51 research outputs found

    Enhanced fish bending model for automatic tuna sizing using computer vision

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    [EN] This paper presents a non-invasive fully automatic procedure to obtain highly accurate fish length estimation in adult Bluefin Tuna, based on a stereoscopic vision system and a deformable model of the fish ventral silhouette. The present work takes a geometric tuna model, which was previously developed by the same authors to discriminate fish in 2D images, and proposes new models to enhance the capabilities of the automatic procedure, from fish discrimination to accurate 3D length estimation. Fish length information is an important indicator of the health of wild fish stocks and for predicting biomass using length-weight relations. The proposal pays special attention to parts of the fish silhouette that have special relevance for accurate length estimation. The models have been designed to best fit the rear part of the fish, in particular the caudal peduncle, and a width parameter has been added to better fit the silhouette. Moreover, algorithms have been developed to extract snout tip and caudal peduncle features, allowing better initialization of model parameters. Snout Fork Length (SFL) measurements using the different models are extracted from images recorded with a stereoscopic vision system in a sea cage containing 312 adult Atlantic Bluefin Tuna. The automatic measurements are compared with two ground truths: one configured with semiautomatic measurements of favourable selected samples and one with real SFL measurements of the tuna stock collected at harvesting. Comparison with the semiautomatic measurements demonstrates that the combination of improved geometric models and feature extraction algorithms delivers good results in terms of fish length estimation error (up to 90% of the samples bounded in a 3% error margin) and number of automatic measurements (up to 950 samples out of 1000). When compared with real SFL measurements of the tuna stock, the system provides a high number of automatic detections (up to 6706 in a video of 135¿min duration, i.e., 50 automatic measurements per minute of recording) and highly accurate length measurements, obtaining no statistically significant difference between automatic and real SFL frequency distributions. This procedure could be extended to other species to assess the size distribution of stocks, as discussed in the paper.This work was supported by funding from ACUSTUNA project ref. CTM2015-70446-R (MINECO/ERDF, EU). This project has been possible thanks to the collaboration of IEO (Spanish Oceanographic Institute). We acknowledge the assistance provided by the Spanish company Grup Balfego S.L. in supplying boats and divers to acquire underwater video in the Mediterranean Sea.Muñoz-Benavent, P.; Andreu García, G.; Valiente González, JM.; Atienza-Vanacloig, V.; Puig Pons, V.; Espinosa Roselló, V. (2018). Enhanced fish bending model for automatic tuna sizing using computer vision. Computers and Electronics in Agriculture. 150:52-61. https://doi.org/10.1016/j.compag.2018.04.005S526115

    Automatic Bluefin Tuna sizing using a stereoscopic vision system

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    [EN] This article presents a non-invasive fully automatic procedure for Bluefin Tuna sizing, based on a stereoscopic vision system and a deformable model of the fish ventral silhouette. An image processing procedure is performed on each video frame to extract individual fish, followed by a fitting proce- dure to adjust the fish model to the extracted targets, adapting it to the bending movements of the fish. The proposed system is able to give accu- rate measurements of tuna snout fork length (SFL) and widths at five predefined silhouette points without manual intervention. In this work, the system is used to study size evolution in adult Atlantic Bluefin Tuna (Thunnus Thynnus) over time in a growing farm. The dataset is composed of 12 pairs of videos, which were acquired once a month in 2015, between July and October, in three grow-out cages of tuna aquaculture facilities on the west Mediterranean coast. Each grow out cage contains between 300 and 650 fish on an approximate volume of 20 000 m3.Measurements were au- tomatically obtained for the 4 consecutive months after caging and suggest a fattening process: SFL shows an increase of just a few centimetres (2%) while themaximum width (A1)shows arelative increaseofmorethan20%,mostlyinthe first 2months in farm. Moreover, a linear relation (with co- efficient of determination R2> 0.98) between SFL and widths for each month is deduced, and a fattening factor (F) is introduced. The validity of the measurements is proved by comparing 15 780 SFL measurements, obtained with our automatic system in the last month, versus ground truth data of a high percentage of the stock under study (1143 out of 1579), obtaining no statistically significant difference. This procedure could be extended to other species to assess the size distribution of stocks, as discussed in the article.This work was supported by funding from ACUSTUNA project ref. CTM2015-70446-R (MINECO/ERDF, EU). This project has been possible thanks to the collaboration of IEO (Spanish Oceanographic Institute).Muñoz-Benavent, P.; Andreu García, G.; Valiente González, JM.; Atienza-Vanacloig, V.; Puig Pons, V.; Espinosa Roselló, V. (2018). Automatic Bluefin Tuna sizing using a stereoscopic vision system. ICES Journal of Marine Science. 75(1):390-401. https://doi.org/10.1093/icesjms/fsx151S39040175

