Modeling and Diagnostic Software for Liquefying-Fuel Rockets

A report presents a study of five modeling and diagnostic computer programs considered for use in an integrated vehicle health management (IVHM) system during testing of liquefying-fuel hybrid rocket engines in the Hybrid Combustion Facility (HCF) at NASA Ames Research Center. Three of the programs -- TEAMS, L2, and RODON -- are model-based reasoning (or diagnostic) programs. The other two programs -- ICS and IMS -- do not attempt to isolate the causes of failures but can be used for detecting faults. In the study, qualitative models (in TEAMS and L2) and quantitative models (in RODON) having varying scope and completeness were created. Each of the models captured the structure and behavior of the HCF as a physical system. It was noted that in the cases of the qualitative models, the temporal aspects of the behavior of the HCF and the abstraction of sensor data are handled outside of the models, and it is necessary to develop additional code for this purpose. A need for additional code was also noted in the case of the quantitative model, though the amount of development effort needed was found to be less than that for the qualitative models

Effect of selective heart rate slowing in heart failure with preserved ejection fraction

Background Heart failure with preserved ejection fraction (HFpEF) is associated with significant morbidity and mortality but is currently refractory to therapy. Despite limited evidence, heart rate reduction has been advocated, on the basis of physiological considerations, as a therapeutic strategy in HFpEF. We tested the hypothesis that heart rate reduction improves exercise capacity in HFpEF. Methods and Results We conducted a randomized, crossover study comparing selective heart rate reduction with the If blocker ivabradine at 7.5 mg twice daily versus placebo for 2 weeks each in 22 symptomatic patients with HFpEF who had objective evidence of exercise limitation (peak oxygen consumption at maximal exercise [GraphicO2 peak] <80% predicted for age and sex). The result was compared with 22 similarly treated matched asymptomatic hypertensive volunteers. The primary end point was the change in GraphicO2 peak. Secondary outcomes included tissue Doppler–derived E/e′ at echocardiography, plasma brain natriuretic peptide, and quality-of-life scores. Ivabradine significantly reduced peak heart rate compared with placebo in the HFpEF (107 versus 129 bpm; P<0.0001) and hypertensive (127 versus 145 bpm; P=0.003) cohorts. Ivabradine compared with placebo significantly worsened the change in GraphicO2 peak in the HFpEF cohort (-2.1 versus 0.9 mL·kg−1·min−1; P=0.003) and significantly reduced submaximal exercise capacity, as determined by the oxygen uptake efficiency slope. No significant effects on the secondary end points were discernable. Conclusion Our observations bring into question the value of heart rate reduction with ivabradine for improving symptoms in a HFpEF population characterized by exercise limitation

The Power+ Plan and citizen’s movement for just transition in Appalachia and beyond

In January 2015, President Obama announced a five-year plan to direct over $1 billion into economic transition and reclamation in Appalachia and elsewhere. The proposed POWER+ plan draws funds from the Abandoned Mine Lands Fund and from five federal agencies. Through 2015, the Alliance for Appalachia and other grassroots organizations lobbied local governments to support POWER+. Dozens of county governments across Central Appalachia have passed resolutions in support. This roundtable reflects on this remarkably successful mobilization for just transition policy. It analyzes POWER+ in historical context of past macrostructural shifts in the relationship of the Corporate to the Local State. Many of the panelists have been doing grassroots organizing to mobilize local governments and elected officials to endorse the POWER+ Plan. Others have been involved in earlier struggles to democratize the relationship between federal, state, and local levels of economic planning. The roundtable will seek to apply lessons from earlier eras of struggle to contemporary challenges of neoliberal globalization

Risk prediction in patients with heart failure: A systematic review and analysis

Objectives This study sought to review the literature for risk prediction models in patients with heart failure and to identify the most consistently reported independent predictors of risk across models. Background Risk assessment provides information about patient prognosis, guides decision making about the type and intensity of care, and enables better understanding of provider performance. Methods MEDLINE and EMBASE were searched from January 1995 to March 2013, followed by hand searches of the retrieved reference lists. Studies were eligible if they reported at least 1 multivariable model for risk prediction of death, hospitalization, or both in patients with heart failure and reported model performance. We ranked reported individual risk predictors by their strength of association with the outcome and assessed the association of model performance with study characteristics. Results Sixty-four main models and 50 modifications from 48 studies met the inclusion criteria. Of the 64 main models, 43 models predicted death, 10 hospitalization, and 11 death or hospitalization. The discriminatory ability of the models for prediction of death appeared to be higher than that for prediction of death or hospitalization or prediction of hospitalization alone (p = 0.0003). A wide variation between studies in clinical settings, population characteristics, sample size, and variables used for model development was observed, but these features were not significantly associated with the discriminatory performance of the models. A few strong predictors emerged for prediction of death; the most consistently reported predictors were age, renal function, blood pressure, blood sodium level, left ventricular ejection fraction, sex, brain natriuretic peptide level, New York Heart Association functional class, diabetes, weight or body mass index, and exercise capacity. Conclusions There are several clinically useful and well-validated death prediction models in patients with heart failure. Although the studies differed in many respects, the models largely included a few common markers of risk

