Stationary states of a spherical Minority Game with ergodicity breaking

Using generating functional and replica techniques, respectively, we study the dynamics and statics of a spherical Minority Game (MG), which in contrast with a spherical MG previously presented in J.Phys A: Math. Gen. 36 11159 (2003) displays a phase with broken ergodicity and dependence of the macroscopic stationary state on initial conditions. The model thus bears more similarity with the original MG. Still, all order parameters including the volatility can computed in the ergodic phases without making any approximations. We also study the effects of market impact correction on the phase diagram. Finally we discuss a continuous-time version of the model as well as the differences between on-line and batch update rules. Our analytical results are confirmed convincingly by comparison with numerical simulations. In an appendix we extend the analysis of the earlier spherical MG to a model with general time-step, and compare the dynamics and statics of the two spherical models.Comment: 26 pages, 8 figures; typo correcte

Переходная зона между шельфом и континентальным склоном северной части Чёрного моря. Ландшафтный подход

На основе данных, полученных с применением обитаемых подводных аппаратов, рассмотрена проблема положения бровки шельфа как важной структурно фациальной границы морского бассейна. Описана ландшафтная фациальная зональность в диапазоне глубин 70–220 м в северной части Черного моря. Выявлено, что смена фаций в переходной зоне между шельфом и материковым склоном от бровки шельфа до глубины около 200 м находится в тесной связи с усилением гипоксии до полной аноксии.На основі даних, отриманих із застосуванням підводних апаратів, розглянуто проблему положення бровки шельфу як важливої структурно фаціальної межі морського басейну. Описано ландшафтну фаціальну зональність в діапазоні глибин 70–20 м у північній частині Чорного моря. Виявлено, що зміна фацій у перехідній зоні між шельфом і материковим схилом від бровки шельфу до глибини близько 200 м тісно пов’язана із збільшенням гіпоксії до повної аноксії.The problem of continental shelf break position as an important structural – facial marine basin boundary discussed on the basis of manned submersibles’ data. The range and setting of Northern Black Sea facial zones in the depths interval 70 220m are described. It’s found that the facial changes are related closely with hypoxia increasing to complete anoxia from the shelf break to the depth of about 200 m

Brucella melitensis MucR, an orthologue of Sinorhizobium meliloti MucR, is involved in resistance to oxidative, detergent, and saline stresses and cell envelope modifications

Brucella spp. and Sinorhizobium meliloti are alphaproteobacteria that share not only an intracellular lifestyle in their respective hosts, but also a crucial requirement for cell envelope components and their timely regulation for a successful infectious cycle. Here, we report the characterization of Brucella melitensis mucR, which encodes a zinc finger transcriptional regulator that has previously been shown to be involved in cellular and mouse infections at early time points. MucR modulates the surface properties of the bacteria and their resistance to environmental stresses (i.e., oxidative stress, cationic peptide, and detergents). We show that B. melitensis mucR is a functional orthologue of S. meliloti mucR, because it was able to restore the production of succinoglycan in an S. meliloti mucR mutant, as detected by calcofluor staining. Similar to S. meliloti MucR, B. melitensis MucR also represses its own transcription and flagellar gene expression via the flagellar master regulator ftcR. More surprisingly, we demonstrate that MucR regulates a lipid A core modification in B. melitensis. These changes could account for the attenuated virulence of a mucR mutant. These data reinforce the idea that there is a common conserved circuitry between plant symbionts and animal pathogens that regulates the relationship they have with their hosts

Direct Repeat 6 from Human Herpesvirus-6B Encodes a Nuclear Protein that Forms a Complex with the Viral DNA Processivity Factor p41

The SalI-L fragment from human herpesvirus 6A (HHV-6A) encodes a protein DR7 that has been reported to produce fibrosarcomas when injected into nude mice, to transform NIH3T3 cells, and to interact with and inhibit the function of p53. The homologous gene in HHV-6B is dr6. Since p53 is deregulated in both HHV-6A and -6B, we characterized the expression of dr6 mRNA and the localization of the translated protein during HHV-6B infection of HCT116 cells. Expression of mRNA from dr6 was inhibited by cycloheximide and partly by phosphonoacetic acid, a known characteristic of herpesvirus early/late genes. DR6 could be detected as a nuclear protein at 24 hpi and accumulated to high levels at 48 and 72 hpi. DR6 located in dots resembling viral replication compartments. Furthermore, a novel interaction between DR6 and the viral DNA processivity factor, p41, could be detected by confocal microscopy and by co-immunoprecipitation analysis. In contrast, DR6 and p53 were found at distinct subcellular locations. Together, our data imply a novel function of DR6 during HHV-6B replication

