Search

The methylation of cytosines at CpG sites in DNA, carried out de novo by DNA methyltransferase Dnmt3a, is a basic epigenetic modification involved in gene regulation and genome stability. Aberrant CpG methylation in gene promoters leads to oncogenesis. In oncogene promoters, CpG sites often colocalize with guanine-rich sequences capable of folding into G-quadruplexes (G4s). Our in vitro study aimed to investigate how parallel G4s formed by a sequence derived from the c-MYC oncogene promoter region affect the activity of the Dnmt3a catalytic domain (Dnmt3a-CD). For this purpose, we designed synthetic oligonucleotide constructs: a c-MYC G4-forming oligonucleotide and linear double-stranded DNA containing an embedded stable extrahelical c-MYC G4. The topology and thermal stability of G4 structures in these DNA models were analyzed using physicochemical techniques. We showed that Dnmt3a-CD specifically binds to an oligonucleotide containing c-MYC G4, resulting in inhibition of its methylation activity. c-MYC G4 formation in a double-stranded context significantly reduces Dnmt3a-CD-induced methylation of a CpG site located in close proximity to the quadruplex structure; this effect depends on the distance between the non-canonical structure and the specific CpG site. One would expect DNA hypomethylation near the G4 structure, while regions distant from this non-canonical form would maintain a regular pattern of high methylation levels. We hypothesize that the G4 structure sequesters the Dnmt3a-CD and impedes its proper binding to B-DNA, resulting in hypomethylation and activation of c-MYC transcription. [ABSTRACT FROM AUTHOR]

In mammals, de novo methylation of cytosines in DNA CpG sites is performed by DNA methyltransferase Dnmt3a. Changes in the methylation status of CpG islands are critical for gene regulation and for the progression of some cancers. Recently, the potential involvement of DNA G-quadruplexes (G4s) in methylation control has been found. Here, we provide evidence for a link between G4 formation and the function of murine DNA methyltransferase Dnmt3a and its individual domains. As DNA models, we used (i) an isolated G4 formed by oligonucleotide capable of folding into parallel quadruplex and (ii) the same G4 inserted into a double-stranded DNA bearing several CpG sites. Using electrophoretic mobility shift and fluorescence polarization assays, we showed that the Dnmt3a catalytic domain (Dnmt3a-CD), in contrast to regulatory PWWP domain, effectively binds the G4 structure formed in both DNA models. The G4-forming oligonucleotide displaced the DNA substrate from its complex with Dnmt3a-CD, resulting in a dramatic suppression of the enzyme activity. In addition, a direct impact of G4 inserted into the DNA duplex on the methylation of a specific CpG site was revealed. Possible mechanisms of G4-mediated epigenetic regulation may include Dnmt3a sequestration at G4 and/or disruption of Dnmt3a oligomerization on the DNA surface. [ABSTRACT FROM AUTHOR]

In this paper, we propose a hybrid model that combines wavelet transform and artificial neural networks (ANN) to forecast the time series of hourly average methane (CH4) concentration. In this work, we want to improve the accuracy of predicting the dynamics of changes in the surface concentration of CH4. The model is based on data from environmental monitoring of greenhouse gases on the Belyy Island of the Yamal-Nenets Autonomous Okrug, Russia. The initial data for building the proposed model were obtained in the period July–August 2017. The time series of the CH4 concentration was decomposed using a discrete wavelet transform into five components—one approximating and four detailing components. These five components, together with synchronized series of meteorological parameters (temperature, humidity, and pressure), were used to train ten ANNs—five autoregressive networks with exogenous input (NARX) and five recurrent neural networks (Elman). The forecast was calculated as the sum of the forecasts for each of the five components. The forecast accuracy was assessed using several indices and a Taylor chart. The hybrid approach improved the accuracy of the forecasts by more than 20%. The hybrid model based on the NARX shown the best accuracy. [ABSTRACT FROM AUTHOR]

