126 research outputs found

    Comparing and Tuning Machine Learning Algorithms to Predict Type 2 Diabetes Mellitus

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    The main goals of this work is to study and compare machine learning algorithms to predict the development of type 2 diabetes mellitus. Four classifi cation algorithms have been considered, studying and comparing the accuracy of each one to predict the incidence of type 2 diabetes mellitus seven years in advance. Specifically, the techniques studied are: Decision Tree, Random Forest, kNN (k-Nearest Neighbors) and Neural Networks. The study not only involves the comparison among these techniques, but also, the tuning of the meta-parameters in each algorithm. The algorithms have been implemented using the language R. The data base used is obtained from the nation-wide cohort [email protected] study. The conclusions will include the accuracy of each algorithm and therefore the best technique for this problem. The best meta-parameters for each algorithm will be also provided.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

    Comprehensive Taxonomies of Nature- and Bio-inspired Optimization: Inspiration Versus Algorithmic Behavior, Critical Analysis Recommendations

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    In recent algorithmic family simulates different biological processes observed in Nature in order to efficiently address complex optimization problems. In the last years the number of bio-inspired optimization approaches in literature has grown considerably, reaching unprecedented levels that dark the future prospects of this field of research. This paper addresses this problem by proposing two comprehensive, principle-based taxonomies that allow researchers to organize existing and future algorithmic developments into well-defined categories, considering two different criteria: the source of inspiration and the behavior of each algorithm. Using these taxonomies we review more than three hundred publications dealing with nature- inspired and bio-inspired algorithms, and proposals falling within each of these categories are examined, leading to a critical summary of design trends and similarities between them, and the identification of the most similar classical algorithm for each reviewed paper. From our analysis we conclude that a poor relationship is often found between the natural inspiration of an algorithm and its behavior. Furthermore, similarities in terms of behavior between different algorithms are greater than what is claimed in their public disclosure: specifically, we show that more than one-third of the reviewed bio-inspired solvers are versions of classical algorithms. Grounded on the conclusions of our critical analysis, we give several recommendations and points of improvement for better methodological practices in this active and growing research field

    Not All Lies Are Equal. A Study Into the Engineering of Political Misinformation in the 2016 US Presidential Election

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    We investigated whether and how political misinformation is engineered using a dataset of four months worth of tweets related to the 2016 presidential election in the United States. The data contained tweets that achieved a signi cant level of exposure and was manually labelled into misinformation and regular information. We found that misinformation was produced by accounts that exhibit different characteristics and behaviour from regular accounts. Moreover, the content of misinformation is more novel, polarised and appears to change through coordination. Our ndings suggest that engineering of political misinformation seems to exploit human traits such as reciprocity and con rmation bias. We argue that investigating how misinformation is created is essential to understand human biases, diffusion and ultimately better produce public policy.The work of M. Molina-Solana was supported by the European Commission under Grant 743623. The work of J. Amador Díaz López was supported by the Imperial College Research Fellowship. The work of J. Gómez-Romero was supported by the Universidad de Granada under Grant P9-2014-ING and in part by the Spanish Ministry of Education, Culture and Sport under the José Castillejo Research Stays Programme

    Modulation of intestinal barrier function by glucocorticoids: Lessons from preclinical models

