Development of a Low-Noise High Common-Mode-Rejection Instrumentation Amplifier

Several previously used instrumentation amplifier circuits were examined to find limitations and possibilities for improvement. One general configuration is analyzed in detail, and methods for improvement are enumerated. An improved amplifier circuit is described and analyzed with respect to common mode rejection and noise. Experimental data are presented showing good agreement between calculated and measured common mode rejection ratio and equivalent noise resistance. The amplifier is shown to be capable of common mode rejection in excess of 140 db for a trimmed circuit at frequencies below 100 Hz and equivalent white noise below 3.0 nv/square root of Hz above 1000 Hz

Psychosocial and physiologic correlates of perceived health among HIV-infected women

The purpose of this study was to identify factors related to perception of physical health in a cohort of HIV-infected women. A descriptive correlational design was used to identify factors influencing perceived physical health in a sample of 275 HIV-infected women in Georgia, South Carolina, and North Carolina. Participants were predominantly single African-American women with household incomes of less than $10,000 per year. Using Spearman’s rho, statistically significant positive correlations (p \u3c .05) were found between perceived physical health and T helper cell count, hope, present life satisfaction, education, and income. Statistically significant positive correlations (p \u3c.05) were observed between perceived physical health and three HIV-specific active coping styles (managing the illness, focusing on others, and positive thinking). Inverse relationships were observed between perceived physical health and HIVrelated symptoms, stage of illness, depression, physical and sexual violence experienced since becoming HIV-infected, history of drug use since becoming HIV-infected, and age. Using backward stepwise selection, 9 of 14 variables were retained in the final model that explained 60% of the variance in physical health at the p \u3c .10 level of significance (R2 = .60). Variables that demonstrated a significant relationship with perceived physical health were HIV-related symptoms, depression, present life satisfaction, age, education, coping by managing the illness, coping through positive thinking, and coping by focusing on the present. These findings support the need to address the psychosocial as well as the physiologic factors associated with HIV/AIDS in developing comprehensive plans of nursing care

Incidence and correlates of violence among HIV-infected women at risk for pregnancy in the southeastern United States

To identify the incidence and correlates of physical and sexual violence among HIV-infected women at risk for pregnancy, a cross-sectional examination was conducted within a longitudinal study of reproductive decision making. Participants consisted of 275 HIVinfected women 17 to 49 years of age (mean = 30.1 years).Women were predominantly African American (87%) and single (82%), with annual incomes of $10,000 or less (66%). Overall, 68% of the women reported experiencing lifetime physical and/or sexual violence. Before becoming HIV infected, 65% of the women reported having been physically or sexually abused. After HIV diagnosis, 33% of the women reported experiencing physical or sexual abuse. Women reporting greater violence were more likely to disclose their HIV-seropositive status to their sex partner. Using logistic regression, greater intent to get pregnant (odds ratio [OR] = 0.933), decreased present life satisfaction (OR = 1.048), having three or more children (OR = 0.474), and history of drug use (OR = 0.794) significantly distinguished between women who reported physical and/or sexual violence and those who did not

The NASA Space Communications Data Networking Architecture

The NASA Space Communications Architecture Working Group (SCAWG) has recently been developing an integrated agency-wide space communications architecture in order to provide the necessary communication and navigation capabilities to support NASA's new Exploration and Science Programs. A critical element of the space communications architecture is the end-to-end Data Networking Architecture, which must provide a wide range of services required for missions ranging from planetary rovers to human spaceflight, and from sub-orbital space to deep space. Requirements for a higher degree of user autonomy and interoperability between a variety of elements must be accommodated within an architecture that necessarily features minimum operational complexity. The architecture must also be scalable and evolvable to meet mission needs for the next 25 years. This paper will describe the recommended NASA Data Networking Architecture, present some of the rationale for the recommendations, and will illustrate an application of the architecture to example NASA missions

Swing-Free Cranes via Input Shaping of Operator Commands

This paper presents an open-loop control method for suppressing payload oscillation or swing caused by operator commanded maneuvers in rotary boom cranes and the method is experimentally verified on a one-sixteenth scale model of a Hagglunds shipboard crane. The crane configuration consists of a payload mass that swings like a spherical pendulum on the end of a lift-line which is attached to a boom capable of hub rotation (slewing) and elevation (luffing). Positioning of the payload is accomplished through the hub and boom angles and the load-line length. Since the configuration of the crane affects the excitation and response of the payload, the swing control scheme must account for the varying geometry of the system. Adaptive forward path command filters are employed to remove components of the command signal which induce payload swing

Predictors of segmental myocardial functional recovery in patients after an acute ST-elevation myocardial infarction

Objective: We hypothesized that Displacement Encoding with Stimulated Echoes (DENSE) and feature-tracking derived circumferential strain would provide incremental prognostic value over the extent of infarction for recovery of segmental myocardial function. Methods: Two hundred and sixty-one patients (mean age 59 years, 73% male) underwent MRI 2 days post-ST elevation myocardial infarction (STEMI) and 241 (92%) underwent repeat imaging 6 months later. The MRI protocol included cine, 2D-cine DENSE, T2 mapping and late enhancement. Wall motion scoring was assessed by 2-blinded observers and adjudicated by a third. (WMS: 1=normal, 2=hypokinetic, 3=akinetic, 4=dyskinetic). WMS improvement was defined as a decrease in WMS ≥ 1, and normalization where WMS = 1 on follow-up. Segmental circumferential strain was derived utilizing DENSE and feature-tracking. A generalized linear mixed model with random effect of subject was constructed and used to account for repeated sampling when investigating predictors of segmental myocardial improvement or normalization Results: At baseline and follow-up, 1416 segments had evaluable data for all parameters. Circumferential strain by DENSE (p < 0.001) and feature-tracking (p < 0.001), extent of oedema (p < 0.001), infarct size (p < 0.001), and microvascular obstruction (p < 0.001) were associates of both improvement and normalization of WMS. Circumferential strain provided incremental predictive value even after accounting for infarct size, extent of oedema and microvascular obstruction, for segmental improvement (DENSE: odds ratio, 95% confidence intervals: 1.08 per −1% peak strain, 1.05–1.12, p < 0.001, feature-tracking: odds ratio, 95% confidence intervals: 1.05 per −1% peak strain, 1.03–1.07, p < 0.001) and segmental normalization (DENSE: 1.08 per −1% peak strain, 1.04–1.12, p < 0.001, feature-tracking: 1.06 per −1% peak strain, 1.04–1.08, p < 0.001). Conclusions: Circumferential strain provides incremental prognostic value over segmental infarct size in patients post STEMI for predicting segmental improvement or normalization by wall-motion scoring

