Search NASA⌕ Search

SEARCH · Search NASA

Results for “physiological temperature”

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 163 records · Page 9
All sourcesNASA NTRSDOE OSTI
NASA NTRS2011

Radiative and Physiological Effects of Increased CO2: How Does This Interaction Affect Climate?

Several climate models indicate that in a 2xCO2 environment, temperature and precipitation would increase and runoff would increase faster than precipitation. These models, however, did not allow the vegetation to increase its leaf density as a response to the physiological effects of increased CO2 and consequent changes in climate. Other assessments included these interactions but did not account for the vegetation downregulation to reduce plant's photosynthetic activity and as such resulted in a weak vegetation negative response. When we combine these interactions in climate simulations with 2xCO2, the associated increase in precipitation contributes primarily to increase evapotranspiration rather than surface runoff, consistent with observations, and results in an additional cooling effect not fully accounted for in previous 2xCO2 simulations. By accelerating the water cycle, this feedback slows but does not alleviate the projected warming, reducing the land surface warming by 0.6 C. Compared to previous studies, these results imply that long term negative feedback from CO2-induced increases in vegetation density could reduce temperature following a stabilization of CO2 concentration.

Bounoua, Lahouari↗
NASA NTRS2011

Psychophysiological Studies in Extreme Environments

This paper reviews the results from two studies that employed the methodology of multiple converging indicators (physiological measures, subjective self-reports and performance metrics) to examine individual differences in the ability of humans to adapt and function in high stress environments. The first study was a joint collaboration between researchers at the US Army Research Laboratory (ARL) and NASA Ames Research Center. Twenty-four men and women active duty soldiers volunteered as participants. Field tests were conducted in the Command and Control Vehicle (C2V), an enclosed armored vehicle, designed to support both stationary and on-the-move operations. This vehicle contains four computer workstations where crew members are expected to perform command decisions in the field under combat conditions. The study objectives were: 1) to determine the incidence of motion sickness in the C2V relative to interior seat orientation/position, and parked, moving and short-haul test conditions; and 2) to determine the impact of the above conditions on cognitive performance, mood, and physiology. Data collected during field tests included heart rate, respiration rate, skin temperature, and skin conductance, self-reports of mood and symptoms, and cognitive performance metrics that included seven subtests in the DELTA performance test battery. Results showed that during 4-hour operational tests over varied terrain motion sickness symptoms increased; performance degraded by at least 5 percent; and physiological response profiles of individuals were categorized based on good and poor cognitive performance. No differences were observed relative to seating orientation or position.

Toscano, William B.↗
NASA NTRS2000

Gravity and thermoregulation: metabolic changes and circadian rhythms

Gravity appears to alter thermoregulation through changes in both the regulated level of body temperature and the rhythmic organization of temperature regulation. Gravity has been hypothesized to have an associated metabolic cost. Increased resting energy expenditure and dietary intake have been observed in animals during centrifuge experiments at hypergravity. Thus far, only animals have shown a corresponding reduction in metabolism in microgravity. Altered heat loss has been proposed as a response to altered gravitational environments, but remains documented only as changes in skin temperature. Changes in circadian timing, including the body temperature rhythm, have been shown in both hypergravity and microgravity, and probably contribute to alterations in sleep and performance. Changes in body temperature regulation may result from circadian disturbance, from the direct or indirect actions of gravity on the regulated temperature, or from changes in thermoregulatory effectors (heat production and heat loss) due to altered gravitational load and convective changes. To date, however, we have little data on the underlying thermoregulatory changes in altered gravity, and thus the precise mechanisms by which gravity alters temperature regulation remain largely unknown.

Non-NASA Center↗
NASA NTRS1973

Temperature

The problems in human comfort in heat stress are emphasized, with less emphasis placed upon cold exposure problems. Physiological parameters related to human thermal interactions are discussed, as well as data concerning thermal protective clothing. The energy balance equation, heat transfer equation, thermal comfort, heat stress, and cold stress are also considered. A two node model of human temperature regulation in FORTRAN is appended.

