Desarrollo de un inmunosensor basado en nanopartículas de oro para detectar atrazina en agua

128 páginas. Maestría en Ciencias e Ingeniería Ambientales.Se desarrolló un inmunosensor empleando un anticuerpo monoclonal anti-atrazina como molécula de biorreconocimiento y nanopartículas de oro (AuNPs) como marcador para la detección electroquímica de atrazina. Las AuNPs fueron sintetizadas en el laboratorio por el método de Turkevich y caracterizadas por métodos ópticos y electroquímicos. Se realizó un inmunoensayo no competitivo tipo sándwich usando partículas paramagnéticas como soporte para la inmovilización del anticuerpo anti-atrazina en combinación con electrodos magneto composite grafito-epoxi los cuales fueron caracterizados previamente de manera electroquímica mediante voltamperometría cíclica. Algunos parámetros experimentales tales como: potencial de oxidación, tiempo de oxidación, concentración de agente bloqueante y cantidad de partículas magnéticas fueron optimizados, lográndose detectar cuantitativamente atrazina con el método de voltamperometría de pulso diferencial calculándose un límite de detección de 0.017 ng/mL, el cual fue obtenido bajo condiciones experimentales óptimas y resultó ser mucho más bajo que la concentración mínima recomendada por la Organización Mundial de la Salud (OMS), la Agencia de Protección al Ambiente de los Estados Unidos (USEPA), Asociación Nacional de Empresas de Agua y Saneamiento (ANEAS) y la Unión Europea (UE). La estrategia y el protocolo desarrollados, son de interés ambiental, teniendo un gran potencial de aplicación para la detección de otros plaguicidas.A detection method based on an immunosensor is proposed by using monoclonal anti-atrazine antibodies as biorecognition molecule (immunosensor) and gold nanoparticles (AuNPs) as label for electrochemical detection of atrazine in water samples.AuNPs were synthetized by means of the Turkevich Method. They were characterized by optical and electrochemical methods. Graphite epoxy-composite electrodes were built, and later characterized by electrochemical methods. Paramagnetic particles were used to immobilize the antibody in combination with a magneto-composite electrodes (epoxy-graphite), a non-competitive sandwich type immunoassay was performed with these electrodes. Atrazine was detected by differential pulse voltammetry. Parameters of oxidation potential, oxidation time, quantity of magnetic particles and blocking agent concentration were optimized. A calibration curve was obtained from quantitative data and a limit of detection of 0.017 ng/mL was calculated; this limit is lower than the minimal amount in waters recommended by World Health Organization (WHO), United States Environmental Protection Agency (USEPA), National Association of Water and Sanitation (NAWS) and the European Union (EU). This environmental immunosensor has good reproducibility and great potential for detection of other pesticides.Consejo Nacional de Ciencia y Tecnología (México)

