Art Text as a Cultural Code of the XIXth Century China in an Age of Transition (The Case of the Haishang School of Painting)

The article explores the paintings of the Haishang school of Chinese painting as an artistic text of the XIXth-century culture. This provides with the argument in favor of the semiotic approach that underlies this research.     Keywords: cultural art text, cultural code, XIXth-century Chinese culture, semiotic approach, Haishang school, symbol, imag

Representation of Happiness in the 19th Century Chinese and Russian Art Texts

The article compares representation of happiness in China and Russia in the 19th century using the examples of paintings by the Chinese Haishan school and Russian Peredvizhniki (The Wanderers) school as the art texts of the era. Keywords: 19th-century culture, art texts, representation of happiness, Peredvizhniki, Haishan School

Neuron participation in a synchrony-encoding assembly

BACKGROUND: Synchronization of action potentials between neurons is considered to be an encoding process that allows the grouping of various and multiple features of an image leading to a coherent perception. How this coding neuronal assembly is configured is debated. We have previously shown that the magnitude of synchronization between excited neurons is stimulus-dependent. In the present investigation we compare the levels of synchronization between synchronizing individual neurons and the synchronizing pool of cells to which they belong. RESULTS: Even though neurons belonged to their respective pools, some cells synchronized for all presented stimuli while others were rather selective and only a few stimulating conditions produced a significant synchronization. In addition the experiments show that one synchronizing pair rarely replicates the level of synchrony between corresponding groups of units. But when synchronizing clusters of neurons increase in number, the correlation (measured as a coefficient of determination) between unit synchronization and the synchronization between the entire pools of cells to which individual neurons belong improves. CONCLUSION: These results prompt the hypothesis that random or spontaneous synchronization becomes progressively less important, whereas coincident spikes related to encoding properties of targets gain significance because a particular configuration of an image biases the excitatory inputs in favor of connections driven by the applied features of the stimulus

Synchrony between orientation-selective neurons is modulated during adaptation-induced plasticity in cat visual cortex

<p>Abstract</p> <p>Background</p> <p>Visual neurons respond essentially to luminance variations occurring within their receptive fields. In primary visual cortex, each neuron is a filter for stimulus features such as orientation, motion direction and velocity, with the appropriate combination of features eliciting maximal firing rate. Temporal correlation of spike trains was proposed as a potential code for linking the neuronal responses evoked by various features of a same object. In the present study, synchrony strength was measured between cells following an adaptation protocol (prolonged exposure to a non-preferred stimulus) which induce plasticity of neurons' orientation preference.</p> <p>Results</p> <p>Multi-unit activity from area 17 of anesthetized adult cats was recorded. Single cells were sorted out and (1) orientation tuning curves were measured before and following 12 min adaptation and 60 min after adaptation (2) pairwise synchrony was measured by an index that was normalized in relation to the cells' firing rate. We first observed that the prolonged presentation of a non-preferred stimulus produces attractive (58%) and repulsive (42%) shifts of cell's tuning curves. It follows that the adaptation-induced plasticity leads to changes in preferred orientation difference, i.e. increase or decrease in tuning properties between neurons. We report here that, after adaptation, the neuron pairs that shared closer tuning properties display a significant increase of synchronization. Recovery from adaptation was accompanied by a return to the initial synchrony level.</p> <p>Conclusion</p> <p>We conclude that synchrony reflects the similarity in neurons' response properties, and varies accordingly when these properties change.</p

Adaptive behavior of neighboring neurons during adaptation-induced plasticity of orientation tuning in V1