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    This work was supported by the "Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas (CIBERehd)", belonging to Instituto de Salud Carlos III, Spain, and grants from: Ministry of Economy and Competitivity, partly with Fondo Europeo de Desarrollo Regional FEDER funds [SAF2017-88457-R, AGL2017-85270-R]; "Junta de Andalucia", Spain [CTS235, CTS164]; "Fondo de Investigaciones Sanitarias, Instituto de Salud Carlos III", Spain (PI19/00819), co-funded by European Regional Development Fund/European Social Fund, "Investing in your future"; "Junta de Castilla y Leon" (SA074P20),Spain; "Fundacio Marato TV3'' (201916-31), Spain; AECC Scientific Foundation (2017/2020), Spain; and "Centro Internacional sobre el Envejecimiento" (OLD-HEPAMARKER, 0348_CIE_6_E), Spain. MAA and MTG were supported by fellowships from the Ministry of Education. MA was supported by a postdoctoral contract with the CIBERehd. Funding for open access charge: Universidad de Granada/CBUA.Glucocorticoids (GCs) are widely used drugs for their anti-inflammatory and immunosuppressant effects, but they are associated with multiple adverse effects. Despite their frequent oral administration, relatively little attention has been paid to the effects of GCs on intestinal barrier function. In this review, we present a summary of the published studies on this matter carried out in animal models and cultured cells. In cultured intestinal epithelial cells, GCs have variable effects in basal conditions and generally enhance barrier function in the presence of inflammatory cytokines such as tumor necrosis factor (TNF). In turn, in rodents and other animals, GCs have been shown to weaken barrier function, with increased permeability and lower production of IgA, which may account for some features observed in stress models. When given to animals with experimental colitis, barrier function may be debilitated or strengthened, despite a positive anti-inflammatory activity. In sepsis models, GCs have a barrier-enhancing effect. These effects are probably related to the inhibition of epithelial cell proliferation and wound healing, modulation of the microbiota and mucus production, and interference with the mucosal immune system. The available information on underlying mechanisms is described and discussed."Centro de Investigacion Biomedica en Red de Enfermedades Hepaticas y Digestivas (CIBERehd), Instituto de Salud Carlos III, SpainMinistry of Economy and CompetitivityEuropean Commission SAF2017-88457-R AGL2017-85270-RJunta de Andalucia European Commission CTS235 CTS164Instituto de Salud Carlos III PI19/00819European Regional Development Fund/European Social Fund, "Investing in your future"Junta de Castilla y Leon SA074P20Fundacio Marato TV3, Spain 201916-31AECC Scientific Foundation, Spain"Centro Internacional sobre el Envejecimiento" (OLD-HEPAMARKER), Spain 0348_CIE_6_EMinistry of EducationCIBERehdUniversidad de Granada/CBU

    A multi-perspective comparison of ESA Academy’s Training and Learning Programme experiences before and throughout COVID-19 pandemic through the eyes of 6 students

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    The forced transition from fully in-person learning to online methodologies incurred by the proliferation of the COVID-19 pandemic has been a major blow to most organisations worldwide. The aim of the present paper is to analyse the impact of the COVID-19 in ESA educational activities from students' perspective, in order to stimulate the future creation of both online and on-site courses. The participation of the authors in the ESA Academy training sessions covers the period from February 2019 to September 2021, thus experiencing not only both on-site and online courses, but also pre- and mid-pandemic learning experiences and course adaptations due to the impact of COVID-19. The wide range of space education experiences gathered by the authors enables a multi-perspective comparison of a variety of topics involving the ESA Academy training sessions such as networking possibilities, course dynamics and content, motivation induced by the course environment, impact on the future career and professional development of the participants, as well as compared to the academic experience of the students at their home universities. The analysis and comparison of the authors' experiences allow to establish correlations between the learning method (in-person or online) and the specific experience outcomes of attending an ESA Academy training session. Finally, some recommendations are provided to further mitigate the COVID-19 impact on space educational activities

    Association between Urine Fluoride and Dental Fluorosis as a Toxicity Factor in a Rural Community in the State of San Luis Potosi

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    Objective. The aim of this study is to investigate urine fluoride concentration as a toxicity factor in a rural community in the state of San Luis Potosi, Mexico. Materials and Methods. A sample of 111 children exposed to high concentrations of fluoride in drinking water (4.13 mg/L) was evaluated. Fluoride exposure was determined by measuring urine fluoride concentration using the potentiometric method with an ion selective electrode. The diagnosis of dental fluorosis was performed by clinical examination, and the severity of damage was determined using Dean’s index and the Thylstrup-Fejerskov (TF) index. Results. The range of exposure in the study population, evaluated through the fluoride content in urine, was 1.1 to 5.9 mg/L, with a mean of 3.14 ± 1.09 mg/L. Dental fluorosis was present in all subjects, of which 95% had severe cases. Higher urine fluoride levels and greater degrees of severity occurred in older children. Conclusions. The results show that dental fluorosis was determined by the presence of fluoride exposure finding a high positive correlation between the severity of fluorosis and urine fluoride concentration and the years of exposure suggested a cumulative effec

    Towards a large-scale twitter observatory for political events

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    Explosion in usage of social media has made its analysis a relevant topic of interest, and particularly so in the political science area. Within Data Science, no other techniques are more widely accepted and appealing than visualisation. However, with datasets growing in size, visualisation tools also require a paradigm shift to remain useful in big data contexts. This work presents our proposal for a Large-Scale Twitter Observatory that enables researchers to efficiently retrieve, analyse and visualise data from this social network to gain actionable insights and knowledge related with political events. In addition to describing the supporting technologies, we put forward a working pipeline and validate the setup with different examples

