Graphene-based textured surface by pulsed laser deposition as a robust platform for surface enhanced Raman scattering applications

International audienceWe have developed a surface enhanced Raman scattering (SERS)-active substrate based on gold nanoparticles-decorated few-layer (fl) graphene grown by pulsed laser deposition. Diamond-Like Carbon film has been converted to fl-graphene after thermal annealing at low temperature. The formation of fl-graphene was confirmed by Raman spectroscopy, and surface morphology was highlighted by scanning electron microscopy. We found that textured fl-graphene film with nanoscale roughness was highly beneficial for SERS detection. Rhodamine 6G and p-aminothiophenol proposed as test molecules were detected with high sensitivity. The detection at low concentration of deltamethrin, an active molecule of a commercial pesticide was further demonstrated

Physiological performance of the cold-water coral Dendrophyllia cornigera reveals its preference for temperate environments

Cold-water corals (CWCs) are key ecosystem engineers in deep-sea benthic communities around the world. Their distribution patterns are related to several abiotic and biotic factors, of which seawater temperature is arguably one of the most important due to its role in coral physiological processes. The CWC Dendrophyllia cornigera has the particular ability to thrive in several locations in which temperatures range from 11 to 17 °C, but to be apparently absent from most CWC reefs at temperatures constantly below 11 °C. This study thus aimed to assess the thermal tolerance of this CWC species, collected in the Mediterranean Sea at 12 °C, and grown at the three relevant temperatures of 8, 12, and 16 °C. This species displayed thermal tolerance to the large range of seawater temperatures investigated, but growth, calcification, respiration, and total organic carbon (TOC) fluxes severely decreased at 8 °C compared to the in situ temperature of 12 °C. Conversely, no significant differences in calcification, respiration, and TOC fluxes were observed between corals maintained at 12 and 16 °C, suggesting that the fitness of this CWC is higher in temperate rather than cold environments. The capacity to maintain physiological functions between 12 and 16 °C allows D. cornigera to be the most abundant CWC species in deep-sea ecosystems where temperatures are too warm for other CWC species (e.g., Canary Islands). This study also shows that not all CWC species occurring in the Mediterranean Sea (at deep-water temperatures of 12-14 °C) are currently living at their upper thermal tolerance limit. © 2014 Springer-Verlag Berlin Heidelber

Cold-water corals research in the lab and in the field: (1) growth rates of four CWC species maintained in aquaria, (2) new research areas: the Galicia Bank and the Avilés canyon (Atlantic and Cantabrian Sea), a scientific and methodological approach

Growth rates of 4 Cold-water Coral (CWC) species (Madrepora occulata, Lophe/ia pertusa, Desmophyllum cristagalli and Dendrophyllia cornigera) from the Mediterranean Sea have been measured under the same and controlled laboratory conditions over a nine months period. Results showed that M. occulata grew faster than the other three species, which presented similar growth rates. These results are discussed and also compared with the growth of tropical coral species maintained in aquaria, but in different light and temperature conditions, which corresponded to the usual culture conditions of these corals. It appeared that the zooxanthellate tropical coral Galaxea fascicularis exhibited similar growth rates than the CWC M. oculata. Further we present new research areas on the Atlantic and Cantabrian continental margin, the Galicia Bank and the Aviles canyon, which are part of the zones studied in the Spanish LIFE project INDEMARES, as well as possible targets as Marine Protected Areas (MPAs) for the NATURA 2000 network. Both areas are studied considering an ecosystem approach, aboarding an integrated study of the physical scenario (hydrography, geomorphology), all ecosystem compartments (fish, endo-, epi-, and suprabenthic and benthopelagic fauna) and the trophic relationships between them. All this information, together with the study of the impact of the fisheries working in the areas, will be integrated in a trophodynamic mass-balance model and will be used to identify vulnerable ecosystems (VE) (as the CWC habitats are) and essential fish habitats (EFH). This methodological approach offers a holistic view of these deep-sea ecosystems and can be used to design more effective and successful management strategies for MPA

The Deep‐water corals of Cyprus: Environmental settings and ecological features (CYprus Cold‐corals Levantine SeA, Eastern MEditerraneaN: CYCLAMEN)

The recently started research project CYCLAMEN (CYprus Cold-corals Levantine SeA, Eastern MEditerraneaN), will conduct the first detailed study of cold-water coral communities in eastern Cypriot waters. Cold-water coral habitats have been found during exploratory surveys. The 2-yr long project will include the environmental characterization of the area, as well as the study of the spatial distribution of cold-water coral communities. In addition to the study of the biology of the coral species, genetic and eco-physiological studies will be included. This project is the first of its kind in Cyprus and will additionally have an associated scientific outreach programme in order to bring these ecosystems, still poorly known, to the general public. The project is led by the Spanish Institute of Oceanography (IEO), and relies on the participation of research Institutions in Cyprus: The Cyprus Institute (CyI) and the NGO Enalia Physis Environmental Research Centre (EPERC); France: Aix-Marseille University – Mediterranean Institute for Biodiversity & Ecology (AMU-IMBE); Greece: The Hellenic Centre for Marine Research (HCMR); Mónaco: Centre Scientifique de Monaco (CSM); United Kingdom: National Oceanography Centre (NOC), and Spain: Universitat de Barcelona (UB). Here we present the conceptual frame of the project, the background knowledge and the first obtained results in the oceanographic cruise carried out in summer 2015

