93 research outputs found
Screening of chemicals for human bioaccumulative potential with a physiologically based toxicokinetic model
Human bioaccumulative potential is an important element in the risk assessment of chemicals. Due to the high number of synthetic chemicals, there exists the need to develop prioritisation strategies. The purpose of this study was to develop a predictive tool for human bioaccumulation risk assessment that incorporates not only the chemical properties of the compounds, but also the processes that tend to decrease the concentration of the compound such as metabolisation. We used a generic physiologically based toxicokinetic model that based on in vitro human liver metabolism data, minimal renal excretion and a constant exposure was able to assess the bioaccumulative potential of a chemical. The approach has been analysed using literature data on well-known bioaccumulative compounds and liver metabolism data from the ECVAM database and a subset of the ToxCast phase I chemical library—in total 94 compounds covering pharmaceuticals, plant protection products and industrial chemicals. Our results provide further evidence that partitioning properties do not allow for a reliable screening criteria for human chemical hazard. Our model, based on a 100% intestinal absorption assumption, suggests that metabolic clearance, plasma protein-binding properties and renal excretion are the main factors in determining whether bioaccumulation will occur and its amount. It is essential that in vitro metabolic clearance tests with metabolic competent cell lines as well as plasma protein-binding assays be performed for suspected bioaccumulative compounds
Multichannel massive audio processing for a generalized crosstalk cancellation and equalization application using GPUs
[EN] Multichannel acoustic signal processing has undergone major development in recent years due to the increased com- plexity of current audio processing applications, which involves the processing of multiple sources, channels, or filters. A gen- eral scenario that appears in this context is the immersive reproduction of binaural audio without the use of headphones, which requires the use of a crosstalk canceler. However, generalized crosstalk cancellation and equalization (GCCE) requires high com- puting capacity, which is a considerable limitation for real-time applications. This paper discusses the design and implementation of all the processing blocks of a multichannel convolution on a GPU for real-time applications. To this end, a very efficient fil- tering method using specific data structures is proposed, which takes advantage of overlap-save filtering and filter fragmentation. It has been shown that, for a real-time application with 22 inputs and 64 outputs, the system is capable of managing 1408 filters of 2048 coefficients with a latency time less than 6 ms. The proposed GPU implementation can be easily adapted to any acoustic environment, demonstrating the validity of these co-processors for managing intensive multichannel audio applications.This work has been partially funded by Spanish Ministerio de Ciencia e Innovacion TEC2009-13741, Generalitat Valenciana PROMETEO 2009/2013 and GV/2010/027, and Universitat Politecnica de Valencia through Programa de Apoyo a la Investigacion y Desarrollo (PAID-05-11).Belloch Rodríguez, JA.; Gonzalez, A.; Martínez Zaldívar, FJ.; Vidal Maciá, AM. (2013). Multichannel massive audio processing for a generalized crosstalk cancellation and equalization application using GPUs. Integrated Computer-Aided Engineering. 20(2):169-182. https://doi.org/10.3233/ICA-130422S16918220
Low-complexity soft ML detection for generalized spatial modulation
[EN] Generalized Spatial Modulation (GSM) is a recent Multiple-Input Multiple-Output (MIMO) scheme, which achieves high spectral and energy efficiencies. Specifically, soft-output detectors have a key role in achiev-ing the highest coding gain when an error-correcting code (ECC) is used. Nowadays, soft-output Maxi-mum Likelihood (ML) detection in MIMO-GSM systems leads to a computational complexity that is un-feasible for real applications; however, it is important to develop low-complexity decoding algorithms that provide a reasonable computational simulation time in order to make a performance benchmark available in MIMO-GSM systems. This paper presents three algorithms that achieve ML performance. In the first algorithm, different strategies are implemented, such as a preprocessing sorting step in order to avoid an exhaustive search. In addition, clipping of the extrinsic log-likelihood ratios (LLRs) can be incor-porating to this algorithm to give a lower cost version. The other two proposed algorithms can only be used with clipping and the results show a significant saving in computational cost. Furthermore clipping allows a wide-trade-off between performance and complexity by only adjusting the clipping parameter.Acknowledgements This work has been partially supported by Spanish Ministry of Science, Innovation and Universities and by European Union through grant RTI2018-098085-BC41 (MCUI/AEI/FEDER) , by GVASimarro, MA.; García Mollá, VM.; Martínez Zaldívar, FJ.; Gonzalez, A. (2022). Low-complexity soft ML detection for generalized spatial modulation. Signal Processing. 196:1-12. https://doi.org/10.1016/j.sigpro.2022.10850911219
Soft MIMO detection through sphere decoding and box optimization
[EN] Achieving optimal detection performance with low complexity is
one of the major challenges, mainly in multiple-input multiple-output
(MIMO) detection. This paper presents three low-complexity Soft-Output
MIMO detection algorithms
that are based mainly on Box Optimization (BO) techniques. The proposed
methods provide good performance with low computational cost using
continuous constrained optimization techniques. The rst proposed
algorithm is a non-optimal Soft-Output detector of reduced complexity.
