453 research outputs found

    Habitat preference of reintroduced dorcas gazelles (Gazella dorcas neglecta) in North Ferlo, Senegal

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    In March 2009, 23 dorcas gazelles (9 males and 14 females) were reintroduced in the Katané enclosure, a 440 ha fenced-in area in the North Ferlo Fauna Reserve (Senegal). In the enclosure, the dorcas gazelle live with other reintroduced (the mohor gazelles and the scimitar-horned oryx) and native ungulate species (the Red-fronted gazelle), as well other native mammals. Seven habitat types were characterized in the enclosure. Habitat preference of dorcas gazelles was studied using presence and abundance of gazelle signs (tracks, latrines, fecal deposits) and direct observations. Seasonal data were collected along a 6-km long transect in the enclosure. The presence of dorcas gazelles is significantly dependent on the type of habitat in the Katané enclosure and they prefer open habitats (plateaus) to habitats with less visibility. This preference did not change according to season and the number of fecal deposits increased with proximity to the fence.This work has been fund by The Spanish National Research Council (CSIC, Economic and Innovation Ministry), the Barcelona Zoo (BSMSA, Barcelona Municipality) and the Direction of National Parks of Senegal (Environment Ministry).Peer reviewe

    Systematic reviews and/or meta-analyses on the safety of chronic hormonal treatment in transsexual people

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    39 p.Las personas transgénero reciben terapia hormonal cruzada de forma crónica para suprimir las características sexuales secundarias natales. El objetivo de esta revision bibliográfica (revisiones sistemáticas y/o metaanálisis sobre seguridad entre 2016 y 2021) fue conocer la seguridad de este tratamiento a largo plazo. Los resultados obtenidos no encuentran una asociación significativa entre el cáncer de mama y el uso de testosterona en hombres transgénero, ni entre en el riesgo quirúrgico en hombres y mujeres transgénero comparado con cisgénero. Sin embargo sí que existieron diferencias estadísticamente significativas entre el riesgo quirúrgico, la función cognitiva, y el perfil lipídico en pacientes transgénero y cisgénero. Se concluye una escasa evidencia científica sobre la seguridad del tratamiento hormonal crónico en pacientes transexuales, objetivándose la necesidad de realizar estudios observacionales en vida real para conocer a largo plazo el riesgo cardiovascular, cognitivo, oncológico y quirúrgico en este grupo de pacientes.Transgender people receive chronic cross-hormonal therapy to suppress natal secondary sex characteristics. The objective of this bibliographic review (systematic reviews and/or meta-analyses on safety between 2016 and 2021) was to determine the long-term safety of this treatment. The results obtained do not find a significant association between breast cancer and the use of testosterone in transgender men, nor between the surgical risk in transgender men and women compared to cisgender. However, there were statistically significant differences between surgical risk, cognitive function, and lipid profile in transgender and cisgender patients. Little scientific evidence is concluded on the safety of chronic hormonal treatment in transsexual patients, pointing out the need to carry out observational studies in real life to determine the long-term cardiovascular, cognitive, oncological and surgical risk in this group of patients.Grado en Medicin

    Simultaneous determination of traces of PT, PD, OS, IR, RH, AG and AU by using magnetic nanoparticles solid phase extraction coupled with ICP OES

