Extracellular vesicle-induced differentiation of neural stem progenitor cells

Neural stem progenitor cells (NSPCs) from E13.5 mouse embryos can be maintained in culture under proliferating conditions. Upon growth-factor removal, they may differentiate toward either neuronal or glial phenotypes or both. Exosomes are small extracellular vesicles that are part of the cell secretome; they may contain and deliver both proteins and genetic material and thus play a role in cell–cell communication, guide axonal growth, modulate synaptic activity and regulate peripheral nerve regeneration. In this work, we were interested in determining whether NSPCs and their progeny can produce and secrete extracellular vesicles (EVs) and if their content can affect cell differentiation. Our results indicate that cultured NSPCs produce and secrete EVs both under proliferating conditions and after differentiation. Treatment of proliferating NSPCs with EVs derived from differentiated NSPCs triggers cell differentiation in a dose-dependent manner, as demonstrated by glial-and neuronal-marker expression

On amenability and co-amenability of algebraic quantum groups and their corepresentations

We introduce and study several amenability properties for unitary corepresentations and *-representations of algebraic quantum groups, which may be used to characterize amenability or co-amenability of such groups. As a background for this study, we also investigate the involved tensor C*-categories.Comment: 46 pages, (some misprints corrected, a couple of remarks and a new reference added

Search for T‐odd, P‐even interactions with a three‐level, directional clock

A new class of T‐violation experiments that are sensitive to the presence of parity‐conserving time‐reversal violating interactions in atoms are considered. (AIP)Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87728/2/66_1.pd

Flow field predictions for a slab delta wing at incidence

Theoretical results are presented for the structure of the hypersonic flow field of a blunt slab delta wing at moderately high angle of attack. Special attention is devoted to the interaction between the boundary layer and the inviscid entropy layer. The results are compared with experimental data. The three-dimensional inviscid flow is computed numerically by a marching finite difference method. Attention is concentrated on the windward side of the delta wing, where detailed comparisons are made with the data for shock shape and surface pressure distributions. Surface streamlines are generated, and used in the boundary layer analysis. The three-dimensional laminar boundary layer is computed numerically using a specially-developed technique based on small cross-flow in streamline coordinates. In the rear sections of the wing the boundary layer decreases drastically in the spanwise direction, so that it is still submerged in the entropy layer at the centerline, but surpasses it near the leading edge. Predicted heat transfer distributions are compared with experimental data

Robot-mediated overground gait training for transfemoral amputees with a powered bilateral hip orthosis: a pilot study

Background: Transfemoral amputation is a serious intervention that alters the locomotion pattern, leading to secondary disorders and reduced quality of life. The outcomes of current gait rehabilitation for TFAs seem to be highly dependent on factors such as the duration and intensity of the treatment and the age or etiology of the patient. Although the use of robotic assistance for prosthetic gait rehabilitation has been limited, robotic technologies have demonstrated positive rehabilitative effects for other mobility disorders and may thus offer a promising solution for the restoration of healthy gait in TFAs. This study therefore explored the feasibility of using a bilateral powered hip orthosis (APO) to train the gait of community-ambulating TFAs and the effects on their walking abilities. Methods: Seven participants (46–71 years old with different mobility levels) were included in the study and assigned to one of two groups (namely Symmetry and Speed groups) according to their prosthesis type, mobility level, and prior experience with the exoskeleton. Each participant engaged in a maximum of 12 sessions, divided into one Enrollment session, one Tuning session, two Assessment sessions (conducted before and after the training program), and eight Training sessions, each consisting of 20 minutes of robotically assisted overground walking combined with additional tasks. The two groups were assisted by different torque-phase profiles, aiming at improving symmetry for the Symmetry group and at maximizing the net power transferred by the APO for the Speed group. During the Assessment sessions, participants performed two 6-min walking tests (6mWTs), one with (Exo) and one without (NoExo) the exoskeleton, at either maximal (Symmetry group) or self-selected (Speed group) speed. Spatio-temporal gait parameters were recorded by commercial measurement equipment as well as by the APO sensors, and metabolic efficiency was estimated via the Cost of Transport (CoT). Additionally, kinetic and kinematic data were recorded before and after treatment in the NoExo condition. Results: The one-month training protocol was found to be a feasible strategy to train TFAs, as all participants smoothly completed the clinical protocol with no relevant mechanical failures of the APO. The walking performance of participants improved after the training. During the 6mWT in NoExo, participants in the Symmetry and Speed groups respectively walked 17.4% and 11.7% farther and increased walking speed by 13.7% and 17.9%, with improved temporal and spatial symmetry for the former group and decreased energetic expenditure for the latter. Gait analysis showed that ankle power, step width, and hip kinematics were modified towards healthy reference levels in both groups. In the Exo condition metabolic efficiency was reduced by 3% for the Symmetry group and more than 20% for the Speed group. Conclusions: This study presents the first pilot study to apply a wearable robotic orthosis (APO) to assist TFAs in an overground gait rehabilitation program. The proposed APO-assisted training program was demonstrated as a feasible strategy to train TFAs in a rehabilitation setting. Subjects improved their walking abilities, although further studies are required to evaluate the effectiveness of the APO compared to other gait interventions. Future protocols will include a lighter version of the APO along with optimized assistive strategies

