Ultrasonic measurement of temperature distributions in extreme environments: Electrical power plants testing in utility-scale steam generators.

Thermal heterogeneities within energy conversion and storage, material processing, nuclear processes, aerospace, and military applications are often inaccessible to characterization by insertion sensors. When sensor deployment is possible, conventional pointwise temperature probes quickly degrade when inserted into harsh environments typical of such processes. We developed spatially-resolved ultrasonic thermometry to noninvasively measure the spatial distributions of thermal properties in such applications, even when sizable thermal gradients are present. Our method divides the path of ultrasonic propagation into segments bound by echogenic features, which create echoes in pulse-echo mode, encoding the information about interior temperature distributions. We use the acquired ultrasonic responses to estimate the internal temperature distributions by solving an inverse problem or concatenating segmental estimates. This work describes the implementation and industrial testing of the developed method at a coal-fired electrical power generation plant. We inserted an echogenically segmented Inconel 625 waveguide into the combustion zone of the utility-scale boiler and continuously acquired ultrasonic data while keeping sensitive components away from the damaging combustion environment. The accuracy of the time-dependent temperature distributions reconstructed from the ultrasonic measurements was comparable to that of thermocouples. The resiliency of ultrasonic thermometry to harsh combustion conditions was far superior to conventional insertion sensors. The measurements obtained during plant operation captured daily steam generation cycles in response to changing customer demand and intermittent contributions of renewable power sources to the power grid. These measurements have revealed new insights into the relationship between the dynamic power generation load and the conditions inside the steam generator. The successful industrial testing of spatially-resolved ultrasonic thermometry in solids indicates that the developed technology has matured to become an attractive alternative to conventional sensing in solving challenging problems of long-term thermal characterizations in extreme environments.

Transcendental Meditation practitioners show reduced expression of the Conserved Transcriptional Response to Adversity.

Background and objectives: A recent exploratory study of transcriptional effects of long-term practice of Transcendental Meditation (TM) technologies found evidence for altered expression of genes associated with health and disease. In the present secondary analysis of those data, we test the more specific hypothesis that this sample of long-term practitioners shows a significant reduction in markers of the "Conserved Transcriptional Response to Adversity" (CTRA), an RNA profile characterized by up-regulated inflammation and down-regulated Type I interferon (IFN) activity. Materials and methods: Data come from a previously published study providing genome-wide transcriptional profiles of peripheral blood mononuclear cells (PBMC) from healthy, 38-year practitioners of TM technologies and matched controls (n = 12, mean age 65). The current analysis specifically tests for differential expression of a previously established CTRA indicator gene score, with cross-validation by promoter-based bioinformatic analysis of CTRA-typical differences in transcription factor activity and monocyte subset cellular origins. Results: Compared to controls, the TM group showed lower expression of a pre-specified set of CTRA indicator genes. These effects were accompanied by genome-wide indications of down-regulated pro-inflammatory transcription factor activity (NF-κB, AP-1), up-regulated activity of Interferon Response Factors (IRF) and reduced transcriptional activity of classical monocytes. Conclusions: A sample of long-term practitioners of TM showed reduced CTRA gene expression in PBMC compared to matched controls, supporting the likely value of further research to evaluate causality and specificity of this potential mechanism of health benefits in meditators.

A mechanistic derivation of the Monod bioreaction equation for a limiting nutrient.

We present a quasi-steady state mechanistic derivation of the Monod bioreaction equation based upon a conceptual model involving aqueous phase diffusive transport of substrate towards a spherical microbe; transport of the substrate across its surface membrane; and reaction depleting the substrate within the microbe. The resulting Monod coefficients [Formula: see text] and [Formula: see text] are dependent upon substrate-species pairs and the mass transfer properties of the system. Two substrate transport scenarios are investigated: (1) a constant rate model that is a function of a constant flux across the surface of the microbe; and (2) a linear rate model that is the product of a constant transport velocity and the concentration of substrate in contact with the surface of the microbe. The model is verified and parameterized using benzene, toluene, and phenol depletion and biomass growth data obtained from Reardon et al. (Biotechnol Bioeng: 385-400, 2000). Calibration results indicate a normalized surface to bulk concentration ratio of nearly unity in all simulations for benzene, toluene, and phenol when paired with P. putida F1, implying that the process is not aqueous phase diffusion limited.

Transcriptomics of Long-Term Meditation Practice: Evidence for Prevention or Reversal of Stress Effects Harmful to Health.

