Search NASA⌕ Search

SEARCH · Search NASA

Results for “Middle Aged”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 records
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

PSR J2030+364I: Radio Discovery and Gamma-ray Study of a Middle-aged Pulsar in the Now Identified Fermi-LAT Source 1FGL J2030.0+3641

In a radio search with the Green Bank Telescope of three unidentified low Galactic latitude Fermi-LAT sources, we have discovered the middle-aged pulsar J2030+3641, associated with IFGL J2030.0+3641 (2FGL J2030.0+3640). Following the detection of gamma-ray pulsations using a radio ephemeris, we have obtained a phase-coherent timing solution based on gamma-ray and radio pulse arrival times that spans the entire Fermi mission. With a rotation period of 0.28, spin-down luminosity of 3 x 10(exp 34) erg/s, and characteristic age of 0.5 Myr, PSR J2030+3641 is a middle-aged neutron star with spin parameters similar to those of the exceedingly gamma-ray-bright and radio-undetected Geminga. Its gamma-ray flux is 1 % that of Geminga, primarily because of its much larger distance, as suggested by the large integrated column density of free electrons, DM = 246 pc/cu cm. We fit the gamma-ray light curve, along with limited radio polarimetric constraints, to four geometrical models of magnetospheric emission, and while none of the fits have high significance some are encouraging and suggest that further refinements of these models may be worthwhile. We argue that not many more non-millisecond radio pulsars may be detected along the Galactic plane that are responsible for LAT sources, but that modified methods to search for gamma-ray pulsations should be productive - PSR J2030+364 I would have been found blindly in gamma rays if only > or approx. 0.8 GeV photons had been considered, owing to its relatively flat spectrum and location in a region of high soft background.

Camilo, F.↗
DOE OSTI2023

Younger facial looks are associate with a lower likelihood of several age-related morbidities in the middle-aged to elderly

Abstract Background Looking older for one’s chronological age is associated with a higher mortality rate. Yet it remains unclear how perceived facial age relates to morbidity and the degree to which facial ageing reflects systemic ageing of the human body. Objectives To investigate the association between ΔPA and age-related morbidities of different organ systems, where ΔPA represents the difference between perceived age (PA) and chronological age. Methods We performed a cross-sectional analysis on data from the Rotterdam Study, a population-based cohort study in the Netherlands. High-resolution facial photographs of 2679 men and women aged 51.5–87.8 years of European descent were used to assess PA. PA was estimated and scored in 5-year categories using these photographs by a panel of men and women who were blinded for chronological age and medical history. A linear mixed model was used to generate the mean PAs. The difference between the mean PA and chronological age was calculated (ΔPA), where a higher (positive) ΔPA means that the person looks younger for their age and a lower (negative) ΔPA that the person looks older. ΔPA was tested as a continuous variable for association with ageing-related morbidities including cardiovascular, pulmonary, ophthalmological, neurocognitive, renal, skeletal and auditory morbidities in separate regression analyses, adjusted for age and sex (model 1) and additionally for body mass index, smoking and sun exposure (model 2). Results We observed 5-year higher ΔPA (i.e. looking younger by 5 years for one’s age) to be associated with less osteoporosis [odds ratio (OR) 0.76, 95% confidence interval (CI) 0.62–0.93], less chronic obstructive pulmonary disease (OR 0.85, 95% CI 0.77–0.95), less age-related hearing loss (model 2; B = −0.76, 95% CI −1.35 to −0.17) and fewer cataracts (OR 0.84, 95% CI 0.73–0.97), but with better global cognitive functioning (g-factor; model 2; B = 0.07, 95% CI 0.04–0.10). Conclusions PA is associated with multiple morbidities and better cognitive function, suggesting that systemic ageing and cognitive ageing are, to an extent, externally visible in the human face.