This paper presents the results of high‐resolution sedimentological analyses of sediment cores from the eastern Gulf of Finland (Baltic Sea). Sampling sites in the periphery of sedimentary basins were selected on the basis of acoustic profiling analyses. The research allowed tracing of the transition from the freshwater Ancylus Lake to the Littorina Sea. A specific transitional layer of 'blue clays', indicating the first stage of brackish water inflow into the Gulf of Finland, was dated to 9.1 ka BP. The date of first appearance of Littorina silty clay sedimentation was as follows: from 8.0 ka BP near Gogland Island, from 7.0 ka BP near Moshchny Island and from 5.9 ka BP near the Berezovye Islands. Holocene cycles of hypoxia, associated with periods of warming, were identified and cycles of 'warming – transgression – anoxic conditions' and 'cooling – regression – oxygen‐rich conditions' were revealed. During the first stage of Littorina transgression (8.0–7.0 ka BP), the near‐bottom environment in the deepest sedimentary basin of the eastern Gulf of Finland was characterized by oxygen deficiency. In contrast, 7.0–6.0 ka BP was dominated by oxygen‐rich conditions and active processes of bioturbation. Anoxic conditions occurred again from 6.0–4.8 ka BP (Holocene Climatic Optimum), resulting in the accumulation of undisturbed silty clays with subhorizontal lamination. The interval from 4.8–2.0 ka was then characterized by oxygen‐rich near‐bottom conditions favourable for benthic organisms. The grain‐size distributions throughout the sediment cores from the easternmost sedimentary basins suggest a relative lowering of the sea level from 3.5–1.8 ka and a rise after 1.8 ka BP. [ABSTRACT FROM AUTHOR]

This paper compares the most applicable models for the forecasting of time series. Models based on artificial neural networks nonlinear autoregressive neural network with external input (NARX), Elman's neural network, and vector autoregression model were implemented. A special algorithm based on the analysis and prediction of the model residuals, which significantly improves the accuracy of the forecast, was proposed. For the prediction, we used the data of the main greenhouse gases methane (CH4) and water vapor (H2O) concentrations measured in summer 2016 in the surface layer of the atmospheric air on the Arctic island Belyy, Russia. The time interval of 192 h was chosen. The time interval was characterized by the significant daily variations in the CH4 concentration; the H2O concentrations did not have a pronounced trend. Values corresponding to the first 168 h of the interval were used for ANN training, and then, concentrations were predicted for the next 24 h. The accuracy of the prediction was determined by the set of errors and indices. The NARX model was more accurate than models based on Elman network and the VAR. The accuracy gain was from 16.5 to 40% for the models, which predicted the CH4 concentration, and from 21 to 58% for the models, which predicted the H2O concentration. The application of the proposed combined approach made it possible to increase the accuracy of the base model from 1.5 to 20% for the CH4 and from 4 to 20% for the H2O (depending on the corresponding errors and indices). The presented Taylor diagram was also showed the advantage of the proposed approach. [ABSTRACT FROM AUTHOR]

In the work, the psychophysical model of the signal detection theory with the nine outcomes (PMSDT9) for a quantitative description of the solution of the sensory problem of detecting an alternating differential signal was proposed. Unlike the classical model, PMSDT9 has the three probability density functions of the subjective intensity and the sign of the differential signal (instead of the two), the two criteria of displacement (instead of the one), and the nine outcomes (instead of the four). The proposed PMSDT9 model generalizes the application of the classical model of the signal detection theory for the less‐equal‐more task. The modified model provides for the existence of the two criteria (the left and the right) and such outcomes as inversion. The obtained experimental results are consistent with the ideas about the noise in sensory systems. [ABSTRACT FROM AUTHOR]

In 2017, a detailed study of the Eastern Gulf of Finland (the Baltic Sea) seafloor was performed to identify and map submerged glacial and postglacial geomorphologic features and collect data pertinent to the understanding of sedimentation in postglacial basins. Two key areas within the Gulf were investigate using a multibeam echosounder, SeaBat 8111 and an EdgeTech 3300-HM acoustic sub-bottom profiling system. High-resolution multibeam bathymetric data (3-m resolution) were used to calculate aspect, slope, terrain ruggedness and bathymetric position index using ArcGIS Spatial Analyst and the Benthic Terrain Modeler toolbox. These data and resultant thematic maps revealed, for the first time, such features as streamlined till ridges, end-moraine ridges, and De Geer moraines that are being used for the reconstruction of the deglaciation in the Eastern Gulf of Finland. This deglaciation occurred between 13.8 and 13.3 ka BP (Pandivere-Neva stage) and 12.25 ka BP (Salpausselkä I stage). Interpretations of the seismic-reflection profiles and 3D models showing the surfaces of till, and the identification of the Late Pleistocene sediment and modern bottom relief, indicate deep relative water-level fall in the Early Holocene and, most likely, several water-level fluctuations during this time. [ABSTRACT FROM AUTHOR]

