Effect of toroidal particle sources on SOL physics in the FT-2 tokamak

Two gas-puffs are used near limiters in the FT-2 tokamak for the purpose of hydrogen refuelling during plasma discharges. This creates toroidal and poloidal asymmetry in particle sources near limiters which has to be considered in modelling. Here, the effect of toroidal asymmetry is simulated using the gyrokinetic code ELMFIRE. Two slightly different toroidal particle sources are used in simulations, and their results are compared with each other, and with experimental measurements to understand the impact of toroidal particle sources on Scrape-off Layer (SOL) physics.Peer reviewe

A MSFD complementary approach for the assessment of pressures, knowledge and data gaps in Southern European Seas : the PERSEUS experience

PERSEUS project aims to identify the most relevant pressures exerted on the ecosystems of the Southern European Seas (SES), highlighting knowledge and data gaps that endanger the achievement of SES Good Environmental Status (GES) as mandated by the Marine Strategy Framework Directive (MSFD). A complementary approach has been adopted, by a meta-analysis of existing literature on pressure/impact/knowledge gaps summarized in tables related to the MSFD descriptors, discriminating open waters from coastal areas. A comparative assessment of the Initial Assessments (IAs) for five SES countries has been also independently performed. The comparison between meta-analysis results and IAs shows similarities for coastal areas only. Major knowledge gaps have been detected for the biodiversity, marine food web, marine litter and underwater noise descriptors. The meta-analysis also allowed the identification of additional research themes targeting research topics that are requested to the achievement of GES. 2015 The Authors. Published by Elsevier Ltd. This is an open access article under the CC BY license.peer-reviewe

Temporal Fluctuations of Zooplankton Communities in Varna Bay (Western Black Sea) and Sevastopol Bay (Northern Black Sea): A Comparative Study

Human activities are mainly concentrated in the coastal regions which appeared less capable to assimilate the adverse effects of those threats. The consequences of foremost pressures to European coastal areas, respectively to the Black Sea such as water pollution, eutrophication, loss of biological diversity, introduction of non-indigenous species, over fishing, land use and landscape deterioration, and coastal erosion have been already well documented (Moncheva et al., 2001, Prodanov et al., 2001, Gubanova et al., 2002, Kamburska, 2004, Kideys et al., 2005, Oguz, 2005, Kamburska et al., 2006). Insufficiency of comparable time series data across the coastal areas of the Black Sea is still a key problem for a comprehensive assessment of the marine environment. The present study is focused on the comparison of the zooplankton quality and quantity parameters in two vulnerable coastal areas Sevastopol Bay (Northern Black Sea) and Varna Bay (Western Black Sea). It aims to assess the current state and long-term trends of zooplankton communities of the two regions of the Black Sea and the response to anthropogenic and environmental shifts. The objectives are: 1) to reveal the structure of zooplankton community in both areas; 2) to contrast temporal variability of the plankton fauna structure in the coastal ecosystems of Northern and Western Black Sea. Observations are based on the long-term data for mesozooplankton abundance, key species and taxonomic groups, temperature and salinity collected at monitoring stations in Varna and Sevastopol Bays during the period 1967 - 2005 (Varna Bay) and 1976-2005 (Sevastopol Bay). The results of inter-annual dynamics of mesozooplankton quantity revealed similarities in the timing of maximum abundance during the 1980s in both areas. The structure of the community significantly shifted over the decades and the reorganization was mainly with respect to dominant groups and species. Thus Oithona nana maintained high density in the period 1976-1980, while Acartia clausi (dominant over the year) and Pleopis polyphemoides were constant components of the plankton fauna with similar dynamics mode in the study regions. In spite of the observed similarities, zooplankton communities in Varna and Sevastopol Bays manifested peculiar features. The total abundance in Varna Bay ranged from 1083 ind.m-3 to 52 978 ind.m-3, while in Sevastopol Bay it varied from only 276 ind.m-3 to 14501 ind.m-3. During the period 1976-1980, the zooplankton amount in Sevastopol Bay was from 2 to 12 fold higher than in Varna Bay. Since the 1980 the total mesozooplankton abundance increased in Varna Bay in contrast to Sevastopol Bay. Noctiluca scintillans was regularly presented in Sevastopol Bay, but with lower numerical abundance compared to Varna Bay where it often reached ¿blooming¿ concentrations. The alterations in zooplankton assemblages could be further attributed to the impacts of climate and anthropogenic activities in both regions.JRC.DDG.H.3-Global environement monitorin

State and Trends of Zooplankton Community in the Coastal Black Sea Ecosystems of Varna and Sevastopol Bays

