Consolidated fuel reprossing program: The implications of force reflection for teleoperation in space

Previous research on teleoperator force feedback is reviewed and results of a testing program which assessed the impact of force reflection on teleoperator task performance are reported. Force relection is a type of force feedback in which the forces acting on the remote portion of the teleoperator are displayed to the operator by back-driving the master controller. The testing program compared three force reflection levels: 4 to 1 (four units of force on the slave produce one unit of force at the master controller), 1 to 1, and infinity to 1 (no force reflection). Time required to complete tasks, rate of occurrence of errors, the maximum force applied to tasks components, and variability in forces applied to components during completion of representative remote handling tasks were used as dependent variables. Operators exhibited lower error rates, lower peak forces, and more consistent application of forces using force relection than they did without it. These data support the hypothesis that force reflection provides useful information for teleoperator users. The earlier literature and the results of the experiment are discussed in terms of their implications for space based teleoperator systems. The discussion described the impact of force reflection on task completion performance and task strategies, as suggested by the literature. It is important to understand the trade-offs involved in using telerobotic systems with and without force reflection

Robotic control of the seven-degree-of-freedom NASA laboratory telerobotic manipulator

A computationally efficient robotic control scheme for the NASA Laboratory Telerobotic Manipulator (LTM) is presented. This scheme utilizes the redundancy of the seven-degree-of-freedom LTM to avoid joint limits and singularities. An analysis to determine singular configurations is presented. Performance criteria are determined based on the joint limits and singularity analysis. The control scheme is developed in the framework of resolved rate control using the gradient projection method, and it does not require the generalized inverse of the Jacobian. An efficient formulation for determining the joint velocities of the LTM is obtained. This control scheme is well suited for real-time implementation, which is essential if the end-effector trajectory is continuously modified based on sensory feedback. Implementation of this scheme on a Motorola 68020 VME bus-based controller of the LTM is in progress. Simulation results demonstrating the redundancy utilization in the robotic mode are presented

Solar System Processes Underlying Planetary Formation, Geodynamics, and the Georeactor

Only three processes, operant during the formation of the Solar System, are responsible for the diversity of matter in the Solar System and are directly responsible for planetary internal-structures, including planetocentric nuclear fission reactors, and for dynamical processes, including and especially, geodynamics. These processes are: (i) Low-pressure, low-temperature condensation from solar matter in the remote reaches of the Solar System or in the interstellar medium; (ii) High-pressure, high-temperature condensation from solar matter associated with planetary-formation by raining out from the interiors of giant-gaseous protoplanets, and; (iii) Stripping of the primordial volatile components from the inner portion of the Solar System by super-intense solar wind associated with T-Tauri phase mass-ejections, presumably during the thermonuclear ignition of the Sun. As described herein, these processes lead logically, in a causally related manner, to a coherent vision of planetary formation with profound implications including, but not limited to, (a) Earth formation as a giant gaseous Jupiter-like planet with vast amounts of stored energy of protoplanetary compression in its rock-plus-alloy kernel; (b) Removal of approximately 300 Earth-masses of primordial gases from the Earth, which began Earth's decompression process, making available the stored energy of protoplanetary compression for driving geodynamic processes, which I have described by the new whole-Earth decompression dynamics and which is responsible for emplacing heat at the mantle-crust-interface at the base of the crust through the process I have described, called mantle decompression thermal-tsunami; and, (c)Uranium accumulations at the planetary centers capable of self-sustained nuclear fission chain reactions.Comment: Invited paper for the Special Issue of Earth, Moon and Planets entitled Neutrino Geophysics Added final corrections for publicatio

Cord Blood-Derived Hematopoietic Stem/Progenitor Cells: Current Challenges in Engraftment, Infection, and Ex Vivo Expansion

Umbilical cord blood has served as an alternative to bone marrow for hematopoietic transplantation since the late 1980s. Numerous clinical studies have proven the efficacy of umbilical cord blood. Moreover, the possible immaturity of cells in umbilical cord blood gives more options to recipients with HLA mismatch and allows for the use of umbilical cord blood from unrelated donors. However, morbidity and mortality rates associated with hematopoietic malignancies still remain relatively high, even after cord blood transplantation. Infections and relapse are the major causes of death after cord blood transplantation in patients with hematopoietic diseases. Recently, new strategies have been introduced to improve these major problems. Establishing better protocols for simple isolation of primitive cells and ex vivo expansion will also be very important. In this short review, we discuss several recent promising findings related to the technical improvement of cord blood transplantation

Clostridium difficile in the ICU

Clostridium difficile has become an increasingly common infectious agent in the healthcare setting. It is generally associated with antibiotic use and causes diarrhea as well as other complications such as pseudomembranous colitis (PMC) and toxic megacolon. This organism poses a serious threat to patients in the intensive care unit (ICU) as it increases hospital length of stay, morbidity, and mortality. Recurrence rates are typically higher in the ICU population as those patients usually have immunocompromised systems, more exposure to antibiotics and proton pump inhibitors, loss of normal nutritional balance, and alterations in their colonic flora. Emergence of more virulent and pathogenic strains has made combating the infection even more difficult. Newer therapies, chemotherapeutic agents, and vaccinations are on the horizon. However, the most effective treatments to date are ceasing the inciting agent, reduction in the use of proton pump inhibitors, and prevention of the disease. In this chapter, we will explore the risk factors, diagnosis, treatment, and prevention of C. difficile infections (CDI) in the ICU