This algorithm
has been compared with the Soft-Output Fixed Complexity (SFSD) algorithm,
obtaining lower complexity and similar performance. The two remaining
algorithms are employed in a turbo receiver, achieving the max-log
Maximum a Posteriori (MAP) performance. The two Soft-Input Soft-Output
(SISO) algorithms were proposed in a previous work for soft-output MIMO
detection. This work presents its extension for iterative decoding. The
SISO algorithms presented
are developed and compared with the SISO Single Tree Search algorithm
(STS), in terms of efficiency and computational cost. The results show
that the proposed algorithms are more efficient for high order
constellation than the STS algorithm.Simarro, MA.; García Mollá, VM.; Vidal Maciá, AM.; Martínez Zaldívar, FJ.; Gonzalez, A. (2018). Soft MIMO detection through sphere decoding and box optimization. Signal Processing. 145:48-58. https://doi.org/10.1016/j.sigpro.2017.11.010S485814
Parallel signal detection for generalized spatial modulation MIMO systems
[EN] Generalized Spatial Modulation is a recently developed technique that is designed to enhance the efficiency of transmissions in MIMO Systems. However, the procedure for correctly retrieving the sent signal at the receiving end is quite demanding. Specifically, the computation of the maximum likelihood solution is computationally very expensive. In this paper, we propose a parallel method for the computation of the maximum likelihood solution using the parallel computing library OpenMP. The proposed parallel algorithm computes the maximum likelihood solution faster than the sequential version, and substantially reduces the worst-case computing times.This work has been partially supported by the Spanish Ministry of Science, Innovation and Universities and by the European Union through grant RTI2018- 098085-BC41 (MCUI/AEI/FEDER), by GVA through PROMETEO/2019/109, and by RED 2018-102668-T.
Open Access funding provided thanks to the CRUE-CSIC agreement with Springer Nature.García Mollá, VM.; Simarro, MA.; Martínez Zaldívar, FJ.; Boratto, M.; Alonso-Jordá, P.; Gonzalez, A. (2022). Parallel signal detection for generalized spatial modulation MIMO systems. The Journal of Supercomputing. 78(5):7059-7077. https://doi.org/10.1007/s11227-021-04163-y7059707778
Intervención educativa dirigida a la promoción de salud bucal en el adulto mayor
Introducción: actualmente el acelerado envejecimiento poblacional constituye una preocupación para diferentes países, entre los que se encuentra Cuba. La realización de actividades de promoción de salud bucal orientada a los adultos mayores posibilita la mejora continua en el bienestar general de este grupo poblacional.Objetivo: evaluar la efectividad de una intervención educativa dirigida a la promoción de salud bucal en el Adulto Mayor.Material y Métodos: se realizó un estudio no observacional cuasi-experimental de antes-después sin grupo control en el período de diciembre 2017- abril 2018 en los adultos mayores de la “Casa de abuelos” de Banes. Sexo, nivel de información sobre el cuidado de la salud bucal, hábitos nocivos y efectividad del programa educativo, constituyeron las variables del estudio. A partir de la información obtenida, se diseñó y aplicó el programa educativo “Sonreír con experiencia”.Resultados: antes de la intervención, los participantes no mantenían conductas adecuadas para el cuidado de la salud bucal y tenían escasos conocimientos sobre los factores de riesgo del cáncer bucal. El programa ofrece acciones para fomentar el cuidado del aparato estomatognático, información sobre los efectos dañinos de los hábitos que predisponen a contraer afecciones bucales, la realización del autoexamen, todo concebido para los ancianos y su familia, lográndose que adquirieran conocimientos con respecto al cuidado y prevención de enfermedades bucales y se convirtieran en promotores en sus hogares.Conclusiones: la intervención educativa permitió elevar el nivel de información y las prácticas encaminadas a prevenir la aparición de enfermedades bucales en este grupo poblacional
Parallel Implementation Strategies for MIMO ID-BICM Systems
[EN] One of the current techniques proposed for multiple transmit and receive antennas wireless communication systems is the use of error control coding and iterative detection and decoding at the receiver. These sophisticated techniques produce a significant increase of the computational cost and require large computational power. The use of modern computer facilities as multicore and multi-GPU (Graphics Processing Unit) processors can decrease the computational time required, representing a promising solution for the receiver implementation in these systems.