Berenson, P. J.↗
DOE OSTI2026

Contrasting Carbon–Water–Energy Dynamics in Perennial and Annual Bioenergy Agroecosystems Using Eddy Covariance and Interpretable Machine Learning

Understanding how agroecosystems respond to environmental variability is fundamental to predicting productivity and sustainability under a changing climate. We analyzed 55 site-years of high-frequency eddy covariance observations from five agroecosystems—two perennial grasses (miscanthus and switchgrass), two annual rotation systems (maize–soybean and sorghum–soybean), and a restored native prairie—to examine ecosystem-scale carbon, water, and energy fluxes. Using an interpretable machine-learning framework with regression tree ensembles, Shapley Additive Explanations, and Accumulated Local Effects, we quantified how environmental and temporal factors regulate gross primary productivity (GPP), evapotranspiration (ET), water-use efficiency, and the Bowen ratio. Perennials exhibited stronger physiological buffering and maintained fluxes across a broader range of temperature and moisture conditions, reflecting deeper rooting and persistent canopy cover. Annuals, in contrast, showed greater short-term variability and stronger coupling to atmospheric demand, with GPP and ET declining rapidly under low humidity or soil moisture. Differences in temperature sensitivity of Bowen ratio further revealed that perennials sustained proportionally greater sensible heat flux under cool conditions, whereas annuals exhibited constrained energy exchange when evaporative demand was low. Together, these results demonstrate that crop life cycle and canopy structure are fundamental determinants of ecosystem-scale carbon–water–energy coupling. By integrating long-term flux observations with interpretable machine learning, this study identifies the environmental drivers that shape agroecosystem function and highlights how conversion from annual to perennial feedstocks can enhance climatic resilience and alter land–atmosphere energy feedbacks. These findings provide a data-driven basis for improving crop and Earth-system models and for guiding bioenergy landscape design under future climate scenarios.

Accumulated Local Effects↗
DOE OSTI2024

TRPV3 activation by different agonists accompanied by lipid dissociation from the vanilloid site

TRPV3 represents both temperature- and ligand-activated transient receptor potential (TRP) channel. Physiologically relevant opening of TRPV3 channels by heat has been captured structurally, while opening by agonists has only been observed in structures of mutant channels. Here, we present cryo-EM structures that illuminate opening and inactivation of wild-type human TRPV3 in response to binding of two types of agonists: either the natural cannabinoid tetrahydrocannabivarin (THCV) or synthetic agonist 2-aminoethoxydiphenylborane (2-APB). We found that THCV binds to the vanilloid site, while 2-APB binds to the S1-S4 base and ARD-TMD linker sites. Despite binding to distally located sites, both agonists induce similar pore opening and cause dissociation of a lipid that occupies the vanilloid site in their absence. Our results uncover different but converging allosteric pathways through which small-molecule agonists activate TRPV3 and provide a framework for drug design and understanding the role of lipids in ion channel function.

59 BASIC BIOLOGICAL SCIENCES↗
NASA NTRS1978

Assess II - A simulated mission of Spacelab

For Assess II, the Spacelab mission simulation conducted in mid-1977, four payload specialists aboard a Convair 990 research aircraft performed six American and six European experiments during nine research flights each of six hours duration in order to evaluate the compatibility of training and experimental design. Mission organization and some initial data from the European experiments are reported. The experiments, conducted over the western U.S., involved infrared astronomy, solar brightness temperature, lidar, airglow TV, and a medical experiment for which physiological parameters were monitored. Conclusions concerning general principles of experiment design are discussed.

Wegmann, H. M.↗
NASA NTRS1988

Acceleration ground test program to verify GAS payload No. 559 structure/support avionics and experiment structural integrity

Acceleration ground tests were conducted on the Get Away Special (GAS) payload 559 to verify the structural integrity of the structure/support avionics and two of the planned three flight experiments. The ITA (Integrated Test Area) Standardized Experiment Module (ISEM) structure was modified to accommodate the experiments for payload 559. The ISEM avionics consisted of a heavy duty sliver zinc power supply, three orthogonal-mounted low range microgravity accelerometers, a tri-axis high range accelerometer, a solid state recorder/programmer sequencer, and pressure and temperature sensors. The tests were conducted using the Gravitational Plant Physiology Laboratory Centrifuge of the University City Science Center in Philadelphia, PA. The launch-powered flight steady state acceleration profile of the shuttle was simulated from lift-off through jettison of the External Tank (3.0 g's). Additional tests were conducted at twice the nominal powered flight acceleration levels (6 g's) and an over-test condition of four times the powered flight loads to 12.6 g's. The present test program has demonstrated the value of conducting ground tests to verify GAS payload experiment integrity and operation before flying on the shuttle.

