137 research outputs found

    Shaking earth: Non-linear seismic processes and the second law of thermodynamics: A case study from Canterbury (New Zealand) earthquakes

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    We would like to express our gratitude to GeoNet for making available the data used in this work. This work was partially sup-ported by the RNM104 and RNM194 (Research Groups belonging to Junta de Andalucia, Spain) , the Spanish National Projects [grant project PID2019-109608GB-I00] , and the Junta de Andalucia Project [grant project A-RNM-421-UGR18] . English language editing was performed by Tornillo Scientific.Earthquakes are non-linear phenomena that are often treated as a chaotic natural processes. We propose the use of the Second Law of Thermodynamics and entropy, H, as an indicator of the equilibrium state of a seismically active region (a seismic system). In this sense, in this paper we demonstrate the exportability of first principles (e.g., thermodynamics laws) to others scientific fields (e.g., seismology). We suggest that the relationship between increasing H and the occurrence of large earthquakes reflects the irreversible transition of a system. From this point of view, a seismic system evolves from an unstable initial state (due to external stresses) to a state of reduced stress after an earthquake. This is an irreversible transition that entails an increase in entropy. In other words, a seismic system is in a metastable situation that can be characterised by the Second Law of Thermodynamics. We investigated two seismic episodes in the Canterbury area of New Zealand: the 2010 Christchurch earthquake (M = 7.2) and the 2016 Kaikoura earthquake (M = 7.8). The results are remarkably in line with our theoretical forecasts. In other words, an earthquake, understood as an irreversible transition, must results in an increase in entropy.Research Groups belonging to Junta de Andalucia, Spain RNM104- RNM194Spanish National Projects PID2019-109608GB-I00Junta de Andalucia A-RNM-421-UGR1

    Resistant/Refractory Hypertension and Sleep Apnoea: Current Knowledge and Future Challenges

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    Hypertension is one of the most frequent cardiovascular risk factors. The population of hypertensive patients includes some phenotypes whose blood pressure levels are particularly difficult to control, thus putting them at greater cardiovascular risk. This is especially true of so-called resistant hypertension (RH) and refractory hypertension (RfH). Recent findings suggest that the former may be due to an alteration in the renin–angiotensin–aldosterone axis, while the latter seems to be more closely related to sympathetic hyper-activation. Both these pathophysiological mechanisms are also activated in patients with obstructive sleep apnoea (OSA). It is not surprising, therefore, that the prevalence of OSA in RH and RfH patients is very high (as reflected in several studies) and that treatment with continuous positive airway pressure (CPAP) manages to reduce blood pressure levels in a clinically significant way in both these groups of hypertensive patients. It is therefore necessary to incorporate into the multidimensional treatment of patients with RH and RfH (changes in lifestyle, control of obesity and drug treatment) a study of the possible existence of OSA, as this is a potentially treatable disease. There are many questions that remain to be answered, especially regarding the ideal combination of treatment in patients with RH/RfH and OSA (drugs, renal denervation, CPAP treatment) and patients’ varying response to CPAP treatment

    Epithelial cells removed in advanced surface ablation (ASA) surgery can be used as a source of corneal samples to perform in vitro studies

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    Producción CientíficaHuman corneal epithelial cells are needed to study corneal pathophysiology in vitro. Due to the limitations of cell lines, the use of primary cells is highly desirable, but the scarcity of human tissues, along with ethical issues, make it difficult to accomplish all required experiments. In advanced surface ablation (ASA), the central corneal epithelium is removed and discarded. We hypothesized that ASA samples could be used to perform in vitro assays. In this study, 29 samples from patients undergoing ASA were recovered in supplemented DMEM/F12 culture medium, RIPA buffer, or RLT lysis buffer. The first aim was to determine whether cells could be maintained in culture. Although with the explant technique, tissue pieces did not attach to the culture surface, after disaggregation, cells showed high viability (90.0 ± 6.0%), attached to plates, and remained viable for up to 14 days. The second aim was to elucidate if ASA samples could be used to study protein or gene expression. Cytokeratin-3, ZO-1, Ki67, and E-cadherin protein expression were confirmed by immunofluorescence. Total protein (485.8 ± 115.8 μg) was isolated from cells in RIPA buffer, and GAPDH was detected by Western blotting, indicating that samples are adequate for protein studies. RNA (9.0 ± 3.6 μg) was isolated from samples in RLT lysis buffer, and GAPDH gene expression was studied by PCR, confirming that samples were also suitable for gene expression studies. These results suggest that samples obtained from corneal surface ablation procedures may constitute a valuable source of human cells to accomplish in vitro studies.Ministerio de Economía, Industria y Competitividad - Fondo Europeo de Desarrollo Regional (project FEDER-CICYT MAT2013-47501-C02-R)Ministerio de Ciencia, Innovación y Universidades - Fondo Europeo de Desarrollo Regional (project RTI2018-094071-B-C21