We study the orbits and polynomial invariants of certain affine action of the super Weyl groupoid of Lie superalgebra gl(n,m), depending on a parameter. We show that for generic values of the parameter all the orbits are finite and separated by certain explicitly given invariants. We also describe explicitly the special set of parameters, for which the algebra of invariants is not finitely generated and does not separate the orbits, some of which are infinite. [ABSTRACT FROM AUTHOR]

The incorporation of chemotherapeutic agent 6-thioguanine (SG) into DNA is a prerequisite for its cytotoxic action. This modification of DNA impedes the activity of enzymes involved in DNA repair and replication. Here, using hemimethylated DNA substrates we demonstrated that DNA methylation by Dnmt3a-CD is reduced if DNA is damaged by the incorporation ofSG into one or two CpG sites separated by nine base pairs. An increase in the number ofSG substitutions did not enhance the effect. Dnmt3a-CD binding to either ofSG-containing DNA substrates was not distorted. Our results suggest thatSG incorporation into DNA may influence epigenetic regulation via DNA methylation. [ABSTRACT FROM PUBLISHER]

A unique geological process of extrusion of lagoon marl from beneath massive migrating sand dunes is characteristic for large segments of the Curonian Spit - a ~100-km-long sandy barrier that separates the Curonian Lagoon from the Baltic Sea. Exposures of a composite set of Holocene organic sediments such as gyttja, clayey gyttja and gyttja clay, collectively referred to as 'lagoon marl', are common along the northern half of the lagoon coast of the spit. The marl outcrops rise up to 3-4 m above the lagoon level and owe their origin to extrusion from their 7-8 m in situ depth beneath the present regional water table. New detailed investigations of the Baltic Sea bottom along the southern half of the Curonian Spit using side-scan sonar, a multibeam echosounder, seismic imaging, sediment sampling and video observations allowed identification and mapping of a unique underwater landscape formed by extensive outcrops of laminated and folded lagoon marl at water depths of 5-15 m. The combined onshore-offshore database indicates that relict lagoon marl was deformed, compacted and dehydrated by a massive dune-covered coastal barrier migrating landward (retrograding) over these sediments during the Littorina Sea transgression in a processes termed 'dune tectonics'. Spatial analysis of the relict sediments traced in offshore geophysical data helped to constrain the rates of the southeast migration of the dune massif. A conceptual model is presented to explain the present context of marl exposures above the regional water table, as well as the occurrence of relict lagoon marl extrusions (diapirs) on the underwater marine slope of the Curonian Spit. [ABSTRACT FROM AUTHOR]

We define the Dunkl and Dunkl-Heckman operators in infinite number of variables and use them to construct the quantum integrals of the Calogero-Moser-Sutherland (CMS) problems at infinity. As a corollary, we have a simple proof of integrability of the deformed quantum CMS systems related to classical Lie superalgebras. We show how this naturally leads to a quantum version of the Moser matrix, which in the deformed case was not known before. [ABSTRACT FROM AUTHOR]

Coastal reclamation is a major feature of contemporary land planning. As a multicomponent natural system, the coastal zone is impacted by various external processes (inundation, erosion, etc.) and land habitat demands an increased focus on anthropogenic activity. For the first time, a coastal vulnerability index (CVI) has been determined for the easternmost area of the Gulf of Finland (the Baltic Sea) (EGoF) in order to assess vulnerability of the coastal zone to erosion. The parameters for the CVI assessment were identified on the basis of existing field observations and analysis of environmental factors expressed in the EGoF. This research is focused on coastal segments prone to the rapid development of erosion, a subject highly relevant for coastal management. The CVI assessment, based on a method proposed by Gornitz (1991), uses seven physical parameters grouped according to geological, geomorphological, lithodynamic and hydrodynamic characteristics. Storminess, or susceptibility to destructive storm events, was applied for the study area not only because of the global increase in storm activity but also because this area undergoes a "bay-effect". An experts' assessment distinguished the most crucial parameters that triggered the coastal erosion process, namely that coastal geology and the number of destructive storms affected coastal processes. • Coastal vulnerability to the erosion processes can be evaluated. • Coastal erosion is governed by a set of climatic, environmental and anthropogenic factors. • Coastal geology and susceptibility to storms play an important role for the erosion. [ABSTRACT FROM AUTHOR]