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    The direct analysis of these target analytes is very limited being essential sample pre-treatment techniques and the use of very sensitive instrumental techniques to carry out determinations. The inductively coupled plasma optical emission spectrometry shows a poor sensitivity because the concentration of some elements in environmental samples is below the detection limit of ICP OES. To solve this problem, preconcentration separation procedures have been proposed, minimizing the spectral and matrix interferences. Thus, enrichment is a very important issue for achievement of low detection limits [1-4]. In this study, a chelating resin 1,5 bis (di 2 pyridil) methylene thiocarbonohydrazide bonded to iron oxide magnetic nanoparticles (DPTH-MNPs) were synthesized. These magnetic nanoparticles were employed as a solid phase extraction (SPE) adsorbent for the separation and concentration of trace amounts of 7 elements (Au, Ag, Pd, Pt, Ir, Rh and Os) from environmental water samples. The main aim of this work was to develop a precise and accurate method for the simultaneous determination of the maximum possible number of elements by using this new absorbent and a multimode sample introduction system (MSIS). The MSIS acts as a system for the generation, separation and introduction of chemical vapours (CVG) and also as an introduction system for sample aerosols, in a simultaneous form, into an inductively coupled plasma-optical emission spectrometer. The on-line SPE-CVG-ICP-OES system developed was applied in the determination of the aforementioned metals in natural water samples (sea water, estuarine, lake and river water), with the least demanding and simple sample preparation procedure. The developed method was validated by analysing natural water certified reference materials (TMDA 54.4 fortified lake waters and SRM 1643e, trace elements in water; and National Institute of Standards and Technology (NIST), NIST-2557 autocatalyst). Sea water, tap water and well water samples collected from Malaga (Spain) were also analysed. The procedure has been demonstrated to be fast, easy, automatic, selective and economical, and the sensitivity was good. The main advantage of DPTH-MNPs is its very good stability and resistance because chemisorption of chelating molecules on the surface of solid supports provides immobility, mechanical stability and insolubility. The precision (RSD), accuracy (by standard addition or recovery) and limit of detection (LOD) were used to evaluate the characteristics of the procedure. Furthermore, the proposed method was applied in the simultaneous determination of the 7 elements mentioned above with a sample throughput of about 13 h-1, thereby, reducing the time of analysis and the volume of reagents and sample required. References [1] M. Tuzen, M. Soylak, D. Citak, H.S. Ferreira, M.G.A. Korn, M.A. Bezerra, A pre-concentration system for determination of copper and nickel in water and food samples employing flame atomic absorption spectrometry, Journal of Haz-ardous Materials 162 (2009) 1041–1045. [2] Y. Cui, X. Chang, Y. Zhai, X. Zhu, H. Zheng, N. Lian, ICP-AES determination of trace elements after preconcentrated with p-dimethylaminobenzaldehyde-modified nanometer SiO2 from sample solution, Microchem. J. 83 (2006) 35–41. [3] P. Liang, B. Hu, Z. Jiang, Y. Qin, T. Peng, Nanometer-sized titanium dioxide micro-column on-line preconcentration of La, Y, Yb, Eu, Dy and their determination by inductively coupled plasma atomic emission spectrometry, J. Anal. Atom. Spectrom. 16 (2001) 863–866. [4] B. Feist, B. Mikula, K. Pytlakowska, B. Puzio, F. Buhl, Determination of heavy metals by ICP-OES and F-AAS after preconcentration with 2,2-bipyridyl and erythrosine, J. Hazard. Mater. 152 (2008) 1122–1129.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Sequential determination of traces of As, Sb and hg by on-line magnetic solid phase extraction coupled with Hr-Cs-Cvg-Gfaas

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    A green and rapid method was developed for the simultaneous separation/preconcentration and sequential monitoring pf arsenic, antimony and mercury by flow injection magnetic solid phase extraction coupled with on-line chemical vapor generation and determination by high resolution continuum source graphite furnace atomic absorption spectrometry. The system is based on chelating/cationic retention of the analytes onto a magnet based reactor designed to contain functionalized magnetic nanoparticles (MNPs). The MNP score allows overcoming the back-pressure problems that usually happen in SPME methods with NPs thanks to the possibility of inmobilizing the MNPs by applying an external magnetic field. Several chemical and flow variables were considered as factors in the optimization process using central composite designs. With the optimized procedure the detection limits obtained were 0.2, 0.003 and 0.4 µg/L for As, Sb and Hg respectively. For the quality control of the analytical performance and the validation of the developed method the analysis of two certified samples TM 24.3 and TMDA 54.4 Fortified Lake Waters was addressed. The results showed good agreement with the certified values.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Cold vapour generation electrothermal atomic absorption spectrometry and solid phase extraction based on a new nanosorbent for sensitive HG determination in environmental samples (sea water and river water)

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    Reunión bianual del Grupo Regional Andaluz de la Sociedad Española de Química AnalíticaMercury is not an essential element for plant or animal life and it is a potential environmental toxic because of its tendency to form covalent bonds with organic molecules and the high stability of the Hg-C bond. Reports estimate a total mercury concentration in natural waters ranging from 0.2 to 100 ng L-1. Due to this fact, highly sensitive methods are required for direct determination of such extremely low levels. In this work, a rapid and simple method was developed for separation and preconcentration of mercury by flow injection solid phase extraction coupled with on-line chemical vapour generation electrothermal atomic absorption spectrometry. The system is based on chelating retention of the analyte onto the mini column filled with a mesoporous silica functionalized with 1,5 bis (di-2-pyridyl) methylene thiocarbohydrazide. The main aim of this work was to develop a precise and accurate method for the determination of the Hg. Under the optima conditions and 120 s preconcentration time, the detection limit obtained was 0.009 μg L-1, with RSDs 3.7 % for 0.2 μg L-1, 4.8 % for 1 μg L-1 and enrichment factor 4, Furthermore, the method proposed has permitted the determination of Hg with a reduction in the analysis time, the sample throughput was about 18 h-1, low consumption of reagents and sample volume. The method was applied to the determination of Hg in sea water and river water. For the quality control of the analytical performance and the validation of the newly developed method, the analysis of two certified samples, TMDA 54.4 Fortified Lake, and LGC6187 River sediment was addressed. The results showed good agreement with the certified values.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    The implementation of project based learning to promote the speaking skill in 9th graders at Jose Antonio Galán High School

