An approach to distributed execution of Ada programs

Intelligent control of the Space Station will require the coordinated execution of computer programs across a substantial number of computing elements. It will be important to develop large subsets of these programs in the form of a single program which executes in a distributed fashion across a number of processors. A translation strategy for distributed execution of Ada programs in which library packages and subprograms may be distributed is described. A preliminary version of the translator is operational. Simple data objects (no records or arrays as yet), subprograms, and static tasks may be referenced remotely

A Robust Wheel Interface With A Novel Adaptive Controller For Computer/robot-Assisted Motivating Rehabilitation

TheraDrive is a low-cost robotic system for post-stroke upper extremity rehabilitation. This system uses off-the-shelf computer gaming wheels with force feedback to help reduce motor impairment and improve function in the arms of stroke survivors. Preliminary results show that the TheraDrive system lacks a robust mechanical linkage that can withstand the forces exerted by patients, lacks a patient-specific adaptive controller to deliver personalized therapy, and is not capable of delivering effective therapy to severely low-functioning patients. A new low-cost, high-force haptic robot with a single degree of freedom has been developed to address these concerns. The resulting TheraDrive consists of an actuated hand crank with a compliant transmission. Actuation is provided by a brushed DC motor, geared to output up to 50 lbf (223 N) at the end effector. To enable safe human-machine interaction, a special compliant element was developed to function also as a failsafe torque limiter. A load cell is used to determine the human-machine interaction forces for use by the robot\u27s impedance controller. The impedance controller renders a virtual spring that attracts or repels the end effector from a moving target that the human must track during therapy exercises. As exercises are performed, an adaptive controller monitors patient performance and adjusts the spring stiffness to ensure that exercises are difficult but doable, which is important for maintaining patient motivation. Experiments with a computer model of a human and robot show the adaptive controller\u27s ability to maintain difficulty of exercises after a period of initial calibration. Seven human subjects (3 normal, 4 stroke-impaired) were used to test this system alongside the original TheraDrive system in order to compare both systems. Data showed that the new system produced a larger change in normalized trajectory tracking error when assistance/resistance was added to exercises when compared to the original TheraDrive. Data also showed that adaptive control led subject performance to be closer to a desired level. Motivation surveys showed no significant difference in subject motivation between the two systems. When asked to choose a preferred system, stroke subjects unanimously chose the new robot

Design and Development of an Affordable Haptic Robot with Force-Feedback and Compliant Actuation to Improve Therapy for Patients with Severe Hemiparesis

The study describes the design and development of a single degree-of-freedom haptic robot, Haptic Theradrive, for post-stroke arm rehabilitation for in-home and clinical use. The robot overcomes many of the weaknesses of its predecessor, the TheraDrive system, that used a Logitech steering wheel as the haptic interface for rehabilitation. Although the original TheraDrive system showed success in a pilot study, its wheel was not able to withstand the rigors of use. A new haptic robot was developed that functions as a drop-in replacement for the Logitech wheel. The new robot can apply larger forces in interacting with the patient, thereby extending the functionality of the system to accommodate low-functioning patients. A new software suite offers appreciably more options for tailored and tuned rehabilitation therapies. In addition to describing the design of the hardware and software, the paper presents the results of simulation and experimental case studies examining the system\u27s performance and usability

Distributed and parallel Ada and the Ada 9X recommendations

Recently, the DoD has sponsored work towards a new version of Ada, intended to support the construction of distributed systems. The revised version, often called Ada 9X, will become the new standard sometimes in the 1990s. It is intended that Ada 9X should provide language features giving limited support for distributed system construction. The requirements for such features are given. Many of the most advanced computer applications involve embedded systems that are comprised of parallel processors or networks of distributed computers. If Ada is to become the widely adopted language envisioned by many, it is essential that suitable compilers and tools be available to facilitate the creation of distributed and parallel Ada programs for these applications. The major languages issues impacting distributed and parallel programming are reviewed, and some principles upon which distributed/parallel language systems should be built are suggested. Based upon these, alternative language concepts for distributed/parallel programming are analyzed

Differences between the Francophone and Anglophone ethno-linguistic groups in the home care setting of Ontario

Although Francophones in Ontario represent the largest population of French-Canadians outside Quebec, little is known about this population, and especially about the older members of this ethno-linguistic group. The scarce literature reports that French-Canadians generally have lower service utilization, lower health status and are at risk of psychological distress compared with Anglo-Canadians. One could postulate that these disparities would be present to a greater extent in Ontario because Francophones are more of a minority

Exercise-induced mechanical hypoalgesia in musculotendinous tissues of the lateral elbow

