Numerical modeling of dispersive shock waves called solibore in a stratified fluid is conducted. The theoretical model is based on extended version of the Korteweg-de Vries equation which takes into account the effects of cubic nonlinearity and Earth rotation. This model is now very popular in the physical oceanography. Initial conditions for simulations correspond to the real observed internal waves of shock-like shape in the Pechora Sea, the Arctic. It is shown that a sharp drop (like kink in the soliton theory) in the depth of the thermocline is conserved at a distance of one–three kilometers, and then it is transformed into dispersive shock waves (shock wave with undulations).
The σ subunit of bacterial RNA polymerase (RNAP) has been implicated in all steps of transcription initiation, including promoter recognition and opening, priming of RNA synthesis, abortive initiation and promoter escape. The post-promoter-recognition σ functions were proposed to depend on its conserved region σ3.2 that directly contacts promoter DNA immediately upstream of the RNAP active centre and occupies the RNA exit path. Analysis of the transcription effects of substitutions and deletions in this region in Escherichia coli σ70 subunit, performed in this work, suggests that (i) individual residues in the σ3.2 finger collectively contribute to RNA priming by RNAP, likely by the positioning of the template DNA strand in the active centre, but are not critical to promoter escape; (ii) the physical presence of σ3.2 in the RNA exit channel is important for promoter escape; (iii) σ3.2 promotes σ dissociation during initiation and suppresses σ-dependent promoter proximal pausing; (iv) σ3.2 contributes to allosteric inhibition of the initiating NTP binding by rifamycins. Thus, region σ3.2 performs distinct functions in transcription initiation and its inhibition by antibiotics. The B-reader element of eukaryotic factor TFIIB likely plays similar roles in RNAPII transcription, revealing common principles in transcription initiation in various domains of life.
N-Methyl-D-aspartate receptors (NMDAr) are involved in multiple physiological functions and neuropsychiatric disorders. Dizocilpine (commonly referred to as MK-801) is a well-known non-competitive NMDAr antagonist with psychotomimetic properties. A combination of electrophysiological and molecular analyses reveals not only the synchrony of baseline oscillations by MK-801, but also more importantly new insight into differential gene expressions in the cerebral cortex, midbrain, hippocampus, ventral striatum, amygdala, and hypothalamus regions after acute low-dose (0.08 mg/kg) MK-801 treatment; only the ventral striatum showed increased gene expression at a high dose (0.16 mg/kg) of MK-801. We believe that our present study will contribute in the understanding of the pathogenic mechanisms of neuropsychiatric disorders.
We often change our behavior to conform to real or imagined group pressure. Social influence on our behavior has been extensively studied in social psychology, but its neural mechanisms have remained largely unknown. Here we demonstrate that the transient downregulation of the posterior medial frontal cortex by theta-burst transcranial magnetic stimulation reduces conformity, as indicated by reduced conformal adjustments in line with group opinion. Both the extent and probability of conformal behavioral adjustments decreased significantly relative to a sham and a control stimulation over another brain area. The posterior part of the medial frontal cortex has previously been implicated in behavioral and attitudinal adjustments. Here, we provide the first interventional evidence of its critical role in social influence on human behavior.
Delineation and analysis of lateral clustering of lipids in model bilayers is an important step toward understanding of the physical processes underlying formation of lipid domains and rafts in cell membranes. Computer modeling methods represent a powerful tool to address the problem since they can detect clusters of only few lipid molecules – this issue still resists easy characterization with modern experimental techniques. In this work, we propose a computational method to detect and analyze parts of membrane with different packing densities and hydrogen bonding patterns. A series of one- and two-component fluid systems containing lipids with the same polar heads and different acyl chains, dioleoylphosphatidylcholine (18:1) and dipalmitoylphosphatidylcholine (16:0), or with same acyl chains and different polar heads, dioleoylphosphatidylserine (18:1) and dioleoylphosphatidylcholine (18:1), were studied via molecular dynamics simulations. Four criteria of clustering were considered. It was shown that the water-lipid interface of biomembranes represents a highly dynamic and “mosaic” picture, whose parameters depend on the bilayer composition. Some systems (e.g., with 20-30% of the anionic lipid) demonstrate unusual clustering properties and demand further investigation at molecular level. Lateral microheterogeneities in fluid lipid bilayers seem to be among the most important factors determining the nature of the membrane-water interface in a cell.