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    Este proyecto tiene como propósito evidenciar el efecto de cómo el Aprendizaje Basado en Proyectos (PBL) puede fomentar la habilidad del habla en el idioma Inglés en estudiantes de noveno grado en un colegio público de Pereira, Colombia. Esta metodología permitió trabajar como temática central problemas ambientales por medio de los cuales se desarrollaron dos proyectos manuales; un jardín vertical y una maqueta de una ciudad utópica. Se usó como soporte teórico los aportes de Chaney (1998) quien define la habilidad del habla como el proceso de producir y compartir información de forma verbal y no verbal en un determinado contexto. Además, se consideraron las contribuciones de Thomas (2000) quien se refiere al Aprendizaje Basado en Proyectos como un modelo que permite la adquisición de conocimientos mediante la elaboración de proyectos que parten de los intereses y necesidades de los estudiantes. Después de implementar este proyecto durante nueve clases, se obtuvo como resultado que para que se fomente la habilidad del habla por medio de esta metodología, es necesario que los estudiantes estén comprometidos e interesados a lo largo del desarrollo del proyecto, de esta manera no solo se fomentaran habilidades como la cooperación y trabajo en grupo sino la habilidad oral en Inglés

    Role of New Functional MRI Techniques in the Diagnosis, Staging, and Followup of Gynecological Cancer: Comparison with PET-CT

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    Recent developments in diagnostic imaging techniques have magnified the role and potential of both MRI and PET-CT in female pelvic imaging. This article reviews the techniques and clinical applications of new functional MRI (fMRI) including diffusion-weighted MRI (DWI), dynamic contrast-enhanced (DCE)-MRI, comparing with PET-CT. These new emerging provide not only anatomic but also functional imaging, allowing detection of small volumes of active tumor at diagnosis and early disease relapse, which may not result in detectable morphological changes at conventional imaging. This information is useful in distinguishing between recurrent/residual tumor and post-treatment changes and assessing treatment response, with a clear impact on patient management. Both PET-CT and now fMRI have proved to be very valuable tools for evaluation of gynecologic tumors. Most papers try to compare these techniques, but in our experience both are complementary in management of these patients. Meanwhile PET-CT is superior in diagnosis of ganglionar disease; fMRI presents higher accuracy in local preoperative staging. Both techniques can be used as biomarkers of tumor response and present high accuracy in diagnosis of local recurrence and peritoneal dissemination, with complementary roles depending on histological type, anatomic location and tumoral volume

    Determination of Pb using F3eO4 GO join to DPTH for ferrofluid based dispersive solid phase extraction

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    In this work has been described a green and rapid method the synthesis of Fe3O4@GO nanospheres via chemical covalent bonding method. The Fe3O4@GO DPTH was applied to ferrofluid based dispersive solid phase extraction of lead as a model analyte using an ionic liquid carrier. The ferro fluid allows the rapid extraction of lead ions using a low amount of sorbent material. Besides, the magnetic separation greatly improved the separation rate. The presented method is highly time saving due to the high dispersion of the sorbent in the aqueous phase and also there is no need to shake the sample solution. The other benefits of the proposed methods are simplicity of operation, low cost, high sorption capacity, high recovery and high preconcentration. In order to optimize the method the following parameters were studied: sample solution pH, concentration of DPTH, extraction time, amount of sorbent, desorption conditions, influence of ionic strength, and tolerance of potentially interfering ions. The sample or standard solution containing Pb(II), DPTH (0.05% ethanol w/v), NaCl (0.5 %, w/v) and buffer (pH = 5.6) was poured into high volume. Then 240 µL of ferrofluid was injected rapidly into the sample solution through a syringe. Thereupon, a dark cloudy suspension was formed, ferrofluid was dispersed thoroughly in solution and the complex of Pb-DPTH was extracted in a few seconds. Subsequently, a strong magnet was placed at the bottom of the tube to let the extractant settle. After about 3 min, the solution became clear and the supernatant was discarded simply by decanting it. Afterwards, the magnet was removed and 1 mL of nitric acid (2.0 mol L−1) was introduced to the vial to desorb the Pb by sonication. Finally, the sorbent was separated by positioning the magnet to the outside of the tube and the concentration of Pb in acidic aqueous phase was determined by ETAAS.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tech

