Midbrain dopaminergic neurons projecting to the ventral striatum code for reward magnitude and probability during reward anticipation and then indicate the difference between actual and predicted outcome. It has been questioned whether such a common system for the prediction and evaluation of reward exists in humans. Using functional magnetic resonance imaging and a guessing task in two large cohorts, we are able to confirm ventral striatal responses coding both reward probability and magnitude during anticipation, permitting the local computation of expected value (EV). However, the ventral striatum only represented the gain-related part of EV (EV ϩ ). At reward delivery, the same area shows a reward probability and magnitude-dependent prediction error signal, best modeled as the difference between actual outcome and EV ϩ . In contrast, loss-related expected value (EV Ϫ ) and the associated prediction error was represented in the amygdala. Thus, the ventral striatum and the amygdala distinctively process the value of a prediction and subsequently compute a prediction error for gains and losses, respectively. Therefore, a homeostatic balance of both systems might be important for generating adequate expectations under uncertainty. Prevalence of either part might render expectations more positive or negative, which could contribute to the pathophysiology of mood disorders like major depression.

The deep waters of the western Mediterranean are known to have an almost constant trend towards higher salinity and temperature values since the 1950s. Recent observations have shown an acceleration of this tendency, which has been attributed by some authors to the effect of the propagation of the signal of the Eastern Mediterranean Transient, from east to west. From 2004 to 2006 five basin‐scale oceanographic cruises evidenced a relevant change in the deep structure of the western Mediterranean. In less than two years almost the whole deep basin has been filled with highly saline and warm new deep water, which substantially renewed the resident deep water. The paper shows evidence of the rapid basin‐wide extension of the event, giving insights into the origin and the propagation of the new deep water towards the basin interior and showing the evolution of the deep characteristics.

Reward processing depends on dopaminergic neurotransmission and is modulated by factors affecting dopamine (DA) reuptake and degradation. We used fMRI and a guessing task sensitive to reward-related activation in the prefrontal cortex and ventral striatum to study how individual variation in genes contributing to DA reuptake [DA transporter (DAT)] and degradation [catechol-o-methyltransferase (COMT)] influences reward processing. Prefrontal activity, evoked by anticipation of reward irrespective of reward probability and magnitude, was COMT genotype-dependent. Volunteers homozygous for the Met allele, associated with lower enzyme activity and presumably greater DA availability, showed larger responses compared with volunteers homozygous for the Val allele. A similar COMT effect was observed in the ventral striatum. As reported previously, the ventral striatum was also found to code gain-related expected value, i.e., the product of reward magnitude and gain probability. Individual differences in ventral striatal sensitivity for value were in part explained by an epistatic gene-gene interaction between COMT and DAT. Although most genotype combinations exhibited the expected activity increase with more likely and larger rewards, two genotype combinations (COMT Met/Met DAT 10R and COMT Val/ Val 9R) were associated with blunted ventral striatal responses. In view of a consistent relationship between reduced reward sensitivity and addiction, our findings point to a potential genetic basis for vulnerability to addiction.is critical to motivational and reward-related functions of the brain, including adaptation through reinforcement learning (1, 2) and decision making (3). Considerable interindividual differences with respect to decision making have been observed (4), and it has been speculated that genetic variability in the dopaminergic system could be related to these differences (5, 6). In addition, interindividual variation in dopaminergic function has been hypothesized as a major factor contributing to inheritable personality traits (7) and addiction (8). However, little is known about how variation in DA-related genes modulates the described physiological properties of the dopaminergic reward system (1-3, 9, 10) and how such physiological variation affects reward processing. To bridge this gap between genetics and behavior, we combined genetics and personality assessment with fMRI measures of brain activation as an intermediate (endo)phenotype (11,12), an approach based on the assumption that brain activation is causally more directly linked to genotype than is behavior (12).In the study of individual differences in DA system physiology, a useful conceptual distinction is often made between tonic and phasic dopaminergic neurotransmission (13,14). In the striatum, a basal level of extracellular DA results from tonic, slow, and irregular ''background'' firing of dopaminergic neurons originating in the ventral tegmental area. By contrast, burst firing of ventral tegmental area neurons induces phasic DA release, a me...

One century of oceanographic measurements has evidenced gradual increases in temperature and salinity of western Mediterranean water masses, even though the vertical stratification has basically remained unchanged. Starting in 2005, the basic structure of the intermediate and deep layers abruptly changed. We report here evidence of reinforced thermohaline variability in the deep western basin with significant dense water formation events producing large amounts of warmer, saltier and denser water masses than ever before. We provide a detailed chronological order to these changes, giving an overview of the new water masses and following their route from the central basin interior to the east (toward the Tyrrhenian) and toward the Atlantic Ocean. As a consequence of this climate shift, new deep waters outflowing through Gibraltar will impact the North Atlantic in terms of salt and heat input. In addition, modifications in the Mediterranean abyssal ecosystems and biogeochemical cycles are to be expected.