Background and Objectives: Stress can overload adaptive mechanisms, leading to epigenetic effects harmful to health. Research on the reversal of these effects is in its infancy. Early results suggest some meditation techniques have health benefits that grow with repeated practice. This study focused on possible transcriptomic effects of 38 years of twice-daily Transcendental Meditation® (TM®) practice. Materials and Methods: First, using Illumina® BeadChip microarray technology, differences in global gene expression in peripheral blood mononuclear cells (PBMCs) were sought between healthy practitioners and tightly matched controls (n = 12, age 65). Second, these microarray results were verified on a subset of genes using quantitative polymerase chain reaction (qPCR) and were validated using qPCR in larger TM and control groups (n = 45, age 63). Bioinformatics investigation employed Ingenuity® Pathway Analysis (IPA®), DAVID, Genomatix, and R packages. Results: The 200 genes and loci found to meet strict criteria for differential expression in the microarray experiment showed contrasting patterns of expression that distinguished the two groups. Differential expression relating to immune function and energy efficiency were most apparent. In the TM group, relative to the control, all 49 genes associated with inflammation were downregulated, while genes associated with antiviral and antibody components of the defense response were upregulated. The largest expression differences were shown by six genes related to erythrocyte function that appeared to reflect a condition of lower energy efficiency in the control group. Results supporting these gene expression differences were obtained with qPCR-measured expression both in the well-matched microarray groups and in the larger, less well-matched groups. Conclusions: These findings are consistent with predictions based on results from earlier randomized trials of meditation and may provide evidence for stress-related molecular mechanisms underlying reductions in anxiety, post-traumatic stress disorder (PTSD), cardiovascular disease (CVD), and other chronic disorders and diseases.

Methane gas transport in unconfined aquifers: A numerical sensitivity study of a controlled release experiment at CFB Borden.

Subsurface leakage of natural gas from petroleum wells can impact freshwater aquifers. Accurate prediction of gas migration in the subsurface will depend on knowledge of permeability, porosity, and flow system conditions. A series of two-dimensional numerical multi-phase flow simulations (CFbio) were conducted to investigate the role of multi-phase parameters (relative permeability and air entry pressure), flow system conditions (intrinsic permeability, anisotropy, and groundwater velocity), and geometric properties (layer thickness and layer lateral continuity) on the flow of gas-phase methane emanating from two variable-rate point sources in an unconfined sandy aquifer. Numerical simulations showed that for a homogeneous, weakly anisotropic aquifer, gas migrates almost exclusively vertically due to buoyancy, before venting to the vadose zone and atmosphere. As vertical migration became restricted through increased anisotropy, inclusion of lower-permeable layers, or increased horizontal groundwater velocity, an increase in the lateral component of gas migration was observed. This led to the formation of a broader lateral migration of the gas-phase plume and establishment of variably distributed vertical preferential flow paths, ultimately resulting in increased gas retention in the aquifer with relatively less methane reaching the vadose zone or atmosphere. The inclusion of a thin layer with moderately lower permeability (1-2 orders of magnitude) and increased air entry pressure was used to depict a fine-grained sand lens within a uniform aquifer. This subtle feature led to the formation of thin gas pools extending up- and down-gradient beneath the lens, allowing methane to travel much farther and faster than by groundwater advection alone, which is consistent with field observations during the experiment. In all scenarios investigated gas-phase methane was shown to migrate predominantly vertically due to buoyancy, until the aquitard permeability was <30% of the aquifer permeability. Our modelling demonstrates that even subtle permeability contrasts, together with capillary pressure changes demarcating grain-scale bedding, will lead to extensive lateral free-phase gas migration, and development of a more extensive and complex zone of impacted aquifer than presupposed.

Trials of Maharishi Ayurveda for cardiovascular disease: A pooled analysis of outcome studies with carotid intima-media thickness.