Mekić, Selma↗
NASA NTRS2023

X-Ray and Near-Infrared Observations of the Middle-aged Pulsar B1055-52, Its Multiwavelength Spectrum, and Proper Motion

Previous observations of the middle-aged γ-ray, X-ray, and radio pulsar B1055–52 indicated some peculiarities, such as a suspected changing of the X-ray flux and spectral parameters, a large excess of the alleged thermal component of the UV spectrum over the Rayleigh–Jeans extension of the X-ray thermal spectrum, and a possible double break in the nonthermal spectral component between the optical and X-ray bands. We observed PSR B1055–52 with the XMM-Newton observatory in X-rays and the Hubble Space Telescope in near-infrared (NIR). The analysis of the XMM-Newton observations does not support the notion of long-term changes in the X-ray flux and broadband X-ray spectrum of the pulsar. Using an observing mode less affected by background noise than the previous XMM-Newton observations, we constrain the power-law (PL) spectral index as X 0.57 0.25 0.26 a = - - + (Fν ∝ ν α ) in the energy band 3–10 keV. From the NIR–optical data we obtain a PL slope αO = −0.24 ± 0.10 for the color index E(B − V ) = 0.03 mag. The slopes and fluxes of the NIR–optical and X-ray nonthermal spectra suggest that the NIR through X-ray emission can be described by the same PL and is generated by the same mechanism, unlike the pulsar’s γ-ray emission. The excess of the UV thermal component over the extension of the X-ray thermal component became smaller but did not disappear, indicating a nonuniformity of the bulk surface temperature. The NIR data also enable us to measure the proper motion accurately, with values μα = 47.5 ± 0.7 mas yr−1 and μδ = −8.7 ± 0.7 mas yr−1 .

B Posselt↗
NASA NTRS1996

Power law behavior of RR-interval variability in healthy middle-aged persons, patients with recent acute myocardial infarction, and patients with heart transplants

BACKGROUND. The purposes of the present study were (1) to establish normal values for the regression of log(power) on log(frequency) for, RR-interval fluctuations in healthy middle-aged persons, (2) to determine the effects of myocardial infarction on the regression of log(power) on log(frequency), (3) to determine the effect of cardiac denervation on the regression of log(power) on log(frequency), and (4) to assess the ability of power law regression parameters to predict death after myocardial infarction. METHODS AND RESULTS. We studied three groups: (1) 715 patients with recent myocardial infarction; (2) 274 healthy persons age and sex matched to the infarct sample; and (3) 19 patients with heart transplants. Twenty-four-hour RR-interval power spectra were computed using fast Fourier transforms and log(power) was regressed on log(frequency) between 10(-4) and 10(-2) Hz. There was a power law relation between log(power) and log(frequency). That is, the function described a descending straight line that had a slope of approximately -1 in healthy subjects. For the myocardial infarction group, the regression line for log(power) on log(frequency) was shifted downward and had a steeper negative slope (-1.15). The transplant (denervated) group showed a larger downward shift in the regression line and a much steeper negative slope (-2.08). The correlation between traditional power spectral bands and slope was weak, and that with log(power) at 10(-4) Hz was only moderate. Slope and log(power) at 10(-4) Hz were used to predict mortality and were compared with the predictive value of traditional power spectral bands. Slope and log(power) at 10(-4) Hz were excellent predictors of all-cause mortality or arrhythmic death. To optimize the prediction of death, we calculated a log(power) intercept that was uncorrelated with the slope of the power law regression line. We found that the combination of slope and zero-correlation log(power) was an outstanding predictor, with a relative risk of > 10, and was better than any combination of the traditional power spectral bands. The combination of slope and log(power) at 10(-4) Hz also was an excellent predictor of death after myocardial infarction. CONCLUSIONS. Myocardial infarction or denervation of the heart causes a steeper slope and decreased height of the power law regression relation between log(power) and log(frequency) of RR-interval fluctuations. Individually and, especially, combined, the power law regression parameters are excellent predictors of death of any cause or arrhythmic death and predict these outcomes better than the traditional power spectral bands.

