that resilience can serve as a protective factor against mental health issues
Ordered Patterns of (3+1)-Dimensional Hadronic Gauged Solitons in the Low-Energy Limit of Quantum Chromodynamics at a Finite Baryon Density, Their Magnetic Fields and Novel BPS Bounds
No full textPublisher Copyright: © 2024 by the authors.In this paper, we will review two analytical approaches to the construction of non-homogeneous Baryonic condensates in the low-energy limit of QCD in (3+1) dimensions. In both cases, the minimal coupling with the Maxwell (Formula presented.) gauge field can be taken explicitly into account. The first approach (which is related to the generalization of the usual spherical hedgehog ansatz to situations without spherical symmetry at a finite Baryon density) allows for the construction of ordered arrays of Baryonic tubes and layers. When the minimal coupling of the Pions to the (Formula presented.) Maxwell gauge field is taken into account, one can show that the electromagnetic field generated by these inhomogeneous Baryonic condensates is of a force-free type (in which the electric and magnetic components have the same size). Thus, it is natural to wonder whether it is also possible to analytically describe magnetized hadronic condensates (namely, Hadronic distributions generating only a magnetic field). The idea of the second approach is to construct a novel BPS bound in the low-energy limit of QCD using the theory of the Hamilton–Jacobi equation. Such an approach allows us to derive a new topological bound which (unlike the usual one in the Skyrme model in terms of the Baryonic charge) can actually be saturated. The nicest example of this phenomenon is a BPS magnetized Baryonic layer. However, the topological charge appearing naturally in the BPS bound is a non-linear function of the Baryonic charge. Such an approach allows us to derive important physical quantities (which would be very difficult to compute with other methods), such as how much one should increase the magnetic flux in order to increase the Baryonic charge by one unit. The novel results of this work include an analysis of the extension of the Hamilton–Jacobi approach to the case in which Skyrme coupling is not negligible. We also discuss some relevant properties of the Dirac operator for quarks coupled to magnetized BPS layers
Evaluation of Fissures and Cracks in Bridges by Applying Digital Image Capture Techniques Using an Unmanned Aerial Vehicle
No full textPublisher Copyright: © 2023 by the authors.The evaluation of cracks and fissures in bridge structures is essential to ensure the long-term safety, durability, and functionality of these infrastructures. In this sense, processing grayscale images and adjusting brightness and contrast levels can improve the visibility of cracks and fissures in bridge structures. These techniques, complemented by professional expertise and efficient inspection tools such as Unmanned Aerial Vehicles (UAVs), allow for a comprehensive and accurate structural integrity assessment. This study used the edge detection technique to analyze photographs obtained with a low-cost UAV as a means of image capture. This tool was used to reach hard-to-reach areas where there could be damage, thus making it easier to detect fissures or cracks. To capture the failures, two case studies, a small bridge and a large bridge, were selected, both located in Concepción City in southern Chile. During both inspections, cracks were detected that could affect the structure of the bridges in the future. To analyze these findings, ImageJ software 1.54h was used, which allowed the length and thickness of the cracks to be measured and evaluated. In addition, to validate the procedure proposed, real values manually measured on-site were compared with those delivered by the software analyses, where no statistically significant differences were found. With the method presented in this study, it was possible to quantify the damage, following the bridge maintenance standards established by the Ministry of Public Works of Chile, whose inspection criteria can be applied to other projects worldwide