Neuroticism Modifies Psychophysiological Responses to Fearful Films

Background: Neuroticism is a personality component frequently found in anxious and depressive psychiatric disorders. The influence of neuroticism on negative emotions could be due to its action on stimuli related to fear and sadness, but this remains debated. Our goal was thus to better understand the impact of neuroticism through verbal and physiological assessment in response to stimuli inducing fear and sadness as compared to another negative emotion (disgust).¦Methods: Fifteen low neurotic and 18 high neurotic subjects were assessed on an emotional attending task by using film excerpts inducing fear, disgust, and sadness. We recorded skin conductance response (SCR) and corrugator muscle activity (frowning) as indices of emotional expression.¦Results: SCR was larger in high neurotic subjects than in low neurotics for fear relative to sadness and disgust. Moreover, corrugator activity and SCR were larger in high than in low neurotic subjects when fear was induced.¦Conclusion: After decades of evidence that individuals higher in neuroticism experience more intense emotional reactions to even minor stressors, our results indicate that they show greater SCR and expressive reactivity specifically to stimuli evoking fear rather than to those inducing sadness or disgust. Fear processing seems mainly under the influence of neuroticism. This modulation of autonomic activity by neurotics in response to threat/fear may explain their increased vulnerability to anxious psychopathologies such as PTSD (post traumatic stress disorder)

Switchable Silver Nanostructures Controlled With an Atomic Force Microscope

International audienc

Synthesis of large area graphene layers by pulsed laser deposition

International audienc

The influence of flow velocity and temperature on zooplankton capture rates by the cold-water coral Dendrophyllia cornigera

Food supply is one of the main factors driving cold-water corals (CWC) distribution, which often concentrate on ridges where local near-bed turbulence/strong currents enhance food availability. However, efficiency in food capture is strongly dependent on current velocity. Moreover, seawater temperature may also affect feeding success, since polyp contraction or nematocyst function could be slower at temperatures belowthe natural thermal range of a species. The non-reef forming CWC Dendrophyllia cornigera occurs in areas at temperatures from 11 to 17 °C, but is apparently absent from most CWC reefs at temperatures constantly below 11 °C. This study thus aimed to assess if a reduction in feeding capacity may contribute to understand the absence of this CWC from strictly cold environments. The efficiency of D. cornigera to capture meso- and macrozooplankton was assessed under different flow speeds (2, 5 and 10 cm s− 1) and temperatures (8, 12, and 16 °C). Flow speeds did not significantly affect the capture of mesozooplankton, whereas capture of macrozooplankton was significantly enhanced with increasing flow speed. Both meso- and macrozooplankton captures were not significantly affected by temperature in D. cornigera. Overall, this CWC species is efficient in capturing zooplankton under a larger range of flow velocities than the widespread CWC Lophelia pertusa, whose capture efficiency significantly decreased from low to high flow speeds. Even if temperature does not directly affect the capture rates of D. cornigera, it may still influence the feeding capacity of this CWC since the capture rates at 8 °C were always in the lowest range of the observed values at each flow speed, and corals maintained at 8 °C required a much longer time to fully expand their polyps once they were placed in the incubation chambers, than corals maintained at 12 and 16 °C.Versión del editor2,263

Effect of salinity on the skeletal chemistry of cultured scleractinian zooxanthellate corals: Cd/Ca ratio as a potential proxy for salinity reconstruction

The effect of salinity on the elemental and isotopic skeletal composition of modern zooxanthellate scleractinian corals (Acropora sp., Montipora verrucosa and Stylophora pistillata) was investigated in order to evaluate potential salinity proxies. Corals were cultured in the laboratory at three salinities (36, 38 and 40). The other environmental parameters were kept constant. For all species analyzed, Sr/Ca, Mg/Ca, U/Ca and Li/Ca ratios were not influenced by salinity changes. The Ba/Ca ratio also lacks a systematic relationship with salinity and exhibits high inter-generic variations, up to one order of magnitude. On the contrary, the Cd/Ca ratio decreases as a function of increasing salinity, and δ18O and δ13C also presented a significant response, but with opposite trends to salinity variations. Since Cd/Ca is usually considered as an upwelling proxy, its salinity dependence could compromise the upwelling signal, unless some corrections can be carried out. Regardless, if the dependence found in the present dataset proved to be widespread and systematic, the Cd/Ca ratio could represent a promising salinometer awaiting further investigation. This study also confirmed the reliability of the well-established temperature proxies Sr/Ca, Mg/Ca and U/Ca, as these ratios were insensitive to salinity variations. Moreover, our results showed that δ18O or δ13C can be considered as reliable temperature recorders as far as the salinity effect is removed from the parameter reconstructed (e.g., temperature). Investigating the influence of salinity on the skeletal chemistry of scleractinian corals grown under controlled environmental conditions confirmed previous results, validated isotopic corrections, and identified a promising proxy of salinity