Design of a Portable and Compact Gyroscopic Device for Hand Rehabilitation

User centered design is an apt process for developing assistive devices, as user needs are given the utmost importance in this approach. On studying current, state of the art hand rehabilitation devices, it was inferred that there exists a need for a compact and portable hand rehabilitation device – one suitable for patients with adversely limited active range of motion of the hand. This thesis proposes a novel hand-held, portable device that is composed of a fully actuated rotor-gimbal assembly (US Patent Application: 62/413,130). The simultaneous motion of the rotor and gimbal results in a controlled gyroscopic torque that acts on the user’s hand. Based on the hand’s strength and mobility, the user may either synchronize the hand movement with that compelled by the device or restrict it. While the former results in the relaxation of muscles, the latter can potentially increase muscle co-ordination and muscle strength. The target specifications of the device were determined through interviews with personnel specialized in the field of hand rehabilitation. A working principle of the device was then established via a proof-of-concept model and mathematical simulations, which were further used to firm up the design parameters. The dynamic analysis of the device was then conducted to attest the structural integrity. Also, the range of forces imposed by the device on the hand were evaluated to be within safe measures through simulation and consecutive comparison with existing literature. Future work includes fabricating the final device and evaluating its performance via experiments with human subjects. hand were evaluated to be within safe measures through simulation and consecutive comparison with existing literature. Future work includes fabricating the final device and evaluating its performance via experiments with human subjects

Heat shock protein 70-2 (HSP70-2) overexpression in breast cancer

Supplementary Methods, Supplementary table, Supplementary Figure Legends. (DOCX 41 kb

Stelleninhaber geht – Wissen bleibt!

In Deutschland nimmt der Anteil älterer Arbeitnehmerinnen und Arbeitnehmer tendenziell zu. Deshalb muss sich die Bibliotheksleitung verstärkt auf das altersbedingte Ausscheiden älterer Arbeitnehmer einstellen. Eine langjährige Fachkraft verfügt über spezielles Erfahrungswissen im direkten Aufgabenfeld. Die Bibliotheksleitung muss den Transfer allen relevanten Wissens, dazu gehört das Erfahrungswissen, vom Stelleninhaber auf seinen Nachfolger ermöglichen und unterstützen. Am Beispiel der Universitätsbibliothek der Bergakademie Freiberg wird untersucht, wie das Wissensmanagement im Rahmen eines Stellenwechsels derzeit geregelt ist. Das geschieht mit Hilfe von Tiefeninterviews in verschiedenen Abteilungen. Die Auswertung der Interviews bildet die Basis für ein Konzept für das Wissensmanagement beim Stellenwechsel an der UB Freiberg. Das Konzept benennt u. a. Maßnahmen zur Identifikation des stellenbezogenen Wissens, Maßnahmen zur Dokumentation des relevanten Wissens und Instrumente zur Wissensweitergabe beim Stellenwechsel

Enhanced oxidative stress by alcohol use in HIV+ patients: possible involvement of cytochrome P450 2E1 and antioxidant enzymes

BACKGROUND: Alcohol consumption is prevalent amongst HIV positive population. Importantly, chronic alcohol use is reported to exacerbate HIV pathogenesis. Although alcohol is known to increase oxidative stress, especially in the liver, there is no clinical evidence that alcohol increases oxidative stress in HIV positive patients. The mechanism by which alcohol increases oxidative stress in HIV positive patients is also unknown. METHODS: To examine the effects of alcohol use on oxidative stress we recruited HIV+ patients who reported mild-to-moderate alcohol use. Strict inclusion and exclusion criteria were applied to reduce the effect of other therapeutic drugs metabolized via the hepatic system as well as the effect of co-morbidities such as active tuberculosis on the interaction between alcohol and HIV infection, respectively. Blood samples were collected from HIV-negative alcohol-users and HIV positive alcohol-users followed by collection of plasma and isolation and fractionation of monocytes from peripheral blood. We then determined oxidative DNA damage, glutathione level, alcohol level, transcriptional level of cytochrome P450 2E1 (CYP2E1) and several antioxidant enzymes, and plasma level of cytokines. RESULTS: Compared to HIV-negative alcohol users, HIV-positive alcohol users demonstrated an increase in oxidative DNA damage in both plasma and CD14+ monocytes, as well as, a relative increase in oxidized/reduced glutathione (GSSG/GSH) in plasma samples. These results suggest an increase in oxidative stress in HIV-positive alcohol users compared with HIV-negative alcohol users. We also examined whether alcohol metabolism, perhaps by CYP2E1, and antioxidant enzymes are involved in alcohol-mediated increased oxidative stress in HIV-positive patients. The results showed a lower plasma alcohol level, which was associated with an increased level of CYP2E1 mRNA in monocytes, in HIV-positive alcohol users compared with HIV-negative alcohol users. Furthermore, the transcription of major antioxidants enzymes (catalase, SOD1, SOD2, GSTK1), and their transcription factor, Nrf2, were reduced in monocytes obtained from HIV positive alcohol users compared to the HIV-negative alcohol user group. However, no significant change in levels of five major cytokines/chemokines were observed between the two groups. CONCLUSIONS: The data suggests that alcohol increases oxidative stress in HIV+ patients, perhaps through CYP2E1- and antioxidant enzymes-mediated pathways. The enhanced oxidative stress is accompanied by a failure of cellular antioxidant mechanisms to maintain redox homeostasis. Overall, the enhanced oxidative stress in monocytes may exacerbate HIV pathogenesis in HIV positive alcohol users