The paper describes changing patterns of commercial fish catch in the downstream part of the Neva River and the eastern Gulf of Finland and analyzes drivers of these changes for the period 1929-1995. We summarize catch data on 20 species and species groups of fishes and lamprey, as well as available abiotic data (salinity, temperature and water transparency). Water transparency gradually decreased during the 20th century being inseparable from a number of non-quantified anthropogenic factors, thus it can be used as an integral index of anthropogenic loading on the ecosystem. Because fisheries statistics were not published regularly, catch data were extracted from archives and various publications. Fishing locations, gear and target species changed over time in relation to each other, reflecting technological developments in fisheries, commercial demands for fishery products and the abundance of fish populations. Until the 18-19th centuries, fisheries took place mostly in rivers where weirs and set nets targeted sturgeon, salmon and whitefish. By the end of the 19th century, herring and smelt were the main targets of fixed nets in coastal areas. A century later, the main commercial species, herring, was harvested with pelagic trawls operating offshore in the Gulf. This evolution in fisheries, along with other anthropogenic activities, caused severe declines in diadromous species. Spawning migrations that make them easy to catch, and their high market value, make diadromous fish more vulnerable than other groups. Canonical correspondence analysis showed that catches of most diadromous species decreased with increasing transparency, which may reflect their response to anthropogenic pressure. Marine and freshwater fish suffered from anthropogenic pressure, but to a lesser extent probably because of a wider distribution and dispersal, and more capital-intensive fishing methods. Catches of marine species, except herring, significantly increased in the 1970-1980s when salinity was comparatively high. We found no correlation of fish catches with temperature.
Although language is a tool for communication, most research in the neuroscience of language has focused on studying words and sentences, while little is known about the brain mechanisms of speech acts, or communicative functions, for which words and sentences are used as tools. Here the neural processing of two types of speech acts, Naming and Requesting, was addressed using the time-resolved event-related potential (ERP) technique. The brain responses for Naming and Request diverged as early as ~120 ms after the onset of the critical words, at the same time as, or even before, the earliest brain manifestations of semantic word properties could be detected. Request-evoked potentials were generally larger in amplitude than those for Naming. The use of identical words in closely matched settings for both speech acts rules out explanation of the difference in terms of phonological, lexical, semantic properties, or word expectancy. The cortical sources underlying the ERP enhancement for Requests were found in the fronto-central cortex, consistent with the activation of action knowledge, as well as in the right temporo-parietal junction (TPJ), possibly reflecting additional implications of speech acts for social interaction and theory of mind. These results provide the first evidence for surprisingly early access to pragmatic and social interactive knowledge, which possibly occurs in parallel with other types of linguistic processing, and thus supports the near-simultaneous access to different subtypes of psycholinguistic information.
This paper examines the early history of agricultural entomology in the Russian empire in the decades before Russian universities and learned societies occupied centre stage in the intellectual life of the country. It aims to contribute to the ongoing discussions of historically contingent relations between ‘amateurs’ and ‘professionals’ in scientific research. It explores the social identities of those people who took part in the production and circulation of scientific knowledge, and argues that in this period Russian officialdom played a major role in these processes. The state officials’ engagement with natural history originated out of a broader information gathering agenda, which was characteristic of the early- to mid-nineteenth century. At the same time, the paper highlights the importance of provincial observers who were indispensable for providing field data for bureaucratic ‘inventorying’ of imperial resources. This dependency on local observers had far reaching implications, including the dissemination of the language and practices of natural history among wider audiences.
Economic, Social, and Budget Problems of the Russian Regions in 2013-16
Understanding and predicting climate change on long time scales has focused increasing attention on the ocean-atmosphere system. Recent research on monsoon, mesoscale processes and upwelling connections between the ocean and atmosphere has guided to new insights about the sensitivity of the climate system to ocean-atmosphere process. So, it is clear to fully understand the nature of these feedbacks and to quantify their effects on climate is very important. It is expectation that this group of papers on different ocean-atmospheric problems will offer a good understanding to ocean-atmosphere processes in a global climate change scenario.
