Exhaled nitric oxide in ethnically diverse highâ altitude native populations: A comparative study

ObjectivesAndean and Tibetan highâ altitude natives exhibit a high concentration of nitric oxide (NO) in the lungs, suggesting that NO plays an adaptive role in offsetting hypobaric hypoxia. We examined the exhaled NO concentration as well as partial pressure of several additional highâ altitude native populations in order to examine the possibility that this putative adaptive trait, that is, high exhaled NO, is universal.MethodsWe recruited two geographically diverse highland native populations, Tawang Monpa (TM), a Tibetan derived population in Northâ Eastern India (n = 95, sampled at an altitude of ~3,200â m), and Peruvian Quechua from the highland Andes (n = 412). The latter included three distinct subgroups defined as those residing at altitude (Qâ HAR, n = 110, sampled at 4,338â m), those born and residing at seaâ level (Qâ BSL, n = 152), and those born at altitude but migrant to seaâ level (Qâ M, n = 150). In addition, we recruited a referent sample of lowland natives of European ancestry from Syracuse, New York. Fraction of exhaled NO concentrations were measured using a NIOX NIMO following the protocol of the manufacturer.ResultsPartial pressure of exhaled nitric oxide (PENO) was significantly lower (pâ <â .05) in both highâ altitude resident groups (TM = 6.2â ±â 0.5 nmHg and Qâ HAR = 5.8â ±â 0.5 nmHg), as compared to the groups measured at sea level (USA = 14.6â ±â 0.7 nmHg, Qâ BSL = 18.9â ±â 1.6 nmHg, and Qâ M = 19.2â ±â 1.7 nmHg). PENO was not significantly different between TM and Qâ HAR (pâ <â .05).ConclusionIn contrast to previous work, we found lower PENO in populations at altitude (compared to seaâ level) and no difference in PENO between Tibetan and Andean highland native populations. These results do not support the hypothesis that high nitric oxide in human lungs is a universal adaptive mechanism of highland native populations to offset hypobaric hypoxia.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/151909/1/ajpa23915.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/151909/2/ajpa23915_am.pd

Development of an Acousto-Ultrasonic Scanning System for Nondestructive Evaluation of Wood and Wood Laminates

An acousto-ultrasonic (AU) scanning system was developed and optimized for wood products. It was found that AU probe alignment, coupling pressure, and stabilization time affect the repeatability of AU readings. After optimization of these factors, the error in AU reading (RMS) was negligible. AU transmission through solid wood also showed a relationship of acoustic attenuation to wood anisotropy. A calculated modulus of elasticity in the direction of wave propagation correlated with wave attenuation characteristics in the TR and LR planes. For wave propagation in the TR plane, the greatest attenuation was observed at a growth ring angle (GRA) of about 45°, corresponding to the lowest modulus of elasticity, which is in this plane. The effect of wood anisotropy (GRA) was found to be a major problem for evaluation of laminated wood, since the received signal was strongly affected by wood properties. Consequently, the effect of anisotropy and natural variability of wood will be the major limiting factor of any acoustic NDE technique applied to many wood products

Acoustic Monitoring of Cold-Setting Adhesive Curing in Wood Laminates: Effect of Clamping Pressure and Detection of Defective Bonds

Many variables affecting adhesive bonding of wood, including moisture content, temperature, surface roughness and contamination, and wood density, are difficult to control and/or measure in industrial conditions. However, the combined effect of these factors may be compensated by controlling process variables, such as clamping pressure and time, and adhesive viscosity, concentration, and spread. This research project investigated an ultrasonic method as a nondestructive means of monitoring bonding processes and assessing the quality of the cured bonds in wood laminates. Monitoring was performed simultaneously at normal and angular (5° nominal) incidence to the bond plane, using pairs of clear Douglas-fir laminates with a single bond line. It was previously reported that ultrasonic transmission is sensitive to curing phases, such as spreading, penetration, curing, and bond thickness. This paper reports the effect of bond defects (uncured, underspread, and uneven spread) and clamping pressure on ultrasonic transmission. The results showed that defective bonds can be detected using patterns of relative attenuation changes during curing and an "unloading effect," measured as the relative transmission reduction after the clamping load is released. Also, transmission through uncured bond lines was strongly affected by pressure, an observation that can be utilized to select optimum clamping pressure

Acousto-Ultrasonic Assessment of Internal Decay in Glulam Beams

An acousto-ultrasonic (AU) through-transmission technique was evaluated for assessing brown-rot decay in Douglas-fir glulam beams that had been removed from service. The effect of decay on different AU signal features was compared to that from normal variations in wood, such as growth ring angle, knots, and moisture gradient. The analysis was based on measurement of velocity, attenuation, shape, and frequency content of the received signals. All of the studied signal features were correlated with the degree of decay; however, they were affected by natural characteristics of wood. Attenuation and signal shape were more affected by the growth ring angle variations and knots than were velocity and frequency features. The effect of knots depended upon size, type, orientation, and distance from the surface. A steep moisture gradient obscured the detection of small degrees of decay, with the greatest effect on signal shape and frequency parameters. This study suggests that multiple signal feature analysis can be used to distinguish decay from certain types of natural wood characteristics such as growth ring angle variations and knots

Applications of aerospace technology in biology and medicine

Utilization of National Aeronautics and Space Administration (NASA) technology in medicine is discussed. The objective is best obtained by stimulation of the introduction of new or improved commercially available medical products incorporating aerospace technology. A bipolar donor/recipient model of medical technology transfer is presented to provide a basis for the team's methodology. That methodology is designed to: (1) identify medical problems and NASA technology that, in combination, constitute opportunities for successful medical products; (2) obtain the early participation of industry in the transfer process; and (3) obtain acceptance by the medical community of new medical products based on NASA technology. Two commercial transfers were completed: the Stowaway, a lightweight wheelchair that provides mobility for the disabled and elderly in the cabin of commercial aircraft, and Micromed, a portable medication infusion pump for the reliable, continuous infusion of medications such as heparin or insulin. The marketing and manufacturing factors critical to the commercialization of the lightweight walker incorporating composite materials were studied. Progress was made in the development and commercialization of each of the 18 currently active projects

Realism, Objectivity, and Evaluation

I discuss Benacerraf's epistemological challenge for realism about areas like mathematics, metalogic, and modality, and describe the pluralist response to it. I explain why normative pluralism is peculiarly unsatisfactory, and use this explanation to formulate a radicalization of Moore's Open Question Argument. According to the argument, the facts -- even the normative facts -- fail to settle the practical questions at the center of our normative lives. One lesson is that the concepts of realism and objectivity, which are widely identified, are actually in tension