This study aimed to determine (a) the influence of noise exposure background (NEB) on the peripheral and central auditory system functioning and (b) the influence of NEB on speech recognition in noise abilities in student musicians. Twenty non-musician students with self-reported low NEB and 18 student musicians with self-reported high NEB completed a battery of tests that consisted of physiological measures, including auditory brainstem responses (ABRs) at three different stimulus rates (11.3 Hz, 51.3 Hz, and 81.3 Hz), and P300, and behavioral measures including conventional and extended high-frequency audiometry, consonant–vowel nucleus–consonant (CNC) word test and AzBio sentence test for assessing speech perception in noise abilities at −9, −6, −3, 0, and +3 dB signal to noise ratios (SNRs). The NEB was negatively associated with performance on the CNC test at all five SNRs. A negative association was found between NEB and performance on the AzBio test at 0 dB SNR. No effect of NEB was found on the amplitude and latency of P300 and the ABR wave I amplitude. More investigations of larger datasets with different NEB and longitudinal measurements are needed to investigate the influence of NEB on word recognition in noise and to understand the specific cognitive processes contributing to the impact of NEB on word recognition in noise. [ABSTRACT FROM AUTHOR]

Objectives: Environmental exposure to persistent organic pollutants (POPs) has been associated with an increased risk of both acute myocardial infarction (AMI) and diabetes mellitus (DM). A study of first-time hospitalizations for AMI with DM as a comorbidity in populations presumed to be exposed or not exposed on the basis of residence near POPs sites was conducted to investigate whether exposure to POPs increases the environmental burden of disease. Materials and Methods: We examined the association between residential proximity to environmental sources of POPs and hospitalization rates for first-time AMI with comorbid DM in 31 428 patients aged 25-74 years, using the New York Statewide Planning and Research Cooperative System data for a 12-year period (1993-2004). Environmental exposure status was assessed based on the zip code of residence. Adjusted relative risks (RR) of AMI hospitalization were estimated by multivariate Poisson regression. Results: Hospitalization rates for first-time AMI with comorbid DM were significantly greater in populations living near POPs sites (adjusted RR = 1.169, 95% CI: 1.014-1.347, p < 0.05). These rates were also significantly higher in African Americans than in Caucasians (adjusted RR = 1.902, 95% CI: 1.659-2.180, p < 0.001), in males (adjusted RR = 1.767, 95% CI: 1.695-1.843, p < 0.001), and for older ages (p for trend < 0.001). These findings, consistent with established non-modifiable risk factors, support the plausibility of our model. Conclusions: Residential proximity to environmental sources of POPs is associated with a significant increase in hospitalization rates for first-time AMI with comorbid DM, compared to respective rates in populations not exposed to POPs. [ABSTRACT FROM AUTHOR]

The natural coastal zone in the Luga Bay and Bjorkezund Strait are characterized by a positive sediment balance. Recent sediment extraction and significant depth increase within the dredging areas in the vicinity of the newly built oil and coal port terminals in Ust-Luga and Primorsk disturb the dynamic equilibrium and sediment balance in the coastal zone. This activity leads to a change in sediment flows, with a high rate of accumulation in ship channels and an increase of coastal erosion. [ABSTRACT FROM AUTHOR]

Abstract: Problem: Whole-body vibration (WBV) is an occupational issue of concern due to adverse health effects or simple discomfort and annoyance. Unlike in Europe, WBV is an emerging topic in the U.S. safety and health (S&H) professional community. We hypothesized that at least one-half of the U.S. occupational S&H professionals knew little or nothing about WBV. Method: We conducted a cross-sectional study (survey) of WBV knowledge among members of the American Society of Safety Engineers. A Likert scale (1-none to 5-expert) was used to determine WBV topic knowledge levels (KL1-5). Results: Analysis of 2,764 responses revealed that 69.5% of the participants self-reported a less than basic WBV understanding. The WBV KL1-5 mean for all participants was 1.94±1.00, corresponding to an awareness of WBV without a depth of understanding. Summary: Many at-risk U.S. workers may not be supported by occupational S&H professionals with adequate WBV knowledge. Impact on Industry: A significant number of U.S. workers may be exposed to unhealthy levels of whole-body vibration. However, the U.S. occupational safety and health community is generally unprepared to anticipate, monitor, and control the whole-body vibration hazard. [Copyright &y& Elsevier]