Non-NASA Center↗
NASA NTRS2008

Suzaku Observations of Thermal and Non-Thermal X-Ray Emission from the Middle-Aged Supernova Remnant G156.2+5.7

We present results from X-ray analysis of a Galactic middle-aged supernova remnant (SNR) G156.2+5.7 which is bright and largely extended in X-ray wavelengths, showing a clear circular shape (radius approx.50'). Using the Suzaku satellite, we observed this SNR in three pointings; partially covering the northwestern (NW) rim, the eastern (E) rim, and the central portion of this SNR. In the NW rim and the central portion, we confirm that the X-ray spectra consist of soft and hard-tail emission, while in the E rim we find no significant hard-tail emission. The soft emission is well fitted by either a one-component or two-component non-equilibrium ionization (NEI) model. In the NW and E rims, a one-component (the swept-up interstellar medium) NEI model well represents the soft emission. On the other hand, in the central portion, a two-component (the interstellar medium and the metal-rich ejecta) NEI model fits the soft emission better than the one-component NEI model from a statistical point of view. The relative abundances in the ejecta component suggest that G156.2+5.7 is a remnant from a core-collapse SN explosion whose progenitor mass is less than 15 Solar Mass. The origin of the hard-tail emission detected in the NW rim and the central portion of the SNR is highly likely non-thermal synchrotron emission from relativistic electrons. In the NW rim, the relativistic electrons seems to be accelerated by a forward shock with a slow velocity of APPROX.500 km/sec.

Katsuda, Satoru↗
NASA NTRS1985

Visceral predictors of cardiovascular deconditioning in late middle-aged men

A number of visceral and behavioral factors connected with cardiovascular deconditioning were investigated, in order to identify a method for predicting the degree of orthostatic intolerance to spaceflight in several late-middle-aged men (55-65 years). Preliminary measurements were made of: mean arterial blood pressure plasma cortisol levels; and norepinephrine levels. Measurements of core temperature; plasma epinephrine level and subjective arousal from sleep were also obtained. Pairwise correlations were found for each of the variables and the time-to-blackout due centrifugal acceleration of up to +3 Gz. It is shown that the men with relatively low resting blood pressure were at greater risk of developing the clinical signs of cardiovascular deconditioning than were the men with higher basal blood pressure. Some applications of the experimental results to the development of selection criteria for Shuttle crews are discussed.

Goldwater, D. J.↗
NASA NTRS1969

Experiences with physical conditioning programs in middle-aged men

Long term effects of physical exercise and conditioning in the prevention and treatment of coronary heart disease are studied. Some aspects of the problem are outlined and difficulties encountered in a group of middle aged business executives using a carefully prescribed, but non-regimented and loosely supervised conditioning program employing commonly used forms of exercise (bicycling and jogging), are described.

Schuster, B.↗
NASA NTRS2021

Orogenic quiescence in Earth’s middle age

Mountain belts modulate denudation flux and hydrologic processes and are thus fundamental to nutrient cycling on Earth’s surface. We used europium anomalies in detrital zircons to track mountain-building processes over Earth’s history. We show that the average thickness of active continental crust varied on billion-year time scales, with the thickest crust formed in the Archean and Phanerozoic. By contrast, the Proterozoic witnessed continuously decreasing crustal thickness, leaving the continents devoid of high mountains until the end of the eon. We link this gradually diminished orogenesis to the long-lived Nuna-Rodinia supercontinent, which altered the mantle thermal structure and weakened the continental lithosphere. This prolonged orogenic quiescence may have resulted in a persistent famine in the oceans and stalled life’s evolution in Earth’s middle age.