The paper focuses on the comparison of the zooplankton quality and quantity parameters in two vulnerable coastal areas Sevastopol Bay (Northern Black Sea) and system Varna Bay-Varna Lake- Beloslav Lake (Western Black Sea). The objectives are: 1) to reveal the structure of zooplankton communities in both areas; and 2) to compare the temporal variability of plankton fauna structure in the coastal ecosystems of Northern and Western Black Sea. The numerical abundance of zooplankton of Varna and Beloslav Lakes showed high density during the whole period compared with Varna and Sevastopol Bays. Zooplankton structure demonstrated a similarity in the investigated regions, evident in: the dominance of N. scintillans at the end of the 1980s-early 1990s; increased percentage share of Meroplankton after 1990s till nowadays; similar changes in species diversity (mostly in Copepoda and Cladocera groups). Diversity and evenness indices in average for a year were rather similar for the three regions and varied from 1.99 (in the lakes 1990-1991) to 3.30 (in Varna Bay, 1997). Fairly better was the ecological state of the zooplankton community in Varna and Sevastopol Bays compared to the Lakes. Cluster analysis differentiated between two main groups (Varna Bay and Sevastopol Bay) with 50 % similarity of Bray-Curtis. More faunal similarities appear between coastal areas of the Black Sea compared to the more polluted lakes watersJRC.H.3-Global environement monitorin

Adaptive Strategy of Thermophilic Oithona davisae in the Cold Black Sea Environment

Annual dynamics of abundance and gender composition, seasonal variations in reproduction, respiration rate and locomotor activity of the new invasive cyclopoid species Oithona davisae were investigated in Sevastopol Bay (Black Sea) from January 2013 till July 2014. The abundance of O. davisae in Sevastopol Bay was highest in September - November at 15 - 23 degrees C and decreased dramatically in winter -spring period at a temperature equal or less than 8 degrees C. From the end of February (8 degrees C) till the middle of May (17.5 degrees C) the population of O. davisae was represented only by adult females. Copepodites were observed first only when the water temperature increased to 17.5 degrees C, and males appeared only in late May at 22 degrees C. The revealed seasonal trends in copepod abundance and reproduction from field and experimental data suggest that winter population of O. davisae survives the cold season in the Black Sea at the stage of fertilized females which give the birth to the next generation in favorable spring conditions. To save energy resources, overwintering females have significantly lower temperature-related weight-specific respiration rate and moving activity than females from summer population. Such unique adaptation strategy facilitated the invasion and successful development of this thermophilic species in the cold Black Sea environment

Ionization of deep impurities by far-infrared radiation

An analysis is made of the ionization of deep impurity centers by high-intensity far-infrared and submillimeter-wavelength radiation, with photon energies tens of times lower than the impurity ionization energy. Within a broad range of intensities and wavelengths, terahertz electric fields of the exciting radiation act as a dc field. Under these conditions, deep-center ionization can be described as multiphonon-assisted tunneling, in which carrier emission is accompanied by defect tunneling in configuration space and electron tunneling in the electric field. The field dependence of the ionization probability permits one to determine the defect tunneling times and the character of the defect adiabatic potentials. The ionization probability deviates from the field dependence e(E)}exp(E2/Ec 2) (where E is the wave field, and Ec is a characteristic field) corresponding to multiphonon-assisted tunneling ionization in relatively low fields, where the defects are ionized through the Poole–Frenkel effect, and in very strong fields, where the ionization is produced by direct tunneling without thermal activation. The effects resulting from the high radiation frequency are considered and it is shown that, at low temperatures, they become dominant

IBD risk loci are enriched in multigenic regulatory modules encompassing putative causative genes

GWAS have identified >200 risk loci for Inflammatory Bowel Disease (IBD). The majority of disease associations are known to be driven by regulatory variants. To identify the putative causative genes that are perturbed by these variants, we generate a large transcriptome data set (nine disease-relevant cell types) and identify 23,650 cis-eQTL. We show that these are determined by ∼9720 regulatory modules, of which ∼3000 operate in multiple tissues and ∼970 on multiple genes. We identify regulatory modules that drive the disease association for 63 of the 200 risk loci, and show that these are enriched in multigenic modules. Based on these analyses, we resequence 45 of the corresponding 100 candidate genes in 6600 Crohn disease (CD) cases and 5500 controls, and show with burden tests that they include likely causative genes. Our analyses indicate that ≥10-fold larger sample sizes will be required to demonstrate the causality of individual genes using this approach

IBD risk loci are enriched in multigenic regulatory modules encompassing putative causative genes

GWAS have identified >200 risk loci for Inflammatory Bowel Disease (IBD). The majority of disease associations are known to be driven by regulatory variants. To identify the putative causative genes that are perturbed by these variants, we generate a large transcriptome data set (nine disease-relevant cell types) and identify 23,650 cis-eQTL. We show that these are determined by ∼9720 regulatory modules, of which ∼3000 operate in multiple tissues and ∼970 on multiple genes. We identify regulatory modules that drive the disease association for 63 of the 200 risk loci, and show that these are enriched in multigenic modules. Based on these analyses, we resequence 45 of the corresponding 100 candidate genes in 6600 Crohn disease (CD) cases and 5500 controls, and show with burden tests that they include likely causative genes. Our analyses indicate that ≥10-fold larger sample sizes will be required to demonstrate the causality of individual genes using this approach