Mass vaccination has played a critical role in the global eradication of smallpox. Various vaccinia virus (VACV) strains, whose origin has not been clearly documented in most cases, have been used as live vaccines in different countries. These VACV strains differed in pathogenicity towards various laboratory animals and in reactogenicity exhibited upon vaccination of humans. In this work, we studied the development of humoral and cellular immune responses in BALB/c mice inoculated intranasally (i.n.) or intradermally (i.d.) with the VACV LIVP strain at a dose of 105 PFU/mouse, which was used in Russia as the first generation smallpox vaccine. Active synthesis of VACV-specific IgM in the mice occurred on day 7 after inoculation, reached a maximum on day 14, and decreased by day 29. Synthesis of virus-specific IgG was detected only from day 14, and the level increased significantly by day 29 after infection of the mice. Immunization (i.n.) resulted in significantly higher production of VACV-specific antibodies compared to that upon i.d. inoculation of LIVP. There were no significant differences in the levels of the T cell response in mice after i.n. or i.d. VACV administration at any time point. The maximum level of VACV-specific T-cells was detected on day 14. By day 29 of the experiment, the level of VACV-specific T-lymphocytes in the spleen of mice significantly decreased for both immunization procedures. On day 30 after immunization with LIVP, mice were infected with the cowpox virus at a dose of 46 LD50. The i.n. immunized mice were resistant to this infection, while 33% of i.d. immunized mice died. Our findings indicate that the level of the humoral immune response to vaccination may play a decisive role in protection of animals from orthopoxvirus reinfection. [ABSTRACT FROM AUTHOR]

Exposure to environmental pollutants may contribute to the development of coronary heart disease (CHD). We determined the ZIP codes containing or abutting each of the approximately 900 hazardous waste sites in New York and identified the major contaminants in each. Three categories of ZIP codes were then distinguished: those containing or abutting sites contaminated with persistent organic pollutants (POPs), those containing only other types of wastes ("other waste"), and those not containing any identified hazardous waste site ("clean"). Effects of residence in each of these ZIP codes on CHD and acute myocardial infarction (AMI) hospital discharge rates were assessed with a negative binomial model, adjusting for age, sex, race, income, and health insurance coverage. Patients living in ZIP codes contaminated with POPs had a statistically significant 15.0% elevation in CHD hospital discharge rates and a 20.0% elevation in AMI discharge rates compared with clean ZIP codes. In neither of the comparisons were rates in other-waste sites significantly greater than in clean sites. In a subset of POP ZIP codes along the Hudson River, where average income is higher and there is less smoking, better diet, and more exercise, the rate of hospitalization for CHD was 35.8% greater and for AMI 39.1% greater than in clean sites. Although the cross-sectional design of the study prevents definite conclusions on causal inference, the results indirectly support the hypothesis that living near a POP-contaminated site constitutes a risk of exposure and of development of CHD and AMI. [ABSTRACT FROM AUTHOR]

The conventional live smallpox vaccine based on the vaccinia virus (VACV) cannot be widely used today because it is highly reactogenic. Therefore, there is a demand for designing VACV variants possessing enhanced immunogenicity, making it possible to reduce the vaccine dose and, therefore, significantly eliminate the pathogenic effect of the VACV on the body. In this study, we analyzed the development of the humoral and T cell-mediated immune responses elicited by immunizing mice with low-dose VACV variants carrying the mutant A34R gene (which increases production of extracellular virions) or the deleted A35R gene (whose protein product inhibits antigen presentation by the major histocompatibility complex class II). The VACV LIVP strain, which is used as a smallpox vaccine in Russia, and its recombinant variants LIVP-A34R*, LIVP-dA35R, and LIVP-A34R*-dA35R, were compared upon intradermal immunization of BALB/c mice at a dose of 104 pfu/animal. The strongest T cell-mediated immunity was detected in mice infected with the LIVP-A34R*-dA35R virus. The parental LIVP strain induced a significantly lower antibody level compared to the strains carrying the modified A34R and A35R genes. Simultaneous modification of the A34R gene and deletion of the A35R gene in VACV LIVP synergistically enhanced the immunogenic properties of the LIVP-A34R*-dA35R virus. [ABSTRACT FROM AUTHOR]