Ming Tang↗
NASA NTRS1997

Comparison of ground-based and space flight energy expenditure and water turnover in middle-aged healthy male US astronauts

Energy requirements during space flight are poorly defined because they depend on metabolic-balance studies, food disappearance, and dietary records. Water turnover has been estimated by balance methods only. The purpose of this study was to determine energy requirements and water turnover for short-term space flights (8-14 d). Subjects were 13 male astronauts aged 36-51 y with normal body mass indexes (BMIs). Total energy expenditure (TEE) was determined during both a ground-based period and space flight and compared with the World Health Organization (WHO) calculations of energy requirements and dietary intake. TEE was not different for the ground-based and the space-flight periods (12.40 +/- 2.83 and 11.70 +/- 1.89 MJ/d, respectively), and the WHO calculation using the moderate activity correction was a good predictor of TEE during space flight. During the ground-based period, energy intake and TEE did not differ, but during space flight energy intake was significantly lower than TEE; body weight was also less at landing than before flight. Water turnover was lower during space flight than during the ground-based period (2.7 +/- 0.6 compared with 3.8 +/- 0.5 L/d), probably because of lower fluid intakes and perspiration loss during flight. This study confirmed that the WHO calculation can be used for male crew members' energy requirements during short space flights.

STS Shuttle Project↗
DOE OSTI2022

The Milky Way’s middle-aged inner ring

Aims. We investigate the metallicity, age, and orbital anatomy of the inner Milky Way, specifically focussing on the outer bar region. Methods. We integrated a sample of APOGEE DR16 inner Galaxy stars in a state of the art bar-bulge potential with a slow pattern speed and investigated the link between the resulting orbits and their [Fe/H] and ages. By superimposing the orbits, we built density, [Fe/H], and age maps of the inner Milky Way, which we divided further using the orbital parameters eccentricity, |Xmax|, and |Zmax|. Results. We find that at low heights from the Galactic plane, the Galactic bar gradually transitions into a radially thick, vertically thin, elongated inner ring with average solar [Fe/H]. This inner ring is mainly composed of stars with AstroNN ages between 4 and 9 Gyr with a peak in age between 6 and 8 Gyr, making the average age of the ring ~6 Gyr. The vertical thickness of the ring decreases markedly towards younger ages. We also find very large L4 Lagrange orbits that have average solar to super-solar metallicities and intermediate ages. Lastly, we confirm a clear X-shape in the [Fe/H] and density distributions at large Galactic heights. Conclusions. The orbital structure obtained for the APOGEE stars reveals that the Milky Way hosts an inner ring-like structure between the planar bar and corotation. This structure is on average metal rich, intermediately aged, and enhances the horizontal metallicity gradient along the bar’s major axis.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2018

Choice reaction time and grip strength as predictors of cardiovascular mortality in middle‐aged and elderly Japanese: from the Radiation Effects Research Foundation Adult Health study

Abstract Background Cognitive function and physical function are important predictors of mortality. Aim To investigate whether or not reaction time (RT) as a cognitive function and grip strength (GS) as a physical function were associated, alone or in combination, with mortality from heart disease or stroke. Methods The subjects included 4901 Adult Health Study participants in Hiroshima who had undergone RT and GS measurements, were 35–74 years old at baseline (1970–1972) and were followed until the end of 2007. Results After adjustment for other potential risk factors, RT was positively and GS was negatively associated with mortality from both heart disease and stroke. These associations were persistent in the model when adjusting simultaneously for RT, GS and other factors, but hazard ratios were attenuated. When we evaluated the associations by baseline age and gender, we found the greater hazard ratios for RT in the younger cohort, but no clear modification by age for GS. The interaction between RT and GS was statistically significant ( P = 0.012) for stroke mortality. In the stratified analyses divided using the age‐specific median value of RT or GS, the estimated hazard ratio of stroke mortality for RT was significant in participants with weak or strong GS but greater in the former, and for GS, it was only significant in participants with slow RT. Conclusion RT and GS, alone and in combination, predicted heart disease and stroke mortalities. Interventions for both cognitive function and physical function may be beneficial for the prevention of cardiovascular disease mortality.