A comprehensive study to assess the impact of impulsive sound on juvenile sea bass

Given the increasing amount of anthropogenically induced underwater sound into the marine environment, a better understanding of the impact of impulsive underwater sound on marine life is needed. This study tackles the impact of impulsive sound, related to pile-driving activities for offshore wind energy development, on the mortality, stress and behaviour of post-larval and juvenile European sea bass Dicentrarchus labrax. A 'worst-case scenario' field experiment was carried out on board of a piling vessel, exposing 68 and 115 days old fish (<2 g wet weight) to the sound generated during 1.5 hours of pile-driving. The number of strikes ranged from 1740 to 3070, with a single strike sound exposure level between 181 and 188 dB re 1 μPa².s, resulting in cumulative sound exposure levels ranging from 215 to 222 dB re 1 μPa².s. Immediate and long-term survival of the exposed fish was high and comparable to the control groups. However, juvenile fish responded to the impulsive underwater sound by a 50% reduction in their oxygen consumption rates, an indicator of secondary stress response. Primary stress responses, measured through cortisol levels are still to be analysed. We didn't find any effect on the condition and fitness of the exposed fish on the long term. Lab experiments performed with a SIG Sparker and a larvaebrator, respectively producing mid-high and lower frequencies, were inadequate to distinguish the determining sound metric or to pursue the exact origin of the stress response. Further away from the sound source, behavioural and masking effects can be expected. A lab experiment was carried out to study the behaviour of juvenile sea bass before, during and after one hour of impulsive sound exposure. In the aquaria, single strike sound levels reached 162 dB re 1 μPa².s, leading to a cumulative sound exposure level of 196 dB re 1 μPa².s after 2400 strikes. We observed that normal behaviour was disturbed, with an increase in startle responses and stationary behaviour at the beginning of the sound exposure experiment. Also, fish dived to the bottom of the aquaria, which is a typical anxiety-related response. However, no spatial preference was observed and normal behaviour was re-established shortly after the sound exposure ceased. These results indicate that impulsive sound close to the sound source creates sound pressure levels that are below the lethal threshold for fish, but above the stress threshold, at least for sea bass <2 g. Furthermore, lower sound levels at a distance from the sound source (in this case pile-driving) can disturb fish behaviour. Under optimal lab conditions, we did not see effects beyond the sound exposure period, but it remains unknown whether the reduced fitness of juvenile fish after exposure is limited in the real world as well

Elasticity-driven interaction between vortices in type-II superconductors

The contribution to the vortex lattice energy which is due to the vortex-induced strains is calculated covering all the magnetic field range which defines the vortex state. This contribution is compared with previously reported ones what shows that, in the most part of the vortex state, it has been notably underestimated until now. The reason of such underestimation is the assumption that only the vortex cores induce strains. In contrast to what is generally assumed, both core and non-core regions are important sources of strains in high-$\kappa$ superconductors.Comment: 10 pages, 1 figure, revtex

Test of Replica Theory: Thermodynamics of 2D Model Systems with Quenched Disorder

We study the statistics of thermodynamic quantities in two related systems with quenched disorder: A (1+1)-dimensional planar lattice of elastic lines in a random potential and the 2-dimensional random bond dimer model. The first system is examined by a replica-symmetric Bethe ansatz (RBA) while the latter is studied numerically by a polynomial algorithm which circumvents slow glassy dynamics. We establish a mapping of the two models which allows for a detailed comparison of RBA predictions and simulations. Over a wide range of disorder strength, the effective lattice stiffness and cumulants of various thermodynamic quantities in both approaches are found to agree excellently. Our comparison provides, for the first time, a detailed quantitative confirmation of the replica approach and renders the planar line lattice a unique testing ground for concepts in random systems.Comment: 16 pages, 14 figure