Nowadays, there is an extensive production and use of plastic materials for different industrial activities. These plastics, either from their primary production sources or through their own ...degradation processes, can contaminate ecosystems with micro- and nanoplastics. Once in the aquatic environment, these microplastics can be the basis for the adsorption of chemical pollutants, favoring that these chemical pollutants disperse more quickly in the environment and can affect living beings. Due to the lack of information on adsorption, three machine learning models (random forest, support vector machine, and artificial neural network) were developed to predict different microplastic/water partition coefficients (log
) using two different approximations (based on the number of input variables). The best-selected machine learning models present, in general, correlation coefficients above 0.92 in the query phase, which indicates that these types of models could be used for the rapid estimation of the absorption of organic contaminants on microplastics.
Biological Ecosystem Networks (BENs) are webs of biological species (nodes) establishing trophic relationships (links). Experimental confirmation of all possible links is difficult and generates a ...huge volume of information. Consequently, computational prediction becomes an important goal. Artificial Neural Networks (ANNs) are Machine Learning (ML) algorithms that may be used to predict BENs, using as input Shannon entropy information measures (Sh
) of known ecosystems to train them. However, it is difficult to select a priori which ANN topology will have a higher accuracy. Interestingly, Auto Machine Learning (AutoML) methods focus on the automatic selection of the more efficient ML algorithms for specific problems. In this work, a preliminary study of a new approach to AutoML selection of ANNs is proposed for the prediction of BENs. We call it the Net-Net AutoML approach, because it uses for the first time Sh
values of both networks involving BENs (networks to be predicted) and ANN topologies (networks to be tested). Twelve types of classifiers have been tested for the Net-Net model including linear, Bayesian, trees-based methods, multilayer perceptrons and deep neuronal networks. The best Net-Net AutoML model for 338,050 outputs of 10 ANN topologies for links of 69 BENs was obtained with a deep fully connected neuronal network, characterized by a test accuracy of 0.866 and a test AUROC of 0.935. This work paves the way for the application of Net-Net AutoML to other systems or ML algorithms.
Global solar irradiation is an important variable that can be used to determine the suitability of an area to install solar systems; nevertheless, due to the limitations of requiring measurement ...stations around the entire world, it can be correlated with different meteorological parameters. To confront this issue, different locations in Rias Baixas (Autonomous Community of Galicia, Spain) and combinations of parameters (month and average temperature, among others) were used to develop various machine learning models (random forest -RF-, support vector machine -SVM- and artificial neural network -ANN-). These three approaches were used to model and predict (one month ahead) monthly global solar irradiation using the data from six measurement stations. Afterwards, these models were applied to seven different measurement stations to check if the knowledge acquired could be extrapolated to other locations. In general, the ANN models offered the best results for the development and testing phases of the model, as well as for the phase of knowledge extrapolation to other locations. In this sense, the selected ANNs obtained a mean absolute percentage error (MAPE) value between 3.9 and 13.8% for the model development and an overall MAPE between 4.1 and 12.5% for the other seven locations. ANNs can be a capable tool for modelling and predicting monthly global solar irradiation in areas where data are available and for extrapolating this knowledge to nearby areas.
This study proposed different techniques to estimate the isotope composition (δ18O), salinity and temperature/potential temperature in the Mediterranean Sea using five different variables: (i–ii) ...geographic coordinates (Longitude, Latitude), (iii) year, (iv) month and (v) depth. Three kinds of models based on artificial neural network (ANN), random forest (RF) and support vector machine (SVM) were developed. According to the results, the random forest models presents the best prediction accuracy for the querying phase and can be used to predict the isotope composition (mean absolute percentage error (MAPE) around 4.98%), salinity (MAPE below 0.20%) and temperature (MAPE around 2.44%). These models could be useful for research works that require the use of past data for these variables.