<p>Abstract</p> <p>Background</p> <p>Sensory neurons display transient changes of their response properties following prolonged exposure to an appropriate stimulus (adaptation). In adult cat primary visual cortex, orientation-selective neurons shift their preferred orientation after being adapted to a non-preferred orientation. The direction of those shifts, towards (attractive) or away (repulsive) from the adapter depends mostly on adaptation duration. How the adaptive behavior of a neuron is related to that of its neighbors remains unclear.</p> <p>Results</p> <p>Here we show that in most cases (75%), cells shift their preferred orientation in the same direction as their neighbors. We also found that cells shifting preferred orientation differently from their neighbors (25%) display three interesting properties: (i) larger variance of absolute shift amplitude, (ii) wider tuning bandwidth and (iii) larger range of preferred orientations among the cluster of cells. Several response properties of V1 neurons depend on their location within the cortical orientation map. Our results suggest that recording sites with both attractive and repulsive shifts following adaptation may be located in close proximity to iso-orientation domain boundaries or pinwheel centers. Indeed, those regions have a more diverse orientation distribution of local inputs that could account for the three properties above. On the other hand, sites with all cells shifting their preferred orientation in the same direction could be located within iso-orientation domains.</p> <p>Conclusions</p> <p>Our results suggest that the direction and amplitude of orientation preference shifts in V1 depend on location within the orientation map. This anisotropy of adaptation-induced plasticity, comparable to that of the visual cortex itself, could have important implications for our understanding of visual adaptation at the psychophysical level.</p

Digital Labs as a Tool of Engineering and Pedagogical Education

В статье рассматриваются широкие возможности использования цифровых лабораторий в учебном процессе в рамках курса физики для студентов инженерных специальностей. Показано, что опыт успешного взаимодействия со студентами при создании виртуальной лабораторной работы повышает у студентов мотивацию к обучению, что приводит к формированию профессиональных базовых компетенций будущего инженера.The article discusses the wide possibilities of using digital laboratories in the educational process as part of a physics course for engineering students. It is shown that the experience of successful interaction with students when creating a virtual laboratory work increases students' motivation to study, which leads to the formation of professional basic competencies of a future engineer

Profile of subpopulation composition of regulatory T lymphocytes and intestinal microbiota in patients with irritable bowel syndrome

The following specificcharacteristics of the composition of intestinal microbiota in patients with irritable bowel syndrome (IBS) were identified using a metagenomic analysis (16 S rRNA): 1) an increase in the representation of Actinobacteria, including Bifidobacterium spp., Firmicutes, including representatives of Streptococcaceae (Streptococcus), Lachnosperaceae (Dorea), Veillonellaceae (Dialister), Proteobacteria (Enterobacteriaceae and Desulfovibrionaceae families); 2) a decrease in the population of Bacteroidetes, including representatives of the families Prevotellacea (Prevotella spp.), Bacteroidaceae (Bacteroides spp.). Firmicutes belonging to the families Clostridiaceae and Ruminococcaceae (Fecalibacterium spp.).Flow cytometry in the study of the subpopulation composition of T regulatory (Treg) lymphocytes in patients with IBS revealed an increase in the number of CD45R0+CD62L+ central memory cells (CM), which can regulate the processes of maturation and differentiation of lymphocytes in lymphoid tissue. A decrease in the expression of exonucleases CD39 and CD73 was detected, which can have a significant effect on their activity. A reduction in effector memory cells (EM) Treg was observed.Changes in the expression level of exonucleases CD39 and CD73 were inversely correlated with the content of Proteobacteria and the representation of the genera Bifidobacterium spp. and Faecalibacterium spp. The content of СЫ Treg was directly correlated with the content of Dorea spp.The results may be indicative of impairment in the processes of Treg differentiation, which are closely related to changes in key components of intestinal microbiocenosis in IBS

Visual Cells Remember Earlier Applied Target: Plasticity of Orientation Selectivity