Detection of opinion spam with character n-grams

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-18117-2_21In this paper we consider the detection of opinion spam as a stylistic classi cation task because, given a particular domain, the deceptive and truthful opinions are similar in content but di ffer in the way opinions are written (style). Particularly, we propose using character ngrams as features since they have shown to capture lexical content as well as stylistic information. We evaluated our approach on a standard corpus composed of 1600 hotel reviews, considering positive and negative reviews. We compared the results obtained with character n-grams against the ones with word n-grams. Moreover, we evaluated the e ffectiveness of character n-grams decreasing the training set size in order to simulate real training conditions. The results obtained show that character n-grams are good features for the detection of opinion spam; they seem to be able to capture better than word n-grams the content of deceptive opinions and the writing style of the deceiver. In particular, results show an improvement of 2:3% and 2:1% over the word-based representations in the detection of positive and negative deceptive opinions respectively. Furthermore, character n-grams allow to obtain a good performance also with a very small training corpus. Using only 25% of the training set, a Na ve Bayes classi er showed F1 values up to 0.80 for both opinion polarities.This work is the result of the collaboration in the frame-work of the WIQEI IRSES project (Grant No. 269180) within the FP7 Marie Curie. The second author was partially supported by the LACCIR programme under project ID R1212LAC006. Accordingly, the work of the third author was in the framework the DIANA-APPLICATIONS-Finding Hidden Knowledge inTexts: Applications (TIN2012-38603-C02-01) project, and the VLC/CAMPUS Microcluster on Multimodal Interaction in Intelligent Systems.Hernández Fusilier, D.; Montes Gomez, M.; Rosso, P.; Guzmán Cabrera, R. (2015). Detection of opinion spam with character n-grams. En Computational Linguistics and Intelligent Text Processing: 16th International Conference, CICLing 2015, Cairo, Egypt, April 14-20, 2015, Proceedings, Part II. Springer International Publishing. 285-294. https://doi.org/10.1007/978-3-319-18117-2_21S285294Blamey, B., Crick, T., Oatley, G.: RU:-) or:-(? character-vs. word-gram feature selection for sentiment classification of OSN corpora. Research and Development in Intelligent Systems XXIX, 207–212 (2012)Drucker, H., Wu, D., Vapnik, V.N.: Support Vector Machines for Spam Categorization. IEEE Transactions on Neural Networks 10(5), 1048–1054 (2002)Feng, S., Banerjee, R., Choi, Y.: Syntactic Stylometry for Deception Detection. Association for Computational Linguistics, short paper. ACL (2012)Feng, S., Xing, L., Gogar, A., Choi, Y.: Distributional Footprints of Deceptive Product Reviews. In: Proceedings of the 2012 International AAAI Conference on WebBlogs and Social Media (June 2012)Gyongyi, Z., Garcia-Molina, H., Pedersen, J.: Combating Web Spam with Trust Rank. In: Proceedings of the Thirtieth International Conference on Very Large Data Bases, vol. 30, pp. 576–587. VLDB Endowment (2004)Hall, M., Eibe, F., Holmes, G., Pfahringer, B., Reutemann, P., Witten, I.: The WEKA Data Mining Software: an Update. SIGKDD Explor. Newsl. 10–18 (2009)Hernández-Fusilier, D., Guzmán-Cabrera, R., Montes-y-Gómez, M., Rosso, P.: Using PU-learning to Detect Deceptive Opinion Spam. In: Proceedings of the 4th Workshop on Computational Approaches to Subjectivity, Sentiment and Social Media Analysis for Computational Linguistics: Human Language Technologies, Atlanta, Georgia, USA, pp. 38–45 (2013)Hernández-Fusilier, D., Montes-y-Gómez, M., Rosso, P., Guzmán-Cabrera, R.: Detecting Positive and Negative Deceptive Opinions using PU-learning. Information Processing & Management (2014), doi:10.1016/j.ipm.2014.11.001Jindal, N., Liu, B.: Opinion Spam and Analysis. In: Proceedings of the International Conference on Web Search and Web Data Mining, pp. 219–230 (2008)Jindal, N., Liu, B., Lim, E.: Finding Unusual Review Patterns Using Unexpected Rules. In: Proceedings of the 19th ACM International Conference on Information and Knowledge Management, CIKM 2010, pp. 210–220(October 2010)Kanaris, I., Kanaris, K., Houvardas, I., Stamatatos, E.: Word versus character n-grams for anti-spam filtering. International Journal on Artificial Intelligence Tools 16(6), 1047–1067 (2007)Lim, E.P., Nguyen, V.A., Jindal, N., Liu, B., Lauw, H.W.: Detecting Product Review Spammers Using Rating Behaviours. In: CIKM, pp. 939–948 (2010)Liu, B.: Sentiment Analysis and Opinion Mining. Synthesis Lecture on Human Language Technologies. Morgan & Claypool Publishers (2012)Mukherjee, A., Liu, B., Wang, J., Glance, N., Jindal, N.: Detecting Group Review Spam. In: Proceedings of the 20th International Conference Companion on World Wide Web, pp. 93–94 (2011)Ntoulas, A., Najork, M., Manasse, M., Fetterly, D.: Detecting Spam Web Pages through Content Analysis. Transactions on Management Information Systems (TMIS), 83–92 (2006)Ott, M., Choi, Y., Cardie, C., Hancock, J.T.: Finding Deceptive Opinion Spam by any Stretch of the Imagination. In: Proceedings of the 49th Annual Meeting of the Association for Computational Linguistics: Human Language Technologies, Portland, Oregon, USA, pp. 309–319 (2011)Ott, M., Cardie, C., Hancock, J.T.: Negative Deceptive Opinion Spam. In: Proceedings of the 2013 Conference of the North American Chapter of the Association for Computational Linguistics: Human Language Technologies, Atlanta, Georgia, USA, pp. 309–319 (2013)Raymond, Y.K., Lau, S.Y., Liao, R., Chi-Wai, K., Kaiquan, X., Yunqing, X., Yuefeng, L.: Text Mining and Probabilistic Modeling for Online Review Spam Detection. ACM Transactions on Management Information Systems 2(4), Article: 25, 1–30 (2011)Stamatatos, E.: On the robustness of authorship attribution based on character n-gram features. Journal of Law & Policy 21(2) (2013)Wu, G., Greene, D., Cunningham, P.: Merging Multiple Criteria to Identify Suspicious Reviews. In: RecSys 2010, pp. 241–244 (2010)Xie, S., Wang, G., Lin, S., Yu, P.S.: Review Spam Detection via Time Series Pattern Discovery. In: Proceedings of the 21st International Conference Companion on World Wide Web, pp. 635–636 (2012)Zhou, L., Sh, Y., Zhang, D.: A Statistical Language Modeling Approach to Online Deception Detection. IEEE Transactions on Knowledge and Data Engineering 20(8), 1077–1081 (2008