It was in the early eighties that a genuine school of spanish biochemists around Severo Ochoa participated in the oncogene races. Malignant cell transformation and oncogenes were put in relation ...during that era. Several prominent scientists coming from Spain have established and maintained a strong tradition of studies in the enzymology of retroviruses and transcriptional events. In this short historical account, we briefly pay tribute to these famous forerunners, by emphasizing both the originality and quality of their work, as well as the many accompanying conceptual and methodological analysis. We start with Àngel Pellicer (1948-) who, amongst other contributions, first established the landmark experimental transfection protocol and nucleated the onset of oncogenetics with his discovery that ras oncogenes were activated by mitogenic factors. Whereas Manuel Perucho (1948-) can be considered as one of the pioneers, if not the founder, of the cloning of human oncogene, through his experiments on H-ras, and he became a milestone in diagnostic detection to allow hospital technicians to screen for mutant ras genes. More known Mariano Barbacid (1949-) established that ras oncogene was a kind of common denominator for cancer, and clarified that their functional differences were by a single point mutation. In conclusion, this history demonstrates how eager spanish biochemists trained by Eladio Viñuela were to maintain the tradition of Severo Ochoa's long-standing scientific reputation in the US.
A principios de los años ochenta, una auténtica escuela de bioquímicos españoles alrededor de Severo Ochoa participó en las competiciones sobre el tema del oncogén. La transformación maligna de la célula y los oncogenes se pusieron en relación durante éste período. Diferentes científicos importantes procedentes de España establecieron y mantuvieron una fuerte tradición de estudios en enzimología de los retrovirus y de los eventos transcripcionales. Ésta corta relación histórica, rinde homenaje a estos conocidos precursores, subrayando tanto la originalidad y calidad de su trabajo, como los muchos análisis conceptuales y metodológicos que lo acompañan. Comenzamos por Àngel Pellicer (1948-) quien, entre otras contribuciones, estableció el primero el histórico protocolo experimental de transfección y nucleó el inicio de la oncogenética con su descubrimiento de que los oncogenes ras se activan por factores mitogénicos. Mientras que Manuel Perucho (1948-) puede ser considerado como uno de los pioneros, sino el fundador, de la clonación del oncogén humano, en base a sus experimentos con H-ras, y se convirtió en un hito en el diagnóstico para la detección que permitía a los técnicos de los hospitales buscar genes ras mutantes. Más conocido, MarianoBarbacid (1949-) demostró que el nivel del oncogén ras estaba era el de denominador común del cáncer, e indicó que sus diferencias funcionales se limitaban a un único punto de mutación. Para concluir, esta historia refleja el afán de los bioquímicos españoles formados por Eladio Viñuela de mantener la reputación científica de Severo Ochoa, de larga tradición en los EE.UU.
Au début des années 1980 une véritable école de biochimistes espagnols autour de Severo Ochoa a participé à la course des oncogènes. La transformation en cellule maligne et les oncogènes ont été mis en relation durant cette période. De réputés scientifiques provenant d'Espagne ont établi et entretenu une tradition vraiment solide en matière de l'enzymologie des rétrovirus et des événements transcriptionnels. Dans cet historique sommaire, nous rendons brièvement hommage à ces précurseurs célèbres, en mettant l'accent tant sur l'originalité et la qualité de leur travail, ainsi que sur les nombreuses analyses conceptuelles et méthodologiques qui les accompagnent. Nous commençons par Àngel Pellicer (1948-) qui, entre différentes contributions, a été à l'origine de l'historique protocole expérimental de transfection, ayant stabilisé la marche initiale de l'oncogénétique avec sa découverte que les oncogènes ras sont activés par des facteurs mitogéniques. Alors que Manuel Perucho (1948-) peut être considéré comme un des pioniers, sinon le fondateur, du clonage de l'oncogène humaine, par ses expériences portant sur H-ras, également il a franchi une étape dans le diagnostique pour la détection permettant aux techniciens de l'hôpital viser les gènes ras mutés. Plus connu, Mariano Barbacid (1949-) a établi que l'oncogène ras était en soi une forme de dénominateur commun au cancer, et a fait apparaître que leur différences fonctionnelles se ramenaient à une unique mutation ponctuelle. En conclusion, cette histoire montre combien les biochimistes espagnols formés par Eladio Viñuela ont su maintenir la tradition de réputation scientifique de longue haleine aux États-Unis de Severo Ochoa.
