A distinct CD38+CD45RA+ population of CD4+, CD8+, and double-negative T cells is controlled by FAS.

The identification and characterization of rare immune cell populations in humans can be facilitated by their growth advantage in the context of specific genetic diseases. Here, we use autoimmune lymphoproliferative syndrome to identify a population of FAS-controlled TCRαβ+ T cells. They include CD4+, CD8+, and double-negative T cells and can be defined by a CD38+CD45RA+T-BET- expression pattern. These unconventional T cells are present in healthy individuals, are generated before birth, are enriched in lymphoid tissue, and do not expand during acute viral infection. They are characterized by a unique molecular signature that is unambiguously different from other known T cell differentiation subsets and independent of CD4 or CD8 expression. Functionally, FAS-controlled T cells represent highly proliferative, noncytotoxic T cells with an IL-10 cytokine bias. Mechanistically, regulation of this physiological population is mediated by FAS and CTLA4 signaling, and its survival is enhanced by mTOR and STAT3 signals. Genetic alterations in these pathways result in expansion of FAS-controlled T cells, which can cause significant lymphoproliferative disease

A new free floating satellite dynamics testbed for hardware-in-the-loop docking experiments

Control & SimulationBiomechatronics & Human-Machine Contro

Increasing impact by mechanical resonance for teleoperated hammering

Series elastic actuators (SEAs) are interesting for usage in harsh environments as they are more robust than rigid actuators. This paper shows how SEAs can be used in teleoperation to increase output velocity in dynamic tasks.A first experiment is presented that tested human ability to achieve higher hammerhead velocities with a flexible hammer than with a rigid hammer, and toevaluate the influence of the resonance frequency. In this experiment, 13 participants executed a hammering task in direct manipulation using flexible hammers in four conditions with resonance frequencies of 3.0 Hz to 9.9 Hz and one condition with a rigid hammer.Then, a second experiment is presented that tested the ability of 32 participants to reproduce the findings of the first experiment in teleoperated manipulation with different feedback conditions: with visual and force feedback, without visual feedback, without force feedback, and with a communication delay of 40 ms.The results indicate that humans can exploit the mechanical resonance of a flexible system to at least double the output velocity without combined force and vision feedback. This is an unexpected result, allowing the design of simpler and more robust teleoperators for dynamic tasks.Accepted Author Manuscript - Copyright 2018 IEEE. Personal use of this material is permitted. Permission from IEEE must be obtained for all other uses, in any current or future media, including reprinting/republishing this material for advertising or promotional purposes, creating new collective works, for resale or redistribution to servers or lists, or reuse of any copyrighted component of this work in other works.Biomechatronics & Human-Machine ControlControl & Simulatio

Kinetics of phosphorothioate oligonucleotide metabolism in biological fluids.

The in vitro stability and metabolism of GEM[91, a 25mer phosphorothioate antisense oligonucleotide complementary to the gag mRNA region of HIV-1, was investigated using capillary electrophoresis (CE). The in vitro degradation of the parent compound at 37 degrees C was followed over the course of 120 h in human plasma. A CE method using laser-induced fluorescence detection was able to detect 5'-end intact metabolites including the parent compound extracted from biological fluids. Because the primary metabolic pathway is believed to be via 3'-exonuclease activity, the results of this study were compared with the stability of the compound in a solution containing 3'-exonuclease. The numerical solution of sequential first-order reactions was used to obtain kinetic parameters. Exonuclease digestion of the parent compound, as measured using an automated CE-UV instrument, yielded striking similarities between the two in vitro systems as well as between in vitro and in vivo systems

Adapting haptic guidance authority based on user grip

Haptic guidance systems support the operator in task execution using additional forces on the input device. Scaling of the guidance forces determines the control authority of the support system. As task complexity may vary, one level of the guidance scaling may be insufficient, and adaptation of the control authority may be helpful. The available literature mostly proposed to adapt the authority based on external cues (e.g. actual performance or safety) and the user had no direct way to modulate the desired level of support. In this paper we investigated a variable authority guidance scheme based on the user grip force. During a user study (with 8 subjects) we explored two opposite approaches to trade the control authority (i.e. increasing or decreasing guidance force magnitude with increased user grip). To simulate increased task difficulty and imperfections of the haptic guidance system, at random times either an unpredictable force disturbance was added or subjects were presented with incorrect guidance. While the performance differences between the fixed- and the variable-authority schemes were not significant, the "decreasing guidance with increased user grip" scheme allowed to substantially reduce the user control effort (steering force), especially when the guidance system was incorrect. The presented method essentially provides additional control over the guidance system without reducing the performance

Real-time data movements acquisition of Taekwondo athletes: first insights

In the last two decades, Taekwondo is a combat sport who has gained popularity, being inducted as an official Olympic Sport since 2000. Lately, more than 4500 federated athletes existing in Portugal have achieved excellent results in national and international competitions recognized by the International Olympic Committee, Portugal Olympic Committee, European Taekwondo Union and World Taekwondo Federation. In this paper, it was performed a study to establish the reliability and accuracy of the Microsoft Kinect 2 in real-time image data collection of the Taekwondo athletes movements. This work will reinforce the research on motion-analysis, targeting the improvement of the athlete’s performance and the establishment of a new level of training and competition, contributing to sport modernization and development.INCT-EN - Instituto Nacional de Ciência e Tecnologia para Excitotoxicidade e Neuroproteção(UID/CEC/00319/2013