Detecting Positive and Negative Deceptive Opinions using PU-learning

[EN] Nowadays a large number of opinion reviews are posted on the Web. Such reviews are a very important source of information for customers and companies. The former rely more than ever on online reviews to make their purchase decisions, and the latter to respond promptly to their clients’ expectations. Unfortunately, due to the business that is behind, there is an increasing number of deceptive opinions, that is, fictitious opinions that have been deliberately written to sound authentic, in order to deceive the consumers promoting a low quality product (positive deceptive opinions) or criticizing a potentially good quality one (negative deceptive opinions). In this paper we focus on the detection of both types of deceptive opinions, positive and negative. Due to the scarcity of examples of deceptive opinions, we propose to approach the problem of the detection of deceptive opinions employing PU-learning. PU-learning is a semi-supervised technique for building a binary classifier on the basis of positive (i.e., deceptive opinions) and unlabeled examples only. Concretely, we propose a novel method that with respect to its original version is much more conservative at the moment of selecting the negative examples (i.e., not deceptive opinions) from the unlabeled ones. The obtained results show that the proposed PU-learning method consistently outperformed the original PU-learning approach. In particular, results show an average improvement of 8.2% and 1.6% over the original approach in the detection of positive and negative deceptive opinions respectively. 2014 Elsevier Ltd. All rights reserved.This work is the result of the collaboration in the framework of the WIQEI IRSES project (Grant No. 269180) within the FP 7 Marie Curie. The work of the third author was in the framework the DIANA-APPLICATIONS-Finding Hidden Knowledge in Texts: Applications (TIN2012-38603-C02-01) project, and the VLC/CAMPUS Microcluster on Multimodal Interaction in Intelligent Systems.Hernández Fusilier, D.; Montes Gómez, M.; Rosso, P.; Guzmán Cabrera, R. (2015). Detecting Positive and Negative Deceptive Opinions using PU-learning. Information Processing and Management. 51(4):433-443. https://doi.org/10.1016/j.ipm.2014.11.001S43344351

Vegetación de la reserva natural de El Amatal, San Diego, La Libertad

El presente estudio de carácter cualitativo y cuantitativo de la vegetación arbórea, arbustiva y herbácea se desarrolló en el área natural de El Amatal, ubicada en el cantón San Diego, municipio y departamento de La Libertad, a 8 km al oriente de la ciudad del Puerto de La Libertad. Se utilizó el método del cuadrado, estableciendo 20 franjas longitudinales de 25 X 100 m (2,500 m2), se colectaron muestras para herbario de los estratos arbóreo, arbustivo y herbáceo. Del análisis cualitativo de la vegetación, se reportan 44 familias; 117 géneros y 130 especies, reportándose dos nuevos récords para la flora salvadoreña (Paspalum arumdlnaceum y Urochloa subquadripara). A las especies arbóreas y arbustivas inventariadas se les aplicó un análisis cuantitativo en el cual los parámetros utilizados fueron: frecuencia, densidad, área basal, en términos absolutos y relativos, con los cuales se estableció el índice de valor de importanci

