Diffusion Maps for dimensionality reduction and visualization of meteorological data

This is the author’s version of a work that was accepted for publication in Neurocomputing. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Neurocomputing, VOL 163, (2015) DOI 10.1016/j.neucom.2014.08.090The growing interest in big data problems implies the need for unsupervised methods for data visualization and dimensionality reduction. Diffusion Maps (DM) is a recent technique that can capture the lower dimensional geometric structure underlying the sample patterns in a way which can be made to be independent of the sampling distribution. Moreover, DM allows us to define an embedding whose Euclidean metric relates to the sample's intrinsic one which, in turn, enables a principled application of k-means clustering. In this work we give a self-contained review of DM and discuss two methods to compute the DM embedding coordinates to new out-of-sample data. Then, we will apply them on two meteorological data problems that involve time and spatial compression of numerical weather forecasts and show how DM is capable to, first, greatly reduce the initial dimension while still capturing relevant information in the original data and, also, how the sample-derived DM embedding coordinates can be extended to new patterns.The authors acknowledge partial support from Spain's grant TIN2010-21575-C02-01 and the UAM{ADIC Chair for Machine Learning. The first author is also supported by an FPI{UAM grant and kindly thanks the Applied Mathematics Department of Yale University for receiving her during her visits

Fatores de estresse percebidos entre carreiras de enfermagem recém entradas

Objective: To determine the prevalent stress factors among new students to the Faculties of Nursing at the Faculties of Nursing at the Universities of Cadiz, Cordoba, Huelva and Seville, and the influence of socio-demographic, academic, socio-economic, orientation and health factors. Design: A descriptive, observational and cross-sectional study. Methodology: 617 first year nursing students were surveyed (with a 95.66 % response rate) by means of two questionnaires, one for socio-demographics and health, the other for the stress perceived by new students. A descriptive analysis of the stress factors was then carried out for the frequency, mean and standard deviation. The relation between factors was examined through differential analysis by means of the Mann-Whitney U and Kruskal-Wallis non-parametric tests. Results: The situations of greatest anxiety among new undergraduates are “taking examinations” and “the amount of work I have to do”. Consequently, the most stressful factor is “academic stress” whilst the least stressful is “feelings of loneliness”. The students who feel most stress across various factors can be identified as: over 25, women, studying outside their home province, and living in rented accommodation during the academic year. Conclusions: Starting a degree in nursing is a stressful time, and students can find their health, quality of life and academic performance negatively affected. The main determinants of stress among new undergraduates are the joint demands of examinations and workload. It would undoubtedly be enlightening to examine this issue further in order to find the possible causes of the problem and to develop strategies that can help in its prevention and so improve the students’ experience of university.Objetivo: Conocer los factores de estrés más prevalentes en el alumnado novel de las Facultades de Enfermería de las Universidades de Cádiz, Córdoba, Huelva y Sevilla, así como su relación con sus características sociodemográficas, académicas, socioeconómicas, de orientación y de salud. Diseño: Estudio observacional, descriptivo, transversal. Metodología: Se encuestó a un total de 617 estudiantes (tasa de respuesta del 95,66 %) del primer curso del grado en Enfermería. Los participantes completaron dos cuestionarios: uno sociodemográfico y de salud; y un  cuestionario de estrés percibido por alumnos noveles. Se realizó un análisis descriptivo de los factores de estrés con frecuencia, media y desviación típica. Las relaciones se examinaron con análisis diferencial a través de estudios no paramétricos U Mann-Whitney y Kruskal-Wallis. Resultados: Las situaciones que más estrés causan a los nuevos universitarios son: “hacer frente a los exámenes” y “la cantidad de trabajo que tengo que afrontar”. En consecuencia, el factor más estresante es el “estrés académico” y el menos estresante el “sentimiento de soledad”. Los estudiantes que perciben mayor estrés en varios factores son: mayores de 25 años, mujeres, el alumnado que procede de otras provincias y los que viven de alquiler durante el curso académico. Conclusiones: La entrada a la universidad produce factores de estrés en el alumnado de enfermería, que pueden afectar a su salud, su calidad de vida y su rendimiento académico. Hacer frentes a los exámenes y la alta carga académica son las principales determinantes de estrés. Sin embargo, sería conveniente indagar más en esta línea con el fin de conocer las posibles causas de este problema y poder desarrollar estrategias de prevención que mejoren la calidad de vida de estos estudiantes.Objetivo: Conhecer os fatores de estresse mais prevalentes em novos alunos das Faculdades de Enfermagem das Universidades de Cádis, Córdoba, Huelva e Sevilha, bem como sua relação com suas características sociodemográficas, acadêmicas, socioeconômicas, de orientação, educacionais e saúde. Delineamento: Estudo observacional, descritivo, transversal. Metodologia: Foram pesquisados ​​617 alunos (taxa de resposta de 95,66 %) do primeiro ano do curso de Enfermagem. Os participantes responderam a dois questionários: sociodemográfico e de saúde; e questionário de estresse percebido por alunos iniciantes. Foi realizada análise descritiva dos fatores de estresse com frequência, média e desvio padrão. Os relacionamentos foram examinados com análise diferencial por meio de estudos não paramétricos de U Mann-Whitney e Kruskal-Wallis. Resultados: As situações que mais estressam os novos estudantes universitários são “fazer exames” e “a quantidade de trabalho que tenho que enfrentar”. Conseqüentemente, o fator mais estressante é o “estresse acadêmico” e o menos estressante são os “sentimentos de solidão”. Os alunos que percebem o maior estresse em vários fatores são: maiores de 25 anos, mulheres, alunos que vêm de outras províncias e aqueles que vivem de aluguel durante o ano letivo. Conclusões: O ingresso na universidade produz fatores estressantes nos estudantes de enfermagem, que podem afetar sua saúde, sua qualidade de vida e seu desempenho acadêmico. A realização de exames e a alta carga acadêmica são apontados como os principais determinantes do estresse. No entanto, seria conveniente aprofundar as investigações nesse sentido para conhecer as possíveis causas desse problema e poder desenvolver estratégias de prevenção que melhorem a qualidade de vida desses alunos