    Tsallis Entropy and Mutability to Characterize Seismic Sequences: The Case of 2007–2014 Northern Chile Earthquakes

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    Partial support from the following two Chilean sources is acknowledged: Fondecyt under contract 1230055, Financiamiento Basal para Centros Científicos y Tecnológicos de Excelencia (Chile) through the Center for Development of Nanoscience and Nanotechnology (CEDENNA) under contract AFB220001. This research has been partially supported by the Agencia Estatal de Investigación (grant no. PID2021-124701NBC21 y C22); the Universidad de Almería (grant no. FEDER/UAL Project UAL2020-RNM-B1980); the Consejería de Universidad, Investigación e Innovación, Junta de Andalucía (grant no. RNM104). PPITUAL, Junta de Andalucía-FEDER 2021–2027. Programa: 54.A. A.P., D.P. and E.E.V. have been partially funded by the Spanish Project LEARNIG PID2022-143083NB-I00 by the Agencia Estatal de Investigación.Seismic data have improved in quality and quantity over the past few decades, enabling better statistical analysis. Statistical physics has proposed new ways to deal with these data to focus the attention on specific matters. The present paper combines these two progressions to find indicators that can help in the definition of areas where seismic risk is developing. Our data comes from the IPOC catalog for 2007 to 2014. It covers the intense seismic activity near Iquique in Northern Chile during March/April 2014. Centered in these hypocenters we concentrate on the rectangle Lat−18 −22 and Lon−72 −68 and deepness between 5 and 70 km, where the major earthquakes originate. The analysis was performed using two complementary techniques: Tsallis entropy and mutability (dynamical entropy). Two possible forecasting indicators emerge: (1) Tsallis entropy (mutability) increases (decreases) broadly about two years before the main MW 8.1 earthquake. (2) Tsallis entropy (mutability) sharply decreases (increases) a few weeks before the MW 8.1 earthquake. The first one is about energy accumulation, and the second one is because of energy relaxation in the parallelepiped of interest. We discuss the implications of these behaviors and project them for possible future studies.Consejería de Universidad, Investigación e Innovación, Junta de Andalucía PID2022-143083NB-I00, RNM104Financiamiento Basal para Centros Científicos y Tecnológicos de Excelencia AFB220001Fondo Nacional de Desarrollo Científico y Tecnológico 1230055 FONDECYTAgencia Estatal de Investigación PID2021-124701NBC21 y C22 AEIUniversidad de Almería UAL2020-RNM-B1980 UA

    Relaciones de similitud y valor discriminativo de los indicadores bibliométricos: los indicadores de Scimago Journal & Country Rank en las revistas generalistas de Paleontología

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    Los objetivos de este trabajo son: (1) analizar las relaciones de similitud de los indicadores bibliométricos; y (2) estudiar el valor de estos para discriminar/agrupar revistas científicas. Como unidades de estudio se utilizaron los 15 indicadores brinda- dos por SCImago Journal Rank (SCImagoJR), aplicados a las 11 revistas paleontológicas generalistas listadas en dicha fuente durante el lapso 1999-2013. Las relaciones de similitud entre los indicadores se estimaron mediante un fenograma, mientras que el valor de los indicadores para agrupar/discriminar revistas se estimó mediante un análisis de componentes principales. Los resultados permiten concluir que, al menos para las revistas consideradas en este estudio, los 15 indicadores utilizados por SCI-magoJR muestran redundancia por grupos, debido a las correlaciones existentes entre indicadores de producción, por una parte, y de citación, por otra. Sin embargo, esto es válido solo a los efectos de agrupar las revistas, ya que al considerar cada indicador por separado se aprecian variaciones entre los mismos, que permiten establecer una caracterización más específica de cada revista e, incluso, colaboran a explicar los resultados del análisis multivariado. Por otra parte, los resultados coinciden con los obtenidos por otros autores al reunir en un mismo grupo al SJR y al número de citas/ documento en un período de dos años y en otro al índice h y al indicador número total de citas en un lapso de tres años.Mesa 4: Métricas de información científico/técnicaDepartamento de Bibliotecologí

