Development of techniques and associated instrumentation for high temperature emissivity measurements

The calibrating and testing procedures for the radiometric emittance measurement apparatus are described. Test results are given for the NBS platinum-rhodium standard (SRM No. 1409), the NBS oxidized Kanthal standard, and the oxidized Rene 41 materials. Results indicate that with the platinum-rhodium standard the measurement system compared with the NBS data to within 0.02 for both total and spectral normal emitttance. Data from the Kanthal strip was consistently higher than NBS values. For oxidized Rene 41, no significant changes in as prepared emittance was observed. The emittance was stable for temperatures up to 1150 K

Development of techniques and associated instrumentation for high temperature emissivity measurements Quarterly progress report, 30 Sep. - 31 Dec. 1970

Emittance measurement techniques for space shuttle materials in high temperature environmental simulatio

Radiative properties of advanced spacecraft heat shield materials

Experimental results are presented to show the effects of simulated reentry exposure by convective heating and by radiant heating on spectral and total emittance of statically oxidized Inconel 617 and Haynes HS188 superalloys to 1260 K and a silicide coatea (R512E) columbium 752 alloy to 1590 K. Convective heating exposures were conducted in a supersonic arc plasma wind tunnel using a wedge-shaped specimen configuration. Radiant tests were conducted at a pressure of .003 atmospheres of dry air at a flow velocity of several meters per second. Convective heating specimens were subjected to 8, 20, and 38 15-min heating cycles, and radiant heating specimens were tested for 10, 20, 50, and 100 30-min heating cycles. Changes in radiative properties are explained in terms of changes in composition resulting from simulated reentry tests. The methods used to evaluate morphological, compositional and crystallographic changes include: Auger electron spectroscopy; scanning electron microscopy; X-ray diffraction analysis; and electron microprobe analysis

Regularized B1+ MAP Estimation in MRI

A challenge in MR imaging is that RF transmit coils produce non-uniform field strengths, so an excitation pulse will produce tip angles that vary substantially from the desired tip angle over the field of view. For parallel transmit excitation (using a coil array), it is important to have a map of the B1+ field strength (and phase) for RF pulse design. Standard B1+ map estimation methods perform poorly in image regions with low spin density. This paper describes a regularized method for B1+ map estimation using MR scans for each coil and for two or more tip angles. Using these scans and exploiting the fact that maps are generally smooth, the iterative algorithm estimates both the magnitude and phase at each coil's B1+ map. Results from both simulations and real MR data show significant improvements over conventional unregularized methods for B1 + mapping.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85868/1/Fessler227.pd

P02.99: Assessment of fetal lung maturity in a non‐invasive fashion

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Spirituality, Faith, and Mild Alzheimer\u27s Disease

There is some evidence for a positive association between spirituality, cognitive, and behavioral functioning in people with Alzheimer’s disease (AD). However, to our knowledge there is no published data to date that provides an explanatory model for these findings. Twenty-eight individuals with mild AD received in-depth interviews and measures of cognitive, behavioral, emotional, and spiritual functioning to gain insight into this question in this mixed methods study. Findings revealed that people with mild AD can actively engage in meaningful discussion about how spirituality influences their experience of living with AD; that they remain deeply devoted to a relationship with the transcendent (i.e., God, higher power, spirit) and their spiritual communities; that they value and benefit from the sacred aspects of their day-to-day lives; and that their core spiritual values, beliefs, and practices can be activated to help them adapt to the uncertainty of living with AD. Additionally, persons with AD who are experiencing spiritual struggle tend to experience a greater degree of anxiety, depression, and behavioral changes as compared to those who do not, suggesting that spiritual struggle is a risk factor for poorer outcomes in this population. Implications for future research, clinical practice, and community care are provided including how researchers and clinicians can effectively adapt traditional measures of spirituality for use with this population; the importance of integrating spirituality into the assessment and treatment of people with AD; and the role spiritual communitie

Regularized Field Map Estimation in MRI

In fast magnetic resonance (MR) imaging with long readout times, such as echo-planar imaging (EPI) and spiral scans, it is important to correct for the effects of field inhomogeneity to reduce image distortion and blurring. Such corrections require an accurate field map, a map of the off-resonance frequency at each voxel. Standard field map estimation methods yield noisy field maps, particularly in image regions with low spin density. This paper describes regularized methods for field map estimation from two or more MR scans having different echo times. These methods exploit the fact that field maps are generally smooth functions. The methods use algorithms that decrease monotonically a regularized least-squares cost function, even though the problem is highly nonlinear. Results show that the proposed regularized methods significantly improve the quality of field map estimates relative to conventional unregularized methods.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/85871/1/Fessler22.pd

Antenatal corticosteroids impact the inflammatory rather than the antiangiogenic profile of women with preeclampsia

Circulating antiangiogenic factors and proinflammatory cytokines are implicated in the pathogenesis of preeclampsia. This study was performed to test the hypothesis that steroids modify the balance of inflammatory and proangiogenic and antiangiogenic factors that potentially contribute to the patient's evolving clinical state. Seventy singleton women, admitted for antenatal corticosteroid treatment, were enrolled prospectively. The study group consisted of 45 hypertensive women: chronic hypertension (n=6), severe preeclampsia (n=32), and superimposed preeclampsia (n=7). Normotensive women with shortened cervix (<2.5 cm) served as controls (n=25). Maternal blood samples of preeclampsia cases were obtained before steroids and then serially up until delivery. A clinical severity score was designed to clinically monitor disease progression. Serum levels of angiogenic factors (soluble fms-like tyrosine kinase-1 [sFlt-1], placental growth factor [PlGF], soluble endoglin [sEng]), endothelin-1 (ET-1), and proinflammatory markers (IL-6, C-reactive protein [CRP]) were assessed before and after steroids. Soluble IL-2 receptor (sIL-2R) and total immunoglobulins (IgG) were measured as markers of T- and B-cell activation, respectively. Steroid treatment coincided with a transient improvement in clinical manifestations of preeclampsia. A significant decrease in IL-6 and CRP was observed although levels of sIL-2R and IgG remained unchanged. Antenatal corticosteroids did not influence the levels of angiogenic factors but ET-1 levels registered a short-lived increase poststeroids. Although a reduction in specific inflammatory mediators in response to antenatal steroids may account for the transient improvement in clinical signs of preeclampsia, inflammation is unlikely to be the major contributor to severe preeclampsia or useful for therapeutic targeting. © 2014 American Heart Association, Inc

Parent-of-origin effects propagate through networks to shape metabolic traits

Parent-of-origin effects are unexpectedly common in complex traits, including metabolic and neurological traits. Parent-of-origin effects can be modified by the environment, but the architecture of these gene-by-environmental effects on phenotypes remains to be unraveled. Previously, quantitative trait loci (QTL) showing context-specific parent-of-origin effects on metabolic traits were mapped in the