    Estimation of Bluefin Tuna (Thunnus thynnus) mean length in sea cages by acoustical means

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    [EN] This paper proposes an indirect method to estimate Bluefin Tuna (Thunnus thynnus) biomass in cages using acoustic techniques. Two Simrad EK60 echosounders working at 120 and 200 kHz and a stereo camera were used to obtain target strength (TS) to fork length (FL) relationships for both operating frequencies. The equipment was placed at the bottom of a floating cage, facing towards the surface to record the ventral aspect of fish. The acoustic and optical recordings were automatically analysed and the combination of acoustic and optical results provided unequivocal TS-FL assignments. Good relationships between TS and FL were obtained for both frequencies even without discriminating data from different fish tilts and without using beam directivity compensation. Stronger correlations were obtained for compensated TS at 200 kHz when reduced tuna swimming tilt was considered. TS measurements were compared to MFS numerical predictions for a Bluefin swimbladder model, with the simulation results showing good agreement with experimental measurements. The results allow the mean tuna length to be predicted in growing or fattening cages from acoustic data raising the possibility of improving production management and of providing a useful tool for catch control estimations made by international organisations (like ICCAT) and government bodies. (c) 2022 The Author(s). Published by Elsevier Ltd. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).This work was supported by funding from the ACUSTUNA pro-ject ref. CTM2015-70446-R (MINECO/ERDF, EU). The authors are grateful for the support provided by Grup Balfego for their collab-oration and implication in installing and maintaining of the exper-imental setup in their tuna cages at l'Ametlla de Mar and for providing an ABFT specimen for x-ray imaging.Puig Pons, V.; Muñoz-Benavent, P.; Pérez Arjona, I.; Ladino-Velásquez, A.; Llorens-Escrich, S.; Andreu García, G.; Valiente González, JM.... (2022). Estimation of Bluefin Tuna (Thunnus thynnus) mean length in sea cages by acoustical means. Applied Acoustics. 197:1-13. https://doi.org/10.1016/j.apacoust.2022.10896011319

    Acción tutorial y competencias transversales: alcance de la contribución de los/as tutores/as de Filosofía y Letras, UA

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    La contribución que nos proponemos presentar atiende dos vertientes de la investigación que hemos llevado a cabo en este curso 2014/2015 en la red en investigación en docencia universitaria dedicada a la Acción tutorial de nuestro centro (Filosofía y Letras, UA). En un primer tiempo, daremos cuenta brevemente del análisis de los resultados obtenidos en las ediciones anteriores. Para ello expondremos cuestiones organizativas que han pretendido conseguir un mayor alcance de la labor de los tutores en colaboración con los tutores par, analizaremos y evaluaremos las medidas de mejora implementadas en el transcurso de las ediciones. En un segundo tiempo, analizaremos y evaluaremos el alcance del equipo de la Acción tutorial en su apoyo a los estudiantes en la adquisición de las competencias transversales. Nuestra investigación tiene como objetivo principal la medición de resultados obtenidos desde la implementación de la figura del tutor par en colaboración con el tutor docente así como la ideación de medidas de optimización para asegurar el espacio necesario para el funcionamiento correcto y pleno de la Acción Tutorial en todas sus dimensiones

    El Programa de Acción Tutorial en la facultad de Filosofía y Letras. Colaboración y coordinación tutores docentes y pares. Análisis, resultados y retos