We examined how emotional context influences processing of emotionally neutral acoustic stimuli in the human auditory cortex. Nine subjects performed a simple discrimination task. In the positive-emotional trials correct performance was awarded with money, whereas in the negative-emotional trials, correct performance resulted in avoidance of the loss of money. Auditory stimuli were identical in both trial types. An event-related brain potential (ERP) N100 deflection, generated in the auditory cortex, was significantly larger in the negative as compared to the positive-emotional trials. This result demonstrates that emotional context influences early sensory-specific cortical processing. In addition, we found some evidence in favor of assumption that processing of positive visual feedback was faster in negative-emotional trials. This was reflected in the tendency for the latency of visual ERPs to be shorter in the latter case. We suggest that our results indicate that the systemic organization at all stages of deployment of behavior depends on emotional context. Dynamics of learning the discrimination task was also dependent on emotional context.
The response of the mouse male germ cells exposed to gold nanoparticles (~2.5 nm) was studied. Our investigation demonstrates that treatment with Au nanoparticles for four days does not impair the architecture of the spermatogenic epithelium. Cytogeneticevaluation using micronucleus assay showed that gold nanoparticles can affect the chromosomes of early primary spermatocytes.
The response of mouse male germ cells exposed to gold nanoparticles (~ 2.5 nm) was studied. Our investigation demostrates that treatment with Au nanoparticles for four days does not impair the architecture of the spermatogenic epithelium. Cytogenetic evaluation using micronucleus assay showed that gold nanoparticles can affect the chromosomes of early primary spermatocytes. However, gold nanoparnicles did not induce chromosome abnomalities in spermatogonial stem cells. Further, the cauda epididymal sperm was isolated on the 14th day after treatment and was incubated in SDS solution (Na sodium dodecyl) and then in a solution containing DTT (dithiothreitol) to induce nuclear chromatin decondensation. Observations showed that after four days of treatment of spermiogenic (postmeiotic) cells with gold nanoparticles the decondensation process had no differences from the control.
It is not surprising that Mubarak’s administration “overlooked” the social explosion. Indeed, statistical data righteously claimed that the country was developing very successfully. Economic growth rates were high (even in the crisis years). Poverty and inequality levels were among the lowest in the Third World. Global food prices were rising, but the government was taking serious measures to mitigate their effect on the poorest layers of the population. Unemployment level (in per cent) was less than in many developed countries of the world and, moreover, was declining, and so were population growth rates. What would be the grounds to expect a full-scale social explosion? Of course, the administration had a sort of reliable information on the presence of certain groups of dissident “bloggers”, but how could one expect that they would be able to inspire to go to the Tahrir any great masses of people? It was even more difficult to figure out that Mubarak’s regime would be painfully struck by its own modernization successes of the 1980s, which led to the sharp decline of crude death rate and especially of infant and child mortality in 1975–1990. Without these successes many young Egyptians vehemently demanding Mubarak’s resignation (or even death) would have been destined to die in early childhood and simply would not have survived to come out to the Tahrir Square.
We studied the interactions in neural processing of auditory and visual speech by recording event-related brain potentials (ERPs). Unisensory (auditory - A and visual - V) and audiovisual (AV) vowels were presented to 11 subjects. AV vowels were phonetically either congruent (e.g., acoustic /a/ and visual /a/) or incongruent (e.g., acoustic /a/ and visual /y/). ERPs to AV stimuli and the sum of the ERPs to A and V stimuli (A+V) were compared. Similar ERPs to AV and A+V were hypothesized to indicate independent processing of A and V stimuli. Differences on the other hand would suggest AV interactions. Three deflections, the first peaking at about 85 ms after the A stimulus onset, were significantly larger in the ERPs to A+V than in the ERPs to both congruent and incongruent AV stimuli. We suggest that these differences reflect AV interactions in the processing of general, non-phonetic, features shared by the acoustic and visual stimulus (spatial location, coincidence in time). The first difference in the ERPs to incongruent and congruent AV vowels peaked at 155 ms from the A stimuli onset. This and two later differences are suggested to reflect interactions at phonetic level. The early general AV interactions probably reflect modified activity in the sensory-specific cortices, whereas the later phonetic AV interactions are likely generated in the heteromodal cortices. Thus, our results suggest that sensory-specific and heteromodal brain regions participate in AV speech integration at separate latencies and are sensitive to different features of A and V speech stimuli.