Cassanto, John M.↗
NASA NTRS2016

Growth Chambers on the International Space Station for Large Plants

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED lighting, and those capabilities continue to expand. The 'Veggie' vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nm), blue, (455 nm) and green (530 nm) LEDs. Interfacing with the light cap is an extendable bellows/baseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

Advanced Plant Habitat↗
NASA NTRS2016

Growth Chambers on the International Space Station for Large Plants

The International Space Station (ISS) now has platforms for conducting research on horticultural plant species under LED (Light Emitting Diodes) lighting, and those capabilities continue to expand. The Veggie vegetable production system was deployed to the ISS as an applied research platform for food production in space. Veggie is capable of growing a wide array of horticultural crops. It was designed for low power usage, low launch mass and stowage volume, and minimal crew time requirements. The Veggie flight hardware consists of a light cap containing red (630 nanometers), blue, (455 nanometers) and green (530 nanometers) LEDs. Interfacing with the light cap is an extendable bellowsbaseplate for enclosing the plant canopy. A second large plant growth chamber, the Advanced Plant Habitat (APH), is will fly to the ISS in 2017. APH will be a fully controllable environment for high-quality plant physiological research. APH will control light (quality, level, and timing), temperature, CO2, relative humidity, and irrigation, while scrubbing any cabin or plant-derived ethylene and other volatile organic compounds. Additional capabilities include sensing of leaf temperature and root zone moisture, root zone temperature, and oxygen concentration. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs (4100K). There will be several internal cameras (visible and IR) to monitor and record plant growth and operations. Veggie and APH are available for research proposals.

Veggie↗
NASA NTRS2016

Plant Habitat (PH)

The International Space Station (ISS) will soon have a platform for conducting fundamental research of Large Plants. Plant Habitat (PH) is designed to be a fully controllable environment for high-quality plant physiological research. PH will control light quality, level, and timing, temperature, CO2, relative humidity, and irrigation, while scrubbing ethylene. Additional capabilities include leaf temperature and root zone moisture and oxygen sensing. The light cap will have red (630 nm), blue (450 nm), green (525 nm), far red (730 nm) and broad spectrum white LEDs. There will be several internal cameras (visible and IR) to monitor and record plant growth and operations.

Advanced Plant Habitat↗
DOE OSTI2022

Cell wall ester modifications and volatile emission signatures of plant response to abiotic stress

Abstract Growth suppression and defence signalling are simultaneous strategies that plants invoke to respond to abiotic stress. Here, we show that the drought stress response of poplar trees ( Populus trichocarpa ) is initiated by a suppression in cell wall derived methanol (MeOH) emissions and activation of acetic acid (AA) fermentation defences. Temperature sensitive emissions dominated by MeOH (AA/MeOH <30%) were observed from physiologically active leaves, branches, detached stems, leaf cell wall isolations and whole ecosystems. In contrast, drought treatment resulted in a suppression of MeOH emissions and strong enhancement in AA emissions together with volatiles acetaldehyde, ethanol, and acetone. These drought‐induced changes coincided with a reduction in stomatal conductance, photosynthesis, transpiration, and leaf water potential. The strong enhancement in AA/MeOH emission ratios during drought (400%–3500%) was associated with an increase in acetate content of whole leaf cell walls, which became significantly 13 C 2 ‐labelled following the delivery of 13 C 2 ‐acetate via the transpiration stream. The results are consistent with both enzymatic and nonenzymatic MeOH and AA production at high temperature in hydrated tissues associated with accelerated primary cell wall growth processes, which are downregulated during drought. While the metabolic source(s) require further investigation, the observations are consistent with drought‐induced activation of aerobic fermentation driving high rates of foliar AA emissions and enhancements in leaf cell wall O ‐acetylation. We suggest that atmospheric AA/MeOH emission ratios could be useful as a highly sensitive signal in studies investigating environmental and biological factors influencing growth‐defence trade‐offs in plants and ecosystems.