In the area of Trk oncogene research has been revealed the different competing hypotheses made at the time of its discovery. A conflict of interest arised within the group who identified it as the ...nerve growth factor receptor (NGF). An auxiliary assumption, on the cardinal importance of the low affinity p75 receptor, resulted in that the consistency of the group take patterns of competence. The level of provocation affected the joint effort. In an environment that reminds the denial that Stehelin was given by Varmus and Bishop, in the race for the Nobel Prize in Physiology or Medicine. Nowadays p75 receptor functions are described as "enigmatic", and accepted that all the neurotrophins interact with two types of receptors: the specific to the ligands of the high-affinity Trk family of receptors and the low affinity p75 receptor (with structural similarities to the tumor necrosis factor and in liaison with the development of eye optical fiber). Against this background, papers concerning this subject and included in the WOK citation database are analysed. Categorizing them through a system of descriptors, according to their original publication date. Complete time vectors are approximated by setting the analysis with a growth model based on Gompertz function. After the criteria used by authorities like Rita Levi-Montalcini, Luigi Cavalli-Sforza, Rodolfo Llinás and Victor McKunsick the selected material resulted in a database with 371 records. These data suggest the opportunity for historical sciences of a non discrimination compliance test performed on multiple hypotheses.
En el área de la investigación sobre el oncogén trk se ha puesto en evidencia las diferentes hipótesis en discordia en el momento de su descubrimiento. Dentro del grupo que lo identificó como el receptor del factor de crecimiento nervioso (NGF), hubo un conflicto de intereses. La importancia cardinal de la existencia complementaria del receptor p75 de baja afinidad, condujo a que la coherencia del grupo cambiase hacia un modelo competitivo. El nivel de provocación afectó al esfuerzo conjunto. En un cuadro que recuerda el desmentido dictado contra Stehelin por parte de Varmus y Bishop, en la carrera por el premio Nobel en Fisiología o Medicina. Actualmente las funciones del receptor p75 se califican de "enigmáticas", y se acepta que todas las neurotrofinas interaccionan con dos tipos de receptores: el específico a los ligandos de la familia de receptores de alta afinidad Trk y el receptor de baja afinidad p75 (que presenta similitudes estructurales con el factor de necrósis tumoral y en relación con el desarrollo de las fibras ópticas). Con éste ambiente, se estudian los documentos sobre este tema, incluidos en la base de datos de citas WOK. Categorizándolos mediante un sistema de descriptores, en función de su fecha de publicación original. Una estimación orientativa de la evolución temporal completa se consigue creando un análisis con un modelo de crecimiento basado en la función de Gompertz. Siguiendo los criterios de autoridades como Rita Levi-Montalcini, Luigi Cavalli-Sforza, Rodolfo Llinás y Victor McKunsick, el material seleccionado dió lugar a una base de datos con 371 registros. Estos datos sugieren la oportunidad para las ciencias históricas de realizar una prueba de conformidad sin discriminación para evaluar las hipótesis múltiples.