Games of Incomplete Information and Myopic Equilibria

A new concept of an equilibrium in games is introduced that solves an open question posed by A. Neyman

Towards Better User Customization of Lower-limb Assistive Devices: Data Driven Control Strategies and a Self-Aligning Knee Mechanism

Despite the advances made in the field of lower-limb assistive walking devices, user customization of such devices remains a challenge. This work proposes three novel solutions towards addressing this challenge. Conventional walking controllers for transfemoral prostheses require tedious tuning of 12-20 control parameters per joint. Moreover, these parameters would have to be re-tuned when the terrain’s slope angle changes. The first contribution of this dissertation is a new control framework that develops a set of relationships based on the correlation between the control parameters and the progress in the gait cycle. These relationships, also called joint parameter functions, were determined through data-driven approaches. Implementation of these functions greatly reduced the number of tuning parameters to 3-6 per joint. For the second contribution, this framework was extended to sloped walking by determining a mapping from the slope angle to the necessary joint parameter functions. While these solutions help improve user-customization of prostheses controllers, the mechanical design limitations of assistive devices must also be addressed. The polycentricity of human joints like the knee hinders user customization of assistive walking devices. State-of-the-art knee orthoses mechanisms result in a rotation axis mismatch between the user’s knee and the device. Such mismatch leads to device migration and high interaction forces. The final contribution of this dissertation is a novel self-aligning knee mechanism suitable for a diverse group of users, easing user-customization

Synergistic Effects on the Elderly People's Motor Control by Wearable Skin-Stretch Device Combined with Haptic Joystick

Cutaneous sensory feedback can be used to provide additional sensory cues to a person performing a motor task where vision is a dominant feedback signal. A haptic joystick has been widely used to guide a user by providing force feedback. However, the benefit of providing force feedback is still debatable due to performance dependency on factors such as the user's skill-level, task difficulty. Meanwhile, recent studies have shown the feasibility of improving a motor task performance by providing skin-stretch feedback. Therefore, a combination of two aforementioned feedback types is deemed to be promising to promote synergistic effects to consistently improve the person's motor performance. In this study, we aimed at identifying the effect of the combined haptic and skin-stretch feedbacks on the aged person's driving motor performance. For the experiment, 15 healthy elderly subjects (age 72.8 ± 6.6 years) were recruited and were instructed to drive a virtual power-wheelchair through four different courses with obstacles. Four augmented sensory feedback conditions were tested: no feedback, force feedback, skin-stretch feedback, and a combination of both force and skin-stretch feedbacks. While the haptic force was provided to the hand by the joystick, the skin-stretch was provided to the steering forearm by a custom-designed wearable skin-stretch device. We tested two hypotheses: (i) an elderly individual's motor control would benefit from receiving information about a desired trajectory from multiple sensory feedback sources, and (ii) the benefit does not depend on task difficulty. Various metrics related to skills and safety were used to evaluate the control performance. Repeated measure ANOVA was performed for those metrics with two factors: task scenario and the type of the augmented sensory feedback. The results revealed that elderly subjects' control performance significantly improved when the combined feedback of both haptic force and skin-stretch feedback was applied. The proposed approach suggest the feasibility to improve people's task performance by the synergistic effects of multiple augmented sensory feedback modalities

Effects of Cigarette Smoke Condensate on Oxidative Stress, Apoptotic Cell Death, and HIV Replication in Human Monocytic Cells.

While cigarette smoking is prevalent amongst HIV-infected patients, the effects of cigarette smoke constituents in cells of myeloid lineage are poorly known. Recently, we have shown that nicotine induces oxidative stress through cytochrome P450 (CYP) 2A6-mediated pathway in U937 monocytic cells. The present study was designed to examine the effect of cigarette smoke condensate (CSC), which contains majority of tobacco constituents, on oxidative stress, cytotoxicity, expression of CYP1A1, and/or HIV-1 replication in HIV-infected (U1) and uninfected U937 cells. The effects of CSC on induction of CYP1 enzymes in HIV-infected primary macrophages were also analyzed. The results showed that the CSC-mediated increase in production of reactive oxygen species (ROS) in U937 cells is dose- and time-dependent. Moreover, CSC treatment was found to induce cytotoxicity in U937 cells through the apoptotic pathway via activation of caspase-3. Importantly, pretreatment with vitamin C blocked the CSC-mediated production of ROS and induction of caspase-3 activity. In U1 cells, acute treatment of CSC increased ROS production at 6H (>2-fold) and both ROS (>2 fold) and HIV-1 replication (>3-fold) after chronic treatment. The CSC mediated effects were associated with robust induction in the expression of CYP1A1 mRNA upon acute CSC treatment of U937 and U1 cells (>20-fold), and upon chronic CSC treatment to U1 cells (>30-fold). In addition, the CYP1A1 induction in U937 cells was mediated through the aromatic hydrocarbon receptor pathway. Lastly, CSC, which is known to increase viral replication in primary macrophages, was also found to induce CYP1 enzymes in HIV-infected primary macrophages. While mRNA levels of both CYP1A1 and CYP1B1 were elevated following CSC treatment, only CYP1B1 protein levels were increased in HIV-infected primary macrophages. In conclusion, these results suggest a possible association between oxidative stress, CYP1 expression, and viral replication in CSC-treated cells of myeloid lineage. This study warrants a closer examination of the role of CYP1B1 in smoking-mediated enhanced HIV replication