59 BASIC BIOLOGICAL SCIENCES↗
DOE OSTI2022

What lies beneath: Vertical temperature heterogeneity in a Mediterranean woodland savanna

As the availability of satellite and airborne thermal infrared remote sensing (TIR-RS) data increases and their spatial, temporal, and spectral resolutions improve, researchers are finding diverse applications for TIR-RS measurements. TIR-RS is now commonly applied in regional- and continental-scale analyses, such as those focused on fire and surface energy balance. However, its application lags in plant physiology and ecology, for which a finer-scale understanding of plant canopy temperatures would be useful to elucidate plant water dynamics, for example. In particular, while methods to disaggregate TIR-RS pixels in horizontal space have advanced, possible vertical stratification of plant canopy temperature and its implications for understanding the correspondence between TIR-RS and finer-scale, field-based thermal measurements (e.g. made with a thermal camera) remain unexplored. Here, we use data from a thermal camera deployed concurrently with the recent ECOSTRESS mission to quantify vertical temperature gradients within tree canopies and temperatures of over- vs. under-story plants in a Mediterranean woodland savanna. We then leverage diverse ancillary data to maximize the geometric comparability of ECOSTRESS and thermal camera measurements, in order to assess the extent to which the two forms of thermal measurements correspond. Specifically, we ask: (1) What are the patterns of intra-canopy and over- vs. under-story vertical temperature in a Mediterranean woodland savanna?, and (2) How can vertically-resolved, but spatially-limited field-based temperature measurements be reconciled with spatially-extensive, but surface-only, temperature measurements of a space-borne remote sensor? Further, we found consistent patterns of vertical thermal heterogeneity both within tree canopies and between ecosystem over- and under-stories. The daytime difference between the top and bottom thirds of blue oak canopies was, on average, 0.48 ° C – and sometimes several times larger. Notably, canopy tops are cooler, likely associated with the under-story grass reaching daytime temperatures often exceeding over-story temperatures by 10° C. Given the consistency of the intra-canopy temperature gradients, we expected the ECOSTRESS sensor would be in better agreement with camera measurements of canopy tops than bulk canopies or canopy bottoms. However, within-canopy gradients were overwhelmed by other sources of disagreement between the measurements, in part associated with upscaling camera measurements across space. Overall, thermal camera and ECOSTRESS measurements were largely in agreement at night (pixel RMSE = 1.1°C), but they were more divergent during times of low (but >0 W/m2) and high incoming solar radiation (daytime pixel RMSE = 3.5°C).

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2020

Physiological Responses of Populus trichocarpa to Warming

This data set contains empirical physiological, morphological, and chemical data collected over time on Western Black Cottonwood (Populs trichocarpa Torr. & A.Gray ex Hook., Salicaceae) clones, between July and December 2019 at Oak Ridge National Lab. The project was designed to experimentally warm P. trichocarpa clones and assess their physiological acclimation of leaves versus roots. Branch cuttings of the Nisqually-1 genotype were obtained from the US Department of Energy Joint Genome Institute (JGI) in Stanford, California, and propagated in leach tubes. Ninety genetically identical clones were planted into specially constructed mesocosm growth boxes and grown for an initial six weeks in the greenhouse, and then grown at three temperature treatments for ten weeks. The daytime air temperatures of treatments were approximately 25°C, 29°C, and 33°C. Measurements on plant physiology and growth were conducted at various intervals throughout the experiment. This dataset contains nine data files in comma separate (*.csv) format.

54 ENVIRONMENTAL SCIENCES↗
DOE OSTI2022

Attributing differences of solar-induced chlorophyll fluorescence (SIF)-gross primary production (GPP) relationships between two C4 crops: corn and miscanthus

There remains limited information to characterize the solar-induced chlorophyll fluorescence (SIF)-gross primary production (GPP) relationship in C4 cropping systems. The annual C4 crop corn and perennial C4 crop miscanthus differ in phenology, canopy structure and leaf physiology. Investigating the SIF-GPP relationships in these species could deepen our understanding of SIF-GPP relationships within C4 crops. Using in situ canopy SIF and GPP measurements for both species along with leaf-level measurements, we found considerable differences in the SIF-GPP relationships between corn and miscanthus, with a stronger SIF-GPP relationship and higher slope of SIF-GPP observed in corn compared to miscanthus. These differences were mainly caused by leaf physiology. For miscanthus, high non-photochemical quenching (NPQ) under high light, temperature and water vapor deficit (VPD) conditions caused a large decline of fluorescence yield (Φ F ), which further led to a SIF midday depression and weakened the SIF-GPP relationship. The larger slope in corn than miscanthus was mainly due to its higher GPP in mid-summer, largely attributed to the higher leaf photosynthesis and less NPQ. Furthermore, our results demonstrated variation of the SIF-GPP relationship within C4 crops and highlighted the importance of leaf physiology in determining canopy SIF behaviors and SIF-GPP relationships.

