A multiresolution method for internal wave detection and color display from satellite images

In the present work an algorithm for wave detection is developed. The followed methodology is based on the multiresolution processing, the wavelet transform and the RGB model. This algorithm has been tested in three SAR images provided by the COSMOSkymed satellite from the ASI. First, Gaussian masks are generated in order to detect edges in the horizontal and vertical directions. This work is repeated in four resolution levels. Each level depends on the size and the variance of the gaussian mask. Once the horizontal and vertical edges are found, it is followed a non-maximal supresion processing to discard not relevant edges. This images are enhanced by morphological processing. To integrate the levels into a single image in order to interpretate the obtained results it is used the RGB model. Each one of the first three levels is introduced in a RGB image channel. Finally the pixels that appear in white are the corresponding to the most important edges, that is, the waves.Ingeniería Técnica de Telecomunicación, especialidad Sonido e ImagenTelekomunikazio Ingeniaritza Teknikoa. Soinua eta Irudia Berezitasun

Impedimetric fingerprinting and structural analysis of isogenic E. coli biofilms using multielectrode arrays

© 2018 Elsevier B.V. Microbial biofilm contamination is an ubiquitous and persistent problem in industry and clinics. The structure of the biofilm, its extracellular matrix and its formation process are very complex. At present, there are only limited options to investigate biofilms outside the lab, as most in situ techniques lack sensitivity and resolution. Impedance-based sensors provide a fast, label-free and sensitive manner to characterize biofilms, although mainly large electrodes have been used so far. Here, we used 60 μm-sized electrode arrays (MEAs) to characterize the structure of biofilms formed by wild type (WT) Escherichia coli TG1 and the isogenic ΔcsgD, ΔcsgB and ΔbcsA mutants. At 24 h of growth, the interfacial resistance at 2 Hz increased by 3.4% and 0.3% for the curli producing strains (WT and ΔbcsA), yet it decreased by 5.7% and 4% for the curli non-producing strains (ΔcsgD and ΔcsgB). The imaginary impedance at 2 Hz decreased for all the strains by 7.2%, 6.9%, 5.1% and 2.5% (WT, ΔbcsA, ΔcsgB and ΔcsgD, respectively). Interestingly, the spatial variation of impedance within each biofilm, resulting from physiological and structural heterogeneity, was significantly different for each biofilm and most pronounced in the WT. Depending on the strain, the biofilm attachment phase lasted between 6 and 10 h, and was characterized by an increase in the interfacial resistance of up to 6% for the WT, 5.5% for ΔcsgD, 3.5% for ΔcsgB and 5% for ΔbcsA, as opposed to the decrease in medium resistance observed during the maturation phase. Overall, impedance-based MEA assays proved effective to differentiate between biofilms with varying structure, detect spatial diversity and explain biofilm life-cycle in terms of attachment and maturation.status: publishe

Development of an active high-density transverse intrafascicular micro-electrode probe

In this work, the development of an active high-density transverse intrafascicular microelectrode (hd-TIME) probe to interface with the peripheral nervous system is presented. The TIME approach is combined with an active probe chip, resulting in improved selectivity and excellent signal-to-noise ratio. The integrated multiplexing capabilities reduce the number of external electrical connections and facilitate the positioning of the probe during implantation, as the most interesting electrodes of the electrode array can be selected after implantation. The probe chip is packaged using thin-film manufacturing techniques to allow for a minimally invasive electronic package. Special attention is paid to the miniaturization, the mechanical flexibility and the hermetic encapsulation of the device. A customized probe chip was designed and packaged using a flexible, implantable thin electronic package (FITEP) process platform. The platform is specifically developed for making slim, ultra-compliant, implantable complementary metal-oxide-semiconductor based electronic devices. Multilayer stacks of polyimide films and HfO2/Al2O3/HfO2 layers deposited via atomic layer deposition act as bidirectional diffusion barriers and are key to the hermetic encapsulation. Their efficacy was demonstrated both by water vapor transmission rate tests and accelerated immersion tests in phosphate buffered saline at 60 °C. Using the hd-TIME probe, an innovative implantation method is developed to prevent the fascicles from moving away when the epineurium is pierced. In addition, by transversally implanting the hd-TIME probe in the proximal sciatic nerve of a rat, selective activation within the nerve was demonstrated. The FITEP process platform can be applied to a broader range of integrated circuits and can be considered as an enabler for other biomedical applications