Dans le domaine de la recherche sur les oncogènes trk se sont manifestées différentes hypothèses au moment de sa découverte. Un conflit d'intérêts est né au sein du groupe qui l'a identifié comme le recepteur du facteur de croissance du nerf (NGF). Une question auxiliaire, sur l'importance cardinale du récepteur à faible affinité p75, a permis que la cohérence du groupe adopte des comportements compétitifs. Le niveau de provocation a touché l'effort commun. Dans un contexte qui rappelle le démenti que Stéhelin s'est vu attribuer de la part de Varmus et Bishop, dans la course au prix Nobel en Physiologie ou Médecine (1989). Au présent les fonctions du récepteur p75 sont qualifiées de "énigmatiques", et est accepté que chacune des neurotrophines interagit avec deux types de récepteurs: les spécifiques aux ligands de la famille des récepteurs à haute affinité trk (à des homogénéités structurelles avec le facteur nécrosant des tumeurs et de concert avec le développement de la fibre optique de l'oeil). Dans ce cadre, les documents sur cette question, compris dans la base de données de citations WOK sont analysés. Pour les classer aux besoins d'un système de descripteurs, d'après leur date de publication. On peut avoir une idée des vecteurs temporels complets en ramenant l'analyse à un modèle de croissance suivant une function de Gompertz. Sur les critères utilisés par des autorités comme Rita Levi-Montalcini, Luigi Cavalli-Sforza, Rodolfo Llinás et Victor McKunsick, les résultats retenus ont permis l'établissement d'une base de données avec 371 registres. Ces données suggèrent l'occasion pour les sciences historiques d'effectuer des tests de conformité de non-discrimination pour évaluer des hypothèses multiples.
Brain Connectome Networks (BCNs) are defined by brain cortex regions (nodes) interacting with others by electrophysiological co-activation (edges). The experimental prediction of new interactions in ...BCNs represents a difficult task due to the large number of edges and the complex connectivity patterns. Fortunately, we can use another special type of networks to achieve this goal—Artificial Neural Networks (ANNs). Thus, ANNs could use node descriptors such as Shannon Entropies (Sh) to predict node connectivity for large datasets including complex systems such as BCN. However, the training of a high number of ANNs for BCNs is a time-consuming task. In this work, we propose the use of a method to automatically determine which ANN topology is more efficient for the BCN prediction. Since a network (ANN) is used to predict the connectivity in another network (BCN), this method was entitled Net-Net AutoML. The algorithm uses Sh descriptors for pairs of nodes in BCNs and for ANN predictors of BCNs. Therefore, it is able to predict the efficiency of new ANN topologies to predict BCNs. The current study used a set of 500,470 examples from 10 different ANNs to predict node connectivity in BCNs and 20 features. After testing five Machine Learning classifiers, the best classification model to predict the ability of an ANN to evaluate node interactions in BCNs was provided by Random Forest (mean test AUROC of 0.9991 ± 0.0001, 10-fold cross-validation). Net-Net AutoML algorithms based on entropy descriptors may become a useful tool in the design of automatic expert systems to select ANN topologies for complex biological systems. The scripts and dataset for this project are available in an open GitHub repository.
The mobility of Spanish biochemists from Europe to the United States over the past 80 years (1927–2006) is approached from a historical perspective. The academic community on human genetics has ...awarded this emigrated Spanish community with the Nobel prize as well as other awards from European foundations. The vertical/horizontal integration methodology offers an opportunity to understand the extremely satisfactory history of a small European community overseas. To piece the puzzle together, continuous reference is made to the theory of systems. To test and use this holistic history, the circulation of the knowledge produced on cancer has been studied as intrinsically related to time by using the algorithmic historiography.
Francisco Duran Reynals and Severo Ochoa have been selected as examples of the vertical integration. The former one because he was the director of an important collaborator, his own wife; the latter, as the founder of a Spanish specific research school in America based in his own work. The simultaneous stay of several young Spanish scientists at the Columbia University (Mariano Barbacid, Manuel Perucho and Ángel Pellicer) serves to design the horizontal integration, to create a holon hierarchy to reflect the criteria of subsidiarity and acceptability, and to focus on the Spanish discoveries and contributions to cancer research.
The transatlantic flows of knowledge generated by the Spanish elite of biochemists in the USA from 1927 on define a network of geographical displacements. As a result, the social structure thus visualizes the identity of the international mobility of scientists who leave for Europe/USA, and their return to Spain. A model of the brain drain of professionals to the USA, that retain 80% of the Spanish cancer researchers, is developed.