Objective: To investigate a multimodality, natural medicine systems approach-Maharishi Ayurveda (MAV)-for prevention or reversal of atherosclerotic cardiovascular disease (ASCVD). Design: Pooled analysis of data from existing trials that used MAV to reduce carotid artery intima-media thickness (CIMT). Settings: Two large medical centers in the U.S. Midwest. Subjects: Thirty-four elderly patients with or at high risk for ASCVD. Interventions: Four components of MAV: Transcendental Meditation™, Ayurvedic diet, Ayurvedic exercise, and Ayurvedic herbal food supplements. Primary outcome measure: CIMT, a surrogate measure of ASCVD, was determined by B-mode ultrasonography. Results: After 9-12 months of intervention, CIMT declined in the MAV group (change in CIMT = -0.15 ± 0.22 mm; 95% CI = -0.22 to 0.01 mm) and increased in the usual care group (change in CIMT = + 0.02 ± 0.06 mm; 95% CI = -0.02 to 0.04). This difference between groups of -0.17 mm was significant [F(1,29) = 14.1, p << .01]. In the MAV group, those individuals showing the largest reductions in CIMT with treatment also had the highest risk factor levels at the start. Baseline data from this subgroup indicated the presence of hypertension, (systolic blood pressure (SBP) = 141 ± 11 mmHg, diastolic blood pressure (DBP) = 80 ± 12 mmHg, means ± SD). They also had elevated waist circumference (91 ± 8 cm), and dyslipidemia (triglyceride-to-HDL-cholesterol ratio = 4.8 ± 2.9). Each individual in this "high-CIMT-change" group, 80% of whom were women, improved notably in one or more risk factors with the MAV intervention. Conclusions: The pooled results of these two trials suggest that MAV multimodality intervention programs, including the Transcendental Meditation technique and heart-healthy Ayurvedic diet, exercise, and herbal food supplements, may be effective in the regression of ASCVD, especially in patients at high risk for cardiovascular disease.

Cardiovascular disease prevention and health promotion with the transcendental meditation program and Maharishi consciousness-based health care.

This article summarizes the background, rationale, and clinical research on a traditional system of natural health care that may be useful in the prevention of cardiovascular disease (CVD) and promotion of health. Results recently reported include reductions in blood pressure, psychosocial stress, surrogate markers for atherosclerotic CVD, and mortality. The randomized clinical trials conducted so far have involved applications to both primary and secondary prevention as well as to health promotion more generally. The results support the applicability of this approach for reducing ethnic health disparities associated with environmental and psychosocial stress. Proposed mechanisms for the effects of this traditional system include enhanced resistance to physiological and psychological stress and improvements in homeostatic and self-repair processes. This system may offer clinical and cost effectiveness advantages for health care, particularly in preventive cardiology.

Psychosocial stress and cardiovascular disease. Part 3: Clinical and policy implications of research on the transcendental meditation program.

Cardiovascular disease (CVD) remains the leading cause of death in the United States today and a major contributor to total health care costs. Psychosocial stress has been implicated in CVD, and psychosocial approaches to primary and secondary prevention are gaining research support. This third article in the series on psychosocial stress and CVD continues the evaluation of one such approach, the Maharishi Transcendental Meditation program, a psychophysiological approach from the Vedic tradition that is systematically taught by qualified teachers throughout the world. Evidence suggests not only that this program can provide benefits in prevention but also that it may reduce CVD-related and other health care expenses. On the basis of data from the studies available to date, the Transcendental Meditation program may be responsible for reductions of 80% or greater in medical insurance claims and payments to physicians. This article evaluates the implications of research on the Transcendental Meditation program for health care policy and for large-scale clinical implementation of the program. The Transcendental Meditation program can be used by individuals of any ethnic or cultural background, and compliance with the practice regimen is generally high. The main steps necessary for wider adoption appear to be: (1) educating health care providers and patients about the nature and expected benefits of the program, and (2) adjustments in public policies at the state and national levels to allow this program to be included in private and public health insurance plans.

Review of controlled research on the transcendental meditation program and cardiovascular disease. Risk factors, morbidity, and mortality.

Because of growing evidence for stress as a major factor contributing to cardiovascular disease (CVD), techniques of meditation are being increasingly used. The Transcendental Meditation (TM) technique is distinct from other techniques of meditation not only in its origin and procedure, but also in the amount and breadth of research testing it. Evidence for its ability to reduce traditional and novel risk factors for CVD includes: 1) decreases in blood pressure, 2) reduced use of tobacco and alcohol, 3) lowering of high cholesterol and lipid oxidation, and 4) decreased psychosocial stress. Changes expected to result from reducing these risk factors, namely, reversal of atherosclerosis, reduction of myocardial ischemia and left ventricular hypertrophy, reduced health insurance claims for CVD, and reduced mortality, also have been found with TM practice. Research on mechanisms suggests that some of the CVD-related benefits as a result of this technique could arise from normalization of neuroendocrine systems whose function has been distorted by chronic stress. Further randomized clinical trials are in progress with a focus on underserved minority populations.

Lowering cortisol and CVD risk in postmenopausal women: a pilot study using the Transcendental Meditation program.