    Reconstrucción ósea acetabular con cotilos no cementados y aporte de aloinjerto en la artroplastia total de cadera : estudio de 35 casos

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    Se han revisado 35 arlroplastias realizadas en 29 pacientes portadores de algún tipo de defecto óseo en el cotilo por fallo de prótesis total de cadera. En el presente estudio incluimos sólo las reconstrucciones acetabulares efectuadas con implantes no cementados. La edad media fue de 60 años (29/79), siendo 19 mujeres y 10 varones. Clasificamos los defectos óseos siguiendo a D'Antonio en segmentarios, cavitarios y mixtos, y para la reparación de dichos defectos utilizamos aloinjerto criopreservado en todos los casos excepto uno, tratado con injerto liofilizado. Valoramos los resultados desde un punto de vista clínico, subjetivo y objetivo (escala de Harris). Desde un punto de vista radiológico se analizaron las migraciones del implante acetabular, la existencia de zonas de radiolucencia, las osificaciones periarticulares y la incorporación o no del injerto óseo utilizado. Desde el punto de vista clínico obtuvimos un 60% de resultados excelentes y buenos, frente a un 40% de regulares y malos. Desde cualquier punto de vista el índice de aflojamiento del componente acetabular fue mucho mayor que el que puede obtenerse con cotilos no defectuososThirty five revision hip arthroplasties performed in 29 patients with acetabular bone defects were reviewed. In this series we only include the acetabular reconstruction performed using non cemented acetabular implants. The mean age of the patients was 60 years (29-79), 19 were female and 10 male. We classified the acetabular bone defects according to D'Antonio, in segmentary, cavitary and combined. To repair these defects, we used criopreserved allograft, except one case in which a liofilized allograft was used. The results were evaluated clinically (modified Harris hip score) and radiographically, looking for acetabular migrations, radiolucent lines, periarticular ossifications and bone graft incorporation. We obtained 60% of excellent and good results. There was 40% of poor and fair results. The acetabular loosening rate was higher than in revision hip arthroplasty without acetabular bone defects

    Fracturas de las espinas tibiales en el niño y en el adulto

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    Presentamos una serie de 29 fracturas de las espinas tibiales en 27 pacientes, 11 niños y 16 adultos. Para su estudio hemos seguido la clasificación de Meyers y McKeever, siendo las fracturas tipo II las más frecuentes. Se registraron las lesiones asociadas de la rodilla, y la más frecuente fue la del ligamento lateral interno; encontramos 2 fracturas de Segond en niños. El tratamiento fue conservador en 7 casos y quirúrgico en los 22 restantes. Para evaluar el resultado final estudiamos el desplazamiento de la fractura, movilidad y laxitudes residuales de la rodilla y fuerza muscular. Usamos las escalas de Lysholm y de Tegner para la valoración funcional. Un estudio radiológico con 3 proyecciones se llevó a cabo en todos los pacientes. El tiempo medio de seguimiento fue de 9,7 años para el grupo de niños y de 8,2 para los adultos. Los resultados globales, de acuerdo con la escala de Lysholm, fueron excelentes, pero se registraron 11 laxitudes anteroposteriores y 4 laterales, aunque 11 de estos 15 pacientes permanecen asintomáticos. Muchas de estas laxitudes aparecen en fracturas anatómicamente reducidas. Sugerimos que debe realizarse estudio artroscópico en estos pacientes para detectar lesiones asociadas que empeoran el resultado.A series of 29 fractures of the tibial spine in 27 patients, 11 children and 16 adults. We followed Meyers and McKeever to classify the fractures, tipe II being the most frecuent. Associated injuries of the knee were registered, being medial collateal ligament the most frecuent. We found 2 Segond fractures in young patients. The treatment was conservative in 7 cases and surgical in the remaining 22. To evaluate the final result we studied the displacement of the fracture, mobility of the knee, anteroposterior and lateral inestabilities, muscle strength. We used the Lysholm and the Tegner rating systems to evaluate the functional result. A complete radiological evaluation (three views) was made in all the patients. The average follow-up times was 9.7 years for the children group, and 8.2 years for the adult group. The overall results according to the Lysholm rating scale were excellent, but 11 anteroposterior and 4 lateral laxities were registered, though 11 of the 15 cases remains asymptomatic. Many of theese laxities appeared in anatomically reduced fractures. We suggest that an arthroscopic study of the patients must be done to detect associated injuries that produces a worse final result