Signature for Pain Recovery IN Teens (SPRINT): protocol for a multisite prospective signature study in chronic musculoskeletal pain

INTRODUCTION: Current treatments for chronic musculoskeletal (MSK) pain are suboptimal. Discovery of robust prognostic markers separating patients who recover from patients with persistent pain and disability is critical for developing patient-specific treatment strategies and conceiving novel approaches that benefit all patients. Given that chronic pain is a biopsychosocial process, this study aims to discover and validate a robust prognostic signature that measures across multiple dimensions in the same adolescent patient cohort with a computational analysis pipeline. This will facilitate risk stratification in adolescent patients with chronic MSK pain and more resourceful allocation of patients to costly and potentially burdensome multidisciplinary pain treatment approaches. METHODS AND ANALYSIS: Here we describe a multi-institutional effort to collect, curate and analyse a high dimensional data set including epidemiological, psychometric, quantitative sensory, brain imaging and biological information collected over the course of 12 months. The aim of this effort is to derive a multivariate model with strong prognostic power regarding the clinical course of adolescent MSK pain and function. ETHICS AND DISSEMINATION: The study complies with the National Institutes of Health policy on the use of a single internal review board (sIRB) for multisite research, with Cincinnati Children's Hospital Medical Center Review Board as the reviewing IRB. Stanford's IRB is a relying IRB within the sIRB. As foreign institutions, the University of Toronto and The Hospital for Sick Children (SickKids) are overseen by their respective ethics boards. All participants provide signed informed consent. We are committed to open-access publication, so that patients, clinicians and scientists have access to the study data and the signature(s) derived. After findings are published, we will upload a limited data set for sharing with other investigators on applicable repositories. TRIAL REGISTRATION NUMBER: NCT04285112

Design tools for complex dynamic security systems.

The development of tools for complex dynamic security systems is not a straight forward engineering task but, rather, a scientific task where discovery of new scientific principles and math is necessary. For years, scientists have observed complex behavior but have had difficulty understanding it. Prominent examples include: insect colony organization, the stock market, molecular interactions, fractals, and emergent behavior. Engineering such systems will be an even greater challenge. This report explores four tools for engineered complex dynamic security systems: Partially Observable Markov Decision Process, Percolation Theory, Graph Theory, and Exergy/Entropy Theory. Additionally, enabling hardware technology for next generation security systems are described: a 100 node wireless sensor network, unmanned ground vehicle and unmanned aerial vehicle

Myosteatosis as a Shared Biomarker for Sarcopenia and Cachexia Using MRI and Ultrasound

PurposeEstablish bedside biomarkers of myosteatosis for sarcopenia and cachexia. We compared ultrasound biomarkers against MRI-based percent fat, histology, and CT-based muscle density among healthy adults and adults undergoing treatment for lung cancer.MethodsWe compared ultrasound and MRI myosteatosis measures among young healthy, older healthy, and older adults with non-small cell lung cancer undergoing systemic treatment, all without significant medical concerns, in a cross-sectional pilot study. We assessed each participant's rectus femoris ultrasound-based echo intensity (EI), shear wave elastography-based shear wave speed, and MRI-based proton density fat-fraction (PDFF). We also assessed BMI, rectus femoris thickness and cross-sectional area. Rectus femoris biopsies were taken for all older adults (n = 20) and we analyzed chest CT scans for older adults undergoing treatment (n = 10). We determined associations between muscle assessments and BMI, and compared these assessments between groups.ResultsA total of 10 young healthy adults, 10 older healthy adults, and 10 older adults undergoing treatment were recruited. PDFF was lower in young adults than in older healthy adults and older adults undergoing treatment (0.3 vs. 2.8 vs. 2.9%, respectively, p = 0.01). Young adults had significantly lower EI than older healthy adults, but not older adults undergoing treatment (48.6 vs. 81.8 vs. 75.4, p = 0.02). When comparing associations between measures, PDFF was strongly associated with EI (ρ = 0.75, p < 0.01) and moderately negatively associated with shear wave speed (ρ = −0.49, p < 0.01) but not BMI, whole leg cross-sectional area, or rectus femoris cross-sectional area. Among participants with CT scans, paraspinal muscle density was significantly associated with PDFF (ρ = −0.70, p = 0.023). Histological markers of inflammation or degradation did not differ between older adult groups.ConclusionPDFF was sensitive to myosteatosis between young adults and both older adult groups. EI was less sensitive to myosteatosis between groups, yet EI was strongly associated with PDFF unlike BMI, which is typically used in cachexia diagnosis. Our results suggest that ultrasound measures may serve to determine myosteatosis at the bedside and are more useful diagnostically than traditional weight assessments like BMI. These results show promise of using EI, shear wave speed, and PDFF proxies of myosteatosis as diagnostic and therapeutic biomarkers of sarcopenia and cachexia