Geoantineutrino Spectrum, 3He/4He-ratio Distribution in the Earth's Interior and Slow Nuclear Burning on the Boundary of the Liquid and Solid Phases of the Earth's Core

The description problem of geoantineutrino spectrum and reactor antineutrino experimental spectrum in KamLAND, which takes place for antineutrino energy \~2.8 MeV, and also the experimental results of the interaction of uranium dioxide and carbide with iron-nickel and silicaalumina melts at high pressure (5-10 GP?) and temperature (1600-2200C) have motivated us to consider the possible consequences of the assumption made by V.Anisichkin and coauthors that there is an actinid shell on boundary of liquid and solid phases of the Earth's core. We have shown that the activation of a natural nuclear reactor operating as the solitary waves of nuclear burning in 238U- and/or 232Th-medium (in particular, the neutron- fission progressive wave of Feoktistov and/or Teller-Ishikawa-Wood) can be such a physical consequence. The simplified model of the kinetics of accumulation and burnup in U-Pu fuel cycle of Feoktistov is developed. The results of the numerical simulation of neutron-fission wave in two-phase UO2/Fe medium on a surface of the Earth's solid core are presented. The georeactor model of 3He origin and the 3He/4He-ratio distribution in the Earth's interior is offered. It is shown that the 3He/4He ratio distribution can be the natural quantitative criterion of georeactor thermal power. On the basis of O'Nions-Evensen-Hamilton geochemical model of mantle differentiation and the crust growth supplied by actinid shell on the boundary of liquid and solid phases of the Earth's core as a nuclear energy source (georeactor with power of 30 TW), the tentative estimation of geoantineutrino intensity and geoantineutrino spectrum on the Earth surface are given.Comment: 28 pages, 12 figures. Added text, formulas, figures and references. Corrected equations. Changed content of some section

The laboratory telerobotic manipulator program

New opportunities for the application of telerobotic systems to enhance human intelligence and dexterity in the hazardous environment of space are presented by the NASA Space Station Program. Because of the need for significant increases in extravehicular activity and the potential increase in hazards associated with space programs, emphasis is being heightened on telerobotic systems research and development. The Laboratory Telerobotic Manipulator (LTM) program is performed to develop and demonstrate ground-based telerobotic manipulator system hardware for research and demonstrations aimed at future NASA applications. The LTM incorporates traction drives, modularity, redundant kinematics, and state-of-the-art hierarchical control techniques to form a basis for merging the diverse technological domains of robust, high-dexterity teleoperations and autonomous robotic operation into common hardware to further NASA's research

Association of a Communication Training Program With Use of Antipsychotics in Nursing Homes

Importance: Off-label antipsychotic prescribing in nursing homes (NHs) is common and is associated with increased risk of mortality in older adults. Prior large-scale, controlled trials in the NH setting failed to show meaningful reductions in antipsychotic use. Objective: To quantify the influence of a large-scale communication training program on NH antipsychotic use called OASIS. Design, Setting, and Participants: This investigation was a quasi-experimental longitudinal study of NHs in Massachusetts enrolled in the OASIS intervention. Participants were residents living in NHs between March 1, 2011, and August 31, 2013. The data were analyzed from December 2015, to March 2016, and from November through December 2016. Exposures: The OASIS educational program targets all NH staff (direct care and nondirect care) using a train-the-trainer model. The program goals were to reframe challenging behaviors of residents with cognitive impairment as the communication of unmet needs, to train staff to anticipate resident needs, and to integrate resident strengths into daily care plans. Main Outcomes and Measures: This study used an interrupted time series model of facility-level prevalence of antipsychotic medication use, other psychotropic medication use (antidepressants, anxiolytics, and hypnotics), and behavioral disturbances to evaluate the intervention\u27s effectiveness in participating facilities compared with control NHs in Massachusetts and New York. The 18-month preintervention (baseline) period was compared with a 3-month training period, a 6-month implementation period, and a 3-month maintenance period. Results: This study included 93 NHs enrolled in the OASIS intervention (27 of which had a high prevalence of antipsychotic use) compared with 831 nonintervention NHs. Among OASIS facilities, prevalences of atypical antipsychotic prescribing were 34.1% at baseline and 26.5% at the study end (absolute reduction of 7.6% and relative reduction of 22.3%) compared with a drop of 22.7% to 18.8% in the comparison facilities (absolute reduction of 3.9% and relative reduction of 17.2%). In the OASIS implementation phase, NHs experienced a reduction in antipsychotic use prevalence among OASIS facilities (-1.20%; 95% CI, -1.85% to -0.09% per quarter) greater than that among non-OASIS facilities (-0.23%; 95% CI, -0.47% to 0.01% per quarter), resulting in a net OASIS influence of -0.97% (95% CI, -1.85% to -0.09%; P = .03). A difference in trend was not sustained in the maintenance phase (difference of 0.93%; 95% CI, -0.66% to 2.54%; P = .48). No increases in other psychotropic medication use or behavioral disturbances were observed. Conclusions and Relevance: Antipsychotic use prevalence declined during OASIS implementation of the intervention, but the decreases did not continue in the maintenance phase. Other psychotropic medication use and behavioral disturbances did not increase. This study adds evidence for nonpharmacological programs to treat behavioral and psychological symptoms of dementia