A novel form of macropinocytosis mediates ultra-rapid transfer of pathological alpha- synuclein to lysosomes

The nervous system spread of alpha-synuclein fibrils leads to Parkinson′s disease (PD) and other synucleinopathies, yet the mechanisms underlying internalization and cell-to-cell transfer are enigmatic. Here we use confocal and superresolution microscopy, subcellular fractionation and electron microscopy of immunogold labelled alpha-synuclein pre-formed fibrils (PFF) to demonstrate that this toxic protein species enters cells using a novel form of ultra-rapid macropinocytosis with transfer to lysosomes in as little as 2 minutes, an unprecedented cell biological kinetic for lysosomal targeting. PFF uptake circumvents classical endosomal pathways and is independent of clathrin. Immunogold-labelled PFF are seen at the highly curved inward edge of membrane ruffles, in newly formed macropinosomes, and in lysosomes. While many of the fibrils remain in lysosomes that continue to take up PFF for hours, a portion are transferred to neighboring naive cells on the external face of vesicles, likely exosomes. These data indicate that PFF uses a novel internalization mechanism as a component of cell-to-cell propagation.

Black-necked spitting cobra (Naja nigricollis) phospholipases A2 cause Trypanosoma brucei death by blocking endocytosis through the flagellar pocket

African trypanosomes, such as Trypanosoma brucei, are flagellated protozoa which proliferate in mammals and cause a variety of diseases in people and animals. In a mammalian host, the external face of the African trypanosome plasma membrane is covered by a densely packed coat formed of variant surface glycoprotein (VSG), which counteracts the host adaptive immune response by antigenic variation. The VSG is attached to the external face of the plasma membrane by covalent attachment of the C-terminus to a glycosylphosphatidylinositol. As the trypanosome grows, newly synthesised VSG is added to the plasma membrane by vesicle fusion to the flagellar pocket, the sole location of exo- and endocytosis. Snake venoms contain dozens of components including proteases and phospholipases. Here, we investigated the effect of Naja nigricollis on T. brucei with the aim of describing the response of the trypanosome to hydrolytic attack on the VSG. We found no evidence for VGS hydrolysis however N. nigricollis venom caused: (i) an enlargement of the flagellar pocket, (ii) the Rab11 positive endosomal compartments to adopt an abnormal dispersed localisation, and (iii) a cell cycle arrest prior to cytokinesis. A single protein family, the phospholipases A2s present in N. nigricollis venom, was necessary and sufficient for the effects. This study provides new molecular insight into T. brucei biology and possibly describes mechanisms that could be exploited for T. brucei targeting.

An outlook on current legal status of the employees as the representatives of public authorities.

The purpose of this article is to determine the features of the legal status of employees as representatives of public authorities, taking into account domestic and foreign experience. The main elements of the legal status of employees as representatives of public authorities in Ukraine are considered. It is noted that, as subjects of state power, employees are obliged to have a transparent, clear and unambiguous status in society. Among other things, they must comply in their direct activities with all the necessary norms and principles of domestic and international law, because the professional quality of their work will always be seen as a kind of external face of society. Attention is also focused on the fact that the efficiency of employees is directly related to the level of their self-organization, as well as a number of internal factors. In addition, it emphasizes the importance of civil servants, as well as persons working in public institutions and agencies of proper protection of the rights, freedoms and legitimate interests of men and citizens. Such a requirement for employees follows from the norms and principles of both domestic legislation (including the Basic Law of Ukraine and the Constitution of Ukraine) and international legal acts and declarations signed and ratified by Ukraine. Author’s definitions of “legal status”, “civil servant” as well as “public authority” are offered. Examples of successful experience of some developed, mostly Western, countries in building such conditions for the daily functioning of the state system and society as a whole, which managed to create a proper legal status of civil servants as public authorities, which would meet all important requirements today.

Analysis of sealing performance of a kind of profiled rubber gasket used in the radial contact seal structure

Sealing performance of standard rubber gaskets in the radial contact seal structure are observed through the experiment. A kind of profiled rubber gasket is proposed to replace the standard gasket. Leakage experiment and numerical simulation are carried out to study the sealing performance and failure mode of the profiled gasket. Several equations are presented to help analyze the failure reason. Results show that sealing performance of the profiled rubber gasket is more reliable than that of the standard rubber gasket. The failure reason of the profiled rubber gasket is that the friction force between the gasket external face and tube wall cannot balance the tube internal pressure. Dimension precision of the metal compressive ring has a great effect on the failure pressure.

