A subgroup of light-driven sodium pumps with an additional Schiff base counterion

Light-driven sodium pumps (NaRs) are unique ion-transporting microbial rhodopsins. The major group of NaRs is characterized by an NDQ motif and has two aspartic acid residues in the central region essential for sodium transport. Here we identify a subgroup of the NDQ rhodopsins bearing an additional glutamic acid residue in the close vicinity to the retinal Schiff base. We thoroughly characterize a member of this subgroup, namely the protein ErNaR from Erythrobacter sp. HL-111 and show that the additional glutamic acid results in almost complete loss of pH sensitivity for sodium-pumping activity, which is in contrast to previously studied NaRs. ErNaR is capable of transporting sodium efficiently even at acidic pH levels. X-ray crystallography and single particle cryo-electron microscopy reveal that the additional glutamic acid residue mediates the connection between the other two Schiff base counterions and strongly interacts with the aspartic acid of the characteristic NDQ motif. Hence, it reduces its pKa. Our findings shed light on a subgroup of NaRs and might serve as a basis for their rational optimization for optogenetics.

Berezin Quantization, Conformal Welding and the Bott-Virasoro Group

Following Nag-Sullivan, we study the representation of the group Diff + ( S 1 ) of diffeomorphisms of the circle on the Hilbert space of holomorphic functions. Conformal welding provides triangular decompositions for the corresponding symplectic transformations. We apply Berezin formalism and lift this decomposition to operators acting on the Fock space. This lift provides quantization of conformal welding, gives a new representative of the Bott-Virasoso cocycle class, and leads to a surprising identity for the Takhtajan-Teo energy functional on Diff + ( S 1 ) .

Structural insights into light-driven anion pumping in cyanobacteria

Transmembrane ion transport is a key process in living cells. Active transport of ions is carried out by various ion transporters including microbial rhodopsins (MRs). MRs perform diverse functions such as active and passive ion transport, photo-sensing, and others. In particular, MRs can pump various monovalent ions like Na⁺, K⁺, Cl^-, I^-, NO₃^-. The only characterized MR proposed to pump sulfate in addition to halides belongs to the cyanobacterium Synechocystis sp. PCC 7509 and is named Synechocystis halorhodopsin (SyHR). The structural study of SyHR may help to understand what makes an MR pump divalent ions. Here we present the crystal structure of SyHR in the ground state, the structure of its sulfate-bound form as well as two photoreaction intermediates, the K and O states. These data reveal the molecular origin of the unique properties of the protein (exceptionally strong chloride binding and proposed pumping of divalent anions) and sheds light on the mechanism of anion release and uptake in cyanobacterial halorhodopsins. The unique properties of SyHR highlight its potential as an optogenetics tool and may help engineer different types of anion pumps with applications in optogenetics.

Planning impairment in schizophrenia: The possible role of abstract thinking and short-term memory

Introduction

The planning impairment is one of the basic aspect of cognitive dysfunction, but its mechanisms in schizophrenia remain unclear.

Objectives

To assess the links between planning and cognitive functioning in schizophrenic patients and in norm.

Methods

50 patients with schizophrenia (age 34.92±8.54; illness duration 8.34±5.87) and 50 healthy volunteers (age 32.42±7.26) were examined. Brief Assessment of Cognition in Schizophrenia, Benton’s test for short-term memory assessment; sub-test Similarity (from WAIS) to assess abstract thinking were used.

Results

Patients showed significantly worse results in all parameters (Tab.1). Table 1: Differences of planning between groups.SchizophreniaNormp-levelTOL-DX92,64±14,48102,52±11,970,00033Similarity16,92±3,9719,76±2,850,00009BVTR Score6,73±1,787,60±1,320,00709

In healthy subjects, significant relationship was found between planning and abstract thinking, and there was no relationship between planning and short-term memory (Tab.2). Table 2: Correlations in the Norm groupSpearman Rp-levelTOL-DX & Similarity0,3925300,004809TOL-DX & BVTR0,1864940,194710

In patients with schizophrenia, the opposite picture was observed (Tab.3). Table 3: Correlations in the Schizophrenia group.Spearman Rp-levelTOL-DX & Similarity0,2623890,071596TOL-DX & BVTR0,3445660,015331

The effectiveness of planning in patients was significantly associated with short-term memory, but not with abstract thinking.