The physiology of ex vitro pineapple ( Ananas comosus L. Merr. var MD-2) as CAM or C3 is regulated by environmental conditions: proteomic and transcriptomic profiles

Pineapple is one of the most important tropical crops worldwide. The use of Temporary Immersion Bioreactors (TIB) for the first stages of pineapple propagation enables precise control of plant growth, increases the rate of plant multiplication, decreases space, energy and labor requirements for pineapple plants in commercial micropropagation. Once the plantlets are ready to be taken from the reactors, they are carefully acclimatized to adapt to natural environmental conditions, and a facultative C3/CAM metabolism in the first two months of growth is characteristic of pineapple plants, depending on environmental conditions. We subjected two sets of micropropagated pineapple plants to C3 and CAM-inducing environmental conditions, determined by light intensity/relative humidity (respectively 40μmol.m-2s-1/85% and 260μmol.m-2.s-1/50%). Leaves of pineapple plants grown under CAM inducing conditions showed higher leaf thickness and more developed cuticles and hypodermic tissue. Proteomic profiles of several proteins, isoenzyme patterns and transcriptomic profiles were also measured. Five major spots were isolated and identified, two of them for the first time in Ananas comosus (OEE 1; OEE 2) and the other three corresponding to small fragments of the large subunit of Rubisco (LSU). PEPC and PEPCK were also detected by immunobloting of 2DE at the end of both ex vitro treatments (C3/CAM) during the dark period. Isoenzymes of SOD and CAT were identified by electrophoresis and the transcript levels of OEE 1 and CAT were associated with CAM metabolism in pineapple plants

Design and validity of a choice-modeling questionnaire to analyze the feasibility of implementing physical activity on prescription at primary health-care settings

