Abstract
When operating low cost autonomous vehicles, we are often faced with the need to apply integro-differential operators to numerical sequences. The need may arise in many different contexts, from vehicle navigation to data collection/estimation, and is strongly reinforced by constraints to the number of deployable sensors. Integration and, particularly, differentiation of discrete data sequences are, however, error prone operations. Even in the absence of noise, the traditional approaches introduce distortions and artifacts in the output data, mostly due to the mismatch between their underlying polynomial model and the spectral contents of the collected data. This article presents an alternative way to apply integro-differential operators to discrete data streams. The operators are applied in a strictly band-limited way, in both time and frequency, and no extraneous artifacts are introduced in the data. No assumptions or models are used, other than assuming that the original data stream was correctly sampled. As such, the procedure can be safely applied to data streams sampled at rates close to Nyquist, without the usual performance degradation.

Abstract
Mean sea level (MSL) in the Baltic Sea is influenced by several factors and therefore presents a complex behaviour over a wide range of time-scales. This work performs a multi-scale analysis of MSL variability in the Baltic Sea using discrete wavelet analysis. The North Atlantic Oscillation (NAO) is well known for having a strong influence in MSL variability over the Baltic; however, the relationship between MSL and NAO at different time-scales is still little understood. In this work a comparison of MSL and NAO variability is performed for a wide range of temporal scales, uncovering distinct relationships in high-frequency and long-term temporal variability. The annual and sub-annual scales are found to account for more than 50% of the total MSL variability. The MSL annual cycle is analysed and a shift from low to high amplitude values is identified in the 1970s for most stations. MSL is found to be anti-correlated to NAO at short time-scales while on the long-term NAO and MSL appear to be positively correlated for most stations. The physical mechanisms behind these distinct relationships deserve deeper study.

Abstract
Long-term continuous in-situ radon field monitoring was carried out in the southern region of Israel, at the Amram Mountain research tunnel in Elat and in shallow boreholes in the Gevanim valley in Makhtesh Ramon. This work shows that long-term radon monitoring based on simultaneous alpha and gamma measurement enables to differentiate between the impact of ambient temperature and pressure on radon transportation within porous media both in sites isolated from outer meteorological influence as in the Amram tunnel and in sites open to the influence of environmental conditions as in the Gevanim boreholes array. It was found that if the monitoring site is a closed measuring space with undisturbed environmental conditions, the radon in the air space will reach equilibrium with the radon in the rock. Then the radon time series as measured by both gamma and alpha detectors exhibit the same temporal variations. The results in this case indicate that the diurnal, intra-seasonal and seasonal variations in the radon concentration are clearly associated with the ambient temperature gradient outside the rock air interface, 100 m above the tunnel. In shallow, open boreholes, no equilibrium between the radon within the porous media and the radon in the open borehole air is necessarily established and the results of radon monitoring are different. Gamma detectors that measure the changes in radon concentrations in the porous rock indicated a clear correlation between radon concentrations and the daily variations of external surface temperature, from about 1 m up to 85 m. Yet the alpha detectors that measure the changes in radon concentrations in very shallow borehole air (about 1 m) reveal a clear anti-correlation with atmospheric pressure waves at semi-daily, daily, and intra-seasonal time scales. At depths of several tens of meters, outer pressure waves induce anti-correlated radon variations lasting the same time, but destroy the ordered radon daily periodicity in the measuring air space, although almost not disturbing the daily radon variation within the surrounding porous media.

Abstract
Echinoderm Mutable Collagenous Tissues (MCTs) undergo nervously mediated, drastic and reversible changes in their passive mechanical properties. MCT mutability is involved in autotomy, posture maintenance and motility, and, as a consequence, it influences all aspects of echinoderm biology (nutrition, reproduction, habitat selection, self-defense and predatory behavior) representing a key-factor for the ecological success of the phylum. Besides this, MCT performance represents a topic of remarkable interest for many different applied fields. A biomimetic research route looks at MCTs as a source of inspiration for the development of smart and innovative biomaterials with great potential for in vitro and in vivo applications when controlled and reversible plasticization and/or stiffening of the extracellular matrix is required. The MIMESIS (Marine Invertebrate Models & Engineered Substrates for Innovative bio-Scaffolds) project has been developed within this scientific context. The selected echinoderm model is the common sea urchin Paracentrotus lividus. This project is based on a multidisciplinary approach combining functional biology with biomaterial engineering. A brief review of recent morphological, biomolecular, biomechanical and biochemical results on P lividus MCTs are here presented in a biotechnological perspective, taking into account also a promising application regarding the use of MCT-derived substrata for cell culture studies.

Abstract
An analytical model based on geometrical optics and multilayer transfer matrix method is applied to determine the sensing properties of tapered optical fiber based SPR sensors incorporating bimetallic (Gold and Silver) layers, particularly when phase interrogation is considered. Phase interrogation is studied as a methodology to attain enhanced sensitivities. The performance of the sensing heads as function of the bimetallic layers and taper parameters is analyzed. It is shown the bimetallic combination is capable to provide larger values of sensitivity compared with the single layer approach. The results derived from this study are guiding the experimental study of these structures.

Abstract
In this work, we address a study of the spectral reflectance of silver nanowire metamaterials in the visible and near-infrared regions. To this end, several samples were fabricated with different fill-ratios and lattice constants, and their respective optical responses characterized in terms of these parameters. We perform a direct comparison between the collected experimental data with the values predicted by different analytical homogenization models to provide a better understanding of the effective optical behavior of this kind of metamaterials.