Shimizu, Masaki↗
DOE OSTI2024

Photosynthetic capacity in middle-aged larch and spruce acclimates independently to experimental warming and elevated CO 2

Photosynthetic acclimation to both warming and elevated CO 2 of boreal trees remains a key uncertainty in modelling the response of photosynthesis to future climates. We investigated the impact of increased growth temperature and elevated CO 2 on photosynthetic capacity (V cmax and J max ) in mature trees of two North American boreal conifers, tamarack and black spruce. We show that V cmax and J max at a standard temperature of 25°C did not change with warming, while V cmax and J max at their thermal optima (T opt ) and growth temperature (T g ) increased. Moreover, V cmax and J max at either 25°C, T opt or T g decreased with elevated CO 2 . The J max /V cmax ratio decreased with warming when assessed at both T opt and T g but did not significantly vary at 25°C. The J max /V cmax increased with elevated CO 2 at either reference temperature. We found no significant interaction between warming and elevated CO 2 on all traits. If this lack of interaction between warming and elevated CO 2 on the V cmax , J max and J max /V cmax ratio is a general trend, it would have significant implications for improving photosynthesis representation in vegetation models. However, future research is required to investigate the widespread nature of this response in a larger number of species and biomes.

60 APPLIED LIFE SCIENCES↗
NASA NTRS1982

Increased hematuria following hypergravic exposure in middle-aged women

The effects of simulated weightlessness on orthostatic tolerance were studied in 9 women (55 to 65 years old) who underwent acceleration and lower body negative pressure before and after 10 days of horizontal bed rest. The results of this study show the first known association of microscopic hematuria with hypergravic and orthostatic stress which suggests similarities to the 'stress hematuria syndrome' previously seen with heavy exercise (Boileau et al., 1980). In addition, the sporadic occurrence of this phenomenon indicates a multifactorial etiology in predisposed individuals. Bedrest or weightlessness simulation per se does not seem to significantly alter renal function, but may decrease microscopic hematuria with an orthostatic component.

Goldwater, D. J.↗
NASA NTRS1987

A sheet description of the emission from middle-aged supernova remnants

The hypothesis that sheetlike shock fronts propagating into large clouds immersed in a fairly uniform intercloud medium can provide a consistent picture accounting for essentially all the observational data for the Cygnus Loop SNR is considered. Filaments are interpreted as line-of-sight projections of portions of the sheet. Variations in the projection of the shock velocity along the line of sight lead naturally to 'turbulent' velocities consistent with observation. An analog model of a large, distorted, bumpy shock front is presented and shown to produce the observed morphology of the remnant's prominent optical filaments. Comparison with the observed morphology supports the idea that regions of optical emission lie on the local outer boundary of the shell and have not been engulfed by the blast wave. Bright X-ray emission arises when the blast wave encounters a preshock medium with an intermediate density higher than average for the adiabatic portion of the remnant, but still lower than that required for the shock to become radiative.

Hester, J. Jeff↗
NASA NTRS1989

Rotational dating of middle-aged stars

By the age of about 100 million years, the rotational velocity of solar mass stars becomes independent of the initial rotation rate on the main sequence, due to the strong dependence of the angular momentum loss rate on the rotation rate; once this common value is reached, the rotation velocity depends only on time and the mass of the star. Thus, the measured rotation rate of a low-mass star provides an estimate of its age when its mass is known. The observed rotation periods of low-mass stars in the Hyades are used to test this conclusion and to check the validity of the theoretical angular momentum loss rates. Adapting the magnetic braking model of Kawaler (1988), the angular momentum loss rate is integrated to derive a relation between rotation period and age, and this relation is converted to a period-age-color relation using simple stellar models. Using this method, a mean rotational age for the Hyades is obtained which is in close agreement with the age determined by isochrone fitting.

Kawaler, Steven D.↗