SMEs Inventive Performance and Profitability in the Markets for Technology

This paper studies the inventive performance and profitability of small and medium sized firms (SMEs) that are “technology specialists” compared to the inventive performance and profitability of SMEs that are instead vertically-integrated. In this paper perspective, “technology specialists” are firms that specialize upstream in generating inventions and trade those inventions in disembodied form with other firms, usually through licensing agreements. Instead, vertically-integrated firms are those firms that both generate inventions and commercialize products incorporating those inventions. We argue that technology specialists achieve a higher inventive performance than vertically-integrated firms, since they can accumulate deeper and broader inventive experience, whilst keeping a more flexible organizational structure. These firms display a lower profitability though, due to the imperfections inherent in invention market transactions and the lower bargaining power caused by the lack of commercialization assets. The theoretical framework is tested through a cross-industry investigation on a sample of European SMEs. Implications for the viability of being a technology specialist as a strategy and for the development of markets for technology are discussed

Yang–Baxter endomorphisms

Every unitary solution of the Yang–Baxter equation (R-matrix) in dimension (Formula presented.) can be viewed as a unitary element of the Cuntz algebra (Formula presented.) and as such defines an endomorphism of (Formula presented.). These Yang–Baxter endomorphisms restrict and extend to several other (Formula presented.) - and von Neumann algebras, and furthermore define a II (Formula presented.) factor associated with an extremal character of the infinite braid group. This paper is devoted to a detailed study of such Yang–Baxter endomorphisms. We discuss the relative commutants of the subfactors induced by Yang–Baxter endomorphisms, a new perspective on algebraic operations on R-matrices such as tensor products and cabling powers, the characters of the infinite braid group defined by R-matrices, and ergodicity properties. This also yields new concrete information on partial traces and spectra of R-matrices

Permutations, tensor products, and Cuntz algebra automorphisms

We study the reduced Weyl groups of the Cuntz algebras O-n from a combinatorial point of view. Their elements correspond bijectively to certain permutations of n(r) elements, which we call stable. We mostly focus on the case r = 2 and general n. A notion of rank is introduced, which is subadditive in a suitable sense. Being of rank 1 corresponds to solving an equation which is reminiscent of the Yang-Baxter equation. Symmetries of stable permutations are also investigated, along with an immersion procedure that allows to obtain stable permutations of (n + 1)(2) objects starting from stable permutations of n(2) objects. A complete description of stable transpositions and of stable 3-cycles of rank 1 is obtained, leading to closed formulas for their number. Other enumerative results are also presented which yield lower and upper bounds for the number of stable permutations

Classification of subsystems, local symmetry generators and intrinsic definition of local observables

We give a general overview of results about subsystems of local nets of von Neumann algebras in close connection with the problem of characterizing the abstract algebra of observables through the existence of Wightman currents