Conclusions

Study results indicate a possible role of basic aspects of mental activity such as short-term memory in planning impairment in patients with schizophrenia. Problem solving and reasoning disorders represent two relatively independent forms of thought disorders in schizophrenia.

Nanoscale mobility mapping in semiconducting polymer films

Local electrical properties of thin films of the polymer PTB7 are studied by conductive atomic force microscopy (C-AFM). Non-uniform nanoscale current distribution in the neat PTB7 film is revealed and connected with the existence of ordered PTB7 crystallites. The shape of local I-V curves is explained by the presence of space charge limited current. We modify an existing semi-empirical model for estimation of the nanoscale hole mobility from our experimental C-AFM measurements. The procedure of nanoscale charge mobility estimation was described and applied to the PTB7 films. The calculated average C-AFM hole mobility is in good agreement with macroscopic values reported for this material. Mapping of nanoscale hole mobility was achieved using the described procedure. Local mobility values, influenced by nanoscale structure, vary more than two times in value and have a root-mean-square value 0.22 × 10^-8 m²/(Vs), which is almost 20% from average hole mobility.

Aging Fits the Disease Criteria of the International Classification of Diseases

The disease criteria used by the World Health Organization (WHO) were applied to human biological aging in order to assess whether aging can be classified as a disease. These criteria were developed for the 11th revision of the International Classification of Diseases (ICD) and included disease diagnostics, mechanisms, course and outcomes, known interventions, and linkage to genetic and environmental factors. RESULTS: Biological aging can be diagnosed with frailty indices, functional, blood-based biomarkers. A number of major causal mechanisms of human aging involved in various organs have been described, such as inflammation, replicative cellular senescence, immune senescence, proteostasis failures, mitochondrial dysfunctions, fibrotic propensity, hormonal aging, body composition changes, etc. We identified a number of clinically proven interventions, as well as genetic and environmental factors of aging. Therefore, aging fits the ICD-11 criteria and can be considered a disease. Our proposal was submitted to the ICD-11 Joint Task force, and this led to the inclusion of the extension code for "Ageing-related" (XT9T) into the "Causality" section of the ICD-11. This might lead to greater focus on biological aging in global health policy and might provide for more opportunities for the new therapy developers.

High-resolution structural insights into the heliorhodopsin family

Rhodopsins are the most abundant light-harvesting proteins. A new family of rhodopsins, heliorhodopsins (HeRs), has recently been discovered. Unlike in the known rhodopsins, in HeRs the N termini face the cytoplasm. The function of HeRs remains unknown. We present the structures of the bacterial HeR-48C12 in two states at the resolution of 1.5 Å, which highlight its remarkable difference from all known rhodopsins. The interior of HeR's extracellular part is completely hydrophobic, while the cytoplasmic part comprises a cavity (Schiff base cavity [SBC]) surrounded by charged amino acids and containing a cluster of water molecules, presumably being a primary proton acceptor from the Schiff base. At acidic pH, a planar triangular molecule (acetate) is present in the SBC. Structure-based bioinformatic analysis identified 10 subfamilies of HeRs, suggesting their diverse biological functions. The structures and available data suggest an enzymatic activity of HeR-48C12 subfamily and their possible involvement in fundamental redox biological processes.

Atomic Force Microscopy Study of Cross-Sections of Perovskite Layers

Improvement of methods for imaging of the volume structure of photoactive layers is one of the important directions towards development of highly efficient solar cells. In particular, volume structure of photoactive layer has critical influence on perovskite solar cell performance and life time. In this study, a perovskite photoactive layer cross-section was prepared by using Focused Ion Beam (FIB) and imaged by Atomic Force Microscopy (AFM) methods. The proposed approach allows using advances of AFM for imaging structure of perovskites in volume. Two different types of perovskite layers was investigated: FAPbBr3 and MAPbBr3. The heterogeneous structure inside film, which consist of large crystals penetrating the film as well as small particles with sizes of several tens nanometers, is typical for FAPbBr3. The ordered nanocrystalline structure with nanocrystals oriented at 45 degree to film surface is observed in MAPbBr3. An optimized sample preparation route, which includes FIB surface polishing by low energy Ga ions at the angles around 10 degree to surface plane, is described and optimal parameters of surface treatment are discussed. Use of AFM phase contrast method provides high contrast imaging of perovskite structure due to strong dependence of phase shift of oscillating probe on materials properties. The described method of imaging can be used for controllable tuning of perovskite structure by changes of the sample preparation routes.

