| 1. |
- Novikova, P. Y., et al.
(författare)
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Sequencing of the genus Arabidopsis identifies a complex history of nonbifurcating speciation and abundant trans-specific polymorphism
- 2016
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 48:9, s. 1077-1082
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Tidskriftsartikel (refereegranskat)abstract
- The notion of species as reproductively isolated units related through a bifurcating tree implies that gene trees should generally agree with the species tree and that sister taxa should not share polymorphisms unless they diverged recently and should be equally closely related to outgroups. It is now possible to evaluate this model systematically. We sequenced multiple individuals from 27 described taxa representing the entire Arabidopsis genus. Cluster analysis identified seven groups, corresponding to described species that capture the structure of the genus. However, at the level of gene trees, only the separation of Arabidopsis thaliana from the remaining species was universally supported, and, overall, the amount of shared polymorphism demonstrated that reproductive isolation was considerably more recent than the estimated divergence times. We uncovered multiple cases of past gene flow that contradict a bifurcating species tree. Finally, we showed that the pattern of divergence differs between gene ontologies, suggesting a role for selection. © 2016 Nature America, Inc. All rights reserved.
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| 2. |
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| 3. |
- Hernandez Bennetts, Victor, 1980-, et al.
(författare)
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A Novel Approach for Gas Discrimination in Natural Environments with Open Sampling Systems
- 2014
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Ingår i: Proceedings of the IEEE Sensors Conference 2014. - : IEEE conference proceedings. ; , s. -2049
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Konferensbidrag (refereegranskat)abstract
- This work presents a gas discrimination approachfor Open Sampling Systems (OSS), composed of non-specificmetal oxide sensors only. In an OSS, as used on robots or insensor networks, the sensors are exposed to the dynamics of theenvironment and thus, most of the data corresponds to highlydiluted samples while high concentrations are sparse. In addition,a positive correlation between class separability and concentra-tion level can be observed. The proposed approach computes theclass posteriors by coupling the pairwise probabilities betweenthe compounds to a confidence model based on an estimation ofthe concentration. In this way a rejection posterior, analogous tothe detection limit of the human nose, is learned. Evaluation wasconducted in indoor and outdoor sites, with an OSS equippedrobot, in the presence of two gases. The results show that theproposed approach achieves a high classification performancewith a low sensitivity to the selection of meta parameters.
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| 4. |
- Hernandez Bennetts, Victor, 1980-, et al.
(författare)
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Combining Non Selective Gas Sensors on a Mobile Robot for Identification and Mapping of Multiple Chemical Compounds
- 2014
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Ingår i: Sensors. - : MDPI AG. - 1424-8220. ; 14:9, s. 17331-17352
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Tidskriftsartikel (refereegranskat)abstract
- In this paper, we address the task of gas distribution modeling in scenarios where multiple heterogeneous compounds are present. Gas distribution modeling is particularly useful in emission monitoring applications where spatial representations of the gaseous patches can be used to identify emission hot spots. In realistic environments, the presence of multiple chemicals is expected and therefore, gas discrimination has to be incorporated in the modeling process. The approach presented in this work addresses the task of gas distribution modeling by combining different non selective gas sensors. Gas discrimination is addressed with an open sampling system, composed by an array of metal oxide sensors and a probabilistic algorithm tailored to uncontrolled environments. For each of the identified compounds, the mapping algorithm generates a calibrated gas distribution model using the classification uncertainty and the concentration readings acquired with a photo ionization detector. The meta parameters of the proposed modeling algorithm are automatically learned from the data. The approach was validated with a gas sensitive robot patrolling outdoor and indoor scenarios, where two different chemicals were released simultaneously. The experimental results show that the generated multi compound maps can be used to accurately predict the location of emitting gas sources.
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| 5. |
- Hernandez Bennetts, Victor Manuel, 1980-, et al.
(författare)
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Towards Real-World Gas Distribution Mapping and Leak Localization Using a Mobile Robot with 3D and Remote Gas Sensing Capabilities
- 2013
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Ingår i: 2013 IEEE INTERNATIONAL CONFERENCE ON ROBOTICS AND AUTOMATION (ICRA). - : IEEE conference proceedings. ; , s. 2335-2340
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Konferensbidrag (refereegranskat)abstract
- Due to its environmental, economical and safety implications, methane leak detection is a crucial task to address in the biogas production industry. In this paper, we introduce Gasbot, a robotic platform that aims to automatize methane emission monitoring in landfills and biogas production sites. The distinctive characteristic of the Gasbot platform is the use of a Tunable Laser Absorption Spectroscopy (TDLAS) sensor. This sensor provides integral concentration measurements over the path of the laser beam. Existing gas distribution mapping algorithms can only handle local measurements obtained from traditional in-situ chemical sensors. In this paper we also describe an algorithm to generate 3D methane concentration maps from integral concentration and depth measurements. The Gasbot platform has been tested in two different scenarios: an underground corridor, where a pipeline leak was simulated and in a decommissioned landfill site, where an artificial methane emission source was introduced.
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| 6. |
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| 7. |
- Sese, M, et al.
(författare)
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[Not Available]
- 2016
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Ingår i: Nutricion hospitalaria. - : ARAN Ediciones. - 1699-5198 .- 0212-1611. ; 33:3, s. 533-539
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Tidskriftsartikel (refereegranskat)abstract
- Antecedentes: los diferentes componentes corporales pueden contribuir al desarrollo de resistencia a la insulina y diabetes mellitus de tipo 2. Elobjetivo del presente estudio fue examinar la asociación entre la masa grasa y la masa libre de grasa con marcadores de resistencia a la insulina,valorando de forma independiente cada uno de ellos y aportando información específi ca por sexo, en una amplia cohorte de adolescentes europeos.Métodos: se realizó un estudio transversal en el ámbito escolar en 925 (430 varones) adolescentes (14,9 ± 1,2 años). Se midieron peso, talla,pliegues cutáneos e impedancia bioeléctrica. Se calcularon índices de masa grasa y libre de grasa y se calculó el índice HOMA. Se realizaronanálisis de regresión múltiple ajustándolos según varios factores de confusión, incluyendo la masa libre de grasa y masa grasa cuando fue posible.Resultados: los índices de masa grasa se asociaron positivamente con HOMA (todos p < 0,01) después de ajustarlos según todos los factoresde confusión, incluidos los marcadores de masa libre de grasa, en ambos sexos. Los índices de masa libre de grasa se asociaron con HOMA,tanto en hombres como en mujeres, después de ajustar por país, estadio puberal, nivel socio-económico y capacidad cardiorrespiratoria, perolas asociaciones desaparecieron al incluir marcadores de masa grasa en el modelo de ajuste.Conclusión: índices de masa grasa obtenidos según diferentes métodos se asocian con la resistencia a la insulina, independientemente de variosfactores de confusión, incluyendo los índices de masa libre de grasa. Además, la cantidad de masa grasa infl uye en la relación de la masa libre de grasacon resistencia a la insulina en adolescentes europeos. Los estudios futuros deberían centrarse no solo en el papel de la masa grasa, sino también enel de otros componentes corporales como la masa libre de grasa, ya que su papel podría variar dependiendo del nivel y distribución de masa grasa.
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