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    La Facultad de Filosofía y Letras de la Universidad de Alicante cuenta ya en su haber con diez años de implementación del Programa de Acción Tutorial, primero en el periodo de impartición de las licenciaturas LRU, y después a partir de 2009/2010 con los grados enmarcados en el Espacio Europeo de Educación Superior. El programa, en base al progresivo margen de funcionamiento otorgado por el ICE ha ido adaptándose a las características de nuestro centro, al perfil de los estudiantes y de las titulaciones impartidas. Tras este fructífero recorrido realizado, contando ya también con 6 ediciones de tutorización par, nos pareció necesaria hacer una revisión de las medidas de mejora aplicadas, hacer un balance de los aciertos y desaciertos, ver qué disfunciones se detectaban y cómo podían preverse nuevas acciones para asegurar el alcance de la Acción Tutorial a todo el alumnado de nuestro centro, logrando la ideal optimización perseguida. Nuestra red se ha propuesto en este curso analizar, entre otros aspectos que definen el programa de la Acción Tutorial en nuestra facultad, la colaboración y coordinación de los/as tutores/as docentes con los/as pares. Nuestra investigación ha permitido situar algunas problemáticas y vislumbrar posibles soluciones así como producir materiales aplicables en próximos cursos

    Use of interactive response devices for the improvement of teaching in the degrees of the Faculty of Sciences

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    La implantación de los nuevos Grados dentro del EEES supone un nuevo enfoque metodológico, pero sobre todo evaluador. El profesor debe esforzarse en ser capaz de valorar no sólo el nivel de conocimientos del alumnado sobre los contenidos, ya que la sociedad actual demanda un perfil de los egresados más completo basado en la formación por competencias. La adquisición de ambas facetas por parte del alumnado se basa principalmente en actividades presenciales y metodologías docentes aplicadas en el desarrollo de las asignaturas, tanto en grupo reducido como en grupo completo. Por tanto, cualquier herramienta adicional que ayude al docente a facilitar esta doble tarea es bien recibida, pues permitirá evaluar el rendimiento académico global del alumnado. Recientemente la Facultad de Ciencias ha puesto en marcha una experiencia piloto mediante la cual un nutrido grupo de profesores ha incorporado en su docencia un sistema de mandos inalámbricos de respuesta. Actualmente, la Facultad de Ciencias dispone de un total de 82 mandos inalámbricos de respuesta y tres antenas receptoras. Esta nueva tecnología ha permitido al docente realizar, de forma interactiva, preguntas colectivas al alumnado y recoger las respuestas individuales de forma inmediata. Los resultados obtenidos en este proyecto nos permiten ser muy optimistas con el uso de esta herramienta y nos animan a continuar en la misma línea. El profesorado participante se ha mostrado dispuesto a continuar empleando esta TIC en su docencia, tratando de abarcar más asignaturas, diversificar el tipo de pruebas, y emplear los mandos de respuesta en grupo completo, cuando el número de alumnos lo permita. La puesta en común de los resultados revela que, de forma general, este tipo de sistemas de respuesta incrementa el nivel de atención del alumnado, ya que se les demanda de forma continuada su participación activa durante la sesión. Se potencia la retención de conceptos, al suministrar en el acto la respuesta correcta a cada pregunta realizada. Permite también al profesorado conocer el nivel previo de conocimientos sobre la materia a impartir, ya que se puede realizar este tipo de preguntas al comienzo de la sesión y enfocar entonces su atención en las debilidades manifestadas. Asimismo se puede testar el grado de adquisición de dichos conocimientos, realizando este tipo de cuestionarios después de la sesión. Además, el tratamiento posterior de los resultados, de forma individualizada, permite gestionar de forma ágil el nivel de conocimientos y adquisición de competencias en lo que es un sistema de evaluación continua, tan necesario en los nuevos enfoques metodológicos nacidos de la implantación del EEES. Por último destacar que el profesorado participante ha considerado que se trata de una herramienta de gran utilidad para la consecución del objetivo de excelencia en la docencia, que además es eficaz y de fácil manejo, y entiende que no debe ser una actividad puntual, sino un proceso transformador en la actividad docente e interacción alumno-profesor, configurándose como una herramienta habitual en los sistemas de enseñanza-aprendizaje.Implementation of the new degrees in the EHEA involve a new methodological approach, but above all evaluation. The teacher should strive to be able to assess not only the level of knowledge of the students on the content, as the current society demands a profile of the most complete graduates based on training by competencies. The acquisition of both facets by students is based mainly on face-to-face activities and teaching methodologies applied in the development of the subjects, both in small group and in whole group. Therefore, any additional tool that helps the teacher to facilitate this double task is well received, since it will allow to evaluate the overall academic performance of the students. Recently the Faculty of Sciences has launched a pilot experience through which a large group of teachers has incorporated into their teaching a system of interactive response devices. Currently, the Faculty of Sciences has a total of 82 wireless response controllers and three receiving antennas. This new technology has enabled the teacher to interact interactively with the students and collect the individual answers immediately. The results obtained in this project allow us to be very optimistic with the use of this tool and encourage us to continue in the same line. The participating teachers have been willing to continue using this ICT in their teaching, trying to cover more subjects, diversify the type of tests, and use the full group response commands, when the number of students allows. The sharing of results reveals that, in a general way, this type of response systems increases the level of attention of the students, since they are continuously demanded their active participation during the session. The retention of concepts is strengthened by providing the correct answer to every question asked. It also allows the faculty to know the previous level of knowledge about the subject to be taught, since this type of questions can be asked at the beginning of the session and then focus their attention on the weaknesses manifested. It is also possible to test the degree of acquisition of this knowledge, performing this type of questionnaire after the session. In addition, the subsequent treatment of the results, in an individualized way, allows to manage in an agile way the level of knowledge and acquisition of competences in what is a system of continuous evaluation, so necessary in the new methodological approaches born from the implantation of the EHEA. Finally, it should be pointed out that the participating teachers have considered that this is a very useful tool for achieving the objective of excellence in teaching, which is also efficient and easy to use and understands that it should not be a specific activity, but a transforming process in the teaching activity and student-teacher interaction, being configured as a habitual tool in the teaching-learning systems