Abstract. The Mediterranean Sea is a semi-enclosed sea characterized by high salinities, temperatures and densities. The net evaporation exceeds the precipitation, driving an anti-estuarine circulation through the Strait of Gibraltar, contributing to very low nutrient concentrations. The Mediterranean Sea has an active overturning circulation, one shallow cell that communicates directly with the Atlantic Ocean, and two deep overturning cells, one in each of the two main basins. It is surrounded by populated areas and is thus sensitive to anthropogenic forcing. Several dramatic changes in the oceanographic and biogeochemical conditions have been observed during the past several decades, emphasizing the need to better monitor and understand the changing conditions and their drivers. During 2011 three oceanographic cruises were conducted in a coordinated fashion in order to produce baseline data of important physical and biogeochemical parameters that can be compared to historic data and be used as reference for future observational campaigns. In this article we provide information on the Mediterranean Sea oceanographic situation, and present a short review that will serve as background information for the special issue in Ocean Science on "Physical, chemical and biological oceanography of the Mediterranean Sea". An important contribution of this article is the set of figures showing the large-scale distributions of physical and chemical properties along the full length of the Mediterranean Sea.

[1] The recent major production of anomalously warm, salty deep water in the northwestern Mediterranean Sea (winters 2004Sea (winters -2005Sea (winters and 2005Sea (winters -2006) is linked to extreme winter air-sea heat and freshwater forcing of the basin.

BackgroundStaphylococci belong to the most important pathogens causing implant-associated infections. Colonization of the implanted medical devices by the formation of a three-dimensional structure made of bacteria and host material called biofilm is considered the most critical factor in these infections. To form a biofilm, bacteria first attach to the surface of the medical device, and then proliferate and accumulate into multilayered cell clusters. Biofilm accumulation may be mediated by polysaccharide and protein factors.Methology/Principal FindingsThe information on Staphylococcus aureus protein factors involved in biofilm accumulation is limited, therefore, we searched the S. aureus Col genome for LPXTG-motif containing potential surface proteins and chose the so far uncharacterized S. aureus surface protein C (SasC) for further investigation. The deduced SasC sequence consists of 2186 amino acids with a molecular mass of 238 kDa and has features typical of Gram-positive surface proteins, such as an N-terminal signal peptide, a C-terminal LPXTG cell wall anchorage motif, and a repeat region consisting of 17 repeats similar to the domain of unknown function 1542 (DUF1542). We heterologously expressed sasC in Staphylococcus carnosus, which led to the formation of huge cell aggregates indicative of intercellular adhesion and biofilm accumulation. To localize the domain conferring cell aggregation, we expressed two subclones of sasC encoding either the N-terminal domain including a motif that is found in various architectures (FIVAR) or 8 of the DUF1542 repeats. SasC or its N-terminal domain, but not the DUF1542 repeat region conferred production of huge cell aggregates, higher attachment to polystyrene, and enhanced biofilm formation to S. carnosus and S. aureus. SasC does not mediate binding to fibrinogen, thrombospondin-1, von Willebrand factor, or platelets as determined by flow cytometry.Conclusions/SignificanceThus, SasC represents a novel S. aureus protein factor involved in cell aggregation and biofilm formation, which may play an important role in colonization during infection with this important pathogen.

The biodiversity of the megabenthic assemblages of the mesophotic zone of a Tyrrhenian seamount (Vercelli Seamount) is described using Remotely Operated Vehicle (ROV) video imaging from 100 m depth to the top of the mount around 61 m depth. This pinnacle hosts a rich coralligenous community characterized by three different assemblages: (i) the top shows a dense covering of the kelp Laminaria rodriguezii; (ii) the southern side biocoenosis is mainly dominated by the octocorals Paramuricea clavata and Eunicella cavolinii; while (iii) the northern side of the seamount assemblage is colonized by active filter-feeding organisms such as sponges (sometimes covering 100% of the surface) with numerous colonies of the ascidian Diazona violacea, and the polychaete Sabella pavonina. This study highlights, also for a Mediterranean seamount, the potential role of an isolated rocky peak penetrating the euphotic zone, to work as an aggregating structure, hosting abundant benthic communities dominated by suspension feeders, whose distribution may vary in accordance to the geomorphology of the area and the different local hydrodynamic conditions.