Novel DNA intercalating anticancer drug curaxin CBL0137 significantly inhibited in vitro DNA methylation by eukaryotic DNA methyltransferase Dnmt3a catalytic domain (Dnmt3a-CD) at low micromolar concentrations (IC 50 3–9 µM). CBL0137 reduced the binding affinity of Dnmt3a-CD to its DNA target, causing up to four-fold increase in the K d of the enzyme/DNA complex. Binding of CBL0137 to Dnmt3a-CD was not observed. The observed decrease in methylation activity of Dnmt3a-CD in the presence of CBL0137 can be explained by curaxin's ability to intercalate into DNA. [ABSTRACT FROM AUTHOR]

The abstract presents new results of geophysical, geological and geoarcheological studies of the Quaternary sediments developed in the coastal zone of the eastern Gulf of Finland (Baltic Sea). Within the area of the Narva-Luga Klint Bay (southern coast of the Gulf of Finland) and in the vicinity of Vysokinskoe Lake (north coast of the Gulf of Finland) ground penetrating radar (GPR) profiling was carried out. GPR systems SIR-2000 and SIR-4000 (GSSI) equipped with antennas of different frequencies (400, 200 and 70 MHz) were used. Different combinations of GPR tools provide different resolution and depth of penetration. Profiling was accompanied by geodetic survey. Total length of GPR profiles was about 80 kilometers. For the first time, a significant amount of high-quality data was obtained on land within the area of coastal marine and glacial deposits distribution. This became possible due to the use of vehicle for profiling. All data were processed by computer center of VSEGEI using RADAN software. As a result of observed data analysis several GPR units were defined. Separation of GPR units was based upon sediment composition and structural differences. This method performs great possibilities for identifying predominantly sandy sediments of different genetic types such as glacial, fluvioglacial, marine and aeolian. Some of detected sediments form relict landforms. In addition, some of revealed borders were identified as erosion horizons. As a result preserved relict landforms and absolute heights of detected units and horizons were determined. These studies allowed to divide deposits accumulated during different stages of the Baltic Sea development in the Late Pleistocene and Holocene and to determine possible paleo-sea levels. Obtained data are well correlated with the Neolithic sites discovered by archaeological research in this area. Studies were carried out in the frame of project № 17-77-20041 of Russian Science Foundation. [ABSTRACT FROM AUTHOR]

Results of VSEGEI research have shown that coastal zone of the Gulf of Finland is strongly affected by erosion processes.The use of drones turned upside down the methods of modern environmental monitoring. Thus, a small quadrocopter makes possible to get an orthophoto of the terrain relatively cheap and very fast comparing to traditional aerial photography methods. Usage of drones in Russian Federation are not regulated by law yet, but we widely use them in our investigations. Regular surveys in the study area allows us to monitor the dynamics of the coastline and additionally the coastal underwater ramparts.Upper part of the coastal geological sequence consists of easily erodible Quaternary deposits represented mainly by Holocene marine sands and Late Pleistocene sandy and clayey loam of glacial origin. Maximal rate of erosion escarpment retreat is about 5 m in vicinity of Kurortny District. For the years without extreme storm events, the mean rates of retreat are less than 0.5 m/year.During long-term observations with the involvement of remote sensing data showed that the coastal zone in the area of the village of Bolshaya Izhora is one of the most dynamic parts of the coast. From 2011 to 2018, the movement of the coast projection (waves) is 180 m. The wavy shore contour moves in the eastern direction with an average speed of 25 m / year. The last analyzes of the dynamics of the coastal zone of Kotlin Island showed (data from the WWII Aerial Photos of August 15, 1939 and modern satellite imagery) that the development has a similar principle: straightening the coast with capes erosion and filling (accumulation) located of the adjacent bays to the East. During 76 years the average erosion rates are 1.2–1.6 m / year.This research was carried out in frame of project № 17-77-20041 of Russian Science Foundation. [ABSTRACT FROM AUTHOR]