Humans often change their beliefs or behavior due to the behavior or opinions of others. This study explored, with the use of human event-related potentials (ERPs), whether social conformity is based on a general performance-monitoring mechanism. We tested the hypothesis that conflicts with a normative group opinion evoke a feedback-related negativity (FRN) often associated with performance monitoring and subsequent adjustment of behavior. The experimental results show that individual judgments of facial attractiveness were adjusted in line with a normative group opinion. A mismatch between individual and group opinions triggered a frontocentral negative deflection with the maximum at 200 ms, similar to FRN. Overall, a conflict with a normative group opinion triggered a cascade of neuronal responses: from an earlier FRN response reflecting a conflict with the normative opinion to a later ERP component (peaking at 380 ms) reflecting a conforming behavioral adjustment. These results add to the growing literature on neuronal mechanisms of social influence by disentangling the conflict-monitoring signal in response to the perceived violation of social norms and the neural signal of a conforming behavioral adjustment.
This study aims to explore the use of the social-ecological system to consider tourism in mountain areas by examining residents' perceptions of tourism impacts and how determined local development tourism policies can affect natural, socio-economic and cultural aspects and provide sustainable development of mountain areas. Residents' perceptions of sustainable tourism development potential, perceived tourism impacts, analysis of community attachment (measured by the length of residence) and employment sector of stakeholder (economic dependence on the tourism industry or some other sectors) were involved in this study. Authors applied Q-methodology and the Principle Component Analysis (PCA) algorithm in a small mountain community of Kopaonik, the Republic of Serbia. The results revealed that residents' agreement/disagreement is connected with two aspects – ecosystem and property rights and that ecosystem can be significantly influenced by all three development policies. Findings suggest that development of future natural conservation plans and new cultural attractions can have positive effects on all parts of social-ecological system. Some practical implications of those findings for tourism planning and development are also discussed. Results show that Q-methodology is an adequate tool for the policy-making process and quantifying stakeholders' views for destinations that base their tourism development on natural resources and especially for those destinations with a tourism-dependent economy.
Protection of the environment can be achieved by creating conditions that ensure the complete absence, or at least minimal content, of hazardous substances in industrial waste. Therefore, in production processes where the main and/or additive product is material with mercury content, the prevention of mercury vapor emissions into the atmosphere is an essential prerequisite for safety and environmental protection. However, achieving these indispensable safety conditions requires significant energy input. Detailed analysis of existing techniques and equipment for mercury extraction from mercury-containing and mercury-contaminated materials as well as plastics containing waste showed that all of the proposed methods are energy-intensive and cannot entirely remove mercury vapor from the emissions. A new technique of the thermal demercurization of mercury-containing materials has been offered. The original feature of the proposed technique is the distillation and condensation of mercury vapor within an inert gas flow circulating in the closed loop system. The offered technique ensures a substantial reduction in energy consumption while cooling the mercury vapor for its condensation and almost entirely eliminates mercury emissions into the atmosphere. Keywords: recycling of mercury-containing materials, environmental protection, energy consumption, thermal demercurization, inert gas flow, closed gas loop system, closed liquid loop system.
The characteristics of nonlinear internal waves in a shallow stratified lake are considered on the example of the Sankhar Lake (Vladimir region, Russia). It is shown that natural variations of temperature in the lake affect the kinematic characteristics of internal waves, especially the coefficient of the quadratic nonlinearity. The theoretical model based on the extended Korteweg–de Vries equation – the Gardner equation is used to estimate the characteristics of internal waves. It is shown that the first mode soliton is a wave of negative polarity. Its amplitude is less than 3 m (depth of the lake up to 15 m). Solitons of the second mode may be of any shape and polarity (compression or depression wave).