    Foro 18 de Historia y Crítica de la Arquitectura Moderna.

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    Grupo de Investigación Aprendizaje en el hábitat Comunitario.Selección de textos del Foro 18 de Historia y Crítica de la Arquitectura Moderna. Libro núm. 7 de la colección de libros del ForoEn un contexto histórico en donde es clara la relación de la humanidad con la arquitectura, en tanto nos han aportado un inmenso legado ético y estético, y que, sin embargo, en la situación actual de la arquitectura se muestra en contradicción ya que prevalece el interés económico y la pronta ganancia por sobre el cuidado de la naturaleza, la sustentabilidad en las ciudades, la identificación estética de la arquitectura y el encuentro social a través del espacio público, se podría tener una primera caracterización de la arquitectura de emergencia. Los once trabajos aquí presentados colocan al centro el quehacer arquitectónico y desde ese punto ofrecen un contexto y diversidad de prácticas y respuestas. Dichos textos cuentan con reflexiones teóricas, exposición de búsquedas a manera de prácticas y valoraciones críticas de ejercicios de distintas escalas. Destaca en esta ocasión la práctica profesional del ejercicio “Reconstrucción de la vivienda Chiapas... una reflexión”, misma que nace del ejercicio mismo, de la búsqueda de soluciones en campo y no del ejercicio de investigación.Día 1: https://youtu.be/Vacp2el_N2ADía 2: https://youtu.be/ujfc8JZsbQwDía 3: https://youtu.be/vD2NxcFjLy

    Clonal chromosomal mosaicism and loss of chromosome Y in elderly men increase vulnerability for SARS-CoV-2

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    The pandemic caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2, COVID-19) had an estimated overall case fatality ratio of 1.38% (pre-vaccination), being 53% higher in males and increasing exponentially with age. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, we found 133 cases (1.42%) with detectable clonal mosaicism for chromosome alterations (mCA) and 226 males (5.08%) with acquired loss of chromosome Y (LOY). Individuals with clonal mosaic events (mCA and/or LOY) showed a 54% increase in the risk of COVID-19 lethality. LOY is associated with transcriptomic biomarkers of immune dysfunction, pro-coagulation activity and cardiovascular risk. Interferon-induced genes involved in the initial immune response to SARS-CoV-2 are also down-regulated in LOY. Thus, mCA and LOY underlie at least part of the sex-biased severity and mortality of COVID-19 in aging patients. Given its potential therapeutic and prognostic relevance, evaluation of clonal mosaicism should be implemented as biomarker of COVID-19 severity in elderly people. Among 9578 individuals diagnosed with COVID-19 in the SCOURGE study, individuals with clonal mosaic events (clonal mosaicism for chromosome alterations and/or loss of chromosome Y) showed an increased risk of COVID-19 lethality
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