The U(n) Gelfand-Zeitlin system as a tropical limit of Ginzburg-Weinstein diffeomorphisms

In this paper, we show that the Ginzburg-Weinstein diffeomorphism [Formula: see text] of Alekseev & Meinrenken (Alekseev, Meinrenken 2007 J. Differential Geom.76, 1-34. (10.4310/jdg/1180135664)) admits a scaling tropical limit on an open dense subset of [Formula: see text] The target of the limit map is a product [Formula: see text], where [Formula: see text] is the interior of a cone, T is a torus, and [Formula: see text] carries an integrable system with natural action-angle coordinates. The pull-back of these coordinates to [Formula: see text] recovers the Gelfand-Zeitlin integrable system of Guillemin & Sternberg (Guillemin, Sternberg 1983 J. Funct. Anal.52, 106-128. (10.1016/0022-1236(83)90092-7)). As a by-product of our proof, we show that the Lagrangian tori of the Flaschka-Ratiu integrable system on the set of upper triangular matrices meet the set of totally positive matrices for sufficiently large action coordinates.This article is part of the theme issue 'Finite dimensional integrable systems: new trends and methods'.

The peculiarity of Experiencing Body by Patients in Schizophrenia

Introduction

By the present, the study of corporeality as a psychological phenomenon in schizophrenia has had a lack of attention. At the focus of works, there have been mainly psychopathological phenomena: cenestopathies, visceral hallucinations and body scheme disturbances. There is an evidence of the necessity for psychological investigations: the execution of radical changes in appearance, a frequent turning to plastic surgery, dysfunctional wearing and transsexuality.

Objectives

The experimental group consisted of 23 patients in schizophrenia of paranoid type (F 20.00). The control group consisted of 27 healthy subjects.

Aim

It is to study the peculiarity of experiencing their own body by patients in schizophrenia.

Methods

There are projective techniques, such as: “A Picture of Me”, “Verbal Self-Portrait”, ‘A Picture of Inner Body” and the psychosemantic test “Classification of Sensations”.

Results

There are statistically significant differences (P < 0.005) found between the groups:

– patients with schizophrenia are characterized for their deficit of experiencing their body. It does not refer to “Myself” and is deinvidualized. The body does not serve as a physical presentation of the subject in a social world;

– a wary attitude is observed in relation to body displays in the form of inner body sensations with a minor (than in norm) awareness relatively to the inner arrangement of their own body. This causes the increase of the quantity of intraceptive sensations categorized by patients in schizophrenia as unhealthy or a threat.

Conclusion

The above-mentioned peculiar features of corporeality in schizophrenia make it a source of negative experiences.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Executive Function Assessment in Young Hospitalized Schizophrenic Patients with the “CANTAB Schizophrenia Battery” (Russian Sample)

Introduction

Impairment of executive function is the fundamental feature of the cognitive dysfunction in schizophrenia has to be measured throughout the illness regularly. Computerized technologies for assessment of cognitive dysfunction are widely used. However, their applicability in hospitalized schizophrenic patients setting should be specially examined.

Objective

Executive function in schizophrenia.

Aims

To test the applicability of “CANTAB” neurocognitive battery for measurement of executive function in young hospitalized schizophrenic patients in Russian sample.

Methods

Fifteen inpatients diagnosed with schizophrenia according to ICD-10 (F 20.хх), 13 males and 2 females, aged 23.5(SD 3.2), disease duration is 5(SD 1.6) years and 16 healthy individuals, 7 males and 9 females, aged 21.3(SD 0.7). Spatial Working Memory (SWM) (Mnemonic Executive function), Stockings of Cambridge (OTS) (Planning Executive function), Intra/Extra-Dimensional Shift (IED) (Cognitive flexibility) were administered.

Results

The majority of patients and controls easily understood the test instructions. Both groups did not have any difficulties with the touchpad. The “CANTAB” demonstrated sensitivity to the impairments of executive function. As a group, patients with schizophrenia performed significantly worse than controls on almost all tests: SWM–Between errors (P = 0.028), Total errors (P = 0.019), Strategy (P = 0.03), Mean time to last response (P = 0.001); OTS–Mean choices to correct (P = 0.044), Problems solved on first choice (P = 0.009), Probability of error given correct (P = 0.021); IED–Total errors (P = 0.015), Total trials (P = 0.002).