Worldwide health policies are trying to implement physical activity on prescription (PAP) at healthcare settings. However, there is not a proper methodology to analyze PHC organizational staff factors. This study aims to validate two questionnaires to assess the self-perception of nurses and general practitioners to implement PAP at primary healthcare (PHC) settings. The designed choice-modeling Google-form questionnaire was sent to 11 expert nurses and 11 expert sports medicine physicians. Experts evaluated each question on a 1–5 points Likert-type scale according to their expertise. Aiken’s V coefficient values =0.75 were used to validate separately each question using the Visual Basic-6.0 software. A total of 10 sports medicine physicians and 10 nurses with 28.4 ± 5.1 y and 16.3 ± 11.8 y of PAP experience, respectively, validated the questionnaire. One expert in each group was not considered for offering 3 ± SD answers in =2 questions respect to the mean of the rest of experts. Final Aiken’s V coefficient values were 0.89 (0.77–1.00) for the nurses’ questionnaire and 0.84 (0.77–0.95) for the physicians’ one. The questionnaires designed to assess the PAP self-perception of PHC nurses and physicians were validated. This methodology could be used to analyze PHC organizational staff factors in order to achieve an efficient PAP implementation in other PHC contexts

Catalytic Asymmetric Synthesis of Bicycloprolines by a 1,3-Dipolar Cycloaddition/Intramolecular Alkylation Strategy

This document is the Accepted Manuscript version of a Published Work that appeared in final form inJournal of Organic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://dx.doi.org/10.1021/acs.joc.6b01100 to Published Work, see http://pubs.acs.org/page/policy/articlesonrequest/index.htmlThe diastereoselective one-pot synthesis of hexahydrocyclopenta [b] pyrrole derivatives (bicycloprolines) has been achieved by base-mediated reactions of (E)-tert-butyl 6-bromo-2-hexenoate with α-imino esters. The catalytic asymmetric version of this process has been efficiently achieved using the CuI/(R)-DTBM-Segphos complex as a catalyst following a two-step 1,3-dipolar cycloaddition/intramolecular alkylation sequence.Financial support of this work by the Ministerio de Economía y Competitividad and Fondo Europeo de Desarrollo Regional (MINECO CTQ2012-35790 and MINECO/FEDER CTQ2015-66954-P) are gratefully acknowledged. M.G.-E. and A.P.-E. thank the MICINN for predoctoral fellowship

Diffusion maps and local models for wind power prediction

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-33266-1_70Proceedings of 22nd International Conference on Artificial Neural Networks, Lausanne, Switzerland, September 11-14, 2012In this work we will apply Diffusion Maps (DM), a recent technique for dimensionality reduction and clustering, to build local models for wind energy forecasting. We will compare ridge regression models for K–means clusters obtained over DM features, against the models obtained for clusters constructed over the original meteorological data or principal components, and also against a global model. We will see that a combination of the DM model for the low wind power region and the global model elsewhere outperforms other options.With partial support from grant TIN2010-21575-C02-01 of Spain’s Ministerio de Economía y Competitividad and the UAM–ADIC Chair for Machine Learning in Modelling and Prediction. The first author is also supported by an FPI-UAM grant and kindly thanks the Applied Mathematics Department of Yale University for receiving her during a visit. The second author is supported by the FPU-MEC grant AP2008-00167. We also thank Red Eléctrica de España, Spain’s TSO, for providing historic wind energy dat

Mouth gape determines the response of marine top predators to long-term fishery-induced changes in food web structure

Here, we analyse changes throughout time in the isotopic niche of the Franciscana dolphin (Pontoporia blainvillei), the South American fur seal (Arctocephalus australis) and the South American sea lion(Otaria flavescens) from the Río de la Plata estuary and adjacent Atlantic Ocean to test the hypothesis that fishing may modify the diet of small-gape predators by reducing the average size of prey. The overall evidence, from stable isotope and stomach contents analyses, reveals major changes in resource partitioning between the three predators considered, mainly because of an increased access of Franciscana dolphins to juvenile demersal fishes. These results are consistent with the changes in the length distribution of demersal fish species resulting from fishing and suggest that Franciscana dolphin has been the most benefited species of the three marine mammal species considered because of its intermediate mouth gape. In conclusion, the impact of fishing on marine mammals goes beyond the simple reduction in prey biomass and is highly dependent on the mouth gape of the species involved