Determination of toxic elements (mercury, cadmium, lead, tin and arsenic) in fish and shellfish samples. Risk assessment for the consumers

The authors would gratefully like to acknowledge the financial support given by Fondo de Investigaciones Sanitarias (reference PI10/00527). They are also grateful to the Spanish Ministry of Education, Culture and Sport for awarding Pablo Olmedo a FPU predoctoral fellowship (reference AP2009-0534) to achieve his PhD degree in the context of this research project.Although fish intake has potential health benefits, the presence of metal contamination in seafood has raised public health concerns. In this study, levels of mercury, cadmium, lead, tin and arsenic have been determined in fresh, canned and frozen fish and shellfish products and compared with the maximum levels currently in force. In a further step, potential human health risks for the consumers were assessed. A total of 485 samples of the 43 most frequently consumed fish and shellfish species in Andalusia (Southern Spain) were analyzed for their toxic elements content. High mercury concentrations were found in some predatory species (blue shark, cat shark, swordfish and tuna), although they were below the regulatory maximum levels. In the case of cadmium, bivalve mollusks such as canned clams and mussels presented higher concentrations than fish, but almost none of the samples analyzed exceeded the maximum levels. Lead concentrations were almost negligible with the exception of frozen common sole, which showed median levels above the legal limit. Tin levels in canned products were far below the maximum regulatory limit, indicating that no significant tin was transferred from the can. Arsenic concentrations were higher in crustaceans such as fresh and frozen shrimps. The risk assessment performed indicated that fish and shellfish products were safe for the average consumer, although a potential risk cannot be dismissed for regular or excessive consumers of particular fish species, such as tuna, swordfish, blue shark and cat shark (for mercury) and common sole (for lead).Instituto de Salud Carlos III PI10/00527Spanish Ministry of Education, Culture and Sport AP2009-053

Design and implementation of an ultrasonic sensor for rapid monitoring of industrial malolactic fermentation of wines

Ultrasound is an emerging technology that can be applied to monitor food processes. However, ultrasonic techniques are usually limited to research activities within a laboratory environment and they are not extensively used in industrial processes. The aim of this paper is to describe a novel ultrasonic sensor designed to monitor physical–chemical changes that occur in wines stored in industrial tanks. Essentially, the sensor consists of an ultrasonic transducer in contact with a buffer rod, mounted inside a stainless steel tube section. This structure allows the ultrasonic sensor to be directly installed in stainless steel tanks of an industrial plant. The operating principle of this design is based on the measurement of ultrasonic velocity of propagation. To test its proper operation, the sensor has been used to measure changes of concentration in aqueous samples and to monitor the progress of a malolactic fermentation of red wines in various commercial wineries. Results show the feasibility of using this sensor for monitoring malolactic fermentations in red wines placed in industrial tanks.Postprint (author's final draft

EXPERIMENTAL AND COMPUTATIONAL STUDY ON THE BUBBLE BEHAVIOR IN A 3-D FLUIDIZED BED WITH A VERTICAL-AXIS, ROTATING DISTRIBUTOR

This work presents experimental measurements in a three-dimensional fluidized bed equipped with a novel vertical-axis, rotating distributor, together with two-fluid (Eulerian-Eulerian) CFD simulation results. The influence of the distributor rotation on the behavior of the bubbles in the experiments and in the CFD results is compared and critically analyzed

Observational Δν\Delta\nu-ρˉ\bar\rho relation for δ\delta Sct stars using eclipsing binaries and space photometry

Delta Scuti ($\delta$ Sct) stars are intermediate-mass pulsators, whose intrinsic oscillations have been studied for decades. However, modelling their pulsations remains a real theoretical challenge, thereby even hampering the precise determination of global stellar parameters. In this work, we used space photometry observations of eclipsing binaries with a $\delta$ Sct component to obtain reliable physical parameters and oscillation frequencies. Using that information, we derived an observational scaling relation between the stellar mean density and a frequency pattern in the oscillation spectrum. This pattern is analogous to the solar-like large separation but in the low order regime. We also show that this relation is independent of the rotation rate. These findings open the possibility of accurately characterizing this type of pulsator and validate the frequency pattern as a new observable for $\delta$ Sct stars.Comment: 11 pages, including 2 pages of appendix, 2 figures, 2 tables, accepted for publication in ApJ

La toma de decisión, ¿es una conducta observable?: Discusión sobre diferentes perspectivas teóricas utilizadas en el estudio del rendimiento deportivo