Forest decline evaluation in Antarctic Beech Forests (Nothofagus antarctica) in Chilean Patagonia by using Landsat TM and ETM+

Antarctic beech forests (Nothofagus antarctica (G. Forst.) Oerst.) have shown a major decline process in the past few decades, together with an important lack of specific studies on this type of forest. The aim of this work was to create cartography of the surface of Antarctic beech forests and to evaluate decline levels in the XII Region of Chile. A study area was selected between the cities of Puerto Natales and Punta Arenas (latitudes 50º40’S to 52º40’S) and from latitudes 60º15’W to 74º15’W, where a random stratified sampling was carried out in 68 plots, in which the forest cover, mortality, height, normal diameter and regeneration were measured. Using two Landsat images (1986-2002), the study area was classified in terms of vegetation cover and forest mortality, by means of the normalized vegetation index (NDVI). The forests in this study area are characterized by their high density, and, in over half their surface (27,873 ha) they exhibit some degree of mortality, with 7,585 ha of forest completely affected. The distribution of the mortality in Antarctic beech on the period 1986-2002 showed an improvement on forests condition, which seems to corroborate the hypothesis of a change on perturbation pattern as the major reason for this forest decline process.Los bosques de ñirre (Nothofagus antarctica) han experimentado en las últimas décadas un importante proceso de mortalidad. El objetivo de este trabajo fue elaborar una cartografía de las masas de ñirre en función de la fracción de cabida cubierta del dosel arbóreo y el nivel de mortalidad en la XII Región de Chile. En una zona entre las ciudades de Puerto Natales y Punta Arenas (50º40’ - 52º40’ S y 69º15’ - 74º15’ O) se realizó un muestreo estratificado en 68 parcelas, donde se midieron: fracción de cabida cubierta, mortandad del arbolado, altura, diámetro normal (DAP) y regeneración. Mediante clasificación de dos imágenes Landsat TM (1986) y ETM+ (2002) se estudiaron el estado de las masas de ñirre y la evolución de la mortandad en un periodo de 16 años, utilizando el índice de vegetación normalizado (NDVI). En el año 2002 los bosques de ñirre se caracterizaban por una elevada fracción de cabida cubierta, tallas y diámetros medios, y una escasa regeneración. Más de la mitad de la superficie de estudio (casi 28.000 ha) presentaba algún grado de mortandad del arbolado, con 7.585 ha de bosques totalmente muertos. El patrón de mortandad, por comparación con el estado del arbolado en 1986, indicó una tendencia a mejorar el estado del arbolado en los últimos 16 años, lo cual parece confirmar la hipótesis de que los procesos de mortandad en esta especie no están asociados a un cambio en el patrón climático en la zona, sino más bien a la modificación del régimen de perturbaciones

Microwave-assisted sol-gel synthesis of an Au-TiO2 photoanode for the advanced oxidation of paracetamol as model pharmaceutical pollutant

An Au-TiO2 photoanode on carbon cloth has been synthesized by microwave-assisted sol-gel method to treat paracetamol solutions at pH 3.0 by photocatalysis (PC), electro-oxidation (EO), photoelectrocatalysis with UVA light (PEC), solar PEC (SPEC) and hybrid methods with photoelectro-Fenton under UVA (PEC+PEF) and sunlight (SPEC+SPEF) irradiation at constant anodic potential (Ean). The photoanode has been characterized by XRD, Raman spectroscopy, HRTEM and SEM-EDS. The counter electrode was a 316L stainless steel plate, which was replaced by an air-diffusion electrode for H2O2 generation in hybrid treatments. The most powerful process was SPEC+SPEF, yielding total paracetamol removal in less than 30 min and 24% mineralization after 180 min, at Ean = +0.82 V. The paracetamol decay followed a pseudo-first-order kinetics in PEC. A lower rate constant was obtained upon increase of pharmaceutical concentration, showing good linear fit using a Langmuir-Hinshelwood model