BACKGROUND: A canonical proposition states that, in mature brain, neurons responsive to sensory stimuli are tuned to specific properties installed shortly after birth. It is amply demonstrated that that neurons in adult visual cortex of cats are orientation-selective that is they respond with the highest firing rates to preferred oriented stimuli. METHODOLOGY/PRINCIPAL FINDINGS: In anesthetized cats, prepared in a conventional fashion for single cell recordings, the present investigation shows that presenting a stimulus uninterruptedly at a non-preferred orientation for twelve minutes induces changes in orientation preference. Across all conditions orientation tuning curves were investigated using a trial by trial method. Contrary to what has been previously reported with shorter adaptation duration, twelve minutes of adaptation induces mostly attractive shifts, i.e. toward the adapter. After a recovery period allowing neurons to restore their original orientation tuning curves, we carried out a second adaptation which produced three major results: (1) more frequent attractive shifts, (2) an increase of their magnitude, and (3) an additional enhancement of responses at the new or acquired preferred orientation. Additionally, we also show that the direction of shifts depends on the duration of the adaptation: shorter adaptation in most cases produces repulsive shifts, whereas adaptation exceeding nine minutes results in attractive shifts, in the same unit. Consequently, shifts in preferred orientation depend on the duration of adaptation. CONCLUSION/SIGNIFICANCE: The supplementary response improvements indicate that neurons in area 17 keep a memory trace of the previous stimulus properties, thereby upgrading cellular performance. It also highlights the dynamic nature of basic neuronal properties in adult cortex since repeated adaptations modified both the orientation tuning selectivity and the response strength to the preferred orientation. These enhanced neuronal responses suggest that the range of neuronal plasticity available to the visual system is broader than anticipated

Ketamine induces a robust whole-brain connectivity pattern that can be differentially modulated by drugs of different mechanism and clinical profile

Ketamine, an N-methyl-D-aspartate receptor (NMDAR) antagonist, has been studied in relation to the glutamate hypothesis of schizophrenia and increases dissociation, positive and negative symptom ratings. Ketamine effects brain function through changes in brain activity; these activity patterns can be modulated by pre-treatment of compounds known to attenuate the effects of ketamine on glutamate release. Ketamine also has marked effects on brain connectivity; we predicted that these changes would also be modulated by compounds known to attenuate glutamate release. Here, we perform task-free pharmacological magnetic resonance imaging (phMRI) to investigate the functional connectivity effects of ketamine in the brain and the potential modulation of these effects by pre-treatment of the compounds lamotrigine and risperidone, compounds hypothesised to differentially modulate glutamate release. Connectivity patterns were assessed by combining windowing, graph theory and multivariate Gaussian process classification. We demonstrate that ketamine has a robust effect on the functional connectivity of the human brain compared to saline (87.5 % accuracy). Ketamine produced a shift from a cortically centred, to a subcortically centred pattern of connections. This effect is strongly modulated by pre-treatment with risperidone (81.25 %) but not lamotrigine (43.75 %). Based on the differential effect of these compounds on ketamine response, we suggest the observed connectivity effects are primarily due to NMDAR blockade rather than downstream glutamatergic effects. The connectivity changes contrast with amplitude of response for which no differential effect between pre-treatments was detected, highlighting the necessity of these techniques in forming an informed view of the mechanistic effects of pharmacological compounds in the human brain

Delta-9-tetrahydrocannabinol, neural oscillations above 20 Hz and induced acute psychosis

Rationale: An acute challenge with delta-9-tetrahydrocannabinol (THC) can induce psychotic symptoms including delusions. High electroencephalography (EEG) frequencies, above 20 Hz, have previously been implicated in psychosis and schizophrenia. Objectives: The objective of this study is to determine the effect of intravenous THC compared to placebo on high-frequency EEG. Methods: A double-blind cross-over study design was used. In the resting state, the high-beta to low-gamma magnitude (21–45 Hz) was investigated (n=13 pairs+4 THC only). Also, the event-related synchronisation (ERS) of motor-associated high gamma was studied using a self-paced button press task (n=15). Results: In the resting state, there was a significant condition × frequency interaction (p=0.00017), consisting of a shift towards higher frequencies under THC conditions (reduced high beta [21–27 Hz] and increased low gamma [27–45 Hz]). There was also a condition × frequency × location interaction (p=0.006), such that the reduction in 21–27-Hz magnitude tended to be more prominent in anterior regions, whilst posterior areas tended to show greater 27–45-Hz increases. This effect was correlated with positive symptoms, as assessed on the Positive and Negative Syndrome Scale (PANSS) (r=0.429, p=0.042). In the motor task, there was a main effect of THC to increase 65–130-Hz ERS (p=0.035) over contra-lateral sensorimotor areas, which was driven by increased magnitude in the higher, 85–130-Hz band (p=0.02) and not the 65–85-Hz band. Conclusions: The THC-induced shift to faster gamma oscillations may represent an over-activation of the cortex, possibly related to saliency misattribution in the delusional state