En este artículo se presenta la evaluación crítica de algunas limitaciones de la investigación tradicional sobre toma de decisión, y se centra principalmente en los estados mentales internos, dándose menor consideración a las acciones de los individuos. Se aportan argumentos basados en hallazgos empíricos que implican que las medidas psicológicas de tomas de decisión no requieren construirse como un rol inferido en cada participante por mecanismos internalizados. En su lugar, consideramos algunas debilidades de la valoración de las tomas de decisión como proceso, que se localizan internamente en la mente de cada participante. Se discuten los marcos de referencia basados en el comportamiento, que consideran las actividades contextualizadas de los atletas a lo largo del proceso de sus acciones deportivas, como expresión de los procesos psicológicos. Se muestra cómo los análisis de variables observables pueden subrayarlas complejas e interconectadas relaciones entre procesos psicológicos y percepción, acción y cognición en los comportamientos orientados a la consecución de metas. La comprensión de los procesos de cognición, percepción y acción puede mejorar mediante la identificación de propiedades clave directamente medibles que capturen las relaciones persona-entorno

Asynchronous sensor fusion of GPS, IMU and CAN-based odometry for heavy-duty vehicles

In heavy-duty vehicles, multiple signals are available to estimate the vehicle's kinematics, such as Inertial Measurement Unit (IMU), Global Positioning System (GPS) and linear and angular speed readings from wheel tachometers on the internal Controller Area Network (CAN). These signals have different noise variance, bandwidth and sampling rate (being the latter, possibly, irregular). In this paper we present a non-linear sensor fusion algorithm allowing asynchronous sampling and non-causal smoothing. It is applied to achieve accuracy improvements when incorporating odometry measurements from CAN bus to standard GPS+IMU kinematic estimation, as well as the robustness against missing data. Our results show that this asynchronous multi-sensor (GPS+IMU+CAN-based odometry) fusion is advantageous in low-speed manoeuvres, improving accuracy and robustness to missing data, thanks to non-causal filtering. The proposed algorithm is based on Extended Kalman Filter and Smoother, with exponential discretization of continuous-time stochastic differential equations, in order to process measurements at arbitrary time instants; it can provide data to subsequent processing steps at arbitrary time instants, not necessarily coincident with the original measurement ones. Given the extra information available in the smoothing case, its estimation performance is less sensitive to the noise-variance parameter setting, compared to causal filtering. Working Matlab code is provided at the end of this work

Wannier-Bloch approach to localization in high harmonics generation in solids

Emission of high-order harmonics from solids provides a new avenue in attosecond science. On one hand, it allows to investigate fundamental processes of the non-linear response of electrons driven by a strong laser pulse in a periodic crystal lattice. On the other hand, it opens new paths toward efficient attosecond pulse generation, novel imaging of electronic wave functions, and enhancement of high-order harmonic generation (HHG) intensity. A key feature of HHG in a solid (as compared to the well-understood phenomena of HHG in an atomic gas) is the delocalization of the process, whereby an electron ionized from one site in the periodic lattice may recombine with any other. Here, we develop an analytic model, based on the localized Wannier wave functions in the valence band and delocalized Bloch functions in the conduction band. This Wannier-Bloch approach assesses the contributions of individual lattice sites to the HHG process, and hence addresses precisely the question of localization of harmonic emission in solids. We apply this model to investigate HHG in a ZnO crystal for two different orientations, corresponding to wider and narrower valence and conduction bands, respectively. Interestingly, for narrower bands, the HHG process shows significant localization, similar to harmonic generation in atoms. For all cases, the delocalized contributions to HHG emission are highest near the band-gap energy. Our results pave the way to controlling localized contributions to HHG in a solid crystal, with hard to overestimate implications for the emerging area of atto-nanoscience

Drive Force and Longitudinal Dynamics Estimation in Heavy-Duty Vehicles

Modelling the dynamic behaviour of heavy vehicles, such as buses or trucks, can be very useful for driving simulation and training, autonomous driving, crash analysis, etc. However, dynamic modelling of a vehicle is a difficult task because there are many subsystems and signals that affect its behaviour. In addition, it might be hard to combine data because available signals come at different rates, or even some samples might be missed due to disturbances or communication issues. In this paper, we propose a non-invasive data acquisition hardware/software setup to carry out several experiments with an urban bus, in order to collect data from one of the internal communication networks and other embedded systems. Subsequently, non-conventional sampling data fusion using a Kalman filter has been implemented to fuse data gathered from different sources, connected through a wireless network (the vehicle's internal CAN bus messages, IMU, GPS, and other sensors placed in pedals). Our results show that the proposed combination of experimental data gathering and multi-rate filtering algorithm allows useful signal estimation for vehicle identification and modelling, even when data samples are missing

La heterogeneidad local y del paisaje no influye en la diversidad funcional de la flora arvense en cultivos cerealistas en clima mediterráneo

Farming intensification and landscape homogenization have been the main cause of plant diversity decline in agro-ecosystems. However, the functional consequences are poorly documented. In this study we analyzed the effects of local and landscape heterogeneity on three functional diversity indices: Functional richness, Functional dispersion and Functional evenness of the emerged weed flora and the seed bank in dryland cereal fields located in Andalusia (Spain)Postprint (published version