Polyethylene terephthalate nanoparticles effect on RAW 264.7 macrophage cells

AbstractPlastic pollution is a major environmental concern due to its pervasiveness which continues to increase year on year, as a result of a continuing acceleration in global plastic production and use. Polyethylene terephthalate (PET) is among the most produced plastics, commonly used as food and beverage containers. Once released in the environment, the degradation of plastic materials produces micro-and nano-plastics, with a particular concern about potential toxicological effects if they cross epithelial barriers via inhalation or ingestion. In this work, the effect of PET nanoparticles (PET-NPs) (≤ 250 d.nm) was assayed on mouse macrophages cell line (RAW 264.7) in in vitro experiments. Results showed that PET nanoparticles were easily internalized by the cells, 15 μg/mL of nanoparticles concentration had exhibited effects in cell proliferation and a slightly increased production of Reactive Oxygen Species (ROS), which seems to trigger cell response as foreign particles related to upregulation of PCDH12, IGH-V10, ROBO1 genes, and cell maintenance functions, related to FTSJ2 gene upregulation. Thus, the RAW 264.7 results showed here are useful towards for a preliminary and understanding of the potentially toxic effects related to PET nanoparticles and complementary to other in vitro assays, as the first step into the development of the risk assessment framework

Digoxina: alternativas a la pauta de descanso

Introduction: Digoxin is characterized by narrow therapeutic margin which makes its dosing difficult and monitoring of its serum levels necessary. This becomes more complex in patients with chronic nephropathy who require a greater dose adjustment. Development of the experience: We present the case of an 88-year-old woman admitted to our unit under treatment with oral digoxin for chronic heart failure with a regimen of 1 tablet daily with rest at weekends, who presented poor symptom control and subtherapeutic serum digoxin levels in controls. Changing the formulation to pediatric oral syrup (Lanacordin® 0.05mg/mL) resulted in better drug levels and symptom control. Conclusions: The use of digoxin in oral syrup may be an alternative to tablet formulation, especially in patients in whom drug level control may be complex due to their comorbidities.Introducción: La digoxina se caracteriza por estrecho margen terapéutico que hace dificultosa su dosificación y sea necesaria una monitorización de sus niveles séricos. Esto se hace más complejo en pacientes con nefropatía crónica que precisan de un mayor ajuste de dosis. Desarrollo de la experiencia: Presentamos el caso de una mujer de 88 años admitida en nuestra unidad en tratamiento con digoxina oral por insuficiencia cardiaca crónica con pauta de 1 comprimido diario con descanso los fines de semana, que presenta mal control de síntomas y niveles séricos de digoxina infraterapéuticos en controles. Al cambiar la formulación a jarabe oral pediátrico (Lanacordin® 0,05mg/mL) se consiguió un mejor nivel de los niveles del fármaco y del control de síntomas. Conclusiones: La utilización de la digoxina en jarabe oral puede ser una alternativa a la formulación con comprimidos, sobre todo en pacientes en los que el control de los niveles del fármaco puede resultar complejo por sus comorbilidades

Análisis de los actuales servicios de información para los centros de investigación

Se exponen los criterios de los autores acerca de la masificación de los servicios personalizados y de valor añadidos en los centros de información al servicio de los centros de investigación, así como las posibilidades inmediatas de la implementación de estos servicios y la consecuente elevación de las prestaciones en los centros de información. Se analizan los criterios que fundamentan la propuesta, la forma de implementación y las posibilidades de aplicación teniendo en cuenta realidades como la cubana. Una vez planteada la filosofía de trabajo a utilizar, se realiza un análisis pormenorizado de los tipos de servicios a implementar. Se señalan las potencialidades de la informetría a la hora de implementar estas modalidades de trabajo que hemos denominado servicio por la obligación que impone la convención