Differences in Falls and Recovery From a Slip Based On an Individual\u27s Lower Extremity Corrective Response

Background: Slips and falls account for high rates of injury and mortality in multiple populations. The corrective responses during the slip perturbation have been well documented. However, when a fall results from a slip, it is unclear which of these responses were inadequate. Objective: The purpose of this study was to examine differences in lower extremity corrective responses of the slip recovery response between individuals who fall and those who recover. Methodology: Sixty-four participants completed this study (32 males & 32 females). Participant’s gait kinematics and kinetics were collected during normal gait (NG) and an unexpected slip (US). A prediction equation for slip outcome and slip severity were created using a binary logistic regression model. Results: Our findings show an increased time to peak hip extension (OR = 1.006, CI: 1.000-1.011) and ankle dorsiflexion (OR = 1.005, CI: 1.001-1.009) moments increased the odds of falling, while the average ankle moment was negatively associated with falling (OR = 0.001, CI: 0.001-0.005). Conclusions: Rapid lower extremity corrective responses appear critical in arresting the slip and preventing a fall. While there are various strategies for slip recovery, our findings suggest that the primary recovery mechanism at the slipping hip may play a vital role in preventing the fall

Differences in falls and recovery from a slip based on an individual’s lower extremity corrective response

Copyright (c) the author(s). This is an open access article under CC BY license (https://creativecommons.org/licenses/by/4.0/) Background: Slips and falls account for high rates of injury and mortality in multiple populations. The corrective responses during the slip perturbation have been well documented. However, when a fall results from a slip, it is unclear which of these responses were inadequate. Objective: The purpose of this study was to examine differences in lower extremity corrective responses of the slip recovery response between individuals who fall and those who recover. Methodology: Sixty-four participants completed this study (32 males & 32 females). Participant’s gait kinematics and kinetics were collected during normal gait (NG) and an unexpected slip (US). A prediction equation for slip outcome and slip severity were created using a binary logistic regression model. Results: Our findings show an increased time to peak hip extension (OR = 1.006, CI: 1.000-1.011) and ankle dorsiflexion (OR = 1.005, CI: 1.001-1.009) moments increased the odds of falling, while the average ankle moment was negatively associated with falling (OR = 0.001, CI: 0.001-0.005). Conclusions: Rapid lower extremity corrective responses appear critical in arresting the slip and preventing a fall. While there are various strategies for slip recovery, our findings suggest that the primary recovery mechanism at the slipping hip may play a vital role in preventing the fall

Metabolic profiling of aortic stenosis and hypertrophic cardiomyopathy identifies mechanistic contrasts in substrate utilization

Aortic stenosis (AS) and hypertrophic cardiomyopathy (HCM) are distinct disorders leading to left ventricular hypertrophy (LVH), but whether cardiac metabolism substantially differs between these in humans remains to be elucidated. We undertook an invasive (aortic root, coronary sinus) metabolic profiling in patients with severe AS and HCM in comparison with non‐LVH controls to investigate cardiac fuel selection and metabolic remodeling. These patients were assessed under different physiological states (at rest, during stress induced by pacing). The identified changes in the metabolome were further validated by metabolomic and orthogonal transcriptomic analysis, in separately recruited patient cohorts. We identified a highly discriminant metabolomic signature in severe AS in all samples, regardless of sampling site, characterized by striking accumulation of long‐chain acylcarnitines, intermediates of fatty acid transport across the inner mitochondrial membrane, and validated this in a separate cohort. Mechanistically, we identify a downregulation in the PPAR‐α transcriptional network, including expression of genes regulating fatty acid oxidation (FAO). In silico modeling of β‐oxidation demonstrated that flux could be inhibited by both the accumulation of fatty acids as a substrate for mitochondria and the accumulation of medium‐chain carnitines which induce competitive inhibition of the acyl‐CoA dehydrogenases. We present a comprehensive analysis of changes in the metabolic pathways (transcriptome to metabolome) in severe AS, and its comparison to HCM. Our results demonstrate a progressive impairment of β‐oxidation from HCM to AS, particularly for FAO of long‐chain fatty acids, and that the PPAR‐α signaling network may be a specific metabolic therapeutic target in AS