The aim of this study was to investigate mechanical sensitivity responses at the lateral elbow to repeated weekly bouts of low load exercise in healthy subjects. Thirteen young men (n = 6) and women participated in 4 weeks of exercise. Arms were randomly allocated to an eccentric-only exercise protocol (ECC: 5 sets of 20 contractions) or to a concentric–eccentric protocol (CON-ECC: 5 sets of 10 eccentric/10 concentric contractions) performed at 30% maximal wrist extension force. Arms were exercised consecutively within each supervised weekly session. Quantitative measures of pressure pain threshold (PPT) recorded at three sites and maximal force for grip and wrist extension were assessed at baseline, and immediately pre/post exercise at each session. Muscle endurance during 100 maximal grip contractions force was assessed at baseline and one week following the final exercise session. Results showed that regardless of protocol, repeated low load exercise resulted in a time-dependent increase in PPT at all sites post exercise Weeks 3 and 4 and persisting at follow up Week 5 (P \u3c 0.02). No significant difference between protocols was evident for any measure. Muscle force and endurance were not significantly augmented compared with baseline. In conclusion mechanical hypoalgesia is induced by repeated low load exercises regardless of exercise mode, and this may prove beneficial if replicated clinically

Extracellular heat shock proteins in cell signaling

AbstractExtracellular stress proteins including heat shock proteins (Hsp) and glucose regulated proteins (Grp) are emerging as important mediators of intercellular signaling and transport. Release of such proteins from cells is triggered by physical trauma and behavioral stress as well as exposure to immunological “danger signals”. Stress protein release occurs both through physiological secretion mechanisms and during cell death by necrosis. After release into the extracellular fluid, Hsp or Grp may then bind to the surfaces of adjacent cells and initiate signal transduction cascades as well as the transport of cargo molecules such as antigenic peptides. In addition Hsp60 and hsp70 are able to enter the bloodstream and may possess the ability to act at distant sites in the body. Many of the effects of extracellular stress proteins are mediated through cell surface receptors. Such receptors include Toll Like Receptors 2 and 4, CD40, CD91, CCR5 and members of the scavenger receptor family such as LOX-1 and SREC-1. The possession of a wide range of receptors for the Hsp and Grp family permits binding to a diverse range of cells and the performance of complex multicellular functions particularly in immune cells and neurones

A Robust Wheel Interface With a Novel Adaptive Controller for Computer/Robot-Assisted Motivating Rehabilitation

TheraDrive is an effective system for post-stroke upper extremity rehabilitation. This system uses off-the-shelf computer gaming wheels with force feedback to help reduce motor impairment and improve function in the arms of stroke survivors. Preliminary results show that the TheraDrive system lacks a robust mechanical linkage that can withstand the large forces exerted by patients, and it lacks a patient-specific adaptive controller to deliver personalized therapy. It is also not capable of delivering effective therapy to severely low-functioning patients. A new low-cost, high-force haptic robot with a single degree of freedom has been developed to address these concerns. The resulting TheraDrive consists of an actuated hand crank with a compliant transmission. Actuation is provided by a brushed DC motor, geared to output up to 23 kgf at the end effector. To enable a human to interact with this system safely, a special compliant element was developed to double as a failsafe torque limiter. A set of strain gauges in the handle of the crank are used to determine the interaction forces between human and robot for use by the robot’s impedance controller. The impedance controller is used to render a one-dimensional force field that attracts or repels the end effector from a moving target point that the human must track during therapy exercises. As exercises are performed, an adaptive controller monitors patient performance and adjusts the force field accordingly. This allows the robot to compensate for gravity, variable mechanical advantage, limited range of motion, and other factors. More importantly, the adaptive controller ensures that exercises are difficult but doable, which is important for maintaining patient motivation. Experiments with a computer model of human and robot show the adaptive controller’s ability to maintain difficulty of exercises after a period of initial calibration

Discovery of Small-Molecule Enhancers of Reactive Oxygen Species That are Nontoxic or Cause Genotype-Selective Cell Death

Elevation of reactive oxygen species (ROS) levels has been observed in many cancer cells relative to nontransformed cells, and recent reports have suggested that small-molecule enhancers of ROS may selectively kill cancer cells in various in vitro and in vivo models. We used a high-throughput screening approach to identify several hundred small-molecule enhancers of ROS in a human osteosarcoma cell line. A minority of these compounds diminished the viability of cancer cell lines, indicating that ROS elevation by small molecules is insufficient to induce death of cancer cell lines. Three chemical probes (BRD5459, BRD56491, BRD9092) are highlighted that most strongly elevate markers of oxidative stress without causing cell death and may be of use in a variety of cellular settings. For example, combining nontoxic ROS-enhancing probes with nontoxic doses of l-buthionine sulfoximine, an inhibitor of glutathione synthesis previously studied in cancer patients, led to potent cell death in more than 20 cases, suggesting that even nontoxic ROS-enhancing treatments may warrant exploration in combination strategies. Additionally, a few ROS-enhancing compounds that contain sites of electrophilicity, including piperlongumine, show selective toxicity for transformed cells over nontransformed cells in an engineered cell-line model of tumorigenesis. These studies suggest that cancer cell lines are more resilient to chemically induced increases in ROS levels than previously thought and highlight electrophilicity as a property that may be more closely associated with cancer-selective cell death than ROS elevation.Chemistry and Chemical Biolog