Abstract
A monthly index based on the persistence of the westerly winds over the English Chanel is constructed for 1685-2008 using daily data from ships' logbooks and comprehensive marine meteorological datasets. The so-called Westerly Index (WI) provides the longest instrumental record of atmospheric circulation currently available. Anomalous WI values are associated with spatially coherent climatic signals in temperature and precipitation over large areas of Europe, which are stronger for precipitation than for temperature and in winter and summer than in transitional seasons. Overall, the WI series accord with the known European climatic history, and reveal that the frequency of the westerlies in the eastern Atlantic during the twentieth century and the Late Maunder Minimum was not exceptional in the context of the last three centuries. It is shown that the WI provides additional and complementary information to the North Atlantic Oscillation (NAO) indices. The analysis of WI series during the industrial era indicates an overall good agreement with the winter and high-summer NAO, with the exception of several multidecadal periods of weakened correlation. These decoupled periods between the frequency and the intensity of the zonal flow are interpreted on the basis of several sources of non-stationarity affecting the centres of the variability of the North Atlantic and their teleconnections. Comparisons with NAO reconstructions and long instrumental indices extending back to the seventeenth century suggest that similar situations have occurred in the past, which call for caution when reconstructing the past atmospheric circulation from climatic proxies. The robustness and extension of its climatic signal, the length of the series and its instrumental nature make the WI an excellent benchmark for proxy calibration in Europe and Greenland.

Abstract
In a climate change context, changes in extreme sea-levels rather than changes in the mean are of particular interest from the coastal protection point of view. In this work, extreme sea-levels in the Baltic Sea are investigated based on daily tide gauge records for the period 1916-2005 using the annual block maxima approach. Extreme events are analysed based on the generalised extreme value distribution considering both stationary and time-varying models. The likelihood ratio test is applied to select between stationary and non-stationary models for the maxima and return values are estimated from the final model. As an independent and complementary approach, quantile regression is applied for comparison with the results from the extreme value approach. The rates of change in the uppermost quantiles are in general consistent and most pronounced for the northernmost stations.

Abstract
Many animal species, during their life cycles, can select specific food elements that meet the special and unique metabolic needs of crucial stages such as growth, gonad maturation or larvae production and brooding. The objective of this study was to analyze the seasonal phytoplankton composition in the stomach contents of the freshwater mussel Anodonta cygnea in order to determine whether it was capable of selecting food seasonally and which were its preferences. Specimens and water samples were collected monthly from Barrinha de Mira lagoon in the northwest of Portugal during one year. From the microalgae composition found in the water and stomach content samples, Chlorophyta presented a clear predominance, followed by Cryptophyta and Bacillariophyta in water samples, and Bacillariophyta and Cyanobacteria in stomach contents. Although mussels ingested algae in a pattern very similar to its abundance in the natural habitat, in some periods specific groups were preferred even if they were present in very low concentrations in the environment. Thus, these animals are capable of selecting food by its specific characteristics and this selectivity may be associated with its physiological cycle, mainly with the reproductive cycle. Namely, the large relative abundance (ratio stomach/environment) peak of blue green algae that co-occur with gamete development covering two other smaller peaks: one of Bacillariophyta that co-occurs with gametogenesis restart and the other of Chlorophyta at the end. In addition, a significant peak of Cryptophyta co-occurs with growth and glochidia brooding periods.

Abstract
Optical fiber sensors based on the phenomenon of plasmonic resonance can be interrogated applying different methods, the most common one being the spectral approach where the measurand information is derived from the reading of the wavelength resonance dip. In principle, a far better performance can be achieved considering the reading of the phase of the light at a specific wavelength located within the spectral plasmonic resonance. This approach is investigated in this work for fiber optic SPR sensors with overlays which are combinations of metallic and dielectric thin films, permitting not only to tune the wavelength of the SPR resonance but also the sensitivity associated with the phase interrogation of the sensors.

Abstract
Surface Plasmon Resonance (SPR) is the base for some of the most sensitive label free optical fiber biosensors. However, most solutions presented to date require the use of fragile fiber optic structure such as adiabatic tapers or side polished fibers. On the other hand, long-period fiber gratings (LPG) present themselves as an interesting solution to attain an evanescent wave refractive index sensor platform while preserving the optical fiber integrity. The combination of these two approaches constitute a powerful platform that can potentially reach the highest sensitivities as it was recently demonstrated by detailed theoretical study [1, 2]. In this work, a LPG-SPR platform is explored in different configurations (metal coating between two LPG - symmetric and asymmetric) operating in the telecom band (around 1550 nm). For this purpose LPGs with period of 396 mu m are combined with tailor made metallic thin films. In particular, the sensing regions were coated with 2 nm of chromium to improve the adhesion to the fiber and 16 nm of gold followed by a 100 nm thick layer of TiO2 dielectric material strategically chosen to attain plasmon resonance in the desired wavelength range. The obtained refractometric platforms were then validated as a biosensor. For this purpose the detection of thrombin using an aptamer based probe was used as a model system for protein detection. The surface of the sensing fibers were cleaned with isopropanol and dried with N-2 and then the aminated thrombin aptamer (5'-[NH2]-GGTTGGTGTGGTTGG-3') was immobilized by physisorption using Poly-L-Lysine (PLL) as cationic polymer. Preliminary results indicate the viability of the LPFG-SPR-APTAMER as a flexible platforms point of care diagnostic biosensors.

Abstract
A new type of fibre-optic refractive index sensor based on a long period fibre grating (LPFG) coated with a titanium dioxide (TiO2) thin film was demonstrated. The wavelength shift of the attenuation bands of this LPFG sensor to changes in the refractive index of the external media from 1.30 to 1.64 RIU was investigated. In order to optimize the sensor the TiO2 thin film thickness deposited around the LPFGs was varied from 10 to 80 nm. It was found that the TiO2 thin film increases the wavelength sensitivity of the LPFG to changes in the surrounding refractive index for values lower and higher than the cladding refractive index. As opposed to the bare LPFG it was shown the possibility to monitor refractive indices lower and higher than cladding refractive index tailoring the TiO2 thickness. An average wavelength sensitivity of 5250 nm/RIU was achieved in the range 1.444 to 1.456 RIU for a TiO2 thickness of 50 nm. In the region between 1.46 and 1.48 RIU the average sensitivity of about 825 nm/RIU was measured for a 40 nm thick film.