Onshore of the eastern Gulf of Finland (Baltic Sea) within the area of the Narva-Luga Klint Bay (lowland between the Narva and Luga rivers) a multiple depositional sequence was formed during the ice sheet degradation. It is represented mainly by periglacial accumulative sandy landforms. During the Holocene the lowland was substantially transformed by coastal-marine and alluvial processes. A relict of presumably glaciofluvial landform (a series of pebble-sand clinoforms forming the glacial delta according to GPR data) (Ryabchuk et al., 2018) located in the area of Holocene deposits development was dated using OSL method. According to this dating the age of subsurface part of the glaciofluvial landform is 13-10.8 thousand cal. yrs. BP. The glaciofluvial deposits are covered by a thin sandy layer which was formed 8.1 ± 0.8 thousand cal. yrs. BP according to OSL dating of the sample collected at the height range from +11.8 to +12.3 m.s.l. Consequently this sandy layer was formed during the first transgression of the Littorina Sea, the maximum of which was achieved 7.5 thousand cal. yrs. BP. The study was supported by Russian Science Foundation (project № 17-77-20041).References:Ryabchuk, D.V., Sergeev, A.Yu., Gerasimov, D.V., Kriiska, A., Nordqvist, K., Budanov, L.M., Kovaleva, O.A., Zhamoida, V.A., Anisimov, M.A., Terekhov, A.V. New data on the postglacial development of Narva-Luga Klint Bay (eastern Gulf of Finland): Results of geoarchaeological research // Journal of Coastal Conservation. 2018 P. 1–20 [ABSTRACT FROM AUTHOR]

Objectives: School-age children with and without parentreported listening difficulties (LiD) were compared on auditory processing, language, memory, and attention abilities. The objective was to extend what is known so far in the literature about children with LiD by using multiple measures and selective novel measures across the above areas. Design: Twenty-six children who were reported by their parents as having LiD and 26 age-matched typically developing children completed clinical tests of auditory processing and multiple measures of language, attention, and memory. All children had normal-range pure-tone hearing thresholds bilaterally. Group differences were examined. Results: In addition to significantly poorer speech-perceptionin- noise scores, children with LiD had reduced speed and accuracy of word retrieval from long-term memory, poorer short-term memory, sentence recall, and inferencing ability. Statistically significant group differences were of moderate effect size; however, standard test scores of children with LiD were not clinically poor. No statistically significant group differences were observed in attention, working memory capacity, vocabulary, and nonverbal IQ. Conclusions: Mild signal-to-noise ratio loss, as reflected by the group mean of children with LiD, supported the children's functional listening problems. In addition, children's relative weakness in select areas of language performance, short-term memory, and long-term memory lexical retrieval speed and accuracy added to previous research on evidence-based areas that need to be evaluated in children with LiD who almost always have heterogenous profiles. Importantly, the functional difficulties faced by children with LiD in relation to their test results indicated, to some extent, that commonly used assessments may not be adequately capturing the children's listening challenges. [ABSTRACT FROM AUTHOR]

Kainate receptors play an important role in the brain. They contribute to postsynaptic depolarization, modulate the release of neurotransmitters such as GABA and glutamate, affect the development of the neuronal network. At the same time, their functions depend not only on the type of neuron expressing them but also on their localization (pre- or postsynaptic). It has been shown in present work that activation of kainate receptors by domoic acid stimulates the secretion of both glutamate and GABA. This effect is observed at a concentration of 100 nM. At higher levels (200–500 nM), domoic acid selectively activates a specific population of GABAergic neurons. The peculiarity of these neurons is increased excitability in the network. This phenomenon can be explained by the weak GABA(A)R-mediated inhibition, as well as by the lower activation threshold of voltage-gated channels. Moreover, activation of these GABAergic neurons by domoic acid leads to the suppression of activity in the network under ammonium-induced hyperexcitation. As shown by inhibitory analysis, this effect is mediated by GABA(A) receptors. The obtained data may be of interest since the suppression of hyperexcitation via the selective activation of GABAergic neurons can be considered as a new potential approach to the treatment of diseases accompanied by increased neuronal activity such as epilepsy, ischemia and hepatic encephalopathy. • Domoic acid selectively activates a specific population of GABAergic neurons. • The peculiarity of these neurons is increased excitability in the network. • Activation of these neurons leads to the suppression of network hyperexcitation. [ABSTRACT FROM AUTHOR]