    The molecular clock protein Bmal1 regulates cell differentiation in mouse embryonic stem cells

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    Mammals optimize their physiology to the light–dark cycle by synchronization of the master circadian clock in the brain with peripheral clocks in the rest of the tissues of the body. Circadian oscillations rely on a negative feedback loop exerted by the molecular clock that is composed by transcriptional activators Bmal1 and Clock, and their negative regulators Period and Cryptochrome. Components of the molecular clock are expressed during early development, but onset of robust circadian oscillations is only detected later during embryogenesis. Here, we have used na¨ıve pluripotent mouse embryonic stem cells (mESCs) to study the role of Bmal1 during early development. We found that, compared to wild-type cells, Bmal12/2 mESCs express higher levels of Nanog protein and altered expression of pluripotencyassociated signalling pathways. Importantly, Bmal12/2 mESCs display deficient multi-lineage cell differentiation capacity during the formation of teratomas and gastrula-like organoids. Overall, we reveal that Bmal1 regulates pluripotent cell differentiation and propose that the molecular clock is an hitherto unrecognized regulator of mammalian development.Ramon y Cajal grant of the Spanish ministry of economy and competitiveness RYC2012-10019Spanish ministry of economy and competitiveness BFU2016-75233-PAndalusian regional government PC-0246-2017Fundacion Progreso y Salud (FPS)Instituto de Salud Carlos III European Union (EU) CPII17/00032 PI17/01574University of Granad

    Isolation and Structural Elucidation of New Amphidinol Analogues from Amphidinium carterae Cultivated in a Pilot-Scale Photobioreactor

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    The demand for valuable products from dinoflagellate biotechnology has increased remarkably in recent years due to their many prospective applications. However, there remain many challenges that need to be addressed in order to make dinoflagellate bioactives a commercial reality. In this article, we describe the technical feasibility of producing and recovering amphidinol analogues (AMs) excreted into a culture broth of Amphidinium carterae ACRN03, successfully cultured in an LED-illuminated pilot-scale (80 L) bubble column photobioreactor operated in fed-batch mode with a pulse feeding strategy. We report on the isolation of new structurally related AMs, amphidinol 24 (1, AM24), amphidinol 25 (2, AM25) and amphidinol 26 (3, AM26), from a singular fraction resulting from the downstream processing. Their planar structures were elucidated by extensive NMR and HRMS analysis, whereas the relative configuration of the C-32®C-47 bis-tetrahydropyran core was confirmed to be antipodal in accord with the recently revised configuration of AM3. The hemolytic activities of the new metabolites and other related derivatives were evaluated, and structure–activity conclusions were established. Their isolation was based on a straightforward and high-performance bioprocess that could be suitable for the commercial development of AMs or other high-value compounds from shear sensitive dinoflagellates

    At the beginnings of the funerary Megalithism in Iberia at Campo de Hockey necropolis

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    The excavations undertaken at the Campo de Hockey site in 2008 led to the identification of a major Neolithic necropolis in the former Island of San Fernando (Bay of Cádiz). This work presents the results of the latest studies, which indicate that the site stands as one of the oldest megalithic necropolises in the Iberian Peninsula. The main aim of this work is to present with precision the chronology of this necropolis through a Bayesian statistical model that confirms that the necropolis was in use from c. 4300 to 3800 cal BC. The presence of prestige grave goods in the earliest and most monumental graves suggest that the Megalithism phenomenon emerged in relation to maritime routes linked to the distribution of exotic products. We also aim to examine funerary practices in these early megalithic communities, and especially their way of life and the social reproduction system. As such, in addition to the chronological information and the Bayesian statistics, we provide the results of a comprehensive interdisciplinary study, including anthropological, archaeometric and genetic data.Archaeological background: the Campo de Hockey settlement Methods - Tomb typology - Radiocarbon dates and Bayesian analysis. - Bioarchaeology. - DNA - Grave goods Results - Tomb typology - Radiocarbon dating: Bayesian analysis - Bioarchaeology. - DNA - Grave goods. Discussion and conclusions
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