Unlike younger women, the risk of cardiovascular disease in older women matches or exceeds that of men. Excessive cortisol may play a role in this increased risk. Here we explore the possibility that the Transcendental Meditation (TM) program may reduce the cortisol response to a metabolic stressor as a way of reducing disease risk in older women. Data from 16 women who were long-term practitioners of transcendental meditation (mean = 23 y) were compared with data from 14 control women matched for age (mean = 75 y, range = 65-92 y). Data on demographics, disease symptoms, and psychological variables were collected, and cortisol response to a metabolic stressor (75 g of glucose, orally) was examined in saliva and urine. Pre-glucose levels of salivary cortisol were identical for the two groups. Post-glucose cortisol rose faster in the controls and was significantly higher than that in the TM women (P < 1 3 10(-4)). Urinary excretion of cortisol during this period was 3 times higher in controls than in the TM women (2.4 +/- 0.17 and 0.83 +/- 0.10 microg/h, respectively; P = 2 x 10(-4)). In addition, the number of months practicing transcendental meditation was inversely correlated with CVD risk factors. Lower cortisol response to metabolic challenge may reflect improved endocrine regulation relevant to the disease-preventing effects of transcendental meditation in older women.

Psychosocial stress and cardiovascular disease: pathophysiological links.

The remarkable decline in cardiovascular disease (CVD) experienced in developed countries over the last 40 years appears to have abated. Currently, many CVD patients continue to show cardiac events despite optimal treatment of traditional risk factors. This evidence suggests that additional interventions, particularly those aimed at nontraditional factors, might be useful for continuing the decline. Psychosocial stress is a newly recognized (nontraditional) risk factor that appears to contribute to all recognized mechanisms underlying cardiac events, specifically, (a) clustering of traditional cardiovascular risk factors, (b) endothelial dysfunction, (c) myocardial ischemia, (d) plaque rupture, (e) thrombosis, and (f) malignant arrhythmias. A better understanding of the behavioral and physiologic associations between psychosocial stress and CVD will assist researchers in identifying effective approaches for reducing or reversing the damaging effects of stress and may lead to further reductions of CVD morbidity and mortality.

Effect of a multimodality natural medicine program on carotid atherosclerosis in older subjects: a pilot trial of Maharishi Vedic Medicine.

Although the onset and progression of coronary heart disease (CHD) involve multiple risk factors, few intervention studies have attempted to modify these factors simultaneously. This pilot study tested the effect of a multimodality intervention involving dietary, exercise, herbal food supplement, and stress reduction approaches from a traditional system of natural medicine, Maharishi Vedic Medicine (MVM). The primary outcome measure was carotid intima-media thickness (IMT), a noninvasive measure of peripheral atherosclerosis and surrogate measure of coronary atherosclerosis. Comparison groups included modern medicine (conventional dietary, exercise, and multivitamin approaches) and usual care (no added intervention). Of 57 healthy seniors (mean age 74 years) randomized to the 3 treatment groups, 46 completed IMT post-testing. Carotid IMT was determined by B-mode ultrasound before and after 1 year of treatment. IMT decreased in a larger fraction of MVM subjects (16 of 20) than in the modern (5 of 9) and usual care (7 of 14) groups combined (i.e., 12 of 23; odds ratio 3.7, p = 0.05). For subjects with multiple CHD risk factors ("high-risk" subjects, n = 15), IMT decreased more in the MVM (-0.32 +/- 0.23 mm, mean +/- SD) than in the usual care (+0.022 +/- 0.085; p = 0.009) or modern (-0.082 +/- 0.095, p = 0.10) groups. Within-group reductions in IMT were significant for all MVM subjects (-0.15 +/- 0.21, n = 20, p = 0.004) and for high-risk MVM subjects (n = 6, p = 0.01). These results show that this multimodality traditional approach can attenuate atherosclerosis in older subjects, particularly those with marked CHD risk.

Psychosocial stress and cardiovascular disease Part 2: effectiveness of the Transcendental Meditation program in treatment and prevention.

Psychosocial stress is a nontraditional risk factor for cardiovascular morbidity and mortality that may respond to behavioral or psychosocial interventions. To date, studies applying such interventions have reported a wide range of success rates in treatment or prevention of cardiovascular disease (CVD). The authors focus on a natural medicine approach that research indicates reduces both psychosocial and traditional risk factors for cardiovascular disease-the Transcendental Meditation (TM) program. Randomized controlled trials, meta-analyses, and other controlled studies indicate this meditation technique reduces risk factors and can slow or reverse the progression of pathophysiological changes underlying cardiovascular disease. Studies with this technique have revealed reductions in blood pressure, carotid artery intima-media thickness, myocardial ischemia, left ventricular hypertrophy, mortality, and other relevant outcomes. The magnitudes of these effects compare favorably with those of conventional interventions for secondary prevention.