    Resultados a largo plazo de la patelectomía total

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    Desde el año 1981 hemos realizado 19 patelectomías totales, 9 por artrosis femoropatelar, 8 por dolor anterior de rodilla y 2 por fracturas conminutas. La edad media en el momento de la intervención era de 48 años (25-80); todos los pacientes con dolor anterior habían sido operados previamente. Con una evolución media de 7,8 años (3-14), hemos realizado una revisión clínica y radiológica. Según la escala de la Sociedad Internacional de Rodilla obtuvimos un 58% de resultados excelentes y buenos, resaltando que continúan con dolor todos los pacientes operados por artrosis y el 50% de los intervenidos por dolor anterior. La patelectomía total es una técnica cada vez menos utilizada, limitándose sus indicaciones a fracturas muy conminutas, artrosis femoropatelar en pacientes en los que estaría contraindicada la artroplastia total y en cuadros de dolor anterior de rodilla rebeldes a otros tratamientosNineteen total patelectomies were performed since 1981. The indication was femoropatellar osteoarthritis in nine cases, anterior knee pain syndrome in eight, and conminute fractures in two. The mean age of the group at the time of operation was 48 years (25-80). A1l the patients with anterior knee pain syndrome had been operated previously. With an average followup time of 7.8 years (3-14), vve reviewed our patients clinically and radiographically. We used the International Knee Society rating scale and found 58% of excellent and good results; 100% of the patients operated because of osteoarthritis and 50% of those operated because an anterior knee pain syndrome have pain at review. Total patellectomy is not a frequent technique. Today, the sole indications are very conminute fractures of the patella, femoropatellar osteoarthritis in those patients in which total knee arthroplasty is not indicated and in the anterior knee pain syndrome not improved with other treatments

    Assessing the impact of continuous evaluation strategies: tradeoff between student performance and instructor effort

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    © 2016 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works[EN] Current opinion on undergraduate studies has led to a reformulation of teaching methodologies to base them not just on learning, but also on skills and competencies. In this approach, the teaching/learning process should accomplish both knowledge assimilation and skill development. Previous works demonstrated that a strategy that uses continuous evaluation is able to meet both objectives. However, those studies did not evaluate and quantify the additional effort required to implement such strategies. This paper evaluates the additional instructor effort required when implementing continuous evaluation in a first-year Computer Fundamentals course in the Computer Engineering degree program at the Technical University of Valencia, Spain. The experiment quantifies how instructor workload increases under different continuous evaluation strategies and how this affects the overall student grade. Both the standard continuous evaluation method and the intensive continuous evaluation method are analyzed, the latter being a proposal that builds upon the standard method by increasing the number of tests and examinations. The results obtained reveal that continuous evaluation improves student grades but that intensive continuous evaluation is liable to generate an excessive instructor overload without having a significant impact on student scores.This work was supported in part by the Department of Computing Engineering (DISCA) and the School of Informatics (ETSINF) of the Universitat Politecnica de Valencia (UPV).Poza-Lujan, J.; Tavares De Araujo Cesariny Calafate, CM.; Posadas-Yagüe, J.; Cano Escribá, JC. (2016). Assessing the impact of continuous evaluation strategies: tradeoff between student performance and instructor effort. IEEE Transactions on Education. 59(1):17-23. doi:10.1109/TE.2015.2418740S172359
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