In this paper we explain how iterative receivers can improve the performance of suboptimal detectors. We also introduce a novel parallel receiver scheme based on a hybrid computing model where CPUs and GPUs work together to accelerate the detection and decoding steps; this design comes to exploit the features of the GPU NVIDIA Kepler architecture respect to the previous one in order to optimize the communication system performance.This work has been partially funded by PROMETEO/2009/013 project of Generalitat Valenciana, projects TEC2009-13741 of the Ministerio Español de Ciencia e Innovación, TEC2012-38142-C04 of the Ministerio Español de Economía y Competitividad, and PAID-05-2011 of Universitat Politècnica de València.Simarro Haro, MDLA.; Ramiro Sánchez, C.; Martínez Zaldívar, FJ.; Vidal Maciá, AM.; González Téllez, A.; Piñero Sipán, MG.; García Mollá, VM. (2013). Parallel Implementation Strategies for MIMO ID-BICM Systems. Waves. 5-13. http://hdl.handle.net/10251/57906S51
The Role of Faults as Barriers in Confined Seismic Sequences: 2021 Seismicity in the Granada Basin (Betic Cordillera)
Fault barriers are key structures for studying seismic hazard in regions of intense brittle
deformation. The interaction between fault sets affects their seismogenic behavior, if some of them act as
barriers. The Granada Basin, in the Betic Cordillera, is a region affected by shallow brittle deformation, as it
was the scenario for the recent Granada 2021 seismic sequence. This seismicity presented a swarm behavior
at the beginning of the sequence, followed by mainshock-aftershock features. Geological and gravity data
presented here reveal that the basement is affected by two sets of NW-SE and NE-SW normal faults and
intensely deformed by vertical NW-SE joints. Improved relocation of the Granada 2021 seismicity reveals a
confined chimney-shape seismicity caused by the activity of a 2 km long NW-SE normal fault segment. The
confinement of the sequence is associated with the NE-SW fault set acting as a barrier that restricts the rupture
area, limiting the maximum magnitude, and favoring the recurrence of events with smaller magnitude. The
chimney-shape of the seismic sequence suggests that the deformation is propagated vertically to the surface,
facilitated by preexisting fractures. The shallow extensional deformation during the uplift of the central Betic
Cordillera drove the activity of the local structures obliquely to the regional extensional trends, as evidenced
by the seismic sequence. This multidisciplinary study improves the knowledge on the origin of the Granada
Basin and underlies the important role of preexisting fractures on fault segmentation and seismic propagation,
decreasing the seismic potential of this area.Spanish projects
Evaluación de la Peligrosidad de Inestabilidades
de Laderas Asociadas a Terremotos
(CGL2015-65602-R AEI-FEDER)B-RNM-301-UGR18 (Junta de Andalucía/FEDER);P18-RT-3275 (Junta de Andalucía/FEDER)Programa Operativo FEDER Andalucía 2014–2020 – call made by the University of Jaén (Ref. 126344)POAIUJA 2021/2022 from the University of JaénAndalusian research groups RNM-148Andalusian research groups RNM-282Andalusian research groups RNM-37
A Model-Based Prioritisation Exercise for the European Water Framework Directive
A model-based prioritisation exercise has been carried out for the Water Framework Directive (WFD) implementation. The approach considers two aspects: the hazard of a certain chemical and its exposure levels, and focuses on aquatic ecosystems, but also takes into account hazards due to secondary poisoning, bioaccumulation through the food chain and potential human health effects. A list provided by EU Member States, Stakeholders and Non-Governmental Organizations comprising 2,034 substances was evaluated according to hazard and exposure criteria. Then 78 substances classified as “of high concern” where analysed and ranked in terms of risk ratio (Predicted Environmental Concentration/Predicted No-Effect Concentration). This exercise has been complemented by a monitoring-based prioritization exercise using data provided by Member States. The proposed approach constitutes the first step in setting the basis for an open modular screening tool that could be used for the next prioritization exercises foreseen by the WFD
Joint effects of nutrients and contaminants on the dynamics of a food chain in marine ecosystems
We analyze the joint effect of contaminants and nutrient loading on
population dynamics of marine food chains by means of bifurcation analysis.
Contaminant toxicity is assumed to alter mortality of some species with a
sigmoidal dose-response relationship. A generic effect of pollutants is to
delay transitions to complex dynamical states towards higher nutrient load
values, but more counterintuitive consequences arising from indirect effects
are described. In particular, the top predator seems to be the species more
affected by pollutants, even when contaminant is toxic only to lower trophic
levels
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