Analysis of tooth stiffness of nutation face gear

Purpose The purpose of this paper is to obtain the single-tooth stiffness, single-tooth time-varying meshing stiffness and comprehensive meshing stiffness of the internal and external face gears and to analyze the influence of the modulus, pressure angle and tooth width of each face gear on the single-tooth stiffness of the gear in nutation face gear transmission. Design/methodology/approach From the point of view of material mechanics, the gear teeth of nutation face gear are simplified as spacial variable cross-section beams. The shear deformation of gear teeth, the bending deformation of tooth root and the additional elastic deformation caused by the base deformation are gotten by simplified trapezoidal section method, thus the stiffness of nutation face gear teeth can be obtained. The comparison with finite element method results verifies the rationality of simplified trapezoidal section method for calculating the tooth stiffness of nutation face gear. Findings The variation of stiffness of internal and external face gears along the meshing line and tooth height in nutation face gear transmission is studied, and the variation laws of single tooth stiffness, single-tooth-pair mesh stiffness and single tooth time-varying meshing stiffness of nutation face gear teeth are obtained. Originality/value Nutation face gear transmission is a new type of transmission. The stiffness of face gear teeth is analyzed, and the variation rules of single tooth stiffness, single-tooth-pair mesh stiffness and single tooth time-varying meshing stiffness of nutation face gear teeth are obtained, which not only enriches the research of nutation face gear transmission but also has important guiding significance for the application of nutation face gear in engineering practice.

Outsider Inspections of Closed Institutions: An Insider Ethnographic View of Institutional Display

This article questions the value of internal inspections of closed institutions by external agencies, drawing on my unanticipated experience of being deeply immersed as a researcher inside a Secure Children’s Home at the time of an inspection. I describe how an ethnographic approach enabled me to see a dramatic change in the staff–young people relations – from adversarial to cooperative – in the presence of outside inspectors. I make sense of this change through an original application, and novel extension, of Goffman’s theorising. I conceptualise the staff and young people as insiders of a ‘total institution’ working together to perform a misleadingly harmonious ‘institutional display’, motivated by a shared sense of institutional identity. I argue that although the potential for insider misrepresentation can be acknowledged, the extent of it cannot be known by outsiders. This finding is of significance for social policy as closed institutions accommodate vulnerable populations and cases of institutional abuses attest the need for external monitoring. This article calls for recognition of the inherent limitation of external face-to-face inspection processes, and research into new methods of assessment.

The main features of professional motivation of students to study chemistry in English

The article presents the results of the development and testing of a methodology for professional motivation of students to study chemistry in English using modern tools for processing statistical information, namely IBM SPSS Statistics 23 («Statistical Package for the Social Sciences»), designed to conduct applied research in the social and pedagogical sciences, and Microsoft Excel. The factors of motivation that are dominant in the motivational structure of students are determined. The distinctive features of the motivational factors of teaching chemistry in English are justified. Reliability indicators are analyzed including consistency and external (face validity), content (content validity), empirical (empirical validity), discriminate validity (discriminate validity) of the developed tool. Justifications are given for the normal distribution of data and the uniformity of variance. Positive correlations were established between the professional motivation of students to study chemistry in English and the general professional motivation for learning (K. Zamfir’s technique as modified by A. A. Rean) and motivation for success (T. Ehlers’s technique). The levels of professional motivation of students of various courses are determined to study chemistry in English. The results of testing and approbation of the method indicate the possibility of its application for research purposes.

Towards establishing internal validity for correlated gene expression measures in imaging genomics of functional networks: why distance corrections and external face validity alone fall short. Reply to “Distance is not everything in imaging genomics of functional networks: reply to a commentary on Correlated gene expression supports synchronous activity in brain networks”

The primary claim of the Richiardi et. al. 2015 Science article1 is that a measure of correlated gene expression, significant strength fraction (SSF), is related to resting state fMRI (rsfMRI) networks. However, there is still debate about this claim and whether spatial proximity, in the form of contiguous clusters, accounts entirely, or only partially, for SSF2,3. Here, thirteen distributed networks were simulated by combining 34 contiguous clusters randomly placed throughout cortex, with resulting edge distance distributions similar to rsfMRI networks. Cluster size was modulated (6-15mm radius) to test its influence on SSF false positive rate (SSF-FPR) among the simulated ‘noise’ networks. The contribution of rsfMRI networks on SSF-FPR was examined by comparing simulations using: 1) all cortical samples 2) all samples with non-rsfMRI cluster centers and 3) only non-rsfMRI samples. Results show that SSF-FPR is influenced only by cluster size (r>0.9, p<0.001), not by rsfMRI samples. Simulations using 14mm radius clusters most resembled rsfMRI networks. When thresholding at p<10-4, the SSF-FPR was 0.47. Genes that maximize SF have high global spatial autocorrelation. In conclusion, SSF is unrelated to rsfMRI networks. The main conclusion of Richiardi et. al. 2015 is based on a finding that is ∼50% likely to be a false positive, not less than 0.01% as originally reported in the article1. We discuss why distance corrections alone and external face validity are insufficient to establish a trustworthy relationship between correlated gene expression measures and rsfMRI networks, and propose more rigorous approaches to preclude common pitfalls in related studies.