Conclusion

The “CANTAB” is an applicable instrument for assessment of the executive function in young hospitalized schizophrenic patients. It can be used both for experimental and clinical needs.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Identification of Anaplasma phagocytophilum in tick populations in Estonia, the European part of Russia and Belarus

Anaplasma phagocytophilum is associated with diseases of goats, sheep, cattle, dogs and horses. In the beginning of the 1990s it was identified as a human pathogen, causing human granulocytic anaplasmosis (HGA) in the USA, Europe and the far east of Russia. A. phagocytophilum is maintained in nature in an enzootic cycle including ticks as the main vector and a wide range of mammalian species as reservoirs. Ixodes ricinus and I. persulcatus ticks were collected in Estonia, Belarus and the European part of Russia and screened for the presence of A. phagocytophilum by real-time PCR. Positive samples were found only among I. ricinus, in 13.4% in the European part of Russia, 4.2% in Belarus, 1.7% in mainland Estonia and 2.6% on Saaremaa Island. Positive samples were sequenced for partial 16S rRNA, groESL and ankA genes and phylogenetic analyses were performed. The results showed that A. phagocytophilum circulating in Eastern Europe belongs to different groESL lineages and 16S rRNA gene variants and also consists of variable numbers of repetitive elements within the ankA gene.

Effect of soil acidification induced by a tea plantation on chemical and mineralogical properties of Alfisols in eastern China

The effect of a tea plantation on soil basic properties, chemical and mineralogical compositions, and magnetic properties of Alfisols from eastern China was studied. Under the tea plantation, acidification took place within a soil depth of 70 cm, with the maximum difference in pH in the upper 17 cm (ΔpH = 2.80). Both the tea plantation and unused soil profiles were predominated by free Fe and Al oxides, i.e. citrate/bicarbonate/dithionite extractable Fe (Fe(d)) and Al (Al(d)). Tea plantation soil was characterized by higher Al(d) and Fe(d) and lower Fe oxalate, Fe(2)O(3) and Al(2)O(3); CaO was depleted, whereas SiO(2) accumulated. Acidification induced by the tea plantation led to destruction of vermiculite followed by dissolution of the hydroxy-Al interlayers within its structure. The data clearly demonstrated that significant soil weathering occurred with acidification caused by tea cultivation. This acidification also resulted in decreased content of ferrimagnetic minerals due to the dissolution of minerals and movement of Fe in the profile.

Improved calibration technique of the infrared imaging bolometer using ultraviolet light-emitting diodes

The technique used until recently utilizing the Ne-He laser for imaging bolometer foils calibration [B. J. Peterson et al., J. Plasma Fusion Res. 2, S1018 (2007)] has showed several issues. The method was based on irradiation of 1 cm spaced set of points on a foil by the laser beam moved by set of mirrors. Issues were the nonuniformity of laser power due to the vacuum window transmission nonuniformity and high reflection coefficient for the laser. Also, due to the limited infrared (IR) window size, it was very time consuming. The new methodology uses a compact ultraviolet (uv) light-emitting diodes installed inside the vacuum chamber in a fixed position and the foil itself will be moved in the XY directions by two vacuum feedthroughs. These will help to avoid the above mentioned issues due to lack of a vacuum window, fixed emitters, higher uv power absorption, and a fixed IR camera position.

Bloodsucking arthropods: the danger for travellers and hazard of vector travelling

The newly obtained data supplemented our knowledge about risk for travellers, tourists and natives of Europe connected with malaria, leishmaniasis and other tropical diseases. It was discovered that healthy carriers of Epstein-Barr virus (nearly 90% of human population) have a great risk to get chronic Burkitt lymphoma disease as a result of Plasmodium falciparum (tropical malaria agent) infection. HIV carriers being occasionally in contact with visceral leishmaniasis vectors (sand-flies infected on dogs in the Mediterranean area) not only got a heavy form of disease but became a source of infection for healthy people. Airport malaria and outbreaks of dengue fever sometimes were (and are) connected with an import of infective Anopheles or Aedes mosquitoes. The high risk of borreliosis and ehrlichiosis infection exists in the forested European areas along the highways, where picnics and other types of recreation of travellers and tourists are typical and where the anthropogenically changed Ixodes ticks subpopulations are distributed. Such physiologically changed part of tick population is more aggressive and "changed ticks" more often are vectors of one, two or even more agent species simultaneously.