The topic of employee commitment and turnover intentions has been a subject of consideration for many years. This study examines the relationship between occupational culture fit, occupational global ...job embeddedness, occupational commitment, and occupational turnover intentions. The investigation was performed at the individual level in manufacturing organizations located in the Midwest of the United States with 201 employees. This non-experimental study includes a quantitative survey design. The survey includes four standardized instruments: occupational culture fit, occupational global job embeddedness, occupational commitment, and occupational turnover intention. Analysis indicates that there is positive relationship exist between occupational culture fit, occupational global job embeddedness, and occupational commitment; and occupational commitment and occupational turnover intentions. The findings enhance the theoretical study of Group and Grid Dimensions of Occupational Cultures Theory, Social Identification Theory and Image Theory by providing empirical evidence needed to validate and expand future investigation. Suggestions for future research include performing research in different geographical regions and other types of manufacturing sectors, such as metal and chemical industries.
The aim of this study is the analysis of the historical complexities associated with cancer registries in Spain. After the acceptance of the International Classification of Diseases in 1900, the ...first cancer incidence survey was in 1902. Following the inteernational initiative by the German Central Committee for Canceer Research (DZK), the Instituto Rubio conducted a census of all cancer patients undeer medical tretment. Spain attended the meeting in Berlin where the International Association for Cancer Research was founded (1908), and the Inteernational Union Against Cancer (IUAC) constitutional congress was held in Madrid (1933). Nonetheless, Spanish was absent from the first cancer registries conference (Copenhagen, September 1946), and from the WHO committe to support cancer registry programming (1950). As a result, contemporary history of Spanish cancer registries starts as late as 1960 in Zaragoza, particularly through the establishment of a Latin language speaking countries registries team.
Este estudio tiene como objetivo analizar las complejidades históricas de los registros de cáncer en España. Tras la aceptación en 1900 de la primera clasificación internacional de enfermedades, se produjo en 1902 el primer estudio de incidencia del cáncer. A causa de la iniciativa internacional del Comité Central Alemán para la Investigación sobre el Cáncer (DZK), el Instituto Rubio realizó un censo de todos los pacientes bajo tratamiento médico. España participó en la fundación en Berlín de la International Association for Cancer Research (1908) y el congreso constituyente de la Unión Internacional Contra el Cáncer (UICC) se reunió en 1933 en Madrid, pero no asistió a la primera conferencia de registros de cáncer (Copenhague, septiembre de 1946), ni al comité de programación del registro de cáncer de la OMS (1950). Como resultado, la historia contemporánea del registro de cáncer español empieza en Zaragoza en 1960. La evolución de las técnicas epidemiológicas permite afirmar que España, pionera en los registros hospitalarios, se convirtió al sistema de registros poblacionales tardíamente, en particular gracias a la instauración de un equipo de los registros latinos en el que Zaragoza jugó un papel importante.
La présente étude a pour objectif l'analyse des situations historiques complexes du registre des cancers en Espagne. Une fois acceptée en 1900 la première classification internationale des maladies, en 1902 s'est effectuée la première étude d'incidence du cancer. Le partenariat international du Comité central allemand pour la recherche sur le cancer (DZK) a mis en disposition le Instituto Rubio d'élaborer un recensement de tous les patients sous traitement médical. L'Espagne a participé à la fondation à Berlin de l'association internationale de la recherche sur le cancer (1908) et le Congrès constituant de l'Union internationale contre le cancer (UICC) s'est tenu à Madrid en 1933, mais n'a participé à la première conférence des registres des cancers (Copenhague, septembre 1946), ni au comité de programmation du registre de cancer de l'OMS (1950). En conséquence, l'histoire contemporaine du registre de cancer espagnol commence en 1960 à Zaragoza. L'évolution des techniques épidémiologiques permet d'affirmer que l'Espagne, pionnière dans le domaine des registres des hôpitaux, ne s'est convertie au système des registres basés sur la population que tardivement, par le biais notamment de la mise en place d'une équipe des registres latins où Zaragoza a joué un rôle important.
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