54 ENVIRONMENTAL SCIENCES↗
NASA NTRS1996

The Physiology of Bed Rest

Prolonged rest in bed has been utilized by physicians and other health-care workers to immobilize and confine patients for rehabilitation and restoration of health since time immemorial. The sitting or horizontal position is sought by the body to relieve the strain of the upright or vertical postures, for example during syncopal situations, bone fractures, muscle injuries, fatigue, and probably also to reduce energy expenditure. Most health-care personnel are aware that adaptive responses occurring during bed rest proceed concomitantly with the healing process; signs and symptoms associated with the former should be differentiated from those of the latter. Not all illnesses and infirmities benefit from prolonged bed rest. Considerations in prescribing bed rest for patients-including duration, body position, mode and duration of exercise, light-dark cycles, temperature, and humidity-have not been investigated adequately. More recently, adaptive physiological responses have been measured in normal, healthy subjects in the horizontal or slightly head-down postures during prolonged bed rest as analogs for the adaptive responses of astronauts exposed to the microgravity environment of outer and bed-rest research.

Fortney, Suzanne M.↗
NASA NTRS2003

The Application of Advanced Cultivation Techniques in the Long Term Maintenance of Space Flight Plant Biological Systems

The development of the International Space Station (ISS) presents extensive opportunities for the implementation of long duration space life sciences studies. Continued attention has been placed in the development of plant growth chamber facilities capable of supporting the cultivation of plants in space flight microgravity conditions. The success of these facilities is largely dependent on their capacity to support the various growth requirements of test plant species. The cultivation requirements for higher plant species are generally complex, requiring specific levels of illumination, temperature, humidity, water, nutrients, and gas composition in order to achieve normal physiological growth and development. The supply of water, nutrients, and oxygen to the plant root system is a factor, which has proven to be particularly challenging in a microgravity space flight environment. The resolution of this issue is particularly important for the more intensive crop cultivation of plants envisaged in Nasa's advanced life support initiative. BioServe Space Technologies is a NASA, Research Partnership Center (RPC) at the University of Colorado, Boulder. BioServe has designed and operated various space flight plant habitat systems, and placed specific emphasis on the development and enhanced performance of subsystem components such as water and nutrient delivery, illumination, gas exchange and atmosphere control, temperature and humidity control. The further development and application of these subsystems to next generation habitats is of significant benefit and contribution towards the development of both the Space Plant biology and the Advanced Life Support Programs. The cooperative agreement between NASA Ames Research center and BioServe was established to support the further implementation of advanced cultivation techniques and protocols to plant habitat systems being coordinated at NASA Ames Research Center. Emphasis was placed on the implementation of passive-based water and nutrient support systems and techniques, which can be used to minimize demands on power, mass, and operational complexity in space flight studies. This effort has direct application to the development of next-generation space flight plant chambers such as the Plant Research Unit (PRU). Work was also directed at the development of in-flight plant preservation techniques and protocols consistent with the interest in applying recent developments in gene chip micro array technologies. Cultivation technologies and protocols were evaluated in a 55 day space flight plant growth study, conducted on the ISS, mission 9A (10/7/02 - 12/7/02).

Heyenga, A. G.↗
NASA NTRS1999

Endogenous thermoregulatory rhythms of squirrel monkeys in thermoneutrality and cold

Whole body heat production (HP) and heat loss (HL) were examined to determine if the free-running circadian rhythm in body temperature (Tb) results from coordinated changes in HP and HL rhythms in thermoneutrality (27 degrees C) as well as mild cold (17 degrees C). Squirrel monkey metabolism (n = 6) was monitored by both indirect and direct calorimetry, with telemetered measurement of Tb and activity. Feeding was also measured. Rhythms of HP, HL, and conductance were tightly coupled with the circadian Tb rhythm at both ambient temperatures (TA). At 17 degrees C, increased HP compensated for higher HL at all phases of the Tb rhythm, resulting in only minor changes to Tb. Parallel compensatory changes of HP and HL were seen at all rhythm phases at both TA. Similar time courses of Tb, HP, and HL in their respective rhythms and the relative stability of Tb during both active and rest periods suggest action of the circadian timing system on Tb set point.

NASA Discipline Regulatory Physiology↗