    Estudio y desarrollo de un sistema de localización precisa de activos y humanos en espacios cerrados para seguridad en entornos con interacción humano robot

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    [ES] Los sistemas RTL (Real Time Location) han permitido hasta el momento el desarrollo de aplicaciones de localización basadas en señales de radiofrecuencia con precisión suficientemente aceptable para la localización, aunque siempre por encima de las decenas de centímetros. Con la aparición del los sistemas de UWB (Ultra Wide Band), se están alcanzando precisiones teóricas por debajo de los 10 centímetros teóricos. Este trabajado aborda la evaluación de un sistema UWB y su aplicación a la determinación de la posición de humanos en entornos industriales, para su integración en sistemas de seguridad de los entornos de trabajo. Estos sistemas permiten una mayor interacción humano robot, al tiempo que proporcionan información relevante sobre eficiencia de los sistemas productivos. Actualmente tanto los robots, como los dispositivos IoT, son parte de la evolución de los sistemas de producción hacia la denominada Industria 4.0. La integración de datos desde todos los puntos de un proceso productivo (maquinas, humanos, productos), permite el control, la supervisión y el análisis, que son necesarios para lograr sistemas eficientes. En el caso de los sistemas IoT, el uso de brokers de comunicaciones con protocolo MQTT es una de las soluciones ampliamente y estandarizada. Por otro lado el uso de la plataforma ROS (Robor Operating System), como middleware de interacción con robots, es también una solución ampliamente aceptada dentro de las aplicaciones de robótica. Bajo esta paradigma de Industria 4.0 tan demandado actualmente, se propone el presente Trabajo Fin de Máster, en tanto se persigue una aplicación realista y practica de la propuesta. En esa línea el trabajo abordará las siguientes fases: -Análisis de las tecnologías de localización mediante radiofrecuencia en interiores -Evaluación de un sistema de localización basado en UWB: precisión, alcance, comportamiento temporal y en entornos de producción. -Diseño de un sistema software de localización de tags -Desarrollo de un módulo software para integración en la arquitectura ROS de un robot móvil: esta tiene como objetivo la integración a nivel de información de los datos sobre localización de robots y humanos -Desarrollo de controladores basados en información de localización: aplicación la generación de trayectorias seguras en entornos con interacción humano-robot -Desarrollo de módulo de evaluación de eficiencia: gestión de los datos de posición, análisis de las rutas y eficiencia en el uso de los recursos. -Evaluación del sistema en entorno real: el trabajo se desarrollará en un laboratorio cuyo equipamiento permite la prueba y tests en situaciones muy cercanas a las reales que se podrían encontrar en un entorno productivo.[EN] RTL (Real Time Location) systems have so far allowed the development of location applications based on radio frequency signals with sufficiently acceptable accuracy for location, but always above tens of centimetres. With the emergence of UWB (Ultra Wide Band) systems, theoretical accuracies below 10 centimeters are being achieved. This work deals with the evaluation of a UWB system and its application to the determination of the position of humans in industrial environments, for its integration into safety systems of working environments. These systems allow greater human-robot interaction, while providing relevant information on the efficiency of production systems. Both robots and IoT devices are now part of the evolution of production systems towards Industry 4.0. The integration of data from all points of a production process (machines, humans, products), allows the control, monitoring and analysis that are necessary to achieve efficient systems. In the case of IoT systems, the use of communication brokers with MQTT protocol is one of the widely standardized solutions. On the other hand, the use of the ROS (Robot Operating System) platform as middleware for interaction with robots is also a widely accepted solution within robotics applications. Under this Industry 4. 0 paradigm, which is so much in demand at the moment, this Master¿s Thread is proposed, while pursuing a realistic and practical application of the proposal. In this context, the work will address the following phases: -Analysis of indoor radiofrequency location technologies. -Evaluation of a localization system based on UWB: accuracy, range, temporal and production environment behaviour. -Design of a tag localization software system. -Development of a software module for integration into the ROS architecture of a mobile robot: this aims to integrate data on the location of robots and humans at the information level. -Development of controllers based on location information: application to generate safe paths in environments with human-robot interaction. -Development of an efficiency evaluation module: position data management, route analysis and resource efficiency. -Evaluation of the system in a real environment: the work will be carried out in a laboratory equipped to allow testing and testing in situations very close to the real ones that could be found in a production environment.Plaza Cano, MDM. (2021). Estudio y desarrollo de un sistema de localización precisa de activos y humanos en espacios cerrados para seguridad en entornos con interacción humano robot. Universitat Politècnica de València. http://hdl.handle.net/10251/174614TFG
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