The key-problems of design, examination, laboratory' and flight testing of the attitude determination and control system (ADCS) dedicated for a microsatellite arc considered. The system consists of three pairs of the reaction wheels, three magnetorquers, set of Sun sensors, three-axis magnetometer and a control unit. ADCS, on one hand, is subjected to the high accuracy and reliability requirements, and, on the other hand, power consumption, total mass and volume limitations. It is meant for the LEO satellite with mass between 10 and 50 kg. The problems are solved within several steps, i.e. preliminary study of the satellite dynamics using asymptotical and numerical techniques, hardware and software design, testing of each actuator and sensor and the whole ACS on the test-bench dedicated specially for such a laboratory simulation. Finally flight testing has been carried out to validate ADCS functioning. In this paper both dynamics of the microsatellite with ADCS and mock-up of ADCS operation are studied. Reaction wheels control law parameters are chosen to provide the maximum degree of stability. The evolution of the reaction wheels angular momentum is also studied and the problem of the desaturation with use of the magnetorquers is solved. Attitude accuracy is estimated in terms of closed-form formulae. Some aspects of in-flight ADCS exploitation onboard the Russian microsatellite "Chibis-M" developed, designed and fabricated by the Institute of Space Research of RAS and orbited from SC "Progress" on 25th of January, 2012 are presented. Flight showed a good correspondence between analytical, numerical and laboratory' study with in-flight testing.
New methods and approaches for carrying out comprehensive measurements of hazardous waves (tsunami, storm surges) and background wave climate with telemetrically related group of ground, surface and underwater based robots are discussed. The design and equipment list of the ground robot are considered. It includes three various types of movers, an add-on for the installation of devices on the mobile platform and the hardware part. Ground robot was tested in 2016 on the coast of Sakhalin Island, cape Svobodny. Based on test results there were made conclusions on the possibility of increasing mobility of the ground robot and expanding its use. Specially designed underwater robot collects data using a video inspection system and a hydrostatic wave recorder with a string sensor. It has the ability to adjust the position of the center of gravity to increase stability when driving on steep slopes of the seabed. The surface robot was designed for conducting detailed bathymetry measurements of investigated water areas by means of a multi-beam echo sounder. Underwater and surface-based robots were tested in July 2017 on Sakhalin Island. Both robotic systems were merged into the united local network. The results of their operation were obtained to verify the data from measuring systems of the ground robot. In 2018, it is planned to conduct a series of tests involving the three robots and merging them into a local network to manage and process data in real-time.
Digit ratio (2D:4D) is a putative marker for prenatal testosterone and is correlated with performance in many sports. Low 2D:4D has been linked to strength but the evidence is mixed and strength is also influenced by mass, testosterone, and behavioural factors. It has been hypothesised that the 2D:4D-strength correlation may be strongest in challenge conditions when short-term changes occur in steroid hormones.
We tested this suggestion in men.
We used a cross-over study design with a challenge (an aggressive video of rugby tackles) and control (a blank screen) condition.
89 healthy men.
Finger lengths (2nd and 4th for both hands), hand-grip strength (HGS), testosterone (T), cortisol (C), aggression (Buss-Perry Aggression Questionnaire) and personality type (Ten Item Personality Measure). In both conditions participants provided saliva samples (for hormone assays).
In the challenge condition there was a highly significant increase in HGS, and modest changes in T, physical aggression and emotional stability. HGS correlated negatively with left hand 2D:4D. In a multiple regression, left hand 2D:4D was negatively related to HGS and emotional stability was positively related to HGS. In the control condition HGS was not correlated with 2D:4D. In a multiple regression, BMI, physical aggression, and emotional stability were significantly related to HGS.
2D:4D is a negative correlate of strength in challenge situations. This finding may in part explain associations between 2D:4D and sports performance.
Neuronal oscillations have been shown to be associated with perceptual, motor and cognitive brain operations. While complex spatio-temporal dynamics are a hallmark of neuronal oscillations, they also represent a formidable challenge for the proper extraction and quantification of oscillatory activity with non-invasive recording techniques such as EEG and MEG. In order to facilitate the study of neuronal oscillations we present a general-purpose pre-processing approach, which can be applied for a wide range of analyses including but not restricted to inverse modeling and multivariate single-trial classification. The idea is to use dimensionality reduction with spatio-spectral decomposition (SSD) instead of the commonly and almost exclusively used principal component analysis (PCA). The key advantage of SSD lies in selecting components explaining oscillations-related variance instead of just any variance as in the case of PCA. For the validation of SSD pre-processing we performed extensive simulations with different inverse modeling algorithms and signal-to-noise ratios. In all these simulations SSD invariably outperformed PCA often by a large margin. Moreover, using a database of multichannel EEG recordings from 80 subjects we show that pre-processing with SSD significantly increases the performance of single-trial classification of imagined movements, compared to the classification with PCA pre-processing or without any dimensionality reduction. Our simulations and analysis of real EEG experiments show that, while not being supervised, the SSD algorithm is capable of extracting components primarily relating to the signal of interest often using as little as 20% of the data variance, instead of > 90% variance as in case of PCA. Given its ease of use, absence of supervision, and capability to efficiently reduce the dimensionality of multivariate EEG/MEG data, we advocate the application of SSD pre-processing for the analysis of spontaneous and induced neuronal oscillations in normal subjects and patients.
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.
ABSTRACT. A nonparametric clustering method, the Bagging Voronoi K-Medoid Alignment algorithm, which simultaneously clusters and aligns spatially/temporally dependent curves, is applied to study various data series from the Elbrus region (Central Caucasus). We used the algorithm to cluster annual curves obtained by smoothing of the following synchronous data series: titanium concentrations in varved (annually laminated) bottom sediments of proglacial Lake Donguz-Orun; an oxygen-18 isotope record in an ice core from Mt. Elbrus; temperature and precipitation observations with a monthly resolution from Teberda and Terskol meteorological stations. The data of different types were clustered independently. Due to restrictions concerned with the availability of meteorological data, we have fulfilled the clustering procedure separately for two periods: 1926–2010 and 1951–2010. The study is aimed to determine whether the instrumental period could be reasonably divided (clustered) into several sub-periods using different climate and proxy time series; to examine the interpretability of the resulting borders of the clusters (resulting time periods); to study typical patterns of intra-annual variations of the data series. The results of clustering suggest that the precipitation and to a lesser degree titanium decadal-scale data may be reasonably grouped, while the temperature and oxygen-18 series are too short to form meaningful clusters; the intercluster boundaries show a notable degree of coherence between temperature and oxygen-18 data, and less between titanium and oxygen-18 as well as for precipitation series; the annual curves for titanium and partially precipitation data reveal much more pronounced intercluster variability than the annual patterns of temperature and oxygen-18 data.
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 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.
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.
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.